Commit | Line | Data |
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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
e2882c85 | 3 | Copyright (C) 2005-2018 Free Software Foundation, Inc. |
ac264b3b MS |
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
ac264b3b MS |
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 | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
ac264b3b MS |
19 | |
20 | #include "defs.h" | |
5af949e3 | 21 | #include "arch-utils.h" |
ac264b3b | 22 | #include "inferior.h" |
45741a9c | 23 | #include "infrun.h" |
ac264b3b MS |
24 | #include "regcache.h" |
25 | #include "gdbcmd.h" | |
26 | #include "infcall.h" | |
3e3b026f | 27 | #include "objfiles.h" |
ac264b3b | 28 | #include "linux-fork.h" |
f973ed9c | 29 | #include "linux-nat.h" |
7a298875 | 30 | #include "gdbthread.h" |
05cba821 | 31 | #include "source.h" |
ac264b3b | 32 | |
5826e159 | 33 | #include "nat/gdb_ptrace.h" |
3c61c145 | 34 | #include "gdb_wait.h" |
2978b111 | 35 | #include <dirent.h> |
ac264b3b MS |
36 | #include <ctype.h> |
37 | ||
38 | struct fork_info *fork_list; | |
39 | static int highest_fork_num; | |
40 | ||
ac264b3b MS |
41 | /* Fork list data structure: */ |
42 | struct fork_info | |
43 | { | |
44 | struct fork_info *next; | |
45 | ptid_t ptid; | |
7a298875 | 46 | ptid_t parent_ptid; |
1777feb0 | 47 | int num; /* Convenient handle (GDB fork id). */ |
3cb5bea9 | 48 | struct regcache *savedregs; /* Convenient for info fork, saves |
ac264b3b MS |
49 | having to actually switch contexts. */ |
50 | int clobber_regs; /* True if we should restore saved regs. */ | |
ac264b3b MS |
51 | off_t *filepos; /* Set of open file descriptors' offsets. */ |
52 | int maxfd; | |
53 | }; | |
54 | ||
55 | /* Fork list methods: */ | |
56 | ||
3cb5bea9 | 57 | int |
ac264b3b MS |
58 | forks_exist_p (void) |
59 | { | |
60 | return (fork_list != NULL); | |
61 | } | |
62 | ||
2f341b6e PA |
63 | /* Return the last fork in the list. */ |
64 | ||
65 | static struct fork_info * | |
66 | find_last_fork (void) | |
67 | { | |
68 | struct fork_info *last; | |
69 | ||
70 | if (fork_list == NULL) | |
71 | return NULL; | |
72 | ||
73 | for (last = fork_list; last->next != NULL; last = last->next) | |
74 | ; | |
75 | return last; | |
76 | } | |
77 | ||
3cb5bea9 | 78 | /* Add a fork to the internal fork list. */ |
ac264b3b | 79 | |
3cb5bea9 | 80 | struct fork_info * |
ac264b3b MS |
81 | add_fork (pid_t pid) |
82 | { | |
83 | struct fork_info *fp; | |
84 | ||
dfd4cc63 | 85 | if (fork_list == NULL && pid != ptid_get_pid (inferior_ptid)) |
ac264b3b MS |
86 | { |
87 | /* Special case -- if this is the first fork in the list | |
88 | (the list is hitherto empty), and if this new fork is | |
89 | NOT the current inferior_ptid, then add inferior_ptid | |
90 | first, as a special zeroeth fork id. */ | |
91 | highest_fork_num = -1; | |
dfd4cc63 | 92 | add_fork (ptid_get_pid (inferior_ptid)); /* safe recursion */ |
ac264b3b MS |
93 | } |
94 | ||
41bf6aca | 95 | fp = XCNEW (struct fork_info); |
f973ed9c | 96 | fp->ptid = ptid_build (pid, pid, 0); |
ac264b3b | 97 | fp->num = ++highest_fork_num; |
2f341b6e PA |
98 | |
99 | if (fork_list == NULL) | |
100 | fork_list = fp; | |
101 | else | |
102 | { | |
103 | struct fork_info *last = find_last_fork (); | |
104 | ||
105 | last->next = fp; | |
106 | } | |
107 | ||
ac264b3b MS |
108 | return fp; |
109 | } | |
110 | ||
111 | static void | |
112 | free_fork (struct fork_info *fp) | |
113 | { | |
114 | /* Notes on step-resume breakpoints: since this is a concern for | |
115 | threads, let's convince ourselves that it's not a concern for | |
116 | forks. There are two ways for a fork_info to be created. First, | |
