Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
0b302171 | 3 | Copyright (C) 2001-2012 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" | |
22 | #include "target.h" | |
d6b0e80f | 23 | #include "gdb_string.h" |
3993f6b1 | 24 | #include "gdb_wait.h" |
d6b0e80f AC |
25 | #include "gdb_assert.h" |
26 | #ifdef HAVE_TKILL_SYSCALL | |
27 | #include <unistd.h> | |
28 | #include <sys/syscall.h> | |
29 | #endif | |
3993f6b1 | 30 | #include <sys/ptrace.h> |
0274a8ce | 31 | #include "linux-nat.h" |
af96c192 | 32 | #include "linux-ptrace.h" |
13da1c97 | 33 | #include "linux-procfs.h" |
ac264b3b | 34 | #include "linux-fork.h" |
d6b0e80f AC |
35 | #include "gdbthread.h" |
36 | #include "gdbcmd.h" | |
37 | #include "regcache.h" | |
4f844a66 | 38 | #include "regset.h" |
10d6c8cd DJ |
39 | #include "inf-ptrace.h" |
40 | #include "auxv.h" | |
dba24537 | 41 | #include <sys/param.h> /* for MAXPATHLEN */ |
1777feb0 | 42 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
43 | #include "elf-bfd.h" /* for elfcore_write_* */ |
44 | #include "gregset.h" /* for gregset */ | |
45 | #include "gdbcore.h" /* for get_exec_file */ | |
46 | #include <ctype.h> /* for isdigit */ | |
1777feb0 | 47 | #include "gdbthread.h" /* for struct thread_info etc. */ |
dba24537 AC |
48 | #include "gdb_stat.h" /* for struct stat */ |
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> | |
55 | #include "gdb_dirent.h" | |
56 | #include "xml-support.h" | |
191c4426 | 57 | #include "terminal.h" |
efcbbd14 | 58 | #include <sys/vfs.h> |
6c95b8df | 59 | #include "solib.h" |
d26e3629 | 60 | #include "linux-osdata.h" |
6432734d | 61 | #include "linux-tdep.h" |
efcbbd14 UW |
62 | |
63 | #ifndef SPUFS_MAGIC | |
64 | #define SPUFS_MAGIC 0x23c9b64e | |
65 | #endif | |
dba24537 | 66 | |
10568435 JK |
67 | #ifdef HAVE_PERSONALITY |
68 | # include <sys/personality.h> | |
69 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
70 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
71 | # endif | |
72 | #endif /* HAVE_PERSONALITY */ | |
73 | ||
1777feb0 | 74 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
75 | |
76 | Waiting for events in sync mode | |
77 | =============================== | |
78 | ||
79 | When waiting for an event in a specific thread, we just use waitpid, passing | |
80 | the specific pid, and not passing WNOHANG. | |
81 | ||
1777feb0 | 82 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 83 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 84 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
85 | miss an event. The solution is to use non-blocking waitpid, together with |
86 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 87 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
88 | flag to check for events in cloned processes. If nothing is found, we use |
89 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
90 | happened to a child process -- and SIGCHLD will be delivered both for events | |
91 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
92 | an event, we get back to calling nonblocking waitpid with and without |
93 | __WCLONED. | |
8a77dff3 VP |
94 | |
95 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 96 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
97 | blocked, the signal becomes pending and sigsuspend immediately |
98 | notices it and returns. | |
99 | ||
100 | Waiting for events in async mode | |
101 | ================================ | |
102 | ||
7feb7d06 PA |
103 | In async mode, GDB should always be ready to handle both user input |
104 | and target events, so neither blocking waitpid nor sigsuspend are | |
105 | viable options. Instead, we should asynchronously notify the GDB main | |
106 | event loop whenever there's an unprocessed event from the target. We | |
107 | detect asynchronous target events by handling SIGCHLD signals. To | |
108 | notify the event loop about target events, the self-pipe trick is used | |
109 | --- a pipe is registered as waitable event source in the event loop, | |
110 | the event loop select/poll's on the read end of this pipe (as well on | |
111 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
112 | byte to this pipe. This is more portable than relying on | |
113 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
114 | emulates them with select/poll+sigprocmask, and that is racy | |
115 | (a.k.a. plain broken). | |
116 | ||
117 | Obviously, if we fail to notify the event loop if there's a target | |
118 | event, it's bad. OTOH, if we notify the event loop when there's no | |
119 | event from the target, linux_nat_wait will detect that there's no real | |
120 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
121 | This is mostly harmless, but it will waste time and is better avoided. | |
122 | ||
123 | The main design point is that every time GDB is outside linux-nat.c, | |
124 | we have a SIGCHLD handler installed that is called when something | |
125 | happens to the target and notifies the GDB event loop. Whenever GDB | |
126 | core decides to handle the event, and calls into linux-nat.c, we | |
127 | process things as in sync mode, except that the we never block in | |
128 | sigsuspend. | |
129 | ||
130 | While processing an event, we may end up momentarily blocked in | |
131 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
132 | return quickly. E.g., in all-stop mode, before reporting to the core | |
133 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
134 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
135 | Note that this is different from blocking indefinitely waiting for the | |
136 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
137 | |
138 | Use of signals | |
139 | ============== | |
140 | ||
141 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
142 | signal is not entirely significant; we just need for a signal to be delivered, | |
143 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
144 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
145 | be queued once; we do not keep track of other sources of SIGSTOP. | |
146 | ||
147 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
148 | use them, because they have special behavior when the signal is generated - | |
149 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
150 | kills the entire thread group. | |
151 | ||
152 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
153 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
154 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
155 | ||
156 | We could use a real-time signal instead. This would solve those problems; we | |
157 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
158 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
159 | generates it, and there are races with trying to find a signal that is not | |
160 | blocked. */ | |
a0ef4274 | 161 | |
dba24537 AC |
162 | #ifndef O_LARGEFILE |
163 | #define O_LARGEFILE 0 | |
164 | #endif | |
0274a8ce | 165 | |
ca2163eb PA |
166 | /* Unlike other extended result codes, WSTOPSIG (status) on |
167 | PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but | |
168 | instead SIGTRAP with bit 7 set. */ | |
169 | #define SYSCALL_SIGTRAP (SIGTRAP | 0x80) | |
170 | ||
10d6c8cd DJ |
171 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
172 | the use of the multi-threaded target. */ | |
173 | static struct target_ops *linux_ops; | |
f973ed9c | 174 | static struct target_ops linux_ops_saved; |
10d6c8cd | 175 | |
9f0bdab8 | 176 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
177 | static void (*linux_nat_new_thread) (struct lwp_info *); |
178 | ||
179 | /* Hook to call prior to resuming a thread. */ | |
180 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 181 | |
5b009018 PA |
182 | /* The method to call, if any, when the siginfo object needs to be |
183 | converted between the layout returned by ptrace, and the layout in | |
184 | the architecture of the inferior. */ | |
185 | static int (*linux_nat_siginfo_fixup) (struct siginfo *, | |
186 | gdb_byte *, | |
187 | int); | |
188 | ||
ac264b3b MS |
