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1 | /* Low level interface to ptrace, for the remote server for GDB. | |
2 | Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, | |
3 | 2006, 2007, 2008, 2009 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "server.h" | |
21 | #include "linux-low.h" | |
22 | ||
23 | #include <sys/wait.h> | |
24 | #include <stdio.h> | |
25 | #include <sys/param.h> | |
26 | #include <sys/ptrace.h> | |
27 | #include <signal.h> | |
28 | #include <sys/ioctl.h> | |
29 | #include <fcntl.h> | |
30 | #include <string.h> | |
31 | #include <stdlib.h> | |
32 | #include <unistd.h> | |
33 | #include <errno.h> | |
34 | #include <sys/syscall.h> | |
35 | #include <sched.h> | |
36 | #include <ctype.h> | |
37 | #include <pwd.h> | |
38 | #include <sys/types.h> | |
39 | #include <dirent.h> | |
40 | ||
41 | #ifndef PTRACE_GETSIGINFO | |
42 | # define PTRACE_GETSIGINFO 0x4202 | |
43 | # define PTRACE_SETSIGINFO 0x4203 | |
44 | #endif | |
45 | ||
46 | #ifndef O_LARGEFILE | |
47 | #define O_LARGEFILE 0 | |
48 | #endif | |
49 | ||
50 | /* If the system headers did not provide the constants, hard-code the normal | |
51 | values. */ | |
52 | #ifndef PTRACE_EVENT_FORK | |
53 | ||
54 | #define PTRACE_SETOPTIONS 0x4200 | |
55 | #define PTRACE_GETEVENTMSG 0x4201 | |
56 | ||
57 | /* options set using PTRACE_SETOPTIONS */ | |
58 | #define PTRACE_O_TRACESYSGOOD 0x00000001 | |
59 | #define PTRACE_O_TRACEFORK 0x00000002 | |
60 | #define PTRACE_O_TRACEVFORK 0x00000004 | |
61 | #define PTRACE_O_TRACECLONE 0x00000008 | |
62 | #define PTRACE_O_TRACEEXEC 0x00000010 | |
63 | #define PTRACE_O_TRACEVFORKDONE 0x00000020 | |
64 | #define PTRACE_O_TRACEEXIT 0x00000040 | |
65 | ||
66 | /* Wait extended result codes for the above trace options. */ | |
67 | #define PTRACE_EVENT_FORK 1 | |
68 | #define PTRACE_EVENT_VFORK 2 | |
69 | #define PTRACE_EVENT_CLONE 3 | |
70 | #define PTRACE_EVENT_EXEC 4 | |
71 | #define PTRACE_EVENT_VFORK_DONE 5 | |
72 | #define PTRACE_EVENT_EXIT 6 | |
73 | ||
74 | #endif /* PTRACE_EVENT_FORK */ | |
75 | ||
76 | /* We can't always assume that this flag is available, but all systems | |
77 | with the ptrace event handlers also have __WALL, so it's safe to use | |
78 | in some contexts. */ | |
79 | #ifndef __WALL | |
80 | #define __WALL 0x40000000 /* Wait for any child. */ | |
81 | #endif | |
82 | ||
83 | #ifdef __UCLIBC__ | |
84 | #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__)) | |
85 | #define HAS_NOMMU | |
86 | #endif | |
87 | #endif | |
88 | ||
89 | /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol | |
90 | representation of the thread ID. | |
91 | ||
92 | ``all_lwps'' is keyed by the process ID - which on Linux is (presently) | |
93 | the same as the LWP ID. | |
94 | ||
95 | ``all_processes'' is keyed by the "overall process ID", which | |
96 | GNU/Linux calls tgid, "thread group ID". */ | |
97 | ||
98 | struct inferior_list all_lwps; | |
99 | ||
100 | /* A list of all unknown processes which receive stop signals. Some other | |
101 | process will presumably claim each of these as forked children | |
102 | momentarily. */ | |
103 | ||
104 | struct inferior_list stopped_pids; | |
105 | ||
106 | /* FIXME this is a bit of a hack, and could be removed. */ | |
107 | int stopping_threads; | |
108 | ||
109 | /* FIXME make into a target method? */ | |
110 | int using_threads = 1; | |
111 | ||
112 | /* This flag is true iff we've just created or attached to our first | |
113 | inferior but it has not stopped yet. As soon as it does, we need | |
114 | to call the low target's arch_setup callback. Doing this only on | |
115 | the first inferior avoids reinializing the architecture on every | |
116 | inferior, and avoids messing with the register caches of the | |
117 | already running inferiors. NOTE: this assumes all inferiors under | |
118 | control of gdbserver have the same architecture. */ | |
119 | static int new_inferior; | |
120 | ||
121 | static void linux_resume_one_lwp (struct inferior_list_entry *entry, | |
122 | int step, int signal, siginfo_t *info); | |
123 | static void linux_resume (struct thread_resume *resume_info, size_t n); | |
124 | static void stop_all_lwps (void); | |
125 | static int linux_wait_for_event (ptid_t ptid, int *wstat, int options); | |
126 | static int check_removed_breakpoint (struct lwp_info *event_child); | |
127 | static void *add_lwp (ptid_t ptid); | |
128 | static int my_waitpid (int pid, int *status, int flags); | |
129 | static int linux_stopped_by_watchpoint (void); | |
130 | static void mark_lwp_dead (struct lwp_info *lwp, int wstat); | |
131 | ||
132 | struct pending_signals | |
133 | { | |
134 | int signal; | |
135 | siginfo_t info; | |
136 | struct pending_signals *prev; | |
137 | }; | |
138 | ||
139 | #define PTRACE_ARG3_TYPE long | |
140 | #define PTRACE_XFER_TYPE long | |
141 | ||
142 | #ifdef HAVE_LINUX_REGSETS | |
143 | static char *disabled_regsets; | |
144 | static int num_regsets; | |
145 | #endif | |
146 | ||
147 | /* The read/write ends of the pipe registered as waitable file in the | |
148 | event loop. */ | |
149 | static int linux_event_pipe[2] = { -1, -1 }; | |
150 | ||
151 | /* True if we're currently in async mode. */ | |
152 | #define target_is_async_p() (linux_event_pipe[0] != -1) | |
153 | ||
154 | static void send_sigstop (struct inferior_list_entry *entry); | |
155 | static void wait_for_sigstop (struct inferior_list_entry *entry); | |
156 | ||
157 | static void | |
158 | delete_lwp (struct lwp_info *lwp) | |
159 | { | |
160 | remove_thread (get_lwp_thread (lwp)); | |
161 | remove_inferior (&all_lwps, &lwp->head); | |
162 | free (lwp); | |
163 | } | |
164 | ||
165 | /* Add a process to the common process list, and set its private | |
166 | data. */ | |
167 | ||
168 | static struct process_info * | |
169 | linux_add_process (int pid, int attached) | |
170 | { | |
171 | struct process_info *proc; | |
172 | ||
173 | /* Is this the first process? If so, then set the arch. */ | |
174 | if (all_processes.head == NULL) | |
175 | new_inferior = 1; | |
176 | ||
177 | proc = add_process (pid, attached); | |
178 | proc->private = xcalloc (1, sizeof (*proc->private)); | |
179 | ||
180 | return proc; | |
181 | } | |
182 | ||
183 | /* Remove a process from the common process list, | |
184 | also freeing all private data. */ | |
185 | ||
186 | static void | |
187 | linux_remove_process (struct process_info *process) | |
188 | { | |
189 | free (process->private); | |
190 | remove_process (process); | |
191 | } | |
192 | ||
193 | /* Handle a GNU/Linux extended wait response. If we see a clone | |
194 | event, we need to add the new LWP to our list (and not report the | |
195 | trap to higher layers). */ | |
196 | ||
197 | static void | |
198 | handle_extended_wait (struct lwp_info *event_child, int wstat) | |
199 | { | |
200 | int event = wstat >> 16; | |
201 | struct lwp_info *new_lwp; | |
202 | ||
203 | if (event == PTRACE_EVENT_CLONE) | |
204 | { | |
205 | ptid_t ptid; | |
206 | unsigned long new_pid; | |
207 | int ret, status = W_STOPCODE (SIGSTOP); | |
208 | ||
209 | ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid); | |
210 | ||
211 | /* If we haven't already seen the new PID stop, wait for it now. */ | |
212 | if (! pull_pid_from_list (&stopped_pids, new_pid)) | |
213 | { | |
214 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
215 | hits the SIGSTOP, but we're already attached. */ | |
216 | ||
217 | ret = my_waitpid (new_pid, &status, __WALL); | |
218 | ||
219 | if (ret == -1) | |
220 | perror_with_name ("waiting for new child"); | |
221 | else if (ret != new_pid) | |
222 | warning ("wait returned unexpected PID %d", ret); | |
223 | else if (!WIFSTOPPED (status)) | |
224 | warning ("wait returned unexpected status 0x%x", status); | |
225 | } | |
226 | ||
227 | ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE); | |
228 | ||
229 | ptid = ptid_build (pid_of (event_child), new_pid, 0); | |
230 | new_lwp = (struct lwp_info *) add_lwp (ptid); | |
231 | add_thread (ptid, new_lwp); | |
232 | ||
233 | /* Normally we will get the pending SIGSTOP. But in some cases | |
234 | we might get another signal delivered to the group first. | |
235 | If we do get another signal, be sure not to lose it. */ | |
236 | if (WSTOPSIG (status) == SIGSTOP) | |
237 | { | |
238 | if (stopping_threads) | |
239 | new_lwp->stopped = 1; | |
240 | else | |
241 | ptrace (PTRACE_CONT, new_pid, 0, 0); | |
242 | } | |
243 | else | |
244 | { | |
245 | new_lwp->stop_expected = 1; | |
246 | if (stopping_threads) | |
247 | { | |
248 | new_lwp->stopped = 1; | |
249 | new_lwp->status_pending_p = 1; | |
250 | new_lwp->status_pending = status; | |
251 | } | |
252 | else | |
253 | /* Pass the signal on. This is what GDB does - except | |
254 | shouldn't we really report it instead? */ | |
255 | ptrace (PTRACE_CONT, new_pid, 0, WSTOPSIG (status)); | |
256 | } | |
257 | ||
258 | /* Always resume the current thread. If we are stopping | |
259 | threads, it will have a pending SIGSTOP; we may as well | |
260 | collect it now. */ | |
261 | linux_resume_one_lwp (&event_child->head, | |
262 | event_child->stepping, 0, NULL); | |
263 | } | |
264 | } | |
265 | ||
266 | /* This function should only be called if the process got a SIGTRAP. | |
267 | The SIGTRAP could mean several things. | |
268 | ||
269 | On i386, where decr_pc_after_break is non-zero: | |
270 | If we were single-stepping this process using PTRACE_SINGLESTEP, | |
271 | we will get only the one SIGTRAP (even if the instruction we | |
272 | stepped over was a breakpoint). The value of $eip will be the | |
273 | next instruction. | |
274 | If we continue the process using PTRACE_CONT, we will get a | |
275 | SIGTRAP when we hit a breakpoint. The value of $eip will be | |
276 | the instruction after the breakpoint (i.e. needs to be | |
277 | decremented). If we report the SIGTRAP to GDB, we must also | |
278 | report the undecremented PC. If we cancel the SIGTRAP, we | |
279 | must resume at the decremented PC. | |
280 | ||
281 | (Presumably, not yet tested) On a non-decr_pc_after_break machine | |
282 | with hardware or kernel single-step: | |
283 | If we single-step over a breakpoint instruction, our PC will | |
284 | point at the following instruction. If we continue and hit a | |
285 | breakpoint instruction, our PC will point at the breakpoint | |
286 | instruction. */ | |
287 | ||
288 | static CORE_ADDR | |
289 | get_stop_pc (void) | |
290 | { | |
291 | CORE_ADDR stop_pc = (*the_low_target.get_pc) (); | |
292 | ||
293 | if (get_thread_lwp (current_inferior)->stepping) | |
294 | return stop_pc; | |
295 | else | |
296 | return stop_pc - the_low_target.decr_pc_after_break; | |
297 | } | |
298 | ||
299 | static void * | |
300 | add_lwp (ptid_t ptid) | |
301 | { | |
302 | struct lwp_info *lwp; | |
303 | ||
304 | lwp = (struct lwp_info *) xmalloc (sizeof (*lwp)); | |
305 | memset (lwp, 0, sizeof (*lwp)); | |
306 | ||
307 | lwp->head.id = ptid; | |
308 | ||
309 | add_inferior_to_list (&all_lwps, &lwp->head); | |
310 | ||
311 | return lwp; | |
312 | } | |
313 | ||
314 | /* Start an inferior process and returns its pid. | |
315 | ALLARGS is a vector of program-name and args. */ | |
316 | ||
317 | static int | |
318 | linux_create_inferior (char *program, char **allargs) | |
319 | { | |
320 | struct lwp_info *new_lwp; | |
321 | int pid; | |
322 | ptid_t ptid; | |
323 | ||
324 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) | |
325 | pid = vfork (); | |
326 | #else | |
327 | pid = fork (); | |
328 | #endif | |
329 | if (pid < 0) | |
330 | perror_with_name ("fork"); | |
331 | ||
332 | if (pid == 0) | |
333 | { | |
334 | ptrace (PTRACE_TRACEME, 0, 0, 0); | |
335 | ||
336 | signal (__SIGRTMIN + 1, SIG_DFL); | |
337 | ||
338 | setpgid (0, 0); | |
339 | ||
340 | execv (program, allargs); | |
341 | if (errno == ENOENT) | |
342 | execvp (program, allargs); | |
343 | ||
344 | fprintf (stderr, "Cannot exec %s: %s.\n", program, | |
345 | strerror (errno)); | |
346 | fflush (stderr); | |
347 | _exit (0177); | |
348 | } | |
349 | ||
350 | linux_add_process (pid, 0); | |
351 | ||
352 | ptid = ptid_build (pid, pid, 0); | |
353 | new_lwp = add_lwp (ptid); | |
354 | add_thread (ptid, new_lwp); | |
355 | new_lwp->must_set_ptrace_flags = 1; | |
356 | ||
357 | return pid; | |
358 | } | |
359 | ||
360 | /* Attach to an inferior process. */ | |
361 | ||
362 | static void | |
363 | linux_attach_lwp_1 (unsigned long lwpid, int initial) | |
364 | { | |
365 | ptid_t ptid; | |
366 | struct lwp_info *new_lwp; | |
367 | ||
368 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) != 0) | |
369 | { | |
370 | if (!initial) | |
371 | { | |
372 | /* If we fail to attach to an LWP, just warn. */ | |
373 | fprintf (stderr, "Cannot attach to lwp %ld: %s (%d)\n", lwpid, | |
374 | strerror (errno), errno); | |
375 | fflush (stderr); | |
