]>
Commit | Line | Data |
---|---|---|
1 | /* Low level interface to ptrace, for the remote server for GDB. | |
2 | Copyright (C) 1995-2019 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include "server.h" | |
20 | #include "linux-low.h" | |
21 | #include "nat/linux-osdata.h" | |
22 | #include "gdbsupport/agent.h" | |
23 | #include "tdesc.h" | |
24 | #include "gdbsupport/rsp-low.h" | |
25 | #include "gdbsupport/signals-state-save-restore.h" | |
26 | #include "nat/linux-nat.h" | |
27 | #include "nat/linux-waitpid.h" | |
28 | #include "gdbsupport/gdb_wait.h" | |
29 | #include "nat/gdb_ptrace.h" | |
30 | #include "nat/linux-ptrace.h" | |
31 | #include "nat/linux-procfs.h" | |
32 | #include "nat/linux-personality.h" | |
33 | #include <signal.h> | |
34 | #include <sys/ioctl.h> | |
35 | #include <fcntl.h> | |
36 | #include <unistd.h> | |
37 | #include <sys/syscall.h> | |
38 | #include <sched.h> | |
39 | #include <ctype.h> | |
40 | #include <pwd.h> | |
41 | #include <sys/types.h> | |
42 | #include <dirent.h> | |
43 | #include <sys/stat.h> | |
44 | #include <sys/vfs.h> | |
45 | #include <sys/uio.h> | |
46 | #include "gdbsupport/filestuff.h" | |
47 | #include "tracepoint.h" | |
48 | #include "hostio.h" | |
49 | #include <inttypes.h> | |
50 | #include "gdbsupport/common-inferior.h" | |
51 | #include "nat/fork-inferior.h" | |
52 | #include "gdbsupport/environ.h" | |
53 | #include "gdbsupport/scoped_restore.h" | |
54 | #ifndef ELFMAG0 | |
55 | /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h | |
56 | then ELFMAG0 will have been defined. If it didn't get included by | |
57 | gdb_proc_service.h then including it will likely introduce a duplicate | |
58 | definition of elf_fpregset_t. */ | |
59 | #include <elf.h> | |
60 | #endif | |
61 | #include "nat/linux-namespaces.h" | |
62 | ||
63 | #ifdef HAVE_PERSONALITY | |
64 | # include <sys/personality.h> | |
65 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
66 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
67 | # endif | |
68 | #endif | |
69 | ||
70 | #ifndef O_LARGEFILE | |
71 | #define O_LARGEFILE 0 | |
72 | #endif | |
73 | ||
74 | #ifndef AT_HWCAP2 | |
75 | #define AT_HWCAP2 26 | |
76 | #endif | |
77 | ||
78 | /* Some targets did not define these ptrace constants from the start, | |
79 | so gdbserver defines them locally here. In the future, these may | |
80 | be removed after they are added to asm/ptrace.h. */ | |
81 | #if !(defined(PT_TEXT_ADDR) \ | |
82 | || defined(PT_DATA_ADDR) \ | |
83 | || defined(PT_TEXT_END_ADDR)) | |
84 | #if defined(__mcoldfire__) | |
85 | /* These are still undefined in 3.10 kernels. */ | |
86 | #define PT_TEXT_ADDR 49*4 | |
87 | #define PT_DATA_ADDR 50*4 | |
88 | #define PT_TEXT_END_ADDR 51*4 | |
89 | /* BFIN already defines these since at least 2.6.32 kernels. */ | |
90 | #elif defined(BFIN) | |
91 | #define PT_TEXT_ADDR 220 | |
92 | #define PT_TEXT_END_ADDR 224 | |
93 | #define PT_DATA_ADDR 228 | |
94 | /* These are still undefined in 3.10 kernels. */ | |
95 | #elif defined(__TMS320C6X__) | |
96 | #define PT_TEXT_ADDR (0x10000*4) | |
97 | #define PT_DATA_ADDR (0x10004*4) | |
98 | #define PT_TEXT_END_ADDR (0x10008*4) | |
99 | #endif | |
100 | #endif | |
101 | ||
102 | #ifdef HAVE_LINUX_BTRACE | |
103 | # include "nat/linux-btrace.h" | |
104 | # include "gdbsupport/btrace-common.h" | |
105 | #endif | |
106 | ||
107 | #ifndef HAVE_ELF32_AUXV_T | |
108 | /* Copied from glibc's elf.h. */ | |
109 | typedef struct | |
110 | { | |
111 | uint32_t a_type; /* Entry type */ | |
112 | union | |
113 | { | |
114 | uint32_t a_val; /* Integer value */ | |
115 | /* We use to have pointer elements added here. We cannot do that, | |
116 | though, since it does not work when using 32-bit definitions | |
117 | on 64-bit platforms and vice versa. */ | |
118 | } a_un; | |
119 | } Elf32_auxv_t; | |
120 | #endif | |
121 | ||
122 | #ifndef HAVE_ELF64_AUXV_T | |
123 | /* Copied from glibc's elf.h. */ | |
124 | typedef struct | |
125 | { | |
126 | uint64_t a_type; /* Entry type */ | |
127 | union | |
128 | { | |
129 | uint64_t a_val; /* Integer value */ | |
130 | /* We use to have pointer elements added here. We cannot do that, | |
131 | though, since it does not work when using 32-bit definitions | |
132 | on 64-bit platforms and vice versa. */ | |
133 | } a_un; | |
134 | } Elf64_auxv_t; | |
135 | #endif | |
136 | ||
137 | /* Does the current host support PTRACE_GETREGSET? */ | |
138 | int have_ptrace_getregset = -1; | |
139 | ||
140 | /* LWP accessors. */ | |
141 | ||
142 | /* See nat/linux-nat.h. */ | |
143 | ||
144 | ptid_t | |
145 | ptid_of_lwp (struct lwp_info *lwp) | |
146 | { | |
147 | return ptid_of (get_lwp_thread (lwp)); | |
148 | } | |
149 | ||
150 | /* See nat/linux-nat.h. */ | |
151 | ||
152 | void | |
153 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
154 | struct arch_lwp_info *info) | |
155 | { | |
156 | lwp->arch_private = info; | |
157 | } | |
158 | ||
159 | /* See nat/linux-nat.h. */ | |
160 | ||
161 | struct arch_lwp_info * | |
162 | lwp_arch_private_info (struct lwp_info *lwp) | |
163 | { | |
164 | return lwp->arch_private; | |
165 | } | |
166 | ||
167 | /* See nat/linux-nat.h. */ | |
168 | ||
169 | int | |
170 | lwp_is_stopped (struct lwp_info *lwp) | |
171 | { | |
172 | return lwp->stopped; | |
173 | } | |
174 | ||
175 | /* See nat/linux-nat.h. */ | |
176 | ||
177 | enum target_stop_reason | |
178 | lwp_stop_reason (struct lwp_info *lwp) | |
179 | { | |
180 | return lwp->stop_reason; | |
181 | } | |
182 | ||
183 | /* See nat/linux-nat.h. */ | |
184 | ||
185 | int | |
186 | lwp_is_stepping (struct lwp_info *lwp) | |
187 | { | |
188 | return lwp->stepping; | |
189 | } | |
190 | ||
191 | /* A list of all unknown processes which receive stop signals. Some | |
192 | other process will presumably claim each of these as forked | |
193 | children momentarily. */ | |
194 | ||
195 | struct simple_pid_list | |
196 | { | |
197 | /* The process ID. */ | |
198 | int pid; | |
199 | ||
200 | /* The status as reported by waitpid. */ | |
201 | int status; | |
202 | ||
203 | /* Next in chain. */ | |
204 | struct simple_pid_list *next; | |
205 | }; | |
206 | struct simple_pid_list *stopped_pids; | |
207 | ||
208 | /* Trivial list manipulation functions to keep track of a list of new | |
209 | stopped processes. */ | |
210 | ||
211 | static void | |
212 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) | |
213 | { | |
214 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); | |
215 | ||
216 | new_pid->pid = pid; | |
217 | new_pid->status = status; | |
218 | new_pid->next = *listp; | |
219 | *listp = new_pid; | |
220 | } | |
221 | ||
222 | static int | |
223 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) | |
224 | { | |
225 | struct simple_pid_list **p; | |
226 | ||
227 | for (p = listp; *p != NULL; p = &(*p)->next) | |
228 | if ((*p)->pid == pid) | |
229 | { | |
230 | struct simple_pid_list *next = (*p)->next; | |
231 | ||
232 | *statusp = (*p)->status; | |
233 | xfree (*p); | |
234 | *p = next; | |
235 | return 1; | |
236 | } | |
237 | return 0; | |
238 | } | |
239 | ||
240 | enum stopping_threads_kind | |
241 | { | |
242 | /* Not stopping threads presently. */ | |
243 | NOT_STOPPING_THREADS, | |
244 | ||
245 | /* Stopping threads. */ | |
246 | STOPPING_THREADS, | |
247 | ||
248 | /* Stopping and suspending threads. */ | |
249 | STOPPING_AND_SUSPENDING_THREADS | |
250 | }; | |
251 | ||
252 | /* This is set while stop_all_lwps is in effect. */ | |
253 | enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS; | |
254 | ||
255 | /* FIXME make into a target method? */ | |
256 | int using_threads = 1; | |
257 | ||
258 | /* True if we're presently stabilizing threads (moving them out of | |
259 | jump pads). */ | |
260 | static int stabilizing_threads; | |
261 | ||
262 | static void linux_resume_one_lwp (struct lwp_info *lwp, | |
263 | int step, int signal, siginfo_t *info); | |
264 | static void linux_resume (struct thread_resume *resume_info, size_t n); | |
265 | static void stop_all_lwps (int suspend, struct lwp_info *except); | |
266 | static void unstop_all_lwps (int unsuspend, struct lwp_info *except); | |
267 | static void unsuspend_all_lwps (struct lwp_info *except); | |
268 | static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, | |
269 | int *wstat, int options); | |
270 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); | |
271 | static struct lwp_info *add_lwp (ptid_t ptid); | |
272 | static void linux_mourn (struct process_info *process); | |
273 | static int linux_stopped_by_watchpoint (void); | |
274 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); | |
275 | static int lwp_is_marked_dead (struct lwp_info *lwp); | |
276 | static void proceed_all_lwps (void); | |
277 | static int finish_step_over (struct lwp_info *lwp); | |
278 | static int kill_lwp (unsigned long lwpid, int signo); | |
279 | static void enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info); | |
280 | static void complete_ongoing_step_over (void); | |
281 | static int linux_low_ptrace_options (int attached); | |
282 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); | |
283 | static void proceed_one_lwp (thread_info *thread, lwp_info *except); | |
284 | ||
285 | /* When the event-loop is doing a step-over, this points at the thread | |
286 | being stepped. */ | |
287 | ptid_t step_over_bkpt; | |
288 | ||
289 | /* True if the low target can hardware single-step. */ | |
290 | ||
291 | static int | |
292 | can_hardware_single_step (void) | |
293 | { | |
294 | if (the_low_target.supports_hardware_single_step != NULL) | |
295 | return the_low_target.supports_hardware_single_step (); | |
296 | else | |
297 | return 0; | |
298 | } | |
299 | ||
300 | /* True if the low target can software single-step. Such targets | |
301 | implement the GET_NEXT_PCS callback. */ | |
302 | ||
303 | static int | |
304 | can_software_single_step (void) | |
305 | { | |
306 | return (the_low_target.get_next_pcs != NULL); | |
307 | } | |
308 | ||
309 | /* True if the low target supports memory breakpoints. If so, we'll | |
310 | have a GET_PC implementation. */ | |
311 | ||
312 | static int | |
313 | supports_breakpoints (void) | |
314 | { | |
315 | return (the_low_target.get_pc != NULL); | |
316 | } | |
317 | ||
318 | /* Returns true if this target can support fast tracepoints. This | |
319 | does not mean that the in-process agent has been loaded in the | |
320 | inferior. */ | |
321 | ||
322 | static int | |
323 | supports_fast_tracepoints (void) | |
324 | { | |
325 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; | |
326 | } | |
327 | ||
328 | /* True if LWP is stopped in its stepping range. */ | |
329 | ||
330 | static int | |
331 | lwp_in_step_range (struct lwp_info *lwp) | |
332 | { | |
333 | CORE_ADDR pc = lwp->stop_pc; | |
334 | ||
335 | return (pc >= lwp->step_range_start && pc < lwp->step_range_end); | |
336 | } | |
337 | ||
338 | struct pending_signals | |
339 | { | |
340 | int signal; | |
341 | siginfo_t info; | |
342 | struct pending_signals *prev; | |
343 | }; | |
344 | ||
345 | /* The read/write ends of the pipe registered as waitable file in the | |
346 | event loop. */ | |
347 | static int linux_event_pipe[2] = { -1, -1 }; | |
348 | ||
349 | /* True if we're currently in async mode. */ | |
350 | #define target_is_async_p() (linux_event_pipe[0] != -1) | |
351 | ||
352 | static void send_sigstop (struct lwp_info *lwp); | |
353 | static void wait_for_sigstop (void); | |
354 | ||
355 | /* Return non-zero if HEADER is a 64-bit ELF file. */ | |
356 | ||
357 | static int | |
358 | elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine) | |
359 | { | |
360 | if (header->e_ident[EI_MAG0] == ELFMAG0 | |
361 | && header->e_ident[EI_MAG1] == ELFMAG1 | |
362 | && header->e_ident[EI_MAG2] == ELFMAG2 | |
363 | && header->e_ident[EI_MAG3] == ELFMAG3) | |
364 | { | |
365 | *machine = header->e_machine; | |
366 | return header->e_ident[EI_CLASS] == ELFCLASS64; | |
367 | ||
368 | } | |
369 | *machine = EM_NONE; | |
370 | return -1; | |
371 | } | |
372 | ||
373 | /* Return non-zero if FILE is a 64-bit ELF file, | |
374 | zero if the file is not a 64-bit ELF file, | |
375 | and -1 if the file is not accessible or doesn't exist. */ | |
376 | ||
377 | static int | |
378 | elf_64_file_p (const char *file, unsigned int *machine) | |
379 | { | |
380 | Elf64_Ehdr header; | |
381 | int fd; | |
382 | ||
383 | fd = open (file, O_RDONLY); | |
384 | if (fd < 0) | |
385 | return -1; | |
386 | ||
387 | if (read (fd, &header, sizeof (header)) != sizeof (header)) | |
388 | { | |
389 | close (fd); | |
390 | return 0; | |
391 | } | |
392 | close (fd); | |
393 | ||
394 | return elf_64_header_p (&header, machine); | |
395 | } | |
396 | ||
397 | /* Accepts an integer PID; Returns true if the executable PID is | |
398 | running is a 64-bit ELF file.. */ | |
399 | ||
400 | int | |
401 | linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine) | |
402 | { | |
403 | char file[PATH_MAX]; | |
404 | ||
405 | sprintf (file, "/proc/%d/exe", pid); | |
406 | return elf_64_file_p (file, machine); | |
407 | } | |
408 | ||
409 | static void | |
410 | delete_lwp (struct lwp_info *lwp) | |
411 | { | |
412 | struct thread_info *thr = get_lwp_thread (lwp); | |
413 | ||
414 | if (debug_threads) | |
415 | debug_printf ("deleting %ld\n", lwpid_of (thr)); | |
416 | ||
417 | remove_thread (thr); | |
418 | ||
419 | if (the_low_target.delete_thread != NULL) | |
420 | the_low_target.delete_thread (lwp->arch_private); | |
421 | else | |
422 | gdb_assert (lwp->arch_private == NULL); | |
423 | ||
424 | free (lwp); | |
425 | } | |
426 | ||
427 | /* Add a process to the common process list, and set its private | |
428 | data. */ | |
429 | ||
430 | static struct process_info * | |
431 | linux_add_process (int pid, int attached) | |
432 | { | |
433 | struct process_info *proc; | |
434 | ||
435 | proc = add_process (pid, attached); | |
436 | proc->priv = XCNEW (struct process_info_private); | |
437 | ||
438 | if (the_low_target.new_process != NULL) | |
439 | proc->priv->arch_private = the_low_target.new_process (); | |
440 | ||
441 | return proc; | |
442 | } | |
443 | ||
444 | static CORE_ADDR get_pc (struct lwp_info *lwp); | |
445 | ||
446 | /* Call the target arch_setup function on the current thread. */ | |
447 | ||
448 | static void | |
449 | linux_arch_setup (void) | |
450 | { | |
451 | the_low_target.arch_setup (); | |
452 | } | |
453 | ||
454 | /* Call the target arch_setup function on THREAD. */ | |
455 | ||
456 | static void | |
457 | linux_arch_setup_thread (struct thread_info *thread) | |
458 | { | |
459 | struct thread_info *saved_thread; | |
460 | ||
461 | saved_thread = current_thread; | |
462 | current_thread = thread; | |
463 | ||
464 | linux_arch_setup (); | |
465 | ||
466 | current_thread = saved_thread; | |
467 | } | |
468 | ||
469 | /* Handle a GNU/Linux extended wait response. If we see a clone, | |
470 | fork, or vfork event, we need to add the new LWP to our list | |
471 | (and return 0 so as not to report the trap to higher layers). | |
472 | If we see an exec event, we will modify ORIG_EVENT_LWP to point | |
473 | to a new LWP representing the new program. */ | |
474 | ||
475 | static int | |
476 | handle_extended_wait (struct lwp_info **orig_event_lwp, int wstat) | |
477 | { | |
478 | client_state &cs = get_client_state (); | |
479 | struct lwp_info *event_lwp = *orig_event_lwp; | |
480 | int event = linux_ptrace_get_extended_event (wstat); | |
481 | struct thread_info *event_thr = get_lwp_thread (event_lwp); | |
482 | struct lwp_info *new_lwp; | |
483 | ||
484 | gdb_assert (event_lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); | |
485 | ||
486 | /* All extended events we currently use are mid-syscall. Only | |
487 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
488 | you have to be using PTRACE_SEIZE to get that. */ | |
489 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
490 | ||
491 | if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK) | |
492 | || (event == PTRACE_EVENT_CLONE)) | |
493 | { | |
494 | ptid_t ptid; | |
495 | unsigned long new_pid; | |
496 | int ret, status; | |
497 | ||
498 | /* Get the pid of the new lwp. */ | |
499 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0, | |
500 | &new_pid); | |
501 | ||
502 | /* If we haven't already seen the new PID stop, wait for it now. */ | |
503 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
504 | { | |
505 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
506 | hits the SIGSTOP, but we're already attached. */ | |
507 | ||
508 | ret = my_waitpid (new_pid, &status, __WALL); | |
509 | ||
510 | if (ret == -1) | |
511 | perror_with_name ("waiting for new child"); | |
512 | else if (ret != new_pid) | |
513 | warning ("wait returned unexpected PID %d", ret); | |
514 | else if (!WIFSTOPPED (status)) | |
515 | warning ("wait returned unexpected status 0x%x", status); | |
516 | } | |
517 | ||
518 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) | |
519 | { | |
520 | struct process_info *parent_proc; | |
521 | struct process_info *child_proc; | |
522 | struct lwp_info *child_lwp; | |
523 | struct thread_info *child_thr; | |
524 | struct target_desc *tdesc; | |
525 | ||
526 | ptid = ptid_t (new_pid, new_pid, 0); | |
527 | ||
528 | if (debug_threads) | |
529 | { | |
530 | debug_printf ("HEW: Got fork event from LWP %ld, " | |
531 | "new child is %d\n", | |
532 | ptid_of (event_thr).lwp (), | |
533 | ptid.pid ()); | |
534 | } | |
535 | ||
536 | /* Add the new process to the tables and clone the breakpoint | |
537 | lists of the parent. We need to do this even if the new process | |
538 | will be detached, since we will need the process object and the | |
539 | breakpoints to remove any breakpoints from memory when we | |
540 | detach, and the client side will access registers. */ | |
541 | child_proc = linux_add_process (new_pid, 0); | |
542 | gdb_assert (child_proc != NULL); | |
543 | child_lwp = add_lwp (ptid); | |
544 | gdb_assert (child_lwp != NULL); | |
545 | child_lwp->stopped = 1; | |
546 | child_lwp->must_set_ptrace_flags = 1; | |
547 | child_lwp->status_pending_p = 0; | |
548 | child_thr = get_lwp_thread (child_lwp); | |
549 | child_thr->last_resume_kind = resume_stop; | |
550 | child_thr->last_status.kind = TARGET_WAITKIND_STOPPED; | |
551 | ||
552 | /* If we're suspending all threads, leave this one suspended | |
553 | too. If the fork/clone parent is stepping over a breakpoint, | |
554 | all other threads have been suspended already. Leave the | |
555 | child suspended too. */ | |
556 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS | |
557 | || event_lwp->bp_reinsert != 0) | |
558 | { | |
559 | if (debug_threads) | |
560 | debug_printf ("HEW: leaving child suspended\n"); | |
561 | child_lwp->suspended = 1; | |
562 | } | |
563 | ||
564 | parent_proc = get_thread_process (event_thr); | |
565 | child_proc->attached = parent_proc->attached; | |
566 | ||
567 | if (event_lwp->bp_reinsert != 0 | |
568 | && can_software_single_step () | |
569 | && event == PTRACE_EVENT_VFORK) | |
570 | { | |
571 | /* If we leave single-step breakpoints there, child will | |
572 | hit it, so uninsert single-step breakpoints from parent | |
573 | (and child). Once vfork child is done, reinsert | |
574 | them back to parent. */ | |
575 | uninsert_single_step_breakpoints (event_thr); | |
576 | } | |
577 | ||
578 | clone_all_breakpoints (child_thr, event_thr); | |
579 | ||
580 | tdesc = allocate_target_description (); | |
581 | copy_target_description (tdesc, parent_proc->tdesc); | |
582 | child_proc->tdesc = tdesc; | |
583 | ||
584 | /* Clone arch-specific process data. */ | |
585 | if (the_low_target.new_fork != NULL) | |
586 | the_low_target.new_fork (parent_proc, child_proc); | |
587 | ||
588 | /* Save fork info in the parent thread. */ | |
589 | if (event == PTRACE_EVENT_FORK) | |
590 | event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED; | |
591 | else if (event == PTRACE_EVENT_VFORK) | |
592 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED; | |
593 | ||
594 | event_lwp->waitstatus.value.related_pid = ptid; | |
595 | ||
596 | /* The status_pending field contains bits denoting the | |
597 | extended event, so when the pending event is handled, | |
598 | the handler will look at lwp->waitstatus. */ | |
599 | event_lwp->status_pending_p = 1; | |
600 | event_lwp->status_pending = wstat; | |
601 | ||
602 | /* Link the threads until the parent event is passed on to | |
603 | higher layers. */ | |
604 | event_lwp->fork_relative = child_lwp; | |
605 | child_lwp->fork_relative = event_lwp; | |
606 | ||
607 | /* If the parent thread is doing step-over with single-step | |
608 | breakpoints, the list of single-step breakpoints are cloned | |
609 | from the parent's. Remove them from the child process. | |
610 | In case of vfork, we'll reinsert them back once vforked | |
611 | child is done. */ | |
612 | if (event_lwp->bp_reinsert != 0 | |
613 | && can_software_single_step ()) | |
614 | { | |
615 | /* The child process is forked and stopped, so it is safe | |
616 | to access its memory without stopping all other threads | |
617 | from other processes. */ | |
618 | delete_single_step_breakpoints (child_thr); | |
619 | ||
620 | gdb_assert (has_single_step_breakpoints (event_thr)); | |
621 | gdb_assert (!has_single_step_breakpoints (child_thr)); | |
622 | } | |
623 | ||
624 | /* Report the event. */ | |
625 | return 0; | |
626 | } | |
627 | ||
628 | if (debug_threads) | |
629 | debug_printf ("HEW: Got clone event " | |
630 | "from LWP %ld, new child is LWP %ld\n", | |
631 | lwpid_of (event_thr), new_pid); | |
632 | ||
633 | ptid = ptid_t (pid_of (event_thr), new_pid, 0); | |
634 | new_lwp = add_lwp (ptid); | |
635 | ||
636 | /* Either we're going to immediately resume the new thread | |
637 | or leave it stopped. linux_resume_one_lwp is a nop if it | |
638 | thinks the thread is currently running, so set this first | |
639 | before calling linux_resume_one_lwp. */ | |
640 | new_lwp->stopped = 1; | |
641 | ||
642 | /* If we're suspending all threads, leave this one suspended | |
643 | too. If the fork/clone parent is stepping over a breakpoint, | |
644 | all other threads have been suspended already. Leave the | |
645 | child suspended too. */ | |
646 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS | |
647 | || event_lwp->bp_reinsert != 0) | |
648 | new_lwp->suspended = 1; | |
649 | ||
650 | /* Normally we will get the pending SIGSTOP. But in some cases | |
651 | we might get another signal delivered to the group first. | |
652 | If we do get another signal, be sure not to lose it. */ | |
653 | if (WSTOPSIG (status) != SIGSTOP) | |
654 | { | |
655 | new_lwp->stop_expected = 1; | |
656 | new_lwp->status_pending_p = 1; | |
657 | new_lwp->status_pending = status; | |
658 | } | |
659 | else if (cs.report_thread_events) | |
660 | { | |
661 | new_lwp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; | |
662 | new_lwp->status_pending_p = 1; | |
663 | new_lwp->status_pending = status; | |
664 | } | |
665 | ||
666 | #ifdef USE_THREAD_DB | |
667 | thread_db_notice_clone (event_thr, ptid); | |
668 | #endif | |
669 | ||
670 | /* Don't report the event. */ | |
671 | return 1; | |
672 | } | |
673 | else if (event == PTRACE_EVENT_VFORK_DONE) | |
674 | { | |
675 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
676 | ||
677 | if (event_lwp->bp_reinsert != 0 && can_software_single_step ()) | |
678 | { | |
679 | reinsert_single_step_breakpoints (event_thr); | |
680 | ||
681 | gdb_assert (has_single_step_breakpoints (event_thr)); | |
682 | } | |
683 | ||
684 | /* Report the event. */ | |
685 | return 0; | |
686 | } | |
687 | else if (event == PTRACE_EVENT_EXEC && cs.report_exec_events) | |
688 | { | |
689 | struct process_info *proc; | |
690 | std::vector<int> syscalls_to_catch; | |
691 | ptid_t event_ptid; | |
692 | pid_t event_pid; | |
693 | ||
694 | if (debug_threads) | |
695 | { | |
696 | debug_printf ("HEW: Got exec event from LWP %ld\n", | |
697 | lwpid_of (event_thr)); | |
698 | } | |
699 | ||
700 | /* Get the event ptid. */ | |
701 | event_ptid = ptid_of (event_thr); | |
702 | event_pid = event_ptid.pid (); | |
703 | ||
704 | /* Save the syscall list from the execing process. */ | |
705 | proc = get_thread_process (event_thr); | |
706 | syscalls_to_catch = std::move (proc->syscalls_to_catch); | |
707 | ||
708 | /* Delete the execing process and all its threads. */ | |
709 | linux_mourn (proc); | |
710 | current_thread = NULL; | |
711 | ||
712 | /* Create a new process/lwp/thread. */ | |
713 | proc = linux_add_process (event_pid, 0); | |
714 | event_lwp = add_lwp (event_ptid); | |
715 | event_thr = get_lwp_thread (event_lwp); | |
716 | gdb_assert (current_thread == event_thr); | |
717 | linux_arch_setup_thread (event_thr); | |
718 | ||
719 | /* Set the event status. */ | |
720 | event_lwp->waitstatus.kind = TARGET_WAITKIND_EXECD; | |
721 | event_lwp->waitstatus.value.execd_pathname | |
722 | = xstrdup (linux_proc_pid_to_exec_file (lwpid_of (event_thr))); | |
723 | ||
724 | /* Mark the exec status as pending. */ | |
725 | event_lwp->stopped = 1; | |
726 | event_lwp->status_pending_p = 1; | |
727 | event_lwp->status_pending = wstat; | |
728 | event_thr->last_resume_kind = resume_continue; | |
729 | event_thr->last_status.kind = TARGET_WAITKIND_IGNORE; | |
730 | ||
731 | /* Update syscall state in the new lwp, effectively mid-syscall too. */ | |
732 | event_lwp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
733 | ||
734 | /* Restore the list to catch. Don't rely on the client, which is free | |
735 | to avoid sending a new list when the architecture doesn't change. | |
736 | Also, for ANY_SYSCALL, the architecture doesn't really matter. */ | |
737 | proc->syscalls_to_catch = std::move (syscalls_to_catch); | |
738 | ||
739 | /* Report the event. */ | |
740 | *orig_event_lwp = event_lwp; | |
741 | return 0; | |
742 | } | |
743 | ||
744 | internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event); | |
745 | } | |
746 | ||
747 | /* Return the PC as read from the regcache of LWP, without any | |
748 | adjustment. */ | |
749 | ||
750 | static CORE_ADDR | |
751 | get_pc (struct lwp_info *lwp) | |
752 | { | |
753 | struct thread_info *saved_thread; | |
754 | struct regcache *regcache; | |
755 | CORE_ADDR pc; | |
756 | ||
757 | if (the_low_target.get_pc == NULL) | |
758 | return 0; | |
759 | ||
760 | saved_thread = current_thread; | |
761 | current_thread = get_lwp_thread (lwp); | |
762 | ||
763 | regcache = get_thread_regcache (current_thread, 1); | |
764 | pc = (*the_low_target.get_pc) (regcache); | |
765 | ||
766 | if (debug_threads) | |
767 | debug_printf ("pc is 0x%lx\n", (long) pc); | |
768 | ||
769 | current_thread = saved_thread; | |
770 | return pc; | |
771 | } | |
772 | ||
773 | /* This function should only be called if LWP got a SYSCALL_SIGTRAP. | |
774 | Fill *SYSNO with the syscall nr trapped. */ | |
775 | ||
776 | static void | |
777 | get_syscall_trapinfo (struct lwp_info *lwp, int *sysno) | |
778 | { | |
779 | struct thread_info *saved_thread; | |
780 | struct regcache *regcache; | |
781 | ||
782 | if (the_low_target.get_syscall_trapinfo == NULL) | |
783 | { | |
784 | /* If we cannot get the syscall trapinfo, report an unknown | |
785 | system call number. */ | |
786 | *sysno = UNKNOWN_SYSCALL; | |
787 | return; | |
788 | } | |
789 | ||
790 | saved_thread = current_thread; | |
791 | current_thread = get_lwp_thread (lwp); | |
792 | ||
793 | regcache = get_thread_regcache (current_thread, 1); | |
794 | (*the_low_target.get_syscall_trapinfo) (regcache, sysno); | |
795 | ||
796 | if (debug_threads) | |
797 | debug_printf ("get_syscall_trapinfo sysno %d\n", *sysno); | |
798 | ||
799 | current_thread = saved_thread; | |
800 | } | |
801 | ||
802 | static int check_stopped_by_watchpoint (struct lwp_info *child); | |
803 | ||
804 | /* Called when the LWP stopped for a signal/trap. If it stopped for a | |
805 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
806 | and save the result in the LWP's stop_reason field. If it stopped | |
807 | for a breakpoint, decrement the PC if necessary on the lwp's | |
808 | architecture. Returns true if we now have the LWP's stop PC. */ | |
809 | ||
810 | static int | |
811 | save_stop_reason (struct lwp_info *lwp) | |
812 | { | |
813 | CORE_ADDR pc; | |
814 | CORE_ADDR sw_breakpoint_pc; | |
815 | struct thread_info *saved_thread; | |
816 | #if USE_SIGTRAP_SIGINFO | |
817 | siginfo_t siginfo; | |
818 | #endif | |
819 | ||
820 | if (the_low_target.get_pc == NULL) | |
821 | return 0; | |
822 | ||
823 | pc = get_pc (lwp); | |
824 | sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break; | |
825 | ||
826 | /* breakpoint_at reads from the current thread. */ | |
827 | saved_thread = current_thread; | |
828 | current_thread = get_lwp_thread (lwp); | |
829 | ||
830 | #if USE_SIGTRAP_SIGINFO | |
831 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
832 | (PTRACE_TYPE_ARG3) 0, &siginfo) == 0) | |
833 | { | |
834 | if (siginfo.si_signo == SIGTRAP) | |
835 | { | |
836 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) | |
837 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
838 | { | |
839 | /* The si_code is ambiguous on this arch -- check debug | |
840 | registers. */ | |
841 | if (!check_stopped_by_watchpoint (lwp)) | |
842 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
843 | } | |
844 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
845 | { | |
846 | /* If we determine the LWP stopped for a SW breakpoint, | |
847 | trust it. Particularly don't check watchpoint | |
848 | registers, because at least on s390, we'd find | |
849 | stopped-by-watchpoint as long as there's a watchpoint | |
850 | set. */ | |
851 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
852 | } | |
853 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
854 | { | |
855 | /* This can indicate either a hardware breakpoint or | |
856 | hardware watchpoint. Check debug registers. */ | |
857 | if (!check_stopped_by_watchpoint (lwp)) | |
858 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
859 | } | |
860 | else if (siginfo.si_code == TRAP_TRACE) | |
861 | { | |
862 | /* We may have single stepped an instruction that | |
863 | triggered a watchpoint. In that case, on some | |
864 | architectures (such as x86), instead of TRAP_HWBKPT, | |
865 | si_code indicates TRAP_TRACE, and we need to check | |
866 | the debug registers separately. */ | |
867 | if (!check_stopped_by_watchpoint (lwp)) | |
868 | lwp->stop_reason = TARGET_STOPPED_BY_SINGLE_STEP; | |
869 | } | |
870 | } | |
871 | } | |
872 | #else | |
873 | /* We may have just stepped a breakpoint instruction. E.g., in | |
874 | non-stop mode, GDB first tells the thread A to step a range, and | |
875 | then the user inserts a breakpoint inside the range. In that | |
876 | case we need to report the breakpoint PC. */ | |
877 | if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc) | |
878 | && (*the_low_target.breakpoint_at) (sw_breakpoint_pc)) | |
879 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
880 | ||
881 | if (hardware_breakpoint_inserted_here (pc)) | |
882 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
883 | ||
884 | if (lwp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
885 | check_stopped_by_watchpoint (lwp); | |
886 | #endif | |
887 | ||
888 | if (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
889 | { | |
890 | if (debug_threads) | |
891 | { | |
892 | struct thread_info *thr = get_lwp_thread (lwp); | |
893 | ||
894 | debug_printf ("CSBB: %s stopped by software breakpoint\n", | |
895 | target_pid_to_str (ptid_of (thr))); | |
896 | } | |
897 | ||
898 | /* Back up the PC if necessary. */ | |
899 | if (pc != sw_breakpoint_pc) | |
900 | { | |
901 | struct regcache *regcache | |
902 | = get_thread_regcache (current_thread, 1); | |
903 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); | |
904 | } | |
905 | ||
906 | /* Update this so we record the correct stop PC below. */ | |
907 | pc = sw_breakpoint_pc; | |
908 | } | |
909 | else if (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
910 | { | |
911 | if (debug_threads) | |
912 | { | |
913 | struct thread_info *thr = get_lwp_thread (lwp); | |
914 | ||
915 | debug_printf ("CSBB: %s stopped by hardware breakpoint\n", | |
916 | target_pid_to_str (ptid_of (thr))); | |
917 | } | |
918 | } | |
919 | else if (lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
920 | { | |
921 | if (debug_threads) | |
922 | { | |
923 | struct thread_info *thr = get_lwp_thread (lwp); | |
924 | ||
925 | debug_printf ("CSBB: %s stopped by hardware watchpoint\n", | |
926 | target_pid_to_str (ptid_of (thr))); | |
927 | } | |
928 | } | |
929 | else if (lwp->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP) | |
930 | { | |
931 | if (debug_threads) | |
932 | { | |
933 | struct thread_info *thr = get_lwp_thread (lwp); | |
934 | ||
935 | debug_printf ("CSBB: %s stopped by trace\n", | |
936 | target_pid_to_str (ptid_of (thr))); | |
937 | } | |
938 | } | |
939 | ||
940 | lwp->stop_pc = pc; | |
941 | current_thread = saved_thread; | |
942 | return 1; | |
943 | } | |
944 | ||
945 | static struct lwp_info * | |
