Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
32d0add0 | 3 | Copyright (C) 2001-2015 Free Software Foundation, Inc. |
3993f6b1 DJ |
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 |
3993f6b1 DJ |
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/>. */ |
3993f6b1 DJ |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
45741a9c | 22 | #include "infrun.h" |
3993f6b1 | 23 | #include "target.h" |
96d7229d LM |
24 | #include "nat/linux-nat.h" |
25 | #include "nat/linux-waitpid.h" | |
3993f6b1 | 26 | #include "gdb_wait.h" |
d6b0e80f AC |
27 | #ifdef HAVE_TKILL_SYSCALL |
28 | #include <unistd.h> | |
29 | #include <sys/syscall.h> | |
30 | #endif | |
3993f6b1 | 31 | #include <sys/ptrace.h> |
0274a8ce | 32 | #include "linux-nat.h" |
125f8a3d GB |
33 | #include "nat/linux-ptrace.h" |
34 | #include "nat/linux-procfs.h" | |
8cc73a39 | 35 | #include "nat/linux-personality.h" |
ac264b3b | 36 | #include "linux-fork.h" |
d6b0e80f AC |
37 | #include "gdbthread.h" |
38 | #include "gdbcmd.h" | |
39 | #include "regcache.h" | |
4f844a66 | 40 | #include "regset.h" |
dab06dbe | 41 | #include "inf-child.h" |
10d6c8cd DJ |
42 | #include "inf-ptrace.h" |
43 | #include "auxv.h" | |
1777feb0 | 44 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
45 | #include "elf-bfd.h" /* for elfcore_write_* */ |
46 | #include "gregset.h" /* for gregset */ | |
47 | #include "gdbcore.h" /* for get_exec_file */ | |
48 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 49 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 50 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 PA |
51 | #include "inf-loop.h" |
52 | #include "event-loop.h" | |
53 | #include "event-top.h" | |
07e059b5 VP |
54 | #include <pwd.h> |
55 | #include <sys/types.h> | |
2978b111 | 56 | #include <dirent.h> |
07e059b5 | 57 | #include "xml-support.h" |
efcbbd14 | 58 | #include <sys/vfs.h> |
6c95b8df | 59 | #include "solib.h" |
125f8a3d | 60 | #include "nat/linux-osdata.h" |
6432734d | 61 | #include "linux-tdep.h" |
7dcd53a0 | 62 | #include "symfile.h" |
5808517f YQ |
63 | #include "agent.h" |
64 | #include "tracepoint.h" | |
87b0bb13 | 65 | #include "buffer.h" |
6ecd4729 | 66 | #include "target-descriptions.h" |
614c279d | 67 | #include "filestuff.h" |
77e371c0 | 68 | #include "objfiles.h" |
efcbbd14 UW |
69 | |
70 | #ifndef SPUFS_MAGIC | |
71 | #define SPUFS_MAGIC 0x23c9b64e | |
72 | #endif | |
dba24537 | 73 | |
1777feb0 | 74 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
75 | |
76 | Waiting for events in sync mode | |
77 | =============================== | |
78 | ||
79 | When waiting for an event in a specific thread, we just use waitpid, passing | |
80 | the specific pid, and not passing WNOHANG. | |
81 | ||
1777feb0 | 82 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 83 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 84 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
85 | miss an event. The solution is to use non-blocking waitpid, together with |
86 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 87 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
88 | flag to check for events in cloned processes. If nothing is found, we use |
89 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
90 | happened to a child process -- and SIGCHLD will be delivered both for events | |
91 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
92 | an event, we get back to calling nonblocking waitpid with and without |
93 | __WCLONED. | |
8a77dff3 VP |
94 | |
95 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 96 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
97 | blocked, the signal becomes pending and sigsuspend immediately |
98 | notices it and returns. | |
99 | ||
100 | Waiting for events in async mode | |
101 | ================================ | |
102 | ||
7feb7d06 PA |
103 | In async mode, GDB should always be ready to handle both user input |
104 | and target events, so neither blocking waitpid nor sigsuspend are | |
105 | viable options. Instead, we should asynchronously notify the GDB main | |
106 | event loop whenever there's an unprocessed event from the target. We | |
107 | detect asynchronous target events by handling SIGCHLD signals. To | |
108 | notify the event loop about target events, the self-pipe trick is used | |
109 | --- a pipe is registered as waitable event source in the event loop, | |
110 | the event loop select/poll's on the read end of this pipe (as well on | |
111 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
112 | byte to this pipe. This is more portable than relying on | |
113 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
114 | emulates them with select/poll+sigprocmask, and that is racy | |
115 | (a.k.a. plain broken). | |
116 | ||
117 | Obviously, if we fail to notify the event loop if there's a target | |
118 | event, it's bad. OTOH, if we notify the event loop when there's no | |
119 | event from the target, linux_nat_wait will detect that there's no real | |
120 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
121 | This is mostly harmless, but it will waste time and is better avoided. | |
122 | ||
123 | The main design point is that every time GDB is outside linux-nat.c, | |
124 | we have a SIGCHLD handler installed that is called when something | |
125 | happens to the target and notifies the GDB event loop. Whenever GDB | |
126 | core decides to handle the event, and calls into linux-nat.c, we | |
127 | process things as in sync mode, except that the we never block in | |
128 | sigsuspend. | |
129 | ||
130 | While processing an event, we may end up momentarily blocked in | |
131 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
132 | return quickly. E.g., in all-stop mode, before reporting to the core | |
133 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
134 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
135 | Note that this is different from blocking indefinitely waiting for the | |
136 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
137 | |
138 | Use of signals | |
139 | ============== | |
140 | ||
141 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
142 | signal is not entirely significant; we just need for a signal to be delivered, | |
143 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
144 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
145 | be queued once; we do not keep track of other sources of SIGSTOP. | |
146 | ||
147 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
148 | use them, because they have special behavior when the signal is generated - | |
149 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
150 | kills the entire thread group. | |
151 | ||
152 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
153 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
154 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
155 | ||
156 | We could use a real-time signal instead. This would solve those problems; we | |
157 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
158 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
159 | generates it, and there are races with trying to find a signal that is not | |
160 | blocked. */ | |
a0ef4274 | 161 | |
dba24537 AC |
162 | #ifndef O_LARGEFILE |
163 | #define O_LARGEFILE 0 | |
164 | #endif | |
0274a8ce | 165 | |
10d6c8cd DJ |
166 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
167 | the use of the multi-threaded target. */ | |
168 | static struct target_ops *linux_ops; | |
f973ed9c | 169 | static struct target_ops linux_ops_saved; |
10d6c8cd | 170 | |
9f0bdab8 | 171 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
172 | static void (*linux_nat_new_thread) (struct lwp_info *); |
173 | ||
26cb8b7c PA |
174 | /* The method to call, if any, when a new fork is attached. */ |
175 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
176 | ||
177 | /* The method to call, if any, when a process is no longer | |
178 | attached. */ | |
179 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
180 | ||
7b50312a PA |
181 | /* Hook to call prior to resuming a thread. */ |
182 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 183 | |
5b009018 PA |
184 | /* The method to call, if any, when the siginfo object needs to be |
185 | converted between the layout returned by ptrace, and the layout in | |
186 | the architecture of the inferior. */ | |
a5362b9a | 187 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
188 | gdb_byte *, |
189 | int); | |
190 | ||
ac264b3b MS |
191 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
192 | Called by our to_xfer_partial. */ | |
4ac248ca | 193 | static target_xfer_partial_ftype *super_xfer_partial; |
10d6c8cd | 194 | |
6a3cb8e8 PA |
195 | /* The saved to_close method, inherited from inf-ptrace.c. |
196 | Called by our to_close. */ | |
197 | static void (*super_close) (struct target_ops *); | |
198 | ||
ccce17b0 | 199 | static unsigned int debug_linux_nat; |
920d2a44 AC |
200 | static void |
201 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
202 | struct cmd_list_element *c, const char *value) | |
203 | { | |
204 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
205 | value); | |
206 | } | |
d6b0e80f | 207 | |
ae087d01 DJ |
208 | struct simple_pid_list |
209 | { | |
210 | int pid; | |
3d799a95 | 211 | int status; |
ae087d01 DJ |
212 | struct simple_pid_list *next; |
213 | }; | |
214 | struct simple_pid_list *stopped_pids; | |
215 | ||
3dd5b83d PA |
216 | /* Async mode support. */ |
217 | ||
b84876c2 PA |
218 | /* The read/write ends of the pipe registered as waitable file in the |
219 | event loop. */ | |
220 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
221 | ||
198297aa PA |
222 | /* True if we're currently in async mode. */ |
223 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
224 | ||
7feb7d06 | 225 | /* Flush the event pipe. */ |
b84876c2 | 226 | |
7feb7d06 PA |
227 | static void |
228 | async_file_flush (void) | |
b84876c2 | 229 | { |
7feb7d06 PA |
230 | int ret; |
231 | char buf; | |
b84876c2 | 232 | |
7feb7d06 | 233 | do |
b84876c2 | 234 | { |
7feb7d06 | 235 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 236 | } |
7feb7d06 | 237 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
238 | } |
239 | ||
7feb7d06 PA |
240 | /* Put something (anything, doesn't matter what, or how much) in event |
241 | pipe, so that the select/poll in the event-loop realizes we have | |
242 | something to process. */ | |
252fbfc8 | 243 | |
b84876c2 | 244 | static void |
7feb7d06 | 245 | async_file_mark (void) |
b84876c2 | 246 | { |
7feb7d06 | 247 | int ret; |
b84876c2 | 248 | |
7feb7d06 PA |
249 | /* It doesn't really matter what the pipe contains, as long we end |
250 | up with something in it. Might as well flush the previous | |
251 | left-overs. */ | |
252 | async_file_flush (); | |
b84876c2 | 253 | |
7feb7d06 | 254 | do |
b84876c2 | 255 | { |
7feb7d06 | 256 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 257 | } |
7feb7d06 | 258 | while (ret == -1 && errno == EINTR); |
b84876c2 | 259 | |
7feb7d06 PA |
260 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
261 | be awakened anyway. */ | |
b84876c2 PA |
262 | } |
263 | ||
7feb7d06 PA |
264 | static int kill_lwp (int lwpid, int signo); |
265 | ||
266 | static int stop_callback (struct lwp_info *lp, void *data); | |
2db9a427 | 267 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
7feb7d06 PA |
268 | |
269 | static void block_child_signals (sigset_t *prev_mask); | |
270 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
271 | |
272 | struct lwp_info; | |
273 | static struct lwp_info *add_lwp (ptid_t ptid); | |
274 | static void purge_lwp_list (int pid); | |
4403d8e9 | 275 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
276 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
277 | ||
8a99810d PA |
278 | static int lwp_status_pending_p (struct lwp_info *lp); |
279 | ||
9c02b525 PA |
280 | static int check_stopped_by_breakpoint (struct lwp_info *lp); |
281 | static int sigtrap_is_event (int status); | |
282 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
283 | ||
ae087d01 DJ |
284 | \f |
285 | /* Trivial list manipulation functions to keep track of a list of | |
286 | new stopped processes. */ | |
287 | static void | |
3d799a95 | 288 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
289 | { |
290 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 291 | |
ae087d01 | 292 | new_pid->pid = pid; |
3d799a95 | 293 | new_pid->status = status; |
ae087d01 DJ |
294 | new_pid->next = *listp; |
295 | *listp = new_pid; | |
296 | } | |
297 | ||
84636d28 PA |
298 | static int |
299 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
300 | { | |
301 | struct simple_pid_list *p; | |
302 | ||
303 | for (p = list; p != NULL; p = p->next) | |
304 | if (p->pid == pid) | |
305 | return 1; | |
306 | return 0; | |
307 | } | |
308 | ||
ae087d01 | 309 | static int |
46a96992 | 310 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
311 | { |
312 | struct simple_pid_list **p; | |
313 | ||
314 | for (p = listp; *p != NULL; p = &(*p)->next) | |
315 | if ((*p)->pid == pid) | |
316 | { | |
317 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 318 | |
46a96992 | 319 | *statusp = (*p)->status; |
ae087d01 DJ |
320 | xfree (*p); |
321 | *p = next; | |
322 | return 1; | |
323 | } | |
324 | return 0; | |
325 | } | |
326 | ||
96d7229d | 327 | /* Initialize ptrace warnings and check for supported ptrace |
beed38b8 JB |
328 | features given PID. |
329 | ||
330 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
331 | |
332 | static void | |
beed38b8 | 333 | linux_init_ptrace (pid_t pid, int attached) |
3993f6b1 | 334 | { |
beed38b8 | 335 | linux_enable_event_reporting (pid, attached); |
96d7229d | 336 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
337 | } |
338 | ||
6d8fd2b7 | 339 | static void |
f045800c | 340 | linux_child_post_attach (struct target_ops *self, int pid) |
4de4c07c | 341 | { |
beed38b8 | 342 | linux_init_ptrace (pid, 1); |
4de4c07c DJ |
343 | } |
344 | ||
10d6c8cd | 345 | static void |
2e97a79e | 346 | linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid) |
4de4c07c | 347 | { |
beed38b8 | 348 | linux_init_ptrace (ptid_get_pid (ptid), 0); |
4de4c07c DJ |
349 | } |
350 | ||
4403d8e9 JK |
351 | /* Return the number of known LWPs in the tgid given by PID. */ |
352 | ||
353 | static int | |
354 | num_lwps (int pid) | |
355 | { | |
356 | int count = 0; | |
357 | struct lwp_info *lp; | |
358 | ||
359 | for (lp = lwp_list; lp; lp = lp->next) | |
360 | if (ptid_get_pid (lp->ptid) == pid) | |
361 | count++; | |
362 | ||
363 | return count; | |
364 | } | |
365 | ||
366 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
367 | ||
368 | static void | |
369 | delete_lwp_cleanup (void *lp_voidp) | |
370 | { | |
371 | struct lwp_info *lp = lp_voidp; | |
372 | ||
373 | delete_lwp (lp->ptid); | |
374 | } | |
375 | ||
d83ad864 DB |
376 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
377 | ptid of the followed inferior. At return, inferior_ptid will be | |
378 | unchanged. */ | |
379 | ||
6d8fd2b7 | 380 | static int |
07107ca6 LM |
381 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
382 | int detach_fork) | |
3993f6b1 | 383 | { |
d83ad864 | 384 | if (!follow_child) |
4de4c07c | 385 | { |
6c95b8df | 386 | struct lwp_info *child_lp = NULL; |
d83ad864 DB |
387 | int status = W_STOPCODE (0); |
388 | struct cleanup *old_chain; | |
389 | int has_vforked; | |
390 | int parent_pid, child_pid; | |
391 | ||
392 | has_vforked = (inferior_thread ()->pending_follow.kind | |
393 | == TARGET_WAITKIND_VFORKED); | |
394 | parent_pid = ptid_get_lwp (inferior_ptid); | |
395 | if (parent_pid == 0) | |
396 | parent_pid = ptid_get_pid (inferior_ptid); | |
397 | child_pid | |
398 | = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid); | |
399 | ||
4de4c07c | 400 | |
1777feb0 | 401 | /* We're already attached to the parent, by default. */ |
d83ad864 DB |
402 | old_chain = save_inferior_ptid (); |
403 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
404 | child_lp = add_lwp (inferior_ptid); | |
405 | child_lp->stopped = 1; | |
406 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 407 | |
ac264b3b MS |
408 | /* Detach new forked process? */ |
409 | if (detach_fork) | |
f75c00e4 | 410 | { |
4403d8e9 JK |
411 | make_cleanup (delete_lwp_cleanup, child_lp); |
412 | ||
4403d8e9 JK |
413 | if (linux_nat_prepare_to_resume != NULL) |
414 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
415 | |
416 | /* When debugging an inferior in an architecture that supports | |
417 | hardware single stepping on a kernel without commit | |
418 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
419 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
420 | set if the parent process had them set. | |
421 | To work around this, single step the child process | |
422 | once before detaching to clear the flags. */ | |
423 | ||
424 | if (!gdbarch_software_single_step_p (target_thread_architecture | |
425 | (child_lp->ptid))) | |
426 | { | |
c077881a HZ |
427 | linux_disable_event_reporting (child_pid); |
428 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
429 | perror_with_name (_("Couldn't do single step")); | |
430 | if (my_waitpid (child_pid, &status, 0) < 0) | |
431 | perror_with_name (_("Couldn't wait vfork process")); | |
432 | } | |
433 | ||
434 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
435 | { |
436 | int signo; | |
437 | ||
438 | signo = WSTOPSIG (status); | |
439 | if (signo != 0 | |
440 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
441 | signo = 0; | |
442 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
443 | } | |
4403d8e9 | 444 | |
d83ad864 | 445 | /* Resets value of inferior_ptid to parent ptid. */ |
4403d8e9 | 446 | do_cleanups (old_chain); |
ac264b3b MS |
447 | } |
448 | else | |
449 | { | |
6c95b8df | 450 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 451 | check_for_thread_db (); |
ac264b3b | 452 | } |
9016a515 | 453 | |
d83ad864 DB |
454 | do_cleanups (old_chain); |
455 | ||
9016a515 DJ |
456 | if (has_vforked) |
457 | { | |
3ced3da4 | 458 | struct lwp_info *parent_lp; |
6c95b8df | 459 | |
3ced3da4 | 460 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
96d7229d | 461 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 462 | |
96d7229d | 463 | if (linux_supports_tracevforkdone ()) |
9016a515 | 464 | { |
6c95b8df PA |
465 | if (debug_linux_nat) |
466 | fprintf_unfiltered (gdb_stdlog, | |
467 | "LCFF: waiting for VFORK_DONE on %d\n", | |
468 | parent_pid); | |
3ced3da4 | 469 | parent_lp->stopped = 1; |
9016a515 | 470 | |
6c95b8df PA |
471 | /* We'll handle the VFORK_DONE event like any other |
472 | event, in target_wait. */ | |
9016a515 DJ |
473 | } |
474 | else | |
475 | { | |
476 | /* We can't insert breakpoints until the child has | |
477 | finished with the shared memory region. We need to | |
478 | wait until that happens. Ideal would be to just | |
479 | call: | |
480 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
481 | - waitpid (parent_pid, &status, __WALL); | |
482 | However, most architectures can't handle a syscall | |
483 | being traced on the way out if it wasn't traced on | |
484 | the way in. | |
485 | ||
486 | We might also think to loop, continuing the child | |
487 | until it exits or gets a SIGTRAP. One problem is | |
488 | that the child might call ptrace with PTRACE_TRACEME. | |
489 | ||
490 | There's no simple and reliable way to figure out when | |
491 | the vforked child will be done with its copy of the | |
492 | shared memory. We could step it out of the syscall, | |
493 | two instructions, let it go, and then single-step the | |
494 | parent once. When we have hardware single-step, this | |
495 | would work; with software single-step it could still | |
496 | be made to work but we'd have to be able to insert | |
497 | single-step breakpoints in the child, and we'd have | |
498 | to insert -just- the single-step breakpoint in the | |
499 | parent. Very awkward. | |
500 | ||
501 | In the end, the best we can do is to make sure it | |
502 | runs for a little while. Hopefully it will be out of | |
503 | range of any breakpoints we reinsert. Usually this | |
504 | is only the single-step breakpoint at vfork's return | |
505 | point. */ | |
506 | ||
6c95b8df PA |
507 | if (debug_linux_nat) |
508 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
509 | "LCFF: no VFORK_DONE " |
510 | "support, sleeping a bit\n"); | |
6c95b8df | 511 | |
9016a515 | 512 | usleep (10000); |
9016a515 | 513 | |
6c95b8df PA |
514 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
515 | and leave it pending. The next linux_nat_resume call | |
516 | will notice a pending event, and bypasses actually | |
517 | resuming the inferior. */ | |
3ced3da4 PA |
518 | parent_lp->status = 0; |
519 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
520 | parent_lp->stopped = 1; | |
6c95b8df PA |
521 | |
522 | /* If we're in async mode, need to tell the event loop | |
523 | there's something here to process. */ | |
d9d41e78 | 524 | if (target_is_async_p ()) |
6c95b8df PA |
525 | async_file_mark (); |
526 | } | |
9016a515 | 527 | } |
4de4c07c | 528 | } |
3993f6b1 | 529 | else |
4de4c07c | 530 | { |
3ced3da4 | 531 | struct lwp_info *child_lp; |
4de4c07c | 532 | |
3ced3da4 PA |
533 | child_lp = add_lwp (inferior_ptid); |
534 | child_lp->stopped = 1; | |
25289eb2 | 535 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 536 | |
6c95b8df | 537 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 538 | check_for_thread_db (); |
4de4c07c DJ |
539 | } |
540 | ||
541 | return 0; | |
542 | } | |
543 | ||
4de4c07c | 544 | \f |
77b06cd7 | 545 | static int |
a863b201 | 546 | linux_child_insert_fork_catchpoint (struct target_ops *self, int pid) |
4de4c07c | 547 | { |
96d7229d | 548 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
549 | } |
550 | ||
eb73ad13 | 551 | static int |
973fc227 | 552 | linux_child_remove_fork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
553 | { |
554 | return 0; | |
555 | } | |
556 | ||
77b06cd7 | 557 | static int |
3ecc7da0 | 558 | linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 559 | { |
96d7229d | 560 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
561 | } |
562 | ||
eb73ad13 | 563 | static int |
e98cf0cd | 564 | linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
565 | { |
566 | return 0; | |
567 | } | |
568 | ||
77b06cd7 | 569 | static int |
ba025e51 | 570 | linux_child_insert_exec_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 571 | { |
96d7229d | 572 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
573 | } |
574 | ||
eb73ad13 | 575 | static int |
758e29d2 | 576 | linux_child_remove_exec_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
577 | { |
578 | return 0; | |
579 | } | |
580 | ||
a96d9b2e | 581 | static int |
ff214e67 TT |
582 | linux_child_set_syscall_catchpoint (struct target_ops *self, |
583 | int pid, int needed, int any_count, | |
a96d9b2e SDJ |
584 | int table_size, int *table) |
585 | { | |
96d7229d | 586 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
587 | return 1; |
588 | ||
a96d9b2e SDJ |
589 | /* On GNU/Linux, we ignore the arguments. It means that we only |
590 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 591 | |
a96d9b2e SDJ |