189 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
190 | Called by our to_xfer_partial. */ | |
191 | static LONGEST (*super_xfer_partial) (struct target_ops *, | |
192 | enum target_object, | |
193 | const char *, gdb_byte *, | |
194 | const gdb_byte *, | |
10d6c8cd DJ |
195 | ULONGEST, LONGEST); |
196 | ||
d6b0e80f | 197 | static int debug_linux_nat; |
920d2a44 AC |
198 | static void |
199 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
200 | struct cmd_list_element *c, const char *value) | |
201 | { | |
202 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
203 | value); | |
204 | } | |
d6b0e80f | 205 | |
ae087d01 DJ |
206 | struct simple_pid_list |
207 | { | |
208 | int pid; | |
3d799a95 | 209 | int status; |
ae087d01 DJ |
210 | struct simple_pid_list *next; |
211 | }; | |
212 | struct simple_pid_list *stopped_pids; | |
213 | ||
3993f6b1 DJ |
214 | /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
215 | can not be used, 1 if it can. */ | |
216 | ||
217 | static int linux_supports_tracefork_flag = -1; | |
218 | ||
3e43a32a MS |
219 | /* This variable is a tri-state flag: -1 for unknown, 0 if |
220 | PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */ | |
a96d9b2e SDJ |
221 | |
222 | static int linux_supports_tracesysgood_flag = -1; | |
223 | ||
9016a515 DJ |
224 | /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
225 | PTRACE_O_TRACEVFORKDONE. */ | |
226 | ||
227 | static int linux_supports_tracevforkdone_flag = -1; | |
228 | ||
a96d9b2e SDJ |
229 | /* Stores the current used ptrace() options. */ |
230 | static int current_ptrace_options = 0; | |
231 | ||
3dd5b83d PA |
232 | /* Async mode support. */ |
233 | ||
b84876c2 PA |
234 | /* The read/write ends of the pipe registered as waitable file in the |
235 | event loop. */ | |
236 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
237 | ||
7feb7d06 | 238 | /* Flush the event pipe. */ |
b84876c2 | 239 | |
7feb7d06 PA |
240 | static void |
241 | async_file_flush (void) | |
b84876c2 | 242 | { |
7feb7d06 PA |
243 | int ret; |
244 | char buf; | |
b84876c2 | 245 | |
7feb7d06 | 246 | do |
b84876c2 | 247 | { |
7feb7d06 | 248 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 249 | } |
7feb7d06 | 250 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
251 | } |
252 | ||
7feb7d06 PA |
253 | /* Put something (anything, doesn't matter what, or how much) in event |
254 | pipe, so that the select/poll in the event-loop realizes we have | |
255 | something to process. */ | |
252fbfc8 | 256 | |
b84876c2 | 257 | static void |
7feb7d06 | 258 | async_file_mark (void) |
b84876c2 | 259 | { |
7feb7d06 | 260 | int ret; |
b84876c2 | 261 | |
7feb7d06 PA |
262 | /* It doesn't really matter what the pipe contains, as long we end |
263 | up with something in it. Might as well flush the previous | |
264 | left-overs. */ | |
265 | async_file_flush (); | |
b84876c2 | 266 | |
7feb7d06 | 267 | do |
b84876c2 | 268 | { |
7feb7d06 | 269 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 270 | } |
7feb7d06 | 271 | while (ret == -1 && errno == EINTR); |
b84876c2 | 272 | |
7feb7d06 PA |
273 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
274 | be awakened anyway. */ | |
b84876c2 PA |
275 | } |
276 | ||
7feb7d06 | 277 | static void linux_nat_async (void (*callback) |
3e43a32a MS |
278 | (enum inferior_event_type event_type, |
279 | void *context), | |
7feb7d06 | 280 | void *context); |
7feb7d06 PA |
281 | static int kill_lwp (int lwpid, int signo); |
282 | ||
283 | static int stop_callback (struct lwp_info *lp, void *data); | |
284 | ||
285 | static void block_child_signals (sigset_t *prev_mask); | |
286 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
287 | |
288 | struct lwp_info; | |
289 | static struct lwp_info *add_lwp (ptid_t ptid); | |
290 | static void purge_lwp_list (int pid); | |
4403d8e9 | 291 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
292 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
293 | ||
ae087d01 DJ |
294 | \f |
295 | /* Trivial list manipulation functions to keep track of a list of | |
296 | new stopped processes. */ | |
297 | static void | |
3d799a95 | 298 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
299 | { |
300 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 301 | |
ae087d01 | 302 | new_pid->pid = pid; |
3d799a95 | 303 | new_pid->status = status; |
ae087d01 DJ |
304 | new_pid->next = *listp; |
305 | *listp = new_pid; | |
306 | } | |
307 | ||
84636d28 PA |
308 | static int |
309 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
310 | { | |
311 | struct simple_pid_list *p; | |
312 | ||
313 | for (p = list; p != NULL; p = p->next) | |
314 | if (p->pid == pid) | |
315 | return 1; | |
316 | return 0; | |
317 | } | |
318 | ||
ae087d01 | 319 | static int |
46a96992 | 320 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
321 | { |
322 | struct simple_pid_list **p; | |
323 | ||
324 | for (p = listp; *p != NULL; p = &(*p)->next) | |
325 | if ((*p)->pid == pid) | |
326 | { | |
327 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 328 | |
46a96992 | 329 | *statusp = (*p)->status; |
ae087d01 DJ |
330 | xfree (*p); |
331 | *p = next; | |
332 | return 1; | |
333 | } | |
334 | return 0; | |
335 | } | |
336 | ||
3993f6b1 DJ |
337 | \f |
338 | /* A helper function for linux_test_for_tracefork, called after fork (). */ | |
339 | ||
340 | static void | |
341 | linux_tracefork_child (void) | |
342 | { | |
3993f6b1 DJ |
343 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
344 | kill (getpid (), SIGSTOP); | |
345 | fork (); | |
48bb3cce | 346 | _exit (0); |
3993f6b1 DJ |
347 | } |
348 | ||
7feb7d06 | 349 | /* Wrapper function for waitpid which handles EINTR. */ |
b957e937 DJ |
350 | |
351 | static int | |
46a96992 | 352 | my_waitpid (int pid, int *statusp, int flags) |
b957e937 DJ |
353 | { |
354 | int ret; | |
b84876c2 | 355 | |
b957e937 DJ |
356 | do |
357 | { | |
46a96992 | 358 | ret = waitpid (pid, statusp, flags); |
b957e937 DJ |
359 | } |
360 | while (ret == -1 && errno == EINTR); | |
361 | ||
362 | return ret; | |
363 | } | |
364 | ||
365 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. | |
366 | ||
367 | First, we try to enable fork tracing on ORIGINAL_PID. If this fails, | |
368 | we know that the feature is not available. This may change the tracing | |
369 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. | |
370 | ||
371 | However, if it succeeds, we don't know for sure that the feature is | |
372 | available; old versions of PTRACE_SETOPTIONS ignored unknown options. We | |
3993f6b1 | 373 | create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
b957e937 DJ |
374 | fork tracing, and let it fork. If the process exits, we assume that we |
375 | can't use TRACEFORK; if we get the fork notification, and we can extract | |
376 | the new child's PID, then we assume that we can. */ | |
3993f6b1 DJ |
377 | |
378 | static void | |
b957e937 | 379 | linux_test_for_tracefork (int original_pid) |
3993f6b1 DJ |
380 | { |
381 | int child_pid, ret, status; | |
382 | long second_pid; | |
7feb7d06 | 383 | sigset_t prev_mask; |
4c28f408 | 384 | |
7feb7d06 PA |
385 | /* We don't want those ptrace calls to be interrupted. */ |
386 | block_child_signals (&prev_mask); | |
3993f6b1 | 387 | |
b957e937 DJ |
388 | linux_supports_tracefork_flag = 0; |
389 | linux_supports_tracevforkdone_flag = 0; | |
390 | ||
391 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); | |
392 | if (ret != 0) | |
7feb7d06 PA |
393 | { |
394 | restore_child_signals_mask (&prev_mask); | |
395 | return; | |
396 | } | |
b957e937 | 397 | |
3993f6b1 DJ |
398 | child_pid = fork (); |
399 | if (child_pid == -1) | |
e2e0b3e5 | 400 | perror_with_name (("fork")); |
3993f6b1 DJ |
401 | |
402 | if (child_pid == 0) | |
403 | linux_tracefork_child (); | |
404 | ||
b957e937 | 405 | ret = my_waitpid (child_pid, &status, 0); |
3993f6b1 | 406 | if (ret == -1) |
e2e0b3e5 | 407 | perror_with_name (("waitpid")); |
3993f6b1 | 408 | else if (ret != child_pid) |
8a3fe4f8 | 409 | error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
3993f6b1 | 410 | if (! WIFSTOPPED (status)) |
