Commit | Line | Data |
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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
32d0add0 | 3 | Copyright (C) 2005-2015 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 MS |
32 | |
33 | #include <sys/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 | ||
41 | /* Prevent warning from -Wmissing-prototypes. */ | |
42 | extern void _initialize_linux_fork (void); | |
43 | ||
ac264b3b MS |
44 | /* Fork list data structure: */ |
45 | struct fork_info | |
46 | { | |
47 | struct fork_info *next; | |
48 | ptid_t ptid; | |
7a298875 | 49 | ptid_t parent_ptid; |
1777feb0 | 50 | int num; /* Convenient handle (GDB fork id). */ |
3cb5bea9 | 51 | struct regcache *savedregs; /* Convenient for info fork, saves |
ac264b3b MS |
52 | having to actually switch contexts. */ |
53 | int clobber_regs; /* True if we should restore saved regs. */ | |
ac264b3b MS |
54 | off_t *filepos; /* Set of open file descriptors' offsets. */ |
55 | int maxfd; | |
56 | }; | |
57 | ||
58 | /* Fork list methods: */ | |
59 | ||
3cb5bea9 | 60 | int |
ac264b3b MS |
61 | forks_exist_p (void) |
62 | { | |
63 | return (fork_list != NULL); | |
64 | } | |
65 | ||
3cb5bea9 | 66 | /* Add a fork to the internal fork list. */ |
ac264b3b | 67 | |
3cb5bea9 | 68 | struct fork_info * |
ac264b3b MS |
69 | add_fork (pid_t pid) |
70 | { | |
71 | struct fork_info *fp; | |
72 | ||
dfd4cc63 | 73 | if (fork_list == NULL && pid != ptid_get_pid (inferior_ptid)) |
ac264b3b MS |
74 | { |
75 | /* Special case -- if this is the first fork in the list | |
76 | (the list is hitherto empty), and if this new fork is | |
77 | NOT the current inferior_ptid, then add inferior_ptid | |
78 | first, as a special zeroeth fork id. */ | |
79 | highest_fork_num = -1; | |
dfd4cc63 | 80 | add_fork (ptid_get_pid (inferior_ptid)); /* safe recursion */ |
ac264b3b MS |
81 | } |
82 | ||
41bf6aca | 83 | fp = XCNEW (struct fork_info); |
f973ed9c | 84 | fp->ptid = ptid_build (pid, pid, 0); |
ac264b3b MS |
85 | fp->num = ++highest_fork_num; |
86 | fp->next = fork_list; | |
87 | fork_list = fp; | |
88 | return fp; | |
89 | } | |
90 | ||
91 | static void | |
92 | free_fork (struct fork_info *fp) | |
93 | { | |
94 | /* Notes on step-resume breakpoints: since this is a concern for | |
95 | threads, let's convince ourselves that it's not a concern for | |
96 | forks. There are two ways for a fork_info to be created. First, | |
97 | by the checkpoint command, in which case we're at a gdb prompt | |
98 | and there can't be any step-resume breakpoint. Second, by a fork | |
99 | in the user program, in which case we *may* have stepped into the | |
100 | fork call, but regardless of whether we follow the parent or the | |
101 | child, we will return to the same place and the step-resume | |
102 | breakpoint, if any, will take care of itself as usual. And | |
103 | unlike threads, we do not save a private copy of the step-resume | |
104 | breakpoint -- so we're OK. */ | |
105 | ||
106 | if (fp) | |
107 | { | |
108 | if (fp->savedregs) | |
109 | regcache_xfree (fp->savedregs); | |
110 | if (fp->filepos) | |
111 | xfree (fp->filepos); | |
112 | xfree (fp); | |
113 | } | |
114 | } | |
115 | ||
116 | static void | |
117 | delete_fork (ptid_t ptid) | |
118 | { | |
119 | struct fork_info *fp, *fpprev; | |
120 | ||
121 | fpprev = NULL; | |
122 | ||
26cb8b7c PA |
123 | linux_nat_forget_process (ptid_get_pid (ptid)); |
124 | ||
ac264b3b MS |
