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ac264b3b MS |
1 | /* GNU/Linux native-dependent code for debugging multiple forks. |
2 | ||
1d506c26 | 3 | Copyright (C) 2005-2024 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" |
57e6a098 | 35 | #include "target/waitstatus.h" |
2978b111 | 36 | #include <dirent.h> |
ac264b3b MS |
37 | #include <ctype.h> |
38 | ||
06974e6c | 39 | #include <list> |
ac264b3b | 40 | |
ac264b3b MS |
41 | /* Fork list data structure: */ |
42 | struct fork_info | |
43 | { | |
06974e6c | 44 | explicit fork_info (pid_t pid) |
184ea2f7 | 45 | : ptid (pid, pid) |
06974e6c PA |
46 | { |
47 | } | |
48 | ||
49 | ~fork_info () | |
50 | { | |
51 | /* Notes on step-resume breakpoints: since this is a concern for | |
52 | threads, let's convince ourselves that it's not a concern for | |
53 | forks. There are two ways for a fork_info to be created. | |
54 | First, by the checkpoint command, in which case we're at a gdb | |
55 | prompt and there can't be any step-resume breakpoint. Second, | |
56 | by a fork in the user program, in which case we *may* have | |
57 | stepped into the fork call, but regardless of whether we follow | |
58 | the parent or the child, we will return to the same place and | |
59 | the step-resume breakpoint, if any, will take care of itself as | |
60 | usual. And unlike threads, we do not save a private copy of | |
61 | the step-resume breakpoint -- so we're OK. */ | |
62 | ||
63 | if (savedregs) | |
64 | delete savedregs; | |
84d53fa9 SM |
65 | |
66 | xfree (filepos); | |
06974e6c PA |
67 | } |
68 | ||
69 | ptid_t ptid = null_ptid; | |
70 | ptid_t parent_ptid = null_ptid; | |
71 | ||
72 | /* Convenient handle (GDB fork id). */ | |
73 | int num = 0; | |
74 | ||
75 | /* Convenient for info fork, saves having to actually switch | |
76 | contexts. */ | |
77 | readonly_detached_regcache *savedregs = nullptr; | |
78 | ||
79 | CORE_ADDR pc = 0; | |
80 | ||
06974e6c PA |
81 | /* Set of open file descriptors' offsets. */ |
82 | off_t *filepos = nullptr; | |
83 | ||
84 | int maxfd = 0; | |
ac264b3b MS |
85 | }; |
86 | ||
06974e6c PA |
87 | static std::list<fork_info> fork_list; |
88 | static int highest_fork_num; | |
89 | ||
ac264b3b MS |
90 | /* Fork list methods: */ |
91 | ||
3cb5bea9 | 92 | int |
ac264b3b MS |
93 | forks_exist_p (void) |
94 | { | |
06974e6c | 95 | return !fork_list.empty (); |
ac264b3b MS |
96 | } |
97 | ||
2f341b6e PA |
98 | /* Return the last fork in the list. */ |
99 | ||
100 | static struct fork_info * | |
101 | find_last_fork (void) | |
102 | { | |
06974e6c | 103 | if (fork_list.empty ()) |
2f341b6e PA |
104 | return NULL; |
105 | ||
06974e6c | 106 | return &fork_list.back (); |
2f341b6e PA |
107 | } |
108 | ||
06974e6c | 109 | /* Return true iff there's one fork in the list. */ |
ac264b3b | 110 | |
06974e6c PA |
111 | static bool |
112 | one_fork_p () | |
ac264b3b | 113 | { |
fa47e446 | 114 | return fork_list.size () == 1; |
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) |
9c742269 | 223 | get_thread_regcache (inferior_thread ())->restore (fp->savedregs); |
ac264b3b | 224 | |
791b663b DJ |
225 | registers_changed (); |
226 | reinit_frame_cache (); | |
227 | ||
9c742269 SM |
228 | inferior_thread ()->set_stop_pc |
229 | (regcache_read_pc (get_thread_regcache (inferior_thread ()))); | |
4ece39c5 TV |
230 | inferior_thread ()->set_executing (false); |
231 | inferior_thread ()->set_resumed (false); | |
ac264b3b MS |
232 | nullify_last_target_wait_ptid (); |