946 | add_lwp (ptid_t ptid) | |
947 | { | |
948 | struct lwp_info *lwp; | |
949 | ||
950 | lwp = XCNEW (struct lwp_info); | |
951 | ||
952 | lwp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
953 | ||
954 | lwp->thread = add_thread (ptid, lwp); | |
955 | ||
956 | if (the_low_target.new_thread != NULL) | |
957 | the_low_target.new_thread (lwp); | |
958 | ||
959 | return lwp; | |
960 | } | |
961 | ||
962 | /* Callback to be used when calling fork_inferior, responsible for | |
963 | actually initiating the tracing of the inferior. */ | |
964 | ||
965 | static void | |
966 | linux_ptrace_fun () | |
967 | { | |
968 | if (ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, | |
969 | (PTRACE_TYPE_ARG4) 0) < 0) | |
970 | trace_start_error_with_name ("ptrace"); | |
971 | ||
972 | if (setpgid (0, 0) < 0) | |
973 | trace_start_error_with_name ("setpgid"); | |
974 | ||
975 | /* If GDBserver is connected to gdb via stdio, redirect the inferior's | |
976 | stdout to stderr so that inferior i/o doesn't corrupt the connection. | |
977 | Also, redirect stdin to /dev/null. */ | |
978 | if (remote_connection_is_stdio ()) | |
979 | { | |
980 | if (close (0) < 0) | |
981 | trace_start_error_with_name ("close"); | |
982 | if (open ("/dev/null", O_RDONLY) < 0) | |
983 | trace_start_error_with_name ("open"); | |
984 | if (dup2 (2, 1) < 0) | |
985 | trace_start_error_with_name ("dup2"); | |
986 | if (write (2, "stdin/stdout redirected\n", | |
987 | sizeof ("stdin/stdout redirected\n") - 1) < 0) | |
988 | { | |
989 | /* Errors ignored. */; | |
990 | } | |
991 | } | |
992 | } | |
993 | ||
994 | /* Start an inferior process and returns its pid. | |
995 | PROGRAM is the name of the program to be started, and PROGRAM_ARGS | |
996 | are its arguments. */ | |
997 | ||
998 | static int | |
999 | linux_create_inferior (const char *program, | |
1000 | const std::vector<char *> &program_args) | |
1001 | { | |
1002 | client_state &cs = get_client_state (); | |
1003 | struct lwp_info *new_lwp; | |
1004 | int pid; | |
1005 | ptid_t ptid; | |
1006 | ||
1007 | { | |
1008 | maybe_disable_address_space_randomization restore_personality | |
1009 | (cs.disable_randomization); | |
1010 | std::string str_program_args = stringify_argv (program_args); | |
1011 | ||
1012 | pid = fork_inferior (program, | |
1013 | str_program_args.c_str (), | |
1014 | get_environ ()->envp (), linux_ptrace_fun, | |
1015 | NULL, NULL, NULL, NULL); | |
1016 | } | |
1017 | ||
1018 | linux_add_process (pid, 0); | |
1019 | ||
1020 | ptid = ptid_t (pid, pid, 0); | |
1021 | new_lwp = add_lwp (ptid); | |
1022 | new_lwp->must_set_ptrace_flags = 1; | |
1023 | ||
1024 | post_fork_inferior (pid, program); | |
1025 | ||
1026 | return pid; | |
1027 | } | |
1028 | ||
1029 | /* Implement the post_create_inferior target_ops method. */ | |
1030 | ||
1031 | static void | |
1032 | linux_post_create_inferior (void) | |
1033 | { | |
1034 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
1035 | ||
1036 | linux_arch_setup (); | |
1037 | ||
1038 | if (lwp->must_set_ptrace_flags) | |
1039 | { | |
1040 | struct process_info *proc = current_process (); | |
1041 | int options = linux_low_ptrace_options (proc->attached); | |
1042 | ||
1043 | linux_enable_event_reporting (lwpid_of (current_thread), options); | |
1044 | lwp->must_set_ptrace_flags = 0; | |
1045 | } | |
1046 | } | |
1047 | ||
1048 | /* Attach to an inferior process. Returns 0 on success, ERRNO on | |
1049 | error. */ | |
1050 | ||
1051 | int | |
1052 | linux_attach_lwp (ptid_t ptid) | |
1053 | { | |
1054 | struct lwp_info *new_lwp; | |
1055 | int lwpid = ptid.lwp (); | |
1056 | ||
1057 | if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0) | |
1058 | != 0) | |
1059 | return errno; | |
1060 | ||
1061 | new_lwp = add_lwp (ptid); | |
1062 | ||
1063 | /* We need to wait for SIGSTOP before being able to make the next | |
1064 | ptrace call on this LWP. */ | |
1065 | new_lwp->must_set_ptrace_flags = 1; | |
1066 | ||
1067 | if (linux_proc_pid_is_stopped (lwpid)) | |
1068 | { | |
1069 | if (debug_threads) | |
1070 | debug_printf ("Attached to a stopped process\n"); | |
1071 | ||
1072 | /* The process is definitely stopped. It is in a job control | |
1073 | stop, unless the kernel predates the TASK_STOPPED / | |
1074 | TASK_TRACED distinction, in which case it might be in a | |
1075 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1076 | can kill it, signal it, et cetera. | |
1077 | ||
1078 | First make sure there is a pending SIGSTOP. Since we are | |
1079 | already attached, the process can not transition from stopped | |
1080 | to running without a PTRACE_CONT; so we know this signal will | |
1081 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1082 | probably already in the queue (unless this kernel is old | |
1083 | enough to use TASK_STOPPED for ptrace stops); but since | |
1084 | SIGSTOP is not an RT signal, it can only be queued once. */ | |
1085 | kill_lwp (lwpid, SIGSTOP); | |
1086 | ||
1087 | /* Finally, resume the stopped process. This will deliver the | |
1088 | SIGSTOP (or a higher priority signal, just like normal | |
1089 | PTRACE_ATTACH), which we'll catch later on. */ | |
1090 | ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); | |
1091 | } | |
1092 | ||
1093 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH | |
1094 | brings it to a halt. | |
1095 | ||
1096 | There are several cases to consider here: | |
1097 | ||
1098 | 1) gdbserver has already attached to the process and is being notified | |
1099 | of a new thread that is being created. | |
1100 | In this case we should ignore that SIGSTOP and resume the | |
1101 | process. This is handled below by setting stop_expected = 1, | |
1102 | and the fact that add_thread sets last_resume_kind == | |
1103 | resume_continue. | |
1104 | ||
1105 | 2) This is the first thread (the process thread), and we're attaching | |
1106 | to it via attach_inferior. | |
1107 | In this case we want the process thread to stop. | |
1108 | This is handled by having linux_attach set last_resume_kind == | |
1109 | resume_stop after we return. | |
1110 | ||
1111 | If the pid we are attaching to is also the tgid, we attach to and | |
1112 | stop all the existing threads. Otherwise, we attach to pid and | |
1113 | ignore any other threads in the same group as this pid. | |
1114 | ||
1115 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all | |
1116 | existing threads. | |
1117 | In this case we want the thread to stop. | |
1118 | FIXME: This case is currently not properly handled. | |
1119 | We should wait for the SIGSTOP but don't. Things work apparently | |
1120 | because enough time passes between when we ptrace (ATTACH) and when | |
1121 | gdb makes the next ptrace call on the thread. | |
1122 | ||
1123 | On the other hand, if we are currently trying to stop all threads, we | |
1124 | should treat the new thread as if we had sent it a SIGSTOP. This works | |
1125 | because we are guaranteed that the add_lwp call above added us to the | |
1126 | end of the list, and so the new thread has not yet reached | |
1127 | wait_for_sigstop (but will). */ | |
1128 | new_lwp->stop_expected = 1; | |
1129 | ||
1130 | return 0; | |
1131 | } | |
1132 | ||
1133 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not | |
1134 | already attached. Returns true if a new LWP is found, false | |
1135 | otherwise. */ | |
1136 | ||
1137 | static int | |
1138 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1139 | { | |
1140 | /* Is this a new thread? */ | |
1141 | if (find_thread_ptid (ptid) == NULL) | |
1142 | { | |
1143 | int lwpid = ptid.lwp (); | |
1144 | int err; | |
1145 | ||
1146 | if (debug_threads) | |
1147 | debug_printf ("Found new lwp %d\n", lwpid); | |
1148 | ||
1149 | err = linux_attach_lwp (ptid); | |
1150 | ||
1151 | /* Be quiet if we simply raced with the thread exiting. EPERM | |
1152 | is returned if the thread's task still exists, and is marked | |
1153 | as exited or zombie, as well as other conditions, so in that | |
1154 | case, confirm the status in /proc/PID/status. */ | |
1155 | if (err == ESRCH | |
1156 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1157 | { | |
1158 | if (debug_threads) | |
1159 | { | |
1160 | debug_printf ("Cannot attach to lwp %d: " | |
1161 | "thread is gone (%d: %s)\n", | |
1162 | lwpid, err, strerror (err)); | |
1163 | } | |
1164 | } | |
1165 | else if (err != 0) | |
1166 | { | |
1167 | std::string reason | |
1168 | = linux_ptrace_attach_fail_reason_string (ptid, err); | |
1169 | ||
1170 | warning (_("Cannot attach to lwp %d: %s"), lwpid, reason.c_str ()); | |
1171 | } | |
1172 | ||
1173 | return 1; | |
1174 | } | |
1175 | return 0; | |
1176 | } | |
1177 | ||
1178 | static void async_file_mark (void); | |
1179 | ||
1180 | /* Attach to PID. If PID is the tgid, attach to it and all | |
1181 | of its threads. */ | |
1182 | ||
1183 | static int | |
1184 | linux_attach (unsigned long pid) | |
1185 | { | |
1186 | struct process_info *proc; | |
1187 | struct thread_info *initial_thread; | |
1188 | ptid_t ptid = ptid_t (pid, pid, 0); | |
1189 | int err; | |
1190 | ||
1191 | proc = linux_add_process (pid, 1); | |
1192 | ||
1193 | /* Attach to PID. We will check for other threads | |
1194 | soon. */ | |
1195 | err = linux_attach_lwp (ptid); | |
1196 | if (err != 0) | |
1197 | { | |
1198 | remove_process (proc); | |
1199 | ||
1200 | std::string reason = linux_ptrace_attach_fail_reason_string (ptid, err); | |
1201 | error ("Cannot attach to process %ld: %s", pid, reason.c_str ()); | |
1202 | } | |
1203 | ||
1204 | /* Don't ignore the initial SIGSTOP if we just attached to this | |
1205 | process. It will be collected by wait shortly. */ | |
1206 | initial_thread = find_thread_ptid (ptid_t (pid, pid, 0)); | |
1207 | initial_thread->last_resume_kind = resume_stop; | |
1208 | ||
1209 | /* We must attach to every LWP. If /proc is mounted, use that to | |
1210 | find them now. On the one hand, the inferior may be using raw | |
1211 | clone instead of using pthreads. On the other hand, even if it | |
1212 | is using pthreads, GDB may not be connected yet (thread_db needs | |
1213 | to do symbol lookups, through qSymbol). Also, thread_db walks | |
1214 | structures in the inferior's address space to find the list of | |
1215 | threads/LWPs, and those structures may well be corrupted. Note | |
1216 | that once thread_db is loaded, we'll still use it to list threads | |
1217 | and associate pthread info with each LWP. */ | |
1218 | linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); | |
1219 | ||
1220 | /* GDB will shortly read the xml target description for this | |
1221 | process, to figure out the process' architecture. But the target | |
1222 | description is only filled in when the first process/thread in | |
1223 | the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do | |
1224 | that now, otherwise, if GDB is fast enough, it could read the | |
1225 | target description _before_ that initial stop. */ | |
1226 | if (non_stop) | |
1227 | { | |
1228 | struct lwp_info *lwp; | |
1229 | int wstat, lwpid; | |
1230 | ptid_t pid_ptid = ptid_t (pid); | |
1231 | ||
1232 | lwpid = linux_wait_for_event_filtered (pid_ptid, pid_ptid, | |
1233 | &wstat, __WALL); | |
1234 | gdb_assert (lwpid > 0); | |
1235 | ||
1236 | lwp = find_lwp_pid (ptid_t (lwpid)); | |
1237 | ||
1238 | if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGSTOP) | |
1239 | { | |
1240 | lwp->status_pending_p = 1; | |
1241 | lwp->status_pending = wstat; | |
1242 | } | |
1243 | ||
1244 | initial_thread->last_resume_kind = resume_continue; | |
1245 | ||
1246 | async_file_mark (); | |
1247 | ||
1248 | gdb_assert (proc->tdesc != NULL); | |
1249 | } | |
1250 | ||
1251 | return 0; | |
1252 | } | |
1253 | ||
1254 | static int | |
1255 | last_thread_of_process_p (int pid) | |
1256 | { | |
1257 | bool seen_one = false; | |
1258 | ||
1259 | thread_info *thread = find_thread (pid, [&] (thread_info *thr_arg) | |
1260 | { | |
1261 | if (!seen_one) | |
1262 | { | |
1263 | /* This is the first thread of this process we see. */ | |
1264 | seen_one = true; | |
1265 | return false; | |
1266 | } | |
1267 | else | |
1268 | { | |
1269 | /* This is the second thread of this process we see. */ | |
1270 | return true; | |
1271 | } | |
1272 | }); | |
1273 | ||
1274 | return thread == NULL; | |
1275 | } | |
1276 | ||
1277 | /* Kill LWP. */ | |
1278 | ||
1279 | static void | |
1280 | linux_kill_one_lwp (struct lwp_info *lwp) | |
1281 | { | |
1282 | struct thread_info *thr = get_lwp_thread (lwp); | |
1283 | int pid = lwpid_of (thr); | |
1284 | ||
1285 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, | |
1286 | there is no signal context, and ptrace(PTRACE_KILL) (or | |
1287 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like | |
1288 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better | |
1289 | alternative is to kill with SIGKILL. We only need one SIGKILL | |
1290 | per process, not one for each thread. But since we still support | |
1291 | support debugging programs using raw clone without CLONE_THREAD, | |
1292 | we send one for each thread. For years, we used PTRACE_KILL | |
1293 | only, so we're being a bit paranoid about some old kernels where | |
1294 | PTRACE_KILL might work better (dubious if there are any such, but | |
1295 | that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL | |
1296 | second, and so we're fine everywhere. */ | |
1297 | ||
1298 | errno = 0; | |
1299 | kill_lwp (pid, SIGKILL); | |
1300 | if (debug_threads) | |
1301 | { | |
1302 | int save_errno = errno; | |
1303 | ||
1304 | debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n", | |
1305 | target_pid_to_str (ptid_of (thr)), | |
1306 | save_errno ? strerror (save_errno) : "OK"); | |
1307 | } | |
1308 | ||
1309 | errno = 0; | |
1310 | ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); | |
1311 | if (debug_threads) | |
1312 | { | |
1313 | int save_errno = errno; | |
1314 | ||
1315 | debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n", | |
1316 | target_pid_to_str (ptid_of (thr)), | |
1317 | save_errno ? strerror (save_errno) : "OK"); | |
1318 | } | |
1319 | } | |
1320 | ||
1321 | /* Kill LWP and wait for it to die. */ | |
1322 | ||
1323 | static void | |
1324 | kill_wait_lwp (struct lwp_info *lwp) | |
1325 | { | |
1326 | struct thread_info *thr = get_lwp_thread (lwp); | |
1327 | int pid = ptid_of (thr).pid (); | |
1328 | int lwpid = ptid_of (thr).lwp (); | |
1329 | int wstat; | |
1330 | int res; | |
1331 | ||
1332 | if (debug_threads) | |
1333 | debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid); | |
1334 | ||
1335 | do | |
1336 | { | |
1337 | linux_kill_one_lwp (lwp); | |
1338 | ||
1339 | /* Make sure it died. Notes: | |
1340 | ||
1341 | - The loop is most likely unnecessary. | |
1342 | ||
1343 | - We don't use linux_wait_for_event as that could delete lwps | |
1344 | while we're iterating over them. We're not interested in | |
1345 | any pending status at this point, only in making sure all | |
1346 | wait status on the kernel side are collected until the | |
1347 | process is reaped. | |
1348 | ||
1349 | - We don't use __WALL here as the __WALL emulation relies on | |
1350 | SIGCHLD, and killing a stopped process doesn't generate | |
1351 | one, nor an exit status. | |
1352 | */ | |
1353 | res = my_waitpid (lwpid, &wstat, 0); | |
1354 | if (res == -1 && errno == ECHILD) | |
1355 | res = my_waitpid (lwpid, &wstat, __WCLONE); | |
1356 | } while (res > 0 && WIFSTOPPED (wstat)); | |
1357 | ||
1358 | /* Even if it was stopped, the child may have already disappeared. | |
1359 | E.g., if it was killed by SIGKILL. */ | |
1360 | if (res < 0 && errno != ECHILD) | |
1361 | perror_with_name ("kill_wait_lwp"); | |
1362 | } | |
1363 | ||
1364 | /* Callback for `for_each_thread'. Kills an lwp of a given process, | |
1365 | except the leader. */ | |
1366 | ||
1367 | static void | |
1368 | kill_one_lwp_callback (thread_info *thread, int pid) | |
1369 | { | |
1370 | struct lwp_info *lwp = get_thread_lwp (thread); | |
1371 | ||
1372 | /* We avoid killing the first thread here, because of a Linux kernel (at | |
1373 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before | |
1374 | the children get a chance to be reaped, it will remain a zombie | |
1375 | forever. */ | |
1376 | ||
1377 | if (lwpid_of (thread) == pid) | |
1378 | { | |
1379 | if (debug_threads) | |
1380 | debug_printf ("lkop: is last of process %s\n", | |
1381 | target_pid_to_str (thread->id)); | |
1382 | return; | |
1383 | } | |
1384 | ||
1385 | kill_wait_lwp (lwp); | |
1386 | } | |
1387 | ||
1388 | static int | |
1389 | linux_kill (process_info *process) | |
1390 | { | |
1391 | int pid = process->pid; | |
1392 | ||
1393 | /* If we're killing a running inferior, make sure it is stopped | |
1394 | first, as PTRACE_KILL will not work otherwise. */ | |
1395 | stop_all_lwps (0, NULL); | |
1396 | ||
1397 | for_each_thread (pid, [&] (thread_info *thread) | |
1398 | { | |
1399 | kill_one_lwp_callback (thread, pid); | |
1400 | }); | |
1401 | ||
1402 | /* See the comment in linux_kill_one_lwp. We did not kill the first | |
1403 | thread in the list, so do so now. */ | |
1404 | lwp_info *lwp = find_lwp_pid (ptid_t (pid)); | |
1405 | ||
1406 | if (lwp == NULL) | |
1407 | { | |
1408 | if (debug_threads) | |
1409 | debug_printf ("lk_1: cannot find lwp for pid: %d\n", | |
1410 | pid); | |
1411 | } | |
1412 | else | |
1413 | kill_wait_lwp (lwp); | |
1414 | ||
1415 | the_target->mourn (process); | |
1416 | ||
1417 | /* Since we presently can only stop all lwps of all processes, we | |
1418 | need to unstop lwps of other processes. */ | |
1419 | unstop_all_lwps (0, NULL); | |
1420 | return 0; | |
1421 | } | |
1422 | ||
1423 | /* Get pending signal of THREAD, for detaching purposes. This is the | |
1424 | signal the thread last stopped for, which we need to deliver to the | |
1425 | thread when detaching, otherwise, it'd be suppressed/lost. */ | |
1426 | ||
1427 | static int | |
1428 | get_detach_signal (struct thread_info *thread) | |
1429 | { | |
1430 | client_state &cs = get_client_state (); | |
1431 | enum gdb_signal signo = GDB_SIGNAL_0; | |
1432 | int status; | |
1433 | struct lwp_info *lp = get_thread_lwp (thread); | |
1434 | ||
1435 | if (lp->status_pending_p) | |
1436 | status = lp->status_pending; | |
1437 | else | |
1438 | { | |
1439 | /* If the thread had been suspended by gdbserver, and it stopped | |
1440 | cleanly, then it'll have stopped with SIGSTOP. But we don't | |
1441 | want to deliver that SIGSTOP. */ | |
1442 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED | |
1443 | || thread->last_status.value.sig == GDB_SIGNAL_0) | |
1444 | return 0; | |
1445 | ||
1446 | /* Otherwise, we may need to deliver the signal we | |
1447 | intercepted. */ | |
1448 | status = lp->last_status; | |
1449 | } | |
1450 | ||
1451 | if (!WIFSTOPPED (status)) | |
1452 | { | |
1453 | if (debug_threads) | |
1454 | debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n", | |
1455 | target_pid_to_str (ptid_of (thread))); | |
1456 | return 0; | |
1457 | } | |
1458 | ||
1459 | /* Extended wait statuses aren't real SIGTRAPs. */ | |
1460 | if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status)) | |
1461 | { | |
1462 | if (debug_threads) | |
1463 | debug_printf ("GPS: lwp %s had stopped with extended " | |
1464 | "status: no pending signal\n", | |
1465 | target_pid_to_str (ptid_of (thread))); | |
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | signo = gdb_signal_from_host (WSTOPSIG (status)); | |
1470 | ||
1471 | if (cs.program_signals_p && !cs.program_signals[signo]) | |
1472 | { | |
1473 | if (debug_threads) | |
1474 | debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n", | |
1475 | target_pid_to_str (ptid_of (thread)), | |
1476 | gdb_signal_to_string (signo)); | |
1477 | return 0; | |
1478 | } | |
1479 | else if (!cs.program_signals_p | |
1480 | /* If we have no way to know which signals GDB does not | |
1481 | want to have passed to the program, assume | |
1482 | SIGTRAP/SIGINT, which is GDB's default. */ | |
1483 | && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT)) | |
1484 | { | |
1485 | if (debug_threads) | |
1486 | debug_printf ("GPS: lwp %s had signal %s, " | |
1487 | "but we don't know if we should pass it. " | |
1488 | "Default to not.\n", | |
1489 | target_pid_to_str (ptid_of (thread)), | |
1490 | gdb_signal_to_string (signo)); | |
1491 | return 0; | |
1492 | } | |
1493 | else | |
1494 | { | |
1495 | if (debug_threads) | |
1496 | debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n", | |
1497 | target_pid_to_str (ptid_of (thread)), | |
1498 | gdb_signal_to_string (signo)); | |
1499 | ||
1500 | return WSTOPSIG (status); | |
1501 | } | |
1502 | } | |
1503 | ||
1504 | /* Detach from LWP. */ | |
1505 | ||
1506 | static void | |
1507 | linux_detach_one_lwp (struct lwp_info *lwp) | |
1508 | { | |
1509 | struct thread_info *thread = get_lwp_thread (lwp); | |
1510 | int sig; | |
1511 | int lwpid; | |
1512 | ||
1513 | /* If there is a pending SIGSTOP, get rid of it. */ | |
1514 | if (lwp->stop_expected) | |
1515 | { | |
1516 | if (debug_threads) | |
1517 | debug_printf ("Sending SIGCONT to %s\n", | |
1518 | target_pid_to_str (ptid_of (thread))); | |
1519 | ||
1520 | kill_lwp (lwpid_of (thread), SIGCONT); | |
1521 | lwp->stop_expected = 0; | |
1522 | } | |
1523 | ||
1524 | /* Pass on any pending signal for this thread. */ | |
1525 | sig = get_detach_signal (thread); | |
1526 | ||
1527 | /* Preparing to resume may try to write registers, and fail if the | |
1528 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1529 | it below, when detach fails with ESRCH. */ | |
1530 | try | |
1531 | { | |
1532 | /* Flush any pending changes to the process's registers. */ | |
1533 | regcache_invalidate_thread (thread); | |
1534 | ||
1535 | /* Finally, let it resume. */ | |
1536 | if (the_low_target.prepare_to_resume != NULL) | |
1537 | the_low_target.prepare_to_resume (lwp); | |
1538 | } | |
1539 | catch (const gdb_exception_error &ex) | |
1540 | { | |
1541 | if (!check_ptrace_stopped_lwp_gone (lwp)) | |
1542 | throw; | |
1543 | } | |
1544 | ||
1545 | lwpid = lwpid_of (thread); | |
1546 | if (ptrace (PTRACE_DETACH, lwpid, (PTRACE_TYPE_ARG3) 0, | |
1547 | (PTRACE_TYPE_ARG4) (long) sig) < 0) | |
1548 | { | |
1549 | int save_errno = errno; | |
1550 | ||
1551 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1552 | zombie. This can happen if one of the already-detached | |
1553 | threads exits the whole thread group. In that case we're | |
1554 | still attached, and must reap the lwp. */ | |
1555 | if (save_errno == ESRCH) | |
1556 | { | |
1557 | int ret, status; | |
1558 | ||
1559 | ret = my_waitpid (lwpid, &status, __WALL); | |
1560 | if (ret == -1) | |
1561 | { | |
1562 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1563 | lwpid, strerror (errno)); | |
1564 | } | |
1565 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1566 | { | |
1567 | warning (_("Reaping LWP %d while detaching " | |
1568 | "returned unexpected status 0x%x"), | |
1569 | lwpid, status); | |
1570 | } | |
1571 | } | |
1572 | else | |
1573 | { | |
1574 | error (_("Can't detach %s: %s"), | |
1575 | target_pid_to_str (ptid_of (thread)), | |
1576 | strerror (save_errno)); | |
1577 | } | |
1578 | } | |
1579 | else if (debug_threads) | |
1580 | { | |
1581 | debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1582 | target_pid_to_str (ptid_of (thread)), | |
1583 | strsignal (sig)); | |
1584 | } | |
1585 | ||
1586 | delete_lwp (lwp); | |
1587 | } | |
1588 | ||
1589 | /* Callback for for_each_thread. Detaches from non-leader threads of a | |
1590 | given process. */ | |
1591 | ||
1592 | static void | |
1593 | linux_detach_lwp_callback (thread_info *thread) | |
1594 | { | |
1595 | /* We don't actually detach from the thread group leader just yet. | |
1596 | If the thread group exits, we must reap the zombie clone lwps | |
1597 | before we're able to reap the leader. */ | |
1598 | if (thread->id.pid () == thread->id.lwp ()) | |
1599 | return; | |
1600 | ||
1601 | lwp_info *lwp = get_thread_lwp (thread); | |
1602 | linux_detach_one_lwp (lwp); | |
1603 | } | |
1604 | ||
1605 | static int | |
1606 | linux_detach (process_info *process) | |
1607 | { | |
1608 | struct lwp_info *main_lwp; | |
1609 | ||
1610 | /* As there's a step over already in progress, let it finish first, | |
1611 | otherwise nesting a stabilize_threads operation on top gets real | |
1612 | messy. */ | |
1613 | complete_ongoing_step_over (); | |
1614 | ||
1615 | /* Stop all threads before detaching. First, ptrace requires that | |
1616 | the thread is stopped to sucessfully detach. Second, thread_db | |
1617 | may need to uninstall thread event breakpoints from memory, which | |
1618 | only works with a stopped process anyway. */ | |
1619 | stop_all_lwps (0, NULL); | |
1620 | ||
1621 | #ifdef USE_THREAD_DB | |
1622 | thread_db_detach (process); | |
1623 | #endif | |
1624 | ||
1625 | /* Stabilize threads (move out of jump pads). */ | |
1626 | stabilize_threads (); | |
1627 | ||
1628 | /* Detach from the clone lwps first. If the thread group exits just | |
1629 | while we're detaching, we must reap the clone lwps before we're | |
1630 | able to reap the leader. */ | |
1631 | for_each_thread (process->pid, linux_detach_lwp_callback); | |
1632 | ||
1633 | main_lwp = find_lwp_pid (ptid_t (process->pid)); | |
1634 | linux_detach_one_lwp (main_lwp); | |
1635 | ||
1636 | the_target->mourn (process); | |
1637 | ||
1638 | /* Since we presently can only stop all lwps of all processes, we | |
1639 | need to unstop lwps of other processes. */ | |
1640 | unstop_all_lwps (0, NULL); | |
1641 | return 0; | |
1642 | } | |
1643 | ||
1644 | /* Remove all LWPs that belong to process PROC from the lwp list. */ | |
1645 | ||
1646 | static void | |
1647 | linux_mourn (struct process_info *process) | |
1648 | { | |
1649 | struct process_info_private *priv; | |
1650 | ||
1651 | #ifdef USE_THREAD_DB | |
1652 | thread_db_mourn (process); | |
1653 | #endif | |
1654 | ||
1655 | for_each_thread (process->pid, [] (thread_info *thread) | |
1656 | { | |
1657 | delete_lwp (get_thread_lwp (thread)); | |
1658 | }); | |
1659 | ||
1660 | /* Freeing all private data. */ | |
1661 | priv = process->priv; | |
1662 | if (the_low_target.delete_process != NULL) | |
1663 | the_low_target.delete_process (priv->arch_private); | |
1664 | else | |
1665 | gdb_assert (priv->arch_private == NULL); | |
1666 | free (priv); | |
1667 | process->priv = NULL; | |
1668 | ||
1669 | remove_process (process); | |
1670 | } | |
1671 | ||
1672 | static void | |
1673 | linux_join (int pid) | |
1674 | { | |
1675 | int status, ret; | |
1676 | ||
1677 | do { | |
1678 | ret = my_waitpid (pid, &status, 0); | |
1679 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
1680 | break; | |
1681 | } while (ret != -1 || errno != ECHILD); | |
1682 | } | |
1683 | ||
1684 | /* Return nonzero if the given thread is still alive. */ | |
1685 | static int | |
1686 | linux_thread_alive (ptid_t ptid) | |
1687 | { | |
1688 | struct lwp_info *lwp = find_lwp_pid (ptid); | |
1689 | ||
1690 | /* We assume we always know if a thread exits. If a whole process | |
1691 | exited but we still haven't been able to report it to GDB, we'll | |
1692 | hold on to the last lwp of the dead process. */ | |
1693 | if (lwp != NULL) | |
1694 | return !lwp_is_marked_dead (lwp); | |
1695 | else | |
1696 | return 0; | |
1697 | } | |
1698 | ||
1699 | /* Return 1 if this lwp still has an interesting status pending. If | |
1700 | not (e.g., it had stopped for a breakpoint that is gone), return | |
1701 | false. */ | |
1702 | ||
1703 | static int | |
1704 | thread_still_has_status_pending_p (struct thread_info *thread) | |
1705 | { | |
1706 | struct lwp_info *lp = get_thread_lwp (thread); | |
1707 | ||
1708 | if (!lp->status_pending_p) | |
1709 | return 0; | |
1710 | ||
1711 | if (thread->last_resume_kind != resume_stop | |
1712 | && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
1713 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) | |
1714 | { | |
1715 | struct thread_info *saved_thread; | |
1716 | CORE_ADDR pc; | |
1717 | int discard = 0; | |
1718 | ||
1719 | gdb_assert (lp->last_status != 0); | |
1720 | ||
1721 | pc = get_pc (lp); | |
1722 | ||
1723 | saved_thread = current_thread; | |
1724 | current_thread = thread; | |
1725 | ||
1726 | if (pc != lp->stop_pc) | |
1727 | { | |
1728 | if (debug_threads) | |
1729 | debug_printf ("PC of %ld changed\n", | |
1730 | lwpid_of (thread)); | |
1731 | discard = 1; | |
1732 | } | |
1733 | ||
1734 | #if !USE_SIGTRAP_SIGINFO | |
1735 | else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
1736 | && !(*the_low_target.breakpoint_at) (pc)) | |
1737 | { | |
1738 | if (debug_threads) | |
1739 | debug_printf ("previous SW breakpoint of %ld gone\n", | |
1740 | lwpid_of (thread)); | |
1741 | discard = 1; | |
1742 | } | |
1743 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT | |
1744 | && !hardware_breakpoint_inserted_here (pc)) | |
1745 | { | |
1746 | if (debug_threads) | |
1747 | debug_printf ("previous HW breakpoint of %ld gone\n", | |
1748 | lwpid_of (thread)); | |
1749 | discard = 1; | |
1750 | } | |
1751 | #endif | |
1752 | ||
1753 | current_thread = saved_thread; | |
1754 | ||
1755 | if (discard) | |
1756 | { | |
1757 | if (debug_threads) | |
1758 | debug_printf ("discarding pending breakpoint status\n"); | |
1759 | lp->status_pending_p = 0; | |
1760 | return 0; | |
1761 | } | |
1762 | } | |
1763 | ||
1764 | return 1; | |
1765 | } | |
1766 | ||
1767 | /* Returns true if LWP is resumed from the client's perspective. */ | |
1768 | ||
1769 | static int | |
1770 | lwp_resumed (struct lwp_info *lwp) | |
1771 | { | |
1772 | struct thread_info *thread = get_lwp_thread (lwp); | |
1773 | ||
1774 | if (thread->last_resume_kind != resume_stop) | |
1775 | return 1; | |
1776 | ||
1777 | /* Did gdb send us a `vCont;t', but we haven't reported the | |
1778 | corresponding stop to gdb yet? If so, the thread is still | |
1779 | resumed/running from gdb's perspective. */ | |
1780 | if (thread->last_resume_kind == resume_stop | |
1781 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) | |
1782 | return 1; | |
1783 | ||
1784 | return 0; | |
1785 | } | |
1786 | ||
1787 | /* Return true if this lwp has an interesting status pending. */ | |
1788 | static bool | |
1789 | status_pending_p_callback (thread_info *thread, ptid_t ptid) | |
1790 | { | |
1791 | struct lwp_info *lp = get_thread_lwp (thread); | |
1792 | ||
1793 | /* Check if we're only interested in events from a specific process | |
1794 | or a specific LWP. */ | |
1795 | if (!thread->id.matches (ptid)) | |
1796 | return 0; | |
1797 | ||
1798 | if (!lwp_resumed (lp)) | |
1799 | return 0; | |
1800 | ||
1801 | if (lp->status_pending_p | |
1802 | && !thread_still_has_status_pending_p (thread)) | |
1803 | { | |
1804 | linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL); | |
1805 | return 0; | |
1806 | } | |
1807 | ||
1808 | return lp->status_pending_p; | |
1809 | } | |
1810 | ||
1811 | struct lwp_info * | |
1812 | find_lwp_pid (ptid_t ptid) | |
1813 | { | |
1814 | thread_info *thread = find_thread ([&] (thread_info *thr_arg) | |
1815 | { | |
1816 | int lwp = ptid.lwp () != 0 ? ptid.lwp () : ptid.pid (); | |
1817 | return thr_arg->id.lwp () == lwp; | |
1818 | }); | |
1819 | ||
1820 | if (thread == NULL) | |
1821 | return NULL; | |
1822 | ||
1823 | return get_thread_lwp (thread); | |
1824 | } | |
1825 | ||
1826 | /* Return the number of known LWPs in the tgid given by PID. */ | |
1827 | ||
1828 | static int | |
1829 | num_lwps (int pid) | |
1830 | { | |
1831 | int count = 0; | |
1832 | ||
1833 | for_each_thread (pid, [&] (thread_info *thread) | |
1834 | { | |
1835 | count++; | |
1836 | }); | |
1837 | ||
1838 | return count; | |
1839 | } | |
1840 | ||
1841 | /* See nat/linux-nat.h. */ | |
1842 | ||
1843 | struct lwp_info * | |
1844 | iterate_over_lwps (ptid_t filter, | |
1845 | gdb::function_view<iterate_over_lwps_ftype> callback) | |
1846 | { | |
1847 | thread_info *thread = find_thread (filter, [&] (thread_info *thr_arg) | |
1848 | { | |
1849 | lwp_info *lwp = get_thread_lwp (thr_arg); | |
1850 | ||
1851 | return callback (lwp); | |
1852 | }); | |
1853 | ||
1854 | if (thread == NULL) | |
1855 | return NULL; | |
1856 | ||
1857 | return get_thread_lwp (thread); | |
1858 | } | |
1859 | ||
1860 | /* Detect zombie thread group leaders, and "exit" them. We can't reap | |
1861 | their exits until all other threads in the group have exited. */ | |
1862 | ||
1863 | static void | |
1864 | check_zombie_leaders (void) | |
1865 | { | |
1866 | for_each_process ([] (process_info *proc) { | |
1867 | pid_t leader_pid = pid_of (proc); | |
1868 | struct lwp_info *leader_lp; | |
1869 | ||
1870 | leader_lp = find_lwp_pid (ptid_t (leader_pid)); | |
1871 | ||
1872 | if (debug_threads) | |
1873 | debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, " | |
1874 | "num_lwps=%d, zombie=%d\n", | |
1875 | leader_pid, leader_lp!= NULL, num_lwps (leader_pid), | |
1876 | linux_proc_pid_is_zombie (leader_pid)); | |
1877 | ||
1878 | if (leader_lp != NULL && !leader_lp->stopped | |
