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1 | /* Low level interface to ptrace, for the remote server for GDB. | |
2 | Copyright (C) 1995-2015 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 "agent.h" | |
23 | #include "tdesc.h" | |
24 | #include "rsp-low.h" | |
25 | ||
26 | #include "nat/linux-nat.h" | |
27 | #include "nat/linux-waitpid.h" | |
28 | #include "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 "filestuff.h" | |
47 | #include "tracepoint.h" | |
48 | #include "hostio.h" | |
49 | #ifndef ELFMAG0 | |
50 | /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h | |
51 | then ELFMAG0 will have been defined. If it didn't get included by | |
52 | gdb_proc_service.h then including it will likely introduce a duplicate | |
53 | definition of elf_fpregset_t. */ | |
54 | #include <elf.h> | |
55 | #endif | |
56 | #include "nat/linux-namespaces.h" | |
57 | ||
58 | #ifndef SPUFS_MAGIC | |
59 | #define SPUFS_MAGIC 0x23c9b64e | |
60 | #endif | |
61 | ||
62 | #ifdef HAVE_PERSONALITY | |
63 | # include <sys/personality.h> | |
64 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
65 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
66 | # endif | |
67 | #endif | |
68 | ||
69 | #ifndef O_LARGEFILE | |
70 | #define O_LARGEFILE 0 | |
71 | #endif | |
72 | ||
73 | #ifndef W_STOPCODE | |
74 | #define W_STOPCODE(sig) ((sig) << 8 | 0x7f) | |
75 | #endif | |
76 | ||
77 | /* This is the kernel's hard limit. Not to be confused with | |
78 | SIGRTMIN. */ | |
79 | #ifndef __SIGRTMIN | |
80 | #define __SIGRTMIN 32 | |
81 | #endif | |
82 | ||
83 | /* Some targets did not define these ptrace constants from the start, | |
84 | so gdbserver defines them locally here. In the future, these may | |
85 | be removed after they are added to asm/ptrace.h. */ | |
86 | #if !(defined(PT_TEXT_ADDR) \ | |
87 | || defined(PT_DATA_ADDR) \ | |
88 | || defined(PT_TEXT_END_ADDR)) | |
89 | #if defined(__mcoldfire__) | |
90 | /* These are still undefined in 3.10 kernels. */ | |
91 | #define PT_TEXT_ADDR 49*4 | |
92 | #define PT_DATA_ADDR 50*4 | |
93 | #define PT_TEXT_END_ADDR 51*4 | |
94 | /* BFIN already defines these since at least 2.6.32 kernels. */ | |
95 | #elif defined(BFIN) | |
96 | #define PT_TEXT_ADDR 220 | |
97 | #define PT_TEXT_END_ADDR 224 | |
98 | #define PT_DATA_ADDR 228 | |
99 | /* These are still undefined in 3.10 kernels. */ | |
100 | #elif defined(__TMS320C6X__) | |
101 | #define PT_TEXT_ADDR (0x10000*4) | |
102 | #define PT_DATA_ADDR (0x10004*4) | |
103 | #define PT_TEXT_END_ADDR (0x10008*4) | |
104 | #endif | |
105 | #endif | |
106 | ||
107 | #ifdef HAVE_LINUX_BTRACE | |
108 | # include "nat/linux-btrace.h" | |
109 | # include "btrace-common.h" | |
110 | #endif | |
111 | ||
112 | #ifndef HAVE_ELF32_AUXV_T | |
113 | /* Copied from glibc's elf.h. */ | |
114 | typedef struct | |
115 | { | |
116 | uint32_t a_type; /* Entry type */ | |
117 | union | |
118 | { | |
119 | uint32_t a_val; /* Integer value */ | |
120 | /* We use to have pointer elements added here. We cannot do that, | |
121 | though, since it does not work when using 32-bit definitions | |
122 | on 64-bit platforms and vice versa. */ | |
123 | } a_un; | |
124 | } Elf32_auxv_t; | |
125 | #endif | |
126 | ||
127 | #ifndef HAVE_ELF64_AUXV_T | |
128 | /* Copied from glibc's elf.h. */ | |
129 | typedef struct | |
130 | { | |
131 | uint64_t a_type; /* Entry type */ | |
132 | union | |
133 | { | |
134 | uint64_t a_val; /* Integer value */ | |
135 | /* We use to have pointer elements added here. We cannot do that, | |
136 | though, since it does not work when using 32-bit definitions | |
137 | on 64-bit platforms and vice versa. */ | |
138 | } a_un; | |
139 | } Elf64_auxv_t; | |
140 | #endif | |
141 | ||
142 | /* LWP accessors. */ | |
143 | ||
144 | /* See nat/linux-nat.h. */ | |
145 | ||
146 | ptid_t | |
147 | ptid_of_lwp (struct lwp_info *lwp) | |
148 | { | |
149 | return ptid_of (get_lwp_thread (lwp)); | |
150 | } | |
151 | ||
152 | /* See nat/linux-nat.h. */ | |
153 | ||
154 | void | |
155 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
156 | struct arch_lwp_info *info) | |
157 | { | |
158 | lwp->arch_private = info; | |
159 | } | |
160 | ||
161 | /* See nat/linux-nat.h. */ | |
162 | ||
163 | struct arch_lwp_info * | |
164 | lwp_arch_private_info (struct lwp_info *lwp) | |
165 | { | |
166 | return lwp->arch_private; | |
167 | } | |
168 | ||
169 | /* See nat/linux-nat.h. */ | |
170 | ||
171 | int | |
172 | lwp_is_stopped (struct lwp_info *lwp) | |
173 | { | |
174 | return lwp->stopped; | |
175 | } | |
176 | ||
177 | /* See nat/linux-nat.h. */ | |
178 | ||
179 | enum target_stop_reason | |
180 | lwp_stop_reason (struct lwp_info *lwp) | |
181 | { | |
182 | return lwp->stop_reason; | |
183 | } | |
184 | ||
185 | /* A list of all unknown processes which receive stop signals. Some | |
186 | other process will presumably claim each of these as forked | |
187 | children momentarily. */ | |
188 | ||
189 | struct simple_pid_list | |
190 | { | |
191 | /* The process ID. */ | |
192 | int pid; | |
193 | ||
194 | /* The status as reported by waitpid. */ | |
195 | int status; | |
196 | ||
197 | /* Next in chain. */ | |
198 | struct simple_pid_list *next; | |
199 | }; | |
200 | struct simple_pid_list *stopped_pids; | |
201 | ||
202 | /* Trivial list manipulation functions to keep track of a list of new | |
203 | stopped processes. */ | |
204 | ||
205 | static void | |
206 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) | |
207 | { | |
208 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
209 | ||
210 | new_pid->pid = pid; | |
211 | new_pid->status = status; | |
212 | new_pid->next = *listp; | |
213 | *listp = new_pid; | |
214 | } | |
215 | ||
216 | static int | |
217 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) | |
218 | { | |
219 | struct simple_pid_list **p; | |
220 | ||
221 | for (p = listp; *p != NULL; p = &(*p)->next) | |
222 | if ((*p)->pid == pid) | |
223 | { | |
224 | struct simple_pid_list *next = (*p)->next; | |
225 | ||
226 | *statusp = (*p)->status; | |
227 | xfree (*p); | |
228 | *p = next; | |
229 | return 1; | |
230 | } | |
231 | return 0; | |
232 | } | |
233 | ||
234 | enum stopping_threads_kind | |
235 | { | |
236 | /* Not stopping threads presently. */ | |
237 | NOT_STOPPING_THREADS, | |
238 | ||
239 | /* Stopping threads. */ | |
240 | STOPPING_THREADS, | |
241 | ||
242 | /* Stopping and suspending threads. */ | |
243 | STOPPING_AND_SUSPENDING_THREADS | |
244 | }; | |
245 | ||
246 | /* This is set while stop_all_lwps is in effect. */ | |
247 | enum stopping_threads_kind stopping_threads = NOT_STOPPING_THREADS; | |
248 | ||
249 | /* FIXME make into a target method? */ | |
250 | int using_threads = 1; | |
251 | ||
252 | /* True if we're presently stabilizing threads (moving them out of | |
253 | jump pads). */ | |
254 | static int stabilizing_threads; | |
255 | ||
256 | static void linux_resume_one_lwp (struct lwp_info *lwp, | |
257 | int step, int signal, siginfo_t *info); | |
258 | static void linux_resume (struct thread_resume *resume_info, size_t n); | |
259 | static void stop_all_lwps (int suspend, struct lwp_info *except); | |
260 | static void unstop_all_lwps (int unsuspend, struct lwp_info *except); | |
261 | static int linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, | |
262 | int *wstat, int options); | |
263 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); | |
264 | static struct lwp_info *add_lwp (ptid_t ptid); | |
265 | static int linux_stopped_by_watchpoint (void); | |
266 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); | |
267 | static void proceed_all_lwps (void); | |
268 | static int finish_step_over (struct lwp_info *lwp); | |
269 | static int kill_lwp (unsigned long lwpid, int signo); | |
270 | ||
271 | /* When the event-loop is doing a step-over, this points at the thread | |
272 | being stepped. */ | |
273 | ptid_t step_over_bkpt; | |
274 | ||
275 | /* True if the low target can hardware single-step. Such targets | |
276 | don't need a BREAKPOINT_REINSERT_ADDR callback. */ | |
277 | ||
278 | static int | |
279 | can_hardware_single_step (void) | |
280 | { | |
281 | return (the_low_target.breakpoint_reinsert_addr == NULL); | |
282 | } | |
283 | ||
284 | /* True if the low target supports memory breakpoints. If so, we'll | |
285 | have a GET_PC implementation. */ | |
286 | ||
287 | static int | |
288 | supports_breakpoints (void) | |
289 | { | |
290 | return (the_low_target.get_pc != NULL); | |
291 | } | |
292 | ||
293 | /* Returns true if this target can support fast tracepoints. This | |
294 | does not mean that the in-process agent has been loaded in the | |
295 | inferior. */ | |
296 | ||
297 | static int | |
298 | supports_fast_tracepoints (void) | |
299 | { | |
300 | return the_low_target.install_fast_tracepoint_jump_pad != NULL; | |
301 | } | |
302 | ||
303 | /* True if LWP is stopped in its stepping range. */ | |
304 | ||
305 | static int | |
306 | lwp_in_step_range (struct lwp_info *lwp) | |
307 | { | |
308 | CORE_ADDR pc = lwp->stop_pc; | |
309 | ||
310 | return (pc >= lwp->step_range_start && pc < lwp->step_range_end); | |
311 | } | |
312 | ||
313 | struct pending_signals | |
314 | { | |
315 | int signal; | |
316 | siginfo_t info; | |
317 | struct pending_signals *prev; | |
318 | }; | |
319 | ||
320 | /* The read/write ends of the pipe registered as waitable file in the | |
321 | event loop. */ | |
322 | static int linux_event_pipe[2] = { -1, -1 }; | |
323 | ||
324 | /* True if we're currently in async mode. */ | |
325 | #define target_is_async_p() (linux_event_pipe[0] != -1) | |
326 | ||
327 | static void send_sigstop (struct lwp_info *lwp); | |
328 | static void wait_for_sigstop (void); | |
329 | ||
330 | /* Return non-zero if HEADER is a 64-bit ELF file. */ | |
331 | ||
332 | static int | |
333 | elf_64_header_p (const Elf64_Ehdr *header, unsigned int *machine) | |
334 | { | |
335 | if (header->e_ident[EI_MAG0] == ELFMAG0 | |
336 | && header->e_ident[EI_MAG1] == ELFMAG1 | |
337 | && header->e_ident[EI_MAG2] == ELFMAG2 | |
338 | && header->e_ident[EI_MAG3] == ELFMAG3) | |
339 | { | |
340 | *machine = header->e_machine; | |
341 | return header->e_ident[EI_CLASS] == ELFCLASS64; | |
342 | ||
343 | } | |
344 | *machine = EM_NONE; | |
345 | return -1; | |
346 | } | |
347 | ||
348 | /* Return non-zero if FILE is a 64-bit ELF file, | |
349 | zero if the file is not a 64-bit ELF file, | |
350 | and -1 if the file is not accessible or doesn't exist. */ | |
351 | ||
352 | static int | |
353 | elf_64_file_p (const char *file, unsigned int *machine) | |
354 | { | |
355 | Elf64_Ehdr header; | |
356 | int fd; | |
357 | ||
358 | fd = open (file, O_RDONLY); | |
359 | if (fd < 0) | |
360 | return -1; | |
361 | ||
362 | if (read (fd, &header, sizeof (header)) != sizeof (header)) | |
363 | { | |
364 | close (fd); | |
365 | return 0; | |
366 | } | |
367 | close (fd); | |
368 | ||
369 | return elf_64_header_p (&header, machine); | |
370 | } | |
371 | ||
372 | /* Accepts an integer PID; Returns true if the executable PID is | |
373 | running is a 64-bit ELF file.. */ | |
374 | ||
375 | int | |
376 | linux_pid_exe_is_elf_64_file (int pid, unsigned int *machine) | |
377 | { | |
378 | char file[PATH_MAX]; | |
379 | ||
380 | sprintf (file, "/proc/%d/exe", pid); | |
381 | return elf_64_file_p (file, machine); | |
382 | } | |
383 | ||
384 | static void | |
385 | delete_lwp (struct lwp_info *lwp) | |
386 | { | |
387 | struct thread_info *thr = get_lwp_thread (lwp); | |
388 | ||
389 | if (debug_threads) | |
390 | debug_printf ("deleting %ld\n", lwpid_of (thr)); | |
391 | ||
392 | remove_thread (thr); | |
393 | free (lwp->arch_private); | |
394 | free (lwp); | |
395 | } | |
396 | ||
397 | /* Add a process to the common process list, and set its private | |
398 | data. */ | |
399 | ||
400 | static struct process_info * | |
401 | linux_add_process (int pid, int attached) | |
402 | { | |
403 | struct process_info *proc; | |
404 | ||
405 | proc = add_process (pid, attached); | |
406 | proc->priv = xcalloc (1, sizeof (*proc->priv)); | |
407 | ||
408 | if (the_low_target.new_process != NULL) | |
409 | proc->priv->arch_private = the_low_target.new_process (); | |
410 | ||
411 | return proc; | |
412 | } | |
413 | ||
414 | static CORE_ADDR get_pc (struct lwp_info *lwp); | |
415 | ||
416 | /* Handle a GNU/Linux extended wait response. If we see a clone | |
417 | event, we need to add the new LWP to our list (and return 0 so as | |
418 | not to report the trap to higher layers). */ | |
419 | ||
420 | static int | |
421 | handle_extended_wait (struct lwp_info *event_lwp, int wstat) | |
422 | { | |
423 | int event = linux_ptrace_get_extended_event (wstat); | |
424 | struct thread_info *event_thr = get_lwp_thread (event_lwp); | |
425 | struct lwp_info *new_lwp; | |
426 | ||
427 | if ((event == PTRACE_EVENT_FORK) || (event == PTRACE_EVENT_VFORK) | |
428 | || (event == PTRACE_EVENT_CLONE)) | |
429 | { | |
430 | ptid_t ptid; | |
431 | unsigned long new_pid; | |
432 | int ret, status; | |
433 | ||
434 | /* Get the pid of the new lwp. */ | |
435 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_thr), (PTRACE_TYPE_ARG3) 0, | |
436 | &new_pid); | |
437 | ||
438 | /* If we haven't already seen the new PID stop, wait for it now. */ | |
439 | if (!pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
440 | { | |
441 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
442 | hits the SIGSTOP, but we're already attached. */ | |
443 | ||
444 | ret = my_waitpid (new_pid, &status, __WALL); | |
445 | ||
446 | if (ret == -1) | |
447 | perror_with_name ("waiting for new child"); | |
448 | else if (ret != new_pid) | |
449 | warning ("wait returned unexpected PID %d", ret); | |
450 | else if (!WIFSTOPPED (status)) | |
451 | warning ("wait returned unexpected status 0x%x", status); | |
452 | } | |
453 | ||
454 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) | |
455 | { | |
456 | struct process_info *parent_proc; | |
457 | struct process_info *child_proc; | |
458 | struct lwp_info *child_lwp; | |
459 | struct thread_info *child_thr; | |
460 | struct target_desc *tdesc; | |
461 | ||
462 | ptid = ptid_build (new_pid, new_pid, 0); | |
463 | ||
464 | if (debug_threads) | |
465 | { | |
466 | debug_printf ("HEW: Got fork event from LWP %ld, " | |
467 | "new child is %d\n", | |
468 | ptid_get_lwp (ptid_of (event_thr)), | |
469 | ptid_get_pid (ptid)); | |
470 | } | |
471 | ||
472 | /* Add the new process to the tables and clone the breakpoint | |
473 | lists of the parent. We need to do this even if the new process | |
474 | will be detached, since we will need the process object and the | |
475 | breakpoints to remove any breakpoints from memory when we | |
476 | detach, and the client side will access registers. */ | |
477 | child_proc = linux_add_process (new_pid, 0); | |
478 | gdb_assert (child_proc != NULL); | |
479 | child_lwp = add_lwp (ptid); | |
480 | gdb_assert (child_lwp != NULL); | |
481 | child_lwp->stopped = 1; | |
482 | child_lwp->must_set_ptrace_flags = 1; | |
483 | child_lwp->status_pending_p = 0; | |
484 | child_thr = get_lwp_thread (child_lwp); | |
485 | child_thr->last_resume_kind = resume_stop; | |
486 | child_thr->last_status.kind = TARGET_WAITKIND_STOPPED; | |
487 | ||
488 | parent_proc = get_thread_process (event_thr); | |
489 | child_proc->attached = parent_proc->attached; | |
490 | clone_all_breakpoints (&child_proc->breakpoints, | |
491 | &child_proc->raw_breakpoints, | |
492 | parent_proc->breakpoints); | |
493 | ||
494 | tdesc = xmalloc (sizeof (struct target_desc)); | |
495 | copy_target_description (tdesc, parent_proc->tdesc); | |
496 | child_proc->tdesc = tdesc; | |
497 | ||
498 | /* Clone arch-specific process data. */ | |
499 | if (the_low_target.new_fork != NULL) | |
500 | the_low_target.new_fork (parent_proc, child_proc); | |
501 | ||
502 | /* Save fork info in the parent thread. */ | |
503 | if (event == PTRACE_EVENT_FORK) | |
504 | event_lwp->waitstatus.kind = TARGET_WAITKIND_FORKED; | |
505 | else if (event == PTRACE_EVENT_VFORK) | |
506 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORKED; | |
507 | ||
508 | event_lwp->waitstatus.value.related_pid = ptid; | |
509 | ||
510 | /* The status_pending field contains bits denoting the | |
511 | extended event, so when the pending event is handled, | |
512 | the handler will look at lwp->waitstatus. */ | |
513 | event_lwp->status_pending_p = 1; | |
514 | event_lwp->status_pending = wstat; | |
515 | ||
516 | /* Report the event. */ | |
517 | return 0; | |
518 | } | |
519 | ||
520 | if (debug_threads) | |
521 | debug_printf ("HEW: Got clone event " | |
522 | "from LWP %ld, new child is LWP %ld\n", | |
523 | lwpid_of (event_thr), new_pid); | |
524 | ||
525 | ptid = ptid_build (pid_of (event_thr), new_pid, 0); | |
526 | new_lwp = add_lwp (ptid); | |
527 | ||
528 | /* Either we're going to immediately resume the new thread | |
529 | or leave it stopped. linux_resume_one_lwp is a nop if it | |
530 | thinks the thread is currently running, so set this first | |
531 | before calling linux_resume_one_lwp. */ | |
532 | new_lwp->stopped = 1; | |
533 | ||
534 | /* If we're suspending all threads, leave this one suspended | |
535 | too. */ | |
536 | if (stopping_threads == STOPPING_AND_SUSPENDING_THREADS) | |
537 | new_lwp->suspended = 1; | |
538 | ||
539 | /* Normally we will get the pending SIGSTOP. But in some cases | |
540 | we might get another signal delivered to the group first. | |
541 | If we do get another signal, be sure not to lose it. */ | |
542 | if (WSTOPSIG (status) != SIGSTOP) | |
543 | { | |
544 | new_lwp->stop_expected = 1; | |
545 | new_lwp->status_pending_p = 1; | |
546 | new_lwp->status_pending = status; | |
547 | } | |
548 | ||
549 | /* Don't report the event. */ | |
550 | return 1; | |
551 | } | |
552 | else if (event == PTRACE_EVENT_VFORK_DONE) | |
553 | { | |
554 | event_lwp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
555 | ||
556 | /* Report the event. */ | |
557 | return 0; | |
558 | } | |
559 | ||
560 | internal_error (__FILE__, __LINE__, _("unknown ptrace event %d"), event); | |
561 | } | |
562 | ||
563 | /* Return the PC as read from the regcache of LWP, without any | |
564 | adjustment. */ | |
565 | ||
566 | static CORE_ADDR | |
567 | get_pc (struct lwp_info *lwp) | |
568 | { | |
569 | struct thread_info *saved_thread; | |
570 | struct regcache *regcache; | |
571 | CORE_ADDR pc; | |
572 | ||
573 | if (the_low_target.get_pc == NULL) | |
574 | return 0; | |
575 | ||
576 | saved_thread = current_thread; | |
577 | current_thread = get_lwp_thread (lwp); | |
578 | ||
579 | regcache = get_thread_regcache (current_thread, 1); | |
580 | pc = (*the_low_target.get_pc) (regcache); | |
581 | ||
582 | if (debug_threads) | |
583 | debug_printf ("pc is 0x%lx\n", (long) pc); | |
584 | ||
585 | current_thread = saved_thread; | |
586 | return pc; | |
587 | } | |
588 | ||
589 | /* This function should only be called if LWP got a SIGTRAP. | |
590 | The SIGTRAP could mean several things. | |
591 | ||
592 | On i386, where decr_pc_after_break is non-zero: | |
593 | ||
594 | If we were single-stepping this process using PTRACE_SINGLESTEP, we | |
595 | will get only the one SIGTRAP. The value of $eip will be the next | |
596 | instruction. If the instruction we stepped over was a breakpoint, | |
597 | we need to decrement the PC. | |
598 | ||
599 | If we continue the process using PTRACE_CONT, we will get a | |
600 | SIGTRAP when we hit a breakpoint. The value of $eip will be | |
601 | the instruction after the breakpoint (i.e. needs to be | |
602 | decremented). If we report the SIGTRAP to GDB, we must also | |
603 | report the undecremented PC. If the breakpoint is removed, we | |
604 | must resume at the decremented PC. | |
605 | ||
606 | On a non-decr_pc_after_break machine with hardware or kernel | |
607 | single-step: | |
608 | ||
609 | If we either single-step a breakpoint instruction, or continue and | |
610 | hit a breakpoint instruction, our PC will point at the breakpoint | |
611 | instruction. */ | |
612 | ||
613 | static int | |
614 | check_stopped_by_breakpoint (struct lwp_info *lwp) | |
615 | { | |
616 | CORE_ADDR pc; | |
617 | CORE_ADDR sw_breakpoint_pc; | |
618 | struct thread_info *saved_thread; | |
619 | #if USE_SIGTRAP_SIGINFO | |
620 | siginfo_t siginfo; | |
621 | #endif | |
622 | ||
623 | if (the_low_target.get_pc == NULL) | |
624 | return 0; | |
625 | ||
626 | pc = get_pc (lwp); | |
627 | sw_breakpoint_pc = pc - the_low_target.decr_pc_after_break; | |
628 | ||
629 | /* breakpoint_at reads from the current thread. */ | |
630 | saved_thread = current_thread; | |
631 | current_thread = get_lwp_thread (lwp); | |
632 | ||
633 | #if USE_SIGTRAP_SIGINFO | |
634 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
635 | (PTRACE_TYPE_ARG3) 0, &siginfo) == 0) | |
636 | { | |
637 | if (siginfo.si_signo == SIGTRAP) | |
638 | { | |
639 | if (siginfo.si_code == GDB_ARCH_TRAP_BRKPT) | |
640 | { | |
641 | if (debug_threads) | |
642 | { | |
643 | struct thread_info *thr = get_lwp_thread (lwp); | |
644 | ||
645 | debug_printf ("CSBB: %s stopped by software breakpoint\n", | |
646 | target_pid_to_str (ptid_of (thr))); | |
647 | } | |
648 | ||
649 | /* Back up the PC if necessary. */ | |
650 | if (pc != sw_breakpoint_pc) | |
651 | { | |
652 | struct regcache *regcache | |
653 | = get_thread_regcache (current_thread, 1); | |
654 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); | |
655 | } | |
656 | ||
657 | lwp->stop_pc = sw_breakpoint_pc; | |
658 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
659 | current_thread = saved_thread; | |
660 | return 1; | |
661 | } | |
662 | else if (siginfo.si_code == TRAP_HWBKPT) | |
663 | { | |
664 | if (debug_threads) | |
665 | { | |
666 | struct thread_info *thr = get_lwp_thread (lwp); | |
667 | ||
668 | debug_printf ("CSBB: %s stopped by hardware " | |
669 | "breakpoint/watchpoint\n", | |
670 | target_pid_to_str (ptid_of (thr))); | |
671 | } | |
672 | ||
673 | lwp->stop_pc = pc; | |
674 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
675 | current_thread = saved_thread; | |
676 | return 1; | |
677 | } | |
678 | else if (siginfo.si_code == TRAP_TRACE) | |
679 | { | |
680 | if (debug_threads) | |
681 | { | |
682 | struct thread_info *thr = get_lwp_thread (lwp); | |
683 | ||
684 | debug_printf ("CSBB: %s stopped by trace\n", | |
685 | target_pid_to_str (ptid_of (thr))); | |
686 | } | |
687 | } | |
688 | } | |
689 | } | |
690 | #else | |
691 | /* We may have just stepped a breakpoint instruction. E.g., in | |
692 | non-stop mode, GDB first tells the thread A to step a range, and | |
693 | then the user inserts a breakpoint inside the range. In that | |
694 | case we need to report the breakpoint PC. */ | |
695 | if ((!lwp->stepping || lwp->stop_pc == sw_breakpoint_pc) | |
696 | && (*the_low_target.breakpoint_at) (sw_breakpoint_pc)) | |
697 | { | |
698 | if (debug_threads) | |
699 | { | |
700 | struct thread_info *thr = get_lwp_thread (lwp); | |
701 | ||
702 | debug_printf ("CSBB: %s stopped by software breakpoint\n", | |
703 | target_pid_to_str (ptid_of (thr))); | |
704 | } | |
705 | ||
706 | /* Back up the PC if necessary. */ | |
707 | if (pc != sw_breakpoint_pc) | |
708 | { | |
709 | struct regcache *regcache | |
710 | = get_thread_regcache (current_thread, 1); | |
711 | (*the_low_target.set_pc) (regcache, sw_breakpoint_pc); | |
712 | } | |
713 | ||
714 | lwp->stop_pc = sw_breakpoint_pc; | |
715 | lwp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
716 | current_thread = saved_thread; | |
717 | return 1; | |
718 | } | |
719 | ||
720 | if (hardware_breakpoint_inserted_here (pc)) | |
721 | { | |
722 | if (debug_threads) | |
723 | { | |
724 | struct thread_info *thr = get_lwp_thread (lwp); | |
725 | ||
726 | debug_printf ("CSBB: %s stopped by hardware breakpoint\n", | |
727 | target_pid_to_str (ptid_of (thr))); | |
728 | } | |
729 | ||
730 | lwp->stop_pc = pc; | |
731 | lwp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
732 | current_thread = saved_thread; | |
733 | return 1; | |
734 | } | |
735 | #endif | |
736 | ||
737 | current_thread = saved_thread; | |
738 | return 0; | |
739 | } | |
740 | ||
741 | static struct lwp_info * | |
742 | add_lwp (ptid_t ptid) | |
743 | { | |
744 | struct lwp_info *lwp; | |
745 | ||
746 | lwp = (struct lwp_info *) xmalloc (sizeof (*lwp)); | |
747 | memset (lwp, 0, sizeof (*lwp)); | |
748 | ||
749 | if (the_low_target.new_thread != NULL) | |
750 | the_low_target.new_thread (lwp); | |
751 | ||
752 | lwp->thread = add_thread (ptid, lwp); | |
753 | ||
754 | return lwp; | |
755 | } | |
756 | ||
757 | /* Start an inferior process and returns its pid. | |
758 | ALLARGS is a vector of program-name and args. */ | |
759 | ||
760 | static int | |
761 | linux_create_inferior (char *program, char **allargs) | |
762 | { | |
763 | struct lwp_info *new_lwp; | |
764 | int pid; | |
765 | ptid_t ptid; | |
766 | struct cleanup *restore_personality | |
767 | = maybe_disable_address_space_randomization (disable_randomization); | |
768 | ||
769 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) | |
770 | pid = vfork (); | |
771 | #else | |
772 | pid = fork (); | |
773 | #endif | |
774 | if (pid < 0) | |
775 | perror_with_name ("fork"); | |
776 | ||
777 | if (pid == 0) | |
778 | { | |
779 | close_most_fds (); | |
780 | ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); | |
781 | ||
782 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ | |
783 | signal (__SIGRTMIN + 1, SIG_DFL); | |
784 | #endif | |
785 | ||
786 | setpgid (0, 0); | |
787 | ||
788 | /* If gdbserver is connected to gdb via stdio, redirect the inferior's | |
789 | stdout to stderr so that inferior i/o doesn't corrupt the connection. | |
790 | Also, redirect stdin to /dev/null. */ | |
791 | if (remote_connection_is_stdio ()) | |
792 | { | |
793 | close (0); | |
794 | open ("/dev/null", O_RDONLY); | |
795 | dup2 (2, 1); | |
796 | if (write (2, "stdin/stdout redirected\n", | |
797 | sizeof ("stdin/stdout redirected\n") - 1) < 0) | |
798 | { | |
799 | /* Errors ignored. */; | |
800 | } | |
801 | } | |
802 | ||
803 | execv (program, allargs); | |
804 | if (errno == ENOENT) | |
805 | execvp (program, allargs); | |
806 | ||
807 | fprintf (stderr, "Cannot exec %s: %s.\n", program, | |
808 | strerror (errno)); | |
809 | fflush (stderr); | |
810 | _exit (0177); | |
811 | } | |
812 | ||
813 | do_cleanups (restore_personality); | |
814 | ||
815 | linux_add_process (pid, 0); | |
816 | ||
817 | ptid = ptid_build (pid, pid, 0); | |
818 | new_lwp = add_lwp (ptid); | |
819 | new_lwp->must_set_ptrace_flags = 1; | |
820 | ||
821 | return pid; | |
822 | } | |
823 | ||
824 | /* Implement the arch_setup target_ops method. */ | |
825 | ||
826 | static void | |
827 | linux_arch_setup (void) | |
828 | { | |
829 | the_low_target.arch_setup (); | |
830 | } | |
831 | ||
832 | /* Attach to an inferior process. Returns 0 on success, ERRNO on | |
833 | error. */ | |
834 | ||
835 | int | |
836 | linux_attach_lwp (ptid_t ptid) | |
837 | { | |
838 | struct lwp_info *new_lwp; | |
839 | int lwpid = ptid_get_lwp (ptid); | |
840 | ||
841 | if (ptrace (PTRACE_ATTACH, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0) | |
842 | != 0) | |
843 | return errno; | |
844 | ||
845 | new_lwp = add_lwp (ptid); | |
846 | ||
847 | /* We need to wait for SIGSTOP before being able to make the next | |
848 | ptrace call on this LWP. */ | |
849 | new_lwp->must_set_ptrace_flags = 1; | |
850 | ||
851 | if (linux_proc_pid_is_stopped (lwpid)) | |
852 | { | |
853 | if (debug_threads) | |
854 | debug_printf ("Attached to a stopped process\n"); | |
855 | ||
856 | /* The process is definitely stopped. It is in a job control | |
857 | stop, unless the kernel predates the TASK_STOPPED / | |
858 | TASK_TRACED distinction, in which case it might be in a | |
859 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
860 | can kill it, signal it, et cetera. | |
861 | ||
862 | First make sure there is a pending SIGSTOP. Since we are | |
863 | already attached, the process can not transition from stopped | |
864 | to running without a PTRACE_CONT; so we know this signal will | |
865 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
866 | probably already in the queue (unless this kernel is old | |
867 | enough to use TASK_STOPPED for ptrace stops); but since | |
868 | SIGSTOP is not an RT signal, it can only be queued once. */ | |
869 | kill_lwp (lwpid, SIGSTOP); | |
870 | ||
871 | /* Finally, resume the stopped process. This will deliver the | |
872 | SIGSTOP (or a higher priority signal, just like normal | |
873 | PTRACE_ATTACH), which we'll catch later on. */ | |
874 | ptrace (PTRACE_CONT, lwpid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); | |
875 | } | |
876 | ||
877 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH | |
878 | brings it to a halt. | |
879 | ||
880 | There are several cases to consider here: | |
881 | ||
882 | 1) gdbserver has already attached to the process and is being notified | |
883 | of a new thread that is being created. | |
884 | In this case we should ignore that SIGSTOP and resume the | |
885 | process. This is handled below by setting stop_expected = 1, | |
886 | and the fact that add_thread sets last_resume_kind == | |
887 | resume_continue. | |
888 | ||
889 | 2) This is the first thread (the process thread), and we're attaching | |
890 | to it via attach_inferior. | |
891 | In this case we want the process thread to stop. | |
892 | This is handled by having linux_attach set last_resume_kind == | |
893 | resume_stop after we return. | |
894 | ||
895 | If the pid we are attaching to is also the tgid, we attach to and | |
896 | stop all the existing threads. Otherwise, we attach to pid and | |
897 | ignore any other threads in the same group as this pid. | |
898 | ||
899 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all | |
900 | existing threads. | |
901 | In this case we want the thread to stop. | |
902 | FIXME: This case is currently not properly handled. | |
903 | We should wait for the SIGSTOP but don't. Things work apparently | |