233 | ||
234 | /* Now restore the file positions of open file descriptors. */ | |
235 | if (fp->filepos) | |
236 | { | |
237 | for (i = 0; i <= fp->maxfd; i++) | |
238 | if (fp->filepos[i] != (off_t) -1) | |
239 | call_lseek (i, fp->filepos[i], SEEK_SET); | |
240 | /* NOTE: I can get away with using SEEK_SET and SEEK_CUR because | |
241 | this is native-only. If it ever has to be cross, we'll have | |
242 | to rethink this. */ | |
243 | } | |
244 | } | |
245 | ||
b7e60d85 | 246 | /* Save infrun state for the fork FP. */ |
ac264b3b | 247 | |
2277426b | 248 | static void |
b7e60d85 | 249 | fork_save_infrun_state (struct fork_info *fp) |
ac264b3b | 250 | { |
d8d2a3ee | 251 | char path[PATH_MAX]; |
ac264b3b MS |
252 | struct dirent *de; |
253 | DIR *d; | |
254 | ||
255 | if (fp->savedregs) | |
c0e383c6 | 256 | delete fp->savedregs; |
ac264b3b | 257 | |
9c742269 SM |
258 | fp->savedregs = new readonly_detached_regcache |
259 | (*get_thread_regcache (inferior_thread ())); | |
260 | fp->pc = regcache_read_pc (get_thread_regcache (inferior_thread ())); | |
ac264b3b | 261 | |
b7e60d85 PA |
262 | /* Now save the 'state' (file position) of all open file descriptors. |
263 | Unfortunately fork does not take care of that for us... */ | |
264 | snprintf (path, PATH_MAX, "/proc/%ld/fd", (long) fp->ptid.pid ()); | |
265 | if ((d = opendir (path)) != NULL) | |
ac264b3b | 266 | { |
b7e60d85 PA |
267 | long tmp; |
268 | ||
269 | fp->maxfd = 0; | |
270 | while ((de = readdir (d)) != NULL) | |
ac264b3b | 271 | { |
b7e60d85 PA |
272 | /* Count open file descriptors (actually find highest |
273 | numbered). */ | |
274 | tmp = strtol (&de->d_name[0], NULL, 10); | |
275 | if (fp->maxfd < tmp) | |
276 | fp->maxfd = tmp; | |
ac264b3b | 277 | } |
b7e60d85 PA |
278 | /* Allocate array of file positions. */ |
279 | fp->filepos = XRESIZEVEC (off_t, fp->filepos, fp->maxfd + 1); | |
280 | ||
281 | /* Initialize to -1 (invalid). */ | |
282 | for (tmp = 0; tmp <= fp->maxfd; tmp++) | |
283 | fp->filepos[tmp] = -1; | |
284 | ||
285 | /* Now find actual file positions. */ | |
286 | rewinddir (d); | |
287 | while ((de = readdir (d)) != NULL) | |
288 | if (isdigit (de->d_name[0])) | |
289 | { | |
290 | tmp = strtol (&de->d_name[0], NULL, 10); | |
291 | fp->filepos[tmp] = call_lseek (tmp, 0, SEEK_CUR); | |
292 | } | |
293 | closedir (d); | |
ac264b3b MS |
294 | } |
295 | } | |
296 | ||
297 | /* Kill 'em all, let God sort 'em out... */ | |
298 | ||
3cb5bea9 | 299 | void |
ac264b3b MS |
300 | linux_fork_killall (void) |
301 | { | |
302 | /* Walk list and kill every pid. No need to treat the | |
303 | current inferior_ptid as special (we do not return a | |
304 | status for it) -- however any process may be a child | |
305 | or a parent, so may get a SIGCHLD from a previously | |
306 | killed child. Wait them all out. */ | |
ac264b3b | 307 | |
06974e6c | 308 | for (fork_info &fi : fork_list) |
56aac7e8 | 309 | { |
06974e6c PA |
310 | pid_t pid = fi.ptid.pid (); |
311 | int status; | |
312 | pid_t ret; | |
56aac7e8 | 313 | do { |
4c28f408 PA |
314 | /* Use SIGKILL instead of PTRACE_KILL because the former works even |
315 | if the thread is running, while the later doesn't. */ | |
316 | kill (pid, SIGKILL); | |
56aac7e8 MS |
317 | ret = waitpid (pid, &status, 0); |
318 | /* We might get a SIGCHLD instead of an exit status. This is | |
319 | aggravated by the first kill above - a child has just | |
320 | died. MVS comment cut-and-pasted from linux-nat. */ | |