1879 | /* Check if there are other threads in the group, as we may | |
1880 | have raced with the inferior simply exiting. */ | |
1881 | && !last_thread_of_process_p (leader_pid) | |
1882 | && linux_proc_pid_is_zombie (leader_pid)) | |
1883 | { | |
1884 | /* A leader zombie can mean one of two things: | |
1885 | ||
1886 | - It exited, and there's an exit status pending | |
1887 | available, or only the leader exited (not the whole | |
1888 | program). In the latter case, we can't waitpid the | |
1889 | leader's exit status until all other threads are gone. | |
1890 | ||
1891 | - There are 3 or more threads in the group, and a thread | |
1892 | other than the leader exec'd. On an exec, the Linux | |
1893 | kernel destroys all other threads (except the execing | |
1894 | one) in the thread group, and resets the execing thread's | |
1895 | tid to the tgid. No exit notification is sent for the | |
1896 | execing thread -- from the ptracer's perspective, it | |
1897 | appears as though the execing thread just vanishes. | |
1898 | Until we reap all other threads except the leader and the | |
1899 | execing thread, the leader will be zombie, and the | |
1900 | execing thread will be in `D (disc sleep)'. As soon as | |
1901 | all other threads are reaped, the execing thread changes | |
1902 | it's tid to the tgid, and the previous (zombie) leader | |
1903 | vanishes, giving place to the "new" leader. We could try | |
1904 | distinguishing the exit and exec cases, by waiting once | |
1905 | more, and seeing if something comes out, but it doesn't | |
1906 | sound useful. The previous leader _does_ go away, and | |
1907 | we'll re-add the new one once we see the exec event | |
1908 | (which is just the same as what would happen if the | |
1909 | previous leader did exit voluntarily before some other | |
1910 | thread execs). */ | |
1911 | ||
1912 | if (debug_threads) | |
1913 | debug_printf ("CZL: Thread group leader %d zombie " | |
1914 | "(it exited, or another thread execd).\n", | |
1915 | leader_pid); | |
1916 | ||
1917 | delete_lwp (leader_lp); | |
1918 | } | |
1919 | }); | |
1920 | } | |
1921 | ||
1922 | /* Callback for `find_thread'. Returns the first LWP that is not | |
1923 | stopped. */ | |
1924 | ||
1925 | static bool | |
1926 | not_stopped_callback (thread_info *thread, ptid_t filter) | |
1927 | { | |
1928 | if (!thread->id.matches (filter)) | |
1929 | return false; | |
1930 | ||
1931 | lwp_info *lwp = get_thread_lwp (thread); | |
1932 | ||
1933 | return !lwp->stopped; | |
1934 | } | |
1935 | ||
1936 | /* Increment LWP's suspend count. */ | |
1937 | ||
1938 | static void | |
1939 | lwp_suspended_inc (struct lwp_info *lwp) | |
1940 | { | |
1941 | lwp->suspended++; | |
1942 | ||
1943 | if (debug_threads && lwp->suspended > 4) | |
1944 | { | |
1945 | struct thread_info *thread = get_lwp_thread (lwp); | |
1946 | ||
1947 | debug_printf ("LWP %ld has a suspiciously high suspend count," | |
1948 | " suspended=%d\n", lwpid_of (thread), lwp->suspended); | |
1949 | } | |
1950 | } | |
1951 | ||
1952 | /* Decrement LWP's suspend count. */ | |
1953 | ||
1954 | static void | |
1955 | lwp_suspended_decr (struct lwp_info *lwp) | |
1956 | { | |
1957 | lwp->suspended--; | |
1958 | ||
1959 | if (lwp->suspended < 0) | |
1960 | { | |
1961 | struct thread_info *thread = get_lwp_thread (lwp); | |
1962 | ||
1963 | internal_error (__FILE__, __LINE__, | |
1964 | "unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread), | |
1965 | lwp->suspended); | |
1966 | } | |
1967 | } | |
1968 | ||
1969 | /* This function should only be called if the LWP got a SIGTRAP. | |
1970 | ||
1971 | Handle any tracepoint steps or hits. Return true if a tracepoint | |
1972 | event was handled, 0 otherwise. */ | |
1973 | ||
1974 | static int | |
1975 | handle_tracepoints (struct lwp_info *lwp) | |
1976 | { | |
1977 | struct thread_info *tinfo = get_lwp_thread (lwp); | |
1978 | int tpoint_related_event = 0; | |
1979 | ||
1980 | gdb_assert (lwp->suspended == 0); | |
1981 | ||
1982 | /* If this tracepoint hit causes a tracing stop, we'll immediately | |
1983 | uninsert tracepoints. To do this, we temporarily pause all | |
1984 | threads, unpatch away, and then unpause threads. We need to make | |
1985 | sure the unpausing doesn't resume LWP too. */ | |
1986 | lwp_suspended_inc (lwp); | |
1987 | ||
1988 | /* And we need to be sure that any all-threads-stopping doesn't try | |
1989 | to move threads out of the jump pads, as it could deadlock the | |
1990 | inferior (LWP could be in the jump pad, maybe even holding the | |
1991 | lock.) */ | |
1992 | ||
1993 | /* Do any necessary step collect actions. */ | |
1994 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); | |
1995 | ||
1996 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); | |
1997 | ||
1998 | /* See if we just hit a tracepoint and do its main collect | |
1999 | actions. */ | |
2000 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); | |
2001 | ||
2002 | lwp_suspended_decr (lwp); | |
2003 | ||
2004 | gdb_assert (lwp->suspended == 0); | |
2005 | gdb_assert (!stabilizing_threads | |
2006 | || (lwp->collecting_fast_tracepoint | |
2007 | != fast_tpoint_collect_result::not_collecting)); | |
2008 | ||
2009 | if (tpoint_related_event) | |
2010 | { | |
2011 | if (debug_threads) | |
2012 | debug_printf ("got a tracepoint event\n"); | |
2013 | return 1; | |
2014 | } | |
2015 | ||
2016 | return 0; | |
2017 | } | |
2018 | ||
2019 | /* Convenience wrapper. Returns information about LWP's fast tracepoint | |
2020 | collection status. */ | |
2021 | ||
2022 | static fast_tpoint_collect_result | |
2023 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, | |
2024 | struct fast_tpoint_collect_status *status) | |
2025 | { | |
2026 | CORE_ADDR thread_area; | |
2027 | struct thread_info *thread = get_lwp_thread (lwp); | |
2028 | ||
2029 | if (the_low_target.get_thread_area == NULL) | |
2030 | return fast_tpoint_collect_result::not_collecting; | |
2031 | ||
2032 | /* Get the thread area address. This is used to recognize which | |
2033 | thread is which when tracing with the in-process agent library. | |
2034 | We don't read anything from the address, and treat it as opaque; | |
2035 | it's the address itself that we assume is unique per-thread. */ | |
2036 | if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1) | |
2037 | return fast_tpoint_collect_result::not_collecting; | |
2038 | ||
2039 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); | |
2040 | } | |
2041 | ||
2042 | /* The reason we resume in the caller, is because we want to be able | |
2043 | to pass lwp->status_pending as WSTAT, and we need to clear | |
2044 | status_pending_p before resuming, otherwise, linux_resume_one_lwp | |
2045 | refuses to resume. */ | |
2046 | ||
2047 | static int | |
2048 | maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat) | |
2049 | { | |
2050 | struct thread_info *saved_thread; | |
2051 | ||
2052 | saved_thread = current_thread; | |
2053 | current_thread = get_lwp_thread (lwp); | |
2054 | ||
2055 | if ((wstat == NULL | |
2056 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) | |
2057 | && supports_fast_tracepoints () | |
2058 | && agent_loaded_p ()) | |
2059 | { | |
2060 | struct fast_tpoint_collect_status status; | |
2061 | ||
2062 | if (debug_threads) | |
2063 | debug_printf ("Checking whether LWP %ld needs to move out of the " | |
2064 | "jump pad.\n", | |
2065 | lwpid_of (current_thread)); | |
2066 | ||
2067 | fast_tpoint_collect_result r | |
2068 | = linux_fast_tracepoint_collecting (lwp, &status); | |
2069 | ||
2070 | if (wstat == NULL | |
2071 | || (WSTOPSIG (*wstat) != SIGILL | |
2072 | && WSTOPSIG (*wstat) != SIGFPE | |
2073 | && WSTOPSIG (*wstat) != SIGSEGV | |
2074 | && WSTOPSIG (*wstat) != SIGBUS)) | |
2075 | { | |
2076 | lwp->collecting_fast_tracepoint = r; | |
2077 | ||
2078 | if (r != fast_tpoint_collect_result::not_collecting) | |
2079 | { | |
2080 | if (r == fast_tpoint_collect_result::before_insn | |
2081 | && lwp->exit_jump_pad_bkpt == NULL) | |
2082 | { | |
2083 | /* Haven't executed the original instruction yet. | |
2084 | Set breakpoint there, and wait till it's hit, | |
2085 | then single-step until exiting the jump pad. */ | |
2086 | lwp->exit_jump_pad_bkpt | |
2087 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); | |
2088 | } | |
2089 | ||
2090 | if (debug_threads) | |
2091 | debug_printf ("Checking whether LWP %ld needs to move out of " | |
2092 | "the jump pad...it does\n", | |
2093 | lwpid_of (current_thread)); | |
2094 | current_thread = saved_thread; | |
2095 | ||
2096 | return 1; | |
2097 | } | |
2098 | } | |
2099 | else | |
2100 | { | |
2101 | /* If we get a synchronous signal while collecting, *and* | |
2102 | while executing the (relocated) original instruction, | |
2103 | reset the PC to point at the tpoint address, before | |
2104 | reporting to GDB. Otherwise, it's an IPA lib bug: just | |
2105 | report the signal to GDB, and pray for the best. */ | |
2106 | ||
2107 | lwp->collecting_fast_tracepoint | |
2108 | = fast_tpoint_collect_result::not_collecting; | |
2109 | ||
2110 | if (r != fast_tpoint_collect_result::not_collecting | |
2111 | && (status.adjusted_insn_addr <= lwp->stop_pc | |
2112 | && lwp->stop_pc < status.adjusted_insn_addr_end)) | |
2113 | { | |
2114 | siginfo_t info; | |
2115 | struct regcache *regcache; | |
2116 | ||
2117 | /* The si_addr on a few signals references the address | |
2118 | of the faulting instruction. Adjust that as | |
2119 | well. */ | |
2120 | if ((WSTOPSIG (*wstat) == SIGILL | |
2121 | || WSTOPSIG (*wstat) == SIGFPE | |
2122 | || WSTOPSIG (*wstat) == SIGBUS | |
2123 | || WSTOPSIG (*wstat) == SIGSEGV) | |
2124 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
2125 | (PTRACE_TYPE_ARG3) 0, &info) == 0 | |
2126 | /* Final check just to make sure we don't clobber | |
2127 | the siginfo of non-kernel-sent signals. */ | |
2128 | && (uintptr_t) info.si_addr == lwp->stop_pc) | |
2129 | { | |
2130 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; | |
2131 | ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread), | |
2132 | (PTRACE_TYPE_ARG3) 0, &info); | |
2133 | } | |
2134 | ||
2135 | regcache = get_thread_regcache (current_thread, 1); | |
2136 | (*the_low_target.set_pc) (regcache, status.tpoint_addr); | |
2137 | lwp->stop_pc = status.tpoint_addr; | |
2138 | ||
2139 | /* Cancel any fast tracepoint lock this thread was | |
2140 | holding. */ | |
2141 | force_unlock_trace_buffer (); | |
2142 | } | |
2143 | ||
2144 | if (lwp->exit_jump_pad_bkpt != NULL) | |
2145 | { | |
2146 | if (debug_threads) | |
2147 | debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. " | |
2148 | "stopping all threads momentarily.\n"); | |
2149 | ||
2150 | stop_all_lwps (1, lwp); | |
2151 | ||
2152 | delete_breakpoint (lwp->exit_jump_pad_bkpt); | |
2153 | lwp->exit_jump_pad_bkpt = NULL; | |
2154 | ||
2155 | unstop_all_lwps (1, lwp); | |
2156 | ||
2157 | gdb_assert (lwp->suspended >= 0); | |
2158 | } | |
2159 | } | |
2160 | } | |
2161 | ||
2162 | if (debug_threads) | |
2163 | debug_printf ("Checking whether LWP %ld needs to move out of the " | |
2164 | "jump pad...no\n", | |
2165 | lwpid_of (current_thread)); | |
2166 | ||
2167 | current_thread = saved_thread; | |
2168 | return 0; | |
2169 | } | |
2170 | ||
2171 | /* Enqueue one signal in the "signals to report later when out of the | |
2172 | jump pad" list. */ | |
2173 | ||
2174 | static void | |
2175 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) | |
2176 | { | |
2177 | struct pending_signals *p_sig; | |
2178 | struct thread_info *thread = get_lwp_thread (lwp); | |
2179 | ||
2180 | if (debug_threads) | |
2181 | debug_printf ("Deferring signal %d for LWP %ld.\n", | |
2182 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
2183 | ||
2184 | if (debug_threads) | |
2185 | { | |
2186 | struct pending_signals *sig; | |
2187 | ||
2188 | for (sig = lwp->pending_signals_to_report; | |
2189 | sig != NULL; | |
2190 | sig = sig->prev) | |
2191 | debug_printf (" Already queued %d\n", | |
2192 | sig->signal); | |
2193 | ||
2194 | debug_printf (" (no more currently queued signals)\n"); | |
2195 | } | |
2196 | ||
2197 | /* Don't enqueue non-RT signals if they are already in the deferred | |
2198 | queue. (SIGSTOP being the easiest signal to see ending up here | |
2199 | twice) */ | |
2200 | if (WSTOPSIG (*wstat) < __SIGRTMIN) | |
2201 | { | |
2202 | struct pending_signals *sig; | |
2203 | ||
2204 | for (sig = lwp->pending_signals_to_report; | |
2205 | sig != NULL; | |
2206 | sig = sig->prev) | |
2207 | { | |
2208 | if (sig->signal == WSTOPSIG (*wstat)) | |
2209 | { | |
2210 | if (debug_threads) | |
2211 | debug_printf ("Not requeuing already queued non-RT signal %d" | |
2212 | " for LWP %ld\n", | |
2213 | sig->signal, | |
2214 | lwpid_of (thread)); | |
2215 | return; | |
2216 | } | |
2217 | } | |
2218 | } | |
2219 | ||
2220 | p_sig = XCNEW (struct pending_signals); | |
2221 | p_sig->prev = lwp->pending_signals_to_report; | |
2222 | p_sig->signal = WSTOPSIG (*wstat); | |
2223 | ||
2224 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
2225 | &p_sig->info); | |
2226 | ||
2227 | lwp->pending_signals_to_report = p_sig; | |
2228 | } | |
2229 | ||
2230 | /* Dequeue one signal from the "signals to report later when out of | |
2231 | the jump pad" list. */ | |
2232 | ||
2233 | static int | |
2234 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) | |
2235 | { | |
2236 | struct thread_info *thread = get_lwp_thread (lwp); | |
2237 | ||
2238 | if (lwp->pending_signals_to_report != NULL) | |
2239 | { | |
2240 | struct pending_signals **p_sig; | |
2241 | ||
2242 | p_sig = &lwp->pending_signals_to_report; | |
2243 | while ((*p_sig)->prev != NULL) | |
2244 | p_sig = &(*p_sig)->prev; | |
2245 | ||
2246 | *wstat = W_STOPCODE ((*p_sig)->signal); | |
2247 | if ((*p_sig)->info.si_signo != 0) | |
2248 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
2249 | &(*p_sig)->info); | |
2250 | free (*p_sig); | |
2251 | *p_sig = NULL; | |
2252 | ||
2253 | if (debug_threads) | |
2254 | debug_printf ("Reporting deferred signal %d for LWP %ld.\n", | |
2255 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
2256 | ||
2257 | if (debug_threads) | |
2258 | { | |
2259 | struct pending_signals *sig; | |
2260 | ||
2261 | for (sig = lwp->pending_signals_to_report; | |
2262 | sig != NULL; | |
2263 | sig = sig->prev) | |
2264 | debug_printf (" Still queued %d\n", | |
2265 | sig->signal); | |
2266 | ||
2267 | debug_printf (" (no more queued signals)\n"); | |
2268 | } | |
2269 | ||
2270 | return 1; | |
2271 | } | |
2272 | ||
2273 | return 0; | |
2274 | } | |
2275 | ||
2276 | /* Fetch the possibly triggered data watchpoint info and store it in | |
2277 | CHILD. | |
2278 | ||
2279 | On some archs, like x86, that use debug registers to set | |
2280 | watchpoints, it's possible that the way to know which watched | |
2281 | address trapped, is to check the register that is used to select | |
2282 | which address to watch. Problem is, between setting the watchpoint | |
2283 | and reading back which data address trapped, the user may change | |
2284 | the set of watchpoints, and, as a consequence, GDB changes the | |
2285 | debug registers in the inferior. To avoid reading back a stale | |
2286 | stopped-data-address when that happens, we cache in LP the fact | |
2287 | that a watchpoint trapped, and the corresponding data address, as | |
2288 | soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug | |
2289 | registers meanwhile, we have the cached data we can rely on. */ | |
2290 | ||
2291 | static int | |
2292 | check_stopped_by_watchpoint (struct lwp_info *child) | |
2293 | { | |
2294 | if (the_low_target.stopped_by_watchpoint != NULL) | |
2295 | { | |
2296 | struct thread_info *saved_thread; | |
2297 | ||
2298 | saved_thread = current_thread; | |
2299 | current_thread = get_lwp_thread (child); | |
2300 | ||
2301 | if (the_low_target.stopped_by_watchpoint ()) | |
2302 | { | |
2303 | child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; | |
2304 | ||
2305 | if (the_low_target.stopped_data_address != NULL) | |
2306 | child->stopped_data_address | |
2307 | = the_low_target.stopped_data_address (); | |
2308 | else | |
2309 | child->stopped_data_address = 0; | |
2310 | } | |
2311 | ||
2312 | current_thread = saved_thread; | |
2313 | } | |
2314 | ||
2315 | return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; | |
2316 | } | |
2317 | ||
2318 | /* Return the ptrace options that we want to try to enable. */ | |
2319 | ||
2320 | static int | |
2321 | linux_low_ptrace_options (int attached) | |
2322 | { | |
2323 | client_state &cs = get_client_state (); | |
2324 | int options = 0; | |
2325 | ||
2326 | if (!attached) | |
2327 | options |= PTRACE_O_EXITKILL; | |
2328 | ||
2329 | if (cs.report_fork_events) | |
2330 | options |= PTRACE_O_TRACEFORK; | |
2331 | ||
2332 | if (cs.report_vfork_events) | |
2333 | options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE); | |
2334 | ||
2335 | if (cs.report_exec_events) | |
2336 | options |= PTRACE_O_TRACEEXEC; | |
2337 | ||
2338 | options |= PTRACE_O_TRACESYSGOOD; | |
2339 | ||
2340 | return options; | |
2341 | } | |
2342 | ||
2343 | /* Do low-level handling of the event, and check if we should go on | |
2344 | and pass it to caller code. Return the affected lwp if we are, or | |
2345 | NULL otherwise. */ | |
2346 | ||
2347 | static struct lwp_info * | |
2348 | linux_low_filter_event (int lwpid, int wstat) | |
2349 | { | |
2350 | client_state &cs = get_client_state (); | |
2351 | struct lwp_info *child; | |
2352 | struct thread_info *thread; | |
2353 | int have_stop_pc = 0; | |
2354 | ||
2355 | child = find_lwp_pid (ptid_t (lwpid)); | |
2356 | ||
2357 | /* Check for stop events reported by a process we didn't already | |
2358 | know about - anything not already in our LWP list. | |
2359 | ||
2360 | If we're expecting to receive stopped processes after | |
2361 | fork, vfork, and clone events, then we'll just add the | |
2362 | new one to our list and go back to waiting for the event | |
2363 | to be reported - the stopped process might be returned | |
2364 | from waitpid before or after the event is. | |
2365 | ||
2366 | But note the case of a non-leader thread exec'ing after the | |
2367 | leader having exited, and gone from our lists (because | |
2368 | check_zombie_leaders deleted it). The non-leader thread | |
2369 | changes its tid to the tgid. */ | |
2370 | ||
2371 | if (WIFSTOPPED (wstat) && child == NULL && WSTOPSIG (wstat) == SIGTRAP | |
2372 | && linux_ptrace_get_extended_event (wstat) == PTRACE_EVENT_EXEC) | |
2373 | { | |
2374 | ptid_t child_ptid; | |
2375 | ||
2376 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2377 | if (debug_threads) | |
2378 | { | |
2379 | debug_printf ("LLW: Re-adding thread group leader LWP %d" | |
2380 | "after exec.\n", lwpid); | |
2381 | } | |
2382 | ||
2383 | child_ptid = ptid_t (lwpid, lwpid, 0); | |
2384 | child = add_lwp (child_ptid); | |
2385 | child->stopped = 1; | |
2386 | current_thread = child->thread; | |
2387 | } | |
2388 | ||
2389 | /* If we didn't find a process, one of two things presumably happened: | |
2390 | - A process we started and then detached from has exited. Ignore it. | |
2391 | - A process we are controlling has forked and the new child's stop | |
2392 | was reported to us by the kernel. Save its PID. */ | |
2393 | if (child == NULL && WIFSTOPPED (wstat)) | |
2394 | { | |
2395 | add_to_pid_list (&stopped_pids, lwpid, wstat); | |
2396 | return NULL; | |
2397 | } | |
2398 | else if (child == NULL) | |
2399 | return NULL; | |
2400 | ||
2401 | thread = get_lwp_thread (child); | |
2402 | ||
2403 | child->stopped = 1; | |
2404 | ||
2405 | child->last_status = wstat; | |
2406 | ||
2407 | /* Check if the thread has exited. */ | |
2408 | if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))) | |
2409 | { | |
2410 | if (debug_threads) | |
2411 | debug_printf ("LLFE: %d exited.\n", lwpid); | |
2412 | ||
2413 | if (finish_step_over (child)) | |
2414 | { | |
2415 | /* Unsuspend all other LWPs, and set them back running again. */ | |
2416 | unsuspend_all_lwps (child); | |
2417 | } | |
2418 | ||
2419 | /* If there is at least one more LWP, then the exit signal was | |
2420 | not the end of the debugged application and should be | |
2421 | ignored, unless GDB wants to hear about thread exits. */ | |
2422 | if (cs.report_thread_events | |
2423 | || last_thread_of_process_p (pid_of (thread))) | |
2424 | { | |
2425 | /* Since events are serialized to GDB core, and we can't | |
2426 | report this one right now. Leave the status pending for | |
2427 | the next time we're able to report it. */ | |
2428 | mark_lwp_dead (child, wstat); | |
2429 | return child; | |
2430 | } | |
2431 | else | |
2432 | { | |
2433 | delete_lwp (child); | |
2434 | return NULL; | |
2435 | } | |
2436 | } | |
2437 | ||
2438 | gdb_assert (WIFSTOPPED (wstat)); | |
2439 | ||
2440 | if (WIFSTOPPED (wstat)) | |
2441 | { | |
2442 | struct process_info *proc; | |
2443 | ||
2444 | /* Architecture-specific setup after inferior is running. */ | |
2445 | proc = find_process_pid (pid_of (thread)); | |
2446 | if (proc->tdesc == NULL) | |
2447 | { | |
2448 | if (proc->attached) | |
2449 | { | |
2450 | /* This needs to happen after we have attached to the | |
2451 | inferior and it is stopped for the first time, but | |
2452 | before we access any inferior registers. */ | |
2453 | linux_arch_setup_thread (thread); | |
2454 | } | |
2455 | else | |
2456 | { | |
2457 | /* The process is started, but GDBserver will do | |
2458 | architecture-specific setup after the program stops at | |
2459 | the first instruction. */ | |
2460 | child->status_pending_p = 1; | |
2461 | child->status_pending = wstat; | |
2462 | return child; | |
2463 | } | |
2464 | } | |
2465 | } | |
2466 | ||
2467 | if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags) | |
2468 | { | |
2469 | struct process_info *proc = find_process_pid (pid_of (thread)); | |
2470 | int options = linux_low_ptrace_options (proc->attached); | |
2471 | ||
2472 | linux_enable_event_reporting (lwpid, options); | |
2473 | child->must_set_ptrace_flags = 0; | |
2474 | } | |
2475 | ||
2476 | /* Always update syscall_state, even if it will be filtered later. */ | |
2477 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SYSCALL_SIGTRAP) | |
2478 | { | |
2479 | child->syscall_state | |
2480 | = (child->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2481 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
2482 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
2483 | } | |
2484 | else | |
2485 | { | |
2486 | /* Almost all other ptrace-stops are known to be outside of system | |
2487 | calls, with further exceptions in handle_extended_wait. */ | |
2488 | child->syscall_state = TARGET_WAITKIND_IGNORE; | |
2489 | } | |
2490 | ||
2491 | /* Be careful to not overwrite stop_pc until save_stop_reason is | |
2492 | called. */ | |
2493 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP | |
2494 | && linux_is_extended_waitstatus (wstat)) | |
2495 | { | |
2496 | child->stop_pc = get_pc (child); | |
2497 | if (handle_extended_wait (&child, wstat)) | |
2498 | { | |
2499 | /* The event has been handled, so just return without | |
2500 | reporting it. */ | |
2501 | return NULL; | |
2502 | } | |
2503 | } | |
2504 | ||
2505 | if (linux_wstatus_maybe_breakpoint (wstat)) | |
2506 | { | |
2507 | if (save_stop_reason (child)) | |
2508 | have_stop_pc = 1; | |
2509 | } | |
2510 | ||
2511 | if (!have_stop_pc) | |
2512 | child->stop_pc = get_pc (child); | |
2513 | ||
2514 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP | |
2515 | && child->stop_expected) | |
2516 | { | |
2517 | if (debug_threads) | |
2518 | debug_printf ("Expected stop.\n"); | |
2519 | child->stop_expected = 0; | |
2520 | ||
2521 | if (thread->last_resume_kind == resume_stop) | |
2522 | { | |
2523 | /* We want to report the stop to the core. Treat the | |
2524 | SIGSTOP as a normal event. */ | |
2525 | if (debug_threads) | |
2526 | debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", | |
2527 | target_pid_to_str (ptid_of (thread))); | |
2528 | } | |
2529 | else if (stopping_threads != NOT_STOPPING_THREADS) | |
2530 | { | |
2531 | /* Stopping threads. We don't want this SIGSTOP to end up | |
2532 | pending. */ | |
2533 | if (debug_threads) | |
2534 | debug_printf ("LLW: SIGSTOP caught for %s " | |
2535 | "while stopping threads.\n", | |
2536 | target_pid_to_str (ptid_of (thread))); | |
2537 | return NULL; | |
2538 | } | |
2539 | else | |
2540 | { | |
2541 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
2542 | if (debug_threads) | |
2543 | debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", | |
2544 | child->stepping ? "step" : "continue", | |
2545 | target_pid_to_str (ptid_of (thread))); | |
2546 | ||
2547 | linux_resume_one_lwp (child, child->stepping, 0, NULL); | |
2548 | return NULL; | |
2549 | } | |
2550 | } | |
2551 | ||
2552 | child->status_pending_p = 1; | |
2553 | child->status_pending = wstat; | |
2554 | return child; | |
2555 | } | |
2556 | ||
2557 | /* Return true if THREAD is doing hardware single step. */ | |
2558 | ||
2559 | static int | |
2560 | maybe_hw_step (struct thread_info *thread) | |
2561 | { | |
2562 | if (can_hardware_single_step ()) | |
2563 | return 1; | |
2564 | else | |
2565 | { | |
2566 | /* GDBserver must insert single-step breakpoint for software | |
2567 | single step. */ | |
2568 | gdb_assert (has_single_step_breakpoints (thread)); | |
2569 | return 0; | |
2570 | } | |
2571 | } | |
2572 | ||
2573 | /* Resume LWPs that are currently stopped without any pending status | |
2574 | to report, but are resumed from the core's perspective. */ | |
2575 | ||
2576 | static void | |
2577 | resume_stopped_resumed_lwps (thread_info *thread) | |
2578 | { | |
2579 | struct lwp_info *lp = get_thread_lwp (thread); | |
2580 | ||
2581 | if (lp->stopped | |
2582 | && !lp->suspended | |
2583 | && !lp->status_pending_p | |
2584 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) | |
2585 | { | |
2586 | int step = 0; | |
2587 | ||
2588 | if (thread->last_resume_kind == resume_step) | |
2589 | step = maybe_hw_step (thread); | |
2590 | ||
2591 | if (debug_threads) | |
2592 | debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", | |
2593 | target_pid_to_str (ptid_of (thread)), | |
2594 | paddress (lp->stop_pc), | |
2595 | step); | |
2596 | ||
2597 | linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL); | |
2598 | } | |
2599 | } | |
2600 | ||
2601 | /* Wait for an event from child(ren) WAIT_PTID, and return any that | |
2602 | match FILTER_PTID (leaving others pending). The PTIDs can be: | |
2603 | minus_one_ptid, to specify any child; a pid PTID, specifying all | |
2604 | lwps of a thread group; or a PTID representing a single lwp. Store | |
2605 | the stop status through the status pointer WSTAT. OPTIONS is | |
2606 | passed to the waitpid call. Return 0 if no event was found and | |
2607 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children | |
2608 | was found. Return the PID of the stopped child otherwise. */ | |
2609 | ||
2610 | static int | |
2611 | linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, | |
2612 | int *wstatp, int options) | |
2613 | { | |
2614 | struct thread_info *event_thread; | |
2615 | struct lwp_info *event_child, *requested_child; | |
2616 | sigset_t block_mask, prev_mask; | |
2617 | ||
2618 | retry: | |
2619 | /* N.B. event_thread points to the thread_info struct that contains | |
2620 | event_child. Keep them in sync. */ | |
2621 | event_thread = NULL; | |
2622 | event_child = NULL; | |
2623 | requested_child = NULL; | |
2624 | ||
2625 | /* Check for a lwp with a pending status. */ | |
2626 | ||
2627 | if (filter_ptid == minus_one_ptid || filter_ptid.is_pid ()) | |
2628 | { | |
2629 | event_thread = find_thread_in_random ([&] (thread_info *thread) | |
2630 | { | |
2631 | return status_pending_p_callback (thread, filter_ptid); | |
2632 | }); | |
2633 | ||
2634 | if (event_thread != NULL) | |
2635 | event_child = get_thread_lwp (event_thread); | |
2636 | if (debug_threads && event_thread) | |
2637 | debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread)); | |
2638 | } | |
2639 | else if (filter_ptid != null_ptid) | |
2640 | { | |
2641 | requested_child = find_lwp_pid (filter_ptid); | |
2642 | ||
2643 | if (stopping_threads == NOT_STOPPING_THREADS | |
2644 | && requested_child->status_pending_p | |
2645 | && (requested_child->collecting_fast_tracepoint | |
2646 | != fast_tpoint_collect_result::not_collecting)) | |
2647 | { | |
2648 | enqueue_one_deferred_signal (requested_child, | |
2649 | &requested_child->status_pending); | |
2650 | requested_child->status_pending_p = 0; | |
2651 | requested_child->status_pending = 0; | |
2652 | linux_resume_one_lwp (requested_child, 0, 0, NULL); | |
2653 | } | |
2654 | ||
2655 | if (requested_child->suspended | |
2656 | && requested_child->status_pending_p) | |
2657 | { | |
2658 | internal_error (__FILE__, __LINE__, | |
2659 | "requesting an event out of a" | |
2660 | " suspended child?"); | |
2661 | } | |
2662 | ||
2663 | if (requested_child->status_pending_p) | |
2664 | { | |
2665 | event_child = requested_child; | |
2666 | event_thread = get_lwp_thread (event_child); | |
2667 | } | |
2668 | } | |
2669 | ||
2670 | if (event_child != NULL) | |
2671 | { | |
2672 | if (debug_threads) | |
2673 | debug_printf ("Got an event from pending child %ld (%04x)\n", | |
2674 | lwpid_of (event_thread), event_child->status_pending); | |
2675 | *wstatp = event_child->status_pending; | |
2676 | event_child->status_pending_p = 0; | |
2677 | event_child->status_pending = 0; | |
2678 | current_thread = event_thread; | |
2679 | return lwpid_of (event_thread); | |
2680 | } | |
2681 | ||
2682 | /* But if we don't find a pending event, we'll have to wait. | |
2683 | ||
2684 | We only enter this loop if no process has a pending wait status. | |
2685 | Thus any action taken in response to a wait status inside this | |
2686 | loop is responding as soon as we detect the status, not after any | |
2687 | pending events. */ | |
2688 | ||
2689 | /* Make sure SIGCHLD is blocked until the sigsuspend below. Block | |
2690 | all signals while here. */ | |
2691 | sigfillset (&block_mask); | |
2692 | sigprocmask (SIG_BLOCK, &block_mask, &prev_mask); | |
2693 | ||
2694 | /* Always pull all events out of the kernel. We'll randomly select | |
2695 | an event LWP out of all that have events, to prevent | |
2696 | starvation. */ | |
2697 | while (event_child == NULL) | |
2698 | { | |
2699 | pid_t ret = 0; | |
2700 | ||
2701 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace | |
2702 | quirks: | |
2703 | ||
2704 | - If the thread group leader exits while other threads in the | |
2705 | thread group still exist, waitpid(TGID, ...) hangs. That | |
2706 | waitpid won't return an exit status until the other threads | |
2707 | in the group are reaped. | |
2708 | ||
2709 | - When a non-leader thread execs, that thread just vanishes | |
2710 | without reporting an exit (so we'd hang if we waited for it | |
2711 | explicitly in that case). The exec event is reported to | |
2712 | the TGID pid. */ | |
2713 | errno = 0; | |
2714 | ret = my_waitpid (-1, wstatp, options | WNOHANG); | |
2715 | ||
2716 | if (debug_threads) | |
2717 | debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n", | |
2718 | ret, errno ? strerror (errno) : "ERRNO-OK"); | |
2719 | ||
2720 | if (ret > 0) | |
2721 | { | |
2722 | if (debug_threads) | |
2723 | { | |
2724 | debug_printf ("LLW: waitpid %ld received %s\n", | |
2725 | (long) ret, status_to_str (*wstatp)); | |
2726 | } | |
2727 | ||
2728 | /* Filter all events. IOW, leave all events pending. We'll | |
2729 | randomly select an event LWP out of all that have events | |
2730 | below. */ | |
2731 | linux_low_filter_event (ret, *wstatp); | |
2732 | /* Retry until nothing comes out of waitpid. A single | |
2733 | SIGCHLD can indicate more than one child stopped. */ | |
2734 | continue; | |
2735 | } | |
2736 | ||
2737 | /* Now that we've pulled all events out of the kernel, resume | |
2738 | LWPs that don't have an interesting event to report. */ | |
2739 | if (stopping_threads == NOT_STOPPING_THREADS) | |
2740 | for_each_thread (resume_stopped_resumed_lwps); | |
2741 | ||
2742 | /* ... and find an LWP with a status to report to the core, if | |
2743 | any. */ | |
2744 | event_thread = find_thread_in_random ([&] (thread_info *thread) | |
2745 | { | |
2746 | return status_pending_p_callback (thread, filter_ptid); | |
2747 | }); | |
2748 | ||
2749 | if (event_thread != NULL) | |
2750 | { | |
2751 | event_child = get_thread_lwp (event_thread); | |
2752 | *wstatp = event_child->status_pending; | |
2753 | event_child->status_pending_p = 0; | |
2754 | event_child->status_pending = 0; | |
2755 | break; | |
2756 | } | |
2757 | ||
2758 | /* Check for zombie thread group leaders. Those can't be reaped | |
2759 | until all other threads in the thread group are. */ | |
2760 | check_zombie_leaders (); | |
2761 | ||
2762 | auto not_stopped = [&] (thread_info *thread) | |
2763 | { | |
2764 | return not_stopped_callback (thread, wait_ptid); | |
2765 | }; | |