3e43a32a MS |
411 | error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), |
412 | status); | |
3993f6b1 | 413 | |
3993f6b1 DJ |
414 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
415 | if (ret != 0) | |
416 | { | |
b957e937 DJ |
417 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
418 | if (ret != 0) | |
419 | { | |
8a3fe4f8 | 420 | warning (_("linux_test_for_tracefork: failed to kill child")); |
7feb7d06 | 421 | restore_child_signals_mask (&prev_mask); |
b957e937 DJ |
422 | return; |
423 | } | |
424 | ||
425 | ret = my_waitpid (child_pid, &status, 0); | |
426 | if (ret != child_pid) | |
3e43a32a MS |
427 | warning (_("linux_test_for_tracefork: failed " |
428 | "to wait for killed child")); | |
b957e937 | 429 | else if (!WIFSIGNALED (status)) |
3e43a32a MS |
430 | warning (_("linux_test_for_tracefork: unexpected " |
431 | "wait status 0x%x from killed child"), status); | |
b957e937 | 432 | |
7feb7d06 | 433 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
434 | return; |
435 | } | |
436 | ||
9016a515 DJ |
437 | /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
438 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, | |
439 | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); | |
440 | linux_supports_tracevforkdone_flag = (ret == 0); | |
441 | ||
b957e937 DJ |
442 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
443 | if (ret != 0) | |
8a3fe4f8 | 444 | warning (_("linux_test_for_tracefork: failed to resume child")); |
b957e937 DJ |
445 | |
446 | ret = my_waitpid (child_pid, &status, 0); | |
447 | ||
3993f6b1 DJ |
448 | if (ret == child_pid && WIFSTOPPED (status) |
449 | && status >> 16 == PTRACE_EVENT_FORK) | |
450 | { | |
451 | second_pid = 0; | |
452 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); | |
453 | if (ret == 0 && second_pid != 0) | |
454 | { | |
455 | int second_status; | |
456 | ||
457 | linux_supports_tracefork_flag = 1; | |
b957e937 DJ |
458 | my_waitpid (second_pid, &second_status, 0); |
459 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); | |
460 | if (ret != 0) | |
3e43a32a MS |
461 | warning (_("linux_test_for_tracefork: " |
462 | "failed to kill second child")); | |
97725dc4 | 463 | my_waitpid (second_pid, &status, 0); |
3993f6b1 DJ |
464 | } |
465 | } | |
b957e937 | 466 | else |
8a3fe4f8 AC |
467 | warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
468 | "(%d, status 0x%x)"), ret, status); | |
3993f6b1 | 469 | |
b957e937 DJ |
470 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
471 | if (ret != 0) | |
8a3fe4f8 | 472 | warning (_("linux_test_for_tracefork: failed to kill child")); |
b957e937 | 473 | my_waitpid (child_pid, &status, 0); |
4c28f408 | 474 | |
7feb7d06 | 475 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
476 | } |
477 | ||
a96d9b2e SDJ |
478 | /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls. |
479 | ||
480 | We try to enable syscall tracing on ORIGINAL_PID. If this fails, | |
481 | we know that the feature is not available. This may change the tracing | |
482 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. */ | |
483 | ||
484 | static void | |
485 | linux_test_for_tracesysgood (int original_pid) | |
486 | { | |
487 | int ret; | |
488 | sigset_t prev_mask; | |
489 | ||
490 | /* We don't want those ptrace calls to be interrupted. */ | |
491 | block_child_signals (&prev_mask); | |
492 | ||
493 | linux_supports_tracesysgood_flag = 0; | |
494 | ||
495 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD); | |
496 | if (ret != 0) | |
497 | goto out; | |
498 | ||
499 | linux_supports_tracesysgood_flag = 1; | |
500 | out: | |
501 | restore_child_signals_mask (&prev_mask); | |
502 | } | |
503 | ||
504 | /* Determine wether we support PTRACE_O_TRACESYSGOOD option available. | |
505 | This function also sets linux_supports_tracesysgood_flag. */ | |
506 | ||
507 | static int | |
508 | linux_supports_tracesysgood (int pid) | |
509 | { | |
510 | if (linux_supports_tracesysgood_flag == -1) | |
511 | linux_test_for_tracesysgood (pid); | |
512 | return linux_supports_tracesysgood_flag; | |
513 | } | |
514 | ||
3993f6b1 DJ |
515 | /* Return non-zero iff we have tracefork functionality available. |
516 | This function also sets linux_supports_tracefork_flag. */ | |
517 | ||
518 | static int | |
b957e937 | 519 | linux_supports_tracefork (int pid) |
3993f6b1 DJ |
520 | { |
521 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 522 | linux_test_for_tracefork (pid); |
3993f6b1 DJ |
523 | return linux_supports_tracefork_flag; |
524 | } | |
525 | ||
9016a515 | 526 | static int |
b957e937 | 527 | linux_supports_tracevforkdone (int pid) |
9016a515 DJ |
528 | { |
529 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 530 | linux_test_for_tracefork (pid); |
9016a515 DJ |
531 | return linux_supports_tracevforkdone_flag; |
532 | } | |
533 | ||
a96d9b2e SDJ |
534 | static void |
535 | linux_enable_tracesysgood (ptid_t ptid) | |
536 | { | |
537 | int pid = ptid_get_lwp (ptid); | |
538 | ||
539 | if (pid == 0) | |
540 | pid = ptid_get_pid (ptid); | |
541 | ||
542 | if (linux_supports_tracesysgood (pid) == 0) | |
543 | return; | |
544 | ||
545 | current_ptrace_options |= PTRACE_O_TRACESYSGOOD; | |
546 | ||
547 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); | |
548 | } | |
549 | ||
3993f6b1 | 550 | \f |
4de4c07c DJ |
551 | void |
552 | linux_enable_event_reporting (ptid_t ptid) | |
553 | { | |
d3587048 | 554 | int pid = ptid_get_lwp (ptid); |
4de4c07c | 555 | |
d3587048 DJ |
556 | if (pid == 0) |
557 | pid = ptid_get_pid (ptid); | |
558 | ||
b957e937 | 559 | if (! linux_supports_tracefork (pid)) |
4de4c07c DJ |
560 | return; |
561 | ||
a96d9b2e SDJ |
562 | current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK |
563 | | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE; | |
564 | ||
b957e937 | 565 | if (linux_supports_tracevforkdone (pid)) |
a96d9b2e | 566 | current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; |
9016a515 DJ |
567 | |
568 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support | |
569 | read-only process state. */ | |
4de4c07c | 570 | |
a96d9b2e | 571 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
4de4c07c DJ |
572 | } |
573 | ||
6d8fd2b7 UW |
574 | static void |
575 | linux_child_post_attach (int pid) | |
4de4c07c DJ |
576 | { |
577 | linux_enable_event_reporting (pid_to_ptid (pid)); | |
a96d9b2e | 578 | linux_enable_tracesysgood (pid_to_ptid (pid)); |
4de4c07c DJ |
579 | } |
580 | ||
10d6c8cd | 581 | static void |
4de4c07c DJ |
582 | linux_child_post_startup_inferior (ptid_t ptid) |
583 | { | |
584 | linux_enable_event_reporting (ptid); | |
a96d9b2e | 585 | linux_enable_tracesysgood (ptid); |
4de4c07c DJ |
586 | } |
587 | ||
4403d8e9 JK |
588 | /* Return the number of known LWPs in the tgid given by PID. */ |
589 | ||
590 | static int | |
591 | num_lwps (int pid) | |
592 | { | |
593 | int count = 0; | |
594 | struct lwp_info *lp; | |
595 | ||
596 | for (lp = lwp_list; lp; lp = lp->next) | |
597 | if (ptid_get_pid (lp->ptid) == pid) | |
598 | count++; | |
599 | ||
600 | return count; | |
601 | } | |
602 | ||
603 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
604 | ||
605 | static void | |
606 | delete_lwp_cleanup (void *lp_voidp) | |
607 | { | |
608 | struct lwp_info *lp = lp_voidp; | |
609 | ||
610 | delete_lwp (lp->ptid); | |
611 | } | |
612 | ||
6d8fd2b7 UW |
613 | static int |
614 | linux_child_follow_fork (struct target_ops *ops, int follow_child) | |
3993f6b1 | 615 | { |
7feb7d06 | 616 | sigset_t prev_mask; |
9016a515 | 617 | int has_vforked; |
4de4c07c DJ |
618 | int parent_pid, child_pid; |
619 | ||
7feb7d06 | 620 | block_child_signals (&prev_mask); |
b84876c2 | 621 | |
e58b0e63 PA |
622 | has_vforked = (inferior_thread ()->pending_follow.kind |
623 | == TARGET_WAITKIND_VFORKED); | |
624 | parent_pid = ptid_get_lwp (inferior_ptid); | |
d3587048 | 625 | if (parent_pid == 0) |
e58b0e63 PA |
626 | parent_pid = ptid_get_pid (inferior_ptid); |
627 | child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); | |
4de4c07c | 628 | |
2277426b PA |