904 | because enough time passes between when we ptrace (ATTACH) and when | |
905 | gdb makes the next ptrace call on the thread. | |
906 | ||
907 | On the other hand, if we are currently trying to stop all threads, we | |
908 | should treat the new thread as if we had sent it a SIGSTOP. This works | |
909 | because we are guaranteed that the add_lwp call above added us to the | |
910 | end of the list, and so the new thread has not yet reached | |
911 | wait_for_sigstop (but will). */ | |
912 | new_lwp->stop_expected = 1; | |
913 | ||
914 | return 0; | |
915 | } | |
916 | ||
917 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not | |
918 | already attached. Returns true if a new LWP is found, false | |
919 | otherwise. */ | |
920 | ||
921 | static int | |
922 | attach_proc_task_lwp_callback (ptid_t ptid) | |
923 | { | |
924 | /* Is this a new thread? */ | |
925 | if (find_thread_ptid (ptid) == NULL) | |
926 | { | |
927 | int lwpid = ptid_get_lwp (ptid); | |
928 | int err; | |
929 | ||
930 | if (debug_threads) | |
931 | debug_printf ("Found new lwp %d\n", lwpid); | |
932 | ||
933 | err = linux_attach_lwp (ptid); | |
934 | ||
935 | /* Be quiet if we simply raced with the thread exiting. EPERM | |
936 | is returned if the thread's task still exists, and is marked | |
937 | as exited or zombie, as well as other conditions, so in that | |
938 | case, confirm the status in /proc/PID/status. */ | |
939 | if (err == ESRCH | |
940 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
941 | { | |
942 | if (debug_threads) | |
943 | { | |
944 | debug_printf ("Cannot attach to lwp %d: " | |
945 | "thread is gone (%d: %s)\n", | |
946 | lwpid, err, strerror (err)); | |
947 | } | |
948 | } | |
949 | else if (err != 0) | |
950 | { | |
951 | warning (_("Cannot attach to lwp %d: %s"), | |
952 | lwpid, | |
953 | linux_ptrace_attach_fail_reason_string (ptid, err)); | |
954 | } | |
955 | ||
956 | return 1; | |
957 | } | |
958 | return 0; | |
959 | } | |
960 | ||
961 | /* Attach to PID. If PID is the tgid, attach to it and all | |
962 | of its threads. */ | |
963 | ||
964 | static int | |
965 | linux_attach (unsigned long pid) | |
966 | { | |
967 | ptid_t ptid = ptid_build (pid, pid, 0); | |
968 | int err; | |
969 | ||
970 | /* Attach to PID. We will check for other threads | |
971 | soon. */ | |
972 | err = linux_attach_lwp (ptid); | |
973 | if (err != 0) | |
974 | error ("Cannot attach to process %ld: %s", | |
975 | pid, linux_ptrace_attach_fail_reason_string (ptid, err)); | |
976 | ||
977 | linux_add_process (pid, 1); | |
978 | ||
979 | if (!non_stop) | |
980 | { | |
981 | struct thread_info *thread; | |
982 | ||
983 | /* Don't ignore the initial SIGSTOP if we just attached to this | |
984 | process. It will be collected by wait shortly. */ | |
985 | thread = find_thread_ptid (ptid_build (pid, pid, 0)); | |
986 | thread->last_resume_kind = resume_stop; | |
987 | } | |
988 | ||
989 | /* We must attach to every LWP. If /proc is mounted, use that to | |
990 | find them now. On the one hand, the inferior may be using raw | |
991 | clone instead of using pthreads. On the other hand, even if it | |
992 | is using pthreads, GDB may not be connected yet (thread_db needs | |
993 | to do symbol lookups, through qSymbol). Also, thread_db walks | |
994 | structures in the inferior's address space to find the list of | |
995 | threads/LWPs, and those structures may well be corrupted. Note | |
996 | that once thread_db is loaded, we'll still use it to list threads | |
997 | and associate pthread info with each LWP. */ | |
998 | linux_proc_attach_tgid_threads (pid, attach_proc_task_lwp_callback); | |
999 | return 0; | |
1000 | } | |
1001 | ||
1002 | struct counter | |
1003 | { | |
1004 | int pid; | |
1005 | int count; | |
1006 | }; | |
1007 | ||
1008 | static int | |
1009 | second_thread_of_pid_p (struct inferior_list_entry *entry, void *args) | |
1010 | { | |
1011 | struct counter *counter = args; | |
1012 | ||
1013 | if (ptid_get_pid (entry->id) == counter->pid) | |
1014 | { | |
1015 | if (++counter->count > 1) | |
1016 | return 1; | |
1017 | } | |
1018 | ||
1019 | return 0; | |
1020 | } | |
1021 | ||
1022 | static int | |
1023 | last_thread_of_process_p (int pid) | |
1024 | { | |
1025 | struct counter counter = { pid , 0 }; | |
1026 | ||
1027 | return (find_inferior (&all_threads, | |
1028 | second_thread_of_pid_p, &counter) == NULL); | |
1029 | } | |
1030 | ||
1031 | /* Kill LWP. */ | |
1032 | ||
1033 | static void | |
1034 | linux_kill_one_lwp (struct lwp_info *lwp) | |
1035 | { | |
1036 | struct thread_info *thr = get_lwp_thread (lwp); | |
1037 | int pid = lwpid_of (thr); | |
1038 | ||
1039 | /* PTRACE_KILL is unreliable. After stepping into a signal handler, | |
1040 | there is no signal context, and ptrace(PTRACE_KILL) (or | |
1041 | ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like | |
1042 | ptrace(CONT, pid, 0,0) and just resumes the tracee. A better | |
1043 | alternative is to kill with SIGKILL. We only need one SIGKILL | |
1044 | per process, not one for each thread. But since we still support | |
1045 | linuxthreads, and we also support debugging programs using raw | |
1046 | clone without CLONE_THREAD, we send one for each thread. For | |
1047 | years, we used PTRACE_KILL only, so we're being a bit paranoid | |
1048 | about some old kernels where PTRACE_KILL might work better | |
1049 | (dubious if there are any such, but that's why it's paranoia), so | |
1050 | we try SIGKILL first, PTRACE_KILL second, and so we're fine | |
1051 | everywhere. */ | |
1052 | ||
1053 | errno = 0; | |
1054 | kill_lwp (pid, SIGKILL); | |
1055 | if (debug_threads) | |
1056 | { | |
1057 | int save_errno = errno; | |
1058 | ||
1059 | debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n", | |
1060 | target_pid_to_str (ptid_of (thr)), | |
1061 | save_errno ? strerror (save_errno) : "OK"); | |
1062 | } | |
1063 | ||
1064 | errno = 0; | |
1065 | ptrace (PTRACE_KILL, pid, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0); | |
1066 | if (debug_threads) | |
1067 | { | |
1068 | int save_errno = errno; | |
1069 | ||
1070 | debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n", | |
1071 | target_pid_to_str (ptid_of (thr)), | |
1072 | save_errno ? strerror (save_errno) : "OK"); | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | /* Kill LWP and wait for it to die. */ | |
1077 | ||
1078 | static void | |
1079 | kill_wait_lwp (struct lwp_info *lwp) | |
1080 | { | |
1081 | struct thread_info *thr = get_lwp_thread (lwp); | |
1082 | int pid = ptid_get_pid (ptid_of (thr)); | |
1083 | int lwpid = ptid_get_lwp (ptid_of (thr)); | |
1084 | int wstat; | |
1085 | int res; | |
1086 | ||
1087 | if (debug_threads) | |
1088 | debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid, pid); | |
1089 | ||
1090 | do | |
1091 | { | |
1092 | linux_kill_one_lwp (lwp); | |
1093 | ||
1094 | /* Make sure it died. Notes: | |
1095 | ||
1096 | - The loop is most likely unnecessary. | |
1097 | ||
1098 | - We don't use linux_wait_for_event as that could delete lwps | |
1099 | while we're iterating over them. We're not interested in | |
1100 | any pending status at this point, only in making sure all | |
1101 | wait status on the kernel side are collected until the | |
1102 | process is reaped. | |
1103 | ||
1104 | - We don't use __WALL here as the __WALL emulation relies on | |
1105 | SIGCHLD, and killing a stopped process doesn't generate | |
1106 | one, nor an exit status. | |
1107 | */ | |
1108 | res = my_waitpid (lwpid, &wstat, 0); | |
1109 | if (res == -1 && errno == ECHILD) | |
1110 | res = my_waitpid (lwpid, &wstat, __WCLONE); | |
1111 | } while (res > 0 && WIFSTOPPED (wstat)); | |
1112 | ||
1113 | /* Even if it was stopped, the child may have already disappeared. | |
1114 | E.g., if it was killed by SIGKILL. */ | |
1115 | if (res < 0 && errno != ECHILD) | |
1116 | perror_with_name ("kill_wait_lwp"); | |
1117 | } | |
1118 | ||
1119 | /* Callback for `find_inferior'. Kills an lwp of a given process, | |
1120 | except the leader. */ | |
1121 | ||
1122 | static int | |
1123 | kill_one_lwp_callback (struct inferior_list_entry *entry, void *args) | |
1124 | { | |
1125 | struct thread_info *thread = (struct thread_info *) entry; | |
1126 | struct lwp_info *lwp = get_thread_lwp (thread); | |
1127 | int pid = * (int *) args; | |
1128 | ||
1129 | if (ptid_get_pid (entry->id) != pid) | |
1130 | return 0; | |
1131 | ||
1132 | /* We avoid killing the first thread here, because of a Linux kernel (at | |
1133 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before | |
1134 | the children get a chance to be reaped, it will remain a zombie | |
1135 | forever. */ | |
1136 | ||
1137 | if (lwpid_of (thread) == pid) | |
1138 | { | |
1139 | if (debug_threads) | |
1140 | debug_printf ("lkop: is last of process %s\n", | |
1141 | target_pid_to_str (entry->id)); | |
1142 | return 0; | |
1143 | } | |
1144 | ||
1145 | kill_wait_lwp (lwp); | |
1146 | return 0; | |
1147 | } | |
1148 | ||
1149 | static int | |
1150 | linux_kill (int pid) | |
1151 | { | |
1152 | struct process_info *process; | |
1153 | struct lwp_info *lwp; | |
1154 | ||
1155 | process = find_process_pid (pid); | |
1156 | if (process == NULL) | |
1157 | return -1; | |
1158 | ||
1159 | /* If we're killing a running inferior, make sure it is stopped | |
1160 | first, as PTRACE_KILL will not work otherwise. */ | |
1161 | stop_all_lwps (0, NULL); | |
1162 | ||
1163 | find_inferior (&all_threads, kill_one_lwp_callback , &pid); | |
1164 | ||
1165 | /* See the comment in linux_kill_one_lwp. We did not kill the first | |
1166 | thread in the list, so do so now. */ | |
1167 | lwp = find_lwp_pid (pid_to_ptid (pid)); | |
1168 | ||
1169 | if (lwp == NULL) | |
1170 | { | |
1171 | if (debug_threads) | |
1172 | debug_printf ("lk_1: cannot find lwp for pid: %d\n", | |
1173 | pid); | |
1174 | } | |
1175 | else | |
1176 | kill_wait_lwp (lwp); | |
1177 | ||
1178 | the_target->mourn (process); | |
1179 | ||
1180 | /* Since we presently can only stop all lwps of all processes, we | |
1181 | need to unstop lwps of other processes. */ | |
1182 | unstop_all_lwps (0, NULL); | |
1183 | return 0; | |
1184 | } | |
1185 | ||
1186 | /* Get pending signal of THREAD, for detaching purposes. This is the | |
1187 | signal the thread last stopped for, which we need to deliver to the | |
1188 | thread when detaching, otherwise, it'd be suppressed/lost. */ | |
1189 | ||
1190 | static int | |
1191 | get_detach_signal (struct thread_info *thread) | |
1192 | { | |
1193 | enum gdb_signal signo = GDB_SIGNAL_0; | |
1194 | int status; | |
1195 | struct lwp_info *lp = get_thread_lwp (thread); | |
1196 | ||
1197 | if (lp->status_pending_p) | |
1198 | status = lp->status_pending; | |
1199 | else | |
1200 | { | |
1201 | /* If the thread had been suspended by gdbserver, and it stopped | |
1202 | cleanly, then it'll have stopped with SIGSTOP. But we don't | |
1203 | want to deliver that SIGSTOP. */ | |
1204 | if (thread->last_status.kind != TARGET_WAITKIND_STOPPED | |
1205 | || thread->last_status.value.sig == GDB_SIGNAL_0) | |
1206 | return 0; | |
1207 | ||
1208 | /* Otherwise, we may need to deliver the signal we | |
1209 | intercepted. */ | |
1210 | status = lp->last_status; | |
1211 | } | |
1212 | ||
1213 | if (!WIFSTOPPED (status)) | |
1214 | { | |
1215 | if (debug_threads) | |
1216 | debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n", | |
1217 | target_pid_to_str (ptid_of (thread))); | |
1218 | return 0; | |
1219 | } | |
1220 | ||
1221 | /* Extended wait statuses aren't real SIGTRAPs. */ | |
1222 | if (WSTOPSIG (status) == SIGTRAP && linux_is_extended_waitstatus (status)) | |
1223 | { | |
1224 | if (debug_threads) | |
1225 | debug_printf ("GPS: lwp %s had stopped with extended " | |
1226 | "status: no pending signal\n", | |
1227 | target_pid_to_str (ptid_of (thread))); | |
1228 | return 0; | |
1229 | } | |
1230 | ||
1231 | signo = gdb_signal_from_host (WSTOPSIG (status)); | |
1232 | ||
1233 | if (program_signals_p && !program_signals[signo]) | |
1234 | { | |
1235 | if (debug_threads) | |
1236 | debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n", | |
1237 | target_pid_to_str (ptid_of (thread)), | |
1238 | gdb_signal_to_string (signo)); | |
1239 | return 0; | |
1240 | } | |
1241 | else if (!program_signals_p | |
1242 | /* If we have no way to know which signals GDB does not | |
1243 | want to have passed to the program, assume | |
1244 | SIGTRAP/SIGINT, which is GDB's default. */ | |
1245 | && (signo == GDB_SIGNAL_TRAP || signo == GDB_SIGNAL_INT)) | |
1246 | { | |
1247 | if (debug_threads) | |
1248 | debug_printf ("GPS: lwp %s had signal %s, " | |
1249 | "but we don't know if we should pass it. " | |
1250 | "Default to not.\n", | |
1251 | target_pid_to_str (ptid_of (thread)), | |
1252 | gdb_signal_to_string (signo)); | |
1253 | return 0; | |
1254 | } | |
1255 | else | |
1256 | { | |
1257 | if (debug_threads) | |
1258 | debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n", | |
1259 | target_pid_to_str (ptid_of (thread)), | |
1260 | gdb_signal_to_string (signo)); | |
1261 | ||
1262 | return WSTOPSIG (status); | |
1263 | } | |
1264 | } | |
1265 | ||
1266 | static int | |
1267 | linux_detach_one_lwp (struct inferior_list_entry *entry, void *args) | |
1268 | { | |
1269 | struct thread_info *thread = (struct thread_info *) entry; | |
1270 | struct lwp_info *lwp = get_thread_lwp (thread); | |
1271 | int pid = * (int *) args; | |
1272 | int sig; | |
1273 | ||
1274 | if (ptid_get_pid (entry->id) != pid) | |
1275 | return 0; | |
1276 | ||
1277 | /* If there is a pending SIGSTOP, get rid of it. */ | |
1278 | if (lwp->stop_expected) | |
1279 | { | |
1280 | if (debug_threads) | |
1281 | debug_printf ("Sending SIGCONT to %s\n", | |
1282 | target_pid_to_str (ptid_of (thread))); | |
1283 | ||
1284 | kill_lwp (lwpid_of (thread), SIGCONT); | |
1285 | lwp->stop_expected = 0; | |
1286 | } | |
1287 | ||
1288 | /* Flush any pending changes to the process's registers. */ | |
1289 | regcache_invalidate_thread (thread); | |
1290 | ||
1291 | /* Pass on any pending signal for this thread. */ | |
1292 | sig = get_detach_signal (thread); | |
1293 | ||
1294 | /* Finally, let it resume. */ | |
1295 | if (the_low_target.prepare_to_resume != NULL) | |
1296 | the_low_target.prepare_to_resume (lwp); | |
1297 | if (ptrace (PTRACE_DETACH, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
1298 | (PTRACE_TYPE_ARG4) (long) sig) < 0) | |
1299 | error (_("Can't detach %s: %s"), | |
1300 | target_pid_to_str (ptid_of (thread)), | |
1301 | strerror (errno)); | |
1302 | ||
1303 | delete_lwp (lwp); | |
1304 | return 0; | |
1305 | } | |
1306 | ||
1307 | static int | |
1308 | linux_detach (int pid) | |
1309 | { | |
1310 | struct process_info *process; | |
1311 | ||
1312 | process = find_process_pid (pid); | |
1313 | if (process == NULL) | |
1314 | return -1; | |
1315 | ||
1316 | /* Stop all threads before detaching. First, ptrace requires that | |
1317 | the thread is stopped to sucessfully detach. Second, thread_db | |
1318 | may need to uninstall thread event breakpoints from memory, which | |
1319 | only works with a stopped process anyway. */ | |
1320 | stop_all_lwps (0, NULL); | |
1321 | ||
1322 | #ifdef USE_THREAD_DB | |
1323 | thread_db_detach (process); | |
1324 | #endif | |
1325 | ||
1326 | /* Stabilize threads (move out of jump pads). */ | |
1327 | stabilize_threads (); | |
1328 | ||
1329 | find_inferior (&all_threads, linux_detach_one_lwp, &pid); | |
1330 | ||
1331 | the_target->mourn (process); | |
1332 | ||
1333 | /* Since we presently can only stop all lwps of all processes, we | |
1334 | need to unstop lwps of other processes. */ | |
1335 | unstop_all_lwps (0, NULL); | |
1336 | return 0; | |
1337 | } | |
1338 | ||
1339 | /* Remove all LWPs that belong to process PROC from the lwp list. */ | |
1340 | ||
1341 | static int | |
1342 | delete_lwp_callback (struct inferior_list_entry *entry, void *proc) | |
1343 | { | |
1344 | struct thread_info *thread = (struct thread_info *) entry; | |
1345 | struct lwp_info *lwp = get_thread_lwp (thread); | |
1346 | struct process_info *process = proc; | |
1347 | ||
1348 | if (pid_of (thread) == pid_of (process)) | |
1349 | delete_lwp (lwp); | |
1350 | ||
1351 | return 0; | |
1352 | } | |
1353 | ||
1354 | static void | |
1355 | linux_mourn (struct process_info *process) | |
1356 | { | |
1357 | struct process_info_private *priv; | |
1358 | ||
1359 | #ifdef USE_THREAD_DB | |
1360 | thread_db_mourn (process); | |
1361 | #endif | |
1362 | ||
1363 | find_inferior (&all_threads, delete_lwp_callback, process); | |
1364 | ||
1365 | /* Freeing all private data. */ | |
1366 | priv = process->priv; | |
1367 | free (priv->arch_private); | |
1368 | free (priv); | |
1369 | process->priv = NULL; | |
1370 | ||
1371 | remove_process (process); | |
1372 | } | |
1373 | ||
1374 | static void | |
1375 | linux_join (int pid) | |
1376 | { | |
1377 | int status, ret; | |
1378 | ||
1379 | do { | |
1380 | ret = my_waitpid (pid, &status, 0); | |
1381 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
1382 | break; | |
1383 | } while (ret != -1 || errno != ECHILD); | |
1384 | } | |
1385 | ||
1386 | /* Return nonzero if the given thread is still alive. */ | |
1387 | static int | |
1388 | linux_thread_alive (ptid_t ptid) | |
1389 | { | |
1390 | struct lwp_info *lwp = find_lwp_pid (ptid); | |
1391 | ||
1392 | /* We assume we always know if a thread exits. If a whole process | |
1393 | exited but we still haven't been able to report it to GDB, we'll | |
1394 | hold on to the last lwp of the dead process. */ | |
1395 | if (lwp != NULL) | |
1396 | return !lwp->dead; | |
1397 | else | |
1398 | return 0; | |
1399 | } | |
1400 | ||
1401 | /* Return 1 if this lwp still has an interesting status pending. If | |
1402 | not (e.g., it had stopped for a breakpoint that is gone), return | |
1403 | false. */ | |
1404 | ||
1405 | static int | |
1406 | thread_still_has_status_pending_p (struct thread_info *thread) | |
1407 | { | |
1408 | struct lwp_info *lp = get_thread_lwp (thread); | |
1409 | ||
1410 | if (!lp->status_pending_p) | |
1411 | return 0; | |
1412 | ||
1413 | /* If we got a `vCont;t', but we haven't reported a stop yet, do | |
1414 | report any status pending the LWP may have. */ | |
1415 | if (thread->last_resume_kind == resume_stop | |
1416 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) | |
1417 | return 0; | |
1418 | ||
1419 | if (thread->last_resume_kind != resume_stop | |
1420 | && (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
1421 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) | |
1422 | { | |
1423 | struct thread_info *saved_thread; | |
1424 | CORE_ADDR pc; | |
1425 | int discard = 0; | |
1426 | ||
1427 | gdb_assert (lp->last_status != 0); | |
1428 | ||
1429 | pc = get_pc (lp); | |
1430 | ||
1431 | saved_thread = current_thread; | |
1432 | current_thread = thread; | |
1433 | ||
1434 | if (pc != lp->stop_pc) | |
1435 | { | |
1436 | if (debug_threads) | |
1437 | debug_printf ("PC of %ld changed\n", | |
1438 | lwpid_of (thread)); | |
1439 | discard = 1; | |
1440 | } | |
1441 | ||
1442 | #if !USE_SIGTRAP_SIGINFO | |
1443 | else if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
1444 | && !(*the_low_target.breakpoint_at) (pc)) | |
1445 | { | |
1446 | if (debug_threads) | |
1447 | debug_printf ("previous SW breakpoint of %ld gone\n", | |
1448 | lwpid_of (thread)); | |
1449 | discard = 1; | |
1450 | } | |
1451 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT | |
1452 | && !hardware_breakpoint_inserted_here (pc)) | |
1453 | { | |
1454 | if (debug_threads) | |
1455 | debug_printf ("previous HW breakpoint of %ld gone\n", | |
1456 | lwpid_of (thread)); | |
1457 | discard = 1; | |
1458 | } | |
1459 | #endif | |
1460 | ||
1461 | current_thread = saved_thread; | |
1462 | ||
1463 | if (discard) | |
1464 | { | |
1465 | if (debug_threads) | |
1466 | debug_printf ("discarding pending breakpoint status\n"); | |
1467 | lp->status_pending_p = 0; | |
1468 | return 0; | |
1469 | } | |
1470 | } | |
1471 | ||
1472 | return 1; | |
1473 | } | |
1474 | ||
1475 | /* Return 1 if this lwp has an interesting status pending. */ | |
1476 | static int | |
1477 | status_pending_p_callback (struct inferior_list_entry *entry, void *arg) | |
1478 | { | |
1479 | struct thread_info *thread = (struct thread_info *) entry; | |
1480 | struct lwp_info *lp = get_thread_lwp (thread); | |
1481 | ptid_t ptid = * (ptid_t *) arg; | |
1482 | ||
1483 | /* Check if we're only interested in events from a specific process | |
1484 | or a specific LWP. */ | |
1485 | if (!ptid_match (ptid_of (thread), ptid)) | |
1486 | return 0; | |
1487 | ||
1488 | if (lp->status_pending_p | |
1489 | && !thread_still_has_status_pending_p (thread)) | |
1490 | { | |
1491 | linux_resume_one_lwp (lp, lp->stepping, GDB_SIGNAL_0, NULL); | |
1492 | return 0; | |
1493 | } | |
1494 | ||
1495 | return lp->status_pending_p; | |
1496 | } | |
1497 | ||
1498 | static int | |
1499 | same_lwp (struct inferior_list_entry *entry, void *data) | |
1500 | { | |
1501 | ptid_t ptid = *(ptid_t *) data; | |
1502 | int lwp; | |
1503 | ||
1504 | if (ptid_get_lwp (ptid) != 0) | |
1505 | lwp = ptid_get_lwp (ptid); | |
1506 | else | |
1507 | lwp = ptid_get_pid (ptid); | |
1508 | ||
1509 | if (ptid_get_lwp (entry->id) == lwp) | |
1510 | return 1; | |
1511 | ||
1512 | return 0; | |
1513 | } | |
1514 | ||
1515 | struct lwp_info * | |
1516 | find_lwp_pid (ptid_t ptid) | |
1517 | { | |
1518 | struct inferior_list_entry *thread | |
1519 | = find_inferior (&all_threads, same_lwp, &ptid); | |
1520 | ||
1521 | if (thread == NULL) | |
1522 | return NULL; | |
1523 | ||
1524 | return get_thread_lwp ((struct thread_info *) thread); | |
1525 | } | |
1526 | ||
1527 | /* Return the number of known LWPs in the tgid given by PID. */ | |
1528 | ||
1529 | static int | |
1530 | num_lwps (int pid) | |
1531 | { | |
1532 | struct inferior_list_entry *inf, *tmp; | |
1533 | int count = 0; | |
1534 | ||
1535 | ALL_INFERIORS (&all_threads, inf, tmp) | |
1536 | { | |
1537 | if (ptid_get_pid (inf->id) == pid) | |
1538 | count++; | |
1539 | } | |
1540 | ||
1541 | return count; | |
1542 | } | |
1543 | ||
1544 | /* The arguments passed to iterate_over_lwps. */ | |
1545 | ||
1546 | struct iterate_over_lwps_args | |
1547 | { | |
1548 | /* The FILTER argument passed to iterate_over_lwps. */ | |
1549 | ptid_t filter; | |
1550 | ||
1551 | /* The CALLBACK argument passed to iterate_over_lwps. */ | |
1552 | iterate_over_lwps_ftype *callback; | |
1553 | ||
1554 | /* The DATA argument passed to iterate_over_lwps. */ | |
1555 | void *data; | |
1556 | }; | |
1557 | ||
1558 | /* Callback for find_inferior used by iterate_over_lwps to filter | |
1559 | calls to the callback supplied to that function. Returning a | |
1560 | nonzero value causes find_inferiors to stop iterating and return | |
1561 | the current inferior_list_entry. Returning zero indicates that | |
1562 | find_inferiors should continue iterating. */ | |
1563 | ||
1564 | static int | |
1565 | iterate_over_lwps_filter (struct inferior_list_entry *entry, void *args_p) | |
1566 | { | |
1567 | struct iterate_over_lwps_args *args | |
1568 | = (struct iterate_over_lwps_args *) args_p; | |
1569 | ||
1570 | if (ptid_match (entry->id, args->filter)) | |
1571 | { | |
1572 | struct thread_info *thr = (struct thread_info *) entry; | |
1573 | struct lwp_info *lwp = get_thread_lwp (thr); | |
1574 | ||
1575 | return (*args->callback) (lwp, args->data); | |
1576 | } | |
1577 | ||
1578 | return 0; | |
1579 | } | |
1580 | ||
1581 | /* See nat/linux-nat.h. */ | |
1582 | ||
1583 | struct lwp_info * | |
1584 | iterate_over_lwps (ptid_t filter, | |
1585 | iterate_over_lwps_ftype callback, | |
1586 | void *data) | |
1587 | { | |
1588 | struct iterate_over_lwps_args args = {filter, callback, data}; | |
1589 | struct inferior_list_entry *entry; | |
1590 | ||
1591 | entry = find_inferior (&all_threads, iterate_over_lwps_filter, &args); | |
1592 | if (entry == NULL) | |
1593 | return NULL; | |
1594 | ||
1595 | return get_thread_lwp ((struct thread_info *) entry); | |
1596 | } | |
1597 | ||
1598 | /* Detect zombie thread group leaders, and "exit" them. We can't reap | |
1599 | their exits until all other threads in the group have exited. */ | |
1600 | ||
1601 | static void | |
1602 | check_zombie_leaders (void) | |
1603 | { | |
1604 | struct process_info *proc, *tmp; | |
1605 | ||
1606 | ALL_PROCESSES (proc, tmp) | |
1607 | { | |
1608 | pid_t leader_pid = pid_of (proc); | |
1609 | struct lwp_info *leader_lp; | |
1610 | ||
1611 | leader_lp = find_lwp_pid (pid_to_ptid (leader_pid)); | |
1612 | ||
1613 | if (debug_threads) | |
1614 | debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, " | |
1615 | "num_lwps=%d, zombie=%d\n", | |
1616 | leader_pid, leader_lp!= NULL, num_lwps (leader_pid), | |
1617 | linux_proc_pid_is_zombie (leader_pid)); | |
1618 | ||
1619 | if (leader_lp != NULL | |
1620 | /* Check if there are other threads in the group, as we may | |
1621 | have raced with the inferior simply exiting. */ | |
1622 | && !last_thread_of_process_p (leader_pid) | |
1623 | && linux_proc_pid_is_zombie (leader_pid)) | |
1624 | { | |
1625 | /* A leader zombie can mean one of two things: | |
1626 | ||
1627 | - It exited, and there's an exit status pending | |
1628 | available, or only the leader exited (not the whole | |
1629 | program). In the latter case, we can't waitpid the | |
1630 | leader's exit status until all other threads are gone. | |
1631 | ||
1632 | - There are 3 or more threads in the group, and a thread | |
1633 | other than the leader exec'd. On an exec, the Linux | |
1634 | kernel destroys all other threads (except the execing | |
1635 | one) in the thread group, and resets the execing thread's | |
1636 | tid to the tgid. No exit notification is sent for the | |
1637 | execing thread -- from the ptracer's perspective, it | |
1638 | appears as though the execing thread just vanishes. | |
1639 | Until we reap all other threads except the leader and the | |
1640 | execing thread, the leader will be zombie, and the | |
1641 | execing thread will be in `D (disc sleep)'. As soon as | |
1642 | all other threads are reaped, the execing thread changes | |
1643 | it's tid to the tgid, and the previous (zombie) leader | |
1644 | vanishes, giving place to the "new" leader. We could try | |
1645 | distinguishing the exit and exec cases, by waiting once | |
1646 | more, and seeing if something comes out, but it doesn't | |
1647 | sound useful. The previous leader _does_ go away, and | |
1648 | we'll re-add the new one once we see the exec event | |
1649 | (which is just the same as what would happen if the | |
1650 | previous leader did exit voluntarily before some other | |
1651 | thread execs). */ | |
1652 | ||
1653 | if (debug_threads) | |
1654 | fprintf (stderr, | |
1655 | "CZL: Thread group leader %d zombie " | |
1656 | "(it exited, or another thread execd).\n", | |
1657 | leader_pid); | |
1658 | ||
1659 | delete_lwp (leader_lp); | |
1660 | } | |
1661 | } | |
1662 | } | |
1663 | ||
1664 | /* Callback for `find_inferior'. Returns the first LWP that is not | |
1665 | stopped. ARG is a PTID filter. */ | |
1666 | ||
1667 | static int | |
1668 | not_stopped_callback (struct inferior_list_entry *entry, void *arg) | |
1669 | { | |
1670 | struct thread_info *thr = (struct thread_info *) entry; | |
1671 | struct lwp_info *lwp; | |
1672 | ptid_t filter = *(ptid_t *) arg; | |
1673 | ||
1674 | if (!ptid_match (ptid_of (thr), filter)) | |
1675 | return 0; | |
1676 | ||
1677 | lwp = get_thread_lwp (thr); | |
1678 | if (!lwp->stopped) | |
1679 | return 1; | |
1680 | ||
1681 | return 0; | |
1682 | } | |
1683 | ||
1684 | /* This function should only be called if the LWP got a SIGTRAP. | |
1685 | ||
1686 | Handle any tracepoint steps or hits. Return true if a tracepoint | |
1687 | event was handled, 0 otherwise. */ | |
1688 | ||
1689 | static int | |
1690 | handle_tracepoints (struct lwp_info *lwp) | |
1691 | { | |
1692 | struct thread_info *tinfo = get_lwp_thread (lwp); | |
1693 | int tpoint_related_event = 0; | |
1694 | ||
1695 | gdb_assert (lwp->suspended == 0); | |
1696 | ||
1697 | /* If this tracepoint hit causes a tracing stop, we'll immediately | |
1698 | uninsert tracepoints. To do this, we temporarily pause all | |
1699 | threads, unpatch away, and then unpause threads. We need to make | |
1700 | sure the unpausing doesn't resume LWP too. */ | |
1701 | lwp->suspended++; | |
1702 | ||
1703 | /* And we need to be sure that any all-threads-stopping doesn't try | |
1704 | to move threads out of the jump pads, as it could deadlock the | |
1705 | inferior (LWP could be in the jump pad, maybe even holding the | |
1706 | lock.) */ | |
1707 | ||
1708 | /* Do any necessary step collect actions. */ | |
1709 | tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc); | |
1710 | ||
1711 | tpoint_related_event |= handle_tracepoint_bkpts (tinfo, lwp->stop_pc); | |
1712 | ||
1713 | /* See if we just hit a tracepoint and do its main collect | |
1714 | actions. */ | |
1715 | tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc); | |
1716 | ||
1717 | lwp->suspended--; | |
1718 | ||
1719 | gdb_assert (lwp->suspended == 0); | |
1720 | gdb_assert (!stabilizing_threads || lwp->collecting_fast_tracepoint); | |
1721 | ||
1722 | if (tpoint_related_event) | |
1723 | { | |
1724 | if (debug_threads) | |
1725 | debug_printf ("got a tracepoint event\n"); | |
1726 | return 1; | |
1727 | } | |
1728 | ||
1729 | return 0; | |
1730 | } | |
1731 | ||
1732 | /* Convenience wrapper. Returns true if LWP is presently collecting a | |
1733 | fast tracepoint. */ | |
1734 | ||
1735 | static int | |
1736 | linux_fast_tracepoint_collecting (struct lwp_info *lwp, | |
1737 | struct fast_tpoint_collect_status *status) | |
1738 | { | |
1739 | CORE_ADDR thread_area; | |
1740 | struct thread_info *thread = get_lwp_thread (lwp); | |
1741 | ||
1742 | if (the_low_target.get_thread_area == NULL) | |
1743 | return 0; | |
1744 | ||
1745 | /* Get the thread area address. This is used to recognize which | |