2766 | ||
2767 | /* If there are no resumed children left in the set of LWPs we | |
2768 | want to wait for, bail. We can't just block in | |
2769 | waitpid/sigsuspend, because lwps might have been left stopped | |
2770 | in trace-stop state, and we'd be stuck forever waiting for | |
2771 | their status to change (which would only happen if we resumed | |
2772 | them). Even if WNOHANG is set, this return code is preferred | |
2773 | over 0 (below), as it is more detailed. */ | |
2774 | if (find_thread (not_stopped) == NULL) | |
2775 | { | |
2776 | if (debug_threads) | |
2777 | debug_printf ("LLW: exit (no unwaited-for LWP)\n"); | |
2778 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2779 | return -1; | |
2780 | } | |
2781 | ||
2782 | /* No interesting event to report to the caller. */ | |
2783 | if ((options & WNOHANG)) | |
2784 | { | |
2785 | if (debug_threads) | |
2786 | debug_printf ("WNOHANG set, no event found\n"); | |
2787 | ||
2788 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2789 | return 0; | |
2790 | } | |
2791 | ||
2792 | /* Block until we get an event reported with SIGCHLD. */ | |
2793 | if (debug_threads) | |
2794 | debug_printf ("sigsuspend'ing\n"); | |
2795 | ||
2796 | sigsuspend (&prev_mask); | |
2797 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2798 | goto retry; | |
2799 | } | |
2800 | ||
2801 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2802 | ||
2803 | current_thread = event_thread; | |
2804 | ||
2805 | return lwpid_of (event_thread); | |
2806 | } | |
2807 | ||
2808 | /* Wait for an event from child(ren) PTID. PTIDs can be: | |
2809 | minus_one_ptid, to specify any child; a pid PTID, specifying all | |
2810 | lwps of a thread group; or a PTID representing a single lwp. Store | |
2811 | the stop status through the status pointer WSTAT. OPTIONS is | |
2812 | passed to the waitpid call. Return 0 if no event was found and | |
2813 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children | |
2814 | was found. Return the PID of the stopped child otherwise. */ | |
2815 | ||
2816 | static int | |
2817 | linux_wait_for_event (ptid_t ptid, int *wstatp, int options) | |
2818 | { | |
2819 | return linux_wait_for_event_filtered (ptid, ptid, wstatp, options); | |
2820 | } | |
2821 | ||
2822 | /* Select one LWP out of those that have events pending. */ | |
2823 | ||
2824 | static void | |
2825 | select_event_lwp (struct lwp_info **orig_lp) | |
2826 | { | |
2827 | struct thread_info *event_thread = NULL; | |
2828 | ||
2829 | /* In all-stop, give preference to the LWP that is being | |
2830 | single-stepped. There will be at most one, and it's the LWP that | |
2831 | the core is most interested in. If we didn't do this, then we'd | |
2832 | have to handle pending step SIGTRAPs somehow in case the core | |
2833 | later continues the previously-stepped thread, otherwise we'd | |
2834 | report the pending SIGTRAP, and the core, not having stepped the | |
2835 | thread, wouldn't understand what the trap was for, and therefore | |
2836 | would report it to the user as a random signal. */ | |
2837 | if (!non_stop) | |
2838 | { | |
2839 | event_thread = find_thread ([] (thread_info *thread) | |
2840 | { | |
2841 | lwp_info *lp = get_thread_lwp (thread); | |
2842 | ||
2843 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE | |
2844 | && thread->last_resume_kind == resume_step | |
2845 | && lp->status_pending_p); | |
2846 | }); | |
2847 | ||
2848 | if (event_thread != NULL) | |
2849 | { | |
2850 | if (debug_threads) | |
2851 | debug_printf ("SEL: Select single-step %s\n", | |
2852 | target_pid_to_str (ptid_of (event_thread))); | |
2853 | } | |
2854 | } | |
2855 | if (event_thread == NULL) | |
2856 | { | |
2857 | /* No single-stepping LWP. Select one at random, out of those | |
2858 | which have had events. */ | |
2859 | ||
2860 | event_thread = find_thread_in_random ([&] (thread_info *thread) | |
2861 | { | |
2862 | lwp_info *lp = get_thread_lwp (thread); | |
2863 | ||
2864 | /* Only resumed LWPs that have an event pending. */ | |
2865 | return (thread->last_status.kind == TARGET_WAITKIND_IGNORE | |
2866 | && lp->status_pending_p); | |
2867 | }); | |
2868 | } | |
2869 | ||
2870 | if (event_thread != NULL) | |
2871 | { | |
2872 | struct lwp_info *event_lp = get_thread_lwp (event_thread); | |
2873 | ||
2874 | /* Switch the event LWP. */ | |
2875 | *orig_lp = event_lp; | |
2876 | } | |
2877 | } | |
2878 | ||
2879 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non | |
2880 | NULL. */ | |
2881 | ||
2882 | static void | |
2883 | unsuspend_all_lwps (struct lwp_info *except) | |
2884 | { | |
2885 | for_each_thread ([&] (thread_info *thread) | |
2886 | { | |
2887 | lwp_info *lwp = get_thread_lwp (thread); | |
2888 | ||
2889 | if (lwp != except) | |
2890 | lwp_suspended_decr (lwp); | |
2891 | }); | |
2892 | } | |
2893 | ||
2894 | static void move_out_of_jump_pad_callback (thread_info *thread); | |
2895 | static bool stuck_in_jump_pad_callback (thread_info *thread); | |
2896 | static bool lwp_running (thread_info *thread); | |
2897 | static ptid_t linux_wait_1 (ptid_t ptid, | |
2898 | struct target_waitstatus *ourstatus, | |
2899 | int target_options); | |
2900 | ||
2901 | /* Stabilize threads (move out of jump pads). | |
2902 | ||
2903 | If a thread is midway collecting a fast tracepoint, we need to | |
2904 | finish the collection and move it out of the jump pad before | |
2905 | reporting the signal. | |
2906 | ||
2907 | This avoids recursion while collecting (when a signal arrives | |
2908 | midway, and the signal handler itself collects), which would trash | |
2909 | the trace buffer. In case the user set a breakpoint in a signal | |
2910 | handler, this avoids the backtrace showing the jump pad, etc.. | |
2911 | Most importantly, there are certain things we can't do safely if | |
2912 | threads are stopped in a jump pad (or in its callee's). For | |
2913 | example: | |
2914 | ||
2915 | - starting a new trace run. A thread still collecting the | |
2916 | previous run, could trash the trace buffer when resumed. The trace | |
2917 | buffer control structures would have been reset but the thread had | |
2918 | no way to tell. The thread could even midway memcpy'ing to the | |
2919 | buffer, which would mean that when resumed, it would clobber the | |
2920 | trace buffer that had been set for a new run. | |
2921 | ||
2922 | - we can't rewrite/reuse the jump pads for new tracepoints | |
2923 | safely. Say you do tstart while a thread is stopped midway while | |
2924 | collecting. When the thread is later resumed, it finishes the | |
2925 | collection, and returns to the jump pad, to execute the original | |
2926 | instruction that was under the tracepoint jump at the time the | |
2927 | older run had been started. If the jump pad had been rewritten | |
2928 | since for something else in the new run, the thread would now | |
2929 | execute the wrong / random instructions. */ | |
2930 | ||
2931 | static void | |
2932 | linux_stabilize_threads (void) | |
2933 | { | |
2934 | thread_info *thread_stuck = find_thread (stuck_in_jump_pad_callback); | |
2935 | ||
2936 | if (thread_stuck != NULL) | |
2937 | { | |
2938 | if (debug_threads) | |
2939 | debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n", | |
2940 | lwpid_of (thread_stuck)); | |
2941 | return; | |
2942 | } | |
2943 | ||
2944 | thread_info *saved_thread = current_thread; | |
2945 | ||
2946 | stabilizing_threads = 1; | |
2947 | ||
2948 | /* Kick 'em all. */ | |
2949 | for_each_thread (move_out_of_jump_pad_callback); | |
2950 | ||
2951 | /* Loop until all are stopped out of the jump pads. */ | |
2952 | while (find_thread (lwp_running) != NULL) | |
2953 | { | |
2954 | struct target_waitstatus ourstatus; | |
2955 | struct lwp_info *lwp; | |
2956 | int wstat; | |
2957 | ||
2958 | /* Note that we go through the full wait even loop. While | |
2959 | moving threads out of jump pad, we need to be able to step | |
2960 | over internal breakpoints and such. */ | |
2961 | linux_wait_1 (minus_one_ptid, &ourstatus, 0); | |
2962 | ||
2963 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) | |
2964 | { | |
2965 | lwp = get_thread_lwp (current_thread); | |
2966 | ||
2967 | /* Lock it. */ | |
2968 | lwp_suspended_inc (lwp); | |
2969 | ||
2970 | if (ourstatus.value.sig != GDB_SIGNAL_0 | |
2971 | || current_thread->last_resume_kind == resume_stop) | |
2972 | { | |
2973 | wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig)); | |
2974 | enqueue_one_deferred_signal (lwp, &wstat); | |
2975 | } | |
2976 | } | |
2977 | } | |
2978 | ||
2979 | unsuspend_all_lwps (NULL); | |
2980 | ||
2981 | stabilizing_threads = 0; | |
2982 | ||
2983 | current_thread = saved_thread; | |
2984 | ||
2985 | if (debug_threads) | |
2986 | { | |
2987 | thread_stuck = find_thread (stuck_in_jump_pad_callback); | |
2988 | ||
2989 | if (thread_stuck != NULL) | |
2990 | debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n", | |
2991 | lwpid_of (thread_stuck)); | |
2992 | } | |
2993 | } | |
2994 | ||
2995 | /* Convenience function that is called when the kernel reports an | |
2996 | event that is not passed out to GDB. */ | |
2997 | ||
2998 | static ptid_t | |
2999 | ignore_event (struct target_waitstatus *ourstatus) | |
3000 | { | |
3001 | /* If we got an event, there may still be others, as a single | |
3002 | SIGCHLD can indicate more than one child stopped. This forces | |
3003 | another target_wait call. */ | |
3004 | async_file_mark (); | |
3005 | ||
3006 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3007 | return null_ptid; | |
3008 | } | |
3009 | ||
3010 | /* Convenience function that is called when the kernel reports an exit | |
3011 | event. This decides whether to report the event to GDB as a | |
3012 | process exit event, a thread exit event, or to suppress the | |
3013 | event. */ | |
3014 | ||
3015 | static ptid_t | |
3016 | filter_exit_event (struct lwp_info *event_child, | |
3017 | struct target_waitstatus *ourstatus) | |
3018 | { | |
3019 | client_state &cs = get_client_state (); | |
3020 | struct thread_info *thread = get_lwp_thread (event_child); | |
3021 | ptid_t ptid = ptid_of (thread); | |
3022 | ||
3023 | if (!last_thread_of_process_p (pid_of (thread))) | |
3024 | { | |
3025 | if (cs.report_thread_events) | |
3026 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; | |
3027 | else | |
3028 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3029 | ||
3030 | delete_lwp (event_child); | |
3031 | } | |
3032 | return ptid; | |
3033 | } | |
3034 | ||
3035 | /* Returns 1 if GDB is interested in any event_child syscalls. */ | |
3036 | ||
3037 | static int | |
3038 | gdb_catching_syscalls_p (struct lwp_info *event_child) | |
3039 | { | |
3040 | struct thread_info *thread = get_lwp_thread (event_child); | |
3041 | struct process_info *proc = get_thread_process (thread); | |
3042 | ||
3043 | return !proc->syscalls_to_catch.empty (); | |
3044 | } | |
3045 | ||
3046 | /* Returns 1 if GDB is interested in the event_child syscall. | |
3047 | Only to be called when stopped reason is SYSCALL_SIGTRAP. */ | |
3048 | ||
3049 | static int | |
3050 | gdb_catch_this_syscall_p (struct lwp_info *event_child) | |
3051 | { | |
3052 | int sysno; | |
3053 | struct thread_info *thread = get_lwp_thread (event_child); | |
3054 | struct process_info *proc = get_thread_process (thread); | |
3055 | ||
3056 | if (proc->syscalls_to_catch.empty ()) | |
3057 | return 0; | |
3058 | ||
3059 | if (proc->syscalls_to_catch[0] == ANY_SYSCALL) | |
3060 | return 1; | |
3061 | ||
3062 | get_syscall_trapinfo (event_child, &sysno); | |
3063 | ||
3064 | for (int iter : proc->syscalls_to_catch) | |
3065 | if (iter == sysno) | |
3066 | return 1; | |
3067 | ||
3068 | return 0; | |
3069 | } | |
3070 | ||
3071 | /* Wait for process, returns status. */ | |
3072 | ||
3073 | static ptid_t | |
3074 | linux_wait_1 (ptid_t ptid, | |
3075 | struct target_waitstatus *ourstatus, int target_options) | |
3076 | { | |
3077 | client_state &cs = get_client_state (); | |
3078 | int w; | |
3079 | struct lwp_info *event_child; | |
3080 | int options; | |
3081 | int pid; | |
3082 | int step_over_finished; | |
3083 | int bp_explains_trap; | |
3084 | int maybe_internal_trap; | |
3085 | int report_to_gdb; | |
3086 | int trace_event; | |
3087 | int in_step_range; | |
3088 | int any_resumed; | |
3089 | ||
3090 | if (debug_threads) | |
3091 | { | |
3092 | debug_enter (); | |
3093 | debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid)); | |
3094 | } | |
3095 | ||
3096 | /* Translate generic target options into linux options. */ | |
3097 | options = __WALL; | |
3098 | if (target_options & TARGET_WNOHANG) | |
3099 | options |= WNOHANG; | |
3100 | ||
3101 | bp_explains_trap = 0; | |
3102 | trace_event = 0; | |
3103 | in_step_range = 0; | |
3104 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3105 | ||
3106 | auto status_pending_p_any = [&] (thread_info *thread) | |
3107 | { | |
3108 | return status_pending_p_callback (thread, minus_one_ptid); | |
3109 | }; | |
3110 | ||
3111 | auto not_stopped = [&] (thread_info *thread) | |
3112 | { | |
3113 | return not_stopped_callback (thread, minus_one_ptid); | |
3114 | }; | |
3115 | ||
3116 | /* Find a resumed LWP, if any. */ | |
3117 | if (find_thread (status_pending_p_any) != NULL) | |
3118 | any_resumed = 1; | |
3119 | else if (find_thread (not_stopped) != NULL) | |
3120 | any_resumed = 1; | |
3121 | else | |
3122 | any_resumed = 0; | |
3123 | ||
3124 | if (step_over_bkpt == null_ptid) | |
3125 | pid = linux_wait_for_event (ptid, &w, options); | |
3126 | else | |
3127 | { | |
3128 | if (debug_threads) | |
3129 | debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n", | |
3130 | target_pid_to_str (step_over_bkpt)); | |
3131 | pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); | |
3132 | } | |
3133 | ||
3134 | if (pid == 0 || (pid == -1 && !any_resumed)) | |
3135 | { | |
3136 | gdb_assert (target_options & TARGET_WNOHANG); | |
3137 | ||
3138 | if (debug_threads) | |
3139 | { | |
3140 | debug_printf ("linux_wait_1 ret = null_ptid, " | |
3141 | "TARGET_WAITKIND_IGNORE\n"); | |
3142 | debug_exit (); | |
3143 | } | |
3144 | ||
3145 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3146 | return null_ptid; | |
3147 | } | |
3148 | else if (pid == -1) | |
3149 | { | |
3150 | if (debug_threads) | |
3151 | { | |
3152 | debug_printf ("linux_wait_1 ret = null_ptid, " | |
3153 | "TARGET_WAITKIND_NO_RESUMED\n"); | |
3154 | debug_exit (); | |
3155 | } | |
3156 | ||
3157 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; | |
3158 | return null_ptid; | |
3159 | } | |
3160 | ||
3161 | event_child = get_thread_lwp (current_thread); | |
3162 | ||
3163 | /* linux_wait_for_event only returns an exit status for the last | |
3164 | child of a process. Report it. */ | |
3165 | if (WIFEXITED (w) || WIFSIGNALED (w)) | |
3166 | { | |
3167 | if (WIFEXITED (w)) | |
3168 | { | |
3169 | ourstatus->kind = TARGET_WAITKIND_EXITED; | |
3170 | ourstatus->value.integer = WEXITSTATUS (w); | |
3171 | ||
3172 | if (debug_threads) | |
3173 | { | |
3174 | debug_printf ("linux_wait_1 ret = %s, exited with " | |
3175 | "retcode %d\n", | |
3176 | target_pid_to_str (ptid_of (current_thread)), | |
3177 | WEXITSTATUS (w)); | |
3178 | debug_exit (); | |
3179 | } | |
3180 | } | |
3181 | else | |
3182 | { | |
3183 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; | |
3184 | ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w)); | |
3185 | ||
3186 | if (debug_threads) | |
3187 | { | |
3188 | debug_printf ("linux_wait_1 ret = %s, terminated with " | |
3189 | "signal %d\n", | |
3190 | target_pid_to_str (ptid_of (current_thread)), | |
3191 | WTERMSIG (w)); | |
3192 | debug_exit (); | |
3193 | } | |
3194 | } | |
3195 | ||
3196 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) | |
3197 | return filter_exit_event (event_child, ourstatus); | |
3198 | ||
3199 | return ptid_of (current_thread); | |
3200 | } | |
3201 | ||
3202 | /* If step-over executes a breakpoint instruction, in the case of a | |
3203 | hardware single step it means a gdb/gdbserver breakpoint had been | |
3204 | planted on top of a permanent breakpoint, in the case of a software | |
3205 | single step it may just mean that gdbserver hit the reinsert breakpoint. | |
3206 | The PC has been adjusted by save_stop_reason to point at | |
3207 | the breakpoint address. | |
3208 | So in the case of the hardware single step advance the PC manually | |
3209 | past the breakpoint and in the case of software single step advance only | |
3210 | if it's not the single_step_breakpoint we are hitting. | |
3211 | This avoids that a program would keep trapping a permanent breakpoint | |
3212 | forever. */ | |
3213 | if (step_over_bkpt != null_ptid | |
3214 | && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3215 | && (event_child->stepping | |
3216 | || !single_step_breakpoint_inserted_here (event_child->stop_pc))) | |
3217 | { | |
3218 | int increment_pc = 0; | |
3219 | int breakpoint_kind = 0; | |
3220 | CORE_ADDR stop_pc = event_child->stop_pc; | |
3221 | ||
3222 | breakpoint_kind = | |
3223 | the_target->breakpoint_kind_from_current_state (&stop_pc); | |
3224 | the_target->sw_breakpoint_from_kind (breakpoint_kind, &increment_pc); | |
3225 | ||
3226 | if (debug_threads) | |
3227 | { | |
3228 | debug_printf ("step-over for %s executed software breakpoint\n", | |
3229 | target_pid_to_str (ptid_of (current_thread))); | |
3230 | } | |
3231 | ||
3232 | if (increment_pc != 0) | |
3233 | { | |
3234 | struct regcache *regcache | |
3235 | = get_thread_regcache (current_thread, 1); | |
3236 | ||
3237 | event_child->stop_pc += increment_pc; | |
3238 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); | |
3239 | ||
3240 | if (!(*the_low_target.breakpoint_at) (event_child->stop_pc)) | |
3241 | event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
3242 | } | |
3243 | } | |
3244 | ||
3245 | /* If this event was not handled before, and is not a SIGTRAP, we | |
3246 | report it. SIGILL and SIGSEGV are also treated as traps in case | |
3247 | a breakpoint is inserted at the current PC. If this target does | |
3248 | not support internal breakpoints at all, we also report the | |
3249 | SIGTRAP without further processing; it's of no concern to us. */ | |
3250 | maybe_internal_trap | |
3251 | = (supports_breakpoints () | |
3252 | && (WSTOPSIG (w) == SIGTRAP | |
3253 | || ((WSTOPSIG (w) == SIGILL | |
3254 | || WSTOPSIG (w) == SIGSEGV) | |
3255 | && (*the_low_target.breakpoint_at) (event_child->stop_pc)))); | |
3256 | ||
3257 | if (maybe_internal_trap) | |
3258 | { | |
3259 | /* Handle anything that requires bookkeeping before deciding to | |
3260 | report the event or continue waiting. */ | |
3261 | ||
3262 | /* First check if we can explain the SIGTRAP with an internal | |
3263 | breakpoint, or if we should possibly report the event to GDB. | |
3264 | Do this before anything that may remove or insert a | |
3265 | breakpoint. */ | |
3266 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); | |
3267 | ||
3268 | /* We have a SIGTRAP, possibly a step-over dance has just | |
3269 | finished. If so, tweak the state machine accordingly, | |
3270 | reinsert breakpoints and delete any single-step | |
3271 | breakpoints. */ | |
3272 | step_over_finished = finish_step_over (event_child); | |
3273 | ||
3274 | /* Now invoke the callbacks of any internal breakpoints there. */ | |
3275 | check_breakpoints (event_child->stop_pc); | |
3276 | ||
3277 | /* Handle tracepoint data collecting. This may overflow the | |
3278 | trace buffer, and cause a tracing stop, removing | |
3279 | breakpoints. */ | |
3280 | trace_event = handle_tracepoints (event_child); | |
3281 | ||
3282 | if (bp_explains_trap) | |
3283 | { | |
3284 | if (debug_threads) | |
3285 | debug_printf ("Hit a gdbserver breakpoint.\n"); | |
3286 | } | |
3287 | } | |
3288 | else | |
3289 | { | |
3290 | /* We have some other signal, possibly a step-over dance was in | |
3291 | progress, and it should be cancelled too. */ | |
3292 | step_over_finished = finish_step_over (event_child); | |
3293 | } | |
3294 | ||
3295 | /* We have all the data we need. Either report the event to GDB, or | |
3296 | resume threads and keep waiting for more. */ | |
3297 | ||
3298 | /* If we're collecting a fast tracepoint, finish the collection and | |
3299 | move out of the jump pad before delivering a signal. See | |
3300 | linux_stabilize_threads. */ | |
3301 | ||
3302 | if (WIFSTOPPED (w) | |
3303 | && WSTOPSIG (w) != SIGTRAP | |
3304 | && supports_fast_tracepoints () | |
3305 | && agent_loaded_p ()) | |
3306 | { | |
3307 | if (debug_threads) | |
3308 | debug_printf ("Got signal %d for LWP %ld. Check if we need " | |
3309 | "to defer or adjust it.\n", | |
3310 | WSTOPSIG (w), lwpid_of (current_thread)); | |
3311 | ||
3312 | /* Allow debugging the jump pad itself. */ | |
3313 | if (current_thread->last_resume_kind != resume_step | |
3314 | && maybe_move_out_of_jump_pad (event_child, &w)) | |
3315 | { | |
3316 | enqueue_one_deferred_signal (event_child, &w); | |
3317 | ||
3318 | if (debug_threads) | |
3319 | debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n", | |
3320 | WSTOPSIG (w), lwpid_of (current_thread)); | |
3321 | ||
3322 | linux_resume_one_lwp (event_child, 0, 0, NULL); | |
3323 | ||
3324 | if (debug_threads) | |
3325 | debug_exit (); | |
3326 | return ignore_event (ourstatus); | |
3327 | } | |
3328 | } | |
3329 | ||
3330 | if (event_child->collecting_fast_tracepoint | |
3331 | != fast_tpoint_collect_result::not_collecting) | |
3332 | { | |
3333 | if (debug_threads) | |
3334 | debug_printf ("LWP %ld was trying to move out of the jump pad (%d). " | |
3335 | "Check if we're already there.\n", | |
3336 | lwpid_of (current_thread), | |
3337 | (int) event_child->collecting_fast_tracepoint); | |
3338 | ||
3339 | trace_event = 1; | |
3340 | ||
3341 | event_child->collecting_fast_tracepoint | |
3342 | = linux_fast_tracepoint_collecting (event_child, NULL); | |
3343 | ||
3344 | if (event_child->collecting_fast_tracepoint | |
3345 | != fast_tpoint_collect_result::before_insn) | |
3346 | { | |
3347 | /* No longer need this breakpoint. */ | |
3348 | if (event_child->exit_jump_pad_bkpt != NULL) | |
3349 | { | |
3350 | if (debug_threads) | |
3351 | debug_printf ("No longer need exit-jump-pad bkpt; removing it." | |
3352 | "stopping all threads momentarily.\n"); | |
3353 | ||
3354 | /* Other running threads could hit this breakpoint. | |
3355 | We don't handle moribund locations like GDB does, | |
3356 | instead we always pause all threads when removing | |
3357 | breakpoints, so that any step-over or | |
3358 | decr_pc_after_break adjustment is always taken | |
3359 | care of while the breakpoint is still | |
3360 | inserted. */ | |
3361 | stop_all_lwps (1, event_child); | |
3362 | ||
3363 | delete_breakpoint (event_child->exit_jump_pad_bkpt); | |
3364 | event_child->exit_jump_pad_bkpt = NULL; | |
3365 | ||
3366 | unstop_all_lwps (1, event_child); | |
3367 | ||
3368 | gdb_assert (event_child->suspended >= 0); | |
3369 | } | |
3370 | } | |
3371 | ||
3372 | if (event_child->collecting_fast_tracepoint | |
3373 | == fast_tpoint_collect_result::not_collecting) | |
3374 | { | |
3375 | if (debug_threads) | |
3376 | debug_printf ("fast tracepoint finished " | |
3377 | "collecting successfully.\n"); | |
3378 | ||
3379 | /* We may have a deferred signal to report. */ | |
3380 | if (dequeue_one_deferred_signal (event_child, &w)) | |
3381 | { | |
3382 | if (debug_threads) | |
3383 | debug_printf ("dequeued one signal.\n"); | |
3384 | } | |
3385 | else | |
3386 | { | |
3387 | if (debug_threads) | |
3388 | debug_printf ("no deferred signals.\n"); | |
3389 | ||
3390 | if (stabilizing_threads) | |
3391 | { | |
3392 | ourstatus->kind = TARGET_WAITKIND_STOPPED; | |
3393 | ourstatus->value.sig = GDB_SIGNAL_0; | |
3394 | ||
3395 | if (debug_threads) | |
3396 | { | |
3397 | debug_printf ("linux_wait_1 ret = %s, stopped " | |
3398 | "while stabilizing threads\n", | |
3399 | target_pid_to_str (ptid_of (current_thread))); | |
3400 | debug_exit (); | |
3401 | } | |
3402 | ||
3403 | return ptid_of (current_thread); | |
3404 | } | |
3405 | } | |
3406 | } | |
3407 | } | |
3408 | ||
3409 | /* Check whether GDB would be interested in this event. */ | |
3410 | ||
3411 | /* Check if GDB is interested in this syscall. */ | |
3412 | if (WIFSTOPPED (w) | |
3413 | && WSTOPSIG (w) == SYSCALL_SIGTRAP | |
3414 | && !gdb_catch_this_syscall_p (event_child)) | |
3415 | { | |
3416 | if (debug_threads) | |
3417 | { | |
3418 | debug_printf ("Ignored syscall for LWP %ld.\n", | |
3419 | lwpid_of (current_thread)); | |
3420 | } | |
3421 | ||
3422 | linux_resume_one_lwp (event_child, event_child->stepping, | |
3423 | 0, NULL); | |
3424 | ||
3425 | if (debug_threads) | |
3426 | debug_exit (); | |
3427 | return ignore_event (ourstatus); | |
3428 | } | |
3429 | ||
3430 | /* If GDB is not interested in this signal, don't stop other | |
3431 | threads, and don't report it to GDB. Just resume the inferior | |
3432 | right away. We do this for threading-related signals as well as | |
3433 | any that GDB specifically requested we ignore. But never ignore | |
3434 | SIGSTOP if we sent it ourselves, and do not ignore signals when | |
3435 | stepping - they may require special handling to skip the signal | |
3436 | handler. Also never ignore signals that could be caused by a | |
3437 | breakpoint. */ | |
3438 | if (WIFSTOPPED (w) | |
3439 | && current_thread->last_resume_kind != resume_step | |
3440 | && ( | |
3441 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) | |
3442 | (current_process ()->priv->thread_db != NULL | |
3443 | && (WSTOPSIG (w) == __SIGRTMIN | |
3444 | || WSTOPSIG (w) == __SIGRTMIN + 1)) | |
3445 | || | |
3446 | #endif | |
3447 | (cs.pass_signals[gdb_signal_from_host (WSTOPSIG (w))] | |
3448 | && !(WSTOPSIG (w) == SIGSTOP | |
3449 | && current_thread->last_resume_kind == resume_stop) | |
3450 | && !linux_wstatus_maybe_breakpoint (w)))) | |
3451 | { | |
3452 | siginfo_t info, *info_p; | |
3453 | ||
3454 | if (debug_threads) | |
3455 | debug_printf ("Ignored signal %d for LWP %ld.\n", | |
3456 | WSTOPSIG (w), lwpid_of (current_thread)); | |
3457 | ||
3458 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
3459 | (PTRACE_TYPE_ARG3) 0, &info) == 0) | |
3460 | info_p = &info; | |
3461 | else | |
3462 | info_p = NULL; | |
3463 | ||
3464 | if (step_over_finished) | |
3465 | { | |
3466 | /* We cancelled this thread's step-over above. We still | |
3467 | need to unsuspend all other LWPs, and set them back | |
3468 | running again while the signal handler runs. */ | |
3469 | unsuspend_all_lwps (event_child); | |
3470 | ||
3471 | /* Enqueue the pending signal info so that proceed_all_lwps | |
3472 | doesn't lose it. */ | |
3473 | enqueue_pending_signal (event_child, WSTOPSIG (w), info_p); | |
3474 | ||
3475 | proceed_all_lwps (); | |
3476 | } | |
3477 | else | |
3478 | { | |
3479 | linux_resume_one_lwp (event_child, event_child->stepping, | |
3480 | WSTOPSIG (w), info_p); | |
3481 | } | |
3482 | ||
3483 | if (debug_threads) | |
3484 | debug_exit (); | |
3485 | ||
3486 | return ignore_event (ourstatus); | |
3487 | } | |
3488 | ||
3489 | /* Note that all addresses are always "out of the step range" when | |
3490 | there's no range to begin with. */ | |
3491 | in_step_range = lwp_in_step_range (event_child); | |
3492 | ||
3493 | /* If GDB wanted this thread to single step, and the thread is out | |
3494 | of the step range, we always want to report the SIGTRAP, and let | |
3495 | GDB handle it. Watchpoints should always be reported. So should | |
3496 | signals we can't explain. A SIGTRAP we can't explain could be a | |
3497 | GDB breakpoint --- we may or not support Z0 breakpoints. If we | |
3498 | do, we're be able to handle GDB breakpoints on top of internal | |
3499 | breakpoints, by handling the internal breakpoint and still | |
3500 | reporting the event to GDB. If we don't, we're out of luck, GDB | |
3501 | won't see the breakpoint hit. If we see a single-step event but | |
3502 | the thread should be continuing, don't pass the trap to gdb. | |
3503 | That indicates that we had previously finished a single-step but | |
3504 | left the single-step pending -- see | |
3505 | complete_ongoing_step_over. */ | |
3506 | report_to_gdb = (!maybe_internal_trap | |
3507 | || (current_thread->last_resume_kind == resume_step | |
3508 | && !in_step_range) | |
3509 | || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT | |
3510 | || (!in_step_range | |
3511 | && !bp_explains_trap | |
3512 | && !trace_event | |
3513 | && !step_over_finished | |
3514 | && !(current_thread->last_resume_kind == resume_continue | |
3515 | && event_child->stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)) | |
3516 | || (gdb_breakpoint_here (event_child->stop_pc) | |
3517 | && gdb_condition_true_at_breakpoint (event_child->stop_pc) | |
3518 | && gdb_no_commands_at_breakpoint (event_child->stop_pc)) | |
3519 | || event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE); | |
3520 | ||
3521 | run_breakpoint_commands (event_child->stop_pc); | |
3522 | ||
3523 | /* We found no reason GDB would want us to stop. We either hit one | |
3524 | of our own breakpoints, or finished an internal step GDB | |
3525 | shouldn't know about. */ | |
3526 | if (!report_to_gdb) | |
3527 | { | |
3528 | if (debug_threads) | |
3529 | { | |
3530 | if (bp_explains_trap) | |
3531 | debug_printf ("Hit a gdbserver breakpoint.\n"); | |
3532 | if (step_over_finished) | |
3533 | debug_printf ("Step-over finished.\n"); | |
3534 | if (trace_event) | |
3535 | debug_printf ("Tracepoint event.\n"); | |
3536 | if (lwp_in_step_range (event_child)) | |
3537 | debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n", | |
3538 | paddress (event_child->stop_pc), | |
3539 | paddress (event_child->step_range_start), | |
3540 | paddress (event_child->step_range_end)); | |
3541 | } | |
3542 | ||
3543 | /* We're not reporting this breakpoint to GDB, so apply the | |
3544 | decr_pc_after_break adjustment to the inferior's regcache | |
3545 | ourselves. */ | |
3546 | ||
3547 | if (the_low_target.set_pc != NULL) | |
3548 | { | |
3549 | struct regcache *regcache | |
3550 | = get_thread_regcache (current_thread, 1); | |
3551 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); | |
3552 | } | |
3553 | ||
3554 | if (step_over_finished) | |
3555 | { | |
3556 | /* If we have finished stepping over a breakpoint, we've | |
3557 | stopped and suspended all LWPs momentarily except the | |
3558 | stepping one. This is where we resume them all again. | |
3559 | We're going to keep waiting, so use proceed, which | |
3560 | handles stepping over the next breakpoint. */ | |
3561 | unsuspend_all_lwps (event_child); | |
3562 | } | |
3563 | else | |
3564 | { | |
3565 | /* Remove the single-step breakpoints if any. Note that | |
3566 | there isn't single-step breakpoint if we finished stepping | |
3567 | over. */ | |
3568 | if (can_software_single_step () | |
3569 | && has_single_step_breakpoints (current_thread)) | |
3570 | { | |
3571 | stop_all_lwps (0, event_child); | |
3572 | delete_single_step_breakpoints (current_thread); | |
3573 | unstop_all_lwps (0, event_child); | |
3574 | } | |
3575 | } | |
3576 | ||
3577 | if (debug_threads) | |
3578 | debug_printf ("proceeding all threads.\n"); | |
3579 | proceed_all_lwps (); | |
3580 | ||
3581 | if (debug_threads) | |
3582 | debug_exit (); | |
3583 | ||
3584 | return ignore_event (ourstatus); | |
3585 | } | |
3586 | ||
3587 | if (debug_threads) | |
3588 | { | |
3589 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3590 | { | |
3591 | std::string str | |
3592 | = target_waitstatus_to_string (&event_child->waitstatus); | |
3593 | ||
3594 | debug_printf ("LWP %ld: extended event with waitstatus %s\n", | |
3595 | lwpid_of (get_lwp_thread (event_child)), str.c_str ()); | |
3596 | } | |
3597 | if (current_thread->last_resume_kind == resume_step) | |
3598 | { | |
3599 | if (event_child->step_range_start == event_child->step_range_end) | |
3600 | debug_printf ("GDB wanted to single-step, reporting event.\n"); | |
3601 | else if (!lwp_in_step_range (event_child)) | |
3602 | debug_printf ("Out of step range, reporting event.\n"); | |
3603 | } | |
3604 | if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
3605 | debug_printf ("Stopped by watchpoint.\n"); | |
3606 | else if (gdb_breakpoint_here (event_child->stop_pc)) | |
3607 | debug_printf ("Stopped by GDB breakpoint.\n"); | |
3608 | if (debug_threads) | |
3609 | debug_printf ("Hit a non-gdbserver trap event.\n"); | |
3610 | } | |
3611 | ||
3612 | /* Alright, we're going to report a stop. */ | |
3613 | ||
3614 | /* Remove single-step breakpoints. */ | |
3615 | if (can_software_single_step ()) | |
3616 | { | |
3617 | /* Remove single-step breakpoints or not. It it is true, stop all | |
3618 | lwps, so that other threads won't hit the breakpoint in the | |
3619 | staled memory. */ | |
3620 | int remove_single_step_breakpoints_p = 0; | |
3621 | ||
3622 | if (non_stop) | |
3623 | { | |
3624 | remove_single_step_breakpoints_p | |
3625 | = has_single_step_breakpoints (current_thread); | |
3626 | } | |
3627 | else | |