629 | if (!detach_fork) |
630 | linux_enable_event_reporting (pid_to_ptid (child_pid)); | |
631 | ||
6c95b8df PA |
632 | if (has_vforked |
633 | && !non_stop /* Non-stop always resumes both branches. */ | |
634 | && (!target_is_async_p () || sync_execution) | |
635 | && !(follow_child || detach_fork || sched_multi)) | |
636 | { | |
637 | /* The parent stays blocked inside the vfork syscall until the | |
638 | child execs or exits. If we don't let the child run, then | |
639 | the parent stays blocked. If we're telling the parent to run | |
640 | in the foreground, the user will not be able to ctrl-c to get | |
641 | back the terminal, effectively hanging the debug session. */ | |
ac74f770 MS |
642 | fprintf_filtered (gdb_stderr, _("\ |
643 | Can not resume the parent process over vfork in the foreground while\n\ | |
644 | holding the child stopped. Try \"set detach-on-fork\" or \ | |
645 | \"set schedule-multiple\".\n")); | |
646 | /* FIXME output string > 80 columns. */ | |
6c95b8df PA |
647 | return 1; |
648 | } | |
649 | ||
4de4c07c DJ |
650 | if (! follow_child) |
651 | { | |
6c95b8df | 652 | struct lwp_info *child_lp = NULL; |
4de4c07c | 653 | |
1777feb0 | 654 | /* We're already attached to the parent, by default. */ |
4de4c07c | 655 | |
ac264b3b MS |
656 | /* Detach new forked process? */ |
657 | if (detach_fork) | |
f75c00e4 | 658 | { |
4403d8e9 JK |
659 | struct cleanup *old_chain; |
660 | ||
6c95b8df PA |
661 | /* Before detaching from the child, remove all breakpoints |
662 | from it. If we forked, then this has already been taken | |
663 | care of by infrun.c. If we vforked however, any | |
664 | breakpoint inserted in the parent is visible in the | |
665 | child, even those added while stopped in a vfork | |
666 | catchpoint. This will remove the breakpoints from the | |
667 | parent also, but they'll be reinserted below. */ | |
668 | if (has_vforked) | |
669 | { | |
670 | /* keep breakpoints list in sync. */ | |
671 | remove_breakpoints_pid (GET_PID (inferior_ptid)); | |
672 | } | |
673 | ||
e85a822c | 674 | if (info_verbose || debug_linux_nat) |
ac264b3b MS |
675 | { |
676 | target_terminal_ours (); | |
677 | fprintf_filtered (gdb_stdlog, | |
3e43a32a MS |
678 | "Detaching after fork from " |
679 | "child process %d.\n", | |
ac264b3b MS |
680 | child_pid); |
681 | } | |
4de4c07c | 682 | |
4403d8e9 JK |
683 | old_chain = save_inferior_ptid (); |
684 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
685 | ||
686 | child_lp = add_lwp (inferior_ptid); | |
687 | child_lp->stopped = 1; | |
688 | child_lp->last_resume_kind = resume_stop; | |
689 | make_cleanup (delete_lwp_cleanup, child_lp); | |
690 | ||
691 | /* CHILD_LP has new PID, therefore linux_nat_new_thread is not called for it. | |
692 | See i386_inferior_data_get for the Linux kernel specifics. | |
693 | Ensure linux_nat_prepare_to_resume will reset the hardware debug | |
694 | registers. It is done by the linux_nat_new_thread call, which is | |
695 | being skipped in add_lwp above for the first lwp of a pid. */ | |
696 | gdb_assert (num_lwps (GET_PID (child_lp->ptid)) == 1); | |
697 | if (linux_nat_new_thread != NULL) | |
698 | linux_nat_new_thread (child_lp); | |
699 | ||
700 | if (linux_nat_prepare_to_resume != NULL) | |
701 | linux_nat_prepare_to_resume (child_lp); | |
ac264b3b | 702 | ptrace (PTRACE_DETACH, child_pid, 0, 0); |
4403d8e9 JK |
703 | |
704 | do_cleanups (old_chain); | |
ac264b3b MS |
705 | } |
706 | else | |
707 | { | |
77435e4c | 708 | struct inferior *parent_inf, *child_inf; |
2277426b | 709 | struct cleanup *old_chain; |
7f9f62ba PA |
710 | |
711 | /* Add process to GDB's tables. */ | |
77435e4c PA |
712 | child_inf = add_inferior (child_pid); |
713 | ||
e58b0e63 | 714 | parent_inf = current_inferior (); |
77435e4c | 715 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 716 | copy_terminal_info (child_inf, parent_inf); |
7f9f62ba | 717 | |
2277426b | 718 | old_chain = save_inferior_ptid (); |
6c95b8df | 719 | save_current_program_space (); |
2277426b PA |
720 | |
721 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
722 | add_thread (inferior_ptid); | |
6c95b8df PA |
723 | child_lp = add_lwp (inferior_ptid); |
724 | child_lp->stopped = 1; | |
25289eb2 | 725 | child_lp->last_resume_kind = resume_stop; |
2277426b | 726 | |
6c95b8df PA |
727 | /* If this is a vfork child, then the address-space is |
728 | shared with the parent. */ | |
729 | if (has_vforked) | |
730 | { | |
731 | child_inf->pspace = parent_inf->pspace; | |
732 | child_inf->aspace = parent_inf->aspace; | |
733 | ||
734 | /* The parent will be frozen until the child is done | |
735 | with the shared region. Keep track of the | |
736 | parent. */ | |
737 | child_inf->vfork_parent = parent_inf; | |
738 | child_inf->pending_detach = 0; | |
739 | parent_inf->vfork_child = child_inf; | |
740 | parent_inf->pending_detach = 0; | |
741 | } | |
742 | else | |
743 | { | |
744 | child_inf->aspace = new_address_space (); | |
745 | child_inf->pspace = add_program_space (child_inf->aspace); | |
746 | child_inf->removable = 1; | |
747 | set_current_program_space (child_inf->pspace); | |
748 | clone_program_space (child_inf->pspace, parent_inf->pspace); | |
749 | ||
750 | /* Let the shared library layer (solib-svr4) learn about | |
751 | this new process, relocate the cloned exec, pull in | |
752 | shared libraries, and install the solib event | |
753 | breakpoint. If a "cloned-VM" event was propagated | |
754 | better throughout the core, this wouldn't be | |
755 | required. */ | |
268a4a75 | 756 | solib_create_inferior_hook (0); |
6c95b8df PA |
757 | } |
758 | ||
759 | /* Let the thread_db layer learn about this new process. */ | |
2277426b PA |
760 | check_for_thread_db (); |
761 | ||
762 | do_cleanups (old_chain); | |
ac264b3b | 763 | } |
9016a515 DJ |
764 | |
765 | if (has_vforked) | |
766 | { | |
3ced3da4 | 767 | struct lwp_info *parent_lp; |
6c95b8df PA |
768 | struct inferior *parent_inf; |
769 | ||
770 | parent_inf = current_inferior (); | |
771 | ||
772 | /* If we detached from the child, then we have to be careful | |
773 | to not insert breakpoints in the parent until the child | |
774 | is done with the shared memory region. However, if we're | |
775 | staying attached to the child, then we can and should | |
776 | insert breakpoints, so that we can debug it. A | |
777 | subsequent child exec or exit is enough to know when does | |
778 | the child stops using the parent's address space. */ | |
779 | parent_inf->waiting_for_vfork_done = detach_fork; | |
56710373 | 780 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
6c95b8df | 781 | |
3ced3da4 | 782 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
b957e937 | 783 | gdb_assert (linux_supports_tracefork_flag >= 0); |
3ced3da4 | 784 | |
b957e937 | 785 | if (linux_supports_tracevforkdone (0)) |
9016a515 | 786 | { |
6c95b8df PA |
787 | if (debug_linux_nat) |
788 | fprintf_unfiltered (gdb_stdlog, | |
789 | "LCFF: waiting for VFORK_DONE on %d\n", | |
790 | parent_pid); | |
3ced3da4 | 791 | parent_lp->stopped = 1; |
9016a515 | 792 | |
6c95b8df PA |
793 | /* We'll handle the VFORK_DONE event like any other |
794 | event, in target_wait. */ | |
9016a515 DJ |
795 | } |
796 | else | |
797 | { | |
798 | /* We can't insert breakpoints until the child has | |
799 | finished with the shared memory region. We need to | |
800 | wait until that happens. Ideal would be to just | |
801 | call: | |
802 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
803 | - waitpid (parent_pid, &status, __WALL); | |
804 | However, most architectures can't handle a syscall | |
805 | being traced on the way out if it wasn't traced on | |
806 | the way in. | |
807 | ||
808 | We might also think to loop, continuing the child | |
809 | until it exits or gets a SIGTRAP. One problem is | |
810 | that the child might call ptrace with PTRACE_TRACEME. | |
811 | ||
812 | There's no simple and reliable way to figure out when | |
813 | the vforked child will be done with its copy of the | |
814 | shared memory. We could step it out of the syscall, | |