117 | by the checkpoint command, in which case we're at a gdb prompt | |
118 | and there can't be any step-resume breakpoint. Second, by a fork | |
119 | in the user program, in which case we *may* have stepped into the | |
120 | fork call, but regardless of whether we follow the parent or the | |
121 | child, we will return to the same place and the step-resume | |
122 | breakpoint, if any, will take care of itself as usual. And | |
123 | unlike threads, we do not save a private copy of the step-resume | |
124 | breakpoint -- so we're OK. */ | |
125 | ||
126 | if (fp) | |
127 | { | |
128 | if (fp->savedregs) | |
c0e383c6 | 129 | delete fp->savedregs; |
ac264b3b MS |
130 | if (fp->filepos) |
131 | xfree (fp->filepos); | |
132 | xfree (fp); | |
133 | } | |
134 | } | |
135 | ||
136 | static void | |
137 | delete_fork (ptid_t ptid) | |
138 | { | |
139 | struct fork_info *fp, *fpprev; | |
140 | ||
141 | fpprev = NULL; | |
142 | ||
26cb8b7c PA |
143 | linux_nat_forget_process (ptid_get_pid (ptid)); |
144 | ||
ac264b3b MS |
145 | for (fp = fork_list; fp; fpprev = fp, fp = fp->next) |
146 | if (ptid_equal (fp->ptid, ptid)) | |
147 | break; | |
148 | ||
149 | if (!fp) | |
150 | return; | |
151 | ||
152 | if (fpprev) | |
153 | fpprev->next = fp->next; | |
154 | else | |
155 | fork_list = fp->next; | |
156 | ||
157 | free_fork (fp); | |
158 | ||
3cb5bea9 | 159 | /* Special case: if there is now only one process in the list, |
ac264b3b MS |
160 | and if it is (hopefully!) the current inferior_ptid, then |
161 | remove it, leaving the list empty -- we're now down to the | |
162 | default case of debugging a single process. */ | |
163 | if (fork_list != NULL && fork_list->next == NULL && | |
164 | ptid_equal (fork_list->ptid, inferior_ptid)) | |
165 | { | |
166 | /* Last fork -- delete from list and handle as solo process | |
167 | (should be a safe recursion). */ | |
168 | delete_fork (inferior_ptid); | |
169 | } | |
170 | } | |
171 | ||
172 | /* Find a fork_info by matching PTID. */ | |
173 | static struct fork_info * | |
174 | find_fork_ptid (ptid_t ptid) | |
175 | { | |
176 | struct fork_info *fp; | |
177 | ||
178 | for (fp = fork_list; fp; fp = fp->next) | |
179 | if (ptid_equal (fp->ptid, ptid)) | |
180 | return fp; | |
181 | ||
182 | return NULL; | |
183 | } | |
184 | ||
185 | /* Find a fork_info by matching ID. */ | |
186 | static struct fork_info * | |
187 | find_fork_id (int num) | |
188 | { | |
189 | struct fork_info *fp; | |
190 | ||
191 | for (fp = fork_list; fp; fp = fp->next) | |
192 | if (fp->num == num) | |
193 | return fp; | |
194 | ||
195 | return NULL; | |
196 | } | |
197 | ||
198 | /* Find a fork_info by matching pid. */ | |
199 | extern struct fork_info * | |
200 | find_fork_pid (pid_t pid) | |
201 | { | |
202 | struct fork_info *fp; | |
203 | ||
204 | for (fp = fork_list; fp; fp = fp->next) | |
205 | if (pid == ptid_get_pid (fp->ptid)) | |
206 | return fp; | |
207 | ||
208 | return NULL; | |
209 | } | |
210 | ||
211 | static ptid_t | |
212 | fork_id_to_ptid (int num) | |
213 | { | |
214 | struct fork_info *fork = find_fork_id (num); | |
215 | if (fork) | |
216 | return fork->ptid; | |
217 | else | |
218 | return pid_to_ptid (-1); | |
219 | } | |
220 | ||
221 | static void | |
222 | init_fork_list (void) | |
223 | { | |
224 | struct fork_info *fp, *fpnext; | |
225 | ||
226 | if (!fork_list) | |
227 | return; | |
228 | ||
229 | for (fp = fork_list; fp; fp = fpnext) | |
230 | { | |
231 | fpnext = fp->next; | |
232 | free_fork (fp); | |
233 | } | |
234 | ||
235 | fork_list = NULL; | |
236 | } | |
237 | ||
238 | /* Fork list <-> gdb interface. */ | |
239 | ||