592 | Also, we do not use the `table' information because we do not |
593 | filter system calls here. We let GDB do the logic for us. */ | |
594 | return 0; | |
595 | } | |
596 | ||
d6b0e80f AC |
597 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
598 | are processes sharing the same VM space. A multi-threaded process | |
599 | is basically a group of such processes. However, such a grouping | |
600 | is almost entirely a user-space issue; the kernel doesn't enforce | |
601 | such a grouping at all (this might change in the future). In | |
602 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
603 | Threads library) to provide such a grouping. | |
604 | ||
605 | It is perfectly well possible to write a multi-threaded application | |
606 | without the assistance of a threads library, by using the clone | |
607 | system call directly. This module should be able to give some | |
608 | rudimentary support for debugging such applications if developers | |
609 | specify the CLONE_PTRACE flag in the clone system call, and are | |
610 | using the Linux kernel 2.4 or above. | |
611 | ||
612 | Note that there are some peculiarities in GNU/Linux that affect | |
613 | this code: | |
614 | ||
615 | - In general one should specify the __WCLONE flag to waitpid in | |
616 | order to make it report events for any of the cloned processes | |
617 | (and leave it out for the initial process). However, if a cloned | |
618 | process has exited the exit status is only reported if the | |
619 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
620 | we cannot use it since GDB must work on older systems too. | |
621 | ||
622 | - When a traced, cloned process exits and is waited for by the | |
623 | debugger, the kernel reassigns it to the original parent and | |
624 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
625 | library doesn't notice this, which leads to the "zombie problem": | |
626 | When debugged a multi-threaded process that spawns a lot of | |
627 | threads will run out of processes, even if the threads exit, | |
628 | because the "zombies" stay around. */ | |
629 | ||
630 | /* List of known LWPs. */ | |
9f0bdab8 | 631 | struct lwp_info *lwp_list; |
d6b0e80f AC |
632 | \f |
633 | ||
d6b0e80f AC |
634 | /* Original signal mask. */ |
635 | static sigset_t normal_mask; | |
636 | ||
637 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
638 | _initialize_linux_nat. */ | |
639 | static sigset_t suspend_mask; | |
640 | ||
7feb7d06 PA |
641 | /* Signals to block to make that sigsuspend work. */ |
642 | static sigset_t blocked_mask; | |
643 | ||
644 | /* SIGCHLD action. */ | |
645 | struct sigaction sigchld_action; | |
b84876c2 | 646 | |
7feb7d06 PA |
647 | /* Block child signals (SIGCHLD and linux threads signals), and store |
648 | the previous mask in PREV_MASK. */ | |
84e46146 | 649 | |
7feb7d06 PA |
650 | static void |
651 | block_child_signals (sigset_t *prev_mask) | |
652 | { | |
653 | /* Make sure SIGCHLD is blocked. */ | |
654 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
655 | sigaddset (&blocked_mask, SIGCHLD); | |
656 | ||
657 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
658 | } | |
659 | ||
660 | /* Restore child signals mask, previously returned by | |
661 | block_child_signals. */ | |
662 | ||
663 | static void | |
664 | restore_child_signals_mask (sigset_t *prev_mask) | |
665 | { | |
666 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
667 | } | |
2455069d UW |
668 | |
669 | /* Mask of signals to pass directly to the inferior. */ | |
670 | static sigset_t pass_mask; | |
671 | ||
672 | /* Update signals to pass to the inferior. */ | |
673 | static void | |
94bedb42 TT |
674 | linux_nat_pass_signals (struct target_ops *self, |
675 | int numsigs, unsigned char *pass_signals) | |
2455069d UW |
676 | { |
677 | int signo; | |
678 | ||
679 | sigemptyset (&pass_mask); | |
680 | ||
681 | for (signo = 1; signo < NSIG; signo++) | |
682 | { | |
2ea28649 | 683 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
684 | if (target_signo < numsigs && pass_signals[target_signo]) |
685 | sigaddset (&pass_mask, signo); | |
686 | } | |
687 | } | |
688 | ||
d6b0e80f AC |
689 | \f |
690 | ||
691 | /* Prototypes for local functions. */ | |
692 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 693 | static int linux_thread_alive (ptid_t ptid); |
8dd27370 | 694 | static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid); |
20ba1ce6 | 695 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
710151dd | 696 | |
d6b0e80f | 697 | \f |
d6b0e80f | 698 | |
7b50312a PA |
699 | /* Destroy and free LP. */ |
700 | ||
701 | static void | |
702 | lwp_free (struct lwp_info *lp) | |
703 | { | |
704 | xfree (lp->arch_private); | |
705 | xfree (lp); | |
706 | } | |
707 | ||
d90e17a7 PA |
708 | /* Remove all LWPs belong to PID from the lwp list. */ |
709 | ||
710 | static void | |
711 | purge_lwp_list (int pid) | |
712 | { | |
713 | struct lwp_info *lp, *lpprev, *lpnext; | |
714 | ||
715 | lpprev = NULL; | |
716 | ||
717 | for (lp = lwp_list; lp; lp = lpnext) | |
718 | { | |
719 | lpnext = lp->next; | |
720 | ||
721 | if (ptid_get_pid (lp->ptid) == pid) | |
722 | { | |
723 | if (lp == lwp_list) | |
724 | lwp_list = lp->next; | |
725 | else | |
726 | lpprev->next = lp->next; | |
727 | ||
7b50312a | 728 | lwp_free (lp); |
d90e17a7 PA |
729 | } |
730 | else | |
731 | lpprev = lp; | |
732 | } | |
733 | } | |
734 | ||
26cb8b7c PA |
735 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
736 | in the process. Return a pointer to the structure describing the | |
737 | new LWP. | |
738 | ||
739 | This differs from add_lwp in that we don't let the arch specific | |
740 | bits know about this new thread. Current clients of this callback | |
741 | take the opportunity to install watchpoints in the new thread, and | |
742 | we shouldn't do that for the first thread. If we're spawning a | |
743 | child ("run"), the thread executes the shell wrapper first, and we | |
744 | shouldn't touch it until it execs the program we want to debug. | |
745 | For "attach", it'd be okay to call the callback, but it's not | |
746 | necessary, because watchpoints can't yet have been inserted into | |
747 | the inferior. */ | |
d6b0e80f AC |
748 | |
749 | static struct lwp_info * | |
26cb8b7c | 750 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
751 | { |
752 | struct lwp_info *lp; | |
753 | ||
dfd4cc63 | 754 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f AC |
755 | |
756 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
757 | ||
758 | memset (lp, 0, sizeof (struct lwp_info)); | |
759 | ||
25289eb2 | 760 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
761 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
762 | ||
763 | lp->ptid = ptid; | |
dc146f7c | 764 | lp->core = -1; |
d6b0e80f AC |
765 | |
766 | lp->next = lwp_list; | |
767 | lwp_list = lp; | |
d6b0e80f | 768 | |
26cb8b7c PA |
769 | return lp; |
770 | } | |
771 | ||
772 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
773 | structure describing the new LWP. The LWP should already be | |
774 | stopped. */ | |
775 | ||
776 | static struct lwp_info * | |
777 | add_lwp (ptid_t ptid) | |
778 | { | |
779 | struct lwp_info *lp; | |
780 | ||
781 | lp = add_initial_lwp (ptid); | |
782 | ||
6e012a6c PA |
783 | /* Let the arch specific bits know about this new thread. Current |
784 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
785 | watchpoints in the new thread. We don't do this for the first |
786 | thread though. See add_initial_lwp. */ | |
787 | if (linux_nat_new_thread != NULL) | |
7b50312a | 788 | linux_nat_new_thread (lp); |
9f0bdab8 | 789 | |
d6b0e80f AC |
790 | return lp; |
791 | } | |
792 | ||
793 | /* Remove the LWP specified by PID from the list. */ | |
794 | ||
795 | static void | |
796 | delete_lwp (ptid_t ptid) | |
797 | { | |
798 | struct lwp_info *lp, *lpprev; | |
799 | ||
800 | lpprev = NULL; | |
801 | ||
802 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
803 | if (ptid_equal (lp->ptid, ptid)) | |
804 | break; | |
805 | ||
806 | if (!lp) | |
807 | return; | |
808 | ||
d6b0e80f AC |
809 | if (lpprev) |
810 | lpprev->next = lp->next; | |
811 | else | |
812 | lwp_list = lp->next; | |
813 | ||
7b50312a | 814 | lwp_free (lp); |
d6b0e80f AC |
815 | } |
816 | ||
817 | /* Return a pointer to the structure describing the LWP corresponding | |
818 | to PID. If no corresponding LWP could be found, return NULL. */ | |
819 | ||
820 | static struct lwp_info * | |
821 | find_lwp_pid (ptid_t ptid) | |
822 | { | |
823 | struct lwp_info *lp; | |
824 | int lwp; | |
825 | ||
dfd4cc63 LM |
826 | if (ptid_lwp_p (ptid)) |
827 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 828 | else |
dfd4cc63 | 829 | lwp = ptid_get_pid (ptid); |
d6b0e80f AC |
830 | |
831 | for (lp = lwp_list; lp; lp = lp->next) | |
dfd4cc63 | 832 | if (lwp == ptid_get_lwp (lp->ptid)) |
d6b0e80f AC |
833 | return lp; |
834 | ||
835 | return NULL; | |
836 | } | |
837 | ||
838 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
839 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
840 | pointer to the structure describing that LWP immediately. | |
841 | Otherwise return NULL. */ | |
842 | ||
843 | struct lwp_info * | |
d90e17a7 PA |
844 | iterate_over_lwps (ptid_t filter, |
845 | int (*callback) (struct lwp_info *, void *), | |
846 | void *data) | |
d6b0e80f AC |
847 | { |
848 | struct lwp_info *lp, *lpnext; | |
849 | ||
850 | for (lp = lwp_list; lp; lp = lpnext) | |
851 | { | |
852 | lpnext = lp->next; | |
d90e17a7 PA |
853 | |
854 | if (ptid_match (lp->ptid, filter)) | |
855 | { | |
856 | if ((*callback) (lp, data)) | |
857 | return lp; | |
858 | } | |
d6b0e80f AC |
859 | } |
860 | ||
861 | return NULL; | |
862 | } | |
863 | ||
2277426b PA |
864 | /* Update our internal state when changing from one checkpoint to |
865 | another indicated by NEW_PTID. We can only switch single-threaded | |
866 | applications, so we only create one new LWP, and the previous list | |
867 | is discarded. */ | |
f973ed9c DJ |
868 | |
869 | void | |
870 | linux_nat_switch_fork (ptid_t new_ptid) | |
871 | { | |
872 | struct lwp_info *lp; | |
873 | ||
dfd4cc63 | 874 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 875 | |
f973ed9c DJ |
876 | lp = add_lwp (new_ptid); |
877 | lp->stopped = 1; | |
e26af52f | 878 | |
2277426b PA |
879 | /* This changes the thread's ptid while preserving the gdb thread |
880 | num. Also changes the inferior pid, while preserving the | |
881 | inferior num. */ | |
882 | thread_change_ptid (inferior_ptid, new_ptid); | |
883 | ||
884 | /* We've just told GDB core that the thread changed target id, but, | |
885 | in fact, it really is a different thread, with different register | |
886 | contents. */ | |
887 | registers_changed (); | |
e26af52f DJ |
888 | } |
889 | ||
e26af52f DJ |
890 | /* Handle the exit of a single thread LP. */ |
891 | ||
892 | static void | |
893 | exit_lwp (struct lwp_info *lp) | |
894 | { | |
e09875d4 | 895 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
896 | |
897 | if (th) | |
e26af52f | 898 | { |
17faa917 DJ |
899 | if (print_thread_events) |
900 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
901 | ||
4f8d22e3 | 902 | delete_thread (lp->ptid); |
e26af52f DJ |
903 | } |
904 | ||
905 | delete_lwp (lp->ptid); | |
906 | } | |
907 | ||
a0ef4274 DJ |
908 | /* Wait for the LWP specified by LP, which we have just attached to. |
909 | Returns a wait status for that LWP, to cache. */ | |
910 | ||
911 | static int | |
912 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
913 | int *signalled) | |
914 | { | |
dfd4cc63 | 915 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
916 | int status; |
917 | ||
644cebc9 | 918 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
919 | { |
920 | if (debug_linux_nat) | |
921 | fprintf_unfiltered (gdb_stdlog, | |
922 | "LNPAW: Attaching to a stopped process\n"); | |
923 | ||
924 | /* The process is definitely stopped. It is in a job control | |
925 | stop, unless the kernel predates the TASK_STOPPED / | |
926 | TASK_TRACED distinction, in which case it might be in a | |
927 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
928 | can kill it, signal it, et cetera. | |
929 | ||
930 | First make sure there is a pending SIGSTOP. Since we are | |
931 | already attached, the process can not transition from stopped | |
932 | to running without a PTRACE_CONT; so we know this signal will | |
933 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
934 | probably already in the queue (unless this kernel is old | |
935 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
936 | is not an RT signal, it can only be queued once. */ | |
937 | kill_lwp (pid, SIGSTOP); | |
938 | ||
939 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
940 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
941 | ptrace (PTRACE_CONT, pid, 0, 0); | |
942 | } | |
943 | ||
944 | /* Make sure the initial process is stopped. The user-level threads | |
945 | layer might want to poke around in the inferior, and that won't | |
946 | work if things haven't stabilized yet. */ | |
947 | new_pid = my_waitpid (pid, &status, 0); | |
948 | if (new_pid == -1 && errno == ECHILD) | |
949 | { | |
950 | if (first) | |
951 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
952 | ||
953 | /* Try again with __WCLONE to check cloned processes. */ | |
954 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
955 | *cloned = 1; | |
956 | } | |
957 | ||
dacc9cb2 PP |
958 | gdb_assert (pid == new_pid); |
959 | ||
960 | if (!WIFSTOPPED (status)) | |
961 | { | |
962 | /* The pid we tried to attach has apparently just exited. */ | |
963 | if (debug_linux_nat) | |
964 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
965 | pid, status_to_str (status)); | |
966 | return status; | |
967 | } | |
a0ef4274 DJ |
968 | |
969 | if (WSTOPSIG (status) != SIGSTOP) | |
970 | { | |
971 | *signalled = 1; | |
972 | if (debug_linux_nat) | |
973 | fprintf_unfiltered (gdb_stdlog, | |
974 | "LNPAW: Received %s after attaching\n", | |
975 | status_to_str (status)); | |
976 | } | |
977 | ||
978 | return status; | |
979 | } | |
980 | ||
84636d28 PA |
981 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
982 | the new LWP could not be attached, or 1 if we're already auto | |
983 | attached to this thread, but haven't processed the | |
984 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
985 | its existance, without considering it an error. */ | |
d6b0e80f | 986 | |
9ee57c33 | 987 | int |
93815fbf | 988 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 989 | { |
9ee57c33 | 990 | struct lwp_info *lp; |
84636d28 | 991 | int lwpid; |
d6b0e80f | 992 | |
dfd4cc63 | 993 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 994 | |
9ee57c33 | 995 | lp = find_lwp_pid (ptid); |
dfd4cc63 | 996 | lwpid = ptid_get_lwp (ptid); |
d6b0e80f | 997 | |
3b27ef47 | 998 | /* We assume that we're already attached to any LWP that is already |
d6b0e80f AC |
999 | in our list of LWPs. If we're not seeing exit events from threads |
1000 | and we've had PID wraparound since we last tried to stop all threads, | |
1001 | this assumption might be wrong; fortunately, this is very unlikely | |
1002 | to happen. */ | |
3b27ef47 | 1003 | if (lp == NULL) |
d6b0e80f | 1004 | { |
a0ef4274 | 1005 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1006 | |
84636d28 | 1007 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1008 | { |
96d7229d | 1009 | if (linux_supports_tracefork ()) |
84636d28 PA |
1010 | { |
1011 | /* If we haven't stopped all threads when we get here, | |
1012 | we may have seen a thread listed in thread_db's list, | |
1013 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1014 | that's the case, ignore this new thread, and let | |
1015 | normal event handling discover it later. */ | |
1016 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1017 | { | |
1018 | /* We've already seen this thread stop, but we | |
1019 | haven't seen the PTRACE_EVENT_CLONE extended | |
1020 | event yet. */ | |
3b27ef47 PA |
1021 | if (debug_linux_nat) |
1022 | fprintf_unfiltered (gdb_stdlog, | |
1023 | "LLAL: attach failed, but already seen " | |
1024 | "this thread %s stop\n", | |
1025 | target_pid_to_str (ptid)); | |
1026 | return 1; | |
84636d28 PA |
1027 | } |
1028 | else | |
1029 | { | |
1030 | int new_pid; | |
1031 | int status; | |
1032 | ||
3b27ef47 PA |
1033 | if (debug_linux_nat) |
1034 | fprintf_unfiltered (gdb_stdlog, | |
1035 | "LLAL: attach failed, and haven't seen " | |
1036 | "this thread %s stop yet\n", | |
1037 | target_pid_to_str (ptid)); | |
1038 | ||
1039 | /* We may or may not be attached to the LWP already. | |
1040 | Try waitpid on it. If that errors, we're not | |
1041 | attached to the LWP yet. Otherwise, we're | |
1042 | already attached. */ | |
a33e3959 | 1043 | gdb_assert (lwpid > 0); |
84636d28 PA |
1044 | new_pid = my_waitpid (lwpid, &status, WNOHANG); |
1045 | if (new_pid == -1 && errno == ECHILD) | |
1046 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1047 | if (new_pid != -1) | |
1048 | { | |
3b27ef47 PA |
1049 | if (new_pid == 0) |
1050 | { | |
1051 | /* The child hasn't stopped for its initial | |
1052 | SIGSTOP stop yet. */ | |
1053 | if (debug_linux_nat) | |
1054 | fprintf_unfiltered (gdb_stdlog, | |
1055 | "LLAL: child hasn't " | |
1056 | "stopped yet\n"); | |
1057 | } | |
1058 | else if (WIFSTOPPED (status)) | |
1059 | { | |
1060 | if (debug_linux_nat) | |
1061 | fprintf_unfiltered (gdb_stdlog, | |
1062 | "LLAL: adding to stopped_pids\n"); | |
1063 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1064 | } | |
84636d28 PA |
1065 | return 1; |
1066 | } | |
1067 | } | |
1068 | } | |
1069 | ||
9ee57c33 DJ |
1070 | /* If we fail to attach to the thread, issue a warning, |
1071 | but continue. One way this can happen is if thread | |
e9efe249 | 1072 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1073 | bug may place threads in the thread list and then fail |
1074 | to create them. */ | |
1075 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1076 | safe_strerror (errno)); | |
1077 | return -1; | |
1078 | } | |
1079 | ||
d6b0e80f AC |
1080 | if (debug_linux_nat) |
1081 | fprintf_unfiltered (gdb_stdlog, | |
1082 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1083 | target_pid_to_str (ptid)); | |
1084 | ||
a0ef4274 | 1085 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1086 | if (!WIFSTOPPED (status)) |
12696c10 | 1087 | return 1; |
dacc9cb2 | 1088 | |
a0ef4274 DJ |
1089 | lp = add_lwp (ptid); |
1090 | lp->stopped = 1; | |
3b27ef47 | 1091 | lp->last_resume_kind = resume_stop; |
a0ef4274 DJ |
1092 | lp->cloned = cloned; |
1093 | lp->signalled = signalled; | |
1094 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1095 | { |
a0ef4274 DJ |
1096 | lp->resumed = 1; |
1097 | lp->status = status; | |
d6b0e80f AC |
1098 | } |
1099 | ||
dfd4cc63 | 1100 | target_post_attach (ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
1101 | |
1102 | if (debug_linux_nat) | |
1103 | { | |
1104 | fprintf_unfiltered (gdb_stdlog, | |
1105 | "LLAL: waitpid %s received %s\n", | |
1106 | target_pid_to_str (ptid), | |
1107 | status_to_str (status)); | |
1108 | } | |
1109 | } | |
9ee57c33 | 1110 | |
9ee57c33 | 1111 | return 0; |
d6b0e80f AC |
1112 | } |
1113 | ||
b84876c2 | 1114 | static void |
136d6dae VP |
1115 | linux_nat_create_inferior (struct target_ops *ops, |
1116 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1117 | int from_tty) |
1118 | { | |
8cc73a39 SDJ |
1119 | struct cleanup *restore_personality |
1120 | = maybe_disable_address_space_randomization (disable_randomization); | |
b84876c2 PA |
1121 | |
1122 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1123 | we have to mask the async mode. */ | |
1124 | ||
2455069d | 1125 | /* Make sure we report all signals during startup. */ |
94bedb42 | 1126 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1127 | |
136d6dae | 1128 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1129 | |
8cc73a39 | 1130 | do_cleanups (restore_personality); |
b84876c2 PA |
1131 | } |
1132 | ||
8784d563 PA |
1133 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1134 | already attached. Returns true if a new LWP is found, false | |
1135 | otherwise. */ | |
1136 | ||
1137 | static int | |
1138 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1139 | { | |
1140 | struct lwp_info *lp; | |
1141 | ||
1142 | /* Ignore LWPs we're already attached to. */ | |
1143 | lp = find_lwp_pid (ptid); | |
1144 | if (lp == NULL) | |
1145 | { | |
1146 | int lwpid = ptid_get_lwp (ptid); | |
1147 | ||
1148 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1149 | { | |
1150 | int err = errno; | |
1151 | ||
1152 | /* Be quiet if we simply raced with the thread exiting. | |
1153 | EPERM is returned if the thread's task still exists, and | |
1154 | is marked as exited or zombie, as well as other | |
1155 | conditions, so in that case, confirm the status in | |
1156 | /proc/PID/status. */ | |
1157 | if (err == ESRCH | |
1158 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1159 | { | |
1160 | if (debug_linux_nat) | |
1161 | { | |
1162 | fprintf_unfiltered (gdb_stdlog, | |
1163 | "Cannot attach to lwp %d: " | |
1164 | "thread is gone (%d: %s)\n", | |
1165 | lwpid, err, safe_strerror (err)); | |
1166 | } | |
1167 | } | |
1168 | else | |
1169 | { | |
f71f0b0d | 1170 | warning (_("Cannot attach to lwp %d: %s"), |
8784d563 PA |
1171 | lwpid, |
1172 | linux_ptrace_attach_fail_reason_string (ptid, | |
1173 | err)); | |
1174 | } | |
1175 | } | |
1176 | else | |
1177 | { | |
1178 | if (debug_linux_nat) | |
1179 | fprintf_unfiltered (gdb_stdlog, | |
1180 | "PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1181 | target_pid_to_str (ptid)); | |
1182 | ||
1183 | lp = add_lwp (ptid); | |
1184 | lp->cloned = 1; | |
1185 | ||
1186 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1187 | PTRACE_ATTACH brings it to a halt. */ | |
1188 | lp->signalled = 1; | |
1189 | ||
1190 | /* We need to wait for a stop before being able to make the | |
1191 | next ptrace call on this LWP. */ | |
1192 | lp->must_set_ptrace_flags = 1; | |
1193 | } | |
1194 | ||
1195 | return 1; | |
1196 | } | |
1197 | return 0; | |
1198 | } | |
1199 | ||
d6b0e80f | 1200 | static void |
c0939df1 | 1201 | linux_nat_attach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f AC |
1202 | { |
1203 | struct lwp_info *lp; | |
d6b0e80f | 1204 | int status; |
af990527 | 1205 | ptid_t ptid; |
87b0bb13 | 1206 | volatile struct gdb_exception ex; |
d6b0e80f | 1207 | |
2455069d | 1208 | /* Make sure we report all signals during attach. */ |
94bedb42 | 1209 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1210 | |
87b0bb13 JK |
1211 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1212 | { | |
1213 | linux_ops->to_attach (ops, args, from_tty); | |
1214 | } | |
1215 | if (ex.reason < 0) | |
1216 | { | |
1217 | pid_t pid = parse_pid_to_attach (args); | |
1218 | struct buffer buffer; | |
1219 | char *message, *buffer_s; | |
1220 | ||
1221 | message = xstrdup (ex.message); | |
1222 | make_cleanup (xfree, message); | |
1223 | ||
1224 | buffer_init (&buffer); | |
7ae1a6a6 | 1225 | linux_ptrace_attach_fail_reason (pid, &buffer); |
87b0bb13 JK |
1226 | |
1227 | buffer_grow_str0 (&buffer, ""); | |
