Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
ecd75fc8 | 3 | Copyright (C) 2001-2014 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 LM |
323 | /* Initialize ptrace warnings and check for supported ptrace |
324 | features given PID. */ | |
3993f6b1 DJ |
325 | |
326 | static void | |
96d7229d | 327 | linux_init_ptrace (pid_t pid) |
3993f6b1 | 328 | { |
96d7229d LM |
329 | linux_enable_event_reporting (pid); |
330 | linux_ptrace_init_warnings (); | |
4de4c07c DJ |
331 | } |
332 | ||
6d8fd2b7 | 333 | static void |
f045800c | 334 | linux_child_post_attach (struct target_ops *self, int pid) |
4de4c07c | 335 | { |
96d7229d | 336 | linux_init_ptrace (pid); |
4de4c07c DJ |
337 | } |
338 | ||
10d6c8cd | 339 | static void |
2e97a79e | 340 | linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid) |
4de4c07c | 341 | { |
96d7229d | 342 | linux_init_ptrace (ptid_get_pid (ptid)); |
4de4c07c DJ |
343 | } |
344 | ||
4403d8e9 JK |
345 | /* Return the number of known LWPs in the tgid given by PID. */ |
346 | ||
347 | static int | |
348 | num_lwps (int pid) | |
349 | { | |
350 | int count = 0; | |
351 | struct lwp_info *lp; | |
352 | ||
353 | for (lp = lwp_list; lp; lp = lp->next) | |
354 | if (ptid_get_pid (lp->ptid) == pid) | |
355 | count++; | |
356 | ||
357 | return count; | |
358 | } | |
359 | ||
360 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
361 | ||
362 | static void | |
363 | delete_lwp_cleanup (void *lp_voidp) | |
364 | { | |
365 | struct lwp_info *lp = lp_voidp; | |
366 | ||
367 | delete_lwp (lp->ptid); | |
368 | } | |
369 | ||
d83ad864 DB |
370 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
371 | ptid of the followed inferior. At return, inferior_ptid will be | |
372 | unchanged. */ | |
373 | ||
6d8fd2b7 | 374 | static int |
07107ca6 LM |
375 | linux_child_follow_fork (struct target_ops *ops, int follow_child, |
376 | int detach_fork) | |
3993f6b1 | 377 | { |
d83ad864 | 378 | if (!follow_child) |
4de4c07c | 379 | { |
6c95b8df | 380 | struct lwp_info *child_lp = NULL; |
d83ad864 DB |
381 | int status = W_STOPCODE (0); |
382 | struct cleanup *old_chain; | |
383 | int has_vforked; | |
384 | int parent_pid, child_pid; | |
385 | ||
386 | has_vforked = (inferior_thread ()->pending_follow.kind | |
387 | == TARGET_WAITKIND_VFORKED); | |
388 | parent_pid = ptid_get_lwp (inferior_ptid); | |
389 | if (parent_pid == 0) | |
390 | parent_pid = ptid_get_pid (inferior_ptid); | |
391 | child_pid | |
392 | = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid); | |
393 | ||
4de4c07c | 394 | |
1777feb0 | 395 | /* We're already attached to the parent, by default. */ |
d83ad864 DB |
396 | old_chain = save_inferior_ptid (); |
397 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
398 | child_lp = add_lwp (inferior_ptid); | |
399 | child_lp->stopped = 1; | |
400 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 401 | |
ac264b3b MS |
402 | /* Detach new forked process? */ |
403 | if (detach_fork) | |
f75c00e4 | 404 | { |
4403d8e9 JK |
405 | make_cleanup (delete_lwp_cleanup, child_lp); |
406 | ||
4403d8e9 JK |
407 | if (linux_nat_prepare_to_resume != NULL) |
408 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
409 | |
410 | /* When debugging an inferior in an architecture that supports | |
411 | hardware single stepping on a kernel without commit | |
412 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
413 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
414 | set if the parent process had them set. | |
415 | To work around this, single step the child process | |
416 | once before detaching to clear the flags. */ | |
417 | ||
418 | if (!gdbarch_software_single_step_p (target_thread_architecture | |
419 | (child_lp->ptid))) | |
420 | { | |
c077881a HZ |
421 | linux_disable_event_reporting (child_pid); |
422 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
423 | perror_with_name (_("Couldn't do single step")); | |
424 | if (my_waitpid (child_pid, &status, 0) < 0) | |
425 | perror_with_name (_("Couldn't wait vfork process")); | |
426 | } | |
427 | ||
428 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
429 | { |
430 | int signo; | |
431 | ||
432 | signo = WSTOPSIG (status); | |
433 | if (signo != 0 | |
434 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
435 | signo = 0; | |
436 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
437 | } | |
4403d8e9 | 438 | |
d83ad864 | 439 | /* Resets value of inferior_ptid to parent ptid. */ |
4403d8e9 | 440 | do_cleanups (old_chain); |
ac264b3b MS |
441 | } |
442 | else | |
443 | { | |
6c95b8df | 444 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 445 | check_for_thread_db (); |
ac264b3b | 446 | } |
9016a515 | 447 | |
d83ad864 DB |
448 | do_cleanups (old_chain); |
449 | ||
9016a515 DJ |
450 | if (has_vforked) |
451 | { | |
3ced3da4 | 452 | struct lwp_info *parent_lp; |
6c95b8df | 453 | |
3ced3da4 | 454 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
96d7229d | 455 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 456 | |
96d7229d | 457 | if (linux_supports_tracevforkdone ()) |
9016a515 | 458 | { |
6c95b8df PA |
459 | if (debug_linux_nat) |
460 | fprintf_unfiltered (gdb_stdlog, | |
461 | "LCFF: waiting for VFORK_DONE on %d\n", | |
462 | parent_pid); | |
3ced3da4 | 463 | parent_lp->stopped = 1; |
9016a515 | 464 | |
6c95b8df PA |
465 | /* We'll handle the VFORK_DONE event like any other |
466 | event, in target_wait. */ | |
9016a515 DJ |
467 | } |
468 | else | |
469 | { | |
470 | /* We can't insert breakpoints until the child has | |
471 | finished with the shared memory region. We need to | |
472 | wait until that happens. Ideal would be to just | |
473 | call: | |
474 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
475 | - waitpid (parent_pid, &status, __WALL); | |
476 | However, most architectures can't handle a syscall | |
477 | being traced on the way out if it wasn't traced on | |
478 | the way in. | |
479 | ||
480 | We might also think to loop, continuing the child | |
481 | until it exits or gets a SIGTRAP. One problem is | |
482 | that the child might call ptrace with PTRACE_TRACEME. | |
483 | ||
484 | There's no simple and reliable way to figure out when | |
485 | the vforked child will be done with its copy of the | |
486 | shared memory. We could step it out of the syscall, | |
487 | two instructions, let it go, and then single-step the | |
488 | parent once. When we have hardware single-step, this | |
489 | would work; with software single-step it could still | |
490 | be made to work but we'd have to be able to insert | |
491 | single-step breakpoints in the child, and we'd have | |
492 | to insert -just- the single-step breakpoint in the | |
493 | parent. Very awkward. | |
494 | ||
495 | In the end, the best we can do is to make sure it | |
496 | runs for a little while. Hopefully it will be out of | |
497 | range of any breakpoints we reinsert. Usually this | |
498 | is only the single-step breakpoint at vfork's return | |
499 | point. */ | |
500 | ||
6c95b8df PA |
501 | if (debug_linux_nat) |
502 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
503 | "LCFF: no VFORK_DONE " |
504 | "support, sleeping a bit\n"); | |
6c95b8df | 505 | |
9016a515 | 506 | usleep (10000); |
9016a515 | 507 | |
6c95b8df PA |
508 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
509 | and leave it pending. The next linux_nat_resume call | |
510 | will notice a pending event, and bypasses actually | |
511 | resuming the inferior. */ | |
3ced3da4 PA |
512 | parent_lp->status = 0; |
513 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
514 | parent_lp->stopped = 1; | |
6c95b8df PA |
515 | |
516 | /* If we're in async mode, need to tell the event loop | |
517 | there's something here to process. */ | |
518 | if (target_can_async_p ()) | |
519 | async_file_mark (); | |
520 | } | |
9016a515 | 521 | } |
4de4c07c | 522 | } |
3993f6b1 | 523 | else |
4de4c07c | 524 | { |
3ced3da4 | 525 | struct lwp_info *child_lp; |
4de4c07c | 526 | |
3ced3da4 PA |
527 | child_lp = add_lwp (inferior_ptid); |
528 | child_lp->stopped = 1; | |
25289eb2 | 529 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 530 | |
6c95b8df | 531 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 532 | check_for_thread_db (); |
4de4c07c DJ |
533 | } |
534 | ||
535 | return 0; | |
536 | } | |
537 | ||
4de4c07c | 538 | \f |
77b06cd7 | 539 | static int |
a863b201 | 540 | linux_child_insert_fork_catchpoint (struct target_ops *self, int pid) |
4de4c07c | 541 | { |
96d7229d | 542 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
543 | } |
544 | ||
eb73ad13 | 545 | static int |
973fc227 | 546 | linux_child_remove_fork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
547 | { |
548 | return 0; | |
549 | } | |
550 | ||
77b06cd7 | 551 | static int |
3ecc7da0 | 552 | linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 553 | { |
96d7229d | 554 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
555 | } |
556 | ||
eb73ad13 | 557 | static int |
e98cf0cd | 558 | linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
559 | { |
560 | return 0; | |
561 | } | |
562 | ||
77b06cd7 | 563 | static int |
ba025e51 | 564 | linux_child_insert_exec_catchpoint (struct target_ops *self, int pid) |
3993f6b1 | 565 | { |
96d7229d | 566 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
567 | } |
568 | ||
eb73ad13 | 569 | static int |
758e29d2 | 570 | linux_child_remove_exec_catchpoint (struct target_ops *self, int pid) |
eb73ad13 PA |
571 | { |
572 | return 0; | |
573 | } | |
574 | ||
a96d9b2e | 575 | static int |
ff214e67 TT |
576 | linux_child_set_syscall_catchpoint (struct target_ops *self, |
577 | int pid, int needed, int any_count, | |
a96d9b2e SDJ |
578 | int table_size, int *table) |
579 | { | |
96d7229d | 580 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
581 | return 1; |
582 | ||
a96d9b2e SDJ |
583 | /* On GNU/Linux, we ignore the arguments. It means that we only |
584 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 585 | |
a96d9b2e SDJ |
586 | Also, we do not use the `table' information because we do not |
587 | filter system calls here. We let GDB do the logic for us. */ | |
588 | return 0; | |
589 | } | |
590 | ||
d6b0e80f AC |
591 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
592 | are processes sharing the same VM space. A multi-threaded process | |
593 | is basically a group of such processes. However, such a grouping | |
594 | is almost entirely a user-space issue; the kernel doesn't enforce | |
595 | such a grouping at all (this might change in the future). In | |
596 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
597 | Threads library) to provide such a grouping. | |
598 | ||
599 | It is perfectly well possible to write a multi-threaded application | |
600 | without the assistance of a threads library, by using the clone | |
601 | system call directly. This module should be able to give some | |
602 | rudimentary support for debugging such applications if developers | |
603 | specify the CLONE_PTRACE flag in the clone system call, and are | |
604 | using the Linux kernel 2.4 or above. | |
605 | ||
606 | Note that there are some peculiarities in GNU/Linux that affect | |
607 | this code: | |
608 | ||
609 | - In general one should specify the __WCLONE flag to waitpid in | |
610 | order to make it report events for any of the cloned processes | |
611 | (and leave it out for the initial process). However, if a cloned | |
612 | process has exited the exit status is only reported if the | |
613 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
614 | we cannot use it since GDB must work on older systems too. | |
615 | ||
616 | - When a traced, cloned process exits and is waited for by the | |
617 | debugger, the kernel reassigns it to the original parent and | |
618 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
619 | library doesn't notice this, which leads to the "zombie problem": | |
620 | When debugged a multi-threaded process that spawns a lot of | |
621 | threads will run out of processes, even if the threads exit, | |
622 | because the "zombies" stay around. */ | |
623 | ||
624 | /* List of known LWPs. */ | |
9f0bdab8 | 625 | struct lwp_info *lwp_list; |
d6b0e80f AC |
626 | \f |
627 | ||
d6b0e80f AC |
628 | /* Original signal mask. */ |
629 | static sigset_t normal_mask; | |
630 | ||
631 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
632 | _initialize_linux_nat. */ | |
633 | static sigset_t suspend_mask; | |
634 | ||
7feb7d06 PA |
635 | /* Signals to block to make that sigsuspend work. */ |
636 | static sigset_t blocked_mask; | |
637 | ||
638 | /* SIGCHLD action. */ | |
639 | struct sigaction sigchld_action; | |
b84876c2 | 640 | |
7feb7d06 PA |
641 | /* Block child signals (SIGCHLD and linux threads signals), and store |
642 | the previous mask in PREV_MASK. */ | |
84e46146 | 643 | |
7feb7d06 PA |
644 | static void |
645 | block_child_signals (sigset_t *prev_mask) | |
646 | { | |
647 | /* Make sure SIGCHLD is blocked. */ | |
648 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
649 | sigaddset (&blocked_mask, SIGCHLD); | |
650 | ||
651 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
652 | } | |
653 | ||
654 | /* Restore child signals mask, previously returned by | |
655 | block_child_signals. */ | |
656 | ||
657 | static void | |
658 | restore_child_signals_mask (sigset_t *prev_mask) | |
659 | { | |
660 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
661 | } | |
2455069d UW |
662 | |
663 | /* Mask of signals to pass directly to the inferior. */ | |
664 | static sigset_t pass_mask; | |
665 | ||
666 | /* Update signals to pass to the inferior. */ | |
667 | static void | |
94bedb42 TT |
668 | linux_nat_pass_signals (struct target_ops *self, |
669 | int numsigs, unsigned char *pass_signals) | |
2455069d UW |
670 | { |
671 | int signo; | |
672 | ||
673 | sigemptyset (&pass_mask); | |
674 | ||
675 | for (signo = 1; signo < NSIG; signo++) | |
676 | { | |
2ea28649 | 677 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
678 | if (target_signo < numsigs && pass_signals[target_signo]) |
679 | sigaddset (&pass_mask, signo); | |
680 | } | |
681 | } | |
682 | ||
d6b0e80f AC |
683 | \f |
684 | ||
685 | /* Prototypes for local functions. */ | |
686 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 687 | static int linux_thread_alive (ptid_t ptid); |
8dd27370 | 688 | static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid); |
710151dd | 689 | |
d6b0e80f | 690 | \f |
d6b0e80f | 691 | |
7b50312a PA |
692 | /* Destroy and free LP. */ |
693 | ||
694 | static void | |
695 | lwp_free (struct lwp_info *lp) | |
696 | { | |
697 | xfree (lp->arch_private); | |
698 | xfree (lp); | |
699 | } | |
700 | ||
d90e17a7 PA |
701 | /* Remove all LWPs belong to PID from the lwp list. */ |
702 | ||
703 | static void | |
704 | purge_lwp_list (int pid) | |
705 | { | |
706 | struct lwp_info *lp, *lpprev, *lpnext; | |
707 | ||
708 | lpprev = NULL; | |
709 | ||
710 | for (lp = lwp_list; lp; lp = lpnext) | |
711 | { | |
712 | lpnext = lp->next; | |
713 | ||
714 | if (ptid_get_pid (lp->ptid) == pid) | |
715 | { | |
716 | if (lp == lwp_list) | |
717 | lwp_list = lp->next; | |
718 | else | |
719 | lpprev->next = lp->next; | |
720 | ||
7b50312a | 721 | lwp_free (lp); |
d90e17a7 PA |
722 | } |
723 | else | |
724 | lpprev = lp; | |
725 | } | |
726 | } | |
727 | ||
26cb8b7c PA |
728 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
729 | in the process. Return a pointer to the structure describing the | |
730 | new LWP. | |
731 | ||
732 | This differs from add_lwp in that we don't let the arch specific | |
733 | bits know about this new thread. Current clients of this callback | |
734 | take the opportunity to install watchpoints in the new thread, and | |
735 | we shouldn't do that for the first thread. If we're spawning a | |
736 | child ("run"), the thread executes the shell wrapper first, and we | |
737 | shouldn't touch it until it execs the program we want to debug. | |
738 | For "attach", it'd be okay to call the callback, but it's not | |
739 | necessary, because watchpoints can't yet have been inserted into | |
740 | the inferior. */ | |
d6b0e80f AC |
741 | |
742 | static struct lwp_info * | |
26cb8b7c | 743 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
744 | { |
745 | struct lwp_info *lp; | |
746 | ||
dfd4cc63 | 747 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f AC |
748 | |
749 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
750 | ||
751 | memset (lp, 0, sizeof (struct lwp_info)); | |
752 | ||
25289eb2 | 753 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
754 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
755 | ||
756 | lp->ptid = ptid; | |
dc146f7c | 757 | lp->core = -1; |
d6b0e80f AC |
758 | |
759 | lp->next = lwp_list; | |
760 | lwp_list = lp; | |
d6b0e80f | 761 | |
26cb8b7c PA |
762 | return lp; |
763 | } | |
764 | ||
765 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
766 | structure describing the new LWP. The LWP should already be | |
767 | stopped. */ | |
768 | ||
769 | static struct lwp_info * | |
770 | add_lwp (ptid_t ptid) | |
771 | { | |
772 | struct lwp_info *lp; | |
773 | ||
774 | lp = add_initial_lwp (ptid); | |
775 | ||
6e012a6c PA |
776 | /* Let the arch specific bits know about this new thread. Current |
777 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
778 | watchpoints in the new thread. We don't do this for the first |
779 | thread though. See add_initial_lwp. */ | |
780 | if (linux_nat_new_thread != NULL) | |
7b50312a | 781 | linux_nat_new_thread (lp); |
9f0bdab8 | 782 | |
d6b0e80f AC |
783 | return lp; |
784 | } | |
785 | ||
786 | /* Remove the LWP specified by PID from the list. */ | |
787 | ||
788 | static void | |
789 | delete_lwp (ptid_t ptid) | |
790 | { | |
791 | struct lwp_info *lp, *lpprev; | |
792 | ||
793 | lpprev = NULL; | |
794 | ||
795 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
796 | if (ptid_equal (lp->ptid, ptid)) | |
797 | break; | |
798 | ||
799 | if (!lp) | |
800 | return; | |
801 | ||
d6b0e80f AC |
802 | if (lpprev) |
803 | lpprev->next = lp->next; | |
804 | else | |
805 | lwp_list = lp->next; | |
806 | ||
7b50312a | 807 | lwp_free (lp); |
d6b0e80f AC |
808 | } |
809 | ||
810 | /* Return a pointer to the structure describing the LWP corresponding | |
811 | to PID. If no corresponding LWP could be found, return NULL. */ | |
812 | ||
813 | static struct lwp_info * | |
814 | find_lwp_pid (ptid_t ptid) | |
815 | { | |
816 | struct lwp_info *lp; | |
817 | int lwp; | |
818 | ||
dfd4cc63 LM |
819 | if (ptid_lwp_p (ptid)) |
820 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 821 | else |
dfd4cc63 | 822 | lwp = ptid_get_pid (ptid); |
d6b0e80f AC |
823 | |
824 | for (lp = lwp_list; lp; lp = lp->next) | |
dfd4cc63 | 825 | if (lwp == ptid_get_lwp (lp->ptid)) |
d6b0e80f AC |
826 | return lp; |
827 | ||
828 | return NULL; | |
829 | } | |
830 | ||
831 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
832 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
833 | pointer to the structure describing that LWP immediately. | |
834 | Otherwise return NULL. */ | |
835 | ||
836 | struct lwp_info * | |
d90e17a7 PA |
837 | iterate_over_lwps (ptid_t filter, |
838 | int (*callback) (struct lwp_info *, void *), | |
839 | void *data) | |
d6b0e80f AC |
840 | { |
841 | struct lwp_info *lp, *lpnext; | |
842 | ||
843 | for (lp = lwp_list; lp; lp = lpnext) | |
844 | { | |
845 | lpnext = lp->next; | |
d90e17a7 PA |
846 | |
847 | if (ptid_match (lp->ptid, filter)) | |
848 | { | |
849 | if ((*callback) (lp, data)) | |
850 | return lp; | |
851 | } | |
d6b0e80f AC |
852 | } |
853 | ||
854 | return NULL; | |
855 | } | |
856 | ||
2277426b PA |
857 | /* Update our internal state when changing from one checkpoint to |
858 | another indicated by NEW_PTID. We can only switch single-threaded | |
859 | applications, so we only create one new LWP, and the previous list | |
860 | is discarded. */ | |
f973ed9c DJ |
861 | |
862 | void | |
863 | linux_nat_switch_fork (ptid_t new_ptid) | |
864 | { | |
865 | struct lwp_info *lp; | |
866 | ||
dfd4cc63 | 867 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 868 | |
f973ed9c DJ |
869 | lp = add_lwp (new_ptid); |
870 | lp->stopped = 1; | |
e26af52f | 871 | |
2277426b PA |
872 | /* This changes the thread's ptid while preserving the gdb thread |
873 | num. Also changes the inferior pid, while preserving the | |
874 | inferior num. */ | |
875 | thread_change_ptid (inferior_ptid, new_ptid); | |
876 | ||
877 | /* We've just told GDB core that the thread changed target id, but, | |
878 | in fact, it really is a different thread, with different register | |
879 | contents. */ | |
880 | registers_changed (); | |
e26af52f DJ |
881 | } |
882 | ||
e26af52f DJ |
883 | /* Handle the exit of a single thread LP. */ |
884 | ||
885 | static void | |
886 | exit_lwp (struct lwp_info *lp) | |
887 | { | |
e09875d4 | 888 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
889 | |
890 | if (th) | |
e26af52f | 891 | { |
17faa917 DJ |
892 | if (print_thread_events) |
893 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
894 | ||
4f8d22e3 | 895 | delete_thread (lp->ptid); |
e26af52f DJ |
896 | } |
897 | ||
898 | delete_lwp (lp->ptid); | |
899 | } | |
900 | ||
a0ef4274 DJ |
901 | /* Wait for the LWP specified by LP, which we have just attached to. |
902 | Returns a wait status for that LWP, to cache. */ | |
903 | ||
904 | static int | |
905 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
906 | int *signalled) | |
907 | { | |
dfd4cc63 | 908 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
909 | int status; |
910 | ||