3cb5bea9 | 240 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
241 | Calls lseek in the (current) inferior process. */ |
242 | ||
243 | static off_t | |
244 | call_lseek (int fd, off_t offset, int whence) | |
245 | { | |
246 | char exp[80]; | |
247 | ||
7022349d | 248 | snprintf (&exp[0], sizeof (exp), "(long) lseek (%d, %ld, %d)", |
ac264b3b MS |
249 | fd, (long) offset, whence); |
250 | return (off_t) parse_and_eval_long (&exp[0]); | |
251 | } | |
252 | ||
253 | /* Load infrun state for the fork PTID. */ | |
254 | ||
255 | static void | |
256 | fork_load_infrun_state (struct fork_info *fp) | |
257 | { | |
258 | extern void nullify_last_target_wait_ptid (); | |
259 | int i; | |
260 | ||
2277426b | 261 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 262 | |
ac264b3b | 263 | if (fp->savedregs && fp->clobber_regs) |
594f7785 | 264 | regcache_cpy (get_current_regcache (), fp->savedregs); |
ac264b3b | 265 | |
791b663b DJ |
266 | registers_changed (); |
267 | reinit_frame_cache (); | |
268 | ||
fb14de7b | 269 | stop_pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
270 | nullify_last_target_wait_ptid (); |
271 | ||
272 | /* Now restore the file positions of open file descriptors. */ | |
273 | if (fp->filepos) | |
274 | { | |
275 | for (i = 0; i <= fp->maxfd; i++) | |
276 | if (fp->filepos[i] != (off_t) -1) | |
277 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
278 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
279 | this is native-only. If it ever has to be cross, we'll have | |
280 | to rethink this. */ | |
281 | } | |
282 | } | |
283 | ||
284 | /* Save infrun state for the fork PTID. | |
285 | Exported for use by linux child_follow_fork. */ | |
286 | ||
2277426b | 287 | static void |
ac264b3b MS |
288 | fork_save_infrun_state (struct fork_info *fp, int clobber_regs) |
289 | { | |
d8d2a3ee | 290 | char path[PATH_MAX]; |
ac264b3b MS |
291 | struct dirent *de; |
292 | DIR *d; | |
293 | ||
294 | if (fp->savedregs) | |
c0e383c6 | 295 | delete fp->savedregs; |
ac264b3b | 296 | |
594f7785 | 297 | fp->savedregs = regcache_dup (get_current_regcache ()); |
ac264b3b | 298 | fp->clobber_regs = clobber_regs; |
ac264b3b MS |
299 | |
300 | if (clobber_regs) | |
301 | { | |
302 | /* Now save the 'state' (file position) of all open file descriptors. | |
303 | Unfortunately fork does not take care of that for us... */ | |
dfd4cc63 LM |
304 | snprintf (path, PATH_MAX, "/proc/%ld/fd", |
305 | (long) ptid_get_pid (fp->ptid)); | |
ac264b3b MS |
306 | if ((d = opendir (path)) != NULL) |
307 | { | |
308 | long tmp; | |
309 | ||
310 | fp->maxfd = 0; | |
311 | while ((de = readdir (d)) != NULL) | |
312 | { | |
313 | /* Count open file descriptors (actually find highest | |
314 | numbered). */ | |
315 | tmp = strtol (&de->d_name[0], NULL, 10); | |
316 | if (fp->maxfd < tmp) | |
317 | fp->maxfd = tmp; | |
318 | } | |
319 | /* Allocate array of file positions. */ | |
224c3ddb | 320 | fp->filepos = XRESIZEVEC (off_t, fp->filepos, fp->maxfd + 1); |
ac264b3b MS |
321 | |
322 | /* Initialize to -1 (invalid). */ | |
323 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
324 | fp->filepos[tmp] = -1; | |
325 | ||
326 | /* Now find actual file positions. */ | |
327 | rewinddir (d); | |
328 | while ((de = readdir (d)) != NULL) | |
329 | if (isdigit (de->d_name[0])) | |
330 | { | |
331 | tmp = strtol (&de->d_name[0], NULL, 10); | |
332 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
333 | } | |
334 | closedir (d); | |
335 | } | |
336 | } | |
337 | } | |
338 | ||
339 | /* Kill 'em all, let God sort 'em out... */ | |
340 | ||
3cb5bea9 | 341 | void |
ac264b3b MS |
342 | linux_fork_killall (void) |
