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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
b811d2c2 | 3 | Copyright (C) 2005-2020 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" |
268a13a5 | 34 | #include "gdbsupport/gdb_wait.h" |
2978b111 | 35 | #include <dirent.h> |
ac264b3b MS |
36 | #include <ctype.h> |
37 | ||
06974e6c | 38 | #include <list> |
ac264b3b | 39 | |
ac264b3b MS |
40 | /* Fork list data structure: */ |
41 | struct fork_info | |
42 | { | |
06974e6c PA |
43 | explicit fork_info (pid_t pid) |
44 | : ptid (pid, pid, 0) | |
45 | { | |
46 | } | |
47 | ||
48 | ~fork_info () | |
49 | { | |
50 | /* Notes on step-resume breakpoints: since this is a concern for | |
51 | threads, let's convince ourselves that it's not a concern for | |
52 | forks. There are two ways for a fork_info to be created. | |
53 | First, by the checkpoint command, in which case we're at a gdb | |
54 | prompt and there can't be any step-resume breakpoint. Second, | |
55 | by a fork in the user program, in which case we *may* have | |
56 | stepped into the fork call, but regardless of whether we follow | |
57 | the parent or the child, we will return to the same place and | |
58 | the step-resume breakpoint, if any, will take care of itself as | |
59 | usual. And unlike threads, we do not save a private copy of | |
60 | the step-resume breakpoint -- so we're OK. */ | |
61 | ||
62 | if (savedregs) | |
63 | delete savedregs; | |
64 | if (filepos) | |
65 | xfree (filepos); | |
66 | } | |
67 | ||
68 | ptid_t ptid = null_ptid; | |
69 | ptid_t parent_ptid = null_ptid; | |
70 | ||
71 | /* Convenient handle (GDB fork id). */ | |
72 | int num = 0; | |
73 | ||
74 | /* Convenient for info fork, saves having to actually switch | |
75 | contexts. */ | |
76 | readonly_detached_regcache *savedregs = nullptr; | |
77 | ||
78 | CORE_ADDR pc = 0; | |
79 | ||
06974e6c PA |
80 | /* Set of open file descriptors' offsets. */ |
81 | off_t *filepos = nullptr; | |
82 | ||
83 | int maxfd = 0; | |
ac264b3b MS |
84 | }; |
85 | ||
06974e6c PA |
86 | static std::list<fork_info> fork_list; |
87 | static int highest_fork_num; | |
88 | ||
ac264b3b MS |
89 | /* Fork list methods: */ |
90 | ||
3cb5bea9 | 91 | int |
ac264b3b MS |
92 | forks_exist_p (void) |
93 | { | |
06974e6c | 94 | return !fork_list.empty (); |
ac264b3b MS |
95 | } |
96 | ||
2f341b6e PA |
97 | /* Return the last fork in the list. */ |
98 | ||
99 | static struct fork_info * | |
100 | find_last_fork (void) | |
101 | { | |
06974e6c | 102 | if (fork_list.empty ()) |
2f341b6e PA |
103 | return NULL; |
104 | ||
06974e6c | 105 | return &fork_list.back (); |
2f341b6e PA |
106 | } |
107 | ||
06974e6c | 108 | /* Return true iff there's one fork in the list. */ |
ac264b3b | 109 | |
06974e6c PA |
110 | static bool |
111 | one_fork_p () | |
ac264b3b | 112 | { |
06974e6c PA |
113 | return (!fork_list.empty () |
114 | && &fork_list.front () == &fork_list.back ()); | |
72f31aea PA |
115 | } |
116 | ||
117 | /* Add a new fork to the internal fork list. */ | |
118 | ||
119 | void | |
120 | add_fork (pid_t pid) | |
121 | { | |
06974e6c | 122 | fork_list.emplace_back (pid); |
2f341b6e | 123 | |
06974e6c PA |
124 | if (one_fork_p ()) |
125 | highest_fork_num = 0; | |
2f341b6e | 126 | |
06974e6c | 127 | fork_info *fp = &fork_list.back (); |
72f31aea | 128 | fp->num = ++highest_fork_num; |
ac264b3b MS |
129 | } |
130 | ||
ac264b3b MS |
131 | static void |
132 | delete_fork (ptid_t ptid) | |