644cebc9 | 911 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
912 | { |
913 | if (debug_linux_nat) | |
914 | fprintf_unfiltered (gdb_stdlog, | |
915 | "LNPAW: Attaching to a stopped process\n"); | |
916 | ||
917 | /* The process is definitely stopped. It is in a job control | |
918 | stop, unless the kernel predates the TASK_STOPPED / | |
919 | TASK_TRACED distinction, in which case it might be in a | |
920 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
921 | can kill it, signal it, et cetera. | |
922 | ||
923 | First make sure there is a pending SIGSTOP. Since we are | |
924 | already attached, the process can not transition from stopped | |
925 | to running without a PTRACE_CONT; so we know this signal will | |
926 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
927 | probably already in the queue (unless this kernel is old | |
928 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
929 | is not an RT signal, it can only be queued once. */ | |
930 | kill_lwp (pid, SIGSTOP); | |
931 | ||
932 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
933 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
934 | ptrace (PTRACE_CONT, pid, 0, 0); | |
935 | } | |
936 | ||
937 | /* Make sure the initial process is stopped. The user-level threads | |
938 | layer might want to poke around in the inferior, and that won't | |
939 | work if things haven't stabilized yet. */ | |
940 | new_pid = my_waitpid (pid, &status, 0); | |
941 | if (new_pid == -1 && errno == ECHILD) | |
942 | { | |
943 | if (first) | |
944 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
945 | ||
946 | /* Try again with __WCLONE to check cloned processes. */ | |
947 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
948 | *cloned = 1; | |
949 | } | |
950 | ||
dacc9cb2 PP |
951 | gdb_assert (pid == new_pid); |
952 | ||
953 | if (!WIFSTOPPED (status)) | |
954 | { | |
955 | /* The pid we tried to attach has apparently just exited. */ | |
956 | if (debug_linux_nat) | |
957 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
958 | pid, status_to_str (status)); | |
959 | return status; | |
960 | } | |
a0ef4274 DJ |
961 | |
962 | if (WSTOPSIG (status) != SIGSTOP) | |
963 | { | |
964 | *signalled = 1; | |
965 | if (debug_linux_nat) | |
966 | fprintf_unfiltered (gdb_stdlog, | |
967 | "LNPAW: Received %s after attaching\n", | |
968 | status_to_str (status)); | |
969 | } | |
970 | ||
971 | return status; | |
972 | } | |
973 | ||
84636d28 PA |
974 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
975 | the new LWP could not be attached, or 1 if we're already auto | |
976 | attached to this thread, but haven't processed the | |
977 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
978 | its existance, without considering it an error. */ | |
d6b0e80f | 979 | |
9ee57c33 | 980 | int |
93815fbf | 981 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 982 | { |
9ee57c33 | 983 | struct lwp_info *lp; |
84636d28 | 984 | int lwpid; |
d6b0e80f | 985 | |
dfd4cc63 | 986 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 987 | |
9ee57c33 | 988 | lp = find_lwp_pid (ptid); |
dfd4cc63 | 989 | lwpid = ptid_get_lwp (ptid); |
d6b0e80f AC |
990 | |
991 | /* We assume that we're already attached to any LWP that has an id | |
992 | equal to the overall process id, and to any LWP that is already | |
993 | in our list of LWPs. If we're not seeing exit events from threads | |
994 | and we've had PID wraparound since we last tried to stop all threads, | |
995 | this assumption might be wrong; fortunately, this is very unlikely | |
996 | to happen. */ | |
dfd4cc63 | 997 | if (lwpid != ptid_get_pid (ptid) && lp == NULL) |
d6b0e80f | 998 | { |
a0ef4274 | 999 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1000 | |
84636d28 | 1001 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1002 | { |
96d7229d | 1003 | if (linux_supports_tracefork ()) |
84636d28 PA |
1004 | { |
1005 | /* If we haven't stopped all threads when we get here, | |
1006 | we may have seen a thread listed in thread_db's list, | |
1007 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1008 | that's the case, ignore this new thread, and let | |
1009 | normal event handling discover it later. */ | |
1010 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1011 | { | |
1012 | /* We've already seen this thread stop, but we | |
1013 | haven't seen the PTRACE_EVENT_CLONE extended | |
1014 | event yet. */ | |
84636d28 PA |
1015 | return 0; |
1016 | } | |
1017 | else | |
1018 | { | |
1019 | int new_pid; | |
1020 | int status; | |
1021 | ||
1022 | /* See if we've got a stop for this new child | |
1023 | pending. If so, we're already attached. */ | |
1024 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1025 | if (new_pid == -1 && errno == ECHILD) | |
1026 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1027 | if (new_pid != -1) | |
1028 | { | |
1029 | if (WIFSTOPPED (status)) | |
1030 | add_to_pid_list (&stopped_pids, lwpid, status); | |
84636d28 PA |
1031 | return 1; |
1032 | } | |
1033 | } | |
1034 | } | |
1035 | ||
9ee57c33 DJ |
1036 | /* If we fail to attach to the thread, issue a warning, |
1037 | but continue. One way this can happen is if thread | |
e9efe249 | 1038 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1039 | bug may place threads in the thread list and then fail |
1040 | to create them. */ | |
1041 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1042 | safe_strerror (errno)); | |
1043 | return -1; | |
1044 | } | |
1045 | ||
d6b0e80f AC |
1046 | if (debug_linux_nat) |
1047 | fprintf_unfiltered (gdb_stdlog, | |
1048 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1049 | target_pid_to_str (ptid)); | |
1050 | ||
a0ef4274 | 1051 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1052 | if (!WIFSTOPPED (status)) |
12696c10 | 1053 | return 1; |
dacc9cb2 | 1054 | |
a0ef4274 DJ |
1055 | lp = add_lwp (ptid); |
1056 | lp->stopped = 1; | |
1057 | lp->cloned = cloned; | |
1058 | lp->signalled = signalled; | |
1059 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1060 | { |
a0ef4274 DJ |
1061 | lp->resumed = 1; |
1062 | lp->status = status; | |
d6b0e80f AC |
1063 | } |
1064 | ||
dfd4cc63 | 1065 | target_post_attach (ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
1066 | |
1067 | if (debug_linux_nat) | |
1068 | { | |
1069 | fprintf_unfiltered (gdb_stdlog, | |
1070 | "LLAL: waitpid %s received %s\n", | |
1071 | target_pid_to_str (ptid), | |
1072 | status_to_str (status)); | |
1073 | } | |
1074 | } | |
1075 | else | |
1076 | { | |
1077 | /* We assume that the LWP representing the original process is | |
1078 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1079 | that the GNU/linux ptrace layer uses to keep track of |
1080 | threads. Note that this won't have already been done since | |
1081 | the main thread will have, we assume, been stopped by an | |
1082 | attach from a different layer. */ | |
9ee57c33 DJ |
1083 | if (lp == NULL) |
1084 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1085 | lp->stopped = 1; |
1086 | } | |
9ee57c33 | 1087 | |
25289eb2 | 1088 | lp->last_resume_kind = resume_stop; |
9ee57c33 | 1089 | return 0; |
d6b0e80f AC |
1090 | } |
1091 | ||
b84876c2 | 1092 | static void |
136d6dae VP |
1093 | linux_nat_create_inferior (struct target_ops *ops, |
1094 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1095 | int from_tty) |
1096 | { | |
10568435 JK |
1097 | #ifdef HAVE_PERSONALITY |
1098 | int personality_orig = 0, personality_set = 0; | |
1099 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1100 | |
1101 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1102 | we have to mask the async mode. */ | |
1103 | ||
10568435 JK |
1104 | #ifdef HAVE_PERSONALITY |
1105 | if (disable_randomization) | |
1106 | { | |
1107 | errno = 0; | |
1108 | personality_orig = personality (0xffffffff); | |
1109 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1110 | { | |
1111 | personality_set = 1; | |
1112 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1113 | } | |
1114 | if (errno != 0 || (personality_set | |
1115 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1116 | warning (_("Error disabling address space randomization: %s"), | |
1117 | safe_strerror (errno)); | |
1118 | } | |
1119 | #endif /* HAVE_PERSONALITY */ | |
1120 | ||
2455069d | 1121 | /* Make sure we report all signals during startup. */ |
94bedb42 | 1122 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1123 | |
136d6dae | 1124 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1125 | |
10568435 JK |
1126 | #ifdef HAVE_PERSONALITY |
1127 | if (personality_set) | |
1128 | { | |
1129 | errno = 0; | |
1130 | personality (personality_orig); | |
1131 | if (errno != 0) | |
1132 | warning (_("Error restoring address space randomization: %s"), | |
1133 | safe_strerror (errno)); | |
1134 | } | |
1135 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1136 | } |
1137 | ||
d6b0e80f | 1138 | static void |
c0939df1 | 1139 | linux_nat_attach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f AC |
1140 | { |
1141 | struct lwp_info *lp; | |
d6b0e80f | 1142 | int status; |
af990527 | 1143 | ptid_t ptid; |
87b0bb13 | 1144 | volatile struct gdb_exception ex; |
d6b0e80f | 1145 | |
2455069d | 1146 | /* Make sure we report all signals during attach. */ |
94bedb42 | 1147 | linux_nat_pass_signals (ops, 0, NULL); |
2455069d | 1148 | |
87b0bb13 JK |
1149 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1150 | { | |
1151 | linux_ops->to_attach (ops, args, from_tty); | |
1152 | } | |
1153 | if (ex.reason < 0) | |
1154 | { | |
1155 | pid_t pid = parse_pid_to_attach (args); | |
1156 | struct buffer buffer; | |
1157 | char *message, *buffer_s; | |
1158 | ||
1159 | message = xstrdup (ex.message); | |
1160 | make_cleanup (xfree, message); | |
1161 | ||
1162 | buffer_init (&buffer); | |
7ae1a6a6 | 1163 | linux_ptrace_attach_fail_reason (pid, &buffer); |
87b0bb13 JK |
1164 | |
1165 | buffer_grow_str0 (&buffer, ""); | |
1166 | buffer_s = buffer_finish (&buffer); | |
1167 | make_cleanup (xfree, buffer_s); | |
1168 | ||
7ae1a6a6 PA |
1169 | if (*buffer_s != '\0') |
1170 | throw_error (ex.error, "warning: %s\n%s", buffer_s, message); | |
1171 | else | |
1172 | throw_error (ex.error, "%s", message); | |
87b0bb13 | 1173 | } |
d6b0e80f | 1174 | |
af990527 PA |
1175 | /* The ptrace base target adds the main thread with (pid,0,0) |
1176 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1177 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1178 | ptid_get_pid (inferior_ptid), | |
1179 | 0); | |
af990527 PA |
1180 | thread_change_ptid (inferior_ptid, ptid); |
1181 | ||
9f0bdab8 | 1182 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1183 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1184 | |
1185 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1186 | &lp->signalled); | |
dacc9cb2 PP |
1187 | if (!WIFSTOPPED (status)) |
1188 | { | |
1189 | if (WIFEXITED (status)) | |
1190 | { | |
1191 | int exit_code = WEXITSTATUS (status); | |
1192 | ||
1193 | target_terminal_ours (); | |
1194 | target_mourn_inferior (); | |
1195 | if (exit_code == 0) | |
1196 | error (_("Unable to attach: program exited normally.")); | |
1197 | else | |
1198 | error (_("Unable to attach: program exited with code %d."), | |
1199 | exit_code); | |
1200 | } | |
1201 | else if (WIFSIGNALED (status)) | |
1202 | { | |
2ea28649 | 1203 | enum gdb_signal signo; |
dacc9cb2 PP |
1204 | |
1205 | target_terminal_ours (); | |
1206 | target_mourn_inferior (); | |
1207 | ||
2ea28649 | 1208 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1209 | error (_("Unable to attach: program terminated with signal " |
1210 | "%s, %s."), | |
2ea28649 PA |
1211 | gdb_signal_to_name (signo), |
1212 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1213 | } |
1214 | ||
1215 | internal_error (__FILE__, __LINE__, | |
1216 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1217 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1218 | } |
1219 | ||
a0ef4274 | 1220 | lp->stopped = 1; |
9f0bdab8 | 1221 | |
a0ef4274 | 1222 | /* Save the wait status to report later. */ |
d6b0e80f | 1223 | lp->resumed = 1; |
a0ef4274 DJ |
1224 | if (debug_linux_nat) |
1225 | fprintf_unfiltered (gdb_stdlog, | |
1226 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1227 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1228 | |
7feb7d06 PA |
1229 | lp->status = status; |
1230 | ||
1231 | if (target_can_async_p ()) | |
1232 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1233 | } |
1234 | ||
a0ef4274 DJ |
1235 | /* Get pending status of LP. */ |
1236 | static int | |
1237 | get_pending_status (struct lwp_info *lp, int *status) | |
1238 | { | |
a493e3e2 | 1239 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1240 | |
1241 | /* If we paused threads momentarily, we may have stored pending | |
1242 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1243 | and GDB core hasn't seen any signal for those threads. | |
1244 | Otherwise, the last signal reported to the core is found in the | |
1245 | thread object's stop_signal. | |
1246 | ||
1247 | There's a corner case that isn't handled here at present. Only | |
1248 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1249 | stop_signal make sense as a real signal to pass to the inferior. | |
1250 | Some catchpoint related events, like | |
1251 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1252 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1253 | those traps are debug API (ptrace in our case) related and |
1254 | induced; the inferior wouldn't see them if it wasn't being | |
1255 | traced. Hence, we should never pass them to the inferior, even | |
1256 | when set to pass state. Since this corner case isn't handled by | |
1257 | infrun.c when proceeding with a signal, for consistency, neither | |
1258 | do we handle it here (or elsewhere in the file we check for | |
1259 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1260 | this is really a corner case. */ | |
1261 | ||
1262 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1263 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1264 | else if (lp->status) |
2ea28649 | 1265 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1266 | else if (non_stop && !is_executing (lp->ptid)) |
1267 | { | |
1268 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1269 | |
16c381f0 | 1270 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1271 | } |
1272 | else if (!non_stop) | |
a0ef4274 | 1273 | { |
ca2163eb PA |
1274 | struct target_waitstatus last; |
1275 | ptid_t last_ptid; | |
4c28f408 | 1276 | |
ca2163eb | 1277 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1278 | |
dfd4cc63 | 1279 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1280 | { |
e09875d4 | 1281 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1282 | |
16c381f0 | 1283 | signo = tp->suspend.stop_signal; |
4c28f408 | 1284 | } |
ca2163eb | 1285 | } |
4c28f408 | 1286 | |
ca2163eb | 1287 | *status = 0; |
4c28f408 | 1288 | |
a493e3e2 | 1289 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1290 | { |
1291 | if (debug_linux_nat) | |
1292 | fprintf_unfiltered (gdb_stdlog, | |
1293 | "GPT: lwp %s has no pending signal\n", | |
1294 | target_pid_to_str (lp->ptid)); | |
1295 | } | |
1296 | else if (!signal_pass_state (signo)) | |
1297 | { | |
1298 | if (debug_linux_nat) | |
3e43a32a MS |
1299 | fprintf_unfiltered (gdb_stdlog, |
1300 | "GPT: lwp %s had signal %s, " | |
1301 | "but it is in no pass state\n", | |
ca2163eb | 1302 | target_pid_to_str (lp->ptid), |
2ea28649 | 1303 | gdb_signal_to_string (signo)); |
a0ef4274 | 1304 | } |
a0ef4274 | 1305 | else |
4c28f408 | 1306 | { |
2ea28649 | 1307 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1308 | |
1309 | if (debug_linux_nat) | |
1310 | fprintf_unfiltered (gdb_stdlog, | |
1311 | "GPT: lwp %s has pending signal %s\n", | |
1312 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1313 | gdb_signal_to_string (signo)); |
4c28f408 | 1314 | } |
a0ef4274 DJ |
1315 | |
1316 | return 0; | |
1317 | } | |
1318 | ||
d6b0e80f AC |
1319 | static int |
1320 | detach_callback (struct lwp_info *lp, void *data) | |
1321 | { | |
1322 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1323 | ||
1324 | if (debug_linux_nat && lp->status) | |
1325 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1326 | strsignal (WSTOPSIG (lp->status)), | |
1327 | target_pid_to_str (lp->ptid)); | |
1328 | ||
a0ef4274 DJ |
1329 | /* If there is a pending SIGSTOP, get rid of it. */ |
1330 | if (lp->signalled) | |
d6b0e80f | 1331 | { |
d6b0e80f AC |
1332 | if (debug_linux_nat) |
1333 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1334 | "DC: Sending SIGCONT to %s\n", |
1335 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1336 | |
dfd4cc63 | 1337 | kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT); |
d6b0e80f | 1338 | lp->signalled = 0; |
d6b0e80f AC |
1339 | } |
1340 | ||
1341 | /* We don't actually detach from the LWP that has an id equal to the | |
1342 | overall process id just yet. */ | |
dfd4cc63 | 1343 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) |
d6b0e80f | 1344 | { |
a0ef4274 DJ |
1345 | int status = 0; |
1346 | ||
1347 | /* Pass on any pending signal for this LWP. */ | |
1348 | get_pending_status (lp, &status); | |
1349 | ||
7b50312a PA |
1350 | if (linux_nat_prepare_to_resume != NULL) |
1351 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f | 1352 | errno = 0; |
dfd4cc63 | 1353 | if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0, |
a0ef4274 | 1354 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1355 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1356 | safe_strerror (errno)); |
1357 | ||
1358 | if (debug_linux_nat) | |
1359 | fprintf_unfiltered (gdb_stdlog, | |
1360 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1361 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1362 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1363 | |
1364 | delete_lwp (lp->ptid); | |
1365 | } | |
1366 | ||
1367 | return 0; | |
1368 | } | |
1369 | ||
1370 | static void | |
52554a0e | 1371 | linux_nat_detach (struct target_ops *ops, const char *args, int from_tty) |
d6b0e80f | 1372 | { |
b84876c2 | 1373 | int pid; |
a0ef4274 | 1374 | int status; |
d90e17a7 PA |
1375 | struct lwp_info *main_lwp; |
1376 | ||
dfd4cc63 | 1377 | pid = ptid_get_pid (inferior_ptid); |
a0ef4274 | 1378 | |
ae5e0686 MK |
1379 | /* Don't unregister from the event loop, as there may be other |
1380 | inferiors running. */ | |
b84876c2 | 1381 | |
4c28f408 PA |
1382 | /* Stop all threads before detaching. ptrace requires that the |
1383 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1384 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1385 | /* ... and wait until all of them have reported back that |
1386 | they're no longer running. */ | |
d90e17a7 | 1387 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1388 | |
d90e17a7 | 1389 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1390 | |
1391 | /* Only the initial process should be left right now. */ | |
dfd4cc63 | 1392 | gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1); |
d90e17a7 PA |
1393 | |
1394 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1395 | |
a0ef4274 DJ |
1396 | /* Pass on any pending signal for the last LWP. */ |
1397 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1398 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1399 | && WIFSTOPPED (status)) |
1400 | { | |
52554a0e TT |
1401 | char *tem; |
1402 | ||
a0ef4274 DJ |
1403 | /* Put the signal number in ARGS so that inf_ptrace_detach will |
1404 | pass it along with PTRACE_DETACH. */ | |
52554a0e | 1405 | tem = alloca (8); |
cde33bf1 | 1406 | xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status)); |
52554a0e | 1407 | args = tem; |
ddabfc73 TT |
1408 | if (debug_linux_nat) |
1409 | fprintf_unfiltered (gdb_stdlog, | |
1410 | "LND: Sending signal %s to %s\n", | |
1411 | args, | |
1412 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1413 | } |
1414 | ||
7b50312a PA |
1415 | if (linux_nat_prepare_to_resume != NULL) |
1416 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1417 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1418 | |
7a7d3353 PA |
1419 | if (forks_exist_p ()) |
1420 | { | |
1421 | /* Multi-fork case. The current inferior_ptid is being detached | |
1422 | from, but there are other viable forks to debug. Detach from | |
1423 | the current fork, and context-switch to the first | |
1424 | available. */ | |
1425 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1426 | } |
1427 | else | |
1428 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1429 | } |
1430 | ||
1431 | /* Resume LP. */ | |
1432 | ||
25289eb2 | 1433 | static void |
e5ef252a | 1434 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1435 | { |
25289eb2 | 1436 | if (lp->stopped) |
6c95b8df | 1437 | { |
dfd4cc63 | 1438 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); |
25289eb2 PA |
1439 | |
1440 | if (inf->vfork_child != NULL) | |
1441 | { | |
1442 | if (debug_linux_nat) | |
1443 | fprintf_unfiltered (gdb_stdlog, | |
1444 | "RC: Not resuming %s (vfork parent)\n", | |
1445 | target_pid_to_str (lp->ptid)); | |
1446 | } | |
1447 | else if (lp->status == 0 | |
1448 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1449 | { | |
1450 | if (debug_linux_nat) | |
1451 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1452 | "RC: Resuming sibling %s, %s, %s\n", |
1453 | target_pid_to_str (lp->ptid), | |
1454 | (signo != GDB_SIGNAL_0 | |
1455 | ? strsignal (gdb_signal_to_host (signo)) | |
1456 | : "0"), | |
1457 | step ? "step" : "resume"); | |
25289eb2 | 1458 | |
7b50312a PA |