343 | { | |
344 | /* Walk list and kill every pid. No need to treat the | |
345 | current inferior_ptid as special (we do not return a | |
346 | status for it) -- however any process may be a child | |
347 | or a parent, so may get a SIGCHLD from a previously | |
348 | killed child. Wait them all out. */ | |
56aac7e8 | 349 | struct fork_info *fp; |
ac264b3b MS |
350 | pid_t pid, ret; |
351 | int status; | |
352 | ||
56aac7e8 MS |
353 | for (fp = fork_list; fp; fp = fp->next) |
354 | { | |
dfd4cc63 | 355 | pid = ptid_get_pid (fp->ptid); |
56aac7e8 | 356 | do { |
4c28f408 PA |
357 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
358 | if the thread is running, while the later doesn't. */ | |
359 | kill (pid, SIGKILL); | |
56aac7e8 MS |
360 | ret = waitpid (pid, &status, 0); |
361 | /* We might get a SIGCHLD instead of an exit status. This is | |
362 | aggravated by the first kill above - a child has just | |
363 | died. MVS comment cut-and-pasted from linux-nat. */ | |
364 | } while (ret == pid && WIFSTOPPED (status)); | |
365 | } | |
366 | init_fork_list (); /* Clear list, prepare to start fresh. */ | |
ac264b3b MS |
367 | } |
368 | ||
369 | /* The current inferior_ptid has exited, but there are other viable | |
370 | forks to debug. Delete the exiting one and context-switch to the | |
371 | first available. */ | |
372 | ||
3cb5bea9 | 373 | void |
ac264b3b MS |
374 | linux_fork_mourn_inferior (void) |
375 | { | |
2f341b6e PA |
376 | struct fork_info *last; |
377 | int status; | |
378 | ||
ac264b3b MS |
379 | /* Wait just one more time to collect the inferior's exit status. |
380 | Do not check whether this succeeds though, since we may be | |
381 | dealing with a process that we attached to. Such a process will | |
382 | only report its exit status to its original parent. */ | |
ac264b3b MS |
383 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); |
384 | ||
385 | /* OK, presumably inferior_ptid is the one who has exited. | |
386 | We need to delete that one from the fork_list, and switch | |
387 | to the next available fork. */ | |
388 | delete_fork (inferior_ptid); | |
791b663b DJ |
389 | |
390 | /* There should still be a fork - if there's only one left, | |
391 | delete_fork won't remove it, because we haven't updated | |
392 | inferior_ptid yet. */ | |
393 | gdb_assert (fork_list); | |
394 | ||
2f341b6e PA |
395 | last = find_last_fork (); |
396 | fork_load_infrun_state (last); | |
791b663b DJ |
397 | printf_filtered (_("[Switching to %s]\n"), |
398 | target_pid_to_str (inferior_ptid)); | |
399 | ||
400 | /* If there's only one fork, switch back to non-fork mode. */ | |
401 | if (fork_list->next == NULL) | |
402 | delete_fork (inferior_ptid); | |
ac264b3b MS |
403 | } |
404 | ||
7a7d3353 PA |
405 | /* The current inferior_ptid is being detached, but there are other |
406 | viable forks to debug. Detach and delete it and context-switch to | |
407 | the first available. */ | |
408 | ||
3cb5bea9 | 409 | void |
6bd6f3b6 | 410 | linux_fork_detach (int from_tty) |
7a7d3353 PA |
411 | { |
412 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
413 | delete it from the fork_list, and switch to the next available | |
414 | fork. */ | |
415 | ||
dfd4cc63 | 416 | if (ptrace (PTRACE_DETACH, ptid_get_pid (inferior_ptid), 0, 0)) |
7a7d3353 PA |
417 | error (_("Unable to detach %s"), target_pid_to_str (inferior_ptid)); |
418 | ||
419 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
420 | |
421 | /* There should still be a fork - if there's only one left, | |
422 | delete_fork won't remove it, because we haven't updated | |
423 | inferior_ptid yet. */ | |
424 | gdb_assert (fork_list); | |