321 | } while (ret == pid && WIFSTOPPED (status)); | |
322 | } | |
06974e6c PA |
323 | |
324 | /* Clear list, prepare to start fresh. */ | |
325 | fork_list.clear (); | |
ac264b3b MS |
326 | } |
327 | ||
328 | /* The current inferior_ptid has exited, but there are other viable | |
329 | forks to debug. Delete the exiting one and context-switch to the | |
330 | first available. */ | |
331 | ||
3cb5bea9 | 332 | void |
ac264b3b MS |
333 | linux_fork_mourn_inferior (void) |
334 | { | |
2f341b6e PA |
335 | struct fork_info *last; |
336 | int status; | |
337 | ||
ac264b3b MS |
338 | /* Wait just one more time to collect the inferior's exit status. |
339 | Do not check whether this succeeds though, since we may be | |
340 | dealing with a process that we attached to. Such a process will | |
341 | only report its exit status to its original parent. */ | |
e99b03dc | 342 | waitpid (inferior_ptid.pid (), &status, 0); |
ac264b3b MS |
343 | |
344 | /* OK, presumably inferior_ptid is the one who has exited. | |
345 | We need to delete that one from the fork_list, and switch | |
346 | to the next available fork. */ | |
347 | delete_fork (inferior_ptid); | |
791b663b DJ |
348 | |
349 | /* There should still be a fork - if there's only one left, | |
350 | delete_fork won't remove it, because we haven't updated | |
351 | inferior_ptid yet. */ | |
06974e6c | 352 | gdb_assert (!fork_list.empty ()); |
791b663b | 353 | |
2f341b6e PA |
354 | last = find_last_fork (); |
355 | fork_load_infrun_state (last); | |
6cb06a8c TT |
356 | gdb_printf (_("[Switching to %s]\n"), |
357 | target_pid_to_str (inferior_ptid).c_str ()); | |
791b663b DJ |
358 | |
359 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 360 | if (one_fork_p ()) |
791b663b | 361 | delete_fork (inferior_ptid); |
ac264b3b MS |
362 | } |
363 | ||
7a7d3353 PA |
364 | /* The current inferior_ptid is being detached, but there are other |
365 | viable forks to debug. Detach and delete it and context-switch to | |
366 | the first available. */ | |
367 | ||
3cb5bea9 | 368 | void |
57e6a098 | 369 | linux_fork_detach (int from_tty, lwp_info *lp) |
7a7d3353 | 370 | { |
57e6a098 KB |
371 | gdb_assert (lp != nullptr); |
372 | gdb_assert (lp->ptid == inferior_ptid); | |
373 | ||
7a7d3353 PA |
374 | /* OK, inferior_ptid is the one we are detaching from. We need to |
375 | delete it from the fork_list, and switch to the next available | |
57e6a098 KB |
376 | fork. But before doing the detach, do make sure that the lwp |
377 | hasn't exited or been terminated first. */ | |
7a7d3353 | 378 | |
57e6a098 KB |
379 | if (lp->waitstatus.kind () != TARGET_WAITKIND_EXITED |
380 | && lp->waitstatus.kind () != TARGET_WAITKIND_THREAD_EXITED | |
381 | && lp->waitstatus.kind () != TARGET_WAITKIND_SIGNALLED) | |
382 | { | |
383 | if (ptrace (PTRACE_DETACH, inferior_ptid.pid (), 0, 0)) | |
384 | error (_("Unable to detach %s"), | |
385 | target_pid_to_str (inferior_ptid).c_str ()); | |
386 | } | |
7a7d3353 PA |
387 | |
388 | delete_fork (inferior_ptid); | |
7a7d3353 PA |
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. */ | |
06974e6c | 393 | gdb_assert (!fork_list.empty ()); |
7a7d3353 | 394 | |
06974e6c | 395 | fork_load_infrun_state (&fork_list.front ()); |
7a7d3353 PA |
396 | |
397 | if (from_tty) | |
6cb06a8c TT |
398 | gdb_printf (_("[Switching to %s]\n"), |
399 | target_pid_to_str (inferior_ptid).c_str ()); | |
7a7d3353 PA |
400 | |
401 | /* If there's only one fork, switch back to non-fork mode. */ | |
06974e6c | 402 | if (one_fork_p ()) |