133 | { | |
e99b03dc | 134 | linux_target->low_forget_process (ptid.pid ()); |
26cb8b7c | 135 | |
06974e6c PA |
136 | for (auto it = fork_list.begin (); it != fork_list.end (); ++it) |
137 | if (it->ptid == ptid) | |
138 | { | |
139 | fork_list.erase (it); | |
ac264b3b | 140 | |
06974e6c PA |
141 | /* Special case: if there is now only one process in the list, |
142 | and if it is (hopefully!) the current inferior_ptid, then | |
143 | remove it, leaving the list empty -- we're now down to the | |
144 | default case of debugging a single process. */ | |
145 | if (one_fork_p () && fork_list.front ().ptid == inferior_ptid) | |
146 | { | |
147 | /* Last fork -- delete from list and handle as solo | |
148 | process (should be a safe recursion). */ | |
149 | delete_fork (inferior_ptid); | |
150 | } | |
151 | return; | |
152 | } | |
ac264b3b MS |
153 | } |
154 | ||
155 | /* Find a fork_info by matching PTID. */ | |
156 | static struct fork_info * | |
157 | find_fork_ptid (ptid_t ptid) | |
158 | { | |
06974e6c PA |
159 | for (fork_info &fi : fork_list) |
160 | if (fi.ptid == ptid) | |
161 | return &fi; | |
ac264b3b MS |
162 | |
163 | return NULL; | |
164 | } | |
165 | ||
166 | /* Find a fork_info by matching ID. */ | |
167 | static struct fork_info * | |
168 | find_fork_id (int num) | |
169 | { | |
06974e6c PA |
170 | for (fork_info &fi : fork_list) |
171 | if (fi.num == num) | |
172 | return &fi; | |
ac264b3b MS |
173 | |
174 | return NULL; | |
175 | } | |
176 | ||
177 | /* Find a fork_info by matching pid. */ | |
178 | extern struct fork_info * | |
179 | find_fork_pid (pid_t pid) | |
180 | { | |
06974e6c PA |
181 | for (fork_info &fi : fork_list) |
182 | if (pid == fi.ptid.pid ()) | |
183 | return &fi; | |
ac264b3b MS |
184 | |
185 | return NULL; | |
186 | } | |
187 | ||
188 | static ptid_t | |
189 | fork_id_to_ptid (int num) | |
190 | { | |
191 | struct fork_info *fork = find_fork_id (num); | |
192 | if (fork) | |
193 | return fork->ptid; | |
194 | else | |
f2907e49 | 195 | return ptid_t (-1); |
ac264b3b MS |
196 | } |
197 | ||
ac264b3b MS |
198 | /* Fork list <-> gdb interface. */ |
199 | ||
3cb5bea9 | 200 | /* Utility function for fork_load/fork_save. |
ac264b3b MS |
201 | Calls lseek in the (current) inferior process. */ |
202 | ||
203 | static off_t | |
204 | call_lseek (int fd, off_t offset, int whence) | |
205 | { | |
206 | char exp[80]; | |
207 | ||
7022349d | 208 | snprintf (&exp[0], sizeof (exp), "(long) lseek (%d, %ld, %d)", |
ac264b3b MS |
209 | fd, (long) offset, whence); |
210 | return (off_t) parse_and_eval_long (&exp[0]); | |
211 | } | |
212 | ||
213 | /* Load infrun state for the fork PTID. */ | |
214 | ||
215 | static void | |
216 | fork_load_infrun_state (struct fork_info *fp) | |
217 | { | |
ac264b3b MS |
218 | int i; |
219 | ||
2277426b | 220 | linux_nat_switch_fork (fp->ptid); |
f973ed9c | 221 | |
b7e60d85 | 222 | if (fp->savedregs) |
fc5b8736 | 223 | get_current_regcache ()->restore (fp->savedregs); |
ac264b3b | 224 | |
791b663b DJ |
225 | registers_changed (); |
226 | reinit_frame_cache (); | |
227 | ||
f2ffa92b PA |
228 | inferior_thread ()->suspend.stop_pc |
229 | = regcache_read_pc (get_current_regcache ()); | |
ac264b3b MS |
230 | nullify_last_target_wait_ptid (); |
231 | ||
232 | /* Now restore the file positions of open file descriptors. */ | |
233 | if (fp->filepos) | |
234 | { | |
235 | for (i = 0; i <= fp->maxfd; i++) | |
236 | if (fp->filepos[i] != (off_t) -1) | |