1746 | thread is which when tracing with the in-process agent library. | |
1747 | We don't read anything from the address, and treat it as opaque; | |
1748 | it's the address itself that we assume is unique per-thread. */ | |
1749 | if ((*the_low_target.get_thread_area) (lwpid_of (thread), &thread_area) == -1) | |
1750 | return 0; | |
1751 | ||
1752 | return fast_tracepoint_collecting (thread_area, lwp->stop_pc, status); | |
1753 | } | |
1754 | ||
1755 | /* The reason we resume in the caller, is because we want to be able | |
1756 | to pass lwp->status_pending as WSTAT, and we need to clear | |
1757 | status_pending_p before resuming, otherwise, linux_resume_one_lwp | |
1758 | refuses to resume. */ | |
1759 | ||
1760 | static int | |
1761 | maybe_move_out_of_jump_pad (struct lwp_info *lwp, int *wstat) | |
1762 | { | |
1763 | struct thread_info *saved_thread; | |
1764 | ||
1765 | saved_thread = current_thread; | |
1766 | current_thread = get_lwp_thread (lwp); | |
1767 | ||
1768 | if ((wstat == NULL | |
1769 | || (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) != SIGTRAP)) | |
1770 | && supports_fast_tracepoints () | |
1771 | && agent_loaded_p ()) | |
1772 | { | |
1773 | struct fast_tpoint_collect_status status; | |
1774 | int r; | |
1775 | ||
1776 | if (debug_threads) | |
1777 | debug_printf ("Checking whether LWP %ld needs to move out of the " | |
1778 | "jump pad.\n", | |
1779 | lwpid_of (current_thread)); | |
1780 | ||
1781 | r = linux_fast_tracepoint_collecting (lwp, &status); | |
1782 | ||
1783 | if (wstat == NULL | |
1784 | || (WSTOPSIG (*wstat) != SIGILL | |
1785 | && WSTOPSIG (*wstat) != SIGFPE | |
1786 | && WSTOPSIG (*wstat) != SIGSEGV | |
1787 | && WSTOPSIG (*wstat) != SIGBUS)) | |
1788 | { | |
1789 | lwp->collecting_fast_tracepoint = r; | |
1790 | ||
1791 | if (r != 0) | |
1792 | { | |
1793 | if (r == 1 && lwp->exit_jump_pad_bkpt == NULL) | |
1794 | { | |
1795 | /* Haven't executed the original instruction yet. | |
1796 | Set breakpoint there, and wait till it's hit, | |
1797 | then single-step until exiting the jump pad. */ | |
1798 | lwp->exit_jump_pad_bkpt | |
1799 | = set_breakpoint_at (status.adjusted_insn_addr, NULL); | |
1800 | } | |
1801 | ||
1802 | if (debug_threads) | |
1803 | debug_printf ("Checking whether LWP %ld needs to move out of " | |
1804 | "the jump pad...it does\n", | |
1805 | lwpid_of (current_thread)); | |
1806 | current_thread = saved_thread; | |
1807 | ||
1808 | return 1; | |
1809 | } | |
1810 | } | |
1811 | else | |
1812 | { | |
1813 | /* If we get a synchronous signal while collecting, *and* | |
1814 | while executing the (relocated) original instruction, | |
1815 | reset the PC to point at the tpoint address, before | |
1816 | reporting to GDB. Otherwise, it's an IPA lib bug: just | |
1817 | report the signal to GDB, and pray for the best. */ | |
1818 | ||
1819 | lwp->collecting_fast_tracepoint = 0; | |
1820 | ||
1821 | if (r != 0 | |
1822 | && (status.adjusted_insn_addr <= lwp->stop_pc | |
1823 | && lwp->stop_pc < status.adjusted_insn_addr_end)) | |
1824 | { | |
1825 | siginfo_t info; | |
1826 | struct regcache *regcache; | |
1827 | ||
1828 | /* The si_addr on a few signals references the address | |
1829 | of the faulting instruction. Adjust that as | |
1830 | well. */ | |
1831 | if ((WSTOPSIG (*wstat) == SIGILL | |
1832 | || WSTOPSIG (*wstat) == SIGFPE | |
1833 | || WSTOPSIG (*wstat) == SIGBUS | |
1834 | || WSTOPSIG (*wstat) == SIGSEGV) | |
1835 | && ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
1836 | (PTRACE_TYPE_ARG3) 0, &info) == 0 | |
1837 | /* Final check just to make sure we don't clobber | |
1838 | the siginfo of non-kernel-sent signals. */ | |
1839 | && (uintptr_t) info.si_addr == lwp->stop_pc) | |
1840 | { | |
1841 | info.si_addr = (void *) (uintptr_t) status.tpoint_addr; | |
1842 | ptrace (PTRACE_SETSIGINFO, lwpid_of (current_thread), | |
1843 | (PTRACE_TYPE_ARG3) 0, &info); | |
1844 | } | |
1845 | ||
1846 | regcache = get_thread_regcache (current_thread, 1); | |
1847 | (*the_low_target.set_pc) (regcache, status.tpoint_addr); | |
1848 | lwp->stop_pc = status.tpoint_addr; | |
1849 | ||
1850 | /* Cancel any fast tracepoint lock this thread was | |
1851 | holding. */ | |
1852 | force_unlock_trace_buffer (); | |
1853 | } | |
1854 | ||
1855 | if (lwp->exit_jump_pad_bkpt != NULL) | |
1856 | { | |
1857 | if (debug_threads) | |
1858 | debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. " | |
1859 | "stopping all threads momentarily.\n"); | |
1860 | ||
1861 | stop_all_lwps (1, lwp); | |
1862 | ||
1863 | delete_breakpoint (lwp->exit_jump_pad_bkpt); | |
1864 | lwp->exit_jump_pad_bkpt = NULL; | |
1865 | ||
1866 | unstop_all_lwps (1, lwp); | |
1867 | ||
1868 | gdb_assert (lwp->suspended >= 0); | |
1869 | } | |
1870 | } | |
1871 | } | |
1872 | ||
1873 | if (debug_threads) | |
1874 | debug_printf ("Checking whether LWP %ld needs to move out of the " | |
1875 | "jump pad...no\n", | |
1876 | lwpid_of (current_thread)); | |
1877 | ||
1878 | current_thread = saved_thread; | |
1879 | return 0; | |
1880 | } | |
1881 | ||
1882 | /* Enqueue one signal in the "signals to report later when out of the | |
1883 | jump pad" list. */ | |
1884 | ||
1885 | static void | |
1886 | enqueue_one_deferred_signal (struct lwp_info *lwp, int *wstat) | |
1887 | { | |
1888 | struct pending_signals *p_sig; | |
1889 | struct thread_info *thread = get_lwp_thread (lwp); | |
1890 | ||
1891 | if (debug_threads) | |
1892 | debug_printf ("Deferring signal %d for LWP %ld.\n", | |
1893 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
1894 | ||
1895 | if (debug_threads) | |
1896 | { | |
1897 | struct pending_signals *sig; | |
1898 | ||
1899 | for (sig = lwp->pending_signals_to_report; | |
1900 | sig != NULL; | |
1901 | sig = sig->prev) | |
1902 | debug_printf (" Already queued %d\n", | |
1903 | sig->signal); | |
1904 | ||
1905 | debug_printf (" (no more currently queued signals)\n"); | |
1906 | } | |
1907 | ||
1908 | /* Don't enqueue non-RT signals if they are already in the deferred | |
1909 | queue. (SIGSTOP being the easiest signal to see ending up here | |
1910 | twice) */ | |
1911 | if (WSTOPSIG (*wstat) < __SIGRTMIN) | |
1912 | { | |
1913 | struct pending_signals *sig; | |
1914 | ||
1915 | for (sig = lwp->pending_signals_to_report; | |
1916 | sig != NULL; | |
1917 | sig = sig->prev) | |
1918 | { | |
1919 | if (sig->signal == WSTOPSIG (*wstat)) | |
1920 | { | |
1921 | if (debug_threads) | |
1922 | debug_printf ("Not requeuing already queued non-RT signal %d" | |
1923 | " for LWP %ld\n", | |
1924 | sig->signal, | |
1925 | lwpid_of (thread)); | |
1926 | return; | |
1927 | } | |
1928 | } | |
1929 | } | |
1930 | ||
1931 | p_sig = xmalloc (sizeof (*p_sig)); | |
1932 | p_sig->prev = lwp->pending_signals_to_report; | |
1933 | p_sig->signal = WSTOPSIG (*wstat); | |
1934 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
1935 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
1936 | &p_sig->info); | |
1937 | ||
1938 | lwp->pending_signals_to_report = p_sig; | |
1939 | } | |
1940 | ||
1941 | /* Dequeue one signal from the "signals to report later when out of | |
1942 | the jump pad" list. */ | |
1943 | ||
1944 | static int | |
1945 | dequeue_one_deferred_signal (struct lwp_info *lwp, int *wstat) | |
1946 | { | |
1947 | struct thread_info *thread = get_lwp_thread (lwp); | |
1948 | ||
1949 | if (lwp->pending_signals_to_report != NULL) | |
1950 | { | |
1951 | struct pending_signals **p_sig; | |
1952 | ||
1953 | p_sig = &lwp->pending_signals_to_report; | |
1954 | while ((*p_sig)->prev != NULL) | |
1955 | p_sig = &(*p_sig)->prev; | |
1956 | ||
1957 | *wstat = W_STOPCODE ((*p_sig)->signal); | |
1958 | if ((*p_sig)->info.si_signo != 0) | |
1959 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
1960 | &(*p_sig)->info); | |
1961 | free (*p_sig); | |
1962 | *p_sig = NULL; | |
1963 | ||
1964 | if (debug_threads) | |
1965 | debug_printf ("Reporting deferred signal %d for LWP %ld.\n", | |
1966 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
1967 | ||
1968 | if (debug_threads) | |
1969 | { | |
1970 | struct pending_signals *sig; | |
1971 | ||
1972 | for (sig = lwp->pending_signals_to_report; | |
1973 | sig != NULL; | |
1974 | sig = sig->prev) | |
1975 | debug_printf (" Still queued %d\n", | |
1976 | sig->signal); | |
1977 | ||
1978 | debug_printf (" (no more queued signals)\n"); | |
1979 | } | |
1980 | ||
1981 | return 1; | |
1982 | } | |
1983 | ||
1984 | return 0; | |
1985 | } | |
1986 | ||
1987 | /* Fetch the possibly triggered data watchpoint info and store it in | |
1988 | CHILD. | |
1989 | ||
1990 | On some archs, like x86, that use debug registers to set | |
1991 | watchpoints, it's possible that the way to know which watched | |
1992 | address trapped, is to check the register that is used to select | |
1993 | which address to watch. Problem is, between setting the watchpoint | |
1994 | and reading back which data address trapped, the user may change | |
1995 | the set of watchpoints, and, as a consequence, GDB changes the | |
1996 | debug registers in the inferior. To avoid reading back a stale | |
1997 | stopped-data-address when that happens, we cache in LP the fact | |
1998 | that a watchpoint trapped, and the corresponding data address, as | |
1999 | soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug | |
2000 | registers meanwhile, we have the cached data we can rely on. */ | |
2001 | ||
2002 | static int | |
2003 | check_stopped_by_watchpoint (struct lwp_info *child) | |
2004 | { | |
2005 | if (the_low_target.stopped_by_watchpoint != NULL) | |
2006 | { | |
2007 | struct thread_info *saved_thread; | |
2008 | ||
2009 | saved_thread = current_thread; | |
2010 | current_thread = get_lwp_thread (child); | |
2011 | ||
2012 | if (the_low_target.stopped_by_watchpoint ()) | |
2013 | { | |
2014 | child->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; | |
2015 | ||
2016 | if (the_low_target.stopped_data_address != NULL) | |
2017 | child->stopped_data_address | |
2018 | = the_low_target.stopped_data_address (); | |
2019 | else | |
2020 | child->stopped_data_address = 0; | |
2021 | } | |
2022 | ||
2023 | current_thread = saved_thread; | |
2024 | } | |
2025 | ||
2026 | return child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; | |
2027 | } | |
2028 | ||
2029 | /* Return the ptrace options that we want to try to enable. */ | |
2030 | ||
2031 | static int | |
2032 | linux_low_ptrace_options (int attached) | |
2033 | { | |
2034 | int options = 0; | |
2035 | ||
2036 | if (!attached) | |
2037 | options |= PTRACE_O_EXITKILL; | |
2038 | ||
2039 | if (report_fork_events) | |
2040 | options |= PTRACE_O_TRACEFORK; | |
2041 | ||
2042 | if (report_vfork_events) | |
2043 | options |= (PTRACE_O_TRACEVFORK | PTRACE_O_TRACEVFORKDONE); | |
2044 | ||
2045 | return options; | |
2046 | } | |
2047 | ||
2048 | /* Do low-level handling of the event, and check if we should go on | |
2049 | and pass it to caller code. Return the affected lwp if we are, or | |
2050 | NULL otherwise. */ | |
2051 | ||
2052 | static struct lwp_info * | |
2053 | linux_low_filter_event (int lwpid, int wstat) | |
2054 | { | |
2055 | struct lwp_info *child; | |
2056 | struct thread_info *thread; | |
2057 | int have_stop_pc = 0; | |
2058 | ||
2059 | child = find_lwp_pid (pid_to_ptid (lwpid)); | |
2060 | ||
2061 | /* If we didn't find a process, one of two things presumably happened: | |
2062 | - A process we started and then detached from has exited. Ignore it. | |
2063 | - A process we are controlling has forked and the new child's stop | |
2064 | was reported to us by the kernel. Save its PID. */ | |
2065 | if (child == NULL && WIFSTOPPED (wstat)) | |
2066 | { | |
2067 | add_to_pid_list (&stopped_pids, lwpid, wstat); | |
2068 | return NULL; | |
2069 | } | |
2070 | else if (child == NULL) | |
2071 | return NULL; | |
2072 | ||
2073 | thread = get_lwp_thread (child); | |
2074 | ||
2075 | child->stopped = 1; | |
2076 | ||
2077 | child->last_status = wstat; | |
2078 | ||
2079 | /* Check if the thread has exited. */ | |
2080 | if ((WIFEXITED (wstat) || WIFSIGNALED (wstat))) | |
2081 | { | |
2082 | if (debug_threads) | |
2083 | debug_printf ("LLFE: %d exited.\n", lwpid); | |
2084 | if (num_lwps (pid_of (thread)) > 1) | |
2085 | { | |
2086 | ||
2087 | /* If there is at least one more LWP, then the exit signal was | |
2088 | not the end of the debugged application and should be | |
2089 | ignored. */ | |
2090 | delete_lwp (child); | |
2091 | return NULL; | |
2092 | } | |
2093 | else | |
2094 | { | |
2095 | /* This was the last lwp in the process. Since events are | |
2096 | serialized to GDB core, and we can't report this one | |
2097 | right now, but GDB core and the other target layers will | |
2098 | want to be notified about the exit code/signal, leave the | |
2099 | status pending for the next time we're able to report | |
2100 | it. */ | |
2101 | mark_lwp_dead (child, wstat); | |
2102 | return child; | |
2103 | } | |
2104 | } | |
2105 | ||
2106 | gdb_assert (WIFSTOPPED (wstat)); | |
2107 | ||
2108 | if (WIFSTOPPED (wstat)) | |
2109 | { | |
2110 | struct process_info *proc; | |
2111 | ||
2112 | /* Architecture-specific setup after inferior is running. */ | |
2113 | proc = find_process_pid (pid_of (thread)); | |
2114 | if (proc->tdesc == NULL) | |
2115 | { | |
2116 | if (proc->attached) | |
2117 | { | |
2118 | struct thread_info *saved_thread; | |
2119 | ||
2120 | /* This needs to happen after we have attached to the | |
2121 | inferior and it is stopped for the first time, but | |
2122 | before we access any inferior registers. */ | |
2123 | saved_thread = current_thread; | |
2124 | current_thread = thread; | |
2125 | ||
2126 | the_low_target.arch_setup (); | |
2127 | ||
2128 | current_thread = saved_thread; | |
2129 | } | |
2130 | else | |
2131 | { | |
2132 | /* The process is started, but GDBserver will do | |
2133 | architecture-specific setup after the program stops at | |
2134 | the first instruction. */ | |
2135 | child->status_pending_p = 1; | |
2136 | child->status_pending = wstat; | |
2137 | return child; | |
2138 | } | |
2139 | } | |
2140 | } | |
2141 | ||
2142 | if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags) | |
2143 | { | |
2144 | struct process_info *proc = find_process_pid (pid_of (thread)); | |
2145 | int options = linux_low_ptrace_options (proc->attached); | |
2146 | ||
2147 | linux_enable_event_reporting (lwpid, options); | |
2148 | child->must_set_ptrace_flags = 0; | |
2149 | } | |
2150 | ||
2151 | /* Be careful to not overwrite stop_pc until | |
2152 | check_stopped_by_breakpoint is called. */ | |
2153 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP | |
2154 | && linux_is_extended_waitstatus (wstat)) | |
2155 | { | |
2156 | child->stop_pc = get_pc (child); | |
2157 | if (handle_extended_wait (child, wstat)) | |
2158 | { | |
2159 | /* The event has been handled, so just return without | |
2160 | reporting it. */ | |
2161 | return NULL; | |
2162 | } | |
2163 | } | |
2164 | ||
2165 | /* Check first whether this was a SW/HW breakpoint before checking | |
2166 | watchpoints, because at least s390 can't tell the data address of | |
2167 | hardware watchpoint hits, and returns stopped-by-watchpoint as | |
2168 | long as there's a watchpoint set. */ | |
2169 | if (WIFSTOPPED (wstat) && linux_wstatus_maybe_breakpoint (wstat)) | |
2170 | { | |
2171 | if (check_stopped_by_breakpoint (child)) | |
2172 | have_stop_pc = 1; | |
2173 | } | |
2174 | ||
2175 | /* Note that TRAP_HWBKPT can indicate either a hardware breakpoint | |
2176 | or hardware watchpoint. Check which is which if we got | |
2177 | TARGET_STOPPED_BY_HW_BREAKPOINT. */ | |
2178 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGTRAP | |
2179 | && (child->stop_reason == TARGET_STOPPED_BY_NO_REASON | |
2180 | || child->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)) | |
2181 | check_stopped_by_watchpoint (child); | |
2182 | ||
2183 | if (!have_stop_pc) | |
2184 | child->stop_pc = get_pc (child); | |
2185 | ||
2186 | if (WIFSTOPPED (wstat) && WSTOPSIG (wstat) == SIGSTOP | |
2187 | && child->stop_expected) | |
2188 | { | |
2189 | if (debug_threads) | |
2190 | debug_printf ("Expected stop.\n"); | |
2191 | child->stop_expected = 0; | |
2192 | ||
2193 | if (thread->last_resume_kind == resume_stop) | |
2194 | { | |
2195 | /* We want to report the stop to the core. Treat the | |
2196 | SIGSTOP as a normal event. */ | |
2197 | if (debug_threads) | |
2198 | debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n", | |
2199 | target_pid_to_str (ptid_of (thread))); | |
2200 | } | |
2201 | else if (stopping_threads != NOT_STOPPING_THREADS) | |
2202 | { | |
2203 | /* Stopping threads. We don't want this SIGSTOP to end up | |
2204 | pending. */ | |
2205 | if (debug_threads) | |
2206 | debug_printf ("LLW: SIGSTOP caught for %s " | |
2207 | "while stopping threads.\n", | |
2208 | target_pid_to_str (ptid_of (thread))); | |
2209 | return NULL; | |
2210 | } | |
2211 | else | |
2212 | { | |
2213 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
2214 | if (debug_threads) | |
2215 | debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", | |
2216 | child->stepping ? "step" : "continue", | |
2217 | target_pid_to_str (ptid_of (thread))); | |
2218 | ||
2219 | linux_resume_one_lwp (child, child->stepping, 0, NULL); | |
2220 | return NULL; | |
2221 | } | |
2222 | } | |
2223 | ||
2224 | child->status_pending_p = 1; | |
2225 | child->status_pending = wstat; | |
2226 | return child; | |
2227 | } | |
2228 | ||
2229 | /* Resume LWPs that are currently stopped without any pending status | |
2230 | to report, but are resumed from the core's perspective. */ | |
2231 | ||
2232 | static void | |
2233 | resume_stopped_resumed_lwps (struct inferior_list_entry *entry) | |
2234 | { | |
2235 | struct thread_info *thread = (struct thread_info *) entry; | |
2236 | struct lwp_info *lp = get_thread_lwp (thread); | |
2237 | ||
2238 | if (lp->stopped | |
2239 | && !lp->status_pending_p | |
2240 | && thread->last_resume_kind != resume_stop | |
2241 | && thread->last_status.kind == TARGET_WAITKIND_IGNORE) | |
2242 | { | |
2243 | int step = thread->last_resume_kind == resume_step; | |
2244 | ||
2245 | if (debug_threads) | |
2246 | debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", | |
2247 | target_pid_to_str (ptid_of (thread)), | |
2248 | paddress (lp->stop_pc), | |
2249 | step); | |
2250 | ||
2251 | linux_resume_one_lwp (lp, step, GDB_SIGNAL_0, NULL); | |
2252 | } | |
2253 | } | |
2254 | ||
2255 | /* Wait for an event from child(ren) WAIT_PTID, and return any that | |
2256 | match FILTER_PTID (leaving others pending). The PTIDs can be: | |
2257 | minus_one_ptid, to specify any child; a pid PTID, specifying all | |
2258 | lwps of a thread group; or a PTID representing a single lwp. Store | |
2259 | the stop status through the status pointer WSTAT. OPTIONS is | |
2260 | passed to the waitpid call. Return 0 if no event was found and | |
2261 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children | |
2262 | was found. Return the PID of the stopped child otherwise. */ | |
2263 | ||
2264 | static int | |
2265 | linux_wait_for_event_filtered (ptid_t wait_ptid, ptid_t filter_ptid, | |
2266 | int *wstatp, int options) | |
2267 | { | |
2268 | struct thread_info *event_thread; | |
2269 | struct lwp_info *event_child, *requested_child; | |
2270 | sigset_t block_mask, prev_mask; | |
2271 | ||
2272 | retry: | |
2273 | /* N.B. event_thread points to the thread_info struct that contains | |
2274 | event_child. Keep them in sync. */ | |
2275 | event_thread = NULL; | |
2276 | event_child = NULL; | |
2277 | requested_child = NULL; | |
2278 | ||
2279 | /* Check for a lwp with a pending status. */ | |
2280 | ||
2281 | if (ptid_equal (filter_ptid, minus_one_ptid) || ptid_is_pid (filter_ptid)) | |
2282 | { | |
2283 | event_thread = (struct thread_info *) | |
2284 | find_inferior (&all_threads, status_pending_p_callback, &filter_ptid); | |
2285 | if (event_thread != NULL) | |
2286 | event_child = get_thread_lwp (event_thread); | |
2287 | if (debug_threads && event_thread) | |
2288 | debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread)); | |
2289 | } | |
2290 | else if (!ptid_equal (filter_ptid, null_ptid)) | |
2291 | { | |
2292 | requested_child = find_lwp_pid (filter_ptid); | |
2293 | ||
2294 | if (stopping_threads == NOT_STOPPING_THREADS | |
2295 | && requested_child->status_pending_p | |
2296 | && requested_child->collecting_fast_tracepoint) | |
2297 | { | |
2298 | enqueue_one_deferred_signal (requested_child, | |
2299 | &requested_child->status_pending); | |
2300 | requested_child->status_pending_p = 0; | |
2301 | requested_child->status_pending = 0; | |
2302 | linux_resume_one_lwp (requested_child, 0, 0, NULL); | |
2303 | } | |
2304 | ||
2305 | if (requested_child->suspended | |
2306 | && requested_child->status_pending_p) | |
2307 | { | |
2308 | internal_error (__FILE__, __LINE__, | |
2309 | "requesting an event out of a" | |
2310 | " suspended child?"); | |
2311 | } | |
2312 | ||
2313 | if (requested_child->status_pending_p) | |
2314 | { | |
2315 | event_child = requested_child; | |
2316 | event_thread = get_lwp_thread (event_child); | |
2317 | } | |
2318 | } | |
2319 | ||
2320 | if (event_child != NULL) | |
2321 | { | |
2322 | if (debug_threads) | |
2323 | debug_printf ("Got an event from pending child %ld (%04x)\n", | |
2324 | lwpid_of (event_thread), event_child->status_pending); | |
2325 | *wstatp = event_child->status_pending; | |
2326 | event_child->status_pending_p = 0; | |
2327 | event_child->status_pending = 0; | |
2328 | current_thread = event_thread; | |
2329 | return lwpid_of (event_thread); | |
2330 | } | |
2331 | ||
2332 | /* But if we don't find a pending event, we'll have to wait. | |
2333 | ||
2334 | We only enter this loop if no process has a pending wait status. | |
2335 | Thus any action taken in response to a wait status inside this | |
2336 | loop is responding as soon as we detect the status, not after any | |
2337 | pending events. */ | |
2338 | ||
2339 | /* Make sure SIGCHLD is blocked until the sigsuspend below. Block | |
2340 | all signals while here. */ | |
2341 | sigfillset (&block_mask); | |
2342 | sigprocmask (SIG_BLOCK, &block_mask, &prev_mask); | |
2343 | ||
2344 | /* Always pull all events out of the kernel. We'll randomly select | |
2345 | an event LWP out of all that have events, to prevent | |
2346 | starvation. */ | |
2347 | while (event_child == NULL) | |
2348 | { | |
2349 | pid_t ret = 0; | |
2350 | ||
2351 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace | |
2352 | quirks: | |
2353 | ||
2354 | - If the thread group leader exits while other threads in the | |
2355 | thread group still exist, waitpid(TGID, ...) hangs. That | |
2356 | waitpid won't return an exit status until the other threads | |
2357 | in the group are reaped. | |
2358 | ||
2359 | - When a non-leader thread execs, that thread just vanishes | |
2360 | without reporting an exit (so we'd hang if we waited for it | |
2361 | explicitly in that case). The exec event is reported to | |
2362 | the TGID pid (although we don't currently enable exec | |
2363 | events). */ | |
2364 | errno = 0; | |
2365 | ret = my_waitpid (-1, wstatp, options | WNOHANG); | |
2366 | ||
2367 | if (debug_threads) | |
2368 | debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n", | |
2369 | ret, errno ? strerror (errno) : "ERRNO-OK"); | |
2370 | ||
2371 | if (ret > 0) | |
2372 | { | |
2373 | if (debug_threads) | |
2374 | { | |
2375 | debug_printf ("LLW: waitpid %ld received %s\n", | |
2376 | (long) ret, status_to_str (*wstatp)); | |
2377 | } | |
2378 | ||
2379 | /* Filter all events. IOW, leave all events pending. We'll | |
2380 | randomly select an event LWP out of all that have events | |
2381 | below. */ | |
2382 | linux_low_filter_event (ret, *wstatp); | |
2383 | /* Retry until nothing comes out of waitpid. A single | |
2384 | SIGCHLD can indicate more than one child stopped. */ | |
2385 | continue; | |
2386 | } | |
2387 | ||
2388 | /* Now that we've pulled all events out of the kernel, resume | |
2389 | LWPs that don't have an interesting event to report. */ | |
2390 | if (stopping_threads == NOT_STOPPING_THREADS) | |
2391 | for_each_inferior (&all_threads, resume_stopped_resumed_lwps); | |
2392 | ||
2393 | /* ... and find an LWP with a status to report to the core, if | |
2394 | any. */ | |
2395 | event_thread = (struct thread_info *) | |
2396 | find_inferior (&all_threads, status_pending_p_callback, &filter_ptid); | |
2397 | if (event_thread != NULL) | |
2398 | { | |
2399 | event_child = get_thread_lwp (event_thread); | |
2400 | *wstatp = event_child->status_pending; | |
2401 | event_child->status_pending_p = 0; | |
2402 | event_child->status_pending = 0; | |
2403 | break; | |
2404 | } | |
2405 | ||
2406 | /* Check for zombie thread group leaders. Those can't be reaped | |
2407 | until all other threads in the thread group are. */ | |
2408 | check_zombie_leaders (); | |
2409 | ||
2410 | /* If there are no resumed children left in the set of LWPs we | |
2411 | want to wait for, bail. We can't just block in | |
2412 | waitpid/sigsuspend, because lwps might have been left stopped | |
2413 | in trace-stop state, and we'd be stuck forever waiting for | |
2414 | their status to change (which would only happen if we resumed | |
2415 | them). Even if WNOHANG is set, this return code is preferred | |
2416 | over 0 (below), as it is more detailed. */ | |
2417 | if ((find_inferior (&all_threads, | |
2418 | not_stopped_callback, | |
2419 | &wait_ptid) == NULL)) | |
2420 | { | |
2421 | if (debug_threads) | |
2422 | debug_printf ("LLW: exit (no unwaited-for LWP)\n"); | |
2423 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2424 | return -1; | |
2425 | } | |
2426 | ||
2427 | /* No interesting event to report to the caller. */ | |
2428 | if ((options & WNOHANG)) | |
2429 | { | |
2430 | if (debug_threads) | |
2431 | debug_printf ("WNOHANG set, no event found\n"); | |
2432 | ||
2433 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2434 | return 0; | |
2435 | } | |
2436 | ||
2437 | /* Block until we get an event reported with SIGCHLD. */ | |
2438 | if (debug_threads) | |
2439 | debug_printf ("sigsuspend'ing\n"); | |
2440 | ||
2441 | sigsuspend (&prev_mask); | |
2442 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2443 | goto retry; | |
2444 | } | |
2445 | ||
2446 | sigprocmask (SIG_SETMASK, &prev_mask, NULL); | |
2447 | ||
2448 | current_thread = event_thread; | |
2449 | ||
2450 | /* Check for thread exit. */ | |
2451 | if (! WIFSTOPPED (*wstatp)) | |
2452 | { | |
2453 | gdb_assert (last_thread_of_process_p (pid_of (event_thread))); | |
2454 | ||
2455 | if (debug_threads) | |
2456 | debug_printf ("LWP %d is the last lwp of process. " | |
2457 | "Process %ld exiting.\n", | |
2458 | pid_of (event_thread), lwpid_of (event_thread)); | |
2459 | return lwpid_of (event_thread); | |
2460 | } | |
2461 | ||
2462 | return lwpid_of (event_thread); | |
2463 | } | |
2464 | ||
2465 | /* Wait for an event from child(ren) PTID. PTIDs can be: | |
2466 | minus_one_ptid, to specify any child; a pid PTID, specifying all | |
2467 | lwps of a thread group; or a PTID representing a single lwp. Store | |
2468 | the stop status through the status pointer WSTAT. OPTIONS is | |
2469 | passed to the waitpid call. Return 0 if no event was found and | |
2470 | OPTIONS contains WNOHANG. Return -1 if no unwaited-for children | |
2471 | was found. Return the PID of the stopped child otherwise. */ | |
2472 | ||
2473 | static int | |
2474 | linux_wait_for_event (ptid_t ptid, int *wstatp, int options) | |
2475 | { | |
2476 | return linux_wait_for_event_filtered (ptid, ptid, wstatp, options); | |
2477 | } | |
2478 | ||
2479 | /* Count the LWP's that have had events. */ | |
2480 | ||
2481 | static int | |
2482 | count_events_callback (struct inferior_list_entry *entry, void *data) | |
2483 | { | |
2484 | struct thread_info *thread = (struct thread_info *) entry; | |
2485 | struct lwp_info *lp = get_thread_lwp (thread); | |
2486 | int *count = data; | |
2487 | ||
2488 | gdb_assert (count != NULL); | |
2489 | ||
2490 | /* Count only resumed LWPs that have an event pending. */ | |
2491 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE | |
2492 | && lp->status_pending_p) | |
2493 | (*count)++; | |
2494 | ||
2495 | return 0; | |
2496 | } | |
2497 | ||
2498 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2499 | ||
2500 | static int | |
2501 | select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data) | |
2502 | { | |
2503 | struct thread_info *thread = (struct thread_info *) entry; | |
2504 | struct lwp_info *lp = get_thread_lwp (thread); | |
2505 | ||
2506 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE | |
2507 | && thread->last_resume_kind == resume_step | |
2508 | && lp->status_pending_p) | |
2509 | return 1; | |
2510 | else | |
2511 | return 0; | |
2512 | } | |
2513 | ||
2514 | /* Select the Nth LWP that has had an event. */ | |
2515 | ||
2516 | static int | |
2517 | select_event_lwp_callback (struct inferior_list_entry *entry, void *data) | |
2518 | { | |
2519 | struct thread_info *thread = (struct thread_info *) entry; | |
2520 | struct lwp_info *lp = get_thread_lwp (thread); | |
2521 | int *selector = data; | |
2522 | ||
2523 | gdb_assert (selector != NULL); | |
2524 | ||
2525 | /* Select only resumed LWPs that have an event pending. */ | |
2526 | if (thread->last_status.kind == TARGET_WAITKIND_IGNORE | |
2527 | && lp->status_pending_p) | |
2528 | if ((*selector)-- == 0) | |
2529 | return 1; | |
2530 | ||
2531 | return 0; | |
2532 | } | |
2533 | ||
2534 | /* Select one LWP out of those that have events pending. */ | |
2535 | ||
2536 | static void | |
2537 | select_event_lwp (struct lwp_info **orig_lp) | |
2538 | { | |
2539 | int num_events = 0; | |
2540 | int random_selector; | |
2541 | struct thread_info *event_thread = NULL; | |
2542 | ||
2543 | /* In all-stop, give preference to the LWP that is being | |
2544 | single-stepped. There will be at most one, and it's the LWP that | |