1228 | buffer_s = buffer_finish (&buffer); | |
1229 | make_cleanup (xfree, buffer_s); | |
1230 | ||
7ae1a6a6 PA |
1231 | if (*buffer_s != '\0') |
1232 | throw_error (ex.error, "warning: %s\n%s", buffer_s, message); | |
1233 | else | |
1234 | throw_error (ex.error, "%s", message); | |
87b0bb13 | 1235 | } |
d6b0e80f | 1236 | |
af990527 PA |
1237 | /* The ptrace base target adds the main thread with (pid,0,0) |
1238 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1239 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1240 | ptid_get_pid (inferior_ptid), | |
1241 | 0); | |
af990527 PA |
1242 | thread_change_ptid (inferior_ptid, ptid); |
1243 | ||
9f0bdab8 | 1244 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1245 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1246 | |
1247 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1248 | &lp->signalled); | |
dacc9cb2 PP |
1249 | if (!WIFSTOPPED (status)) |
1250 | { | |
1251 | if (WIFEXITED (status)) | |
1252 | { | |
1253 | int exit_code = WEXITSTATUS (status); | |
1254 | ||
1255 | target_terminal_ours (); | |
1256 | target_mourn_inferior (); | |
1257 | if (exit_code == 0) | |
1258 | error (_("Unable to attach: program exited normally.")); | |
1259 | else | |
1260 | error (_("Unable to attach: program exited with code %d."), | |
1261 | exit_code); | |
1262 | } | |
1263 | else if (WIFSIGNALED (status)) | |
1264 | { | |
2ea28649 | 1265 | enum gdb_signal signo; |
dacc9cb2 PP |
1266 | |
1267 | target_terminal_ours (); | |
1268 | target_mourn_inferior (); | |
1269 | ||
2ea28649 | 1270 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1271 | error (_("Unable to attach: program terminated with signal " |
1272 | "%s, %s."), | |
2ea28649 PA |
1273 | gdb_signal_to_name (signo), |
1274 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1275 | } |
1276 | ||
1277 | internal_error (__FILE__, __LINE__, | |
1278 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1279 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1280 | } |
1281 | ||
a0ef4274 | 1282 | lp->stopped = 1; |
9f0bdab8 | 1283 | |
a0ef4274 | 1284 | /* Save the wait status to report later. */ |
d6b0e80f | 1285 | lp->resumed = 1; |
a0ef4274 DJ |
1286 | if (debug_linux_nat) |
1287 | fprintf_unfiltered (gdb_stdlog, | |
1288 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1289 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1290 | |
7feb7d06 PA |
1291 | lp->status = status; |
1292 | ||
8784d563 PA |
1293 | /* We must attach to every LWP. If /proc is mounted, use that to |
1294 | find them now. The inferior may be using raw clone instead of | |
1295 | using pthreads. But even if it is using pthreads, thread_db | |
1296 | walks structures in the inferior's address space to find the list | |
1297 | of threads/LWPs, and those structures may well be corrupted. | |
1298 | Note that once thread_db is loaded, we'll still use it to list | |
1299 | threads and associate pthread info with each LWP. */ | |
1300 | linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid), | |
1301 | attach_proc_task_lwp_callback); | |
1302 | ||
7feb7d06 PA |
1303 | if (target_can_async_p ()) |
1304 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1305 | } |
1306 | ||
a0ef4274 DJ |
1307 | /* Get pending status of LP. */ |
1308 | static int | |
1309 | get_pending_status (struct lwp_info *lp, int *status) | |
1310 | { | |
a493e3e2 | 1311 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1312 | |
1313 | /* If we paused threads momentarily, we may have stored pending | |
1314 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1315 | and GDB core hasn't seen any signal for those threads. | |
1316 | Otherwise, the last signal reported to the core is found in the | |
1317 | thread object's stop_signal. | |
1318 | ||
1319 | There's a corner case that isn't handled here at present. Only | |
1320 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1321 | stop_signal make sense as a real signal to pass to the inferior. | |
1322 | Some catchpoint related events, like | |
1323 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1324 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1325 | those traps are debug API (ptrace in our case) related and |
1326 | induced; the inferior wouldn't see them if it wasn't being | |
1327 | traced. Hence, we should never pass them to the inferior, even | |
1328 | when set to pass state. Since this corner case isn't handled by | |
1329 | infrun.c when proceeding with a signal, for consistency, neither | |
1330 | do we handle it here (or elsewhere in the file we check for | |
1331 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1332 | this is really a corner case. */ | |
1333 | ||
1334 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1335 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1336 | else if (lp->status) |
2ea28649 | 1337 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1338 | else if (non_stop && !is_executing (lp->ptid)) |
1339 | { | |
1340 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1341 | |
16c381f0 | 1342 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1343 | } |
1344 | else if (!non_stop) | |
a0ef4274 | 1345 | { |
ca2163eb PA |
1346 | struct target_waitstatus last; |
1347 | ptid_t last_ptid; | |
4c28f408 | 1348 | |
ca2163eb | 1349 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1350 | |
dfd4cc63 | 1351 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1352 | { |
e09875d4 | 1353 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1354 | |
16c381f0 | 1355 | signo = tp->suspend.stop_signal; |
4c28f408 | 1356 | } |
ca2163eb | 1357 | } |
4c28f408 | 1358 | |
ca2163eb | 1359 | *status = 0; |
4c28f408 | 1360 | |
a493e3e2 | 1361 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1362 | { |
1363 | if (debug_linux_nat) | |
1364 | fprintf_unfiltered (gdb_stdlog, | |
1365 | "GPT: lwp %s has no pending signal\n", | |
1366 | target_pid_to_str (lp->ptid)); | |
1367 | } | |
1368 | else if (!signal_pass_state (signo)) | |
1369 | { | |
1370 | if (debug_linux_nat) | |
3e43a32a MS |
1371 | fprintf_unfiltered (gdb_stdlog, |
1372 | "GPT: lwp %s had signal %s, " | |
1373 | "but it is in no pass state\n", | |
ca2163eb | 1374 | target_pid_to_str (lp->ptid), |
2ea28649 | 1375 | gdb_signal_to_string (signo)); |
a0ef4274 | 1376 | } |
a0ef4274 | 1377 | else |
4c28f408 | 1378 | { |
2ea28649 | 1379 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1380 | |
1381 | if (debug_linux_nat) | |
1382 | fprintf_unfiltered (gdb_stdlog, | |
1383 | "GPT: lwp %s has pending signal %s\n", | |
1384 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1385 | gdb_signal_to_string (signo)); |
4c28f408 | 1386 | } |
a0ef4274 DJ |
1387 | |
1388 | return 0; | |
1389 | } | |
1390 | ||
d6b0e80f AC |
1391 | static int |
1392 | detach_callback (struct lwp_info *lp, void *data) | |
1393 | { | |
1394 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1395 | ||
1396 | if (debug_linux_nat && lp->status) | |
1397 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1398 | strsignal (WSTOPSIG (lp->status)), | |
1399 | target_pid_to_str (lp->ptid)); | |
1400 | ||
a0ef4274 DJ |
1401 | /* If there is a pending SIGSTOP, get rid of it. */ |
1402 | if (lp->signalled) | |
d6b0e80f | 1403 | { |
d6b0e80f AC |
1404 | if (debug_linux_nat) |
1405 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1406 | "DC: Sending SIGCONT to %s\n", |
1407 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1408 | |
dfd4cc63 | 1409 | kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT); |
d6b0e80f | 1410 | lp->signalled = 0; |
d6b0e80f AC |
1411 | } |
1412 | ||
1413 | /* We don't actually detach from the LWP that has an id equal to the | |
1414 | overall process id just yet. */ | |
dfd4cc63 | 1415 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) |
d6b0e80f | 1416 | { |
a0ef4274 DJ |
1417 | int status = 0; |
1418 | ||
1419 | /* Pass on any pending signal for this LWP. */ | |
1420 | get_pending_status (lp, &status); | |
1421 | ||
7b50312a PA |
1422 | if (linux_nat_prepare_to_resume != NULL) |
1423 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f | 1424 | errno = 0; |
dfd4cc63 | 1425 | if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0, |
a0ef4274 | 1426 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1427 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1428 | safe_strerror (errno)); |
1429 | ||
1430 | if (debug_linux_nat) | |
1431 | fprintf_unfiltered (gdb_stdlog, | |
1432 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1433 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1434 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1435 | |
1436 | delete_lwp (lp->ptid); | |
1437 | } | |
1438 | ||
1439 | return 0; | |
1440 | } | |
1441 | ||
1442 | static void | |
52554a0e | 1443 | linux_nat_detach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f | 1444 | { |
b84876c2 | 1445 | int pid; |
a0ef4274 | 1446 | int status; |
d90e17a7 PA |
1447 | struct lwp_info *main_lwp; |
1448 | ||
dfd4cc63 | 1449 | pid = ptid_get_pid (inferior_ptid); |
a0ef4274 | 1450 | |
ae5e0686 MK |
1451 | /* Don't unregister from the event loop, as there may be other |
1452 | inferiors running. */ | |
b84876c2 | 1453 | |
4c28f408 PA |
1454 | /* Stop all threads before detaching. ptrace requires that the |
1455 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1456 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1457 | /* ... and wait until all of them have reported back that |
1458 | they're no longer running. */ | |
d90e17a7 | 1459 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1460 | |
d90e17a7 | 1461 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1462 | |
1463 | /* Only the initial process should be left right now. */ | |
dfd4cc63 | 1464 | gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1); |
d90e17a7 PA |
1465 | |
1466 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1467 | |
a0ef4274 DJ |
1468 | /* Pass on any pending signal for the last LWP. */ |
1469 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1470 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1471 | && WIFSTOPPED (status)) |
1472 | { | |
52554a0e TT |
1473 | char *tem; |
1474 | ||
a0ef4274 DJ |
1475 | /* Put the signal number in ARGS so that inf_ptrace_detach will |
1476 | pass it along with PTRACE_DETACH. */ | |
52554a0e | 1477 | tem = alloca (8); |
cde33bf1 | 1478 | xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status)); |
52554a0e | 1479 | args = tem; |
ddabfc73 TT |
1480 | if (debug_linux_nat) |
1481 | fprintf_unfiltered (gdb_stdlog, | |
1482 | "LND: Sending signal %s to %s\n", | |
1483 | args, | |
1484 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1485 | } |
1486 | ||
7b50312a PA |
1487 | if (linux_nat_prepare_to_resume != NULL) |
1488 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1489 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1490 | |
7a7d3353 PA |
1491 | if (forks_exist_p ()) |
1492 | { | |
1493 | /* Multi-fork case. The current inferior_ptid is being detached | |
1494 | from, but there are other viable forks to debug. Detach from | |
1495 | the current fork, and context-switch to the first | |
1496 | available. */ | |
1497 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1498 | } |
1499 | else | |
1500 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1501 | } |
1502 | ||
8a99810d PA |
1503 | /* Resume execution of the inferior process. If STEP is nonzero, |
1504 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1505 | ||
1506 | static void | |
1507 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1508 | { | |
1509 | ptid_t ptid; | |
1510 | ||
1511 | lp->step = step; | |
9c02b525 PA |
1512 | |
1513 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1514 | We only presently need that if the LWP is stepped though (to | |
1515 | handle the case of stepping a breakpoint instruction). */ | |
1516 | if (step) | |
1517 | { | |
1518 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
1519 | ||
1520 | lp->stop_pc = regcache_read_pc (regcache); | |
1521 | } | |
1522 | else | |
1523 | lp->stop_pc = 0; | |
1524 | ||
8a99810d PA |
1525 | if (linux_nat_prepare_to_resume != NULL) |
1526 | linux_nat_prepare_to_resume (lp); | |
1527 | /* Convert to something the lower layer understands. */ | |
1528 | ptid = pid_to_ptid (ptid_get_lwp (lp->ptid)); | |
1529 | linux_ops->to_resume (linux_ops, ptid, step, signo); | |
9c02b525 | 1530 | lp->stop_reason = LWP_STOPPED_BY_NO_REASON; |
8a99810d PA |
1531 | lp->stopped = 0; |
1532 | registers_changed_ptid (lp->ptid); | |
1533 | } | |
1534 | ||
d6b0e80f AC |
1535 | /* Resume LP. */ |
1536 | ||
25289eb2 | 1537 | static void |
e5ef252a | 1538 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1539 | { |
25289eb2 | 1540 | if (lp->stopped) |
6c95b8df | 1541 | { |
c9657e70 | 1542 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
25289eb2 PA |
1543 | |
1544 | if (inf->vfork_child != NULL) | |
1545 | { | |
1546 | if (debug_linux_nat) | |
1547 | fprintf_unfiltered (gdb_stdlog, | |
1548 | "RC: Not resuming %s (vfork parent)\n", | |
1549 | target_pid_to_str (lp->ptid)); | |
1550 | } | |
8a99810d | 1551 | else if (!lwp_status_pending_p (lp)) |
25289eb2 PA |
1552 | { |
1553 | if (debug_linux_nat) | |
1554 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1555 | "RC: Resuming sibling %s, %s, %s\n", |
1556 | target_pid_to_str (lp->ptid), | |
1557 | (signo != GDB_SIGNAL_0 | |
1558 | ? strsignal (gdb_signal_to_host (signo)) | |
1559 | : "0"), | |
1560 | step ? "step" : "resume"); | |
25289eb2 | 1561 | |
8a99810d | 1562 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1563 | } |
1564 | else | |
1565 | { | |
1566 | if (debug_linux_nat) | |
1567 | fprintf_unfiltered (gdb_stdlog, | |
1568 | "RC: Not resuming sibling %s (has pending)\n", | |
1569 | target_pid_to_str (lp->ptid)); | |
1570 | } | |
6c95b8df | 1571 | } |
25289eb2 | 1572 | else |
d6b0e80f | 1573 | { |
d90e17a7 PA |
1574 | if (debug_linux_nat) |
1575 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1576 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1577 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1578 | } |
25289eb2 | 1579 | } |
d6b0e80f | 1580 | |
8817a6f2 PA |
1581 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1582 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1583 | |
25289eb2 | 1584 | static int |
8817a6f2 | 1585 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1586 | { |
e5ef252a PA |
1587 | enum gdb_signal signo = GDB_SIGNAL_0; |
1588 | ||
8817a6f2 PA |
1589 | if (lp == except) |
1590 | return 0; | |
1591 | ||
e5ef252a PA |
1592 | if (lp->stopped) |
1593 | { | |
1594 | struct thread_info *thread; | |
1595 | ||
1596 | thread = find_thread_ptid (lp->ptid); | |
1597 | if (thread != NULL) | |
1598 | { | |
70509625 | 1599 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1600 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1601 | } | |
1602 | } | |
1603 | ||
1604 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1605 | return 0; |
1606 | } | |
1607 | ||
1608 | static int | |
1609 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1610 | { | |
1611 | lp->resumed = 0; | |
25289eb2 | 1612 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1613 | return 0; |
1614 | } | |
1615 | ||
1616 | static int | |
1617 | resume_set_callback (struct lwp_info *lp, void *data) | |
1618 | { | |
1619 | lp->resumed = 1; | |
25289eb2 | 1620 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1621 | return 0; |
1622 | } | |
1623 | ||
1624 | static void | |
28439f5e | 1625 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1626 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1627 | { |
1628 | struct lwp_info *lp; | |
d90e17a7 | 1629 | int resume_many; |
d6b0e80f | 1630 | |
76f50ad1 DJ |
1631 | if (debug_linux_nat) |
1632 | fprintf_unfiltered (gdb_stdlog, | |
1633 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1634 | step ? "step" : "resume", | |
1635 | target_pid_to_str (ptid), | |
a493e3e2 | 1636 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1637 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1638 | target_pid_to_str (inferior_ptid)); |
1639 | ||
d6b0e80f | 1640 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1641 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1642 | || ptid_is_pid (ptid)); | |
4c28f408 | 1643 | |
e3e9f5a2 PA |
1644 | /* Mark the lwps we're resuming as resumed. */ |
1645 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1646 | |
d90e17a7 PA |
1647 | /* See if it's the current inferior that should be handled |
1648 | specially. */ | |
1649 | if (resume_many) | |
1650 | lp = find_lwp_pid (inferior_ptid); | |
1651 | else | |
1652 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1653 | gdb_assert (lp != NULL); |
d6b0e80f | 1654 | |
9f0bdab8 | 1655 | /* Remember if we're stepping. */ |
25289eb2 | 1656 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1657 | |
9f0bdab8 DJ |
1658 | /* If we have a pending wait status for this thread, there is no |
1659 | point in resuming the process. But first make sure that | |
1660 | linux_nat_wait won't preemptively handle the event - we | |
1661 | should never take this short-circuit if we are going to | |
1662 | leave LP running, since we have skipped resuming all the | |
1663 | other threads. This bit of code needs to be synchronized | |
1664 | with linux_nat_wait. */ | |
76f50ad1 | 1665 | |
9f0bdab8 DJ |
1666 | if (lp->status && WIFSTOPPED (lp->status)) |
1667 | { | |
2455069d UW |
1668 | if (!lp->step |
1669 | && WSTOPSIG (lp->status) | |
1670 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1671 | { |
9f0bdab8 DJ |
1672 | if (debug_linux_nat) |
1673 | fprintf_unfiltered (gdb_stdlog, | |
1674 | "LLR: Not short circuiting for ignored " | |
1675 | "status 0x%x\n", lp->status); | |
1676 | ||
d6b0e80f AC |
1677 | /* FIXME: What should we do if we are supposed to continue |
1678 | this thread with a signal? */ | |
a493e3e2 | 1679 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1680 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1681 | lp->status = 0; |
1682 | } | |
1683 | } | |
76f50ad1 | 1684 | |
8a99810d | 1685 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1686 | { |
1687 | /* FIXME: What should we do if we are supposed to continue | |
1688 | this thread with a signal? */ | |
a493e3e2 | 1689 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1690 | |
9f0bdab8 DJ |
1691 | if (debug_linux_nat) |
1692 | fprintf_unfiltered (gdb_stdlog, | |
1693 | "LLR: Short circuiting for status 0x%x\n", | |
1694 | lp->status); | |
d6b0e80f | 1695 | |
7feb7d06 PA |
1696 | if (target_can_async_p ()) |
1697 | { | |
1698 | target_async (inferior_event_handler, 0); | |
1699 | /* Tell the event loop we have something to process. */ | |
1700 | async_file_mark (); | |
1701 | } | |
9f0bdab8 | 1702 | return; |
d6b0e80f AC |
1703 | } |
1704 | ||
d90e17a7 | 1705 | if (resume_many) |
8817a6f2 | 1706 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 | 1707 | |
8a99810d | 1708 | linux_resume_one_lwp (lp, step, signo); |
9f0bdab8 | 1709 | |
d6b0e80f AC |
1710 | if (debug_linux_nat) |
1711 | fprintf_unfiltered (gdb_stdlog, | |
1712 | "LLR: %s %s, %s (resume event thread)\n", | |
1713 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1714 | target_pid_to_str (ptid), | |
a493e3e2 | 1715 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1716 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 PA |
1717 | |
1718 | if (target_can_async_p ()) | |
8ea051c5 | 1719 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1720 | } |
1721 | ||
c5f62d5f | 1722 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1723 | |
1724 | static int | |
1725 | kill_lwp (int lwpid, int signo) | |
1726 | { | |
c5f62d5f DE |
1727 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1728 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1729 | |
1730 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1731 | { |
1732 | static int tkill_failed; | |
1733 | ||
1734 | if (!tkill_failed) | |
1735 | { | |
1736 | int ret; | |
1737 | ||
1738 | errno = 0; | |
1739 | ret = syscall (__NR_tkill, lwpid, signo); | |
1740 | if (errno != ENOSYS) | |
1741 | return ret; | |
1742 | tkill_failed = 1; | |
1743 | } | |
1744 | } | |
d6b0e80f AC |
1745 | #endif |
1746 | ||
1747 | return kill (lwpid, signo); | |
1748 | } | |
1749 | ||
ca2163eb PA |
1750 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1751 | event, check if the core is interested in it: if not, ignore the | |
1752 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1753 | syscall entry/exit status, since the ptrace event itself doesn't | |
1754 | indicate it, and report the trap to higher layers. */ | |
1755 | ||
1756 | static int | |
1757 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1758 | { | |
1759 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1760 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1761 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1762 | ||
1763 | if (stopping) | |
1764 | { | |
1765 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1766 | makes it so that the LWP reports an immediate syscall return, | |
1767 | followed by the SIGSTOP. Skip seeing that "return" using | |
1768 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1769 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1770 | entry event. If we didn't do this (and returned 0), we'd | |
1771 | leave a syscall entry pending, and our caller, by using | |
1772 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1773 | itself. Later, when the user re-resumes this LWP, we'd see | |
1774 | another syscall entry event and we'd mistake it for a return. | |
1775 | ||
1776 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1777 | (leaving immediately with LWP->signalled set, without issuing | |
1778 | a PTRACE_CONT), it would still be problematic to leave this | |
1779 | syscall enter pending, as later when the thread is resumed, | |
1780 | it would then see the same syscall exit mentioned above, | |
1781 | followed by the delayed SIGSTOP, while the syscall didn't | |
1782 | actually get to execute. It seems it would be even more | |
1783 | confusing to the user. */ | |
1784 | ||
1785 | if (debug_linux_nat) | |
1786 | fprintf_unfiltered (gdb_stdlog, | |
1787 | "LHST: ignoring syscall %d " | |
1788 | "for LWP %ld (stopping threads), " | |
1789 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1790 | syscall_number, | |
dfd4cc63 | 1791 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1792 | |
1793 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1794 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1795 | lp->stopped = 0; |
ca2163eb PA |
1796 | return 1; |
1797 | } | |
1798 | ||
1799 | if (catch_syscall_enabled ()) | |
1800 | { | |
1801 | /* Always update the entry/return state, even if this particular | |
1802 | syscall isn't interesting to the core now. In async mode, | |
1803 | the user could install a new catchpoint for this syscall | |
1804 | between syscall enter/return, and we'll need to know to | |
1805 | report a syscall return if that happens. */ | |
1806 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1807 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1808 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1809 | ||
