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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" | |
ac264b3b | 35 | #include "linux-fork.h" |
d6b0e80f AC |
36 | #include "gdbthread.h" |
37 | #include "gdbcmd.h" | |
38 | #include "regcache.h" | |
4f844a66 | 39 | #include "regset.h" |
dab06dbe | 40 | #include "inf-child.h" |
10d6c8cd DJ |
41 | #include "inf-ptrace.h" |
42 | #include "auxv.h" | |
1777feb0 | 43 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
44 | #include "elf-bfd.h" /* for elfcore_write_* */ |
45 | #include "gregset.h" /* for gregset */ | |
46 | #include "gdbcore.h" /* for get_exec_file */ | |
47 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 48 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 49 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 PA |
50 | #include "inf-loop.h" |
51 | #include "event-loop.h" | |
52 | #include "event-top.h" | |
07e059b5 VP |
53 | #include <pwd.h> |
54 | #include <sys/types.h> | |
2978b111 | 55 | #include <dirent.h> |
07e059b5 | 56 | #include "xml-support.h" |
efcbbd14 | 57 | #include <sys/vfs.h> |
6c95b8df | 58 | #include "solib.h" |
125f8a3d | 59 | #include "nat/linux-osdata.h" |
6432734d | 60 | #include "linux-tdep.h" |
7dcd53a0 | 61 | #include "symfile.h" |
5808517f YQ |
62 | #include "agent.h" |
63 | #include "tracepoint.h" | |
87b0bb13 | 64 | #include "buffer.h" |
6ecd4729 | 65 | #include "target-descriptions.h" |
614c279d | 66 | #include "filestuff.h" |
77e371c0 | 67 | #include "objfiles.h" |
efcbbd14 UW |
68 | |
69 | #ifndef SPUFS_MAGIC | |
70 | #define SPUFS_MAGIC 0x23c9b64e | |
71 | #endif | |
dba24537 | 72 | |
10568435 JK |
73 | #ifdef HAVE_PERSONALITY |
74 | # include <sys/personality.h> | |
75 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
76 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
77 | # endif | |
78 | #endif /* HAVE_PERSONALITY */ | |
79 | ||
1777feb0 | 80 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
81 | |
82 | Waiting for events in sync mode | |
83 | =============================== | |
84 | ||
85 | When waiting for an event in a specific thread, we just use waitpid, passing | |
86 | the specific pid, and not passing WNOHANG. | |
87 | ||
1777feb0 | 88 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 89 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 90 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
91 | miss an event. The solution is to use non-blocking waitpid, together with |
92 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 93 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
94 | flag to check for events in cloned processes. If nothing is found, we use |
95 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
96 | happened to a child process -- and SIGCHLD will be delivered both for events | |
97 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
98 | an event, we get back to calling nonblocking waitpid with and without |
99 | __WCLONED. | |
8a77dff3 VP |
100 | |
101 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 102 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
103 | blocked, the signal becomes pending and sigsuspend immediately |
104 | notices it and returns. | |
105 | ||
106 | Waiting for events in async mode | |
107 | ================================ | |
108 | ||
7feb7d06 PA |
109 | In async mode, GDB should always be ready to handle both user input |
110 | and target events, so neither blocking waitpid nor sigsuspend are | |
111 | viable options. Instead, we should asynchronously notify the GDB main | |
112 | event loop whenever there's an unprocessed event from the target. We | |
113 | detect asynchronous target events by handling SIGCHLD signals. To | |
114 | notify the event loop about target events, the self-pipe trick is used | |
115 | --- a pipe is registered as waitable event source in the event loop, | |
116 | the event loop select/poll's on the read end of this pipe (as well on | |
117 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
118 | byte to this pipe. This is more portable than relying on | |
119 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
120 | emulates them with select/poll+sigprocmask, and that is racy | |
121 | (a.k.a. plain broken). | |
122 | ||
123 | Obviously, if we fail to notify the event loop if there's a target | |
124 | event, it's bad. OTOH, if we notify the event loop when there's no | |
125 | event from the target, linux_nat_wait will detect that there's no real | |
126 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
127 | This is mostly harmless, but it will waste time and is better avoided. | |
128 | ||
129 | The main design point is that every time GDB is outside linux-nat.c, | |
130 | we have a SIGCHLD handler installed that is called when something | |
131 | happens to the target and notifies the GDB event loop. Whenever GDB | |
132 | core decides to handle the event, and calls into linux-nat.c, we | |
133 | process things as in sync mode, except that the we never block in | |
134 | sigsuspend. | |
135 | ||
136 | While processing an event, we may end up momentarily blocked in | |
137 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
138 | return quickly. E.g., in all-stop mode, before reporting to the core | |
139 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
140 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
141 | Note that this is different from blocking indefinitely waiting for the | |
142 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
143 | |
144 | Use of signals | |
145 | ============== | |
146 | ||
147 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
148 | signal is not entirely significant; we just need for a signal to be delivered, | |
149 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
150 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
151 | be queued once; we do not keep track of other sources of SIGSTOP. | |
152 | ||
153 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
154 | use them, because they have special behavior when the signal is generated - | |
155 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
156 | kills the entire thread group. | |
157 | ||
158 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
159 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
160 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
161 | ||
162 | We could use a real-time signal instead. This would solve those problems; we | |
163 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
164 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
165 | generates it, and there are races with trying to find a signal that is not | |
166 | blocked. */ | |
a0ef4274 | 167 | |
dba24537 AC |
168 | #ifndef O_LARGEFILE |
169 | #define O_LARGEFILE 0 | |
170 | #endif | |
0274a8ce | 171 | |
10d6c8cd DJ |
172 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
173 | the use of the multi-threaded target. */ | |
174 | static struct target_ops *linux_ops; | |
f973ed9c | 175 | static struct target_ops linux_ops_saved; |
10d6c8cd | 176 | |
9f0bdab8 | 177 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
178 | static void (*linux_nat_new_thread) (struct lwp_info *); |
179 | ||
26cb8b7c PA |
180 | /* The method to call, if any, when a new fork is attached. */ |
181 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
182 | ||
183 | /* The method to call, if any, when a process is no longer | |
184 | attached. */ | |
185 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
186 | ||
7b50312a PA |
187 | /* Hook to call prior to resuming a thread. */ |
188 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 189 | |
5b009018 PA |
190 | /* The method to call, if any, when the siginfo object needs to be |
191 | converted between the layout returned by ptrace, and the layout in | |
192 | the architecture of the inferior. */ | |
a5362b9a | 193 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
194 | gdb_byte *, |
195 | int); | |
196 | ||
ac264b3b MS |
197 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
198 | Called by our to_xfer_partial. */ | |
4ac248ca | 199 | static target_xfer_partial_ftype *super_xfer_partial; |
10d6c8cd | 200 | |
6a3cb8e8 PA |
201 | /* The saved to_close method, inherited from inf-ptrace.c. |
202 | Called by our to_close. */ | |
203 | static void (*super_close) (struct target_ops *); | |
204 | ||
ccce17b0 | 205 | static unsigned int debug_linux_nat; |
920d2a44 AC |
206 | static void |
207 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
208 | struct cmd_list_element *c, const char *value) | |
209 | { | |
210 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
211 | value); | |
212 | } | |
d6b0e80f | 213 | |
ae087d01 DJ |
214 | struct simple_pid_list |
215 | { | |
216 | int pid; | |
3d799a95 | 217 | int status; |
ae087d01 DJ |
218 | struct simple_pid_list *next; |
219 | }; | |
220 | struct simple_pid_list *stopped_pids; | |
221 | ||
3dd5b83d PA |
222 | /* Async mode support. */ |
223 | ||
b84876c2 PA |
224 | /* The read/write ends of the pipe registered as waitable file in the |
225 | event loop. */ | |
226 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
227 | ||
7feb7d06 | 228 | /* Flush the event pipe. */ |
b84876c2 | 229 | |
7feb7d06 PA |
230 | static void |
231 | async_file_flush (void) | |
b84876c2 | 232 | { |
7feb7d06 PA |
233 | int ret; |
234 | char buf; | |
b84876c2 | 235 | |
7feb7d06 | 236 | do |
b84876c2 | 237 | { |
7feb7d06 | 238 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 239 | } |
7feb7d06 | 240 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
241 | } |
242 | ||
7feb7d06 PA |
243 | /* Put something (anything, doesn't matter what, or how much) in event |
244 | pipe, so that the select/poll in the event-loop realizes we have | |
245 | something to process. */ | |
252fbfc8 | 246 | |
b84876c2 | 247 | static void |
7feb7d06 | 248 | async_file_mark (void) |
b84876c2 | 249 | { |
7feb7d06 | 250 | int ret; |
b84876c2 | 251 | |
7feb7d06 PA |
252 | /* It doesn't really matter what the pipe contains, as long we end |
253 | up with something in it. Might as well flush the previous | |
254 | left-overs. */ | |
255 | async_file_flush (); | |
b84876c2 | 256 | |
7feb7d06 | 257 | do |
b84876c2 | 258 | { |
7feb7d06 | 259 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 260 | } |
7feb7d06 | 261 | while (ret == -1 && errno == EINTR); |
b84876c2 | 262 | |
7feb7d06 PA |
263 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
264 | be awakened anyway. */ | |
b84876c2 PA |
265 | } |
266 | ||
7feb7d06 PA |
267 | static int kill_lwp (int lwpid, int signo); |
268 | ||
269 | static int stop_callback (struct lwp_info *lp, void *data); | |
270 | ||
271 | static void block_child_signals (sigset_t *prev_mask); | |
272 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
273 | |
274 | struct lwp_info; | |
275 | static struct lwp_info *add_lwp (ptid_t ptid); | |
276 | static void purge_lwp_list (int pid); | |
4403d8e9 | 277 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
278 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
279 | ||
ae087d01 DJ |
280 | \f |
281 | /* Trivial list manipulation functions to keep track of a list of | |
282 | new stopped processes. */ | |
283 | static void | |
3d799a95 | 284 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
285 | { |
286 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 287 | |
ae087d01 | 288 | new_pid->pid = pid; |
3d799a95 | 289 | new_pid->status = status; |
ae087d01 DJ |
290 | new_pid->next = *listp; |
291 | *listp = new_pid; | |
292 | } | |
293 | ||
84636d28 PA |
294 | static int |
295 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
296 | { | |
297 | struct simple_pid_list *p; | |
298 | ||
299 | for (p = list; p != NULL; p = p->next) | |
300 | if (p->pid == pid) | |
301 | return 1; | |
302 | return 0; | |
303 | } | |
304 | ||
ae087d01 | 305 | static int |
46a96992 | 306 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
307 | { |
308 | struct simple_pid_list **p; | |
309 | ||
310 | for (p = listp; *p != NULL; p = &(*p)->next) | |
311 | if ((*p)->pid == pid) | |
312 | { | |
313 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 314 | |
46a96992 | 315 | *statusp = (*p)->status; |
ae087d01 DJ |
316 | xfree (*p); |
317 | *p = next; | |
318 | return 1; | |
319 | } | |
320 | return 0; | |
321 | } | |
322 | ||
96d7229d | 323 | /* Initialize ptrace warnings and check for supported ptrace |
beed38b8 JB |
324 | features given PID. |
325 | ||
326 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
327 | |
328 | static void | |
beed38b8 | 329 | linux_init_ptrace (pid_t pid, int attached) |
3993f6b1 | 330 | { |
beed38b8 | 331 | linux_enable_event_reporting (pid, attached); |
96d7229d | 332 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
333 | } |
334 | ||
6d8fd2b7 | 335 | static void |
f045800c | 336 | linux_child_post_attach (struct target_ops *self, int pid) |
4de4c07c | 337 | { |
beed38b8 | 338 | linux_init_ptrace (pid, 1); |
4de4c07c DJ |
339 | } |
340 | ||
10d6c8cd | 341 | static void |
2e97a79e | 342 | linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid) |
4de4c07c | 343 | { |
beed38b8 | 344 | linux_init_ptrace (ptid_get_pid (ptid), 0); |
4de4c07c DJ |
345 | } |
346 | ||
4403d8e9 JK |
347 | /* Return the number of known LWPs in the tgid given by PID. */ |
348 | ||
349 | static int | |
350 | num_lwps (int pid) | |
351 | { | |
352 | int count = 0; | |
353 | struct lwp_info *lp; | |
354 | ||
355 | for (lp = lwp_list; lp; lp = lp->next) | |
356 | if (ptid_get_pid (lp->ptid) == pid) | |
357 | count++; | |
358 | ||
359 | return count; | |
360 | } | |
361 | ||
362 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
363 | ||
364 | static void | |
365 | delete_lwp_cleanup (void *lp_voidp) | |
366 | { | |
367 | struct lwp_info *lp = lp_voidp; | |
368 | ||
369 | delete_lwp (lp->ptid); | |
370 | } | |
371 | ||
d83ad864 DB |
372 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
373 | ptid of the followed inferior. At return, inferior_ptid will be | |
374 | unchanged. */ | |
375 | ||
6d8fd2b7 | 376 | static int |
07107ca6 LM |
377 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
378 | int detach_fork) | |
3993f6b1 | 379 | { |
d83ad864 | 380 | if (!follow_child) |
4de4c07c | 381 | { |
6c95b8df | 382 | struct lwp_info *child_lp = NULL; |
d83ad864 DB |
383 | int status = W_STOPCODE (0); |
384 | struct cleanup *old_chain; | |
385 | int has_vforked; | |
386 | int parent_pid, child_pid; | |
387 | ||
388 | has_vforked = (inferior_thread ()->pending_follow.kind | |
389 | == TARGET_WAITKIND_VFORKED); | |
390 | parent_pid = ptid_get_lwp (inferior_ptid); | |
391 | if (parent_pid == 0) | |
392 | parent_pid = ptid_get_pid (inferior_ptid); | |
393 | child_pid | |
394 | = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid); | |
395 | ||
4de4c07c | 396 | |
1777feb0 | 397 | /* We're already attached to the parent, by default. */ |
d83ad864 DB |
398 | old_chain = save_inferior_ptid (); |
399 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
400 | child_lp = add_lwp (inferior_ptid); | |
401 | child_lp->stopped = 1; | |
402 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 403 | |
ac264b3b MS |
404 | /* Detach new forked process? */ |
405 | if (detach_fork) | |
f75c00e4 | 406 | { |
4403d8e9 JK |
407 | make_cleanup (delete_lwp_cleanup, child_lp); |
408 | ||
4403d8e9 JK |
409 | if (linux_nat_prepare_to_resume != NULL) |
410 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
411 | |
412 | /* When debugging an inferior in an architecture that supports | |
413 | hardware single stepping on a kernel without commit | |
414 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
415 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
416 | set if the parent process had them set. | |
417 | To work around this, single step the child process | |
418 | once before detaching to clear the flags. */ | |
419 | ||
420 | if (!gdbarch_software_single_step_p (target_thread_architecture | |
421 | (child_lp->ptid))) | |
422 | { | |
c077881a HZ |
423 | linux_disable_event_reporting (child_pid); |
424 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
425 | perror_with_name (_("Couldn't do single step")); | |
426 | if (my_waitpid (child_pid, &status, 0) < 0) | |
427 | perror_with_name (_("Couldn't wait vfork process")); | |
428 | } | |
429 | ||
430 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
431 | { |
432 | int signo; | |
433 | ||
434 | signo = WSTOPSIG (status); | |
435 | if (signo != 0 | |
436 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
437 | signo = 0; | |
438 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
439 | } | |
4403d8e9 | 440 | |
d83ad864 | 441 | /* Resets value of inferior_ptid to parent ptid. */ |
4403d8e9 | 442 | do_cleanups (old_chain); |
ac264b3b MS |
443 | } |
444 | else | |
445 | { | |
6c95b8df | 446 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 447 | check_for_thread_db (); |
ac264b3b | 448 | } |
9016a515 | 449 | |
d83ad864 DB |
450 | do_cleanups (old_chain); |
451 | ||
9016a515 DJ |
452 | if (has_vforked) |
453 | { | |
3ced3da4 | 454 | struct lwp_info *parent_lp; |
6c95b8df | 455 | |
3ced3da4 | 456 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
96d7229d | 457 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 458 | |
96d7229d | 459 | if (linux_supports_tracevforkdone ()) |
9016a515 | 460 | { |
6c95b8df PA |
461 | if (debug_linux_nat) |
462 | fprintf_unfiltered (gdb_stdlog, | |
463 | "LCFF: waiting for VFORK_DONE on %d\n", | |
464 | parent_pid); | |
3ced3da4 | 465 | parent_lp->stopped = 1; |
9016a515 | 466 | |
6c95b8df PA |
467 | /* We'll handle the VFORK_DONE event like any other |
468 | event, in target_wait. */ | |
9016a515 DJ |
469 | } |
470 | else | |
471 | { | |
472 | /* We can't insert breakpoints until the child has | |
473 | finished with the shared memory region. We need to | |
474 | wait until that happens. Ideal would be to just | |
475 | call: | |
476 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
477 | - waitpid (parent_pid, &status, __WALL); | |
478 | However, most architectures can't handle a syscall | |
479 | being traced on the way out if it wasn't traced on | |
480 | the way in. | |
481 | ||
482 | We might also think to loop, continuing the child | |
483 | until it exits or gets a SIGTRAP. One problem is | |
484 | that the child might call ptrace with PTRACE_TRACEME. | |
485 | ||
486 | There's no simple and reliable way to figure out when | |
487 | the vforked child will be done with its copy of the | |
488 | shared memory. We could step it out of the syscall, | |
489 | two instructions, let it go, and then single-step the | |
490 | parent once. When we have hardware single-step, this | |
491 | would work; with software single-step it could still | |
492 | be made to work but we'd have to be able to insert | |
493 | single-step breakpoints in the child, and we'd have | |
494 | to insert -just- the single-step breakpoint in the | |
495 | parent. Very awkward. | |
496 | ||
497 | In the end, the best we can do is to make sure it | |
498 | runs for a little while. Hopefully it will be out of | |
499 | range of any breakpoints we reinsert. Usually this | |
500 | is only the single-step breakpoint at vfork's return | |
501 | point. */ | |
502 | ||
6c95b8df PA |
503 | if (debug_linux_nat) |
504 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
505 | "LCFF: no VFORK_DONE " |
506 | "support, sleeping a bit\n"); | |
6c95b8df | 507 | |
9016a515 | 508 | usleep (10000); |
9016a515 | 509 | |
6c95b8df PA |
510 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
511 | and leave it pending. The next linux_nat_resume call | |
512 | will notice a pending event, and bypasses actually | |
513 | resuming the inferior. */ | |
3ced3da4 PA |
514 | parent_lp->status = 0; |
515 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
516 | parent_lp->stopped = 1; | |
6c95b8df PA |
517 | |
518 | /* If we're in async mode, need to tell the event loop | |
519 | there's something here to process. */ | |
520 | if (target_can_async_p ()) | |
521 | async_file_mark (); | |
522 | } | |
9016a515 | 523 | } |
4de4c07c | 524 | } |
3993f6b1 | 525 | else |
4de4c07c | 526 | { |
3ced3da4 | 527 | struct lwp_info *child_lp; |
4de4c07c | 528 | |
3ced3da4 PA |
529 | child_lp = add_lwp (inferior_ptid); |
530 | child_lp->stopped = 1; | |
25289eb2 | 531 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 532 | |
6c95b8df | 533 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 534 | check_for_thread_db (); |
4de4c07c DJ |
535 | } |
536 | ||
537 | return 0; | |
538 | } | |
539 | ||
4de4c07c | 540 | \f |
77b06cd7 | 541 | static int |
a863b201 | 542 | linux_child_insert_fork_catchpoint (struct target_ops *self, int pid) |
4de4c07c | 543 | { |
96d7229d | 544 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
545 | } |
546 | ||
eb73ad13 | 547 | static int |
973fc227 | 548 | linux_child_remove_fork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
549 | { |
550 | return 0; | |
551 | } | |
552 | ||
77b06cd7 | 553 | static int |
3ecc7da0 | 554 | linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 555 | { |
96d7229d | 556 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
557 | } |
558 | ||
eb73ad13 | 559 | static int |
e98cf0cd | 560 | linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
561 | { |
562 | return 0; | |
563 | } | |
564 | ||
77b06cd7 | 565 | static int |
ba025e51 | 566 | linux_child_insert_exec_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 567 | { |
96d7229d | 568 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
569 | } |
570 | ||
eb73ad13 | 571 | static int |
758e29d2 | 572 | linux_child_remove_exec_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
573 | { |
574 | return 0; | |
575 | } | |
576 | ||
a96d9b2e | 577 | static int |
ff214e67 TT |
578 | linux_child_set_syscall_catchpoint (struct target_ops *self, |
579 | int pid, int needed, int any_count, | |
a96d9b2e SDJ |
580 | int table_size, int *table) |
581 | { | |
96d7229d | 582 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
583 | return 1; |
584 | ||
a96d9b2e SDJ |
585 | /* On GNU/Linux, we ignore the arguments. It means that we only |
586 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 587 | |
a96d9b2e SDJ |
588 | Also, we do not use the `table' information because we do not |
589 | filter system calls here. We let GDB do the logic for us. */ | |
590 | return 0; | |
591 | } | |
592 | ||
d6b0e80f AC |
593 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
594 | are processes sharing the same VM space. A multi-threaded process | |
595 | is basically a group of such processes. However, such a grouping | |
596 | is almost entirely a user-space issue; the kernel doesn't enforce | |
597 | such a grouping at all (this might change in the future). In | |
598 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
599 | Threads library) to provide such a grouping. | |
600 | ||
601 | It is perfectly well possible to write a multi-threaded application | |
602 | without the assistance of a threads library, by using the clone | |
603 | system call directly. This module should be able to give some | |