815 | two instructions, let it go, and then single-step the | |
816 | parent once. When we have hardware single-step, this | |
817 | would work; with software single-step it could still | |
818 | be made to work but we'd have to be able to insert | |
819 | single-step breakpoints in the child, and we'd have | |
820 | to insert -just- the single-step breakpoint in the | |
821 | parent. Very awkward. | |
822 | ||
823 | In the end, the best we can do is to make sure it | |
824 | runs for a little while. Hopefully it will be out of | |
825 | range of any breakpoints we reinsert. Usually this | |
826 | is only the single-step breakpoint at vfork's return | |
827 | point. */ | |
828 | ||
6c95b8df PA |
829 | if (debug_linux_nat) |
830 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
831 | "LCFF: no VFORK_DONE " |
832 | "support, sleeping a bit\n"); | |
6c95b8df | 833 | |
9016a515 | 834 | usleep (10000); |
9016a515 | 835 | |
6c95b8df PA |
836 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
837 | and leave it pending. The next linux_nat_resume call | |
838 | will notice a pending event, and bypasses actually | |
839 | resuming the inferior. */ | |
3ced3da4 PA |
840 | parent_lp->status = 0; |
841 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
842 | parent_lp->stopped = 1; | |
6c95b8df PA |
843 | |
844 | /* If we're in async mode, need to tell the event loop | |
845 | there's something here to process. */ | |
846 | if (target_can_async_p ()) | |
847 | async_file_mark (); | |
848 | } | |
9016a515 | 849 | } |
4de4c07c | 850 | } |
3993f6b1 | 851 | else |
4de4c07c | 852 | { |
77435e4c | 853 | struct inferior *parent_inf, *child_inf; |
3ced3da4 | 854 | struct lwp_info *child_lp; |
6c95b8df | 855 | struct program_space *parent_pspace; |
4de4c07c | 856 | |
e85a822c | 857 | if (info_verbose || debug_linux_nat) |
f75c00e4 DJ |
858 | { |
859 | target_terminal_ours (); | |
6c95b8df | 860 | if (has_vforked) |
3e43a32a MS |
861 | fprintf_filtered (gdb_stdlog, |
862 | _("Attaching after process %d " | |
863 | "vfork to child process %d.\n"), | |
6c95b8df PA |
864 | parent_pid, child_pid); |
865 | else | |
3e43a32a MS |
866 | fprintf_filtered (gdb_stdlog, |
867 | _("Attaching after process %d " | |
868 | "fork to child process %d.\n"), | |
6c95b8df | 869 | parent_pid, child_pid); |
f75c00e4 | 870 | } |
4de4c07c | 871 | |
7a7d3353 PA |
872 | /* Add the new inferior first, so that the target_detach below |
873 | doesn't unpush the target. */ | |
874 | ||
77435e4c PA |
875 | child_inf = add_inferior (child_pid); |
876 | ||
e58b0e63 | 877 | parent_inf = current_inferior (); |
77435e4c | 878 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 879 | copy_terminal_info (child_inf, parent_inf); |
7a7d3353 | 880 | |
6c95b8df | 881 | parent_pspace = parent_inf->pspace; |
9016a515 | 882 | |
6c95b8df PA |
883 | /* If we're vforking, we want to hold on to the parent until the |
884 | child exits or execs. At child exec or exit time we can | |
885 | remove the old breakpoints from the parent and detach or | |
886 | resume debugging it. Otherwise, detach the parent now; we'll | |
887 | want to reuse it's program/address spaces, but we can't set | |
888 | them to the child before removing breakpoints from the | |
889 | parent, otherwise, the breakpoints module could decide to | |
890 | remove breakpoints from the wrong process (since they'd be | |
891 | assigned to the same address space). */ | |
9016a515 DJ |
892 | |
893 | if (has_vforked) | |
7f9f62ba | 894 | { |
6c95b8df PA |
895 | gdb_assert (child_inf->vfork_parent == NULL); |
896 | gdb_assert (parent_inf->vfork_child == NULL); | |
897 | child_inf->vfork_parent = parent_inf; | |
898 | child_inf->pending_detach = 0; | |
899 | parent_inf->vfork_child = child_inf; | |
900 | parent_inf->pending_detach = detach_fork; | |
901 | parent_inf->waiting_for_vfork_done = 0; | |
ac264b3b | 902 | } |
2277426b | 903 | else if (detach_fork) |
b84876c2 | 904 | target_detach (NULL, 0); |
4de4c07c | 905 | |
6c95b8df PA |
906 | /* Note that the detach above makes PARENT_INF dangling. */ |
907 | ||
908 | /* Add the child thread to the appropriate lists, and switch to | |
909 | this new thread, before cloning the program space, and | |
910 | informing the solib layer about this new process. */ | |
911 | ||
9f0bdab8 | 912 | inferior_ptid = ptid_build (child_pid, child_pid, 0); |
2277426b | 913 | add_thread (inferior_ptid); |
3ced3da4 PA |
914 | child_lp = add_lwp (inferior_ptid); |
915 | child_lp->stopped = 1; | |
25289eb2 | 916 | child_lp->last_resume_kind = resume_stop; |
6c95b8df PA |
917 | |
918 | /* If this is a vfork child, then the address-space is shared | |
919 | with the parent. If we detached from the parent, then we can | |
920 | reuse the parent's program/address spaces. */ | |
921 | if (has_vforked || detach_fork) | |
922 | { | |
923 | child_inf->pspace = parent_pspace; | |
924 | child_inf->aspace = child_inf->pspace->aspace; | |
925 | } | |
926 | else | |
927 | { | |
928 | child_inf->aspace = new_address_space (); | |
929 | child_inf->pspace = add_program_space (child_inf->aspace); | |
930 | child_inf->removable = 1; | |
931 | set_current_program_space (child_inf->pspace); | |
932 | clone_program_space (child_inf->pspace, parent_pspace); | |
933 | ||
934 | /* Let the shared library layer (solib-svr4) learn about | |
935 | this new process, relocate the cloned exec, pull in | |
936 | shared libraries, and install the solib event breakpoint. | |
937 | If a "cloned-VM" event was propagated better throughout | |
938 | the core, this wouldn't be required. */ | |
268a4a75 | 939 | solib_create_inferior_hook (0); |
6c95b8df | 940 | } |
ac264b3b | 941 | |
6c95b8df | 942 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 943 | check_for_thread_db (); |
4de4c07c DJ |
944 | } |
945 | ||
7feb7d06 | 946 | restore_child_signals_mask (&prev_mask); |
4de4c07c DJ |
947 | return 0; |
948 | } | |
949 | ||
4de4c07c | 950 | \f |
77b06cd7 | 951 | static int |
6d8fd2b7 | 952 | linux_child_insert_fork_catchpoint (int pid) |
4de4c07c | 953 | { |
77b06cd7 | 954 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
955 | } |
956 | ||
eb73ad13 PA |
957 | static int |
958 | linux_child_remove_fork_catchpoint (int pid) | |
959 | { | |
960 | return 0; | |
961 | } | |
962 | ||
77b06cd7 | 963 | static int |
6d8fd2b7 | 964 | linux_child_insert_vfork_catchpoint (int pid) |
3993f6b1 | 965 | { |
77b06cd7 | 966 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
967 | } |
968 | ||
eb73ad13 PA |
969 | static int |
970 | linux_child_remove_vfork_catchpoint (int pid) | |
971 | { | |
972 | return 0; | |
973 | } | |
974 | ||
77b06cd7 | 975 | static int |
6d8fd2b7 | 976 | linux_child_insert_exec_catchpoint (int pid) |
3993f6b1 | 977 | { |
77b06cd7 | 978 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
979 | } |
980 | ||
eb73ad13 PA |
981 | static int |
982 | linux_child_remove_exec_catchpoint (int pid) | |
983 | { | |
984 | return 0; | |
985 | } | |
986 | ||
a96d9b2e SDJ |
987 | static int |
988 | linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, | |
989 | int table_size, int *table) | |
990 | { | |
77b06cd7 TJB |
991 | if (!linux_supports_tracesysgood (pid)) |
992 | return 1; | |
993 | ||
a96d9b2e SDJ |
994 | /* On GNU/Linux, we ignore the arguments. It means that we only |
995 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 996 | |
a96d9b2e SDJ |
997 | Also, we do not use the `table' information because we do not |
998 | filter system calls here. We let GDB do the logic for us. */ | |
999 | return 0; | |
1000 | } | |
1001 | ||
d6b0e80f AC |
1002 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
1003 | are processes sharing the same VM space. A multi-threaded process | |
1004 | is basically a group of such processes. However, such a grouping | |
1005 | is almost entirely a user-space issue; the kernel doesn't enforce | |
1006 | such a grouping at all (this might change in the future). In | |
1007 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
1008 | Threads library) to provide such a grouping. | |