1810 | if (catching_syscall_number (syscall_number)) | |
1811 | { | |
1812 | /* Alright, an event to report. */ | |
1813 | ourstatus->kind = lp->syscall_state; | |
1814 | ourstatus->value.syscall_number = syscall_number; | |
1815 | ||
1816 | if (debug_linux_nat) | |
1817 | fprintf_unfiltered (gdb_stdlog, | |
1818 | "LHST: stopping for %s of syscall %d" | |
1819 | " for LWP %ld\n", | |
3e43a32a MS |
1820 | lp->syscall_state |
1821 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1822 | ? "entry" : "return", |
1823 | syscall_number, | |
dfd4cc63 | 1824 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1825 | return 0; |
1826 | } | |
1827 | ||
1828 | if (debug_linux_nat) | |
1829 | fprintf_unfiltered (gdb_stdlog, | |
1830 | "LHST: ignoring %s of syscall %d " | |
1831 | "for LWP %ld\n", | |
1832 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1833 | ? "entry" : "return", | |
1834 | syscall_number, | |
dfd4cc63 | 1835 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1836 | } |
1837 | else | |
1838 | { | |
1839 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1840 | before on this LWP, it could happen that the user removes all | |
1841 | syscall catchpoints before we get to process this event. | |
1842 | There are two noteworthy issues here: | |
1843 | ||
1844 | - When stopped at a syscall entry event, resuming with | |
1845 | PT_STEP still resumes executing the syscall and reports a | |
1846 | syscall return. | |
1847 | ||
1848 | - Only PT_SYSCALL catches syscall enters. If we last | |
1849 | single-stepped this thread, then this event can't be a | |
1850 | syscall enter. If we last single-stepped this thread, this | |
1851 | has to be a syscall exit. | |
1852 | ||
1853 | The points above mean that the next resume, be it PT_STEP or | |
1854 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1855 | if (debug_linux_nat) | |
1856 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1857 | "LHST: caught syscall event " |
1858 | "with no syscall catchpoints." | |
ca2163eb PA |
1859 | " %d for LWP %ld, ignoring\n", |
1860 | syscall_number, | |
dfd4cc63 | 1861 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1862 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1863 | } | |
1864 | ||
1865 | /* The core isn't interested in this event. For efficiency, avoid | |
1866 | stopping all threads only to have the core resume them all again. | |
1867 | Since we're not stopping threads, if we're still syscall tracing | |
1868 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1869 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1870 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1871 | ||
8a99810d | 1872 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1873 | return 1; |
1874 | } | |
1875 | ||
3d799a95 DJ |
1876 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1877 | event, we need to add the new LWP to our list (and not report the | |
1878 | trap to higher layers). This function returns non-zero if the | |
1879 | event should be ignored and we should wait again. If STOPPING is | |
1880 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1881 | |
1882 | static int | |
3d799a95 DJ |
1883 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1884 | int stopping) | |
d6b0e80f | 1885 | { |
dfd4cc63 | 1886 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1887 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1888 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1889 | |
3d799a95 DJ |
1890 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1891 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1892 | { |
3d799a95 DJ |
1893 | unsigned long new_pid; |
1894 | int ret; | |
1895 | ||
1896 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1897 | |
3d799a95 DJ |
1898 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1899 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1900 | { | |
1901 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1902 | hits the SIGSTOP, but we're already attached. */ | |
1903 | ret = my_waitpid (new_pid, &status, | |
1904 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
1905 | if (ret == -1) | |
1906 | perror_with_name (_("waiting for new child")); | |
1907 | else if (ret != new_pid) | |
1908 | internal_error (__FILE__, __LINE__, | |
1909 | _("wait returned unexpected PID %d"), ret); | |
1910 | else if (!WIFSTOPPED (status)) | |
1911 | internal_error (__FILE__, __LINE__, | |
1912 | _("wait returned unexpected status 0x%x"), status); | |
1913 | } | |
1914 | ||
3a3e9ee3 | 1915 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 1916 | |
26cb8b7c PA |
1917 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1918 | { | |
1919 | /* The arch-specific native code may need to know about new | |
1920 | forks even if those end up never mapped to an | |
1921 | inferior. */ | |
1922 | if (linux_nat_new_fork != NULL) | |
1923 | linux_nat_new_fork (lp, new_pid); | |
1924 | } | |
1925 | ||
2277426b | 1926 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 1927 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 1928 | { |
2277426b PA |
1929 | /* Handle checkpointing by linux-fork.c here as a special |
1930 | case. We don't want the follow-fork-mode or 'catch fork' | |
1931 | to interfere with this. */ | |
1932 | ||
1933 | /* This won't actually modify the breakpoint list, but will | |
1934 | physically remove the breakpoints from the child. */ | |
d80ee84f | 1935 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
1936 | |
1937 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1938 | if (!find_fork_pid (new_pid)) |
1939 | add_fork (new_pid); | |
2277426b PA |
1940 | |
1941 | /* Report as spurious, so that infrun doesn't want to follow | |
1942 | this fork. We're actually doing an infcall in | |
1943 | linux-fork.c. */ | |
1944 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1945 | |
1946 | /* Report the stop to the core. */ | |
1947 | return 0; | |
1948 | } | |
1949 | ||
3d799a95 DJ |
1950 | if (event == PTRACE_EVENT_FORK) |
1951 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1952 | else if (event == PTRACE_EVENT_VFORK) | |
1953 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 1954 | else |
3d799a95 | 1955 | { |
78768c4a JK |
1956 | struct lwp_info *new_lp; |
1957 | ||
3d799a95 | 1958 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1959 | |
3c4d7e12 PA |
1960 | if (debug_linux_nat) |
1961 | fprintf_unfiltered (gdb_stdlog, | |
1962 | "LHEW: Got clone event " | |
1963 | "from LWP %d, new child is LWP %ld\n", | |
1964 | pid, new_pid); | |
1965 | ||
dfd4cc63 | 1966 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
3d799a95 | 1967 | new_lp->cloned = 1; |
4c28f408 | 1968 | new_lp->stopped = 1; |
d6b0e80f | 1969 | |
3d799a95 DJ |
1970 | if (WSTOPSIG (status) != SIGSTOP) |
1971 | { | |
1972 | /* This can happen if someone starts sending signals to | |
1973 | the new thread before it gets a chance to run, which | |
1974 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1975 | This is an unlikely case, and harder to handle for | |
1976 | fork / vfork than for clone, so we do not try - but | |
1977 | we handle it for clone events here. We'll send | |
1978 | the other signal on to the thread below. */ | |
1979 | ||
1980 | new_lp->signalled = 1; | |
1981 | } | |
1982 | else | |
79395f92 PA |
1983 | { |
1984 | struct thread_info *tp; | |
1985 | ||
1986 | /* When we stop for an event in some other thread, and | |
1987 | pull the thread list just as this thread has cloned, | |
1988 | we'll have seen the new thread in the thread_db list | |
1989 | before handling the CLONE event (glibc's | |
1990 | pthread_create adds the new thread to the thread list | |
1991 | before clone'ing, and has the kernel fill in the | |
1992 | thread's tid on the clone call with | |
1993 | CLONE_PARENT_SETTID). If that happened, and the core | |
1994 | had requested the new thread to stop, we'll have | |
1995 | killed it with SIGSTOP. But since SIGSTOP is not an | |
1996 | RT signal, it can only be queued once. We need to be | |
1997 | careful to not resume the LWP if we wanted it to | |
1998 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 1999 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2000 | tp = find_thread_ptid (new_lp->ptid); |
2001 | if (tp != NULL && tp->stop_requested) | |
2002 | new_lp->last_resume_kind = resume_stop; | |
2003 | else | |
2004 | status = 0; | |
2005 | } | |
d6b0e80f | 2006 | |
2db9a427 PA |
2007 | /* If the thread_db layer is active, let it record the user |
2008 | level thread id and status, and add the thread to GDB's | |
2009 | list. */ | |
2010 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 2011 | { |
2db9a427 PA |
2012 | /* The process is not using thread_db. Add the LWP to |
2013 | GDB's list. */ | |
2014 | target_post_attach (ptid_get_lwp (new_lp->ptid)); | |
2015 | add_thread (new_lp->ptid); | |
2016 | } | |
4c28f408 | 2017 | |
2db9a427 PA |
2018 | if (!stopping) |
2019 | { | |
2020 | set_running (new_lp->ptid, 1); | |
2021 | set_executing (new_lp->ptid, 1); | |
2022 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced | |
2023 | resume_stop. */ | |
2024 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2025 | } |
2026 | ||
79395f92 PA |
2027 | if (status != 0) |
2028 | { | |
2029 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2030 | gdb_assert (new_lp->status == 0); | |
2031 | ||
2032 | /* Save the wait status to report later. */ | |
2033 | if (debug_linux_nat) | |
2034 | fprintf_unfiltered (gdb_stdlog, | |
2035 | "LHEW: waitpid of new LWP %ld, " | |
2036 | "saving status %s\n", | |
dfd4cc63 | 2037 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
2038 | status_to_str (status)); |
2039 | new_lp->status = status; | |
2040 | } | |
2041 | ||
20ba1ce6 | 2042 | new_lp->resumed = !stopping; |
3d799a95 DJ |
2043 | return 1; |
2044 | } | |
2045 | ||
2046 | return 0; | |
d6b0e80f AC |
2047 | } |
2048 | ||
3d799a95 DJ |
2049 | if (event == PTRACE_EVENT_EXEC) |
2050 | { | |
a75724bc PA |
2051 | if (debug_linux_nat) |
2052 | fprintf_unfiltered (gdb_stdlog, | |
2053 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2054 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2055 | |
3d799a95 DJ |
2056 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2057 | ourstatus->value.execd_pathname | |
8dd27370 | 2058 | = xstrdup (linux_child_pid_to_exec_file (NULL, pid)); |
3d799a95 | 2059 | |
8af756ef PA |
2060 | /* The thread that execed must have been resumed, but, when a |
2061 | thread execs, it changes its tid to the tgid, and the old | |
2062 | tgid thread might have not been resumed. */ | |
2063 | lp->resumed = 1; | |
6c95b8df PA |
2064 | return 0; |
2065 | } | |
2066 | ||
2067 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2068 | { | |
2069 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2070 | { |
6c95b8df | 2071 | if (debug_linux_nat) |
3e43a32a MS |
2072 | fprintf_unfiltered (gdb_stdlog, |
2073 | "LHEW: Got expected PTRACE_EVENT_" | |
2074 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2075 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2076 | |
6c95b8df PA |
2077 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2078 | return 0; | |
3d799a95 DJ |
2079 | } |
2080 | ||
6c95b8df | 2081 | if (debug_linux_nat) |
3e43a32a MS |
2082 | fprintf_unfiltered (gdb_stdlog, |
2083 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
20ba1ce6 | 2084 | "from LWP %ld: ignoring\n", |
dfd4cc63 | 2085 | ptid_get_lwp (lp->ptid)); |
6c95b8df | 2086 | return 1; |
3d799a95 DJ |
2087 | } |
2088 | ||
2089 | internal_error (__FILE__, __LINE__, | |
2090 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2091 | } |
2092 | ||
2093 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2094 | exited. */ | |
2095 | ||
2096 | static int | |
2097 | wait_lwp (struct lwp_info *lp) | |
2098 | { | |
2099 | pid_t pid; | |
432b4d03 | 2100 | int status = 0; |
d6b0e80f | 2101 | int thread_dead = 0; |
432b4d03 | 2102 | sigset_t prev_mask; |
d6b0e80f AC |
2103 | |
2104 | gdb_assert (!lp->stopped); | |
2105 | gdb_assert (lp->status == 0); | |
2106 | ||
432b4d03 JK |
2107 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2108 | block_child_signals (&prev_mask); | |
2109 | ||
2110 | for (;;) | |
d6b0e80f | 2111 | { |
432b4d03 JK |
2112 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2113 | was right and we should just call sigsuspend. */ | |
2114 | ||
dfd4cc63 | 2115 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG); |
d6b0e80f | 2116 | if (pid == -1 && errno == ECHILD) |
dfd4cc63 | 2117 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2118 | if (pid == -1 && errno == ECHILD) |
2119 | { | |
2120 | /* The thread has previously exited. We need to delete it | |
2121 | now because, for some vendor 2.4 kernels with NPTL | |
2122 | support backported, there won't be an exit event unless | |
2123 | it is the main thread. 2.6 kernels will report an exit | |
2124 | event for each thread that exits, as expected. */ | |
2125 | thread_dead = 1; | |
2126 | if (debug_linux_nat) | |
2127 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2128 | target_pid_to_str (lp->ptid)); | |
2129 | } | |
432b4d03 JK |
2130 | if (pid != 0) |
2131 | break; | |
2132 | ||
2133 | /* Bugs 10970, 12702. | |
2134 | Thread group leader may have exited in which case we'll lock up in | |
2135 | waitpid if there are other threads, even if they are all zombies too. | |
2136 | Basically, we're not supposed to use waitpid this way. | |
2137 | __WCLONE is not applicable for the leader so we can't use that. | |
2138 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2139 | process; it gets ESRCH both for the zombie and for running processes. | |
2140 | ||
2141 | As a workaround, check if we're waiting for the thread group leader and | |
2142 | if it's a zombie, and avoid calling waitpid if it is. | |
2143 | ||
2144 | This is racy, what if the tgl becomes a zombie right after we check? | |
2145 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2146 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2147 | |
dfd4cc63 LM |
2148 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2149 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2150 | { |
d6b0e80f AC |
2151 | thread_dead = 1; |
2152 | if (debug_linux_nat) | |
432b4d03 JK |
2153 | fprintf_unfiltered (gdb_stdlog, |
2154 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2155 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2156 | break; |
d6b0e80f | 2157 | } |
432b4d03 JK |
2158 | |
2159 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2160 | get invoked despite our caller had them intentionally blocked by | |
2161 | block_child_signals. This is sensitive only to the loop of | |
2162 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2163 | again before it gets to sigsuspend so we can safely let the handlers | |
2164 | get executed here. */ | |
2165 | ||
d36bf488 DE |
2166 | if (debug_linux_nat) |
2167 | fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n"); | |
432b4d03 JK |
2168 | sigsuspend (&suspend_mask); |
2169 | } | |
2170 | ||
2171 | restore_child_signals_mask (&prev_mask); | |
2172 | ||
d6b0e80f AC |
2173 | if (!thread_dead) |
2174 | { | |
dfd4cc63 | 2175 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2176 | |
2177 | if (debug_linux_nat) | |
2178 | { | |
2179 | fprintf_unfiltered (gdb_stdlog, | |
2180 | "WL: waitpid %s received %s\n", | |
2181 | target_pid_to_str (lp->ptid), | |
2182 | status_to_str (status)); | |
2183 | } | |
d6b0e80f | 2184 | |
a9f4bb21 PA |
2185 | /* Check if the thread has exited. */ |
2186 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2187 | { | |
2188 | thread_dead = 1; | |
2189 | if (debug_linux_nat) | |
2190 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2191 | target_pid_to_str (lp->ptid)); | |
2192 | } | |
d6b0e80f AC |
2193 | } |
2194 | ||
2195 | if (thread_dead) | |
2196 | { | |
e26af52f | 2197 | exit_lwp (lp); |
d6b0e80f AC |
2198 | return 0; |
2199 | } | |
2200 | ||
2201 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2202 | lp->stopped = 1; |
d6b0e80f | 2203 | |
8784d563 PA |
2204 | if (lp->must_set_ptrace_flags) |
2205 | { | |
2206 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
2207 | ||
2208 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
2209 | lp->must_set_ptrace_flags = 0; | |
2210 | } | |
2211 | ||
ca2163eb PA |
2212 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2213 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2214 | { | |
2215 | /* No longer need the sysgood bit. The ptrace event ends up | |
2216 | recorded in lp->waitstatus if we care for it. We can carry | |
2217 | on handling the event like a regular SIGTRAP from here | |
2218 | on. */ | |
2219 | status = W_STOPCODE (SIGTRAP); | |
2220 | if (linux_handle_syscall_trap (lp, 1)) | |
2221 | return wait_lwp (lp); | |
2222 | } | |
2223 | ||
d6b0e80f | 2224 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2225 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2226 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2227 | { |
2228 | if (debug_linux_nat) | |
2229 | fprintf_unfiltered (gdb_stdlog, | |
2230 | "WL: Handling extended status 0x%06x\n", | |
2231 | status); | |
20ba1ce6 PA |
2232 | linux_handle_extended_wait (lp, status, 1); |
2233 | return 0; | |
d6b0e80f AC |
2234 | } |
2235 | ||
2236 | return status; | |
2237 | } | |
2238 | ||
2239 | /* Send a SIGSTOP to LP. */ | |
2240 | ||
2241 | static int | |
2242 | stop_callback (struct lwp_info *lp, void *data) | |
2243 | { | |
2244 | if (!lp->stopped && !lp->signalled) | |
2245 | { | |
2246 | int ret; | |
2247 | ||
2248 | if (debug_linux_nat) | |
2249 | { | |
2250 | fprintf_unfiltered (gdb_stdlog, | |
2251 | "SC: kill %s **<SIGSTOP>**\n", | |
2252 | target_pid_to_str (lp->ptid)); | |
2253 | } | |
2254 | errno = 0; | |
dfd4cc63 | 2255 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2256 | if (debug_linux_nat) |
2257 | { | |
2258 | fprintf_unfiltered (gdb_stdlog, | |
2259 | "SC: lwp kill %d %s\n", | |
2260 | ret, | |
2261 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2262 | } | |
2263 | ||
2264 | lp->signalled = 1; | |
2265 | gdb_assert (lp->status == 0); | |
2266 | } | |
2267 | ||
2268 | return 0; | |
2269 | } | |
2270 | ||
7b50312a PA |
2271 | /* Request a stop on LWP. */ |
2272 | ||
2273 | void | |
2274 | linux_stop_lwp (struct lwp_info *lwp) | |
2275 | { | |
2276 | stop_callback (lwp, NULL); | |
2277 | } | |
2278 | ||
2db9a427 PA |
2279 | /* See linux-nat.h */ |
2280 | ||
2281 | void | |
2282 | linux_stop_and_wait_all_lwps (void) | |
2283 | { | |
2284 | /* Stop all LWP's ... */ | |
2285 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); | |
2286 | ||
2287 | /* ... and wait until all of them have reported back that | |
2288 | they're no longer running. */ | |
2289 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); | |
2290 | } | |
2291 | ||
2292 | /* See linux-nat.h */ | |
2293 | ||
2294 | void | |
2295 | linux_unstop_all_lwps (void) | |
2296 | { | |
2297 | iterate_over_lwps (minus_one_ptid, | |
2298 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
2299 | } | |
2300 | ||
57380f4e | 2301 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2302 | |
2303 | static int | |
57380f4e DJ |
2304 | linux_nat_has_pending_sigint (int pid) |
2305 | { | |
2306 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2307 | |
2308 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2309 | ||
2310 | if (sigismember (&pending, SIGINT) | |
2311 | && !sigismember (&ignored, SIGINT)) | |
2312 | return 1; | |
2313 | ||
2314 | return 0; | |
2315 | } | |
2316 | ||
2317 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2318 | ||
2319 | static int | |
2320 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2321 | { |
57380f4e DJ |
2322 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2323 | flag to consume the next one. */ | |
2324 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2325 | && WSTOPSIG (lp->status) == SIGINT) | |
2326 | lp->status = 0; | |
2327 | else | |
2328 | lp->ignore_sigint = 1; | |
2329 | ||
2330 | return 0; | |
2331 | } | |
2332 | ||
2333 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2334 | This function is called after we know the LWP has stopped; if the LWP | |
2335 | stopped before the expected SIGINT was delivered, then it will never have | |
2336 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2337 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2338 | |
57380f4e DJ |
2339 | static void |
2340 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2341 | { | |
2342 | if (!lp->ignore_sigint) | |
2343 | return; | |
2344 | ||
dfd4cc63 | 2345 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2346 | { |
2347 | if (debug_linux_nat) | |
2348 | fprintf_unfiltered (gdb_stdlog, | |
2349 | "MCIS: Clearing bogus flag for %s\n", | |
2350 | target_pid_to_str (lp->ptid)); | |
2351 | lp->ignore_sigint = 0; | |
2352 | } | |
2353 | } | |
2354 | ||
ebec9a0f PA |
2355 | /* Fetch the possible triggered data watchpoint info and store it in |
2356 | LP. | |
2357 | ||
2358 | On some archs, like x86, that use debug registers to set | |
2359 | watchpoints, it's possible that the way to know which watched | |
2360 | address trapped, is to check the register that is used to select | |
2361 | which address to watch. Problem is, between setting the watchpoint | |
2362 | and reading back which data address trapped, the user may change | |
2363 | the set of watchpoints, and, as a consequence, GDB changes the | |
2364 | debug registers in the inferior. To avoid reading back a stale | |
2365 | stopped-data-address when that happens, we cache in LP the fact | |
2366 | that a watchpoint trapped, and the corresponding data address, as | |
2367 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2368 | registers meanwhile, we have the cached data we can rely on. */ | |
2369 | ||
9c02b525 PA |
2370 | static int |
2371 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f PA |
2372 | { |
2373 | struct cleanup *old_chain; | |
2374 | ||
2375 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
9c02b525 | 2376 | return 0; |
ebec9a0f PA |
2377 | |
2378 | old_chain = save_inferior_ptid (); | |
2379 | inferior_ptid = lp->ptid; | |
2380 | ||
9c02b525 | 2381 | if (linux_ops->to_stopped_by_watchpoint (linux_ops)) |
ebec9a0f | 2382 | { |
9c02b525 PA |
2383 | lp->stop_reason = LWP_STOPPED_BY_WATCHPOINT; |
2384 | ||
ebec9a0f PA |
2385 | if (linux_ops->to_stopped_data_address != NULL) |
2386 | lp->stopped_data_address_p = | |
2387 | linux_ops->to_stopped_data_address (¤t_target, | |
2388 | &lp->stopped_data_address); | |
2389 | else | |
2390 | lp->stopped_data_address_p = 0; | |
2391 | } | |
2392 | ||
2393 | do_cleanups (old_chain); | |
9c02b525 PA |
2394 | |
2395 | return lp->stop_reason == LWP_STOPPED_BY_WATCHPOINT; | |
2396 | } | |
2397 | ||
2398 | /* Called when the LWP stopped for a trap that could be explained by a | |
2399 | watchpoint or a breakpoint. */ | |
2400 | ||
2401 | static void | |
2402 | save_sigtrap (struct lwp_info *lp) | |
2403 | { | |
2404 | gdb_assert (lp->stop_reason == LWP_STOPPED_BY_NO_REASON); | |
2405 | gdb_assert (lp->status != 0); | |
2406 | ||
2407 | if (check_stopped_by_watchpoint (lp)) | |
2408 | return; | |
2409 | ||