425 | ||
426 | fork_load_infrun_state (fork_list); | |
427 | ||
428 | if (from_tty) | |
429 | printf_filtered (_("[Switching to %s]\n"), | |
430 | target_pid_to_str (inferior_ptid)); | |
431 | ||
432 | /* If there's only one fork, switch back to non-fork mode. */ | |
433 | if (fork_list->next == NULL) | |
434 | delete_fork (inferior_ptid); | |
435 | } | |
436 | ||
7a298875 HZ |
437 | static void |
438 | inferior_call_waitpid_cleanup (void *fp) | |
439 | { | |
9a3c8263 | 440 | struct fork_info *oldfp = (struct fork_info *) fp; |
7a298875 | 441 | |
e17c9e56 HZ |
442 | if (oldfp) |
443 | { | |
1777feb0 | 444 | /* Switch back to inferior_ptid. */ |
e17c9e56 HZ |
445 | remove_breakpoints (); |
446 | fork_load_infrun_state (oldfp); | |
447 | insert_breakpoints (); | |
448 | } | |
7a298875 HZ |
449 | } |
450 | ||
451 | static int | |
452 | inferior_call_waitpid (ptid_t pptid, int pid) | |
453 | { | |
454 | struct objfile *waitpid_objf; | |
455 | struct value *waitpid_fn = NULL; | |
e17c9e56 | 456 | struct value *argv[4], *retv; |
7a298875 HZ |
457 | struct gdbarch *gdbarch = get_current_arch (); |
458 | struct fork_info *oldfp = NULL, *newfp = NULL; | |
e17c9e56 | 459 | struct cleanup *old_cleanup; |
7a298875 HZ |
460 | int ret = -1; |
461 | ||
462 | if (!ptid_equal (pptid, inferior_ptid)) | |
463 | { | |
464 | /* Switch to pptid. */ | |
465 | oldfp = find_fork_ptid (inferior_ptid); | |
466 | gdb_assert (oldfp != NULL); | |
467 | newfp = find_fork_ptid (pptid); | |
da3ecdc6 | 468 | gdb_assert (newfp != NULL); |
7a298875 HZ |
469 | fork_save_infrun_state (oldfp, 1); |
470 | remove_breakpoints (); | |
471 | fork_load_infrun_state (newfp); | |
472 | insert_breakpoints (); | |
7a298875 HZ |
473 | } |
474 | ||
e17c9e56 HZ |
475 | old_cleanup = make_cleanup (inferior_call_waitpid_cleanup, oldfp); |
476 | ||
7a298875 | 477 | /* Get the waitpid_fn. */ |
3b7344d5 | 478 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 479 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
480 | if (!waitpid_fn |
481 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 HZ |
482 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
483 | if (!waitpid_fn) | |
484 | goto out; | |
485 | ||
486 | /* Get the argv. */ | |
487 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
488 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
489 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
490 | argv[3] = 0; | |
491 | ||
7022349d | 492 | retv = call_function_by_hand (waitpid_fn, NULL, 3, argv); |
e17c9e56 HZ |
493 | if (value_as_long (retv) < 0) |
494 | goto out; | |
7a298875 HZ |
495 | |
496 | ret = 0; | |
497 | ||
498 | out: | |
e17c9e56 | 499 | do_cleanups (old_cleanup); |
7a298875 HZ |
500 | return ret; |
501 | } | |
502 | ||
ac264b3b MS |
503 | /* Fork list <-> user interface. */ |
504 | ||
505 | static void | |
5b64bf74 | 506 | delete_checkpoint_command (const char *args, int from_tty) |
ac264b3b | 507 | { |
e17c9e56 | 508 | ptid_t ptid, pptid; |
7a298875 | 509 | struct fork_info *fi; |
ac264b3b MS |
510 | |
511 | if (!args || !*args) | |
2277426b | 512 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
513 | |
514 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
515 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 516 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
517 | |
518 | if (ptid_equal (ptid, inferior_ptid)) | |
3cb5bea9 PA |
519 | error (_("\ |
520 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 521 | |
dfd4cc63 | 522 | if (ptrace (PTRACE_KILL, ptid_get_pid (ptid), 0, 0)) |
54ba13f7 | 523 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid)); |
ac264b3b | 524 | |