237 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
238 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
239 | this is native-only. If it ever has to be cross, we'll have | |
240 | to rethink this. */ | |
241 | } | |
242 | } | |
243 | ||
b7e60d85 | 244 | /* Save infrun state for the fork FP. */ |
ac264b3b | 245 | |
2277426b | 246 | static void |
b7e60d85 | 247 | fork_save_infrun_state (struct fork_info *fp) |
ac264b3b | 248 | { |
d8d2a3ee | 249 | char path[PATH_MAX]; |
ac264b3b MS |
250 | struct dirent *de; |
251 | DIR *d; | |
252 | ||
253 | if (fp->savedregs) | |
c0e383c6 | 254 | delete fp->savedregs; |
ac264b3b | 255 | |
daf6667d YQ |
256 | fp->savedregs = new readonly_detached_regcache (*get_current_regcache ()); |
257 | fp->pc = regcache_read_pc (get_current_regcache ()); | |
ac264b3b | 258 | |
b7e60d85 PA |
259 | /* Now save the 'state' (file position) of all open file descriptors. |
260 | Unfortunately fork does not take care of that for us... */ | |
261 | snprintf (path, PATH_MAX, "/proc/%ld/fd", (long) fp->ptid.pid ()); | |
262 | if ((d = opendir (path)) != NULL) | |
ac264b3b | 263 | { |
b7e60d85 PA |
264 | long tmp; |
265 | ||
266 | fp->maxfd = 0; | |
267 | while ((de = readdir (d)) != NULL) | |
ac264b3b | 268 | { |
b7e60d85 PA |
269 | /* Count open file descriptors (actually find highest |
270 | numbered). */ | |
271 | tmp = strtol (&de->d_name[0], NULL, 10); | |
272 | if (fp->maxfd < tmp) | |
273 | fp->maxfd = tmp; | |
ac264b3b | 274 | } |
b7e60d85 PA |
275 | /* Allocate array of file positions. */ |
276 | fp->filepos = XRESIZEVEC (off_t, fp->filepos, fp->maxfd + 1); | |
277 | ||
278 | /* Initialize to -1 (invalid). */ | |
279 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
280 | fp->filepos[tmp] = -1; | |
281 | ||
282 | /* Now find actual file positions. */ | |
283 | rewinddir (d); | |
284 | while ((de = readdir (d)) != NULL) | |
285 | if (isdigit (de->d_name[0])) | |
286 | { | |
287 | tmp = strtol (&de->d_name[0], NULL, 10); | |
288 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
289 | } | |
290 | closedir (d); | |
ac264b3b MS |
291 | } |
292 | } | |
293 | ||
294 | /* Kill 'em all, let God sort 'em out... */ | |
295 | ||
3cb5bea9 | 296 | void |
ac264b3b MS |
297 | linux_fork_killall (void) |
298 | { | |
299 | /* Walk list and kill every pid. No need to treat the | |
300 | current inferior_ptid as special (we do not return a | |
301 | status for it) -- however any process may be a child | |
302 | or a parent, so may get a SIGCHLD from a previously | |
303 | killed child. Wait them all out. */ | |
ac264b3b | 304 | |
06974e6c | 305 | for (fork_info &fi : fork_list) |
56aac7e8 | 306 | { |
06974e6c PA |
307 | pid_t pid = fi.ptid.pid (); |
308 | int status; | |
309 | pid_t ret; | |
56aac7e8 | 310 | do { |
4c28f408 PA |
311 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
312 | if the thread is running, while the later doesn't. */ | |
313 | kill (pid, SIGKILL); | |
56aac7e8 MS |
314 | ret = waitpid (pid, &status, 0); |
315 | /* We might get a SIGCHLD instead of an exit status. This is | |
316 | aggravated by the first kill above - a child has just | |
317 | died. MVS comment cut-and-pasted from linux-nat. */ | |
318 | } while (ret == pid && WIFSTOPPED (status)); | |
319 | } | |
06974e6c PA |
320 | |
321 | /* Clear list, prepare to start fresh. */ | |
322 | fork_list.clear (); | |
ac264b3b MS |
323 | } |
324 | ||
325 | /* The current inferior_ptid has exited, but there are other viable | |