2410 | if (linux_nat_status_is_event (lp->status)) | |
2411 | check_stopped_by_breakpoint (lp); | |
ebec9a0f PA |
2412 | } |
2413 | ||
9c02b525 | 2414 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f PA |
2415 | |
2416 | static int | |
6a109b6b | 2417 | linux_nat_stopped_by_watchpoint (struct target_ops *ops) |
ebec9a0f PA |
2418 | { |
2419 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2420 | ||
2421 | gdb_assert (lp != NULL); | |
2422 | ||
9c02b525 | 2423 | return lp->stop_reason == LWP_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2424 | } |
2425 | ||
2426 | static int | |
2427 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2428 | { | |
2429 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2430 | ||
2431 | gdb_assert (lp != NULL); | |
2432 | ||
2433 | *addr_p = lp->stopped_data_address; | |
2434 | ||
2435 | return lp->stopped_data_address_p; | |
2436 | } | |
2437 | ||
26ab7092 JK |
2438 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2439 | ||
2440 | static int | |
2441 | sigtrap_is_event (int status) | |
2442 | { | |
2443 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2444 | } | |
2445 | ||
26ab7092 JK |
2446 | /* Set alternative SIGTRAP-like events recognizer. If |
2447 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2448 | applied. */ | |
2449 | ||
2450 | void | |
2451 | linux_nat_set_status_is_event (struct target_ops *t, | |
2452 | int (*status_is_event) (int status)) | |
2453 | { | |
2454 | linux_nat_status_is_event = status_is_event; | |
2455 | } | |
2456 | ||
57380f4e DJ |
2457 | /* Wait until LP is stopped. */ |
2458 | ||
2459 | static int | |
2460 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2461 | { | |
c9657e70 | 2462 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
6c95b8df PA |
2463 | |
2464 | /* If this is a vfork parent, bail out, it is not going to report | |
2465 | any SIGSTOP until the vfork is done with. */ | |
2466 | if (inf->vfork_child != NULL) | |
2467 | return 0; | |
2468 | ||
d6b0e80f AC |
2469 | if (!lp->stopped) |
2470 | { | |
2471 | int status; | |
2472 | ||
2473 | status = wait_lwp (lp); | |
2474 | if (status == 0) | |
2475 | return 0; | |
2476 | ||
57380f4e DJ |
2477 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2478 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2479 | { |
57380f4e | 2480 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2481 | |
2482 | errno = 0; | |
dfd4cc63 | 2483 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2484 | lp->stopped = 0; |
d6b0e80f AC |
2485 | if (debug_linux_nat) |
2486 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2487 | "PTRACE_CONT %s, 0, 0 (%s) " |
2488 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2489 | target_pid_to_str (lp->ptid), |
2490 | errno ? safe_strerror (errno) : "OK"); | |
2491 | ||
57380f4e | 2492 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2493 | } |
2494 | ||
57380f4e DJ |
2495 | maybe_clear_ignore_sigint (lp); |
2496 | ||
d6b0e80f AC |
2497 | if (WSTOPSIG (status) != SIGSTOP) |
2498 | { | |
e5ef252a | 2499 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2500 | |
e5ef252a PA |
2501 | if (debug_linux_nat) |
2502 | fprintf_unfiltered (gdb_stdlog, | |
2503 | "SWC: Pending event %s in %s\n", | |
2504 | status_to_str ((int) status), | |
2505 | target_pid_to_str (lp->ptid)); | |
2506 | ||
2507 | /* Save the sigtrap event. */ | |
2508 | lp->status = status; | |
e5ef252a | 2509 | gdb_assert (lp->signalled); |
9c02b525 | 2510 | save_sigtrap (lp); |
d6b0e80f AC |
2511 | } |
2512 | else | |
2513 | { | |
2514 | /* We caught the SIGSTOP that we intended to catch, so | |
2515 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2516 | |
2517 | if (debug_linux_nat) | |
2518 | fprintf_unfiltered (gdb_stdlog, | |
2519 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2520 | target_pid_to_str (lp->ptid)); | |
2521 | ||
e5ef252a PA |
2522 | /* Reset SIGNALLED only after the stop_wait_callback call |
2523 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2524 | lp->signalled = 0; |
2525 | } | |
2526 | } | |
2527 | ||
2528 | return 0; | |
2529 | } | |
2530 | ||
9c02b525 PA |
2531 | /* Return non-zero if LP has a wait status pending. Discard the |
2532 | pending event and resume the LWP if the event that originally | |
2533 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2534 | |
2535 | static int | |
2536 | status_callback (struct lwp_info *lp, void *data) | |
2537 | { | |
2538 | /* Only report a pending wait status if we pretend that this has | |
2539 | indeed been resumed. */ | |
ca2163eb PA |
2540 | if (!lp->resumed) |
2541 | return 0; | |
2542 | ||
9c02b525 PA |
2543 | if (lp->stop_reason == LWP_STOPPED_BY_SW_BREAKPOINT |
2544 | || lp->stop_reason == LWP_STOPPED_BY_HW_BREAKPOINT) | |
2545 | { | |
2546 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
2547 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2548 | CORE_ADDR pc; | |
2549 | int discard = 0; | |
2550 | ||
2551 | gdb_assert (lp->status != 0); | |
2552 | ||
2553 | pc = regcache_read_pc (regcache); | |
2554 | ||
2555 | if (pc != lp->stop_pc) | |
2556 | { | |
2557 | if (debug_linux_nat) | |
2558 | fprintf_unfiltered (gdb_stdlog, | |
2559 | "SC: PC of %s changed. was=%s, now=%s\n", | |
2560 | target_pid_to_str (lp->ptid), | |
2561 | paddress (target_gdbarch (), lp->stop_pc), | |
2562 | paddress (target_gdbarch (), pc)); | |
2563 | discard = 1; | |
2564 | } | |
2565 | else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) | |
2566 | { | |
2567 | if (debug_linux_nat) | |
2568 | fprintf_unfiltered (gdb_stdlog, | |
2569 | "SC: previous breakpoint of %s, at %s gone\n", | |
2570 | target_pid_to_str (lp->ptid), | |
2571 | paddress (target_gdbarch (), lp->stop_pc)); | |
2572 | ||
2573 | discard = 1; | |
2574 | } | |
2575 | ||
2576 | if (discard) | |
2577 | { | |
2578 | if (debug_linux_nat) | |
2579 | fprintf_unfiltered (gdb_stdlog, | |
2580 | "SC: pending event of %s cancelled.\n", | |
2581 | target_pid_to_str (lp->ptid)); | |
2582 | ||
2583 | lp->status = 0; | |
2584 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2585 | return 0; | |
2586 | } | |
2587 | return 1; | |
2588 | } | |
2589 | ||
8a99810d | 2590 | return lwp_status_pending_p (lp); |
d6b0e80f AC |
2591 | } |
2592 | ||
2593 | /* Return non-zero if LP isn't stopped. */ | |
2594 | ||
2595 | static int | |
2596 | running_callback (struct lwp_info *lp, void *data) | |
2597 | { | |
25289eb2 | 2598 | return (!lp->stopped |
8a99810d | 2599 | || (lwp_status_pending_p (lp) && lp->resumed)); |
d6b0e80f AC |
2600 | } |
2601 | ||
2602 | /* Count the LWP's that have had events. */ | |
2603 | ||
2604 | static int | |
2605 | count_events_callback (struct lwp_info *lp, void *data) | |
2606 | { | |
2607 | int *count = data; | |
2608 | ||
2609 | gdb_assert (count != NULL); | |
2610 | ||
9c02b525 PA |
2611 | /* Select only resumed LWPs that have an event pending. */ |
2612 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2613 | (*count)++; |
2614 | ||
2615 | return 0; | |
2616 | } | |
2617 | ||
2618 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2619 | ||
2620 | static int | |
2621 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2622 | { | |
25289eb2 PA |
2623 | if (lp->last_resume_kind == resume_step |
2624 | && lp->status != 0) | |
d6b0e80f AC |
2625 | return 1; |
2626 | else | |
2627 | return 0; | |
2628 | } | |
2629 | ||
8a99810d PA |
2630 | /* Returns true if LP has a status pending. */ |
2631 | ||
2632 | static int | |
2633 | lwp_status_pending_p (struct lwp_info *lp) | |
2634 | { | |
2635 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2636 | can have pending process exits recorded in lp->status and | |
2637 | W_EXITCODE(0,0) happens to be 0. */ | |
2638 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2639 | } | |
2640 | ||
d6b0e80f AC |
2641 | /* Select the Nth LWP that has had a SIGTRAP event. */ |
2642 | ||
2643 | static int | |
2644 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2645 | { | |
2646 | int *selector = data; | |
2647 | ||
2648 | gdb_assert (selector != NULL); | |
2649 | ||
9c02b525 PA |
2650 | /* Select only resumed LWPs that have an event pending. */ |
2651 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2652 | if ((*selector)-- == 0) |
2653 | return 1; | |
2654 | ||
2655 | return 0; | |
2656 | } | |
2657 | ||
9c02b525 PA |
2658 | /* Called when the LWP got a signal/trap that could be explained by a |
2659 | software or hardware breakpoint. */ | |
2660 | ||
710151dd | 2661 | static int |
9c02b525 | 2662 | check_stopped_by_breakpoint (struct lwp_info *lp) |
710151dd PA |
2663 | { |
2664 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2665 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2666 | LWP. We will handle the current event, eventually we will resume | |
2667 | this LWP, and this breakpoint will trap again. | |
2668 | ||
2669 | If we do not do this, then we run the risk that the user will | |
2670 | delete or disable the breakpoint, but the LWP will have already | |
2671 | tripped on it. */ | |
2672 | ||
515630c5 UW |
2673 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2674 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2675 | CORE_ADDR pc; | |
9c02b525 PA |
2676 | CORE_ADDR sw_bp_pc; |
2677 | ||
2678 | pc = regcache_read_pc (regcache); | |
2679 | sw_bp_pc = pc - target_decr_pc_after_break (gdbarch); | |
515630c5 | 2680 | |
9c02b525 PA |
2681 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
2682 | && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache), | |
2683 | sw_bp_pc)) | |
710151dd | 2684 | { |
9c02b525 PA |
2685 | /* The LWP was either continued, or stepped a software |
2686 | breakpoint instruction. */ | |
710151dd PA |
2687 | if (debug_linux_nat) |
2688 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2689 | "CB: Push back software breakpoint for %s\n", |
710151dd PA |
2690 | target_pid_to_str (lp->ptid)); |
2691 | ||
2692 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2693 | if (pc != sw_bp_pc) |
2694 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2695 | |
9c02b525 PA |
2696 | lp->stop_pc = sw_bp_pc; |
2697 | lp->stop_reason = LWP_STOPPED_BY_SW_BREAKPOINT; | |
710151dd PA |
2698 | return 1; |
2699 | } | |
710151dd | 2700 | |
9c02b525 PA |
2701 | if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
2702 | { | |
2703 | if (debug_linux_nat) | |
2704 | fprintf_unfiltered (gdb_stdlog, | |
2705 | "CB: Push back hardware breakpoint for %s\n", | |
2706 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 2707 | |
9c02b525 PA |
2708 | lp->stop_pc = pc; |
2709 | lp->stop_reason = LWP_STOPPED_BY_HW_BREAKPOINT; | |
2710 | return 1; | |
2711 | } | |
d6b0e80f AC |
2712 | |
2713 | return 0; | |
2714 | } | |
2715 | ||
2716 | /* Select one LWP out of those that have events pending. */ | |
2717 | ||
2718 | static void | |
d90e17a7 | 2719 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2720 | { |
2721 | int num_events = 0; | |
2722 | int random_selector; | |
9c02b525 | 2723 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2724 | |
ac264b3b | 2725 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2726 | (*orig_lp)->status = *status; |
2727 | ||
9c02b525 PA |
2728 | /* In all-stop, give preference to the LWP that is being |
2729 | single-stepped. There will be at most one, and it will be the | |
2730 | LWP that the core is most interested in. If we didn't do this, | |
2731 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2732 | the core later continues the previously-stepped thread, as | |
2733 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2734 | having stepped the thread, wouldn't understand what the trap was | |
2735 | for, and therefore would report it to the user as a random | |
2736 | signal. */ | |
2737 | if (!non_stop) | |
d6b0e80f | 2738 | { |
9c02b525 PA |
2739 | event_lp = iterate_over_lwps (filter, |
2740 | select_singlestep_lwp_callback, NULL); | |
2741 | if (event_lp != NULL) | |
2742 | { | |
2743 | if (debug_linux_nat) | |
2744 | fprintf_unfiltered (gdb_stdlog, | |
2745 | "SEL: Select single-step %s\n", | |
2746 | target_pid_to_str (event_lp->ptid)); | |
2747 | } | |
d6b0e80f | 2748 | } |
9c02b525 PA |
2749 | |
2750 | if (event_lp == NULL) | |
d6b0e80f | 2751 | { |
9c02b525 | 2752 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2753 | |
9c02b525 | 2754 | /* First see how many events we have. */ |
d90e17a7 | 2755 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f | 2756 | |
9c02b525 PA |
2757 | /* Now randomly pick a LWP out of those that have had |
2758 | events. */ | |
d6b0e80f AC |
2759 | random_selector = (int) |
2760 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2761 | ||
2762 | if (debug_linux_nat && num_events > 1) | |
2763 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2764 | "SEL: Found %d events, selecting #%d\n", |
d6b0e80f AC |
2765 | num_events, random_selector); |
2766 | ||
d90e17a7 PA |
2767 | event_lp = iterate_over_lwps (filter, |
2768 | select_event_lwp_callback, | |
d6b0e80f AC |
2769 | &random_selector); |
2770 | } | |
2771 | ||
2772 | if (event_lp != NULL) | |
2773 | { | |
2774 | /* Switch the event LWP. */ | |
2775 | *orig_lp = event_lp; | |
2776 | *status = event_lp->status; | |
2777 | } | |
2778 | ||
2779 | /* Flush the wait status for the event LWP. */ | |
2780 | (*orig_lp)->status = 0; | |
2781 | } | |
2782 | ||
2783 | /* Return non-zero if LP has been resumed. */ | |
2784 | ||
2785 | static int | |
2786 | resumed_callback (struct lwp_info *lp, void *data) | |
2787 | { | |
2788 | return lp->resumed; | |
2789 | } | |
2790 | ||
12d9289a PA |
2791 | /* Stop an active thread, verify it still exists, then resume it. If |
2792 | the thread ends up with a pending status, then it is not resumed, | |
2793 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2794 | |
2795 | static int | |
2796 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2797 | { | |
25289eb2 | 2798 | if (!lp->stopped) |
d6b0e80f | 2799 | { |
25289eb2 PA |
2800 | ptid_t ptid = lp->ptid; |
2801 | ||
d6b0e80f AC |
2802 | stop_callback (lp, NULL); |
2803 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2804 | |
2805 | /* Resume if the lwp still exists, and the core wanted it | |
2806 | running. */ | |
12d9289a PA |
2807 | lp = find_lwp_pid (ptid); |
2808 | if (lp != NULL) | |
25289eb2 | 2809 | { |
12d9289a | 2810 | if (lp->last_resume_kind == resume_stop |
8a99810d | 2811 | && !lwp_status_pending_p (lp)) |
12d9289a PA |
2812 | { |
2813 | /* The core wanted the LWP to stop. Even if it stopped | |
2814 | cleanly (with SIGSTOP), leave the event pending. */ | |
2815 | if (debug_linux_nat) | |
2816 | fprintf_unfiltered (gdb_stdlog, | |
2817 | "SARC: core wanted LWP %ld stopped " | |
2818 | "(leaving SIGSTOP pending)\n", | |
dfd4cc63 | 2819 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2820 | lp->status = W_STOPCODE (SIGSTOP); |
2821 | } | |
2822 | ||
8a99810d | 2823 | if (!lwp_status_pending_p (lp)) |
12d9289a PA |
2824 | { |
2825 | if (debug_linux_nat) | |
2826 | fprintf_unfiltered (gdb_stdlog, | |
2827 | "SARC: re-resuming LWP %ld\n", | |
dfd4cc63 | 2828 | ptid_get_lwp (lp->ptid)); |
e5ef252a | 2829 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
2830 | } |
2831 | else | |
2832 | { | |
2833 | if (debug_linux_nat) | |
2834 | fprintf_unfiltered (gdb_stdlog, | |
2835 | "SARC: not re-resuming LWP %ld " | |
2836 | "(has pending)\n", | |
dfd4cc63 | 2837 | ptid_get_lwp (lp->ptid)); |
12d9289a | 2838 | } |
25289eb2 | 2839 | } |
d6b0e80f AC |
2840 | } |
2841 | return 0; | |
2842 | } | |
2843 | ||
02f3fc28 | 2844 | /* Check if we should go on and pass this event to common code. |
9c02b525 | 2845 | Return the affected lwp if we are, or NULL otherwise. */ |
12d9289a | 2846 | |
02f3fc28 | 2847 | static struct lwp_info * |
9c02b525 | 2848 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2849 | { |
2850 | struct lwp_info *lp; | |
89a5711c | 2851 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 PA |
2852 | |
2853 | lp = find_lwp_pid (pid_to_ptid (lwpid)); | |
2854 | ||
2855 | /* Check for stop events reported by a process we didn't already | |
2856 | know about - anything not already in our LWP list. | |
2857 | ||
2858 | If we're expecting to receive stopped processes after | |
2859 | fork, vfork, and clone events, then we'll just add the | |
2860 | new one to our list and go back to waiting for the event | |
2861 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2862 | from waitpid before or after the event is. |
2863 | ||
2864 | But note the case of a non-leader thread exec'ing after the | |
2865 | leader having exited, and gone from our lists. The non-leader | |
2866 | thread changes its tid to the tgid. */ | |
2867 | ||
2868 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2869 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2870 | { |
2871 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2872 | if (debug_linux_nat) | |
2873 | fprintf_unfiltered (gdb_stdlog, | |
2874 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2875 | lwpid); | |
2876 | ||
dfd4cc63 | 2877 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2878 | lp->stopped = 1; |
2879 | lp->resumed = 1; | |
2880 | add_thread (lp->ptid); | |
2881 | } | |
2882 | ||
02f3fc28 PA |
2883 | if (WIFSTOPPED (status) && !lp) |
2884 | { | |
3b27ef47 PA |
2885 | if (debug_linux_nat) |
2886 | fprintf_unfiltered (gdb_stdlog, | |
2887 | "LHEW: saving LWP %ld status %s in stopped_pids list\n", | |
2888 | (long) lwpid, status_to_str (status)); | |
84636d28 | 2889 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2890 | return NULL; |
2891 | } | |
2892 | ||
2893 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2894 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2895 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2896 | exits. */ |
2897 | if (!WIFSTOPPED (status) && !lp) | |
2898 | return NULL; | |
2899 | ||
8817a6f2 PA |
2900 | /* This LWP is stopped now. (And if dead, this prevents it from |
2901 | ever being continued.) */ | |
2902 | lp->stopped = 1; | |
2903 | ||
8784d563 PA |
2904 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2905 | { | |
2906 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
2907 | ||
2908 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), inf->attach_flag); | |
2909 | lp->must_set_ptrace_flags = 0; | |
2910 | } | |
2911 | ||
ca2163eb PA |
2912 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2913 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2914 | { | |
2915 | /* No longer need the sysgood bit. The ptrace event ends up | |
2916 | recorded in lp->waitstatus if we care for it. We can carry | |
2917 | on handling the event like a regular SIGTRAP from here | |
2918 | on. */ | |
2919 | status = W_STOPCODE (SIGTRAP); | |
2920 | if (linux_handle_syscall_trap (lp, 0)) | |
2921 | return NULL; | |
2922 | } | |
02f3fc28 | 2923 | |
ca2163eb | 2924 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2925 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2926 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
2927 | { |
2928 | if (debug_linux_nat) | |
2929 | fprintf_unfiltered (gdb_stdlog, | |
2930 | "LLW: Handling extended status 0x%06x\n", | |
2931 | status); | |
2932 | if (linux_handle_extended_wait (lp, status, 0)) | |
2933 | return NULL; | |
2934 | } | |
2935 | ||
2936 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2937 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2938 | { | |
2939 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
02f3fc28 | 2940 | { |
9c02b525 PA |
2941 | /* If this is the main thread, we must stop all threads and |
2942 | verify if they are still alive. This is because in the | |
2943 | nptl thread model on Linux 2.4, there is no signal issued | |
2944 | for exiting LWPs other than the main thread. We only get | |
2945 | the main thread exit signal once all child threads have | |
2946 | already exited. If we stop all the threads and use the | |
2947 | stop_wait_callback to check if they have exited we can | |
2948 | determine whether this signal should be ignored or | |
2949 | whether it means the end of the debugged application, | |
2950 | regardless of which threading model is being used. */ | |
2951 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) | |
2952 | { | |
2953 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
2954 | stop_and_resume_callback, NULL); | |
2955 | } | |
2956 | ||
2957 | if (debug_linux_nat) | |
2958 | fprintf_unfiltered (gdb_stdlog, | |
2959 | "LLW: %s exited.\n", | |
2960 | target_pid_to_str (lp->ptid)); | |
2961 | ||
2962 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
2963 | { | |
2964 | /* If there is at least one more LWP, then the exit signal | |
2965 | was not the end of the debugged application and should be | |
2966 | ignored. */ | |
2967 | exit_lwp (lp); | |
2968 | return NULL; | |
2969 | } | |
02f3fc28 PA |
2970 | } |
2971 | ||
9c02b525 PA |
2972 | gdb_assert (lp->resumed); |
2973 | ||
02f3fc28 PA |
2974 | if (debug_linux_nat) |
2975 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 PA |
2976 | "Process %ld exited\n", |
2977 | ptid_get_lwp (lp->ptid)); | |
02f3fc28 | 2978 | |
9c02b525 PA |
2979 | /* This was the last lwp in the process. Since events are |
2980 | serialized to GDB core, we may not be able report this one | |
2981 | right now, but GDB core and the other target layers will want | |
2982 | to be notified about the exit code/signal, leave the status | |
2983 | pending for the next time we're able to report it. */ | |
2984 | ||
2985 | /* Dead LWP's aren't expected to reported a pending sigstop. */ | |
2986 | lp->signalled = 0; | |
2987 | ||
2988 | /* Store the pending event in the waitstatus, because | |
2989 | W_EXITCODE(0,0) == 0. */ | |
2990 | store_waitstatus (&lp->waitstatus, status); | |
2991 | return lp; | |
02f3fc28 PA |
2992 | } |
2993 | ||
2994 | /* Check if the current LWP has previously exited. In the nptl | |
2995 | thread model, LWPs other than the main thread do not issue | |
2996 | signals when they exit so we must check whenever the thread has | |
2997 | stopped. A similar check is made in stop_wait_callback(). */ | |
dfd4cc63 | 2998 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 2999 | { |
dfd4cc63 | 3000 | ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid)); |
d90e17a7 | 3001 | |
02f3fc28 PA |
3002 | if (debug_linux_nat) |
3003 | fprintf_unfiltered (gdb_stdlog, | |
3004 | "LLW: %s exited.\n", | |
3005 | target_pid_to_str (lp->ptid)); | |
3006 | ||
3007 | exit_lwp (lp); | |
3008 | ||
3009 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3010 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3011 | |
3012 | /* Discard the event. */ | |
3013 | return NULL; | |
3014 | } | |
3015 | ||
3016 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3017 | an attempt to stop an LWP. */ | |
3018 | if (lp->signalled | |
3019 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3020 | { | |
3021 | if (debug_linux_nat) | |
3022 | fprintf_unfiltered (gdb_stdlog, | |
3023 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3024 | target_pid_to_str (lp->ptid)); | |
3025 | ||
02f3fc28 PA |
3026 | lp->signalled = 0; |
3027 | ||
25289eb2 PA |
3028 | if (lp->last_resume_kind != resume_stop) |
3029 | { | |
3030 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3031 | |