604 | rudimentary support for debugging such applications if developers | |
605 | specify the CLONE_PTRACE flag in the clone system call, and are | |
606 | using the Linux kernel 2.4 or above. | |
607 | ||
608 | Note that there are some peculiarities in GNU/Linux that affect | |
609 | this code: | |
610 | ||
611 | - In general one should specify the __WCLONE flag to waitpid in | |
612 | order to make it report events for any of the cloned processes | |
613 | (and leave it out for the initial process). However, if a cloned | |
614 | process has exited the exit status is only reported if the | |
615 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
616 | we cannot use it since GDB must work on older systems too. | |
617 | ||
618 | - When a traced, cloned process exits and is waited for by the | |
619 | debugger, the kernel reassigns it to the original parent and | |
620 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
621 | library doesn't notice this, which leads to the "zombie problem": | |
622 | When debugged a multi-threaded process that spawns a lot of | |
623 | threads will run out of processes, even if the threads exit, | |
624 | because the "zombies" stay around. */ | |
625 | ||
626 | /* List of known LWPs. */ | |
9f0bdab8 | 627 | struct lwp_info *lwp_list; |
d6b0e80f AC |
628 | \f |
629 | ||
d6b0e80f AC |
630 | /* Original signal mask. */ |
631 | static sigset_t normal_mask; | |
632 | ||
633 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
634 | _initialize_linux_nat. */ | |
635 | static sigset_t suspend_mask; | |
636 | ||
7feb7d06 PA |
637 | /* Signals to block to make that sigsuspend work. */ |
638 | static sigset_t blocked_mask; | |
639 | ||
640 | /* SIGCHLD action. */ | |
641 | struct sigaction sigchld_action; | |
b84876c2 | 642 | |
7feb7d06 PA |
643 | /* Block child signals (SIGCHLD and linux threads signals), and store |
644 | the previous mask in PREV_MASK. */ | |
84e46146 | 645 | |
7feb7d06 PA |
646 | static void |
647 | block_child_signals (sigset_t *prev_mask) | |
648 | { | |
649 | /* Make sure SIGCHLD is blocked. */ | |
650 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
651 | sigaddset (&blocked_mask, SIGCHLD); | |
652 | ||
653 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
654 | } | |
655 | ||
656 | /* Restore child signals mask, previously returned by | |
657 | block_child_signals. */ | |
658 | ||
659 | static void | |
660 | restore_child_signals_mask (sigset_t *prev_mask) | |
661 | { | |
662 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
663 | } | |
2455069d UW |
664 | |
665 | /* Mask of signals to pass directly to the inferior. */ | |
666 | static sigset_t pass_mask; | |
667 | ||
668 | /* Update signals to pass to the inferior. */ | |
669 | static void | |
94bedb42 TT |
670 | linux_nat_pass_signals (struct target_ops *self, |
671 | int numsigs, unsigned char *pass_signals) | |
2455069d UW |
672 | { |
673 | int signo; | |
674 | ||
675 | sigemptyset (&pass_mask); | |
676 | ||
677 | for (signo = 1; signo < NSIG; signo++) | |
678 | { | |
2ea28649 | 679 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
680 | if (target_signo < numsigs && pass_signals[target_signo]) |
681 | sigaddset (&pass_mask, signo); | |
682 | } | |
683 | } | |
684 | ||
d6b0e80f AC |
685 | \f |
686 | ||
687 | /* Prototypes for local functions. */ | |
688 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 689 | static int linux_thread_alive (ptid_t ptid); |
8dd27370 | 690 | static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid); |
710151dd | 691 | |
d6b0e80f | 692 | \f |
d6b0e80f | 693 | |
7b50312a PA |
694 | /* Destroy and free LP. */ |
695 | ||
696 | static void | |
697 | lwp_free (struct lwp_info *lp) | |
698 | { | |
699 | xfree (lp->arch_private); | |
700 | xfree (lp); | |
701 | } | |
702 | ||
d90e17a7 PA |
703 | /* Remove all LWPs belong to PID from the lwp list. */ |
704 | ||
705 | static void | |
706 | purge_lwp_list (int pid) | |
707 | { | |
708 | struct lwp_info *lp, *lpprev, *lpnext; | |
709 | ||
710 | lpprev = NULL; | |
711 | ||
712 | for (lp = lwp_list; lp; lp = lpnext) | |
713 | { | |
714 | lpnext = lp->next; | |
715 | ||
716 | if (ptid_get_pid (lp->ptid) == pid) | |
717 | { | |
718 | if (lp == lwp_list) | |
719 | lwp_list = lp->next; | |
720 | else | |
721 | lpprev->next = lp->next; | |
722 | ||
7b50312a | 723 | lwp_free (lp); |
d90e17a7 PA |
724 | } |
725 | else | |
726 | lpprev = lp; | |
727 | } | |
728 | } | |
729 | ||
26cb8b7c PA |
730 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
731 | in the process. Return a pointer to the structure describing the | |
732 | new LWP. | |
733 | ||
734 | This differs from add_lwp in that we don't let the arch specific | |
735 | bits know about this new thread. Current clients of this callback | |
736 | take the opportunity to install watchpoints in the new thread, and | |
737 | we shouldn't do that for the first thread. If we're spawning a | |
738 | child ("run"), the thread executes the shell wrapper first, and we | |
739 | shouldn't touch it until it execs the program we want to debug. | |
740 | For "attach", it'd be okay to call the callback, but it's not | |
741 | necessary, because watchpoints can't yet have been inserted into | |
742 | the inferior. */ | |
d6b0e80f AC |
743 | |
744 | static struct lwp_info * | |
26cb8b7c | 745 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
746 | { |
747 | struct lwp_info *lp; | |
748 | ||
dfd4cc63 | 749 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f AC |
750 | |
751 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
752 | ||
753 | memset (lp, 0, sizeof (struct lwp_info)); | |
754 | ||
25289eb2 | 755 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
756 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
757 | ||
758 | lp->ptid = ptid; | |
dc146f7c | 759 | lp->core = -1; |
d6b0e80f AC |
760 | |
761 | lp->next = lwp_list; | |
762 | lwp_list = lp; | |
d6b0e80f | 763 | |
26cb8b7c PA |
764 | return lp; |
765 | } | |
766 | ||
767 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
768 | structure describing the new LWP. The LWP should already be | |
769 | stopped. */ | |
770 | ||
771 | static struct lwp_info * | |
772 | add_lwp (ptid_t ptid) | |
773 | { | |
774 | struct lwp_info *lp; | |
775 | ||
776 | lp = add_initial_lwp (ptid); | |
777 | ||
6e012a6c PA |
778 | /* Let the arch specific bits know about this new thread. Current |
779 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
780 | watchpoints in the new thread. We don't do this for the first |
781 | thread though. See add_initial_lwp. */ | |
782 | if (linux_nat_new_thread != NULL) | |
7b50312a | 783 | linux_nat_new_thread (lp); |
9f0bdab8 | 784 | |
d6b0e80f AC |
785 | return lp; |
786 | } | |
787 | ||
788 | /* Remove the LWP specified by PID from the list. */ | |
789 | ||
790 | static void | |
791 | delete_lwp (ptid_t ptid) | |
792 | { | |
793 | struct lwp_info *lp, *lpprev; | |
794 | ||
795 | lpprev = NULL; | |
796 | ||
797 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
798 | if (ptid_equal (lp->ptid, ptid)) | |
799 | break; | |
800 | ||
801 | if (!lp) | |
802 | return; | |
803 | ||
d6b0e80f AC |
804 | if (lpprev) |
805 | lpprev->next = lp->next; | |
806 | else | |
807 | lwp_list = lp->next; | |
808 | ||
7b50312a | 809 | lwp_free (lp); |
d6b0e80f AC |
810 | } |
811 | ||
812 | /* Return a pointer to the structure describing the LWP corresponding | |
813 | to PID. If no corresponding LWP could be found, return NULL. */ | |
814 | ||
815 | static struct lwp_info * | |
816 | find_lwp_pid (ptid_t ptid) | |
817 | { | |
818 | struct lwp_info *lp; | |
819 | int lwp; | |
820 | ||
dfd4cc63 LM |
821 | if (ptid_lwp_p (ptid)) |
822 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 823 | else |
dfd4cc63 | 824 | lwp = ptid_get_pid (ptid); |
d6b0e80f AC |
825 | |
826 | for (lp = lwp_list; lp; lp = lp->next) | |
dfd4cc63 | 827 | if (lwp == ptid_get_lwp (lp->ptid)) |
d6b0e80f AC |
828 | return lp; |
829 | ||
830 | return NULL; | |
831 | } | |
832 | ||
833 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
834 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
835 | pointer to the structure describing that LWP immediately. | |
836 | Otherwise return NULL. */ | |
837 | ||
838 | struct lwp_info * | |
d90e17a7 PA |
839 | iterate_over_lwps (ptid_t filter, |
840 | int (*callback) (struct lwp_info *, void *), | |
841 | void *data) | |
d6b0e80f AC |
842 | { |
843 | struct lwp_info *lp, *lpnext; | |
844 | ||
845 | for (lp = lwp_list; lp; lp = lpnext) | |
846 | { | |
847 | lpnext = lp->next; | |
d90e17a7 PA |
848 | |
849 | if (ptid_match (lp->ptid, filter)) | |
850 | { | |
851 | if ((*callback) (lp, data)) | |
852 | return lp; | |
853 | } | |
d6b0e80f AC |
854 | } |
855 | ||
856 | return NULL; | |
857 | } | |
858 | ||
2277426b PA |
859 | /* Update our internal state when changing from one checkpoint to |
860 | another indicated by NEW_PTID. We can only switch single-threaded | |
861 | applications, so we only create one new LWP, and the previous list | |
862 | is discarded. */ | |
f973ed9c DJ |
863 | |
864 | void | |
865 | linux_nat_switch_fork (ptid_t new_ptid) | |
866 | { | |
867 | struct lwp_info *lp; | |
868 | ||
dfd4cc63 | 869 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 870 | |
f973ed9c DJ |
871 | lp = add_lwp (new_ptid); |
872 | lp->stopped = 1; | |
e26af52f | 873 | |
2277426b PA |
874 | /* This changes the thread's ptid while preserving the gdb thread |
875 | num. Also changes the inferior pid, while preserving the | |
876 | inferior num. */ | |
877 | thread_change_ptid (inferior_ptid, new_ptid); | |
878 | ||
879 | /* We've just told GDB core that the thread changed target id, but, | |
880 | in fact, it really is a different thread, with different register | |
881 | contents. */ | |
882 | registers_changed (); | |
e26af52f DJ |
883 | } |
884 | ||
e26af52f DJ |
885 | /* Handle the exit of a single thread LP. */ |
886 | ||
887 | static void | |
888 | exit_lwp (struct lwp_info *lp) | |
889 | { | |
e09875d4 | 890 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
891 | |
892 | if (th) | |
e26af52f | 893 | { |
17faa917 DJ |
894 | if (print_thread_events) |
895 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
896 | ||
4f8d22e3 | 897 | delete_thread (lp->ptid); |
e26af52f DJ |
898 | } |
899 | ||
900 | delete_lwp (lp->ptid); | |
901 | } | |
902 | ||
a0ef4274 DJ |
903 | /* Wait for the LWP specified by LP, which we have just attached to. |
904 | Returns a wait status for that LWP, to cache. */ | |
905 | ||
906 | static int | |
907 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
908 | int *signalled) | |
909 | { | |
dfd4cc63 | 910 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
911 | int status; |
912 | ||
644cebc9 | 913 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
914 | { |
915 | if (debug_linux_nat) | |
916 | fprintf_unfiltered (gdb_stdlog, | |
917 | "LNPAW: Attaching to a stopped process\n"); | |
918 | ||
919 | /* The process is definitely stopped. It is in a job control | |
920 | stop, unless the kernel predates the TASK_STOPPED / | |
921 | TASK_TRACED distinction, in which case it might be in a | |
922 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
923 | can kill it, signal it, et cetera. | |
924 | ||
925 | First make sure there is a pending SIGSTOP. Since we are | |
926 | already attached, the process can not transition from stopped | |
927 | to running without a PTRACE_CONT; so we know this signal will | |
928 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
929 | probably already in the queue (unless this kernel is old | |
930 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
931 | is not an RT signal, it can only be queued once. */ | |
932 | kill_lwp (pid, SIGSTOP); | |
933 | ||
934 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
935 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
936 | ptrace (PTRACE_CONT, pid, 0, 0); | |
937 | } | |
938 | ||
939 | /* Make sure the initial process is stopped. The user-level threads | |
940 | layer might want to poke around in the inferior, and that won't | |
941 | work if things haven't stabilized yet. */ | |
942 | new_pid = my_waitpid (pid, &status, 0); | |
943 | if (new_pid == -1 && errno == ECHILD) | |
944 | { | |
945 | if (first) | |
946 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
947 | ||
948 | /* Try again with __WCLONE to check cloned processes. */ | |
949 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
950 | *cloned = 1; | |
951 | } | |
952 | ||
dacc9cb2 PP |
953 | gdb_assert (pid == new_pid); |
954 | ||
955 | if (!WIFSTOPPED (status)) | |
956 | { | |
957 | /* The pid we tried to attach has apparently just exited. */ | |
958 | if (debug_linux_nat) | |
959 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
960 | pid, status_to_str (status)); | |
961 | return status; | |
962 | } | |
a0ef4274 DJ |
963 | |
964 | if (WSTOPSIG (status) != SIGSTOP) | |
965 | { | |
966 | *signalled = 1; | |
967 | if (debug_linux_nat) | |
968 | fprintf_unfiltered (gdb_stdlog, | |
969 | "LNPAW: Received %s after attaching\n", | |
970 | status_to_str (status)); | |
971 | } | |
972 | ||
973 | return status; | |
974 | } | |
975 | ||
84636d28 PA |
976 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
977 | the new LWP could not be attached, or 1 if we're already auto | |
978 | attached to this thread, but haven't processed the | |
979 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
980 | its existance, without considering it an error. */ | |
d6b0e80f | 981 | |
9ee57c33 | 982 | int |
93815fbf | 983 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 984 | { |
9ee57c33 | 985 | struct lwp_info *lp; |
84636d28 | 986 | int lwpid; |
d6b0e80f | 987 | |
dfd4cc63 | 988 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 989 | |
9ee57c33 | 990 | lp = find_lwp_pid (ptid); |
dfd4cc63 | 991 | lwpid = ptid_get_lwp (ptid); |
d6b0e80f AC |
992 | |
993 | /* We assume that we're already attached to any LWP that has an id | |
994 | equal to the overall process id, and to any LWP that is already | |
995 | in our list of LWPs. If we're not seeing exit events from threads | |
996 | and we've had PID wraparound since we last tried to stop all threads, | |
997 | this assumption might be wrong; fortunately, this is very unlikely | |
998 | to happen. */ | |
dfd4cc63 | 999 | if (lwpid != ptid_get_pid (ptid) && lp == NULL) |
d6b0e80f | 1000 | { |
a0ef4274 | 1001 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1002 | |
84636d28 | 1003 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1004 | { |
96d7229d | 1005 | if (linux_supports_tracefork ()) |
84636d28 PA |
1006 | { |
1007 | /* If we haven't stopped all threads when we get here, | |
1008 | we may have seen a thread listed in thread_db's list, | |
1009 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1010 | that's the case, ignore this new thread, and let | |
1011 | normal event handling discover it later. */ | |
1012 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1013 | { | |
1014 | /* We've already seen this thread stop, but we | |
1015 | haven't seen the PTRACE_EVENT_CLONE extended | |
1016 | event yet. */ | |
84636d28 PA |
1017 | return 0; |
1018 | } | |
1019 | else | |
1020 | { | |
1021 | int new_pid; | |
1022 | int status; | |
1023 | ||
1024 | /* See if we've got a stop for this new child | |
1025 | pending. If so, we're already attached. */ | |
1026 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1027 | if (new_pid == -1 && errno == ECHILD) | |
1028 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1029 | if (new_pid != -1) | |
1030 | { | |
1031 | if (WIFSTOPPED (status)) | |
1032 | add_to_pid_list (&stopped_pids, lwpid, status); | |
84636d28 PA |
1033 | return 1; |
1034 | } | |
1035 | } | |
1036 | } | |
1037 | ||
9ee57c33 DJ |
1038 | /* If we fail to attach to the thread, issue a warning, |
1039 | but continue. One way this can happen is if thread | |
e9efe249 | 1040 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1041 | bug may place threads in the thread list and then fail |
1042 | to create them. */ | |
1043 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1044 | safe_strerror (errno)); | |
1045 | return -1; | |
1046 | } | |
1047 | ||
d6b0e80f AC |
1048 | if (debug_linux_nat) |
1049 | fprintf_unfiltered (gdb_stdlog, | |
1050 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1051 | target_pid_to_str (ptid)); | |
1052 | ||
a0ef4274 | 1053 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1054 | if (!WIFSTOPPED (status)) |
12696c10 | 1055 | return 1; |
dacc9cb2 | 1056 | |
a0ef4274 DJ |
1057 | lp = add_lwp (ptid); |
1058 | lp->stopped = 1; | |
1059 | lp->cloned = cloned; | |
1060 | lp->signalled = signalled; | |
1061 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1062 | { |
a0ef4274 DJ |
1063 | lp->resumed = 1; |
1064 | lp->status = status; | |
d6b0e80f AC |
1065 | } |
1066 | ||
dfd4cc63 | 1067 | target_post_attach (ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
1068 | |
1069 | if (debug_linux_nat) | |
1070 | { | |
1071 | fprintf_unfiltered (gdb_stdlog, | |
1072 | "LLAL: waitpid %s received %s\n", | |
1073 | target_pid_to_str (ptid), | |
1074 | status_to_str (status)); | |
1075 | } | |
1076 | } | |
1077 | else | |
1078 | { | |
1079 | /* We assume that the LWP representing the original process is | |
1080 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1081 | that the GNU/linux ptrace layer uses to keep track of |
1082 | threads. Note that this won't have already been done since | |
1083 | the main thread will have, we assume, been stopped by an | |
1084 | attach from a different layer. */ | |
9ee57c33 DJ |
1085 | if (lp == NULL) |
1086 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1087 | lp->stopped = 1; |
1088 | } | |
9ee57c33 | 1089 | |
25289eb2 | 1090 | lp->last_resume_kind = resume_stop; |
9ee57c33 | 1091 | return 0; |
d6b0e80f AC |
1092 | } |
1093 | ||
b84876c2 | 1094 | static void |
136d6dae VP |
1095 | linux_nat_create_inferior (struct target_ops *ops, |
1096 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1097 | int from_tty) |
1098 | { | |
10568435 JK |
1099 | #ifdef HAVE_PERSONALITY |
1100 | int personality_orig = 0, personality_set = 0; | |
1101 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1102 | |
1103 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1104 | we have to mask the async mode. */ | |
1105 | ||
10568435 JK |
1106 | #ifdef HAVE_PERSONALITY |
1107 | if (disable_randomization) | |
1108 | { | |
1109 | errno = 0; | |
1110 | personality_orig = personality (0xffffffff); | |
1111 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1112 | { | |
1113 | personality_set = 1; | |
1114 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1115 | } | |
1116 | if (errno != 0 || (personality_set | |
1117 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1118 | warning (_("Error disabling address space randomization: %s"), | |
1119 | safe_strerror (errno)); | |
1120 | } | |
1121 | #endif /* HAVE_PERSONALITY */ | |
1122 | ||
2455069d | 1123 | /* Make sure we report all signals during startup. */ |
94bedb42 | 1124 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1125 | |
136d6dae | 1126 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1127 | |
10568435 JK |
1128 | #ifdef HAVE_PERSONALITY |
1129 | if (personality_set) | |
1130 | { | |
1131 | errno = 0; | |
1132 | personality (personality_orig); | |
1133 | if (errno != 0) | |
1134 | warning (_("Error restoring address space randomization: %s"), | |
1135 | safe_strerror (errno)); | |
1136 | } | |
1137 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1138 | } |
1139 | ||
d6b0e80f | 1140 | static void |
c0939df1 | 1141 | linux_nat_attach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f AC |
1142 | { |
1143 | struct lwp_info *lp; | |
d6b0e80f | 1144 | int status; |
af990527 | 1145 | ptid_t ptid; |
87b0bb13 | 1146 | volatile struct gdb_exception ex; |
d6b0e80f | 1147 | |
2455069d | 1148 | /* Make sure we report all signals during attach. */ |
94bedb42 | 1149 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1150 | |
87b0bb13 JK |
1151 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1152 | { | |
1153 | linux_ops->to_attach (ops, args, from_tty); | |
1154 | } | |
1155 | if (ex.reason < 0) | |
1156 | { | |
1157 | pid_t pid = parse_pid_to_attach (args); | |
1158 | struct buffer buffer; | |
1159 | char *message, *buffer_s; | |
1160 | ||
1161 | message = xstrdup (ex.message); | |
1162 | make_cleanup (xfree, message); | |
1163 | ||
1164 | buffer_init (&buffer); | |
7ae1a6a6 | 1165 | linux_ptrace_attach_fail_reason (pid, &buffer); |
87b0bb13 JK |
1166 | |
1167 | buffer_grow_str0 (&buffer, ""); | |
1168 | buffer_s = buffer_finish (&buffer); | |
1169 | make_cleanup (xfree, buffer_s); | |
1170 | ||
7ae1a6a6 PA |
1171 | if (*buffer_s != '\0') |
1172 | throw_error (ex.error, "warning: %s\n%s", buffer_s, message); | |
1173 | else | |
1174 | throw_error (ex.error, "%s", message); | |
87b0bb13 | 1175 | } |
d6b0e80f | 1176 | |
af990527 PA |
1177 | /* The ptrace base target adds the main thread with (pid,0,0) |
1178 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1179 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1180 | ptid_get_pid (inferior_ptid), | |
1181 | 0); | |
af990527 PA |
1182 | thread_change_ptid (inferior_ptid, ptid); |
1183 | ||
9f0bdab8 | 1184 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1185 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1186 | |
1187 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1188 | &lp->signalled); | |
dacc9cb2 PP |
1189 | if (!WIFSTOPPED (status)) |
1190 | { | |
1191 | if (WIFEXITED (status)) | |
1192 | { | |
1193 | int exit_code = WEXITSTATUS (status); | |
1194 | ||
1195 | target_terminal_ours (); | |
1196 | target_mourn_inferior (); | |
1197 | if (exit_code == 0) | |
1198 | error (_("Unable to attach: program exited normally.")); | |
1199 | else | |
1200 | error (_("Unable to attach: program exited with code %d."), | |
1201 | exit_code); | |
1202 | } | |
1203 | else if (WIFSIGNALED (status)) | |
1204 | { | |
2ea28649 | 1205 | enum gdb_signal signo; |
dacc9cb2 PP |
1206 | |
1207 | target_terminal_ours (); | |
1208 | target_mourn_inferior (); | |
1209 | ||
2ea28649 | 1210 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1211 | error (_("Unable to attach: program terminated with signal " |
1212 | "%s, %s."), | |
2ea28649 PA |
1213 | gdb_signal_to_name (signo), |
1214 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1215 | } |
1216 | ||
1217 | internal_error (__FILE__, __LINE__, | |
1218 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1219 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1220 | } |
1221 | ||
a0ef4274 | 1222 | lp->stopped = 1; |
9f0bdab8 | 1223 | |
a0ef4274 | 1224 | /* Save the wait status to report later. */ |
d6b0e80f | 1225 | lp->resumed = 1; |
a0ef4274 DJ |
1226 | if (debug_linux_nat) |
1227 | fprintf_unfiltered (gdb_stdlog, | |
1228 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1229 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1230 | |
7feb7d06 PA |
1231 | lp->status = status; |
1232 | ||
1233 | if (target_can_async_p ()) | |