376 | return; | |
377 | } | |
378 | else | |
379 | /* If we fail to attach to a process, report an error. */ | |
380 | error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid, | |
381 | strerror (errno), errno); | |
382 | } | |
383 | ||
384 | if (initial) | |
385 | /* NOTE/FIXME: This lwp might have not been the tgid. */ | |
386 | ptid = ptid_build (lwpid, lwpid, 0); | |
387 | else | |
388 | { | |
389 | /* Note that extracting the pid from the current inferior is | |
390 | safe, since we're always called in the context of the same | |
391 | process as this new thread. */ | |
392 | int pid = pid_of (get_thread_lwp (current_inferior)); | |
393 | ptid = ptid_build (pid, lwpid, 0); | |
394 | } | |
395 | ||
396 | new_lwp = (struct lwp_info *) add_lwp (ptid); | |
397 | add_thread (ptid, new_lwp); | |
398 | ||
399 | ||
400 | /* We need to wait for SIGSTOP before being able to make the next | |
401 | ptrace call on this LWP. */ | |
402 | new_lwp->must_set_ptrace_flags = 1; | |
403 | ||
404 | /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH | |
405 | brings it to a halt. | |
406 | ||
407 | There are several cases to consider here: | |
408 | ||
409 | 1) gdbserver has already attached to the process and is being notified | |
410 | of a new thread that is being created. | |
411 | In this case we should ignore that SIGSTOP and resume the process. | |
412 | This is handled below by setting stop_expected = 1. | |
413 | ||
414 | 2) This is the first thread (the process thread), and we're attaching | |
415 | to it via attach_inferior. | |
416 | In this case we want the process thread to stop. | |
417 | This is handled by having linux_attach clear stop_expected after | |
418 | we return. | |
419 | ??? If the process already has several threads we leave the other | |
420 | threads running. | |
421 | ||
422 | 3) GDB is connecting to gdbserver and is requesting an enumeration of all | |
423 | existing threads. | |
424 | In this case we want the thread to stop. | |
425 | FIXME: This case is currently not properly handled. | |
426 | We should wait for the SIGSTOP but don't. Things work apparently | |
427 | because enough time passes between when we ptrace (ATTACH) and when | |
428 | gdb makes the next ptrace call on the thread. | |
429 | ||
430 | On the other hand, if we are currently trying to stop all threads, we | |
431 | should treat the new thread as if we had sent it a SIGSTOP. This works | |
432 | because we are guaranteed that the add_lwp call above added us to the | |
433 | end of the list, and so the new thread has not yet reached | |
434 | wait_for_sigstop (but will). */ | |
435 | if (! stopping_threads) | |
436 | new_lwp->stop_expected = 1; | |
437 | } | |
438 | ||
439 | void | |
440 | linux_attach_lwp (unsigned long lwpid) | |
441 | { | |
442 | linux_attach_lwp_1 (lwpid, 0); | |
443 | } | |
444 | ||
445 | int | |
446 | linux_attach (unsigned long pid) | |
447 | { | |
448 | struct lwp_info *lwp; | |
449 | ||
450 | linux_attach_lwp_1 (pid, 1); | |
451 | ||
452 | linux_add_process (pid, 1); | |
453 | ||
454 | if (!non_stop) | |
455 | { | |
456 | /* Don't ignore the initial SIGSTOP if we just attached to this | |
457 | process. It will be collected by wait shortly. */ | |
458 | lwp = (struct lwp_info *) find_inferior_id (&all_lwps, | |
459 | ptid_build (pid, pid, 0)); | |
460 | lwp->stop_expected = 0; | |
461 | } | |
462 | ||
463 | return 0; | |
464 | } | |
465 | ||
466 | struct counter | |
467 | { | |
468 | int pid; | |
469 | int count; | |
470 | }; | |
471 | ||
472 | static int | |
473 | second_thread_of_pid_p (struct inferior_list_entry *entry, void *args) | |
474 | { | |
475 | struct counter *counter = args; | |
476 | ||
477 | if (ptid_get_pid (entry->id) == counter->pid) | |
478 | { | |
479 | if (++counter->count > 1) | |
480 | return 1; | |
481 | } | |
482 | ||
483 | return 0; | |
484 | } | |
485 | ||
486 | static int | |
487 | last_thread_of_process_p (struct thread_info *thread) | |
488 | { | |
489 | ptid_t ptid = ((struct inferior_list_entry *)thread)->id; | |
490 | int pid = ptid_get_pid (ptid); | |
491 | struct counter counter = { pid , 0 }; | |
492 | ||
493 | return (find_inferior (&all_threads, | |
494 | second_thread_of_pid_p, &counter) == NULL); | |
495 | } | |
496 | ||
497 | /* Kill the inferior lwp. */ | |
498 | ||
499 | static int | |
500 | linux_kill_one_lwp (struct inferior_list_entry *entry, void *args) | |
501 | { | |
502 | struct thread_info *thread = (struct thread_info *) entry; | |
503 | struct lwp_info *lwp = get_thread_lwp (thread); | |
504 | int wstat; | |
505 | int pid = * (int *) args; | |
506 | ||
507 | if (ptid_get_pid (entry->id) != pid) | |
508 | return 0; | |
509 | ||
510 | /* We avoid killing the first thread here, because of a Linux kernel (at | |
511 | least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before | |
512 | the children get a chance to be reaped, it will remain a zombie | |
513 | forever. */ | |
514 | ||
515 | if (last_thread_of_process_p (thread)) | |
516 | { | |
517 | if (debug_threads) | |
518 | fprintf (stderr, "lkop: is last of process %s\n", | |
519 | target_pid_to_str (entry->id)); | |
520 | return 0; | |
521 | } | |
522 | ||
523 | /* If we're killing a running inferior, make sure it is stopped | |
524 | first, as PTRACE_KILL will not work otherwise. */ | |
525 | if (!lwp->stopped) | |
526 | send_sigstop (&lwp->head); | |
527 | ||
528 | do | |
529 | { | |
530 | ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0); | |
531 | ||
532 | /* Make sure it died. The loop is most likely unnecessary. */ | |
533 | pid = linux_wait_for_event (lwp->head.id, &wstat, __WALL); | |
534 | } while (pid > 0 && WIFSTOPPED (wstat)); | |
535 | ||
536 | return 0; | |
537 | } | |
538 | ||
539 | static int | |
540 | linux_kill (int pid) | |
541 | { | |
542 | struct process_info *process; | |
543 | struct lwp_info *lwp; | |
544 | struct thread_info *thread; | |
545 | int wstat; | |
546 | int lwpid; | |
547 | ||
548 | process = find_process_pid (pid); | |
549 | if (process == NULL) | |
550 | return -1; | |
551 | ||
552 | find_inferior (&all_threads, linux_kill_one_lwp, &pid); | |
553 | ||
554 | /* See the comment in linux_kill_one_lwp. We did not kill the first | |
555 | thread in the list, so do so now. */ | |
556 | lwp = find_lwp_pid (pid_to_ptid (pid)); | |
557 | thread = get_lwp_thread (lwp); | |
558 | ||
559 | if (debug_threads) | |
560 | fprintf (stderr, "lk_1: killing lwp %ld, for pid: %d\n", | |
561 | lwpid_of (lwp), pid); | |
562 | ||
563 | /* If we're killing a running inferior, make sure it is stopped | |
564 | first, as PTRACE_KILL will not work otherwise. */ | |
565 | if (!lwp->stopped) | |
566 | send_sigstop (&lwp->head); | |
567 | ||
568 | do | |
569 | { | |
570 | ptrace (PTRACE_KILL, lwpid_of (lwp), 0, 0); | |
571 | ||
572 | /* Make sure it died. The loop is most likely unnecessary. */ | |
573 | lwpid = linux_wait_for_event (lwp->head.id, &wstat, __WALL); | |
574 | } while (lwpid > 0 && WIFSTOPPED (wstat)); | |
575 | ||
576 | delete_lwp (lwp); | |
577 | linux_remove_process (process); | |
578 | return 0; | |
579 | } | |
580 | ||
581 | static int | |
582 | linux_detach_one_lwp (struct inferior_list_entry *entry, void *args) | |
583 | { | |
584 | struct thread_info *thread = (struct thread_info *) entry; | |
585 | struct lwp_info *lwp = get_thread_lwp (thread); | |
586 | int pid = * (int *) args; | |
587 | ||
588 | if (ptid_get_pid (entry->id) != pid) | |
589 | return 0; | |
590 | ||
591 | /* If we're detaching from a running inferior, make sure it is | |
592 | stopped first, as PTRACE_DETACH will not work otherwise. */ | |
593 | if (!lwp->stopped) | |
594 | { | |
595 | int lwpid = lwpid_of (lwp); | |
596 | ||
597 | stopping_threads = 1; | |
598 | send_sigstop (&lwp->head); | |
599 | ||
600 | /* If this detects a new thread through a clone event, the new | |
601 | thread is appended to the end of the lwp list, so we'll | |
602 | eventually detach from it. */ | |
603 | wait_for_sigstop (&lwp->head); | |
604 | stopping_threads = 0; | |
605 | ||
606 | /* If LWP exits while we're trying to stop it, there's nothing | |
607 | left to do. */ | |
608 | lwp = find_lwp_pid (pid_to_ptid (lwpid)); | |
609 | if (lwp == NULL) | |
610 | return 0; | |
611 | } | |
612 | ||
613 | /* Make sure the process isn't stopped at a breakpoint that's | |
614 | no longer there. */ | |
615 | check_removed_breakpoint (lwp); | |
616 | ||
617 | /* If this process is stopped but is expecting a SIGSTOP, then make | |
618 | sure we take care of that now. This isn't absolutely guaranteed | |
619 | to collect the SIGSTOP, but is fairly likely to. */ | |
620 | if (lwp->stop_expected) | |
621 | { | |
622 | int wstat; | |
623 | /* Clear stop_expected, so that the SIGSTOP will be reported. */ | |
624 | lwp->stop_expected = 0; | |
625 | if (lwp->stopped) | |
626 | linux_resume_one_lwp (&lwp->head, 0, 0, NULL); | |
627 | linux_wait_for_event (lwp->head.id, &wstat, __WALL); | |
628 | } | |
629 | ||
630 | /* Flush any pending changes to the process's registers. */ | |
631 | regcache_invalidate_one ((struct inferior_list_entry *) | |
632 | get_lwp_thread (lwp)); | |
633 | ||
634 | /* Finally, let it resume. */ | |
635 | ptrace (PTRACE_DETACH, lwpid_of (lwp), 0, 0); | |
636 | ||
637 | delete_lwp (lwp); | |
638 | return 0; | |
639 | } | |
640 | ||
641 | static int | |
642 | any_thread_of (struct inferior_list_entry *entry, void *args) | |
643 | { | |
644 | int *pid_p = args; | |
645 | ||
646 | if (ptid_get_pid (entry->id) == *pid_p) | |
647 | return 1; | |
648 | ||
649 | return 0; | |
650 | } | |
651 | ||
652 | static int | |
653 | linux_detach (int pid) | |
654 | { | |
655 | struct process_info *process; | |
656 | ||
657 | process = find_process_pid (pid); | |
658 | if (process == NULL) | |
659 | return -1; | |
660 | ||
661 | current_inferior = | |
662 | (struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid); | |
663 | ||
664 | delete_all_breakpoints (); | |
665 | find_inferior (&all_threads, linux_detach_one_lwp, &pid); | |
666 | linux_remove_process (process); | |
667 | return 0; | |
668 | } | |
669 | ||
670 | static void | |
671 | linux_join (int pid) | |
672 | { | |
673 | int status, ret; | |
674 | struct process_info *process; | |
675 | ||
676 | process = find_process_pid (pid); | |
677 | if (process == NULL) | |
678 | return; | |
679 | ||
680 | do { | |
681 | ret = my_waitpid (pid, &status, 0); | |
682 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
683 | break; | |
684 | } while (ret != -1 || errno != ECHILD); | |
685 | } | |
686 | ||
687 | /* Return nonzero if the given thread is still alive. */ | |
688 | static int | |
689 | linux_thread_alive (ptid_t ptid) | |
690 | { | |
691 | struct lwp_info *lwp = find_lwp_pid (ptid); | |
692 | ||
693 | /* We assume we always know if a thread exits. If a whole process | |
694 | exited but we still haven't been able to report it to GDB, we'll | |
695 | hold on to the last lwp of the dead process. */ | |
696 | if (lwp != NULL) | |
697 | return !lwp->dead; | |
698 | else | |
699 | return 0; | |
700 | } | |
701 | ||
702 | /* Return nonzero if this process stopped at a breakpoint which | |
703 | no longer appears to be inserted. Also adjust the PC | |
704 | appropriately to resume where the breakpoint used to be. */ | |
705 | static int | |
706 | check_removed_breakpoint (struct lwp_info *event_child) | |
707 | { | |
708 | CORE_ADDR stop_pc; | |
709 | struct thread_info *saved_inferior; | |
710 | ||
711 | if (event_child->pending_is_breakpoint == 0) | |
712 | return 0; | |
713 | ||
714 | if (debug_threads) | |
715 | fprintf (stderr, "Checking for breakpoint in lwp %ld.\n", | |
716 | lwpid_of (event_child)); | |
717 | ||
718 | saved_inferior = current_inferior; | |
719 | current_inferior = get_lwp_thread (event_child); | |
720 | ||
721 | stop_pc = get_stop_pc (); | |
722 | ||
723 | /* If the PC has changed since we stopped, then we shouldn't do | |
724 | anything. This happens if, for instance, GDB handled the | |
725 | decr_pc_after_break subtraction itself. */ | |
726 | if (stop_pc != event_child->pending_stop_pc) | |
727 | { | |
728 | if (debug_threads) | |
729 | fprintf (stderr, "Ignoring, PC was changed. Old PC was 0x%08llx\n", | |
730 | event_child->pending_stop_pc); | |
731 | ||
732 | event_child->pending_is_breakpoint = 0; | |
733 | current_inferior = saved_inferior; | |
734 | return 0; | |
735 | } | |
736 | ||
737 | /* If the breakpoint is still there, we will report hitting it. */ | |
738 | if ((*the_low_target.breakpoint_at) (stop_pc)) | |
739 | { | |
740 | if (debug_threads) | |
741 | fprintf (stderr, "Ignoring, breakpoint is still present.\n"); | |
742 | current_inferior = saved_inferior; | |
743 | return 0; | |
744 | } | |
745 | ||
746 | if (debug_threads) | |
747 | fprintf (stderr, "Removed breakpoint.\n"); | |
748 | ||