7a7d3353 PA |
403 | delete_fork (inferior_ptid); |
404 | } | |
405 | ||
a07c8880 AB |
406 | /* Temporarily switch to the infrun state stored on the fork_info |
407 | identified by a given ptid_t. When this object goes out of scope, | |
408 | restore the currently selected infrun state. */ | |
7a298875 | 409 | |
a07c8880 AB |
410 | class scoped_switch_fork_info |
411 | { | |
412 | public: | |
413 | /* Switch to the infrun state held on the fork_info identified by | |
414 | PPTID. If PPTID is the current inferior then no switch is done. */ | |
1ef8573c | 415 | explicit scoped_switch_fork_info (ptid_t pptid) |
a07c8880 AB |
416 | : m_oldfp (nullptr) |
417 | { | |
418 | if (pptid != inferior_ptid) | |
419 | { | |
420 | struct fork_info *newfp = nullptr; | |
421 | ||
422 | /* Switch to pptid. */ | |
423 | m_oldfp = find_fork_ptid (inferior_ptid); | |
424 | gdb_assert (m_oldfp != nullptr); | |
425 | newfp = find_fork_ptid (pptid); | |
426 | gdb_assert (newfp != nullptr); | |
b7e60d85 | 427 | fork_save_infrun_state (m_oldfp); |
a07c8880 AB |
428 | remove_breakpoints (); |
429 | fork_load_infrun_state (newfp); | |
430 | insert_breakpoints (); | |
431 | } | |
432 | } | |
433 | ||
434 | /* Restore the previously selected infrun state. If the constructor | |
435 | didn't need to switch states, then nothing is done here either. */ | |
436 | ~scoped_switch_fork_info () | |
437 | { | |
438 | if (m_oldfp != nullptr) | |
439 | { | |
440 | /* Switch back to inferior_ptid. */ | |
a70b8144 | 441 | try |
1ef8573c AB |
442 | { |
443 | remove_breakpoints (); | |
444 | fork_load_infrun_state (m_oldfp); | |
445 | insert_breakpoints (); | |
446 | } | |
96e3f4e3 KB |
447 | catch (const gdb_exception_quit &ex) |
448 | { | |
449 | /* We can't throw from a destructor, so re-set the quit flag | |
450 | for later QUIT checking. */ | |
451 | set_quit_flag (); | |
452 | } | |
453 | catch (const gdb_exception_forced_quit &ex) | |
454 | { | |
455 | /* Like above, but (eventually) cause GDB to terminate by | |
456 | setting sync_quit_force_run. */ | |
457 | set_force_quit_flag (); | |
458 | } | |
230d2906 | 459 | catch (const gdb_exception &ex) |
1ef8573c AB |
460 | { |
461 | warning (_("Couldn't restore checkpoint state in %s: %s"), | |
3d6e9d23 TT |
462 | target_pid_to_str (m_oldfp->ptid).c_str (), |
463 | ex.what ()); | |
1ef8573c | 464 | } |
a07c8880 AB |
465 | } |
466 | } | |
467 | ||
468 | DISABLE_COPY_AND_ASSIGN (scoped_switch_fork_info); | |
469 | ||
470 | private: | |
471 | /* The fork_info for the previously selected infrun state, or nullptr if | |
472 | we were already in the desired state, and nothing needs to be | |
473 | restored. */ | |
474 | struct fork_info *m_oldfp; | |
475 | }; | |
7a298875 HZ |
476 | |
477 | static int | |
478 | inferior_call_waitpid (ptid_t pptid, int pid) | |
479 | { | |
480 | struct objfile *waitpid_objf; | |
481 | struct value *waitpid_fn = NULL; | |
7a298875 HZ |
482 | int ret = -1; |
483 | ||
a07c8880 | 484 | scoped_switch_fork_info switch_fork_info (pptid); |
e17c9e56 | 485 | |
7a298875 | 486 | /* Get the waitpid_fn. */ |
3b7344d5 | 487 | if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) |
7a298875 | 488 | waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); |
3b7344d5 TT |
489 | if (!waitpid_fn |
490 | && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) | |
7a298875 | 491 | waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); |
a07c8880 AB |
492 | if (waitpid_fn != nullptr) |
493 | { | |