1234 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1235 | } |
1236 | ||
a0ef4274 DJ |
1237 | /* Get pending status of LP. */ |
1238 | static int | |
1239 | get_pending_status (struct lwp_info *lp, int *status) | |
1240 | { | |
a493e3e2 | 1241 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1242 | |
1243 | /* If we paused threads momentarily, we may have stored pending | |
1244 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1245 | and GDB core hasn't seen any signal for those threads. | |
1246 | Otherwise, the last signal reported to the core is found in the | |
1247 | thread object's stop_signal. | |
1248 | ||
1249 | There's a corner case that isn't handled here at present. Only | |
1250 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1251 | stop_signal make sense as a real signal to pass to the inferior. | |
1252 | Some catchpoint related events, like | |
1253 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1254 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1255 | those traps are debug API (ptrace in our case) related and |
1256 | induced; the inferior wouldn't see them if it wasn't being | |
1257 | traced. Hence, we should never pass them to the inferior, even | |
1258 | when set to pass state. Since this corner case isn't handled by | |
1259 | infrun.c when proceeding with a signal, for consistency, neither | |
1260 | do we handle it here (or elsewhere in the file we check for | |
1261 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1262 | this is really a corner case. */ | |
1263 | ||
1264 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1265 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1266 | else if (lp->status) |
2ea28649 | 1267 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1268 | else if (non_stop && !is_executing (lp->ptid)) |
1269 | { | |
1270 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1271 | |
16c381f0 | 1272 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1273 | } |
1274 | else if (!non_stop) | |
a0ef4274 | 1275 | { |
ca2163eb PA |
1276 | struct target_waitstatus last; |
1277 | ptid_t last_ptid; | |
4c28f408 | 1278 | |
ca2163eb | 1279 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1280 | |
dfd4cc63 | 1281 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1282 | { |
e09875d4 | 1283 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1284 | |
16c381f0 | 1285 | signo = tp->suspend.stop_signal; |
4c28f408 | 1286 | } |
ca2163eb | 1287 | } |
4c28f408 | 1288 | |
ca2163eb | 1289 | *status = 0; |
4c28f408 | 1290 | |
a493e3e2 | 1291 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1292 | { |
1293 | if (debug_linux_nat) | |
1294 | fprintf_unfiltered (gdb_stdlog, | |
1295 | "GPT: lwp %s has no pending signal\n", | |
1296 | target_pid_to_str (lp->ptid)); | |
1297 | } | |
1298 | else if (!signal_pass_state (signo)) | |
1299 | { | |
1300 | if (debug_linux_nat) | |
3e43a32a MS |
1301 | fprintf_unfiltered (gdb_stdlog, |
1302 | "GPT: lwp %s had signal %s, " | |
1303 | "but it is in no pass state\n", | |
ca2163eb | 1304 | target_pid_to_str (lp->ptid), |
2ea28649 | 1305 | gdb_signal_to_string (signo)); |
a0ef4274 | 1306 | } |
a0ef4274 | 1307 | else |
4c28f408 | 1308 | { |
2ea28649 | 1309 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1310 | |
1311 | if (debug_linux_nat) | |
1312 | fprintf_unfiltered (gdb_stdlog, | |
1313 | "GPT: lwp %s has pending signal %s\n", | |
1314 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1315 | gdb_signal_to_string (signo)); |
4c28f408 | 1316 | } |
a0ef4274 DJ |
1317 | |
1318 | return 0; | |
1319 | } | |
1320 | ||
d6b0e80f AC |
1321 | static int |
1322 | detach_callback (struct lwp_info *lp, void *data) | |
1323 | { | |
1324 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1325 | ||
1326 | if (debug_linux_nat && lp->status) | |
1327 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1328 | strsignal (WSTOPSIG (lp->status)), | |
1329 | target_pid_to_str (lp->ptid)); | |
1330 | ||
a0ef4274 DJ |
1331 | /* If there is a pending SIGSTOP, get rid of it. */ |
1332 | if (lp->signalled) | |
d6b0e80f | 1333 | { |
d6b0e80f AC |
1334 | if (debug_linux_nat) |
1335 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1336 | "DC: Sending SIGCONT to %s\n", |
1337 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1338 | |
dfd4cc63 | 1339 | kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT); |
d6b0e80f | 1340 | lp->signalled = 0; |
d6b0e80f AC |
1341 | } |
1342 | ||
1343 | /* We don't actually detach from the LWP that has an id equal to the | |
1344 | overall process id just yet. */ | |
dfd4cc63 | 1345 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) |
d6b0e80f | 1346 | { |
a0ef4274 DJ |
1347 | int status = 0; |
1348 | ||
1349 | /* Pass on any pending signal for this LWP. */ | |
1350 | get_pending_status (lp, &status); | |
1351 | ||
7b50312a PA |
1352 | if (linux_nat_prepare_to_resume != NULL) |
1353 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f | 1354 | errno = 0; |
dfd4cc63 | 1355 | if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0, |
a0ef4274 | 1356 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1357 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1358 | safe_strerror (errno)); |
1359 | ||
1360 | if (debug_linux_nat) | |
1361 | fprintf_unfiltered (gdb_stdlog, | |
1362 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1363 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1364 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1365 | |
1366 | delete_lwp (lp->ptid); | |
1367 | } | |
1368 | ||
1369 | return 0; | |
1370 | } | |
1371 | ||
1372 | static void | |
52554a0e | 1373 | linux_nat_detach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f | 1374 | { |
b84876c2 | 1375 | int pid; |
a0ef4274 | 1376 | int status; |
d90e17a7 PA |
1377 | struct lwp_info *main_lwp; |
1378 | ||
dfd4cc63 | 1379 | pid = ptid_get_pid (inferior_ptid); |
a0ef4274 | 1380 | |
ae5e0686 MK |
1381 | /* Don't unregister from the event loop, as there may be other |
1382 | inferiors running. */ | |
b84876c2 | 1383 | |
4c28f408 PA |
1384 | /* Stop all threads before detaching. ptrace requires that the |
1385 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1386 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1387 | /* ... and wait until all of them have reported back that |
1388 | they're no longer running. */ | |
d90e17a7 | 1389 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1390 | |
d90e17a7 | 1391 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1392 | |
1393 | /* Only the initial process should be left right now. */ | |
dfd4cc63 | 1394 | gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1); |
d90e17a7 PA |
1395 | |
1396 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1397 | |
a0ef4274 DJ |
1398 | /* Pass on any pending signal for the last LWP. */ |
1399 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1400 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1401 | && WIFSTOPPED (status)) |
1402 | { | |
52554a0e TT |
1403 | char *tem; |
1404 | ||
a0ef4274 DJ |
1405 | /* Put the signal number in ARGS so that inf_ptrace_detach will |
1406 | pass it along with PTRACE_DETACH. */ | |
52554a0e | 1407 | tem = alloca (8); |
cde33bf1 | 1408 | xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status)); |
52554a0e | 1409 | args = tem; |
ddabfc73 TT |
1410 | if (debug_linux_nat) |
1411 | fprintf_unfiltered (gdb_stdlog, | |
1412 | "LND: Sending signal %s to %s\n", | |
1413 | args, | |
1414 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1415 | } |
1416 | ||
7b50312a PA |
1417 | if (linux_nat_prepare_to_resume != NULL) |
1418 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1419 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1420 | |
7a7d3353 PA |
1421 | if (forks_exist_p ()) |
1422 | { | |
1423 | /* Multi-fork case. The current inferior_ptid is being detached | |
1424 | from, but there are other viable forks to debug. Detach from | |
1425 | the current fork, and context-switch to the first | |
1426 | available. */ | |
1427 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1428 | } |
1429 | else | |
1430 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1431 | } |
1432 | ||
1433 | /* Resume LP. */ | |
1434 | ||
25289eb2 | 1435 | static void |
e5ef252a | 1436 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1437 | { |
25289eb2 | 1438 | if (lp->stopped) |
6c95b8df | 1439 | { |
c9657e70 | 1440 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
25289eb2 PA |
1441 | |
1442 | if (inf->vfork_child != NULL) | |
1443 | { | |
1444 | if (debug_linux_nat) | |
1445 | fprintf_unfiltered (gdb_stdlog, | |
1446 | "RC: Not resuming %s (vfork parent)\n", | |
1447 | target_pid_to_str (lp->ptid)); | |
1448 | } | |
1449 | else if (lp->status == 0 | |
1450 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1451 | { | |
1452 | if (debug_linux_nat) | |
1453 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1454 | "RC: Resuming sibling %s, %s, %s\n", |
1455 | target_pid_to_str (lp->ptid), | |
1456 | (signo != GDB_SIGNAL_0 | |
1457 | ? strsignal (gdb_signal_to_host (signo)) | |
1458 | : "0"), | |
1459 | step ? "step" : "resume"); | |
25289eb2 | 1460 | |
7b50312a PA |
1461 | if (linux_nat_prepare_to_resume != NULL) |
1462 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 1463 | linux_ops->to_resume (linux_ops, |
dfd4cc63 | 1464 | pid_to_ptid (ptid_get_lwp (lp->ptid)), |
e5ef252a | 1465 | step, signo); |
25289eb2 PA |
1466 | lp->stopped = 0; |
1467 | lp->step = step; | |
25289eb2 PA |
1468 | lp->stopped_by_watchpoint = 0; |
1469 | } | |
1470 | else | |
1471 | { | |
1472 | if (debug_linux_nat) | |
1473 | fprintf_unfiltered (gdb_stdlog, | |
1474 | "RC: Not resuming sibling %s (has pending)\n", | |
1475 | target_pid_to_str (lp->ptid)); | |
1476 | } | |
6c95b8df | 1477 | } |
25289eb2 | 1478 | else |
d6b0e80f | 1479 | { |
d90e17a7 PA |
1480 | if (debug_linux_nat) |
1481 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1482 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1483 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1484 | } |
25289eb2 | 1485 | } |
d6b0e80f | 1486 | |
8817a6f2 PA |
1487 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1488 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1489 | |
25289eb2 | 1490 | static int |
8817a6f2 | 1491 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1492 | { |
e5ef252a PA |
1493 | enum gdb_signal signo = GDB_SIGNAL_0; |
1494 | ||
8817a6f2 PA |
1495 | if (lp == except) |
1496 | return 0; | |
1497 | ||
e5ef252a PA |
1498 | if (lp->stopped) |
1499 | { | |
1500 | struct thread_info *thread; | |
1501 | ||
1502 | thread = find_thread_ptid (lp->ptid); | |
1503 | if (thread != NULL) | |
1504 | { | |
70509625 | 1505 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1506 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1507 | } | |
1508 | } | |
1509 | ||
1510 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1511 | return 0; |
1512 | } | |
1513 | ||
1514 | static int | |
1515 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1516 | { | |
1517 | lp->resumed = 0; | |
25289eb2 | 1518 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1519 | return 0; |
1520 | } | |
1521 | ||
1522 | static int | |
1523 | resume_set_callback (struct lwp_info *lp, void *data) | |
1524 | { | |
1525 | lp->resumed = 1; | |
25289eb2 | 1526 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1527 | return 0; |
1528 | } | |
1529 | ||
1530 | static void | |
28439f5e | 1531 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1532 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1533 | { |
1534 | struct lwp_info *lp; | |
d90e17a7 | 1535 | int resume_many; |
d6b0e80f | 1536 | |
76f50ad1 DJ |
1537 | if (debug_linux_nat) |
1538 | fprintf_unfiltered (gdb_stdlog, | |
1539 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1540 | step ? "step" : "resume", | |
1541 | target_pid_to_str (ptid), | |
a493e3e2 | 1542 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1543 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1544 | target_pid_to_str (inferior_ptid)); |
1545 | ||
d6b0e80f | 1546 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1547 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1548 | || ptid_is_pid (ptid)); | |
4c28f408 | 1549 | |
e3e9f5a2 PA |
1550 | /* Mark the lwps we're resuming as resumed. */ |
1551 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1552 | |
d90e17a7 PA |
1553 | /* See if it's the current inferior that should be handled |
1554 | specially. */ | |
1555 | if (resume_many) | |
1556 | lp = find_lwp_pid (inferior_ptid); | |
1557 | else | |
1558 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1559 | gdb_assert (lp != NULL); |
d6b0e80f | 1560 | |
9f0bdab8 DJ |
1561 | /* Remember if we're stepping. */ |
1562 | lp->step = step; | |
25289eb2 | 1563 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1564 | |
9f0bdab8 DJ |
1565 | /* If we have a pending wait status for this thread, there is no |
1566 | point in resuming the process. But first make sure that | |
1567 | linux_nat_wait won't preemptively handle the event - we | |
1568 | should never take this short-circuit if we are going to | |
1569 | leave LP running, since we have skipped resuming all the | |
1570 | other threads. This bit of code needs to be synchronized | |
1571 | with linux_nat_wait. */ | |
76f50ad1 | 1572 | |
9f0bdab8 DJ |
1573 | if (lp->status && WIFSTOPPED (lp->status)) |
1574 | { | |
2455069d UW |
1575 | if (!lp->step |
1576 | && WSTOPSIG (lp->status) | |
1577 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1578 | { |
9f0bdab8 DJ |
1579 | if (debug_linux_nat) |
1580 | fprintf_unfiltered (gdb_stdlog, | |
1581 | "LLR: Not short circuiting for ignored " | |
1582 | "status 0x%x\n", lp->status); | |
1583 | ||
d6b0e80f AC |
1584 | /* FIXME: What should we do if we are supposed to continue |
1585 | this thread with a signal? */ | |
a493e3e2 | 1586 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1587 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1588 | lp->status = 0; |
1589 | } | |
1590 | } | |
76f50ad1 | 1591 | |
6c95b8df | 1592 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
1593 | { |
1594 | /* FIXME: What should we do if we are supposed to continue | |
1595 | this thread with a signal? */ | |
a493e3e2 | 1596 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1597 | |
9f0bdab8 DJ |
1598 | if (debug_linux_nat) |
1599 | fprintf_unfiltered (gdb_stdlog, | |
1600 | "LLR: Short circuiting for status 0x%x\n", | |
1601 | lp->status); | |
d6b0e80f | 1602 | |
7feb7d06 PA |
1603 | if (target_can_async_p ()) |
1604 | { | |
1605 | target_async (inferior_event_handler, 0); | |
1606 | /* Tell the event loop we have something to process. */ | |
1607 | async_file_mark (); | |
1608 | } | |
9f0bdab8 | 1609 | return; |
d6b0e80f AC |
1610 | } |
1611 | ||
d90e17a7 | 1612 | if (resume_many) |
8817a6f2 | 1613 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 PA |
1614 | |
1615 | /* Convert to something the lower layer understands. */ | |
dfd4cc63 | 1616 | ptid = pid_to_ptid (ptid_get_lwp (lp->ptid)); |
d6b0e80f | 1617 | |
7b50312a PA |
1618 | if (linux_nat_prepare_to_resume != NULL) |
1619 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 1620 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 1621 | lp->stopped_by_watchpoint = 0; |
8817a6f2 | 1622 | lp->stopped = 0; |
9f0bdab8 | 1623 | |
d6b0e80f AC |
1624 | if (debug_linux_nat) |
1625 | fprintf_unfiltered (gdb_stdlog, | |
1626 | "LLR: %s %s, %s (resume event thread)\n", | |
1627 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1628 | target_pid_to_str (ptid), | |
a493e3e2 | 1629 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1630 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 PA |
1631 | |
1632 | if (target_can_async_p ()) | |
8ea051c5 | 1633 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1634 | } |
1635 | ||
c5f62d5f | 1636 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1637 | |
1638 | static int | |
1639 | kill_lwp (int lwpid, int signo) | |
1640 | { | |
c5f62d5f DE |
1641 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1642 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1643 | |
1644 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1645 | { |
1646 | static int tkill_failed; | |
1647 | ||
1648 | if (!tkill_failed) | |
1649 | { | |
1650 | int ret; | |
1651 | ||
1652 | errno = 0; | |
1653 | ret = syscall (__NR_tkill, lwpid, signo); | |
1654 | if (errno != ENOSYS) | |
1655 | return ret; | |
1656 | tkill_failed = 1; | |
1657 | } | |
1658 | } | |
d6b0e80f AC |
1659 | #endif |
1660 | ||
1661 | return kill (lwpid, signo); | |
1662 | } | |
1663 | ||
ca2163eb PA |
1664 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1665 | event, check if the core is interested in it: if not, ignore the | |
1666 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1667 | syscall entry/exit status, since the ptrace event itself doesn't | |
1668 | indicate it, and report the trap to higher layers. */ | |
1669 | ||
1670 | static int | |
1671 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1672 | { | |
1673 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1674 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1675 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1676 | ||
1677 | if (stopping) | |
1678 | { | |
1679 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1680 | makes it so that the LWP reports an immediate syscall return, | |
1681 | followed by the SIGSTOP. Skip seeing that "return" using | |
1682 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1683 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1684 | entry event. If we didn't do this (and returned 0), we'd | |
1685 | leave a syscall entry pending, and our caller, by using | |
1686 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1687 | itself. Later, when the user re-resumes this LWP, we'd see | |
1688 | another syscall entry event and we'd mistake it for a return. | |
1689 | ||
1690 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1691 | (leaving immediately with LWP->signalled set, without issuing | |
1692 | a PTRACE_CONT), it would still be problematic to leave this | |
1693 | syscall enter pending, as later when the thread is resumed, | |
1694 | it would then see the same syscall exit mentioned above, | |
1695 | followed by the delayed SIGSTOP, while the syscall didn't | |
1696 | actually get to execute. It seems it would be even more | |
1697 | confusing to the user. */ | |
1698 | ||
1699 | if (debug_linux_nat) | |
1700 | fprintf_unfiltered (gdb_stdlog, | |
1701 | "LHST: ignoring syscall %d " | |
1702 | "for LWP %ld (stopping threads), " | |
1703 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1704 | syscall_number, | |
dfd4cc63 | 1705 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1706 | |
1707 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1708 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1709 | lp->stopped = 0; |
ca2163eb PA |
1710 | return 1; |
1711 | } | |
1712 | ||
1713 | if (catch_syscall_enabled ()) | |
1714 | { | |
1715 | /* Always update the entry/return state, even if this particular | |
1716 | syscall isn't interesting to the core now. In async mode, | |
1717 | the user could install a new catchpoint for this syscall | |
1718 | between syscall enter/return, and we'll need to know to | |
1719 | report a syscall return if that happens. */ | |
1720 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1721 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1722 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1723 | ||
1724 | if (catching_syscall_number (syscall_number)) | |
1725 | { | |
1726 | /* Alright, an event to report. */ | |
1727 | ourstatus->kind = lp->syscall_state; | |
1728 | ourstatus->value.syscall_number = syscall_number; | |
1729 | ||
1730 | if (debug_linux_nat) | |
1731 | fprintf_unfiltered (gdb_stdlog, | |
1732 | "LHST: stopping for %s of syscall %d" | |
1733 | " for LWP %ld\n", | |
3e43a32a MS |
1734 | lp->syscall_state |
1735 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1736 | ? "entry" : "return", |
1737 | syscall_number, | |
dfd4cc63 | 1738 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1739 | return 0; |
1740 | } | |
1741 | ||
1742 | if (debug_linux_nat) | |
1743 | fprintf_unfiltered (gdb_stdlog, | |
1744 | "LHST: ignoring %s of syscall %d " | |
1745 | "for LWP %ld\n", | |
1746 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1747 | ? "entry" : "return", | |
1748 | syscall_number, | |
dfd4cc63 | 1749 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1750 | } |
1751 | else | |
1752 | { | |
1753 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1754 | before on this LWP, it could happen that the user removes all | |
1755 | syscall catchpoints before we get to process this event. | |
1756 | There are two noteworthy issues here: | |
1757 | ||
1758 | - When stopped at a syscall entry event, resuming with | |
1759 | PT_STEP still resumes executing the syscall and reports a | |
1760 | syscall return. | |
1761 | ||
1762 | - Only PT_SYSCALL catches syscall enters. If we last | |
1763 | single-stepped this thread, then this event can't be a | |
1764 | syscall enter. If we last single-stepped this thread, this | |
1765 | has to be a syscall exit. | |
1766 | ||
1767 | The points above mean that the next resume, be it PT_STEP or | |
1768 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1769 | if (debug_linux_nat) | |
1770 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1771 | "LHST: caught syscall event " |
1772 | "with no syscall catchpoints." | |
ca2163eb PA |
1773 | " %d for LWP %ld, ignoring\n", |
1774 | syscall_number, | |
dfd4cc63 | 1775 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1776 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1777 | } | |
1778 | ||
1779 | /* The core isn't interested in this event. For efficiency, avoid | |
1780 | stopping all threads only to have the core resume them all again. | |
1781 | Since we're not stopping threads, if we're still syscall tracing | |
1782 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1783 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1784 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1785 | ||
1786 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
1787 | fill a regcache. */ | |
1788 | registers_changed (); | |
7b50312a PA |
1789 | if (linux_nat_prepare_to_resume != NULL) |
1790 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 1791 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 1792 | lp->step, GDB_SIGNAL_0); |
8817a6f2 | 1793 | lp->stopped = 0; |
ca2163eb PA |
1794 | return 1; |
1795 | } | |
1796 | ||
3d799a95 DJ |
1797 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1798 | event, we need to add the new LWP to our list (and not report the | |
1799 | trap to higher layers). This function returns non-zero if the | |
1800 | event should be ignored and we should wait again. If STOPPING is | |
1801 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1802 | |
1803 | static int | |
3d799a95 DJ |
1804 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1805 | int stopping) | |