8a99810d | 3032 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3033 | if (debug_linux_nat) |
3034 | fprintf_unfiltered (gdb_stdlog, | |
3035 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3036 | lp->step ? | |
3037 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3038 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3039 | |
25289eb2 | 3040 | gdb_assert (lp->resumed); |
02f3fc28 | 3041 | |
25289eb2 PA |
3042 | /* Discard the event. */ |
3043 | return NULL; | |
3044 | } | |
02f3fc28 PA |
3045 | } |
3046 | ||
57380f4e DJ |
3047 | /* Make sure we don't report a SIGINT that we have already displayed |
3048 | for another thread. */ | |
3049 | if (lp->ignore_sigint | |
3050 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3051 | { | |
3052 | if (debug_linux_nat) | |
3053 | fprintf_unfiltered (gdb_stdlog, | |
3054 | "LLW: Delayed SIGINT caught for %s.\n", | |
3055 | target_pid_to_str (lp->ptid)); | |
3056 | ||
3057 | /* This is a delayed SIGINT. */ | |
3058 | lp->ignore_sigint = 0; | |
3059 | ||
8a99810d | 3060 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3061 | if (debug_linux_nat) |
3062 | fprintf_unfiltered (gdb_stdlog, | |
3063 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3064 | lp->step ? | |
3065 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3066 | target_pid_to_str (lp->ptid)); | |
57380f4e DJ |
3067 | gdb_assert (lp->resumed); |
3068 | ||
3069 | /* Discard the event. */ | |
3070 | return NULL; | |
3071 | } | |
3072 | ||
9c02b525 PA |
3073 | /* Don't report signals that GDB isn't interested in, such as |
3074 | signals that are neither printed nor stopped upon. Stopping all | |
3075 | threads can be a bit time-consuming so if we want decent | |
3076 | performance with heavily multi-threaded programs, especially when | |
3077 | they're using a high frequency timer, we'd better avoid it if we | |
3078 | can. */ | |
3079 | if (WIFSTOPPED (status)) | |
3080 | { | |
3081 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3082 | ||
3083 | if (!non_stop) | |
3084 | { | |
3085 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3086 | to implement target_stop (see linux_nat_stop) in | |
3087 | non-stop. */ | |
3088 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3089 | { | |
3090 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3091 | forwarded to the entire process group, that is, all LWPs | |
3092 | will receive it - unless they're using CLONE_THREAD to | |
3093 | share signals. Since we only want to report it once, we | |
3094 | mark it as ignored for all LWPs except this one. */ | |
3095 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
3096 | set_ignore_sigint, NULL); | |
3097 | lp->ignore_sigint = 0; | |
3098 | } | |
3099 | else | |
3100 | maybe_clear_ignore_sigint (lp); | |
3101 | } | |
3102 | ||
3103 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 AT |
3104 | Otherwise, signals in pass_mask may be short-circuited |
3105 | except signals that might be caused by a breakpoint. */ | |
9c02b525 | 3106 | if (!lp->step |
c9587f88 AT |
3107 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
3108 | && !linux_wstatus_maybe_breakpoint (status)) | |
9c02b525 PA |
3109 | { |
3110 | linux_resume_one_lwp (lp, lp->step, signo); | |
3111 | if (debug_linux_nat) | |
3112 | fprintf_unfiltered (gdb_stdlog, | |
3113 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3114 | lp->step ? | |
3115 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3116 | target_pid_to_str (lp->ptid), | |
3117 | (signo != GDB_SIGNAL_0 | |
3118 | ? strsignal (gdb_signal_to_host (signo)) | |
3119 | : "0")); | |
3120 | return NULL; | |
3121 | } | |
3122 | } | |
3123 | ||
02f3fc28 PA |
3124 | /* An interesting event. */ |
3125 | gdb_assert (lp); | |
ca2163eb | 3126 | lp->status = status; |
9c02b525 | 3127 | save_sigtrap (lp); |
02f3fc28 PA |
3128 | return lp; |
3129 | } | |
3130 | ||
0e5bf2a8 PA |
3131 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3132 | their exits until all other threads in the group have exited. */ | |
3133 | ||
3134 | static void | |
3135 | check_zombie_leaders (void) | |
3136 | { | |
3137 | struct inferior *inf; | |
3138 | ||
3139 | ALL_INFERIORS (inf) | |
3140 | { | |
3141 | struct lwp_info *leader_lp; | |
3142 | ||
3143 | if (inf->pid == 0) | |
3144 | continue; | |
3145 | ||
3146 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3147 | if (leader_lp != NULL | |
3148 | /* Check if there are other threads in the group, as we may | |
3149 | have raced with the inferior simply exiting. */ | |
3150 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3151 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3152 | { |
3153 | if (debug_linux_nat) | |
3154 | fprintf_unfiltered (gdb_stdlog, | |
3155 | "CZL: Thread group leader %d zombie " | |
3156 | "(it exited, or another thread execd).\n", | |
3157 | inf->pid); | |
3158 | ||
3159 | /* A leader zombie can mean one of two things: | |
3160 | ||
3161 | - It exited, and there's an exit status pending | |
3162 | available, or only the leader exited (not the whole | |
3163 | program). In the latter case, we can't waitpid the | |
3164 | leader's exit status until all other threads are gone. | |
3165 | ||
3166 | - There are 3 or more threads in the group, and a thread | |
3167 | other than the leader exec'd. On an exec, the Linux | |
3168 | kernel destroys all other threads (except the execing | |
3169 | one) in the thread group, and resets the execing thread's | |
3170 | tid to the tgid. No exit notification is sent for the | |
3171 | execing thread -- from the ptracer's perspective, it | |
3172 | appears as though the execing thread just vanishes. | |
3173 | Until we reap all other threads except the leader and the | |
3174 | execing thread, the leader will be zombie, and the | |
3175 | execing thread will be in `D (disc sleep)'. As soon as | |
3176 | all other threads are reaped, the execing thread changes | |
3177 | it's tid to the tgid, and the previous (zombie) leader | |
3178 | vanishes, giving place to the "new" leader. We could try | |
3179 | distinguishing the exit and exec cases, by waiting once | |
3180 | more, and seeing if something comes out, but it doesn't | |
3181 | sound useful. The previous leader _does_ go away, and | |
3182 | we'll re-add the new one once we see the exec event | |
3183 | (which is just the same as what would happen if the | |
3184 | previous leader did exit voluntarily before some other | |
3185 | thread execs). */ | |
3186 | ||
3187 | if (debug_linux_nat) | |
3188 | fprintf_unfiltered (gdb_stdlog, | |
3189 | "CZL: Thread group leader %d vanished.\n", | |
3190 | inf->pid); | |
3191 | exit_lwp (leader_lp); | |
3192 | } | |
3193 | } | |
3194 | } | |
3195 | ||
d6b0e80f | 3196 | static ptid_t |
7feb7d06 | 3197 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3198 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3199 | int target_options) | |
d6b0e80f | 3200 | { |
fc9b8e47 | 3201 | sigset_t prev_mask; |
4b60df3d | 3202 | enum resume_kind last_resume_kind; |
12d9289a | 3203 | struct lwp_info *lp; |
12d9289a | 3204 | int status; |
d6b0e80f | 3205 | |
01124a23 | 3206 | if (debug_linux_nat) |
b84876c2 PA |
3207 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3208 | ||
f973ed9c DJ |
3209 | /* The first time we get here after starting a new inferior, we may |
3210 | not have added it to the LWP list yet - this is the earliest | |
3211 | moment at which we know its PID. */ | |
d90e17a7 | 3212 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3213 | { |
27c9d204 PA |
3214 | /* Upgrade the main thread's ptid. */ |
3215 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3216 | ptid_build (ptid_get_pid (inferior_ptid), |
3217 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3218 | |
26cb8b7c | 3219 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3220 | lp->resumed = 1; |
3221 | } | |
3222 | ||
12696c10 | 3223 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3224 | block_child_signals (&prev_mask); |
d6b0e80f | 3225 | |
d6b0e80f | 3226 | /* First check if there is a LWP with a wait status pending. */ |
8a99810d PA |
3227 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3228 | if (lp != NULL) | |
d6b0e80f AC |
3229 | { |
3230 | if (debug_linux_nat) | |
d6b0e80f AC |
3231 | fprintf_unfiltered (gdb_stdlog, |
3232 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3233 | status_to_str (lp->status), |
d6b0e80f | 3234 | target_pid_to_str (lp->ptid)); |
d6b0e80f AC |
3235 | } |
3236 | ||
d9d41e78 | 3237 | if (!target_is_async_p ()) |
b84876c2 PA |
3238 | { |
3239 | /* Causes SIGINT to be passed on to the attached process. */ | |
3240 | set_sigint_trap (); | |
b84876c2 | 3241 | } |
d6b0e80f | 3242 | |
9c02b525 PA |
3243 | /* But if we don't find a pending event, we'll have to wait. Always |
3244 | pull all events out of the kernel. We'll randomly select an | |
3245 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3246 | |
d90e17a7 | 3247 | while (lp == NULL) |
d6b0e80f AC |
3248 | { |
3249 | pid_t lwpid; | |
3250 | ||
0e5bf2a8 PA |
3251 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3252 | quirks: | |
3253 | ||
3254 | - If the thread group leader exits while other threads in the | |
3255 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3256 | waitpid won't return an exit status until the other threads | |
3257 | in the group are reapped. | |
3258 | ||
3259 | - When a non-leader thread execs, that thread just vanishes | |
3260 | without reporting an exit (so we'd hang if we waited for it | |
3261 | explicitly in that case). The exec event is reported to | |
3262 | the TGID pid. */ | |
3263 | ||
3264 | errno = 0; | |
3265 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3266 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3267 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3268 | ||
3269 | if (debug_linux_nat) | |
3270 | fprintf_unfiltered (gdb_stdlog, | |
3271 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3272 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3273 | |
d6b0e80f AC |
3274 | if (lwpid > 0) |
3275 | { | |
d6b0e80f AC |
3276 | if (debug_linux_nat) |
3277 | { | |
3278 | fprintf_unfiltered (gdb_stdlog, | |
3279 | "LLW: waitpid %ld received %s\n", | |
3280 | (long) lwpid, status_to_str (status)); | |
3281 | } | |
3282 | ||
9c02b525 | 3283 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3284 | /* Retry until nothing comes out of waitpid. A single |
3285 | SIGCHLD can indicate more than one child stopped. */ | |
3286 | continue; | |
d6b0e80f AC |
3287 | } |
3288 | ||
20ba1ce6 PA |
3289 | /* Now that we've pulled all events out of the kernel, resume |
3290 | LWPs that don't have an interesting event to report. */ | |
3291 | iterate_over_lwps (minus_one_ptid, | |
3292 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
3293 | ||
3294 | /* ... and find an LWP with a status to report to the core, if | |
3295 | any. */ | |
9c02b525 PA |
3296 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3297 | if (lp != NULL) | |
3298 | break; | |
3299 | ||
0e5bf2a8 PA |
3300 | /* Check for zombie thread group leaders. Those can't be reaped |
3301 | until all other threads in the thread group are. */ | |
3302 | check_zombie_leaders (); | |
d6b0e80f | 3303 | |
0e5bf2a8 PA |
3304 | /* If there are no resumed children left, bail. We'd be stuck |
3305 | forever in the sigsuspend call below otherwise. */ | |
3306 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3307 | { | |
3308 | if (debug_linux_nat) | |
3309 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3310 | |
0e5bf2a8 | 3311 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3312 | |
d9d41e78 | 3313 | if (!target_is_async_p ()) |
0e5bf2a8 | 3314 | clear_sigint_trap (); |
b84876c2 | 3315 | |
0e5bf2a8 PA |
3316 | restore_child_signals_mask (&prev_mask); |
3317 | return minus_one_ptid; | |
d6b0e80f | 3318 | } |
28736962 | 3319 | |
0e5bf2a8 PA |
3320 | /* No interesting event to report to the core. */ |
3321 | ||
3322 | if (target_options & TARGET_WNOHANG) | |
3323 | { | |
01124a23 | 3324 | if (debug_linux_nat) |
28736962 PA |
3325 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3326 | ||
0e5bf2a8 | 3327 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3328 | restore_child_signals_mask (&prev_mask); |
3329 | return minus_one_ptid; | |
3330 | } | |
d6b0e80f AC |
3331 | |
3332 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3333 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3334 | |
3335 | /* Block until we get an event reported with SIGCHLD. */ | |
d36bf488 DE |
3336 | if (debug_linux_nat) |
3337 | fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n"); | |
0e5bf2a8 | 3338 | sigsuspend (&suspend_mask); |
d6b0e80f AC |
3339 | } |
3340 | ||
d9d41e78 | 3341 | if (!target_is_async_p ()) |
d26b5354 | 3342 | clear_sigint_trap (); |
d6b0e80f AC |
3343 | |
3344 | gdb_assert (lp); | |
3345 | ||
ca2163eb PA |
3346 | status = lp->status; |
3347 | lp->status = 0; | |
3348 | ||
4c28f408 PA |
3349 | if (!non_stop) |
3350 | { | |
3351 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3352 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3353 | |
3354 | /* ... and wait until all of them have reported back that | |
3355 | they're no longer running. */ | |
d90e17a7 | 3356 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
9c02b525 PA |
3357 | } |
3358 | ||
3359 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3360 | among those that have had events. Giving equal priority to all | |
3361 | LWPs that have had events helps prevent starvation. */ | |
3362 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) | |
3363 | select_event_lwp (ptid, &lp, &status); | |
3364 | ||
3365 | gdb_assert (lp != NULL); | |
3366 | ||
3367 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
3368 | it was a software breakpoint. */ | |
3369 | if (lp->stop_reason == LWP_STOPPED_BY_SW_BREAKPOINT) | |
3370 | { | |
3371 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
3372 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3373 | int decr_pc = target_decr_pc_after_break (gdbarch); | |
4c28f408 | 3374 | |
9c02b525 PA |
3375 | if (decr_pc != 0) |
3376 | { | |
3377 | CORE_ADDR pc; | |
d6b0e80f | 3378 | |
9c02b525 PA |
3379 | pc = regcache_read_pc (regcache); |
3380 | regcache_write_pc (regcache, pc + decr_pc); | |
3381 | } | |
3382 | } | |
e3e9f5a2 | 3383 | |
9c02b525 PA |
3384 | /* We'll need this to determine whether to report a SIGSTOP as |
3385 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3386 | clears it. */ | |
3387 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3388 | |
9c02b525 PA |
3389 | if (!non_stop) |
3390 | { | |
e3e9f5a2 PA |
3391 | /* In all-stop, from the core's perspective, all LWPs are now |
3392 | stopped until a new resume action is sent over. */ | |
3393 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3394 | } | |
3395 | else | |
25289eb2 | 3396 | { |
4b60df3d | 3397 | resume_clear_callback (lp, NULL); |
25289eb2 | 3398 | } |
d6b0e80f | 3399 | |
26ab7092 | 3400 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3401 | { |
d6b0e80f AC |
3402 | if (debug_linux_nat) |
3403 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3404 | "LLW: trap ptid is %s.\n", |
3405 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3406 | } |
d6b0e80f AC |
3407 | |
3408 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3409 | { | |
3410 | *ourstatus = lp->waitstatus; | |
3411 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3412 | } | |
3413 | else | |
3414 | store_waitstatus (ourstatus, status); | |
3415 | ||
01124a23 | 3416 | if (debug_linux_nat) |
b84876c2 PA |
3417 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3418 | ||
7feb7d06 | 3419 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3420 | |
4b60df3d | 3421 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3422 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3423 | && WSTOPSIG (status) == SIGSTOP) | |
3424 | { | |
3425 | /* A thread that has been requested to stop by GDB with | |
3426 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3427 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3428 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3429 | } |
3430 | ||
1e225492 JK |
3431 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3432 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3433 | lp->core = -1; | |
3434 | else | |
2e794194 | 3435 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3436 | |
f973ed9c | 3437 | return lp->ptid; |
d6b0e80f AC |
3438 | } |
3439 | ||
e3e9f5a2 PA |
3440 | /* Resume LWPs that are currently stopped without any pending status |
3441 | to report, but are resumed from the core's perspective. */ | |
3442 | ||
3443 | static int | |
3444 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3445 | { | |
3446 | ptid_t *wait_ptid_p = data; | |
3447 | ||
3448 | if (lp->stopped | |
3449 | && lp->resumed | |
8a99810d | 3450 | && !lwp_status_pending_p (lp)) |
e3e9f5a2 | 3451 | { |
336060f3 PA |
3452 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3453 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3454 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3455 | ||
e3e9f5a2 PA |
3456 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3457 | immediately, and we're not waiting for this LWP. */ | |
3458 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3459 | { | |
e3e9f5a2 PA |
3460 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3461 | return 0; | |
3462 | } | |
3463 | ||
3464 | if (debug_linux_nat) | |
3465 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3466 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3467 | target_pid_to_str (lp->ptid), | |
3468 | paddress (gdbarch, pc), | |
3469 | lp->step); | |
e3e9f5a2 | 3470 | |
8a99810d | 3471 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
e3e9f5a2 PA |
3472 | } |
3473 | ||
3474 | return 0; | |
3475 | } | |
3476 | ||
7feb7d06 PA |
3477 | static ptid_t |
3478 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3479 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3480 | int target_options) | |
7feb7d06 PA |
3481 | { |
3482 | ptid_t event_ptid; | |
3483 | ||
3484 | if (debug_linux_nat) | |
09826ec5 PA |
3485 | { |
3486 | char *options_string; | |
3487 | ||
3488 | options_string = target_options_to_string (target_options); | |
3489 | fprintf_unfiltered (gdb_stdlog, | |
3490 | "linux_nat_wait: [%s], [%s]\n", | |
3491 | target_pid_to_str (ptid), | |
3492 | options_string); | |
3493 | xfree (options_string); | |
3494 | } | |
7feb7d06 PA |
3495 | |
3496 | /* Flush the async file first. */ | |
d9d41e78 | 3497 | if (target_is_async_p ()) |
7feb7d06 PA |
3498 | async_file_flush (); |
3499 | ||
e3e9f5a2 PA |
3500 | /* Resume LWPs that are currently stopped without any pending status |
3501 | to report, but are resumed from the core's perspective. LWPs get | |
3502 | in this state if we find them stopping at a time we're not | |
3503 | interested in reporting the event (target_wait on a | |
3504 | specific_process, for example, see linux_nat_wait_1), and | |
3505 | meanwhile the event became uninteresting. Don't bother resuming | |
3506 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3507 | if (non_stop) | |
3508 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3509 | ||
47608cb1 | 3510 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3511 | |
3512 | /* If we requested any event, and something came out, assume there | |
3513 | may be more. If we requested a specific lwp or process, also | |
3514 | assume there may be more. */ | |
d9d41e78 | 3515 | if (target_is_async_p () |
6953d224 PA |
3516 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3517 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3518 | || !ptid_equal (ptid, minus_one_ptid))) |
3519 | async_file_mark (); | |
3520 | ||
7feb7d06 PA |
3521 | return event_ptid; |
3522 | } | |
3523 | ||
d6b0e80f AC |
3524 | static int |
3525 | kill_callback (struct lwp_info *lp, void *data) | |
3526 | { | |
ed731959 JK |
3527 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3528 | ||
3529 | errno = 0; | |
69ff6be5 | 3530 | kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL); |
ed731959 | 3531 | if (debug_linux_nat) |
57745c90 PA |
3532 | { |
3533 | int save_errno = errno; | |
3534 | ||
3535 | fprintf_unfiltered (gdb_stdlog, | |
3536 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3537 | target_pid_to_str (lp->ptid), | |
3538 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3539 | } | |
ed731959 JK |
3540 | |
3541 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3542 | ||
d6b0e80f | 3543 | errno = 0; |
dfd4cc63 | 3544 | ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0); |
d6b0e80f | 3545 | if (debug_linux_nat) |
57745c90 PA |
3546 | { |
3547 | int save_errno = errno; | |
3548 | ||
3549 | fprintf_unfiltered (gdb_stdlog, | |
3550 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3551 | target_pid_to_str (lp->ptid), | |
3552 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3553 | } | |
d6b0e80f AC |
3554 | |
3555 | return 0; | |
3556 | } | |
3557 | ||
3558 | static int | |
3559 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3560 | { | |
3561 | pid_t pid; | |
3562 | ||
3563 | /* We must make sure that there are no pending events (delayed | |
3564 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3565 | program doesn't interfere with any following debugging session. */ | |
3566 | ||
3567 | /* For cloned processes we must check both with __WCLONE and | |
3568 | without, since the exit status of a cloned process isn't reported | |
3569 | with __WCLONE. */ | |
3570 | if (lp->cloned) | |
3571 | { | |
3572 | do | |
3573 | { | |
dfd4cc63 | 3574 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE); |
e85a822c | 3575 | if (pid != (pid_t) -1) |
d6b0e80f | 3576 | { |
e85a822c DJ |
3577 | if (debug_linux_nat) |
3578 | fprintf_unfiltered (gdb_stdlog, | |
3579 | "KWC: wait %s received unknown.\n", | |
3580 | target_pid_to_str (lp->ptid)); | |
3581 | /* The Linux kernel sometimes fails to kill a thread | |
3582 | completely after PTRACE_KILL; that goes from the stop | |
3583 | point in do_fork out to the one in | |
3584 | get_signal_to_deliever and waits again. So kill it | |
3585 | again. */ | |
3586 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3587 | } |
3588 | } | |
dfd4cc63 | 3589 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3590 | |
3591 | gdb_assert (pid == -1 && errno == ECHILD); | |
3592 | } | |
3593 | ||
3594 | do | |
3595 | { | |
dfd4cc63 | 3596 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0); |
e85a822c | 3597 | if (pid != (pid_t) -1) |
d6b0e80f | 3598 | { |
e85a822c DJ |
3599 | if (debug_linux_nat) |
3600 | fprintf_unfiltered (gdb_stdlog, | |
3601 | "KWC: wait %s received unk.\n", | |
3602 | target_pid_to_str (lp->ptid)); | |
3603 | /* See the call to kill_callback above. */ | |
3604 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3605 | } |
3606 | } | |
dfd4cc63 | 3607 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3608 | |
3609 | gdb_assert (pid == -1 && errno == ECHILD); | |
3610 | return 0; | |
3611 | } | |
3612 | ||
3613 | static void | |
7d85a9c0 | 3614 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3615 | { |
f973ed9c DJ |
3616 | struct target_waitstatus last; |