2545 | the core is most interested in. If we didn't do this, then we'd | |
2546 | have to handle pending step SIGTRAPs somehow in case the core | |
2547 | later continues the previously-stepped thread, otherwise we'd | |
2548 | report the pending SIGTRAP, and the core, not having stepped the | |
2549 | thread, wouldn't understand what the trap was for, and therefore | |
2550 | would report it to the user as a random signal. */ | |
2551 | if (!non_stop) | |
2552 | { | |
2553 | event_thread | |
2554 | = (struct thread_info *) find_inferior (&all_threads, | |
2555 | select_singlestep_lwp_callback, | |
2556 | NULL); | |
2557 | if (event_thread != NULL) | |
2558 | { | |
2559 | if (debug_threads) | |
2560 | debug_printf ("SEL: Select single-step %s\n", | |
2561 | target_pid_to_str (ptid_of (event_thread))); | |
2562 | } | |
2563 | } | |
2564 | if (event_thread == NULL) | |
2565 | { | |
2566 | /* No single-stepping LWP. Select one at random, out of those | |
2567 | which have had events. */ | |
2568 | ||
2569 | /* First see how many events we have. */ | |
2570 | find_inferior (&all_threads, count_events_callback, &num_events); | |
2571 | gdb_assert (num_events > 0); | |
2572 | ||
2573 | /* Now randomly pick a LWP out of those that have had | |
2574 | events. */ | |
2575 | random_selector = (int) | |
2576 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2577 | ||
2578 | if (debug_threads && num_events > 1) | |
2579 | debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n", | |
2580 | num_events, random_selector); | |
2581 | ||
2582 | event_thread | |
2583 | = (struct thread_info *) find_inferior (&all_threads, | |
2584 | select_event_lwp_callback, | |
2585 | &random_selector); | |
2586 | } | |
2587 | ||
2588 | if (event_thread != NULL) | |
2589 | { | |
2590 | struct lwp_info *event_lp = get_thread_lwp (event_thread); | |
2591 | ||
2592 | /* Switch the event LWP. */ | |
2593 | *orig_lp = event_lp; | |
2594 | } | |
2595 | } | |
2596 | ||
2597 | /* Decrement the suspend count of an LWP. */ | |
2598 | ||
2599 | static int | |
2600 | unsuspend_one_lwp (struct inferior_list_entry *entry, void *except) | |
2601 | { | |
2602 | struct thread_info *thread = (struct thread_info *) entry; | |
2603 | struct lwp_info *lwp = get_thread_lwp (thread); | |
2604 | ||
2605 | /* Ignore EXCEPT. */ | |
2606 | if (lwp == except) | |
2607 | return 0; | |
2608 | ||
2609 | lwp->suspended--; | |
2610 | ||
2611 | gdb_assert (lwp->suspended >= 0); | |
2612 | return 0; | |
2613 | } | |
2614 | ||
2615 | /* Decrement the suspend count of all LWPs, except EXCEPT, if non | |
2616 | NULL. */ | |
2617 | ||
2618 | static void | |
2619 | unsuspend_all_lwps (struct lwp_info *except) | |
2620 | { | |
2621 | find_inferior (&all_threads, unsuspend_one_lwp, except); | |
2622 | } | |
2623 | ||
2624 | static void move_out_of_jump_pad_callback (struct inferior_list_entry *entry); | |
2625 | static int stuck_in_jump_pad_callback (struct inferior_list_entry *entry, | |
2626 | void *data); | |
2627 | static int lwp_running (struct inferior_list_entry *entry, void *data); | |
2628 | static ptid_t linux_wait_1 (ptid_t ptid, | |
2629 | struct target_waitstatus *ourstatus, | |
2630 | int target_options); | |
2631 | ||
2632 | /* Stabilize threads (move out of jump pads). | |
2633 | ||
2634 | If a thread is midway collecting a fast tracepoint, we need to | |
2635 | finish the collection and move it out of the jump pad before | |
2636 | reporting the signal. | |
2637 | ||
2638 | This avoids recursion while collecting (when a signal arrives | |
2639 | midway, and the signal handler itself collects), which would trash | |
2640 | the trace buffer. In case the user set a breakpoint in a signal | |
2641 | handler, this avoids the backtrace showing the jump pad, etc.. | |
2642 | Most importantly, there are certain things we can't do safely if | |
2643 | threads are stopped in a jump pad (or in its callee's). For | |
2644 | example: | |
2645 | ||
2646 | - starting a new trace run. A thread still collecting the | |
2647 | previous run, could trash the trace buffer when resumed. The trace | |
2648 | buffer control structures would have been reset but the thread had | |
2649 | no way to tell. The thread could even midway memcpy'ing to the | |
2650 | buffer, which would mean that when resumed, it would clobber the | |
2651 | trace buffer that had been set for a new run. | |
2652 | ||
2653 | - we can't rewrite/reuse the jump pads for new tracepoints | |
2654 | safely. Say you do tstart while a thread is stopped midway while | |
2655 | collecting. When the thread is later resumed, it finishes the | |
2656 | collection, and returns to the jump pad, to execute the original | |
2657 | instruction that was under the tracepoint jump at the time the | |
2658 | older run had been started. If the jump pad had been rewritten | |
2659 | since for something else in the new run, the thread would now | |
2660 | execute the wrong / random instructions. */ | |
2661 | ||
2662 | static void | |
2663 | linux_stabilize_threads (void) | |
2664 | { | |
2665 | struct thread_info *saved_thread; | |
2666 | struct thread_info *thread_stuck; | |
2667 | ||
2668 | thread_stuck | |
2669 | = (struct thread_info *) find_inferior (&all_threads, | |
2670 | stuck_in_jump_pad_callback, | |
2671 | NULL); | |
2672 | if (thread_stuck != NULL) | |
2673 | { | |
2674 | if (debug_threads) | |
2675 | debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n", | |
2676 | lwpid_of (thread_stuck)); | |
2677 | return; | |
2678 | } | |
2679 | ||
2680 | saved_thread = current_thread; | |
2681 | ||
2682 | stabilizing_threads = 1; | |
2683 | ||
2684 | /* Kick 'em all. */ | |
2685 | for_each_inferior (&all_threads, move_out_of_jump_pad_callback); | |
2686 | ||
2687 | /* Loop until all are stopped out of the jump pads. */ | |
2688 | while (find_inferior (&all_threads, lwp_running, NULL) != NULL) | |
2689 | { | |
2690 | struct target_waitstatus ourstatus; | |
2691 | struct lwp_info *lwp; | |
2692 | int wstat; | |
2693 | ||
2694 | /* Note that we go through the full wait even loop. While | |
2695 | moving threads out of jump pad, we need to be able to step | |
2696 | over internal breakpoints and such. */ | |
2697 | linux_wait_1 (minus_one_ptid, &ourstatus, 0); | |
2698 | ||
2699 | if (ourstatus.kind == TARGET_WAITKIND_STOPPED) | |
2700 | { | |
2701 | lwp = get_thread_lwp (current_thread); | |
2702 | ||
2703 | /* Lock it. */ | |
2704 | lwp->suspended++; | |
2705 | ||
2706 | if (ourstatus.value.sig != GDB_SIGNAL_0 | |
2707 | || current_thread->last_resume_kind == resume_stop) | |
2708 | { | |
2709 | wstat = W_STOPCODE (gdb_signal_to_host (ourstatus.value.sig)); | |
2710 | enqueue_one_deferred_signal (lwp, &wstat); | |
2711 | } | |
2712 | } | |
2713 | } | |
2714 | ||
2715 | find_inferior (&all_threads, unsuspend_one_lwp, NULL); | |
2716 | ||
2717 | stabilizing_threads = 0; | |
2718 | ||
2719 | current_thread = saved_thread; | |
2720 | ||
2721 | if (debug_threads) | |
2722 | { | |
2723 | thread_stuck | |
2724 | = (struct thread_info *) find_inferior (&all_threads, | |
2725 | stuck_in_jump_pad_callback, | |
2726 | NULL); | |
2727 | if (thread_stuck != NULL) | |
2728 | debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n", | |
2729 | lwpid_of (thread_stuck)); | |
2730 | } | |
2731 | } | |
2732 | ||
2733 | static void async_file_mark (void); | |
2734 | ||
2735 | /* Convenience function that is called when the kernel reports an | |
2736 | event that is not passed out to GDB. */ | |
2737 | ||
2738 | static ptid_t | |
2739 | ignore_event (struct target_waitstatus *ourstatus) | |
2740 | { | |
2741 | /* If we got an event, there may still be others, as a single | |
2742 | SIGCHLD can indicate more than one child stopped. This forces | |
2743 | another target_wait call. */ | |
2744 | async_file_mark (); | |
2745 | ||
2746 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
2747 | return null_ptid; | |
2748 | } | |
2749 | ||
2750 | /* Return non-zero if WAITSTATUS reflects an extended linux | |
2751 | event. Otherwise, return zero. */ | |
2752 | ||
2753 | static int | |
2754 | extended_event_reported (const struct target_waitstatus *waitstatus) | |
2755 | { | |
2756 | if (waitstatus == NULL) | |
2757 | return 0; | |
2758 | ||
2759 | return (waitstatus->kind == TARGET_WAITKIND_FORKED | |
2760 | || waitstatus->kind == TARGET_WAITKIND_VFORKED | |
2761 | || waitstatus->kind == TARGET_WAITKIND_VFORK_DONE); | |
2762 | } | |
2763 | ||
2764 | /* Wait for process, returns status. */ | |
2765 | ||
2766 | static ptid_t | |
2767 | linux_wait_1 (ptid_t ptid, | |
2768 | struct target_waitstatus *ourstatus, int target_options) | |
2769 | { | |
2770 | int w; | |
2771 | struct lwp_info *event_child; | |
2772 | int options; | |
2773 | int pid; | |
2774 | int step_over_finished; | |
2775 | int bp_explains_trap; | |
2776 | int maybe_internal_trap; | |
2777 | int report_to_gdb; | |
2778 | int trace_event; | |
2779 | int in_step_range; | |
2780 | ||
2781 | if (debug_threads) | |
2782 | { | |
2783 | debug_enter (); | |
2784 | debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid)); | |
2785 | } | |
2786 | ||
2787 | /* Translate generic target options into linux options. */ | |
2788 | options = __WALL; | |
2789 | if (target_options & TARGET_WNOHANG) | |
2790 | options |= WNOHANG; | |
2791 | ||
2792 | bp_explains_trap = 0; | |
2793 | trace_event = 0; | |
2794 | in_step_range = 0; | |
2795 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
2796 | ||
2797 | if (ptid_equal (step_over_bkpt, null_ptid)) | |
2798 | pid = linux_wait_for_event (ptid, &w, options); | |
2799 | else | |
2800 | { | |
2801 | if (debug_threads) | |
2802 | debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n", | |
2803 | target_pid_to_str (step_over_bkpt)); | |
2804 | pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG); | |
2805 | } | |
2806 | ||
2807 | if (pid == 0) | |
2808 | { | |
2809 | gdb_assert (target_options & TARGET_WNOHANG); | |
2810 | ||
2811 | if (debug_threads) | |
2812 | { | |
2813 | debug_printf ("linux_wait_1 ret = null_ptid, " | |
2814 | "TARGET_WAITKIND_IGNORE\n"); | |
2815 | debug_exit (); | |
2816 | } | |
2817 | ||
2818 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
2819 | return null_ptid; | |
2820 | } | |
2821 | else if (pid == -1) | |
2822 | { | |
2823 | if (debug_threads) | |
2824 | { | |
2825 | debug_printf ("linux_wait_1 ret = null_ptid, " | |
2826 | "TARGET_WAITKIND_NO_RESUMED\n"); | |
2827 | debug_exit (); | |
2828 | } | |
2829 | ||
2830 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; | |
2831 | return null_ptid; | |
2832 | } | |
2833 | ||
2834 | event_child = get_thread_lwp (current_thread); | |
2835 | ||
2836 | /* linux_wait_for_event only returns an exit status for the last | |
2837 | child of a process. Report it. */ | |
2838 | if (WIFEXITED (w) || WIFSIGNALED (w)) | |
2839 | { | |
2840 | if (WIFEXITED (w)) | |
2841 | { | |
2842 | ourstatus->kind = TARGET_WAITKIND_EXITED; | |
2843 | ourstatus->value.integer = WEXITSTATUS (w); | |
2844 | ||
2845 | if (debug_threads) | |
2846 | { | |
2847 | debug_printf ("linux_wait_1 ret = %s, exited with " | |
2848 | "retcode %d\n", | |
2849 | target_pid_to_str (ptid_of (current_thread)), | |
2850 | WEXITSTATUS (w)); | |
2851 | debug_exit (); | |
2852 | } | |
2853 | } | |
2854 | else | |
2855 | { | |
2856 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; | |
2857 | ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w)); | |
2858 | ||
2859 | if (debug_threads) | |
2860 | { | |
2861 | debug_printf ("linux_wait_1 ret = %s, terminated with " | |
2862 | "signal %d\n", | |
2863 | target_pid_to_str (ptid_of (current_thread)), | |
2864 | WTERMSIG (w)); | |
2865 | debug_exit (); | |
2866 | } | |
2867 | } | |
2868 | ||
2869 | return ptid_of (current_thread); | |
2870 | } | |
2871 | ||
2872 | /* If step-over executes a breakpoint instruction, it means a | |
2873 | gdb/gdbserver breakpoint had been planted on top of a permanent | |
2874 | breakpoint. The PC has been adjusted by | |
2875 | check_stopped_by_breakpoint to point at the breakpoint address. | |
2876 | Advance the PC manually past the breakpoint, otherwise the | |
2877 | program would keep trapping the permanent breakpoint forever. */ | |
2878 | if (!ptid_equal (step_over_bkpt, null_ptid) | |
2879 | && event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2880 | { | |
2881 | unsigned int increment_pc = the_low_target.breakpoint_len; | |
2882 | ||
2883 | if (debug_threads) | |
2884 | { | |
2885 | debug_printf ("step-over for %s executed software breakpoint\n", | |
2886 | target_pid_to_str (ptid_of (current_thread))); | |
2887 | } | |
2888 | ||
2889 | if (increment_pc != 0) | |
2890 | { | |
2891 | struct regcache *regcache | |
2892 | = get_thread_regcache (current_thread, 1); | |
2893 | ||
2894 | event_child->stop_pc += increment_pc; | |
2895 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); | |
2896 | ||
2897 | if (!(*the_low_target.breakpoint_at) (event_child->stop_pc)) | |
2898 | event_child->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
2899 | } | |
2900 | } | |
2901 | ||
2902 | /* If this event was not handled before, and is not a SIGTRAP, we | |
2903 | report it. SIGILL and SIGSEGV are also treated as traps in case | |
2904 | a breakpoint is inserted at the current PC. If this target does | |
2905 | not support internal breakpoints at all, we also report the | |
2906 | SIGTRAP without further processing; it's of no concern to us. */ | |
2907 | maybe_internal_trap | |
2908 | = (supports_breakpoints () | |
2909 | && (WSTOPSIG (w) == SIGTRAP | |
2910 | || ((WSTOPSIG (w) == SIGILL | |
2911 | || WSTOPSIG (w) == SIGSEGV) | |
2912 | && (*the_low_target.breakpoint_at) (event_child->stop_pc)))); | |
2913 | ||
2914 | if (maybe_internal_trap) | |
2915 | { | |
2916 | /* Handle anything that requires bookkeeping before deciding to | |
2917 | report the event or continue waiting. */ | |
2918 | ||
2919 | /* First check if we can explain the SIGTRAP with an internal | |
2920 | breakpoint, or if we should possibly report the event to GDB. | |
2921 | Do this before anything that may remove or insert a | |
2922 | breakpoint. */ | |
2923 | bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc); | |
2924 | ||
2925 | /* We have a SIGTRAP, possibly a step-over dance has just | |
2926 | finished. If so, tweak the state machine accordingly, | |
2927 | reinsert breakpoints and delete any reinsert (software | |
2928 | single-step) breakpoints. */ | |
2929 | step_over_finished = finish_step_over (event_child); | |
2930 | ||
2931 | /* Now invoke the callbacks of any internal breakpoints there. */ | |
2932 | check_breakpoints (event_child->stop_pc); | |
2933 | ||
2934 | /* Handle tracepoint data collecting. This may overflow the | |
2935 | trace buffer, and cause a tracing stop, removing | |
2936 | breakpoints. */ | |
2937 | trace_event = handle_tracepoints (event_child); | |
2938 | ||
2939 | if (bp_explains_trap) | |
2940 | { | |
2941 | /* If we stepped or ran into an internal breakpoint, we've | |
2942 | already handled it. So next time we resume (from this | |
2943 | PC), we should step over it. */ | |
2944 | if (debug_threads) | |
2945 | debug_printf ("Hit a gdbserver breakpoint.\n"); | |
2946 | ||
2947 | if (breakpoint_here (event_child->stop_pc)) | |
2948 | event_child->need_step_over = 1; | |
2949 | } | |
2950 | } | |
2951 | else | |
2952 | { | |
2953 | /* We have some other signal, possibly a step-over dance was in | |
2954 | progress, and it should be cancelled too. */ | |
2955 | step_over_finished = finish_step_over (event_child); | |
2956 | } | |
2957 | ||
2958 | /* We have all the data we need. Either report the event to GDB, or | |
2959 | resume threads and keep waiting for more. */ | |
2960 | ||
2961 | /* If we're collecting a fast tracepoint, finish the collection and | |
2962 | move out of the jump pad before delivering a signal. See | |
2963 | linux_stabilize_threads. */ | |
2964 | ||
2965 | if (WIFSTOPPED (w) | |
2966 | && WSTOPSIG (w) != SIGTRAP | |
2967 | && supports_fast_tracepoints () | |
2968 | && agent_loaded_p ()) | |
2969 | { | |
2970 | if (debug_threads) | |
2971 | debug_printf ("Got signal %d for LWP %ld. Check if we need " | |
2972 | "to defer or adjust it.\n", | |
2973 | WSTOPSIG (w), lwpid_of (current_thread)); | |
2974 | ||
2975 | /* Allow debugging the jump pad itself. */ | |
2976 | if (current_thread->last_resume_kind != resume_step | |
2977 | && maybe_move_out_of_jump_pad (event_child, &w)) | |
2978 | { | |
2979 | enqueue_one_deferred_signal (event_child, &w); | |
2980 | ||
2981 | if (debug_threads) | |
2982 | debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n", | |
2983 | WSTOPSIG (w), lwpid_of (current_thread)); | |
2984 | ||
2985 | linux_resume_one_lwp (event_child, 0, 0, NULL); | |
2986 | ||
2987 | return ignore_event (ourstatus); | |
2988 | } | |
2989 | } | |
2990 | ||
2991 | if (event_child->collecting_fast_tracepoint) | |
2992 | { | |
2993 | if (debug_threads) | |
2994 | debug_printf ("LWP %ld was trying to move out of the jump pad (%d). " | |
2995 | "Check if we're already there.\n", | |
2996 | lwpid_of (current_thread), | |
2997 | event_child->collecting_fast_tracepoint); | |
2998 | ||
2999 | trace_event = 1; | |
3000 | ||
3001 | event_child->collecting_fast_tracepoint | |
3002 | = linux_fast_tracepoint_collecting (event_child, NULL); | |
3003 | ||
3004 | if (event_child->collecting_fast_tracepoint != 1) | |
3005 | { | |
3006 | /* No longer need this breakpoint. */ | |
3007 | if (event_child->exit_jump_pad_bkpt != NULL) | |
3008 | { | |
3009 | if (debug_threads) | |
3010 | debug_printf ("No longer need exit-jump-pad bkpt; removing it." | |
3011 | "stopping all threads momentarily.\n"); | |
3012 | ||
3013 | /* Other running threads could hit this breakpoint. | |
3014 | We don't handle moribund locations like GDB does, | |
3015 | instead we always pause all threads when removing | |
3016 | breakpoints, so that any step-over or | |
3017 | decr_pc_after_break adjustment is always taken | |
3018 | care of while the breakpoint is still | |
3019 | inserted. */ | |
3020 | stop_all_lwps (1, event_child); | |
3021 | ||
3022 | delete_breakpoint (event_child->exit_jump_pad_bkpt); | |
3023 | event_child->exit_jump_pad_bkpt = NULL; | |
3024 | ||
3025 | unstop_all_lwps (1, event_child); | |
3026 | ||
3027 | gdb_assert (event_child->suspended >= 0); | |
3028 | } | |
3029 | } | |
3030 | ||
3031 | if (event_child->collecting_fast_tracepoint == 0) | |
3032 | { | |
3033 | if (debug_threads) | |
3034 | debug_printf ("fast tracepoint finished " | |
3035 | "collecting successfully.\n"); | |
3036 | ||
3037 | /* We may have a deferred signal to report. */ | |
3038 | if (dequeue_one_deferred_signal (event_child, &w)) | |
3039 | { | |
3040 | if (debug_threads) | |
3041 | debug_printf ("dequeued one signal.\n"); | |
3042 | } | |
3043 | else | |
3044 | { | |
3045 | if (debug_threads) | |
3046 | debug_printf ("no deferred signals.\n"); | |
3047 | ||
3048 | if (stabilizing_threads) | |
3049 | { | |
3050 | ourstatus->kind = TARGET_WAITKIND_STOPPED; | |
3051 | ourstatus->value.sig = GDB_SIGNAL_0; | |
3052 | ||
3053 | if (debug_threads) | |
3054 | { | |
3055 | debug_printf ("linux_wait_1 ret = %s, stopped " | |
3056 | "while stabilizing threads\n", | |
3057 | target_pid_to_str (ptid_of (current_thread))); | |
3058 | debug_exit (); | |
3059 | } | |
3060 | ||
3061 | return ptid_of (current_thread); | |
3062 | } | |
3063 | } | |
3064 | } | |
3065 | } | |
3066 | ||
3067 | /* Check whether GDB would be interested in this event. */ | |
3068 | ||
3069 | /* If GDB is not interested in this signal, don't stop other | |
3070 | threads, and don't report it to GDB. Just resume the inferior | |
3071 | right away. We do this for threading-related signals as well as | |
3072 | any that GDB specifically requested we ignore. But never ignore | |
3073 | SIGSTOP if we sent it ourselves, and do not ignore signals when | |
3074 | stepping - they may require special handling to skip the signal | |
3075 | handler. Also never ignore signals that could be caused by a | |
3076 | breakpoint. */ | |
3077 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's | |
3078 | thread library? */ | |
3079 | if (WIFSTOPPED (w) | |
3080 | && current_thread->last_resume_kind != resume_step | |
3081 | && ( | |
3082 | #if defined (USE_THREAD_DB) && !defined (__ANDROID__) | |
3083 | (current_process ()->priv->thread_db != NULL | |
3084 | && (WSTOPSIG (w) == __SIGRTMIN | |
3085 | || WSTOPSIG (w) == __SIGRTMIN + 1)) | |
3086 | || | |
3087 | #endif | |
3088 | (pass_signals[gdb_signal_from_host (WSTOPSIG (w))] | |
3089 | && !(WSTOPSIG (w) == SIGSTOP | |
3090 | && current_thread->last_resume_kind == resume_stop) | |
3091 | && !linux_wstatus_maybe_breakpoint (w)))) | |
3092 | { | |
3093 | siginfo_t info, *info_p; | |
3094 | ||
3095 | if (debug_threads) | |
3096 | debug_printf ("Ignored signal %d for LWP %ld.\n", | |
3097 | WSTOPSIG (w), lwpid_of (current_thread)); | |
3098 | ||
3099 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (current_thread), | |
3100 | (PTRACE_TYPE_ARG3) 0, &info) == 0) | |
3101 | info_p = &info; | |
3102 | else | |
3103 | info_p = NULL; | |
3104 | linux_resume_one_lwp (event_child, event_child->stepping, | |
3105 | WSTOPSIG (w), info_p); | |
3106 | return ignore_event (ourstatus); | |
3107 | } | |
3108 | ||
3109 | /* Note that all addresses are always "out of the step range" when | |
3110 | there's no range to begin with. */ | |
3111 | in_step_range = lwp_in_step_range (event_child); | |
3112 | ||
3113 | /* If GDB wanted this thread to single step, and the thread is out | |
3114 | of the step range, we always want to report the SIGTRAP, and let | |
3115 | GDB handle it. Watchpoints should always be reported. So should | |
3116 | signals we can't explain. A SIGTRAP we can't explain could be a | |
3117 | GDB breakpoint --- we may or not support Z0 breakpoints. If we | |
3118 | do, we're be able to handle GDB breakpoints on top of internal | |
3119 | breakpoints, by handling the internal breakpoint and still | |
3120 | reporting the event to GDB. If we don't, we're out of luck, GDB | |
3121 | won't see the breakpoint hit. */ | |
3122 | report_to_gdb = (!maybe_internal_trap | |
3123 | || (current_thread->last_resume_kind == resume_step | |
3124 | && !in_step_range) | |
3125 | || event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT | |
3126 | || (!step_over_finished && !in_step_range | |
3127 | && !bp_explains_trap && !trace_event) | |
3128 | || (gdb_breakpoint_here (event_child->stop_pc) | |
3129 | && gdb_condition_true_at_breakpoint (event_child->stop_pc) | |
3130 | && gdb_no_commands_at_breakpoint (event_child->stop_pc)) | |
3131 | || extended_event_reported (&event_child->waitstatus)); | |
3132 | ||
3133 | run_breakpoint_commands (event_child->stop_pc); | |
3134 | ||
3135 | /* We found no reason GDB would want us to stop. We either hit one | |
3136 | of our own breakpoints, or finished an internal step GDB | |
3137 | shouldn't know about. */ | |
3138 | if (!report_to_gdb) | |
3139 | { | |
3140 | if (debug_threads) | |
3141 | { | |
3142 | if (bp_explains_trap) | |
3143 | debug_printf ("Hit a gdbserver breakpoint.\n"); | |
3144 | if (step_over_finished) | |
3145 | debug_printf ("Step-over finished.\n"); | |
3146 | if (trace_event) | |
3147 | debug_printf ("Tracepoint event.\n"); | |
3148 | if (lwp_in_step_range (event_child)) | |
3149 | debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n", | |
3150 | paddress (event_child->stop_pc), | |
3151 | paddress (event_child->step_range_start), | |
3152 | paddress (event_child->step_range_end)); | |
3153 | if (extended_event_reported (&event_child->waitstatus)) | |
3154 | { | |
3155 | char *str = target_waitstatus_to_string (ourstatus); | |
3156 | debug_printf ("LWP %ld: extended event with waitstatus %s\n", | |
3157 | lwpid_of (get_lwp_thread (event_child)), str); | |
3158 | xfree (str); | |
3159 | } | |
3160 | } | |
3161 | ||
3162 | /* We're not reporting this breakpoint to GDB, so apply the | |
3163 | decr_pc_after_break adjustment to the inferior's regcache | |
3164 | ourselves. */ | |
3165 | ||
3166 | if (the_low_target.set_pc != NULL) | |
3167 | { | |
3168 | struct regcache *regcache | |
3169 | = get_thread_regcache (current_thread, 1); | |
3170 | (*the_low_target.set_pc) (regcache, event_child->stop_pc); | |
3171 | } | |
3172 | ||
3173 | /* We may have finished stepping over a breakpoint. If so, | |
3174 | we've stopped and suspended all LWPs momentarily except the | |
3175 | stepping one. This is where we resume them all again. We're | |
3176 | going to keep waiting, so use proceed, which handles stepping | |
3177 | over the next breakpoint. */ | |
3178 | if (debug_threads) | |
3179 | debug_printf ("proceeding all threads.\n"); | |
3180 | ||
3181 | if (step_over_finished) | |
3182 | unsuspend_all_lwps (event_child); | |
3183 | ||
3184 | proceed_all_lwps (); | |
3185 | return ignore_event (ourstatus); | |
3186 | } | |
3187 | ||
3188 | if (debug_threads) | |
3189 | { | |
3190 | if (current_thread->last_resume_kind == resume_step) | |
3191 | { | |
3192 | if (event_child->step_range_start == event_child->step_range_end) | |
3193 | debug_printf ("GDB wanted to single-step, reporting event.\n"); | |
3194 | else if (!lwp_in_step_range (event_child)) | |
3195 | debug_printf ("Out of step range, reporting event.\n"); | |
3196 | } | |
3197 | if (event_child->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
3198 | debug_printf ("Stopped by watchpoint.\n"); | |
3199 | else if (gdb_breakpoint_here (event_child->stop_pc)) | |
3200 | debug_printf ("Stopped by GDB breakpoint.\n"); | |
3201 | if (debug_threads) | |
3202 | debug_printf ("Hit a non-gdbserver trap event.\n"); | |
3203 | } | |
3204 | ||
3205 | /* Alright, we're going to report a stop. */ | |
3206 | ||
3207 | if (!stabilizing_threads) | |
3208 | { | |
3209 | /* In all-stop, stop all threads. */ | |
3210 | if (!non_stop) | |
3211 | stop_all_lwps (0, NULL); | |
3212 | ||
3213 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3214 | from among those that have had events. Giving equal priority | |
3215 | to all LWPs that have had events helps prevent | |
3216 | starvation. */ | |
3217 | if (ptid_equal (ptid, minus_one_ptid)) | |
3218 | { | |
3219 | event_child->status_pending_p = 1; | |
3220 | event_child->status_pending = w; | |
3221 | ||
3222 | select_event_lwp (&event_child); | |
3223 | ||
3224 | /* current_thread and event_child must stay in sync. */ | |
3225 | current_thread = get_lwp_thread (event_child); | |
3226 | ||
3227 | event_child->status_pending_p = 0; | |
3228 | w = event_child->status_pending; | |
3229 | } | |
3230 | ||
3231 | if (step_over_finished) | |
3232 | { | |
3233 | if (!non_stop) | |
3234 | { | |
3235 | /* If we were doing a step-over, all other threads but | |
3236 | the stepping one had been paused in start_step_over, | |
3237 | with their suspend counts incremented. We don't want | |
3238 | to do a full unstop/unpause, because we're in | |
3239 | all-stop mode (so we want threads stopped), but we | |
3240 | still need to unsuspend the other threads, to | |
3241 | decrement their `suspended' count back. */ | |
3242 | unsuspend_all_lwps (event_child); | |
3243 | } | |
3244 | else | |
3245 | { | |
3246 | /* If we just finished a step-over, then all threads had | |
3247 | been momentarily paused. In all-stop, that's fine, | |
3248 | we want threads stopped by now anyway. In non-stop, | |
3249 | we need to re-resume threads that GDB wanted to be | |
3250 | running. */ | |
3251 | unstop_all_lwps (1, event_child); | |
3252 | } | |
3253 | } | |
3254 | ||
3255 | /* Stabilize threads (move out of jump pads). */ | |
3256 | if (!non_stop) | |
3257 | stabilize_threads (); | |
3258 | } | |
3259 | else | |
3260 | { | |
3261 | /* If we just finished a step-over, then all threads had been | |
3262 | momentarily paused. In all-stop, that's fine, we want | |
3263 | threads stopped by now anyway. In non-stop, we need to | |
3264 | re-resume threads that GDB wanted to be running. */ | |
3265 | if (step_over_finished) | |
3266 | unstop_all_lwps (1, event_child); | |
3267 | } | |
3268 | ||
3269 | if (extended_event_reported (&event_child->waitstatus)) | |
3270 | { | |
3271 | /* If the reported event is a fork, vfork or exec, let GDB know. */ | |
3272 | ourstatus->kind = event_child->waitstatus.kind; | |
3273 | ourstatus->value = event_child->waitstatus.value; | |
3274 | ||
3275 | /* Clear the event lwp's waitstatus since we handled it already. */ | |
3276 | event_child->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3277 | } | |
3278 | else | |
3279 | ourstatus->kind = TARGET_WAITKIND_STOPPED; | |
3280 | ||
3281 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
3282 | it was a software breakpoint, and the client doesn't know we can | |
3283 | adjust the breakpoint ourselves. */ | |
3284 | if (event_child->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3285 | && !swbreak_feature) | |
3286 | { | |
3287 | int decr_pc = the_low_target.decr_pc_after_break; | |
3288 | ||
3289 | if (decr_pc != 0) | |
3290 | { | |
3291 | struct regcache *regcache | |
3292 | = get_thread_regcache (current_thread, 1); | |
3293 | (*the_low_target.set_pc) (regcache, event_child->stop_pc + decr_pc); | |
3294 | } | |
3295 | } | |
3296 | ||
3297 | if (current_thread->last_resume_kind == resume_stop | |
3298 | && WSTOPSIG (w) == SIGSTOP) | |
3299 | { | |
3300 | /* A thread that has been requested to stop by GDB with vCont;t, | |
3301 | and it stopped cleanly, so report as SIG0. The use of | |
3302 | SIGSTOP is an implementation detail. */ | |
3303 | ourstatus->value.sig = GDB_SIGNAL_0; | |
3304 | } | |
3305 | else if (current_thread->last_resume_kind == resume_stop | |
3306 | && WSTOPSIG (w) != SIGSTOP) | |
3307 | { | |
3308 | /* A thread that has been requested to stop by GDB with vCont;t, | |
3309 | but, it stopped for other reasons. */ | |
3310 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); | |
3311 | } | |