125 | for (fp = fork_list; fp; fpprev = fp, fp = fp->next) |
126 | if (ptid_equal (fp->ptid, ptid)) | |
127 | break; | |
128 | ||
129 | if (!fp) | |
130 | return; | |
131 | ||
132 | if (fpprev) | |
133 | fpprev->next = fp->next; | |
134 | else | |
135 | fork_list = fp->next; | |
136 | ||
137 | free_fork (fp); | |
138 | ||
3cb5bea9 | 139 | /* Special case: if there is now only one process in the list, |
ac264b3b MS |
140 | and if it is (hopefully!) the current inferior_ptid, then |
141 | remove it, leaving the list empty -- we're now down to the | |
142 | default case of debugging a single process. */ | |
143 | if (fork_list != NULL && fork_list->next == NULL && | |
144 | ptid_equal (fork_list->ptid, inferior_ptid)) | |
145 | { | |
146 | /* Last fork -- delete from list and handle as solo process | |
147 | (should be a safe recursion). */ | |
148 | delete_fork (inferior_ptid); | |
149 | } | |
150 | } | |
151 | ||
152 | /* Find a fork_info by matching PTID. */ | |
153 | static struct fork_info * | |
154 | find_fork_ptid (ptid_t ptid) | |
155 | { | |
156 | struct fork_info *fp; | |
157 | ||
158 | for (fp = fork_list; fp; fp = fp->next) | |
159 | if (ptid_equal (fp->ptid, ptid)) | |
160 | return fp; | |
161 | ||
162 | return NULL; | |
163 | } | |
164 | ||
165 | /* Find a fork_info by matching ID. */ | |
166 | static struct fork_info * | |
167 | find_fork_id (int num) | |
168 | { | |
169 | struct fork_info *fp; | |
170 | ||
171 | for (fp = fork_list; fp; fp = fp->next) | |
172 | if (fp->num == num) | |
173 | return fp; | |
174 | ||
175 | return NULL; | |
176 | } | |
177 | ||
178 | /* Find a fork_info by matching pid. */ | |
179 | extern struct fork_info * | |
180 | find_fork_pid (pid_t pid) | |
181 | { | |
182 | struct fork_info *fp; | |
183 | ||
184 | for (fp = fork_list; fp; fp = fp->next) | |
185 | if (pid == ptid_get_pid (fp->ptid)) | |
186 | return fp; | |
187 | ||
188 | return NULL; | |
189 | } | |
190 | ||
191 | static ptid_t | |
192 | fork_id_to_ptid (int num) | |
193 | { | |
194 | struct fork_info *fork = find_fork_id (num); | |
195 | if (fork) | |
196 | return fork->ptid; | |
197 | else | |
198 | return pid_to_ptid (-1); | |
199 | } | |
200 | ||
201 | static void | |
202 | init_fork_list (void) | |
203 | { | |
204 | struct fork_info *fp, *fpnext; | |
205 | ||
206 | if (!fork_list) | |
207 | return; | |
208 | ||
209 | for (fp = fork_list; fp; fp = fpnext) | |
210 | { | |
211 | fpnext = fp->next; | |
212 | free_fork (fp); | |
213 | } | |
214 | ||
215 | fork_list = NULL; | |
216 | } | |
217 | ||
218 | /* Fork list <-> gdb interface. */ | |
219 | ||
3cb5bea9 | 220 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
221 | Calls lseek in the (current) inferior process. */ |
222 | ||
223 | static off_t | |
224 | call_lseek (int fd, off_t offset, int whence) | |
225 | { | |
226 | char exp[80]; | |
227 | ||
228 | snprintf (&exp[0], sizeof (exp), "lseek (%d, %ld, %d)", | |
229 | fd, (long) offset, whence); | |
230 | return (off_t) parse_and_eval_long (&exp[0]); | |
231 | } | |
232 | ||
233 | /* Load infrun state for the fork PTID. */ | |
234 | ||
235 | static void | |
236 | fork_load_infrun_state (struct fork_info *fp) | |
237 | { | |
238 | extern void nullify_last_target_wait_ptid (); | |
239 | int i; | |
240 | ||
2277426b | 241 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 242 | |
ac264b3b | 243 | if (fp->savedregs && fp->clobber_regs) |
594f7785 | 244 | regcache_cpy (get_current_regcache (), fp->savedregs); |
ac264b3b | 245 | |