1459 | if (linux_nat_prepare_to_resume != NULL) |
1460 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 1461 | linux_ops->to_resume (linux_ops, |
dfd4cc63 | 1462 | pid_to_ptid (ptid_get_lwp (lp->ptid)), |
e5ef252a | 1463 | step, signo); |
25289eb2 PA |
1464 | lp->stopped = 0; |
1465 | lp->step = step; | |
25289eb2 PA |
1466 | lp->stopped_by_watchpoint = 0; |
1467 | } | |
1468 | else | |
1469 | { | |
1470 | if (debug_linux_nat) | |
1471 | fprintf_unfiltered (gdb_stdlog, | |
1472 | "RC: Not resuming sibling %s (has pending)\n", | |
1473 | target_pid_to_str (lp->ptid)); | |
1474 | } | |
6c95b8df | 1475 | } |
25289eb2 | 1476 | else |
d6b0e80f | 1477 | { |
d90e17a7 PA |
1478 | if (debug_linux_nat) |
1479 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1480 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1481 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1482 | } |
25289eb2 | 1483 | } |
d6b0e80f | 1484 | |
8817a6f2 PA |
1485 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1486 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1487 | |
25289eb2 | 1488 | static int |
8817a6f2 | 1489 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1490 | { |
e5ef252a PA |
1491 | enum gdb_signal signo = GDB_SIGNAL_0; |
1492 | ||
8817a6f2 PA |
1493 | if (lp == except) |
1494 | return 0; | |
1495 | ||
e5ef252a PA |
1496 | if (lp->stopped) |
1497 | { | |
1498 | struct thread_info *thread; | |
1499 | ||
1500 | thread = find_thread_ptid (lp->ptid); | |
1501 | if (thread != NULL) | |
1502 | { | |
70509625 | 1503 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1504 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1505 | } | |
1506 | } | |
1507 | ||
1508 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1509 | return 0; |
1510 | } | |
1511 | ||
1512 | static int | |
1513 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1514 | { | |
1515 | lp->resumed = 0; | |
25289eb2 | 1516 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1517 | return 0; |
1518 | } | |
1519 | ||
1520 | static int | |
1521 | resume_set_callback (struct lwp_info *lp, void *data) | |
1522 | { | |
1523 | lp->resumed = 1; | |
25289eb2 | 1524 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1525 | return 0; |
1526 | } | |
1527 | ||
1528 | static void | |
28439f5e | 1529 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1530 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1531 | { |
1532 | struct lwp_info *lp; | |
d90e17a7 | 1533 | int resume_many; |
d6b0e80f | 1534 | |
76f50ad1 DJ |
1535 | if (debug_linux_nat) |
1536 | fprintf_unfiltered (gdb_stdlog, | |
1537 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1538 | step ? "step" : "resume", | |
1539 | target_pid_to_str (ptid), | |
a493e3e2 | 1540 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1541 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1542 | target_pid_to_str (inferior_ptid)); |
1543 | ||
d6b0e80f | 1544 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1545 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1546 | || ptid_is_pid (ptid)); | |
4c28f408 | 1547 | |
e3e9f5a2 PA |
1548 | /* Mark the lwps we're resuming as resumed. */ |
1549 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1550 | |
d90e17a7 PA |
1551 | /* See if it's the current inferior that should be handled |
1552 | specially. */ | |
1553 | if (resume_many) | |
1554 | lp = find_lwp_pid (inferior_ptid); | |
1555 | else | |
1556 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1557 | gdb_assert (lp != NULL); |
d6b0e80f | 1558 | |
9f0bdab8 DJ |
1559 | /* Remember if we're stepping. */ |
1560 | lp->step = step; | |
25289eb2 | 1561 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1562 | |
9f0bdab8 DJ |
1563 | /* If we have a pending wait status for this thread, there is no |
1564 | point in resuming the process. But first make sure that | |
1565 | linux_nat_wait won't preemptively handle the event - we | |
1566 | should never take this short-circuit if we are going to | |
1567 | leave LP running, since we have skipped resuming all the | |
1568 | other threads. This bit of code needs to be synchronized | |
1569 | with linux_nat_wait. */ | |
76f50ad1 | 1570 | |
9f0bdab8 DJ |
1571 | if (lp->status && WIFSTOPPED (lp->status)) |
1572 | { | |
2455069d UW |
1573 | if (!lp->step |
1574 | && WSTOPSIG (lp->status) | |
1575 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1576 | { |
9f0bdab8 DJ |
1577 | if (debug_linux_nat) |
1578 | fprintf_unfiltered (gdb_stdlog, | |
1579 | "LLR: Not short circuiting for ignored " | |
1580 | "status 0x%x\n", lp->status); | |
1581 | ||
d6b0e80f AC |
1582 | /* FIXME: What should we do if we are supposed to continue |
1583 | this thread with a signal? */ | |
a493e3e2 | 1584 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1585 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1586 | lp->status = 0; |
1587 | } | |
1588 | } | |
76f50ad1 | 1589 | |
6c95b8df | 1590 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
1591 | { |
1592 | /* FIXME: What should we do if we are supposed to continue | |
1593 | this thread with a signal? */ | |
a493e3e2 | 1594 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1595 | |
9f0bdab8 DJ |
1596 | if (debug_linux_nat) |
1597 | fprintf_unfiltered (gdb_stdlog, | |
1598 | "LLR: Short circuiting for status 0x%x\n", | |
1599 | lp->status); | |
d6b0e80f | 1600 | |
7feb7d06 PA |
1601 | if (target_can_async_p ()) |
1602 | { | |
1603 | target_async (inferior_event_handler, 0); | |
1604 | /* Tell the event loop we have something to process. */ | |
1605 | async_file_mark (); | |
1606 | } | |
9f0bdab8 | 1607 | return; |
d6b0e80f AC |
1608 | } |
1609 | ||
d90e17a7 | 1610 | if (resume_many) |
8817a6f2 | 1611 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 PA |
1612 | |
1613 | /* Convert to something the lower layer understands. */ | |
dfd4cc63 | 1614 | ptid = pid_to_ptid (ptid_get_lwp (lp->ptid)); |
d6b0e80f | 1615 | |
7b50312a PA |
1616 | if (linux_nat_prepare_to_resume != NULL) |
1617 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 1618 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 1619 | lp->stopped_by_watchpoint = 0; |
8817a6f2 | 1620 | lp->stopped = 0; |
9f0bdab8 | 1621 | |
d6b0e80f AC |
1622 | if (debug_linux_nat) |
1623 | fprintf_unfiltered (gdb_stdlog, | |
1624 | "LLR: %s %s, %s (resume event thread)\n", | |
1625 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1626 | target_pid_to_str (ptid), | |
a493e3e2 | 1627 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1628 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 PA |
1629 | |
1630 | if (target_can_async_p ()) | |
8ea051c5 | 1631 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
1632 | } |
1633 | ||
c5f62d5f | 1634 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1635 | |
1636 | static int | |
1637 | kill_lwp (int lwpid, int signo) | |
1638 | { | |
c5f62d5f DE |
1639 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
1640 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
1641 | |
1642 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
1643 | { |
1644 | static int tkill_failed; | |
1645 | ||
1646 | if (!tkill_failed) | |
1647 | { | |
1648 | int ret; | |
1649 | ||
1650 | errno = 0; | |
1651 | ret = syscall (__NR_tkill, lwpid, signo); | |
1652 | if (errno != ENOSYS) | |
1653 | return ret; | |
1654 | tkill_failed = 1; | |
1655 | } | |
1656 | } | |
d6b0e80f AC |
1657 | #endif |
1658 | ||
1659 | return kill (lwpid, signo); | |
1660 | } | |
1661 | ||
ca2163eb PA |
1662 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1663 | event, check if the core is interested in it: if not, ignore the | |
1664 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1665 | syscall entry/exit status, since the ptrace event itself doesn't | |
1666 | indicate it, and report the trap to higher layers. */ | |
1667 | ||
1668 | static int | |
1669 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1670 | { | |
1671 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1672 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1673 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1674 | ||
1675 | if (stopping) | |
1676 | { | |
1677 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1678 | makes it so that the LWP reports an immediate syscall return, | |
1679 | followed by the SIGSTOP. Skip seeing that "return" using | |
1680 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1681 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1682 | entry event. If we didn't do this (and returned 0), we'd | |
1683 | leave a syscall entry pending, and our caller, by using | |
1684 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1685 | itself. Later, when the user re-resumes this LWP, we'd see | |
1686 | another syscall entry event and we'd mistake it for a return. | |
1687 | ||
1688 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1689 | (leaving immediately with LWP->signalled set, without issuing | |
1690 | a PTRACE_CONT), it would still be problematic to leave this | |
1691 | syscall enter pending, as later when the thread is resumed, | |
1692 | it would then see the same syscall exit mentioned above, | |
1693 | followed by the delayed SIGSTOP, while the syscall didn't | |
1694 | actually get to execute. It seems it would be even more | |
1695 | confusing to the user. */ | |
1696 | ||
1697 | if (debug_linux_nat) | |
1698 | fprintf_unfiltered (gdb_stdlog, | |
1699 | "LHST: ignoring syscall %d " | |
1700 | "for LWP %ld (stopping threads), " | |
1701 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1702 | syscall_number, | |
dfd4cc63 | 1703 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1704 | |
1705 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1706 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1707 | lp->stopped = 0; |
ca2163eb PA |
1708 | return 1; |
1709 | } | |
1710 | ||
1711 | if (catch_syscall_enabled ()) | |
1712 | { | |
1713 | /* Always update the entry/return state, even if this particular | |
1714 | syscall isn't interesting to the core now. In async mode, | |
1715 | the user could install a new catchpoint for this syscall | |
1716 | between syscall enter/return, and we'll need to know to | |
1717 | report a syscall return if that happens. */ | |
1718 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1719 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1720 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1721 | ||
1722 | if (catching_syscall_number (syscall_number)) | |
1723 | { | |
1724 | /* Alright, an event to report. */ | |
1725 | ourstatus->kind = lp->syscall_state; | |
1726 | ourstatus->value.syscall_number = syscall_number; | |
1727 | ||
1728 | if (debug_linux_nat) | |
1729 | fprintf_unfiltered (gdb_stdlog, | |
1730 | "LHST: stopping for %s of syscall %d" | |
1731 | " for LWP %ld\n", | |
3e43a32a MS |
1732 | lp->syscall_state |
1733 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1734 | ? "entry" : "return", |
1735 | syscall_number, | |
dfd4cc63 | 1736 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1737 | return 0; |
1738 | } | |
1739 | ||
1740 | if (debug_linux_nat) | |
1741 | fprintf_unfiltered (gdb_stdlog, | |
1742 | "LHST: ignoring %s of syscall %d " | |
1743 | "for LWP %ld\n", | |
1744 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1745 | ? "entry" : "return", | |
1746 | syscall_number, | |
dfd4cc63 | 1747 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1748 | } |
1749 | else | |
1750 | { | |
1751 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1752 | before on this LWP, it could happen that the user removes all | |
1753 | syscall catchpoints before we get to process this event. | |
1754 | There are two noteworthy issues here: | |
1755 | ||
1756 | - When stopped at a syscall entry event, resuming with | |
1757 | PT_STEP still resumes executing the syscall and reports a | |
1758 | syscall return. | |
1759 | ||
1760 | - Only PT_SYSCALL catches syscall enters. If we last | |
1761 | single-stepped this thread, then this event can't be a | |
1762 | syscall enter. If we last single-stepped this thread, this | |
1763 | has to be a syscall exit. | |
1764 | ||
1765 | The points above mean that the next resume, be it PT_STEP or | |
1766 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1767 | if (debug_linux_nat) | |
1768 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1769 | "LHST: caught syscall event " |
1770 | "with no syscall catchpoints." | |
ca2163eb PA |
1771 | " %d for LWP %ld, ignoring\n", |
1772 | syscall_number, | |
dfd4cc63 | 1773 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1774 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1775 | } | |
1776 | ||
1777 | /* The core isn't interested in this event. For efficiency, avoid | |
1778 | stopping all threads only to have the core resume them all again. | |
1779 | Since we're not stopping threads, if we're still syscall tracing | |
1780 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1781 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1782 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1783 | ||
1784 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
1785 | fill a regcache. */ | |
1786 | registers_changed (); | |
7b50312a PA |
1787 | if (linux_nat_prepare_to_resume != NULL) |
1788 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 1789 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 1790 | lp->step, GDB_SIGNAL_0); |
8817a6f2 | 1791 | lp->stopped = 0; |
ca2163eb PA |
1792 | return 1; |
1793 | } | |
1794 | ||
3d799a95 DJ |
1795 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1796 | event, we need to add the new LWP to our list (and not report the | |
1797 | trap to higher layers). This function returns non-zero if the | |
1798 | event should be ignored and we should wait again. If STOPPING is | |
1799 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1800 | |
1801 | static int | |
3d799a95 DJ |
1802 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
1803 | int stopping) | |
d6b0e80f | 1804 | { |
dfd4cc63 | 1805 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1806 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1807 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1808 | |
3d799a95 DJ |
1809 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1810 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1811 | { |
3d799a95 DJ |
1812 | unsigned long new_pid; |
1813 | int ret; | |
1814 | ||
1815 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1816 | |
3d799a95 DJ |
1817 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1818 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1819 | { | |
1820 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1821 | hits the SIGSTOP, but we're already attached. */ | |
1822 | ret = my_waitpid (new_pid, &status, | |
1823 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
1824 | if (ret == -1) | |
1825 | perror_with_name (_("waiting for new child")); | |
1826 | else if (ret != new_pid) | |
1827 | internal_error (__FILE__, __LINE__, | |
1828 | _("wait returned unexpected PID %d"), ret); | |
1829 | else if (!WIFSTOPPED (status)) | |
1830 | internal_error (__FILE__, __LINE__, | |
1831 | _("wait returned unexpected status 0x%x"), status); | |
1832 | } | |
1833 | ||
3a3e9ee3 | 1834 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 1835 | |
26cb8b7c PA |
1836 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1837 | { | |
1838 | /* The arch-specific native code may need to know about new | |
1839 | forks even if those end up never mapped to an | |
1840 | inferior. */ | |
1841 | if (linux_nat_new_fork != NULL) | |
1842 | linux_nat_new_fork (lp, new_pid); | |
1843 | } | |
1844 | ||
2277426b | 1845 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 1846 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 1847 | { |
2277426b PA |
1848 | /* Handle checkpointing by linux-fork.c here as a special |
1849 | case. We don't want the follow-fork-mode or 'catch fork' | |
1850 | to interfere with this. */ | |
1851 | ||
1852 | /* This won't actually modify the breakpoint list, but will | |
1853 | physically remove the breakpoints from the child. */ | |
d80ee84f | 1854 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
1855 | |
1856 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1857 | if (!find_fork_pid (new_pid)) |
1858 | add_fork (new_pid); | |
2277426b PA |
1859 | |
1860 | /* Report as spurious, so that infrun doesn't want to follow | |
1861 | this fork. We're actually doing an infcall in | |
1862 | linux-fork.c. */ | |
1863 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
1864 | |
1865 | /* Report the stop to the core. */ | |
1866 | return 0; | |
1867 | } | |
1868 | ||
3d799a95 DJ |
1869 | if (event == PTRACE_EVENT_FORK) |
1870 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
1871 | else if (event == PTRACE_EVENT_VFORK) | |
1872 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 1873 | else |
3d799a95 | 1874 | { |
78768c4a JK |
1875 | struct lwp_info *new_lp; |
1876 | ||
3d799a95 | 1877 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 1878 | |
3c4d7e12 PA |
1879 | if (debug_linux_nat) |
1880 | fprintf_unfiltered (gdb_stdlog, | |
1881 | "LHEW: Got clone event " | |
1882 | "from LWP %d, new child is LWP %ld\n", | |
1883 | pid, new_pid); | |
1884 | ||
dfd4cc63 | 1885 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
3d799a95 | 1886 | new_lp->cloned = 1; |
4c28f408 | 1887 | new_lp->stopped = 1; |
d6b0e80f | 1888 | |
3d799a95 DJ |
1889 | if (WSTOPSIG (status) != SIGSTOP) |
1890 | { | |
1891 | /* This can happen if someone starts sending signals to | |
1892 | the new thread before it gets a chance to run, which | |
1893 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1894 | This is an unlikely case, and harder to handle for | |
1895 | fork / vfork than for clone, so we do not try - but | |
1896 | we handle it for clone events here. We'll send | |
1897 | the other signal on to the thread below. */ | |
1898 | ||
1899 | new_lp->signalled = 1; | |
1900 | } | |
1901 | else | |
79395f92 PA |
1902 | { |
1903 | struct thread_info *tp; | |
1904 | ||
1905 | /* When we stop for an event in some other thread, and | |
1906 | pull the thread list just as this thread has cloned, | |
1907 | we'll have seen the new thread in the thread_db list | |
1908 | before handling the CLONE event (glibc's | |
1909 | pthread_create adds the new thread to the thread list | |
1910 | before clone'ing, and has the kernel fill in the | |
1911 | thread's tid on the clone call with | |
1912 | CLONE_PARENT_SETTID). If that happened, and the core | |
1913 | had requested the new thread to stop, we'll have | |
1914 | killed it with SIGSTOP. But since SIGSTOP is not an | |
1915 | RT signal, it can only be queued once. We need to be | |
1916 | careful to not resume the LWP if we wanted it to | |
1917 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 1918 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
1919 | tp = find_thread_ptid (new_lp->ptid); |
1920 | if (tp != NULL && tp->stop_requested) | |
1921 | new_lp->last_resume_kind = resume_stop; | |
1922 | else | |
1923 | status = 0; | |
1924 | } | |
d6b0e80f | 1925 | |
4c28f408 | 1926 | if (non_stop) |
3d799a95 | 1927 | { |
4c28f408 PA |
1928 | /* Add the new thread to GDB's lists as soon as possible |
1929 | so that: | |
1930 | ||
1931 | 1) the frontend doesn't have to wait for a stop to | |
1932 | display them, and, | |
1933 | ||
1934 | 2) we tag it with the correct running state. */ | |
1935 | ||
1936 | /* If the thread_db layer is active, let it know about | |
1937 | this new thread, and add it to GDB's list. */ | |
1938 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
1939 | { | |
1940 | /* We're not using thread_db. Add it to GDB's | |
1941 | list. */ | |
dfd4cc63 | 1942 | target_post_attach (ptid_get_lwp (new_lp->ptid)); |
4c28f408 PA |
1943 | add_thread (new_lp->ptid); |
1944 | } | |
1945 | ||
1946 | if (!stopping) | |
1947 | { | |
1948 | set_running (new_lp->ptid, 1); | |
1949 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
1950 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
1951 | resume_stop. */ | |
1952 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
1953 | } |
1954 | } | |
1955 | ||
79395f92 PA |
1956 | if (status != 0) |
1957 | { | |
1958 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
1959 | gdb_assert (new_lp->status == 0); | |
1960 | ||
1961 | /* Save the wait status to report later. */ | |
1962 | if (debug_linux_nat) | |
1963 | fprintf_unfiltered (gdb_stdlog, | |
1964 | "LHEW: waitpid of new LWP %ld, " | |
1965 | "saving status %s\n", | |
dfd4cc63 | 1966 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
1967 | status_to_str (status)); |
1968 | new_lp->status = status; | |
1969 | } | |
1970 | ||
ca2163eb PA |
1971 | /* Note the need to use the low target ops to resume, to |
1972 | handle resuming with PT_SYSCALL if we have syscall | |
1973 | catchpoints. */ | |
4c28f408 PA |
1974 | if (!stopping) |
1975 | { | |
3d799a95 | 1976 | new_lp->resumed = 1; |
ca2163eb | 1977 | |
79395f92 | 1978 | if (status == 0) |
ad34eb2f | 1979 | { |
e21ffe51 | 1980 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
1981 | if (debug_linux_nat) |
1982 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 | 1983 | "LHEW: resuming new LWP %ld\n", |
dfd4cc63 | 1984 | ptid_get_lwp (new_lp->ptid)); |
7b50312a PA |
1985 | if (linux_nat_prepare_to_resume != NULL) |
1986 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 1987 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 1988 | 0, GDB_SIGNAL_0); |
79395f92 | 1989 | new_lp->stopped = 0; |
ad34eb2f JK |
1990 | } |