494 | struct gdbarch *gdbarch = get_current_arch (); | |
495 | struct value *argv[3], *retv; | |
7a298875 | 496 | |
a07c8880 AB |
497 | /* Get the argv. */ |
498 | argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); | |
499 | argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); | |
500 | argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); | |
7a298875 | 501 | |
a07c8880 | 502 | retv = call_function_by_hand (waitpid_fn, NULL, argv); |
7a298875 | 503 | |
a07c8880 AB |
504 | if (value_as_long (retv) >= 0) |
505 | ret = 0; | |
506 | } | |
7a298875 | 507 | |
7a298875 HZ |
508 | return ret; |
509 | } | |
510 | ||
ac264b3b MS |
511 | /* Fork list <-> user interface. */ |
512 | ||
513 | static void | |
5b64bf74 | 514 | delete_checkpoint_command (const char *args, int from_tty) |
ac264b3b | 515 | { |
e17c9e56 | 516 | ptid_t ptid, pptid; |
7a298875 | 517 | struct fork_info *fi; |
ac264b3b MS |
518 | |
519 | if (!args || !*args) | |
2277426b | 520 | error (_("Requires argument (checkpoint id to delete)")); |
ac264b3b MS |
521 | |
522 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 523 | if (ptid == minus_one_ptid) |
2277426b | 524 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 525 | |
d7e15655 | 526 | if (ptid == inferior_ptid) |
3cb5bea9 PA |
527 | error (_("\ |
528 | Please switch to another checkpoint before deleting the current one")); | |
ac264b3b | 529 | |
e99b03dc | 530 | if (ptrace (PTRACE_KILL, ptid.pid (), 0, 0)) |
a068643d | 531 | error (_("Unable to kill pid %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b | 532 | |
7a298875 HZ |
533 | fi = find_fork_ptid (ptid); |
534 | gdb_assert (fi); | |
e17c9e56 | 535 | pptid = fi->parent_ptid; |
7a298875 | 536 | |
ac264b3b | 537 | if (from_tty) |
6cb06a8c | 538 | gdb_printf (_("Killed %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
539 | |
540 | delete_fork (ptid); | |
7a298875 | 541 | |
83094d3d TV |
542 | if (pptid == null_ptid) |
543 | { | |
544 | int status; | |
545 | /* Wait to collect the inferior's exit status. Do not check whether | |
546 | this succeeds though, since we may be dealing with a process that we | |
547 | attached to. Such a process will only report its exit status to its | |
548 | original parent. */ | |
549 | waitpid (ptid.pid (), &status, 0); | |
550 | return; | |
551 | } | |
552 | ||
7a298875 HZ |
553 | /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint |
554 | list, waitpid the ptid. | |
00431a78 | 555 | If fi->parent_ptid is a part of lwp and it is stopped, waitpid the |
7a298875 | 556 | ptid. */ |
9213a6d7 | 557 | thread_info *parent = linux_target->find_thread (pptid); |
00431a78 PA |
558 | if ((parent == NULL && find_fork_ptid (pptid)) |
559 | || (parent != NULL && parent->state == THREAD_STOPPED)) | |
7a298875 | 560 | { |
e99b03dc | 561 | if (inferior_call_waitpid (pptid, ptid.pid ())) |
dda83cd7 | 562 | warning (_("Unable to wait pid %s"), |
a068643d | 563 | target_pid_to_str (ptid).c_str ()); |
7a298875 | 564 | } |
ac264b3b MS |
565 | } |
566 | ||
567 | static void | |
5b64bf74 | 568 | detach_checkpoint_command (const char *args, int from_tty) |
ac264b3b MS |
569 | { |
570 | ptid_t ptid; | |
571 | ||
572 | if (!args || !*args) | |
2277426b | 573 | error (_("Requires argument (checkpoint id to detach)")); |
ac264b3b MS |
574 | |
575 | ptid = fork_id_to_ptid (parse_and_eval_long (args)); | |
d7e15655 | 576 | if (ptid == minus_one_ptid) |
2277426b | 577 | error (_("No such checkpoint id, %s"), args); |