791b663b DJ |
246 | registers_changed (); |
247 | reinit_frame_cache (); | |
248 | ||
fb14de7b | 249 | stop_pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
250 | nullify_last_target_wait_ptid (); |
251 | ||
252 | /* Now restore the file positions of open file descriptors. */ | |
253 | if (fp->filepos) | |
254 | { | |
255 | for (i = 0; i <= fp->maxfd; i++) | |
256 | if (fp->filepos[i] != (off_t) -1) | |
257 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
258 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
259 | this is native-only. If it ever has to be cross, we'll have | |
260 | to rethink this. */ | |
261 | } | |
262 | } | |
263 | ||
264 | /* Save infrun state for the fork PTID. | |
265 | Exported for use by linux child_follow_fork. */ | |
266 | ||
2277426b | 267 | static void |
ac264b3b MS |
268 | fork_save_infrun_state (struct fork_info *fp, int clobber_regs) |
269 | { | |
d8d2a3ee | 270 | char path[PATH_MAX]; |
ac264b3b MS |
271 | struct dirent *de; |
272 | DIR *d; | |
273 | ||
274 | if (fp->savedregs) | |
275 | regcache_xfree (fp->savedregs); | |
276 | ||
594f7785 | 277 | fp->savedregs = regcache_dup (get_current_regcache ()); |
ac264b3b | 278 | fp->clobber_regs = clobber_regs; |
ac264b3b MS |
279 | |
280 | if (clobber_regs) | |
281 | { | |
282 | /* Now save the 'state' (file position) of all open file descriptors. | |
283 | Unfortunately fork does not take care of that for us... */ | |
dfd4cc63 LM |
284 | snprintf (path, PATH_MAX, "/proc/%ld/fd", |
285 | (long) ptid_get_pid (fp->ptid)); | |
ac264b3b MS |
286 | if ((d = opendir (path)) != NULL) |
287 | { | |
288 | long tmp; | |
289 | ||
290 | fp->maxfd = 0; | |
291 | while ((de = readdir (d)) != NULL) | |
292 | { | |
293 | /* Count open file descriptors (actually find highest | |
294 | numbered). */ | |
295 | tmp = strtol (&de->d_name[0], NULL, 10); | |
296 | if (fp->maxfd < tmp) | |
297 | fp->maxfd = tmp; | |
298 | } | |
299 | /* Allocate array of file positions. */ | |
3cb5bea9 | 300 | fp->filepos = xrealloc (fp->filepos, |
ac264b3b MS |
301 | (fp->maxfd + 1) * sizeof (*fp->filepos)); |
302 | ||
303 | /* Initialize to -1 (invalid). */ | |
304 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
305 | fp->filepos[tmp] = -1; | |
306 | ||
307 | /* Now find actual file positions. */ | |
308 | rewinddir (d); | |
309 | while ((de = readdir (d)) != NULL) | |
310 | if (isdigit (de->d_name[0])) | |
311 | { | |
312 | tmp = strtol (&de->d_name[0], NULL, 10); | |
313 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
314 | } | |
315 | closedir (d); | |
316 | } | |
317 | } | |
318 | } | |
319 | ||
320 | /* Kill 'em all, let God sort 'em out... */ | |
321 | ||
3cb5bea9 | 322 | void |
ac264b3b MS |
323 | linux_fork_killall (void) |
324 | { | |
325 | /* Walk list and kill every pid. No need to treat the | |
326 | current inferior_ptid as special (we do not return a | |
327 | status for it) -- however any process may be a child | |
328 | or a parent, so may get a SIGCHLD from a previously | |
329 | killed child. Wait them all out. */ | |
56aac7e8 | 330 | struct fork_info *fp; |
ac264b3b MS |
331 | pid_t pid, ret; |
332 | int status; | |
333 | ||
56aac7e8 MS |
334 | for (fp = fork_list; fp; fp = fp->next) |
335 | { | |
dfd4cc63 | 336 | pid = ptid_get_pid (fp->ptid); |
56aac7e8 | 337 | do { |
4c28f408 PA |
338 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
339 | if the thread is running, while the later doesn't. */ | |
340 | kill (pid, SIGKILL); | |