1991 | } | |
d6b0e80f | 1992 | |
3d799a95 DJ |
1993 | if (debug_linux_nat) |
1994 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 1995 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
1996 | if (linux_nat_prepare_to_resume != NULL) |
1997 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
1998 | linux_ops->to_resume (linux_ops, |
1999 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
a493e3e2 | 2000 | 0, GDB_SIGNAL_0); |
8817a6f2 | 2001 | lp->stopped = 0; |
3d799a95 DJ |
2002 | return 1; |
2003 | } | |
2004 | ||
2005 | return 0; | |
d6b0e80f AC |
2006 | } |
2007 | ||
3d799a95 DJ |
2008 | if (event == PTRACE_EVENT_EXEC) |
2009 | { | |
a75724bc PA |
2010 | if (debug_linux_nat) |
2011 | fprintf_unfiltered (gdb_stdlog, | |
2012 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2013 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2014 | |
3d799a95 DJ |
2015 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2016 | ourstatus->value.execd_pathname | |
8dd27370 | 2017 | = xstrdup (linux_child_pid_to_exec_file (NULL, pid)); |
3d799a95 | 2018 | |
6c95b8df PA |
2019 | return 0; |
2020 | } | |
2021 | ||
2022 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2023 | { | |
2024 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2025 | { |
6c95b8df | 2026 | if (debug_linux_nat) |
3e43a32a MS |
2027 | fprintf_unfiltered (gdb_stdlog, |
2028 | "LHEW: Got expected PTRACE_EVENT_" | |
2029 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2030 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2031 | |
6c95b8df PA |
2032 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2033 | return 0; | |
3d799a95 DJ |
2034 | } |
2035 | ||
6c95b8df | 2036 | if (debug_linux_nat) |
3e43a32a MS |
2037 | fprintf_unfiltered (gdb_stdlog, |
2038 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2039 | "from LWP %ld: resuming\n", | |
dfd4cc63 LM |
2040 | ptid_get_lwp (lp->ptid)); |
2041 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); | |
6c95b8df | 2042 | return 1; |
3d799a95 DJ |
2043 | } |
2044 | ||
2045 | internal_error (__FILE__, __LINE__, | |
2046 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2047 | } |
2048 | ||
2049 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2050 | exited. */ | |
2051 | ||
2052 | static int | |
2053 | wait_lwp (struct lwp_info *lp) | |
2054 | { | |
2055 | pid_t pid; | |
432b4d03 | 2056 | int status = 0; |
d6b0e80f | 2057 | int thread_dead = 0; |
432b4d03 | 2058 | sigset_t prev_mask; |
d6b0e80f AC |
2059 | |
2060 | gdb_assert (!lp->stopped); | |
2061 | gdb_assert (lp->status == 0); | |
2062 | ||
432b4d03 JK |
2063 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2064 | block_child_signals (&prev_mask); | |
2065 | ||
2066 | for (;;) | |
d6b0e80f | 2067 | { |
432b4d03 JK |
2068 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2069 | was right and we should just call sigsuspend. */ | |
2070 | ||
dfd4cc63 | 2071 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG); |
d6b0e80f | 2072 | if (pid == -1 && errno == ECHILD) |
dfd4cc63 | 2073 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2074 | if (pid == -1 && errno == ECHILD) |
2075 | { | |
2076 | /* The thread has previously exited. We need to delete it | |
2077 | now because, for some vendor 2.4 kernels with NPTL | |
2078 | support backported, there won't be an exit event unless | |
2079 | it is the main thread. 2.6 kernels will report an exit | |
2080 | event for each thread that exits, as expected. */ | |
2081 | thread_dead = 1; | |
2082 | if (debug_linux_nat) | |
2083 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2084 | target_pid_to_str (lp->ptid)); | |
2085 | } | |
432b4d03 JK |
2086 | if (pid != 0) |
2087 | break; | |
2088 | ||
2089 | /* Bugs 10970, 12702. | |
2090 | Thread group leader may have exited in which case we'll lock up in | |
2091 | waitpid if there are other threads, even if they are all zombies too. | |
2092 | Basically, we're not supposed to use waitpid this way. | |
2093 | __WCLONE is not applicable for the leader so we can't use that. | |
2094 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2095 | process; it gets ESRCH both for the zombie and for running processes. | |
2096 | ||
2097 | As a workaround, check if we're waiting for the thread group leader and | |
2098 | if it's a zombie, and avoid calling waitpid if it is. | |
2099 | ||
2100 | This is racy, what if the tgl becomes a zombie right after we check? | |
2101 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2102 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2103 | |
dfd4cc63 LM |
2104 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2105 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2106 | { |
d6b0e80f AC |
2107 | thread_dead = 1; |
2108 | if (debug_linux_nat) | |
432b4d03 JK |
2109 | fprintf_unfiltered (gdb_stdlog, |
2110 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2111 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2112 | break; |
d6b0e80f | 2113 | } |
432b4d03 JK |
2114 | |
2115 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2116 | get invoked despite our caller had them intentionally blocked by | |
2117 | block_child_signals. This is sensitive only to the loop of | |
2118 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2119 | again before it gets to sigsuspend so we can safely let the handlers | |
2120 | get executed here. */ | |
2121 | ||
d36bf488 DE |
2122 | if (debug_linux_nat) |
2123 | fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n"); | |
432b4d03 JK |
2124 | sigsuspend (&suspend_mask); |
2125 | } | |
2126 | ||
2127 | restore_child_signals_mask (&prev_mask); | |
2128 | ||
d6b0e80f AC |
2129 | if (!thread_dead) |
2130 | { | |
dfd4cc63 | 2131 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2132 | |
2133 | if (debug_linux_nat) | |
2134 | { | |
2135 | fprintf_unfiltered (gdb_stdlog, | |
2136 | "WL: waitpid %s received %s\n", | |
2137 | target_pid_to_str (lp->ptid), | |
2138 | status_to_str (status)); | |
2139 | } | |
d6b0e80f | 2140 | |
a9f4bb21 PA |
2141 | /* Check if the thread has exited. */ |
2142 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2143 | { | |
2144 | thread_dead = 1; | |
2145 | if (debug_linux_nat) | |
2146 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2147 | target_pid_to_str (lp->ptid)); | |
2148 | } | |
d6b0e80f AC |
2149 | } |
2150 | ||
2151 | if (thread_dead) | |
2152 | { | |
e26af52f | 2153 | exit_lwp (lp); |
d6b0e80f AC |
2154 | return 0; |
2155 | } | |
2156 | ||
2157 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2158 | lp->stopped = 1; |
d6b0e80f | 2159 | |
ca2163eb PA |
2160 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2161 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2162 | { | |
2163 | /* No longer need the sysgood bit. The ptrace event ends up | |
2164 | recorded in lp->waitstatus if we care for it. We can carry | |
2165 | on handling the event like a regular SIGTRAP from here | |
2166 | on. */ | |
2167 | status = W_STOPCODE (SIGTRAP); | |
2168 | if (linux_handle_syscall_trap (lp, 1)) | |
2169 | return wait_lwp (lp); | |
2170 | } | |
2171 | ||
d6b0e80f | 2172 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2173 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2174 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2175 | { |
2176 | if (debug_linux_nat) | |
2177 | fprintf_unfiltered (gdb_stdlog, | |
2178 | "WL: Handling extended status 0x%06x\n", | |
2179 | status); | |
3d799a95 | 2180 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2181 | return wait_lwp (lp); |
2182 | } | |
2183 | ||
2184 | return status; | |
2185 | } | |
2186 | ||
2187 | /* Send a SIGSTOP to LP. */ | |
2188 | ||
2189 | static int | |
2190 | stop_callback (struct lwp_info *lp, void *data) | |
2191 | { | |
2192 | if (!lp->stopped && !lp->signalled) | |
2193 | { | |
2194 | int ret; | |
2195 | ||
2196 | if (debug_linux_nat) | |
2197 | { | |
2198 | fprintf_unfiltered (gdb_stdlog, | |
2199 | "SC: kill %s **<SIGSTOP>**\n", | |
2200 | target_pid_to_str (lp->ptid)); | |
2201 | } | |
2202 | errno = 0; | |
dfd4cc63 | 2203 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2204 | if (debug_linux_nat) |
2205 | { | |
2206 | fprintf_unfiltered (gdb_stdlog, | |
2207 | "SC: lwp kill %d %s\n", | |
2208 | ret, | |
2209 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2210 | } | |
2211 | ||
2212 | lp->signalled = 1; | |
2213 | gdb_assert (lp->status == 0); | |
2214 | } | |
2215 | ||
2216 | return 0; | |
2217 | } | |
2218 | ||
7b50312a PA |
2219 | /* Request a stop on LWP. */ |
2220 | ||
2221 | void | |
2222 | linux_stop_lwp (struct lwp_info *lwp) | |
2223 | { | |
2224 | stop_callback (lwp, NULL); | |
2225 | } | |
2226 | ||
57380f4e | 2227 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2228 | |
2229 | static int | |
57380f4e DJ |
2230 | linux_nat_has_pending_sigint (int pid) |
2231 | { | |
2232 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2233 | |
2234 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2235 | ||
2236 | if (sigismember (&pending, SIGINT) | |
2237 | && !sigismember (&ignored, SIGINT)) | |
2238 | return 1; | |
2239 | ||
2240 | return 0; | |
2241 | } | |
2242 | ||
2243 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2244 | ||
2245 | static int | |
2246 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2247 | { |
57380f4e DJ |
2248 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2249 | flag to consume the next one. */ | |
2250 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2251 | && WSTOPSIG (lp->status) == SIGINT) | |
2252 | lp->status = 0; | |
2253 | else | |
2254 | lp->ignore_sigint = 1; | |
2255 | ||
2256 | return 0; | |
2257 | } | |
2258 | ||
2259 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2260 | This function is called after we know the LWP has stopped; if the LWP | |
2261 | stopped before the expected SIGINT was delivered, then it will never have | |
2262 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2263 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2264 | |
57380f4e DJ |
2265 | static void |
2266 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2267 | { | |
2268 | if (!lp->ignore_sigint) | |
2269 | return; | |
2270 | ||
dfd4cc63 | 2271 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2272 | { |
2273 | if (debug_linux_nat) | |
2274 | fprintf_unfiltered (gdb_stdlog, | |
2275 | "MCIS: Clearing bogus flag for %s\n", | |
2276 | target_pid_to_str (lp->ptid)); | |
2277 | lp->ignore_sigint = 0; | |
2278 | } | |
2279 | } | |
2280 | ||
ebec9a0f PA |
2281 | /* Fetch the possible triggered data watchpoint info and store it in |
2282 | LP. | |
2283 | ||
2284 | On some archs, like x86, that use debug registers to set | |
2285 | watchpoints, it's possible that the way to know which watched | |
2286 | address trapped, is to check the register that is used to select | |
2287 | which address to watch. Problem is, between setting the watchpoint | |
2288 | and reading back which data address trapped, the user may change | |
2289 | the set of watchpoints, and, as a consequence, GDB changes the | |
2290 | debug registers in the inferior. To avoid reading back a stale | |
2291 | stopped-data-address when that happens, we cache in LP the fact | |
2292 | that a watchpoint trapped, and the corresponding data address, as | |
2293 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2294 | registers meanwhile, we have the cached data we can rely on. */ | |
2295 | ||
2296 | static void | |
2297 | save_sigtrap (struct lwp_info *lp) | |
2298 | { | |
2299 | struct cleanup *old_chain; | |
2300 | ||
2301 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2302 | { | |
2303 | lp->stopped_by_watchpoint = 0; | |
2304 | return; | |
2305 | } | |
2306 | ||
2307 | old_chain = save_inferior_ptid (); | |
2308 | inferior_ptid = lp->ptid; | |
2309 | ||
6a109b6b | 2310 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (linux_ops); |
ebec9a0f PA |
2311 | |
2312 | if (lp->stopped_by_watchpoint) | |
2313 | { | |
2314 | if (linux_ops->to_stopped_data_address != NULL) | |
2315 | lp->stopped_data_address_p = | |
2316 | linux_ops->to_stopped_data_address (¤t_target, | |
2317 | &lp->stopped_data_address); | |
2318 | else | |
2319 | lp->stopped_data_address_p = 0; | |
2320 | } | |
2321 | ||
2322 | do_cleanups (old_chain); | |
2323 | } | |
2324 | ||
2325 | /* See save_sigtrap. */ | |
2326 | ||
2327 | static int | |
6a109b6b | 2328 | linux_nat_stopped_by_watchpoint (struct target_ops *ops) |
ebec9a0f PA |
2329 | { |
2330 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2331 | ||
2332 | gdb_assert (lp != NULL); | |
2333 | ||
2334 | return lp->stopped_by_watchpoint; | |
2335 | } | |
2336 | ||
2337 | static int | |
2338 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2339 | { | |
2340 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2341 | ||
2342 | gdb_assert (lp != NULL); | |
2343 | ||
2344 | *addr_p = lp->stopped_data_address; | |
2345 | ||
2346 | return lp->stopped_data_address_p; | |
2347 | } | |
2348 | ||
26ab7092 JK |
2349 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2350 | ||
2351 | static int | |
2352 | sigtrap_is_event (int status) | |
2353 | { | |
2354 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2355 | } | |
2356 | ||
2357 | /* SIGTRAP-like events recognizer. */ | |
2358 | ||
2359 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2360 | ||
00390b84 JK |
2361 | /* Check for SIGTRAP-like events in LP. */ |
2362 | ||
2363 | static int | |
2364 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2365 | { | |
2366 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2367 | have pending process exits recorded in lp->status | |
2368 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2369 | lp->status_p flag. */ | |
2370 | ||
2371 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2372 | && linux_nat_status_is_event (lp->status)); | |
2373 | } | |
2374 | ||
26ab7092 JK |
2375 | /* Set alternative SIGTRAP-like events recognizer. If |
2376 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2377 | applied. */ | |
2378 | ||
2379 | void | |
2380 | linux_nat_set_status_is_event (struct target_ops *t, | |
2381 | int (*status_is_event) (int status)) | |
2382 | { | |
2383 | linux_nat_status_is_event = status_is_event; | |
2384 | } | |
2385 | ||
57380f4e DJ |
2386 | /* Wait until LP is stopped. */ |
2387 | ||
2388 | static int | |
2389 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2390 | { | |
dfd4cc63 | 2391 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); |
6c95b8df PA |
2392 | |
2393 | /* If this is a vfork parent, bail out, it is not going to report | |
2394 | any SIGSTOP until the vfork is done with. */ | |
2395 | if (inf->vfork_child != NULL) | |
2396 | return 0; | |
2397 | ||
d6b0e80f AC |
2398 | if (!lp->stopped) |
2399 | { | |
2400 | int status; | |
2401 | ||
2402 | status = wait_lwp (lp); | |
2403 | if (status == 0) | |
2404 | return 0; | |
2405 | ||
57380f4e DJ |
2406 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2407 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2408 | { |
57380f4e | 2409 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2410 | |
2411 | errno = 0; | |
dfd4cc63 | 2412 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2413 | lp->stopped = 0; |
d6b0e80f AC |
2414 | if (debug_linux_nat) |
2415 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2416 | "PTRACE_CONT %s, 0, 0 (%s) " |
2417 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2418 | target_pid_to_str (lp->ptid), |
2419 | errno ? safe_strerror (errno) : "OK"); | |
2420 | ||
57380f4e | 2421 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2422 | } |
2423 | ||
57380f4e DJ |
2424 | maybe_clear_ignore_sigint (lp); |
2425 | ||
d6b0e80f AC |
2426 | if (WSTOPSIG (status) != SIGSTOP) |
2427 | { | |
e5ef252a | 2428 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2429 | |
e5ef252a PA |
2430 | save_sigtrap (lp); |
2431 | ||
2432 | if (debug_linux_nat) | |
2433 | fprintf_unfiltered (gdb_stdlog, | |
2434 | "SWC: Pending event %s in %s\n", | |
2435 | status_to_str ((int) status), | |
2436 | target_pid_to_str (lp->ptid)); | |
2437 | ||
2438 | /* Save the sigtrap event. */ | |
2439 | lp->status = status; | |
e5ef252a | 2440 | gdb_assert (lp->signalled); |
d6b0e80f AC |
2441 | } |
2442 | else | |
2443 | { | |
2444 | /* We caught the SIGSTOP that we intended to catch, so | |
2445 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2446 | |
2447 | if (debug_linux_nat) | |
2448 | fprintf_unfiltered (gdb_stdlog, | |
2449 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2450 | target_pid_to_str (lp->ptid)); | |
2451 | ||
e5ef252a PA |
2452 | /* Reset SIGNALLED only after the stop_wait_callback call |
2453 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2454 | lp->signalled = 0; |
2455 | } | |
2456 | } | |
2457 | ||
2458 | return 0; | |
2459 | } | |
2460 | ||
d6b0e80f AC |
2461 | /* Return non-zero if LP has a wait status pending. */ |
2462 | ||
2463 | static int | |
2464 | status_callback (struct lwp_info *lp, void *data) | |
2465 | { | |
2466 | /* Only report a pending wait status if we pretend that this has | |
2467 | indeed been resumed. */ | |
ca2163eb PA |
2468 | if (!lp->resumed) |
2469 | return 0; | |
2470 | ||
2471 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2472 | { | |
2473 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2474 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2475 | 0', so a clean process exit can not be stored pending in |
2476 | lp->status, it is indistinguishable from | |
2477 | no-pending-status. */ | |
2478 | return 1; | |
2479 | } | |
2480 | ||
2481 | if (lp->status != 0) | |
2482 | return 1; | |
2483 | ||
2484 | return 0; | |
d6b0e80f AC |
2485 | } |
2486 | ||
2487 | /* Return non-zero if LP isn't stopped. */ | |
2488 | ||
2489 | static int | |
2490 | running_callback (struct lwp_info *lp, void *data) | |
2491 | { | |
25289eb2 PA |
2492 | return (!lp->stopped |
2493 | || ((lp->status != 0 | |
2494 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2495 | && lp->resumed)); | |
d6b0e80f AC |
2496 | } |
2497 | ||
2498 | /* Count the LWP's that have had events. */ | |
2499 | ||
2500 | static int | |
2501 | count_events_callback (struct lwp_info *lp, void *data) | |
2502 | { | |
2503 | int *count = data; | |
2504 | ||
2505 | gdb_assert (count != NULL); | |
2506 | ||
e09490f1 | 2507 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2508 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2509 | (*count)++; |
2510 | ||
2511 | return 0; | |
2512 | } | |
2513 | ||
2514 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2515 | ||
2516 | static int | |
2517 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2518 | { | |
25289eb2 PA |
2519 | if (lp->last_resume_kind == resume_step |
2520 | && lp->status != 0) | |
d6b0e80f AC |
2521 | return 1; |
2522 | else | |
2523 | return 0; | |
2524 | } | |
2525 | ||
2526 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2527 | ||
2528 | static int | |
2529 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2530 | { | |
2531 | int *selector = data; | |
2532 | ||
2533 | gdb_assert (selector != NULL); | |
2534 | ||
1777feb0 | 2535 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2536 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2537 | if ((*selector)-- == 0) |
2538 | return 1; | |
2539 | ||
2540 | return 0; | |
2541 | } | |
2542 | ||
710151dd PA |
2543 | static int |
2544 | cancel_breakpoint (struct lwp_info *lp) | |
2545 | { | |
2546 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2547 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2548 | LWP. We will handle the current event, eventually we will resume | |
2549 | this LWP, and this breakpoint will trap again. | |
2550 | ||
2551 | If we do not do this, then we run the risk that the user will | |
2552 | delete or disable the breakpoint, but the LWP will have already | |
2553 | tripped on it. */ | |
2554 | ||
515630c5 UW |
2555 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
2556 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
2557 | CORE_ADDR pc; | |
2558 | ||
118e6252 | 2559 | pc = regcache_read_pc (regcache) - target_decr_pc_after_break (gdbarch); |
6c95b8df | 2560 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
2561 | { |
2562 | if (debug_linux_nat) | |
2563 | fprintf_unfiltered (gdb_stdlog, | |
2564 | "CB: Push back breakpoint for %s\n", | |
2565 | target_pid_to_str (lp->ptid)); | |
2566 | ||
2567 | /* Back up the PC if necessary. */ | |
118e6252 | 2568 | if (target_decr_pc_after_break (gdbarch)) |
515630c5 UW |
2569 | regcache_write_pc (regcache, pc); |
2570 | ||
710151dd PA |
2571 | return 1; |
2572 | } | |
2573 | return 0; | |
2574 | } | |
2575 | ||
d6b0e80f AC |
2576 | static int |
2577 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
2578 | { | |
2579 | struct lwp_info *event_lp = data; | |
2580 | ||
2581 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
2582 | if (lp == event_lp) | |
2583 | return 0; | |
2584 | ||
2585 | /* If a LWP other than the LWP that we're reporting an event for has | |
2586 | hit a GDB breakpoint (as opposed to some random trap signal), | |
2587 | then just arrange for it to hit it again later. We don't keep | |
2588 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2589 | LWP. We will handle the current event, eventually we will resume | |
2590 | all LWPs, and this one will get its breakpoint trap again. | |
2591 | ||
2592 | If we do not do this, then we run the risk that the user will | |
2593 | delete or disable the breakpoint, but the LWP will have already | |
2594 | tripped on it. */ | |
2595 | ||
00390b84 | 2596 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