ac264b3b | 578 | |
d7e15655 | 579 | if (ptid == inferior_ptid) |
2277426b PA |
580 | error (_("\ |
581 | Please switch to another checkpoint before detaching the current one")); | |
ac264b3b | 582 | |
e99b03dc | 583 | if (ptrace (PTRACE_DETACH, ptid.pid (), 0, 0)) |
a068643d | 584 | error (_("Unable to detach %s"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
585 | |
586 | if (from_tty) | |
6cb06a8c | 587 | gdb_printf (_("Detached %s\n"), target_pid_to_str (ptid).c_str ()); |
ac264b3b MS |
588 | |
589 | delete_fork (ptid); | |
590 | } | |
591 | ||
3cb5bea9 | 592 | /* Print information about currently known checkpoints. */ |
ac264b3b MS |
593 | |
594 | static void | |
1d12d88f | 595 | info_checkpoints_command (const char *arg, int from_tty) |
ac264b3b | 596 | { |
5af949e3 | 597 | struct gdbarch *gdbarch = get_current_arch (); |
b8db102d | 598 | int requested = -1; |
94e037b4 | 599 | bool printed = false; |
b8db102d MS |
600 | |
601 | if (arg && *arg) | |
602 | requested = (int) parse_and_eval_long (arg); | |
ac264b3b | 603 | |
06974e6c | 604 | for (const fork_info &fi : fork_list) |
ac264b3b | 605 | { |
06974e6c | 606 | if (requested > 0 && fi.num != requested) |
b8db102d | 607 | continue; |
94e037b4 | 608 | printed = true; |
b8db102d | 609 | |
cdf2a0fe TV |
610 | bool is_current = fi.ptid == inferior_ptid; |
611 | if (is_current) | |
6cb06a8c | 612 | gdb_printf ("* "); |
ac264b3b | 613 | else |
6cb06a8c | 614 | gdb_printf (" "); |
daf6667d | 615 | |
6cb06a8c | 616 | gdb_printf ("%d %s", fi.num, target_pid_to_str (fi.ptid).c_str ()); |
06974e6c | 617 | if (fi.num == 0) |
6cb06a8c | 618 | gdb_printf (_(" (main process)")); |
cdf2a0fe TV |
619 | |
620 | if (is_current && inferior_thread ()->state == THREAD_RUNNING) | |
621 | { | |
622 | gdb_printf (_(" <running>\n")); | |
623 | continue; | |
624 | } | |
625 | ||
6cb06a8c | 626 | gdb_printf (_(" at ")); |
cdf2a0fe TV |
627 | ULONGEST pc |
628 | = (is_current | |
629 | ? regcache_read_pc (get_thread_regcache (inferior_thread ())) | |
630 | : fi.pc); | |
0426ad51 | 631 | gdb_puts (paddress (gdbarch, pc)); |
ac264b3b | 632 | |
06974e6c | 633 | symtab_and_line sal = find_pc_line (pc, 0); |
ac264b3b | 634 | if (sal.symtab) |
6cb06a8c TT |
635 | gdb_printf (_(", file %s"), |
636 | symtab_to_filename_for_display (sal.symtab)); | |
ac264b3b | 637 | if (sal.line) |
6cb06a8c | 638 | gdb_printf (_(", line %d"), sal.line); |
ac264b3b MS |
639 | if (!sal.symtab && !sal.line) |
640 | { | |
7cbd4a93 | 641 | struct bound_minimal_symbol msym; |
ac264b3b MS |
642 | |
643 | msym = lookup_minimal_symbol_by_pc (pc); | |
7cbd4a93 | 644 | if (msym.minsym) |
6cb06a8c | 645 | gdb_printf (", <%s>", msym.minsym->linkage_name ()); |
ac264b3b MS |
646 | } |
647 | ||
a11ac3b3 | 648 | gdb_putc ('\n'); |
ac264b3b | 649 | } |
94e037b4 TV |
650 | |
651 | if (!printed) | |
b8db102d MS |
652 | { |
653 | if (requested > 0) | |
6cb06a8c | 654 | gdb_printf (_("No checkpoint number %d.\n"), requested); |
b8db102d | 655 | else |
6cb06a8c | 656 | gdb_printf (_("No checkpoints.\n")); |
b8db102d | 657 | } |
ac264b3b MS |
658 | } |
659 | ||
2277426b PA |
660 | /* The PID of the process we're checkpointing. */ |
661 | static int checkpointing_pid = 0; | |
ac264b3b | 662 | |
2277426b PA |
663 | int |
664 | linux_fork_checkpointing_p (int pid) | |
ac264b3b | 665 | { |
2277426b | 666 | return (checkpointing_pid == pid); |
ac264b3b MS |
667 | } |
668 | ||
92f6badc KP |
669 | /* Return true if the current inferior is multi-threaded. */ |