326 | forks to debug. Delete the exiting one and context-switch to the | |
327 | first available. */ | |
328 | ||
3cb5bea9 | 329 | void |
ac264b3b MS |
330 | linux_fork_mourn_inferior (void) |
331 | { | |
2f341b6e PA |
332 | struct fork_info *last; |
333 | int status; | |
334 | ||
ac264b3b MS |
335 | /* Wait just one more time to collect the inferior's exit status. |
336 | Do not check whether this succeeds though, since we may be | |
337 | dealing with a process that we attached to. Such a process will | |
338 | only report its exit status to its original parent. */ | |
e99b03dc | 339 | waitpid (inferior_ptid.pid (), &status, 0); |
ac264b3b MS |
340 | |
341 | /* OK, presumably inferior_ptid is the one who has exited. | |
342 | We need to delete that one from the fork_list, and switch | |
343 | to the next available fork. */ | |
344 | delete_fork (inferior_ptid); | |
791b663b DJ |
345 | |
346 | /* There should still be a fork - if there's only one left, | |
347 | delete_fork won't remove it, because we haven't updated | |
348 | inferior_ptid yet. */ | |
06974e6c | 349 | gdb_assert (!fork_list.empty ()); |
791b663b | 350 | |
2f341b6e PA |
351 | last = find_last_fork (); |
352 | fork_load_infrun_state (last); | |
791b663b | 353 | printf_filtered (_("[Switching to %s]\n"), |
a068643d | 354 | target_pid_to_str (inferior_ptid).c_str ()); |
791b663b DJ |
355 | |
356 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 357 | if (one_fork_p ()) |
791b663b | 358 | delete_fork (inferior_ptid); |
ac264b3b MS |
359 | } |
360 | ||
7a7d3353 PA |
361 | /* The current inferior_ptid is being detached, but there are other |
362 | viable forks to debug. Detach and delete it and context-switch to | |
363 | the first available. */ | |
364 | ||
3cb5bea9 | 365 | void |
6bd6f3b6 | 366 | linux_fork_detach (int from_tty) |
7a7d3353 PA |
367 | { |
368 | /* OK, inferior_ptid is the one we are detaching from. We need to | |
369 | delete it from the fork_list, and switch to the next available | |
370 | fork. */ | |
371 | ||
e99b03dc | 372 | if (ptrace (PTRACE_DETACH, inferior_ptid.pid (), 0, 0)) |
a068643d TT |
373 | error (_("Unable to detach %s"), |
374 | target_pid_to_str (inferior_ptid).c_str ()); | |
7a7d3353 PA |
375 | |
376 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
377 | |
378 | /* There should still be a fork - if there's only one left, | |
379 | delete_fork won't remove it, because we haven't updated | |
380 | inferior_ptid yet. */ | |
06974e6c | 381 | gdb_assert (!fork_list.empty ()); |
7a7d3353 | 382 | |
06974e6c | 383 | fork_load_infrun_state (&fork_list.front ()); |
7a7d3353 PA |
384 | |
385 | if (from_tty) | |
386 | printf_filtered (_("[Switching to %s]\n"), | |
a068643d | 387 | target_pid_to_str (inferior_ptid).c_str ()); |
7a7d3353 PA |
388 | |
389 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 390 | if (one_fork_p ()) |
7a7d3353 PA |
391 | delete_fork (inferior_ptid); |
392 | } | |
393 | ||
a07c8880 AB |
394 | /* Temporarily switch to the infrun state stored on the fork_info |
395 | identified by a given ptid_t. When this object goes out of scope, | |
396 | restore the currently selected infrun state. */ | |
7a298875 | 397 | |
a07c8880 AB |
398 | class scoped_switch_fork_info |
399 | { | |
400 | public: | |
401 | /* Switch to the infrun state held on the fork_info identified by | |
402 | PPTID. If PPTID is the current inferior then no switch is done. */ | |