2597 | && cancel_breakpoint (lp)) |
2598 | /* Throw away the SIGTRAP. */ | |
2599 | lp->status = 0; | |
d6b0e80f AC |
2600 | |
2601 | return 0; | |
2602 | } | |
2603 | ||
2604 | /* Select one LWP out of those that have events pending. */ | |
2605 | ||
2606 | static void | |
d90e17a7 | 2607 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2608 | { |
2609 | int num_events = 0; | |
2610 | int random_selector; | |
2611 | struct lwp_info *event_lp; | |
2612 | ||
ac264b3b | 2613 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2614 | (*orig_lp)->status = *status; |
2615 | ||
2616 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
2617 | event_lp = iterate_over_lwps (filter, |
2618 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
2619 | if (event_lp != NULL) |
2620 | { | |
2621 | if (debug_linux_nat) | |
2622 | fprintf_unfiltered (gdb_stdlog, | |
2623 | "SEL: Select single-step %s\n", | |
2624 | target_pid_to_str (event_lp->ptid)); | |
2625 | } | |
2626 | else | |
2627 | { | |
2628 | /* No single-stepping LWP. Select one at random, out of those | |
2629 | which have had SIGTRAP events. */ | |
2630 | ||
2631 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 2632 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
2633 | |
2634 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
2635 | random_selector = (int) | |
2636 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2637 | ||
2638 | if (debug_linux_nat && num_events > 1) | |
2639 | fprintf_unfiltered (gdb_stdlog, | |
2640 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
2641 | num_events, random_selector); | |
2642 | ||
d90e17a7 PA |
2643 | event_lp = iterate_over_lwps (filter, |
2644 | select_event_lwp_callback, | |
d6b0e80f AC |
2645 | &random_selector); |
2646 | } | |
2647 | ||
2648 | if (event_lp != NULL) | |
2649 | { | |
2650 | /* Switch the event LWP. */ | |
2651 | *orig_lp = event_lp; | |
2652 | *status = event_lp->status; | |
2653 | } | |
2654 | ||
2655 | /* Flush the wait status for the event LWP. */ | |
2656 | (*orig_lp)->status = 0; | |
2657 | } | |
2658 | ||
2659 | /* Return non-zero if LP has been resumed. */ | |
2660 | ||
2661 | static int | |
2662 | resumed_callback (struct lwp_info *lp, void *data) | |
2663 | { | |
2664 | return lp->resumed; | |
2665 | } | |
2666 | ||
12d9289a PA |
2667 | /* Stop an active thread, verify it still exists, then resume it. If |
2668 | the thread ends up with a pending status, then it is not resumed, | |
2669 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
2670 | |
2671 | static int | |
2672 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
2673 | { | |
12d9289a PA |
2674 | int *new_pending_p = data; |
2675 | ||
25289eb2 | 2676 | if (!lp->stopped) |
d6b0e80f | 2677 | { |
25289eb2 PA |
2678 | ptid_t ptid = lp->ptid; |
2679 | ||
d6b0e80f AC |
2680 | stop_callback (lp, NULL); |
2681 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
2682 | |
2683 | /* Resume if the lwp still exists, and the core wanted it | |
2684 | running. */ | |
12d9289a PA |
2685 | lp = find_lwp_pid (ptid); |
2686 | if (lp != NULL) | |
25289eb2 | 2687 | { |
12d9289a PA |
2688 | if (lp->last_resume_kind == resume_stop |
2689 | && lp->status == 0) | |
2690 | { | |
2691 | /* The core wanted the LWP to stop. Even if it stopped | |
2692 | cleanly (with SIGSTOP), leave the event pending. */ | |
2693 | if (debug_linux_nat) | |
2694 | fprintf_unfiltered (gdb_stdlog, | |
2695 | "SARC: core wanted LWP %ld stopped " | |
2696 | "(leaving SIGSTOP pending)\n", | |
dfd4cc63 | 2697 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2698 | lp->status = W_STOPCODE (SIGSTOP); |
2699 | } | |
2700 | ||
2701 | if (lp->status == 0) | |
2702 | { | |
2703 | if (debug_linux_nat) | |
2704 | fprintf_unfiltered (gdb_stdlog, | |
2705 | "SARC: re-resuming LWP %ld\n", | |
dfd4cc63 | 2706 | ptid_get_lwp (lp->ptid)); |
e5ef252a | 2707 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
2708 | } |
2709 | else | |
2710 | { | |
2711 | if (debug_linux_nat) | |
2712 | fprintf_unfiltered (gdb_stdlog, | |
2713 | "SARC: not re-resuming LWP %ld " | |
2714 | "(has pending)\n", | |
dfd4cc63 | 2715 | ptid_get_lwp (lp->ptid)); |
12d9289a PA |
2716 | if (new_pending_p) |
2717 | *new_pending_p = 1; | |
2718 | } | |
25289eb2 | 2719 | } |
d6b0e80f AC |
2720 | } |
2721 | return 0; | |
2722 | } | |
2723 | ||
02f3fc28 | 2724 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
2725 | Return the affected lwp if we are, or NULL otherwise. If we stop |
2726 | all lwps temporarily, we may end up with new pending events in some | |
2727 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
2728 | ||
02f3fc28 | 2729 | static struct lwp_info * |
0e5bf2a8 | 2730 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
2731 | { |
2732 | struct lwp_info *lp; | |
89a5711c | 2733 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2734 | |
12d9289a PA |
2735 | *new_pending_p = 0; |
2736 | ||
02f3fc28 PA |
2737 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
2738 | ||
2739 | /* Check for stop events reported by a process we didn't already | |
2740 | know about - anything not already in our LWP list. | |
2741 | ||
2742 | If we're expecting to receive stopped processes after | |
2743 | fork, vfork, and clone events, then we'll just add the | |
2744 | new one to our list and go back to waiting for the event | |
2745 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2746 | from waitpid before or after the event is. |
2747 | ||
2748 | But note the case of a non-leader thread exec'ing after the | |
2749 | leader having exited, and gone from our lists. The non-leader | |
2750 | thread changes its tid to the tgid. */ | |
2751 | ||
2752 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2753 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2754 | { |
2755 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2756 | if (debug_linux_nat) | |
2757 | fprintf_unfiltered (gdb_stdlog, | |
2758 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2759 | lwpid); | |
2760 | ||
dfd4cc63 | 2761 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2762 | lp->stopped = 1; |
2763 | lp->resumed = 1; | |
2764 | add_thread (lp->ptid); | |
2765 | } | |
2766 | ||
02f3fc28 PA |
2767 | if (WIFSTOPPED (status) && !lp) |
2768 | { | |
84636d28 | 2769 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2770 | return NULL; |
2771 | } | |
2772 | ||
2773 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2774 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2775 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2776 | exits. */ |
2777 | if (!WIFSTOPPED (status) && !lp) | |
2778 | return NULL; | |
2779 | ||
8817a6f2 PA |
2780 | /* This LWP is stopped now. (And if dead, this prevents it from |
2781 | ever being continued.) */ | |
2782 | lp->stopped = 1; | |
2783 | ||
ca2163eb PA |
2784 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2785 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2786 | { | |
2787 | /* No longer need the sysgood bit. The ptrace event ends up | |
2788 | recorded in lp->waitstatus if we care for it. We can carry | |
2789 | on handling the event like a regular SIGTRAP from here | |
2790 | on. */ | |
2791 | status = W_STOPCODE (SIGTRAP); | |
2792 | if (linux_handle_syscall_trap (lp, 0)) | |
2793 | return NULL; | |
2794 | } | |
02f3fc28 | 2795 | |
ca2163eb | 2796 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2797 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2798 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
2799 | { |
2800 | if (debug_linux_nat) | |
2801 | fprintf_unfiltered (gdb_stdlog, | |
2802 | "LLW: Handling extended status 0x%06x\n", | |
2803 | status); | |
2804 | if (linux_handle_extended_wait (lp, status, 0)) | |
2805 | return NULL; | |
2806 | } | |
2807 | ||
26ab7092 | 2808 | if (linux_nat_status_is_event (status)) |
da559b09 | 2809 | save_sigtrap (lp); |
ca2163eb | 2810 | |
02f3fc28 | 2811 | /* Check if the thread has exited. */ |
d90e17a7 | 2812 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
dfd4cc63 | 2813 | && num_lwps (ptid_get_pid (lp->ptid)) > 1) |
02f3fc28 | 2814 | { |
9db03742 JB |
2815 | /* If this is the main thread, we must stop all threads and verify |
2816 | if they are still alive. This is because in the nptl thread model | |
2817 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
2818 | other than the main thread. We only get the main thread exit |
2819 | signal once all child threads have already exited. If we | |
2820 | stop all the threads and use the stop_wait_callback to check | |
2821 | if they have exited we can determine whether this signal | |
2822 | should be ignored or whether it means the end of the debugged | |
2823 | application, regardless of which threading model is being | |
5d3b6af6 | 2824 | used. */ |
dfd4cc63 | 2825 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) |
02f3fc28 | 2826 | { |
dfd4cc63 | 2827 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), |
12d9289a | 2828 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
2829 | } |
2830 | ||
2831 | if (debug_linux_nat) | |
2832 | fprintf_unfiltered (gdb_stdlog, | |
2833 | "LLW: %s exited.\n", | |
2834 | target_pid_to_str (lp->ptid)); | |
2835 | ||
dfd4cc63 | 2836 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1) |
9db03742 JB |
2837 | { |
2838 | /* If there is at least one more LWP, then the exit signal | |
2839 | was not the end of the debugged application and should be | |
2840 | ignored. */ | |
2841 | exit_lwp (lp); | |
2842 | return NULL; | |
2843 | } | |
02f3fc28 PA |
2844 | } |
2845 | ||
2846 | /* Check if the current LWP has previously exited. In the nptl | |
2847 | thread model, LWPs other than the main thread do not issue | |
2848 | signals when they exit so we must check whenever the thread has | |
2849 | stopped. A similar check is made in stop_wait_callback(). */ | |
dfd4cc63 | 2850 | if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 2851 | { |
dfd4cc63 | 2852 | ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid)); |
d90e17a7 | 2853 | |
02f3fc28 PA |
2854 | if (debug_linux_nat) |
2855 | fprintf_unfiltered (gdb_stdlog, | |
2856 | "LLW: %s exited.\n", | |
2857 | target_pid_to_str (lp->ptid)); | |
2858 | ||
2859 | exit_lwp (lp); | |
2860 | ||
2861 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 2862 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
2863 | |
2864 | /* Discard the event. */ | |
2865 | return NULL; | |
2866 | } | |
2867 | ||
2868 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
2869 | an attempt to stop an LWP. */ | |
2870 | if (lp->signalled | |
2871 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2872 | { | |
2873 | if (debug_linux_nat) | |
2874 | fprintf_unfiltered (gdb_stdlog, | |
2875 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
2876 | target_pid_to_str (lp->ptid)); | |
2877 | ||
02f3fc28 PA |
2878 | lp->signalled = 0; |
2879 | ||
25289eb2 PA |
2880 | if (lp->last_resume_kind != resume_stop) |
2881 | { | |
2882 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 2883 | |
25289eb2 PA |
2884 | registers_changed (); |
2885 | ||
7b50312a PA |
2886 | if (linux_nat_prepare_to_resume != NULL) |
2887 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
2888 | linux_ops->to_resume (linux_ops, |
2889 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
2890 | lp->step, GDB_SIGNAL_0); | |
25289eb2 PA |
2891 | if (debug_linux_nat) |
2892 | fprintf_unfiltered (gdb_stdlog, | |
2893 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
2894 | lp->step ? | |
2895 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2896 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 2897 | |
25289eb2 PA |
2898 | lp->stopped = 0; |
2899 | gdb_assert (lp->resumed); | |
02f3fc28 | 2900 | |
25289eb2 PA |
2901 | /* Discard the event. */ |
2902 | return NULL; | |
2903 | } | |
02f3fc28 PA |
2904 | } |
2905 | ||
57380f4e DJ |
2906 | /* Make sure we don't report a SIGINT that we have already displayed |
2907 | for another thread. */ | |
2908 | if (lp->ignore_sigint | |
2909 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2910 | { | |
2911 | if (debug_linux_nat) | |
2912 | fprintf_unfiltered (gdb_stdlog, | |
2913 | "LLW: Delayed SIGINT caught for %s.\n", | |
2914 | target_pid_to_str (lp->ptid)); | |
2915 | ||
2916 | /* This is a delayed SIGINT. */ | |
2917 | lp->ignore_sigint = 0; | |
2918 | ||
2919 | registers_changed (); | |
7b50312a PA |
2920 | if (linux_nat_prepare_to_resume != NULL) |
2921 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 2922 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 2923 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
2924 | if (debug_linux_nat) |
2925 | fprintf_unfiltered (gdb_stdlog, | |
2926 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
2927 | lp->step ? | |
2928 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2929 | target_pid_to_str (lp->ptid)); | |
2930 | ||
2931 | lp->stopped = 0; | |
2932 | gdb_assert (lp->resumed); | |
2933 | ||
2934 | /* Discard the event. */ | |
2935 | return NULL; | |
2936 | } | |
2937 | ||
02f3fc28 PA |
2938 | /* An interesting event. */ |
2939 | gdb_assert (lp); | |
ca2163eb | 2940 | lp->status = status; |
02f3fc28 PA |
2941 | return lp; |
2942 | } | |
2943 | ||
0e5bf2a8 PA |
2944 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
2945 | their exits until all other threads in the group have exited. */ | |
2946 | ||
2947 | static void | |
2948 | check_zombie_leaders (void) | |
2949 | { | |
2950 | struct inferior *inf; | |
2951 | ||
2952 | ALL_INFERIORS (inf) | |
2953 | { | |
2954 | struct lwp_info *leader_lp; | |
2955 | ||
2956 | if (inf->pid == 0) | |
2957 | continue; | |
2958 | ||
2959 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
2960 | if (leader_lp != NULL | |
2961 | /* Check if there are other threads in the group, as we may | |
2962 | have raced with the inferior simply exiting. */ | |
2963 | && num_lwps (inf->pid) > 1 | |
5f572dec | 2964 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
2965 | { |
2966 | if (debug_linux_nat) | |
2967 | fprintf_unfiltered (gdb_stdlog, | |
2968 | "CZL: Thread group leader %d zombie " | |
2969 | "(it exited, or another thread execd).\n", | |
2970 | inf->pid); | |
2971 | ||
2972 | /* A leader zombie can mean one of two things: | |
2973 | ||
2974 | - It exited, and there's an exit status pending | |
2975 | available, or only the leader exited (not the whole | |
2976 | program). In the latter case, we can't waitpid the | |
2977 | leader's exit status until all other threads are gone. | |
2978 | ||
2979 | - There are 3 or more threads in the group, and a thread | |
2980 | other than the leader exec'd. On an exec, the Linux | |
2981 | kernel destroys all other threads (except the execing | |
2982 | one) in the thread group, and resets the execing thread's | |
2983 | tid to the tgid. No exit notification is sent for the | |
2984 | execing thread -- from the ptracer's perspective, it | |
2985 | appears as though the execing thread just vanishes. | |
2986 | Until we reap all other threads except the leader and the | |
2987 | execing thread, the leader will be zombie, and the | |
2988 | execing thread will be in `D (disc sleep)'. As soon as | |
2989 | all other threads are reaped, the execing thread changes | |
2990 | it's tid to the tgid, and the previous (zombie) leader | |
2991 | vanishes, giving place to the "new" leader. We could try | |
2992 | distinguishing the exit and exec cases, by waiting once | |
2993 | more, and seeing if something comes out, but it doesn't | |
2994 | sound useful. The previous leader _does_ go away, and | |
2995 | we'll re-add the new one once we see the exec event | |
2996 | (which is just the same as what would happen if the | |
2997 | previous leader did exit voluntarily before some other | |
2998 | thread execs). */ | |
2999 | ||
3000 | if (debug_linux_nat) | |
3001 | fprintf_unfiltered (gdb_stdlog, | |
3002 | "CZL: Thread group leader %d vanished.\n", | |
3003 | inf->pid); | |
3004 | exit_lwp (leader_lp); | |
3005 | } | |
3006 | } | |
3007 | } | |
3008 | ||
d6b0e80f | 3009 | static ptid_t |
7feb7d06 | 3010 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3011 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3012 | int target_options) | |
d6b0e80f | 3013 | { |
7feb7d06 | 3014 | static sigset_t prev_mask; |
4b60df3d | 3015 | enum resume_kind last_resume_kind; |
12d9289a | 3016 | struct lwp_info *lp; |
12d9289a | 3017 | int status; |
d6b0e80f | 3018 | |
01124a23 | 3019 | if (debug_linux_nat) |
b84876c2 PA |
3020 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3021 | ||
f973ed9c DJ |
3022 | /* The first time we get here after starting a new inferior, we may |
3023 | not have added it to the LWP list yet - this is the earliest | |
3024 | moment at which we know its PID. */ | |
d90e17a7 | 3025 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3026 | { |
27c9d204 PA |
3027 | /* Upgrade the main thread's ptid. */ |
3028 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3029 | ptid_build (ptid_get_pid (inferior_ptid), |
3030 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3031 | |
26cb8b7c | 3032 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3033 | lp->resumed = 1; |
3034 | } | |
3035 | ||
12696c10 | 3036 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3037 | block_child_signals (&prev_mask); |
d6b0e80f AC |
3038 | |
3039 | retry: | |
d90e17a7 PA |
3040 | lp = NULL; |
3041 | status = 0; | |
d6b0e80f AC |
3042 | |
3043 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3044 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3045 | { |
0e5bf2a8 | 3046 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3047 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3048 | if (lp) |
3049 | { | |
ca2163eb | 3050 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3051 | fprintf_unfiltered (gdb_stdlog, |
3052 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3053 | status_to_str (lp->status), |
d6b0e80f AC |
3054 | target_pid_to_str (lp->ptid)); |
3055 | } | |
d6b0e80f | 3056 | } |
dfd4cc63 | 3057 | else if (ptid_lwp_p (ptid)) |
d6b0e80f AC |
3058 | { |
3059 | if (debug_linux_nat) | |
3060 | fprintf_unfiltered (gdb_stdlog, | |
3061 | "LLW: Waiting for specific LWP %s.\n", | |
3062 | target_pid_to_str (ptid)); | |
3063 | ||
3064 | /* We have a specific LWP to check. */ | |
3065 | lp = find_lwp_pid (ptid); | |
3066 | gdb_assert (lp); | |
d6b0e80f | 3067 | |
ca2163eb | 3068 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3069 | fprintf_unfiltered (gdb_stdlog, |
3070 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3071 | status_to_str (lp->status), |
d6b0e80f AC |
3072 | target_pid_to_str (lp->ptid)); |
3073 | ||
d90e17a7 PA |
3074 | /* We check for lp->waitstatus in addition to lp->status, |
3075 | because we can have pending process exits recorded in | |
3076 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3077 | an additional lp->status_p flag. */ | |
ca2163eb | 3078 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3079 | lp = NULL; |
d6b0e80f AC |
3080 | } |
3081 | ||
b84876c2 PA |
3082 | if (!target_can_async_p ()) |
3083 | { | |
3084 | /* Causes SIGINT to be passed on to the attached process. */ | |
3085 | set_sigint_trap (); | |
b84876c2 | 3086 | } |
d6b0e80f | 3087 | |
0e5bf2a8 | 3088 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3089 | |
d90e17a7 | 3090 | while (lp == NULL) |
d6b0e80f AC |
3091 | { |
3092 | pid_t lwpid; | |
3093 | ||
0e5bf2a8 PA |
3094 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3095 | quirks: | |
3096 | ||
3097 | - If the thread group leader exits while other threads in the | |
3098 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3099 | waitpid won't return an exit status until the other threads | |
3100 | in the group are reapped. | |
3101 | ||
3102 | - When a non-leader thread execs, that thread just vanishes | |
3103 | without reporting an exit (so we'd hang if we waited for it | |
3104 | explicitly in that case). The exec event is reported to | |
3105 | the TGID pid. */ | |
3106 | ||
3107 | errno = 0; | |
3108 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3109 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3110 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3111 | ||
3112 | if (debug_linux_nat) | |
3113 | fprintf_unfiltered (gdb_stdlog, | |
3114 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3115 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3116 | |
d6b0e80f AC |
3117 | if (lwpid > 0) |
3118 | { | |
12d9289a PA |
3119 | /* If this is true, then we paused LWPs momentarily, and may |
3120 | now have pending events to handle. */ | |
3121 | int new_pending; | |
3122 | ||
d6b0e80f AC |
3123 | if (debug_linux_nat) |
3124 | { | |
3125 | fprintf_unfiltered (gdb_stdlog, | |
3126 | "LLW: waitpid %ld received %s\n", | |
3127 | (long) lwpid, status_to_str (status)); | |
3128 | } | |
3129 | ||
0e5bf2a8 | 3130 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3131 | |
33355866 JK |
3132 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3133 | status = 0; | |
3134 | ||
0e5bf2a8 | 3135 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3136 | { |
e3e9f5a2 PA |
3137 | gdb_assert (lp->resumed); |
3138 | ||
d90e17a7 | 3139 | if (debug_linux_nat) |
2f693f9d SDJ |
3140 | fprintf_unfiltered (gdb_stdlog, |
3141 | "LWP %ld got an event %06x, " | |
3142 | "leaving pending.\n", | |
3143 | ptid_get_lwp (lp->ptid), lp->status); | |
d90e17a7 | 3144 | |
ca2163eb | 3145 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3146 | { |
ca2163eb | 3147 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3148 | { |