56aac7e8 MS |
341 | ret = waitpid (pid, &status, 0); |
342 | /* We might get a SIGCHLD instead of an exit status. This is | |
343 | aggravated by the first kill above - a child has just | |
344 | died. MVS comment cut-and-pasted from linux-nat. */ | |
345 | } while (ret == pid && WIFSTOPPED (status)); | |
346 | } | |
347 | init_fork_list (); /* Clear list, prepare to start fresh. */ | |
ac264b3b MS |
348 | } |
349 | ||
350 | /* The current inferior_ptid has exited, but there are other viable | |
351 | forks to debug. Delete the exiting one and context-switch to the | |
352 | first available. */ | |
353 | ||
3cb5bea9 | 354 | void |
ac264b3b MS |
355 | linux_fork_mourn_inferior (void) |
356 | { | |
357 | /* Wait just one more time to collect the inferior's exit status. | |
358 | Do not check whether this succeeds though, since we may be | |
359 | dealing with a process that we attached to. Such a process will | |
360 | only report its exit status to its original parent. */ | |
361 | int status; | |
362 | ||
363 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); | |
364 | ||
365 | /* OK, presumably inferior_ptid is the one who has exited. | |
366 | We need to delete that one from the fork_list, and switch | |
367 | to the next available fork. */ | |
368 | delete_fork (inferior_ptid); | |
791b663b DJ |
369 | |
370 | /* There should still be a fork - if there's only one left, | |
371 | delete_fork won't remove it, because we haven't updated | |
372 | inferior_ptid yet. */ | |
373 | gdb_assert (fork_list); | |
374 | ||
375 | fork_load_infrun_state (fork_list); | |
376 | printf_filtered (_("[Switching to %s]\n"), | |
377 | target_pid_to_str (inferior_ptid)); | |
378 | ||
379 | /* If there's only one fork, switch back to non-fork mode. */ | |
380 | if (fork_list->next == NULL) | |
381 | delete_fork (inferior_ptid); | |
ac264b3b MS |
382 | } |
383 | ||
7a7d3353 PA |
384 | /* The current inferior_ptid is being detached, but there are other |
385 | viable forks to debug. Detach and delete it and context-switch to | |
386 | the first available. */ | |
387 | ||
3cb5bea9 | 388 | void |
52554a0e | 389 | linux_fork_detach (const char *args, int from_tty) |
7a7d3353 PA |
390 | { |
391 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
392 | delete it from the fork_list, and switch to the next available | |
393 | fork. */ | |
394 | ||
dfd4cc63 | 395 | if (ptrace (PTRACE_DETACH, ptid_get_pid (inferior_ptid), 0, 0)) |
7a7d3353 PA |
396 | error (_("Unable to detach %s"), target_pid_to_str (inferior_ptid)); |
397 | ||
398 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
399 | |
400 | /* There should still be a fork - if there's only one left, | |
401 | delete_fork won't remove it, because we haven't updated | |
402 | inferior_ptid yet. */ | |
403 | gdb_assert (fork_list); | |
404 | ||
405 | fork_load_infrun_state (fork_list); | |
406 | ||
407 | if (from_tty) | |
408 | printf_filtered (_("[Switching to %s]\n"), | |
409 | target_pid_to_str (inferior_ptid)); | |
410 | ||
411 | /* If there's only one fork, switch back to non-fork mode. */ | |
412 | if (fork_list->next == NULL) | |
413 | delete_fork (inferior_ptid); | |
414 | } | |
415 | ||
7a298875 HZ |
416 | static void |
417 | inferior_call_waitpid_cleanup (void *fp) | |
418 | { | |
419 | struct fork_info *oldfp = fp; | |
420 | ||
e17c9e56 HZ |
421 | if (oldfp) |
422 | { | |
1777feb0 | 423 | /* Switch back to inferior_ptid. */ |
e17c9e56 HZ |
424 | remove_breakpoints (); |