3312 | else if (ourstatus->kind == TARGET_WAITKIND_STOPPED) | |
3313 | { | |
3314 | ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w)); | |
3315 | } | |
3316 | ||
3317 | gdb_assert (ptid_equal (step_over_bkpt, null_ptid)); | |
3318 | ||
3319 | if (debug_threads) | |
3320 | { | |
3321 | debug_printf ("linux_wait_1 ret = %s, %d, %d\n", | |
3322 | target_pid_to_str (ptid_of (current_thread)), | |
3323 | ourstatus->kind, ourstatus->value.sig); | |
3324 | debug_exit (); | |
3325 | } | |
3326 | ||
3327 | return ptid_of (current_thread); | |
3328 | } | |
3329 | ||
3330 | /* Get rid of any pending event in the pipe. */ | |
3331 | static void | |
3332 | async_file_flush (void) | |
3333 | { | |
3334 | int ret; | |
3335 | char buf; | |
3336 | ||
3337 | do | |
3338 | ret = read (linux_event_pipe[0], &buf, 1); | |
3339 | while (ret >= 0 || (ret == -1 && errno == EINTR)); | |
3340 | } | |
3341 | ||
3342 | /* Put something in the pipe, so the event loop wakes up. */ | |
3343 | static void | |
3344 | async_file_mark (void) | |
3345 | { | |
3346 | int ret; | |
3347 | ||
3348 | async_file_flush (); | |
3349 | ||
3350 | do | |
3351 | ret = write (linux_event_pipe[1], "+", 1); | |
3352 | while (ret == 0 || (ret == -1 && errno == EINTR)); | |
3353 | ||
3354 | /* Ignore EAGAIN. If the pipe is full, the event loop will already | |
3355 | be awakened anyway. */ | |
3356 | } | |
3357 | ||
3358 | static ptid_t | |
3359 | linux_wait (ptid_t ptid, | |
3360 | struct target_waitstatus *ourstatus, int target_options) | |
3361 | { | |
3362 | ptid_t event_ptid; | |
3363 | ||
3364 | /* Flush the async file first. */ | |
3365 | if (target_is_async_p ()) | |
3366 | async_file_flush (); | |
3367 | ||
3368 | do | |
3369 | { | |
3370 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); | |
3371 | } | |
3372 | while ((target_options & TARGET_WNOHANG) == 0 | |
3373 | && ptid_equal (event_ptid, null_ptid) | |
3374 | && ourstatus->kind == TARGET_WAITKIND_IGNORE); | |
3375 | ||
3376 | /* If at least one stop was reported, there may be more. A single | |
3377 | SIGCHLD can signal more than one child stop. */ | |
3378 | if (target_is_async_p () | |
3379 | && (target_options & TARGET_WNOHANG) != 0 | |
3380 | && !ptid_equal (event_ptid, null_ptid)) | |
3381 | async_file_mark (); | |
3382 | ||
3383 | return event_ptid; | |
3384 | } | |
3385 | ||
3386 | /* Send a signal to an LWP. */ | |
3387 | ||
3388 | static int | |
3389 | kill_lwp (unsigned long lwpid, int signo) | |
3390 | { | |
3391 | /* Use tkill, if possible, in case we are using nptl threads. If tkill | |
3392 | fails, then we are not using nptl threads and we should be using kill. */ | |
3393 | ||
3394 | #ifdef __NR_tkill | |
3395 | { | |
3396 | static int tkill_failed; | |
3397 | ||
3398 | if (!tkill_failed) | |
3399 | { | |
3400 | int ret; | |
3401 | ||
3402 | errno = 0; | |
3403 | ret = syscall (__NR_tkill, lwpid, signo); | |
3404 | if (errno != ENOSYS) | |
3405 | return ret; | |
3406 | tkill_failed = 1; | |
3407 | } | |
3408 | } | |
3409 | #endif | |
3410 | ||
3411 | return kill (lwpid, signo); | |
3412 | } | |
3413 | ||
3414 | void | |
3415 | linux_stop_lwp (struct lwp_info *lwp) | |
3416 | { | |
3417 | send_sigstop (lwp); | |
3418 | } | |
3419 | ||
3420 | static void | |
3421 | send_sigstop (struct lwp_info *lwp) | |
3422 | { | |
3423 | int pid; | |
3424 | ||
3425 | pid = lwpid_of (get_lwp_thread (lwp)); | |
3426 | ||
3427 | /* If we already have a pending stop signal for this process, don't | |
3428 | send another. */ | |
3429 | if (lwp->stop_expected) | |
3430 | { | |
3431 | if (debug_threads) | |
3432 | debug_printf ("Have pending sigstop for lwp %d\n", pid); | |
3433 | ||
3434 | return; | |
3435 | } | |
3436 | ||
3437 | if (debug_threads) | |
3438 | debug_printf ("Sending sigstop to lwp %d\n", pid); | |
3439 | ||
3440 | lwp->stop_expected = 1; | |
3441 | kill_lwp (pid, SIGSTOP); | |
3442 | } | |
3443 | ||
3444 | static int | |
3445 | send_sigstop_callback (struct inferior_list_entry *entry, void *except) | |
3446 | { | |
3447 | struct thread_info *thread = (struct thread_info *) entry; | |
3448 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3449 | ||
3450 | /* Ignore EXCEPT. */ | |
3451 | if (lwp == except) | |
3452 | return 0; | |
3453 | ||
3454 | if (lwp->stopped) | |
3455 | return 0; | |
3456 | ||
3457 | send_sigstop (lwp); | |
3458 | return 0; | |
3459 | } | |
3460 | ||
3461 | /* Increment the suspend count of an LWP, and stop it, if not stopped | |
3462 | yet. */ | |
3463 | static int | |
3464 | suspend_and_send_sigstop_callback (struct inferior_list_entry *entry, | |
3465 | void *except) | |
3466 | { | |
3467 | struct thread_info *thread = (struct thread_info *) entry; | |
3468 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3469 | ||
3470 | /* Ignore EXCEPT. */ | |
3471 | if (lwp == except) | |
3472 | return 0; | |
3473 | ||
3474 | lwp->suspended++; | |
3475 | ||
3476 | return send_sigstop_callback (entry, except); | |
3477 | } | |
3478 | ||
3479 | static void | |
3480 | mark_lwp_dead (struct lwp_info *lwp, int wstat) | |
3481 | { | |
3482 | /* It's dead, really. */ | |
3483 | lwp->dead = 1; | |
3484 | ||
3485 | /* Store the exit status for later. */ | |
3486 | lwp->status_pending_p = 1; | |
3487 | lwp->status_pending = wstat; | |
3488 | ||
3489 | /* Prevent trying to stop it. */ | |
3490 | lwp->stopped = 1; | |
3491 | ||
3492 | /* No further stops are expected from a dead lwp. */ | |
3493 | lwp->stop_expected = 0; | |
3494 | } | |
3495 | ||
3496 | /* Wait for all children to stop for the SIGSTOPs we just queued. */ | |
3497 | ||
3498 | static void | |
3499 | wait_for_sigstop (void) | |
3500 | { | |
3501 | struct thread_info *saved_thread; | |
3502 | ptid_t saved_tid; | |
3503 | int wstat; | |
3504 | int ret; | |
3505 | ||
3506 | saved_thread = current_thread; | |
3507 | if (saved_thread != NULL) | |
3508 | saved_tid = saved_thread->entry.id; | |
3509 | else | |
3510 | saved_tid = null_ptid; /* avoid bogus unused warning */ | |
3511 | ||
3512 | if (debug_threads) | |
3513 | debug_printf ("wait_for_sigstop: pulling events\n"); | |
3514 | ||
3515 | /* Passing NULL_PTID as filter indicates we want all events to be | |
3516 | left pending. Eventually this returns when there are no | |
3517 | unwaited-for children left. */ | |
3518 | ret = linux_wait_for_event_filtered (minus_one_ptid, null_ptid, | |
3519 | &wstat, __WALL); | |
3520 | gdb_assert (ret == -1); | |
3521 | ||
3522 | if (saved_thread == NULL || linux_thread_alive (saved_tid)) | |
3523 | current_thread = saved_thread; | |
3524 | else | |
3525 | { | |
3526 | if (debug_threads) | |
3527 | debug_printf ("Previously current thread died.\n"); | |
3528 | ||
3529 | if (non_stop) | |
3530 | { | |
3531 | /* We can't change the current inferior behind GDB's back, | |
3532 | otherwise, a subsequent command may apply to the wrong | |
3533 | process. */ | |
3534 | current_thread = NULL; | |
3535 | } | |
3536 | else | |
3537 | { | |
3538 | /* Set a valid thread as current. */ | |
3539 | set_desired_thread (0); | |
3540 | } | |
3541 | } | |
3542 | } | |
3543 | ||
3544 | /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't | |
3545 | move it out, because we need to report the stop event to GDB. For | |
3546 | example, if the user puts a breakpoint in the jump pad, it's | |
3547 | because she wants to debug it. */ | |
3548 | ||
3549 | static int | |
3550 | stuck_in_jump_pad_callback (struct inferior_list_entry *entry, void *data) | |
3551 | { | |
3552 | struct thread_info *thread = (struct thread_info *) entry; | |
3553 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3554 | ||
3555 | gdb_assert (lwp->suspended == 0); | |
3556 | gdb_assert (lwp->stopped); | |
3557 | ||
3558 | /* Allow debugging the jump pad, gdb_collect, etc.. */ | |
3559 | return (supports_fast_tracepoints () | |
3560 | && agent_loaded_p () | |
3561 | && (gdb_breakpoint_here (lwp->stop_pc) | |
3562 | || lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT | |
3563 | || thread->last_resume_kind == resume_step) | |
3564 | && linux_fast_tracepoint_collecting (lwp, NULL)); | |
3565 | } | |
3566 | ||
3567 | static void | |
3568 | move_out_of_jump_pad_callback (struct inferior_list_entry *entry) | |
3569 | { | |
3570 | struct thread_info *thread = (struct thread_info *) entry; | |
3571 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3572 | int *wstat; | |
3573 | ||
3574 | gdb_assert (lwp->suspended == 0); | |
3575 | gdb_assert (lwp->stopped); | |
3576 | ||
3577 | wstat = lwp->status_pending_p ? &lwp->status_pending : NULL; | |
3578 | ||
3579 | /* Allow debugging the jump pad, gdb_collect, etc. */ | |
3580 | if (!gdb_breakpoint_here (lwp->stop_pc) | |
3581 | && lwp->stop_reason != TARGET_STOPPED_BY_WATCHPOINT | |
3582 | && thread->last_resume_kind != resume_step | |
3583 | && maybe_move_out_of_jump_pad (lwp, wstat)) | |
3584 | { | |
3585 | if (debug_threads) | |
3586 | debug_printf ("LWP %ld needs stabilizing (in jump pad)\n", | |
3587 | lwpid_of (thread)); | |
3588 | ||
3589 | if (wstat) | |
3590 | { | |
3591 | lwp->status_pending_p = 0; | |
3592 | enqueue_one_deferred_signal (lwp, wstat); | |
3593 | ||
3594 | if (debug_threads) | |
3595 | debug_printf ("Signal %d for LWP %ld deferred " | |
3596 | "(in jump pad)\n", | |
3597 | WSTOPSIG (*wstat), lwpid_of (thread)); | |
3598 | } | |
3599 | ||
3600 | linux_resume_one_lwp (lwp, 0, 0, NULL); | |
3601 | } | |
3602 | else | |
3603 | lwp->suspended++; | |
3604 | } | |
3605 | ||
3606 | static int | |
3607 | lwp_running (struct inferior_list_entry *entry, void *data) | |
3608 | { | |
3609 | struct thread_info *thread = (struct thread_info *) entry; | |
3610 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3611 | ||
3612 | if (lwp->dead) | |
3613 | return 0; | |
3614 | if (lwp->stopped) | |
3615 | return 0; | |
3616 | return 1; | |
3617 | } | |
3618 | ||
3619 | /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL. | |
3620 | If SUSPEND, then also increase the suspend count of every LWP, | |
3621 | except EXCEPT. */ | |
3622 | ||
3623 | static void | |
3624 | stop_all_lwps (int suspend, struct lwp_info *except) | |
3625 | { | |
3626 | /* Should not be called recursively. */ | |
3627 | gdb_assert (stopping_threads == NOT_STOPPING_THREADS); | |
3628 | ||
3629 | if (debug_threads) | |
3630 | { | |
3631 | debug_enter (); | |
3632 | debug_printf ("stop_all_lwps (%s, except=%s)\n", | |
3633 | suspend ? "stop-and-suspend" : "stop", | |
3634 | except != NULL | |
3635 | ? target_pid_to_str (ptid_of (get_lwp_thread (except))) | |
3636 | : "none"); | |
3637 | } | |
3638 | ||
3639 | stopping_threads = (suspend | |
3640 | ? STOPPING_AND_SUSPENDING_THREADS | |
3641 | : STOPPING_THREADS); | |
3642 | ||
3643 | if (suspend) | |
3644 | find_inferior (&all_threads, suspend_and_send_sigstop_callback, except); | |
3645 | else | |
3646 | find_inferior (&all_threads, send_sigstop_callback, except); | |
3647 | wait_for_sigstop (); | |
3648 | stopping_threads = NOT_STOPPING_THREADS; | |
3649 | ||
3650 | if (debug_threads) | |
3651 | { | |
3652 | debug_printf ("stop_all_lwps done, setting stopping_threads " | |
3653 | "back to !stopping\n"); | |
3654 | debug_exit (); | |
3655 | } | |
3656 | } | |
3657 | ||
3658 | /* Resume execution of LWP. If STEP is nonzero, single-step it. If | |
3659 | SIGNAL is nonzero, give it that signal. */ | |
3660 | ||
3661 | static void | |
3662 | linux_resume_one_lwp_throw (struct lwp_info *lwp, | |
3663 | int step, int signal, siginfo_t *info) | |
3664 | { | |
3665 | struct thread_info *thread = get_lwp_thread (lwp); | |
3666 | struct thread_info *saved_thread; | |
3667 | int fast_tp_collecting; | |
3668 | struct process_info *proc = get_thread_process (thread); | |
3669 | ||
3670 | /* Note that target description may not be initialised | |
3671 | (proc->tdesc == NULL) at this point because the program hasn't | |
3672 | stopped at the first instruction yet. It means GDBserver skips | |
3673 | the extra traps from the wrapper program (see option --wrapper). | |
3674 | Code in this function that requires register access should be | |
3675 | guarded by proc->tdesc == NULL or something else. */ | |
3676 | ||
3677 | if (lwp->stopped == 0) | |
3678 | return; | |
3679 | ||
3680 | fast_tp_collecting = lwp->collecting_fast_tracepoint; | |
3681 | ||
3682 | gdb_assert (!stabilizing_threads || fast_tp_collecting); | |
3683 | ||
3684 | /* Cancel actions that rely on GDB not changing the PC (e.g., the | |
3685 | user used the "jump" command, or "set $pc = foo"). */ | |
3686 | if (thread->while_stepping != NULL && lwp->stop_pc != get_pc (lwp)) | |
3687 | { | |
3688 | /* Collecting 'while-stepping' actions doesn't make sense | |
3689 | anymore. */ | |
3690 | release_while_stepping_state_list (thread); | |
3691 | } | |
3692 | ||
3693 | /* If we have pending signals or status, and a new signal, enqueue the | |
3694 | signal. Also enqueue the signal if we are waiting to reinsert a | |
3695 | breakpoint; it will be picked up again below. */ | |
3696 | if (signal != 0 | |
3697 | && (lwp->status_pending_p | |
3698 | || lwp->pending_signals != NULL | |
3699 | || lwp->bp_reinsert != 0 | |
3700 | || fast_tp_collecting)) | |
3701 | { | |
3702 | struct pending_signals *p_sig; | |
3703 | p_sig = xmalloc (sizeof (*p_sig)); | |
3704 | p_sig->prev = lwp->pending_signals; | |
3705 | p_sig->signal = signal; | |
3706 | if (info == NULL) | |
3707 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
3708 | else | |
3709 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); | |
3710 | lwp->pending_signals = p_sig; | |
3711 | } | |
3712 | ||
3713 | if (lwp->status_pending_p) | |
3714 | { | |
3715 | if (debug_threads) | |
3716 | debug_printf ("Not resuming lwp %ld (%s, signal %d, stop %s);" | |
3717 | " has pending status\n", | |
3718 | lwpid_of (thread), step ? "step" : "continue", signal, | |
3719 | lwp->stop_expected ? "expected" : "not expected"); | |
3720 | return; | |
3721 | } | |
3722 | ||
3723 | saved_thread = current_thread; | |
3724 | current_thread = thread; | |
3725 | ||
3726 | if (debug_threads) | |
3727 | debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n", | |
3728 | lwpid_of (thread), step ? "step" : "continue", signal, | |
3729 | lwp->stop_expected ? "expected" : "not expected"); | |
3730 | ||
3731 | /* This bit needs some thinking about. If we get a signal that | |
3732 | we must report while a single-step reinsert is still pending, | |
3733 | we often end up resuming the thread. It might be better to | |
3734 | (ew) allow a stack of pending events; then we could be sure that | |
3735 | the reinsert happened right away and not lose any signals. | |
3736 | ||
3737 | Making this stack would also shrink the window in which breakpoints are | |
3738 | uninserted (see comment in linux_wait_for_lwp) but not enough for | |
3739 | complete correctness, so it won't solve that problem. It may be | |
3740 | worthwhile just to solve this one, however. */ | |
3741 | if (lwp->bp_reinsert != 0) | |
3742 | { | |
3743 | if (debug_threads) | |
3744 | debug_printf (" pending reinsert at 0x%s\n", | |
3745 | paddress (lwp->bp_reinsert)); | |
3746 | ||
3747 | if (can_hardware_single_step ()) | |
3748 | { | |
3749 | if (fast_tp_collecting == 0) | |
3750 | { | |
3751 | if (step == 0) | |
3752 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); | |
3753 | if (lwp->suspended) | |
3754 | fprintf (stderr, "BAD - reinserting and suspended(%d).\n", | |
3755 | lwp->suspended); | |
3756 | } | |
3757 | ||
3758 | step = 1; | |
3759 | } | |
3760 | ||
3761 | /* Postpone any pending signal. It was enqueued above. */ | |
3762 | signal = 0; | |
3763 | } | |
3764 | ||
3765 | if (fast_tp_collecting == 1) | |
3766 | { | |
3767 | if (debug_threads) | |
3768 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" | |
3769 | " (exit-jump-pad-bkpt)\n", | |
3770 | lwpid_of (thread)); | |
3771 | ||
3772 | /* Postpone any pending signal. It was enqueued above. */ | |
3773 | signal = 0; | |
3774 | } | |
3775 | else if (fast_tp_collecting == 2) | |
3776 | { | |
3777 | if (debug_threads) | |
3778 | debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad" | |
3779 | " single-stepping\n", | |
3780 | lwpid_of (thread)); | |
3781 | ||
3782 | if (can_hardware_single_step ()) | |
3783 | step = 1; | |
3784 | else | |
3785 | { | |
3786 | internal_error (__FILE__, __LINE__, | |
3787 | "moving out of jump pad single-stepping" | |
3788 | " not implemented on this target"); | |
3789 | } | |
3790 | ||
3791 | /* Postpone any pending signal. It was enqueued above. */ | |
3792 | signal = 0; | |
3793 | } | |
3794 | ||
3795 | /* If we have while-stepping actions in this thread set it stepping. | |
3796 | If we have a signal to deliver, it may or may not be set to | |
3797 | SIG_IGN, we don't know. Assume so, and allow collecting | |
3798 | while-stepping into a signal handler. A possible smart thing to | |
3799 | do would be to set an internal breakpoint at the signal return | |
3800 | address, continue, and carry on catching this while-stepping | |
3801 | action only when that breakpoint is hit. A future | |
3802 | enhancement. */ | |
3803 | if (thread->while_stepping != NULL | |
3804 | && can_hardware_single_step ()) | |
3805 | { | |
3806 | if (debug_threads) | |
3807 | debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n", | |
3808 | lwpid_of (thread)); | |
3809 | step = 1; | |
3810 | } | |
3811 | ||
3812 | if (proc->tdesc != NULL && the_low_target.get_pc != NULL) | |
3813 | { | |
3814 | struct regcache *regcache = get_thread_regcache (current_thread, 1); | |
3815 | ||
3816 | lwp->stop_pc = (*the_low_target.get_pc) (regcache); | |
3817 | ||
3818 | if (debug_threads) | |
3819 | { | |
3820 | debug_printf (" %s from pc 0x%lx\n", step ? "step" : "continue", | |
3821 | (long) lwp->stop_pc); | |
3822 | } | |
3823 | } | |
3824 | ||
3825 | /* If we have pending signals, consume one unless we are trying to | |
3826 | reinsert a breakpoint or we're trying to finish a fast tracepoint | |
3827 | collect. */ | |
3828 | if (lwp->pending_signals != NULL | |
3829 | && lwp->bp_reinsert == 0 | |
3830 | && fast_tp_collecting == 0) | |
3831 | { | |
3832 | struct pending_signals **p_sig; | |
3833 | ||
3834 | p_sig = &lwp->pending_signals; | |
3835 | while ((*p_sig)->prev != NULL) | |
3836 | p_sig = &(*p_sig)->prev; | |
3837 | ||
3838 | signal = (*p_sig)->signal; | |
3839 | if ((*p_sig)->info.si_signo != 0) | |
3840 | ptrace (PTRACE_SETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
3841 | &(*p_sig)->info); | |
3842 | ||
3843 | free (*p_sig); | |
3844 | *p_sig = NULL; | |
3845 | } | |
3846 | ||
3847 | if (the_low_target.prepare_to_resume != NULL) | |
3848 | the_low_target.prepare_to_resume (lwp); | |
3849 | ||
3850 | regcache_invalidate_thread (thread); | |
3851 | errno = 0; | |
3852 | lwp->stepping = step; | |
3853 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (thread), | |
3854 | (PTRACE_TYPE_ARG3) 0, | |
3855 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
3856 | of coercing an 8 byte integer to a 4 byte pointer. */ | |
3857 | (PTRACE_TYPE_ARG4) (uintptr_t) signal); | |
3858 | ||
3859 | current_thread = saved_thread; | |
3860 | if (errno) | |
3861 | perror_with_name ("resuming thread"); | |
3862 | ||
3863 | /* Successfully resumed. Clear state that no longer makes sense, | |
3864 | and mark the LWP as running. Must not do this before resuming | |
3865 | otherwise if that fails other code will be confused. E.g., we'd | |
3866 | later try to stop the LWP and hang forever waiting for a stop | |
3867 | status. Note that we must not throw after this is cleared, | |
3868 | otherwise handle_zombie_lwp_error would get confused. */ | |
3869 | lwp->stopped = 0; | |
3870 | lwp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
3871 | } | |
3872 | ||
3873 | /* Called when we try to resume a stopped LWP and that errors out. If | |
3874 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
3875 | or about to become), discard the error, clear any pending status | |
3876 | the LWP may have, and return true (we'll collect the exit status | |
3877 | soon enough). Otherwise, return false. */ | |
3878 | ||
3879 | static int | |
3880 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
3881 | { | |
3882 | struct thread_info *thread = get_lwp_thread (lp); | |
3883 | ||
3884 | /* If we get an error after resuming the LWP successfully, we'd | |
3885 | confuse !T state for the LWP being gone. */ | |
3886 | gdb_assert (lp->stopped); | |
3887 | ||
3888 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
3889 | because even if ptrace failed with ESRCH, the tracee may be "not | |
3890 | yet fully dead", but already refusing ptrace requests. In that | |
3891 | case the tracee has 'R (Running)' state for a little bit | |
3892 | (observed in Linux 3.18). See also the note on ESRCH in the | |
3893 | ptrace(2) man page. Instead, check whether the LWP has any state | |
3894 | other than ptrace-stopped. */ | |
3895 | ||
3896 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
3897 | if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread)) == 0) | |
3898 | { | |
3899 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
3900 | lp->status_pending_p = 0; | |
3901 | return 1; | |
3902 | } | |
3903 | return 0; | |
3904 | } | |
3905 | ||
3906 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
3907 | disappears while we try to resume it. */ | |
3908 | ||
3909 | static void | |
3910 | linux_resume_one_lwp (struct lwp_info *lwp, | |
3911 | int step, int signal, siginfo_t *info) | |
3912 | { | |
3913 | TRY | |
3914 | { | |
3915 | linux_resume_one_lwp_throw (lwp, step, signal, info); | |
3916 | } | |
3917 | CATCH (ex, RETURN_MASK_ERROR) | |
3918 | { | |
3919 | if (!check_ptrace_stopped_lwp_gone (lwp)) | |
3920 | throw_exception (ex); | |
3921 | } | |
3922 | END_CATCH | |
3923 | } | |
3924 | ||
3925 | struct thread_resume_array | |
3926 | { | |
3927 | struct thread_resume *resume; | |
3928 | size_t n; | |
3929 | }; | |
3930 | ||
3931 | /* This function is called once per thread via find_inferior. | |
3932 | ARG is a pointer to a thread_resume_array struct. | |
3933 | We look up the thread specified by ENTRY in ARG, and mark the thread | |
3934 | with a pointer to the appropriate resume request. | |
3935 | ||
3936 | This algorithm is O(threads * resume elements), but resume elements | |
3937 | is small (and will remain small at least until GDB supports thread | |
3938 | suspension). */ | |
3939 | ||
3940 | static int | |
3941 | linux_set_resume_request (struct inferior_list_entry *entry, void *arg) | |
3942 | { | |
3943 | struct thread_info *thread = (struct thread_info *) entry; | |
3944 | struct lwp_info *lwp = get_thread_lwp (thread); | |
3945 | int ndx; | |
3946 | struct thread_resume_array *r; | |
3947 | ||
3948 | r = arg; | |
3949 | ||
3950 | for (ndx = 0; ndx < r->n; ndx++) | |
3951 | { | |
3952 | ptid_t ptid = r->resume[ndx].thread; | |
3953 | if (ptid_equal (ptid, minus_one_ptid) | |
3954 | || ptid_equal (ptid, entry->id) | |
3955 | /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads | |
3956 | of PID'. */ | |
3957 | || (ptid_get_pid (ptid) == pid_of (thread) | |
3958 | && (ptid_is_pid (ptid) | |
3959 | || ptid_get_lwp (ptid) == -1))) | |
3960 | { | |
3961 | if (r->resume[ndx].kind == resume_stop | |
3962 | && thread->last_resume_kind == resume_stop) | |
3963 | { | |
3964 | if (debug_threads) | |
3965 | debug_printf ("already %s LWP %ld at GDB's request\n", | |
3966 | (thread->last_status.kind | |
3967 | == TARGET_WAITKIND_STOPPED) | |
3968 | ? "stopped" | |
3969 | : "stopping", | |
3970 | lwpid_of (thread)); | |
3971 | ||
3972 | continue; | |
3973 | } | |
3974 | ||
3975 | lwp->resume = &r->resume[ndx]; | |
3976 | thread->last_resume_kind = lwp->resume->kind; | |
3977 | ||
3978 | lwp->step_range_start = lwp->resume->step_range_start; | |
3979 | lwp->step_range_end = lwp->resume->step_range_end; | |
3980 | ||
3981 | /* If we had a deferred signal to report, dequeue one now. | |
3982 | This can happen if LWP gets more than one signal while | |
3983 | trying to get out of a jump pad. */ | |
3984 | if (lwp->stopped | |
3985 | && !lwp->status_pending_p | |
3986 | && dequeue_one_deferred_signal (lwp, &lwp->status_pending)) | |
3987 | { | |
3988 | lwp->status_pending_p = 1; | |
3989 | ||
3990 | if (debug_threads) | |
3991 | debug_printf ("Dequeueing deferred signal %d for LWP %ld, " | |
3992 | "leaving status pending.\n", | |
3993 | WSTOPSIG (lwp->status_pending), | |
3994 | lwpid_of (thread)); | |
3995 | } | |
3996 | ||
3997 | return 0; | |
3998 | } | |
3999 | } | |
4000 | ||
4001 | /* No resume action for this thread. */ | |
4002 | lwp->resume = NULL; | |
4003 | ||
4004 | return 0; | |
4005 | } | |
4006 | ||
4007 | /* find_inferior callback for linux_resume. | |
4008 | Set *FLAG_P if this lwp has an interesting status pending. */ | |
4009 | ||
4010 | static int | |
4011 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) | |
4012 | { | |
4013 | struct thread_info *thread = (struct thread_info *) entry; | |
4014 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4015 | ||
4016 | /* LWPs which will not be resumed are not interesting, because | |
4017 | we might not wait for them next time through linux_wait. */ | |
4018 | if (lwp->resume == NULL) | |
4019 | return 0; | |
4020 | ||
4021 | if (thread_still_has_status_pending_p (thread)) | |
4022 | * (int *) flag_p = 1; | |
4023 | ||
4024 | return 0; | |
4025 | } | |
4026 | ||
4027 | /* Return 1 if this lwp that GDB wants running is stopped at an | |
4028 | internal breakpoint that we need to step over. It assumes that any | |
4029 | required STOP_PC adjustment has already been propagated to the | |
4030 | inferior's regcache. */ | |
4031 | ||
4032 | static int | |
4033 | need_step_over_p (struct inferior_list_entry *entry, void *dummy) | |
4034 | { | |
4035 | struct thread_info *thread = (struct thread_info *) entry; | |
4036 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4037 | struct thread_info *saved_thread; | |
4038 | CORE_ADDR pc; | |
4039 | struct process_info *proc = get_thread_process (thread); | |
4040 | ||
4041 | /* GDBserver is skipping the extra traps from the wrapper program, | |
4042 | don't have to do step over. */ | |
4043 | if (proc->tdesc == NULL) | |
4044 | return 0; | |
4045 | ||
4046 | /* LWPs which will not be resumed are not interesting, because we | |
4047 | might not wait for them next time through linux_wait. */ | |
4048 | ||
4049 | if (!lwp->stopped) | |
4050 | { | |
4051 | if (debug_threads) | |
4052 | debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n", | |
4053 | lwpid_of (thread)); | |
4054 | return 0; | |
4055 | } | |
4056 | ||
4057 | if (thread->last_resume_kind == resume_stop) | |
4058 | { | |
4059 | if (debug_threads) | |
4060 | debug_printf ("Need step over [LWP %ld]? Ignoring, should remain" | |
4061 | " stopped\n", | |
4062 | lwpid_of (thread)); | |
4063 | return 0; | |
4064 | } | |
4065 | ||
4066 | gdb_assert (lwp->suspended >= 0); | |
4067 | ||
4068 | if (lwp->suspended) | |
4069 | { | |
4070 | if (debug_threads) | |
4071 | debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n", | |
4072 | lwpid_of (thread)); | |
4073 | return 0; | |
4074 | } | |
4075 | ||
4076 | if (!lwp->need_step_over) | |
4077 | { | |
4078 | if (debug_threads) | |
4079 | debug_printf ("Need step over [LWP %ld]? No\n", lwpid_of (thread)); | |
4080 | } | |
4081 | ||
4082 | if (lwp->status_pending_p) | |
4083 | { | |
4084 | if (debug_threads) | |
4085 | debug_printf ("Need step over [LWP %ld]? Ignoring, has pending" | |
4086 | " status.\n", | |
4087 | lwpid_of (thread)); | |
4088 | return 0; | |
4089 | } | |
4090 | ||
4091 | /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already, | |
4092 | or we have. */ | |
4093 | pc = get_pc (lwp); | |
4094 | ||
4095 | /* If the PC has changed since we stopped, then don't do anything, | |
4096 | and let the breakpoint/tracepoint be hit. This happens if, for | |
4097 | instance, GDB handled the decr_pc_after_break subtraction itself, | |
4098 | GDB is OOL stepping this thread, or the user has issued a "jump" | |
4099 | command, or poked thread's registers herself. */ | |
4100 | if (pc != lwp->stop_pc) | |
4101 | { | |
4102 | if (debug_threads) | |
4103 | debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. " | |
4104 | "Old stop_pc was 0x%s, PC is now 0x%s\n", | |
4105 | lwpid_of (thread), | |
4106 | paddress (lwp->stop_pc), paddress (pc)); | |
4107 | ||
4108 | lwp->need_step_over = 0; | |
4109 | return 0; | |
4110 | } | |
4111 | ||
4112 | saved_thread = current_thread; | |
4113 | current_thread = thread; | |
4114 | ||
4115 | /* We can only step over breakpoints we know about. */ | |
4116 | if (breakpoint_here (pc) || fast_tracepoint_jump_here (pc)) | |
4117 | { | |
4118 | /* Don't step over a breakpoint that GDB expects to hit | |
4119 | though. If the condition is being evaluated on the target's side | |
4120 | and it evaluate to false, step over this breakpoint as well. */ | |
4121 | if (gdb_breakpoint_here (pc) | |
4122 | && gdb_condition_true_at_breakpoint (pc) | |
4123 | && gdb_no_commands_at_breakpoint (pc)) | |
4124 | { | |
4125 | if (debug_threads) | |
4126 | debug_printf ("Need step over [LWP %ld]? yes, but found" | |
4127 | " GDB breakpoint at 0x%s; skipping step over\n", | |
4128 | lwpid_of (thread), paddress (pc)); | |
4129 | ||
4130 | current_thread = saved_thread; | |
4131 | return 0; | |
4132 | } | |
4133 | else | |
4134 | { | |
4135 | if (debug_threads) | |
4136 | debug_printf ("Need step over [LWP %ld]? yes, " | |
4137 | "found breakpoint at 0x%s\n", | |
4138 | lwpid_of (thread), paddress (pc)); | |
4139 | ||
4140 | /* We've found an lwp that needs stepping over --- return 1 so | |
4141 | that find_inferior stops looking. */ | |
4142 | current_thread = saved_thread; | |
4143 | ||
4144 | /* If the step over is cancelled, this is set again. */ | |
4145 | lwp->need_step_over = 0; | |
4146 | return 1; | |
4147 | } | |
4148 | } | |
4149 | ||
4150 | current_thread = saved_thread; | |
4151 | ||
4152 | if (debug_threads) | |