e3e9f5a2 PA |
3149 | /* Cancel breakpoint hits. The breakpoint may |
3150 | be removed before we fetch events from this | |
3151 | process to report to the core. It is best | |
3152 | not to assume the moribund breakpoints | |
3153 | heuristic always handles these cases --- it | |
3154 | could be too many events go through to the | |
3155 | core before this one is handled. All-stop | |
3156 | always cancels breakpoint hits in all | |
3157 | threads. */ | |
3158 | if (non_stop | |
00390b84 | 3159 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3160 | && cancel_breakpoint (lp)) |
3161 | { | |
3162 | /* Throw away the SIGTRAP. */ | |
3163 | lp->status = 0; | |
3164 | ||
3165 | if (debug_linux_nat) | |
2f693f9d SDJ |
3166 | fprintf_unfiltered (gdb_stdlog, |
3167 | "LLW: LWP %ld hit a " | |
3168 | "breakpoint while " | |
3169 | "waiting for another " | |
3170 | "process; " | |
3171 | "cancelled it\n", | |
3172 | ptid_get_lwp (lp->ptid)); | |
e3e9f5a2 | 3173 | } |
d90e17a7 PA |
3174 | } |
3175 | else | |
8817a6f2 | 3176 | lp->signalled = 0; |
d90e17a7 | 3177 | } |
33355866 | 3178 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3179 | { |
3180 | if (debug_linux_nat) | |
2f693f9d SDJ |
3181 | fprintf_unfiltered (gdb_stdlog, |
3182 | "Process %ld exited while stopping " | |
3183 | "LWPs\n", | |
3184 | ptid_get_lwp (lp->ptid)); | |
d90e17a7 PA |
3185 | |
3186 | /* This was the last lwp in the process. Since | |
3187 | events are serialized to GDB core, and we can't | |
3188 | report this one right now, but GDB core and the | |
3189 | other target layers will want to be notified | |
3190 | about the exit code/signal, leave the status | |
3191 | pending for the next time we're able to report | |
3192 | it. */ | |
d90e17a7 | 3193 | |
d90e17a7 PA |
3194 | /* Dead LWP's aren't expected to reported a pending |
3195 | sigstop. */ | |
3196 | lp->signalled = 0; | |
3197 | ||
3198 | /* Store the pending event in the waitstatus as | |
3199 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3200 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3201 | } |
3202 | ||
3203 | /* Keep looking. */ | |
3204 | lp = NULL; | |
d6b0e80f AC |
3205 | } |
3206 | ||
0e5bf2a8 | 3207 | if (new_pending) |
d90e17a7 | 3208 | { |
0e5bf2a8 PA |
3209 | /* Some LWP now has a pending event. Go all the way |
3210 | back to check it. */ | |
3211 | goto retry; | |
3212 | } | |
12d9289a | 3213 | |
0e5bf2a8 PA |
3214 | if (lp) |
3215 | { | |
3216 | /* We got an event to report to the core. */ | |
3217 | break; | |
d90e17a7 | 3218 | } |
0e5bf2a8 PA |
3219 | |
3220 | /* Retry until nothing comes out of waitpid. A single | |
3221 | SIGCHLD can indicate more than one child stopped. */ | |
3222 | continue; | |
d6b0e80f AC |
3223 | } |
3224 | ||
0e5bf2a8 PA |
3225 | /* Check for zombie thread group leaders. Those can't be reaped |
3226 | until all other threads in the thread group are. */ | |
3227 | check_zombie_leaders (); | |
d6b0e80f | 3228 | |
0e5bf2a8 PA |
3229 | /* If there are no resumed children left, bail. We'd be stuck |
3230 | forever in the sigsuspend call below otherwise. */ | |
3231 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3232 | { | |
3233 | if (debug_linux_nat) | |
3234 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3235 | |
0e5bf2a8 | 3236 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3237 | |
0e5bf2a8 PA |
3238 | if (!target_can_async_p ()) |
3239 | clear_sigint_trap (); | |
b84876c2 | 3240 | |
0e5bf2a8 PA |
3241 | restore_child_signals_mask (&prev_mask); |
3242 | return minus_one_ptid; | |
d6b0e80f | 3243 | } |
28736962 | 3244 | |
0e5bf2a8 PA |
3245 | /* No interesting event to report to the core. */ |
3246 | ||
3247 | if (target_options & TARGET_WNOHANG) | |
3248 | { | |
01124a23 | 3249 | if (debug_linux_nat) |
28736962 PA |
3250 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3251 | ||
0e5bf2a8 | 3252 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3253 | restore_child_signals_mask (&prev_mask); |
3254 | return minus_one_ptid; | |
3255 | } | |
d6b0e80f AC |
3256 | |
3257 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3258 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3259 | |
3260 | /* Block until we get an event reported with SIGCHLD. */ | |
d36bf488 DE |
3261 | if (debug_linux_nat) |
3262 | fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n"); | |
0e5bf2a8 | 3263 | sigsuspend (&suspend_mask); |
d6b0e80f AC |
3264 | } |
3265 | ||
b84876c2 | 3266 | if (!target_can_async_p ()) |
d26b5354 | 3267 | clear_sigint_trap (); |
d6b0e80f AC |
3268 | |
3269 | gdb_assert (lp); | |
3270 | ||
ca2163eb PA |
3271 | status = lp->status; |
3272 | lp->status = 0; | |
3273 | ||
d6b0e80f AC |
3274 | /* Don't report signals that GDB isn't interested in, such as |
3275 | signals that are neither printed nor stopped upon. Stopping all | |
3276 | threads can be a bit time-consuming so if we want decent | |
3277 | performance with heavily multi-threaded programs, especially when | |
3278 | they're using a high frequency timer, we'd better avoid it if we | |
3279 | can. */ | |
3280 | ||
3281 | if (WIFSTOPPED (status)) | |
3282 | { | |
2ea28649 | 3283 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3284 | |
2455069d UW |
3285 | /* When using hardware single-step, we need to report every signal. |
3286 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3287 | if (!lp->step |
2455069d | 3288 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3289 | { |
3290 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3291 | here? It is not clear we should. GDB may not expect | |
3292 | other threads to run. On the other hand, not resuming | |
3293 | newly attached threads may cause an unwanted delay in | |
3294 | getting them running. */ | |
3295 | registers_changed (); | |
7b50312a PA |
3296 | if (linux_nat_prepare_to_resume != NULL) |
3297 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 LM |
3298 | linux_ops->to_resume (linux_ops, |
3299 | pid_to_ptid (ptid_get_lwp (lp->ptid)), | |
10d6c8cd | 3300 | lp->step, signo); |
d6b0e80f AC |
3301 | if (debug_linux_nat) |
3302 | fprintf_unfiltered (gdb_stdlog, | |
3303 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3304 | lp->step ? | |
3305 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3306 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3307 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3308 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3309 | : "0")); |
d6b0e80f | 3310 | lp->stopped = 0; |
d6b0e80f AC |
3311 | goto retry; |
3312 | } | |
3313 | ||
1ad15515 | 3314 | if (!non_stop) |
d6b0e80f | 3315 | { |
1ad15515 PA |
3316 | /* Only do the below in all-stop, as we currently use SIGINT |
3317 | to implement target_stop (see linux_nat_stop) in | |
3318 | non-stop. */ | |
a493e3e2 | 3319 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3320 | { |
3321 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3322 | forwarded to the entire process group, that is, all LWPs | |
3323 | will receive it - unless they're using CLONE_THREAD to | |
3324 | share signals. Since we only want to report it once, we | |
3325 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3326 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3327 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3328 | lp->ignore_sigint = 0; |
3329 | } | |
3330 | else | |
3331 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3332 | } |
3333 | } | |
3334 | ||
3335 | /* This LWP is stopped now. */ | |
3336 | lp->stopped = 1; | |
3337 | ||
3338 | if (debug_linux_nat) | |
3339 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3340 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3341 | ||
4c28f408 PA |
3342 | if (!non_stop) |
3343 | { | |
3344 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3345 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3346 | |
3347 | /* ... and wait until all of them have reported back that | |
3348 | they're no longer running. */ | |
d90e17a7 | 3349 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3350 | |
3351 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3352 | from among those that have had events. Giving equal priority | |
3353 | to all LWPs that have had events helps prevent | |
3354 | starvation. */ | |
0e5bf2a8 | 3355 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3356 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3357 | |
e3e9f5a2 PA |
3358 | /* Now that we've selected our final event LWP, cancel any |
3359 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3360 | See the comment in cancel_breakpoints_callback to find out | |
3361 | why. */ | |
3362 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3363 | ||
4b60df3d PA |
3364 | /* We'll need this to determine whether to report a SIGSTOP as |
3365 | TARGET_WAITKIND_0. Need to take a copy because | |
3366 | resume_clear_callback clears it. */ | |
3367 | last_resume_kind = lp->last_resume_kind; | |
3368 | ||
e3e9f5a2 PA |
3369 | /* In all-stop, from the core's perspective, all LWPs are now |
3370 | stopped until a new resume action is sent over. */ | |
3371 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3372 | } | |
3373 | else | |
25289eb2 | 3374 | { |
4b60df3d PA |
3375 | /* See above. */ |
3376 | last_resume_kind = lp->last_resume_kind; | |
3377 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3378 | } |
d6b0e80f | 3379 | |
26ab7092 | 3380 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3381 | { |
d6b0e80f AC |
3382 | if (debug_linux_nat) |
3383 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3384 | "LLW: trap ptid is %s.\n", |
3385 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3386 | } |
d6b0e80f AC |
3387 | |
3388 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3389 | { | |
3390 | *ourstatus = lp->waitstatus; | |
3391 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3392 | } | |
3393 | else | |
3394 | store_waitstatus (ourstatus, status); | |
3395 | ||
01124a23 | 3396 | if (debug_linux_nat) |
b84876c2 PA |
3397 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3398 | ||
7feb7d06 | 3399 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3400 | |
4b60df3d | 3401 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3402 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3403 | && WSTOPSIG (status) == SIGSTOP) | |
3404 | { | |
3405 | /* A thread that has been requested to stop by GDB with | |
3406 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3407 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3408 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3409 | } |
3410 | ||
1e225492 JK |
3411 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3412 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3413 | lp->core = -1; | |
3414 | else | |
2e794194 | 3415 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3416 | |
f973ed9c | 3417 | return lp->ptid; |
d6b0e80f AC |
3418 | } |
3419 | ||
e3e9f5a2 PA |
3420 | /* Resume LWPs that are currently stopped without any pending status |
3421 | to report, but are resumed from the core's perspective. */ | |
3422 | ||
3423 | static int | |
3424 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3425 | { | |
3426 | ptid_t *wait_ptid_p = data; | |
3427 | ||
3428 | if (lp->stopped | |
3429 | && lp->resumed | |
3430 | && lp->status == 0 | |
3431 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3432 | { | |
336060f3 PA |
3433 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3434 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3435 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3436 | ||
e3e9f5a2 PA |
3437 | gdb_assert (is_executing (lp->ptid)); |
3438 | ||
3439 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3440 | immediately, and we're not waiting for this LWP. */ | |
3441 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3442 | { | |
e3e9f5a2 PA |
3443 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3444 | return 0; | |
3445 | } | |
3446 | ||
3447 | if (debug_linux_nat) | |
3448 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3449 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3450 | target_pid_to_str (lp->ptid), | |
3451 | paddress (gdbarch, pc), | |
3452 | lp->step); | |
e3e9f5a2 | 3453 | |
336060f3 | 3454 | registers_changed (); |
7b50312a PA |
3455 | if (linux_nat_prepare_to_resume != NULL) |
3456 | linux_nat_prepare_to_resume (lp); | |
dfd4cc63 | 3457 | linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)), |
a493e3e2 | 3458 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3459 | lp->stopped = 0; |
e3e9f5a2 PA |
3460 | lp->stopped_by_watchpoint = 0; |
3461 | } | |
3462 | ||
3463 | return 0; | |
3464 | } | |
3465 | ||
7feb7d06 PA |
3466 | static ptid_t |
3467 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3468 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3469 | int target_options) | |
7feb7d06 PA |
3470 | { |
3471 | ptid_t event_ptid; | |
3472 | ||
3473 | if (debug_linux_nat) | |
09826ec5 PA |
3474 | { |
3475 | char *options_string; | |
3476 | ||
3477 | options_string = target_options_to_string (target_options); | |
3478 | fprintf_unfiltered (gdb_stdlog, | |
3479 | "linux_nat_wait: [%s], [%s]\n", | |
3480 | target_pid_to_str (ptid), | |
3481 | options_string); | |
3482 | xfree (options_string); | |
3483 | } | |
7feb7d06 PA |
3484 | |
3485 | /* Flush the async file first. */ | |
3486 | if (target_can_async_p ()) | |
3487 | async_file_flush (); | |
3488 | ||
e3e9f5a2 PA |
3489 | /* Resume LWPs that are currently stopped without any pending status |
3490 | to report, but are resumed from the core's perspective. LWPs get | |
3491 | in this state if we find them stopping at a time we're not | |
3492 | interested in reporting the event (target_wait on a | |
3493 | specific_process, for example, see linux_nat_wait_1), and | |
3494 | meanwhile the event became uninteresting. Don't bother resuming | |
3495 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3496 | if (non_stop) | |
3497 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3498 | ||
47608cb1 | 3499 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3500 | |
3501 | /* If we requested any event, and something came out, assume there | |
3502 | may be more. If we requested a specific lwp or process, also | |
3503 | assume there may be more. */ | |
3504 | if (target_can_async_p () | |
6953d224 PA |
3505 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3506 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3507 | || !ptid_equal (ptid, minus_one_ptid))) |
3508 | async_file_mark (); | |
3509 | ||
3510 | /* Get ready for the next event. */ | |
3511 | if (target_can_async_p ()) | |
3512 | target_async (inferior_event_handler, 0); | |
3513 | ||
3514 | return event_ptid; | |
3515 | } | |
3516 | ||
d6b0e80f AC |
3517 | static int |
3518 | kill_callback (struct lwp_info *lp, void *data) | |
3519 | { | |
ed731959 JK |
3520 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3521 | ||
3522 | errno = 0; | |
69ff6be5 | 3523 | kill_lwp (ptid_get_lwp (lp->ptid), SIGKILL); |
ed731959 | 3524 | if (debug_linux_nat) |
57745c90 PA |
3525 | { |
3526 | int save_errno = errno; | |
3527 | ||
3528 | fprintf_unfiltered (gdb_stdlog, | |
3529 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3530 | target_pid_to_str (lp->ptid), | |
3531 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3532 | } | |
ed731959 JK |
3533 | |
3534 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3535 | ||
d6b0e80f | 3536 | errno = 0; |
dfd4cc63 | 3537 | ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0); |
d6b0e80f | 3538 | if (debug_linux_nat) |
57745c90 PA |
3539 | { |
3540 | int save_errno = errno; | |
3541 | ||
3542 | fprintf_unfiltered (gdb_stdlog, | |
3543 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3544 | target_pid_to_str (lp->ptid), | |
3545 | save_errno ? safe_strerror (save_errno) : "OK"); | |
3546 | } | |
d6b0e80f AC |
3547 | |
3548 | return 0; | |
3549 | } | |
3550 | ||
3551 | static int | |
3552 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3553 | { | |
3554 | pid_t pid; | |
3555 | ||
3556 | /* We must make sure that there are no pending events (delayed | |
3557 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3558 | program doesn't interfere with any following debugging session. */ | |
3559 | ||
3560 | /* For cloned processes we must check both with __WCLONE and | |
3561 | without, since the exit status of a cloned process isn't reported | |
3562 | with __WCLONE. */ | |
3563 | if (lp->cloned) | |
3564 | { | |
3565 | do | |
3566 | { | |
dfd4cc63 | 3567 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE); |
e85a822c | 3568 | if (pid != (pid_t) -1) |
d6b0e80f | 3569 | { |
e85a822c DJ |
3570 | if (debug_linux_nat) |
3571 | fprintf_unfiltered (gdb_stdlog, | |
3572 | "KWC: wait %s received unknown.\n", | |
3573 | target_pid_to_str (lp->ptid)); | |
3574 | /* The Linux kernel sometimes fails to kill a thread | |
3575 | completely after PTRACE_KILL; that goes from the stop | |
3576 | point in do_fork out to the one in | |
3577 | get_signal_to_deliever and waits again. So kill it | |
3578 | again. */ | |
3579 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3580 | } |
3581 | } | |
dfd4cc63 | 3582 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3583 | |
3584 | gdb_assert (pid == -1 && errno == ECHILD); | |
3585 | } | |
3586 | ||
3587 | do | |
3588 | { | |
dfd4cc63 | 3589 | pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0); |
e85a822c | 3590 | if (pid != (pid_t) -1) |
d6b0e80f | 3591 | { |
e85a822c DJ |
3592 | if (debug_linux_nat) |
3593 | fprintf_unfiltered (gdb_stdlog, | |
3594 | "KWC: wait %s received unk.\n", | |
3595 | target_pid_to_str (lp->ptid)); | |
3596 | /* See the call to kill_callback above. */ | |
3597 | kill_callback (lp, NULL); | |
d6b0e80f AC |
3598 | } |
3599 | } | |
dfd4cc63 | 3600 | while (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
3601 | |
3602 | gdb_assert (pid == -1 && errno == ECHILD); | |
3603 | return 0; | |
3604 | } | |
3605 | ||
3606 | static void | |
7d85a9c0 | 3607 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 3608 | { |
f973ed9c DJ |
3609 | struct target_waitstatus last; |
3610 | ptid_t last_ptid; | |
3611 | int status; | |
d6b0e80f | 3612 | |
f973ed9c DJ |
3613 | /* If we're stopped while forking and we haven't followed yet, |
3614 | kill the other task. We need to do this first because the | |
3615 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 3616 | |
f973ed9c | 3617 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 3618 | |
f973ed9c DJ |
3619 | if (last.kind == TARGET_WAITKIND_FORKED |
3620 | || last.kind == TARGET_WAITKIND_VFORKED) | |
3621 | { | |
dfd4cc63 | 3622 | ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0); |
f973ed9c | 3623 | wait (&status); |
26cb8b7c PA |
3624 | |
3625 | /* Let the arch-specific native code know this process is | |
3626 | gone. */ | |
dfd4cc63 | 3627 | linux_nat_forget_process (ptid_get_pid (last.value.related_pid)); |
f973ed9c DJ |
3628 | } |
3629 | ||
3630 | if (forks_exist_p ()) | |
7feb7d06 | 3631 | linux_fork_killall (); |
f973ed9c DJ |
3632 | else |
3633 | { | |
d90e17a7 | 3634 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3635 | |
4c28f408 PA |
3636 | /* Stop all threads before killing them, since ptrace requires |
3637 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3638 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3639 | /* ... and wait until all of them have reported back that |
3640 | they're no longer running. */ | |
d90e17a7 | 3641 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3642 | |
f973ed9c | 3643 | /* Kill all LWP's ... */ |
d90e17a7 | 3644 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3645 | |
3646 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3647 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3648 | } |
3649 | ||
3650 | target_mourn_inferior (); | |
d6b0e80f AC |
3651 | } |
3652 | ||
3653 | static void | |
136d6dae | 3654 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 3655 | { |
26cb8b7c PA |
3656 | int pid = ptid_get_pid (inferior_ptid); |
3657 | ||
3658 | purge_lwp_list (pid); | |
d6b0e80f | 3659 | |
f973ed9c | 3660 | if (! forks_exist_p ()) |
d90e17a7 PA |
3661 | /* Normal case, no other forks available. */ |
3662 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
3663 | else |
3664 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3665 | there are other viable forks to debug. Delete the exiting | |
3666 | one and context-switch to the first available. */ | |
3667 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3668 | |
3669 | /* Let the arch-specific native code know this process is gone. */ | |
3670 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3671 | } |
3672 | ||
5b009018 PA |
3673 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3674 | layout of the inferiors' architecture. */ | |
3675 | ||
3676 | static void | |
a5362b9a | 3677 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3678 | { |
3679 | int done = 0; | |
3680 | ||
3681 | if (linux_nat_siginfo_fixup != NULL) | |
3682 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3683 | ||
3684 | /* If there was no callback, or the callback didn't do anything, | |
3685 | then just do a straight memcpy. */ | |
3686 | if (!done) | |
3687 | { | |
3688 | if (direction == 1) | |
a5362b9a | 3689 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3690 | else |
a5362b9a | 3691 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3692 | } |
3693 | } | |
3694 | ||
9b409511 | 3695 | static enum target_xfer_status |
4aa995e1 PA |
3696 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