425 | fork_load_infrun_state (oldfp); | |
426 | insert_breakpoints (); | |
427 | } | |
7a298875 HZ |
428 | } |
429 | ||
430 | static int | |
431 | inferior_call_waitpid (ptid_t pptid, int pid) | |
432 | { | |
433 | struct objfile *waitpid_objf; | |
434 | struct value *waitpid_fn = NULL; | |
e17c9e56 | 435 | struct value *argv[4], *retv; |
7a298875 HZ |
436 | struct gdbarch *gdbarch = get_current_arch (); |
437 | struct fork_info *oldfp = NULL, *newfp = NULL; | |
e17c9e56 | 438 | struct cleanup *old_cleanup; |
7a298875 HZ |
439 | int ret = -1; |
440 | ||
441 | if (!ptid_equal (pptid, inferior_ptid)) | |
442 | { | |
443 | /* Switch to pptid. */ | |
444 | oldfp = find_fork_ptid (inferior_ptid); | |
445 | gdb_assert (oldfp != NULL); | |
446 | newfp = find_fork_ptid (pptid); | |
da3ecdc6 | 447 | gdb_assert (newfp != NULL); |
7a298875 HZ |
448 | fork_save_infrun_state (oldfp, 1); |
449 | remove_breakpoints (); | |
450 | fork_load_infrun_state (newfp); | |
451 | insert_breakpoints (); | |
7a298875 HZ |
452 | } |
453 | ||
e17c9e56 HZ |
454 | old_cleanup = make_cleanup (inferior_call_waitpid_cleanup, oldfp); |
455 | ||
7a298875 | 456 | /* Get the waitpid_fn. */ |
3b7344d5 | 457 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 458 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
459 | if (!waitpid_fn |
460 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 HZ |
461 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
462 | if (!waitpid_fn) | |
463 | goto out; | |
464 | ||
465 | /* Get the argv. */ | |
466 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
467 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
468 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
469 | argv[3] = 0; | |
470 | ||
e17c9e56 HZ |
471 | retv = call_function_by_hand (waitpid_fn, 3, argv); |
472 | if (value_as_long (retv) < 0) | |
473 | goto out; | |
7a298875 HZ |
474 | |
475 | ret = 0; | |
476 | ||
477 | out: | |
e17c9e56 | 478 | do_cleanups (old_cleanup); |
7a298875 HZ |
479 | return ret; |
480 | } | |
481 | ||
ac264b3b MS |
482 | /* Fork list <-> user interface. */ |
483 | ||
484 | static void | |
3cb5bea9 | 485 | delete_checkpoint_command (char *args, int from_tty) |
ac264b3b | 486 | { |
e17c9e56 | 487 | ptid_t ptid, pptid; |
7a298875 | 488 | struct fork_info *fi; |
ac264b3b MS |
489 | |
490 | if (!args || !*args) | |
2277426b | 491 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
492 | |
493 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
494 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 495 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
496 | |
497 | if (ptid_equal (ptid, inferior_ptid)) | |
3cb5bea9 PA |
498 | error (_("\ |
499 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 500 | |
dfd4cc63 | 501 | if (ptrace (PTRACE_KILL, ptid_get_pid (ptid), 0, 0)) |
54ba13f7 | 502 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid)); |
ac264b3b | 503 | |
7a298875 HZ |
504 | fi = find_fork_ptid (ptid); |
505 | gdb_assert (fi); | |
e17c9e56 | 506 | pptid = fi->parent_ptid; |
7a298875 | 507 | |
ac264b3b MS |
508 | if (from_tty) |
509 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid)); | |
510 | ||
511 | delete_fork (ptid); | |
7a298875 HZ |
512 | |
513 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
514 | list, waitpid the ptid. | |
515 | If fi->parent_ptid is a part of lwp and it is stoped, waitpid the | |
516 | ptid. */ | |
e17c9e56 HZ |