749 | /* For decr_pc_after_break targets, here is where we perform the | |
750 | decrement. We go immediately from this function to resuming, | |
751 | and can not safely call get_stop_pc () again. */ | |
752 | if (the_low_target.set_pc != NULL) | |
753 | (*the_low_target.set_pc) (stop_pc); | |
754 | ||
755 | /* We consumed the pending SIGTRAP. */ | |
756 | event_child->pending_is_breakpoint = 0; | |
757 | event_child->status_pending_p = 0; | |
758 | event_child->status_pending = 0; | |
759 | ||
760 | current_inferior = saved_inferior; | |
761 | return 1; | |
762 | } | |
763 | ||
764 | /* Return 1 if this lwp has an interesting status pending. This | |
765 | function may silently resume an inferior lwp. */ | |
766 | static int | |
767 | status_pending_p (struct inferior_list_entry *entry, void *arg) | |
768 | { | |
769 | struct lwp_info *lwp = (struct lwp_info *) entry; | |
770 | ptid_t ptid = * (ptid_t *) arg; | |
771 | ||
772 | /* Check if we're only interested in events from a specific process | |
773 | or its lwps. */ | |
774 | if (!ptid_equal (minus_one_ptid, ptid) | |
775 | && ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id)) | |
776 | return 0; | |
777 | ||
778 | if (lwp->status_pending_p && !lwp->suspended) | |
779 | if (check_removed_breakpoint (lwp)) | |
780 | { | |
781 | /* This thread was stopped at a breakpoint, and the breakpoint | |
782 | is now gone. We were told to continue (or step...) all threads, | |
783 | so GDB isn't trying to single-step past this breakpoint. | |
784 | So instead of reporting the old SIGTRAP, pretend we got to | |
785 | the breakpoint just after it was removed instead of just | |
786 | before; resume the process. */ | |
787 | linux_resume_one_lwp (&lwp->head, 0, 0, NULL); | |
788 | return 0; | |
789 | } | |
790 | ||
791 | return (lwp->status_pending_p && !lwp->suspended); | |
792 | } | |
793 | ||
794 | static int | |
795 | same_lwp (struct inferior_list_entry *entry, void *data) | |
796 | { | |
797 | ptid_t ptid = *(ptid_t *) data; | |
798 | int lwp; | |
799 | ||
800 | if (ptid_get_lwp (ptid) != 0) | |
801 | lwp = ptid_get_lwp (ptid); | |
802 | else | |
803 | lwp = ptid_get_pid (ptid); | |
804 | ||
805 | if (ptid_get_lwp (entry->id) == lwp) | |
806 | return 1; | |
807 | ||
808 | return 0; | |
809 | } | |
810 | ||
811 | struct lwp_info * | |
812 | find_lwp_pid (ptid_t ptid) | |
813 | { | |
814 | return (struct lwp_info*) find_inferior (&all_lwps, same_lwp, &ptid); | |
815 | } | |
816 | ||
817 | static struct lwp_info * | |
818 | linux_wait_for_lwp (ptid_t ptid, int *wstatp, int options) | |
819 | { | |
820 | int ret; | |
821 | int to_wait_for = -1; | |
822 | struct lwp_info *child = NULL; | |
823 | ||
824 | if (debug_threads) | |
825 | fprintf (stderr, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid)); | |
826 | ||
827 | if (ptid_equal (ptid, minus_one_ptid)) | |
828 | to_wait_for = -1; /* any child */ | |
829 | else | |
830 | to_wait_for = ptid_get_lwp (ptid); /* this lwp only */ | |
831 | ||
832 | options |= __WALL; | |
833 | ||
834 | retry: | |
835 | ||
836 | ret = my_waitpid (to_wait_for, wstatp, options); | |
837 | if (ret == 0 || (ret == -1 && errno == ECHILD && (options & WNOHANG))) | |
838 | return NULL; | |
839 | else if (ret == -1) | |
840 | perror_with_name ("waitpid"); | |
841 | ||
842 | if (debug_threads | |
843 | && (!WIFSTOPPED (*wstatp) | |
844 | || (WSTOPSIG (*wstatp) != 32 | |
845 | && WSTOPSIG (*wstatp) != 33))) | |
846 | fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp); | |
847 | ||
848 | child = find_lwp_pid (pid_to_ptid (ret)); | |
849 | ||
850 | /* If we didn't find a process, one of two things presumably happened: | |
851 | - A process we started and then detached from has exited. Ignore it. | |
852 | - A process we are controlling has forked and the new child's stop | |
853 | was reported to us by the kernel. Save its PID. */ | |
854 | if (child == NULL && WIFSTOPPED (*wstatp)) | |
855 | { | |
856 | add_pid_to_list (&stopped_pids, ret); | |
857 | goto retry; | |
858 | } | |
859 | else if (child == NULL) | |
860 | goto retry; | |
861 | ||
862 | child->stopped = 1; | |
863 | child->pending_is_breakpoint = 0; | |
864 | ||
865 | child->last_status = *wstatp; | |
866 | ||
867 | /* Architecture-specific setup after inferior is running. | |
868 | This needs to happen after we have attached to the inferior | |
869 | and it is stopped for the first time, but before we access | |
870 | any inferior registers. */ | |
871 | if (new_inferior) | |
872 | { | |
873 | the_low_target.arch_setup (); | |
874 | #ifdef HAVE_LINUX_REGSETS | |
875 | memset (disabled_regsets, 0, num_regsets); | |
876 | #endif | |
877 | new_inferior = 0; | |
878 | } | |
879 | ||
880 | if (debug_threads | |
881 | && WIFSTOPPED (*wstatp)) | |
882 | { | |
883 | struct thread_info *saved_inferior = current_inferior; | |
884 | current_inferior = (struct thread_info *) | |
885 | find_inferior_id (&all_threads, child->head.id); | |
886 | /* For testing only; i386_stop_pc prints out a diagnostic. */ | |
887 | if (the_low_target.get_pc != NULL) | |
888 | get_stop_pc (); | |
889 | current_inferior = saved_inferior; | |
890 | } | |
891 | ||
892 | return child; | |
893 | } | |
894 | ||
895 | /* Wait for an event from child PID. If PID is -1, wait for any | |
896 | child. Store the stop status through the status pointer WSTAT. | |
897 | OPTIONS is passed to the waitpid call. Return 0 if no child stop | |
898 | event was found and OPTIONS contains WNOHANG. Return the PID of | |
899 | the stopped child otherwise. */ | |
900 | ||
901 | static int | |
902 | linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options) | |
903 | { | |
904 | CORE_ADDR stop_pc; | |
905 | struct lwp_info *event_child = NULL; | |
906 | int bp_status; | |
907 | struct lwp_info *requested_child = NULL; | |
908 | ||
909 | /* Check for a lwp with a pending status. */ | |
910 | /* It is possible that the user changed the pending task's registers since | |
911 | it stopped. We correctly handle the change of PC if we hit a breakpoint | |
912 | (in check_removed_breakpoint); signals should be reported anyway. */ | |
913 | ||
914 | if (ptid_equal (ptid, minus_one_ptid) | |
915 | || ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid)) | |
916 | { | |
917 | event_child = (struct lwp_info *) | |
918 | find_inferior (&all_lwps, status_pending_p, &ptid); | |
919 | if (debug_threads && event_child) | |
920 | fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child)); | |
921 | } | |
922 | else | |
923 | { | |
924 | requested_child = find_lwp_pid (ptid); | |
925 | if (requested_child->status_pending_p | |
926 | && !check_removed_breakpoint (requested_child)) | |
927 | event_child = requested_child; | |
928 | } | |
929 | ||
930 | if (event_child != NULL) | |
931 | { | |
932 | if (debug_threads) | |
933 | fprintf (stderr, "Got an event from pending child %ld (%04x)\n", | |
934 | lwpid_of (event_child), event_child->status_pending); | |
935 | *wstat = event_child->status_pending; | |
936 | event_child->status_pending_p = 0; | |
937 | event_child->status_pending = 0; | |
938 | current_inferior = get_lwp_thread (event_child); | |
939 | return lwpid_of (event_child); | |
940 | } | |
941 | ||
942 | /* We only enter this loop if no process has a pending wait status. Thus | |
943 | any action taken in response to a wait status inside this loop is | |
944 | responding as soon as we detect the status, not after any pending | |
945 | events. */ | |
946 | while (1) | |
947 | { | |
948 | event_child = linux_wait_for_lwp (ptid, wstat, options); | |
949 | ||
950 | if ((options & WNOHANG) && event_child == NULL) | |
951 | return 0; | |
952 | ||
953 | if (event_child == NULL) | |
954 | error ("event from unknown child"); | |
955 | ||
956 | current_inferior = get_lwp_thread (event_child); | |
957 | ||
958 | /* Check for thread exit. */ | |
959 | if (! WIFSTOPPED (*wstat)) | |
960 | { | |
961 | if (debug_threads) | |
962 | fprintf (stderr, "LWP %ld exiting\n", lwpid_of (event_child)); | |
963 | ||
964 | /* If the last thread is exiting, just return. */ | |
965 | if (last_thread_of_process_p (current_inferior)) | |
966 | { | |
967 | if (debug_threads) | |
968 | fprintf (stderr, "LWP %ld is last lwp of process\n", | |
969 | lwpid_of (event_child)); | |
970 | return lwpid_of (event_child); | |
971 | } | |
972 | ||
973 | delete_lwp (event_child); | |
974 | ||
975 | if (!non_stop) | |
976 | { | |
977 | current_inferior = (struct thread_info *) all_threads.head; | |
978 | if (debug_threads) | |
979 | fprintf (stderr, "Current inferior is now %ld\n", | |
980 | lwpid_of (get_thread_lwp (current_inferior))); | |
981 | } | |
982 | else | |
983 | { | |
984 | current_inferior = NULL; | |
985 | if (debug_threads) | |
986 | fprintf (stderr, "Current inferior is now <NULL>\n"); | |
987 | } | |
988 | ||
989 | /* If we were waiting for this particular child to do something... | |
990 | well, it did something. */ | |
991 | if (requested_child != NULL) | |
992 | return lwpid_of (event_child); | |
993 | ||
994 | /* Wait for a more interesting event. */ | |
995 | continue; | |
996 | } | |
997 | ||
998 | if (event_child->must_set_ptrace_flags) | |
999 | { | |
1000 | ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child), | |
1001 | 0, PTRACE_O_TRACECLONE); | |
1002 | event_child->must_set_ptrace_flags = 0; | |
1003 | } | |
1004 | ||
1005 | if (WIFSTOPPED (*wstat) | |
1006 | && WSTOPSIG (*wstat) == SIGSTOP | |
1007 | && event_child->stop_expected) | |
1008 | { | |
1009 | if (debug_threads) | |
1010 | fprintf (stderr, "Expected stop.\n"); | |
1011 | event_child->stop_expected = 0; | |
1012 | linux_resume_one_lwp (&event_child->head, | |
1013 | event_child->stepping, 0, NULL); | |
1014 | continue; | |
1015 | } | |
1016 | ||
1017 | if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP | |
1018 | && *wstat >> 16 != 0) | |
1019 | { | |
1020 | handle_extended_wait (event_child, *wstat); | |
1021 | continue; | |
1022 | } | |
1023 | ||
1024 | /* If GDB is not interested in this signal, don't stop other | |
1025 | threads, and don't report it to GDB. Just resume the | |
1026 | inferior right away. We do this for threading-related | |
1027 | signals as well as any that GDB specifically requested we | |
1028 | ignore. But never ignore SIGSTOP if we sent it ourselves, | |
1029 | and do not ignore signals when stepping - they may require | |
1030 | special handling to skip the signal handler. */ | |
1031 | /* FIXME drow/2002-06-09: Get signal numbers from the inferior's | |
1032 | thread library? */ | |
1033 | if (WIFSTOPPED (*wstat) | |
1034 | && !event_child->stepping | |
1035 | && ( | |
1036 | #ifdef USE_THREAD_DB | |
1037 | (current_process ()->private->thread_db_active | |
1038 | && (WSTOPSIG (*wstat) == __SIGRTMIN | |
1039 | || WSTOPSIG (*wstat) == __SIGRTMIN + 1)) | |
1040 | || | |
1041 | #endif | |
1042 | (pass_signals[target_signal_from_host (WSTOPSIG (*wstat))] | |
1043 | && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads)))) | |
1044 | { | |
1045 | siginfo_t info, *info_p; | |
1046 | ||
1047 | if (debug_threads) | |
1048 | fprintf (stderr, "Ignored signal %d for LWP %ld.\n", | |
1049 | WSTOPSIG (*wstat), lwpid_of (event_child)); | |
1050 | ||
1051 | if (ptrace (PTRACE_GETSIGINFO, lwpid_of (event_child), 0, &info) == 0) | |
1052 | info_p = &info; | |
1053 | else | |
1054 | info_p = NULL; | |
1055 | linux_resume_one_lwp (&event_child->head, | |
1056 | event_child->stepping, | |
1057 | WSTOPSIG (*wstat), info_p); | |
1058 | continue; | |
1059 | } | |
1060 | ||
1061 | /* If this event was not handled above, and is not a SIGTRAP, report | |
1062 | it. */ | |
1063 | if (!WIFSTOPPED (*wstat) || WSTOPSIG (*wstat) != SIGTRAP) | |
1064 | return lwpid_of (event_child); | |
1065 | ||
1066 | /* If this target does not support breakpoints, we simply report the | |
1067 | SIGTRAP; it's of no concern to us. */ | |
1068 | if (the_low_target.get_pc == NULL) | |
1069 | return lwpid_of (event_child); | |
1070 | ||
1071 | stop_pc = get_stop_pc (); | |
1072 | ||
1073 | /* bp_reinsert will only be set if we were single-stepping. | |
1074 | Notice that we will resume the process after hitting | |
1075 | a gdbserver breakpoint; single-stepping to/over one | |
1076 | is not supported (yet). */ | |
1077 | if (event_child->bp_reinsert != 0) | |
1078 | { | |
1079 | if (debug_threads) | |
1080 | fprintf (stderr, "Reinserted breakpoint.\n"); | |
1081 | reinsert_breakpoint (event_child->bp_reinsert); | |
1082 | event_child->bp_reinsert = 0; | |
1083 | ||
1084 | /* Clear the single-stepping flag and SIGTRAP as we resume. */ | |
1085 | linux_resume_one_lwp (&event_child->head, 0, 0, NULL); | |
1086 | continue; | |
1087 | } | |
1088 | ||
1089 | bp_status = check_breakpoints (stop_pc); | |
1090 | ||
1091 | if (bp_status != 0) | |
1092 | { | |
1093 | if (debug_threads) | |