1009 | ||
1010 | It is perfectly well possible to write a multi-threaded application | |
1011 | without the assistance of a threads library, by using the clone | |
1012 | system call directly. This module should be able to give some | |
1013 | rudimentary support for debugging such applications if developers | |
1014 | specify the CLONE_PTRACE flag in the clone system call, and are | |
1015 | using the Linux kernel 2.4 or above. | |
1016 | ||
1017 | Note that there are some peculiarities in GNU/Linux that affect | |
1018 | this code: | |
1019 | ||
1020 | - In general one should specify the __WCLONE flag to waitpid in | |
1021 | order to make it report events for any of the cloned processes | |
1022 | (and leave it out for the initial process). However, if a cloned | |
1023 | process has exited the exit status is only reported if the | |
1024 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
1025 | we cannot use it since GDB must work on older systems too. | |
1026 | ||
1027 | - When a traced, cloned process exits and is waited for by the | |
1028 | debugger, the kernel reassigns it to the original parent and | |
1029 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
1030 | library doesn't notice this, which leads to the "zombie problem": | |
1031 | When debugged a multi-threaded process that spawns a lot of | |
1032 | threads will run out of processes, even if the threads exit, | |
1033 | because the "zombies" stay around. */ | |
1034 | ||
1035 | /* List of known LWPs. */ | |
9f0bdab8 | 1036 | struct lwp_info *lwp_list; |
d6b0e80f AC |
1037 | \f |
1038 | ||
d6b0e80f AC |
1039 | /* Original signal mask. */ |
1040 | static sigset_t normal_mask; | |
1041 | ||
1042 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
1043 | _initialize_linux_nat. */ | |
1044 | static sigset_t suspend_mask; | |
1045 | ||
7feb7d06 PA |
1046 | /* Signals to block to make that sigsuspend work. */ |
1047 | static sigset_t blocked_mask; | |
1048 | ||
1049 | /* SIGCHLD action. */ | |
1050 | struct sigaction sigchld_action; | |
b84876c2 | 1051 | |
7feb7d06 PA |
1052 | /* Block child signals (SIGCHLD and linux threads signals), and store |
1053 | the previous mask in PREV_MASK. */ | |
84e46146 | 1054 | |
7feb7d06 PA |
1055 | static void |
1056 | block_child_signals (sigset_t *prev_mask) | |
1057 | { | |
1058 | /* Make sure SIGCHLD is blocked. */ | |
1059 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
1060 | sigaddset (&blocked_mask, SIGCHLD); | |
1061 | ||
1062 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
1063 | } | |
1064 | ||
1065 | /* Restore child signals mask, previously returned by | |
1066 | block_child_signals. */ | |
1067 | ||
1068 | static void | |
1069 | restore_child_signals_mask (sigset_t *prev_mask) | |
1070 | { | |
1071 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
1072 | } | |
2455069d UW |
1073 | |
1074 | /* Mask of signals to pass directly to the inferior. */ | |
1075 | static sigset_t pass_mask; | |
1076 | ||
1077 | /* Update signals to pass to the inferior. */ | |
1078 | static void | |
1079 | linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) | |
1080 | { | |
1081 | int signo; | |
1082 | ||
1083 | sigemptyset (&pass_mask); | |
1084 | ||
1085 | for (signo = 1; signo < NSIG; signo++) | |
1086 | { | |
1087 | int target_signo = target_signal_from_host (signo); | |
1088 | if (target_signo < numsigs && pass_signals[target_signo]) | |
1089 | sigaddset (&pass_mask, signo); | |
1090 | } | |
1091 | } | |
1092 | ||
d6b0e80f AC |
1093 | \f |
1094 | ||
1095 | /* Prototypes for local functions. */ | |
1096 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 1097 | static int linux_thread_alive (ptid_t ptid); |
6d8fd2b7 | 1098 | static char *linux_child_pid_to_exec_file (int pid); |
710151dd | 1099 | |
d6b0e80f AC |
1100 | \f |
1101 | /* Convert wait status STATUS to a string. Used for printing debug | |
1102 | messages only. */ | |
1103 | ||
1104 | static char * | |
1105 | status_to_str (int status) | |
1106 | { | |
1107 | static char buf[64]; | |
1108 | ||
1109 | if (WIFSTOPPED (status)) | |
206aa767 | 1110 | { |
ca2163eb | 1111 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
206aa767 DE |
1112 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
1113 | strsignal (SIGTRAP)); | |
1114 | else | |
1115 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
1116 | strsignal (WSTOPSIG (status))); | |
1117 | } | |
d6b0e80f AC |
1118 | else if (WIFSIGNALED (status)) |
1119 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
ba9b2ec3 | 1120 | strsignal (WTERMSIG (status))); |
d6b0e80f AC |
1121 | else |
1122 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
1123 | ||
1124 | return buf; | |
1125 | } | |
1126 | ||
7b50312a PA |
1127 | /* Destroy and free LP. */ |
1128 | ||
1129 | static void | |
1130 | lwp_free (struct lwp_info *lp) | |
1131 | { | |
1132 | xfree (lp->arch_private); | |
1133 | xfree (lp); | |
1134 | } | |
1135 | ||
d90e17a7 PA |
1136 | /* Remove all LWPs belong to PID from the lwp list. */ |
1137 | ||
1138 | static void | |
1139 | purge_lwp_list (int pid) | |
1140 | { | |
1141 | struct lwp_info *lp, *lpprev, *lpnext; | |
1142 | ||
1143 | lpprev = NULL; | |
1144 | ||
1145 | for (lp = lwp_list; lp; lp = lpnext) | |
1146 | { | |
1147 | lpnext = lp->next; | |
1148 | ||
1149 | if (ptid_get_pid (lp->ptid) == pid) | |
1150 | { | |
1151 | if (lp == lwp_list) | |
1152 | lwp_list = lp->next; | |
1153 | else | |
1154 | lpprev->next = lp->next; | |
1155 | ||
7b50312a | 1156 | lwp_free (lp); |
d90e17a7 PA |
1157 | } |
1158 | else | |
1159 | lpprev = lp; | |
1160 | } | |
1161 | } | |
1162 | ||
f973ed9c | 1163 | /* Add the LWP specified by PID to the list. Return a pointer to the |
9f0bdab8 DJ |
1164 | structure describing the new LWP. The LWP should already be stopped |
1165 | (with an exception for the very first LWP). */ | |
d6b0e80f AC |
1166 | |
1167 | static struct lwp_info * | |
1168 | add_lwp (ptid_t ptid) | |
1169 | { | |
1170 | struct lwp_info *lp; | |
1171 | ||
1172 | gdb_assert (is_lwp (ptid)); | |
1173 | ||
1174 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
1175 | ||
1176 | memset (lp, 0, sizeof (struct lwp_info)); | |
1177 | ||
25289eb2 | 1178 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1179 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
1180 | ||
1181 | lp->ptid = ptid; | |
dc146f7c | 1182 | lp->core = -1; |
d6b0e80f AC |
1183 | |
1184 | lp->next = lwp_list; | |
1185 | lwp_list = lp; | |
d6b0e80f | 1186 | |
6e012a6c PA |
1187 | /* Let the arch specific bits know about this new thread. Current |
1188 | clients of this callback take the opportunity to install | |
1189 | watchpoints in the new thread. Don't do this for the first | |
1190 | thread though. If we're spawning a child ("run"), the thread | |
1191 | executes the shell wrapper first, and we shouldn't touch it until | |
1192 | it execs the program we want to debug. For "attach", it'd be | |
1193 | okay to call the callback, but it's not necessary, because | |
1194 | watchpoints can't yet have been inserted into the inferior. */ | |
1195 | if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL) | |
7b50312a | 1196 | linux_nat_new_thread (lp); |
9f0bdab8 | 1197 | |
d6b0e80f AC |
1198 | return lp; |
1199 | } | |
1200 | ||
1201 | /* Remove the LWP specified by PID from the list. */ | |
1202 | ||
1203 | static void | |
1204 | delete_lwp (ptid_t ptid) | |
1205 | { | |
1206 | struct lwp_info *lp, *lpprev; | |
1207 | ||
1208 | lpprev = NULL; | |
1209 | ||
1210 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
1211 | if (ptid_equal (lp->ptid, ptid)) | |
1212 | break; | |
1213 | ||
1214 | if (!lp) | |
1215 | return; | |
1216 | ||
d6b0e80f AC |
1217 | if (lpprev) |
1218 | lpprev->next = lp->next; | |
1219 | else | |
1220 | lwp_list = lp->next; | |
1221 | ||
7b50312a | 1222 | lwp_free (lp); |
d6b0e80f AC |
1223 | } |
1224 | ||
1225 | /* Return a pointer to the structure describing the LWP corresponding | |
1226 | to PID. If no corresponding LWP could be found, return NULL. */ | |
1227 | ||