670 | ||
e52c971f PA |
671 | static bool |
672 | inf_has_multiple_threads () | |
92f6badc KP |
673 | { |
674 | int count = 0; | |
675 | ||
e52c971f PA |
676 | /* Return true as soon as we see the second thread of the current |
677 | inferior. */ | |
678 | for (thread_info *tp ATTRIBUTE_UNUSED : current_inferior ()->threads ()) | |
679 | if (++count > 1) | |
680 | return true; | |
681 | ||
682 | return false; | |
92f6badc KP |
683 | } |
684 | ||
ac264b3b | 685 | static void |
0b39b52e | 686 | checkpoint_command (const char *args, int from_tty) |
ac264b3b | 687 | { |
3e3b026f UW |
688 | struct objfile *fork_objf; |
689 | struct gdbarch *gdbarch; | |
ac264b3b MS |
690 | struct target_waitstatus last_target_waitstatus; |
691 | ptid_t last_target_ptid; | |
692 | struct value *fork_fn = NULL, *ret; | |
693 | struct fork_info *fp; | |
694 | pid_t retpid; | |
74960c60 | 695 | |
55f6301a | 696 | if (!target_has_execution ()) |
92f6badc KP |
697 | error (_("The program is not being run.")); |
698 | ||
699 | /* Ensure that the inferior is not multithreaded. */ | |
700 | update_thread_list (); | |
701 | if (inf_has_multiple_threads ()) | |
702 | error (_("checkpoint: can't checkpoint multiple threads.")); | |
703 | ||
ac264b3b MS |
704 | /* Make the inferior fork, record its (and gdb's) state. */ |
705 | ||
3b7344d5 | 706 | if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) |
3e3b026f | 707 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b | 708 | if (!fork_fn) |
3b7344d5 | 709 | if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) |
3e3b026f | 710 | fork_fn = find_function_in_inferior ("fork", &fork_objf); |
ac264b3b MS |
711 | if (!fork_fn) |
712 | error (_("checkpoint: can't find fork function in inferior.")); | |
713 | ||
08feed99 | 714 | gdbarch = fork_objf->arch (); |
3e3b026f | 715 | ret = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); |
2277426b PA |
716 | |
717 | /* Tell linux-nat.c that we're checkpointing this inferior. */ | |
b7b633e9 TT |
718 | { |
719 | scoped_restore save_pid | |
e99b03dc | 720 | = make_scoped_restore (&checkpointing_pid, inferior_ptid.pid ()); |
b7b633e9 | 721 | |
e71585ff | 722 | ret = call_function_by_hand (fork_fn, NULL, {}); |
b7b633e9 | 723 | } |
2277426b | 724 | |
ac264b3b MS |
725 | if (!ret) /* Probably can't happen. */ |
726 | error (_("checkpoint: call_function_by_hand returned null.")); | |
727 | ||
728 | retpid = value_as_long (ret); | |
5b6d1e4f | 729 | get_last_target_status (nullptr, &last_target_ptid, &last_target_waitstatus); |
6f9d33d8 PP |
730 | |
731 | fp = find_fork_pid (retpid); | |
732 | ||
ac264b3b MS |
733 | if (from_tty) |
734 | { | |
735 | int parent_pid; | |
736 | ||
6cb06a8c TT |
737 | gdb_printf (_("checkpoint %d: fork returned pid %ld.\n"), |
738 | fp != NULL ? fp->num : -1, (long) retpid); | |
ac264b3b MS |
739 | if (info_verbose) |
740 | { | |
e38504b3 | 741 | parent_pid = last_target_ptid.lwp (); |
ac264b3b | 742 | if (parent_pid == 0) |
e99b03dc | 743 | parent_pid = last_target_ptid.pid (); |
6cb06a8c TT |
744 | gdb_printf (_(" gdb says parent = %ld.\n"), |
745 | (long) parent_pid); | |
ac264b3b MS |
746 | } |
747 | } | |
748 | ||
ac264b3b MS |
749 | if (!fp) |
750 | error (_("Failed to find new fork")); | |
72f31aea | 751 | |
06974e6c | 752 | if (one_fork_p ()) |
72f31aea PA |
753 | { |
754 | /* Special case -- if this is the first fork in the list (the | |
755 | list was hitherto empty), then add inferior_ptid first, as a | |
756 | special zeroeth fork id. */ | |