3628 | { | |
3629 | /* In all-stop, a stop reply cancels all previous resume | |
3630 | requests. Delete all single-step breakpoints. */ | |
3631 | ||
3632 | find_thread ([&] (thread_info *thread) { | |
3633 | if (has_single_step_breakpoints (thread)) | |
3634 | { | |
3635 | remove_single_step_breakpoints_p = 1; | |
3636 | return true; | |
3637 | } | |
3638 | ||
3639 | return false; | |
3640 | }); | |
3641 | } | |
3642 | ||
3643 | if (remove_single_step_breakpoints_p) | |
3644 | { | |
3645 | /* If we remove single-step breakpoints from memory, stop all lwps, | |
3646 | so that other threads won't hit the breakpoint in the staled | |
3647 | memory. */ | |
3648 | stop_all_lwps (0, event_child); | |
3649 | ||
3650 | if (non_stop) | |
3651 | { | |
3652 | gdb_assert (has_single_step_breakpoints (current_thread)); | |
3653 | delete_single_step_breakpoints (current_thread); | |
3654 | } | |
3655 | else | |
3656 | { | |
3657 | for_each_thread ([] (thread_info *thread){ | |
3658 | if (has_single_step_breakpoints (thread)) | |
3659 | delete_single_step_breakpoints (thread); | |
3660 | }); | |
3661 | } | |
3662 | ||
3663 | unstop_all_lwps (0, event_child); | |
3664 | } | |
3665 | } | |
3666 | ||
3667 | if (!stabilizing_threads) | |
3668 | { | |
3669 | /* In all-stop, stop all threads. */ | |
3670 | if (!non_stop) | |
3671 | stop_all_lwps (0, NULL); | |
3672 | ||
3673 | if (step_over_finished) | |
3674 | { | |
3675 | if (!non_stop) | |
3676 | { | |
3677 | /* If we were doing a step-over, all other threads but | |
3678 | the stepping one had been paused in start_step_over, | |
3679 | with their suspend counts incremented. We don't want | |
3680 | to do a full unstop/unpause, because we're in | |
3681 | all-stop mode (so we want threads stopped), but we | |
3682 | still need to unsuspend the other threads, to | |
3683 | decrement their `suspended' count back. */ | |
3684 | unsuspend_all_lwps (event_child); | |
3685 | } | |
3686 | else | |
3687 | { | |
3688 | /* If we just finished a step-over, then all threads had | |
3689 | been momentarily paused. In all-stop, that's fine, | |
3690 | we want threads stopped by now anyway. In non-stop, | |
3691 | we need to re-resume threads that GDB wanted to be | |
3692 | running. */ | |
3693 | unstop_all_lwps (1, event_child); | |
3694 | } | |
3695 | } | |
3696 | ||
3697 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3698 | from among those that have had events. Giving equal priority | |
3699 | to all LWPs that have had events helps prevent | |
3700 | starvation. */ | |
3701 | if (ptid == minus_one_ptid) | |
3702 | { | |
3703 | event_child->status_pending_p = 1; | |
3704 | event_child->status_pending = w; | |
3705 | ||
3706 | select_event_lwp (&event_child); | |
3707 | ||
3708 | /* current_thread and event_child must stay in sync. */ | |
3709 | current_thread = get_lwp_thread (event_child); | |
3710 | ||
3711 | event_child->status_pending_p = 0; | |
3712 | w = event_child->status_pending; | |
3713 | } | |
3714 | ||
3715 | ||
3716 | /* Stabilize threads (move out of jump pads). */ | |
3717 | if (!non_stop) | |
3718 | stabilize_threads (); | |
3719 | } | |
3720 | else | |
3721 | { | |
3722 | /* If we just finished a step-over, then all threads had been | |
3723 | momentarily paused. In all-stop, that's fine, we want | |
3724 | threads stopped by now anyway. In non-stop, we need to | |
3725 | re-resume threads that GDB wanted to be running. */ | |
3726 | if (step_over_finished) | |
3727 | unstop_all_lwps (1, event_child); | |
3728 | } | |
3729 | ||
3730 | if (event_child->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3731 | { | |
3732 | /* If the reported event is an exit, fork, vfork or exec, let | |
3733 | GDB know. */ | |
3734 | ||
3735 | /* Break the unreported fork relationship chain. */ | |
3736 | if (event_child->waitstatus.kind == TARGET_WAITKIND_FORKED | |
3737 | || event_child->waitstatus.kind == TARGET_WAITKIND_VFORKED) | |
3738 | { | |
3739 | event_child->fork_relative->fork_relative = NULL; | |
3740 | event_child->fork_relative = NULL; | |
3741 | } | |
3742 | ||
3743 | *ourstatus = event_child->waitstatus; | |
3744 | /* Clear the event lwp's waitstatus since we handled it already. */ | |
3745 | event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3746 | } | |
3747 | else | |
3748 | ourstatus->kind = TARGET_WAITKIND_STOPPED; | |
3749 | ||
3750 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
3751 | it was a software breakpoint, and the client doesn't know we can | |
3752 | adjust the breakpoint ourselves. */ | |
3753 | if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3754 | && !cs.swbreak_feature) | |
3755 | { | |
3756 | int decr_pc = the_low_target.decr_pc_after_break; | |
3757 | ||
3758 | if (decr_pc != 0) | |
3759 | { | |
3760 | struct regcache *regcache | |
3761 | = get_thread_regcache (current_thread, 1); | |
3762 | (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc); | |
3763 | } | |
3764 | } | |
3765 | ||
3766 | if (WSTOPSIG (w) == SYSCALL_SIGTRAP) | |
3767 | { | |
3768 | get_syscall_trapinfo (event_child, | |
3769 | &ourstatus->value.syscall_number); | |
3770 | ourstatus->kind = event_child->syscall_state; | |
3771 | } | |
3772 | else if (current_thread->last_resume_kind == resume_stop | |
3773 | && WSTOPSIG (w) == SIGSTOP) | |
3774 | { | |
3775 | /* A thread that has been requested to stop by GDB with vCont;t, | |
3776 | and it stopped cleanly, so report as SIG0. The use of | |
3777 | SIGSTOP is an implementation detail. */ | |
3778 | ourstatus->value.sig = GDB_SIGNAL_0; | |
3779 | } | |
3780 | else if (current_thread->last_resume_kind == resume_stop | |
3781 | && WSTOPSIG (w) != SIGSTOP) | |
3782 | { | |
3783 | /* A thread that has been requested to stop by GDB with vCont;t, | |
3784 | but, it stopped for other reasons. */ | |
3785 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); | |
3786 | } | |
3787 | else if (ourstatus->kind == TARGET_WAITKIND_STOPPED) | |
3788 | { | |
3789 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); | |
3790 | } | |
3791 | ||
3792 | gdb_assert (step_over_bkpt == null_ptid); | |
3793 | ||
3794 | if (debug_threads) | |
3795 | { | |
3796 | debug_printf ("linux_wait_1 ret = %s, %d, %d\n", | |
3797 | target_pid_to_str (ptid_of (current_thread)), | |
3798 | ourstatus->kind, ourstatus->value.sig); | |
3799 | debug_exit (); | |
3800 | } | |
3801 | ||
3802 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) | |
3803 | return filter_exit_event (event_child, ourstatus); | |
3804 | ||
3805 | return ptid_of (current_thread); | |
3806 | } | |
3807 | ||
3808 | /* Get rid of any pending event in the pipe. */ | |
3809 | static void | |
3810 | async_file_flush (void) | |
3811 | { | |
3812 | int ret; | |
3813 | char buf; | |
3814 | ||
3815 | do | |
3816 | ret = read (linux_event_pipe[0], &buf, 1); | |
3817 | while (ret >= 0 || (ret == -1 && errno == EINTR)); | |
3818 | } | |
3819 | ||
3820 | /* Put something in the pipe, so the event loop wakes up. */ | |
3821 | static void | |
3822 | async_file_mark (void) | |
3823 | { | |
3824 | int ret; | |
3825 | ||
3826 | async_file_flush (); | |
3827 | ||
3828 | do | |
3829 | ret = write (linux_event_pipe[1], "+", 1); | |
3830 | while (ret == 0 || (ret == -1 && errno == EINTR)); | |
3831 | ||
3832 | /* Ignore EAGAIN. If the pipe is full, the event loop will already | |
3833 | be awakened anyway. */ | |
3834 | } | |
3835 | ||
3836 | static ptid_t | |
3837 | linux_wait (ptid_t ptid, | |
3838 | struct target_waitstatus *ourstatus, int target_options) | |
3839 | { | |
3840 | ptid_t event_ptid; | |
3841 | ||
3842 | /* Flush the async file first. */ | |
3843 | if (target_is_async_p ()) | |
3844 | async_file_flush (); | |
3845 | ||
3846 | do | |
3847 | { | |
3848 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); | |
3849 | } | |
3850 | while ((target_options & TARGET_WNOHANG) == 0 | |
3851 | && event_ptid == null_ptid | |
3852 | && ourstatus->kind == TARGET_WAITKIND_IGNORE); | |
3853 | ||
3854 | /* If at least one stop was reported, there may be more. A single | |
3855 | SIGCHLD can signal more than one child stop. */ | |
3856 | if (target_is_async_p () | |
3857 | && (target_options & TARGET_WNOHANG) != 0 | |
3858 | && event_ptid != null_ptid) | |
3859 | async_file_mark (); | |
3860 | ||
3861 | return event_ptid; | |
3862 | } | |
3863 | ||
3864 | /* Send a signal to an LWP. */ | |
3865 | ||
3866 | static int | |
3867 | kill_lwp (unsigned long lwpid, int signo) | |
3868 | { | |
3869 | int ret; | |
3870 | ||
3871 | errno = 0; | |
3872 | ret = syscall (__NR_tkill, lwpid, signo); | |
3873 | if (errno == ENOSYS) | |
3874 | { | |
3875 | /* If tkill fails, then we are not using nptl threads, a | |
3876 | configuration we no longer support. */ | |
3877 | perror_with_name (("tkill")); | |
3878 | } | |
3879 | return ret; | |
3880 | } | |
3881 | ||
3882 | void | |
3883 | linux_stop_lwp (struct lwp_info *lwp) | |
3884 | { | |
3885 | send_sigstop (lwp); | |
3886 | } | |
3887 | ||
3888 | static void | |
3889 | send_sigstop (struct lwp_info *lwp) | |
3890 | { | |
3891 | int pid; | |
3892 | ||
3893 | pid = lwpid_of (get_lwp_thread (lwp)); | |
3894 | ||
3895 | /* If we already have a pending stop signal for this process, don't | |
3896 | send another. */ | |
3897 | if (lwp->stop_expected) | |
3898 | { | |
3899 | if (debug_threads) | |
3900 | debug_printf ("Have pending sigstop for lwp %d\n", pid); | |
3901 | ||
3902 | return; | |
3903 | } | |
3904 | ||
3905 | if (debug_threads) | |
3906 | debug_printf ("Sending sigstop to lwp %d\n", pid); | |
3907 | ||
3908 | lwp->stop_expected = 1; | |
3909 | kill_lwp (pid, SIGSTOP); | |
3910 | } | |
3911 | ||
3912 | static void | |
3913 | send_sigstop (thread_info *thread, lwp_info *except) | |
3914 | { | |
3915 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3916 | ||
3917 | /* Ignore EXCEPT. */ | |
3918 | if (lwp == except) | |
3919 | return; | |
3920 | ||
3921 | if (lwp->stopped) | |
3922 | return; | |
3923 | ||
3924 | send_sigstop (lwp); | |
3925 | } | |
3926 | ||
3927 | /* Increment the suspend count of an LWP, and stop it, if not stopped | |
3928 | yet. */ | |
3929 | static void | |
3930 | suspend_and_send_sigstop (thread_info *thread, lwp_info *except) | |
3931 | { | |
3932 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3933 | ||
3934 | /* Ignore EXCEPT. */ | |
3935 | if (lwp == except) | |
3936 | return; | |
3937 | ||
3938 | lwp_suspended_inc (lwp); | |
3939 | ||
3940 | send_sigstop (thread, except); | |
3941 | } | |
3942 | ||
3943 | static void | |
3944 | mark_lwp_dead (struct lwp_info *lwp, int wstat) | |
3945 | { | |
3946 | /* Store the exit status for later. */ | |
3947 | lwp->status_pending_p = 1; | |
3948 | lwp->status_pending = wstat; | |
3949 | ||
3950 | /* Store in waitstatus as well, as there's nothing else to process | |
3951 | for this event. */ | |
3952 | if (WIFEXITED (wstat)) | |
3953 | { | |
3954 | lwp->waitstatus.kind = TARGET_WAITKIND_EXITED; | |
3955 | lwp->waitstatus.value.integer = WEXITSTATUS (wstat); | |
3956 | } | |
3957 | else if (WIFSIGNALED (wstat)) | |
3958 | { | |
3959 | lwp->waitstatus.kind = TARGET_WAITKIND_SIGNALLED; | |
3960 | lwp->waitstatus.value.sig = gdb_signal_from_host (WTERMSIG (wstat)); | |
3961 | } | |
3962 | ||
3963 | /* Prevent trying to stop it. */ | |
3964 | lwp->stopped = 1; | |
3965 | ||
3966 | /* No further stops are expected from a dead lwp. */ | |
3967 | lwp->stop_expected = 0; | |
3968 | } | |
3969 | ||
3970 | /* Return true if LWP has exited already, and has a pending exit event | |
3971 | to report to GDB. */ | |
3972 | ||
3973 | static int | |
3974 | lwp_is_marked_dead (struct lwp_info *lwp) | |
3975 | { | |
3976 | return (lwp->status_pending_p | |
3977 | && (WIFEXITED (lwp->status_pending) | |
3978 | || WIFSIGNALED (lwp->status_pending))); | |
3979 | } | |
3980 | ||
3981 | /* Wait for all children to stop for the SIGSTOPs we just queued. */ | |
3982 | ||
3983 | static void | |
3984 | wait_for_sigstop (void) | |
3985 | { | |
3986 | struct thread_info *saved_thread; | |
3987 | ptid_t saved_tid; | |
3988 | int wstat; | |
3989 | int ret; | |
3990 | ||
3991 | saved_thread = current_thread; | |
3992 | if (saved_thread != NULL) | |
3993 | saved_tid = saved_thread->id; | |
3994 | else | |
3995 | saved_tid = null_ptid; /* avoid bogus unused warning */ | |
3996 | ||
3997 | if (debug_threads) | |
3998 | debug_printf ("wait_for_sigstop: pulling events\n"); | |
3999 | ||
4000 | /* Passing NULL_PTID as filter indicates we want all events to be | |
4001 | left pending. Eventually this returns when there are no | |
4002 | unwaited-for children left. */ | |
4003 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, | |
4004 | &wstat, __WALL); | |
4005 | gdb_assert (ret == -1); | |
4006 | ||
4007 | if (saved_thread == NULL || linux_thread_alive (saved_tid)) | |
4008 | current_thread = saved_thread; | |
4009 | else | |
4010 | { | |
4011 | if (debug_threads) | |
4012 | debug_printf ("Previously current thread died.\n"); | |
4013 | ||
4014 | /* We can't change the current inferior behind GDB's back, | |
4015 | otherwise, a subsequent command may apply to the wrong | |
4016 | process. */ | |
4017 | current_thread = NULL; | |
4018 | } | |
4019 | } | |
4020 | ||
4021 | /* Returns true if THREAD is stopped in a jump pad, and we can't | |
4022 | move it out, because we need to report the stop event to GDB. For | |
4023 | example, if the user puts a breakpoint in the jump pad, it's | |
4024 | because she wants to debug it. */ | |
4025 | ||
4026 | static bool | |
4027 | stuck_in_jump_pad_callback (thread_info *thread) | |
4028 | { | |
4029 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4030 | ||
4031 | if (lwp->suspended != 0) | |
4032 | { | |
4033 | internal_error (__FILE__, __LINE__, | |
4034 | "LWP %ld is suspended, suspended=%d\n", | |
4035 | lwpid_of (thread), lwp->suspended); | |
4036 | } | |
4037 | gdb_assert (lwp->stopped); | |
4038 | ||
4039 | /* Allow debugging the jump pad, gdb_collect, etc.. */ | |
4040 | return (supports_fast_tracepoints () | |
4041 | && agent_loaded_p () | |
4042 | && (gdb_breakpoint_here (lwp->stop_pc) | |
4043 | || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT | |
4044 | || thread->last_resume_kind == resume_step) | |
4045 | && (linux_fast_tracepoint_collecting (lwp, NULL) | |
4046 | != fast_tpoint_collect_result::not_collecting)); | |
4047 | } | |
4048 | ||
4049 | static void | |
4050 | move_out_of_jump_pad_callback (thread_info *thread) | |
4051 | { | |
4052 | struct thread_info *saved_thread; | |
4053 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4054 | int *wstat; | |
4055 | ||
4056 | if (lwp->suspended != 0) | |
4057 | { | |
4058 | internal_error (__FILE__, __LINE__, | |
4059 | "LWP %ld is suspended, suspended=%d\n", | |
4060 | lwpid_of (thread), lwp->suspended); | |
4061 | } | |
4062 | gdb_assert (lwp->stopped); | |
4063 | ||
4064 | /* For gdb_breakpoint_here. */ | |
4065 | saved_thread = current_thread; | |
4066 | current_thread = thread; | |
4067 | ||
4068 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; | |
4069 | ||
4070 | /* Allow debugging the jump pad, gdb_collect, etc. */ | |
4071 | if (!gdb_breakpoint_here (lwp->stop_pc) | |
4072 | && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT | |
4073 | && thread->last_resume_kind != resume_step | |
4074 | && maybe_move_out_of_jump_pad (lwp, wstat)) | |
4075 | { | |
4076 | if (debug_threads) | |
4077 | debug_printf ("LWP %ld needs stabilizing (in jump pad)\n", | |
4078 | lwpid_of (thread)); | |
4079 | ||
4080 | if (wstat) | |
4081 | { | |
4082 | lwp->status_pending_p = 0; | |
4083 | enqueue_one_deferred_signal (lwp, wstat); | |
4084 | ||
4085 | if (debug_threads) | |
4086 | debug_printf ("Signal %d for LWP %ld deferred " | |
4087 | "(in jump pad)\n", | |
4088 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
4089 | } | |
4090 | ||
4091 | linux_resume_one_lwp (lwp, 0, 0, NULL); | |
4092 | } | |
4093 | else | |
4094 | lwp_suspended_inc (lwp); | |
4095 | ||
4096 | current_thread = saved_thread; | |
4097 | } | |
4098 | ||
4099 | static bool | |
4100 | lwp_running (thread_info *thread) | |
4101 | { | |
4102 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4103 | ||
4104 | if (lwp_is_marked_dead (lwp)) | |
4105 | return false; | |
4106 | ||
4107 | return !lwp->stopped; | |
4108 | } | |
4109 | ||
4110 | /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL. | |
4111 | If SUSPEND, then also increase the suspend count of every LWP, | |
4112 | except EXCEPT. */ | |
4113 | ||
4114 | static void | |
4115 | stop_all_lwps (int suspend, struct lwp_info *except) | |
4116 | { | |
4117 | /* Should not be called recursively. */ | |
4118 | gdb_assert (stopping_threads == NOT_STOPPING_THREADS); | |
4119 | ||
4120 | if (debug_threads) | |
4121 | { | |
4122 | debug_enter (); | |
4123 | debug_printf ("stop_all_lwps (%s, except=%s)\n", | |
4124 | suspend ? "stop-and-suspend" : "stop", | |
4125 | except != NULL | |
4126 | ? target_pid_to_str (ptid_of (get_lwp_thread (except))) | |
4127 | : "none"); | |
4128 | } | |
4129 | ||
4130 | stopping_threads = (suspend | |
4131 | ? STOPPING_AND_SUSPENDING_THREADS | |
4132 | : STOPPING_THREADS); | |
4133 | ||
4134 | if (suspend) | |
4135 | for_each_thread ([&] (thread_info *thread) | |
4136 | { | |
4137 | suspend_and_send_sigstop (thread, except); | |
4138 | }); | |
4139 | else | |
4140 | for_each_thread ([&] (thread_info *thread) | |
4141 | { | |
4142 | send_sigstop (thread, except); | |
4143 | }); | |
4144 | ||
4145 | wait_for_sigstop (); | |
4146 | stopping_threads = NOT_STOPPING_THREADS; | |
4147 | ||
4148 | if (debug_threads) | |
4149 | { | |
4150 | debug_printf ("stop_all_lwps done, setting stopping_threads " | |
4151 | "back to !stopping\n"); | |
4152 | debug_exit (); | |
4153 | } | |
4154 | } | |
4155 | ||
4156 | /* Enqueue one signal in the chain of signals which need to be | |
4157 | delivered to this process on next resume. */ | |
4158 | ||
4159 | static void | |
4160 | enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info) | |
4161 | { | |
4162 | struct pending_signals *p_sig = XNEW (struct pending_signals); | |
4163 | ||
4164 | p_sig->prev = lwp->pending_signals; | |
4165 | p_sig->signal = signal; | |
4166 | if (info == NULL) | |
4167 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
4168 | else | |
4169 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); | |
4170 | lwp->pending_signals = p_sig; | |
4171 | } | |
4172 | ||
4173 | /* Install breakpoints for software single stepping. */ | |
4174 | ||
4175 | static void | |
4176 | install_software_single_step_breakpoints (struct lwp_info *lwp) | |
4177 | { | |
4178 | struct thread_info *thread = get_lwp_thread (lwp); | |
4179 | struct regcache *regcache = get_thread_regcache (thread, 1); | |
4180 | ||
4181 | scoped_restore save_current_thread = make_scoped_restore (¤t_thread); | |
4182 | ||
4183 | current_thread = thread; | |
4184 | std::vector<CORE_ADDR> next_pcs = the_low_target.get_next_pcs (regcache); | |
4185 | ||
4186 | for (CORE_ADDR pc : next_pcs) | |
4187 | set_single_step_breakpoint (pc, current_ptid); | |
4188 | } | |
4189 | ||
4190 | /* Single step via hardware or software single step. | |
4191 | Return 1 if hardware single stepping, 0 if software single stepping | |
4192 | or can't single step. */ | |
4193 | ||
4194 | static int | |
4195 | single_step (struct lwp_info* lwp) | |
4196 | { | |
4197 | int step = 0; | |
4198 | ||
4199 | if (can_hardware_single_step ()) | |
4200 | { | |
4201 | step = 1; | |
4202 | } | |
4203 | else if (can_software_single_step ()) | |
4204 | { | |
4205 | install_software_single_step_breakpoints (lwp); | |
4206 | step = 0; | |
4207 | } | |
4208 | else | |
4209 | { | |
4210 | if (debug_threads) | |
4211 | debug_printf ("stepping is not implemented on this target"); | |
4212 | } | |
4213 | ||
4214 | return step; | |
4215 | } | |
4216 | ||
4217 | /* The signal can be delivered to the inferior if we are not trying to | |
4218 | finish a fast tracepoint collect. Since signal can be delivered in | |
4219 | the step-over, the program may go to signal handler and trap again | |
4220 | after return from the signal handler. We can live with the spurious | |
4221 | double traps. */ | |
4222 | ||
4223 | static int | |
4224 | lwp_signal_can_be_delivered (struct lwp_info *lwp) | |
4225 | { | |
4226 | return (lwp->collecting_fast_tracepoint | |
4227 | == fast_tpoint_collect_result::not_collecting); | |
4228 | } | |
4229 | ||
4230 | /* Resume execution of LWP. If STEP is nonzero, single-step it. If | |
4231 | SIGNAL is nonzero, give it that signal. */ | |
4232 | ||
4233 | static void | |
4234 | linux_resume_one_lwp_throw (struct lwp_info *lwp, | |
4235 | int step, int signal, siginfo_t *info) | |
4236 | { | |
4237 | struct thread_info *thread = get_lwp_thread (lwp); | |
4238 | struct thread_info *saved_thread; | |
4239 | int ptrace_request; | |
4240 | struct process_info *proc = get_thread_process (thread); | |
4241 | ||
4242 | /* Note that target description may not be initialised | |
4243 | (proc->tdesc == NULL) at this point because the program hasn't | |
4244 | stopped at the first instruction yet. It means GDBserver skips | |
4245 | the extra traps from the wrapper program (see option --wrapper). | |
4246 | Code in this function that requires register access should be | |
4247 | guarded by proc->tdesc == NULL or something else. */ | |
4248 | ||
4249 | if (lwp->stopped == 0) | |
4250 | return; | |
4251 | ||
4252 | gdb_assert (lwp->waitstatus.kind == TARGET_WAITKIND_IGNORE); | |
4253 | ||
4254 | fast_tpoint_collect_result fast_tp_collecting | |
4255 | = lwp->collecting_fast_tracepoint; | |
4256 | ||
4257 | gdb_assert (!stabilizing_threads | |
4258 | || (fast_tp_collecting | |
4259 | != fast_tpoint_collect_result::not_collecting)); | |
4260 | ||
4261 | /* Cancel actions that rely on GDB not changing the PC (e.g., the | |
4262 | user used the "jump" command, or "set $pc = foo"). */ | |
4263 | if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp)) | |
4264 | { | |
4265 | /* Collecting 'while-stepping' actions doesn't make sense | |
4266 | anymore. */ | |
4267 | release_while_stepping_state_list (thread); | |
4268 | } | |
4269 | ||
4270 | /* If we have pending signals or status, and a new signal, enqueue the | |
4271 | signal. Also enqueue the signal if it can't be delivered to the | |
4272 | inferior right now. */ | |
4273 | if (signal != 0 | |
4274 | && (lwp->status_pending_p | |
4275 | || lwp->pending_signals != NULL | |
4276 | || !lwp_signal_can_be_delivered (lwp))) | |
4277 | { | |
4278 | enqueue_pending_signal (lwp, signal, info); | |
4279 | ||
4280 | /* Postpone any pending signal. It was enqueued above. */ | |
4281 | signal = 0; | |
4282 | } | |
4283 | ||
4284 | if (lwp->status_pending_p) | |
4285 | { | |
4286 | if (debug_threads) | |
4287 | debug_printf ("Not resuming lwp %ld (%s, stop %s);" | |
4288 | " has pending status\n", | |
4289 | lwpid_of (thread), step ? "step" : "continue", | |
4290 | lwp->stop_expected ? "expected" : "not expected"); | |
4291 | return; | |
4292 | } | |
4293 | ||
4294 | saved_thread = current_thread; | |
4295 | current_thread = thread; | |
4296 | ||
4297 | /* This bit needs some thinking about. If we get a signal that | |
4298 | we must report while a single-step reinsert is still pending, | |
4299 | we often end up resuming the thread. It might be better to | |
4300 | (ew) allow a stack of pending events; then we could be sure that | |
4301 | the reinsert happened right away and not lose any signals. | |
4302 | ||
4303 | Making this stack would also shrink the window in which breakpoints are | |
4304 | uninserted (see comment in linux_wait_for_lwp) but not enough for | |
4305 | complete correctness, so it won't solve that problem. It may be | |
4306 | worthwhile just to solve this one, however. */ | |
4307 | if (lwp->bp_reinsert != 0) | |
4308 | { | |
4309 | if (debug_threads) | |
4310 | debug_printf (" pending reinsert at 0x%s\n", | |
4311 | paddress (lwp->bp_reinsert)); | |
4312 | ||
4313 | if (can_hardware_single_step ()) | |
4314 | { | |
4315 | if (fast_tp_collecting == fast_tpoint_collect_result::not_collecting) | |
4316 | { | |
4317 | if (step == 0) | |
4318 | warning ("BAD - reinserting but not stepping."); | |
4319 | if (lwp->suspended) | |
4320 | warning ("BAD - reinserting and suspended(%d).", | |
4321 | lwp->suspended); | |
4322 | } | |
4323 | } | |
4324 | ||
4325 | step = maybe_hw_step (thread); | |
4326 | } | |
4327 | ||
4328 | if (fast_tp_collecting == fast_tpoint_collect_result::before_insn) | |
4329 | { | |
4330 | if (debug_threads) | |
4331 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" | |
4332 | " (exit-jump-pad-bkpt)\n", | |
4333 | lwpid_of (thread)); | |
4334 | } | |
4335 | else if (fast_tp_collecting == fast_tpoint_collect_result::at_insn) | |
4336 | { | |
4337 | if (debug_threads) | |
4338 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" | |
4339 | " single-stepping\n", | |
4340 | lwpid_of (thread)); | |
4341 | ||
4342 | if (can_hardware_single_step ()) | |
4343 | step = 1; | |
4344 | else | |
4345 | { | |
4346 | internal_error (__FILE__, __LINE__, | |
4347 | "moving out of jump pad single-stepping" | |
4348 | " not implemented on this target"); | |
4349 | } | |
4350 | } | |
4351 | ||
4352 | /* If we have while-stepping actions in this thread set it stepping. | |
4353 | If we have a signal to deliver, it may or may not be set to | |
4354 | SIG_IGN, we don't know. Assume so, and allow collecting | |
4355 | while-stepping into a signal handler. A possible smart thing to | |
4356 | do would be to set an internal breakpoint at the signal return | |
4357 | address, continue, and carry on catching this while-stepping | |
4358 | action only when that breakpoint is hit. A future | |
4359 | enhancement. */ | |
4360 | if (thread->while_stepping != NULL) | |
4361 | { | |
4362 | if (debug_threads) | |
4363 | debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n", | |
4364 | lwpid_of (thread)); | |
4365 | ||
4366 | step = single_step (lwp); | |
4367 | } | |
4368 | ||
4369 | if (proc->tdesc != NULL && the_low_target.get_pc != NULL) | |
4370 | { | |
4371 | struct regcache *regcache = get_thread_regcache (current_thread, 1); | |
4372 | ||
4373 | lwp->stop_pc = (*the_low_target.get_pc) (regcache); | |
4374 | ||
4375 | if (debug_threads) | |
4376 | { | |
4377 | debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue", | |
4378 | (long) lwp->stop_pc); | |
4379 | } | |
4380 | } | |
4381 | ||
4382 | /* If we have pending signals, consume one if it can be delivered to | |
4383 | the inferior. */ | |
4384 | if (lwp->pending_signals != NULL && lwp_signal_can_be_delivered (lwp)) | |
4385 | { | |
4386 | struct pending_signals **p_sig; | |
4387 | ||
4388 | p_sig = &lwp->pending_signals; | |
4389 | while ((*p_sig)->prev != NULL) | |
4390 | p_sig = &(*p_sig)->prev; | |
4391 | ||
4392 | signal = (*p_sig)->signal; | |
4393 | if ((*p_sig)->info.si_signo != 0) | |
4394 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
4395 | &(*p_sig)->info); | |
4396 | ||
4397 | free (*p_sig); | |
4398 | *p_sig = NULL; | |
4399 | } | |
4400 | ||
4401 | if (debug_threads) | |
4402 | debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n", | |
4403 | lwpid_of (thread), step ? "step" : "continue", signal, | |
4404 | lwp->stop_expected ? "expected" : "not expected"); | |
4405 | ||
4406 | if (the_low_target.prepare_to_resume != NULL) | |
4407 | the_low_target.prepare_to_resume (lwp); | |
4408 | ||
4409 | regcache_invalidate_thread (thread); | |
4410 | errno = 0; | |
4411 | lwp->stepping = step; | |
4412 | if (step) | |
4413 | ptrace_request = PTRACE_SINGLESTEP; | |
4414 | else if (gdb_catching_syscalls_p (lwp)) | |
4415 | ptrace_request = PTRACE_SYSCALL; | |
4416 | else | |
4417 | ptrace_request = PTRACE_CONT; | |
4418 | ptrace (ptrace_request, | |
4419 | lwpid_of (thread), | |
4420 | (PTRACE_TYPE_ARG3) 0, | |
4421 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
4422 | of coercing an 8 byte integer to a 4 byte pointer. */ | |
4423 | (PTRACE_TYPE_ARG4) (uintptr_t) signal); | |
4424 | ||
4425 | current_thread = saved_thread; | |
4426 | if (errno) | |
4427 | perror_with_name ("resuming thread"); | |
4428 | ||
4429 | /* Successfully resumed. Clear state that no longer makes sense, | |
4430 | and mark the LWP as running. Must not do this before resuming | |
4431 | otherwise if that fails other code will be confused. E.g., we'd | |
4432 | later try to stop the LWP and hang forever waiting for a stop | |
4433 | status. Note that we must not throw after this is cleared, | |
4434 | otherwise handle_zombie_lwp_error would get confused. */ | |
4435 | lwp->stopped = 0; | |
4436 | lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
4437 | } | |
4438 | ||
4439 | /* Called when we try to resume a stopped LWP and that errors out. If | |
4440 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
4441 | or about to become), discard the error, clear any pending status | |
4442 | the LWP may have, and return true (we'll collect the exit status | |
4443 | soon enough). Otherwise, return false. */ | |
4444 | ||
4445 | static int | |
4446 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
4447 | { | |
4448 | struct thread_info *thread = get_lwp_thread (lp); | |
4449 | ||
4450 | /* If we get an error after resuming the LWP successfully, we'd | |
4451 | confuse !T state for the LWP being gone. */ | |
4452 | gdb_assert (lp->stopped); | |
4453 | ||
4454 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
4455 | because even if ptrace failed with ESRCH, the tracee may be "not | |
4456 | yet fully dead", but already refusing ptrace requests. In that | |
4457 | case the tracee has 'R (Running)' state for a little bit | |
4458 | (observed in Linux 3.18). See also the note on ESRCH in the | |
4459 | ptrace(2) man page. Instead, check whether the LWP has any state | |
4460 | other than ptrace-stopped. */ | |
4461 | ||
4462 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
4463 | if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0) | |
4464 | { | |
4465 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
4466 | lp->status_pending_p = 0; | |
4467 | return 1; | |
4468 | } | |
4469 | return 0; | |
4470 | } | |
4471 | ||
4472 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
4473 | disappears while we try to resume it. */ | |
4474 | ||
4475 | static void | |
4476 | linux_resume_one_lwp (struct lwp_info *lwp, | |
4477 | int step, int signal, siginfo_t *info) | |
4478 | { | |
4479 | try | |
4480 | { | |
4481 | linux_resume_one_lwp_throw (lwp, step, signal, info); | |
4482 | } | |
4483 | catch (const gdb_exception_error &ex) | |
4484 | { | |
4485 | if (!check_ptrace_stopped_lwp_gone (lwp)) | |
4486 | throw; | |
4487 | } | |
4488 | } | |
4489 | ||
4490 | /* This function is called once per thread via for_each_thread. | |
4491 | We look up which resume request applies to THREAD and mark it with a | |
4492 | pointer to the appropriate resume request. | |
4493 | ||
4494 | This algorithm is O(threads * resume elements), but resume elements | |
4495 | is small (and will remain small at least until GDB supports thread | |
4496 | suspension). */ | |
4497 | ||
4498 | static void | |
4499 | linux_set_resume_request (thread_info *thread, thread_resume *resume, size_t n) | |
4500 | { | |
4501 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4502 | ||
4503 | for (int ndx = 0; ndx < n; ndx++) | |
4504 | { | |
4505 | ptid_t ptid = resume[ndx].thread; | |
4506 | if (ptid == minus_one_ptid | |
4507 | || ptid == thread->id | |
4508 | /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads | |
4509 | of PID'. */ | |
4510 | || (ptid.pid () == pid_of (thread) | |
4511 | && (ptid.is_pid () | |
4512 | || ptid.lwp () == -1))) | |
4513 | { | |
4514 | if (resume[ndx].kind == resume_stop | |
4515 | && thread->last_resume_kind == resume_stop) | |
4516 | { | |
4517 | if (debug_threads) | |
4518 | debug_printf ("already %s LWP %ld at GDB's request\n", | |
4519 | (thread->last_status.kind | |
4520 | == TARGET_WAITKIND_STOPPED) | |
4521 | ? "stopped" | |
4522 | : "stopping", | |
4523 | lwpid_of (thread)); | |
4524 | ||
4525 | continue; | |
4526 | } | |
4527 | ||
4528 | /* Ignore (wildcard) resume requests for already-resumed | |
4529 | threads. */ | |
4530 | if (resume[ndx].kind != resume_stop | |
4531 | && thread->last_resume_kind != resume_stop) | |
4532 | { | |
4533 | if (debug_threads) | |
4534 | debug_printf ("already %s LWP %ld at GDB's request\n", | |
4535 | (thread->last_resume_kind | |
4536 | == resume_step) | |
4537 | ? "stepping" | |
4538 | : "continuing", | |
4539 | lwpid_of (thread)); | |
4540 | continue; | |
4541 | } | |
4542 | ||
4543 | /* Don't let wildcard resumes resume fork children that GDB | |
4544 | does not yet know are new fork children. */ | |
4545 | if (lwp->fork_relative != NULL) | |
4546 | { | |
4547 | struct lwp_info *rel = lwp->fork_relative; | |
4548 | ||
4549 | if (rel->status_pending_p | |
4550 | && (rel->waitstatus.kind == TARGET_WAITKIND_FORKED | |
4551 | || rel->waitstatus.kind == TARGET_WAITKIND_VFORKED)) | |
4552 | { | |
4553 | if (debug_threads) | |
4554 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", | |