1094 | fprintf (stderr, "Hit a gdbserver breakpoint.\n"); | |
1095 | ||
1096 | /* We hit one of our own breakpoints. We mark it as a pending | |
1097 | breakpoint, so that check_removed_breakpoint () will do the PC | |
1098 | adjustment for us at the appropriate time. */ | |
1099 | event_child->pending_is_breakpoint = 1; | |
1100 | event_child->pending_stop_pc = stop_pc; | |
1101 | ||
1102 | /* We may need to put the breakpoint back. We continue in the event | |
1103 | loop instead of simply replacing the breakpoint right away, | |
1104 | in order to not lose signals sent to the thread that hit the | |
1105 | breakpoint. Unfortunately this increases the window where another | |
1106 | thread could sneak past the removed breakpoint. For the current | |
1107 | use of server-side breakpoints (thread creation) this is | |
1108 | acceptable; but it needs to be considered before this breakpoint | |
1109 | mechanism can be used in more general ways. For some breakpoints | |
1110 | it may be necessary to stop all other threads, but that should | |
1111 | be avoided where possible. | |
1112 | ||
1113 | If breakpoint_reinsert_addr is NULL, that means that we can | |
1114 | use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint, | |
1115 | mark it for reinsertion, and single-step. | |
1116 | ||
1117 | Otherwise, call the target function to figure out where we need | |
1118 | our temporary breakpoint, create it, and continue executing this | |
1119 | process. */ | |
1120 | ||
1121 | /* NOTE: we're lifting breakpoints in non-stop mode. This | |
1122 | is currently only used for thread event breakpoints, so | |
1123 | it isn't that bad as long as we have PTRACE_EVENT_CLONE | |
1124 | events. */ | |
1125 | if (bp_status == 2) | |
1126 | /* No need to reinsert. */ | |
1127 | linux_resume_one_lwp (&event_child->head, 0, 0, NULL); | |
1128 | else if (the_low_target.breakpoint_reinsert_addr == NULL) | |
1129 | { | |
1130 | event_child->bp_reinsert = stop_pc; | |
1131 | uninsert_breakpoint (stop_pc); | |
1132 | linux_resume_one_lwp (&event_child->head, 1, 0, NULL); | |
1133 | } | |
1134 | else | |
1135 | { | |
1136 | reinsert_breakpoint_by_bp | |
1137 | (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ()); | |
1138 | linux_resume_one_lwp (&event_child->head, 0, 0, NULL); | |
1139 | } | |
1140 | ||
1141 | continue; | |
1142 | } | |
1143 | ||
1144 | if (debug_threads) | |
1145 | fprintf (stderr, "Hit a non-gdbserver breakpoint.\n"); | |
1146 | ||
1147 | /* If we were single-stepping, we definitely want to report the | |
1148 | SIGTRAP. Although the single-step operation has completed, | |
1149 | do not clear clear the stepping flag yet; we need to check it | |
1150 | in wait_for_sigstop. */ | |
1151 | if (event_child->stepping) | |
1152 | return lwpid_of (event_child); | |
1153 | ||
1154 | /* A SIGTRAP that we can't explain. It may have been a breakpoint. | |
1155 | Check if it is a breakpoint, and if so mark the process information | |
1156 | accordingly. This will handle both the necessary fiddling with the | |
1157 | PC on decr_pc_after_break targets and suppressing extra threads | |
1158 | hitting a breakpoint if two hit it at once and then GDB removes it | |
1159 | after the first is reported. Arguably it would be better to report | |
1160 | multiple threads hitting breakpoints simultaneously, but the current | |
1161 | remote protocol does not allow this. */ | |
1162 | if ((*the_low_target.breakpoint_at) (stop_pc)) | |
1163 | { | |
1164 | event_child->pending_is_breakpoint = 1; | |
1165 | event_child->pending_stop_pc = stop_pc; | |
1166 | } | |
1167 | ||
1168 | return lwpid_of (event_child); | |
1169 | } | |
1170 | ||
1171 | /* NOTREACHED */ | |
1172 | return 0; | |
1173 | } | |
1174 | ||
1175 | static int | |
1176 | linux_wait_for_event (ptid_t ptid, int *wstat, int options) | |
1177 | { | |
1178 | ptid_t wait_ptid; | |
1179 | ||
1180 | if (ptid_is_pid (ptid)) | |
1181 | { | |
1182 | /* A request to wait for a specific tgid. This is not possible | |
1183 | with waitpid, so instead, we wait for any child, and leave | |
1184 | children we're not interested in right now with a pending | |
1185 | status to report later. */ | |
1186 | wait_ptid = minus_one_ptid; | |
1187 | } | |
1188 | else | |
1189 | wait_ptid = ptid; | |
1190 | ||
1191 | while (1) | |
1192 | { | |
1193 | int event_pid; | |
1194 | ||
1195 | event_pid = linux_wait_for_event_1 (wait_ptid, wstat, options); | |
1196 | ||
1197 | if (event_pid > 0 | |
1198 | && ptid_is_pid (ptid) && ptid_get_pid (ptid) != event_pid) | |
1199 | { | |
1200 | struct lwp_info *event_child = find_lwp_pid (pid_to_ptid (event_pid)); | |
1201 | ||
1202 | if (! WIFSTOPPED (*wstat)) | |
1203 | mark_lwp_dead (event_child, *wstat); | |
1204 | else | |
1205 | { | |
1206 | event_child->status_pending_p = 1; | |
1207 | event_child->status_pending = *wstat; | |
1208 | } | |
1209 | } | |
1210 | else | |
1211 | return event_pid; | |
1212 | } | |
1213 | } | |
1214 | ||
1215 | /* Wait for process, returns status. */ | |
1216 | ||
1217 | static ptid_t | |
1218 | linux_wait_1 (ptid_t ptid, | |
1219 | struct target_waitstatus *ourstatus, int target_options) | |
1220 | { | |
1221 | int w; | |
1222 | struct thread_info *thread = NULL; | |
1223 | struct lwp_info *lwp = NULL; | |
1224 | int options; | |
1225 | int pid; | |
1226 | ||
1227 | /* Translate generic target options into linux options. */ | |
1228 | options = __WALL; | |
1229 | if (target_options & TARGET_WNOHANG) | |
1230 | options |= WNOHANG; | |
1231 | ||
1232 | retry: | |
1233 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
1234 | ||
1235 | /* If we were only supposed to resume one thread, only wait for | |
1236 | that thread - if it's still alive. If it died, however - which | |
1237 | can happen if we're coming from the thread death case below - | |
1238 | then we need to make sure we restart the other threads. We could | |
1239 | pick a thread at random or restart all; restarting all is less | |
1240 | arbitrary. */ | |
1241 | if (!non_stop | |
1242 | && !ptid_equal (cont_thread, null_ptid) | |
1243 | && !ptid_equal (cont_thread, minus_one_ptid)) | |
1244 | { | |
1245 | thread = (struct thread_info *) find_inferior_id (&all_threads, | |
1246 | cont_thread); | |
1247 | ||
1248 | /* No stepping, no signal - unless one is pending already, of course. */ | |
1249 | if (thread == NULL) | |
1250 | { | |
1251 | struct thread_resume resume_info; | |
1252 | resume_info.thread = minus_one_ptid; | |
1253 | resume_info.kind = resume_continue; | |
1254 | resume_info.sig = 0; | |
1255 | linux_resume (&resume_info, 1); | |
1256 | } | |
1257 | else | |
1258 | ptid = cont_thread; | |
1259 | } | |
1260 | ||
1261 | pid = linux_wait_for_event (ptid, &w, options); | |
1262 | if (pid == 0) /* only if TARGET_WNOHANG */ | |
1263 | return null_ptid; | |
1264 | ||
1265 | lwp = get_thread_lwp (current_inferior); | |
1266 | ||
1267 | /* If we are waiting for a particular child, and it exited, | |
1268 | linux_wait_for_event will return its exit status. Similarly if | |
1269 | the last child exited. If this is not the last child, however, | |
1270 | do not report it as exited until there is a 'thread exited' response | |
1271 | available in the remote protocol. Instead, just wait for another event. | |
1272 | This should be safe, because if the thread crashed we will already | |
1273 | have reported the termination signal to GDB; that should stop any | |
1274 | in-progress stepping operations, etc. | |
1275 | ||
1276 | Report the exit status of the last thread to exit. This matches | |
1277 | LinuxThreads' behavior. */ | |
1278 | ||
1279 | if (last_thread_of_process_p (current_inferior)) | |
1280 | { | |
1281 | if (WIFEXITED (w) || WIFSIGNALED (w)) | |
1282 | { | |
1283 | int pid = pid_of (lwp); | |
1284 | struct process_info *process = find_process_pid (pid); | |
1285 | ||
1286 | delete_lwp (lwp); | |
1287 | linux_remove_process (process); | |
1288 | ||
1289 | current_inferior = NULL; | |
1290 | ||
1291 | if (WIFEXITED (w)) | |
1292 | { | |
1293 | ourstatus->kind = TARGET_WAITKIND_EXITED; | |
1294 | ourstatus->value.integer = WEXITSTATUS (w); | |
1295 | ||
1296 | if (debug_threads) | |
1297 | fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); | |
1298 | } | |
1299 | else | |
1300 | { | |
1301 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; | |
1302 | ourstatus->value.sig = target_signal_from_host (WTERMSIG (w)); | |
1303 | ||
1304 | if (debug_threads) | |
1305 | fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); | |
1306 | ||
1307 | } | |
1308 | ||
1309 | return pid_to_ptid (pid); | |
1310 | } | |
1311 | } | |
1312 | else | |
1313 | { | |
1314 | if (!WIFSTOPPED (w)) | |
1315 | goto retry; | |
1316 | } | |
1317 | ||
1318 | /* In all-stop, stop all threads. Be careful to only do this if | |
1319 | we're about to report an event to GDB. */ | |
1320 | if (!non_stop) | |
1321 | stop_all_lwps (); | |
1322 | ||
1323 | ourstatus->kind = TARGET_WAITKIND_STOPPED; | |
1324 | ||
1325 | if (lwp->suspended && WSTOPSIG (w) == SIGSTOP) | |
1326 | { | |
1327 | /* A thread that has been requested to stop by GDB with vCont;t, | |
1328 | and it stopped cleanly, so report as SIG0. The use of | |
1329 | SIGSTOP is an implementation detail. */ | |
1330 | ourstatus->value.sig = TARGET_SIGNAL_0; | |
1331 | } | |
1332 | else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP) | |
1333 | { | |
1334 | /* A thread that has been requested to stop by GDB with vCont;t, | |
1335 | but, it stopped for other reasons. Set stop_expected so the | |
1336 | pending SIGSTOP is ignored and the LWP is resumed. */ | |
1337 | lwp->stop_expected = 1; | |
1338 | ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w)); | |
1339 | } | |
1340 | else | |
1341 | { | |
1342 | ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w)); | |
1343 | } | |
1344 | ||
1345 | if (debug_threads) | |
1346 | fprintf (stderr, "linux_wait ret = %s, %d, %d\n", | |
1347 | target_pid_to_str (lwp->head.id), | |
1348 | ourstatus->kind, | |
1349 | ourstatus->value.sig); | |
1350 | ||
1351 | return lwp->head.id; | |
1352 | } | |
1353 | ||
1354 | /* Get rid of any pending event in the pipe. */ | |
1355 | static void | |
1356 | async_file_flush (void) | |
1357 | { | |
1358 | int ret; | |
1359 | char buf; | |
1360 | ||
1361 | do | |
1362 | ret = read (linux_event_pipe[0], &buf, 1); | |
1363 | while (ret >= 0 || (ret == -1 && errno == EINTR)); | |
1364 | } | |
1365 | ||
1366 | /* Put something in the pipe, so the event loop wakes up. */ | |
1367 | static void | |
1368 | async_file_mark (void) | |
1369 | { | |
1370 | int ret; | |
1371 | ||
1372 | async_file_flush (); | |
1373 | ||
1374 | do | |
1375 | ret = write (linux_event_pipe[1], "+", 1); | |
1376 | while (ret == 0 || (ret == -1 && errno == EINTR)); | |
1377 | ||
1378 | /* Ignore EAGAIN. If the pipe is full, the event loop will already | |
1379 | be awakened anyway. */ | |
1380 | } | |
1381 | ||
1382 | static ptid_t | |
1383 | linux_wait (ptid_t ptid, | |
1384 | struct target_waitstatus *ourstatus, int target_options) | |
1385 | { | |
1386 | ptid_t event_ptid; | |
1387 | ||
1388 | if (debug_threads) | |
1389 | fprintf (stderr, "linux_wait: [%s]\n", target_pid_to_str (ptid)); | |
1390 | ||
1391 | /* Flush the async file first. */ | |
1392 | if (target_is_async_p ()) | |
1393 | async_file_flush (); | |
1394 | ||
1395 | event_ptid = linux_wait_1 (ptid, ourstatus, target_options); | |
1396 | ||
1397 | /* If at least one stop was reported, there may be more. A single | |
1398 | SIGCHLD can signal more than one child stop. */ | |
1399 | if (target_is_async_p () | |
1400 | && (target_options & TARGET_WNOHANG) != 0 | |
1401 | && !ptid_equal (event_ptid, null_ptid)) | |
1402 | async_file_mark (); | |
1403 | ||
1404 | return event_ptid; | |
1405 | } | |
1406 | ||
1407 | /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if | |
1408 | thread groups are in use, we need to use tkill. */ | |
1409 | ||
1410 | static int | |
1411 | kill_lwp (unsigned long lwpid, int signo) | |
1412 | { | |
1413 | static int tkill_failed; | |
1414 | ||
1415 | errno = 0; | |
1416 | ||
1417 | #ifdef SYS_tkill | |
1418 | if (!tkill_failed) | |
1419 | { | |
1420 | int ret = syscall (SYS_tkill, lwpid, signo); | |
1421 | if (errno != ENOSYS) | |
1422 | return ret; | |
1423 | errno = 0; | |
1424 | tkill_failed = 1; | |
1425 | } | |
1426 | #endif | |
1427 | ||
1428 | return kill (lwpid, signo); | |
1429 | } | |
1430 | ||
1431 | static void | |
1432 | send_sigstop (struct inferior_list_entry *entry) | |
1433 | { | |
1434 | struct lwp_info *lwp = (struct lwp_info *) entry; | |
1435 | int pid; | |
1436 | ||
1437 | if (lwp->stopped) | |
1438 | return; | |
1439 | ||
1440 | pid = lwpid_of (lwp); | |
1441 | ||
1442 | /* If we already have a pending stop signal for this process, don't | |
1443 | send another. */ | |