517 | if ((!find_thread_ptid (pptid) && find_fork_ptid (pptid)) |
518 | || (find_thread_ptid (pptid) && is_stopped (pptid))) | |
7a298875 | 519 | { |
dfd4cc63 | 520 | if (inferior_call_waitpid (pptid, ptid_get_pid (ptid))) |
7a298875 HZ |
521 | warning (_("Unable to wait pid %s"), target_pid_to_str (ptid)); |
522 | } | |
ac264b3b MS |
523 | } |
524 | ||
525 | static void | |
3cb5bea9 | 526 | detach_checkpoint_command (char *args, int from_tty) |
ac264b3b MS |
527 | { |
528 | ptid_t ptid; | |
529 | ||
530 | if (!args || !*args) | |
2277426b | 531 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
532 | |
533 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
534 | if (ptid_equal (ptid, minus_one_ptid)) | |
2277426b | 535 | error (_("No such checkpoint id, %s"), args); |
ac264b3b MS |
536 | |
537 | if (ptid_equal (ptid, inferior_ptid)) | |
2277426b PA |
538 | error (_("\ |
539 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 540 | |
dfd4cc63 | 541 | if (ptrace (PTRACE_DETACH, ptid_get_pid (ptid), 0, 0)) |
ac264b3b MS |
542 | error (_("Unable to detach %s"), target_pid_to_str (ptid)); |
543 | ||
544 | if (from_tty) | |
545 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid)); | |
546 | ||
547 | delete_fork (ptid); | |
548 | } | |
549 | ||
3cb5bea9 | 550 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
551 | |
552 | static void | |
3cb5bea9 | 553 | info_checkpoints_command (char *arg, int from_tty) |
ac264b3b | 554 | { |
5af949e3 | 555 | struct gdbarch *gdbarch = get_current_arch (); |
ac264b3b | 556 | struct symtab_and_line sal; |
ac264b3b | 557 | struct fork_info *fp; |
ac264b3b | 558 | ULONGEST pc; |
b8db102d MS |
559 | int requested = -1; |
560 | struct fork_info *printed = NULL; | |
561 | ||
562 | if (arg && *arg) | |
563 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b MS |
564 | |
565 | for (fp = fork_list; fp; fp = fp->next) | |
566 | { | |
b8db102d MS |
567 | if (requested > 0 && fp->num != requested) |
568 | continue; | |
569 | ||
570 | printed = fp; | |
ac264b3b MS |
571 | if (ptid_equal (fp->ptid, inferior_ptid)) |
572 | { | |
573 | printf_filtered ("* "); | |
fb14de7b | 574 | pc = regcache_read_pc (get_current_regcache ()); |
ac264b3b MS |
575 | } |
576 | else | |
577 | { | |
578 | printf_filtered (" "); | |
2277426b | 579 | pc = regcache_read_pc (fp->savedregs); |
ac264b3b MS |
580 | } |
581 | printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid)); | |
582 | if (fp->num == 0) | |
583 | printf_filtered (_(" (main process)")); | |
584 | printf_filtered (_(" at ")); | |
5af949e3 | 585 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b MS |
586 | |
587 | sal = find_pc_line (pc, 0); | |
588 | if (sal.symtab) | |
05cba821 JK |
589 | printf_filtered (_(", file %s"), |
590 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b MS |
591 | if (sal.line) |
592 | printf_filtered (_(", line %d"), sal.line); | |
593 | if (!sal.symtab && !sal.line) | |
594 | { | |
7cbd4a93 | 595 | struct bound_minimal_symbol msym; |
ac264b3b MS |
596 | |
597 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 | 598 | if (msym.minsym) |
efd66ac6 | 599 | printf_filtered (", <%s>", MSYMBOL_LINKAGE_NAME (msym.minsym)); |
ac264b3b MS |
600 | } |
601 | ||
602 | putchar_filtered ('\n'); | |
603 | } | |
b8db102d MS |
604 | if (printed == NULL) |
605 | { | |
606 | if (requested > 0) | |
2277426b | 607 | printf_filtered (_("No checkpoint number %d.\n"), requested); |
b8db102d | 608 | else |
2277426b | 609 | printf_filtered (_("No checkpoints.\n")); |