4153 | debug_printf ("Need step over [LWP %ld]? No, no breakpoint found" | |
4154 | " at 0x%s\n", | |
4155 | lwpid_of (thread), paddress (pc)); | |
4156 | ||
4157 | return 0; | |
4158 | } | |
4159 | ||
4160 | /* Start a step-over operation on LWP. When LWP stopped at a | |
4161 | breakpoint, to make progress, we need to remove the breakpoint out | |
4162 | of the way. If we let other threads run while we do that, they may | |
4163 | pass by the breakpoint location and miss hitting it. To avoid | |
4164 | that, a step-over momentarily stops all threads while LWP is | |
4165 | single-stepped while the breakpoint is temporarily uninserted from | |
4166 | the inferior. When the single-step finishes, we reinsert the | |
4167 | breakpoint, and let all threads that are supposed to be running, | |
4168 | run again. | |
4169 | ||
4170 | On targets that don't support hardware single-step, we don't | |
4171 | currently support full software single-stepping. Instead, we only | |
4172 | support stepping over the thread event breakpoint, by asking the | |
4173 | low target where to place a reinsert breakpoint. Since this | |
4174 | routine assumes the breakpoint being stepped over is a thread event | |
4175 | breakpoint, it usually assumes the return address of the current | |
4176 | function is a good enough place to set the reinsert breakpoint. */ | |
4177 | ||
4178 | static int | |
4179 | start_step_over (struct lwp_info *lwp) | |
4180 | { | |
4181 | struct thread_info *thread = get_lwp_thread (lwp); | |
4182 | struct thread_info *saved_thread; | |
4183 | CORE_ADDR pc; | |
4184 | int step; | |
4185 | ||
4186 | if (debug_threads) | |
4187 | debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n", | |
4188 | lwpid_of (thread)); | |
4189 | ||
4190 | stop_all_lwps (1, lwp); | |
4191 | gdb_assert (lwp->suspended == 0); | |
4192 | ||
4193 | if (debug_threads) | |
4194 | debug_printf ("Done stopping all threads for step-over.\n"); | |
4195 | ||
4196 | /* Note, we should always reach here with an already adjusted PC, | |
4197 | either by GDB (if we're resuming due to GDB's request), or by our | |
4198 | caller, if we just finished handling an internal breakpoint GDB | |
4199 | shouldn't care about. */ | |
4200 | pc = get_pc (lwp); | |
4201 | ||
4202 | saved_thread = current_thread; | |
4203 | current_thread = thread; | |
4204 | ||
4205 | lwp->bp_reinsert = pc; | |
4206 | uninsert_breakpoints_at (pc); | |
4207 | uninsert_fast_tracepoint_jumps_at (pc); | |
4208 | ||
4209 | if (can_hardware_single_step ()) | |
4210 | { | |
4211 | step = 1; | |
4212 | } | |
4213 | else | |
4214 | { | |
4215 | CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) (); | |
4216 | set_reinsert_breakpoint (raddr); | |
4217 | step = 0; | |
4218 | } | |
4219 | ||
4220 | current_thread = saved_thread; | |
4221 | ||
4222 | linux_resume_one_lwp (lwp, step, 0, NULL); | |
4223 | ||
4224 | /* Require next event from this LWP. */ | |
4225 | step_over_bkpt = thread->entry.id; | |
4226 | return 1; | |
4227 | } | |
4228 | ||
4229 | /* Finish a step-over. Reinsert the breakpoint we had uninserted in | |
4230 | start_step_over, if still there, and delete any reinsert | |
4231 | breakpoints we've set, on non hardware single-step targets. */ | |
4232 | ||
4233 | static int | |
4234 | finish_step_over (struct lwp_info *lwp) | |
4235 | { | |
4236 | if (lwp->bp_reinsert != 0) | |
4237 | { | |
4238 | if (debug_threads) | |
4239 | debug_printf ("Finished step over.\n"); | |
4240 | ||
4241 | /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there | |
4242 | may be no breakpoint to reinsert there by now. */ | |
4243 | reinsert_breakpoints_at (lwp->bp_reinsert); | |
4244 | reinsert_fast_tracepoint_jumps_at (lwp->bp_reinsert); | |
4245 | ||
4246 | lwp->bp_reinsert = 0; | |
4247 | ||
4248 | /* Delete any software-single-step reinsert breakpoints. No | |
4249 | longer needed. We don't have to worry about other threads | |
4250 | hitting this trap, and later not being able to explain it, | |
4251 | because we were stepping over a breakpoint, and we hold all | |
4252 | threads but LWP stopped while doing that. */ | |
4253 | if (!can_hardware_single_step ()) | |
4254 | delete_reinsert_breakpoints (); | |
4255 | ||
4256 | step_over_bkpt = null_ptid; | |
4257 | return 1; | |
4258 | } | |
4259 | else | |
4260 | return 0; | |
4261 | } | |
4262 | ||
4263 | /* This function is called once per thread. We check the thread's resume | |
4264 | request, which will tell us whether to resume, step, or leave the thread | |
4265 | stopped; and what signal, if any, it should be sent. | |
4266 | ||
4267 | For threads which we aren't explicitly told otherwise, we preserve | |
4268 | the stepping flag; this is used for stepping over gdbserver-placed | |
4269 | breakpoints. | |
4270 | ||
4271 | If pending_flags was set in any thread, we queue any needed | |
4272 | signals, since we won't actually resume. We already have a pending | |
4273 | event to report, so we don't need to preserve any step requests; | |
4274 | they should be re-issued if necessary. */ | |
4275 | ||
4276 | static int | |
4277 | linux_resume_one_thread (struct inferior_list_entry *entry, void *arg) | |
4278 | { | |
4279 | struct thread_info *thread = (struct thread_info *) entry; | |
4280 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4281 | int step; | |
4282 | int leave_all_stopped = * (int *) arg; | |
4283 | int leave_pending; | |
4284 | ||
4285 | if (lwp->resume == NULL) | |
4286 | return 0; | |
4287 | ||
4288 | if (lwp->resume->kind == resume_stop) | |
4289 | { | |
4290 | if (debug_threads) | |
4291 | debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread)); | |
4292 | ||
4293 | if (!lwp->stopped) | |
4294 | { | |
4295 | if (debug_threads) | |
4296 | debug_printf ("stopping LWP %ld\n", lwpid_of (thread)); | |
4297 | ||
4298 | /* Stop the thread, and wait for the event asynchronously, | |
4299 | through the event loop. */ | |
4300 | send_sigstop (lwp); | |
4301 | } | |
4302 | else | |
4303 | { | |
4304 | if (debug_threads) | |
4305 | debug_printf ("already stopped LWP %ld\n", | |
4306 | lwpid_of (thread)); | |
4307 | ||
4308 | /* The LWP may have been stopped in an internal event that | |
4309 | was not meant to be notified back to GDB (e.g., gdbserver | |
4310 | breakpoint), so we should be reporting a stop event in | |
4311 | this case too. */ | |
4312 | ||
4313 | /* If the thread already has a pending SIGSTOP, this is a | |
4314 | no-op. Otherwise, something later will presumably resume | |
4315 | the thread and this will cause it to cancel any pending | |
4316 | operation, due to last_resume_kind == resume_stop. If | |
4317 | the thread already has a pending status to report, we | |
4318 | will still report it the next time we wait - see | |
4319 | status_pending_p_callback. */ | |
4320 | ||
4321 | /* If we already have a pending signal to report, then | |
4322 | there's no need to queue a SIGSTOP, as this means we're | |
4323 | midway through moving the LWP out of the jumppad, and we | |
4324 | will report the pending signal as soon as that is | |
4325 | finished. */ | |
4326 | if (lwp->pending_signals_to_report == NULL) | |
4327 | send_sigstop (lwp); | |
4328 | } | |
4329 | ||
4330 | /* For stop requests, we're done. */ | |
4331 | lwp->resume = NULL; | |
4332 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; | |
4333 | return 0; | |
4334 | } | |
4335 | ||
4336 | /* If this thread which is about to be resumed has a pending status, | |
4337 | then don't resume any threads - we can just report the pending | |
4338 | status. Make sure to queue any signals that would otherwise be | |
4339 | sent. In all-stop mode, we do this decision based on if *any* | |
4340 | thread has a pending status. If there's a thread that needs the | |
4341 | step-over-breakpoint dance, then don't resume any other thread | |
4342 | but that particular one. */ | |
4343 | leave_pending = (lwp->status_pending_p || leave_all_stopped); | |
4344 | ||
4345 | if (!leave_pending) | |
4346 | { | |
4347 | if (debug_threads) | |
4348 | debug_printf ("resuming LWP %ld\n", lwpid_of (thread)); | |
4349 | ||
4350 | step = (lwp->resume->kind == resume_step); | |
4351 | linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL); | |
4352 | } | |
4353 | else | |
4354 | { | |
4355 | if (debug_threads) | |
4356 | debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread)); | |
4357 | ||
4358 | /* If we have a new signal, enqueue the signal. */ | |
4359 | if (lwp->resume->sig != 0) | |
4360 | { | |
4361 | struct pending_signals *p_sig; | |
4362 | p_sig = xmalloc (sizeof (*p_sig)); | |
4363 | p_sig->prev = lwp->pending_signals; | |
4364 | p_sig->signal = lwp->resume->sig; | |
4365 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
4366 | ||
4367 | /* If this is the same signal we were previously stopped by, | |
4368 | make sure to queue its siginfo. We can ignore the return | |
4369 | value of ptrace; if it fails, we'll skip | |
4370 | PTRACE_SETSIGINFO. */ | |
4371 | if (WIFSTOPPED (lwp->last_status) | |
4372 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig) | |
4373 | ptrace (PTRACE_GETSIGINFO, lwpid_of (thread), (PTRACE_TYPE_ARG3) 0, | |
4374 | &p_sig->info); | |
4375 | ||
4376 | lwp->pending_signals = p_sig; | |
4377 | } | |
4378 | } | |
4379 | ||
4380 | thread->last_status.kind = TARGET_WAITKIND_IGNORE; | |
4381 | lwp->resume = NULL; | |
4382 | return 0; | |
4383 | } | |
4384 | ||
4385 | static void | |
4386 | linux_resume (struct thread_resume *resume_info, size_t n) | |
4387 | { | |
4388 | struct thread_resume_array array = { resume_info, n }; | |
4389 | struct thread_info *need_step_over = NULL; | |
4390 | int any_pending; | |
4391 | int leave_all_stopped; | |
4392 | ||
4393 | if (debug_threads) | |
4394 | { | |
4395 | debug_enter (); | |
4396 | debug_printf ("linux_resume:\n"); | |
4397 | } | |
4398 | ||
4399 | find_inferior (&all_threads, linux_set_resume_request, &array); | |
4400 | ||
4401 | /* If there is a thread which would otherwise be resumed, which has | |
4402 | a pending status, then don't resume any threads - we can just | |
4403 | report the pending status. Make sure to queue any signals that | |
4404 | would otherwise be sent. In non-stop mode, we'll apply this | |
4405 | logic to each thread individually. We consume all pending events | |
4406 | before considering to start a step-over (in all-stop). */ | |
4407 | any_pending = 0; | |
4408 | if (!non_stop) | |
4409 | find_inferior (&all_threads, resume_status_pending_p, &any_pending); | |
4410 | ||
4411 | /* If there is a thread which would otherwise be resumed, which is | |
4412 | stopped at a breakpoint that needs stepping over, then don't | |
4413 | resume any threads - have it step over the breakpoint with all | |
4414 | other threads stopped, then resume all threads again. Make sure | |
4415 | to queue any signals that would otherwise be delivered or | |
4416 | queued. */ | |
4417 | if (!any_pending && supports_breakpoints ()) | |
4418 | need_step_over | |
4419 | = (struct thread_info *) find_inferior (&all_threads, | |
4420 | need_step_over_p, NULL); | |
4421 | ||
4422 | leave_all_stopped = (need_step_over != NULL || any_pending); | |
4423 | ||
4424 | if (debug_threads) | |
4425 | { | |
4426 | if (need_step_over != NULL) | |
4427 | debug_printf ("Not resuming all, need step over\n"); | |
4428 | else if (any_pending) | |
4429 | debug_printf ("Not resuming, all-stop and found " | |
4430 | "an LWP with pending status\n"); | |
4431 | else | |
4432 | debug_printf ("Resuming, no pending status or step over needed\n"); | |
4433 | } | |
4434 | ||
4435 | /* Even if we're leaving threads stopped, queue all signals we'd | |
4436 | otherwise deliver. */ | |
4437 | find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped); | |
4438 | ||
4439 | if (need_step_over) | |
4440 | start_step_over (get_thread_lwp (need_step_over)); | |
4441 | ||
4442 | if (debug_threads) | |
4443 | { | |
4444 | debug_printf ("linux_resume done\n"); | |
4445 | debug_exit (); | |
4446 | } | |
4447 | } | |
4448 | ||
4449 | /* This function is called once per thread. We check the thread's | |
4450 | last resume request, which will tell us whether to resume, step, or | |
4451 | leave the thread stopped. Any signal the client requested to be | |
4452 | delivered has already been enqueued at this point. | |
4453 | ||
4454 | If any thread that GDB wants running is stopped at an internal | |
4455 | breakpoint that needs stepping over, we start a step-over operation | |
4456 | on that particular thread, and leave all others stopped. */ | |
4457 | ||
4458 | static int | |
4459 | proceed_one_lwp (struct inferior_list_entry *entry, void *except) | |
4460 | { | |
4461 | struct thread_info *thread = (struct thread_info *) entry; | |
4462 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4463 | int step; | |
4464 | ||
4465 | if (lwp == except) | |
4466 | return 0; | |
4467 | ||
4468 | if (debug_threads) | |
4469 | debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread)); | |
4470 | ||
4471 | if (!lwp->stopped) | |
4472 | { | |
4473 | if (debug_threads) | |
4474 | debug_printf (" LWP %ld already running\n", lwpid_of (thread)); | |
4475 | return 0; | |
4476 | } | |
4477 | ||
4478 | if (thread->last_resume_kind == resume_stop | |
4479 | && thread->last_status.kind != TARGET_WAITKIND_IGNORE) | |
4480 | { | |
4481 | if (debug_threads) | |
4482 | debug_printf (" client wants LWP to remain %ld stopped\n", | |
4483 | lwpid_of (thread)); | |
4484 | return 0; | |
4485 | } | |
4486 | ||
4487 | if (lwp->status_pending_p) | |
4488 | { | |
4489 | if (debug_threads) | |
4490 | debug_printf (" LWP %ld has pending status, leaving stopped\n", | |
4491 | lwpid_of (thread)); | |
4492 | return 0; | |
4493 | } | |
4494 | ||
4495 | gdb_assert (lwp->suspended >= 0); | |
4496 | ||
4497 | if (lwp->suspended) | |
4498 | { | |
4499 | if (debug_threads) | |
4500 | debug_printf (" LWP %ld is suspended\n", lwpid_of (thread)); | |
4501 | return 0; | |
4502 | } | |
4503 | ||
4504 | if (thread->last_resume_kind == resume_stop | |
4505 | && lwp->pending_signals_to_report == NULL | |
4506 | && lwp->collecting_fast_tracepoint == 0) | |
4507 | { | |
4508 | /* We haven't reported this LWP as stopped yet (otherwise, the | |
4509 | last_status.kind check above would catch it, and we wouldn't | |
4510 | reach here. This LWP may have been momentarily paused by a | |
4511 | stop_all_lwps call while handling for example, another LWP's | |
4512 | step-over. In that case, the pending expected SIGSTOP signal | |
4513 | that was queued at vCont;t handling time will have already | |
4514 | been consumed by wait_for_sigstop, and so we need to requeue | |
4515 | another one here. Note that if the LWP already has a SIGSTOP | |
4516 | pending, this is a no-op. */ | |
4517 | ||
4518 | if (debug_threads) | |
4519 | debug_printf ("Client wants LWP %ld to stop. " | |
4520 | "Making sure it has a SIGSTOP pending\n", | |
4521 | lwpid_of (thread)); | |
4522 | ||
4523 | send_sigstop (lwp); | |
4524 | } | |
4525 | ||
4526 | step = thread->last_resume_kind == resume_step; | |
4527 | linux_resume_one_lwp (lwp, step, 0, NULL); | |
4528 | return 0; | |
4529 | } | |
4530 | ||
4531 | static int | |
4532 | unsuspend_and_proceed_one_lwp (struct inferior_list_entry *entry, void *except) | |
4533 | { | |
4534 | struct thread_info *thread = (struct thread_info *) entry; | |
4535 | struct lwp_info *lwp = get_thread_lwp (thread); | |
4536 | ||
4537 | if (lwp == except) | |
4538 | return 0; | |
4539 | ||
4540 | lwp->suspended--; | |
4541 | gdb_assert (lwp->suspended >= 0); | |
4542 | ||
4543 | return proceed_one_lwp (entry, except); | |
4544 | } | |
4545 | ||
4546 | /* When we finish a step-over, set threads running again. If there's | |
4547 | another thread that may need a step-over, now's the time to start | |
4548 | it. Eventually, we'll move all threads past their breakpoints. */ | |
4549 | ||
4550 | static void | |
4551 | proceed_all_lwps (void) | |
4552 | { | |
4553 | struct thread_info *need_step_over; | |
4554 | ||
4555 | /* If there is a thread which would otherwise be resumed, which is | |
4556 | stopped at a breakpoint that needs stepping over, then don't | |
4557 | resume any threads - have it step over the breakpoint with all | |
4558 | other threads stopped, then resume all threads again. */ | |
4559 | ||
4560 | if (supports_breakpoints ()) | |
4561 | { | |
4562 | need_step_over | |
4563 | = (struct thread_info *) find_inferior (&all_threads, | |
4564 | need_step_over_p, NULL); | |
4565 | ||
4566 | if (need_step_over != NULL) | |
4567 | { | |
4568 | if (debug_threads) | |
4569 | debug_printf ("proceed_all_lwps: found " | |
4570 | "thread %ld needing a step-over\n", | |
4571 | lwpid_of (need_step_over)); | |
4572 | ||
4573 | start_step_over (get_thread_lwp (need_step_over)); | |
4574 | return; | |
4575 | } | |
4576 | } | |
4577 | ||
4578 | if (debug_threads) | |
4579 | debug_printf ("Proceeding, no step-over needed\n"); | |
4580 | ||
4581 | find_inferior (&all_threads, proceed_one_lwp, NULL); | |
4582 | } | |
4583 | ||
4584 | /* Stopped LWPs that the client wanted to be running, that don't have | |
4585 | pending statuses, are set to run again, except for EXCEPT, if not | |
4586 | NULL. This undoes a stop_all_lwps call. */ | |
4587 | ||
4588 | static void | |
4589 | unstop_all_lwps (int unsuspend, struct lwp_info *except) | |
4590 | { | |
4591 | if (debug_threads) | |
4592 | { | |
4593 | debug_enter (); | |
4594 | if (except) | |
4595 | debug_printf ("unstopping all lwps, except=(LWP %ld)\n", | |
4596 | lwpid_of (get_lwp_thread (except))); | |
4597 | else | |
4598 | debug_printf ("unstopping all lwps\n"); | |
4599 | } | |
4600 | ||
4601 | if (unsuspend) | |
4602 | find_inferior (&all_threads, unsuspend_and_proceed_one_lwp, except); | |
4603 | else | |
4604 | find_inferior (&all_threads, proceed_one_lwp, except); | |
4605 | ||
4606 | if (debug_threads) | |
4607 | { | |
4608 | debug_printf ("unstop_all_lwps done\n"); | |
4609 | debug_exit (); | |
4610 | } | |
4611 | } | |
4612 | ||
4613 | ||
4614 | #ifdef HAVE_LINUX_REGSETS | |
4615 | ||
4616 | #define use_linux_regsets 1 | |
4617 | ||
4618 | /* Returns true if REGSET has been disabled. */ | |
4619 | ||
4620 | static int | |
4621 | regset_disabled (struct regsets_info *info, struct regset_info *regset) | |
4622 | { | |
4623 | return (info->disabled_regsets != NULL | |
4624 | && info->disabled_regsets[regset - info->regsets]); | |
4625 | } | |
4626 | ||
4627 | /* Disable REGSET. */ | |
4628 | ||
4629 | static void | |
4630 | disable_regset (struct regsets_info *info, struct regset_info *regset) | |
4631 | { | |
4632 | int dr_offset; | |
4633 | ||
4634 | dr_offset = regset - info->regsets; | |
4635 | if (info->disabled_regsets == NULL) | |
4636 | info->disabled_regsets = xcalloc (1, info->num_regsets); | |
4637 | info->disabled_regsets[dr_offset] = 1; | |
4638 | } | |
4639 | ||
4640 | static int | |
4641 | regsets_fetch_inferior_registers (struct regsets_info *regsets_info, | |
4642 | struct regcache *regcache) | |
4643 | { | |
4644 | struct regset_info *regset; | |
4645 | int saw_general_regs = 0; | |
4646 | int pid; | |
4647 | struct iovec iov; | |
4648 | ||
4649 | pid = lwpid_of (current_thread); | |
4650 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) | |
4651 | { | |
4652 | void *buf, *data; | |
4653 | int nt_type, res; | |
4654 | ||
4655 | if (regset->size == 0 || regset_disabled (regsets_info, regset)) | |
4656 | continue; | |
4657 | ||
4658 | buf = xmalloc (regset->size); | |
4659 | ||
4660 | nt_type = regset->nt_type; | |
4661 | if (nt_type) | |
4662 | { | |
4663 | iov.iov_base = buf; | |
4664 | iov.iov_len = regset->size; | |
4665 | data = (void *) &iov; | |
4666 | } | |
4667 | else | |
4668 | data = buf; | |
4669 | ||
4670 | #ifndef __sparc__ | |
4671 | res = ptrace (regset->get_request, pid, | |
4672 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
4673 | #else | |
4674 | res = ptrace (regset->get_request, pid, data, nt_type); | |
4675 | #endif | |
4676 | if (res < 0) | |
4677 | { | |
4678 | if (errno == EIO) | |
4679 | { | |
4680 | /* If we get EIO on a regset, do not try it again for | |
4681 | this process mode. */ | |
4682 | disable_regset (regsets_info, regset); | |
4683 | } | |
4684 | else if (errno == ENODATA) | |
4685 | { | |
4686 | /* ENODATA may be returned if the regset is currently | |
4687 | not "active". This can happen in normal operation, | |
4688 | so suppress the warning in this case. */ | |
4689 | } | |
4690 | else | |
4691 | { | |
4692 | char s[256]; | |
4693 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", | |
4694 | pid); | |
4695 | perror (s); | |
4696 | } | |
4697 | } | |
4698 | else | |
4699 | { | |
4700 | if (regset->type == GENERAL_REGS) | |
4701 | saw_general_regs = 1; | |
4702 | regset->store_function (regcache, buf); | |
4703 | } | |
4704 | free (buf); | |
4705 | } | |
4706 | if (saw_general_regs) | |
4707 | return 0; | |
4708 | else | |
4709 | return 1; | |
4710 | } | |
4711 | ||
4712 | static int | |
4713 | regsets_store_inferior_registers (struct regsets_info *regsets_info, | |
4714 | struct regcache *regcache) | |
4715 | { | |
4716 | struct regset_info *regset; | |
4717 | int saw_general_regs = 0; | |
4718 | int pid; | |
4719 | struct iovec iov; | |
4720 | ||
4721 | pid = lwpid_of (current_thread); | |
4722 | for (regset = regsets_info->regsets; regset->size >= 0; regset++) | |
4723 | { | |
4724 | void *buf, *data; | |
4725 | int nt_type, res; | |
4726 | ||
4727 | if (regset->size == 0 || regset_disabled (regsets_info, regset) | |
4728 | || regset->fill_function == NULL) | |
4729 | continue; | |
4730 | ||
4731 | buf = xmalloc (regset->size); | |
4732 | ||
4733 | /* First fill the buffer with the current register set contents, | |
4734 | in case there are any items in the kernel's regset that are | |
4735 | not in gdbserver's regcache. */ | |
4736 | ||
4737 | nt_type = regset->nt_type; | |
4738 | if (nt_type) | |
4739 | { | |
4740 | iov.iov_base = buf; | |
4741 | iov.iov_len = regset->size; | |
4742 | data = (void *) &iov; | |
4743 | } | |
4744 | else | |
4745 | data = buf; | |
4746 | ||
4747 | #ifndef __sparc__ | |
4748 | res = ptrace (regset->get_request, pid, | |
4749 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
4750 | #else | |
4751 | res = ptrace (regset->get_request, pid, data, nt_type); | |
4752 | #endif | |
4753 | ||
4754 | if (res == 0) | |
4755 | { | |
4756 | /* Then overlay our cached registers on that. */ | |
4757 | regset->fill_function (regcache, buf); | |
4758 | ||
4759 | /* Only now do we write the register set. */ | |
4760 | #ifndef __sparc__ | |
4761 | res = ptrace (regset->set_request, pid, | |
4762 | (PTRACE_TYPE_ARG3) (long) nt_type, data); | |
4763 | #else | |
4764 | res = ptrace (regset->set_request, pid, data, nt_type); | |
4765 | #endif | |
4766 | } | |
4767 | ||
4768 | if (res < 0) | |
4769 | { | |
4770 | if (errno == EIO) | |
4771 | { | |
4772 | /* If we get EIO on a regset, do not try it again for | |
4773 | this process mode. */ | |
4774 | disable_regset (regsets_info, regset); | |
4775 | } | |
4776 | else if (errno == ESRCH) | |
4777 | { | |
4778 | /* At this point, ESRCH should mean the process is | |
4779 | already gone, in which case we simply ignore attempts | |
4780 | to change its registers. See also the related | |
4781 | comment in linux_resume_one_lwp. */ | |
4782 | free (buf); | |
4783 | return 0; | |
4784 | } | |
4785 | else | |
4786 | { | |
4787 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); | |
4788 | } | |
4789 | } | |
4790 | else if (regset->type == GENERAL_REGS) | |
4791 | saw_general_regs = 1; | |
4792 | free (buf); | |
4793 | } | |
4794 | if (saw_general_regs) | |
4795 | return 0; | |
4796 | else | |
4797 | return 1; | |
4798 | } | |
4799 | ||
4800 | #else /* !HAVE_LINUX_REGSETS */ | |
4801 | ||
4802 | #define use_linux_regsets 0 | |
4803 | #define regsets_fetch_inferior_registers(regsets_info, regcache) 1 | |
4804 | #define regsets_store_inferior_registers(regsets_info, regcache) 1 | |
4805 | ||
4806 | #endif | |
4807 | ||
4808 | /* Return 1 if register REGNO is supported by one of the regset ptrace | |
4809 | calls or 0 if it has to be transferred individually. */ | |
4810 | ||
4811 | static int | |
4812 | linux_register_in_regsets (const struct regs_info *regs_info, int regno) | |
4813 | { | |
4814 | unsigned char mask = 1 << (regno % 8); | |
4815 | size_t index = regno / 8; | |
4816 | ||
4817 | return (use_linux_regsets | |
4818 | && (regs_info->regset_bitmap == NULL | |
4819 | || (regs_info->regset_bitmap[index] & mask) != 0)); | |
4820 | } | |
4821 | ||
4822 | #ifdef HAVE_LINUX_USRREGS | |
4823 | ||
4824 | int | |
4825 | register_addr (const struct usrregs_info *usrregs, int regnum) | |
4826 | { | |
4827 | int addr; | |
4828 | ||
4829 | if (regnum < 0 || regnum >= usrregs->num_regs) | |
4830 | error ("Invalid register number %d.", regnum); | |
4831 | ||
4832 | addr = usrregs->regmap[regnum]; | |
4833 | ||
4834 | return addr; | |
4835 | } | |
4836 | ||
4837 | /* Fetch one register. */ | |
4838 | static void | |
4839 | fetch_register (const struct usrregs_info *usrregs, | |
4840 | struct regcache *regcache, int regno) | |
4841 | { | |
4842 | CORE_ADDR regaddr; | |
4843 | int i, size; | |
4844 | char *buf; | |
4845 | int pid; | |
4846 | ||
4847 | if (regno >= usrregs->num_regs) | |
4848 | return; | |
4849 | if ((*the_low_target.cannot_fetch_register) (regno)) | |
4850 | return; | |
4851 | ||
4852 | regaddr = register_addr (usrregs, regno); | |
4853 | if (regaddr == -1) | |
4854 | return; | |
4855 | ||
4856 | size = ((register_size (regcache->tdesc, regno) | |
4857 | + sizeof (PTRACE_XFER_TYPE) - 1) | |
4858 | & -sizeof (PTRACE_XFER_TYPE)); | |
4859 | buf = alloca (size); | |
4860 | ||
4861 | pid = lwpid_of (current_thread); | |
4862 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
4863 | { | |
4864 | errno = 0; | |
4865 | *(PTRACE_XFER_TYPE *) (buf + i) = | |
4866 | ptrace (PTRACE_PEEKUSER, pid, | |
4867 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
4868 | of coercing an 8 byte integer to a 4 byte pointer. */ | |
4869 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, (PTRACE_TYPE_ARG4) 0); | |
4870 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
4871 | if (errno != 0) | |
4872 | error ("reading register %d: %s", regno, strerror (errno)); | |
4873 | } | |
4874 | ||
4875 | if (the_low_target.supply_ptrace_register) | |
4876 | the_low_target.supply_ptrace_register (regcache, regno, buf); | |
4877 | else | |
4878 | supply_register (regcache, regno, buf); | |
4879 | } | |
4880 | ||
4881 | /* Store one register. */ | |
4882 | static void | |
4883 | store_register (const struct usrregs_info *usrregs, | |
4884 | struct regcache *regcache, int regno) | |
4885 | { | |
4886 | CORE_ADDR regaddr; | |
4887 | int i, size; | |
4888 | char *buf; | |
4889 | int pid; | |
4890 | ||
4891 | if (regno >= usrregs->num_regs) | |
4892 | return; | |
4893 | if ((*the_low_target.cannot_store_register) (regno)) | |
4894 | return; | |
4895 | ||
4896 | regaddr = register_addr (usrregs, regno); | |
4897 | if (regaddr == -1) | |
4898 | return; | |
4899 | ||
4900 | size = ((register_size (regcache->tdesc, regno) | |
4901 | + sizeof (PTRACE_XFER_TYPE) - 1) | |
4902 | & -sizeof (PTRACE_XFER_TYPE)); | |
4903 | buf = alloca (size); | |
4904 | memset (buf, 0, size); | |
4905 | ||
4906 | if (the_low_target.collect_ptrace_register) | |
4907 | the_low_target.collect_ptrace_register (regcache, regno, buf); | |
4908 | else | |
4909 | collect_register (regcache, regno, buf); | |
4910 | ||
4911 | pid = lwpid_of (current_thread); | |
4912 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
4913 | { | |
4914 | errno = 0; | |
4915 | ptrace (PTRACE_POKEUSER, pid, | |
4916 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
4917 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
4918 | (PTRACE_TYPE_ARG3) (uintptr_t) regaddr, | |
4919 | (PTRACE_TYPE_ARG4) *(PTRACE_XFER_TYPE *) (buf + i)); | |
4920 | if (errno != 0) | |
4921 | { | |
4922 | /* At this point, ESRCH should mean the process is | |
4923 | already gone, in which case we simply ignore attempts | |
4924 | to change its registers. See also the related | |
4925 | comment in linux_resume_one_lwp. */ | |
4926 | if (errno == ESRCH) | |
4927 | return; | |
4928 | ||
4929 | if ((*the_low_target.cannot_store_register) (regno) == 0) | |
4930 | error ("writing register %d: %s", regno, strerror (errno)); | |
4931 | } | |
4932 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
4933 | } | |
4934 | } | |
4935 | ||
4936 | /* Fetch all registers, or just one, from the child process. | |
4937 | If REGNO is -1, do this for all registers, skipping any that are | |
4938 | assumed to have been retrieved by regsets_fetch_inferior_registers, | |
4939 | unless ALL is non-zero. | |
4940 | Otherwise, REGNO specifies which register (so we can save time). */ | |
4941 | static void | |
4942 | usr_fetch_inferior_registers (const struct regs_info *regs_info, | |
4943 | struct regcache *regcache, int regno, int all) | |
4944 | { | |
4945 | struct usrregs_info *usr = regs_info->usrregs; | |
4946 | ||
4947 | if (regno == -1) | |
4948 | { | |
4949 | for (regno = 0; regno < usr->num_regs; regno++) | |
4950 | if (all || !linux_register_in_regsets (regs_info, regno)) | |
4951 | fetch_register (usr, regcache, regno); | |
4952 | } | |
4953 | else | |
4954 | fetch_register (usr, regcache, regno); | |
4955 | } | |
4956 | ||
4957 | /* Store our register values back into the inferior. | |
4958 | If REGNO is -1, do this for all registers, skipping any that are | |
4959 | assumed to have been saved by regsets_store_inferior_registers, | |
4960 | unless ALL is non-zero. | |
4961 | Otherwise, REGNO specifies which register (so we can save time). */ | |
4962 | static void | |
4963 | usr_store_inferior_registers (const struct regs_info *regs_info, | |
4964 | struct regcache *regcache, int regno, int all) | |
4965 | { | |
4966 | struct usrregs_info *usr = regs_info->usrregs; | |
4967 | ||
4968 | if (regno == -1) | |
4969 | { | |