1444 | if (lwp->stop_expected) | |
1445 | { | |
1446 | if (debug_threads) | |
1447 | fprintf (stderr, "Have pending sigstop for lwp %d\n", pid); | |
1448 | ||
1449 | /* We clear the stop_expected flag so that wait_for_sigstop | |
1450 | will receive the SIGSTOP event (instead of silently resuming and | |
1451 | waiting again). It'll be reset below. */ | |
1452 | lwp->stop_expected = 0; | |
1453 | return; | |
1454 | } | |
1455 | ||
1456 | if (debug_threads) | |
1457 | fprintf (stderr, "Sending sigstop to lwp %d\n", pid); | |
1458 | ||
1459 | kill_lwp (pid, SIGSTOP); | |
1460 | } | |
1461 | ||
1462 | static void | |
1463 | mark_lwp_dead (struct lwp_info *lwp, int wstat) | |
1464 | { | |
1465 | /* It's dead, really. */ | |
1466 | lwp->dead = 1; | |
1467 | ||
1468 | /* Store the exit status for later. */ | |
1469 | lwp->status_pending_p = 1; | |
1470 | lwp->status_pending = wstat; | |
1471 | ||
1472 | /* So that check_removed_breakpoint doesn't try to figure out if | |
1473 | this is stopped at a breakpoint. */ | |
1474 | lwp->pending_is_breakpoint = 0; | |
1475 | ||
1476 | /* Prevent trying to stop it. */ | |
1477 | lwp->stopped = 1; | |
1478 | ||
1479 | /* No further stops are expected from a dead lwp. */ | |
1480 | lwp->stop_expected = 0; | |
1481 | } | |
1482 | ||
1483 | static void | |
1484 | wait_for_sigstop (struct inferior_list_entry *entry) | |
1485 | { | |
1486 | struct lwp_info *lwp = (struct lwp_info *) entry; | |
1487 | struct thread_info *saved_inferior; | |
1488 | int wstat; | |
1489 | ptid_t saved_tid; | |
1490 | ptid_t ptid; | |
1491 | ||
1492 | if (lwp->stopped) | |
1493 | return; | |
1494 | ||
1495 | saved_inferior = current_inferior; | |
1496 | if (saved_inferior != NULL) | |
1497 | saved_tid = ((struct inferior_list_entry *) saved_inferior)->id; | |
1498 | else | |
1499 | saved_tid = null_ptid; /* avoid bogus unused warning */ | |
1500 | ||
1501 | ptid = lwp->head.id; | |
1502 | ||
1503 | linux_wait_for_event (ptid, &wstat, __WALL); | |
1504 | ||
1505 | /* If we stopped with a non-SIGSTOP signal, save it for later | |
1506 | and record the pending SIGSTOP. If the process exited, just | |
1507 | return. */ | |
1508 | if (WIFSTOPPED (wstat) | |
1509 | && WSTOPSIG (wstat) != SIGSTOP) | |
1510 | { | |
1511 | if (debug_threads) | |
1512 | fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n", | |
1513 | lwpid_of (lwp), wstat); | |
1514 | ||
1515 | /* Do not leave a pending single-step finish to be reported to | |
1516 | the client. The client will give us a new action for this | |
1517 | thread, possibly a continue request --- otherwise, the client | |
1518 | would consider this pending SIGTRAP reported later a spurious | |
1519 | signal. */ | |
1520 | if (WSTOPSIG (wstat) == SIGTRAP | |
1521 | && lwp->stepping | |
1522 | && !linux_stopped_by_watchpoint ()) | |
1523 | { | |
1524 | if (debug_threads) | |
1525 | fprintf (stderr, " single-step SIGTRAP ignored\n"); | |
1526 | } | |
1527 | else | |
1528 | { | |
1529 | lwp->status_pending_p = 1; | |
1530 | lwp->status_pending = wstat; | |
1531 | } | |
1532 | lwp->stop_expected = 1; | |
1533 | } | |
1534 | else if (!WIFSTOPPED (wstat)) | |
1535 | { | |
1536 | if (debug_threads) | |
1537 | fprintf (stderr, "Process %ld exited while stopping LWPs\n", | |
1538 | lwpid_of (lwp)); | |
1539 | ||
1540 | /* Leave this status pending for the next time we're able to | |
1541 | report it. In the mean time, we'll report this lwp as dead | |
1542 | to GDB, so GDB doesn't try to read registers and memory from | |
1543 | it. */ | |
1544 | mark_lwp_dead (lwp, wstat); | |
1545 | } | |
1546 | ||
1547 | if (saved_inferior == NULL || linux_thread_alive (saved_tid)) | |
1548 | current_inferior = saved_inferior; | |
1549 | else | |
1550 | { | |
1551 | if (debug_threads) | |
1552 | fprintf (stderr, "Previously current thread died.\n"); | |
1553 | ||
1554 | if (non_stop) | |
1555 | { | |
1556 | /* We can't change the current inferior behind GDB's back, | |
1557 | otherwise, a subsequent command may apply to the wrong | |
1558 | process. */ | |
1559 | current_inferior = NULL; | |
1560 | } | |
1561 | else | |
1562 | { | |
1563 | /* Set a valid thread as current. */ | |
1564 | set_desired_inferior (0); | |
1565 | } | |
1566 | } | |
1567 | } | |
1568 | ||
1569 | static void | |
1570 | stop_all_lwps (void) | |
1571 | { | |
1572 | stopping_threads = 1; | |
1573 | for_each_inferior (&all_lwps, send_sigstop); | |
1574 | for_each_inferior (&all_lwps, wait_for_sigstop); | |
1575 | stopping_threads = 0; | |
1576 | } | |
1577 | ||
1578 | /* Resume execution of the inferior process. | |
1579 | If STEP is nonzero, single-step it. | |
1580 | If SIGNAL is nonzero, give it that signal. */ | |
1581 | ||
1582 | static void | |
1583 | linux_resume_one_lwp (struct inferior_list_entry *entry, | |
1584 | int step, int signal, siginfo_t *info) | |
1585 | { | |
1586 | struct lwp_info *lwp = (struct lwp_info *) entry; | |
1587 | struct thread_info *saved_inferior; | |
1588 | ||
1589 | if (lwp->stopped == 0) | |
1590 | return; | |
1591 | ||
1592 | /* If we have pending signals or status, and a new signal, enqueue the | |
1593 | signal. Also enqueue the signal if we are waiting to reinsert a | |
1594 | breakpoint; it will be picked up again below. */ | |
1595 | if (signal != 0 | |
1596 | && (lwp->status_pending_p || lwp->pending_signals != NULL | |
1597 | || lwp->bp_reinsert != 0)) | |
1598 | { | |
1599 | struct pending_signals *p_sig; | |
1600 | p_sig = xmalloc (sizeof (*p_sig)); | |
1601 | p_sig->prev = lwp->pending_signals; | |
1602 | p_sig->signal = signal; | |
1603 | if (info == NULL) | |
1604 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
1605 | else | |
1606 | memcpy (&p_sig->info, info, sizeof (siginfo_t)); | |
1607 | lwp->pending_signals = p_sig; | |
1608 | } | |
1609 | ||
1610 | if (lwp->status_pending_p && !check_removed_breakpoint (lwp)) | |
1611 | return; | |
1612 | ||
1613 | saved_inferior = current_inferior; | |
1614 | current_inferior = get_lwp_thread (lwp); | |
1615 | ||
1616 | if (debug_threads) | |
1617 | fprintf (stderr, "Resuming lwp %ld (%s, signal %d, stop %s)\n", | |
1618 | lwpid_of (lwp), step ? "step" : "continue", signal, | |
1619 | lwp->stop_expected ? "expected" : "not expected"); | |
1620 | ||
1621 | /* This bit needs some thinking about. If we get a signal that | |
1622 | we must report while a single-step reinsert is still pending, | |
1623 | we often end up resuming the thread. It might be better to | |
1624 | (ew) allow a stack of pending events; then we could be sure that | |
1625 | the reinsert happened right away and not lose any signals. | |
1626 | ||
1627 | Making this stack would also shrink the window in which breakpoints are | |
1628 | uninserted (see comment in linux_wait_for_lwp) but not enough for | |
1629 | complete correctness, so it won't solve that problem. It may be | |
1630 | worthwhile just to solve this one, however. */ | |
1631 | if (lwp->bp_reinsert != 0) | |
1632 | { | |
1633 | if (debug_threads) | |
1634 | fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert); | |
1635 | if (step == 0) | |
1636 | fprintf (stderr, "BAD - reinserting but not stepping.\n"); | |
1637 | step = 1; | |
1638 | ||
1639 | /* Postpone any pending signal. It was enqueued above. */ | |
1640 | signal = 0; | |
1641 | } | |
1642 | ||
1643 | check_removed_breakpoint (lwp); | |
1644 | ||
1645 | if (debug_threads && the_low_target.get_pc != NULL) | |
1646 | { | |
1647 | fprintf (stderr, " "); | |
1648 | (*the_low_target.get_pc) (); | |
1649 | } | |
1650 | ||
1651 | /* If we have pending signals, consume one unless we are trying to reinsert | |
1652 | a breakpoint. */ | |
1653 | if (lwp->pending_signals != NULL && lwp->bp_reinsert == 0) | |
1654 | { | |
1655 | struct pending_signals **p_sig; | |
1656 | ||
1657 | p_sig = &lwp->pending_signals; | |
1658 | while ((*p_sig)->prev != NULL) | |
1659 | p_sig = &(*p_sig)->prev; | |
1660 | ||
1661 | signal = (*p_sig)->signal; | |
1662 | if ((*p_sig)->info.si_signo != 0) | |
1663 | ptrace (PTRACE_SETSIGINFO, lwpid_of (lwp), 0, &(*p_sig)->info); | |
1664 | ||
1665 | free (*p_sig); | |
1666 | *p_sig = NULL; | |
1667 | } | |
1668 | ||
1669 | regcache_invalidate_one ((struct inferior_list_entry *) | |
1670 | get_lwp_thread (lwp)); | |
1671 | errno = 0; | |
1672 | lwp->stopped = 0; | |
1673 | lwp->stepping = step; | |
1674 | ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, signal); | |
1675 | ||
1676 | current_inferior = saved_inferior; | |
1677 | if (errno) | |
1678 | { | |
1679 | /* ESRCH from ptrace either means that the thread was already | |
1680 | running (an error) or that it is gone (a race condition). If | |
1681 | it's gone, we will get a notification the next time we wait, | |
1682 | so we can ignore the error. We could differentiate these | |
1683 | two, but it's tricky without waiting; the thread still exists | |
1684 | as a zombie, so sending it signal 0 would succeed. So just | |
1685 | ignore ESRCH. */ | |
1686 | if (errno == ESRCH) | |
1687 | return; | |
1688 | ||
1689 | perror_with_name ("ptrace"); | |
1690 | } | |
1691 | } | |
1692 | ||
1693 | struct thread_resume_array | |
1694 | { | |
1695 | struct thread_resume *resume; | |
1696 | size_t n; | |
1697 | }; | |
1698 | ||
1699 | /* This function is called once per thread. We look up the thread | |
1700 | in RESUME_PTR, and mark the thread with a pointer to the appropriate | |
1701 | resume request. | |
1702 | ||
1703 | This algorithm is O(threads * resume elements), but resume elements | |
1704 | is small (and will remain small at least until GDB supports thread | |
1705 | suspension). */ | |
1706 | static int | |
1707 | linux_set_resume_request (struct inferior_list_entry *entry, void *arg) | |
1708 | { | |
1709 | struct lwp_info *lwp; | |
1710 | struct thread_info *thread; | |
1711 | int ndx; | |
1712 | struct thread_resume_array *r; | |
1713 | ||
1714 | thread = (struct thread_info *) entry; | |
1715 | lwp = get_thread_lwp (thread); | |
1716 | r = arg; | |
1717 | ||
1718 | for (ndx = 0; ndx < r->n; ndx++) | |
1719 | { | |
1720 | ptid_t ptid = r->resume[ndx].thread; | |
1721 | if (ptid_equal (ptid, minus_one_ptid) | |
1722 | || ptid_equal (ptid, entry->id) | |
1723 | || (ptid_is_pid (ptid) | |
1724 | && (ptid_get_pid (ptid) == pid_of (lwp))) | |
1725 | || (ptid_get_lwp (ptid) == -1 | |
1726 | && (ptid_get_pid (ptid) == pid_of (lwp)))) | |
1727 | { | |
1728 | lwp->resume = &r->resume[ndx]; | |
1729 | return 0; | |
1730 | } | |
1731 | } | |
1732 | ||
1733 | /* No resume action for this thread. */ | |
1734 | lwp->resume = NULL; | |
1735 | ||
1736 | return 0; | |
1737 | } | |
1738 | ||
1739 | ||
1740 | /* Set *FLAG_P if this lwp has an interesting status pending. */ | |
1741 | static int | |
1742 | resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p) | |
1743 | { | |
1744 | struct lwp_info *lwp = (struct lwp_info *) entry; | |
1745 | ||
1746 | /* LWPs which will not be resumed are not interesting, because | |
1747 | we might not wait for them next time through linux_wait. */ | |
1748 | if (lwp->resume == NULL) | |
1749 | return 0; | |
1750 | ||
1751 | /* If this thread has a removed breakpoint, we won't have any | |
1752 | events to report later, so check now. check_removed_breakpoint | |
1753 | may clear status_pending_p. We avoid calling check_removed_breakpoint | |
1754 | for any thread that we are not otherwise going to resume - this | |
1755 | lets us preserve stopped status when two threads hit a breakpoint. | |
1756 | GDB removes the breakpoint to single-step a particular thread | |
1757 | past it, then re-inserts it and resumes all threads. We want | |
1758 | to report the second thread without resuming it in the interim. */ | |
1759 | if (lwp->status_pending_p) | |
1760 | check_removed_breakpoint (lwp); | |
1761 | ||
1762 | if (lwp->status_pending_p) | |
1763 | * (int *) flag_p = 1; | |
1764 | ||
1765 | return 0; | |
1766 | } | |
1767 | ||
1768 | /* This function is called once per thread. We check the thread's resume | |
1769 | request, which will tell us whether to resume, step, or leave the thread | |
1770 | stopped; and what signal, if any, it should be sent. | |
1771 | ||
1772 | For threads which we aren't explicitly told otherwise, we preserve | |
1773 | the stepping flag; this is used for stepping over gdbserver-placed | |
1774 | breakpoints. | |
1775 | ||
1776 | If pending_flags was set in any thread, we queue any needed | |
1777 | signals, since we won't actually resume. We already have a pending | |
1778 | event to report, so we don't need to preserve any step requests; | |
1779 | they should be re-issued if necessary. */ | |
1780 | ||
1781 | static int | |
1782 | linux_resume_one_thread (struct inferior_list_entry *entry, void *arg) | |
1783 | { | |
1784 | struct lwp_info *lwp; | |
1785 | struct thread_info *thread; | |
1786 | int step; | |