b8db102d | 610 | } |
ac264b3b MS |
611 | } |
612 | ||
2277426b PA |
613 | /* The PID of the process we're checkpointing. */ |
614 | static int checkpointing_pid = 0; | |
ac264b3b | 615 | |
2277426b PA |
616 | int |
617 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 618 | { |
2277426b | 619 | return (checkpointing_pid == pid); |
ac264b3b MS |
620 | } |
621 | ||
92f6badc KP |
622 | /* Callback for iterate over threads. Used to check whether |
623 | the current inferior is multi-threaded. Returns true as soon | |
624 | as it sees the second thread of the current inferior. */ | |
625 | ||
626 | static int | |
627 | inf_has_multiple_thread_cb (struct thread_info *tp, void *data) | |
628 | { | |
629 | int *count_p = (int *) data; | |
630 | ||
631 | if (current_inferior ()->pid == ptid_get_pid (tp->ptid)) | |
632 | (*count_p)++; | |
633 | ||
634 | /* Stop the iteration if multiple threads have been detected. */ | |
635 | return *count_p > 1; | |
636 | } | |
637 | ||
638 | /* Return true if the current inferior is multi-threaded. */ | |
639 | ||
640 | static int | |
641 | inf_has_multiple_threads (void) | |
642 | { | |
643 | int count = 0; | |
644 | ||
645 | iterate_over_threads (inf_has_multiple_thread_cb, &count); | |
646 | return (count > 1); | |
647 | } | |
648 | ||
ac264b3b MS |
649 | static void |
650 | checkpoint_command (char *args, int from_tty) | |
651 | { | |
3e3b026f UW |
652 | struct objfile *fork_objf; |
653 | struct gdbarch *gdbarch; | |
ac264b3b MS |
654 | struct target_waitstatus last_target_waitstatus; |
655 | ptid_t last_target_ptid; | |
656 | struct value *fork_fn = NULL, *ret; | |
657 | struct fork_info *fp; | |
658 | pid_t retpid; | |
659 | struct cleanup *old_chain; | |
74960c60 | 660 | |
92f6badc KP |
661 | if (!target_has_execution) |
662 | error (_("The program is not being run.")); | |
663 | ||
664 | /* Ensure that the inferior is not multithreaded. */ | |
665 | update_thread_list (); | |
666 | if (inf_has_multiple_threads ()) | |
667 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
668 | ||
ac264b3b MS |
669 | /* Make the inferior fork, record its (and gdb's) state. */ |
670 | ||
3b7344d5 | 671 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 672 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 673 | if (!fork_fn) |
3b7344d5 | 674 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 675 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
676 | if (!fork_fn) |
677 | error (_("checkpoint: can't find fork function in inferior.")); | |
678 | ||
3e3b026f UW |
679 | gdbarch = get_objfile_arch (fork_objf); |
680 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
681 | |
682 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
683 | old_chain = make_cleanup_restore_integer (&checkpointing_pid); | |
dfd4cc63 | 684 | checkpointing_pid = ptid_get_pid (inferior_ptid); |
2277426b | 685 | |
ac264b3b MS |
686 | ret = call_function_by_hand (fork_fn, 0, &ret); |
687 | do_cleanups (old_chain); | |
688 | if (!ret) /* Probably can't happen. */ | |
689 | error (_("checkpoint: call_function_by_hand returned null.")); | |
690 | ||
691 | retpid = value_as_long (ret); | |
692 | get_last_target_status (&last_target_ptid, &last_target_waitstatus); | |
6f9d33d8 PP |
693 | |
694 | fp = find_fork_pid (retpid); | |
695 | ||
ac264b3b MS |
696 | if (from_tty) |
697 | { | |
698 | int parent_pid; | |
699 | ||
6f9d33d8 PP |
700 | printf_filtered (_("checkpoint %d: fork returned pid %ld.\n"), |