1ef8573c | 403 | explicit scoped_switch_fork_info (ptid_t pptid) |
a07c8880 AB |
404 | : m_oldfp (nullptr) |
405 | { | |
406 | if (pptid != inferior_ptid) | |
407 | { | |
408 | struct fork_info *newfp = nullptr; | |
409 | ||
410 | /* Switch to pptid. */ | |
411 | m_oldfp = find_fork_ptid (inferior_ptid); | |
412 | gdb_assert (m_oldfp != nullptr); | |
413 | newfp = find_fork_ptid (pptid); | |
414 | gdb_assert (newfp != nullptr); | |
b7e60d85 | 415 | fork_save_infrun_state (m_oldfp); |
a07c8880 AB |
416 | remove_breakpoints (); |
417 | fork_load_infrun_state (newfp); | |
418 | insert_breakpoints (); | |
419 | } | |
420 | } | |
421 | ||
422 | /* Restore the previously selected infrun state. If the constructor | |
423 | didn't need to switch states, then nothing is done here either. */ | |
424 | ~scoped_switch_fork_info () | |
425 | { | |
426 | if (m_oldfp != nullptr) | |
427 | { | |
428 | /* Switch back to inferior_ptid. */ | |
a70b8144 | 429 | try |
1ef8573c AB |
430 | { |
431 | remove_breakpoints (); | |
432 | fork_load_infrun_state (m_oldfp); | |
433 | insert_breakpoints (); | |
434 | } | |
230d2906 | 435 | catch (const gdb_exception &ex) |
1ef8573c AB |
436 | { |
437 | warning (_("Couldn't restore checkpoint state in %s: %s"), | |
3d6e9d23 TT |
438 | target_pid_to_str (m_oldfp->ptid).c_str (), |
439 | ex.what ()); | |
1ef8573c | 440 | } |
a07c8880 AB |
441 | } |
442 | } | |
443 | ||
444 | DISABLE_COPY_AND_ASSIGN (scoped_switch_fork_info); | |
445 | ||
446 | private: | |
447 | /* The fork_info for the previously selected infrun state, or nullptr if | |
448 | we were already in the desired state, and nothing needs to be | |
449 | restored. */ | |
450 | struct fork_info *m_oldfp; | |
451 | }; | |
7a298875 HZ |
452 | |
453 | static int | |
454 | inferior_call_waitpid (ptid_t pptid, int pid) | |
455 | { | |
456 | struct objfile *waitpid_objf; | |
457 | struct value *waitpid_fn = NULL; | |
7a298875 HZ |
458 | int ret = -1; |
459 | ||
a07c8880 | 460 | scoped_switch_fork_info switch_fork_info (pptid); |
e17c9e56 | 461 | |
7a298875 | 462 | /* Get the waitpid_fn. */ |
3b7344d5 | 463 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 464 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
465 | if (!waitpid_fn |
466 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 | 467 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
a07c8880 AB |
468 | if (waitpid_fn != nullptr) |
469 | { | |
470 | struct gdbarch *gdbarch = get_current_arch (); | |
471 | struct value *argv[3], *retv; | |
7a298875 | 472 | |
a07c8880 AB |
473 | /* Get the argv. */ |
474 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
475 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
476 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
7a298875 | 477 | |
a07c8880 | 478 | retv = call_function_by_hand (waitpid_fn, NULL, argv); |
7a298875 | 479 | |
a07c8880 AB |
480 | if (value_as_long (retv) >= 0) |
481 | ret = 0; | |
482 | } | |
7a298875 | 483 | |
7a298875 HZ |
484 | return ret; |
485 | } | |
486 | ||
ac264b3b MS |
487 | /* Fork list <-> user interface. */ |
488 | ||
489 | static void | |
5b64bf74 | 490 | delete_checkpoint_command (const char *args, int from_tty) |
ac264b3b | 491 | { |
e17c9e56 | 492 | ptid_t ptid, pptid; |
7a298875 | 493 | struct fork_info *fi; |
ac264b3b MS |
494 | |
495 | if (!args || !*args) | |
2277426b | 496 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
497 | |
498 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 499 | if (ptid == minus_one_ptid) |