4555 | lwpid_of (thread)); | |
4556 | continue; | |
4557 | } | |
4558 | } | |
4559 | ||
4560 | /* If the thread has a pending event that has already been | |
4561 | reported to GDBserver core, but GDB has not pulled the | |
4562 | event out of the vStopped queue yet, likewise, ignore the | |
4563 | (wildcard) resume request. */ | |
4564 | if (in_queued_stop_replies (thread->id)) | |
4565 | { | |
4566 | if (debug_threads) | |
4567 | debug_printf ("not resuming LWP %ld: has queued stop reply\n", | |
4568 | lwpid_of (thread)); | |
4569 | continue; | |
4570 | } | |
4571 | ||
4572 | lwp->resume = &resume[ndx]; | |
4573 | thread->last_resume_kind = lwp->resume->kind; | |
4574 | ||
4575 | lwp->step_range_start = lwp->resume->step_range_start; | |
4576 | lwp->step_range_end = lwp->resume->step_range_end; | |
4577 | ||
4578 | /* If we had a deferred signal to report, dequeue one now. | |
4579 | This can happen if LWP gets more than one signal while | |
4580 | trying to get out of a jump pad. */ | |
4581 | if (lwp->stopped | |
4582 | && !lwp->status_pending_p | |
4583 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) | |
4584 | { | |
4585 | lwp->status_pending_p = 1; | |
4586 | ||
4587 | if (debug_threads) | |
4588 | debug_printf ("Dequeueing deferred signal %d for LWP %ld, " | |
4589 | "leaving status pending.\n", | |
4590 | WSTOPSIG (lwp->status_pending), | |
4591 | lwpid_of (thread)); | |
4592 | } | |
4593 | ||
4594 | return; | |
4595 | } | |
4596 | } | |
4597 | ||
4598 | /* No resume action for this thread. */ | |
4599 | lwp->resume = NULL; | |
4600 | } | |
4601 | ||
4602 | /* find_thread callback for linux_resume. Return true if this lwp has an | |
4603 | interesting status pending. */ | |
4604 | ||
4605 | static bool | |
4606 | resume_status_pending_p (thread_info *thread) | |
4607 | { | |
4608 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4609 | ||
4610 | /* LWPs which will not be resumed are not interesting, because | |
4611 | we might not wait for them next time through linux_wait. */ | |
4612 | if (lwp->resume == NULL) | |
4613 | return false; | |
4614 | ||
4615 | return thread_still_has_status_pending_p (thread); | |
4616 | } | |
4617 | ||
4618 | /* Return 1 if this lwp that GDB wants running is stopped at an | |
4619 | internal breakpoint that we need to step over. It assumes that any | |
4620 | required STOP_PC adjustment has already been propagated to the | |
4621 | inferior's regcache. */ | |
4622 | ||
4623 | static bool | |
4624 | need_step_over_p (thread_info *thread) | |
4625 | { | |
4626 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4627 | struct thread_info *saved_thread; | |
4628 | CORE_ADDR pc; | |
4629 | struct process_info *proc = get_thread_process (thread); | |
4630 | ||
4631 | /* GDBserver is skipping the extra traps from the wrapper program, | |
4632 | don't have to do step over. */ | |
4633 | if (proc->tdesc == NULL) | |
4634 | return false; | |
4635 | ||
4636 | /* LWPs which will not be resumed are not interesting, because we | |
4637 | might not wait for them next time through linux_wait. */ | |
4638 | ||
4639 | if (!lwp->stopped) | |
4640 | { | |
4641 | if (debug_threads) | |
4642 | debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n", | |
4643 | lwpid_of (thread)); | |
4644 | return false; | |
4645 | } | |
4646 | ||
4647 | if (thread->last_resume_kind == resume_stop) | |
4648 | { | |
4649 | if (debug_threads) | |
4650 | debug_printf ("Need step over [LWP %ld]? Ignoring, should remain" | |
4651 | " stopped\n", | |
4652 | lwpid_of (thread)); | |
4653 | return false; | |
4654 | } | |
4655 | ||
4656 | gdb_assert (lwp->suspended >= 0); | |
4657 | ||
4658 | if (lwp->suspended) | |
4659 | { | |
4660 | if (debug_threads) | |
4661 | debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n", | |
4662 | lwpid_of (thread)); | |
4663 | return false; | |
4664 | } | |
4665 | ||
4666 | if (lwp->status_pending_p) | |
4667 | { | |
4668 | if (debug_threads) | |
4669 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" | |
4670 | " status.\n", | |
4671 | lwpid_of (thread)); | |
4672 | return false; | |
4673 | } | |
4674 | ||
4675 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, | |
4676 | or we have. */ | |
4677 | pc = get_pc (lwp); | |
4678 | ||
4679 | /* If the PC has changed since we stopped, then don't do anything, | |
4680 | and let the breakpoint/tracepoint be hit. This happens if, for | |
4681 | instance, GDB handled the decr_pc_after_break subtraction itself, | |
4682 | GDB is OOL stepping this thread, or the user has issued a "jump" | |
4683 | command, or poked thread's registers herself. */ | |
4684 | if (pc != lwp->stop_pc) | |
4685 | { | |
4686 | if (debug_threads) | |
4687 | debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. " | |
4688 | "Old stop_pc was 0x%s, PC is now 0x%s\n", | |
4689 | lwpid_of (thread), | |
4690 | paddress (lwp->stop_pc), paddress (pc)); | |
4691 | return false; | |
4692 | } | |
4693 | ||
4694 | /* On software single step target, resume the inferior with signal | |
4695 | rather than stepping over. */ | |
4696 | if (can_software_single_step () | |
4697 | && lwp->pending_signals != NULL | |
4698 | && lwp_signal_can_be_delivered (lwp)) | |
4699 | { | |
4700 | if (debug_threads) | |
4701 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" | |
4702 | " signals.\n", | |
4703 | lwpid_of (thread)); | |
4704 | ||
4705 | return false; | |
4706 | } | |
4707 | ||
4708 | saved_thread = current_thread; | |
4709 | current_thread = thread; | |
4710 | ||
4711 | /* We can only step over breakpoints we know about. */ | |
4712 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) | |
4713 | { | |
4714 | /* Don't step over a breakpoint that GDB expects to hit | |
4715 | though. If the condition is being evaluated on the target's side | |
4716 | and it evaluate to false, step over this breakpoint as well. */ | |
4717 | if (gdb_breakpoint_here (pc) | |
4718 | && gdb_condition_true_at_breakpoint (pc) | |
4719 | && gdb_no_commands_at_breakpoint (pc)) | |
4720 | { | |
4721 | if (debug_threads) | |
4722 | debug_printf ("Need step over [LWP %ld]? yes, but found" | |
4723 | " GDB breakpoint at 0x%s; skipping step over\n", | |
4724 | lwpid_of (thread), paddress (pc)); | |
4725 | ||
4726 | current_thread = saved_thread; | |
4727 | return false; | |
4728 | } | |
4729 | else | |
4730 | { | |
4731 | if (debug_threads) | |
4732 | debug_printf ("Need step over [LWP %ld]? yes, " | |
4733 | "found breakpoint at 0x%s\n", | |
4734 | lwpid_of (thread), paddress (pc)); | |
4735 | ||
4736 | /* We've found an lwp that needs stepping over --- return 1 so | |
4737 | that find_thread stops looking. */ | |
4738 | current_thread = saved_thread; | |
4739 | ||
4740 | return true; | |
4741 | } | |
4742 | } | |
4743 | ||
4744 | current_thread = saved_thread; | |
4745 | ||
4746 | if (debug_threads) | |
4747 | debug_printf ("Need step over [LWP %ld]? No, no breakpoint found" | |
4748 | " at 0x%s\n", | |
4749 | lwpid_of (thread), paddress (pc)); | |
4750 | ||
4751 | return false; | |
4752 | } | |
4753 | ||
4754 | /* Start a step-over operation on LWP. When LWP stopped at a | |
4755 | breakpoint, to make progress, we need to remove the breakpoint out | |
4756 | of the way. If we let other threads run while we do that, they may | |
4757 | pass by the breakpoint location and miss hitting it. To avoid | |
4758 | that, a step-over momentarily stops all threads while LWP is | |
4759 | single-stepped by either hardware or software while the breakpoint | |
4760 | is temporarily uninserted from the inferior. When the single-step | |
4761 | finishes, we reinsert the breakpoint, and let all threads that are | |
4762 | supposed to be running, run again. */ | |
4763 | ||
4764 | static int | |
4765 | start_step_over (struct lwp_info *lwp) | |
4766 | { | |
4767 | struct thread_info *thread = get_lwp_thread (lwp); | |
4768 | struct thread_info *saved_thread; | |
4769 | CORE_ADDR pc; | |
4770 | int step; | |
4771 | ||
4772 | if (debug_threads) | |
4773 | debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n", | |
4774 | lwpid_of (thread)); | |
4775 | ||
4776 | stop_all_lwps (1, lwp); | |
4777 | ||
4778 | if (lwp->suspended != 0) | |
4779 | { | |
4780 | internal_error (__FILE__, __LINE__, | |
4781 | "LWP %ld suspended=%d\n", lwpid_of (thread), | |
4782 | lwp->suspended); | |
4783 | } | |
4784 | ||
4785 | if (debug_threads) | |
4786 | debug_printf ("Done stopping all threads for step-over.\n"); | |
4787 | ||
4788 | /* Note, we should always reach here with an already adjusted PC, | |
4789 | either by GDB (if we're resuming due to GDB's request), or by our | |
4790 | caller, if we just finished handling an internal breakpoint GDB | |
4791 | shouldn't care about. */ | |
4792 | pc = get_pc (lwp); | |
4793 | ||
4794 | saved_thread = current_thread; | |
4795 | current_thread = thread; | |
4796 | ||
4797 | lwp->bp_reinsert = pc; | |
4798 | uninsert_breakpoints_at (pc); | |
4799 | uninsert_fast_tracepoint_jumps_at (pc); | |
4800 | ||
4801 | step = single_step (lwp); | |
4802 | ||
4803 | current_thread = saved_thread; | |
4804 | ||
4805 | linux_resume_one_lwp (lwp, step, 0, NULL); | |
4806 | ||
4807 | /* Require next event from this LWP. */ | |
4808 | step_over_bkpt = thread->id; | |
4809 | return 1; | |
4810 | } | |
4811 | ||
4812 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in | |
4813 | start_step_over, if still there, and delete any single-step | |
4814 | breakpoints we've set, on non hardware single-step targets. */ | |
4815 | ||
4816 | static int | |
4817 | finish_step_over (struct lwp_info *lwp) | |
4818 | { | |
4819 | if (lwp->bp_reinsert != 0) | |
4820 | { | |
4821 | struct thread_info *saved_thread = current_thread; | |
4822 | ||
4823 | if (debug_threads) | |
4824 | debug_printf ("Finished step over.\n"); | |
4825 | ||
4826 | current_thread = get_lwp_thread (lwp); | |
4827 | ||
4828 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there | |
4829 | may be no breakpoint to reinsert there by now. */ | |
4830 | reinsert_breakpoints_at (lwp->bp_reinsert); | |
4831 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); | |
4832 | ||
4833 | lwp->bp_reinsert = 0; | |
4834 | ||
4835 | /* Delete any single-step breakpoints. No longer needed. We | |
4836 | don't have to worry about other threads hitting this trap, | |
4837 | and later not being able to explain it, because we were | |
4838 | stepping over a breakpoint, and we hold all threads but | |
4839 | LWP stopped while doing that. */ | |
4840 | if (!can_hardware_single_step ()) | |
4841 | { | |
4842 | gdb_assert (has_single_step_breakpoints (current_thread)); | |
4843 | delete_single_step_breakpoints (current_thread); | |
4844 | } | |
4845 | ||
4846 | step_over_bkpt = null_ptid; | |
4847 | current_thread = saved_thread; | |
4848 | return 1; | |
4849 | } | |
4850 | else | |
4851 | return 0; | |
4852 | } | |
4853 | ||
4854 | /* If there's a step over in progress, wait until all threads stop | |
4855 | (that is, until the stepping thread finishes its step), and | |
4856 | unsuspend all lwps. The stepping thread ends with its status | |
4857 | pending, which is processed later when we get back to processing | |
4858 | events. */ | |
4859 | ||
4860 | static void | |
4861 | complete_ongoing_step_over (void) | |
4862 | { | |
4863 | if (step_over_bkpt != null_ptid) | |
4864 | { | |
4865 | struct lwp_info *lwp; | |
4866 | int wstat; | |
4867 | int ret; | |
4868 | ||
4869 | if (debug_threads) | |
4870 | debug_printf ("detach: step over in progress, finish it first\n"); | |
4871 | ||
4872 | /* Passing NULL_PTID as filter indicates we want all events to | |
4873 | be left pending. Eventually this returns when there are no | |
4874 | unwaited-for children left. */ | |
4875 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, | |
4876 | &wstat, __WALL); | |
4877 | gdb_assert (ret == -1); | |
4878 | ||
4879 | lwp = find_lwp_pid (step_over_bkpt); | |
4880 | if (lwp != NULL) | |
4881 | finish_step_over (lwp); | |
4882 | step_over_bkpt = null_ptid; | |
4883 | unsuspend_all_lwps (lwp); | |
4884 | } | |
4885 | } | |
4886 | ||
4887 | /* This function is called once per thread. We check the thread's resume | |
4888 | request, which will tell us whether to resume, step, or leave the thread | |
4889 | stopped; and what signal, if any, it should be sent. | |
4890 | ||
4891 | For threads which we aren't explicitly told otherwise, we preserve | |
4892 | the stepping flag; this is used for stepping over gdbserver-placed | |
4893 | breakpoints. | |
4894 | ||
4895 | If pending_flags was set in any thread, we queue any needed | |
4896 | signals, since we won't actually resume. We already have a pending | |
4897 | event to report, so we don't need to preserve any step requests; | |
4898 | they should be re-issued if necessary. */ | |
4899 | ||
4900 | static void | |
4901 | linux_resume_one_thread (thread_info *thread, bool leave_all_stopped) | |
4902 | { | |
4903 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4904 | int leave_pending; | |
4905 | ||
4906 | if (lwp->resume == NULL) | |
4907 | return; | |
4908 | ||
4909 | if (lwp->resume->kind == resume_stop) | |
4910 | { | |
4911 | if (debug_threads) | |
4912 | debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread)); | |
4913 | ||
4914 | if (!lwp->stopped) | |
4915 | { | |
4916 | if (debug_threads) | |
4917 | debug_printf ("stopping LWP %ld\n", lwpid_of (thread)); | |
4918 | ||
4919 | /* Stop the thread, and wait for the event asynchronously, | |
4920 | through the event loop. */ | |
4921 | send_sigstop (lwp); | |
4922 | } | |
4923 | else | |
4924 | { | |
4925 | if (debug_threads) | |
4926 | debug_printf ("already stopped LWP %ld\n", | |
4927 | lwpid_of (thread)); | |
4928 | ||
4929 | /* The LWP may have been stopped in an internal event that | |
4930 | was not meant to be notified back to GDB (e.g., gdbserver | |
4931 | breakpoint), so we should be reporting a stop event in | |
4932 | this case too. */ | |
4933 | ||
4934 | /* If the thread already has a pending SIGSTOP, this is a | |
4935 | no-op. Otherwise, something later will presumably resume | |
4936 | the thread and this will cause it to cancel any pending | |
4937 | operation, due to last_resume_kind == resume_stop. If | |
4938 | the thread already has a pending status to report, we | |
4939 | will still report it the next time we wait - see | |
4940 | status_pending_p_callback. */ | |
4941 | ||
4942 | /* If we already have a pending signal to report, then | |
4943 | there's no need to queue a SIGSTOP, as this means we're | |
4944 | midway through moving the LWP out of the jumppad, and we | |
4945 | will report the pending signal as soon as that is | |
4946 | finished. */ | |
4947 | if (lwp->pending_signals_to_report == NULL) | |
4948 | send_sigstop (lwp); | |
4949 | } | |
4950 | ||
4951 | /* For stop requests, we're done. */ | |
4952 | lwp->resume = NULL; | |
4953 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; | |
4954 | return; | |
4955 | } | |
4956 | ||
4957 | /* If this thread which is about to be resumed has a pending status, | |
4958 | then don't resume it - we can just report the pending status. | |
4959 | Likewise if it is suspended, because e.g., another thread is | |
4960 | stepping past a breakpoint. Make sure to queue any signals that | |
4961 | would otherwise be sent. In all-stop mode, we do this decision | |
4962 | based on if *any* thread has a pending status. If there's a | |
4963 | thread that needs the step-over-breakpoint dance, then don't | |
4964 | resume any other thread but that particular one. */ | |
4965 | leave_pending = (lwp->suspended | |
4966 | || lwp->status_pending_p | |
4967 | || leave_all_stopped); | |
4968 | ||
4969 | /* If we have a new signal, enqueue the signal. */ | |
4970 | if (lwp->resume->sig != 0) | |
4971 | { | |
4972 | siginfo_t info, *info_p; | |
4973 | ||
4974 | /* If this is the same signal we were previously stopped by, | |
4975 | make sure to queue its siginfo. */ | |
4976 | if (WIFSTOPPED (lwp->last_status) | |
4977 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig | |
4978 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), | |
4979 | (PTRACE_TYPE_ARG3) 0, &info) == 0) | |
4980 | info_p = &info; | |
4981 | else | |
4982 | info_p = NULL; | |
4983 | ||
4984 | enqueue_pending_signal (lwp, lwp->resume->sig, info_p); | |
4985 | } | |
4986 | ||
4987 | if (!leave_pending) | |
4988 | { | |
4989 | if (debug_threads) | |
4990 | debug_printf ("resuming LWP %ld\n", lwpid_of (thread)); | |
4991 | ||
4992 | proceed_one_lwp (thread, NULL); | |
4993 | } | |
4994 | else | |
4995 | { | |
4996 | if (debug_threads) | |
4997 | debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread)); | |
4998 | } | |
4999 | ||
5000 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; | |
5001 | lwp->resume = NULL; | |
5002 | } | |
5003 | ||
5004 | static void | |
5005 | linux_resume (struct thread_resume *resume_info, size_t n) | |
5006 | { | |
5007 | struct thread_info *need_step_over = NULL; | |
5008 | ||
5009 | if (debug_threads) | |
5010 | { | |
5011 | debug_enter (); | |
5012 | debug_printf ("linux_resume:\n"); | |
5013 | } | |
5014 | ||
5015 | for_each_thread ([&] (thread_info *thread) | |
5016 | { | |
5017 | linux_set_resume_request (thread, resume_info, n); | |
5018 | }); | |
5019 | ||
5020 | /* If there is a thread which would otherwise be resumed, which has | |
5021 | a pending status, then don't resume any threads - we can just | |
5022 | report the pending status. Make sure to queue any signals that | |
5023 | would otherwise be sent. In non-stop mode, we'll apply this | |
5024 | logic to each thread individually. We consume all pending events | |
5025 | before considering to start a step-over (in all-stop). */ | |
5026 | bool any_pending = false; | |
5027 | if (!non_stop) | |
5028 | any_pending = find_thread (resume_status_pending_p) != NULL; | |
5029 | ||
5030 | /* If there is a thread which would otherwise be resumed, which is | |
5031 | stopped at a breakpoint that needs stepping over, then don't | |
5032 | resume any threads - have it step over the breakpoint with all | |
5033 | other threads stopped, then resume all threads again. Make sure | |
5034 | to queue any signals that would otherwise be delivered or | |
5035 | queued. */ | |
5036 | if (!any_pending && supports_breakpoints ()) | |
5037 | need_step_over = find_thread (need_step_over_p); | |
5038 | ||
5039 | bool leave_all_stopped = (need_step_over != NULL || any_pending); | |
5040 | ||
5041 | if (debug_threads) | |
5042 | { | |
5043 | if (need_step_over != NULL) | |
5044 | debug_printf ("Not resuming all, need step over\n"); | |
5045 | else if (any_pending) | |
5046 | debug_printf ("Not resuming, all-stop and found " | |
5047 | "an LWP with pending status\n"); | |
5048 | else | |
5049 | debug_printf ("Resuming, no pending status or step over needed\n"); | |
5050 | } | |
5051 | ||
5052 | /* Even if we're leaving threads stopped, queue all signals we'd | |
5053 | otherwise deliver. */ | |
5054 | for_each_thread ([&] (thread_info *thread) | |
5055 | { | |
5056 | linux_resume_one_thread (thread, leave_all_stopped); | |
5057 | }); | |
5058 | ||
5059 | if (need_step_over) | |
5060 | start_step_over (get_thread_lwp (need_step_over)); | |
5061 | ||
5062 | if (debug_threads) | |
5063 | { | |
5064 | debug_printf ("linux_resume done\n"); | |
5065 | debug_exit (); | |
5066 | } | |
5067 | ||
5068 | /* We may have events that were pending that can/should be sent to | |
5069 | the client now. Trigger a linux_wait call. */ | |
5070 | if (target_is_async_p ()) | |
5071 | async_file_mark (); | |
5072 | } | |
5073 | ||
5074 | /* This function is called once per thread. We check the thread's | |
5075 | last resume request, which will tell us whether to resume, step, or | |
5076 | leave the thread stopped. Any signal the client requested to be | |
5077 | delivered has already been enqueued at this point. | |
5078 | ||
5079 | If any thread that GDB wants running is stopped at an internal | |
5080 | breakpoint that needs stepping over, we start a step-over operation | |
5081 | on that particular thread, and leave all others stopped. */ | |
5082 | ||
5083 | static void | |
5084 | proceed_one_lwp (thread_info *thread, lwp_info *except) | |
5085 | { | |
5086 | struct lwp_info *lwp = get_thread_lwp (thread); | |
5087 | int step; | |
5088 | ||
5089 | if (lwp == except) | |
5090 | return; | |
5091 | ||
5092 | if (debug_threads) | |
5093 | debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread)); | |
5094 | ||
5095 | if (!lwp->stopped) | |
5096 | { | |
5097 | if (debug_threads) | |
5098 | debug_printf (" LWP %ld already running\n", lwpid_of (thread)); | |
5099 | return; | |
5100 | } | |
5101 | ||
5102 | if (thread->last_resume_kind == resume_stop | |
5103 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) | |
5104 | { | |
5105 | if (debug_threads) | |
5106 | debug_printf (" client wants LWP to remain %ld stopped\n", | |
5107 | lwpid_of (thread)); | |
5108 | return; | |
5109 | } | |
5110 | ||
5111 | if (lwp->status_pending_p) | |
5112 | { | |
5113 | if (debug_threads) | |
5114 | debug_printf (" LWP %ld has pending status, leaving stopped\n", | |
5115 | lwpid_of (thread)); | |
5116 | return; | |
5117 | } | |
5118 | ||
5119 | gdb_assert (lwp->suspended >= 0); | |
5120 | ||
5121 | if (lwp->suspended) | |
5122 | { | |
5123 | if (debug_threads) | |
5124 | debug_printf (" LWP %ld is suspended\n", lwpid_of (thread)); | |
5125 | return; | |
5126 | } | |
5127 | ||
5128 | if (thread->last_resume_kind == resume_stop | |
5129 | && lwp->pending_signals_to_report == NULL | |
5130 | && (lwp->collecting_fast_tracepoint | |
5131 | == fast_tpoint_collect_result::not_collecting)) | |
5132 | { | |
5133 | /* We haven't reported this LWP as stopped yet (otherwise, the | |
5134 | last_status.kind check above would catch it, and we wouldn't | |
5135 | reach here. This LWP may have been momentarily paused by a | |
5136 | stop_all_lwps call while handling for example, another LWP's | |
5137 | step-over. In that case, the pending expected SIGSTOP signal | |
5138 | that was queued at vCont;t handling time will have already | |
5139 | been consumed by wait_for_sigstop, and so we need to requeue | |
5140 | another one here. Note that if the LWP already has a SIGSTOP | |
5141 | pending, this is a no-op. */ | |
5142 | ||
5143 | if (debug_threads) | |
5144 | debug_printf ("Client wants LWP %ld to stop. " | |
5145 | "Making sure it has a SIGSTOP pending\n", | |
5146 | lwpid_of (thread)); | |
5147 | ||
5148 | send_sigstop (lwp); | |
5149 | } | |
5150 | ||
5151 | if (thread->last_resume_kind == resume_step) | |
5152 | { | |
5153 | if (debug_threads) | |
5154 | debug_printf (" stepping LWP %ld, client wants it stepping\n", | |
5155 | lwpid_of (thread)); | |
5156 | ||
5157 | /* If resume_step is requested by GDB, install single-step | |
5158 | breakpoints when the thread is about to be actually resumed if | |
5159 | the single-step breakpoints weren't removed. */ | |
5160 | if (can_software_single_step () | |
5161 | && !has_single_step_breakpoints (thread)) | |
5162 | install_software_single_step_breakpoints (lwp); | |
5163 | ||
5164 | step = maybe_hw_step (thread); | |
5165 | } | |
5166 | else if (lwp->bp_reinsert != 0) | |
5167 | { | |
5168 | if (debug_threads) | |
5169 | debug_printf (" stepping LWP %ld, reinsert set\n", | |
5170 | lwpid_of (thread)); | |
5171 | ||
5172 | step = maybe_hw_step (thread); | |
5173 | } | |
5174 | else | |
5175 | step = 0; | |
5176 | ||
5177 | linux_resume_one_lwp (lwp, step, 0, NULL); | |
5178 | } | |
5179 | ||
5180 | static void | |
5181 | unsuspend_and_proceed_one_lwp (thread_info *thread, lwp_info *except) | |
5182 | { | |
5183 | struct lwp_info *lwp = get_thread_lwp (thread); | |
5184 | ||
5185 | if (lwp == except) | |
5186 | return; | |
5187 | ||
5188 | lwp_suspended_decr (lwp); | |
5189 | ||
5190 | proceed_one_lwp (thread, except); | |
5191 | } | |
5192 | ||
5193 | /* When we finish a step-over, set threads running again. If there's | |
5194 | another thread that may need a step-over, now's the time to start | |
5195 | it. Eventually, we'll move all threads past their breakpoints. */ | |
5196 | ||
5197 | static void | |
5198 | proceed_all_lwps (void) | |
5199 | { | |
5200 | struct thread_info *need_step_over; | |
5201 | ||
5202 | /* If there is a thread which would otherwise be resumed, which is | |
5203 | stopped at a breakpoint that needs stepping over, then don't | |
5204 | resume any threads - have it step over the breakpoint with all | |
5205 | other threads stopped, then resume all threads again. */ | |
5206 | ||
5207 | if (supports_breakpoints ()) | |
5208 | { | |
5209 | need_step_over = find_thread (need_step_over_p); | |
5210 | ||
5211 | if (need_step_over != NULL) | |
5212 | { | |
5213 | if (debug_threads) | |
5214 | debug_printf ("proceed_all_lwps: found " | |
5215 | "thread %ld needing a step-over\n", | |
5216 | lwpid_of (need_step_over)); | |
5217 | ||
5218 | start_step_over (get_thread_lwp (need_step_over)); | |
5219 | return; | |
5220 | } | |
5221 | } | |
5222 | ||
5223 | if (debug_threads) | |
5224 | debug_printf ("Proceeding, no step-over needed\n"); | |
5225 | ||
5226 | for_each_thread ([] (thread_info *thread) | |
5227 | { | |
5228 | proceed_one_lwp (thread, NULL); | |
5229 | }); | |
5230 | } | |
5231 | ||
5232 | /* Stopped LWPs that the client wanted to be running, that don't have | |
5233 | pending statuses, are set to run again, except for EXCEPT, if not | |
5234 | NULL. This undoes a stop_all_lwps call. */ | |
5235 | ||
5236 | static void | |
5237 | unstop_all_lwps (int unsuspend, struct lwp_info *except) | |
5238 | { | |
5239 | if (debug_threads) | |
5240 | { | |
5241 | debug_enter (); | |
5242 | if (except) | |
5243 | debug_printf ("unstopping all lwps, except=(LWP %ld)\n", | |
5244 | lwpid_of (get_lwp_thread (except))); | |
5245 | else | |
5246 | debug_printf ("unstopping all lwps\n"); | |
5247 | } | |
5248 | ||
5249 | if (unsuspend) | |
5250 | for_each_thread ([&] (thread_info *thread) | |
5251 | { | |
5252 | unsuspend_and_proceed_one_lwp (thread, except); | |
5253 | }); | |
5254 | else | |
5255 | for_each_thread ([&] (thread_info *thread) | |
5256 | { | |
5257 | proceed_one_lwp (thread, except); | |
5258 | }); | |
5259 | ||
5260 | if (debug_threads) | |
5261 | { | |
5262 | debug_printf ("unstop_all_lwps done\n"); | |
5263 | debug_exit (); | |
5264 | } | |
5265 | } | |
5266 | ||
5267 | ||
5268 | #ifdef HAVE_LINUX_REGSETS | |
5269 | ||
5270 | #define use_linux_regsets 1 | |
5271 | ||
5272 | /* Returns true if REGSET has been disabled. */ | |
5273 | ||
5274 | static int | |
5275 | regset_disabled (struct regsets_info *info, struct regset_info *regset) | |
5276 | { | |
5277 | return (info->disabled_regsets != NULL | |
5278 | && info->disabled_regsets[regset - info->regsets]); | |
5279 | } | |
5280 | ||
5281 | /* Disable REGSET. */ | |
5282 | ||
5283 | static void | |
5284 | disable_regset (struct regsets_info *info, struct regset_info *regset) | |
5285 | { | |
5286 | int dr_offset; | |
5287 | ||
5288 | dr_offset = regset - info->regsets; | |
5289 | if (info->disabled_regsets == NULL) | |
5290 | info->disabled_regsets = (char *) xcalloc (1, info->num_regsets); | |
5291 | info->disabled_regsets[dr_offset] = 1; | |
5292 | } | |
5293 | ||
5294 | static int | |
5295 | regsets_fetch_inferior_registers (struct regsets_info *regsets_info, | |
5296 | struct regcache *regcache) | |
5297 | { | |
5298 | struct regset_info *regset; | |
5299 | int saw_general_regs = 0; | |
5300 | int pid; | |
5301 | struct iovec iov; | |
5302 | ||
5303 | pid = lwpid_of (current_thread); | |
5304 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) | |
5305 | { | |
5306 | void *buf, *data; | |
5307 | int nt_type, res; | |
5308 | ||
5309 | if (regset->size == 0 || regset_disabled (regsets_info, regset)) | |
5310 | continue; | |
5311 | ||
5312 | buf = xmalloc (regset->size); | |
5313 | ||
5314 | nt_type = regset->nt_type; | |
5315 | if (nt_type) | |
5316 | { | |
5317 | iov.iov_base = buf; | |
5318 | iov.iov_len = regset->size; | |
5319 | data = (void *) &iov; | |
5320 | } | |
5321 | else | |
5322 | data = buf; | |
5323 | ||
5324 | #ifndef __sparc__ | |
5325 | res = ptrace (regset->get_request, pid, | |
5326 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
5327 | #else | |
5328 | res = ptrace (regset->get_request, pid, data, nt_type); | |
5329 | #endif | |
5330 | if (res < 0) | |
5331 | { | |
5332 | if (errno == EIO | |
5333 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) | |
5334 | { | |
5335 | /* If we get EIO on a regset, or an EINVAL and the regset is | |
5336 | optional, do not try it again for this process mode. */ | |
5337 | disable_regset (regsets_info, regset); | |
5338 | } | |
5339 | else if (errno == ENODATA) | |
5340 | { | |
5341 | /* ENODATA may be returned if the regset is currently | |
5342 | not "active". This can happen in normal operation, | |
5343 | so suppress the warning in this case. */ | |
5344 | } | |
5345 | else if (errno == ESRCH) | |
5346 | { | |
5347 | /* At this point, ESRCH should mean the process is | |
5348 | already gone, in which case we simply ignore attempts | |
5349 | to read its registers. */ | |
5350 | } | |
5351 | else | |
5352 | { | |
5353 | char s[256]; | |
5354 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", | |
5355 | pid); | |
5356 | perror (s); | |
5357 | } | |
5358 | } | |
5359 | else | |
5360 | { | |
5361 | if (regset->type == GENERAL_REGS) | |
5362 | saw_general_regs = 1; | |
5363 | regset->store_function (regcache, buf); | |
5364 | } | |
5365 | free (buf); | |
5366 | } | |
5367 | if (saw_general_regs) | |
5368 | return 0; | |
5369 | else | |
5370 | return 1; | |
5371 | } | |
5372 | ||
5373 | static int | |
5374 | regsets_store_inferior_registers (struct regsets_info *regsets_info, | |
5375 | struct regcache *regcache) | |
5376 | { | |
5377 | struct regset_info *regset; | |
5378 | int saw_general_regs = 0; | |
5379 | int pid; | |
5380 | struct iovec iov; | |
5381 | ||
5382 | pid = lwpid_of (current_thread); | |
5383 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) | |
5384 | { | |
5385 | void *buf, *data; | |
5386 | int nt_type, res; | |
5387 | ||
5388 | if (regset->size == 0 || regset_disabled (regsets_info, regset) | |
5389 | || regset->fill_function == NULL) | |
5390 | continue; | |
5391 | ||
5392 | buf = xmalloc (regset->size); | |
5393 | ||
5394 | /* First fill the buffer with the current register set contents, | |
5395 | in case there are any items in the kernel's regset that are | |
5396 | not in gdbserver's regcache. */ | |
5397 | ||
5398 | nt_type = regset->nt_type; | |
5399 | if (nt_type) | |
5400 | { | |
5401 | iov.iov_base = buf; | |
5402 | iov.iov_len = regset->size; | |
5403 | data = (void *) &iov; | |
5404 | } | |
5405 | else | |
5406 | data = buf; | |
5407 | ||
5408 | #ifndef __sparc__ | |
5409 | res = ptrace (regset->get_request, pid, | |
5410 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
5411 | #else | |
5412 | res = ptrace (regset->get_request, pid, data, nt_type); | |
5413 | #endif | |
5414 | ||
5415 | if (res == 0) | |
5416 | { | |
5417 | /* Then overlay our cached registers on that. */ | |
5418 | regset->fill_function (regcache, buf); | |
5419 | ||
5420 | /* Only now do we write the register set. */ | |
5421 | #ifndef __sparc__ | |
5422 | res = ptrace (regset->set_request, pid, | |
5423 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
5424 | #else | |
5425 | res = ptrace (regset->set_request, pid, data, nt_type); | |
5426 | #endif | |
5427 | } | |
5428 | ||
5429 | if (res < 0) | |
5430 | { | |
5431 | if (errno == EIO | |
5432 | || (errno == EINVAL && regset->type == OPTIONAL_REGS)) | |
5433 | { | |
5434 | /* If we get EIO on a regset, or an EINVAL and the regset is | |
5435 | optional, do not try it again for this process mode. */ | |
5436 | disable_regset (regsets_info, regset); | |
5437 | } | |
5438 | else if (errno == ESRCH) | |
5439 | { | |
5440 | /* At this point, ESRCH should mean the process is | |
5441 | already gone, in which case we simply ignore attempts | |
5442 | to change its registers. See also the related | |
5443 | comment in linux_resume_one_lwp. */ | |
5444 | free (buf); | |
5445 | return 0; | |
5446 | } | |
5447 | else | |
5448 | { | |
5449 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); | |
5450 | } | |
5451 | } | |
5452 | else if (regset->type == GENERAL_REGS) | |
5453 | saw_general_regs = 1; | |
5454 | free (buf); | |
5455 | } | |
5456 | if (saw_general_regs) | |
5457 | return 0; | |
5458 | else | |
5459 | return 1; | |
5460 | } | |
5461 | ||
5462 | #else /* !HAVE_LINUX_REGSETS */ | |
5463 | ||
5464 | #define use_linux_regsets 0 | |
5465 | #define regsets_fetch_inferior_registers(regsets_info, regcache) 1 | |
5466 | #define regsets_store_inferior_registers(regsets_info, regcache) 1 | |
5467 | ||
5468 | #endif | |
5469 | ||
5470 | /* Return 1 if register REGNO is supported by one of the regset ptrace | |
5471 | calls or 0 if it has to be transferred individually. */ | |
5472 | ||
5473 | static int | |
5474 | linux_register_in_regsets (const struct regs_info *regs_info, int regno) | |