1228 | static struct lwp_info * | |
1229 | find_lwp_pid (ptid_t ptid) | |
1230 | { | |
1231 | struct lwp_info *lp; | |
1232 | int lwp; | |
1233 | ||
1234 | if (is_lwp (ptid)) | |
1235 | lwp = GET_LWP (ptid); | |
1236 | else | |
1237 | lwp = GET_PID (ptid); | |
1238 | ||
1239 | for (lp = lwp_list; lp; lp = lp->next) | |
1240 | if (lwp == GET_LWP (lp->ptid)) | |
1241 | return lp; | |
1242 | ||
1243 | return NULL; | |
1244 | } | |
1245 | ||
1246 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
1247 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
1248 | pointer to the structure describing that LWP immediately. | |
1249 | Otherwise return NULL. */ | |
1250 | ||
1251 | struct lwp_info * | |
d90e17a7 PA |
1252 | iterate_over_lwps (ptid_t filter, |
1253 | int (*callback) (struct lwp_info *, void *), | |
1254 | void *data) | |
d6b0e80f AC |
1255 | { |
1256 | struct lwp_info *lp, *lpnext; | |
1257 | ||
1258 | for (lp = lwp_list; lp; lp = lpnext) | |
1259 | { | |
1260 | lpnext = lp->next; | |
d90e17a7 PA |
1261 | |
1262 | if (ptid_match (lp->ptid, filter)) | |
1263 | { | |
1264 | if ((*callback) (lp, data)) | |
1265 | return lp; | |
1266 | } | |
d6b0e80f AC |
1267 | } |
1268 | ||
1269 | return NULL; | |
1270 | } | |
1271 | ||
4403d8e9 JK |
1272 | /* Iterate like iterate_over_lwps does except when forking-off a child call |
1273 | CALLBACK with CALLBACK_DATA specifically only for that new child PID. */ | |
1274 | ||
1275 | void | |
1276 | linux_nat_iterate_watchpoint_lwps | |
1277 | (linux_nat_iterate_watchpoint_lwps_ftype callback, void *callback_data) | |
1278 | { | |
1279 | int inferior_pid = ptid_get_pid (inferior_ptid); | |
1280 | struct inferior *inf = current_inferior (); | |
1281 | ||
1282 | if (inf->pid == inferior_pid) | |
1283 | { | |
1284 | /* Iterate all the threads of the current inferior. Without specifying | |
1285 | INFERIOR_PID it would iterate all threads of all inferiors, which is | |
1286 | inappropriate for watchpoints. */ | |
1287 | ||
1288 | iterate_over_lwps (pid_to_ptid (inferior_pid), callback, callback_data); | |
1289 | } | |
1290 | else | |
1291 | { | |
1292 | /* Detaching a new child PID temporarily present in INFERIOR_PID. */ | |
1293 | ||
1294 | struct lwp_info *child_lp; | |
1295 | struct cleanup *old_chain; | |
1296 | pid_t child_pid = GET_PID (inferior_ptid); | |
1297 | ptid_t child_ptid = ptid_build (child_pid, child_pid, 0); | |
1298 | ||
1299 | gdb_assert (!is_lwp (inferior_ptid)); | |
1300 | gdb_assert (find_lwp_pid (child_ptid) == NULL); | |
1301 | child_lp = add_lwp (child_ptid); | |
1302 | child_lp->stopped = 1; | |
1303 | child_lp->last_resume_kind = resume_stop; | |
1304 | old_chain = make_cleanup (delete_lwp_cleanup, child_lp); | |
1305 | ||
1306 | callback (child_lp, callback_data); | |
1307 | ||
1308 | do_cleanups (old_chain); | |
1309 | } | |
1310 | } | |
1311 | ||
2277426b PA |
1312 | /* Update our internal state when changing from one checkpoint to |
1313 | another indicated by NEW_PTID. We can only switch single-threaded | |
1314 | applications, so we only create one new LWP, and the previous list | |
1315 | is discarded. */ | |
f973ed9c DJ |
1316 | |
1317 | void | |
1318 | linux_nat_switch_fork (ptid_t new_ptid) | |
1319 | { | |
1320 | struct lwp_info *lp; | |
1321 | ||
2277426b PA |
1322 | purge_lwp_list (GET_PID (inferior_ptid)); |
1323 | ||
f973ed9c DJ |
1324 | lp = add_lwp (new_ptid); |
1325 | lp->stopped = 1; | |
e26af52f | 1326 | |
2277426b PA |
1327 | /* This changes the thread's ptid while preserving the gdb thread |
1328 | num. Also changes the inferior pid, while preserving the | |
1329 | inferior num. */ | |
1330 | thread_change_ptid (inferior_ptid, new_ptid); | |
1331 | ||
1332 | /* We've just told GDB core that the thread changed target id, but, | |
1333 | in fact, it really is a different thread, with different register | |
1334 | contents. */ | |
1335 | registers_changed (); | |
e26af52f DJ |
1336 | } |
1337 | ||
e26af52f DJ |
1338 | /* Handle the exit of a single thread LP. */ |
1339 | ||
1340 | static void | |
1341 | exit_lwp (struct lwp_info *lp) | |
1342 | { | |
e09875d4 | 1343 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1344 | |
1345 | if (th) | |
e26af52f | 1346 | { |
17faa917 DJ |
1347 | if (print_thread_events) |
1348 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1349 | ||
4f8d22e3 | 1350 | delete_thread (lp->ptid); |
e26af52f DJ |
1351 | } |
1352 | ||
1353 | delete_lwp (lp->ptid); | |
1354 | } | |
1355 | ||
a0ef4274 DJ |
1356 | /* Detect `T (stopped)' in `/proc/PID/status'. |
1357 | Other states including `T (tracing stop)' are reported as false. */ | |
1358 | ||
1359 | static int | |
1360 | pid_is_stopped (pid_t pid) | |
1361 | { | |
1362 | FILE *status_file; | |
1363 | char buf[100]; | |
1364 | int retval = 0; | |
1365 | ||
1366 | snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid); | |
1367 | status_file = fopen (buf, "r"); | |
1368 | if (status_file != NULL) | |
1369 | { | |
1370 | int have_state = 0; | |
1371 | ||
1372 | while (fgets (buf, sizeof (buf), status_file)) | |
1373 | { | |
1374 | if (strncmp (buf, "State:", 6) == 0) | |
1375 | { | |
1376 | have_state = 1; | |
1377 | break; | |
1378 | } | |
1379 | } | |
1380 | if (have_state && strstr (buf, "T (stopped)") != NULL) | |
1381 | retval = 1; | |
1382 | fclose (status_file); | |
1383 | } | |
1384 | return retval; | |
1385 | } | |
1386 | ||
1387 | /* Wait for the LWP specified by LP, which we have just attached to. | |
1388 | Returns a wait status for that LWP, to cache. */ | |
1389 | ||
1390 | static int | |
1391 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
1392 | int *signalled) | |
1393 | { | |
1394 | pid_t new_pid, pid = GET_LWP (ptid); | |
1395 | int status; | |
1396 | ||
1397 | if (pid_is_stopped (pid)) | |
1398 | { | |
1399 | if (debug_linux_nat) | |
1400 | fprintf_unfiltered (gdb_stdlog, | |
1401 | "LNPAW: Attaching to a stopped process\n"); | |
1402 | ||
1403 | /* The process is definitely stopped. It is in a job control | |
1404 | stop, unless the kernel predates the TASK_STOPPED / | |
1405 | TASK_TRACED distinction, in which case it might be in a | |
1406 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1407 | can kill it, signal it, et cetera. | |
1408 | ||
1409 | First make sure there is a pending SIGSTOP. Since we are | |
1410 | already attached, the process can not transition from stopped | |
1411 | to running without a PTRACE_CONT; so we know this signal will | |
1412 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1413 | probably already in the queue (unless this kernel is old | |
1414 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1415 | is not an RT signal, it can only be queued once. */ | |
1416 | kill_lwp (pid, SIGSTOP); | |
1417 | ||
1418 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1419 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1420 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1421 | } | |
1422 | ||
1423 | /* Make sure the initial process is stopped. The user-level threads | |
1424 | layer might want to poke around in the inferior, and that won't | |
1425 | work if things haven't stabilized yet. */ | |
1426 | new_pid = my_waitpid (pid, &status, 0); | |
1427 | if (new_pid == -1 && errno == ECHILD) | |
1428 | { | |
1429 | if (first) | |
1430 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
1431 | ||
1432 | /* Try again with __WCLONE to check cloned processes. */ | |
1433 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
1434 | *cloned = 1; | |
1435 | } | |
1436 | ||
dacc9cb2 PP |
1437 | gdb_assert (pid == new_pid); |
1438 | ||
1439 | if (!WIFSTOPPED (status)) | |
1440 | { | |
1441 | /* The pid we tried to attach has apparently just exited. */ | |
1442 | if (debug_linux_nat) | |
1443 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1444 | pid, status_to_str (status)); | |
1445 | return status; | |
1446 | } | |
a0ef4274 DJ |
1447 | |
1448 | if (WSTOPSIG (status) != SIGSTOP) | |
1449 | { | |
1450 | *signalled = 1; | |
1451 | if (debug_linux_nat) | |
1452 | fprintf_unfiltered (gdb_stdlog, | |