1787 | int pending_flag = * (int *) arg; | |
1788 | ||
1789 | thread = (struct thread_info *) entry; | |
1790 | lwp = get_thread_lwp (thread); | |
1791 | ||
1792 | if (lwp->resume == NULL) | |
1793 | return 0; | |
1794 | ||
1795 | if (lwp->resume->kind == resume_stop) | |
1796 | { | |
1797 | if (debug_threads) | |
1798 | fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp)); | |
1799 | ||
1800 | if (!lwp->stopped) | |
1801 | { | |
1802 | if (debug_threads) | |
1803 | fprintf (stderr, "running -> suspending LWP %ld\n", lwpid_of (lwp)); | |
1804 | ||
1805 | lwp->suspended = 1; | |
1806 | send_sigstop (&lwp->head); | |
1807 | } | |
1808 | else | |
1809 | { | |
1810 | if (debug_threads) | |
1811 | { | |
1812 | if (lwp->suspended) | |
1813 | fprintf (stderr, "already stopped/suspended LWP %ld\n", | |
1814 | lwpid_of (lwp)); | |
1815 | else | |
1816 | fprintf (stderr, "already stopped/not suspended LWP %ld\n", | |
1817 | lwpid_of (lwp)); | |
1818 | } | |
1819 | ||
1820 | /* Make sure we leave the LWP suspended, so we don't try to | |
1821 | resume it without GDB telling us to. FIXME: The LWP may | |
1822 | have been stopped in an internal event that was not meant | |
1823 | to be notified back to GDB (e.g., gdbserver breakpoint), | |
1824 | so we should be reporting a stop event in that case | |
1825 | too. */ | |
1826 | lwp->suspended = 1; | |
1827 | } | |
1828 | ||
1829 | /* For stop requests, we're done. */ | |
1830 | lwp->resume = NULL; | |
1831 | return 0; | |
1832 | } | |
1833 | else | |
1834 | lwp->suspended = 0; | |
1835 | ||
1836 | /* If this thread which is about to be resumed has a pending status, | |
1837 | then don't resume any threads - we can just report the pending | |
1838 | status. Make sure to queue any signals that would otherwise be | |
1839 | sent. In all-stop mode, we do this decision based on if *any* | |
1840 | thread has a pending status. */ | |
1841 | if (non_stop) | |
1842 | resume_status_pending_p (&lwp->head, &pending_flag); | |
1843 | ||
1844 | if (!pending_flag) | |
1845 | { | |
1846 | if (debug_threads) | |
1847 | fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp)); | |
1848 | ||
1849 | if (ptid_equal (lwp->resume->thread, minus_one_ptid) | |
1850 | && lwp->stepping | |
1851 | && lwp->pending_is_breakpoint) | |
1852 | step = 1; | |
1853 | else | |
1854 | step = (lwp->resume->kind == resume_step); | |
1855 | ||
1856 | linux_resume_one_lwp (&lwp->head, step, lwp->resume->sig, NULL); | |
1857 | } | |
1858 | else | |
1859 | { | |
1860 | if (debug_threads) | |
1861 | fprintf (stderr, "leaving LWP %ld stopped\n", lwpid_of (lwp)); | |
1862 | ||
1863 | /* If we have a new signal, enqueue the signal. */ | |
1864 | if (lwp->resume->sig != 0) | |
1865 | { | |
1866 | struct pending_signals *p_sig; | |
1867 | p_sig = xmalloc (sizeof (*p_sig)); | |
1868 | p_sig->prev = lwp->pending_signals; | |
1869 | p_sig->signal = lwp->resume->sig; | |
1870 | memset (&p_sig->info, 0, sizeof (siginfo_t)); | |
1871 | ||
1872 | /* If this is the same signal we were previously stopped by, | |
1873 | make sure to queue its siginfo. We can ignore the return | |
1874 | value of ptrace; if it fails, we'll skip | |
1875 | PTRACE_SETSIGINFO. */ | |
1876 | if (WIFSTOPPED (lwp->last_status) | |
1877 | && WSTOPSIG (lwp->last_status) == lwp->resume->sig) | |
1878 | ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &p_sig->info); | |
1879 | ||
1880 | lwp->pending_signals = p_sig; | |
1881 | } | |
1882 | } | |
1883 | ||
1884 | lwp->resume = NULL; | |
1885 | return 0; | |
1886 | } | |
1887 | ||
1888 | static void | |
1889 | linux_resume (struct thread_resume *resume_info, size_t n) | |
1890 | { | |
1891 | int pending_flag; | |
1892 | struct thread_resume_array array = { resume_info, n }; | |
1893 | ||
1894 | find_inferior (&all_threads, linux_set_resume_request, &array); | |
1895 | ||
1896 | /* If there is a thread which would otherwise be resumed, which | |
1897 | has a pending status, then don't resume any threads - we can just | |
1898 | report the pending status. Make sure to queue any signals | |
1899 | that would otherwise be sent. In non-stop mode, we'll apply this | |
1900 | logic to each thread individually. */ | |
1901 | pending_flag = 0; | |
1902 | if (!non_stop) | |
1903 | find_inferior (&all_lwps, resume_status_pending_p, &pending_flag); | |
1904 | ||
1905 | if (debug_threads) | |
1906 | { | |
1907 | if (pending_flag) | |
1908 | fprintf (stderr, "Not resuming, pending status\n"); | |
1909 | else | |
1910 | fprintf (stderr, "Resuming, no pending status\n"); | |
1911 | } | |
1912 | ||
1913 | find_inferior (&all_threads, linux_resume_one_thread, &pending_flag); | |
1914 | } | |
1915 | ||
1916 | #ifdef HAVE_LINUX_USRREGS | |
1917 | ||
1918 | int | |
1919 | register_addr (int regnum) | |
1920 | { | |
1921 | int addr; | |
1922 | ||
1923 | if (regnum < 0 || regnum >= the_low_target.num_regs) | |
1924 | error ("Invalid register number %d.", regnum); | |
1925 | ||
1926 | addr = the_low_target.regmap[regnum]; | |
1927 | ||
1928 | return addr; | |
1929 | } | |
1930 | ||
1931 | /* Fetch one register. */ | |
1932 | static void | |
1933 | fetch_register (int regno) | |
1934 | { | |
1935 | CORE_ADDR regaddr; | |
1936 | int i, size; | |
1937 | char *buf; | |
1938 | int pid; | |
1939 | ||
1940 | if (regno >= the_low_target.num_regs) | |
1941 | return; | |
1942 | if ((*the_low_target.cannot_fetch_register) (regno)) | |
1943 | return; | |
1944 | ||
1945 | regaddr = register_addr (regno); | |
1946 | if (regaddr == -1) | |
1947 | return; | |
1948 | ||
1949 | pid = lwpid_of (get_thread_lwp (current_inferior)); | |
1950 | size = ((register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) | |
1951 | & - sizeof (PTRACE_XFER_TYPE)); | |
1952 | buf = alloca (size); | |
1953 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
1954 | { | |
1955 | errno = 0; | |
1956 | *(PTRACE_XFER_TYPE *) (buf + i) = | |
1957 | ptrace (PTRACE_PEEKUSER, pid, (PTRACE_ARG3_TYPE) regaddr, 0); | |
1958 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
1959 | if (errno != 0) | |
1960 | { | |
1961 | /* Warning, not error, in case we are attached; sometimes the | |
1962 | kernel doesn't let us at the registers. */ | |
1963 | char *err = strerror (errno); | |
1964 | char *msg = alloca (strlen (err) + 128); | |
1965 | sprintf (msg, "reading register %d: %s", regno, err); | |
1966 | error (msg); | |
1967 | goto error_exit; | |
1968 | } | |
1969 | } | |
1970 | ||
1971 | if (the_low_target.supply_ptrace_register) | |
1972 | the_low_target.supply_ptrace_register (regno, buf); | |
1973 | else | |
1974 | supply_register (regno, buf); | |
1975 | ||
1976 | error_exit:; | |
1977 | } | |
1978 | ||
1979 | /* Fetch all registers, or just one, from the child process. */ | |
1980 | static void | |
1981 | usr_fetch_inferior_registers (int regno) | |
1982 | { | |
1983 | if (regno == -1 || regno == 0) | |
1984 | for (regno = 0; regno < the_low_target.num_regs; regno++) | |
1985 | fetch_register (regno); | |
1986 | else | |
1987 | fetch_register (regno); | |
1988 | } | |
1989 | ||
1990 | /* Store our register values back into the inferior. | |
1991 | If REGNO is -1, do this for all registers. | |
1992 | Otherwise, REGNO specifies which register (so we can save time). */ | |
1993 | static void | |
1994 | usr_store_inferior_registers (int regno) | |
1995 | { | |
1996 | CORE_ADDR regaddr; | |
1997 | int i, size; | |
1998 | char *buf; | |
1999 | int pid; | |
2000 | ||
2001 | if (regno >= 0) | |
2002 | { | |
2003 | if (regno >= the_low_target.num_regs) | |
2004 | return; | |
2005 | ||
2006 | if ((*the_low_target.cannot_store_register) (regno) == 1) | |
2007 | return; | |
2008 | ||
2009 | regaddr = register_addr (regno); | |
2010 | if (regaddr == -1) | |
2011 | return; | |
2012 | errno = 0; | |
2013 | size = (register_size (regno) + sizeof (PTRACE_XFER_TYPE) - 1) | |
2014 | & - sizeof (PTRACE_XFER_TYPE); | |
2015 | buf = alloca (size); | |
2016 | memset (buf, 0, size); | |
2017 | ||
2018 | if (the_low_target.collect_ptrace_register) | |
2019 | the_low_target.collect_ptrace_register (regno, buf); | |
2020 | else | |
2021 | collect_register (regno, buf); | |
2022 | ||
2023 | pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2024 | for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE)) | |
2025 | { | |
2026 | errno = 0; | |
2027 | ptrace (PTRACE_POKEUSER, pid, (PTRACE_ARG3_TYPE) regaddr, | |
2028 | *(PTRACE_XFER_TYPE *) (buf + i)); | |
2029 | if (errno != 0) | |
2030 | { | |
2031 | /* At this point, ESRCH should mean the process is | |
2032 | already gone, in which case we simply ignore attempts | |
2033 | to change its registers. See also the related | |
2034 | comment in linux_resume_one_lwp. */ | |
2035 | if (errno == ESRCH) | |
2036 | return; | |
2037 | ||
2038 | if ((*the_low_target.cannot_store_register) (regno) == 0) | |
2039 | { | |
2040 | char *err = strerror (errno); | |
2041 | char *msg = alloca (strlen (err) + 128); | |
2042 | sprintf (msg, "writing register %d: %s", | |
2043 | regno, err); | |
2044 | error (msg); | |
2045 | return; | |
2046 | } | |
2047 | } | |
2048 | regaddr += sizeof (PTRACE_XFER_TYPE); | |
2049 | } | |
2050 | } | |
2051 | else | |
2052 | for (regno = 0; regno < the_low_target.num_regs; regno++) | |
2053 | usr_store_inferior_registers (regno); | |
2054 | } | |
2055 | #endif /* HAVE_LINUX_USRREGS */ | |
2056 | ||
2057 | ||
2058 | ||
2059 | #ifdef HAVE_LINUX_REGSETS | |
2060 | ||
2061 | static int | |
2062 | regsets_fetch_inferior_registers () | |
2063 | { | |
2064 | struct regset_info *regset; | |
2065 | int saw_general_regs = 0; | |
2066 | int pid; | |
2067 | ||
2068 | regset = target_regsets; | |
2069 | ||
2070 | pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2071 | while (regset->size >= 0) | |
2072 | { | |
2073 | void *buf; | |
2074 | int res; | |
2075 | ||
2076 | if (regset->size == 0 || disabled_regsets[regset - target_regsets]) | |
2077 | { | |
2078 | regset ++; | |
2079 | continue; | |
2080 | } | |
2081 | ||
2082 | buf = xmalloc (regset->size); | |
2083 | #ifndef __sparc__ | |
2084 | res = ptrace (regset->get_request, pid, 0, buf); | |
2085 | #else | |
2086 | res = ptrace (regset->get_request, pid, buf, 0); | |
2087 | #endif | |
2088 | if (res < 0) | |
2089 | { | |
2090 | if (errno == EIO) | |
2091 | { | |
2092 | /* If we get EIO on a regset, do not try it again for | |
2093 | this process. */ | |
2094 | disabled_regsets[regset - target_regsets] = 1; | |
2095 | continue; | |
2096 | } | |
2097 | else | |
2098 | { | |
2099 | char s[256]; | |
2100 | sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", | |
2101 | pid); | |
2102 | perror (s); | |
2103 | } | |
2104 | } | |
2105 | else if (regset->type == GENERAL_REGS) | |
2106 | saw_general_regs = 1; | |
2107 | regset->store_function (buf); | |
2108 | regset ++; | |
2109 | } | |
2110 | if (saw_general_regs) | |
2111 | return 0; | |
2112 | else | |
2113 | return 1; | |
2114 | } | |
2115 | ||
2116 | static int | |
2117 | regsets_store_inferior_registers () | |
2118 | { | |
2119 | struct regset_info *regset; | |
2120 | int saw_general_regs = 0; | |
2121 | int pid; | |
2122 | ||
2123 | regset = target_regsets; | |
2124 | ||
2125 | pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2126 | while (regset->size >= 0) | |
2127 | { | |
2128 | void *buf; | |
2129 | int res; | |
2130 | ||
2131 | if (regset->size == 0 || disabled_regsets[regset - target_regsets]) | |
2132 | { | |
2133 | regset ++; | |
2134 | continue; | |
2135 | } | |
2136 | ||
2137 | buf = xmalloc (regset->size); | |
2138 | ||
2139 | /* First fill the buffer with the current register set contents, | |
2140 | in case there are any items in the kernel's regset that are | |
2141 | not in gdbserver's regcache. */ | |
2142 | #ifndef __sparc__ | |
2143 | res = ptrace (regset->get_request, pid, 0, buf); | |
2144 | #else | |
2145 | res = ptrace (regset->get_request, pid, buf, 0); | |
2146 | #endif | |
2147 | ||
2148 | if (res == 0) | |
2149 | { | |
2150 | /* Then overlay our cached registers on that. */ | |
2151 | regset->fill_function (buf); | |
2152 | ||
2153 | /* Only now do we write the register set. */ | |
2154 | #ifndef __sparc__ | |
2155 | res = ptrace (regset->set_request, pid, 0, buf); | |
2156 | #else | |
2157 | res = ptrace (regset->set_request, pid, buf, 0); | |
2158 | #endif | |
2159 | } | |
2160 | ||
2161 | if (res < 0) | |
2162 | { | |
2163 | if (errno == EIO) | |
2164 | { | |
2165 | /* If we get EIO on a regset, do not try it again for | |
2166 | this process. */ | |
2167 | disabled_regsets[regset - target_regsets] = 1; | |
2168 | continue; | |
2169 | } | |
2170 | else if (errno == ESRCH) | |
2171 | { | |
2172 | /* At this point, ESRCH should mean the process is | |
2173 | already gone, in which case we simply ignore attempts | |
2174 | to change its registers. See also the related | |