3617 | ptid_t last_ptid; | |
3618 | int status; | |
d6b0e80f | 3619 | |
f973ed9c DJ |
3620 | /* If we're stopped while forking and we haven't followed yet, |
3621 | kill the other task. We need to do this first because the | |
3622 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3623 | |
f973ed9c | 3624 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3625 | |
f973ed9c DJ |
3626 | if (last.kind == TARGET_WAITKIND_FORKED |
3627 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3628 | { | |
dfd4cc63 | 3629 | ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0); |
f973ed9c | 3630 | wait (&status); |
26cb8b7c PA |
3631 | |
3632 | /* Let the arch-specific native code know this process is | |
3633 | gone. */ | |
dfd4cc63 | 3634 | linux_nat_forget_process (ptid_get_pid (last.value.related_pid)); |
f973ed9c DJ |
3635 | } |
3636 | ||
3637 | if (forks_exist_p ()) | |
7feb7d06 | 3638 | linux_fork_killall (); |
f973ed9c DJ |
3639 | else |
3640 | { | |
d90e17a7 | 3641 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3642 | |
4c28f408 PA |
3643 | /* Stop all threads before killing them, since ptrace requires |
3644 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3645 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3646 | /* ... and wait until all of them have reported back that |
3647 | they're no longer running. */ | |
d90e17a7 | 3648 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3649 | |
f973ed9c | 3650 | /* Kill all LWP's ... */ |
d90e17a7 | 3651 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3652 | |
3653 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3654 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3655 | } |
3656 | ||
3657 | target_mourn_inferior (); | |
d6b0e80f AC |
3658 | } |
3659 | ||
3660 | static void | |
136d6dae | 3661 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3662 | { |
26cb8b7c PA |
3663 | int pid = ptid_get_pid (inferior_ptid); |
3664 | ||
3665 | purge_lwp_list (pid); | |
d6b0e80f | 3666 | |
f973ed9c | 3667 | if (! forks_exist_p ()) |
d90e17a7 PA |
3668 | /* Normal case, no other forks available. */ |
3669 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3670 | else |
3671 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3672 | there are other viable forks to debug. Delete the exiting | |
3673 | one and context-switch to the first available. */ | |
3674 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3675 | |
3676 | /* Let the arch-specific native code know this process is gone. */ | |
3677 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3678 | } |
3679 | ||
5b009018 PA |
3680 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3681 | layout of the inferiors' architecture. */ | |
3682 | ||
3683 | static void | |
a5362b9a | 3684 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3685 | { |
3686 | int done = 0; | |
3687 | ||
3688 | if (linux_nat_siginfo_fixup != NULL) | |
3689 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3690 | ||
3691 | /* If there was no callback, or the callback didn't do anything, | |
3692 | then just do a straight memcpy. */ | |
3693 | if (!done) | |
3694 | { | |
3695 | if (direction == 1) | |
a5362b9a | 3696 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3697 | else |
a5362b9a | 3698 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3699 | } |
3700 | } | |
3701 | ||
9b409511 | 3702 | static enum target_xfer_status |
4aa995e1 PA |
3703 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
3704 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
3705 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3706 | ULONGEST *xfered_len) | |
4aa995e1 | 3707 | { |
4aa995e1 | 3708 | int pid; |
a5362b9a TS |
3709 | siginfo_t siginfo; |
3710 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3711 | |
3712 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3713 | gdb_assert (readbuf || writebuf); | |
3714 | ||
dfd4cc63 | 3715 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3716 | if (pid == 0) |
dfd4cc63 | 3717 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3718 | |
3719 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3720 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3721 | |
3722 | errno = 0; | |
3723 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3724 | if (errno != 0) | |
2ed4b548 | 3725 | return TARGET_XFER_E_IO; |
4aa995e1 | 3726 | |
5b009018 PA |
3727 | /* When GDB is built as a 64-bit application, ptrace writes into |
3728 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3729 | inferior with a 64-bit GDB should look the same as debugging it | |
3730 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3731 | the converted layout, so any read/write will have to be done | |
3732 | post-conversion. */ | |
3733 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3734 | ||
4aa995e1 PA |
3735 | if (offset + len > sizeof (siginfo)) |
3736 | len = sizeof (siginfo) - offset; | |
3737 | ||
3738 | if (readbuf != NULL) | |
5b009018 | 3739 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3740 | else |
3741 | { | |
5b009018 PA |
3742 | memcpy (inf_siginfo + offset, writebuf, len); |
3743 | ||
3744 | /* Convert back to ptrace layout before flushing it out. */ | |
3745 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3746 | ||
4aa995e1 PA |
3747 | errno = 0; |
3748 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3749 | if (errno != 0) | |
2ed4b548 | 3750 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3751 | } |
3752 | ||
9b409511 YQ |
3753 | *xfered_len = len; |
3754 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3755 | } |
3756 | ||
9b409511 | 3757 | static enum target_xfer_status |
10d6c8cd DJ |
3758 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
3759 | const char *annex, gdb_byte *readbuf, | |
3760 | const gdb_byte *writebuf, | |
9b409511 | 3761 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
d6b0e80f | 3762 | { |
4aa995e1 | 3763 | struct cleanup *old_chain; |
9b409511 | 3764 | enum target_xfer_status xfer; |
d6b0e80f | 3765 | |
4aa995e1 PA |
3766 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3767 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
9b409511 | 3768 | offset, len, xfered_len); |
4aa995e1 | 3769 | |
c35b1492 PA |
3770 | /* The target is connected but no live inferior is selected. Pass |
3771 | this request down to a lower stratum (e.g., the executable | |
3772 | file). */ | |
3773 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3774 | return TARGET_XFER_EOF; |
c35b1492 | 3775 | |
4aa995e1 PA |
3776 | old_chain = save_inferior_ptid (); |
3777 | ||
dfd4cc63 LM |
3778 | if (ptid_lwp_p (inferior_ptid)) |
3779 | inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid)); | |
d6b0e80f | 3780 | |
10d6c8cd | 3781 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 | 3782 | offset, len, xfered_len); |
d6b0e80f AC |
3783 | |
3784 | do_cleanups (old_chain); | |
3785 | return xfer; | |
3786 | } | |
3787 | ||
3788 | static int | |
28439f5e | 3789 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 3790 | { |
8c6a60d1 | 3791 | int err, tmp_errno; |
4c28f408 | 3792 | |
dfd4cc63 | 3793 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 3794 | |
4c28f408 PA |
3795 | /* Send signal 0 instead of anything ptrace, because ptracing a |
3796 | running thread errors out claiming that the thread doesn't | |
3797 | exist. */ | |
dfd4cc63 | 3798 | err = kill_lwp (ptid_get_lwp (ptid), 0); |
8c6a60d1 | 3799 | tmp_errno = errno; |
d6b0e80f AC |
3800 | if (debug_linux_nat) |
3801 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 3802 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 3803 | target_pid_to_str (ptid), |
8c6a60d1 | 3804 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 3805 | |
4c28f408 | 3806 | if (err != 0) |
d6b0e80f AC |
3807 | return 0; |
3808 | ||
3809 | return 1; | |
3810 | } | |
3811 | ||
28439f5e PA |
3812 | static int |
3813 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
3814 | { | |
3815 | return linux_thread_alive (ptid); | |
3816 | } | |
3817 | ||
d6b0e80f | 3818 | static char * |
117de6a9 | 3819 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
3820 | { |
3821 | static char buf[64]; | |
3822 | ||
dfd4cc63 LM |
3823 | if (ptid_lwp_p (ptid) |
3824 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
3825 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 3826 | { |
dfd4cc63 | 3827 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
3828 | return buf; |
3829 | } | |
3830 | ||
3831 | return normal_pid_to_str (ptid); | |
3832 | } | |
3833 | ||
4694da01 | 3834 | static char * |
503a628d | 3835 | linux_nat_thread_name (struct target_ops *self, struct thread_info *thr) |
4694da01 TT |
3836 | { |
3837 | int pid = ptid_get_pid (thr->ptid); | |
3838 | long lwp = ptid_get_lwp (thr->ptid); | |
3839 | #define FORMAT "/proc/%d/task/%ld/comm" | |
3840 | char buf[sizeof (FORMAT) + 30]; | |
3841 | FILE *comm_file; | |
3842 | char *result = NULL; | |
3843 | ||
3844 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 3845 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
3846 | if (comm_file) |
3847 | { | |
3848 | /* Not exported by the kernel, so we define it here. */ | |
3849 | #define COMM_LEN 16 | |
3850 | static char line[COMM_LEN + 1]; | |
3851 | ||
3852 | if (fgets (line, sizeof (line), comm_file)) | |
3853 | { | |
3854 | char *nl = strchr (line, '\n'); | |
3855 | ||
3856 | if (nl) | |
3857 | *nl = '\0'; | |
3858 | if (*line != '\0') | |
3859 | result = line; | |
3860 | } | |
3861 | ||
3862 | fclose (comm_file); | |
3863 | } | |
3864 | ||
3865 | #undef COMM_LEN | |
3866 | #undef FORMAT | |
3867 | ||
3868 | return result; | |
3869 | } | |
3870 | ||
dba24537 AC |
3871 | /* Accepts an integer PID; Returns a string representing a file that |
3872 | can be opened to get the symbols for the child process. */ | |
3873 | ||
6d8fd2b7 | 3874 | static char * |
8dd27370 | 3875 | linux_child_pid_to_exec_file (struct target_ops *self, int pid) |
dba24537 | 3876 | { |
b4ab256d HZ |
3877 | static char buf[PATH_MAX]; |
3878 | char name[PATH_MAX]; | |
dba24537 | 3879 | |
b4ab256d HZ |
3880 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
3881 | memset (buf, 0, PATH_MAX); | |
3882 | if (readlink (name, buf, PATH_MAX - 1) <= 0) | |
3883 | strcpy (buf, name); | |
dba24537 | 3884 | |
b4ab256d | 3885 | return buf; |
dba24537 AC |
3886 | } |
3887 | ||
10d6c8cd DJ |
3888 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
3889 | filesystem. Because we can use a single read() call for /proc, this | |
3890 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
3891 | but it doesn't support writes. */ | |
3892 | ||
9b409511 | 3893 | static enum target_xfer_status |
10d6c8cd DJ |
3894 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
3895 | const char *annex, gdb_byte *readbuf, | |
3896 | const gdb_byte *writebuf, | |
9b409511 | 3897 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3898 | { |
10d6c8cd DJ |
3899 | LONGEST ret; |
3900 | int fd; | |
dba24537 AC |
3901 | char filename[64]; |
3902 | ||
10d6c8cd | 3903 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
3904 | return 0; |
3905 | ||
3906 | /* Don't bother for one word. */ | |
3907 | if (len < 3 * sizeof (long)) | |
9b409511 | 3908 | return TARGET_XFER_EOF; |
dba24537 AC |
3909 | |
3910 | /* We could keep this file open and cache it - possibly one per | |
3911 | thread. That requires some juggling, but is even faster. */ | |
cde33bf1 YQ |
3912 | xsnprintf (filename, sizeof filename, "/proc/%d/mem", |
3913 | ptid_get_pid (inferior_ptid)); | |
614c279d | 3914 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 | 3915 | if (fd == -1) |
9b409511 | 3916 | return TARGET_XFER_EOF; |
dba24537 AC |
3917 | |
3918 | /* If pread64 is available, use it. It's faster if the kernel | |
3919 | supports it (only one syscall), and it's 64-bit safe even on | |
3920 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
3921 | application). */ | |
3922 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 3923 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 3924 | #else |
10d6c8cd | 3925 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
3926 | #endif |
3927 | ret = 0; | |
3928 | else | |
3929 | ret = len; | |
3930 | ||
3931 | close (fd); | |
9b409511 YQ |
3932 | |
3933 | if (ret == 0) | |
3934 | return TARGET_XFER_EOF; | |
3935 | else | |
3936 | { | |
3937 | *xfered_len = ret; | |
3938 | return TARGET_XFER_OK; | |
3939 | } | |
dba24537 AC |
3940 | } |
3941 | ||
efcbbd14 UW |
3942 | |
3943 | /* Enumerate spufs IDs for process PID. */ | |
3944 | static LONGEST | |
b55e14c7 | 3945 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 3946 | { |
f5656ead | 3947 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
3948 | LONGEST pos = 0; |
3949 | LONGEST written = 0; | |
3950 | char path[128]; | |
3951 | DIR *dir; | |
3952 | struct dirent *entry; | |
3953 | ||
3954 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
3955 | dir = opendir (path); | |
3956 | if (!dir) | |
3957 | return -1; | |
3958 | ||
3959 | rewinddir (dir); | |
3960 | while ((entry = readdir (dir)) != NULL) | |
3961 | { | |
3962 | struct stat st; | |
3963 | struct statfs stfs; | |
3964 | int fd; | |
3965 | ||
3966 | fd = atoi (entry->d_name); | |
3967 | if (!fd) | |
3968 | continue; | |
3969 | ||
3970 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
3971 | if (stat (path, &st) != 0) | |
3972 | continue; | |
3973 | if (!S_ISDIR (st.st_mode)) | |
3974 | continue; | |
3975 | ||
3976 | if (statfs (path, &stfs) != 0) | |
3977 | continue; | |
3978 | if (stfs.f_type != SPUFS_MAGIC) | |
3979 | continue; | |
3980 | ||
3981 | if (pos >= offset && pos + 4 <= offset + len) | |
3982 | { | |
3983 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
3984 | written += 4; | |
3985 | } | |
3986 | pos += 4; | |
3987 | } | |
3988 | ||
3989 | closedir (dir); | |
3990 | return written; | |
3991 | } | |
3992 | ||
3993 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
3994 | object type, using the /proc file system. */ | |
9b409511 YQ |
3995 | |
3996 | static enum target_xfer_status | |
efcbbd14 UW |
3997 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
3998 | const char *annex, gdb_byte *readbuf, | |
3999 | const gdb_byte *writebuf, | |
9b409511 | 4000 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
4001 | { |
4002 | char buf[128]; | |
4003 | int fd = 0; | |
4004 | int ret = -1; | |
dfd4cc63 | 4005 | int pid = ptid_get_pid (inferior_ptid); |
efcbbd14 UW |
4006 | |
4007 | if (!annex) | |
4008 | { | |
4009 | if (!readbuf) | |
2ed4b548 | 4010 | return TARGET_XFER_E_IO; |
efcbbd14 | 4011 | else |
9b409511 YQ |
4012 | { |
4013 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4014 | ||
4015 | if (l < 0) | |
4016 | return TARGET_XFER_E_IO; | |
4017 | else if (l == 0) | |
4018 | return TARGET_XFER_EOF; | |
4019 | else | |
4020 | { | |
4021 | *xfered_len = (ULONGEST) l; | |
4022 | return TARGET_XFER_OK; | |
4023 | } | |
4024 | } | |
efcbbd14 UW |
4025 | } |
4026 | ||
4027 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4028 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4029 | if (fd <= 0) |
2ed4b548 | 4030 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4031 | |
4032 | if (offset != 0 | |
4033 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4034 | { | |
4035 | close (fd); | |
9b409511 | 4036 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4037 | } |
4038 | ||
4039 | if (writebuf) | |
4040 | ret = write (fd, writebuf, (size_t) len); | |
4041 | else if (readbuf) | |
4042 | ret = read (fd, readbuf, (size_t) len); | |
4043 | ||
4044 | close (fd); | |
9b409511 YQ |
4045 | |
4046 | if (ret < 0) | |
4047 | return TARGET_XFER_E_IO; | |
4048 | else if (ret == 0) | |
4049 | return TARGET_XFER_EOF; | |
4050 | else | |
4051 | { | |
4052 | *xfered_len = (ULONGEST) ret; | |
4053 | return TARGET_XFER_OK; | |
4054 | } | |
efcbbd14 UW |
4055 | } |
4056 | ||
4057 | ||
dba24537 AC |
4058 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4059 | ||
4060 | static void | |
4061 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4062 | { | |
4063 | int len = strlen (line) - 1; | |
4064 | const char *p; | |
4065 | int signum; | |
4066 | ||
4067 | if (line[len] != '\n') | |
8a3fe4f8 | 4068 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4069 | |
4070 | p = line; | |
4071 | signum = len * 4; | |
4072 | while (len-- > 0) | |
4073 | { | |
4074 | int digit; | |
4075 | ||
4076 | if (*p >= '0' && *p <= '9') | |
4077 | digit = *p - '0'; | |
4078 | else if (*p >= 'a' && *p <= 'f') | |
4079 | digit = *p - 'a' + 10; | |
4080 | else | |
8a3fe4f8 | 4081 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4082 | |
4083 | signum -= 4; | |
4084 | ||
4085 | if (digit & 1) | |
4086 | sigaddset (sigs, signum + 1); | |
4087 | if (digit & 2) | |
4088 | sigaddset (sigs, signum + 2); | |
4089 | if (digit & 4) | |
4090 | sigaddset (sigs, signum + 3); | |
4091 | if (digit & 8) | |
4092 | sigaddset (sigs, signum + 4); | |
4093 | ||
4094 | p++; | |
4095 | } | |
4096 | } | |
4097 | ||
4098 | /* Find process PID's pending signals from /proc/pid/status and set | |
4099 | SIGS to match. */ | |
4100 | ||
4101 | void | |
3e43a32a MS |
4102 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4103 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4104 | { |
4105 | FILE *procfile; | |
d8d2a3ee | 4106 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4107 | struct cleanup *cleanup; |
dba24537 AC |
4108 | |
4109 | sigemptyset (pending); | |
4110 | sigemptyset (blocked); | |
4111 | sigemptyset (ignored); | |
cde33bf1 | 4112 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
614c279d | 4113 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4114 | if (procfile == NULL) |
8a3fe4f8 | 4115 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4116 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4117 | |
d8d2a3ee | 4118 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4119 | { |
4120 | /* Normal queued signals are on the SigPnd line in the status | |
4121 | file. However, 2.6 kernels also have a "shared" pending | |
4122 | queue for delivering signals to a thread group, so check for | |
4123 | a ShdPnd line also. | |
4124 | ||
4125 | Unfortunately some Red Hat kernels include the shared pending | |
4126 | queue but not the ShdPnd status field. */ | |
4127 | ||
4128 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4129 | add_line_to_sigset (buffer + 8, pending); | |
4130 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4131 | add_line_to_sigset (buffer + 8, pending); | |
4132 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4133 | add_line_to_sigset (buffer + 8, blocked); | |
4134 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4135 | add_line_to_sigset (buffer + 8, ignored); | |
4136 | } | |
4137 | ||
7c8a8b04 | 4138 | do_cleanups (cleanup); |
dba24537 AC |
4139 | } |
4140 | ||
9b409511 | 4141 | static enum target_xfer_status |
07e059b5 | 4142 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
e0881a8e | 4143 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4144 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4145 | ULONGEST *xfered_len) | |
07e059b5 | 4146 | { |
07e059b5 VP |
4147 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4148 | ||
9b409511 YQ |
4149 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4150 | if (*xfered_len == 0) | |
4151 | return TARGET_XFER_EOF; | |
4152 | else | |
4153 | return TARGET_XFER_OK; | |
07e059b5 VP |
4154 | } |
4155 | ||
9b409511 | 4156 | static enum target_xfer_status |
10d6c8cd DJ |
4157 | linux_xfer_partial (struct target_ops *ops, enum target_object object, |
4158 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
4159 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4160 | ULONGEST *xfered_len) | |
10d6c8cd | 4161 | { |
9b409511 | 4162 | enum target_xfer_status xfer; |
10d6c8cd DJ |
4163 | |
4164 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4165 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
9b409511 | 4166 | offset, len, xfered_len); |
10d6c8cd | 4167 | |
07e059b5 VP |
4168 | if (object == TARGET_OBJECT_OSDATA) |
4169 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4170 | offset, len, xfered_len); |
07e059b5 | 4171 | |
efcbbd14 UW |
4172 | if (object == TARGET_OBJECT_SPU) |
4173 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4174 | offset, len, xfered_len); |
efcbbd14 | 4175 | |
8f313923 JK |
4176 | /* GDB calculates all the addresses in possibly larget width of the address. |
4177 | Address width needs to be masked before its final use - either by | |
4178 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4179 | ||
4180 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4181 | ||
4182 | if (object == TARGET_OBJECT_MEMORY) | |
4183 | { | |
f5656ead | 4184 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4185 | |
4186 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4187 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4188 | } | |
4189 | ||
10d6c8cd | 4190 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 YQ |
4191 | offset, len, xfered_len); |
4192 | if (xfer != TARGET_XFER_EOF) | |
10d6c8cd DJ |
4193 | return xfer; |
4194 | ||
4195 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4196 | offset, len, xfered_len); |
10d6c8cd DJ |
4197 | } |
4198 | ||
5808517f YQ |
4199 | static void |
4200 | cleanup_target_stop (void *arg) | |
4201 | { | |
4202 | ptid_t *ptid = (ptid_t *) arg; | |
4203 | ||
4204 | gdb_assert (arg != NULL); | |
4205 | ||
4206 | /* Unpause all */ | |
a493e3e2 | 4207 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4208 | } |
4209 | ||
4210 | static VEC(static_tracepoint_marker_p) * | |
c686c57f TT |
4211 | linux_child_static_tracepoint_markers_by_strid (struct target_ops *self, |
4212 | const char *strid) | |
5808517f YQ |
4213 | { |
4214 | char s[IPA_CMD_BUF_SIZE]; | |
4215 | struct cleanup *old_chain; | |
4216 | int pid = ptid_get_pid (inferior_ptid); | |
4217 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4218 | struct static_tracepoint_marker *marker = NULL; | |
4219 | char *p = s; | |
4220 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4221 | ||
4222 | /* Pause all */ | |
4223 | target_stop (ptid); | |
4224 | ||
4225 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4226 | s[sizeof ("qTfSTM")] = 0; | |
4227 | ||
42476b70 | 4228 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4229 | |
4230 | old_chain = make_cleanup (free_current_marker, &marker); | |
4231 | make_cleanup (cleanup_target_stop, &ptid); | |
4232 | ||
4233 | while (*p++ == 'm') | |
4234 | { | |
4235 | if (marker == NULL) | |
4236 | marker = XCNEW (struct static_tracepoint_marker); | |
4237 | ||
4238 | do | |
4239 | { | |
4240 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4241 | ||
4242 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4243 | { | |
4244 | VEC_safe_push (static_tracepoint_marker_p, | |
4245 | markers, marker); | |
4246 | marker = NULL; | |
4247 | } | |
4248 | else | |
4249 | { | |
4250 | release_static_tracepoint_marker (marker); | |
4251 | memset (marker, 0, sizeof (*marker)); | |
4252 | } | |
4253 | } | |
4254 | while (*p++ == ','); /* comma-separated list */ | |
4255 | ||