3697 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
3698 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3699 | ULONGEST *xfered_len) | |
4aa995e1 | 3700 | { |
4aa995e1 | 3701 | int pid; |
a5362b9a TS |
3702 | siginfo_t siginfo; |
3703 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3704 | |
3705 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3706 | gdb_assert (readbuf || writebuf); | |
3707 | ||
dfd4cc63 | 3708 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3709 | if (pid == 0) |
dfd4cc63 | 3710 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3711 | |
3712 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3713 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3714 | |
3715 | errno = 0; | |
3716 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3717 | if (errno != 0) | |
2ed4b548 | 3718 | return TARGET_XFER_E_IO; |
4aa995e1 | 3719 | |
5b009018 PA |
3720 | /* When GDB is built as a 64-bit application, ptrace writes into |
3721 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3722 | inferior with a 64-bit GDB should look the same as debugging it | |
3723 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3724 | the converted layout, so any read/write will have to be done | |
3725 | post-conversion. */ | |
3726 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3727 | ||
4aa995e1 PA |
3728 | if (offset + len > sizeof (siginfo)) |
3729 | len = sizeof (siginfo) - offset; | |
3730 | ||
3731 | if (readbuf != NULL) | |
5b009018 | 3732 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3733 | else |
3734 | { | |
5b009018 PA |
3735 | memcpy (inf_siginfo + offset, writebuf, len); |
3736 | ||
3737 | /* Convert back to ptrace layout before flushing it out. */ | |
3738 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3739 | ||
4aa995e1 PA |
3740 | errno = 0; |
3741 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3742 | if (errno != 0) | |
2ed4b548 | 3743 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3744 | } |
3745 | ||
9b409511 YQ |
3746 | *xfered_len = len; |
3747 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3748 | } |
3749 | ||
9b409511 | 3750 | static enum target_xfer_status |
10d6c8cd DJ |
3751 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
3752 | const char *annex, gdb_byte *readbuf, | |
3753 | const gdb_byte *writebuf, | |
9b409511 | 3754 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
d6b0e80f | 3755 | { |
4aa995e1 | 3756 | struct cleanup *old_chain; |
9b409511 | 3757 | enum target_xfer_status xfer; |
d6b0e80f | 3758 | |
4aa995e1 PA |
3759 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
3760 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
9b409511 | 3761 | offset, len, xfered_len); |
4aa995e1 | 3762 | |
c35b1492 PA |
3763 | /* The target is connected but no live inferior is selected. Pass |
3764 | this request down to a lower stratum (e.g., the executable | |
3765 | file). */ | |
3766 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3767 | return TARGET_XFER_EOF; |
c35b1492 | 3768 | |
4aa995e1 PA |
3769 | old_chain = save_inferior_ptid (); |
3770 | ||
dfd4cc63 LM |
3771 | if (ptid_lwp_p (inferior_ptid)) |
3772 | inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid)); | |
d6b0e80f | 3773 | |
10d6c8cd | 3774 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 | 3775 | offset, len, xfered_len); |
d6b0e80f AC |
3776 | |
3777 | do_cleanups (old_chain); | |
3778 | return xfer; | |
3779 | } | |
3780 | ||
3781 | static int | |
28439f5e | 3782 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 3783 | { |
8c6a60d1 | 3784 | int err, tmp_errno; |
4c28f408 | 3785 | |
dfd4cc63 | 3786 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 3787 | |
4c28f408 PA |
3788 | /* Send signal 0 instead of anything ptrace, because ptracing a |
3789 | running thread errors out claiming that the thread doesn't | |
3790 | exist. */ | |
dfd4cc63 | 3791 | err = kill_lwp (ptid_get_lwp (ptid), 0); |
8c6a60d1 | 3792 | tmp_errno = errno; |
d6b0e80f AC |
3793 | if (debug_linux_nat) |
3794 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 3795 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 3796 | target_pid_to_str (ptid), |
8c6a60d1 | 3797 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 3798 | |
4c28f408 | 3799 | if (err != 0) |
d6b0e80f AC |
3800 | return 0; |
3801 | ||
3802 | return 1; | |
3803 | } | |
3804 | ||
28439f5e PA |
3805 | static int |
3806 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
3807 | { | |
3808 | return linux_thread_alive (ptid); | |
3809 | } | |
3810 | ||
d6b0e80f | 3811 | static char * |
117de6a9 | 3812 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
3813 | { |
3814 | static char buf[64]; | |
3815 | ||
dfd4cc63 LM |
3816 | if (ptid_lwp_p (ptid) |
3817 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
3818 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 3819 | { |
dfd4cc63 | 3820 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
3821 | return buf; |
3822 | } | |
3823 | ||
3824 | return normal_pid_to_str (ptid); | |
3825 | } | |
3826 | ||
4694da01 | 3827 | static char * |
503a628d | 3828 | linux_nat_thread_name (struct target_ops *self, struct thread_info *thr) |
4694da01 TT |
3829 | { |
3830 | int pid = ptid_get_pid (thr->ptid); | |
3831 | long lwp = ptid_get_lwp (thr->ptid); | |
3832 | #define FORMAT "/proc/%d/task/%ld/comm" | |
3833 | char buf[sizeof (FORMAT) + 30]; | |
3834 | FILE *comm_file; | |
3835 | char *result = NULL; | |
3836 | ||
3837 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
614c279d | 3838 | comm_file = gdb_fopen_cloexec (buf, "r"); |
4694da01 TT |
3839 | if (comm_file) |
3840 | { | |
3841 | /* Not exported by the kernel, so we define it here. */ | |
3842 | #define COMM_LEN 16 | |
3843 | static char line[COMM_LEN + 1]; | |
3844 | ||
3845 | if (fgets (line, sizeof (line), comm_file)) | |
3846 | { | |
3847 | char *nl = strchr (line, '\n'); | |
3848 | ||
3849 | if (nl) | |
3850 | *nl = '\0'; | |
3851 | if (*line != '\0') | |
3852 | result = line; | |
3853 | } | |
3854 | ||
3855 | fclose (comm_file); | |
3856 | } | |
3857 | ||
3858 | #undef COMM_LEN | |
3859 | #undef FORMAT | |
3860 | ||
3861 | return result; | |
3862 | } | |
3863 | ||
dba24537 AC |
3864 | /* Accepts an integer PID; Returns a string representing a file that |
3865 | can be opened to get the symbols for the child process. */ | |
3866 | ||
6d8fd2b7 | 3867 | static char * |
8dd27370 | 3868 | linux_child_pid_to_exec_file (struct target_ops *self, int pid) |
dba24537 | 3869 | { |
b4ab256d HZ |
3870 | static char buf[PATH_MAX]; |
3871 | char name[PATH_MAX]; | |
dba24537 | 3872 | |
b4ab256d HZ |
3873 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
3874 | memset (buf, 0, PATH_MAX); | |
3875 | if (readlink (name, buf, PATH_MAX - 1) <= 0) | |
3876 | strcpy (buf, name); | |
dba24537 | 3877 | |
b4ab256d | 3878 | return buf; |
dba24537 AC |
3879 | } |
3880 | ||
10d6c8cd DJ |
3881 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
3882 | filesystem. Because we can use a single read() call for /proc, this | |
3883 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
3884 | but it doesn't support writes. */ | |
3885 | ||
9b409511 | 3886 | static enum target_xfer_status |
10d6c8cd DJ |
3887 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
3888 | const char *annex, gdb_byte *readbuf, | |
3889 | const gdb_byte *writebuf, | |
9b409511 | 3890 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 3891 | { |
10d6c8cd DJ |
3892 | LONGEST ret; |
3893 | int fd; | |
dba24537 AC |
3894 | char filename[64]; |
3895 | ||
10d6c8cd | 3896 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
3897 | return 0; |
3898 | ||
3899 | /* Don't bother for one word. */ | |
3900 | if (len < 3 * sizeof (long)) | |
9b409511 | 3901 | return TARGET_XFER_EOF; |
dba24537 AC |
3902 | |
3903 | /* We could keep this file open and cache it - possibly one per | |
3904 | thread. That requires some juggling, but is even faster. */ | |
cde33bf1 YQ |
3905 | xsnprintf (filename, sizeof filename, "/proc/%d/mem", |
3906 | ptid_get_pid (inferior_ptid)); | |
614c279d | 3907 | fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0); |
dba24537 | 3908 | if (fd == -1) |
9b409511 | 3909 | return TARGET_XFER_EOF; |
dba24537 AC |
3910 | |
3911 | /* If pread64 is available, use it. It's faster if the kernel | |
3912 | supports it (only one syscall), and it's 64-bit safe even on | |
3913 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
3914 | application). */ | |
3915 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 3916 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 3917 | #else |
10d6c8cd | 3918 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
3919 | #endif |
3920 | ret = 0; | |
3921 | else | |
3922 | ret = len; | |
3923 | ||
3924 | close (fd); | |
9b409511 YQ |
3925 | |
3926 | if (ret == 0) | |
3927 | return TARGET_XFER_EOF; | |
3928 | else | |
3929 | { | |
3930 | *xfered_len = ret; | |
3931 | return TARGET_XFER_OK; | |
3932 | } | |
dba24537 AC |
3933 | } |
3934 | ||
efcbbd14 UW |
3935 | |
3936 | /* Enumerate spufs IDs for process PID. */ | |
3937 | static LONGEST | |
b55e14c7 | 3938 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 3939 | { |
f5656ead | 3940 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
3941 | LONGEST pos = 0; |
3942 | LONGEST written = 0; | |
3943 | char path[128]; | |
3944 | DIR *dir; | |
3945 | struct dirent *entry; | |
3946 | ||
3947 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
3948 | dir = opendir (path); | |
3949 | if (!dir) | |
3950 | return -1; | |
3951 | ||
3952 | rewinddir (dir); | |
3953 | while ((entry = readdir (dir)) != NULL) | |
3954 | { | |
3955 | struct stat st; | |
3956 | struct statfs stfs; | |
3957 | int fd; | |
3958 | ||
3959 | fd = atoi (entry->d_name); | |
3960 | if (!fd) | |
3961 | continue; | |
3962 | ||
3963 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
3964 | if (stat (path, &st) != 0) | |
3965 | continue; | |
3966 | if (!S_ISDIR (st.st_mode)) | |
3967 | continue; | |
3968 | ||
3969 | if (statfs (path, &stfs) != 0) | |
3970 | continue; | |
3971 | if (stfs.f_type != SPUFS_MAGIC) | |
3972 | continue; | |
3973 | ||
3974 | if (pos >= offset && pos + 4 <= offset + len) | |
3975 | { | |
3976 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
3977 | written += 4; | |
3978 | } | |
3979 | pos += 4; | |
3980 | } | |
3981 | ||
3982 | closedir (dir); | |
3983 | return written; | |
3984 | } | |
3985 | ||
3986 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
3987 | object type, using the /proc file system. */ | |
9b409511 YQ |
3988 | |
3989 | static enum target_xfer_status | |
efcbbd14 UW |
3990 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
3991 | const char *annex, gdb_byte *readbuf, | |
3992 | const gdb_byte *writebuf, | |
9b409511 | 3993 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
3994 | { |
3995 | char buf[128]; | |
3996 | int fd = 0; | |
3997 | int ret = -1; | |
dfd4cc63 | 3998 | int pid = ptid_get_pid (inferior_ptid); |
efcbbd14 UW |
3999 | |
4000 | if (!annex) | |
4001 | { | |
4002 | if (!readbuf) | |
2ed4b548 | 4003 | return TARGET_XFER_E_IO; |
efcbbd14 | 4004 | else |
9b409511 YQ |
4005 | { |
4006 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4007 | ||
4008 | if (l < 0) | |
4009 | return TARGET_XFER_E_IO; | |
4010 | else if (l == 0) | |
4011 | return TARGET_XFER_EOF; | |
4012 | else | |
4013 | { | |
4014 | *xfered_len = (ULONGEST) l; | |
4015 | return TARGET_XFER_OK; | |
4016 | } | |
4017 | } | |
efcbbd14 UW |
4018 | } |
4019 | ||
4020 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4021 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4022 | if (fd <= 0) |
2ed4b548 | 4023 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4024 | |
4025 | if (offset != 0 | |
4026 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4027 | { | |
4028 | close (fd); | |
9b409511 | 4029 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4030 | } |
4031 | ||
4032 | if (writebuf) | |
4033 | ret = write (fd, writebuf, (size_t) len); | |
4034 | else if (readbuf) | |
4035 | ret = read (fd, readbuf, (size_t) len); | |
4036 | ||
4037 | close (fd); | |
9b409511 YQ |
4038 | |
4039 | if (ret < 0) | |
4040 | return TARGET_XFER_E_IO; | |
4041 | else if (ret == 0) | |
4042 | return TARGET_XFER_EOF; | |
4043 | else | |
4044 | { | |
4045 | *xfered_len = (ULONGEST) ret; | |
4046 | return TARGET_XFER_OK; | |
4047 | } | |
efcbbd14 UW |
4048 | } |
4049 | ||
4050 | ||
dba24537 AC |
4051 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4052 | ||
4053 | static void | |
4054 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4055 | { | |
4056 | int len = strlen (line) - 1; | |
4057 | const char *p; | |
4058 | int signum; | |
4059 | ||
4060 | if (line[len] != '\n') | |
8a3fe4f8 | 4061 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4062 | |
4063 | p = line; | |
4064 | signum = len * 4; | |
4065 | while (len-- > 0) | |
4066 | { | |
4067 | int digit; | |
4068 | ||
4069 | if (*p >= '0' && *p <= '9') | |
4070 | digit = *p - '0'; | |
4071 | else if (*p >= 'a' && *p <= 'f') | |
4072 | digit = *p - 'a' + 10; | |
4073 | else | |
8a3fe4f8 | 4074 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4075 | |
4076 | signum -= 4; | |
4077 | ||
4078 | if (digit & 1) | |
4079 | sigaddset (sigs, signum + 1); | |
4080 | if (digit & 2) | |
4081 | sigaddset (sigs, signum + 2); | |
4082 | if (digit & 4) | |
4083 | sigaddset (sigs, signum + 3); | |
4084 | if (digit & 8) | |
4085 | sigaddset (sigs, signum + 4); | |
4086 | ||
4087 | p++; | |
4088 | } | |
4089 | } | |
4090 | ||
4091 | /* Find process PID's pending signals from /proc/pid/status and set | |
4092 | SIGS to match. */ | |
4093 | ||
4094 | void | |
3e43a32a MS |
4095 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4096 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4097 | { |
4098 | FILE *procfile; | |
d8d2a3ee | 4099 | char buffer[PATH_MAX], fname[PATH_MAX]; |
7c8a8b04 | 4100 | struct cleanup *cleanup; |
dba24537 AC |
4101 | |
4102 | sigemptyset (pending); | |
4103 | sigemptyset (blocked); | |
4104 | sigemptyset (ignored); | |
cde33bf1 | 4105 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
614c279d | 4106 | procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4107 | if (procfile == NULL) |
8a3fe4f8 | 4108 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4109 | cleanup = make_cleanup_fclose (procfile); |
dba24537 | 4110 | |
d8d2a3ee | 4111 | while (fgets (buffer, PATH_MAX, procfile) != NULL) |
dba24537 AC |
4112 | { |
4113 | /* Normal queued signals are on the SigPnd line in the status | |
4114 | file. However, 2.6 kernels also have a "shared" pending | |
4115 | queue for delivering signals to a thread group, so check for | |
4116 | a ShdPnd line also. | |
4117 | ||
4118 | Unfortunately some Red Hat kernels include the shared pending | |
4119 | queue but not the ShdPnd status field. */ | |
4120 | ||
4121 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4122 | add_line_to_sigset (buffer + 8, pending); | |
4123 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4124 | add_line_to_sigset (buffer + 8, pending); | |
4125 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4126 | add_line_to_sigset (buffer + 8, blocked); | |
4127 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4128 | add_line_to_sigset (buffer + 8, ignored); | |
4129 | } | |
4130 | ||
7c8a8b04 | 4131 | do_cleanups (cleanup); |
dba24537 AC |
4132 | } |
4133 | ||
9b409511 | 4134 | static enum target_xfer_status |
07e059b5 | 4135 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
e0881a8e | 4136 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4137 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4138 | ULONGEST *xfered_len) | |
07e059b5 | 4139 | { |
07e059b5 VP |
4140 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4141 | ||
9b409511 YQ |
4142 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4143 | if (*xfered_len == 0) | |
4144 | return TARGET_XFER_EOF; | |
4145 | else | |
4146 | return TARGET_XFER_OK; | |
07e059b5 VP |
4147 | } |
4148 | ||
9b409511 | 4149 | static enum target_xfer_status |
10d6c8cd DJ |
4150 | linux_xfer_partial (struct target_ops *ops, enum target_object object, |
4151 | const char *annex, gdb_byte *readbuf, | |
9b409511 YQ |
4152 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4153 | ULONGEST *xfered_len) | |
10d6c8cd | 4154 | { |
9b409511 | 4155 | enum target_xfer_status xfer; |
10d6c8cd DJ |
4156 | |
4157 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4158 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
9b409511 | 4159 | offset, len, xfered_len); |
10d6c8cd | 4160 | |
07e059b5 VP |
4161 | if (object == TARGET_OBJECT_OSDATA) |
4162 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4163 | offset, len, xfered_len); |
07e059b5 | 4164 | |
efcbbd14 UW |
4165 | if (object == TARGET_OBJECT_SPU) |
4166 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4167 | offset, len, xfered_len); |
efcbbd14 | 4168 | |
8f313923 JK |
4169 | /* GDB calculates all the addresses in possibly larget width of the address. |
4170 | Address width needs to be masked before its final use - either by | |
4171 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4172 | ||
4173 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4174 | ||
4175 | if (object == TARGET_OBJECT_MEMORY) | |
4176 | { | |
f5656ead | 4177 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4178 | |
4179 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4180 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4181 | } | |
4182 | ||
10d6c8cd | 4183 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
9b409511 YQ |
4184 | offset, len, xfered_len); |
4185 | if (xfer != TARGET_XFER_EOF) | |
10d6c8cd DJ |
4186 | return xfer; |
4187 | ||
4188 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
9b409511 | 4189 | offset, len, xfered_len); |
10d6c8cd DJ |
4190 | } |
4191 | ||
5808517f YQ |
4192 | static void |
4193 | cleanup_target_stop (void *arg) | |
4194 | { | |
4195 | ptid_t *ptid = (ptid_t *) arg; | |
4196 | ||
4197 | gdb_assert (arg != NULL); | |
4198 | ||
4199 | /* Unpause all */ | |
a493e3e2 | 4200 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4201 | } |
4202 | ||
4203 | static VEC(static_tracepoint_marker_p) * | |
c686c57f TT |
4204 | linux_child_static_tracepoint_markers_by_strid (struct target_ops *self, |
4205 | const char *strid) | |
5808517f YQ |
4206 | { |
4207 | char s[IPA_CMD_BUF_SIZE]; | |
4208 | struct cleanup *old_chain; | |
4209 | int pid = ptid_get_pid (inferior_ptid); | |
4210 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4211 | struct static_tracepoint_marker *marker = NULL; | |
4212 | char *p = s; | |
4213 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4214 | ||
4215 | /* Pause all */ | |
4216 | target_stop (ptid); | |
4217 | ||
4218 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4219 | s[sizeof ("qTfSTM")] = 0; | |
4220 | ||
42476b70 | 4221 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4222 | |
4223 | old_chain = make_cleanup (free_current_marker, &marker); | |
4224 | make_cleanup (cleanup_target_stop, &ptid); | |
4225 | ||
4226 | while (*p++ == 'm') | |
4227 | { | |
4228 | if (marker == NULL) | |
4229 | marker = XCNEW (struct static_tracepoint_marker); | |
4230 | ||
4231 | do | |
4232 | { | |
4233 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4234 | ||
4235 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4236 | { | |
4237 | VEC_safe_push (static_tracepoint_marker_p, | |
4238 | markers, marker); | |
4239 | marker = NULL; | |
4240 | } | |
4241 | else | |
4242 | { | |
4243 | release_static_tracepoint_marker (marker); | |
4244 | memset (marker, 0, sizeof (*marker)); | |
4245 | } | |
4246 | } | |
4247 | while (*p++ == ','); /* comma-separated list */ | |
4248 | ||
4249 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4250 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4251 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4252 | p = s; |
4253 | } | |
4254 | ||
4255 | do_cleanups (old_chain); | |
4256 | ||
4257 | return markers; | |
4258 | } | |
4259 | ||
e9efe249 | 4260 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4261 | it with local methods. */ |
4262 | ||
910122bf UW |
4263 | static void |
4264 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4265 | { |
6d8fd2b7 | 4266 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4267 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4268 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4269 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4270 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4271 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4272 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4273 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4274 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4275 | t->to_post_attach = linux_child_post_attach; |
4276 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4277 | |
4278 | super_xfer_partial = t->to_xfer_partial; | |
4279 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4280 | |
4281 | t->to_static_tracepoint_markers_by_strid | |
4282 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4283 | } |
4284 | ||
4285 | struct target_ops * | |
4286 | linux_target (void) | |
4287 | { | |
4288 | struct target_ops *t; | |
4289 | ||
4290 | t = inf_ptrace_target (); | |
4291 | linux_target_install_ops (t); | |
4292 | ||
4293 | return t; | |
4294 | } | |
4295 | ||
4296 | struct target_ops * | |
7714d83a | 4297 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4298 | { |
4299 | struct target_ops *t; | |
4300 | ||