d6b0e80f | 1806 | { |
dfd4cc63 | 1807 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1808 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1809 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1810 | |
3d799a95 DJ |
1811 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1812 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1813 | { |
3d799a95 DJ |
1814 | unsigned long new_pid; |
1815 | int ret; | |
1816 | ||
1817 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1818 | |
3d799a95 DJ |
1819 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1820 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1821 | { | |
1822 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1823 | hits the SIGSTOP, but we're already attached. */ | |
1824 | ret = my_waitpid (new_pid, &status, | |
1825 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
1826 | if (ret == -1) | |
1827 | perror_with_name (_("waiting for new child")); | |
1828 | else if (ret != new_pid) | |
1829 | internal_error (__FILE__, __LINE__, | |
1830 | _("wait returned unexpected PID %d"), ret); | |
1831 | else if (!WIFSTOPPED (status)) | |
1832 | internal_error (__FILE__, __LINE__, | |
1833 | _("wait returned unexpected status 0x%x"), status); | |
1834 | } | |
1835 | ||
3a3e9ee3 | 1836 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 1837 | |
26cb8b7c PA |
1838 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1839 | { | |
1840 | /* The arch-specific native code may need to know about new | |
1841 | forks even if those end up never mapped to an | |
1842 | inferior. */ | |
1843 | if (linux_nat_new_fork != NULL) | |
1844 | linux_nat_new_fork (lp, new_pid); | |
1845 | } | |
1846 | ||
2277426b | 1847 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 1848 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 1849 | { |
2277426b PA |
1850 | /* Handle checkpointing by linux-fork.c here as a special |
1851 | case. We don't want the follow-fork-mode or 'catch fork' | |
1852 | to interfere with this. */ | |
1853 | ||
1854 | /* This won't actually modify the breakpoint list, but will | |
1855 | physically remove the breakpoints from the child. */ | |
d80ee84f | 1856 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
1857 | |
1858 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1859 | if (!find_fork_pid (new_pid)) |
1860 | add_fork (new_pid); | |
2277426b PA |
1861 | |
1862 | /* Report as spurious, so that infrun doesn't want to follow | |
1863 | this fork. We're actually doing an infcall in | |
1864 | linux-fork.c. */ | |
1865 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1866 | |
1867 | /* Report the stop to the core. */ | |
1868 | return 0; | |
1869 | } | |
1870 | ||
3d799a95 DJ |
1871 | if (event == PTRACE_EVENT_FORK) |
1872 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1873 | else if (event == PTRACE_EVENT_VFORK) | |
1874 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 1875 | else |
3d799a95 | 1876 | { |
78768c4a JK |
1877 | struct lwp_info *new_lp; |
1878 | ||
3d799a95 | 1879 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1880 | |
3c4d7e12 PA |
1881 | if (debug_linux_nat) |
1882 | fprintf_unfiltered (gdb_stdlog, | |
1883 | "LHEW: Got clone event " | |
1884 | "from LWP %d, new child is LWP %ld\n", | |
1885 | pid, new_pid); | |
1886 | ||
dfd4cc63 | 1887 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
3d799a95 | 1888 | new_lp->cloned = 1; |
4c28f408 | 1889 | new_lp->stopped = 1; |
d6b0e80f | 1890 | |
3d799a95 DJ |
1891 | if (WSTOPSIG (status) != SIGSTOP) |
1892 | { | |
1893 | /* This can happen if someone starts sending signals to | |
1894 | the new thread before it gets a chance to run, which | |
1895 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1896 | This is an unlikely case, and harder to handle for | |
1897 | fork / vfork than for clone, so we do not try - but | |
1898 | we handle it for clone events here. We'll send | |
1899 | the other signal on to the thread below. */ | |
1900 | ||
1901 | new_lp->signalled = 1; | |
1902 | } | |
1903 | else | |
79395f92 PA |
1904 | { |
1905 | struct thread_info *tp; | |
1906 | ||
1907 | /* When we stop for an event in some other thread, and | |
1908 | pull the thread list just as this thread has cloned, | |
1909 | we'll have seen the new thread in the thread_db list | |
1910 | before handling the CLONE event (glibc's | |
1911 | pthread_create adds the new thread to the thread list | |
1912 | before clone'ing, and has the kernel fill in the | |
1913 | thread's tid on the clone call with | |
1914 | CLONE_PARENT_SETTID). If that happened, and the core | |
1915 | had requested the new thread to stop, we'll have | |
1916 | killed it with SIGSTOP. But since SIGSTOP is not an | |
1917 | RT signal, it can only be queued once. We need to be | |
1918 | careful to not resume the LWP if we wanted it to | |
1919 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 1920 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
1921 | tp = find_thread_ptid (new_lp->ptid); |
1922 | if (tp != NULL && tp->stop_requested) | |
1923 | new_lp->last_resume_kind = resume_stop; | |
1924 | else | |
1925 | status = 0; | |
1926 | } | |
d6b0e80f | 1927 | |
4c28f408 | 1928 | if (non_stop) |
3d799a95 | 1929 | { |
4c28f408 PA |
1930 | /* Add the new thread to GDB's lists as soon as possible |
1931 | so that: | |
1932 | ||
1933 | 1) the frontend doesn't have to wait for a stop to | |
1934 | display them, and, | |
1935 | ||
1936 | 2) we tag it with the correct running state. */ | |
1937 | ||
1938 | /* If the thread_db layer is active, let it know about | |
1939 | this new thread, and add it to GDB's list. */ | |
1940 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
1941 | { | |
1942 | /* We're not using thread_db. Add it to GDB's | |
1943 | list. */ | |
dfd4cc63 | 1944 | target_post_attach (ptid_get_lwp (new_lp->ptid)); |
4c28f408 PA |
1945 | add_thread (new_lp->ptid); |
1946 | } | |
1947 | ||
1948 | if (!stopping) | |
1949 | { | |
1950 | set_running (new_lp->ptid, 1); | |
1951 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
1952 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
1953 | resume_stop. */ | |
1954 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
1955 | } |
1956 | } | |
1957 | ||
79395f92 PA |
1958 | if (status != 0) |
1959 | { | |
1960 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
1961 | gdb_assert (new_lp->status == 0); | |
1962 | ||
1963 | /* Save the wait status to report later. */ | |
1964 | if (debug_linux_nat) | |
1965 | fprintf_unfiltered (gdb_stdlog, | |
1966 | "LHEW: waitpid of new LWP %ld, " | |
1967 | "saving status %s\n", | |
dfd4cc63 | 1968 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
1969 | status_to_str (status)); |
1970 | new_lp->status = status; | |
1971 | } | |
1972 | ||
ca2163eb PA |
1973 | /* Note the need to use the low target ops to resume, to |
1974 | handle resuming with PT_SYSCALL if we have syscall | |
1975 | catchpoints. */ | |
4c28f408 PA |
1976 | if (!stopping) |
1977 | { | |
3d799a95 | 1978 | new_lp->resumed = 1; |
ca2163eb | 1979 | |
79395f92 | 1980 | if (status == 0) |
ad34eb2f | 1981 | { |
e21ffe51 | 1982 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
1983 | if (debug_linux_nat) |
1984 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 | 1985 | "LHEW: resuming new LWP %ld\n", |
dfd4cc63 | 1986 | ptid_get_lwp (new_lp->ptid)); |
7b50312a PA |
1987 | if (linux_nat_prepare_to_resume != NULL) |
1988 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 1989 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 1990 | 0, GDB_SIGNAL_0); |
79395f92 | 1991 | new_lp->stopped = 0; |
ad34eb2f JK |
1992 | } |
1993 | } | |
d6b0e80f | 1994 | |
3d799a95 DJ |
1995 | if (debug_linux_nat) |
1996 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 1997 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
1998 | if (linux_nat_prepare_to_resume != NULL) |
1999 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
2000 | linux_ops->to_resume (linux_ops, |
2001 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
a493e3e2 | 2002 | 0, GDB_SIGNAL_0); |
8817a6f2 | 2003 | lp->stopped = 0; |
3d799a95 DJ |
2004 | return 1; |
2005 | } | |
2006 | ||
2007 | return 0; | |
d6b0e80f AC |
2008 | } |
2009 | ||
3d799a95 DJ |
2010 | if (event == PTRACE_EVENT_EXEC) |
2011 | { | |
a75724bc PA |
2012 | if (debug_linux_nat) |
2013 | fprintf_unfiltered (gdb_stdlog, | |
2014 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2015 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2016 | |
3d799a95 DJ |
2017 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2018 | ourstatus->value.execd_pathname | |
8dd27370 | 2019 | = xstrdup (linux_child_pid_to_exec_file (NULL, pid)); |
3d799a95 | 2020 | |
6c95b8df PA |
2021 | return 0; |
2022 | } | |
2023 | ||
2024 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2025 | { | |
2026 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2027 | { |
6c95b8df | 2028 | if (debug_linux_nat) |
3e43a32a MS |
2029 | fprintf_unfiltered (gdb_stdlog, |
2030 | "LHEW: Got expected PTRACE_EVENT_" | |
2031 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2032 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2033 | |
6c95b8df PA |
2034 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2035 | return 0; | |
3d799a95 DJ |
2036 | } |
2037 | ||
6c95b8df | 2038 | if (debug_linux_nat) |
3e43a32a MS |
2039 | fprintf_unfiltered (gdb_stdlog, |
2040 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2041 | "from LWP %ld: resuming\n", | |
dfd4cc63 LM |
2042 | ptid_get_lwp (lp->ptid)); |
2043 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); | |
6c95b8df | 2044 | return 1; |
3d799a95 DJ |
2045 | } |
2046 | ||
2047 | internal_error (__FILE__, __LINE__, | |
2048 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2049 | } |
2050 | ||
2051 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2052 | exited. */ | |
2053 | ||
2054 | static int | |
2055 | wait_lwp (struct lwp_info *lp) | |
2056 | { | |
2057 | pid_t pid; | |
432b4d03 | 2058 | int status = 0; |
d6b0e80f | 2059 | int thread_dead = 0; |
432b4d03 | 2060 | sigset_t prev_mask; |
d6b0e80f AC |
2061 | |
2062 | gdb_assert (!lp->stopped); | |
2063 | gdb_assert (lp->status == 0); | |
2064 | ||
432b4d03 JK |
2065 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2066 | block_child_signals (&prev_mask); | |
2067 | ||
2068 | for (;;) | |
d6b0e80f | 2069 | { |
432b4d03 JK |
2070 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2071 | was right and we should just call sigsuspend. */ | |
2072 | ||
dfd4cc63 | 2073 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG); |
d6b0e80f | 2074 | if (pid == -1 && errno == ECHILD) |
dfd4cc63 | 2075 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2076 | if (pid == -1 && errno == ECHILD) |
2077 | { | |
2078 | /* The thread has previously exited. We need to delete it | |
2079 | now because, for some vendor 2.4 kernels with NPTL | |
2080 | support backported, there won't be an exit event unless | |
2081 | it is the main thread. 2.6 kernels will report an exit | |
2082 | event for each thread that exits, as expected. */ | |
2083 | thread_dead = 1; | |
2084 | if (debug_linux_nat) | |
2085 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2086 | target_pid_to_str (lp->ptid)); | |
2087 | } | |
432b4d03 JK |
2088 | if (pid != 0) |
2089 | break; | |
2090 | ||
2091 | /* Bugs 10970, 12702. | |
2092 | Thread group leader may have exited in which case we'll lock up in | |
2093 | waitpid if there are other threads, even if they are all zombies too. | |
2094 | Basically, we're not supposed to use waitpid this way. | |
2095 | __WCLONE is not applicable for the leader so we can't use that. | |
2096 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2097 | process; it gets ESRCH both for the zombie and for running processes. | |
2098 | ||
2099 | As a workaround, check if we're waiting for the thread group leader and | |
2100 | if it's a zombie, and avoid calling waitpid if it is. | |
2101 | ||
2102 | This is racy, what if the tgl becomes a zombie right after we check? | |
2103 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2104 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2105 | |
dfd4cc63 LM |
2106 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2107 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2108 | { |
d6b0e80f AC |
2109 | thread_dead = 1; |
2110 | if (debug_linux_nat) | |
432b4d03 JK |
2111 | fprintf_unfiltered (gdb_stdlog, |
2112 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2113 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2114 | break; |
d6b0e80f | 2115 | } |
432b4d03 JK |
2116 | |
2117 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2118 | get invoked despite our caller had them intentionally blocked by | |
2119 | block_child_signals. This is sensitive only to the loop of | |
2120 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2121 | again before it gets to sigsuspend so we can safely let the handlers | |
2122 | get executed here. */ | |
2123 | ||
d36bf488 DE |
2124 | if (debug_linux_nat) |
2125 | fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n"); | |
432b4d03 JK |
2126 | sigsuspend (&suspend_mask); |
2127 | } | |
2128 | ||
2129 | restore_child_signals_mask (&prev_mask); | |
2130 | ||
d6b0e80f AC |
2131 | if (!thread_dead) |
2132 | { | |
dfd4cc63 | 2133 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2134 | |
2135 | if (debug_linux_nat) | |
2136 | { | |
2137 | fprintf_unfiltered (gdb_stdlog, | |
2138 | "WL: waitpid %s received %s\n", | |
2139 | target_pid_to_str (lp->ptid), | |
2140 | status_to_str (status)); | |
2141 | } | |
d6b0e80f | 2142 | |
a9f4bb21 PA |
2143 | /* Check if the thread has exited. */ |
2144 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2145 | { | |
2146 | thread_dead = 1; | |
2147 | if (debug_linux_nat) | |
2148 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2149 | target_pid_to_str (lp->ptid)); | |
2150 | } | |
d6b0e80f AC |
2151 | } |
2152 | ||
2153 | if (thread_dead) | |
2154 | { | |
e26af52f | 2155 | exit_lwp (lp); |
d6b0e80f AC |
2156 | return 0; |
2157 | } | |
2158 | ||
2159 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2160 | lp->stopped = 1; |
d6b0e80f | 2161 | |
ca2163eb PA |
2162 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2163 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2164 | { | |
2165 | /* No longer need the sysgood bit. The ptrace event ends up | |
2166 | recorded in lp->waitstatus if we care for it. We can carry | |
2167 | on handling the event like a regular SIGTRAP from here | |
2168 | on. */ | |
2169 | status = W_STOPCODE (SIGTRAP); | |
2170 | if (linux_handle_syscall_trap (lp, 1)) | |
2171 | return wait_lwp (lp); | |
2172 | } | |
2173 | ||
d6b0e80f | 2174 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2175 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2176 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2177 | { |
2178 | if (debug_linux_nat) | |
2179 | fprintf_unfiltered (gdb_stdlog, | |
2180 | "WL: Handling extended status 0x%06x\n", | |
2181 | status); | |
3d799a95 | 2182 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2183 | return wait_lwp (lp); |
2184 | } | |
2185 | ||
2186 | return status; | |
2187 | } | |
2188 | ||
2189 | /* Send a SIGSTOP to LP. */ | |
2190 | ||
2191 | static int | |
2192 | stop_callback (struct lwp_info *lp, void *data) | |
2193 | { | |
2194 | if (!lp->stopped && !lp->signalled) | |
2195 | { | |
2196 | int ret; | |
2197 | ||
2198 | if (debug_linux_nat) | |
2199 | { | |
2200 | fprintf_unfiltered (gdb_stdlog, | |
2201 | "SC: kill %s **<SIGSTOP>**\n", | |
2202 | target_pid_to_str (lp->ptid)); | |
2203 | } | |
2204 | errno = 0; | |
dfd4cc63 | 2205 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2206 | if (debug_linux_nat) |
2207 | { | |
2208 | fprintf_unfiltered (gdb_stdlog, | |
2209 | "SC: lwp kill %d %s\n", | |
2210 | ret, | |
2211 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2212 | } | |
2213 | ||
2214 | lp->signalled = 1; | |
2215 | gdb_assert (lp->status == 0); | |
2216 | } | |
2217 | ||
2218 | return 0; | |
2219 | } | |
2220 | ||
7b50312a PA |
2221 | /* Request a stop on LWP. */ |
2222 | ||
2223 | void | |
2224 | linux_stop_lwp (struct lwp_info *lwp) | |
2225 | { | |
2226 | stop_callback (lwp, NULL); | |
2227 | } | |
2228 | ||
57380f4e | 2229 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2230 | |
2231 | static int | |
57380f4e DJ |
2232 | linux_nat_has_pending_sigint (int pid) |
2233 | { | |
2234 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2235 | |
2236 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2237 | ||
2238 | if (sigismember (&pending, SIGINT) | |
2239 | && !sigismember (&ignored, SIGINT)) | |
2240 | return 1; | |
2241 | ||
2242 | return 0; | |
2243 | } | |
2244 | ||
2245 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2246 | ||
2247 | static int | |
2248 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2249 | { |
57380f4e DJ |
2250 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2251 | flag to consume the next one. */ | |
2252 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2253 | && WSTOPSIG (lp->status) == SIGINT) | |
2254 | lp->status = 0; | |
2255 | else | |
2256 | lp->ignore_sigint = 1; | |
2257 | ||
2258 | return 0; | |
2259 | } | |
2260 | ||
2261 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2262 | This function is called after we know the LWP has stopped; if the LWP | |
2263 | stopped before the expected SIGINT was delivered, then it will never have | |
2264 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2265 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2266 | |
57380f4e DJ |
2267 | static void |
2268 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2269 | { | |
2270 | if (!lp->ignore_sigint) | |
2271 | return; | |
2272 | ||
dfd4cc63 | 2273 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2274 | { |
2275 | if (debug_linux_nat) | |
2276 | fprintf_unfiltered (gdb_stdlog, | |
2277 | "MCIS: Clearing bogus flag for %s\n", | |
2278 | target_pid_to_str (lp->ptid)); | |
2279 | lp->ignore_sigint = 0; | |
2280 | } | |
2281 | } | |
2282 | ||
ebec9a0f PA |
2283 | /* Fetch the possible triggered data watchpoint info and store it in |
2284 | LP. | |
2285 | ||
2286 | On some archs, like x86, that use debug registers to set | |
2287 | watchpoints, it's possible that the way to know which watched | |
2288 | address trapped, is to check the register that is used to select | |
2289 | which address to watch. Problem is, between setting the watchpoint | |
2290 | and reading back which data address trapped, the user may change | |
2291 | the set of watchpoints, and, as a consequence, GDB changes the | |
2292 | debug registers in the inferior. To avoid reading back a stale | |
2293 | stopped-data-address when that happens, we cache in LP the fact | |
2294 | that a watchpoint trapped, and the corresponding data address, as | |
2295 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2296 | registers meanwhile, we have the cached data we can rely on. */ | |
2297 | ||
2298 | static void | |
2299 | save_sigtrap (struct lwp_info *lp) | |
2300 | { | |
2301 | struct cleanup *old_chain; | |
2302 | ||
2303 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2304 | { | |
2305 | lp->stopped_by_watchpoint = 0; | |
2306 | return; | |
2307 | } | |
2308 | ||
2309 | old_chain = save_inferior_ptid (); | |
2310 | inferior_ptid = lp->ptid; | |
2311 | ||
6a109b6b | 2312 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (linux_ops); |
ebec9a0f PA |
2313 | |
2314 | if (lp->stopped_by_watchpoint) | |
2315 | { | |
2316 | if (linux_ops->to_stopped_data_address != NULL) | |
2317 | lp->stopped_data_address_p = | |
2318 | linux_ops->to_stopped_data_address (¤t_target, | |
2319 | &lp->stopped_data_address); | |
2320 | else | |
2321 | lp->stopped_data_address_p = 0; | |
2322 | } | |
2323 | ||
2324 | do_cleanups (old_chain); | |
2325 | } | |
2326 | ||
2327 | /* See save_sigtrap. */ | |
2328 | ||
2329 | static int | |
6a109b6b | 2330 | linux_nat_stopped_by_watchpoint (struct target_ops *ops) |
ebec9a0f PA |
2331 | { |
2332 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2333 | ||
2334 | gdb_assert (lp != NULL); | |
2335 | ||
2336 | return lp->stopped_by_watchpoint; | |
2337 | } | |
2338 | ||
2339 | static int | |
2340 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2341 | { | |
2342 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2343 | ||
2344 | gdb_assert (lp != NULL); | |
2345 | ||
2346 | *addr_p = lp->stopped_data_address; | |
2347 | ||
2348 | return lp->stopped_data_address_p; | |
2349 | } | |
2350 | ||
26ab7092 JK |
2351 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2352 | ||
2353 | static int | |
2354 | sigtrap_is_event (int status) | |
2355 | { | |
2356 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2357 | } | |
2358 | ||
2359 | /* SIGTRAP-like events recognizer. */ | |
2360 | ||
2361 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2362 | ||
00390b84 JK |
2363 | /* Check for SIGTRAP-like events in LP. */ |
2364 | ||
2365 | static int | |
2366 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2367 | { | |
2368 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2369 | have pending process exits recorded in lp->status | |
2370 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2371 | lp->status_p flag. */ | |
2372 | ||
2373 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2374 | && linux_nat_status_is_event (lp->status)); | |
2375 | } | |
2376 | ||
26ab7092 JK |
2377 | /* Set alternative SIGTRAP-like events recognizer. If |
2378 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2379 | applied. */ | |
2380 | ||
2381 | void | |
2382 | linux_nat_set_status_is_event (struct target_ops *t, | |
2383 | int (*status_is_event) (int status)) | |
2384 | { | |
2385 | linux_nat_status_is_event = status_is_event; | |
2386 | } | |
2387 | ||
57380f4e DJ |
2388 | /* Wait until LP is stopped. */ |
2389 | ||
2390 | static int | |
2391 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2392 | { | |
c9657e70 | 2393 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
6c95b8df PA |
2394 | |
2395 | /* If this is a vfork parent, bail out, it is not going to report | |
2396 | any SIGSTOP until the vfork is done with. */ | |
2397 | if (inf->vfork_child != NULL) | |
2398 | return 0; | |
2399 | ||
d6b0e80f AC |
2400 | if (!lp->stopped) |
2401 | { | |
2402 | int status; | |
2403 | ||
2404 | status = wait_lwp (lp); | |
2405 | if (status == 0) | |
2406 | return 0; | |
2407 | ||
57380f4e DJ |
2408 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2409 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2410 | { |
57380f4e | 2411 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2412 | |
2413 | errno = 0; | |
dfd4cc63 | 2414 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2415 | lp->stopped = 0; |
d6b0e80f AC |
2416 | if (debug_linux_nat) |
2417 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2418 | "PTRACE_CONT %s, 0, 0 (%s) " |
2419 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2420 | target_pid_to_str (lp->ptid), |