2175 | comment in linux_resume_one_lwp. */ | |
2176 | return 0; | |
2177 | } | |
2178 | else | |
2179 | { | |
2180 | perror ("Warning: ptrace(regsets_store_inferior_registers)"); | |
2181 | } | |
2182 | } | |
2183 | else if (regset->type == GENERAL_REGS) | |
2184 | saw_general_regs = 1; | |
2185 | regset ++; | |
2186 | free (buf); | |
2187 | } | |
2188 | if (saw_general_regs) | |
2189 | return 0; | |
2190 | else | |
2191 | return 1; | |
2192 | return 0; | |
2193 | } | |
2194 | ||
2195 | #endif /* HAVE_LINUX_REGSETS */ | |
2196 | ||
2197 | ||
2198 | void | |
2199 | linux_fetch_registers (int regno) | |
2200 | { | |
2201 | #ifdef HAVE_LINUX_REGSETS | |
2202 | if (regsets_fetch_inferior_registers () == 0) | |
2203 | return; | |
2204 | #endif | |
2205 | #ifdef HAVE_LINUX_USRREGS | |
2206 | usr_fetch_inferior_registers (regno); | |
2207 | #endif | |
2208 | } | |
2209 | ||
2210 | void | |
2211 | linux_store_registers (int regno) | |
2212 | { | |
2213 | #ifdef HAVE_LINUX_REGSETS | |
2214 | if (regsets_store_inferior_registers () == 0) | |
2215 | return; | |
2216 | #endif | |
2217 | #ifdef HAVE_LINUX_USRREGS | |
2218 | usr_store_inferior_registers (regno); | |
2219 | #endif | |
2220 | } | |
2221 | ||
2222 | ||
2223 | /* Copy LEN bytes from inferior's memory starting at MEMADDR | |
2224 | to debugger memory starting at MYADDR. */ | |
2225 | ||
2226 | static int | |
2227 | linux_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) | |
2228 | { | |
2229 | register int i; | |
2230 | /* Round starting address down to longword boundary. */ | |
2231 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
2232 | /* Round ending address up; get number of longwords that makes. */ | |
2233 | register int count | |
2234 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) | |
2235 | / sizeof (PTRACE_XFER_TYPE); | |
2236 | /* Allocate buffer of that many longwords. */ | |
2237 | register PTRACE_XFER_TYPE *buffer | |
2238 | = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
2239 | int fd; | |
2240 | char filename[64]; | |
2241 | int pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2242 | ||
2243 | /* Try using /proc. Don't bother for one word. */ | |
2244 | if (len >= 3 * sizeof (long)) | |
2245 | { | |
2246 | /* We could keep this file open and cache it - possibly one per | |
2247 | thread. That requires some juggling, but is even faster. */ | |
2248 | sprintf (filename, "/proc/%d/mem", pid); | |
2249 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
2250 | if (fd == -1) | |
2251 | goto no_proc; | |
2252 | ||
2253 | /* If pread64 is available, use it. It's faster if the kernel | |
2254 | supports it (only one syscall), and it's 64-bit safe even on | |
2255 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
2256 | application). */ | |
2257 | #ifdef HAVE_PREAD64 | |
2258 | if (pread64 (fd, myaddr, len, memaddr) != len) | |
2259 | #else | |
2260 | if (lseek (fd, memaddr, SEEK_SET) == -1 || read (fd, memaddr, len) != len) | |
2261 | #endif | |
2262 | { | |
2263 | close (fd); | |
2264 | goto no_proc; | |
2265 | } | |
2266 | ||
2267 | close (fd); | |
2268 | return 0; | |
2269 | } | |
2270 | ||
2271 | no_proc: | |
2272 | /* Read all the longwords */ | |
2273 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
2274 | { | |
2275 | errno = 0; | |
2276 | buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0); | |
2277 | if (errno) | |
2278 | return errno; | |
2279 | } | |
2280 | ||
2281 | /* Copy appropriate bytes out of the buffer. */ | |
2282 | memcpy (myaddr, | |
2283 | (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), | |
2284 | len); | |
2285 | ||
2286 | return 0; | |
2287 | } | |
2288 | ||
2289 | /* Copy LEN bytes of data from debugger memory at MYADDR | |
2290 | to inferior's memory at MEMADDR. | |
2291 | On failure (cannot write the inferior) | |
2292 | returns the value of errno. */ | |
2293 | ||
2294 | static int | |
2295 | linux_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len) | |
2296 | { | |
2297 | register int i; | |
2298 | /* Round starting address down to longword boundary. */ | |
2299 | register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); | |
2300 | /* Round ending address up; get number of longwords that makes. */ | |
2301 | register int count | |
2302 | = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); | |
2303 | /* Allocate buffer of that many longwords. */ | |
2304 | register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); | |
2305 | int pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2306 | ||
2307 | if (debug_threads) | |
2308 | { | |
2309 | fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr); | |
2310 | } | |
2311 | ||
2312 | /* Fill start and end extra bytes of buffer with existing memory data. */ | |
2313 | ||
2314 | buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0); | |
2315 | ||
2316 | if (count > 1) | |
2317 | { | |
2318 | buffer[count - 1] | |
2319 | = ptrace (PTRACE_PEEKTEXT, pid, | |
2320 | (PTRACE_ARG3_TYPE) (addr + (count - 1) | |
2321 | * sizeof (PTRACE_XFER_TYPE)), | |
2322 | 0); | |
2323 | } | |
2324 | ||
2325 | /* Copy data to be written over corresponding part of buffer */ | |
2326 | ||
2327 | memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); | |
2328 | ||
2329 | /* Write the entire buffer. */ | |
2330 | ||
2331 | for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) | |
2332 | { | |
2333 | errno = 0; | |
2334 | ptrace (PTRACE_POKETEXT, pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); | |
2335 | if (errno) | |
2336 | return errno; | |
2337 | } | |
2338 | ||
2339 | return 0; | |
2340 | } | |
2341 | ||
2342 | static int linux_supports_tracefork_flag; | |
2343 | ||
2344 | /* Helper functions for linux_test_for_tracefork, called via clone (). */ | |
2345 | ||
2346 | static int | |
2347 | linux_tracefork_grandchild (void *arg) | |
2348 | { | |
2349 | _exit (0); | |
2350 | } | |
2351 | ||
2352 | #define STACK_SIZE 4096 | |
2353 | ||
2354 | static int | |
2355 | linux_tracefork_child (void *arg) | |
2356 | { | |
2357 | ptrace (PTRACE_TRACEME, 0, 0, 0); | |
2358 | kill (getpid (), SIGSTOP); | |
2359 | #ifdef __ia64__ | |
2360 | __clone2 (linux_tracefork_grandchild, arg, STACK_SIZE, | |
2361 | CLONE_VM | SIGCHLD, NULL); | |
2362 | #else | |
2363 | clone (linux_tracefork_grandchild, arg + STACK_SIZE, | |
2364 | CLONE_VM | SIGCHLD, NULL); | |
2365 | #endif | |
2366 | _exit (0); | |
2367 | } | |
2368 | ||
2369 | /* Wrapper function for waitpid which handles EINTR, and emulates | |
2370 | __WALL for systems where that is not available. */ | |
2371 | ||
2372 | static int | |
2373 | my_waitpid (int pid, int *status, int flags) | |
2374 | { | |
2375 | int ret, out_errno; | |
2376 | ||
2377 | if (debug_threads) | |
2378 | fprintf (stderr, "my_waitpid (%d, 0x%x)\n", pid, flags); | |
2379 | ||
2380 | if (flags & __WALL) | |
2381 | { | |
2382 | sigset_t block_mask, org_mask, wake_mask; | |
2383 | int wnohang; | |
2384 | ||
2385 | wnohang = (flags & WNOHANG) != 0; | |
2386 | flags &= ~(__WALL | __WCLONE); | |
2387 | flags |= WNOHANG; | |
2388 | ||
2389 | /* Block all signals while here. This avoids knowing about | |
2390 | LinuxThread's signals. */ | |
2391 | sigfillset (&block_mask); | |
2392 | sigprocmask (SIG_BLOCK, &block_mask, &org_mask); | |
2393 | ||
2394 | /* ... except during the sigsuspend below. */ | |
2395 | sigemptyset (&wake_mask); | |
2396 | ||
2397 | while (1) | |
2398 | { | |
2399 | /* Since all signals are blocked, there's no need to check | |
2400 | for EINTR here. */ | |
2401 | ret = waitpid (pid, status, flags); | |
2402 | out_errno = errno; | |
2403 | ||
2404 | if (ret == -1 && out_errno != ECHILD) | |
2405 | break; | |
2406 | else if (ret > 0) | |
2407 | break; | |
2408 | ||
2409 | if (flags & __WCLONE) | |
2410 | { | |
2411 | /* We've tried both flavors now. If WNOHANG is set, | |
2412 | there's nothing else to do, just bail out. */ | |
2413 | if (wnohang) | |
2414 | break; | |
2415 | ||
2416 | if (debug_threads) | |
2417 | fprintf (stderr, "blocking\n"); | |
2418 | ||
2419 | /* Block waiting for signals. */ | |
2420 | sigsuspend (&wake_mask); | |
2421 | } | |
2422 | ||
2423 | flags ^= __WCLONE; | |
2424 | } | |
2425 | ||
2426 | sigprocmask (SIG_SETMASK, &org_mask, NULL); | |
2427 | } | |
2428 | else | |
2429 | { | |
2430 | do | |
2431 | ret = waitpid (pid, status, flags); | |
2432 | while (ret == -1 && errno == EINTR); | |
2433 | out_errno = errno; | |
2434 | } | |
2435 | ||
2436 | if (debug_threads) | |
2437 | fprintf (stderr, "my_waitpid (%d, 0x%x): status(%x), %d\n", | |
2438 | pid, flags, status ? *status : -1, ret); | |
2439 | ||
2440 | errno = out_errno; | |
2441 | return ret; | |
2442 | } | |
2443 | ||
2444 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make | |
2445 | sure that we can enable the option, and that it had the desired | |
2446 | effect. */ | |
2447 | ||
2448 | static void | |
2449 | linux_test_for_tracefork (void) | |
2450 | { | |
2451 | int child_pid, ret, status; | |
2452 | long second_pid; | |
2453 | char *stack = xmalloc (STACK_SIZE * 4); | |
2454 | ||
2455 | linux_supports_tracefork_flag = 0; | |
2456 | ||
2457 | /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */ | |
2458 | #ifdef __ia64__ | |
2459 | child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE, | |
2460 | CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2); | |
2461 | #else | |
2462 | child_pid = clone (linux_tracefork_child, stack + STACK_SIZE, | |
2463 | CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2); | |
2464 | #endif | |
2465 | if (child_pid == -1) | |
2466 | perror_with_name ("clone"); | |
2467 | ||
2468 | ret = my_waitpid (child_pid, &status, 0); | |
2469 | if (ret == -1) | |
2470 | perror_with_name ("waitpid"); | |
2471 | else if (ret != child_pid) | |
2472 | error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret); | |
2473 | if (! WIFSTOPPED (status)) | |
2474 | error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status); | |
2475 | ||
2476 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); | |
2477 | if (ret != 0) | |
2478 | { | |
2479 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); | |
2480 | if (ret != 0) | |
2481 | { | |
2482 | warning ("linux_test_for_tracefork: failed to kill child"); | |
2483 | return; | |
2484 | } | |
2485 | ||
2486 | ret = my_waitpid (child_pid, &status, 0); | |
2487 | if (ret != child_pid) | |
2488 | warning ("linux_test_for_tracefork: failed to wait for killed child"); | |
2489 | else if (!WIFSIGNALED (status)) | |
2490 | warning ("linux_test_for_tracefork: unexpected wait status 0x%x from " | |
2491 | "killed child", status); | |
2492 | ||
2493 | return; | |
2494 | } | |
2495 | ||
2496 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); | |
2497 | if (ret != 0) | |
2498 | warning ("linux_test_for_tracefork: failed to resume child"); | |
2499 | ||
2500 | ret = my_waitpid (child_pid, &status, 0); | |
2501 | ||
2502 | if (ret == child_pid && WIFSTOPPED (status) | |
2503 | && status >> 16 == PTRACE_EVENT_FORK) | |
2504 | { | |
2505 | second_pid = 0; | |
2506 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); | |
2507 | if (ret == 0 && second_pid != 0) | |
2508 | { | |
2509 | int second_status; | |
2510 | ||
2511 | linux_supports_tracefork_flag = 1; | |
2512 | my_waitpid (second_pid, &second_status, 0); | |
2513 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); | |
2514 | if (ret != 0) | |
2515 | warning ("linux_test_for_tracefork: failed to kill second child"); | |
2516 | my_waitpid (second_pid, &status, 0); | |
2517 | } | |
2518 | } | |
2519 | else | |
2520 | warning ("linux_test_for_tracefork: unexpected result from waitpid " | |
2521 | "(%d, status 0x%x)", ret, status); | |
2522 | ||
2523 | do | |
2524 | { | |
2525 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); | |
2526 | if (ret != 0) | |
2527 | warning ("linux_test_for_tracefork: failed to kill child"); | |
2528 | my_waitpid (child_pid, &status, 0); | |
2529 | } | |
2530 | while (WIFSTOPPED (status)); | |
2531 | ||
2532 | free (stack); | |
2533 | } | |
2534 | ||
2535 | ||
2536 | static void | |
2537 | linux_look_up_symbols (void) | |
2538 | { | |
2539 | #ifdef USE_THREAD_DB | |
2540 | struct process_info *proc = current_process (); | |
2541 | ||
2542 | if (proc->private->thread_db_active) | |
2543 | return; | |
2544 | ||
2545 | proc->private->thread_db_active | |
2546 | = thread_db_init (!linux_supports_tracefork_flag); | |
2547 | #endif | |
2548 | } | |
2549 | ||
2550 | static void | |
2551 | linux_request_interrupt (void) | |
2552 | { | |
2553 | extern unsigned long signal_pid; | |
2554 | ||
2555 | if (!ptid_equal (cont_thread, null_ptid) | |
2556 | && !ptid_equal (cont_thread, minus_one_ptid)) | |
2557 | { | |
2558 | struct lwp_info *lwp; | |
2559 | int lwpid; | |
2560 | ||
2561 | lwp = get_thread_lwp (current_inferior); | |
2562 | lwpid = lwpid_of (lwp); | |