2277426b | 500 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 501 | |
d7e15655 | 502 | if (ptid == inferior_ptid) |
3cb5bea9 PA |
503 | error (_("\ |
504 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 505 | |
e99b03dc | 506 | if (ptrace (PTRACE_KILL, ptid.pid (), 0, 0)) |
a068643d | 507 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b | 508 | |
7a298875 HZ |
509 | fi = find_fork_ptid (ptid); |
510 | gdb_assert (fi); | |
e17c9e56 | 511 | pptid = fi->parent_ptid; |
7a298875 | 512 | |
ac264b3b | 513 | if (from_tty) |
a068643d | 514 | printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
515 | |
516 | delete_fork (ptid); | |
7a298875 HZ |
517 | |
518 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint | |
519 | list, waitpid the ptid. | |
00431a78 | 520 | If fi->parent_ptid is a part of lwp and it is stopped, waitpid the |
7a298875 | 521 | ptid. */ |
00431a78 PA |
522 | thread_info *parent = find_thread_ptid (pptid); |
523 | if ((parent == NULL && find_fork_ptid (pptid)) | |
524 | || (parent != NULL && parent->state == THREAD_STOPPED)) | |
7a298875 | 525 | { |
e99b03dc | 526 | if (inferior_call_waitpid (pptid, ptid.pid ())) |
a068643d TT |
527 | warning (_("Unable to wait pid %s"), |
528 | target_pid_to_str (ptid).c_str ()); | |
7a298875 | 529 | } |
ac264b3b MS |
530 | } |
531 | ||
532 | static void | |
5b64bf74 | 533 | detach_checkpoint_command (const char *args, int from_tty) |
ac264b3b MS |
534 | { |
535 | ptid_t ptid; | |
536 | ||
537 | if (!args || !*args) | |
2277426b | 538 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
539 | |
540 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 541 | if (ptid == minus_one_ptid) |
2277426b | 542 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 543 | |
d7e15655 | 544 | if (ptid == inferior_ptid) |
2277426b PA |
545 | error (_("\ |
546 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 547 | |
e99b03dc | 548 | if (ptrace (PTRACE_DETACH, ptid.pid (), 0, 0)) |
a068643d | 549 | error (_("Unable to detach %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
550 | |
551 | if (from_tty) | |
a068643d | 552 | printf_filtered (_("Detached %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
553 | |
554 | delete_fork (ptid); | |
555 | } | |
556 | ||
3cb5bea9 | 557 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
558 | |
559 | static void | |
1d12d88f | 560 | info_checkpoints_command (const char *arg, int from_tty) |
ac264b3b | 561 | { |
5af949e3 | 562 | struct gdbarch *gdbarch = get_current_arch (); |
b8db102d | 563 | int requested = -1; |
06974e6c | 564 | const fork_info *printed = NULL; |
b8db102d MS |
565 | |
566 | if (arg && *arg) | |
567 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b | 568 | |
06974e6c | 569 | for (const fork_info &fi : fork_list) |
ac264b3b | 570 | { |
06974e6c | 571 | if (requested > 0 && fi.num != requested) |
b8db102d MS |
572 | continue; |
573 | ||
06974e6c PA |
574 | printed = &fi; |
575 | if (fi.ptid == inferior_ptid) | |
daf6667d | 576 | printf_filtered ("* "); |
ac264b3b | 577 | else |
daf6667d YQ |
578 | printf_filtered (" "); |
579 | ||
06974e6c | 580 | ULONGEST pc = fi.pc; |
a068643d | 581 | printf_filtered ("%d %s", fi.num, target_pid_to_str (fi.ptid).c_str ()); |
06974e6c | 582 | if (fi.num == 0) |
ac264b3b MS |
583 | printf_filtered (_(" (main process)")); |
584 | printf_filtered (_(" at ")); | |
5af949e3 | 585 | fputs_filtered (paddress (gdbarch, pc), gdb_stdout); |