06974e6c | 757 | fork_list.emplace_front (inferior_ptid.pid ()); |
72f31aea PA |
758 | } |
759 | ||
b7e60d85 | 760 | fork_save_infrun_state (fp); |
7a298875 | 761 | fp->parent_ptid = last_target_ptid; |
ac264b3b MS |
762 | } |
763 | ||
764 | static void | |
765 | linux_fork_context (struct fork_info *newfp, int from_tty) | |
766 | { | |
767 | /* Now we attempt to switch processes. */ | |
0d14fc63 | 768 | struct fork_info *oldfp; |
ac264b3b | 769 | |
0d14fc63 | 770 | gdb_assert (newfp != NULL); |
ac264b3b | 771 | |
0d14fc63 PA |
772 | oldfp = find_fork_ptid (inferior_ptid); |
773 | gdb_assert (oldfp != NULL); | |
ac264b3b | 774 | |
b7e60d85 | 775 | fork_save_infrun_state (oldfp); |
74960c60 | 776 | remove_breakpoints (); |
ac264b3b | 777 | fork_load_infrun_state (newfp); |
74960c60 | 778 | insert_breakpoints (); |
ac264b3b | 779 | |
6cb06a8c TT |
780 | gdb_printf (_("Switching to %s\n"), |
781 | target_pid_to_str (inferior_ptid).c_str ()); | |
ac264b3b | 782 | |
08d72866 | 783 | print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); |
ac264b3b MS |
784 | } |
785 | ||
2277426b | 786 | /* Switch inferior process (checkpoint) context, by checkpoint id. */ |
ac264b3b | 787 | static void |
0b39b52e | 788 | restart_command (const char *args, int from_tty) |
ac264b3b MS |
789 | { |
790 | struct fork_info *fp; | |
791 | ||
792 | if (!args || !*args) | |
793 | error (_("Requires argument (checkpoint id to restart)")); | |
794 | ||
795 | if ((fp = find_fork_id (parse_and_eval_long (args))) == NULL) | |
796 | error (_("Not found: checkpoint id %s"), args); | |
797 | ||
798 | linux_fork_context (fp, from_tty); | |
799 | } | |
800 | ||
6c265988 | 801 | void _initialize_linux_fork (); |
ac264b3b | 802 | void |
6c265988 | 803 | _initialize_linux_fork () |
ac264b3b | 804 | { |
ac264b3b MS |
805 | /* Checkpoint command: create a fork of the inferior process |
806 | and set it aside for later debugging. */ | |
807 | ||
808 | add_com ("checkpoint", class_obscure, checkpoint_command, _("\ | |
809 | Fork a duplicate process (experimental).")); | |
810 | ||
2277426b PA |
811 | /* Restart command: restore the context of a specified checkpoint |
812 | process. */ | |
ac264b3b MS |
813 | |
814 | add_com ("restart", class_obscure, restart_command, _("\ | |
590042fc PW |
815 | Restore program context from a checkpoint.\n\ |
816 | Usage: restart N\n\ | |
c8a15b78 | 817 | Argument N is checkpoint ID, as displayed by 'info checkpoints'.")); |
ac264b3b | 818 | |
b8db102d | 819 | /* Delete checkpoint command: kill the process and remove it from |
3cb5bea9 | 820 | the fork list. */ |
ac264b3b | 821 | |
3cb5bea9 | 822 | add_cmd ("checkpoint", class_obscure, delete_checkpoint_command, _("\ |
2277426b | 823 | Delete a checkpoint (experimental)."), |
b8db102d | 824 | &deletelist); |
ac264b3b | 825 | |
3cb5bea9 | 826 | /* Detach checkpoint command: release the process to run independently, |
ac264b3b MS |
827 | and remove it from the fork list. */ |
828 | ||
3cb5bea9 | 829 | add_cmd ("checkpoint", class_obscure, detach_checkpoint_command, _("\ |
2277426b | 830 | Detach from a checkpoint (experimental)."), |
f73adfeb | 831 | &detachlist); |
ac264b3b | 832 | |
3cb5bea9 | 833 | /* Info checkpoints command: list all forks/checkpoints |
ac264b3b MS |
834 | currently under gdb's control. */ |
835 | ||
3cb5bea9 | 836 | add_info ("checkpoints", info_checkpoints_command, |
2277426b | 837 | _("IDs of currently known checkpoints.")); |
ac264b3b | 838 | } |