5475 | { | |
5476 | unsigned char mask = 1 << (regno % 8); | |
5477 | size_t index = regno / 8; | |
5478 | ||
5479 | return (use_linux_regsets | |
5480 | && (regs_info->regset_bitmap == NULL | |
5481 | || (regs_info->regset_bitmap[index] & mask) != 0)); | |
5482 | } | |
5483 | ||
5484 | #ifdef HAVE_LINUX_USRREGS | |
5485 | ||
5486 | static int | |
5487 | register_addr (const struct usrregs_info *usrregs, int regnum) | |
5488 | { | |
5489 | int addr; | |
5490 | ||
5491 | if (regnum < 0 || regnum >= usrregs->num_regs) | |
5492 | error ("Invalid register number %d.", regnum); | |
5493 | ||
5494 | addr = usrregs->regmap[regnum]; | |
5495 | ||
5496 | return addr; | |
5497 | } | |
5498 | ||
5499 | /* Fetch one register. */ | |
5500 | static void | |
5501 | fetch_register (const struct usrregs_info *usrregs, | |
5502 | struct regcache *regcache, int regno) | |
5503 | { | |
5504 | CORE_ADDR regaddr; | |
5505 | int i, size; | |
5506 | char *buf; | |
5507 | int pid; | |
5508 | ||
5509 | if (regno >= usrregs->num_regs) | |
5510 | return; | |
5511 | if ((*the_low_target.cannot_fetch_register) (regno)) | |
5512 | return; | |
5513 | ||
5514 | regaddr = register_addr (usrregs, regno); | |
5515 | if (regaddr == -1) | |
5516 | return; | |
5517 | ||
5518 | size = ((register_size (regcache->tdesc, regno) | |
5519 | + sizeof (PTRACE_XFER_TYPE) - 1) | |
5520 | & -sizeof (PTRACE_XFER_TYPE)); | |
5521 | buf = (char *) alloca (size); | |
5522 | ||
5523 | pid = lwpid_of (current_thread); | |
5524 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
5525 | { | |
5526 | errno = 0; | |
5527 | *(PTRACE_XFER_TYPE *) (buf + i) = | |
5528 | ptrace (PTRACE_PEEKUSER, pid, | |
5529 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5530 | of coercing an 8 byte integer to a 4 byte pointer. */ | |
5531 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0); | |
5532 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
5533 | if (errno != 0) | |
5534 | { | |
5535 | /* Mark register REGNO unavailable. */ | |
5536 | supply_register (regcache, regno, NULL); | |
5537 | return; | |
5538 | } | |
5539 | } | |
5540 | ||
5541 | if (the_low_target.supply_ptrace_register) | |
5542 | the_low_target.supply_ptrace_register (regcache, regno, buf); | |
5543 | else | |
5544 | supply_register (regcache, regno, buf); | |
5545 | } | |
5546 | ||
5547 | /* Store one register. */ | |
5548 | static void | |
5549 | store_register (const struct usrregs_info *usrregs, | |
5550 | struct regcache *regcache, int regno) | |
5551 | { | |
5552 | CORE_ADDR regaddr; | |
5553 | int i, size; | |
5554 | char *buf; | |
5555 | int pid; | |
5556 | ||
5557 | if (regno >= usrregs->num_regs) | |
5558 | return; | |
5559 | if ((*the_low_target.cannot_store_register) (regno)) | |
5560 | return; | |
5561 | ||
5562 | regaddr = register_addr (usrregs, regno); | |
5563 | if (regaddr == -1) | |
5564 | return; | |
5565 | ||
5566 | size = ((register_size (regcache->tdesc, regno) | |
5567 | + sizeof (PTRACE_XFER_TYPE) - 1) | |
5568 | & -sizeof (PTRACE_XFER_TYPE)); | |
5569 | buf = (char *) alloca (size); | |
5570 | memset (buf, 0, size); | |
5571 | ||
5572 | if (the_low_target.collect_ptrace_register) | |
5573 | the_low_target.collect_ptrace_register (regcache, regno, buf); | |
5574 | else | |
5575 | collect_register (regcache, regno, buf); | |
5576 | ||
5577 | pid = lwpid_of (current_thread); | |
5578 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
5579 | { | |
5580 | errno = 0; | |
5581 | ptrace (PTRACE_POKEUSER, pid, | |
5582 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5583 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5584 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, | |
5585 | (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i)); | |
5586 | if (errno != 0) | |
5587 | { | |
5588 | /* At this point, ESRCH should mean the process is | |
5589 | already gone, in which case we simply ignore attempts | |
5590 | to change its registers. See also the related | |
5591 | comment in linux_resume_one_lwp. */ | |
5592 | if (errno == ESRCH) | |
5593 | return; | |
5594 | ||
5595 | if ((*the_low_target.cannot_store_register) (regno) == 0) | |
5596 | error ("writing register %d: %s", regno, strerror (errno)); | |
5597 | } | |
5598 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
5599 | } | |
5600 | } | |
5601 | ||
5602 | /* Fetch all registers, or just one, from the child process. | |
5603 | If REGNO is -1, do this for all registers, skipping any that are | |
5604 | assumed to have been retrieved by regsets_fetch_inferior_registers, | |
5605 | unless ALL is non-zero. | |
5606 | Otherwise, REGNO specifies which register (so we can save time). */ | |
5607 | static void | |
5608 | usr_fetch_inferior_registers (const struct regs_info *regs_info, | |
5609 | struct regcache *regcache, int regno, int all) | |
5610 | { | |
5611 | struct usrregs_info *usr = regs_info->usrregs; | |
5612 | ||
5613 | if (regno == -1) | |
5614 | { | |
5615 | for (regno = 0; regno < usr->num_regs; regno++) | |
5616 | if (all || !linux_register_in_regsets (regs_info, regno)) | |
5617 | fetch_register (usr, regcache, regno); | |
5618 | } | |
5619 | else | |
5620 | fetch_register (usr, regcache, regno); | |
5621 | } | |
5622 | ||
5623 | /* Store our register values back into the inferior. | |
5624 | If REGNO is -1, do this for all registers, skipping any that are | |
5625 | assumed to have been saved by regsets_store_inferior_registers, | |
5626 | unless ALL is non-zero. | |
5627 | Otherwise, REGNO specifies which register (so we can save time). */ | |
5628 | static void | |
5629 | usr_store_inferior_registers (const struct regs_info *regs_info, | |
5630 | struct regcache *regcache, int regno, int all) | |
5631 | { | |
5632 | struct usrregs_info *usr = regs_info->usrregs; | |
5633 | ||
5634 | if (regno == -1) | |
5635 | { | |
5636 | for (regno = 0; regno < usr->num_regs; regno++) | |
5637 | if (all || !linux_register_in_regsets (regs_info, regno)) | |
5638 | store_register (usr, regcache, regno); | |
5639 | } | |
5640 | else | |
5641 | store_register (usr, regcache, regno); | |
5642 | } | |
5643 | ||
5644 | #else /* !HAVE_LINUX_USRREGS */ | |
5645 | ||
5646 | #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0) | |
5647 | #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0) | |
5648 | ||
5649 | #endif | |
5650 | ||
5651 | ||
5652 | static void | |
5653 | linux_fetch_registers (struct regcache *regcache, int regno) | |
5654 | { | |
5655 | int use_regsets; | |
5656 | int all = 0; | |
5657 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); | |
5658 | ||
5659 | if (regno == -1) | |
5660 | { | |
5661 | if (the_low_target.fetch_register != NULL | |
5662 | && regs_info->usrregs != NULL) | |
5663 | for (regno = 0; regno < regs_info->usrregs->num_regs; regno++) | |
5664 | (*the_low_target.fetch_register) (regcache, regno); | |
5665 | ||
5666 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache); | |
5667 | if (regs_info->usrregs != NULL) | |
5668 | usr_fetch_inferior_registers (regs_info, regcache, -1, all); | |
5669 | } | |
5670 | else | |
5671 | { | |
5672 | if (the_low_target.fetch_register != NULL | |
5673 | && (*the_low_target.fetch_register) (regcache, regno)) | |
5674 | return; | |
5675 | ||
5676 | use_regsets = linux_register_in_regsets (regs_info, regno); | |
5677 | if (use_regsets) | |
5678 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, | |
5679 | regcache); | |
5680 | if ((!use_regsets || all) && regs_info->usrregs != NULL) | |
5681 | usr_fetch_inferior_registers (regs_info, regcache, regno, 1); | |
5682 | } | |
5683 | } | |
5684 | ||
5685 | static void | |
5686 | linux_store_registers (struct regcache *regcache, int regno) | |
5687 | { | |
5688 | int use_regsets; | |
5689 | int all = 0; | |
5690 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); | |
5691 | ||
5692 | if (regno == -1) | |
5693 | { | |
5694 | all = regsets_store_inferior_registers (regs_info->regsets_info, | |
5695 | regcache); | |
5696 | if (regs_info->usrregs != NULL) | |
5697 | usr_store_inferior_registers (regs_info, regcache, regno, all); | |
5698 | } | |
5699 | else | |
5700 | { | |
5701 | use_regsets = linux_register_in_regsets (regs_info, regno); | |
5702 | if (use_regsets) | |
5703 | all = regsets_store_inferior_registers (regs_info->regsets_info, | |
5704 | regcache); | |
5705 | if ((!use_regsets || all) && regs_info->usrregs != NULL) | |
5706 | usr_store_inferior_registers (regs_info, regcache, regno, 1); | |
5707 | } | |
5708 | } | |
5709 | ||
5710 | ||
5711 | /* Copy LEN bytes from inferior's memory starting at MEMADDR | |
5712 | to debugger memory starting at MYADDR. */ | |
5713 | ||
5714 | static int | |
5715 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) | |
5716 | { | |
5717 | int pid = lwpid_of (current_thread); | |
5718 | PTRACE_XFER_TYPE *buffer; | |
5719 | CORE_ADDR addr; | |
5720 | int count; | |
5721 | char filename[64]; | |
5722 | int i; | |
5723 | int ret; | |
5724 | int fd; | |
5725 | ||
5726 | /* Try using /proc. Don't bother for one word. */ | |
5727 | if (len >= 3 * sizeof (long)) | |
5728 | { | |
5729 | int bytes; | |
5730 | ||
5731 | /* We could keep this file open and cache it - possibly one per | |
5732 | thread. That requires some juggling, but is even faster. */ | |
5733 | sprintf (filename, "/proc/%d/mem", pid); | |
5734 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
5735 | if (fd == -1) | |
5736 | goto no_proc; | |
5737 | ||
5738 | /* If pread64 is available, use it. It's faster if the kernel | |
5739 | supports it (only one syscall), and it's 64-bit safe even on | |
5740 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
5741 | application). */ | |
5742 | #ifdef HAVE_PREAD64 | |
5743 | bytes = pread64 (fd, myaddr, len, memaddr); | |
5744 | #else | |
5745 | bytes = -1; | |
5746 | if (lseek (fd, memaddr, SEEK_SET) != -1) | |
5747 | bytes = read (fd, myaddr, len); | |
5748 | #endif | |
5749 | ||
5750 | close (fd); | |
5751 | if (bytes == len) | |
5752 | return 0; | |
5753 | ||
5754 | /* Some data was read, we'll try to get the rest with ptrace. */ | |
5755 | if (bytes > 0) | |
5756 | { | |
5757 | memaddr += bytes; | |
5758 | myaddr += bytes; | |
5759 | len -= bytes; | |
5760 | } | |
5761 | } | |
5762 | ||
5763 | no_proc: | |
5764 | /* Round starting address down to longword boundary. */ | |
5765 | addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
5766 | /* Round ending address up; get number of longwords that makes. */ | |
5767 | count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
5768 | / sizeof (PTRACE_XFER_TYPE)); | |
5769 | /* Allocate buffer of that many longwords. */ | |
5770 | buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); | |
5771 | ||
5772 | /* Read all the longwords */ | |
5773 | errno = 0; | |
5774 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
5775 | { | |
5776 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning | |
5777 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5778 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, | |
5779 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5780 | (PTRACE_TYPE_ARG4) 0); | |
5781 | if (errno) | |
5782 | break; | |
5783 | } | |
5784 | ret = errno; | |
5785 | ||
5786 | /* Copy appropriate bytes out of the buffer. */ | |
5787 | if (i > 0) | |
5788 | { | |
5789 | i *= sizeof (PTRACE_XFER_TYPE); | |
5790 | i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1); | |
5791 | memcpy (myaddr, | |
5792 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), | |
5793 | i < len ? i : len); | |
5794 | } | |
5795 | ||
5796 | return ret; | |
5797 | } | |
5798 | ||
5799 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's | |
5800 | memory at MEMADDR. On failure (cannot write to the inferior) | |
5801 | returns the value of errno. Always succeeds if LEN is zero. */ | |
5802 | ||
5803 | static int | |
5804 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) | |
5805 | { | |
5806 | int i; | |
5807 | /* Round starting address down to longword boundary. */ | |
5808 | CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
5809 | /* Round ending address up; get number of longwords that makes. */ | |
5810 | int count | |
5811 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
5812 | / sizeof (PTRACE_XFER_TYPE); | |
5813 | ||
5814 | /* Allocate buffer of that many longwords. */ | |
5815 | PTRACE_XFER_TYPE *buffer = XALLOCAVEC (PTRACE_XFER_TYPE, count); | |
5816 | ||
5817 | int pid = lwpid_of (current_thread); | |
5818 | ||
5819 | if (len == 0) | |
5820 | { | |
5821 | /* Zero length write always succeeds. */ | |
5822 | return 0; | |
5823 | } | |
5824 | ||
5825 | if (debug_threads) | |
5826 | { | |
5827 | /* Dump up to four bytes. */ | |
5828 | char str[4 * 2 + 1]; | |
5829 | char *p = str; | |
5830 | int dump = len < 4 ? len : 4; | |
5831 | ||
5832 | for (i = 0; i < dump; i++) | |
5833 | { | |
5834 | sprintf (p, "%02x", myaddr[i]); | |
5835 | p += 2; | |
5836 | } | |
5837 | *p = '\0'; | |
5838 | ||
5839 | debug_printf ("Writing %s to 0x%08lx in process %d\n", | |
5840 | str, (long) memaddr, pid); | |
5841 | } | |
5842 | ||
5843 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
5844 | ||
5845 | errno = 0; | |
5846 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning | |
5847 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5848 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, | |
5849 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5850 | (PTRACE_TYPE_ARG4) 0); | |
5851 | if (errno) | |
5852 | return errno; | |
5853 | ||
5854 | if (count > 1) | |
5855 | { | |
5856 | errno = 0; | |
5857 | buffer[count - 1] | |
5858 | = ptrace (PTRACE_PEEKTEXT, pid, | |
5859 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5860 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5861 | (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1) | |
5862 | * sizeof (PTRACE_XFER_TYPE)), | |
5863 | (PTRACE_TYPE_ARG4) 0); | |
5864 | if (errno) | |
5865 | return errno; | |
5866 | } | |
5867 | ||
5868 | /* Copy data to be written over corresponding part of buffer. */ | |
5869 | ||
5870 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), | |
5871 | myaddr, len); | |
5872 | ||
5873 | /* Write the entire buffer. */ | |
5874 | ||
5875 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
5876 | { | |
5877 | errno = 0; | |
5878 | ptrace (PTRACE_POKETEXT, pid, | |
5879 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5880 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5881 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5882 | (PTRACE_TYPE_ARG4) buffer[i]); | |
5883 | if (errno) | |
5884 | return errno; | |
5885 | } | |
5886 | ||
5887 | return 0; | |
5888 | } | |
5889 | ||
5890 | static void | |
5891 | linux_look_up_symbols (void) | |
5892 | { | |
5893 | #ifdef USE_THREAD_DB | |
5894 | struct process_info *proc = current_process (); | |
5895 | ||
5896 | if (proc->priv->thread_db != NULL) | |
5897 | return; | |
5898 | ||
5899 | thread_db_init (); | |
5900 | #endif | |
5901 | } | |
5902 | ||
5903 | static void | |
5904 | linux_request_interrupt (void) | |
5905 | { | |
5906 | /* Send a SIGINT to the process group. This acts just like the user | |
5907 | typed a ^C on the controlling terminal. */ | |
5908 | kill (-signal_pid, SIGINT); | |
5909 | } | |
5910 | ||
5911 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET | |
5912 | to debugger memory starting at MYADDR. */ | |
5913 | ||
5914 | static int | |
5915 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) | |
5916 | { | |
5917 | char filename[PATH_MAX]; | |
5918 | int fd, n; | |
5919 | int pid = lwpid_of (current_thread); | |
5920 | ||
5921 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); | |
5922 | ||
5923 | fd = open (filename, O_RDONLY); | |
5924 | if (fd < 0) | |
5925 | return -1; | |
5926 | ||
5927 | if (offset != (CORE_ADDR) 0 | |
5928 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
5929 | n = -1; | |
5930 | else | |
5931 | n = read (fd, myaddr, len); | |
5932 | ||
5933 | close (fd); | |
5934 | ||
5935 | return n; | |
5936 | } | |
5937 | ||
5938 | /* These breakpoint and watchpoint related wrapper functions simply | |
5939 | pass on the function call if the target has registered a | |
5940 | corresponding function. */ | |
5941 | ||
5942 | static int | |
5943 | linux_supports_z_point_type (char z_type) | |
5944 | { | |
5945 | return (the_low_target.supports_z_point_type != NULL | |
5946 | && the_low_target.supports_z_point_type (z_type)); | |
5947 | } | |
5948 | ||
5949 | static int | |
5950 | linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr, | |
5951 | int size, struct raw_breakpoint *bp) | |
5952 | { | |
5953 | if (type == raw_bkpt_type_sw) | |
5954 | return insert_memory_breakpoint (bp); | |
5955 | else if (the_low_target.insert_point != NULL) | |
5956 | return the_low_target.insert_point (type, addr, size, bp); | |
5957 | else | |
5958 | /* Unsupported (see target.h). */ | |
5959 | return 1; | |
5960 | } | |
5961 | ||
5962 | static int | |
5963 | linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr, | |
5964 | int size, struct raw_breakpoint *bp) | |
5965 | { | |
5966 | if (type == raw_bkpt_type_sw) | |
5967 | return remove_memory_breakpoint (bp); | |
5968 | else if (the_low_target.remove_point != NULL) | |
5969 | return the_low_target.remove_point (type, addr, size, bp); | |
5970 | else | |
5971 | /* Unsupported (see target.h). */ | |
5972 | return 1; | |
5973 | } | |
5974 | ||
5975 | /* Implement the to_stopped_by_sw_breakpoint target_ops | |
5976 | method. */ | |
5977 | ||
5978 | static int | |
5979 | linux_stopped_by_sw_breakpoint (void) | |
5980 | { | |
5981 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
5982 | ||
5983 | return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT); | |
5984 | } | |
5985 | ||
5986 | /* Implement the to_supports_stopped_by_sw_breakpoint target_ops | |
5987 | method. */ | |
5988 | ||
5989 | static int | |
5990 | linux_supports_stopped_by_sw_breakpoint (void) | |
5991 | { | |
5992 | return USE_SIGTRAP_SIGINFO; | |
5993 | } | |
5994 | ||
5995 | /* Implement the to_stopped_by_hw_breakpoint target_ops | |
5996 | method. */ | |
5997 | ||
5998 | static int | |
5999 | linux_stopped_by_hw_breakpoint (void) | |
6000 | { | |
6001 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
6002 | ||
6003 | return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT); | |
6004 | } | |
6005 | ||
6006 | /* Implement the to_supports_stopped_by_hw_breakpoint target_ops | |
6007 | method. */ | |
6008 | ||
6009 | static int | |
6010 | linux_supports_stopped_by_hw_breakpoint (void) | |
6011 | { | |
6012 | return USE_SIGTRAP_SIGINFO; | |
6013 | } | |
6014 | ||
6015 | /* Implement the supports_hardware_single_step target_ops method. */ | |
6016 | ||
6017 | static int | |
6018 | linux_supports_hardware_single_step (void) | |
6019 | { | |
6020 | return can_hardware_single_step (); | |
6021 | } | |
6022 | ||
6023 | static int | |
6024 | linux_supports_software_single_step (void) | |
6025 | { | |
6026 | return can_software_single_step (); | |
6027 | } | |
6028 | ||
6029 | static int | |
6030 | linux_stopped_by_watchpoint (void) | |
6031 | { | |
6032 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
6033 | ||
6034 | return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; | |
6035 | } | |
6036 | ||
6037 | static CORE_ADDR | |
6038 | linux_stopped_data_address (void) | |
6039 | { | |
6040 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
6041 | ||
6042 | return lwp->stopped_data_address; | |
6043 | } | |
6044 | ||
6045 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ | |
6046 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ | |
6047 | && defined(PT_TEXT_END_ADDR) | |
6048 | ||
6049 | /* This is only used for targets that define PT_TEXT_ADDR, | |
6050 | PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly | |
6051 | the target has different ways of acquiring this information, like | |
6052 | loadmaps. */ | |
6053 | ||
6054 | /* Under uClinux, programs are loaded at non-zero offsets, which we need | |
6055 | to tell gdb about. */ | |
6056 | ||
6057 | static int | |
6058 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) | |
6059 | { | |
6060 | unsigned long text, text_end, data; | |
6061 | int pid = lwpid_of (current_thread); | |
6062 | ||
6063 | errno = 0; | |
6064 | ||
6065 | text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR, | |
6066 | (PTRACE_TYPE_ARG4) 0); | |
6067 | text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR, | |
6068 | (PTRACE_TYPE_ARG4) 0); | |
6069 | data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR, | |
6070 | (PTRACE_TYPE_ARG4) 0); | |
6071 | ||
6072 | if (errno == 0) | |
6073 | { | |
6074 | /* Both text and data offsets produced at compile-time (and so | |
6075 | used by gdb) are relative to the beginning of the program, | |
6076 | with the data segment immediately following the text segment. | |
6077 | However, the actual runtime layout in memory may put the data | |
6078 | somewhere else, so when we send gdb a data base-address, we | |
6079 | use the real data base address and subtract the compile-time | |
6080 | data base-address from it (which is just the length of the | |
6081 | text segment). BSS immediately follows data in both | |
6082 | cases. */ | |
6083 | *text_p = text; | |
6084 | *data_p = data - (text_end - text); | |
6085 | ||
6086 | return 1; | |
6087 | } | |
6088 | return 0; | |
6089 | } | |
6090 | #endif | |
6091 | ||
6092 | static int | |
6093 | linux_qxfer_osdata (const char *annex, | |
6094 | unsigned char *readbuf, unsigned const char *writebuf, | |
6095 | CORE_ADDR offset, int len) | |
6096 | { | |
6097 | return linux_common_xfer_osdata (annex, readbuf, offset, len); | |
6098 | } | |
6099 | ||
6100 | /* Convert a native/host siginfo object, into/from the siginfo in the | |
6101 | layout of the inferiors' architecture. */ | |
6102 | ||
6103 | static void | |
6104 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) | |
6105 | { | |
6106 | int done = 0; | |
6107 | ||
6108 | if (the_low_target.siginfo_fixup != NULL) | |
6109 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); | |
6110 | ||
6111 | /* If there was no callback, or the callback didn't do anything, | |
6112 | then just do a straight memcpy. */ | |
6113 | if (!done) | |
6114 | { | |
6115 | if (direction == 1) | |
6116 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); | |
6117 | else | |
6118 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); | |
6119 | } | |
6120 | } | |
6121 | ||
6122 | static int | |
6123 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, | |
6124 | unsigned const char *writebuf, CORE_ADDR offset, int len) | |
6125 | { | |
6126 | int pid; | |
6127 | siginfo_t siginfo; | |
6128 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
6129 | ||
6130 | if (current_thread == NULL) | |
6131 | return -1; | |
6132 | ||
6133 | pid = lwpid_of (current_thread); | |
6134 | ||
6135 | if (debug_threads) | |
6136 | debug_printf ("%s siginfo for lwp %d.\n", | |
6137 | readbuf != NULL ? "Reading" : "Writing", | |
6138 | pid); | |
6139 | ||
6140 | if (offset >= sizeof (siginfo)) | |
6141 | return -1; | |
6142 | ||
6143 | if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) | |
6144 | return -1; | |
6145 | ||
6146 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into | |
6147 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
6148 | inferior with a 64-bit GDBSERVER should look the same as debugging it | |
6149 | with a 32-bit GDBSERVER, we need to convert it. */ | |
6150 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
6151 | ||
6152 | if (offset + len > sizeof (siginfo)) | |
6153 | len = sizeof (siginfo) - offset; | |
6154 | ||
6155 | if (readbuf != NULL) | |
6156 | memcpy (readbuf, inf_siginfo + offset, len); | |
6157 | else | |
6158 | { | |
6159 | memcpy (inf_siginfo + offset, writebuf, len); | |
6160 | ||
6161 | /* Convert back to ptrace layout before flushing it out. */ | |
6162 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
6163 | ||
6164 | if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) | |
6165 | return -1; | |
6166 | } | |
6167 | ||
6168 | return len; | |
6169 | } | |
6170 | ||
6171 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, | |
6172 | so we notice when children change state; as the handler for the | |
6173 | sigsuspend in my_waitpid. */ | |
6174 | ||
6175 | static void | |
6176 | sigchld_handler (int signo) | |
6177 | { | |
6178 | int old_errno = errno; | |
6179 | ||
6180 | if (debug_threads) | |
6181 | { | |
6182 | do | |
6183 | { | |
6184 | /* Use the async signal safe debug function. */ | |
6185 | if (debug_write ("sigchld_handler\n", | |
6186 | sizeof ("sigchld_handler\n") - 1) < 0) | |
6187 | break; /* just ignore */ | |
6188 | } while (0); | |
6189 | } | |
6190 | ||
6191 | if (target_is_async_p ()) | |
6192 | async_file_mark (); /* trigger a linux_wait */ | |
6193 | ||
6194 | errno = old_errno; | |
6195 | } | |
6196 | ||
6197 | static int | |
6198 | linux_supports_non_stop (void) | |
6199 | { | |
6200 | return 1; | |
6201 | } | |
6202 | ||
6203 | static int | |
6204 | linux_async (int enable) | |
6205 | { | |
6206 | int previous = target_is_async_p (); | |
6207 | ||
6208 | if (debug_threads) | |
6209 | debug_printf ("linux_async (%d), previous=%d\n", | |
6210 | enable, previous); | |
6211 | ||
6212 | if (previous != enable) | |
6213 | { | |
6214 | sigset_t mask; | |
6215 | sigemptyset (&mask); | |
6216 | sigaddset (&mask, SIGCHLD); | |
6217 | ||
6218 | sigprocmask (SIG_BLOCK, &mask, NULL); | |
6219 | ||
6220 | if (enable) | |
6221 | { | |
6222 | if (pipe (linux_event_pipe) == -1) | |
6223 | { | |
6224 | linux_event_pipe[0] = -1; | |
6225 | linux_event_pipe[1] = -1; | |
6226 | sigprocmask (SIG_UNBLOCK, &mask, NULL); | |
6227 | ||
6228 | warning ("creating event pipe failed."); | |
6229 | return previous; | |
6230 | } | |
6231 | ||
6232 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); | |
6233 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); | |
6234 | ||
6235 | /* Register the event loop handler. */ | |
6236 | add_file_handler (linux_event_pipe[0], | |
6237 | handle_target_event, NULL); | |
6238 | ||
6239 | /* Always trigger a linux_wait. */ | |
6240 | async_file_mark (); | |
6241 | } | |
6242 | else | |
6243 | { | |
6244 | delete_file_handler (linux_event_pipe[0]); | |
6245 | ||
6246 | close (linux_event_pipe[0]); | |
6247 | close (linux_event_pipe[1]); | |
6248 | linux_event_pipe[0] = -1; | |
6249 | linux_event_pipe[1] = -1; | |
6250 | } | |
6251 | ||
6252 | sigprocmask (SIG_UNBLOCK, &mask, NULL); | |
6253 | } | |
6254 | ||
6255 | return previous; | |
6256 | } | |
6257 | ||
6258 | static int | |
6259 | linux_start_non_stop (int nonstop) | |
6260 | { | |
6261 | /* Register or unregister from event-loop accordingly. */ | |
6262 | linux_async (nonstop); | |
6263 | ||
6264 | if (target_is_async_p () != (nonstop != 0)) | |
6265 | return -1; | |
6266 | ||
6267 | return 0; | |
6268 | } | |
6269 | ||
6270 | static int | |
6271 | linux_supports_multi_process (void) | |
6272 | { | |
6273 | return 1; | |
6274 | } | |
6275 | ||
6276 | /* Check if fork events are supported. */ | |
6277 | ||
6278 | static int | |
6279 | linux_supports_fork_events (void) | |
6280 | { | |
6281 | return linux_supports_tracefork (); | |
6282 | } | |
6283 | ||
6284 | /* Check if vfork events are supported. */ | |
6285 | ||
6286 | static int | |
6287 | linux_supports_vfork_events (void) | |
6288 | { | |
6289 | return linux_supports_tracefork (); | |
6290 | } | |
6291 | ||
6292 | /* Check if exec events are supported. */ | |
6293 | ||
6294 | static int | |
6295 | linux_supports_exec_events (void) | |
6296 | { | |
6297 | return linux_supports_traceexec (); | |
6298 | } | |
6299 | ||
6300 | /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the | |
6301 | ptrace flags for all inferiors. This is in case the new GDB connection | |
6302 | doesn't support the same set of events that the previous one did. */ | |
6303 | ||
6304 | static void | |
6305 | linux_handle_new_gdb_connection (void) | |
6306 | { | |
6307 | /* Request that all the lwps reset their ptrace options. */ | |
6308 | for_each_thread ([] (thread_info *thread) | |
6309 | { | |
6310 | struct lwp_info *lwp = get_thread_lwp (thread); | |
6311 | ||
6312 | if (!lwp->stopped) | |
6313 | { | |
6314 | /* Stop the lwp so we can modify its ptrace options. */ | |
6315 | lwp->must_set_ptrace_flags = 1; | |
6316 | linux_stop_lwp (lwp); | |
6317 | } | |
6318 | else | |
6319 | { | |
6320 | /* Already stopped; go ahead and set the ptrace options. */ | |
6321 | struct process_info *proc = find_process_pid (pid_of (thread)); | |
6322 | int options = linux_low_ptrace_options (proc->attached); | |
6323 | ||
6324 | linux_enable_event_reporting (lwpid_of (thread), options); | |
6325 | lwp->must_set_ptrace_flags = 0; | |
6326 | } | |
6327 | }); | |
6328 | } | |
6329 | ||
6330 | static int | |
6331 | linux_supports_disable_randomization (void) | |
6332 | { | |
6333 | #ifdef HAVE_PERSONALITY | |
6334 | return 1; | |
6335 | #else | |
6336 | return 0; | |
6337 | #endif | |
6338 | } | |
6339 | ||
6340 | static int | |
6341 | linux_supports_agent (void) | |
6342 | { | |
6343 | return 1; | |
6344 | } | |
6345 | ||
6346 | static int | |
6347 | linux_supports_range_stepping (void) | |
6348 | { | |
6349 | if (can_software_single_step ()) | |
6350 | return 1; | |
6351 | if (*the_low_target.supports_range_stepping == NULL) | |
6352 | return 0; | |
6353 | ||
6354 | return (*the_low_target.supports_range_stepping) (); | |
6355 | } | |
6356 | ||
6357 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC | |
6358 | struct target_loadseg | |
6359 | { | |
6360 | /* Core address to which the segment is mapped. */ | |
6361 | Elf32_Addr addr; | |
6362 | /* VMA recorded in the program header. */ | |
6363 | Elf32_Addr p_vaddr; | |
6364 | /* Size of this segment in memory. */ | |
6365 | Elf32_Word p_memsz; | |
6366 | }; | |
6367 | ||
6368 | # if defined PT_GETDSBT | |
6369 | struct target_loadmap | |
6370 | { | |
6371 | /* Protocol version number, must be zero. */ | |
6372 | Elf32_Word version; | |
6373 | /* Pointer to the DSBT table, its size, and the DSBT index. */ | |
6374 | unsigned *dsbt_table; | |
6375 | unsigned dsbt_size, dsbt_index; | |
6376 | /* Number of segments in this map. */ | |
6377 | Elf32_Word nsegs; | |
6378 | /* The actual memory map. */ | |
6379 | struct target_loadseg segs[/*nsegs*/]; | |
6380 | }; | |
6381 | # define LINUX_LOADMAP PT_GETDSBT | |
6382 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC | |
6383 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP | |
6384 | # else | |
6385 | struct target_loadmap | |
6386 | { | |
6387 | /* Protocol version number, must be zero. */ | |
6388 | Elf32_Half version; | |
6389 | /* Number of segments in this map. */ | |
6390 | Elf32_Half nsegs; | |
6391 | /* The actual memory map. */ | |
6392 | struct target_loadseg segs[/*nsegs*/]; | |
6393 | }; | |
6394 | # define LINUX_LOADMAP PTRACE_GETFDPIC | |
6395 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC | |
6396 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP | |
6397 | # endif | |
6398 | ||
6399 | static int | |
6400 | linux_read_loadmap (const char *annex, CORE_ADDR offset, | |
6401 | unsigned char *myaddr, unsigned int len) | |
6402 | { | |
6403 | int pid = lwpid_of (current_thread); | |
6404 | int addr = -1; | |
6405 | struct target_loadmap *data = NULL; | |
6406 | unsigned int actual_length, copy_length; | |
6407 | ||
6408 | if (strcmp (annex, "exec") == 0) | |
6409 | addr = (int) LINUX_LOADMAP_EXEC; | |
6410 | else if (strcmp (annex, "interp") == 0) | |
6411 | addr = (int) LINUX_LOADMAP_INTERP; | |
6412 | else | |
6413 | return -1; | |
6414 | ||
6415 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) | |
6416 | return -1; | |
6417 | ||
6418 | if (data == NULL) | |
6419 | return -1; | |
6420 | ||
6421 | actual_length = sizeof (struct target_loadmap) | |
6422 | + sizeof (struct target_loadseg) * data->nsegs; | |
6423 | ||
6424 | if (offset < 0 || offset > actual_length) | |
6425 | return -1; | |
6426 | ||
6427 | copy_length = actual_length - offset < len ? actual_length - offset : len; | |
6428 | memcpy (myaddr, (char *) data + offset, copy_length); | |
6429 | return copy_length; | |
6430 | } | |
6431 | #else | |
6432 | # define linux_read_loadmap NULL | |
6433 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ | |
6434 | ||
6435 | static void | |
6436 | linux_process_qsupported (char **features, int count) | |
6437 | { | |
6438 | if (the_low_target.process_qsupported != NULL) | |
6439 | the_low_target.process_qsupported (features, count); | |
6440 | } | |
6441 | ||
6442 | static int | |
6443 | linux_supports_catch_syscall (void) | |
6444 | { | |
6445 | return (the_low_target.get_syscall_trapinfo != NULL | |
6446 | && linux_supports_tracesysgood ()); | |
6447 | } | |
6448 | ||
6449 | static int | |
6450 | linux_get_ipa_tdesc_idx (void) | |
6451 | { | |
6452 | if (the_low_target.get_ipa_tdesc_idx == NULL) | |
6453 | return 0; | |
6454 | ||
6455 | return (*the_low_target.get_ipa_tdesc_idx) (); | |
6456 | } | |
6457 | ||
6458 | static int | |