4970 | for (regno = 0; regno < usr->num_regs; regno++) | |
4971 | if (all || !linux_register_in_regsets (regs_info, regno)) | |
4972 | store_register (usr, regcache, regno); | |
4973 | } | |
4974 | else | |
4975 | store_register (usr, regcache, regno); | |
4976 | } | |
4977 | ||
4978 | #else /* !HAVE_LINUX_USRREGS */ | |
4979 | ||
4980 | #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0) | |
4981 | #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0) | |
4982 | ||
4983 | #endif | |
4984 | ||
4985 | ||
4986 | void | |
4987 | linux_fetch_registers (struct regcache *regcache, int regno) | |
4988 | { | |
4989 | int use_regsets; | |
4990 | int all = 0; | |
4991 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); | |
4992 | ||
4993 | if (regno == -1) | |
4994 | { | |
4995 | if (the_low_target.fetch_register != NULL | |
4996 | && regs_info->usrregs != NULL) | |
4997 | for (regno = 0; regno < regs_info->usrregs->num_regs; regno++) | |
4998 | (*the_low_target.fetch_register) (regcache, regno); | |
4999 | ||
5000 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, regcache); | |
5001 | if (regs_info->usrregs != NULL) | |
5002 | usr_fetch_inferior_registers (regs_info, regcache, -1, all); | |
5003 | } | |
5004 | else | |
5005 | { | |
5006 | if (the_low_target.fetch_register != NULL | |
5007 | && (*the_low_target.fetch_register) (regcache, regno)) | |
5008 | return; | |
5009 | ||
5010 | use_regsets = linux_register_in_regsets (regs_info, regno); | |
5011 | if (use_regsets) | |
5012 | all = regsets_fetch_inferior_registers (regs_info->regsets_info, | |
5013 | regcache); | |
5014 | if ((!use_regsets || all) && regs_info->usrregs != NULL) | |
5015 | usr_fetch_inferior_registers (regs_info, regcache, regno, 1); | |
5016 | } | |
5017 | } | |
5018 | ||
5019 | void | |
5020 | linux_store_registers (struct regcache *regcache, int regno) | |
5021 | { | |
5022 | int use_regsets; | |
5023 | int all = 0; | |
5024 | const struct regs_info *regs_info = (*the_low_target.regs_info) (); | |
5025 | ||
5026 | if (regno == -1) | |
5027 | { | |
5028 | all = regsets_store_inferior_registers (regs_info->regsets_info, | |
5029 | regcache); | |
5030 | if (regs_info->usrregs != NULL) | |
5031 | usr_store_inferior_registers (regs_info, regcache, regno, all); | |
5032 | } | |
5033 | else | |
5034 | { | |
5035 | use_regsets = linux_register_in_regsets (regs_info, regno); | |
5036 | if (use_regsets) | |
5037 | all = regsets_store_inferior_registers (regs_info->regsets_info, | |
5038 | regcache); | |
5039 | if ((!use_regsets || all) && regs_info->usrregs != NULL) | |
5040 | usr_store_inferior_registers (regs_info, regcache, regno, 1); | |
5041 | } | |
5042 | } | |
5043 | ||
5044 | ||
5045 | /* Copy LEN bytes from inferior's memory starting at MEMADDR | |
5046 | to debugger memory starting at MYADDR. */ | |
5047 | ||
5048 | static int | |
5049 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) | |
5050 | { | |
5051 | int pid = lwpid_of (current_thread); | |
5052 | register PTRACE_XFER_TYPE *buffer; | |
5053 | register CORE_ADDR addr; | |
5054 | register int count; | |
5055 | char filename[64]; | |
5056 | register int i; | |
5057 | int ret; | |
5058 | int fd; | |
5059 | ||
5060 | /* Try using /proc. Don't bother for one word. */ | |
5061 | if (len >= 3 * sizeof (long)) | |
5062 | { | |
5063 | int bytes; | |
5064 | ||
5065 | /* We could keep this file open and cache it - possibly one per | |
5066 | thread. That requires some juggling, but is even faster. */ | |
5067 | sprintf (filename, "/proc/%d/mem", pid); | |
5068 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
5069 | if (fd == -1) | |
5070 | goto no_proc; | |
5071 | ||
5072 | /* If pread64 is available, use it. It's faster if the kernel | |
5073 | supports it (only one syscall), and it's 64-bit safe even on | |
5074 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
5075 | application). */ | |
5076 | #ifdef HAVE_PREAD64 | |
5077 | bytes = pread64 (fd, myaddr, len, memaddr); | |
5078 | #else | |
5079 | bytes = -1; | |
5080 | if (lseek (fd, memaddr, SEEK_SET) != -1) | |
5081 | bytes = read (fd, myaddr, len); | |
5082 | #endif | |
5083 | ||
5084 | close (fd); | |
5085 | if (bytes == len) | |
5086 | return 0; | |
5087 | ||
5088 | /* Some data was read, we'll try to get the rest with ptrace. */ | |
5089 | if (bytes > 0) | |
5090 | { | |
5091 | memaddr += bytes; | |
5092 | myaddr += bytes; | |
5093 | len -= bytes; | |
5094 | } | |
5095 | } | |
5096 | ||
5097 | no_proc: | |
5098 | /* Round starting address down to longword boundary. */ | |
5099 | addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
5100 | /* Round ending address up; get number of longwords that makes. */ | |
5101 | count = ((((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
5102 | / sizeof (PTRACE_XFER_TYPE)); | |
5103 | /* Allocate buffer of that many longwords. */ | |
5104 | buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
5105 | ||
5106 | /* Read all the longwords */ | |
5107 | errno = 0; | |
5108 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
5109 | { | |
5110 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning | |
5111 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5112 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, | |
5113 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5114 | (PTRACE_TYPE_ARG4) 0); | |
5115 | if (errno) | |
5116 | break; | |
5117 | } | |
5118 | ret = errno; | |
5119 | ||
5120 | /* Copy appropriate bytes out of the buffer. */ | |
5121 | if (i > 0) | |
5122 | { | |
5123 | i *= sizeof (PTRACE_XFER_TYPE); | |
5124 | i -= memaddr & (sizeof (PTRACE_XFER_TYPE) - 1); | |
5125 | memcpy (myaddr, | |
5126 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), | |
5127 | i < len ? i : len); | |
5128 | } | |
5129 | ||
5130 | return ret; | |
5131 | } | |
5132 | ||
5133 | /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's | |
5134 | memory at MEMADDR. On failure (cannot write to the inferior) | |
5135 | returns the value of errno. Always succeeds if LEN is zero. */ | |
5136 | ||
5137 | static int | |
5138 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) | |
5139 | { | |
5140 | register int i; | |
5141 | /* Round starting address down to longword boundary. */ | |
5142 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
5143 | /* Round ending address up; get number of longwords that makes. */ | |
5144 | register int count | |
5145 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
5146 | / sizeof (PTRACE_XFER_TYPE); | |
5147 | ||
5148 | /* Allocate buffer of that many longwords. */ | |
5149 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) | |
5150 | alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
5151 | ||
5152 | int pid = lwpid_of (current_thread); | |
5153 | ||
5154 | if (len == 0) | |
5155 | { | |
5156 | /* Zero length write always succeeds. */ | |
5157 | return 0; | |
5158 | } | |
5159 | ||
5160 | if (debug_threads) | |
5161 | { | |
5162 | /* Dump up to four bytes. */ | |
5163 | unsigned int val = * (unsigned int *) myaddr; | |
5164 | if (len == 1) | |
5165 | val = val & 0xff; | |
5166 | else if (len == 2) | |
5167 | val = val & 0xffff; | |
5168 | else if (len == 3) | |
5169 | val = val & 0xffffff; | |
5170 | debug_printf ("Writing %0*x to 0x%08lx in process %d\n", | |
5171 | 2 * ((len < 4) ? len : 4), val, (long)memaddr, pid); | |
5172 | } | |
5173 | ||
5174 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
5175 | ||
5176 | errno = 0; | |
5177 | /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning | |
5178 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5179 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, | |
5180 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5181 | (PTRACE_TYPE_ARG4) 0); | |
5182 | if (errno) | |
5183 | return errno; | |
5184 | ||
5185 | if (count > 1) | |
5186 | { | |
5187 | errno = 0; | |
5188 | buffer[count - 1] | |
5189 | = ptrace (PTRACE_PEEKTEXT, pid, | |
5190 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5191 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5192 | (PTRACE_TYPE_ARG3) (uintptr_t) (addr + (count - 1) | |
5193 | * sizeof (PTRACE_XFER_TYPE)), | |
5194 | (PTRACE_TYPE_ARG4) 0); | |
5195 | if (errno) | |
5196 | return errno; | |
5197 | } | |
5198 | ||
5199 | /* Copy data to be written over corresponding part of buffer. */ | |
5200 | ||
5201 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), | |
5202 | myaddr, len); | |
5203 | ||
5204 | /* Write the entire buffer. */ | |
5205 | ||
5206 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
5207 | { | |
5208 | errno = 0; | |
5209 | ptrace (PTRACE_POKETEXT, pid, | |
5210 | /* Coerce to a uintptr_t first to avoid potential gcc warning | |
5211 | about coercing an 8 byte integer to a 4 byte pointer. */ | |
5212 | (PTRACE_TYPE_ARG3) (uintptr_t) addr, | |
5213 | (PTRACE_TYPE_ARG4) buffer[i]); | |
5214 | if (errno) | |
5215 | return errno; | |
5216 | } | |
5217 | ||
5218 | return 0; | |
5219 | } | |
5220 | ||
5221 | static void | |
5222 | linux_look_up_symbols (void) | |
5223 | { | |
5224 | #ifdef USE_THREAD_DB | |
5225 | struct process_info *proc = current_process (); | |
5226 | ||
5227 | if (proc->priv->thread_db != NULL) | |
5228 | return; | |
5229 | ||
5230 | /* If the kernel supports tracing clones, then we don't need to | |
5231 | use the magic thread event breakpoint to learn about | |
5232 | threads. */ | |
5233 | thread_db_init (!linux_supports_traceclone ()); | |
5234 | #endif | |
5235 | } | |
5236 | ||
5237 | static void | |
5238 | linux_request_interrupt (void) | |
5239 | { | |
5240 | extern unsigned long signal_pid; | |
5241 | ||
5242 | /* Send a SIGINT to the process group. This acts just like the user | |
5243 | typed a ^C on the controlling terminal. */ | |
5244 | kill (-signal_pid, SIGINT); | |
5245 | } | |
5246 | ||
5247 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET | |
5248 | to debugger memory starting at MYADDR. */ | |
5249 | ||
5250 | static int | |
5251 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) | |
5252 | { | |
5253 | char filename[PATH_MAX]; | |
5254 | int fd, n; | |
5255 | int pid = lwpid_of (current_thread); | |
5256 | ||
5257 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); | |
5258 | ||
5259 | fd = open (filename, O_RDONLY); | |
5260 | if (fd < 0) | |
5261 | return -1; | |
5262 | ||
5263 | if (offset != (CORE_ADDR) 0 | |
5264 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
5265 | n = -1; | |
5266 | else | |
5267 | n = read (fd, myaddr, len); | |
5268 | ||
5269 | close (fd); | |
5270 | ||
5271 | return n; | |
5272 | } | |
5273 | ||
5274 | /* These breakpoint and watchpoint related wrapper functions simply | |
5275 | pass on the function call if the target has registered a | |
5276 | corresponding function. */ | |
5277 | ||
5278 | static int | |
5279 | linux_supports_z_point_type (char z_type) | |
5280 | { | |
5281 | return (the_low_target.supports_z_point_type != NULL | |
5282 | && the_low_target.supports_z_point_type (z_type)); | |
5283 | } | |
5284 | ||
5285 | static int | |
5286 | linux_insert_point (enum raw_bkpt_type type, CORE_ADDR addr, | |
5287 | int size, struct raw_breakpoint *bp) | |
5288 | { | |
5289 | if (type == raw_bkpt_type_sw) | |
5290 | return insert_memory_breakpoint (bp); | |
5291 | else if (the_low_target.insert_point != NULL) | |
5292 | return the_low_target.insert_point (type, addr, size, bp); | |
5293 | else | |
5294 | /* Unsupported (see target.h). */ | |
5295 | return 1; | |
5296 | } | |
5297 | ||
5298 | static int | |
5299 | linux_remove_point (enum raw_bkpt_type type, CORE_ADDR addr, | |
5300 | int size, struct raw_breakpoint *bp) | |
5301 | { | |
5302 | if (type == raw_bkpt_type_sw) | |
5303 | return remove_memory_breakpoint (bp); | |
5304 | else if (the_low_target.remove_point != NULL) | |
5305 | return the_low_target.remove_point (type, addr, size, bp); | |
5306 | else | |
5307 | /* Unsupported (see target.h). */ | |
5308 | return 1; | |
5309 | } | |
5310 | ||
5311 | /* Implement the to_stopped_by_sw_breakpoint target_ops | |
5312 | method. */ | |
5313 | ||
5314 | static int | |
5315 | linux_stopped_by_sw_breakpoint (void) | |
5316 | { | |
5317 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
5318 | ||
5319 | return (lwp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT); | |
5320 | } | |
5321 | ||
5322 | /* Implement the to_supports_stopped_by_sw_breakpoint target_ops | |
5323 | method. */ | |
5324 | ||
5325 | static int | |
5326 | linux_supports_stopped_by_sw_breakpoint (void) | |
5327 | { | |
5328 | return USE_SIGTRAP_SIGINFO; | |
5329 | } | |
5330 | ||
5331 | /* Implement the to_stopped_by_hw_breakpoint target_ops | |
5332 | method. */ | |
5333 | ||
5334 | static int | |
5335 | linux_stopped_by_hw_breakpoint (void) | |
5336 | { | |
5337 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
5338 | ||
5339 | return (lwp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT); | |
5340 | } | |
5341 | ||
5342 | /* Implement the to_supports_stopped_by_hw_breakpoint target_ops | |
5343 | method. */ | |
5344 | ||
5345 | static int | |
5346 | linux_supports_stopped_by_hw_breakpoint (void) | |
5347 | { | |
5348 | return USE_SIGTRAP_SIGINFO; | |
5349 | } | |
5350 | ||
5351 | /* Implement the supports_conditional_breakpoints target_ops | |
5352 | method. */ | |
5353 | ||
5354 | static int | |
5355 | linux_supports_conditional_breakpoints (void) | |
5356 | { | |
5357 | /* GDBserver needs to step over the breakpoint if the condition is | |
5358 | false. GDBserver software single step is too simple, so disable | |
5359 | conditional breakpoints if the target doesn't have hardware single | |
5360 | step. */ | |
5361 | return can_hardware_single_step (); | |
5362 | } | |
5363 | ||
5364 | static int | |
5365 | linux_stopped_by_watchpoint (void) | |
5366 | { | |
5367 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
5368 | ||
5369 | return lwp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; | |
5370 | } | |
5371 | ||
5372 | static CORE_ADDR | |
5373 | linux_stopped_data_address (void) | |
5374 | { | |
5375 | struct lwp_info *lwp = get_thread_lwp (current_thread); | |
5376 | ||
5377 | return lwp->stopped_data_address; | |
5378 | } | |
5379 | ||
5380 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ | |
5381 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ | |
5382 | && defined(PT_TEXT_END_ADDR) | |
5383 | ||
5384 | /* This is only used for targets that define PT_TEXT_ADDR, | |
5385 | PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly | |
5386 | the target has different ways of acquiring this information, like | |
5387 | loadmaps. */ | |
5388 | ||
5389 | /* Under uClinux, programs are loaded at non-zero offsets, which we need | |
5390 | to tell gdb about. */ | |
5391 | ||
5392 | static int | |
5393 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) | |
5394 | { | |
5395 | unsigned long text, text_end, data; | |
5396 | int pid = lwpid_of (current_thread); | |
5397 | ||
5398 | errno = 0; | |
5399 | ||
5400 | text = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_ADDR, | |
5401 | (PTRACE_TYPE_ARG4) 0); | |
5402 | text_end = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_TEXT_END_ADDR, | |
5403 | (PTRACE_TYPE_ARG4) 0); | |
5404 | data = ptrace (PTRACE_PEEKUSER, pid, (PTRACE_TYPE_ARG3) PT_DATA_ADDR, | |
5405 | (PTRACE_TYPE_ARG4) 0); | |
5406 | ||
5407 | if (errno == 0) | |
5408 | { | |
5409 | /* Both text and data offsets produced at compile-time (and so | |
5410 | used by gdb) are relative to the beginning of the program, | |
5411 | with the data segment immediately following the text segment. | |
5412 | However, the actual runtime layout in memory may put the data | |
5413 | somewhere else, so when we send gdb a data base-address, we | |
5414 | use the real data base address and subtract the compile-time | |
5415 | data base-address from it (which is just the length of the | |
5416 | text segment). BSS immediately follows data in both | |
5417 | cases. */ | |
5418 | *text_p = text; | |
5419 | *data_p = data - (text_end - text); | |
5420 | ||
5421 | return 1; | |
5422 | } | |
5423 | return 0; | |
5424 | } | |
5425 | #endif | |
5426 | ||
5427 | static int | |
5428 | linux_qxfer_osdata (const char *annex, | |
5429 | unsigned char *readbuf, unsigned const char *writebuf, | |
5430 | CORE_ADDR offset, int len) | |
5431 | { | |
5432 | return linux_common_xfer_osdata (annex, readbuf, offset, len); | |
5433 | } | |
5434 | ||
5435 | /* Convert a native/host siginfo object, into/from the siginfo in the | |
5436 | layout of the inferiors' architecture. */ | |
5437 | ||
5438 | static void | |
5439 | siginfo_fixup (siginfo_t *siginfo, void *inf_siginfo, int direction) | |
5440 | { | |
5441 | int done = 0; | |
5442 | ||
5443 | if (the_low_target.siginfo_fixup != NULL) | |
5444 | done = the_low_target.siginfo_fixup (siginfo, inf_siginfo, direction); | |
5445 | ||
5446 | /* If there was no callback, or the callback didn't do anything, | |
5447 | then just do a straight memcpy. */ | |
5448 | if (!done) | |
5449 | { | |
5450 | if (direction == 1) | |
5451 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); | |
5452 | else | |
5453 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); | |
5454 | } | |
5455 | } | |
5456 | ||
5457 | static int | |
5458 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, | |
5459 | unsigned const char *writebuf, CORE_ADDR offset, int len) | |
5460 | { | |
5461 | int pid; | |
5462 | siginfo_t siginfo; | |
5463 | char inf_siginfo[sizeof (siginfo_t)]; | |
5464 | ||
5465 | if (current_thread == NULL) | |
5466 | return -1; | |
5467 | ||
5468 | pid = lwpid_of (current_thread); | |
5469 | ||
5470 | if (debug_threads) | |
5471 | debug_printf ("%s siginfo for lwp %d.\n", | |
5472 | readbuf != NULL ? "Reading" : "Writing", | |
5473 | pid); | |
5474 | ||
5475 | if (offset >= sizeof (siginfo)) | |
5476 | return -1; | |
5477 | ||
5478 | if (ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) | |
5479 | return -1; | |
5480 | ||
5481 | /* When GDBSERVER is built as a 64-bit application, ptrace writes into | |
5482 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
5483 | inferior with a 64-bit GDBSERVER should look the same as debugging it | |
5484 | with a 32-bit GDBSERVER, we need to convert it. */ | |
5485 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
5486 | ||
5487 | if (offset + len > sizeof (siginfo)) | |
5488 | len = sizeof (siginfo) - offset; | |
5489 | ||
5490 | if (readbuf != NULL) | |
5491 | memcpy (readbuf, inf_siginfo + offset, len); | |
5492 | else | |
5493 | { | |
5494 | memcpy (inf_siginfo + offset, writebuf, len); | |
5495 | ||
5496 | /* Convert back to ptrace layout before flushing it out. */ | |
5497 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
5498 | ||
5499 | if (ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo) != 0) | |
5500 | return -1; | |
5501 | } | |
5502 | ||
5503 | return len; | |
5504 | } | |
5505 | ||
5506 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, | |
5507 | so we notice when children change state; as the handler for the | |
5508 | sigsuspend in my_waitpid. */ | |
5509 | ||
5510 | static void | |
5511 | sigchld_handler (int signo) | |
5512 | { | |
5513 | int old_errno = errno; | |
5514 | ||
5515 | if (debug_threads) | |
5516 | { | |
5517 | do | |
5518 | { | |
5519 | /* fprintf is not async-signal-safe, so call write | |
5520 | directly. */ | |
5521 | if (write (2, "sigchld_handler\n", | |
5522 | sizeof ("sigchld_handler\n") - 1) < 0) | |
5523 | break; /* just ignore */ | |
5524 | } while (0); | |
5525 | } | |
5526 | ||
5527 | if (target_is_async_p ()) | |
5528 | async_file_mark (); /* trigger a linux_wait */ | |
5529 | ||
5530 | errno = old_errno; | |
5531 | } | |
5532 | ||
5533 | static int | |
5534 | linux_supports_non_stop (void) | |
5535 | { | |
5536 | return 1; | |
5537 | } | |
5538 | ||
5539 | static int | |
5540 | linux_async (int enable) | |
5541 | { | |
5542 | int previous = target_is_async_p (); | |
5543 | ||
5544 | if (debug_threads) | |
5545 | debug_printf ("linux_async (%d), previous=%d\n", | |
5546 | enable, previous); | |
5547 | ||
5548 | if (previous != enable) | |
5549 | { | |
5550 | sigset_t mask; | |
5551 | sigemptyset (&mask); | |
5552 | sigaddset (&mask, SIGCHLD); | |
5553 | ||
5554 | sigprocmask (SIG_BLOCK, &mask, NULL); | |
5555 | ||
5556 | if (enable) | |
5557 | { | |
5558 | if (pipe (linux_event_pipe) == -1) | |
5559 | { | |
5560 | linux_event_pipe[0] = -1; | |
5561 | linux_event_pipe[1] = -1; | |
5562 | sigprocmask (SIG_UNBLOCK, &mask, NULL); | |
5563 | ||
5564 | warning ("creating event pipe failed."); | |
5565 | return previous; | |
5566 | } | |
5567 | ||
5568 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); | |
5569 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); | |
5570 | ||
5571 | /* Register the event loop handler. */ | |
5572 | add_file_handler (linux_event_pipe[0], | |
5573 | handle_target_event, NULL); | |
5574 | ||
5575 | /* Always trigger a linux_wait. */ | |
5576 | async_file_mark (); | |
5577 | } | |
5578 | else | |
5579 | { | |
5580 | delete_file_handler (linux_event_pipe[0]); | |
5581 | ||
5582 | close (linux_event_pipe[0]); | |
5583 | close (linux_event_pipe[1]); | |
5584 | linux_event_pipe[0] = -1; | |
5585 | linux_event_pipe[1] = -1; | |
5586 | } | |
5587 | ||
5588 | sigprocmask (SIG_UNBLOCK, &mask, NULL); | |
5589 | } | |
5590 | ||
5591 | return previous; | |
5592 | } | |
5593 | ||
5594 | static int | |
5595 | linux_start_non_stop (int nonstop) | |
5596 | { | |
5597 | /* Register or unregister from event-loop accordingly. */ | |
5598 | linux_async (nonstop); | |
5599 | ||
5600 | if (target_is_async_p () != (nonstop != 0)) | |
5601 | return -1; | |
5602 | ||
5603 | return 0; | |
5604 | } | |
5605 | ||
5606 | static int | |
5607 | linux_supports_multi_process (void) | |
5608 | { | |
5609 | return 1; | |
5610 | } | |
5611 | ||
5612 | /* Check if fork events are supported. */ | |
5613 | ||
5614 | static int | |
5615 | linux_supports_fork_events (void) | |
5616 | { | |
5617 | return linux_supports_tracefork (); | |
5618 | } | |
5619 | ||
5620 | /* Check if vfork events are supported. */ | |
5621 | ||
5622 | static int | |
5623 | linux_supports_vfork_events (void) | |
5624 | { | |
5625 | return linux_supports_tracefork (); | |
5626 | } | |
5627 | ||
5628 | /* Callback for 'find_inferior'. Set the (possibly changed) ptrace | |
5629 | options for the specified lwp. */ | |
5630 | ||
5631 | static int | |
5632 | reset_lwp_ptrace_options_callback (struct inferior_list_entry *entry, | |
5633 | void *args) | |
5634 | { | |
5635 | struct thread_info *thread = (struct thread_info *) entry; | |
5636 | struct lwp_info *lwp = get_thread_lwp (thread); | |
5637 | ||
5638 | if (!lwp->stopped) | |
5639 | { | |
5640 | /* Stop the lwp so we can modify its ptrace options. */ | |
5641 | lwp->must_set_ptrace_flags = 1; | |
5642 | linux_stop_lwp (lwp); | |
5643 | } | |
5644 | else | |
5645 | { | |
5646 | /* Already stopped; go ahead and set the ptrace options. */ | |
5647 | struct process_info *proc = find_process_pid (pid_of (thread)); | |
5648 | int options = linux_low_ptrace_options (proc->attached); | |
5649 | ||
5650 | linux_enable_event_reporting (lwpid_of (thread), options); | |
5651 | lwp->must_set_ptrace_flags = 0; | |
5652 | } | |
5653 | ||
5654 | return 0; | |
5655 | } | |
5656 | ||
5657 | /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the | |
5658 | ptrace flags for all inferiors. This is in case the new GDB connection | |
5659 | doesn't support the same set of events that the previous one did. */ | |
5660 | ||
5661 | static void | |
5662 | linux_handle_new_gdb_connection (void) | |
5663 | { | |
5664 | pid_t pid; | |
5665 | ||
5666 | /* Request that all the lwps reset their ptrace options. */ | |
5667 | find_inferior (&all_threads, reset_lwp_ptrace_options_callback , &pid); | |
5668 | } | |
5669 | ||
5670 | static int | |
5671 | linux_supports_disable_randomization (void) | |
5672 | { | |
5673 | #ifdef HAVE_PERSONALITY | |
5674 | return 1; | |
5675 | #else | |
5676 | return 0; | |
5677 | #endif | |
5678 | } | |
5679 | ||
5680 | static int | |
5681 | linux_supports_agent (void) | |
5682 | { | |
5683 | return 1; | |
5684 | } | |
5685 | ||
5686 | static int | |
5687 | linux_supports_range_stepping (void) | |
5688 | { | |
5689 | if (*the_low_target.supports_range_stepping == NULL) | |
5690 | return 0; | |
5691 | ||
5692 | return (*the_low_target.supports_range_stepping) (); | |
5693 | } | |
5694 | ||
5695 | /* Enumerate spufs IDs for process PID. */ | |
5696 | static int | |
5697 | spu_enumerate_spu_ids (long pid, unsigned char *buf, CORE_ADDR offset, int len) | |
5698 | { | |
5699 | int pos = 0; | |
5700 | int written = 0; | |
5701 | char path[128]; | |
5702 | DIR *dir; | |
5703 | struct dirent *entry; | |
5704 | ||
5705 | sprintf (path, "/proc/%ld/fd", pid); | |
5706 | dir = opendir (path); | |
5707 | if (!dir) | |
5708 | return -1; | |
5709 | ||
5710 | rewinddir (dir); | |
5711 | while ((entry = readdir (dir)) != NULL) | |
5712 | { | |
5713 | struct stat st; | |
5714 | struct statfs stfs; | |
5715 | int fd; | |
5716 | ||
5717 | fd = atoi (entry->d_name); | |
5718 | if (!fd) | |
5719 | continue; | |
5720 | ||
5721 | sprintf (path, "/proc/%ld/fd/%d", pid, fd); | |
5722 | if (stat (path, &st) != 0) | |
5723 | continue; | |
5724 | if (!S_ISDIR (st.st_mode)) | |
5725 | continue; | |
5726 | ||
5727 | if (statfs (path, &stfs) != 0) | |
5728 | continue; | |
5729 | if (stfs.f_type != SPUFS_MAGIC) | |
5730 | continue; | |
5731 | ||
5732 | if (pos >= offset && pos + 4 <= offset + len) | |
5733 | { | |
5734 | *(unsigned int *)(buf + pos - offset) = fd; | |
5735 | written += 4; | |
5736 | } | |
5737 | pos += 4; | |
5738 | } | |
5739 | ||
5740 | closedir (dir); | |
5741 | return written; | |
5742 | } | |
5743 | ||
5744 | /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
5745 | object type, using the /proc file system. */ | |
5746 | static int | |
5747 | linux_qxfer_spu (const char *annex, unsigned char *readbuf, | |
5748 | unsigned const char *writebuf, | |
5749 | CORE_ADDR offset, int len) | |
5750 | { | |
5751 | long pid = lwpid_of (current_thread); | |
5752 | char buf[128]; | |
5753 | int fd = 0; | |
5754 | int ret = 0; | |
5755 | ||
5756 | if (!writebuf && !readbuf) | |
5757 | return -1; | |
5758 | ||
5759 | if (!*annex) | |
5760 | { | |
5761 | if (!readbuf) | |
5762 | return -1; | |
5763 | else | |
5764 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
5765 | } | |
5766 | ||
5767 | sprintf (buf, "/proc/%ld/fd/%s", pid, annex); | |
5768 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); | |
5769 | if (fd <= 0) | |
5770 | return -1; | |
5771 | ||
5772 | if (offset != 0 | |
5773 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
5774 | { | |
5775 | close (fd); | |
5776 | return 0; | |
5777 | } | |
5778 | ||
5779 | if (writebuf) | |
5780 | ret = write (fd, writebuf, (size_t) len); | |
5781 | else | |
5782 | ret = read (fd, readbuf, (size_t) len); | |
5783 | ||
5784 | close (fd); | |
5785 | return ret; | |
5786 | } | |
5787 | ||
5788 | #if defined PT_GETDSBT || defined PTRACE_GETFDPIC | |
5789 | struct target_loadseg | |
5790 | { | |
5791 | /* Core address to which the segment is mapped. */ | |
5792 | Elf32_Addr addr; | |
5793 | /* VMA recorded in the program header. */ | |
5794 | Elf32_Addr p_vaddr; | |
5795 | /* Size of this segment in memory. */ | |
5796 | Elf32_Word p_memsz; | |
5797 | }; | |
5798 | ||
5799 | # if defined PT_GETDSBT | |
5800 | struct target_loadmap | |
5801 | { | |
5802 | /* Protocol version number, must be zero. */ | |
5803 | Elf32_Word version; | |
5804 | /* Pointer to the DSBT table, its size, and the DSBT index. */ | |
5805 | unsigned *dsbt_table; | |
5806 | unsigned dsbt_size, dsbt_index; | |
5807 | /* Number of segments in this map. */ | |
5808 | Elf32_Word nsegs; | |
5809 | /* The actual memory map. */ | |
5810 | struct target_loadseg segs[/*nsegs*/]; | |
5811 | }; | |
5812 | # define LINUX_LOADMAP PT_GETDSBT | |
5813 | # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC | |
5814 | # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP | |
5815 | # else | |
5816 | struct target_loadmap | |
5817 | { | |
5818 | /* Protocol version number, must be zero. */ | |
5819 | Elf32_Half version; | |
5820 | /* Number of segments in this map. */ | |
5821 | Elf32_Half nsegs; | |
5822 | /* The actual memory map. */ | |
5823 | struct target_loadseg segs[/*nsegs*/]; | |
5824 | }; | |
5825 | # define LINUX_LOADMAP PTRACE_GETFDPIC | |
5826 | # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC | |
5827 | # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP | |
5828 | # endif | |
5829 | ||
5830 | static int | |
5831 | linux_read_loadmap (const char *annex, CORE_ADDR offset, | |
5832 | unsigned char *myaddr, unsigned int len) | |
5833 | { | |
5834 | int pid = lwpid_of (current_thread); | |
5835 | int addr = -1; | |
5836 | struct target_loadmap *data = NULL; | |
5837 | unsigned int actual_length, copy_length; | |
5838 | ||
5839 | if (strcmp (annex, "exec") == 0) | |
5840 | addr = (int) LINUX_LOADMAP_EXEC; | |
5841 | else if (strcmp (annex, "interp") == 0) | |
5842 | addr = (int) LINUX_LOADMAP_INTERP; | |
5843 | else | |
5844 | return -1; | |
5845 | ||
5846 | if (ptrace (LINUX_LOADMAP, pid, addr, &data) != 0) | |
5847 | return -1; | |
5848 | ||
5849 | if (data == NULL) | |
5850 | return -1; | |
5851 | ||
5852 | actual_length = sizeof (struct target_loadmap) | |
5853 | + sizeof (struct target_loadseg) * data->nsegs; | |
5854 | ||
5855 | if (offset < 0 || offset > actual_length) | |
5856 | return -1; | |
5857 | ||
5858 | copy_length = actual_length - offset < len ? actual_length - offset : len; | |
5859 | memcpy (myaddr, (char *) data + offset, copy_length); | |
5860 | return copy_length; | |
5861 | } | |
5862 | #else | |
5863 | # define linux_read_loadmap NULL | |
5864 | #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */ | |
5865 | ||
5866 | static void | |
5867 | linux_process_qsupported (const char *query) | |
5868 | { | |