2421 | errno ? safe_strerror (errno) : "OK"); | |
2422 | ||
57380f4e | 2423 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2424 | } |
2425 | ||
57380f4e DJ |
2426 | maybe_clear_ignore_sigint (lp); |
2427 | ||
d6b0e80f AC |
2428 | if (WSTOPSIG (status) != SIGSTOP) |
2429 | { | |
e5ef252a | 2430 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2431 | |
e5ef252a PA |
2432 | save_sigtrap (lp); |
2433 | ||
2434 | if (debug_linux_nat) | |
2435 | fprintf_unfiltered (gdb_stdlog, | |
2436 | "SWC: Pending event %s in %s\n", | |
2437 | status_to_str ((int) status), | |
2438 | target_pid_to_str (lp->ptid)); | |
2439 | ||
2440 | /* Save the sigtrap event. */ | |
2441 | lp->status = status; | |
e5ef252a | 2442 | gdb_assert (lp->signalled); |
d6b0e80f AC |
2443 | } |
2444 | else | |
2445 | { | |
2446 | /* We caught the SIGSTOP that we intended to catch, so | |
2447 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2448 | |
2449 | if (debug_linux_nat) | |
2450 | fprintf_unfiltered (gdb_stdlog, | |
2451 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2452 | target_pid_to_str (lp->ptid)); | |
2453 | ||
e5ef252a PA |
2454 | /* Reset SIGNALLED only after the stop_wait_callback call |
2455 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2456 | lp->signalled = 0; |
2457 | } | |
2458 | } | |
2459 | ||
2460 | return 0; | |
2461 | } | |
2462 | ||
d6b0e80f AC |
2463 | /* Return non-zero if LP has a wait status pending. */ |
2464 | ||
2465 | static int | |
2466 | status_callback (struct lwp_info *lp, void *data) | |
2467 | { | |
2468 | /* Only report a pending wait status if we pretend that this has | |
2469 | indeed been resumed. */ | |
ca2163eb PA |
2470 | if (!lp->resumed) |
2471 | return 0; | |
2472 | ||
2473 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2474 | { | |
2475 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2476 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2477 | 0', so a clean process exit can not be stored pending in |
2478 | lp->status, it is indistinguishable from | |
2479 | no-pending-status. */ | |
2480 | return 1; | |
2481 | } | |
2482 | ||
2483 | if (lp->status != 0) | |
2484 | return 1; | |
2485 | ||
2486 | return 0; | |
d6b0e80f AC |
2487 | } |
2488 | ||
2489 | /* Return non-zero if LP isn't stopped. */ | |
2490 | ||
2491 | static int | |
2492 | running_callback (struct lwp_info *lp, void *data) | |
2493 | { | |
25289eb2 PA |
2494 | return (!lp->stopped |
2495 | || ((lp->status != 0 | |
2496 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2497 | && lp->resumed)); | |
d6b0e80f AC |
2498 | } |
2499 | ||
2500 | /* Count the LWP's that have had events. */ | |
2501 | ||
2502 | static int | |
2503 | count_events_callback (struct lwp_info *lp, void *data) | |
2504 | { | |
2505 | int *count = data; | |
2506 | ||
2507 | gdb_assert (count != NULL); | |
2508 | ||
e09490f1 | 2509 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2510 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2511 | (*count)++; |
2512 | ||
2513 | return 0; | |
2514 | } | |
2515 | ||
2516 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2517 | ||
2518 | static int | |
2519 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2520 | { | |
25289eb2 PA |
2521 | if (lp->last_resume_kind == resume_step |
2522 | && lp->status != 0) | |
d6b0e80f AC |
2523 | return 1; |
2524 | else | |
2525 | return 0; | |
2526 | } | |
2527 | ||
2528 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2529 | ||
2530 | static int | |
2531 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2532 | { | |
2533 | int *selector = data; | |
2534 | ||
2535 | gdb_assert (selector != NULL); | |
2536 | ||
1777feb0 | 2537 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2538 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2539 | if ((*selector)-- == 0) |
2540 | return 1; | |
2541 | ||
2542 | return 0; | |
2543 | } | |
2544 | ||
710151dd PA |
2545 | static int |
2546 | cancel_breakpoint (struct lwp_info *lp) | |
2547 | { | |
2548 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2549 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2550 | LWP. We will handle the current event, eventually we will resume | |
2551 | this LWP, and this breakpoint will trap again. | |
2552 | ||
2553 | If we do not do this, then we run the risk that the user will | |
2554 | delete or disable the breakpoint, but the LWP will have already | |
2555 | tripped on it. */ | |
2556 | ||
515630c5 UW |
2557 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2558 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2559 | CORE_ADDR pc; | |
2560 | ||
118e6252 | 2561 | pc = regcache_read_pc (regcache) - target_decr_pc_after_break (gdbarch); |
6c95b8df | 2562 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
2563 | { |
2564 | if (debug_linux_nat) | |
2565 | fprintf_unfiltered (gdb_stdlog, | |
2566 | "CB: Push back breakpoint for %s\n", | |
2567 | target_pid_to_str (lp->ptid)); | |
2568 | ||
2569 | /* Back up the PC if necessary. */ | |
118e6252 | 2570 | if (target_decr_pc_after_break (gdbarch)) |
515630c5 UW |
2571 | regcache_write_pc (regcache, pc); |
2572 | ||
710151dd PA |
2573 | return 1; |
2574 | } | |
2575 | return 0; | |
2576 | } | |
2577 | ||
d6b0e80f AC |
2578 | static int |
2579 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
2580 | { | |
2581 | struct lwp_info *event_lp = data; | |
2582 | ||
2583 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
2584 | if (lp == event_lp) | |
2585 | return 0; | |
2586 | ||
2587 | /* If a LWP other than the LWP that we're reporting an event for has | |
2588 | hit a GDB breakpoint (as opposed to some random trap signal), | |
2589 | then just arrange for it to hit it again later. We don't keep | |
2590 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2591 | LWP. We will handle the current event, eventually we will resume | |
2592 | all LWPs, and this one will get its breakpoint trap again. | |
2593 | ||
2594 | If we do not do this, then we run the risk that the user will | |
2595 | delete or disable the breakpoint, but the LWP will have already | |
2596 | tripped on it. */ | |
2597 | ||
00390b84 | 2598 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
2599 | && cancel_breakpoint (lp)) |
2600 | /* Throw away the SIGTRAP. */ | |
2601 | lp->status = 0; | |
d6b0e80f AC |
2602 | |
2603 | return 0; | |
2604 | } | |
2605 | ||
2606 | /* Select one LWP out of those that have events pending. */ | |
2607 | ||
2608 | static void | |
d90e17a7 | 2609 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2610 | { |
2611 | int num_events = 0; | |
2612 | int random_selector; | |
2613 | struct lwp_info *event_lp; | |
2614 | ||
ac264b3b | 2615 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2616 | (*orig_lp)->status = *status; |
2617 | ||
2618 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
2619 | event_lp = iterate_over_lwps (filter, |
2620 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
2621 | if (event_lp != NULL) |
2622 | { | |
2623 | if (debug_linux_nat) | |
2624 | fprintf_unfiltered (gdb_stdlog, | |
2625 | "SEL: Select single-step %s\n", | |
2626 | target_pid_to_str (event_lp->ptid)); | |
2627 | } | |
2628 | else | |
2629 | { | |
2630 | /* No single-stepping LWP. Select one at random, out of those | |
2631 | which have had SIGTRAP events. */ | |
2632 | ||
2633 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 2634 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
2635 | |
2636 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
2637 | random_selector = (int) | |
2638 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2639 | ||
2640 | if (debug_linux_nat && num_events > 1) | |
2641 | fprintf_unfiltered (gdb_stdlog, | |
2642 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
2643 | num_events, random_selector); | |
2644 | ||
d90e17a7 PA |
2645 | event_lp = iterate_over_lwps (filter, |
2646 | select_event_lwp_callback, | |
d6b0e80f AC |
2647 | &random_selector); |
2648 | } | |
2649 | ||
2650 | if (event_lp != NULL) | |
2651 | { | |
2652 | /* Switch the event LWP. */ | |
2653 | *orig_lp = event_lp; | |
2654 | *status = event_lp->status; | |
2655 | } | |
2656 | ||
2657 | /* Flush the wait status for the event LWP. */ | |
2658 | (*orig_lp)->status = 0; | |
2659 | } | |
2660 | ||
2661 | /* Return non-zero if LP has been resumed. */ | |
2662 | ||
2663 | static int | |
2664 | resumed_callback (struct lwp_info *lp, void *data) | |
2665 | { | |
2666 | return lp->resumed; | |
2667 | } | |
2668 | ||
12d9289a PA |
2669 | /* Stop an active thread, verify it still exists, then resume it. If |
2670 | the thread ends up with a pending status, then it is not resumed, | |
2671 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2672 | |
2673 | static int | |
2674 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2675 | { | |
12d9289a PA |
2676 | int *new_pending_p = data; |
2677 | ||
25289eb2 | 2678 | if (!lp->stopped) |
d6b0e80f | 2679 | { |
25289eb2 PA |
2680 | ptid_t ptid = lp->ptid; |
2681 | ||
d6b0e80f AC |
2682 | stop_callback (lp, NULL); |
2683 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2684 | |
2685 | /* Resume if the lwp still exists, and the core wanted it | |
2686 | running. */ | |
12d9289a PA |
2687 | lp = find_lwp_pid (ptid); |
2688 | if (lp != NULL) | |
25289eb2 | 2689 | { |
12d9289a PA |
2690 | if (lp->last_resume_kind == resume_stop |
2691 | && lp->status == 0) | |
2692 | { | |
2693 | /* The core wanted the LWP to stop. Even if it stopped | |
2694 | cleanly (with SIGSTOP), leave the event pending. */ | |
2695 | if (debug_linux_nat) | |
2696 | fprintf_unfiltered (gdb_stdlog, | |
2697 | "SARC: core wanted LWP %ld stopped " | |
2698 | "(leaving SIGSTOP pending)\n", | |
dfd4cc63 | 2699 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2700 | lp->status = W_STOPCODE (SIGSTOP); |
2701 | } | |
2702 | ||
2703 | if (lp->status == 0) | |
2704 | { | |
2705 | if (debug_linux_nat) | |
2706 | fprintf_unfiltered (gdb_stdlog, | |
2707 | "SARC: re-resuming LWP %ld\n", | |
dfd4cc63 | 2708 | ptid_get_lwp (lp->ptid)); |
e5ef252a | 2709 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
2710 | } |
2711 | else | |
2712 | { | |
2713 | if (debug_linux_nat) | |
2714 | fprintf_unfiltered (gdb_stdlog, | |
2715 | "SARC: not re-resuming LWP %ld " | |
2716 | "(has pending)\n", | |
dfd4cc63 | 2717 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2718 | if (new_pending_p) |
2719 | *new_pending_p = 1; | |
2720 | } | |
25289eb2 | 2721 | } |
d6b0e80f AC |
2722 | } |
2723 | return 0; | |
2724 | } | |
2725 | ||
02f3fc28 | 2726 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
2727 | Return the affected lwp if we are, or NULL otherwise. If we stop |
2728 | all lwps temporarily, we may end up with new pending events in some | |
2729 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
2730 | ||
02f3fc28 | 2731 | static struct lwp_info * |
0e5bf2a8 | 2732 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
2733 | { |
2734 | struct lwp_info *lp; | |
89a5711c | 2735 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2736 | |
12d9289a PA |
2737 | *new_pending_p = 0; |
2738 | ||
02f3fc28 PA |
2739 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
2740 | ||
2741 | /* Check for stop events reported by a process we didn't already | |
2742 | know about - anything not already in our LWP list. | |
2743 | ||
2744 | If we're expecting to receive stopped processes after | |
2745 | fork, vfork, and clone events, then we'll just add the | |
2746 | new one to our list and go back to waiting for the event | |
2747 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2748 | from waitpid before or after the event is. |
2749 | ||
2750 | But note the case of a non-leader thread exec'ing after the | |
2751 | leader having exited, and gone from our lists. The non-leader | |
2752 | thread changes its tid to the tgid. */ | |
2753 | ||
2754 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2755 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2756 | { |
2757 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2758 | if (debug_linux_nat) | |
2759 | fprintf_unfiltered (gdb_stdlog, | |
2760 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2761 | lwpid); | |
2762 | ||
dfd4cc63 | 2763 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2764 | lp->stopped = 1; |
2765 | lp->resumed = 1; | |
2766 | add_thread (lp->ptid); | |
2767 | } | |
2768 | ||
02f3fc28 PA |
2769 | if (WIFSTOPPED (status) && !lp) |
2770 | { | |
84636d28 | 2771 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2772 | return NULL; |
2773 | } | |
2774 | ||
2775 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2776 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2777 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2778 | exits. */ |
2779 | if (!WIFSTOPPED (status) && !lp) | |
2780 | return NULL; | |
2781 | ||
8817a6f2 PA |
2782 | /* This LWP is stopped now. (And if dead, this prevents it from |
2783 | ever being continued.) */ | |
2784 | lp->stopped = 1; | |
2785 | ||
ca2163eb PA |
2786 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2787 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2788 | { | |
2789 | /* No longer need the sysgood bit. The ptrace event ends up | |
2790 | recorded in lp->waitstatus if we care for it. We can carry | |
2791 | on handling the event like a regular SIGTRAP from here | |
2792 | on. */ | |
2793 | status = W_STOPCODE (SIGTRAP); | |
2794 | if (linux_handle_syscall_trap (lp, 0)) | |
2795 | return NULL; | |
2796 | } | |
02f3fc28 | 2797 | |
ca2163eb | 2798 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2799 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2800 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
2801 | { |
2802 | if (debug_linux_nat) | |
2803 | fprintf_unfiltered (gdb_stdlog, | |
2804 | "LLW: Handling extended status 0x%06x\n", | |
2805 | status); | |
2806 | if (linux_handle_extended_wait (lp, status, 0)) | |
2807 | return NULL; | |
2808 | } | |
2809 | ||
26ab7092 | 2810 | if (linux_nat_status_is_event (status)) |
da559b09 | 2811 | save_sigtrap (lp); |
ca2163eb | 2812 | |
02f3fc28 | 2813 | /* Check if the thread has exited. */ |
d90e17a7 | 2814 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
dfd4cc63 | 2815 | && num_lwps (ptid_get_pid (lp->ptid)) > 1) |
02f3fc28 | 2816 | { |
9db03742 JB |
2817 | /* If this is the main thread, we must stop all threads and verify |
2818 | if they are still alive. This is because in the nptl thread model | |
2819 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
2820 | other than the main thread. We only get the main thread exit |
2821 | signal once all child threads have already exited. If we | |
2822 | stop all the threads and use the stop_wait_callback to check | |
2823 | if they have exited we can determine whether this signal | |
2824 | should be ignored or whether it means the end of the debugged | |
2825 | application, regardless of which threading model is being | |
5d3b6af6 | 2826 | used. */ |
dfd4cc63 | 2827 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) |
02f3fc28 | 2828 | { |
dfd4cc63 | 2829 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), |
12d9289a | 2830 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
2831 | } |
2832 | ||
2833 | if (debug_linux_nat) | |
2834 | fprintf_unfiltered (gdb_stdlog, | |
2835 | "LLW: %s exited.\n", | |
2836 | target_pid_to_str (lp->ptid)); | |
2837 | ||
dfd4cc63 | 2838 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) |
9db03742 JB |
2839 | { |
2840 | /* If there is at least one more LWP, then the exit signal | |
2841 | was not the end of the debugged application and should be | |
2842 | ignored. */ | |
2843 | exit_lwp (lp); | |
2844 | return NULL; | |
2845 | } | |
02f3fc28 PA |
2846 | } |
2847 | ||
2848 | /* Check if the current LWP has previously exited. In the nptl | |
2849 | thread model, LWPs other than the main thread do not issue | |
2850 | signals when they exit so we must check whenever the thread has | |
2851 | stopped. A similar check is made in stop_wait_callback(). */ | |
dfd4cc63 | 2852 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 2853 | { |
dfd4cc63 | 2854 | ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid)); |
d90e17a7 | 2855 | |
02f3fc28 PA |
2856 | if (debug_linux_nat) |
2857 | fprintf_unfiltered (gdb_stdlog, | |
2858 | "LLW: %s exited.\n", | |
2859 | target_pid_to_str (lp->ptid)); | |
2860 | ||
2861 | exit_lwp (lp); | |
2862 | ||
2863 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 2864 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
2865 | |
2866 | /* Discard the event. */ | |
2867 | return NULL; | |
2868 | } | |
2869 | ||
2870 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
2871 | an attempt to stop an LWP. */ | |
2872 | if (lp->signalled | |
2873 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2874 | { | |
2875 | if (debug_linux_nat) | |
2876 | fprintf_unfiltered (gdb_stdlog, | |
2877 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
2878 | target_pid_to_str (lp->ptid)); | |
2879 | ||
02f3fc28 PA |
2880 | lp->signalled = 0; |
2881 | ||
25289eb2 PA |
2882 | if (lp->last_resume_kind != resume_stop) |
2883 | { | |
2884 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 2885 | |
25289eb2 PA |
2886 | registers_changed (); |
2887 | ||
7b50312a PA |
2888 | if (linux_nat_prepare_to_resume != NULL) |
2889 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
2890 | linux_ops->to_resume (linux_ops, |
2891 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
2892 | lp->step, GDB_SIGNAL_0); | |
25289eb2 PA |
2893 | if (debug_linux_nat) |
2894 | fprintf_unfiltered (gdb_stdlog, | |
2895 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
2896 | lp->step ? | |
2897 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2898 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 2899 | |
25289eb2 PA |
2900 | lp->stopped = 0; |
2901 | gdb_assert (lp->resumed); | |
02f3fc28 | 2902 | |
25289eb2 PA |
2903 | /* Discard the event. */ |
2904 | return NULL; | |
2905 | } | |
02f3fc28 PA |
2906 | } |
2907 | ||
57380f4e DJ |
2908 | /* Make sure we don't report a SIGINT that we have already displayed |
2909 | for another thread. */ | |
2910 | if (lp->ignore_sigint | |
2911 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2912 | { | |
2913 | if (debug_linux_nat) | |
2914 | fprintf_unfiltered (gdb_stdlog, | |
2915 | "LLW: Delayed SIGINT caught for %s.\n", | |
2916 | target_pid_to_str (lp->ptid)); | |
2917 | ||
2918 | /* This is a delayed SIGINT. */ | |
2919 | lp->ignore_sigint = 0; | |
2920 | ||
2921 | registers_changed (); | |
7b50312a PA |
2922 | if (linux_nat_prepare_to_resume != NULL) |
2923 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 2924 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 2925 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
2926 | if (debug_linux_nat) |
2927 | fprintf_unfiltered (gdb_stdlog, | |
2928 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
2929 | lp->step ? | |
2930 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2931 | target_pid_to_str (lp->ptid)); | |
2932 | ||
2933 | lp->stopped = 0; | |
2934 | gdb_assert (lp->resumed); | |
2935 | ||
2936 | /* Discard the event. */ | |
2937 | return NULL; | |
2938 | } | |
2939 | ||
02f3fc28 PA |
2940 | /* An interesting event. */ |
2941 | gdb_assert (lp); | |
ca2163eb | 2942 | lp->status = status; |
02f3fc28 PA |
2943 | return lp; |
2944 | } | |
2945 | ||
0e5bf2a8 PA |
2946 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
2947 | their exits until all other threads in the group have exited. */ | |
2948 | ||
2949 | static void | |
2950 | check_zombie_leaders (void) | |
2951 | { | |
2952 | struct inferior *inf; | |
2953 | ||
2954 | ALL_INFERIORS (inf) | |
2955 | { | |
2956 | struct lwp_info *leader_lp; | |
2957 | ||
2958 | if (inf->pid == 0) | |
2959 | continue; | |
2960 | ||
2961 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
2962 | if (leader_lp != NULL | |
2963 | /* Check if there are other threads in the group, as we may | |
2964 | have raced with the inferior simply exiting. */ | |
2965 | && num_lwps (inf->pid) > 1 | |
5f572dec | 2966 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
2967 | { |
2968 | if (debug_linux_nat) | |
2969 | fprintf_unfiltered (gdb_stdlog, | |
2970 | "CZL: Thread group leader %d zombie " | |
2971 | "(it exited, or another thread execd).\n", | |
2972 | inf->pid); | |
2973 | ||
2974 | /* A leader zombie can mean one of two things: | |
2975 | ||
2976 | - It exited, and there's an exit status pending | |
2977 | available, or only the leader exited (not the whole | |
2978 | program). In the latter case, we can't waitpid the | |
2979 | leader's exit status until all other threads are gone. | |
2980 | ||
2981 | - There are 3 or more threads in the group, and a thread | |
2982 | other than the leader exec'd. On an exec, the Linux | |
2983 | kernel destroys all other threads (except the execing | |
2984 | one) in the thread group, and resets the execing thread's | |
2985 | tid to the tgid. No exit notification is sent for the | |
2986 | execing thread -- from the ptracer's perspective, it | |
2987 | appears as though the execing thread just vanishes. | |
2988 | Until we reap all other threads except the leader and the | |
2989 | execing thread, the leader will be zombie, and the | |
2990 | execing thread will be in `D (disc sleep)'. As soon as | |
2991 | all other threads are reaped, the execing thread changes | |
2992 | it's tid to the tgid, and the previous (zombie) leader | |
2993 | vanishes, giving place to the "new" leader. We could try | |
2994 | distinguishing the exit and exec cases, by waiting once | |
2995 | more, and seeing if something comes out, but it doesn't | |
2996 | sound useful. The previous leader _does_ go away, and | |
2997 | we'll re-add the new one once we see the exec event | |
2998 | (which is just the same as what would happen if the | |
2999 | previous leader did exit voluntarily before some other | |
3000 | thread execs). */ | |
3001 | ||
3002 | if (debug_linux_nat) | |
3003 | fprintf_unfiltered (gdb_stdlog, | |
3004 | "CZL: Thread group leader %d vanished.\n", | |
3005 | inf->pid); | |
3006 | exit_lwp (leader_lp); | |
3007 | } | |
3008 | } | |
3009 | } | |
3010 | ||
d6b0e80f | 3011 | static ptid_t |
7feb7d06 | 3012 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3013 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3014 | int target_options) | |
d6b0e80f | 3015 | { |
fc9b8e47 | 3016 | sigset_t prev_mask; |
4b60df3d | 3017 | enum resume_kind last_resume_kind; |
12d9289a | 3018 | struct lwp_info *lp; |
12d9289a | 3019 | int status; |
d6b0e80f | 3020 | |
01124a23 | 3021 | if (debug_linux_nat) |
b84876c2 PA |
3022 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3023 | ||
f973ed9c DJ |
3024 | /* The first time we get here after starting a new inferior, we may |
3025 | not have added it to the LWP list yet - this is the earliest | |
3026 | moment at which we know its PID. */ | |
d90e17a7 | 3027 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3028 | { |
27c9d204 PA |
3029 | /* Upgrade the main thread's ptid. */ |