4301 | t = inf_ptrace_trad_target (register_u_offset); | |
4302 | linux_target_install_ops (t); | |
10d6c8cd | 4303 | |
10d6c8cd DJ |
4304 | return t; |
4305 | } | |
4306 | ||
b84876c2 PA |
4307 | /* target_is_async_p implementation. */ |
4308 | ||
4309 | static int | |
6a109b6b | 4310 | linux_nat_is_async_p (struct target_ops *ops) |
b84876c2 PA |
4311 | { |
4312 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4313 | it explicitly with the "set target-async" command. |
b84876c2 | 4314 | Someday, linux will always be async. */ |
3dd5b83d | 4315 | return target_async_permitted; |
b84876c2 PA |
4316 | } |
4317 | ||
4318 | /* target_can_async_p implementation. */ | |
4319 | ||
4320 | static int | |
6a109b6b | 4321 | linux_nat_can_async_p (struct target_ops *ops) |
b84876c2 PA |
4322 | { |
4323 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4324 | it explicitly with the "set target-async" command. |
b84876c2 | 4325 | Someday, linux will always be async. */ |
3dd5b83d | 4326 | return target_async_permitted; |
b84876c2 PA |
4327 | } |
4328 | ||
9908b566 | 4329 | static int |
2a9a2795 | 4330 | linux_nat_supports_non_stop (struct target_ops *self) |
9908b566 VP |
4331 | { |
4332 | return 1; | |
4333 | } | |
4334 | ||
d90e17a7 PA |
4335 | /* True if we want to support multi-process. To be removed when GDB |
4336 | supports multi-exec. */ | |
4337 | ||
2277426b | 4338 | int linux_multi_process = 1; |
d90e17a7 PA |
4339 | |
4340 | static int | |
86ce2668 | 4341 | linux_nat_supports_multi_process (struct target_ops *self) |
d90e17a7 PA |
4342 | { |
4343 | return linux_multi_process; | |
4344 | } | |
4345 | ||
03583c20 | 4346 | static int |
2bfc0540 | 4347 | linux_nat_supports_disable_randomization (struct target_ops *self) |
03583c20 UW |
4348 | { |
4349 | #ifdef HAVE_PERSONALITY | |
4350 | return 1; | |
4351 | #else | |
4352 | return 0; | |
4353 | #endif | |
4354 | } | |
4355 | ||
b84876c2 PA |
4356 | static int async_terminal_is_ours = 1; |
4357 | ||
4d4ca2a1 DE |
4358 | /* target_terminal_inferior implementation. |
4359 | ||
4360 | This is a wrapper around child_terminal_inferior to add async support. */ | |
b84876c2 PA |
4361 | |
4362 | static void | |
d2f640d4 | 4363 | linux_nat_terminal_inferior (struct target_ops *self) |
b84876c2 PA |
4364 | { |
4365 | if (!target_is_async_p ()) | |
4366 | { | |
4367 | /* Async mode is disabled. */ | |
d6b64346 | 4368 | child_terminal_inferior (self); |
b84876c2 PA |
4369 | return; |
4370 | } | |
4371 | ||
d6b64346 | 4372 | child_terminal_inferior (self); |
b84876c2 | 4373 | |
d9d2d8b6 | 4374 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4375 | if (!async_terminal_is_ours) |
4376 | return; | |
4377 | ||
4378 | delete_file_handler (input_fd); | |
4379 | async_terminal_is_ours = 0; | |
4380 | set_sigint_trap (); | |
4381 | } | |
4382 | ||
4d4ca2a1 DE |
4383 | /* target_terminal_ours implementation. |
4384 | ||
4385 | This is a wrapper around child_terminal_ours to add async support (and | |
4386 | implement the target_terminal_ours vs target_terminal_ours_for_output | |
4387 | distinction). child_terminal_ours is currently no different than | |
4388 | child_terminal_ours_for_output. | |
4389 | We leave target_terminal_ours_for_output alone, leaving it to | |
4390 | child_terminal_ours_for_output. */ | |
b84876c2 | 4391 | |
2c0b251b | 4392 | static void |
e3594fd1 | 4393 | linux_nat_terminal_ours (struct target_ops *self) |
b84876c2 PA |
4394 | { |
4395 | if (!target_is_async_p ()) | |
4396 | { | |
4397 | /* Async mode is disabled. */ | |
d6b64346 | 4398 | child_terminal_ours (self); |
b84876c2 PA |
4399 | return; |
4400 | } | |
4401 | ||
4402 | /* GDB should never give the terminal to the inferior if the | |
4403 | inferior is running in the background (run&, continue&, etc.), | |
4404 | but claiming it sure should. */ | |
d6b64346 | 4405 | child_terminal_ours (self); |
b84876c2 | 4406 | |
b84876c2 PA |
4407 | if (async_terminal_is_ours) |
4408 | return; | |
4409 | ||
4410 | clear_sigint_trap (); | |
4411 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4412 | async_terminal_is_ours = 1; | |
4413 | } | |
4414 | ||
4415 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4416 | void *context); | |
4417 | static void *async_client_context; | |
4418 | ||
7feb7d06 PA |
4419 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4420 | so we notice when any child changes state, and notify the | |
4421 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4422 | above to wait for the arrival of a SIGCHLD. */ | |
4423 | ||
b84876c2 | 4424 | static void |
7feb7d06 | 4425 | sigchld_handler (int signo) |
b84876c2 | 4426 | { |
7feb7d06 PA |
4427 | int old_errno = errno; |
4428 | ||
01124a23 DE |
4429 | if (debug_linux_nat) |
4430 | ui_file_write_async_safe (gdb_stdlog, | |
4431 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4432 | |
4433 | if (signo == SIGCHLD | |
4434 | && linux_nat_event_pipe[0] != -1) | |
4435 | async_file_mark (); /* Let the event loop know that there are | |
4436 | events to handle. */ | |
4437 | ||
4438 | errno = old_errno; | |
4439 | } | |
4440 | ||
4441 | /* Callback registered with the target events file descriptor. */ | |
4442 | ||
4443 | static void | |
4444 | handle_target_event (int error, gdb_client_data client_data) | |
4445 | { | |
4446 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4447 | } | |
4448 | ||
4449 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4450 | ||
4451 | static int | |
4452 | linux_async_pipe (int enable) | |
4453 | { | |
4454 | int previous = (linux_nat_event_pipe[0] != -1); | |
4455 | ||
4456 | if (previous != enable) | |
4457 | { | |
4458 | sigset_t prev_mask; | |
4459 | ||
12696c10 PA |
4460 | /* Block child signals while we create/destroy the pipe, as |
4461 | their handler writes to it. */ | |
7feb7d06 PA |
4462 | block_child_signals (&prev_mask); |
4463 | ||
4464 | if (enable) | |
4465 | { | |
614c279d | 4466 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4467 | internal_error (__FILE__, __LINE__, |
4468 | "creating event pipe failed."); | |
4469 | ||
4470 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4471 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4472 | } | |
4473 | else | |
4474 | { | |
4475 | close (linux_nat_event_pipe[0]); | |
4476 | close (linux_nat_event_pipe[1]); | |
4477 | linux_nat_event_pipe[0] = -1; | |
4478 | linux_nat_event_pipe[1] = -1; | |
4479 | } | |
4480 | ||
4481 | restore_child_signals_mask (&prev_mask); | |
4482 | } | |
4483 | ||
4484 | return previous; | |
b84876c2 PA |
4485 | } |
4486 | ||
4487 | /* target_async implementation. */ | |
4488 | ||
4489 | static void | |
6a109b6b TT |
4490 | linux_nat_async (struct target_ops *ops, |
4491 | void (*callback) (enum inferior_event_type event_type, | |
4492 | void *context), | |
4493 | void *context) | |
b84876c2 | 4494 | { |
b84876c2 PA |
4495 | if (callback != NULL) |
4496 | { | |
4497 | async_client_callback = callback; | |
4498 | async_client_context = context; | |
7feb7d06 PA |
4499 | if (!linux_async_pipe (1)) |
4500 | { | |
4501 | add_file_handler (linux_nat_event_pipe[0], | |
4502 | handle_target_event, NULL); | |
4503 | /* There may be pending events to handle. Tell the event loop | |
4504 | to poll them. */ | |
4505 | async_file_mark (); | |
4506 | } | |
b84876c2 PA |
4507 | } |
4508 | else | |
4509 | { | |
4510 | async_client_callback = callback; | |
4511 | async_client_context = context; | |
b84876c2 | 4512 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4513 | linux_async_pipe (0); |
b84876c2 PA |
4514 | } |
4515 | return; | |
4516 | } | |
4517 | ||
a493e3e2 | 4518 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4519 | event came out. */ |
4520 | ||
4c28f408 | 4521 | static int |
252fbfc8 | 4522 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4523 | { |
d90e17a7 | 4524 | if (!lwp->stopped) |
252fbfc8 | 4525 | { |
d90e17a7 PA |
4526 | if (debug_linux_nat) |
4527 | fprintf_unfiltered (gdb_stdlog, | |
4528 | "LNSL: running -> suspending %s\n", | |
4529 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4530 | |
252fbfc8 | 4531 | |
25289eb2 PA |
4532 | if (lwp->last_resume_kind == resume_stop) |
4533 | { | |
4534 | if (debug_linux_nat) | |
4535 | fprintf_unfiltered (gdb_stdlog, | |
4536 | "linux-nat: already stopping LWP %ld at " | |
4537 | "GDB's request\n", | |
4538 | ptid_get_lwp (lwp->ptid)); | |
4539 | return 0; | |
4540 | } | |
252fbfc8 | 4541 | |
25289eb2 PA |
4542 | stop_callback (lwp, NULL); |
4543 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4544 | } |
4545 | else | |
4546 | { | |
4547 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4548 | |
d90e17a7 PA |
4549 | if (debug_linux_nat) |
4550 | { | |
e09875d4 | 4551 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4552 | fprintf_unfiltered (gdb_stdlog, |
4553 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4554 | target_pid_to_str (lwp->ptid)); |
4555 | else | |
3e43a32a MS |
4556 | fprintf_unfiltered (gdb_stdlog, |
4557 | "LNSL: already stopped/no " | |
4558 | "stop_requested yet %s\n", | |
d90e17a7 | 4559 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4560 | } |
4561 | } | |
4c28f408 PA |
4562 | return 0; |
4563 | } | |
4564 | ||
4565 | static void | |
1eab8a48 | 4566 | linux_nat_stop (struct target_ops *self, ptid_t ptid) |
4c28f408 PA |
4567 | { |
4568 | if (non_stop) | |
d90e17a7 | 4569 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 | 4570 | else |
1eab8a48 | 4571 | linux_ops->to_stop (linux_ops, ptid); |
4c28f408 PA |
4572 | } |
4573 | ||
d90e17a7 | 4574 | static void |
de90e03d | 4575 | linux_nat_close (struct target_ops *self) |
d90e17a7 PA |
4576 | { |
4577 | /* Unregister from the event loop. */ | |
9debeba0 DE |
4578 | if (linux_nat_is_async_p (self)) |
4579 | linux_nat_async (self, NULL, NULL); | |
d90e17a7 | 4580 | |
d90e17a7 | 4581 | if (linux_ops->to_close) |
de90e03d | 4582 | linux_ops->to_close (linux_ops); |
6a3cb8e8 PA |
4583 | |
4584 | super_close (self); | |
d90e17a7 PA |
4585 | } |
4586 | ||
c0694254 PA |
4587 | /* When requests are passed down from the linux-nat layer to the |
4588 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4589 | used. The address space pointer is stored in the inferior object, | |
4590 | but the common code that is passed such ptid can't tell whether | |
4591 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4592 | look up the "main" process id from the lwp here. */ | |
4593 | ||
70221824 | 4594 | static struct address_space * |
c0694254 PA |
4595 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
4596 | { | |
4597 | struct lwp_info *lwp; | |
4598 | struct inferior *inf; | |
4599 | int pid; | |
4600 | ||
dfd4cc63 | 4601 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4602 | { |
4603 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4604 | tgid. */ | |
4605 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4606 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4607 | } |
4608 | else | |
4609 | { | |
4610 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4611 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4612 | } |
4613 | ||
4614 | inf = find_inferior_pid (pid); | |
4615 | gdb_assert (inf != NULL); | |
4616 | return inf->aspace; | |
4617 | } | |
4618 | ||
dc146f7c VP |
4619 | /* Return the cached value of the processor core for thread PTID. */ |
4620 | ||
70221824 | 4621 | static int |
dc146f7c VP |
4622 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
4623 | { | |
4624 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4625 | |
dc146f7c VP |
4626 | if (info) |
4627 | return info->core; | |
4628 | return -1; | |
4629 | } | |
4630 | ||
f973ed9c DJ |
4631 | void |
4632 | linux_nat_add_target (struct target_ops *t) | |
4633 | { | |
f973ed9c DJ |
4634 | /* Save the provided single-threaded target. We save this in a separate |
4635 | variable because another target we've inherited from (e.g. inf-ptrace) | |
4636 | may have saved a pointer to T; we want to use it for the final | |
4637 | process stratum target. */ | |
4638 | linux_ops_saved = *t; | |
4639 | linux_ops = &linux_ops_saved; | |
4640 | ||
4641 | /* Override some methods for multithreading. */ | |
b84876c2 | 4642 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
4643 | t->to_attach = linux_nat_attach; |
4644 | t->to_detach = linux_nat_detach; | |
4645 | t->to_resume = linux_nat_resume; | |
4646 | t->to_wait = linux_nat_wait; | |
2455069d | 4647 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
4648 | t->to_xfer_partial = linux_nat_xfer_partial; |
4649 | t->to_kill = linux_nat_kill; | |
4650 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
4651 | t->to_thread_alive = linux_nat_thread_alive; | |
4652 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 4653 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 4654 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 4655 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
4656 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
4657 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 4658 | |
b84876c2 PA |
4659 | t->to_can_async_p = linux_nat_can_async_p; |
4660 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 4661 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 4662 | t->to_async = linux_nat_async; |
b84876c2 PA |
4663 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
4664 | t->to_terminal_ours = linux_nat_terminal_ours; | |
6a3cb8e8 PA |
4665 | |
4666 | super_close = t->to_close; | |
d90e17a7 | 4667 | t->to_close = linux_nat_close; |
b84876c2 | 4668 | |
4c28f408 PA |
4669 | /* Methods for non-stop support. */ |
4670 | t->to_stop = linux_nat_stop; | |
4671 | ||
d90e17a7 PA |
4672 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
4673 | ||
03583c20 UW |
4674 | t->to_supports_disable_randomization |
4675 | = linux_nat_supports_disable_randomization; | |
4676 | ||
dc146f7c VP |
4677 | t->to_core_of_thread = linux_nat_core_of_thread; |
4678 | ||
f973ed9c DJ |
4679 | /* We don't change the stratum; this target will sit at |
4680 | process_stratum and thread_db will set at thread_stratum. This | |
4681 | is a little strange, since this is a multi-threaded-capable | |
4682 | target, but we want to be on the stack below thread_db, and we | |
4683 | also want to be used for single-threaded processes. */ | |
4684 | ||
4685 | add_target (t); | |
f973ed9c DJ |
4686 | } |
4687 | ||
9f0bdab8 DJ |
4688 | /* Register a method to call whenever a new thread is attached. */ |
4689 | void | |
7b50312a PA |
4690 | linux_nat_set_new_thread (struct target_ops *t, |
4691 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4692 | { |
4693 | /* Save the pointer. We only support a single registered instance | |
4694 | of the GNU/Linux native target, so we do not need to map this to | |
4695 | T. */ | |
4696 | linux_nat_new_thread = new_thread; | |
4697 | } | |
4698 | ||
26cb8b7c PA |
4699 | /* See declaration in linux-nat.h. */ |
4700 | ||
4701 | void | |
4702 | linux_nat_set_new_fork (struct target_ops *t, | |
4703 | linux_nat_new_fork_ftype *new_fork) | |
4704 | { | |
4705 | /* Save the pointer. */ | |
4706 | linux_nat_new_fork = new_fork; | |
4707 | } | |
4708 | ||
4709 | /* See declaration in linux-nat.h. */ | |
4710 | ||
4711 | void | |
4712 | linux_nat_set_forget_process (struct target_ops *t, | |
4713 | linux_nat_forget_process_ftype *fn) | |
4714 | { | |
4715 | /* Save the pointer. */ | |
4716 | linux_nat_forget_process_hook = fn; | |
4717 | } | |
4718 | ||
4719 | /* See declaration in linux-nat.h. */ | |
4720 | ||
4721 | void | |
4722 | linux_nat_forget_process (pid_t pid) | |
4723 | { | |
4724 | if (linux_nat_forget_process_hook != NULL) | |
4725 | linux_nat_forget_process_hook (pid); | |
4726 | } | |
4727 | ||
5b009018 PA |
4728 | /* Register a method that converts a siginfo object between the layout |
4729 | that ptrace returns, and the layout in the architecture of the | |
4730 | inferior. */ | |
4731 | void | |
4732 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4733 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4734 | gdb_byte *, |
4735 | int)) | |
4736 | { | |
4737 | /* Save the pointer. */ | |
4738 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4739 | } | |
4740 | ||
7b50312a PA |
4741 | /* Register a method to call prior to resuming a thread. */ |
4742 | ||
4743 | void | |
4744 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4745 | void (*prepare_to_resume) (struct lwp_info *)) | |
4746 | { | |
4747 | /* Save the pointer. */ | |
4748 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4749 | } | |
4750 | ||
f865ee35 JK |
4751 | /* See linux-nat.h. */ |
4752 | ||
4753 | int | |
4754 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4755 | { |
da559b09 | 4756 | int pid; |
9f0bdab8 | 4757 | |
dfd4cc63 | 4758 | pid = ptid_get_lwp (ptid); |
da559b09 | 4759 | if (pid == 0) |
dfd4cc63 | 4760 | pid = ptid_get_pid (ptid); |
f865ee35 | 4761 | |
da559b09 JK |
4762 | errno = 0; |
4763 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4764 | if (errno != 0) | |
4765 | { | |
4766 | memset (siginfo, 0, sizeof (*siginfo)); | |
4767 | return 0; | |
4768 | } | |
f865ee35 | 4769 | return 1; |
9f0bdab8 DJ |
4770 | } |
4771 | ||
2c0b251b PA |
4772 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
4773 | extern initialize_file_ftype _initialize_linux_nat; | |
4774 | ||
d6b0e80f AC |
4775 | void |
4776 | _initialize_linux_nat (void) | |
4777 | { | |
ccce17b0 YQ |
4778 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4779 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4780 | Set debugging of GNU/Linux lwp module."), _("\ |
4781 | Show debugging of GNU/Linux lwp module."), _("\ | |
4782 | Enables printf debugging output."), | |
ccce17b0 YQ |
4783 | NULL, |
4784 | show_debug_linux_nat, | |
4785 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4786 | |
b84876c2 | 4787 | /* Save this mask as the default. */ |
d6b0e80f AC |
4788 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4789 | ||
7feb7d06 PA |
4790 | /* Install a SIGCHLD handler. */ |
4791 | sigchld_action.sa_handler = sigchld_handler; | |
4792 | sigemptyset (&sigchld_action.sa_mask); | |
4793 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4794 | |
4795 | /* Make it the default. */ | |
7feb7d06 | 4796 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4797 | |
4798 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4799 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4800 | sigdelset (&suspend_mask, SIGCHLD); | |
4801 | ||
7feb7d06 | 4802 | sigemptyset (&blocked_mask); |
8009206a TT |
4803 | |
4804 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to | |
4805 | support read-only process state. */ | |
4806 | linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD | |
4807 | | PTRACE_O_TRACEVFORKDONE | |
4808 | | PTRACE_O_TRACEVFORK | |
4809 | | PTRACE_O_TRACEFORK | |
4810 | | PTRACE_O_TRACEEXEC); | |
d6b0e80f AC |
4811 | } |
4812 | \f | |
4813 | ||
4814 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4815 | the GNU/Linux Threads library and therefore doesn't really belong | |
4816 | here. */ | |
4817 | ||
4818 | /* Read variable NAME in the target and return its value if found. | |
4819 | Otherwise return zero. It is assumed that the type of the variable | |
4820 | is `int'. */ | |
4821 | ||
4822 | static int | |
4823 | get_signo (const char *name) | |
4824 | { | |
3b7344d5 | 4825 | struct bound_minimal_symbol ms; |
d6b0e80f AC |
4826 | int signo; |
4827 | ||
4828 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
3b7344d5 | 4829 | if (ms.minsym == NULL) |
d6b0e80f AC |
4830 | return 0; |
4831 | ||
77e371c0 | 4832 | if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
4833 | sizeof (signo)) != 0) |
4834 | return 0; | |
4835 | ||
4836 | return signo; | |
4837 | } | |
4838 | ||
4839 | /* Return the set of signals used by the threads library in *SET. */ | |
4840 | ||
4841 | void | |
4842 | lin_thread_get_thread_signals (sigset_t *set) | |
4843 | { | |
4844 | struct sigaction action; | |
4845 | int restart, cancel; | |
4846 | ||
b84876c2 | 4847 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
4848 | sigemptyset (set); |
4849 | ||
4850 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
4851 | cancel = get_signo ("__pthread_sig_cancel"); |
4852 | ||
4853 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
4854 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
4855 | not provide any way for the debugger to query the signal numbers - | |
4856 | fortunately they don't change! */ | |
4857 | ||
d6b0e80f | 4858 | if (restart == 0) |
17fbb0bd | 4859 | restart = __SIGRTMIN; |
d6b0e80f | 4860 | |
d6b0e80f | 4861 | if (cancel == 0) |
17fbb0bd | 4862 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
4863 | |
4864 | sigaddset (set, restart); | |
4865 | sigaddset (set, cancel); | |
4866 | ||
4867 | /* The GNU/Linux Threads library makes terminating threads send a | |
4868 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
4869 | those (to prevent them from terminating GDB itself, which is | |
4870 | likely to be their default action) and treat them the same way as | |
4871 | SIGCHLD. */ | |
4872 | ||
4873 | action.sa_handler = sigchld_handler; | |
4874 | sigemptyset (&action.sa_mask); | |
58aecb61 | 4875 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
4876 | sigaction (cancel, &action, NULL); |
4877 | ||
4878 | /* We block the "cancel" signal throughout this code ... */ | |
4879 | sigaddset (&blocked_mask, cancel); | |
4880 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
4881 | ||
4882 | /* ... except during a sigsuspend. */ | |
4883 | sigdelset (&suspend_mask, cancel); | |
4884 | } |