6459 | linux_supports_tracepoints (void) | |
6460 | { | |
6461 | if (*the_low_target.supports_tracepoints == NULL) | |
6462 | return 0; | |
6463 | ||
6464 | return (*the_low_target.supports_tracepoints) (); | |
6465 | } | |
6466 | ||
6467 | static CORE_ADDR | |
6468 | linux_read_pc (struct regcache *regcache) | |
6469 | { | |
6470 | if (the_low_target.get_pc == NULL) | |
6471 | return 0; | |
6472 | ||
6473 | return (*the_low_target.get_pc) (regcache); | |
6474 | } | |
6475 | ||
6476 | static void | |
6477 | linux_write_pc (struct regcache *regcache, CORE_ADDR pc) | |
6478 | { | |
6479 | gdb_assert (the_low_target.set_pc != NULL); | |
6480 | ||
6481 | (*the_low_target.set_pc) (regcache, pc); | |
6482 | } | |
6483 | ||
6484 | static int | |
6485 | linux_thread_stopped (struct thread_info *thread) | |
6486 | { | |
6487 | return get_thread_lwp (thread)->stopped; | |
6488 | } | |
6489 | ||
6490 | /* This exposes stop-all-threads functionality to other modules. */ | |
6491 | ||
6492 | static void | |
6493 | linux_pause_all (int freeze) | |
6494 | { | |
6495 | stop_all_lwps (freeze, NULL); | |
6496 | } | |
6497 | ||
6498 | /* This exposes unstop-all-threads functionality to other gdbserver | |
6499 | modules. */ | |
6500 | ||
6501 | static void | |
6502 | linux_unpause_all (int unfreeze) | |
6503 | { | |
6504 | unstop_all_lwps (unfreeze, NULL); | |
6505 | } | |
6506 | ||
6507 | static int | |
6508 | linux_prepare_to_access_memory (void) | |
6509 | { | |
6510 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a | |
6511 | running LWP. */ | |
6512 | if (non_stop) | |
6513 | linux_pause_all (1); | |
6514 | return 0; | |
6515 | } | |
6516 | ||
6517 | static void | |
6518 | linux_done_accessing_memory (void) | |
6519 | { | |
6520 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a | |
6521 | running LWP. */ | |
6522 | if (non_stop) | |
6523 | linux_unpause_all (1); | |
6524 | } | |
6525 | ||
6526 | static int | |
6527 | linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr, | |
6528 | CORE_ADDR collector, | |
6529 | CORE_ADDR lockaddr, | |
6530 | ULONGEST orig_size, | |
6531 | CORE_ADDR *jump_entry, | |
6532 | CORE_ADDR *trampoline, | |
6533 | ULONGEST *trampoline_size, | |
6534 | unsigned char *jjump_pad_insn, | |
6535 | ULONGEST *jjump_pad_insn_size, | |
6536 | CORE_ADDR *adjusted_insn_addr, | |
6537 | CORE_ADDR *adjusted_insn_addr_end, | |
6538 | char *err) | |
6539 | { | |
6540 | return (*the_low_target.install_fast_tracepoint_jump_pad) | |
6541 | (tpoint, tpaddr, collector, lockaddr, orig_size, | |
6542 | jump_entry, trampoline, trampoline_size, | |
6543 | jjump_pad_insn, jjump_pad_insn_size, | |
6544 | adjusted_insn_addr, adjusted_insn_addr_end, | |
6545 | err); | |
6546 | } | |
6547 | ||
6548 | static struct emit_ops * | |
6549 | linux_emit_ops (void) | |
6550 | { | |
6551 | if (the_low_target.emit_ops != NULL) | |
6552 | return (*the_low_target.emit_ops) (); | |
6553 | else | |
6554 | return NULL; | |
6555 | } | |
6556 | ||
6557 | static int | |
6558 | linux_get_min_fast_tracepoint_insn_len (void) | |
6559 | { | |
6560 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); | |
6561 | } | |
6562 | ||
6563 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ | |
6564 | ||
6565 | static int | |
6566 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, | |
6567 | CORE_ADDR *phdr_memaddr, int *num_phdr) | |
6568 | { | |
6569 | char filename[PATH_MAX]; | |
6570 | int fd; | |
6571 | const int auxv_size = is_elf64 | |
6572 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); | |
6573 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ | |
6574 | ||
6575 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); | |
6576 | ||
6577 | fd = open (filename, O_RDONLY); | |
6578 | if (fd < 0) | |
6579 | return 1; | |
6580 | ||
6581 | *phdr_memaddr = 0; | |
6582 | *num_phdr = 0; | |
6583 | while (read (fd, buf, auxv_size) == auxv_size | |
6584 | && (*phdr_memaddr == 0 || *num_phdr == 0)) | |
6585 | { | |
6586 | if (is_elf64) | |
6587 | { | |
6588 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; | |
6589 | ||
6590 | switch (aux->a_type) | |
6591 | { | |
6592 | case AT_PHDR: | |
6593 | *phdr_memaddr = aux->a_un.a_val; | |
6594 | break; | |
6595 | case AT_PHNUM: | |
6596 | *num_phdr = aux->a_un.a_val; | |
6597 | break; | |
6598 | } | |
6599 | } | |
6600 | else | |
6601 | { | |
6602 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; | |
6603 | ||
6604 | switch (aux->a_type) | |
6605 | { | |
6606 | case AT_PHDR: | |
6607 | *phdr_memaddr = aux->a_un.a_val; | |
6608 | break; | |
6609 | case AT_PHNUM: | |
6610 | *num_phdr = aux->a_un.a_val; | |
6611 | break; | |
6612 | } | |
6613 | } | |
6614 | } | |
6615 | ||
6616 | close (fd); | |
6617 | ||
6618 | if (*phdr_memaddr == 0 || *num_phdr == 0) | |
6619 | { | |
6620 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " | |
6621 | "phdr_memaddr = %ld, phdr_num = %d", | |
6622 | (long) *phdr_memaddr, *num_phdr); | |
6623 | return 2; | |
6624 | } | |
6625 | ||
6626 | return 0; | |
6627 | } | |
6628 | ||
6629 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ | |
6630 | ||
6631 | static CORE_ADDR | |
6632 | get_dynamic (const int pid, const int is_elf64) | |
6633 | { | |
6634 | CORE_ADDR phdr_memaddr, relocation; | |
6635 | int num_phdr, i; | |
6636 | unsigned char *phdr_buf; | |
6637 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); | |
6638 | ||
6639 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) | |
6640 | return 0; | |
6641 | ||
6642 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ | |
6643 | phdr_buf = (unsigned char *) alloca (num_phdr * phdr_size); | |
6644 | ||
6645 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) | |
6646 | return 0; | |
6647 | ||
6648 | /* Compute relocation: it is expected to be 0 for "regular" executables, | |
6649 | non-zero for PIE ones. */ | |
6650 | relocation = -1; | |
6651 | for (i = 0; relocation == -1 && i < num_phdr; i++) | |
6652 | if (is_elf64) | |
6653 | { | |
6654 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); | |
6655 | ||
6656 | if (p->p_type == PT_PHDR) | |
6657 | relocation = phdr_memaddr - p->p_vaddr; | |
6658 | } | |
6659 | else | |
6660 | { | |
6661 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); | |
6662 | ||
6663 | if (p->p_type == PT_PHDR) | |
6664 | relocation = phdr_memaddr - p->p_vaddr; | |
6665 | } | |
6666 | ||
6667 | if (relocation == -1) | |
6668 | { | |
6669 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately | |
6670 | any real world executables, including PIE executables, have always | |
6671 | PT_PHDR present. PT_PHDR is not present in some shared libraries or | |
6672 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for | |
6673 | or present DT_DEBUG anyway (fpc binaries are statically linked). | |
6674 | ||
6675 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. | |
6676 | ||
6677 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ | |
6678 | ||
6679 | return 0; | |
6680 | } | |
6681 | ||
6682 | for (i = 0; i < num_phdr; i++) | |
6683 | { | |
6684 | if (is_elf64) | |
6685 | { | |
6686 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); | |
6687 | ||
6688 | if (p->p_type == PT_DYNAMIC) | |
6689 | return p->p_vaddr + relocation; | |
6690 | } | |
6691 | else | |
6692 | { | |
6693 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); | |
6694 | ||
6695 | if (p->p_type == PT_DYNAMIC) | |
6696 | return p->p_vaddr + relocation; | |
6697 | } | |
6698 | } | |
6699 | ||
6700 | return 0; | |
6701 | } | |
6702 | ||
6703 | /* Return &_r_debug in the inferior, or -1 if not present. Return value | |
6704 | can be 0 if the inferior does not yet have the library list initialized. | |
6705 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of | |
6706 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ | |
6707 | ||
6708 | static CORE_ADDR | |
6709 | get_r_debug (const int pid, const int is_elf64) | |
6710 | { | |
6711 | CORE_ADDR dynamic_memaddr; | |
6712 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); | |
6713 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ | |
6714 | CORE_ADDR map = -1; | |
6715 | ||
6716 | dynamic_memaddr = get_dynamic (pid, is_elf64); | |
6717 | if (dynamic_memaddr == 0) | |
6718 | return map; | |
6719 | ||
6720 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) | |
6721 | { | |
6722 | if (is_elf64) | |
6723 | { | |
6724 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; | |
6725 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL | |
6726 | union | |
6727 | { | |
6728 | Elf64_Xword map; | |
6729 | unsigned char buf[sizeof (Elf64_Xword)]; | |
6730 | } | |
6731 | rld_map; | |
6732 | #endif | |
6733 | #ifdef DT_MIPS_RLD_MAP | |
6734 | if (dyn->d_tag == DT_MIPS_RLD_MAP) | |
6735 | { | |
6736 | if (linux_read_memory (dyn->d_un.d_val, | |
6737 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6738 | return rld_map.map; | |
6739 | else | |
6740 | break; | |
6741 | } | |
6742 | #endif /* DT_MIPS_RLD_MAP */ | |
6743 | #ifdef DT_MIPS_RLD_MAP_REL | |
6744 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) | |
6745 | { | |
6746 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, | |
6747 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6748 | return rld_map.map; | |
6749 | else | |
6750 | break; | |
6751 | } | |
6752 | #endif /* DT_MIPS_RLD_MAP_REL */ | |
6753 | ||
6754 | if (dyn->d_tag == DT_DEBUG && map == -1) | |
6755 | map = dyn->d_un.d_val; | |
6756 | ||
6757 | if (dyn->d_tag == DT_NULL) | |
6758 | break; | |
6759 | } | |
6760 | else | |
6761 | { | |
6762 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; | |
6763 | #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL | |
6764 | union | |
6765 | { | |
6766 | Elf32_Word map; | |
6767 | unsigned char buf[sizeof (Elf32_Word)]; | |
6768 | } | |
6769 | rld_map; | |
6770 | #endif | |
6771 | #ifdef DT_MIPS_RLD_MAP | |
6772 | if (dyn->d_tag == DT_MIPS_RLD_MAP) | |
6773 | { | |
6774 | if (linux_read_memory (dyn->d_un.d_val, | |
6775 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6776 | return rld_map.map; | |
6777 | else | |
6778 | break; | |
6779 | } | |
6780 | #endif /* DT_MIPS_RLD_MAP */ | |
6781 | #ifdef DT_MIPS_RLD_MAP_REL | |
6782 | if (dyn->d_tag == DT_MIPS_RLD_MAP_REL) | |
6783 | { | |
6784 | if (linux_read_memory (dyn->d_un.d_val + dynamic_memaddr, | |
6785 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6786 | return rld_map.map; | |
6787 | else | |
6788 | break; | |
6789 | } | |
6790 | #endif /* DT_MIPS_RLD_MAP_REL */ | |
6791 | ||
6792 | if (dyn->d_tag == DT_DEBUG && map == -1) | |
6793 | map = dyn->d_un.d_val; | |
6794 | ||
6795 | if (dyn->d_tag == DT_NULL) | |
6796 | break; | |
6797 | } | |
6798 | ||
6799 | dynamic_memaddr += dyn_size; | |
6800 | } | |
6801 | ||
6802 | return map; | |
6803 | } | |
6804 | ||
6805 | /* Read one pointer from MEMADDR in the inferior. */ | |
6806 | ||
6807 | static int | |
6808 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) | |
6809 | { | |
6810 | int ret; | |
6811 | ||
6812 | /* Go through a union so this works on either big or little endian | |
6813 | hosts, when the inferior's pointer size is smaller than the size | |
6814 | of CORE_ADDR. It is assumed the inferior's endianness is the | |
6815 | same of the superior's. */ | |
6816 | union | |
6817 | { | |
6818 | CORE_ADDR core_addr; | |
6819 | unsigned int ui; | |
6820 | unsigned char uc; | |
6821 | } addr; | |
6822 | ||
6823 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); | |
6824 | if (ret == 0) | |
6825 | { | |
6826 | if (ptr_size == sizeof (CORE_ADDR)) | |
6827 | *ptr = addr.core_addr; | |
6828 | else if (ptr_size == sizeof (unsigned int)) | |
6829 | *ptr = addr.ui; | |
6830 | else | |
6831 | gdb_assert_not_reached ("unhandled pointer size"); | |
6832 | } | |
6833 | return ret; | |
6834 | } | |
6835 | ||
6836 | struct link_map_offsets | |
6837 | { | |
6838 | /* Offset and size of r_debug.r_version. */ | |
6839 | int r_version_offset; | |
6840 | ||
6841 | /* Offset and size of r_debug.r_map. */ | |
6842 | int r_map_offset; | |
6843 | ||
6844 | /* Offset to l_addr field in struct link_map. */ | |
6845 | int l_addr_offset; | |
6846 | ||
6847 | /* Offset to l_name field in struct link_map. */ | |
6848 | int l_name_offset; | |
6849 | ||
6850 | /* Offset to l_ld field in struct link_map. */ | |
6851 | int l_ld_offset; | |
6852 | ||
6853 | /* Offset to l_next field in struct link_map. */ | |
6854 | int l_next_offset; | |
6855 | ||
6856 | /* Offset to l_prev field in struct link_map. */ | |
6857 | int l_prev_offset; | |
6858 | }; | |
6859 | ||
6860 | /* Construct qXfer:libraries-svr4:read reply. */ | |
6861 | ||
6862 | static int | |
6863 | linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, | |
6864 | unsigned const char *writebuf, | |
6865 | CORE_ADDR offset, int len) | |
6866 | { | |
6867 | struct process_info_private *const priv = current_process ()->priv; | |
6868 | char filename[PATH_MAX]; | |
6869 | int pid, is_elf64; | |
6870 | ||
6871 | static const struct link_map_offsets lmo_32bit_offsets = | |
6872 | { | |
6873 | 0, /* r_version offset. */ | |
6874 | 4, /* r_debug.r_map offset. */ | |
6875 | 0, /* l_addr offset in link_map. */ | |
6876 | 4, /* l_name offset in link_map. */ | |
6877 | 8, /* l_ld offset in link_map. */ | |
6878 | 12, /* l_next offset in link_map. */ | |
6879 | 16 /* l_prev offset in link_map. */ | |
6880 | }; | |
6881 | ||
6882 | static const struct link_map_offsets lmo_64bit_offsets = | |
6883 | { | |
6884 | 0, /* r_version offset. */ | |
6885 | 8, /* r_debug.r_map offset. */ | |
6886 | 0, /* l_addr offset in link_map. */ | |
6887 | 8, /* l_name offset in link_map. */ | |
6888 | 16, /* l_ld offset in link_map. */ | |
6889 | 24, /* l_next offset in link_map. */ | |
6890 | 32 /* l_prev offset in link_map. */ | |
6891 | }; | |
6892 | const struct link_map_offsets *lmo; | |
6893 | unsigned int machine; | |
6894 | int ptr_size; | |
6895 | CORE_ADDR lm_addr = 0, lm_prev = 0; | |
6896 | CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev; | |
6897 | int header_done = 0; | |
6898 | ||
6899 | if (writebuf != NULL) | |
6900 | return -2; | |
6901 | if (readbuf == NULL) | |
6902 | return -1; | |
6903 | ||
6904 | pid = lwpid_of (current_thread); | |
6905 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); | |
6906 | is_elf64 = elf_64_file_p (filename, &machine); | |
6907 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; | |
6908 | ptr_size = is_elf64 ? 8 : 4; | |
6909 | ||
6910 | while (annex[0] != '\0') | |
6911 | { | |
6912 | const char *sep; | |
6913 | CORE_ADDR *addrp; | |
6914 | int name_len; | |
6915 | ||
6916 | sep = strchr (annex, '='); | |
6917 | if (sep == NULL) | |
6918 | break; | |
6919 | ||
6920 | name_len = sep - annex; | |
6921 | if (name_len == 5 && startswith (annex, "start")) | |
6922 | addrp = &lm_addr; | |
6923 | else if (name_len == 4 && startswith (annex, "prev")) | |
6924 | addrp = &lm_prev; | |
6925 | else | |
6926 | { | |
6927 | annex = strchr (sep, ';'); | |
6928 | if (annex == NULL) | |
6929 | break; | |
6930 | annex++; | |
6931 | continue; | |
6932 | } | |
6933 | ||
6934 | annex = decode_address_to_semicolon (addrp, sep + 1); | |
6935 | } | |
6936 | ||
6937 | if (lm_addr == 0) | |
6938 | { | |
6939 | int r_version = 0; | |
6940 | ||
6941 | if (priv->r_debug == 0) | |
6942 | priv->r_debug = get_r_debug (pid, is_elf64); | |
6943 | ||
6944 | /* We failed to find DT_DEBUG. Such situation will not change | |
6945 | for this inferior - do not retry it. Report it to GDB as | |
6946 | E01, see for the reasons at the GDB solib-svr4.c side. */ | |
6947 | if (priv->r_debug == (CORE_ADDR) -1) | |
6948 | return -1; | |
6949 | ||
6950 | if (priv->r_debug != 0) | |
6951 | { | |
6952 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, | |
6953 | (unsigned char *) &r_version, | |
6954 | sizeof (r_version)) != 0 | |
6955 | || r_version != 1) | |
6956 | { | |
6957 | warning ("unexpected r_debug version %d", r_version); | |
6958 | } | |
6959 | else if (read_one_ptr (priv->r_debug + lmo->r_map_offset, | |
6960 | &lm_addr, ptr_size) != 0) | |
6961 | { | |
6962 | warning ("unable to read r_map from 0x%lx", | |
6963 | (long) priv->r_debug + lmo->r_map_offset); | |
6964 | } | |
6965 | } | |
6966 | } | |
6967 | ||
6968 | std::string document = "<library-list-svr4 version=\"1.0\""; | |
6969 | ||
6970 | while (lm_addr | |
6971 | && read_one_ptr (lm_addr + lmo->l_name_offset, | |
6972 | &l_name, ptr_size) == 0 | |
6973 | && read_one_ptr (lm_addr + lmo->l_addr_offset, | |
6974 | &l_addr, ptr_size) == 0 | |
6975 | && read_one_ptr (lm_addr + lmo->l_ld_offset, | |
6976 | &l_ld, ptr_size) == 0 | |
6977 | && read_one_ptr (lm_addr + lmo->l_prev_offset, | |
6978 | &l_prev, ptr_size) == 0 | |
6979 | && read_one_ptr (lm_addr + lmo->l_next_offset, | |
6980 | &l_next, ptr_size) == 0) | |
6981 | { | |
6982 | unsigned char libname[PATH_MAX]; | |
6983 | ||
6984 | if (lm_prev != l_prev) | |
6985 | { | |
6986 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", | |
6987 | (long) lm_prev, (long) l_prev); | |
6988 | break; | |
6989 | } | |
6990 | ||
6991 | /* Ignore the first entry even if it has valid name as the first entry | |
6992 | corresponds to the main executable. The first entry should not be | |
6993 | skipped if the dynamic loader was loaded late by a static executable | |
6994 | (see solib-svr4.c parameter ignore_first). But in such case the main | |
6995 | executable does not have PT_DYNAMIC present and this function already | |
6996 | exited above due to failed get_r_debug. */ | |
6997 | if (lm_prev == 0) | |
6998 | string_appendf (document, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); | |
6999 | else | |
7000 | { | |
7001 | /* Not checking for error because reading may stop before | |
7002 | we've got PATH_MAX worth of characters. */ | |
7003 | libname[0] = '\0'; | |
7004 | linux_read_memory (l_name, libname, sizeof (libname) - 1); | |
7005 | libname[sizeof (libname) - 1] = '\0'; | |
7006 | if (libname[0] != '\0') | |
7007 | { | |
7008 | if (!header_done) | |
7009 | { | |
7010 | /* Terminate `<library-list-svr4'. */ | |
7011 | document += '>'; | |
7012 | header_done = 1; | |
7013 | } | |
7014 | ||
7015 | string_appendf (document, "<library name=\""); | |
7016 | xml_escape_text_append (&document, (char *) libname); | |
7017 | string_appendf (document, "\" lm=\"0x%lx\" " | |
7018 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", | |
7019 | (unsigned long) lm_addr, (unsigned long) l_addr, | |
7020 | (unsigned long) l_ld); | |
7021 | } | |
7022 | } | |
7023 | ||
7024 | lm_prev = lm_addr; | |
7025 | lm_addr = l_next; | |
7026 | } | |
7027 | ||
7028 | if (!header_done) | |
7029 | { | |
7030 | /* Empty list; terminate `<library-list-svr4'. */ | |
7031 | document += "/>"; | |
7032 | } | |
7033 | else | |
7034 | document += "</library-list-svr4>"; | |
7035 | ||
7036 | int document_len = document.length (); | |
7037 | if (offset < document_len) | |
7038 | document_len -= offset; | |
7039 | else | |
7040 | document_len = 0; | |
7041 | if (len > document_len) | |
7042 | len = document_len; | |
7043 | ||
7044 | memcpy (readbuf, document.data () + offset, len); | |
7045 | ||
7046 | return len; | |
7047 | } | |
7048 | ||
7049 | #ifdef HAVE_LINUX_BTRACE | |
7050 | ||
7051 | /* See to_disable_btrace target method. */ | |
7052 | ||
7053 | static int | |
7054 | linux_low_disable_btrace (struct btrace_target_info *tinfo) | |
7055 | { | |
7056 | enum btrace_error err; | |
7057 | ||
7058 | err = linux_disable_btrace (tinfo); | |
7059 | return (err == BTRACE_ERR_NONE ? 0 : -1); | |
7060 | } | |
7061 | ||
7062 | /* Encode an Intel Processor Trace configuration. */ | |
7063 | ||
7064 | static void | |
7065 | linux_low_encode_pt_config (struct buffer *buffer, | |
7066 | const struct btrace_data_pt_config *config) | |
7067 | { | |
7068 | buffer_grow_str (buffer, "<pt-config>\n"); | |
7069 | ||
7070 | switch (config->cpu.vendor) | |
7071 | { | |
7072 | case CV_INTEL: | |
7073 | buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" " | |
7074 | "model=\"%u\" stepping=\"%u\"/>\n", | |
7075 | config->cpu.family, config->cpu.model, | |
7076 | config->cpu.stepping); | |
7077 | break; | |
7078 | ||
7079 | default: | |
7080 | break; | |
7081 | } | |
7082 | ||
7083 | buffer_grow_str (buffer, "</pt-config>\n"); | |
7084 | } | |
7085 | ||
7086 | /* Encode a raw buffer. */ | |
7087 | ||
7088 | static void | |
7089 | linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data, | |
7090 | unsigned int size) | |
7091 | { | |
7092 | if (size == 0) | |
7093 | return; | |
7094 | ||
7095 | /* We use hex encoding - see gdbsupport/rsp-low.h. */ | |
7096 | buffer_grow_str (buffer, "<raw>\n"); | |
7097 | ||
7098 | while (size-- > 0) | |
7099 | { | |
7100 | char elem[2]; | |
7101 | ||
7102 | elem[0] = tohex ((*data >> 4) & 0xf); | |
7103 | elem[1] = tohex (*data++ & 0xf); | |
7104 | ||
7105 | buffer_grow (buffer, elem, 2); | |
7106 | } | |
7107 | ||
7108 | buffer_grow_str (buffer, "</raw>\n"); | |
7109 | } | |
7110 | ||
7111 | /* See to_read_btrace target method. */ | |
7112 | ||
7113 | static int | |
7114 | linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer, | |
7115 | enum btrace_read_type type) | |
7116 | { | |
7117 | struct btrace_data btrace; | |
7118 | enum btrace_error err; | |
7119 | ||
7120 | err = linux_read_btrace (&btrace, tinfo, type); | |
7121 | if (err != BTRACE_ERR_NONE) | |
7122 | { | |
7123 | if (err == BTRACE_ERR_OVERFLOW) | |
7124 | buffer_grow_str0 (buffer, "E.Overflow."); | |
7125 | else | |
7126 | buffer_grow_str0 (buffer, "E.Generic Error."); | |
7127 | ||
7128 | return -1; | |
7129 | } | |
7130 | ||
7131 | switch (btrace.format) | |
7132 | { | |
7133 | case BTRACE_FORMAT_NONE: | |
7134 | buffer_grow_str0 (buffer, "E.No Trace."); | |
7135 | return -1; | |
7136 | ||
7137 | case BTRACE_FORMAT_BTS: | |
7138 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); | |
7139 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); | |
7140 | ||
7141 | for (const btrace_block &block : *btrace.variant.bts.blocks) | |
7142 | buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n", | |
7143 | paddress (block.begin), paddress (block.end)); | |
7144 | ||
7145 | buffer_grow_str0 (buffer, "</btrace>\n"); | |
7146 | break; | |
7147 | ||
7148 | case BTRACE_FORMAT_PT: | |
7149 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); | |
7150 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); | |
7151 | buffer_grow_str (buffer, "<pt>\n"); | |
7152 | ||
7153 | linux_low_encode_pt_config (buffer, &btrace.variant.pt.config); | |
7154 | ||
7155 | linux_low_encode_raw (buffer, btrace.variant.pt.data, | |
7156 | btrace.variant.pt.size); | |
7157 | ||
7158 | buffer_grow_str (buffer, "</pt>\n"); | |
7159 | buffer_grow_str0 (buffer, "</btrace>\n"); | |
7160 | break; | |
7161 | ||
7162 | default: | |
7163 | buffer_grow_str0 (buffer, "E.Unsupported Trace Format."); | |
7164 | return -1; | |
7165 | } | |
7166 | ||
7167 | return 0; | |
7168 | } | |
7169 | ||
7170 | /* See to_btrace_conf target method. */ | |
7171 | ||
7172 | static int | |
7173 | linux_low_btrace_conf (const struct btrace_target_info *tinfo, | |
7174 | struct buffer *buffer) | |
7175 | { | |
7176 | const struct btrace_config *conf; | |
7177 | ||
7178 | buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n"); | |
7179 | buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n"); | |
7180 | ||
7181 | conf = linux_btrace_conf (tinfo); | |
7182 | if (conf != NULL) | |
7183 | { | |
7184 | switch (conf->format) | |
7185 | { | |
7186 | case BTRACE_FORMAT_NONE: | |
7187 | break; | |
7188 | ||
7189 | case BTRACE_FORMAT_BTS: | |
7190 | buffer_xml_printf (buffer, "<bts"); | |
7191 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size); | |
7192 | buffer_xml_printf (buffer, " />\n"); | |
7193 | break; | |
7194 | ||
7195 | case BTRACE_FORMAT_PT: | |
7196 | buffer_xml_printf (buffer, "<pt"); | |
7197 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size); | |
7198 | buffer_xml_printf (buffer, "/>\n"); | |
7199 | break; | |
7200 | } | |
7201 | } | |
7202 | ||
7203 | buffer_grow_str0 (buffer, "</btrace-conf>\n"); | |
7204 | return 0; | |
7205 | } | |
7206 | #endif /* HAVE_LINUX_BTRACE */ | |
7207 | ||
7208 | /* See nat/linux-nat.h. */ | |
7209 | ||
7210 | ptid_t | |
7211 | current_lwp_ptid (void) | |
7212 | { | |
7213 | return ptid_of (current_thread); | |
7214 | } | |
7215 | ||
7216 | /* Implementation of the target_ops method "breakpoint_kind_from_pc". */ | |
7217 | ||
7218 | static int | |
7219 | linux_breakpoint_kind_from_pc (CORE_ADDR *pcptr) | |
7220 | { | |
7221 | if (the_low_target.breakpoint_kind_from_pc != NULL) | |
7222 | return (*the_low_target.breakpoint_kind_from_pc) (pcptr); | |
7223 | else | |
7224 | return default_breakpoint_kind_from_pc (pcptr); | |
7225 | } | |
7226 | ||
7227 | /* Implementation of the target_ops method "sw_breakpoint_from_kind". */ | |
7228 | ||
7229 | static const gdb_byte * | |
7230 | linux_sw_breakpoint_from_kind (int kind, int *size) | |
7231 | { | |
7232 | gdb_assert (the_low_target.sw_breakpoint_from_kind != NULL); | |
7233 | ||
7234 | return (*the_low_target.sw_breakpoint_from_kind) (kind, size); | |
7235 | } | |
7236 | ||
7237 | /* Implementation of the target_ops method | |
7238 | "breakpoint_kind_from_current_state". */ | |
7239 | ||
7240 | static int | |
7241 | linux_breakpoint_kind_from_current_state (CORE_ADDR *pcptr) | |
7242 | { | |
7243 | if (the_low_target.breakpoint_kind_from_current_state != NULL) | |
7244 | return (*the_low_target.breakpoint_kind_from_current_state) (pcptr); | |
7245 | else | |
7246 | return linux_breakpoint_kind_from_pc (pcptr); | |
7247 | } | |
7248 | ||
7249 | /* Default implementation of linux_target_ops method "set_pc" for | |
7250 | 32-bit pc register which is literally named "pc". */ | |
7251 | ||
7252 | void | |
7253 | linux_set_pc_32bit (struct regcache *regcache, CORE_ADDR pc) | |
7254 | { | |
7255 | uint32_t newpc = pc; | |
7256 | ||
7257 | supply_register_by_name (regcache, "pc", &newpc); | |
7258 | } | |
7259 | ||
7260 | /* Default implementation of linux_target_ops method "get_pc" for | |
7261 | 32-bit pc register which is literally named "pc". */ | |
7262 | ||
7263 | CORE_ADDR | |
7264 | linux_get_pc_32bit (struct regcache *regcache) | |
7265 | { | |
7266 | uint32_t pc; | |
7267 | ||
7268 | collect_register_by_name (regcache, "pc", &pc); | |
7269 | if (debug_threads) | |
7270 | debug_printf ("stop pc is 0x%" PRIx32 "\n", pc); | |
7271 | return pc; | |
7272 | } | |
7273 | ||
7274 | /* Default implementation of linux_target_ops method "set_pc" for | |
7275 | 64-bit pc register which is literally named "pc". */ | |
7276 | ||
7277 | void | |
7278 | linux_set_pc_64bit (struct regcache *regcache, CORE_ADDR pc) | |
7279 | { | |
7280 | uint64_t newpc = pc; | |
7281 | ||
7282 | supply_register_by_name (regcache, "pc", &newpc); | |
7283 | } | |
7284 | ||
7285 | /* Default implementation of linux_target_ops method "get_pc" for | |
7286 | 64-bit pc register which is literally named "pc". */ | |
7287 | ||
7288 | CORE_ADDR | |
7289 | linux_get_pc_64bit (struct regcache *regcache) | |
7290 | { | |
7291 | uint64_t pc; | |
7292 | ||
7293 | collect_register_by_name (regcache, "pc", &pc); | |
7294 | if (debug_threads) | |
7295 | debug_printf ("stop pc is 0x%" PRIx64 "\n", pc); | |
7296 | return pc; | |
7297 | } | |
7298 | ||
7299 | /* See linux-low.h. */ | |
7300 | ||
7301 | int | |
7302 | linux_get_auxv (int wordsize, CORE_ADDR match, CORE_ADDR *valp) | |
7303 | { | |
7304 | gdb_byte *data = (gdb_byte *) alloca (2 * wordsize); | |
7305 | int offset = 0; | |
7306 | ||
7307 | gdb_assert (wordsize == 4 || wordsize == 8); | |
7308 | ||
7309 | while ((*the_target->read_auxv) (offset, data, 2 * wordsize) == 2 * wordsize) | |
7310 | { | |
7311 | if (wordsize == 4) | |
7312 | { | |
7313 | uint32_t *data_p = (uint32_t *) data; | |
7314 | if (data_p[0] == match) | |
7315 | { | |
7316 | *valp = data_p[1]; | |
7317 | return 1; | |
7318 | } | |
7319 | } | |
7320 | else | |
7321 | { | |
7322 | uint64_t *data_p = (uint64_t *) data; | |
7323 | if (data_p[0] == match) | |
7324 | { | |
7325 | *valp = data_p[1]; | |
7326 | return 1; | |
7327 | } | |
7328 | } | |
7329 | ||
7330 | offset += 2 * wordsize; | |
7331 | } | |
7332 | ||
7333 | return 0; | |
7334 | } | |
7335 | ||
7336 | /* See linux-low.h. */ | |
7337 | ||
7338 | CORE_ADDR | |
7339 | linux_get_hwcap (int wordsize) | |
7340 | { | |
7341 | CORE_ADDR hwcap = 0; | |
7342 | linux_get_auxv (wordsize, AT_HWCAP, &hwcap); | |
7343 | return hwcap; | |
7344 | } | |
7345 | ||
7346 | /* See linux-low.h. */ | |
7347 | ||
7348 | CORE_ADDR | |
7349 | linux_get_hwcap2 (int wordsize) | |
7350 | { | |
7351 | CORE_ADDR hwcap2 = 0; | |
7352 | linux_get_auxv (wordsize, AT_HWCAP2, &hwcap2); | |
7353 | return hwcap2; | |
7354 | } | |
7355 | ||
7356 | static struct target_ops linux_target_ops = { | |
7357 | linux_create_inferior, | |
7358 | linux_post_create_inferior, | |
7359 | linux_attach, | |
7360 | linux_kill, | |
7361 | linux_detach, | |
7362 | linux_mourn, | |
7363 | linux_join, | |
7364 | linux_thread_alive, | |
7365 | linux_resume, | |
7366 | linux_wait, | |
7367 | linux_fetch_registers, | |
7368 | linux_store_registers, | |
7369 | linux_prepare_to_access_memory, | |
7370 | linux_done_accessing_memory, | |
7371 | linux_read_memory, | |
7372 | linux_write_memory, | |
7373 | linux_look_up_symbols, | |
7374 | linux_request_interrupt, | |
7375 | linux_read_auxv, | |
7376 | linux_supports_z_point_type, | |
7377 | linux_insert_point, | |
7378 | linux_remove_point, | |
7379 | linux_stopped_by_sw_breakpoint, | |
7380 | linux_supports_stopped_by_sw_breakpoint, | |
7381 | linux_stopped_by_hw_breakpoint, | |
7382 | linux_supports_stopped_by_hw_breakpoint, | |
7383 | linux_supports_hardware_single_step, | |
7384 | linux_stopped_by_watchpoint, | |
7385 | linux_stopped_data_address, | |
7386 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ | |
7387 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ | |
7388 | && defined(PT_TEXT_END_ADDR) | |
7389 | linux_read_offsets, | |
7390 | #else | |
7391 | NULL, | |
7392 | #endif | |
7393 | #ifdef USE_THREAD_DB | |
7394 | thread_db_get_tls_address, | |
7395 | #else | |
7396 | NULL, | |
7397 | #endif | |
7398 | hostio_last_error_from_errno, | |
7399 | linux_qxfer_osdata, | |
7400 | linux_xfer_siginfo, | |
7401 | linux_supports_non_stop, | |
7402 | linux_async, | |
7403 | linux_start_non_stop, | |
7404 | linux_supports_multi_process, | |
7405 | linux_supports_fork_events, | |
7406 | linux_supports_vfork_events, | |
7407 | linux_supports_exec_events, | |
7408 | linux_handle_new_gdb_connection, | |
7409 | #ifdef USE_THREAD_DB | |
7410 | thread_db_handle_monitor_command, | |
7411 | #else | |
7412 | NULL, | |
7413 | #endif | |
7414 | linux_common_core_of_thread, | |
7415 | linux_read_loadmap, | |
7416 | linux_process_qsupported, | |
7417 | linux_supports_tracepoints, | |
7418 | linux_read_pc, | |
7419 | linux_write_pc, | |
7420 | linux_thread_stopped, | |
7421 | NULL, | |
7422 | linux_pause_all, | |
7423 | linux_unpause_all, | |
7424 | linux_stabilize_threads, | |
7425 | linux_install_fast_tracepoint_jump_pad, | |
7426 | linux_emit_ops, | |
7427 | linux_supports_disable_randomization, | |
7428 | linux_get_min_fast_tracepoint_insn_len, | |
7429 | linux_qxfer_libraries_svr4, | |
7430 | linux_supports_agent, | |
7431 | #ifdef HAVE_LINUX_BTRACE | |
7432 | linux_enable_btrace, | |
7433 | linux_low_disable_btrace, | |
7434 | linux_low_read_btrace, | |
7435 | linux_low_btrace_conf, | |
7436 | #else | |
7437 | NULL, | |
7438 | NULL, | |
7439 | NULL, | |
7440 | NULL, | |
7441 | #endif | |
7442 | linux_supports_range_stepping, | |
7443 | linux_proc_pid_to_exec_file, | |
7444 | linux_mntns_open_cloexec, | |
7445 | linux_mntns_unlink, | |
7446 | linux_mntns_readlink, | |
7447 | linux_breakpoint_kind_from_pc, | |
7448 | linux_sw_breakpoint_from_kind, | |
7449 | linux_proc_tid_get_name, | |
7450 | linux_breakpoint_kind_from_current_state, | |
7451 | linux_supports_software_single_step, | |
7452 | linux_supports_catch_syscall, | |
7453 | linux_get_ipa_tdesc_idx, | |
7454 | #if USE_THREAD_DB | |
7455 | thread_db_thread_handle, | |
7456 | #else | |
7457 | NULL, | |
7458 | #endif | |
7459 | }; | |
7460 | ||
7461 | #ifdef HAVE_LINUX_REGSETS | |
7462 | void | |
7463 | initialize_regsets_info (struct regsets_info *info) | |
7464 | { | |
7465 | for (info->num_regsets = 0; | |
7466 | info->regsets[info->num_regsets].size >= 0; | |
7467 | info->num_regsets++) | |
7468 | ; | |
7469 | } | |
7470 | #endif | |
7471 | ||
7472 | void | |
7473 | initialize_low (void) | |
7474 | { | |
7475 | struct sigaction sigchld_action; | |
7476 | ||
7477 | memset (&sigchld_action, 0, sizeof (sigchld_action)); | |
7478 | set_target_ops (&linux_target_ops); | |
7479 | ||
7480 | linux_ptrace_init_warnings (); | |
7481 | linux_proc_init_warnings (); | |
7482 | ||
7483 | sigchld_action.sa_handler = sigchld_handler; | |
7484 | sigemptyset (&sigchld_action.sa_mask); | |
7485 | sigchld_action.sa_flags = SA_RESTART; | |
7486 | sigaction (SIGCHLD, &sigchld_action, NULL); | |
7487 | ||
7488 | initialize_low_arch (); | |
7489 | ||
7490 | linux_check_ptrace_features (); | |
7491 | } |