3030 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3031 | ptid_build (ptid_get_pid (inferior_ptid), |
3032 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3033 | |
26cb8b7c | 3034 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3035 | lp->resumed = 1; |
3036 | } | |
3037 | ||
12696c10 | 3038 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3039 | block_child_signals (&prev_mask); |
d6b0e80f AC |
3040 | |
3041 | retry: | |
d90e17a7 PA |
3042 | lp = NULL; |
3043 | status = 0; | |
d6b0e80f AC |
3044 | |
3045 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3046 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3047 | { |
0e5bf2a8 | 3048 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3049 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3050 | if (lp) |
3051 | { | |
ca2163eb | 3052 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3053 | fprintf_unfiltered (gdb_stdlog, |
3054 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3055 | status_to_str (lp->status), |
d6b0e80f AC |
3056 | target_pid_to_str (lp->ptid)); |
3057 | } | |
d6b0e80f | 3058 | } |
dfd4cc63 | 3059 | else if (ptid_lwp_p (ptid)) |
d6b0e80f AC |
3060 | { |
3061 | if (debug_linux_nat) | |
3062 | fprintf_unfiltered (gdb_stdlog, | |
3063 | "LLW: Waiting for specific LWP %s.\n", | |
3064 | target_pid_to_str (ptid)); | |
3065 | ||
3066 | /* We have a specific LWP to check. */ | |
3067 | lp = find_lwp_pid (ptid); | |
3068 | gdb_assert (lp); | |
d6b0e80f | 3069 | |
ca2163eb | 3070 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3071 | fprintf_unfiltered (gdb_stdlog, |
3072 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3073 | status_to_str (lp->status), |
d6b0e80f AC |
3074 | target_pid_to_str (lp->ptid)); |
3075 | ||
d90e17a7 PA |
3076 | /* We check for lp->waitstatus in addition to lp->status, |
3077 | because we can have pending process exits recorded in | |
3078 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3079 | an additional lp->status_p flag. */ | |
ca2163eb | 3080 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3081 | lp = NULL; |
d6b0e80f AC |
3082 | } |
3083 | ||
b84876c2 PA |
3084 | if (!target_can_async_p ()) |
3085 | { | |
3086 | /* Causes SIGINT to be passed on to the attached process. */ | |
3087 | set_sigint_trap (); | |
b84876c2 | 3088 | } |
d6b0e80f | 3089 | |
0e5bf2a8 | 3090 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3091 | |
d90e17a7 | 3092 | while (lp == NULL) |
d6b0e80f AC |
3093 | { |
3094 | pid_t lwpid; | |
3095 | ||
0e5bf2a8 PA |
3096 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3097 | quirks: | |
3098 | ||
3099 | - If the thread group leader exits while other threads in the | |
3100 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3101 | waitpid won't return an exit status until the other threads | |
3102 | in the group are reapped. | |
3103 | ||
3104 | - When a non-leader thread execs, that thread just vanishes | |
3105 | without reporting an exit (so we'd hang if we waited for it | |
3106 | explicitly in that case). The exec event is reported to | |
3107 | the TGID pid. */ | |
3108 | ||
3109 | errno = 0; | |
3110 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3111 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3112 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3113 | ||
3114 | if (debug_linux_nat) | |
3115 | fprintf_unfiltered (gdb_stdlog, | |
3116 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3117 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3118 | |
d6b0e80f AC |
3119 | if (lwpid > 0) |
3120 | { | |
12d9289a PA |
3121 | /* If this is true, then we paused LWPs momentarily, and may |
3122 | now have pending events to handle. */ | |
3123 | int new_pending; | |
3124 | ||
d6b0e80f AC |
3125 | if (debug_linux_nat) |
3126 | { | |
3127 | fprintf_unfiltered (gdb_stdlog, | |
3128 | "LLW: waitpid %ld received %s\n", | |
3129 | (long) lwpid, status_to_str (status)); | |
3130 | } | |
3131 | ||
0e5bf2a8 | 3132 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3133 | |
33355866 JK |
3134 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3135 | status = 0; | |
3136 | ||
0e5bf2a8 | 3137 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3138 | { |
e3e9f5a2 PA |
3139 | gdb_assert (lp->resumed); |
3140 | ||
d90e17a7 | 3141 | if (debug_linux_nat) |
2f693f9d SDJ |
3142 | fprintf_unfiltered (gdb_stdlog, |
3143 | "LWP %ld got an event %06x, " | |
3144 | "leaving pending.\n", | |
3145 | ptid_get_lwp (lp->ptid), lp->status); | |
d90e17a7 | 3146 | |
ca2163eb | 3147 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3148 | { |
ca2163eb | 3149 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3150 | { |
e3e9f5a2 PA |
3151 | /* Cancel breakpoint hits. The breakpoint may |
3152 | be removed before we fetch events from this | |
3153 | process to report to the core. It is best | |
3154 | not to assume the moribund breakpoints | |
3155 | heuristic always handles these cases --- it | |
3156 | could be too many events go through to the | |
3157 | core before this one is handled. All-stop | |
3158 | always cancels breakpoint hits in all | |
3159 | threads. */ | |
3160 | if (non_stop | |
00390b84 | 3161 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3162 | && cancel_breakpoint (lp)) |
3163 | { | |
3164 | /* Throw away the SIGTRAP. */ | |
3165 | lp->status = 0; | |
3166 | ||
3167 | if (debug_linux_nat) | |
2f693f9d SDJ |
3168 | fprintf_unfiltered (gdb_stdlog, |
3169 | "LLW: LWP %ld hit a " | |
3170 | "breakpoint while " | |
3171 | "waiting for another " | |
3172 | "process; " | |
3173 | "cancelled it\n", | |
3174 | ptid_get_lwp (lp->ptid)); | |
e3e9f5a2 | 3175 | } |
d90e17a7 PA |
3176 | } |
3177 | else | |
8817a6f2 | 3178 | lp->signalled = 0; |
d90e17a7 | 3179 | } |
33355866 | 3180 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3181 | { |
3182 | if (debug_linux_nat) | |
2f693f9d SDJ |
3183 | fprintf_unfiltered (gdb_stdlog, |
3184 | "Process %ld exited while stopping " | |
3185 | "LWPs\n", | |
3186 | ptid_get_lwp (lp->ptid)); | |
d90e17a7 PA |
3187 | |
3188 | /* This was the last lwp in the process. Since | |
3189 | events are serialized to GDB core, and we can't | |
3190 | report this one right now, but GDB core and the | |
3191 | other target layers will want to be notified | |
3192 | about the exit code/signal, leave the status | |
3193 | pending for the next time we're able to report | |
3194 | it. */ | |
d90e17a7 | 3195 | |
d90e17a7 PA |
3196 | /* Dead LWP's aren't expected to reported a pending |
3197 | sigstop. */ | |
3198 | lp->signalled = 0; | |
3199 | ||
3200 | /* Store the pending event in the waitstatus as | |
3201 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3202 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3203 | } |
3204 | ||
3205 | /* Keep looking. */ | |
3206 | lp = NULL; | |
d6b0e80f AC |
3207 | } |
3208 | ||
0e5bf2a8 | 3209 | if (new_pending) |
d90e17a7 | 3210 | { |
0e5bf2a8 PA |
3211 | /* Some LWP now has a pending event. Go all the way |
3212 | back to check it. */ | |
3213 | goto retry; | |
3214 | } | |
12d9289a | 3215 | |
0e5bf2a8 PA |
3216 | if (lp) |
3217 | { | |
3218 | /* We got an event to report to the core. */ | |
3219 | break; | |
d90e17a7 | 3220 | } |
0e5bf2a8 PA |
3221 | |
3222 | /* Retry until nothing comes out of waitpid. A single | |
3223 | SIGCHLD can indicate more than one child stopped. */ | |
3224 | continue; | |
d6b0e80f AC |
3225 | } |
3226 | ||
0e5bf2a8 PA |
3227 | /* Check for zombie thread group leaders. Those can't be reaped |
3228 | until all other threads in the thread group are. */ | |
3229 | check_zombie_leaders (); | |
d6b0e80f | 3230 | |
0e5bf2a8 PA |
3231 | /* If there are no resumed children left, bail. We'd be stuck |
3232 | forever in the sigsuspend call below otherwise. */ | |
3233 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3234 | { | |
3235 | if (debug_linux_nat) | |
3236 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3237 | |
0e5bf2a8 | 3238 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3239 | |
0e5bf2a8 PA |
3240 | if (!target_can_async_p ()) |
3241 | clear_sigint_trap (); | |
b84876c2 | 3242 | |
0e5bf2a8 PA |
3243 | restore_child_signals_mask (&prev_mask); |
3244 | return minus_one_ptid; | |
d6b0e80f | 3245 | } |
28736962 | 3246 | |
0e5bf2a8 PA |
3247 | /* No interesting event to report to the core. */ |
3248 | ||
3249 | if (target_options & TARGET_WNOHANG) | |
3250 | { | |
01124a23 | 3251 | if (debug_linux_nat) |
28736962 PA |
3252 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3253 | ||
0e5bf2a8 | 3254 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3255 | restore_child_signals_mask (&prev_mask); |
3256 | return minus_one_ptid; | |
3257 | } | |
d6b0e80f AC |
3258 | |
3259 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3260 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3261 | |
3262 | /* Block until we get an event reported with SIGCHLD. */ | |
d36bf488 DE |
3263 | if (debug_linux_nat) |
3264 | fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n"); | |
0e5bf2a8 | 3265 | sigsuspend (&suspend_mask); |
d6b0e80f AC |
3266 | } |
3267 | ||
b84876c2 | 3268 | if (!target_can_async_p ()) |
d26b5354 | 3269 | clear_sigint_trap (); |
d6b0e80f AC |
3270 | |
3271 | gdb_assert (lp); | |
3272 | ||
ca2163eb PA |
3273 | status = lp->status; |
3274 | lp->status = 0; | |
3275 | ||
d6b0e80f AC |
3276 | /* Don't report signals that GDB isn't interested in, such as |
3277 | signals that are neither printed nor stopped upon. Stopping all | |
3278 | threads can be a bit time-consuming so if we want decent | |
3279 | performance with heavily multi-threaded programs, especially when | |
3280 | they're using a high frequency timer, we'd better avoid it if we | |
3281 | can. */ | |
3282 | ||
3283 | if (WIFSTOPPED (status)) | |
3284 | { | |
2ea28649 | 3285 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3286 | |
2455069d UW |
3287 | /* When using hardware single-step, we need to report every signal. |
3288 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3289 | if (!lp->step |
2455069d | 3290 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3291 | { |
3292 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3293 | here? It is not clear we should. GDB may not expect | |
3294 | other threads to run. On the other hand, not resuming | |
3295 | newly attached threads may cause an unwanted delay in | |
3296 | getting them running. */ | |
3297 | registers_changed (); | |
7b50312a PA |
3298 | if (linux_nat_prepare_to_resume != NULL) |
3299 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
3300 | linux_ops->to_resume (linux_ops, |
3301 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
10d6c8cd | 3302 | lp->step, signo); |
d6b0e80f AC |
3303 | if (debug_linux_nat) |
3304 | fprintf_unfiltered (gdb_stdlog, | |
3305 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3306 | lp->step ? | |
3307 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3308 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3309 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3310 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3311 | : "0")); |
d6b0e80f | 3312 | lp->stopped = 0; |
d6b0e80f AC |
3313 | goto retry; |
3314 | } | |
3315 | ||
1ad15515 | 3316 | if (!non_stop) |
d6b0e80f | 3317 | { |
1ad15515 PA |
3318 | /* Only do the below in all-stop, as we currently use SIGINT |
3319 | to implement target_stop (see linux_nat_stop) in | |
3320 | non-stop. */ | |
a493e3e2 | 3321 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3322 | { |
3323 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3324 | forwarded to the entire process group, that is, all LWPs | |
3325 | will receive it - unless they're using CLONE_THREAD to | |
3326 | share signals. Since we only want to report it once, we | |
3327 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3328 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3329 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3330 | lp->ignore_sigint = 0; |
3331 | } | |
3332 | else | |
3333 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3334 | } |
3335 | } | |
3336 | ||
3337 | /* This LWP is stopped now. */ | |
3338 | lp->stopped = 1; | |
3339 | ||
3340 | if (debug_linux_nat) | |
3341 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3342 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3343 | ||
4c28f408 PA |
3344 | if (!non_stop) |
3345 | { | |
3346 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3347 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3348 | |
3349 | /* ... and wait until all of them have reported back that | |
3350 | they're no longer running. */ | |
d90e17a7 | 3351 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3352 | |
3353 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3354 | from among those that have had events. Giving equal priority | |
3355 | to all LWPs that have had events helps prevent | |
3356 | starvation. */ | |
0e5bf2a8 | 3357 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3358 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3359 | |
e3e9f5a2 PA |
3360 | /* Now that we've selected our final event LWP, cancel any |
3361 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3362 | See the comment in cancel_breakpoints_callback to find out | |
3363 | why. */ | |
3364 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3365 | ||
4b60df3d PA |
3366 | /* We'll need this to determine whether to report a SIGSTOP as |
3367 | TARGET_WAITKIND_0. Need to take a copy because | |
3368 | resume_clear_callback clears it. */ | |
3369 | last_resume_kind = lp->last_resume_kind; | |
3370 | ||
e3e9f5a2 PA |
3371 | /* In all-stop, from the core's perspective, all LWPs are now |
3372 | stopped until a new resume action is sent over. */ | |
3373 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3374 | } | |
3375 | else | |
25289eb2 | 3376 | { |
4b60df3d PA |
3377 | /* See above. */ |
3378 | last_resume_kind = lp->last_resume_kind; | |
3379 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3380 | } |
d6b0e80f | 3381 | |
26ab7092 | 3382 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3383 | { |
d6b0e80f AC |
3384 | if (debug_linux_nat) |
3385 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3386 | "LLW: trap ptid is %s.\n", |
3387 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3388 | } |
d6b0e80f AC |
3389 | |
3390 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3391 | { | |
3392 | *ourstatus = lp->waitstatus; | |
3393 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3394 | } | |
3395 | else | |
3396 | store_waitstatus (ourstatus, status); | |
3397 | ||
01124a23 | 3398 | if (debug_linux_nat) |
b84876c2 PA |
3399 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3400 | ||
7feb7d06 | 3401 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3402 | |
4b60df3d | 3403 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3404 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3405 | && WSTOPSIG (status) == SIGSTOP) | |
3406 | { | |
3407 | /* A thread that has been requested to stop by GDB with | |
3408 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3409 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3410 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3411 | } |
3412 | ||
1e225492 JK |
3413 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3414 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3415 | lp->core = -1; | |
3416 | else | |
2e794194 | 3417 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3418 | |
f973ed9c | 3419 | return lp->ptid; |
d6b0e80f AC |
3420 | } |
3421 | ||
e3e9f5a2 PA |
3422 | /* Resume LWPs that are currently stopped without any pending status |
3423 | to report, but are resumed from the core's perspective. */ | |
3424 | ||
3425 | static int | |
3426 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3427 | { | |
3428 | ptid_t *wait_ptid_p = data; | |
3429 | ||
3430 | if (lp->stopped | |
3431 | && lp->resumed | |
3432 | && lp->status == 0 | |
3433 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3434 | { | |
336060f3 PA |
3435 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3436 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3437 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3438 | ||
e3e9f5a2 PA |
3439 | gdb_assert (is_executing (lp->ptid)); |
3440 | ||
3441 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3442 | immediately, and we're not waiting for this LWP. */ | |
3443 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3444 | { | |
e3e9f5a2 PA |
3445 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3446 | return 0; | |
3447 | } | |
3448 | ||
3449 | if (debug_linux_nat) | |
3450 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3451 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3452 | target_pid_to_str (lp->ptid), | |
3453 | paddress (gdbarch, pc), | |
3454 | lp->step); | |
e3e9f5a2 | 3455 | |
336060f3 | 3456 | registers_changed (); |
7b50312a PA |
3457 | if (linux_nat_prepare_to_resume != NULL) |
3458 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 3459 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 3460 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3461 | lp->stopped = 0; |
e3e9f5a2 PA |
3462 | lp->stopped_by_watchpoint = 0; |
3463 | } | |
3464 | ||
3465 | return 0; | |
3466 | } | |
3467 | ||
7feb7d06 PA |
3468 | static ptid_t |
3469 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3470 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3471 | int target_options) | |
7feb7d06 PA |
3472 | { |
3473 | ptid_t event_ptid; | |
3474 | ||
3475 | if (debug_linux_nat) | |
09826ec5 PA |
3476 | { |
3477 | char *options_string; | |
3478 | ||
3479 | options_string = target_options_to_string (target_options); | |
3480 | fprintf_unfiltered (gdb_stdlog, | |
3481 | "linux_nat_wait: [%s], [%s]\n", | |
3482 | target_pid_to_str (ptid), | |
3483 | options_string); | |
3484 | xfree (options_string); | |
3485 | } | |
7feb7d06 PA |
3486 | |
3487 | /* Flush the async file first. */ | |
3488 | if (target_can_async_p ()) | |
3489 | async_file_flush (); | |
3490 | ||
e3e9f5a2 PA |
3491 | /* Resume LWPs that are currently stopped without any pending status |
3492 | to report, but are resumed from the core's perspective. LWPs get | |
3493 | in this state if we find them stopping at a time we're not | |
3494 | interested in reporting the event (target_wait on a | |
3495 | specific_process, for example, see linux_nat_wait_1), and | |
3496 | meanwhile the event became uninteresting. Don't bother resuming | |
3497 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3498 | if (non_stop) | |
3499 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3500 | ||
47608cb1 | 3501 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3502 | |
3503 | /* If we requested any event, and something came out, assume there | |
3504 | may be more. If we requested a specific lwp or process, also | |
3505 | assume there may be more. */ | |
3506 | if (target_can_async_p () | |
6953d224 PA |
3507 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3508 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3509 | || !ptid_equal (ptid, minus_one_ptid))) |
3510 | async_file_mark (); | |
3511 | ||
3512 | /* Get ready for the next event. */ | |
3513 | if (target_can_async_p ()) | |
3514 | target_async (inferior_event_handler, 0); | |
3515 | ||
3516 | return event_ptid; | |
3517 | } | |
3518 | ||
d6b0e80f AC |
3519 | static int |
3520 | kill_callback (struct lwp_info *lp, void *data) | |
3521 | { | |
ed731959 JK |
3522 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3523 | ||
3524 | errno = 0; | |
69ff6be5 | 3525 | kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL); |
ed731959 | 3526 | if (debug_linux_nat) |
57745c90 PA |
3527 | { |
3528 | int save_errno = errno; | |
3529 | ||
3530 | fprintf_unfiltered (gdb_stdlog, | |
3531 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3532 | target_pid_to_str (lp->ptid), | |
3533 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3534 | } | |
ed731959 JK |
3535 | |
3536 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3537 | ||
d6b0e80f | 3538 | errno = 0; |
dfd4cc63 | 3539 | ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0); |
d6b0e80f | 3540 | if (debug_linux_nat) |
57745c90 PA |
3541 | { |
3542 | int save_errno = errno; | |
3543 | ||
3544 | fprintf_unfiltered (gdb_stdlog, | |
3545 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3546 | target_pid_to_str (lp->ptid), | |
3547 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3548 | } | |
d6b0e80f AC |
3549 | |
3550 | return 0; | |
3551 | } | |
3552 | ||
3553 | static int | |
3554 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3555 | { | |
3556 | pid_t pid; | |
3557 | ||
3558 | /* We must make sure that there are no pending events (delayed | |
3559 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3560 | program doesn't interfere with any following debugging session. */ | |
3561 | ||
3562 | /* For cloned processes we must check both with __WCLONE and | |
3563 | without, since the exit status of a cloned process isn't reported | |
3564 | with __WCLONE. */ | |
3565 | if (lp->cloned) | |
3566 | { | |
3567 | do | |
3568 | { | |
dfd4cc63 | 3569 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE); |
e85a822c | 3570 | if (pid != (pid_t) -1) |
d6b0e80f | 3571 | { |
e85a822c DJ |
3572 | if (debug_linux_nat) |
3573 | fprintf_unfiltered (gdb_stdlog, | |
3574 | "KWC: wait %s received unknown.\n", | |
3575 | target_pid_to_str (lp->ptid)); | |
3576 | /* The Linux kernel sometimes fails to kill a thread | |
3577 | completely after PTRACE_KILL; that goes from the stop | |
3578 | point in do_fork out to the one in | |
3579 | get_signal_to_deliever and waits again. So kill it | |
3580 | again. */ | |
3581 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3582 | } |
3583 | } | |
dfd4cc63 | 3584 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3585 | |
3586 | gdb_assert (pid == -1 && errno == ECHILD); | |
3587 | } | |
3588 | ||
3589 | do | |
3590 | { | |
dfd4cc63 | 3591 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0); |
e85a822c | 3592 | if (pid != (pid_t) -1) |
d6b0e80f | 3593 | { |
e85a822c DJ |
3594 | if (debug_linux_nat) |
3595 | fprintf_unfiltered (gdb_stdlog, | |
3596 | "KWC: wait %s received unk.\n", | |
3597 | target_pid_to_str (lp->ptid)); | |
3598 | /* See the call to kill_callback above. */ | |
3599 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3600 | } |
3601 | } | |
dfd4cc63 | 3602 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3603 | |
3604 | gdb_assert (pid == -1 && errno == ECHILD); | |
3605 | return 0; | |
3606 | } | |
3607 | ||
3608 | static void | |
7d85a9c0 | 3609 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3610 | { |
f973ed9c DJ |
3611 | struct target_waitstatus last; |
3612 | ptid_t last_ptid; | |
3613 | int status; | |
d6b0e80f | 3614 | |
f973ed9c DJ |
3615 | /* If we're stopped while forking and we haven't followed yet, |
3616 | kill the other task. We need to do this first because the | |
3617 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3618 | |
f973ed9c | 3619 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3620 | |