2563 | kill_lwp (lwpid, SIGINT); | |
2564 | } | |
2565 | else | |
2566 | kill_lwp (signal_pid, SIGINT); | |
2567 | } | |
2568 | ||
2569 | /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET | |
2570 | to debugger memory starting at MYADDR. */ | |
2571 | ||
2572 | static int | |
2573 | linux_read_auxv (CORE_ADDR offset, unsigned char *myaddr, unsigned int len) | |
2574 | { | |
2575 | char filename[PATH_MAX]; | |
2576 | int fd, n; | |
2577 | int pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2578 | ||
2579 | snprintf (filename, sizeof filename, "/proc/%d/auxv", pid); | |
2580 | ||
2581 | fd = open (filename, O_RDONLY); | |
2582 | if (fd < 0) | |
2583 | return -1; | |
2584 | ||
2585 | if (offset != (CORE_ADDR) 0 | |
2586 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
2587 | n = -1; | |
2588 | else | |
2589 | n = read (fd, myaddr, len); | |
2590 | ||
2591 | close (fd); | |
2592 | ||
2593 | return n; | |
2594 | } | |
2595 | ||
2596 | /* These watchpoint related wrapper functions simply pass on the function call | |
2597 | if the target has registered a corresponding function. */ | |
2598 | ||
2599 | static int | |
2600 | linux_insert_watchpoint (char type, CORE_ADDR addr, int len) | |
2601 | { | |
2602 | if (the_low_target.insert_watchpoint != NULL) | |
2603 | return the_low_target.insert_watchpoint (type, addr, len); | |
2604 | else | |
2605 | /* Unsupported (see target.h). */ | |
2606 | return 1; | |
2607 | } | |
2608 | ||
2609 | static int | |
2610 | linux_remove_watchpoint (char type, CORE_ADDR addr, int len) | |
2611 | { | |
2612 | if (the_low_target.remove_watchpoint != NULL) | |
2613 | return the_low_target.remove_watchpoint (type, addr, len); | |
2614 | else | |
2615 | /* Unsupported (see target.h). */ | |
2616 | return 1; | |
2617 | } | |
2618 | ||
2619 | static int | |
2620 | linux_stopped_by_watchpoint (void) | |
2621 | { | |
2622 | if (the_low_target.stopped_by_watchpoint != NULL) | |
2623 | return the_low_target.stopped_by_watchpoint (); | |
2624 | else | |
2625 | return 0; | |
2626 | } | |
2627 | ||
2628 | static CORE_ADDR | |
2629 | linux_stopped_data_address (void) | |
2630 | { | |
2631 | if (the_low_target.stopped_data_address != NULL) | |
2632 | return the_low_target.stopped_data_address (); | |
2633 | else | |
2634 | return 0; | |
2635 | } | |
2636 | ||
2637 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) | |
2638 | #if defined(__mcoldfire__) | |
2639 | /* These should really be defined in the kernel's ptrace.h header. */ | |
2640 | #define PT_TEXT_ADDR 49*4 | |
2641 | #define PT_DATA_ADDR 50*4 | |
2642 | #define PT_TEXT_END_ADDR 51*4 | |
2643 | #endif | |
2644 | ||
2645 | /* Under uClinux, programs are loaded at non-zero offsets, which we need | |
2646 | to tell gdb about. */ | |
2647 | ||
2648 | static int | |
2649 | linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p) | |
2650 | { | |
2651 | #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR) | |
2652 | unsigned long text, text_end, data; | |
2653 | int pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2654 | ||
2655 | errno = 0; | |
2656 | ||
2657 | text = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_ADDR, 0); | |
2658 | text_end = ptrace (PTRACE_PEEKUSER, pid, (long)PT_TEXT_END_ADDR, 0); | |
2659 | data = ptrace (PTRACE_PEEKUSER, pid, (long)PT_DATA_ADDR, 0); | |
2660 | ||
2661 | if (errno == 0) | |
2662 | { | |
2663 | /* Both text and data offsets produced at compile-time (and so | |
2664 | used by gdb) are relative to the beginning of the program, | |
2665 | with the data segment immediately following the text segment. | |
2666 | However, the actual runtime layout in memory may put the data | |
2667 | somewhere else, so when we send gdb a data base-address, we | |
2668 | use the real data base address and subtract the compile-time | |
2669 | data base-address from it (which is just the length of the | |
2670 | text segment). BSS immediately follows data in both | |
2671 | cases. */ | |
2672 | *text_p = text; | |
2673 | *data_p = data - (text_end - text); | |
2674 | ||
2675 | return 1; | |
2676 | } | |
2677 | #endif | |
2678 | return 0; | |
2679 | } | |
2680 | #endif | |
2681 | ||
2682 | static int | |
2683 | linux_qxfer_osdata (const char *annex, | |
2684 | unsigned char *readbuf, unsigned const char *writebuf, | |
2685 | CORE_ADDR offset, int len) | |
2686 | { | |
2687 | /* We make the process list snapshot when the object starts to be | |
2688 | read. */ | |
2689 | static const char *buf; | |
2690 | static long len_avail = -1; | |
2691 | static struct buffer buffer; | |
2692 | ||
2693 | DIR *dirp; | |
2694 | ||
2695 | if (strcmp (annex, "processes") != 0) | |
2696 | return 0; | |
2697 | ||
2698 | if (!readbuf || writebuf) | |
2699 | return 0; | |
2700 | ||
2701 | if (offset == 0) | |
2702 | { | |
2703 | if (len_avail != -1 && len_avail != 0) | |
2704 | buffer_free (&buffer); | |
2705 | len_avail = 0; | |
2706 | buf = NULL; | |
2707 | buffer_init (&buffer); | |
2708 | buffer_grow_str (&buffer, "<osdata type=\"processes\">"); | |
2709 | ||
2710 | dirp = opendir ("/proc"); | |
2711 | if (dirp) | |
2712 | { | |
2713 | struct dirent *dp; | |
2714 | while ((dp = readdir (dirp)) != NULL) | |
2715 | { | |
2716 | struct stat statbuf; | |
2717 | char procentry[sizeof ("/proc/4294967295")]; | |
2718 | ||
2719 | if (!isdigit (dp->d_name[0]) | |
2720 | || strlen (dp->d_name) > sizeof ("4294967295") - 1) | |
2721 | continue; | |
2722 | ||
2723 | sprintf (procentry, "/proc/%s", dp->d_name); | |
2724 | if (stat (procentry, &statbuf) == 0 | |
2725 | && S_ISDIR (statbuf.st_mode)) | |
2726 | { | |
2727 | char pathname[128]; | |
2728 | FILE *f; | |
2729 | char cmd[MAXPATHLEN + 1]; | |
2730 | struct passwd *entry; | |
2731 | ||
2732 | sprintf (pathname, "/proc/%s/cmdline", dp->d_name); | |
2733 | entry = getpwuid (statbuf.st_uid); | |
2734 | ||
2735 | if ((f = fopen (pathname, "r")) != NULL) | |
2736 | { | |
2737 | size_t len = fread (cmd, 1, sizeof (cmd) - 1, f); | |
2738 | if (len > 0) | |
2739 | { | |
2740 | int i; | |
2741 | for (i = 0; i < len; i++) | |
2742 | if (cmd[i] == '\0') | |
2743 | cmd[i] = ' '; | |
2744 | cmd[len] = '\0'; | |
2745 | ||
2746 | buffer_xml_printf ( | |
2747 | &buffer, | |
2748 | "<item>" | |
2749 | "<column name=\"pid\">%s</column>" | |
2750 | "<column name=\"user\">%s</column>" | |
2751 | "<column name=\"command\">%s</column>" | |
2752 | "</item>", | |
2753 | dp->d_name, | |
2754 | entry ? entry->pw_name : "?", | |
2755 | cmd); | |
2756 | } | |
2757 | fclose (f); | |
2758 | } | |
2759 | } | |
2760 | } | |
2761 | ||
2762 | closedir (dirp); | |
2763 | } | |
2764 | buffer_grow_str0 (&buffer, "</osdata>\n"); | |
2765 | buf = buffer_finish (&buffer); | |
2766 | len_avail = strlen (buf); | |
2767 | } | |
2768 | ||
2769 | if (offset >= len_avail) | |
2770 | { | |
2771 | /* Done. Get rid of the data. */ | |
2772 | buffer_free (&buffer); | |
2773 | buf = NULL; | |
2774 | len_avail = 0; | |
2775 | return 0; | |
2776 | } | |
2777 | ||
2778 | if (len > len_avail - offset) | |
2779 | len = len_avail - offset; | |
2780 | memcpy (readbuf, buf + offset, len); | |
2781 | ||
2782 | return len; | |
2783 | } | |
2784 | ||
2785 | static int | |
2786 | linux_xfer_siginfo (const char *annex, unsigned char *readbuf, | |
2787 | unsigned const char *writebuf, CORE_ADDR offset, int len) | |
2788 | { | |
2789 | struct siginfo siginfo; | |
2790 | long pid = -1; | |
2791 | ||
2792 | if (current_inferior == NULL) | |
2793 | return -1; | |
2794 | ||
2795 | pid = lwpid_of (get_thread_lwp (current_inferior)); | |
2796 | ||
2797 | if (debug_threads) | |
2798 | fprintf (stderr, "%s siginfo for lwp %ld.\n", | |
2799 | readbuf != NULL ? "Reading" : "Writing", | |
2800 | pid); | |
2801 | ||
2802 | if (offset > sizeof (siginfo)) | |
2803 | return -1; | |
2804 | ||
2805 | if (ptrace (PTRACE_GETSIGINFO, pid, 0, &siginfo) != 0) | |
2806 | return -1; | |
2807 | ||
2808 | if (offset + len > sizeof (siginfo)) | |
2809 | len = sizeof (siginfo) - offset; | |
2810 | ||
2811 | if (readbuf != NULL) | |
2812 | memcpy (readbuf, (char *) &siginfo + offset, len); | |
2813 | else | |
2814 | { | |
2815 | memcpy ((char *) &siginfo + offset, writebuf, len); | |
2816 | if (ptrace (PTRACE_SETSIGINFO, pid, 0, &siginfo) != 0) | |
2817 | return -1; | |
2818 | } | |
2819 | ||
2820 | return len; | |
2821 | } | |
2822 | ||
2823 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, | |
2824 | so we notice when children change state; as the handler for the | |
2825 | sigsuspend in my_waitpid. */ | |
2826 | ||
2827 | static void | |
2828 | sigchld_handler (int signo) | |
2829 | { | |
2830 | int old_errno = errno; | |
2831 | ||
2832 | if (debug_threads) | |
2833 | /* fprintf is not async-signal-safe, so call write directly. */ | |
2834 | write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1); | |
2835 | ||
2836 | if (target_is_async_p ()) | |
2837 | async_file_mark (); /* trigger a linux_wait */ | |
2838 | ||
2839 | errno = old_errno; | |
2840 | } | |
2841 | ||
2842 | static int | |
2843 | linux_supports_non_stop (void) | |
2844 | { | |
2845 | return 1; | |
2846 | } | |
2847 | ||
2848 | static int | |
2849 | linux_async (int enable) | |
2850 | { | |
2851 | int previous = (linux_event_pipe[0] != -1); | |
2852 | ||
2853 | if (previous != enable) | |
2854 | { | |
2855 | sigset_t mask; | |
2856 | sigemptyset (&mask); | |
2857 | sigaddset (&mask, SIGCHLD); | |
2858 | ||
2859 | sigprocmask (SIG_BLOCK, &mask, NULL); | |
2860 | ||
2861 | if (enable) | |
2862 | { | |
2863 | if (pipe (linux_event_pipe) == -1) | |
2864 | fatal ("creating event pipe failed."); | |
2865 | ||
2866 | fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK); | |
2867 | fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK); | |
2868 | ||
2869 | /* Register the event loop handler. */ | |
2870 | add_file_handler (linux_event_pipe[0], | |
2871 | handle_target_event, NULL); | |
2872 | ||
2873 | /* Always trigger a linux_wait. */ | |
2874 | async_file_mark (); | |
2875 | } | |
2876 | else | |
2877 | { | |
2878 | delete_file_handler (linux_event_pipe[0]); | |
2879 | ||
2880 | close (linux_event_pipe[0]); | |
2881 | close (linux_event_pipe[1]); | |
2882 | linux_event_pipe[0] = -1; | |
2883 | linux_event_pipe[1] = -1; | |
2884 | } | |
2885 | ||
2886 | sigprocmask (SIG_UNBLOCK, &mask, NULL); | |
2887 | } | |
2888 | ||
2889 | return previous; | |
2890 | } | |
2891 | ||
2892 | static int | |
2893 | linux_start_non_stop (int nonstop) | |
2894 | { | |
2895 | /* Register or unregister from event-loop accordingly. */ | |
2896 | linux_async (nonstop); | |
2897 | return 0; | |
2898 | } | |
2899 | ||
2900 | static struct target_ops linux_target_ops = { | |
2901 | linux_create_inferior, | |
2902 | linux_attach, | |
2903 | linux_kill, | |
2904 | linux_detach, | |
2905 | linux_join, | |
2906 | linux_thread_alive, | |
2907 | linux_resume, | |
2908 | linux_wait, | |
2909 | linux_fetch_registers, | |
2910 | linux_store_registers, | |
2911 | linux_read_memory, | |
2912 | linux_write_memory, | |
2913 | linux_look_up_symbols, | |
2914 | linux_request_interrupt, | |
2915 | linux_read_auxv, | |
2916 | linux_insert_watchpoint, | |
2917 | linux_remove_watchpoint, | |
2918 | linux_stopped_by_watchpoint, | |
2919 | linux_stopped_data_address, | |
2920 | #if defined(__UCLIBC__) && defined(HAS_NOMMU) | |
2921 | linux_read_offsets, | |
2922 | #else | |
2923 | NULL, | |
2924 | #endif | |
2925 | #ifdef USE_THREAD_DB | |
2926 | thread_db_get_tls_address, | |
2927 | #else | |
2928 | NULL, | |
2929 | #endif | |
2930 | NULL, | |
2931 | hostio_last_error_from_errno, | |
2932 | linux_qxfer_osdata, | |
2933 | linux_xfer_siginfo, | |
2934 | linux_supports_non_stop, | |
2935 | linux_async, | |
2936 | linux_start_non_stop, | |
2937 | }; | |
2938 | ||
2939 | static void | |
2940 | linux_init_signals () | |
2941 | { | |
2942 | /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads | |
2943 | to find what the cancel signal actually is. */ | |
2944 | signal (__SIGRTMIN+1, SIG_IGN); | |
2945 | } | |
2946 | ||
2947 | void | |
2948 | initialize_low (void) | |
2949 | { | |
2950 | struct sigaction sigchld_action; | |
2951 | memset (&sigchld_action, 0, sizeof (sigchld_action)); | |
2952 | set_target_ops (&linux_target_ops); | |
2953 | set_breakpoint_data (the_low_target.breakpoint, | |
2954 | the_low_target.breakpoint_len); | |
2955 | linux_init_signals (); | |
2956 | linux_test_for_tracefork (); | |
2957 | #ifdef HAVE_LINUX_REGSETS | |
2958 | for (num_regsets = 0; target_regsets[num_regsets].size >= 0; num_regsets++) | |
2959 | ; | |
2960 | disabled_regsets = xmalloc (num_regsets); | |
2961 | #endif | |
2962 | ||
2963 | sigchld_action.sa_handler = sigchld_handler; | |
2964 | sigemptyset (&sigchld_action.sa_mask); | |
2965 | sigchld_action.sa_flags = SA_RESTART; | |
2966 | sigaction (SIGCHLD, &sigchld_action, NULL); | |
2967 | } |