701 | fp != NULL ? fp->num : -1, (long) retpid); | |
ac264b3b MS |
702 | if (info_verbose) |
703 | { | |
704 | parent_pid = ptid_get_lwp (last_target_ptid); | |
705 | if (parent_pid == 0) | |
706 | parent_pid = ptid_get_pid (last_target_ptid); | |
3cb5bea9 | 707 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
708 | (long) parent_pid); |
709 | } | |
710 | } | |
711 | ||
ac264b3b MS |
712 | if (!fp) |
713 | error (_("Failed to find new fork")); | |
714 | fork_save_infrun_state (fp, 1); | |
7a298875 | 715 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
716 | } |
717 | ||
718 | static void | |
719 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
720 | { | |
721 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 722 | struct fork_info *oldfp; |
ac264b3b | 723 | |
0d14fc63 | 724 | gdb_assert (newfp != NULL); |
ac264b3b | 725 | |
0d14fc63 PA |
726 | oldfp = find_fork_ptid (inferior_ptid); |
727 | gdb_assert (oldfp != NULL); | |
ac264b3b MS |
728 | |
729 | fork_save_infrun_state (oldfp, 1); | |
74960c60 | 730 | remove_breakpoints (); |
ac264b3b | 731 | fork_load_infrun_state (newfp); |
74960c60 | 732 | insert_breakpoints (); |
ac264b3b | 733 | |
3cb5bea9 | 734 | printf_filtered (_("Switching to %s\n"), |
ac264b3b MS |
735 | target_pid_to_str (inferior_ptid)); |
736 | ||
08d72866 | 737 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
738 | } |
739 | ||
2277426b | 740 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b MS |
741 | static void |
742 | restart_command (char *args, int from_tty) | |
743 | { | |
744 | struct fork_info *fp; | |
745 | ||
746 | if (!args || !*args) | |
747 | error (_("Requires argument (checkpoint id to restart)")); | |
748 | ||
749 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
750 | error (_("Not found: checkpoint id %s"), args); | |
751 | ||
752 | linux_fork_context (fp, from_tty); | |
753 | } | |
754 | ||
755 | void | |
756 | _initialize_linux_fork (void) | |
757 | { | |
758 | init_fork_list (); | |
759 | ||
ac264b3b MS |
760 | /* Checkpoint command: create a fork of the inferior process |
761 | and set it aside for later debugging. */ | |
762 | ||
763 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
764 | Fork a duplicate process (experimental).")); | |
765 | ||
2277426b PA |
766 | /* Restart command: restore the context of a specified checkpoint |
767 | process. */ | |
ac264b3b MS |
768 | |
769 | add_com ("restart", class_obscure, restart_command, _("\ | |
770 | restart <n>: restore program context from a checkpoint.\n\ | |
771 | Argument 'n' is checkpoint ID, as displayed by 'info checkpoints'.")); | |
772 | ||
b8db102d | 773 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 774 | the fork list. */ |
ac264b3b | 775 | |
3cb5bea9 | 776 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 777 | Delete a checkpoint (experimental)."), |
b8db102d | 778 | &deletelist); |
ac264b3b | 779 | |
3cb5bea9 | 780 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
781 | and remove it from the fork list. */ |
782 | ||
3cb5bea9 | 783 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 784 | Detach from a checkpoint (experimental)."), |
f73adfeb | 785 | &detachlist); |
ac264b3b | 786 | |
3cb5bea9 | 787 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
788 | currently under gdb's control. */ |
789 | ||
3cb5bea9 | 790 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 791 | _("IDs of currently known checkpoints.")); |
ac264b3b | 792 | } |