7a298875 HZ |
525 | fi = find_fork_ptid (ptid); |
526 | gdb_assert (fi); | |
e17c9e56 | 527 | pptid = fi->parent_ptid; |
7a298875 | 528 | |
ac264b3b MS |
529 | if (from_tty) |
530 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid)); | |
531 | ||
532 | delete_fork (ptid); | |
7a298875 HZ |
533 | |
534 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
535 | list, waitpid the ptid. | |
536 | If fi->parent_ptid is a part of lwp and it is stoped, waitpid the | |
537 | ptid. */ | |
e17c9e56 HZ |
538 | if ((!find_thread_ptid (pptid) && find_fork_ptid (pptid)) |
539 | || (find_thread_ptid (pptid) && is_stopped (pptid))) | |
7a298875 | 540 | { |
dfd4cc63 | 541 | if (inferior_call_waitpid (pptid, ptid_get_pid (ptid))) |
7a298875 HZ |
542 | warning (_("Unable to wait pid %s"), target_pid_to_str (ptid)); |
543 | } | |
ac264b3b MS |
544 | } |
545 | ||
546 | static void | |
5b64bf74 | 547 | detach_checkpoint_command (const char *args, int from_tty) |
ac264b3b MS |
548 | { |
549 | ptid_t ptid; | |
550 | ||
551 | if (!args || !*args) | |
2277426b | 552 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
553 | |
554 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
555 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 556 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
557 | |
558 | if (ptid_equal (ptid, inferior_ptid)) | |
2277426b PA |
559 | error (_("\ |
560 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 561 | |
dfd4cc63 | 562 | if (ptrace (PTRACE_DETACH, ptid_get_pid (ptid), 0, 0)) |
ac264b3b MS |
563 | error (_("Unable to detach %s"), target_pid_to_str (ptid)); |
564 | ||
565 | if (from_tty) | |
566 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid)); | |
567 | ||
568 | delete_fork (ptid); | |
569 | } | |
570 | ||
3cb5bea9 | 571 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
572 | |
573 | static void | |
1d12d88f | 574 | info_checkpoints_command (const char *arg, int from_tty) |
ac264b3b | 575 | { |
5af949e3 | 576 | struct gdbarch *gdbarch = get_current_arch (); |
ac264b3b | 577 | struct symtab_and_line sal; |
ac264b3b | 578 | struct fork_info *fp; |
ac264b3b | 579 | ULONGEST pc; |
b8db102d MS |
580 | int requested = -1; |
581 | struct fork_info *printed = NULL; | |
582 | ||
583 | if (arg && *arg) | |
584 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b MS |
585 | |
586 | for (fp = fork_list; fp; fp = fp->next) | |
587 | { | |
b8db102d MS |
588 | if (requested > 0 && fp->num != requested) |
589 | continue; | |
590 | ||
591 | printed = fp; | |
ac264b3b MS |
592 | if (ptid_equal (fp->ptid, inferior_ptid)) |
593 | { | |
594 | printf_filtered ("* "); | |
fb14de7b | 595 | pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
596 | } |
597 | else | |
598 | { | |
599 | printf_filtered (" "); | |
2277426b | 600 | pc = regcache_read_pc (fp->savedregs); |
ac264b3b MS |
601 | } |
602 | printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid)); | |
603 | if (fp->num == 0) | |
604 | printf_filtered (_(" (main process)")); | |
605 | printf_filtered (_(" at ")); | |
5af949e3 | 606 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b MS |
607 | |
608 | sal = find_pc_line (pc, 0); | |
609 | if (sal.symtab) | |
05cba821 JK |
610 | printf_filtered (_(", file %s"), |
611 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b MS |
612 | if (sal.line) |
613 | printf_filtered (_(", line %d"), sal.line); | |
614 | if (!sal.symtab && !sal.line) | |
615 | { | |
7cbd4a93 | 616 | struct bound_minimal_symbol msym; |
ac264b3b MS |
617 | |
618 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 | 619 | if (msym.minsym) |
efd66ac6 | 620 | printf_filtered (", <%s>", MSYMBOL_LINKAGE_NAME (msym.minsym)); |