f973ed9c DJ |
3621 | if (last.kind == TARGET_WAITKIND_FORKED |
3622 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3623 | { | |
dfd4cc63 | 3624 | ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0); |
f973ed9c | 3625 | wait (&status); |
26cb8b7c PA |
3626 | |
3627 | /* Let the arch-specific native code know this process is | |
3628 | gone. */ | |
dfd4cc63 | 3629 | linux_nat_forget_process (ptid_get_pid (last.value.related_pid)); |
f973ed9c DJ |
3630 | } |
3631 | ||
3632 | if (forks_exist_p ()) | |
7feb7d06 | 3633 | linux_fork_killall (); |
f973ed9c DJ |
3634 | else |
3635 | { | |
d90e17a7 | 3636 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3637 | |
4c28f408 PA |
3638 | /* Stop all threads before killing them, since ptrace requires |
3639 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3640 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3641 | /* ... and wait until all of them have reported back that |
3642 | they're no longer running. */ | |
d90e17a7 | 3643 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3644 | |
f973ed9c | 3645 | /* Kill all LWP's ... */ |
d90e17a7 | 3646 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3647 | |
3648 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3649 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3650 | } |
3651 | ||
3652 | target_mourn_inferior (); | |
d6b0e80f AC |
3653 | } |
3654 | ||
3655 | static void | |
136d6dae | 3656 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3657 | { |
26cb8b7c PA |
3658 | int pid = ptid_get_pid (inferior_ptid); |
3659 | ||
3660 | purge_lwp_list (pid); | |
d6b0e80f | 3661 | |
f973ed9c | 3662 | if (! forks_exist_p ()) |
d90e17a7 PA |
3663 | /* Normal case, no other forks available. */ |
3664 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3665 | else |
3666 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3667 | there are other viable forks to debug. Delete the exiting | |
3668 | one and context-switch to the first available. */ | |
3669 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3670 | |
3671 | /* Let the arch-specific native code know this process is gone. */ | |
3672 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3673 | } |
3674 | ||
5b009018 PA |
3675 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3676 | layout of the inferiors' architecture. */ | |
3677 | ||
3678 | static void | |
a5362b9a | 3679 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3680 | { |
3681 | int done = 0; | |
3682 | ||
3683 | if (linux_nat_siginfo_fixup != NULL) | |
3684 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3685 | ||
3686 | /* If there was no callback, or the callback didn't do anything, | |
3687 | then just do a straight memcpy. */ | |
3688 | if (!done) | |
3689 | { | |
3690 | if (direction == 1) | |
a5362b9a | 3691 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3692 | else |
a5362b9a | 3693 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3694 | } |
3695 | } | |
3696 | ||
9b409511 | 3697 | static enum target_xfer_status |
4aa995e1 PA |
3698 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
3699 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
3700 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3701 | ULONGEST *xfered_len) | |
4aa995e1 | 3702 | { |
4aa995e1 | 3703 | int pid; |
a5362b9a TS |
3704 | siginfo_t siginfo; |
3705 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3706 | |
3707 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3708 | gdb_assert (readbuf || writebuf); | |
3709 | ||
dfd4cc63 | 3710 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3711 | if (pid == 0) |
dfd4cc63 | 3712 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3713 | |
3714 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3715 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3716 | |
3717 | errno = 0; | |
3718 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3719 | if (errno != 0) | |
2ed4b548 | 3720 | return TARGET_XFER_E_IO; |
4aa995e1 | 3721 | |
5b009018 PA |
3722 | /* When GDB is built as a 64-bit application, ptrace writes into |
3723 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3724 | inferior with a 64-bit GDB should look the same as debugging it | |
3725 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3726 | the converted layout, so any read/write will have to be done | |
3727 | post-conversion. */ | |
3728 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3729 | ||
4aa995e1 PA |
3730 | if (offset + len > sizeof (siginfo)) |
3731 | len = sizeof (siginfo) - offset; | |
3732 | ||
3733 | if (readbuf != NULL) | |
5b009018 | 3734 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3735 | else |
3736 | { | |
5b009018 PA |
3737 | memcpy (inf_siginfo + offset, writebuf, len); |
3738 | ||
3739 | /* Convert back to ptrace layout before flushing it out. */ | |
3740 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3741 | ||
4aa995e1 PA |
3742 | errno = 0; |
3743 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3744 | if (errno != 0) | |
2ed4b548 | 3745 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3746 | } |
3747 | ||
9b409511 YQ |
3748 | *xfered_len = len; |
3749 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3750 | } |
3751 | ||
9b409511 | 3752 | static enum target_xfer_status |
10d6c8cd DJ |
3753 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
3754 | const char *annex, gdb_byte *readbuf, | |
3755 | const gdb_byte *writebuf, | |
9b409511 | 3756 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
d6b0e80f | 3757 | { |
4aa995e1 | 3758 | struct cleanup *old_chain; |
9b409511 | 3759 | enum target_xfer_status xfer; |
d6b0e80f | 3760 | |
4aa995e1 PA |
3761 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3762 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
9b409511 | 3763 | offset, len, xfered_len); |
4aa995e1 | 3764 | |
c35b1492 PA |
3765 | /* The target is connected but no live inferior is selected. Pass |
3766 | this request down to a lower stratum (e.g., the executable | |
3767 | file). */ | |
3768 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3769 | return TARGET_XFER_EOF; |
c35b1492 | 3770 | |
4aa995e1 PA |
3771 | old_chain = save_inferior_ptid (); |
3772 | ||
dfd4cc63 LM |
3773 | if (ptid_lwp_p (inferior_ptid)) |
3774 | inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid)); | |
d6b0e80f | 3775 | |
10d6c8cd | 3776 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 | 3777 | offset, len, xfered_len); |
d6b0e80f AC |
3778 | |
3779 | do_cleanups (old_chain); | |
3780 | return xfer; | |
3781 | } | |
3782 | ||
3783 | static int | |
28439f5e | 3784 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 3785 | { |
8c6a60d1 | 3786 | int err, tmp_errno; |
4c28f408 | 3787 | |
dfd4cc63 | 3788 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 3789 | |
4c28f408 PA |
3790 | /* Send signal 0 instead of anything ptrace, because ptracing a |
3791 | running thread errors out claiming that the thread doesn't | |
3792 | exist. */ | |
dfd4cc63 | 3793 | err = kill_lwp (ptid_get_lwp (ptid), 0); |
8c6a60d1 | 3794 | tmp_errno = errno; |
d6b0e80f AC |
3795 | if (debug_linux_nat) |
3796 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 3797 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 3798 | target_pid_to_str (ptid), |
8c6a60d1 | 3799 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 3800 | |
4c28f408 | 3801 | if (err != 0) |
d6b0e80f AC |
3802 | return 0; |
3803 | ||
3804 | return 1; | |
3805 | } | |
3806 | ||
28439f5e PA |
3807 | static int |
3808 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
3809 | { | |
3810 | return linux_thread_alive (ptid); | |
3811 | } | |
3812 | ||
d6b0e80f | 3813 | static char * |
117de6a9 | 3814 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
3815 | { |
3816 | static char buf[64]; | |
3817 | ||
dfd4cc63 LM |
3818 | if (ptid_lwp_p (ptid) |
3819 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
3820 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 3821 | { |
dfd4cc63 | 3822 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
3823 | return buf; |
3824 | } | |
3825 | ||
3826 | return normal_pid_to_str (ptid); | |
3827 | } | |
3828 | ||
4694da01 | 3829 | static char * |
503a628d | 3830 | linux_nat_thread_name (struct target_ops *self, struct thread_info *thr) |
4694da01 TT |
3831 | { |
3832 | int pid = ptid_get_pid (thr->ptid); | |
3833 | long lwp = ptid_get_lwp (thr->ptid); | |
3834 | #define FORMAT "/proc/%d/task/%ld/comm" | |
3835 | char buf[sizeof (FORMAT) + 30]; | |
3836 | FILE *comm_file; | |
3837 | char *result = NULL; | |
3838 | ||
3839 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 3840 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
3841 | if (comm_file) |
3842 | { | |
3843 | /* Not exported by the kernel, so we define it here. */ | |
3844 | #define COMM_LEN 16 | |
3845 | static char line[COMM_LEN + 1]; | |
3846 | ||
3847 | if (fgets (line, sizeof (line), comm_file)) | |
3848 | { | |
3849 | char *nl = strchr (line, '\n'); | |
3850 | ||
3851 | if (nl) | |
3852 | *nl = '\0'; | |
3853 | if (*line != '\0') | |
3854 | result = line; | |
3855 | } | |
3856 | ||
3857 | fclose (comm_file); | |
3858 | } | |
3859 | ||
3860 | #undef COMM_LEN | |
3861 | #undef FORMAT | |
3862 | ||
3863 | return result; | |
3864 | } | |
3865 | ||
dba24537 AC |
3866 | /* Accepts an integer PID; Returns a string representing a file that |
3867 | can be opened to get the symbols for the child process. */ | |
3868 | ||
6d8fd2b7 | 3869 | static char * |
8dd27370 | 3870 | linux_child_pid_to_exec_file (struct target_ops *self, int pid) |
dba24537 | 3871 | { |
b4ab256d HZ |
3872 | static char buf[PATH_MAX]; |
3873 | char name[PATH_MAX]; | |
dba24537 | 3874 | |
b4ab256d HZ |
3875 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
3876 | memset (buf, 0, PATH_MAX); | |
3877 | if (readlink (name, buf, PATH_MAX - 1) <= 0) | |
3878 | strcpy (buf, name); | |
dba24537 | 3879 | |
b4ab256d | 3880 | return buf; |
dba24537 AC |
3881 | } |
3882 | ||
10d6c8cd DJ |
3883 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
3884 | filesystem. Because we can use a single read() call for /proc, this | |
3885 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
3886 | but it doesn't support writes. */ | |
3887 | ||
9b409511 | 3888 | static enum target_xfer_status |
10d6c8cd DJ |
3889 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
3890 | const char *annex, gdb_byte *readbuf, | |
3891 | const gdb_byte *writebuf, | |
9b409511 | 3892 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3893 | { |
10d6c8cd DJ |
3894 | LONGEST ret; |
3895 | int fd; | |
dba24537 AC |
3896 | char filename[64]; |
3897 | ||
10d6c8cd | 3898 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
3899 | return 0; |
3900 | ||
3901 | /* Don't bother for one word. */ | |
3902 | if (len < 3 * sizeof (long)) | |
9b409511 | 3903 | return TARGET_XFER_EOF; |
dba24537 AC |
3904 | |
3905 | /* We could keep this file open and cache it - possibly one per | |
3906 | thread. That requires some juggling, but is even faster. */ | |
cde33bf1 YQ |
3907 | xsnprintf (filename, sizeof filename, "/proc/%d/mem", |
3908 | ptid_get_pid (inferior_ptid)); | |
614c279d | 3909 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 | 3910 | if (fd == -1) |
9b409511 | 3911 | return TARGET_XFER_EOF; |
dba24537 AC |
3912 | |
3913 | /* If pread64 is available, use it. It's faster if the kernel | |
3914 | supports it (only one syscall), and it's 64-bit safe even on | |
3915 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
3916 | application). */ | |
3917 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 3918 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 3919 | #else |
10d6c8cd | 3920 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
3921 | #endif |
3922 | ret = 0; | |
3923 | else | |
3924 | ret = len; | |
3925 | ||
3926 | close (fd); | |
9b409511 YQ |
3927 | |
3928 | if (ret == 0) | |
3929 | return TARGET_XFER_EOF; | |
3930 | else | |
3931 | { | |
3932 | *xfered_len = ret; | |
3933 | return TARGET_XFER_OK; | |
3934 | } | |
dba24537 AC |
3935 | } |
3936 | ||
efcbbd14 UW |
3937 | |
3938 | /* Enumerate spufs IDs for process PID. */ | |
3939 | static LONGEST | |
b55e14c7 | 3940 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 3941 | { |
f5656ead | 3942 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
3943 | LONGEST pos = 0; |
3944 | LONGEST written = 0; | |
3945 | char path[128]; | |
3946 | DIR *dir; | |
3947 | struct dirent *entry; | |
3948 | ||
3949 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
3950 | dir = opendir (path); | |
3951 | if (!dir) | |
3952 | return -1; | |
3953 | ||
3954 | rewinddir (dir); | |
3955 | while ((entry = readdir (dir)) != NULL) | |
3956 | { | |
3957 | struct stat st; | |
3958 | struct statfs stfs; | |
3959 | int fd; | |
3960 | ||
3961 | fd = atoi (entry->d_name); | |
3962 | if (!fd) | |
3963 | continue; | |
3964 | ||
3965 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
3966 | if (stat (path, &st) != 0) | |
3967 | continue; | |
3968 | if (!S_ISDIR (st.st_mode)) | |
3969 | continue; | |
3970 | ||
3971 | if (statfs (path, &stfs) != 0) | |
3972 | continue; | |
3973 | if (stfs.f_type != SPUFS_MAGIC) | |
3974 | continue; | |
3975 | ||
3976 | if (pos >= offset && pos + 4 <= offset + len) | |
3977 | { | |
3978 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
3979 | written += 4; | |
3980 | } | |
3981 | pos += 4; | |
3982 | } | |
3983 | ||
3984 | closedir (dir); | |
3985 | return written; | |
3986 | } | |
3987 | ||
3988 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
3989 | object type, using the /proc file system. */ | |
9b409511 YQ |
3990 | |
3991 | static enum target_xfer_status | |
efcbbd14 UW |
3992 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
3993 | const char *annex, gdb_byte *readbuf, | |
3994 | const gdb_byte *writebuf, | |
9b409511 | 3995 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
3996 | { |
3997 | char buf[128]; | |
3998 | int fd = 0; | |
3999 | int ret = -1; | |
dfd4cc63 | 4000 | int pid = ptid_get_pid (inferior_ptid); |
efcbbd14 UW |
4001 | |
4002 | if (!annex) | |
4003 | { | |
4004 | if (!readbuf) | |
2ed4b548 | 4005 | return TARGET_XFER_E_IO; |
efcbbd14 | 4006 | else |
9b409511 YQ |
4007 | { |
4008 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4009 | ||
4010 | if (l < 0) | |
4011 | return TARGET_XFER_E_IO; | |
4012 | else if (l == 0) | |
4013 | return TARGET_XFER_EOF; | |
4014 | else | |
4015 | { | |
4016 | *xfered_len = (ULONGEST) l; | |
4017 | return TARGET_XFER_OK; | |
4018 | } | |
4019 | } | |
efcbbd14 UW |
4020 | } |
4021 | ||
4022 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4023 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4024 | if (fd <= 0) |
2ed4b548 | 4025 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4026 | |
4027 | if (offset != 0 | |
4028 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4029 | { | |
4030 | close (fd); | |
9b409511 | 4031 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4032 | } |
4033 | ||
4034 | if (writebuf) | |
4035 | ret = write (fd, writebuf, (size_t) len); | |
4036 | else if (readbuf) | |
4037 | ret = read (fd, readbuf, (size_t) len); | |
4038 | ||
4039 | close (fd); | |
9b409511 YQ |
4040 | |
4041 | if (ret < 0) | |
4042 | return TARGET_XFER_E_IO; | |
4043 | else if (ret == 0) | |
4044 | return TARGET_XFER_EOF; | |
4045 | else | |
4046 | { | |
4047 | *xfered_len = (ULONGEST) ret; | |
4048 | return TARGET_XFER_OK; | |
4049 | } | |
efcbbd14 UW |
4050 | } |
4051 | ||
4052 | ||
dba24537 AC |
4053 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4054 | ||
4055 | static void | |
4056 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4057 | { | |
4058 | int len = strlen (line) - 1; | |
4059 | const char *p; | |
4060 | int signum; | |
4061 | ||
4062 | if (line[len] != '\n') | |
8a3fe4f8 | 4063 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4064 | |
4065 | p = line; | |
4066 | signum = len * 4; | |
4067 | while (len-- > 0) | |
4068 | { | |
4069 | int digit; | |
4070 | ||
4071 | if (*p >= '0' && *p <= '9') | |
4072 | digit = *p - '0'; | |
4073 | else if (*p >= 'a' && *p <= 'f') | |
4074 | digit = *p - 'a' + 10; | |
4075 | else | |
8a3fe4f8 | 4076 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4077 | |
4078 | signum -= 4; | |
4079 | ||
4080 | if (digit & 1) | |
4081 | sigaddset (sigs, signum + 1); | |
4082 | if (digit & 2) | |
4083 | sigaddset (sigs, signum + 2); | |
4084 | if (digit & 4) | |
4085 | sigaddset (sigs, signum + 3); | |
4086 | if (digit & 8) | |
4087 | sigaddset (sigs, signum + 4); | |
4088 | ||
4089 | p++; | |
4090 | } | |
4091 | } | |
4092 | ||
4093 | /* Find process PID's pending signals from /proc/pid/status and set | |
4094 | SIGS to match. */ | |
4095 | ||
4096 | void | |
3e43a32a MS |
4097 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4098 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4099 | { |
4100 | FILE *procfile; | |
d8d2a3ee | 4101 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4102 | struct cleanup *cleanup; |
dba24537 AC |
4103 | |
4104 | sigemptyset (pending); | |
4105 | sigemptyset (blocked); | |
4106 | sigemptyset (ignored); | |
cde33bf1 | 4107 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
614c279d | 4108 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4109 | if (procfile == NULL) |
8a3fe4f8 | 4110 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4111 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4112 | |
d8d2a3ee | 4113 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4114 | { |
4115 | /* Normal queued signals are on the SigPnd line in the status | |
4116 | file. However, 2.6 kernels also have a "shared" pending | |
4117 | queue for delivering signals to a thread group, so check for | |
4118 | a ShdPnd line also. | |
4119 | ||
4120 | Unfortunately some Red Hat kernels include the shared pending | |
4121 | queue but not the ShdPnd status field. */ | |
4122 | ||
4123 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4124 | add_line_to_sigset (buffer + 8, pending); | |
4125 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4126 | add_line_to_sigset (buffer + 8, pending); | |
4127 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4128 | add_line_to_sigset (buffer + 8, blocked); | |
4129 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4130 | add_line_to_sigset (buffer + 8, ignored); | |
4131 | } | |
4132 | ||
7c8a8b04 | 4133 | do_cleanups (cleanup); |
dba24537 AC |
4134 | } |
4135 | ||
9b409511 | 4136 | static enum target_xfer_status |
07e059b5 | 4137 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
e0881a8e | 4138 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4139 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4140 | ULONGEST *xfered_len) | |
07e059b5 | 4141 | { |
07e059b5 VP |
4142 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4143 | ||
9b409511 YQ |
4144 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4145 | if (*xfered_len == 0) | |
4146 | return TARGET_XFER_EOF; | |
4147 | else | |
4148 | return TARGET_XFER_OK; | |
07e059b5 VP |
4149 | } |
4150 | ||
9b409511 | 4151 | static enum target_xfer_status |
10d6c8cd DJ |
4152 | linux_xfer_partial (struct target_ops *ops, enum target_object object, |
4153 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
4154 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4155 | ULONGEST *xfered_len) | |
10d6c8cd | 4156 | { |
9b409511 | 4157 | enum target_xfer_status xfer; |
10d6c8cd DJ |
4158 | |
4159 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4160 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
9b409511 | 4161 | offset, len, xfered_len); |
10d6c8cd | 4162 | |
07e059b5 VP |
4163 | if (object == TARGET_OBJECT_OSDATA) |
4164 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4165 | offset, len, xfered_len); |
07e059b5 | 4166 | |
efcbbd14 UW |
4167 | if (object == TARGET_OBJECT_SPU) |
4168 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4169 | offset, len, xfered_len); |
efcbbd14 | 4170 | |
8f313923 JK |
4171 | /* GDB calculates all the addresses in possibly larget width of the address. |
4172 | Address width needs to be masked before its final use - either by | |
4173 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4174 | ||
4175 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4176 | ||
4177 | if (object == TARGET_OBJECT_MEMORY) | |
4178 | { | |
f5656ead | 4179 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4180 | |
4181 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4182 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4183 | } | |
4184 | ||
10d6c8cd | 4185 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 YQ |
4186 | offset, len, xfered_len); |
4187 | if (xfer != TARGET_XFER_EOF) | |
10d6c8cd DJ |
4188 | return xfer; |
4189 | ||
4190 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4191 | offset, len, xfered_len); |
10d6c8cd DJ |
4192 | } |
4193 | ||
5808517f YQ |
4194 | static void |
4195 | cleanup_target_stop (void *arg) | |
4196 | { | |
4197 | ptid_t *ptid = (ptid_t *) arg; | |
4198 | ||
4199 | gdb_assert (arg != NULL); | |
4200 | ||
4201 | /* Unpause all */ | |
a493e3e2 | 4202 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4203 | } |
4204 | ||
4205 | static VEC(static_tracepoint_marker_p) * | |
c686c57f TT |
4206 | linux_child_static_tracepoint_markers_by_strid (struct target_ops *self, |
4207 | const char *strid) | |
5808517f YQ |
4208 | { |
4209 | char s[IPA_CMD_BUF_SIZE]; | |
4210 | struct cleanup *old_chain; | |
4211 | int pid = ptid_get_pid (inferior_ptid); | |
4212 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4213 | struct static_tracepoint_marker *marker = NULL; | |
4214 | char *p = s; | |
4215 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4216 | ||
4217 | /* Pause all */ | |
4218 | target_stop (ptid); | |
4219 | ||
4220 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4221 | s[sizeof ("qTfSTM")] = 0; | |
4222 | ||
42476b70 | 4223 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4224 | |
4225 | old_chain = make_cleanup (free_current_marker, &marker); | |
4226 | make_cleanup (cleanup_target_stop, &ptid); | |
4227 | ||
4228 | while (*p++ == 'm') | |
4229 | { | |
4230 | if (marker == NULL) | |
4231 | marker = XCNEW (struct static_tracepoint_marker); | |
4232 | ||
4233 | do | |
4234 | { | |
4235 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4236 | ||
4237 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4238 | { | |
4239 | VEC_safe_push (static_tracepoint_marker_p, | |
4240 | markers, marker); | |
4241 | marker = NULL; | |
4242 | } | |
4243 | else | |
4244 | { | |
4245 | release_static_tracepoint_marker (marker); | |
4246 | memset (marker, 0, sizeof (*marker)); | |
4247 | } | |
4248 | } | |
4249 | while (*p++ == ','); /* comma-separated list */ | |
4250 | ||
4251 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4252 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4253 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4254 | p = s; |
4255 | } | |
4256 | ||
4257 | do_cleanups (old_chain); | |
4258 | ||
4259 | return markers; | |
4260 | } | |