ac264b3b | 586 | |
06974e6c | 587 | symtab_and_line sal = find_pc_line (pc, 0); |
ac264b3b | 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) |
c9d95fa3 | 599 | printf_filtered (", <%s>", msym.minsym->linkage_name ()); |
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 | /* Return true if the current inferior is multi-threaded. */ |
623 | ||
e52c971f PA |
624 | static bool |
625 | inf_has_multiple_threads () | |
92f6badc KP |
626 | { |
627 | int count = 0; | |
628 | ||
e52c971f PA |
629 | /* Return true as soon as we see the second thread of the current |
630 | inferior. */ | |
631 | for (thread_info *tp ATTRIBUTE_UNUSED : current_inferior ()->threads ()) | |
632 | if (++count > 1) | |
633 | return true; | |
634 | ||
635 | return false; | |
92f6badc KP |
636 | } |
637 | ||
ac264b3b | 638 | static void |
0b39b52e | 639 | checkpoint_command (const char *args, int from_tty) |
ac264b3b | 640 | { |
3e3b026f UW |
641 | struct objfile *fork_objf; |
642 | struct gdbarch *gdbarch; | |
ac264b3b MS |
643 | struct target_waitstatus last_target_waitstatus; |
644 | ptid_t last_target_ptid; | |
645 | struct value *fork_fn = NULL, *ret; | |
646 | struct fork_info *fp; | |
647 | pid_t retpid; | |
74960c60 | 648 | |
92f6badc KP |
649 | if (!target_has_execution) |
650 | error (_("The program is not being run.")); | |
651 | ||
652 | /* Ensure that the inferior is not multithreaded. */ | |
653 | update_thread_list (); | |
654 | if (inf_has_multiple_threads ()) | |
655 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
656 | ||
ac264b3b MS |
657 | /* Make the inferior fork, record its (and gdb's) state. */ |
658 | ||
3b7344d5 | 659 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 660 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 661 | if (!fork_fn) |
3b7344d5 | 662 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 663 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
664 | if (!fork_fn) |
665 | error (_("checkpoint: can't find fork function in inferior.")); | |
666 | ||
3e3b026f UW |
667 | gdbarch = get_objfile_arch (fork_objf); |
668 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
2277426b PA |
669 | |
670 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
b7b633e9 TT |
671 | { |
672 | scoped_restore save_pid | |
e99b03dc | 673 | = make_scoped_restore (&checkpointing_pid, inferior_ptid.pid ()); |
b7b633e9 | 674 | |
e71585ff | 675 | ret = call_function_by_hand (fork_fn, NULL, {}); |
b7b633e9 | 676 | } |
2277426b | 677 | |
ac264b3b MS |
678 | if (!ret) /* Probably can't happen. */ |
679 | error (_("checkpoint: call_function_by_hand returned null.")); | |
680 | ||
681 | retpid = value_as_long (ret); | |
682 | get_last_target_status (&last_target_ptid, &last_target_waitstatus); | |
6f9d33d8 PP |
683 | |
684 | fp = find_fork_pid (retpid); | |
685 | ||
ac264b3b MS |
686 | if (from_tty) |
687 | { | |
688 | int parent_pid; | |
689 | ||
6f9d33d8 PP |
690 | printf_filtered (_("checkpoint %d: fork returned pid %ld.\n"), |
691 | fp != NULL ? fp->num : -1, (long) retpid); | |
ac264b3b MS |
692 | if (info_verbose) |
693 | { | |
e38504b3 | 694 | parent_pid = last_target_ptid.lwp (); |
ac264b3b | 695 | if (parent_pid == 0) |
e99b03dc | 696 | parent_pid = last_target_ptid.pid (); |
3cb5bea9 | 697 | printf_filtered (_(" gdb says parent = %ld.\n"), |
ac264b3b MS |
698 | (long) parent_pid); |
699 | } | |
700 | } | |
701 | ||
ac264b3b MS |
702 | if (!fp) |