ac264b3b MS |
621 | } |
622 | ||
623 | putchar_filtered ('\n'); | |
624 | } | |
b8db102d MS |
625 | if (printed == NULL) |
626 | { | |
627 | if (requested > 0) | |
2277426b | 628 | printf_filtered (_("No checkpoint number %d.\n"), requested); |
b8db102d | 629 | else |
2277426b | 630 | printf_filtered (_("No checkpoints.\n")); |
b8db102d | 631 | } |
ac264b3b MS |
632 | } |
633 | ||
2277426b PA |
634 | /* The PID of the process we're checkpointing. */ |
635 | static int checkpointing_pid = 0; | |
ac264b3b | 636 | |
2277426b PA |
637 | int |
638 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 639 | { |
2277426b | 640 | return (checkpointing_pid == pid); |
ac264b3b MS |
641 | } |
642 | ||
92f6badc KP |
643 | /* Callback for iterate over threads. Used to check whether |
644 | the current inferior is multi-threaded. Returns true as soon | |
645 | as it sees the second thread of the current inferior. */ | |
646 | ||
647 | static int | |
648 | inf_has_multiple_thread_cb (struct thread_info *tp, void *data) | |
649 | { | |
650 | int *count_p = (int *) data; | |
651 | ||
652 | if (current_inferior ()->pid == ptid_get_pid (tp->ptid)) | |
653 | (*count_p)++; | |
654 | ||
655 | /* Stop the iteration if multiple threads have been detected. */ | |
656 | return *count_p > 1; | |
657 | } | |
658 | ||
659 | /* Return true if the current inferior is multi-threaded. */ | |
660 | ||
661 | static int | |
662 | inf_has_multiple_threads (void) | |
663 | { | |
664 | int count = 0; | |
665 | ||
666 | iterate_over_threads (inf_has_multiple_thread_cb, &count); | |
667 | return (count > 1); | |
668 | } | |
669 | ||
ac264b3b | 670 | static void |
0b39b52e | 671 | checkpoint_command (const char *args, int from_tty) |
ac264b3b | 672 | { |
3e3b026f UW |
673 | struct objfile *fork_objf; |
674 | struct gdbarch *gdbarch; | |
ac264b3b MS |
675 | struct target_waitstatus last_target_waitstatus; |
676 | ptid_t last_target_ptid; | |
677 | struct value *fork_fn = NULL, *ret; | |
678 | struct fork_info *fp; | |
679 | pid_t retpid; | |
74960c60 | 680 | |
92f6badc KP |
681 | if (!target_has_execution) |
682 | error (_("The program is not being run.")); | |
683 | ||
684 | /* Ensure that the inferior is not multithreaded. */ | |
685 | update_thread_list (); | |
686 | if (inf_has_multiple_threads ()) | |
687 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
688 | ||
ac264b3b MS |
689 | /* Make the inferior fork, record its (and gdb's) state. */ |
690 | ||
3b7344d5 | 691 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 692 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 693 | if (!fork_fn) |
3b7344d5 | 694 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 695 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
696 | if (!fork_fn) |
697 | error (_("checkpoint: can't find fork function in inferior.")); | |
698 | ||
3e3b026f UW |
699 | gdbarch = get_objfile_arch (fork_objf); |
700 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
701 | |
702 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
b7b633e9 TT |
703 | { |
704 | scoped_restore save_pid | |
705 | = make_scoped_restore (&checkpointing_pid, ptid_get_pid (inferior_ptid)); | |
706 | ||
7022349d | 707 | ret = call_function_by_hand (fork_fn, NULL, 0, &ret); |
b7b633e9 | 708 | } |
2277426b | 709 | |
ac264b3b MS |
710 | if (!ret) /* Probably can't happen. */ |
711 | error (_("checkpoint: call_function_by_hand returned null.")); | |
712 | ||
713 | retpid = value_as_long (ret); | |
714 | get_last_target_status (&last_target_ptid, &last_target_waitstatus); | |
6f9d33d8 PP |
715 | |
716 | fp = find_fork_pid (retpid); | |