4256 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4257 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4258 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4259 | p = s; |
4260 | } | |
4261 | ||
4262 | do_cleanups (old_chain); | |
4263 | ||
4264 | return markers; | |
4265 | } | |
4266 | ||
e9efe249 | 4267 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4268 | it with local methods. */ |
4269 | ||
910122bf UW |
4270 | static void |
4271 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4272 | { |
6d8fd2b7 | 4273 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4274 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4275 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4276 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4277 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4278 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4279 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4280 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4281 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4282 | t->to_post_attach = linux_child_post_attach; |
4283 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4284 | |
4285 | super_xfer_partial = t->to_xfer_partial; | |
4286 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4287 | |
4288 | t->to_static_tracepoint_markers_by_strid | |
4289 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4290 | } |
4291 | ||
4292 | struct target_ops * | |
4293 | linux_target (void) | |
4294 | { | |
4295 | struct target_ops *t; | |
4296 | ||
4297 | t = inf_ptrace_target (); | |
4298 | linux_target_install_ops (t); | |
4299 | ||
4300 | return t; | |
4301 | } | |
4302 | ||
4303 | struct target_ops * | |
7714d83a | 4304 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4305 | { |
4306 | struct target_ops *t; | |
4307 | ||
4308 | t = inf_ptrace_trad_target (register_u_offset); | |
4309 | linux_target_install_ops (t); | |
10d6c8cd | 4310 | |
10d6c8cd DJ |
4311 | return t; |
4312 | } | |
4313 | ||
b84876c2 PA |
4314 | /* target_is_async_p implementation. */ |
4315 | ||
4316 | static int | |
6a109b6b | 4317 | linux_nat_is_async_p (struct target_ops *ops) |
b84876c2 | 4318 | { |
198297aa | 4319 | return linux_is_async_p (); |
b84876c2 PA |
4320 | } |
4321 | ||
4322 | /* target_can_async_p implementation. */ | |
4323 | ||
4324 | static int | |
6a109b6b | 4325 | linux_nat_can_async_p (struct target_ops *ops) |
b84876c2 PA |
4326 | { |
4327 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4328 | it explicitly with the "set target-async" command. |
b84876c2 | 4329 | Someday, linux will always be async. */ |
3dd5b83d | 4330 | return target_async_permitted; |
b84876c2 PA |
4331 | } |
4332 | ||
9908b566 | 4333 | static int |
2a9a2795 | 4334 | linux_nat_supports_non_stop (struct target_ops *self) |
9908b566 VP |
4335 | { |
4336 | return 1; | |
4337 | } | |
4338 | ||
d90e17a7 PA |
4339 | /* True if we want to support multi-process. To be removed when GDB |
4340 | supports multi-exec. */ | |
4341 | ||
2277426b | 4342 | int linux_multi_process = 1; |
d90e17a7 PA |
4343 | |
4344 | static int | |
86ce2668 | 4345 | linux_nat_supports_multi_process (struct target_ops *self) |
d90e17a7 PA |
4346 | { |
4347 | return linux_multi_process; | |
4348 | } | |
4349 | ||
03583c20 | 4350 | static int |
2bfc0540 | 4351 | linux_nat_supports_disable_randomization (struct target_ops *self) |
03583c20 UW |
4352 | { |
4353 | #ifdef HAVE_PERSONALITY | |
4354 | return 1; | |
4355 | #else | |
4356 | return 0; | |
4357 | #endif | |
4358 | } | |
4359 | ||
b84876c2 PA |
4360 | static int async_terminal_is_ours = 1; |
4361 | ||
4d4ca2a1 DE |
4362 | /* target_terminal_inferior implementation. |
4363 | ||
4364 | This is a wrapper around child_terminal_inferior to add async support. */ | |
b84876c2 PA |
4365 | |
4366 | static void | |
d2f640d4 | 4367 | linux_nat_terminal_inferior (struct target_ops *self) |
b84876c2 | 4368 | { |
198297aa PA |
4369 | /* Like target_terminal_inferior, use target_can_async_p, not |
4370 | target_is_async_p, since at this point the target is not async | |
4371 | yet. If it can async, then we know it will become async prior to | |
4372 | resume. */ | |
4373 | if (!target_can_async_p ()) | |
b84876c2 PA |
4374 | { |
4375 | /* Async mode is disabled. */ | |
d6b64346 | 4376 | child_terminal_inferior (self); |
b84876c2 PA |
4377 | return; |
4378 | } | |
4379 | ||
d6b64346 | 4380 | child_terminal_inferior (self); |
b84876c2 | 4381 | |
d9d2d8b6 | 4382 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4383 | if (!async_terminal_is_ours) |
4384 | return; | |
4385 | ||
4386 | delete_file_handler (input_fd); | |
4387 | async_terminal_is_ours = 0; | |
4388 | set_sigint_trap (); | |
4389 | } | |
4390 | ||
4d4ca2a1 DE |
4391 | /* target_terminal_ours implementation. |
4392 | ||
4393 | This is a wrapper around child_terminal_ours to add async support (and | |
4394 | implement the target_terminal_ours vs target_terminal_ours_for_output | |
4395 | distinction). child_terminal_ours is currently no different than | |
4396 | child_terminal_ours_for_output. | |
4397 | We leave target_terminal_ours_for_output alone, leaving it to | |
4398 | child_terminal_ours_for_output. */ | |
b84876c2 | 4399 | |
2c0b251b | 4400 | static void |
e3594fd1 | 4401 | linux_nat_terminal_ours (struct target_ops *self) |
b84876c2 | 4402 | { |
b84876c2 PA |
4403 | /* GDB should never give the terminal to the inferior if the |
4404 | inferior is running in the background (run&, continue&, etc.), | |
4405 | but claiming it sure should. */ | |
d6b64346 | 4406 | child_terminal_ours (self); |
b84876c2 | 4407 | |
b84876c2 PA |
4408 | if (async_terminal_is_ours) |
4409 | return; | |
4410 | ||
4411 | clear_sigint_trap (); | |
4412 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4413 | async_terminal_is_ours = 1; | |
4414 | } | |
4415 | ||
4416 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4417 | void *context); | |
4418 | static void *async_client_context; | |
4419 | ||
7feb7d06 PA |
4420 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4421 | so we notice when any child changes state, and notify the | |
4422 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4423 | above to wait for the arrival of a SIGCHLD. */ | |
4424 | ||
b84876c2 | 4425 | static void |
7feb7d06 | 4426 | sigchld_handler (int signo) |
b84876c2 | 4427 | { |
7feb7d06 PA |
4428 | int old_errno = errno; |
4429 | ||
01124a23 DE |
4430 | if (debug_linux_nat) |
4431 | ui_file_write_async_safe (gdb_stdlog, | |
4432 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4433 | |
4434 | if (signo == SIGCHLD | |
4435 | && linux_nat_event_pipe[0] != -1) | |
4436 | async_file_mark (); /* Let the event loop know that there are | |
4437 | events to handle. */ | |
4438 | ||
4439 | errno = old_errno; | |
4440 | } | |
4441 | ||
4442 | /* Callback registered with the target events file descriptor. */ | |
4443 | ||
4444 | static void | |
4445 | handle_target_event (int error, gdb_client_data client_data) | |
4446 | { | |
4447 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4448 | } | |
4449 | ||
4450 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4451 | ||
4452 | static int | |
4453 | linux_async_pipe (int enable) | |
4454 | { | |
198297aa | 4455 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4456 | |
4457 | if (previous != enable) | |
4458 | { | |
4459 | sigset_t prev_mask; | |
4460 | ||
12696c10 PA |
4461 | /* Block child signals while we create/destroy the pipe, as |
4462 | their handler writes to it. */ | |
7feb7d06 PA |
4463 | block_child_signals (&prev_mask); |
4464 | ||
4465 | if (enable) | |
4466 | { | |
614c279d | 4467 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4468 | internal_error (__FILE__, __LINE__, |
4469 | "creating event pipe failed."); | |
4470 | ||
4471 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4472 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4473 | } | |
4474 | else | |
4475 | { | |
4476 | close (linux_nat_event_pipe[0]); | |
4477 | close (linux_nat_event_pipe[1]); | |
4478 | linux_nat_event_pipe[0] = -1; | |
4479 | linux_nat_event_pipe[1] = -1; | |
4480 | } | |
4481 | ||
4482 | restore_child_signals_mask (&prev_mask); | |
4483 | } | |
4484 | ||
4485 | return previous; | |
b84876c2 PA |
4486 | } |
4487 | ||
4488 | /* target_async implementation. */ | |
4489 | ||
4490 | static void | |
6a109b6b TT |
4491 | linux_nat_async (struct target_ops *ops, |
4492 | void (*callback) (enum inferior_event_type event_type, | |
4493 | void *context), | |
4494 | void *context) | |
b84876c2 | 4495 | { |
b84876c2 PA |
4496 | if (callback != NULL) |
4497 | { | |
4498 | async_client_callback = callback; | |
4499 | async_client_context = context; | |
7feb7d06 PA |
4500 | if (!linux_async_pipe (1)) |
4501 | { | |
4502 | add_file_handler (linux_nat_event_pipe[0], | |
4503 | handle_target_event, NULL); | |
4504 | /* There may be pending events to handle. Tell the event loop | |
4505 | to poll them. */ | |
4506 | async_file_mark (); | |
4507 | } | |
b84876c2 PA |
4508 | } |
4509 | else | |
4510 | { | |
4511 | async_client_callback = callback; | |
4512 | async_client_context = context; | |
b84876c2 | 4513 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4514 | linux_async_pipe (0); |
b84876c2 PA |
4515 | } |
4516 | return; | |
4517 | } | |
4518 | ||
a493e3e2 | 4519 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4520 | event came out. */ |
4521 | ||
4c28f408 | 4522 | static int |
252fbfc8 | 4523 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4524 | { |
d90e17a7 | 4525 | if (!lwp->stopped) |
252fbfc8 | 4526 | { |
d90e17a7 PA |
4527 | if (debug_linux_nat) |
4528 | fprintf_unfiltered (gdb_stdlog, | |
4529 | "LNSL: running -> suspending %s\n", | |
4530 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4531 | |
252fbfc8 | 4532 | |
25289eb2 PA |
4533 | if (lwp->last_resume_kind == resume_stop) |
4534 | { | |
4535 | if (debug_linux_nat) | |
4536 | fprintf_unfiltered (gdb_stdlog, | |
4537 | "linux-nat: already stopping LWP %ld at " | |
4538 | "GDB's request\n", | |
4539 | ptid_get_lwp (lwp->ptid)); | |
4540 | return 0; | |
4541 | } | |
252fbfc8 | 4542 | |
25289eb2 PA |
4543 | stop_callback (lwp, NULL); |
4544 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4545 | } |
4546 | else | |
4547 | { | |
4548 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4549 | |
d90e17a7 PA |
4550 | if (debug_linux_nat) |
4551 | { | |
e09875d4 | 4552 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4553 | fprintf_unfiltered (gdb_stdlog, |
4554 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4555 | target_pid_to_str (lwp->ptid)); |
4556 | else | |
3e43a32a MS |
4557 | fprintf_unfiltered (gdb_stdlog, |
4558 | "LNSL: already stopped/no " | |
4559 | "stop_requested yet %s\n", | |
d90e17a7 | 4560 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4561 | } |
4562 | } | |
4c28f408 PA |
4563 | return 0; |
4564 | } | |
4565 | ||
4566 | static void | |
1eab8a48 | 4567 | linux_nat_stop (struct target_ops *self, ptid_t ptid) |
4c28f408 PA |
4568 | { |
4569 | if (non_stop) | |
d90e17a7 | 4570 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 | 4571 | else |
1eab8a48 | 4572 | linux_ops->to_stop (linux_ops, ptid); |
4c28f408 PA |
4573 | } |
4574 | ||
d90e17a7 | 4575 | static void |
de90e03d | 4576 | linux_nat_close (struct target_ops *self) |
d90e17a7 PA |
4577 | { |
4578 | /* Unregister from the event loop. */ | |
9debeba0 DE |
4579 | if (linux_nat_is_async_p (self)) |
4580 | linux_nat_async (self, NULL, NULL); | |
d90e17a7 | 4581 | |
d90e17a7 | 4582 | if (linux_ops->to_close) |
de90e03d | 4583 | linux_ops->to_close (linux_ops); |
6a3cb8e8 PA |
4584 | |
4585 | super_close (self); | |
d90e17a7 PA |
4586 | } |
4587 | ||
c0694254 PA |
4588 | /* When requests are passed down from the linux-nat layer to the |
4589 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4590 | used. The address space pointer is stored in the inferior object, | |
4591 | but the common code that is passed such ptid can't tell whether | |
4592 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4593 | look up the "main" process id from the lwp here. */ | |
4594 | ||
70221824 | 4595 | static struct address_space * |
c0694254 PA |
4596 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4597 | { | |
4598 | struct lwp_info *lwp; | |
4599 | struct inferior *inf; | |
4600 | int pid; | |
4601 | ||
dfd4cc63 | 4602 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4603 | { |
4604 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4605 | tgid. */ | |
4606 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4607 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4608 | } |
4609 | else | |
4610 | { | |
4611 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4612 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4613 | } |
4614 | ||
4615 | inf = find_inferior_pid (pid); | |
4616 | gdb_assert (inf != NULL); | |
4617 | return inf->aspace; | |
4618 | } | |
4619 | ||
dc146f7c VP |
4620 | /* Return the cached value of the processor core for thread PTID. */ |
4621 | ||
70221824 | 4622 | static int |
dc146f7c VP |
4623 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4624 | { | |
4625 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4626 | |
dc146f7c VP |
4627 | if (info) |
4628 | return info->core; | |
4629 | return -1; | |
4630 | } | |
4631 | ||
f973ed9c DJ |
4632 | void |
4633 | linux_nat_add_target (struct target_ops *t) | |
4634 | { | |
f973ed9c DJ |
4635 | /* Save the provided single-threaded target. We save this in a separate |
4636 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4637 | may have saved a pointer to T; we want to use it for the final | |
4638 | process stratum target. */ | |
4639 | linux_ops_saved = *t; | |
4640 | linux_ops = &linux_ops_saved; | |
4641 | ||
4642 | /* Override some methods for multithreading. */ | |
b84876c2 | 4643 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4644 | t->to_attach = linux_nat_attach; |
4645 | t->to_detach = linux_nat_detach; | |
4646 | t->to_resume = linux_nat_resume; | |
4647 | t->to_wait = linux_nat_wait; | |
2455069d | 4648 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4649 | t->to_xfer_partial = linux_nat_xfer_partial; |
4650 | t->to_kill = linux_nat_kill; | |
4651 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4652 | t->to_thread_alive = linux_nat_thread_alive; | |
4653 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4654 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4655 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4656 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4657 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4658 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 4659 | |
b84876c2 PA |
4660 | t->to_can_async_p = linux_nat_can_async_p; |
4661 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4662 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4663 | t->to_async = linux_nat_async; |
b84876c2 PA |
4664 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4665 | t->to_terminal_ours = linux_nat_terminal_ours; | |
6a3cb8e8 PA |
4666 | |
4667 | super_close = t->to_close; | |
d90e17a7 | 4668 | t->to_close = linux_nat_close; |
b84876c2 | 4669 | |
4c28f408 PA |
4670 | /* Methods for non-stop support. */ |
4671 | t->to_stop = linux_nat_stop; | |
4672 | ||
d90e17a7 PA |
4673 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4674 | ||
03583c20 UW |
4675 | t->to_supports_disable_randomization |
4676 | = linux_nat_supports_disable_randomization; | |
4677 | ||
dc146f7c VP |
4678 | t->to_core_of_thread = linux_nat_core_of_thread; |
4679 | ||
f973ed9c DJ |
4680 | /* We don't change the stratum; this target will sit at |
4681 | process_stratum and thread_db will set at thread_stratum. This | |
4682 | is a little strange, since this is a multi-threaded-capable | |
4683 | target, but we want to be on the stack below thread_db, and we | |
4684 | also want to be used for single-threaded processes. */ | |
4685 | ||
4686 | add_target (t); | |
f973ed9c DJ |
4687 | } |
4688 | ||
9f0bdab8 DJ |
4689 | /* Register a method to call whenever a new thread is attached. */ |
4690 | void | |
7b50312a PA |
4691 | linux_nat_set_new_thread (struct target_ops *t, |
4692 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4693 | { |
4694 | /* Save the pointer. We only support a single registered instance | |
4695 | of the GNU/Linux native target, so we do not need to map this to | |
4696 | T. */ | |
4697 | linux_nat_new_thread = new_thread; | |
4698 | } | |
4699 | ||
26cb8b7c PA |
4700 | /* See declaration in linux-nat.h. */ |
4701 | ||
4702 | void | |
4703 | linux_nat_set_new_fork (struct target_ops *t, | |
4704 | linux_nat_new_fork_ftype *new_fork) | |
4705 | { | |
4706 | /* Save the pointer. */ | |
4707 | linux_nat_new_fork = new_fork; | |
4708 | } | |
4709 | ||
4710 | /* See declaration in linux-nat.h. */ | |
4711 | ||
4712 | void | |
4713 | linux_nat_set_forget_process (struct target_ops *t, | |
4714 | linux_nat_forget_process_ftype *fn) | |
4715 | { | |
4716 | /* Save the pointer. */ | |
4717 | linux_nat_forget_process_hook = fn; | |
4718 | } | |
4719 | ||
4720 | /* See declaration in linux-nat.h. */ | |
4721 | ||
4722 | void | |
4723 | linux_nat_forget_process (pid_t pid) | |
4724 | { | |
4725 | if (linux_nat_forget_process_hook != NULL) | |
4726 | linux_nat_forget_process_hook (pid); | |
4727 | } | |
4728 | ||
5b009018 PA |
4729 | /* Register a method that converts a siginfo object between the layout |
4730 | that ptrace returns, and the layout in the architecture of the | |
4731 | inferior. */ | |
4732 | void | |
4733 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4734 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4735 | gdb_byte *, |
4736 | int)) | |
4737 | { | |
4738 | /* Save the pointer. */ | |
4739 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4740 | } | |
4741 | ||
7b50312a PA |
4742 | /* Register a method to call prior to resuming a thread. */ |
4743 | ||
4744 | void | |
4745 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4746 | void (*prepare_to_resume) (struct lwp_info *)) | |
4747 | { | |
4748 | /* Save the pointer. */ | |
4749 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4750 | } | |
4751 | ||
f865ee35 JK |
4752 | /* See linux-nat.h. */ |
4753 | ||
4754 | int | |
4755 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4756 | { |
da559b09 | 4757 | int pid; |
9f0bdab8 | 4758 | |
dfd4cc63 | 4759 | pid = ptid_get_lwp (ptid); |
da559b09 | 4760 | if (pid == 0) |
dfd4cc63 | 4761 | pid = ptid_get_pid (ptid); |
f865ee35 | 4762 | |
da559b09 JK |
4763 | errno = 0; |
4764 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4765 | if (errno != 0) | |
4766 | { | |
4767 | memset (siginfo, 0, sizeof (*siginfo)); | |
4768 | return 0; | |
4769 | } | |
f865ee35 | 4770 | return 1; |
9f0bdab8 DJ |
4771 | } |
4772 | ||
2c0b251b PA |
4773 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4774 | extern initialize_file_ftype _initialize_linux_nat; | |
4775 | ||
d6b0e80f AC |
4776 | void |
4777 | _initialize_linux_nat (void) | |
4778 | { | |
ccce17b0 YQ |
4779 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4780 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4781 | Set debugging of GNU/Linux lwp module."), _("\ |
4782 | Show debugging of GNU/Linux lwp module."), _("\ | |
4783 | Enables printf debugging output."), | |
ccce17b0 YQ |
4784 | NULL, |
4785 | show_debug_linux_nat, | |
4786 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4787 | |
b84876c2 | 4788 | /* Save this mask as the default. */ |
d6b0e80f AC |
4789 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4790 | ||
7feb7d06 PA |
4791 | /* Install a SIGCHLD handler. */ |
4792 | sigchld_action.sa_handler = sigchld_handler; | |
4793 | sigemptyset (&sigchld_action.sa_mask); | |
4794 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4795 | |
4796 | /* Make it the default. */ | |
7feb7d06 | 4797 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4798 | |
4799 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4800 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4801 | sigdelset (&suspend_mask, SIGCHLD); | |
4802 | ||
7feb7d06 | 4803 | sigemptyset (&blocked_mask); |
8009206a TT |
4804 | |
4805 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to | |
4806 | support read-only process state. */ | |
4807 | linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD | |
4808 | | PTRACE_O_TRACEVFORKDONE | |
4809 | | PTRACE_O_TRACEVFORK | |
4810 | | PTRACE_O_TRACEFORK | |
4811 | | PTRACE_O_TRACEEXEC); | |
d6b0e80f AC |
4812 | } |
4813 | \f | |
4814 | ||
4815 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4816 | the GNU/Linux Threads library and therefore doesn't really belong | |
4817 | here. */ | |
4818 | ||
4819 | /* Read variable NAME in the target and return its value if found. | |
4820 | Otherwise return zero. It is assumed that the type of the variable | |
4821 | is `int'. */ | |
4822 | ||
4823 | static int | |
4824 | get_signo (const char *name) | |
4825 | { | |
3b7344d5 | 4826 | struct bound_minimal_symbol ms; |
d6b0e80f AC |
4827 | int signo; |
4828 | ||
4829 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
3b7344d5 | 4830 | if (ms.minsym == NULL) |
d6b0e80f AC |
4831 | return 0; |
4832 | ||
77e371c0 | 4833 | if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
4834 | sizeof (signo)) != 0) |
4835 | return 0; | |
4836 | ||
4837 | return signo; | |
4838 | } | |
4839 | ||
4840 | /* Return the set of signals used by the threads library in *SET. */ | |
4841 | ||
4842 | void | |
4843 | lin_thread_get_thread_signals (sigset_t *set) | |
4844 | { | |
4845 | struct sigaction action; | |
4846 | int restart, cancel; | |
4847 | ||
b84876c2 | 4848 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
4849 | sigemptyset (set); |
4850 | ||
4851 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
4852 | cancel = get_signo ("__pthread_sig_cancel"); |
4853 | ||
4854 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
4855 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
4856 | not provide any way for the debugger to query the signal numbers - | |
4857 | fortunately they don't change! */ | |
4858 | ||
d6b0e80f | 4859 | if (restart == 0) |
17fbb0bd | 4860 | restart = __SIGRTMIN; |
d6b0e80f | 4861 | |
d6b0e80f | 4862 | if (cancel == 0) |
17fbb0bd | 4863 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
4864 | |
4865 | sigaddset (set, restart); | |
4866 | sigaddset (set, cancel); | |
4867 | ||
4868 | /* The GNU/Linux Threads library makes terminating threads send a | |
4869 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
4870 | those (to prevent them from terminating GDB itself, which is | |
4871 | likely to be their default action) and treat them the same way as | |
4872 | SIGCHLD. */ | |
4873 | ||
4874 | action.sa_handler = sigchld_handler; | |
4875 | sigemptyset (&action.sa_mask); | |
58aecb61 | 4876 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
4877 | sigaction (cancel, &action, NULL); |
4878 | ||
4879 | /* We block the "cancel" signal throughout this code ... */ | |
4880 | sigaddset (&blocked_mask, cancel); | |
4881 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
4882 | ||
4883 | /* ... except during a sigsuspend. */ | |
4884 | sigdelset (&suspend_mask, cancel); | |
4885 | } |