703 | error (_("Failed to find new fork")); | |
72f31aea | 704 | |
06974e6c | 705 | if (one_fork_p ()) |
72f31aea PA |
706 | { |
707 | /* Special case -- if this is the first fork in the list (the | |
708 | list was hitherto empty), then add inferior_ptid first, as a | |
709 | special zeroeth fork id. */ | |
06974e6c | 710 | fork_list.emplace_front (inferior_ptid.pid ()); |
72f31aea PA |
711 | } |
712 | ||
b7e60d85 | 713 | fork_save_infrun_state (fp); |
7a298875 | 714 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
715 | } |
716 | ||
717 | static void | |
718 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
719 | { | |
720 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 721 | struct fork_info *oldfp; |
ac264b3b | 722 | |
0d14fc63 | 723 | gdb_assert (newfp != NULL); |
ac264b3b | 724 | |
0d14fc63 PA |
725 | oldfp = find_fork_ptid (inferior_ptid); |
726 | gdb_assert (oldfp != NULL); | |
ac264b3b | 727 | |
b7e60d85 | 728 | fork_save_infrun_state (oldfp); |
74960c60 | 729 | remove_breakpoints (); |
ac264b3b | 730 | fork_load_infrun_state (newfp); |
74960c60 | 731 | insert_breakpoints (); |
ac264b3b | 732 | |
3cb5bea9 | 733 | printf_filtered (_("Switching to %s\n"), |
a068643d | 734 | target_pid_to_str (inferior_ptid).c_str ()); |
ac264b3b | 735 | |
08d72866 | 736 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
737 | } |
738 | ||
2277426b | 739 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b | 740 | static void |
0b39b52e | 741 | restart_command (const char *args, int from_tty) |
ac264b3b MS |
742 | { |
743 | struct fork_info *fp; | |
744 | ||
745 | if (!args || !*args) | |
746 | error (_("Requires argument (checkpoint id to restart)")); | |
747 | ||
748 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
749 | error (_("Not found: checkpoint id %s"), args); | |
750 | ||
751 | linux_fork_context (fp, from_tty); | |
752 | } | |
753 | ||
754 | void | |
755 | _initialize_linux_fork (void) | |
756 | { | |
ac264b3b MS |
757 | /* Checkpoint command: create a fork of the inferior process |
758 | and set it aside for later debugging. */ | |
759 | ||
760 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
761 | Fork a duplicate process (experimental).")); | |
762 | ||
2277426b PA |
763 | /* Restart command: restore the context of a specified checkpoint |
764 | process. */ | |
ac264b3b MS |
765 | |
766 | add_com ("restart", class_obscure, restart_command, _("\ | |
590042fc PW |
767 | Restore program context from a checkpoint.\n\ |
768 | Usage: restart N\n\ | |
c8a15b78 | 769 | Argument N is checkpoint ID, as displayed by 'info checkpoints'.")); |
ac264b3b | 770 | |
b8db102d | 771 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 772 | the fork list. */ |
ac264b3b | 773 | |
3cb5bea9 | 774 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 775 | Delete a checkpoint (experimental)."), |
b8db102d | 776 | &deletelist); |
ac264b3b | 777 | |
3cb5bea9 | 778 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
779 | and remove it from the fork list. */ |
780 | ||
3cb5bea9 | 781 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 782 | Detach from a checkpoint (experimental)."), |
f73adfeb | 783 | &detachlist); |
ac264b3b | 784 | |
3cb5bea9 | 785 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
786 | currently under gdb's control. */ |
787 | ||
3cb5bea9 | 788 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 789 | _("IDs of currently known checkpoints.")); |
ac264b3b | 790 | } |