717 | ||
ac264b3b MS |
718 | if (from_tty) |
719 | { | |
720 | int parent_pid; | |
721 | ||
6f9d33d8 PP |
722 | printf_filtered (_("checkpoint %d: fork returned pid %ld.\n"), |
723 | fp != NULL ? fp->num : -1, (long) retpid); | |
ac264b3b MS |
724 | if (info_verbose) |
725 | { | |
726 | parent_pid = ptid_get_lwp (last_target_ptid); | |
727 | if (parent_pid == 0) | |
728 | parent_pid = ptid_get_pid (last_target_ptid); | |
3cb5bea9 | 729 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
730 | (long) parent_pid); |
731 | } | |
732 | } | |
733 | ||
ac264b3b MS |
734 | if (!fp) |
735 | error (_("Failed to find new fork")); | |
736 | fork_save_infrun_state (fp, 1); | |
7a298875 | 737 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
738 | } |
739 | ||
740 | static void | |
741 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
742 | { | |
743 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 744 | struct fork_info *oldfp; |
ac264b3b | 745 | |
0d14fc63 | 746 | gdb_assert (newfp != NULL); |
ac264b3b | 747 | |
0d14fc63 PA |
748 | oldfp = find_fork_ptid (inferior_ptid); |
749 | gdb_assert (oldfp != NULL); | |
ac264b3b MS |
750 | |
751 | fork_save_infrun_state (oldfp, 1); | |
74960c60 | 752 | remove_breakpoints (); |
ac264b3b | 753 | fork_load_infrun_state (newfp); |
74960c60 | 754 | insert_breakpoints (); |
ac264b3b | 755 | |
3cb5bea9 | 756 | printf_filtered (_("Switching to %s\n"), |
ac264b3b MS |
757 | target_pid_to_str (inferior_ptid)); |
758 | ||
08d72866 | 759 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
760 | } |
761 | ||
2277426b | 762 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b | 763 | static void |
0b39b52e | 764 | restart_command (const char *args, int from_tty) |
ac264b3b MS |
765 | { |
766 | struct fork_info *fp; | |
767 | ||
768 | if (!args || !*args) | |
769 | error (_("Requires argument (checkpoint id to restart)")); | |
770 | ||
771 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
772 | error (_("Not found: checkpoint id %s"), args); | |
773 | ||
774 | linux_fork_context (fp, from_tty); | |
775 | } | |
776 | ||
777 | void | |
778 | _initialize_linux_fork (void) | |
779 | { | |
780 | init_fork_list (); | |
781 | ||
ac264b3b MS |
782 | /* Checkpoint command: create a fork of the inferior process |
783 | and set it aside for later debugging. */ | |
784 | ||
785 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
786 | Fork a duplicate process (experimental).")); | |
787 | ||
2277426b PA |
788 | /* Restart command: restore the context of a specified checkpoint |
789 | process. */ | |
ac264b3b MS |
790 | |
791 | add_com ("restart", class_obscure, restart_command, _("\ | |
792 | restart <n>: restore program context from a checkpoint.\n\ | |
793 | Argument 'n' is checkpoint ID, as displayed by 'info checkpoints'.")); | |
794 | ||
b8db102d | 795 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 796 | the fork list. */ |
ac264b3b | 797 | |
3cb5bea9 | 798 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 799 | Delete a checkpoint (experimental)."), |
b8db102d | 800 | &deletelist); |
ac264b3b | 801 | |
3cb5bea9 | 802 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
803 | and remove it from the fork list. */ |
804 | ||
3cb5bea9 | 805 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 806 | Detach from a checkpoint (experimental)."), |
f73adfeb | 807 | &detachlist); |
ac264b3b | 808 | |
3cb5bea9 | 809 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
810 | currently under gdb's control. */ |
811 | ||
3cb5bea9 | 812 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 813 | _("IDs of currently known checkpoints.")); |
ac264b3b | 814 | } |