5869 | if (the_low_target.process_qsupported != NULL) | |
5870 | the_low_target.process_qsupported (query); | |
5871 | } | |
5872 | ||
5873 | static int | |
5874 | linux_supports_tracepoints (void) | |
5875 | { | |
5876 | if (*the_low_target.supports_tracepoints == NULL) | |
5877 | return 0; | |
5878 | ||
5879 | return (*the_low_target.supports_tracepoints) (); | |
5880 | } | |
5881 | ||
5882 | static CORE_ADDR | |
5883 | linux_read_pc (struct regcache *regcache) | |
5884 | { | |
5885 | if (the_low_target.get_pc == NULL) | |
5886 | return 0; | |
5887 | ||
5888 | return (*the_low_target.get_pc) (regcache); | |
5889 | } | |
5890 | ||
5891 | static void | |
5892 | linux_write_pc (struct regcache *regcache, CORE_ADDR pc) | |
5893 | { | |
5894 | gdb_assert (the_low_target.set_pc != NULL); | |
5895 | ||
5896 | (*the_low_target.set_pc) (regcache, pc); | |
5897 | } | |
5898 | ||
5899 | static int | |
5900 | linux_thread_stopped (struct thread_info *thread) | |
5901 | { | |
5902 | return get_thread_lwp (thread)->stopped; | |
5903 | } | |
5904 | ||
5905 | /* This exposes stop-all-threads functionality to other modules. */ | |
5906 | ||
5907 | static void | |
5908 | linux_pause_all (int freeze) | |
5909 | { | |
5910 | stop_all_lwps (freeze, NULL); | |
5911 | } | |
5912 | ||
5913 | /* This exposes unstop-all-threads functionality to other gdbserver | |
5914 | modules. */ | |
5915 | ||
5916 | static void | |
5917 | linux_unpause_all (int unfreeze) | |
5918 | { | |
5919 | unstop_all_lwps (unfreeze, NULL); | |
5920 | } | |
5921 | ||
5922 | static int | |
5923 | linux_prepare_to_access_memory (void) | |
5924 | { | |
5925 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a | |
5926 | running LWP. */ | |
5927 | if (non_stop) | |
5928 | linux_pause_all (1); | |
5929 | return 0; | |
5930 | } | |
5931 | ||
5932 | static void | |
5933 | linux_done_accessing_memory (void) | |
5934 | { | |
5935 | /* Neither ptrace nor /proc/PID/mem allow accessing memory through a | |
5936 | running LWP. */ | |
5937 | if (non_stop) | |
5938 | linux_unpause_all (1); | |
5939 | } | |
5940 | ||
5941 | static int | |
5942 | linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr, | |
5943 | CORE_ADDR collector, | |
5944 | CORE_ADDR lockaddr, | |
5945 | ULONGEST orig_size, | |
5946 | CORE_ADDR *jump_entry, | |
5947 | CORE_ADDR *trampoline, | |
5948 | ULONGEST *trampoline_size, | |
5949 | unsigned char *jjump_pad_insn, | |
5950 | ULONGEST *jjump_pad_insn_size, | |
5951 | CORE_ADDR *adjusted_insn_addr, | |
5952 | CORE_ADDR *adjusted_insn_addr_end, | |
5953 | char *err) | |
5954 | { | |
5955 | return (*the_low_target.install_fast_tracepoint_jump_pad) | |
5956 | (tpoint, tpaddr, collector, lockaddr, orig_size, | |
5957 | jump_entry, trampoline, trampoline_size, | |
5958 | jjump_pad_insn, jjump_pad_insn_size, | |
5959 | adjusted_insn_addr, adjusted_insn_addr_end, | |
5960 | err); | |
5961 | } | |
5962 | ||
5963 | static struct emit_ops * | |
5964 | linux_emit_ops (void) | |
5965 | { | |
5966 | if (the_low_target.emit_ops != NULL) | |
5967 | return (*the_low_target.emit_ops) (); | |
5968 | else | |
5969 | return NULL; | |
5970 | } | |
5971 | ||
5972 | static int | |
5973 | linux_get_min_fast_tracepoint_insn_len (void) | |
5974 | { | |
5975 | return (*the_low_target.get_min_fast_tracepoint_insn_len) (); | |
5976 | } | |
5977 | ||
5978 | /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */ | |
5979 | ||
5980 | static int | |
5981 | get_phdr_phnum_from_proc_auxv (const int pid, const int is_elf64, | |
5982 | CORE_ADDR *phdr_memaddr, int *num_phdr) | |
5983 | { | |
5984 | char filename[PATH_MAX]; | |
5985 | int fd; | |
5986 | const int auxv_size = is_elf64 | |
5987 | ? sizeof (Elf64_auxv_t) : sizeof (Elf32_auxv_t); | |
5988 | char buf[sizeof (Elf64_auxv_t)]; /* The larger of the two. */ | |
5989 | ||
5990 | xsnprintf (filename, sizeof filename, "/proc/%d/auxv", pid); | |
5991 | ||
5992 | fd = open (filename, O_RDONLY); | |
5993 | if (fd < 0) | |
5994 | return 1; | |
5995 | ||
5996 | *phdr_memaddr = 0; | |
5997 | *num_phdr = 0; | |
5998 | while (read (fd, buf, auxv_size) == auxv_size | |
5999 | && (*phdr_memaddr == 0 || *num_phdr == 0)) | |
6000 | { | |
6001 | if (is_elf64) | |
6002 | { | |
6003 | Elf64_auxv_t *const aux = (Elf64_auxv_t *) buf; | |
6004 | ||
6005 | switch (aux->a_type) | |
6006 | { | |
6007 | case AT_PHDR: | |
6008 | *phdr_memaddr = aux->a_un.a_val; | |
6009 | break; | |
6010 | case AT_PHNUM: | |
6011 | *num_phdr = aux->a_un.a_val; | |
6012 | break; | |
6013 | } | |
6014 | } | |
6015 | else | |
6016 | { | |
6017 | Elf32_auxv_t *const aux = (Elf32_auxv_t *) buf; | |
6018 | ||
6019 | switch (aux->a_type) | |
6020 | { | |
6021 | case AT_PHDR: | |
6022 | *phdr_memaddr = aux->a_un.a_val; | |
6023 | break; | |
6024 | case AT_PHNUM: | |
6025 | *num_phdr = aux->a_un.a_val; | |
6026 | break; | |
6027 | } | |
6028 | } | |
6029 | } | |
6030 | ||
6031 | close (fd); | |
6032 | ||
6033 | if (*phdr_memaddr == 0 || *num_phdr == 0) | |
6034 | { | |
6035 | warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: " | |
6036 | "phdr_memaddr = %ld, phdr_num = %d", | |
6037 | (long) *phdr_memaddr, *num_phdr); | |
6038 | return 2; | |
6039 | } | |
6040 | ||
6041 | return 0; | |
6042 | } | |
6043 | ||
6044 | /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */ | |
6045 | ||
6046 | static CORE_ADDR | |
6047 | get_dynamic (const int pid, const int is_elf64) | |
6048 | { | |
6049 | CORE_ADDR phdr_memaddr, relocation; | |
6050 | int num_phdr, i; | |
6051 | unsigned char *phdr_buf; | |
6052 | const int phdr_size = is_elf64 ? sizeof (Elf64_Phdr) : sizeof (Elf32_Phdr); | |
6053 | ||
6054 | if (get_phdr_phnum_from_proc_auxv (pid, is_elf64, &phdr_memaddr, &num_phdr)) | |
6055 | return 0; | |
6056 | ||
6057 | gdb_assert (num_phdr < 100); /* Basic sanity check. */ | |
6058 | phdr_buf = alloca (num_phdr * phdr_size); | |
6059 | ||
6060 | if (linux_read_memory (phdr_memaddr, phdr_buf, num_phdr * phdr_size)) | |
6061 | return 0; | |
6062 | ||
6063 | /* Compute relocation: it is expected to be 0 for "regular" executables, | |
6064 | non-zero for PIE ones. */ | |
6065 | relocation = -1; | |
6066 | for (i = 0; relocation == -1 && i < num_phdr; i++) | |
6067 | if (is_elf64) | |
6068 | { | |
6069 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); | |
6070 | ||
6071 | if (p->p_type == PT_PHDR) | |
6072 | relocation = phdr_memaddr - p->p_vaddr; | |
6073 | } | |
6074 | else | |
6075 | { | |
6076 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); | |
6077 | ||
6078 | if (p->p_type == PT_PHDR) | |
6079 | relocation = phdr_memaddr - p->p_vaddr; | |
6080 | } | |
6081 | ||
6082 | if (relocation == -1) | |
6083 | { | |
6084 | /* PT_PHDR is optional, but necessary for PIE in general. Fortunately | |
6085 | any real world executables, including PIE executables, have always | |
6086 | PT_PHDR present. PT_PHDR is not present in some shared libraries or | |
6087 | in fpc (Free Pascal 2.4) binaries but neither of those have a need for | |
6088 | or present DT_DEBUG anyway (fpc binaries are statically linked). | |
6089 | ||
6090 | Therefore if there exists DT_DEBUG there is always also PT_PHDR. | |
6091 | ||
6092 | GDB could find RELOCATION also from AT_ENTRY - e_entry. */ | |
6093 | ||
6094 | return 0; | |
6095 | } | |
6096 | ||
6097 | for (i = 0; i < num_phdr; i++) | |
6098 | { | |
6099 | if (is_elf64) | |
6100 | { | |
6101 | Elf64_Phdr *const p = (Elf64_Phdr *) (phdr_buf + i * phdr_size); | |
6102 | ||
6103 | if (p->p_type == PT_DYNAMIC) | |
6104 | return p->p_vaddr + relocation; | |
6105 | } | |
6106 | else | |
6107 | { | |
6108 | Elf32_Phdr *const p = (Elf32_Phdr *) (phdr_buf + i * phdr_size); | |
6109 | ||
6110 | if (p->p_type == PT_DYNAMIC) | |
6111 | return p->p_vaddr + relocation; | |
6112 | } | |
6113 | } | |
6114 | ||
6115 | return 0; | |
6116 | } | |
6117 | ||
6118 | /* Return &_r_debug in the inferior, or -1 if not present. Return value | |
6119 | can be 0 if the inferior does not yet have the library list initialized. | |
6120 | We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of | |
6121 | DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */ | |
6122 | ||
6123 | static CORE_ADDR | |
6124 | get_r_debug (const int pid, const int is_elf64) | |
6125 | { | |
6126 | CORE_ADDR dynamic_memaddr; | |
6127 | const int dyn_size = is_elf64 ? sizeof (Elf64_Dyn) : sizeof (Elf32_Dyn); | |
6128 | unsigned char buf[sizeof (Elf64_Dyn)]; /* The larger of the two. */ | |
6129 | CORE_ADDR map = -1; | |
6130 | ||
6131 | dynamic_memaddr = get_dynamic (pid, is_elf64); | |
6132 | if (dynamic_memaddr == 0) | |
6133 | return map; | |
6134 | ||
6135 | while (linux_read_memory (dynamic_memaddr, buf, dyn_size) == 0) | |
6136 | { | |
6137 | if (is_elf64) | |
6138 | { | |
6139 | Elf64_Dyn *const dyn = (Elf64_Dyn *) buf; | |
6140 | #ifdef DT_MIPS_RLD_MAP | |
6141 | union | |
6142 | { | |
6143 | Elf64_Xword map; | |
6144 | unsigned char buf[sizeof (Elf64_Xword)]; | |
6145 | } | |
6146 | rld_map; | |
6147 | ||
6148 | if (dyn->d_tag == DT_MIPS_RLD_MAP) | |
6149 | { | |
6150 | if (linux_read_memory (dyn->d_un.d_val, | |
6151 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6152 | return rld_map.map; | |
6153 | else | |
6154 | break; | |
6155 | } | |
6156 | #endif /* DT_MIPS_RLD_MAP */ | |
6157 | ||
6158 | if (dyn->d_tag == DT_DEBUG && map == -1) | |
6159 | map = dyn->d_un.d_val; | |
6160 | ||
6161 | if (dyn->d_tag == DT_NULL) | |
6162 | break; | |
6163 | } | |
6164 | else | |
6165 | { | |
6166 | Elf32_Dyn *const dyn = (Elf32_Dyn *) buf; | |
6167 | #ifdef DT_MIPS_RLD_MAP | |
6168 | union | |
6169 | { | |
6170 | Elf32_Word map; | |
6171 | unsigned char buf[sizeof (Elf32_Word)]; | |
6172 | } | |
6173 | rld_map; | |
6174 | ||
6175 | if (dyn->d_tag == DT_MIPS_RLD_MAP) | |
6176 | { | |
6177 | if (linux_read_memory (dyn->d_un.d_val, | |
6178 | rld_map.buf, sizeof (rld_map.buf)) == 0) | |
6179 | return rld_map.map; | |
6180 | else | |
6181 | break; | |
6182 | } | |
6183 | #endif /* DT_MIPS_RLD_MAP */ | |
6184 | ||
6185 | if (dyn->d_tag == DT_DEBUG && map == -1) | |
6186 | map = dyn->d_un.d_val; | |
6187 | ||
6188 | if (dyn->d_tag == DT_NULL) | |
6189 | break; | |
6190 | } | |
6191 | ||
6192 | dynamic_memaddr += dyn_size; | |
6193 | } | |
6194 | ||
6195 | return map; | |
6196 | } | |
6197 | ||
6198 | /* Read one pointer from MEMADDR in the inferior. */ | |
6199 | ||
6200 | static int | |
6201 | read_one_ptr (CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size) | |
6202 | { | |
6203 | int ret; | |
6204 | ||
6205 | /* Go through a union so this works on either big or little endian | |
6206 | hosts, when the inferior's pointer size is smaller than the size | |
6207 | of CORE_ADDR. It is assumed the inferior's endianness is the | |
6208 | same of the superior's. */ | |
6209 | union | |
6210 | { | |
6211 | CORE_ADDR core_addr; | |
6212 | unsigned int ui; | |
6213 | unsigned char uc; | |
6214 | } addr; | |
6215 | ||
6216 | ret = linux_read_memory (memaddr, &addr.uc, ptr_size); | |
6217 | if (ret == 0) | |
6218 | { | |
6219 | if (ptr_size == sizeof (CORE_ADDR)) | |
6220 | *ptr = addr.core_addr; | |
6221 | else if (ptr_size == sizeof (unsigned int)) | |
6222 | *ptr = addr.ui; | |
6223 | else | |
6224 | gdb_assert_not_reached ("unhandled pointer size"); | |
6225 | } | |
6226 | return ret; | |
6227 | } | |
6228 | ||
6229 | struct link_map_offsets | |
6230 | { | |
6231 | /* Offset and size of r_debug.r_version. */ | |
6232 | int r_version_offset; | |
6233 | ||
6234 | /* Offset and size of r_debug.r_map. */ | |
6235 | int r_map_offset; | |
6236 | ||
6237 | /* Offset to l_addr field in struct link_map. */ | |
6238 | int l_addr_offset; | |
6239 | ||
6240 | /* Offset to l_name field in struct link_map. */ | |
6241 | int l_name_offset; | |
6242 | ||
6243 | /* Offset to l_ld field in struct link_map. */ | |
6244 | int l_ld_offset; | |
6245 | ||
6246 | /* Offset to l_next field in struct link_map. */ | |
6247 | int l_next_offset; | |
6248 | ||
6249 | /* Offset to l_prev field in struct link_map. */ | |
6250 | int l_prev_offset; | |
6251 | }; | |
6252 | ||
6253 | /* Construct qXfer:libraries-svr4:read reply. */ | |
6254 | ||
6255 | static int | |
6256 | linux_qxfer_libraries_svr4 (const char *annex, unsigned char *readbuf, | |
6257 | unsigned const char *writebuf, | |
6258 | CORE_ADDR offset, int len) | |
6259 | { | |
6260 | char *document; | |
6261 | unsigned document_len; | |
6262 | struct process_info_private *const priv = current_process ()->priv; | |
6263 | char filename[PATH_MAX]; | |
6264 | int pid, is_elf64; | |
6265 | ||
6266 | static const struct link_map_offsets lmo_32bit_offsets = | |
6267 | { | |
6268 | 0, /* r_version offset. */ | |
6269 | 4, /* r_debug.r_map offset. */ | |
6270 | 0, /* l_addr offset in link_map. */ | |
6271 | 4, /* l_name offset in link_map. */ | |
6272 | 8, /* l_ld offset in link_map. */ | |
6273 | 12, /* l_next offset in link_map. */ | |
6274 | 16 /* l_prev offset in link_map. */ | |
6275 | }; | |
6276 | ||
6277 | static const struct link_map_offsets lmo_64bit_offsets = | |
6278 | { | |
6279 | 0, /* r_version offset. */ | |
6280 | 8, /* r_debug.r_map offset. */ | |
6281 | 0, /* l_addr offset in link_map. */ | |
6282 | 8, /* l_name offset in link_map. */ | |
6283 | 16, /* l_ld offset in link_map. */ | |
6284 | 24, /* l_next offset in link_map. */ | |
6285 | 32 /* l_prev offset in link_map. */ | |
6286 | }; | |
6287 | const struct link_map_offsets *lmo; | |
6288 | unsigned int machine; | |
6289 | int ptr_size; | |
6290 | CORE_ADDR lm_addr = 0, lm_prev = 0; | |
6291 | int allocated = 1024; | |
6292 | char *p; | |
6293 | CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev; | |
6294 | int header_done = 0; | |
6295 | ||
6296 | if (writebuf != NULL) | |
6297 | return -2; | |
6298 | if (readbuf == NULL) | |
6299 | return -1; | |
6300 | ||
6301 | pid = lwpid_of (current_thread); | |
6302 | xsnprintf (filename, sizeof filename, "/proc/%d/exe", pid); | |
6303 | is_elf64 = elf_64_file_p (filename, &machine); | |
6304 | lmo = is_elf64 ? &lmo_64bit_offsets : &lmo_32bit_offsets; | |
6305 | ptr_size = is_elf64 ? 8 : 4; | |
6306 | ||
6307 | while (annex[0] != '\0') | |
6308 | { | |
6309 | const char *sep; | |
6310 | CORE_ADDR *addrp; | |
6311 | int len; | |
6312 | ||
6313 | sep = strchr (annex, '='); | |
6314 | if (sep == NULL) | |
6315 | break; | |
6316 | ||
6317 | len = sep - annex; | |
6318 | if (len == 5 && startswith (annex, "start")) | |
6319 | addrp = &lm_addr; | |
6320 | else if (len == 4 && startswith (annex, "prev")) | |
6321 | addrp = &lm_prev; | |
6322 | else | |
6323 | { | |
6324 | annex = strchr (sep, ';'); | |
6325 | if (annex == NULL) | |
6326 | break; | |
6327 | annex++; | |
6328 | continue; | |
6329 | } | |
6330 | ||
6331 | annex = decode_address_to_semicolon (addrp, sep + 1); | |
6332 | } | |
6333 | ||
6334 | if (lm_addr == 0) | |
6335 | { | |
6336 | int r_version = 0; | |
6337 | ||
6338 | if (priv->r_debug == 0) | |
6339 | priv->r_debug = get_r_debug (pid, is_elf64); | |
6340 | ||
6341 | /* We failed to find DT_DEBUG. Such situation will not change | |
6342 | for this inferior - do not retry it. Report it to GDB as | |
6343 | E01, see for the reasons at the GDB solib-svr4.c side. */ | |
6344 | if (priv->r_debug == (CORE_ADDR) -1) | |
6345 | return -1; | |
6346 | ||
6347 | if (priv->r_debug != 0) | |
6348 | { | |
6349 | if (linux_read_memory (priv->r_debug + lmo->r_version_offset, | |
6350 | (unsigned char *) &r_version, | |
6351 | sizeof (r_version)) != 0 | |
6352 | || r_version != 1) | |
6353 | { | |
6354 | warning ("unexpected r_debug version %d", r_version); | |
6355 | } | |
6356 | else if (read_one_ptr (priv->r_debug + lmo->r_map_offset, | |
6357 | &lm_addr, ptr_size) != 0) | |
6358 | { | |
6359 | warning ("unable to read r_map from 0x%lx", | |
6360 | (long) priv->r_debug + lmo->r_map_offset); | |
6361 | } | |
6362 | } | |
6363 | } | |
6364 | ||
6365 | document = xmalloc (allocated); | |
6366 | strcpy (document, "<library-list-svr4 version=\"1.0\""); | |
6367 | p = document + strlen (document); | |
6368 | ||
6369 | while (lm_addr | |
6370 | && read_one_ptr (lm_addr + lmo->l_name_offset, | |
6371 | &l_name, ptr_size) == 0 | |
6372 | && read_one_ptr (lm_addr + lmo->l_addr_offset, | |
6373 | &l_addr, ptr_size) == 0 | |
6374 | && read_one_ptr (lm_addr + lmo->l_ld_offset, | |
6375 | &l_ld, ptr_size) == 0 | |
6376 | && read_one_ptr (lm_addr + lmo->l_prev_offset, | |
6377 | &l_prev, ptr_size) == 0 | |
6378 | && read_one_ptr (lm_addr + lmo->l_next_offset, | |
6379 | &l_next, ptr_size) == 0) | |
6380 | { | |
6381 | unsigned char libname[PATH_MAX]; | |
6382 | ||
6383 | if (lm_prev != l_prev) | |
6384 | { | |
6385 | warning ("Corrupted shared library list: 0x%lx != 0x%lx", | |
6386 | (long) lm_prev, (long) l_prev); | |
6387 | break; | |
6388 | } | |
6389 | ||
6390 | /* Ignore the first entry even if it has valid name as the first entry | |
6391 | corresponds to the main executable. The first entry should not be | |
6392 | skipped if the dynamic loader was loaded late by a static executable | |
6393 | (see solib-svr4.c parameter ignore_first). But in such case the main | |
6394 | executable does not have PT_DYNAMIC present and this function already | |
6395 | exited above due to failed get_r_debug. */ | |
6396 | if (lm_prev == 0) | |
6397 | { | |
6398 | sprintf (p, " main-lm=\"0x%lx\"", (unsigned long) lm_addr); | |
6399 | p = p + strlen (p); | |
6400 | } | |
6401 | else | |
6402 | { | |
6403 | /* Not checking for error because reading may stop before | |
6404 | we've got PATH_MAX worth of characters. */ | |
6405 | libname[0] = '\0'; | |
6406 | linux_read_memory (l_name, libname, sizeof (libname) - 1); | |
6407 | libname[sizeof (libname) - 1] = '\0'; | |
6408 | if (libname[0] != '\0') | |
6409 | { | |
6410 | /* 6x the size for xml_escape_text below. */ | |
6411 | size_t len = 6 * strlen ((char *) libname); | |
6412 | char *name; | |
6413 | ||
6414 | if (!header_done) | |
6415 | { | |
6416 | /* Terminate `<library-list-svr4'. */ | |
6417 | *p++ = '>'; | |
6418 | header_done = 1; | |
6419 | } | |
6420 | ||
6421 | while (allocated < p - document + len + 200) | |
6422 | { | |
6423 | /* Expand to guarantee sufficient storage. */ | |
6424 | uintptr_t document_len = p - document; | |
6425 | ||
6426 | document = xrealloc (document, 2 * allocated); | |
6427 | allocated *= 2; | |
6428 | p = document + document_len; | |
6429 | } | |
6430 | ||
6431 | name = xml_escape_text ((char *) libname); | |
6432 | p += sprintf (p, "<library name=\"%s\" lm=\"0x%lx\" " | |
6433 | "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>", | |
6434 | name, (unsigned long) lm_addr, | |
6435 | (unsigned long) l_addr, (unsigned long) l_ld); | |
6436 | free (name); | |
6437 | } | |
6438 | } | |
6439 | ||
6440 | lm_prev = lm_addr; | |
6441 | lm_addr = l_next; | |
6442 | } | |
6443 | ||
6444 | if (!header_done) | |
6445 | { | |
6446 | /* Empty list; terminate `<library-list-svr4'. */ | |
6447 | strcpy (p, "/>"); | |
6448 | } | |
6449 | else | |
6450 | strcpy (p, "</library-list-svr4>"); | |
6451 | ||
6452 | document_len = strlen (document); | |
6453 | if (offset < document_len) | |
6454 | document_len -= offset; | |
6455 | else | |
6456 | document_len = 0; | |
6457 | if (len > document_len) | |
6458 | len = document_len; | |
6459 | ||
6460 | memcpy (readbuf, document + offset, len); | |
6461 | xfree (document); | |
6462 | ||
6463 | return len; | |
6464 | } | |
6465 | ||
6466 | #ifdef HAVE_LINUX_BTRACE | |
6467 | ||
6468 | /* See to_enable_btrace target method. */ | |
6469 | ||
6470 | static struct btrace_target_info * | |
6471 | linux_low_enable_btrace (ptid_t ptid, const struct btrace_config *conf) | |
6472 | { | |
6473 | struct btrace_target_info *tinfo; | |
6474 | ||
6475 | tinfo = linux_enable_btrace (ptid, conf); | |
6476 | ||
6477 | if (tinfo != NULL && tinfo->ptr_bits == 0) | |
6478 | { | |
6479 | struct thread_info *thread = find_thread_ptid (ptid); | |
6480 | struct regcache *regcache = get_thread_regcache (thread, 0); | |
6481 | ||
6482 | tinfo->ptr_bits = register_size (regcache->tdesc, 0) * 8; | |
6483 | } | |
6484 | ||
6485 | return tinfo; | |
6486 | } | |
6487 | ||
6488 | /* See to_disable_btrace target method. */ | |
6489 | ||
6490 | static int | |
6491 | linux_low_disable_btrace (struct btrace_target_info *tinfo) | |
6492 | { | |
6493 | enum btrace_error err; | |
6494 | ||
6495 | err = linux_disable_btrace (tinfo); | |
6496 | return (err == BTRACE_ERR_NONE ? 0 : -1); | |
6497 | } | |
6498 | ||
6499 | /* Encode an Intel(R) Processor Trace configuration. */ | |
6500 | ||
6501 | static void | |
6502 | linux_low_encode_pt_config (struct buffer *buffer, | |
6503 | const struct btrace_data_pt_config *config) | |
6504 | { | |
6505 | buffer_grow_str (buffer, "<pt-config>\n"); | |
6506 | ||
6507 | switch (config->cpu.vendor) | |
6508 | { | |
6509 | case CV_INTEL: | |
6510 | buffer_xml_printf (buffer, "<cpu vendor=\"GenuineIntel\" family=\"%u\" " | |
6511 | "model=\"%u\" stepping=\"%u\"/>\n", | |
6512 | config->cpu.family, config->cpu.model, | |
6513 | config->cpu.stepping); | |
6514 | break; | |
6515 | ||
6516 | default: | |
6517 | break; | |
6518 | } | |
6519 | ||
6520 | buffer_grow_str (buffer, "</pt-config>\n"); | |
6521 | } | |
6522 | ||
6523 | /* Encode a raw buffer. */ | |
6524 | ||
6525 | static void | |
6526 | linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data, | |
6527 | unsigned int size) | |
6528 | { | |
6529 | if (size == 0) | |
6530 | return; | |
6531 | ||
6532 | /* We use hex encoding - see common/rsp-low.h. */ | |
6533 | buffer_grow_str (buffer, "<raw>\n"); | |
6534 | ||
6535 | while (size-- > 0) | |
6536 | { | |
6537 | char elem[2]; | |
6538 | ||
6539 | elem[0] = tohex ((*data >> 4) & 0xf); | |
6540 | elem[1] = tohex (*data++ & 0xf); | |
6541 | ||
6542 | buffer_grow (buffer, elem, 2); | |
6543 | } | |
6544 | ||
6545 | buffer_grow_str (buffer, "</raw>\n"); | |
6546 | } | |
6547 | ||
6548 | /* See to_read_btrace target method. */ | |
6549 | ||
6550 | static int | |
6551 | linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer, | |
6552 | int type) | |
6553 | { | |
6554 | struct btrace_data btrace; | |
6555 | struct btrace_block *block; | |
6556 | enum btrace_error err; | |
6557 | int i; | |
6558 | ||
6559 | btrace_data_init (&btrace); | |
6560 | ||
6561 | err = linux_read_btrace (&btrace, tinfo, type); | |
6562 | if (err != BTRACE_ERR_NONE) | |
6563 | { | |
6564 | if (err == BTRACE_ERR_OVERFLOW) | |
6565 | buffer_grow_str0 (buffer, "E.Overflow."); | |
6566 | else | |
6567 | buffer_grow_str0 (buffer, "E.Generic Error."); | |
6568 | ||
6569 | goto err; | |
6570 | } | |
6571 | ||
6572 | switch (btrace.format) | |
6573 | { | |
6574 | case BTRACE_FORMAT_NONE: | |
6575 | buffer_grow_str0 (buffer, "E.No Trace."); | |
6576 | goto err; | |
6577 | ||
6578 | case BTRACE_FORMAT_BTS: | |
6579 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); | |
6580 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); | |
6581 | ||
6582 | for (i = 0; | |
6583 | VEC_iterate (btrace_block_s, btrace.variant.bts.blocks, i, block); | |
6584 | i++) | |
6585 | buffer_xml_printf (buffer, "<block begin=\"0x%s\" end=\"0x%s\"/>\n", | |
6586 | paddress (block->begin), paddress (block->end)); | |
6587 | ||
6588 | buffer_grow_str0 (buffer, "</btrace>\n"); | |
6589 | break; | |
6590 | ||
6591 | case BTRACE_FORMAT_PT: | |
6592 | buffer_grow_str (buffer, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n"); | |
6593 | buffer_grow_str (buffer, "<btrace version=\"1.0\">\n"); | |
6594 | buffer_grow_str (buffer, "<pt>\n"); | |
6595 | ||
6596 | linux_low_encode_pt_config (buffer, &btrace.variant.pt.config); | |
6597 | ||
6598 | linux_low_encode_raw (buffer, btrace.variant.pt.data, | |
6599 | btrace.variant.pt.size); | |
6600 | ||
6601 | buffer_grow_str (buffer, "</pt>\n"); | |
6602 | buffer_grow_str0 (buffer, "</btrace>\n"); | |
6603 | break; | |
6604 | ||
6605 | default: | |
6606 | buffer_grow_str0 (buffer, "E.Unsupported Trace Format."); | |
6607 | goto err; | |
6608 | } | |
6609 | ||
6610 | btrace_data_fini (&btrace); | |
6611 | return 0; | |
6612 | ||
6613 | err: | |
6614 | btrace_data_fini (&btrace); | |
6615 | return -1; | |
6616 | } | |
6617 | ||
6618 | /* See to_btrace_conf target method. */ | |
6619 | ||
6620 | static int | |
6621 | linux_low_btrace_conf (const struct btrace_target_info *tinfo, | |
6622 | struct buffer *buffer) | |
6623 | { | |
6624 | const struct btrace_config *conf; | |
6625 | ||
6626 | buffer_grow_str (buffer, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n"); | |
6627 | buffer_grow_str (buffer, "<btrace-conf version=\"1.0\">\n"); | |
6628 | ||
6629 | conf = linux_btrace_conf (tinfo); | |
6630 | if (conf != NULL) | |
6631 | { | |
6632 | switch (conf->format) | |
6633 | { | |
6634 | case BTRACE_FORMAT_NONE: | |
6635 | break; | |
6636 | ||
6637 | case BTRACE_FORMAT_BTS: | |
6638 | buffer_xml_printf (buffer, "<bts"); | |
6639 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->bts.size); | |
6640 | buffer_xml_printf (buffer, " />\n"); | |
6641 | break; | |
6642 | ||
6643 | case BTRACE_FORMAT_PT: | |
6644 | buffer_xml_printf (buffer, "<pt"); | |
6645 | buffer_xml_printf (buffer, " size=\"0x%x\"", conf->pt.size); | |
6646 | buffer_xml_printf (buffer, "/>\n"); | |
6647 | break; | |
6648 | } | |
6649 | } | |
6650 | ||
6651 | buffer_grow_str0 (buffer, "</btrace-conf>\n"); | |
6652 | return 0; | |
6653 | } | |
6654 | #endif /* HAVE_LINUX_BTRACE */ | |
6655 | ||
6656 | /* See nat/linux-nat.h. */ | |
6657 | ||
6658 | ptid_t | |
6659 | current_lwp_ptid (void) | |
6660 | { | |
6661 | return ptid_of (current_thread); | |
6662 | } | |
6663 | ||
6664 | static struct target_ops linux_target_ops = { | |
6665 | linux_create_inferior, | |
6666 | linux_arch_setup, | |
6667 | linux_attach, | |
6668 | linux_kill, | |
6669 | linux_detach, | |
6670 | linux_mourn, | |
6671 | linux_join, | |
6672 | linux_thread_alive, | |
6673 | linux_resume, | |
6674 | linux_wait, | |
6675 | linux_fetch_registers, | |
6676 | linux_store_registers, | |
6677 | linux_prepare_to_access_memory, | |
6678 | linux_done_accessing_memory, | |
6679 | linux_read_memory, | |
6680 | linux_write_memory, | |
6681 | linux_look_up_symbols, | |
6682 | linux_request_interrupt, | |
6683 | linux_read_auxv, | |
6684 | linux_supports_z_point_type, | |
6685 | linux_insert_point, | |
6686 | linux_remove_point, | |
6687 | linux_stopped_by_sw_breakpoint, | |
6688 | linux_supports_stopped_by_sw_breakpoint, | |
6689 | linux_stopped_by_hw_breakpoint, | |
6690 | linux_supports_stopped_by_hw_breakpoint, | |
6691 | linux_supports_conditional_breakpoints, | |
6692 | linux_stopped_by_watchpoint, | |
6693 | linux_stopped_data_address, | |
6694 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) \ | |
6695 | && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \ | |
6696 | && defined(PT_TEXT_END_ADDR) | |
6697 | linux_read_offsets, | |
6698 | #else | |
6699 | NULL, | |
6700 | #endif | |
6701 | #ifdef USE_THREAD_DB | |
6702 | thread_db_get_tls_address, | |
6703 | #else | |
6704 | NULL, | |
6705 | #endif | |
6706 | linux_qxfer_spu, | |
6707 | hostio_last_error_from_errno, | |
6708 | linux_qxfer_osdata, | |
6709 | linux_xfer_siginfo, | |
6710 | linux_supports_non_stop, | |
6711 | linux_async, | |
6712 | linux_start_non_stop, | |
6713 | linux_supports_multi_process, | |
6714 | linux_supports_fork_events, | |
6715 | linux_supports_vfork_events, | |
6716 | linux_handle_new_gdb_connection, | |
6717 | #ifdef USE_THREAD_DB | |
6718 | thread_db_handle_monitor_command, | |
6719 | #else | |
6720 | NULL, | |
6721 | #endif | |
6722 | linux_common_core_of_thread, | |
6723 | linux_read_loadmap, | |
6724 | linux_process_qsupported, | |
6725 | linux_supports_tracepoints, | |
6726 | linux_read_pc, | |
6727 | linux_write_pc, | |
6728 | linux_thread_stopped, | |
6729 | NULL, | |
6730 | linux_pause_all, | |
6731 | linux_unpause_all, | |
6732 | linux_stabilize_threads, | |
6733 | linux_install_fast_tracepoint_jump_pad, | |
6734 | linux_emit_ops, | |
6735 | linux_supports_disable_randomization, | |
6736 | linux_get_min_fast_tracepoint_insn_len, | |
6737 | linux_qxfer_libraries_svr4, | |
6738 | linux_supports_agent, | |
6739 | #ifdef HAVE_LINUX_BTRACE | |
6740 | linux_supports_btrace, | |
6741 | linux_low_enable_btrace, | |
6742 | linux_low_disable_btrace, | |
6743 | linux_low_read_btrace, | |
6744 | linux_low_btrace_conf, | |
6745 | #else | |
6746 | NULL, | |
6747 | NULL, | |
6748 | NULL, | |
6749 | NULL, | |
6750 | NULL, | |
6751 | #endif | |
6752 | linux_supports_range_stepping, | |
6753 | linux_proc_pid_to_exec_file, | |
6754 | linux_mntns_open_cloexec, | |
6755 | linux_mntns_unlink, | |
6756 | linux_mntns_readlink, | |
6757 | }; | |
6758 | ||
6759 | static void | |
6760 | linux_init_signals () | |
6761 | { | |
6762 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads | |
6763 | to find what the cancel signal actually is. */ | |
6764 | #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */ | |
6765 | signal (__SIGRTMIN+1, SIG_IGN); | |
6766 | #endif | |
6767 | } | |
6768 | ||
6769 | #ifdef HAVE_LINUX_REGSETS | |
6770 | void | |
6771 | initialize_regsets_info (struct regsets_info *info) | |
6772 | { | |
6773 | for (info->num_regsets = 0; | |
6774 | info->regsets[info->num_regsets].size >= 0; | |
6775 | info->num_regsets++) | |
6776 | ; | |
6777 | } | |
6778 | #endif | |
6779 | ||
6780 | void | |
6781 | initialize_low (void) | |
6782 | { | |
6783 | struct sigaction sigchld_action; | |
6784 | memset (&sigchld_action, 0, sizeof (sigchld_action)); | |
6785 | set_target_ops (&linux_target_ops); | |
6786 | set_breakpoint_data (the_low_target.breakpoint, | |
6787 | the_low_target.breakpoint_len); | |
6788 | linux_init_signals (); | |
6789 | linux_ptrace_init_warnings (); | |
6790 | ||
6791 | sigchld_action.sa_handler = sigchld_handler; | |
6792 | sigemptyset (&sigchld_action.sa_mask); | |
6793 | sigchld_action.sa_flags = SA_RESTART; | |
6794 | sigaction (SIGCHLD, &sigchld_action, NULL); | |
6795 | ||
6796 | initialize_low_arch (); | |
6797 | ||
6798 | linux_check_ptrace_features (); | |
6799 | } |