4261 | ||
e9efe249 | 4262 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4263 | it with local methods. */ |
4264 | ||
910122bf UW |
4265 | static void |
4266 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4267 | { |
6d8fd2b7 | 4268 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4269 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4270 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4271 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4272 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4273 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4274 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4275 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4276 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4277 | t->to_post_attach = linux_child_post_attach; |
4278 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4279 | |
4280 | super_xfer_partial = t->to_xfer_partial; | |
4281 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4282 | |
4283 | t->to_static_tracepoint_markers_by_strid | |
4284 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4285 | } |
4286 | ||
4287 | struct target_ops * | |
4288 | linux_target (void) | |
4289 | { | |
4290 | struct target_ops *t; | |
4291 | ||
4292 | t = inf_ptrace_target (); | |
4293 | linux_target_install_ops (t); | |
4294 | ||
4295 | return t; | |
4296 | } | |
4297 | ||
4298 | struct target_ops * | |
7714d83a | 4299 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4300 | { |
4301 | struct target_ops *t; | |
4302 | ||
4303 | t = inf_ptrace_trad_target (register_u_offset); | |
4304 | linux_target_install_ops (t); | |
10d6c8cd | 4305 | |
10d6c8cd DJ |
4306 | return t; |
4307 | } | |
4308 | ||
b84876c2 PA |
4309 | /* target_is_async_p implementation. */ |
4310 | ||
4311 | static int | |
6a109b6b | 4312 | linux_nat_is_async_p (struct target_ops *ops) |
b84876c2 PA |
4313 | { |
4314 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4315 | it explicitly with the "set target-async" command. |
b84876c2 | 4316 | Someday, linux will always be async. */ |
3dd5b83d | 4317 | return target_async_permitted; |
b84876c2 PA |
4318 | } |
4319 | ||
4320 | /* target_can_async_p implementation. */ | |
4321 | ||
4322 | static int | |
6a109b6b | 4323 | linux_nat_can_async_p (struct target_ops *ops) |
b84876c2 PA |
4324 | { |
4325 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4326 | it explicitly with the "set target-async" command. |
b84876c2 | 4327 | Someday, linux will always be async. */ |
3dd5b83d | 4328 | return target_async_permitted; |
b84876c2 PA |
4329 | } |
4330 | ||
9908b566 | 4331 | static int |
2a9a2795 | 4332 | linux_nat_supports_non_stop (struct target_ops *self) |
9908b566 VP |
4333 | { |
4334 | return 1; | |
4335 | } | |
4336 | ||
d90e17a7 PA |
4337 | /* True if we want to support multi-process. To be removed when GDB |
4338 | supports multi-exec. */ | |
4339 | ||
2277426b | 4340 | int linux_multi_process = 1; |
d90e17a7 PA |
4341 | |
4342 | static int | |
86ce2668 | 4343 | linux_nat_supports_multi_process (struct target_ops *self) |
d90e17a7 PA |
4344 | { |
4345 | return linux_multi_process; | |
4346 | } | |
4347 | ||
03583c20 | 4348 | static int |
2bfc0540 | 4349 | linux_nat_supports_disable_randomization (struct target_ops *self) |
03583c20 UW |
4350 | { |
4351 | #ifdef HAVE_PERSONALITY | |
4352 | return 1; | |
4353 | #else | |
4354 | return 0; | |
4355 | #endif | |
4356 | } | |
4357 | ||
b84876c2 PA |
4358 | static int async_terminal_is_ours = 1; |
4359 | ||
4d4ca2a1 DE |
4360 | /* target_terminal_inferior implementation. |
4361 | ||
4362 | This is a wrapper around child_terminal_inferior to add async support. */ | |
b84876c2 PA |
4363 | |
4364 | static void | |
d2f640d4 | 4365 | linux_nat_terminal_inferior (struct target_ops *self) |
b84876c2 PA |
4366 | { |
4367 | if (!target_is_async_p ()) | |
4368 | { | |
4369 | /* Async mode is disabled. */ | |
d6b64346 | 4370 | child_terminal_inferior (self); |
b84876c2 PA |
4371 | return; |
4372 | } | |
4373 | ||
d6b64346 | 4374 | child_terminal_inferior (self); |
b84876c2 | 4375 | |
d9d2d8b6 | 4376 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4377 | if (!async_terminal_is_ours) |
4378 | return; | |
4379 | ||
4380 | delete_file_handler (input_fd); | |
4381 | async_terminal_is_ours = 0; | |
4382 | set_sigint_trap (); | |
4383 | } | |
4384 | ||
4d4ca2a1 DE |
4385 | /* target_terminal_ours implementation. |
4386 | ||
4387 | This is a wrapper around child_terminal_ours to add async support (and | |
4388 | implement the target_terminal_ours vs target_terminal_ours_for_output | |
4389 | distinction). child_terminal_ours is currently no different than | |
4390 | child_terminal_ours_for_output. | |
4391 | We leave target_terminal_ours_for_output alone, leaving it to | |
4392 | child_terminal_ours_for_output. */ | |
b84876c2 | 4393 | |
2c0b251b | 4394 | static void |
e3594fd1 | 4395 | linux_nat_terminal_ours (struct target_ops *self) |
b84876c2 PA |
4396 | { |
4397 | if (!target_is_async_p ()) | |
4398 | { | |
4399 | /* Async mode is disabled. */ | |
d6b64346 | 4400 | child_terminal_ours (self); |
b84876c2 PA |
4401 | return; |
4402 | } | |
4403 | ||
4404 | /* GDB should never give the terminal to the inferior if the | |
4405 | inferior is running in the background (run&, continue&, etc.), | |
4406 | but claiming it sure should. */ | |
d6b64346 | 4407 | child_terminal_ours (self); |
b84876c2 | 4408 | |
b84876c2 PA |
4409 | if (async_terminal_is_ours) |
4410 | return; | |
4411 | ||
4412 | clear_sigint_trap (); | |
4413 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4414 | async_terminal_is_ours = 1; | |
4415 | } | |
4416 | ||
4417 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4418 | void *context); | |
4419 | static void *async_client_context; | |
4420 | ||
7feb7d06 PA |
4421 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4422 | so we notice when any child changes state, and notify the | |
4423 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4424 | above to wait for the arrival of a SIGCHLD. */ | |
4425 | ||
b84876c2 | 4426 | static void |
7feb7d06 | 4427 | sigchld_handler (int signo) |
b84876c2 | 4428 | { |
7feb7d06 PA |
4429 | int old_errno = errno; |
4430 | ||
01124a23 DE |
4431 | if (debug_linux_nat) |
4432 | ui_file_write_async_safe (gdb_stdlog, | |
4433 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4434 | |
4435 | if (signo == SIGCHLD | |
4436 | && linux_nat_event_pipe[0] != -1) | |
4437 | async_file_mark (); /* Let the event loop know that there are | |
4438 | events to handle. */ | |
4439 | ||
4440 | errno = old_errno; | |
4441 | } | |
4442 | ||
4443 | /* Callback registered with the target events file descriptor. */ | |
4444 | ||
4445 | static void | |
4446 | handle_target_event (int error, gdb_client_data client_data) | |
4447 | { | |
4448 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4449 | } | |
4450 | ||
4451 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4452 | ||
4453 | static int | |
4454 | linux_async_pipe (int enable) | |
4455 | { | |
4456 | int previous = (linux_nat_event_pipe[0] != -1); | |
4457 | ||
4458 | if (previous != enable) | |
4459 | { | |
4460 | sigset_t prev_mask; | |
4461 | ||
12696c10 PA |
4462 | /* Block child signals while we create/destroy the pipe, as |
4463 | their handler writes to it. */ | |
7feb7d06 PA |
4464 | block_child_signals (&prev_mask); |
4465 | ||
4466 | if (enable) | |
4467 | { | |
614c279d | 4468 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4469 | internal_error (__FILE__, __LINE__, |
4470 | "creating event pipe failed."); | |
4471 | ||
4472 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4473 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4474 | } | |
4475 | else | |
4476 | { | |
4477 | close (linux_nat_event_pipe[0]); | |
4478 | close (linux_nat_event_pipe[1]); | |
4479 | linux_nat_event_pipe[0] = -1; | |
4480 | linux_nat_event_pipe[1] = -1; | |
4481 | } | |
4482 | ||
4483 | restore_child_signals_mask (&prev_mask); | |
4484 | } | |
4485 | ||
4486 | return previous; | |
b84876c2 PA |
4487 | } |
4488 | ||
4489 | /* target_async implementation. */ | |
4490 | ||
4491 | static void | |
6a109b6b TT |
4492 | linux_nat_async (struct target_ops *ops, |
4493 | void (*callback) (enum inferior_event_type event_type, | |
4494 | void *context), | |
4495 | void *context) | |
b84876c2 | 4496 | { |
b84876c2 PA |
4497 | if (callback != NULL) |
4498 | { | |
4499 | async_client_callback = callback; | |
4500 | async_client_context = context; | |
7feb7d06 PA |
4501 | if (!linux_async_pipe (1)) |
4502 | { | |
4503 | add_file_handler (linux_nat_event_pipe[0], | |
4504 | handle_target_event, NULL); | |
4505 | /* There may be pending events to handle. Tell the event loop | |
4506 | to poll them. */ | |
4507 | async_file_mark (); | |
4508 | } | |
b84876c2 PA |
4509 | } |
4510 | else | |
4511 | { | |
4512 | async_client_callback = callback; | |
4513 | async_client_context = context; | |
b84876c2 | 4514 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4515 | linux_async_pipe (0); |
b84876c2 PA |
4516 | } |
4517 | return; | |
4518 | } | |
4519 | ||
a493e3e2 | 4520 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4521 | event came out. */ |
4522 | ||
4c28f408 | 4523 | static int |
252fbfc8 | 4524 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4525 | { |
d90e17a7 | 4526 | if (!lwp->stopped) |
252fbfc8 | 4527 | { |
d90e17a7 PA |
4528 | if (debug_linux_nat) |
4529 | fprintf_unfiltered (gdb_stdlog, | |
4530 | "LNSL: running -> suspending %s\n", | |
4531 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4532 | |
252fbfc8 | 4533 | |
25289eb2 PA |
4534 | if (lwp->last_resume_kind == resume_stop) |
4535 | { | |
4536 | if (debug_linux_nat) | |
4537 | fprintf_unfiltered (gdb_stdlog, | |
4538 | "linux-nat: already stopping LWP %ld at " | |
4539 | "GDB's request\n", | |
4540 | ptid_get_lwp (lwp->ptid)); | |
4541 | return 0; | |
4542 | } | |
252fbfc8 | 4543 | |
25289eb2 PA |
4544 | stop_callback (lwp, NULL); |
4545 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4546 | } |
4547 | else | |
4548 | { | |
4549 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4550 | |
d90e17a7 PA |
4551 | if (debug_linux_nat) |
4552 | { | |
e09875d4 | 4553 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4554 | fprintf_unfiltered (gdb_stdlog, |
4555 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4556 | target_pid_to_str (lwp->ptid)); |
4557 | else | |
3e43a32a MS |
4558 | fprintf_unfiltered (gdb_stdlog, |
4559 | "LNSL: already stopped/no " | |
4560 | "stop_requested yet %s\n", | |
d90e17a7 | 4561 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4562 | } |
4563 | } | |
4c28f408 PA |
4564 | return 0; |
4565 | } | |
4566 | ||
4567 | static void | |
1eab8a48 | 4568 | linux_nat_stop (struct target_ops *self, ptid_t ptid) |
4c28f408 PA |
4569 | { |
4570 | if (non_stop) | |
d90e17a7 | 4571 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 | 4572 | else |
1eab8a48 | 4573 | linux_ops->to_stop (linux_ops, ptid); |
4c28f408 PA |
4574 | } |
4575 | ||
d90e17a7 | 4576 | static void |
de90e03d | 4577 | linux_nat_close (struct target_ops *self) |
d90e17a7 PA |
4578 | { |
4579 | /* Unregister from the event loop. */ | |
9debeba0 DE |
4580 | if (linux_nat_is_async_p (self)) |
4581 | linux_nat_async (self, NULL, NULL); | |
d90e17a7 | 4582 | |
d90e17a7 | 4583 | if (linux_ops->to_close) |
de90e03d | 4584 | linux_ops->to_close (linux_ops); |
6a3cb8e8 PA |
4585 | |
4586 | super_close (self); | |
d90e17a7 PA |
4587 | } |
4588 | ||
c0694254 PA |
4589 | /* When requests are passed down from the linux-nat layer to the |
4590 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4591 | used. The address space pointer is stored in the inferior object, | |
4592 | but the common code that is passed such ptid can't tell whether | |
4593 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4594 | look up the "main" process id from the lwp here. */ | |
4595 | ||
70221824 | 4596 | static struct address_space * |
c0694254 PA |
4597 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4598 | { | |
4599 | struct lwp_info *lwp; | |
4600 | struct inferior *inf; | |
4601 | int pid; | |
4602 | ||
dfd4cc63 | 4603 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4604 | { |
4605 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4606 | tgid. */ | |
4607 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4608 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4609 | } |
4610 | else | |
4611 | { | |
4612 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4613 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4614 | } |
4615 | ||
4616 | inf = find_inferior_pid (pid); | |
4617 | gdb_assert (inf != NULL); | |
4618 | return inf->aspace; | |
4619 | } | |
4620 | ||
dc146f7c VP |
4621 | /* Return the cached value of the processor core for thread PTID. */ |
4622 | ||
70221824 | 4623 | static int |
dc146f7c VP |
4624 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4625 | { | |
4626 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4627 | |
dc146f7c VP |
4628 | if (info) |
4629 | return info->core; | |
4630 | return -1; | |
4631 | } | |
4632 | ||
f973ed9c DJ |
4633 | void |
4634 | linux_nat_add_target (struct target_ops *t) | |
4635 | { | |
f973ed9c DJ |
4636 | /* Save the provided single-threaded target. We save this in a separate |
4637 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4638 | may have saved a pointer to T; we want to use it for the final | |
4639 | process stratum target. */ | |
4640 | linux_ops_saved = *t; | |
4641 | linux_ops = &linux_ops_saved; | |
4642 | ||
4643 | /* Override some methods for multithreading. */ | |
b84876c2 | 4644 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4645 | t->to_attach = linux_nat_attach; |
4646 | t->to_detach = linux_nat_detach; | |
4647 | t->to_resume = linux_nat_resume; | |
4648 | t->to_wait = linux_nat_wait; | |
2455069d | 4649 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4650 | t->to_xfer_partial = linux_nat_xfer_partial; |
4651 | t->to_kill = linux_nat_kill; | |
4652 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4653 | t->to_thread_alive = linux_nat_thread_alive; | |
4654 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4655 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4656 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4657 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4658 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4659 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 4660 | |
b84876c2 PA |
4661 | t->to_can_async_p = linux_nat_can_async_p; |
4662 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4663 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4664 | t->to_async = linux_nat_async; |
b84876c2 PA |
4665 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4666 | t->to_terminal_ours = linux_nat_terminal_ours; | |
6a3cb8e8 PA |
4667 | |
4668 | super_close = t->to_close; | |
d90e17a7 | 4669 | t->to_close = linux_nat_close; |
b84876c2 | 4670 | |
4c28f408 PA |
4671 | /* Methods for non-stop support. */ |
4672 | t->to_stop = linux_nat_stop; | |
4673 | ||
d90e17a7 PA |
4674 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4675 | ||
03583c20 UW |
4676 | t->to_supports_disable_randomization |
4677 | = linux_nat_supports_disable_randomization; | |
4678 | ||
dc146f7c VP |
4679 | t->to_core_of_thread = linux_nat_core_of_thread; |
4680 | ||
f973ed9c DJ |
4681 | /* We don't change the stratum; this target will sit at |
4682 | process_stratum and thread_db will set at thread_stratum. This | |
4683 | is a little strange, since this is a multi-threaded-capable | |
4684 | target, but we want to be on the stack below thread_db, and we | |
4685 | also want to be used for single-threaded processes. */ | |
4686 | ||
4687 | add_target (t); | |
f973ed9c DJ |
4688 | } |
4689 | ||
9f0bdab8 DJ |
4690 | /* Register a method to call whenever a new thread is attached. */ |
4691 | void | |
7b50312a PA |
4692 | linux_nat_set_new_thread (struct target_ops *t, |
4693 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4694 | { |
4695 | /* Save the pointer. We only support a single registered instance | |
4696 | of the GNU/Linux native target, so we do not need to map this to | |
4697 | T. */ | |
4698 | linux_nat_new_thread = new_thread; | |
4699 | } | |
4700 | ||
26cb8b7c PA |
4701 | /* See declaration in linux-nat.h. */ |
4702 | ||
4703 | void | |
4704 | linux_nat_set_new_fork (struct target_ops *t, | |
4705 | linux_nat_new_fork_ftype *new_fork) | |
4706 | { | |
4707 | /* Save the pointer. */ | |
4708 | linux_nat_new_fork = new_fork; | |
4709 | } | |
4710 | ||
4711 | /* See declaration in linux-nat.h. */ | |
4712 | ||
4713 | void | |
4714 | linux_nat_set_forget_process (struct target_ops *t, | |
4715 | linux_nat_forget_process_ftype *fn) | |
4716 | { | |
4717 | /* Save the pointer. */ | |
4718 | linux_nat_forget_process_hook = fn; | |
4719 | } | |
4720 | ||
4721 | /* See declaration in linux-nat.h. */ | |
4722 | ||
4723 | void | |
4724 | linux_nat_forget_process (pid_t pid) | |
4725 | { | |
4726 | if (linux_nat_forget_process_hook != NULL) | |
4727 | linux_nat_forget_process_hook (pid); | |
4728 | } | |
4729 | ||
5b009018 PA |
4730 | /* Register a method that converts a siginfo object between the layout |
4731 | that ptrace returns, and the layout in the architecture of the | |
4732 | inferior. */ | |
4733 | void | |
4734 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4735 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4736 | gdb_byte *, |
4737 | int)) | |
4738 | { | |
4739 | /* Save the pointer. */ | |
4740 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4741 | } | |
4742 | ||
7b50312a PA |
4743 | /* Register a method to call prior to resuming a thread. */ |
4744 | ||
4745 | void | |
4746 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4747 | void (*prepare_to_resume) (struct lwp_info *)) | |
4748 | { | |
4749 | /* Save the pointer. */ | |
4750 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4751 | } | |
4752 | ||
f865ee35 JK |
4753 | /* See linux-nat.h. */ |
4754 | ||
4755 | int | |
4756 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4757 | { |
da559b09 | 4758 | int pid; |
9f0bdab8 | 4759 | |
dfd4cc63 | 4760 | pid = ptid_get_lwp (ptid); |
da559b09 | 4761 | if (pid == 0) |
dfd4cc63 | 4762 | pid = ptid_get_pid (ptid); |
f865ee35 | 4763 | |
da559b09 JK |
4764 | errno = 0; |
4765 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4766 | if (errno != 0) | |
4767 | { | |
4768 | memset (siginfo, 0, sizeof (*siginfo)); | |
4769 | return 0; | |
4770 | } | |
f865ee35 | 4771 | return 1; |
9f0bdab8 DJ |
4772 | } |
4773 | ||
2c0b251b PA |
4774 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4775 | extern initialize_file_ftype _initialize_linux_nat; | |
4776 | ||
d6b0e80f AC |
4777 | void |
4778 | _initialize_linux_nat (void) | |
4779 | { | |
ccce17b0 YQ |
4780 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4781 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4782 | Set debugging of GNU/Linux lwp module."), _("\ |
4783 | Show debugging of GNU/Linux lwp module."), _("\ | |
4784 | Enables printf debugging output."), | |
ccce17b0 YQ |
4785 | NULL, |
4786 | show_debug_linux_nat, | |
4787 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4788 | |
b84876c2 | 4789 | /* Save this mask as the default. */ |
d6b0e80f AC |
4790 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4791 | ||
7feb7d06 PA |
4792 | /* Install a SIGCHLD handler. */ |
4793 | sigchld_action.sa_handler = sigchld_handler; | |
4794 | sigemptyset (&sigchld_action.sa_mask); | |
4795 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4796 | |
4797 | /* Make it the default. */ | |
7feb7d06 | 4798 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4799 | |
4800 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4801 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4802 | sigdelset (&suspend_mask, SIGCHLD); | |
4803 | ||
7feb7d06 | 4804 | sigemptyset (&blocked_mask); |
8009206a TT |
4805 | |
4806 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to | |
4807 | support read-only process state. */ | |
4808 | linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD | |
4809 | | PTRACE_O_TRACEVFORKDONE | |
4810 | | PTRACE_O_TRACEVFORK | |
4811 | | PTRACE_O_TRACEFORK | |
4812 | | PTRACE_O_TRACEEXEC); | |
d6b0e80f AC |
4813 | } |
4814 | \f | |
4815 | ||
4816 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4817 | the GNU/Linux Threads library and therefore doesn't really belong | |
4818 | here. */ | |
4819 | ||
4820 | /* Read variable NAME in the target and return its value if found. | |
4821 | Otherwise return zero. It is assumed that the type of the variable | |
4822 | is `int'. */ | |
4823 | ||
4824 | static int | |
4825 | get_signo (const char *name) | |
4826 | { | |
3b7344d5 | 4827 | struct bound_minimal_symbol ms; |
d6b0e80f AC |
4828 | int signo; |
4829 | ||
4830 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
3b7344d5 | 4831 | if (ms.minsym == NULL) |
d6b0e80f AC |
4832 | return 0; |
4833 | ||
77e371c0 | 4834 | if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
4835 | sizeof (signo)) != 0) |
4836 | return 0; | |
4837 | ||
4838 | return signo; | |
4839 | } | |
4840 | ||
4841 | /* Return the set of signals used by the threads library in *SET. */ | |
4842 | ||
4843 | void | |
4844 | lin_thread_get_thread_signals (sigset_t *set) | |
4845 | { | |
4846 | struct sigaction action; | |
4847 | int restart, cancel; | |
4848 | ||
b84876c2 | 4849 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
4850 | sigemptyset (set); |
4851 | ||
4852 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
4853 | cancel = get_signo ("__pthread_sig_cancel"); |
4854 | ||
4855 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
4856 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
4857 | not provide any way for the debugger to query the signal numbers - | |
4858 | fortunately they don't change! */ | |
4859 | ||
d6b0e80f | 4860 | if (restart == 0) |
17fbb0bd | 4861 | restart = __SIGRTMIN; |
d6b0e80f | 4862 | |
d6b0e80f | 4863 | if (cancel == 0) |
17fbb0bd | 4864 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
4865 | |
4866 | sigaddset (set, restart); | |
4867 | sigaddset (set, cancel); | |
4868 | ||
4869 | /* The GNU/Linux Threads library makes terminating threads send a | |
4870 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
4871 | those (to prevent them from terminating GDB itself, which is | |
4872 | likely to be their default action) and treat them the same way as | |
4873 | SIGCHLD. */ | |
4874 | ||
4875 | action.sa_handler = sigchld_handler; | |
4876 | sigemptyset (&action.sa_mask); | |
58aecb61 | 4877 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
4878 | sigaction (cancel, &action, NULL); |
4879 | ||
4880 | /* We block the "cancel" signal throughout this code ... */ | |
4881 | sigaddset (&blocked_mask, cancel); | |
4882 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
4883 | ||
4884 | /* ... except during a sigsuspend. */ | |
4885 | sigdelset (&suspend_mask, cancel); | |
4886 | } |