1453 | "LNPAW: Received %s after attaching\n", | |
1454 | status_to_str (status)); | |
1455 | } | |
1456 | ||
1457 | return status; | |
1458 | } | |
1459 | ||
84636d28 PA |
1460 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1461 | the new LWP could not be attached, or 1 if we're already auto | |
1462 | attached to this thread, but haven't processed the | |
1463 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1464 | its existance, without considering it an error. */ | |
d6b0e80f | 1465 | |
9ee57c33 | 1466 | int |
93815fbf | 1467 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1468 | { |
9ee57c33 | 1469 | struct lwp_info *lp; |
7feb7d06 | 1470 | sigset_t prev_mask; |
84636d28 | 1471 | int lwpid; |
d6b0e80f AC |
1472 | |
1473 | gdb_assert (is_lwp (ptid)); | |
1474 | ||
7feb7d06 | 1475 | block_child_signals (&prev_mask); |
d6b0e80f | 1476 | |
9ee57c33 | 1477 | lp = find_lwp_pid (ptid); |
84636d28 | 1478 | lwpid = GET_LWP (ptid); |
d6b0e80f AC |
1479 | |
1480 | /* We assume that we're already attached to any LWP that has an id | |
1481 | equal to the overall process id, and to any LWP that is already | |
1482 | in our list of LWPs. If we're not seeing exit events from threads | |
1483 | and we've had PID wraparound since we last tried to stop all threads, | |
1484 | this assumption might be wrong; fortunately, this is very unlikely | |
1485 | to happen. */ | |
84636d28 | 1486 | if (lwpid != GET_PID (ptid) && lp == NULL) |
d6b0e80f | 1487 | { |
a0ef4274 | 1488 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1489 | |
84636d28 | 1490 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1491 | { |
84636d28 PA |
1492 | if (linux_supports_tracefork_flag) |
1493 | { | |
1494 | /* If we haven't stopped all threads when we get here, | |
1495 | we may have seen a thread listed in thread_db's list, | |
1496 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1497 | that's the case, ignore this new thread, and let | |
1498 | normal event handling discover it later. */ | |
1499 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1500 | { | |
1501 | /* We've already seen this thread stop, but we | |
1502 | haven't seen the PTRACE_EVENT_CLONE extended | |
1503 | event yet. */ | |
1504 | restore_child_signals_mask (&prev_mask); | |
1505 | return 0; | |
1506 | } | |
1507 | else | |
1508 | { | |
1509 | int new_pid; | |
1510 | int status; | |
1511 | ||
1512 | /* See if we've got a stop for this new child | |
1513 | pending. If so, we're already attached. */ | |
1514 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1515 | if (new_pid == -1 && errno == ECHILD) | |
1516 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1517 | if (new_pid != -1) | |
1518 | { | |
1519 | if (WIFSTOPPED (status)) | |
1520 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1521 | ||
1522 | restore_child_signals_mask (&prev_mask); | |
1523 | return 1; | |
1524 | } | |
1525 | } | |
1526 | } | |
1527 | ||
9ee57c33 DJ |
1528 | /* If we fail to attach to the thread, issue a warning, |
1529 | but continue. One way this can happen is if thread | |
e9efe249 | 1530 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1531 | bug may place threads in the thread list and then fail |
1532 | to create them. */ | |
1533 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1534 | safe_strerror (errno)); | |
7feb7d06 | 1535 | restore_child_signals_mask (&prev_mask); |
9ee57c33 DJ |
1536 | return -1; |
1537 | } | |
1538 | ||
d6b0e80f AC |
1539 | if (debug_linux_nat) |
1540 | fprintf_unfiltered (gdb_stdlog, | |
1541 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1542 | target_pid_to_str (ptid)); | |
1543 | ||
a0ef4274 | 1544 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1545 | if (!WIFSTOPPED (status)) |
673c2bbe DE |
1546 | { |
1547 | restore_child_signals_mask (&prev_mask); | |
f687d035 | 1548 | return 1; |
673c2bbe | 1549 | } |
dacc9cb2 | 1550 | |
a0ef4274 DJ |
1551 | lp = add_lwp (ptid); |
1552 | lp->stopped = 1; | |
1553 | lp->cloned = cloned; | |
1554 | lp->signalled = signalled; | |
1555 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1556 | { |
a0ef4274 DJ |
1557 | lp->resumed = 1; |
1558 | lp->status = status; | |
d6b0e80f AC |
1559 | } |
1560 | ||
a0ef4274 | 1561 | target_post_attach (GET_LWP (lp->ptid)); |
d6b0e80f AC |
1562 | |
1563 | if (debug_linux_nat) | |
1564 | { | |
1565 | fprintf_unfiltered (gdb_stdlog, | |
1566 | "LLAL: waitpid %s received %s\n", | |
1567 | target_pid_to_str (ptid), | |
1568 | status_to_str (status)); | |
1569 | } | |
1570 | } | |
1571 | else | |
1572 | { | |
1573 | /* We assume that the LWP representing the original process is | |
1574 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1575 | that the GNU/linux ptrace layer uses to keep track of |
1576 | threads. Note that this won't have already been done since | |
1577 | the main thread will have, we assume, been stopped by an | |
1578 | attach from a different layer. */ | |
9ee57c33 DJ |
1579 | if (lp == NULL) |
1580 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1581 | lp->stopped = 1; |
1582 | } | |
9ee57c33 | 1583 | |
25289eb2 | 1584 | lp->last_resume_kind = resume_stop; |
7feb7d06 | 1585 | restore_child_signals_mask (&prev_mask); |
9ee57c33 | 1586 | return 0; |
d6b0e80f AC |
1587 | } |
1588 | ||
b84876c2 | 1589 | static void |
136d6dae VP |
1590 | linux_nat_create_inferior (struct target_ops *ops, |
1591 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1592 | int from_tty) |
1593 | { | |
10568435 JK |
1594 | #ifdef HAVE_PERSONALITY |
1595 | int personality_orig = 0, personality_set = 0; | |
1596 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1597 | |
1598 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1599 | we have to mask the async mode. */ | |
1600 | ||
10568435 JK |
1601 | #ifdef HAVE_PERSONALITY |
1602 | if (disable_randomization) | |
1603 | { | |
1604 | errno = 0; | |
1605 | personality_orig = personality (0xffffffff); | |
1606 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1607 | { | |
1608 | personality_set = 1; | |
1609 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1610 | } | |
1611 | if (errno != 0 || (personality_set | |
1612 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1613 | warning (_("Error disabling address space randomization: %s"), | |
1614 | safe_strerror (errno)); | |
1615 | } | |
1616 | #endif /* HAVE_PERSONALITY */ | |
1617 | ||
2455069d UW |
1618 | /* Make sure we report all signals during startup. */ |
1619 | linux_nat_pass_signals (0, NULL); | |
1620 | ||
136d6dae | 1621 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1622 | |
10568435 JK |
1623 | #ifdef HAVE_PERSONALITY |
1624 | if (personality_set) | |
1625 | { | |
1626 | errno = 0; | |
1627 | personality (personality_orig); | |
1628 | if (errno != 0) | |
1629 | warning (_("Error restoring address space randomization: %s"), | |
1630 | safe_strerror (errno)); | |
1631 | } | |
1632 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1633 | } |
1634 | ||
d6b0e80f | 1635 | static void |
136d6dae | 1636 | linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f AC |
1637 | { |
1638 | struct lwp_info *lp; | |
d6b0e80f | 1639 | int status; |
af990527 | 1640 | ptid_t ptid; |
d6b0e80f | 1641 | |
2455069d UW |
1642 | /* Make sure we report all signals during attach. */ |
1643 | linux_nat_pass_signals (0, NULL); | |
1644 | ||
136d6dae | 1645 | linux_ops->to_attach (ops, args, from_tty); |
d6b0e80f | 1646 | |
af990527 PA |
1647 | /* The ptrace base target adds the main thread with (pid,0,0) |
1648 | format. Decorate it with lwp info. */ | |
1649 | ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); | |
1650 | thread_change_ptid (inferior_ptid, ptid); | |
1651 | ||
9f0bdab8 | 1652 | /* Add the initial process as the first LWP to the list. */ |
af990527 | 1653 | lp = add_lwp (ptid); |
a0ef4274 DJ |
1654 | |
1655 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1656 | &lp->signalled); | |
dacc9cb2 PP |
1657 | if (!WIFSTOPPED (status)) |
1658 | { | |
1659 | if (WIFEXITED (status)) | |
1660 | { | |
1661 | int exit_code = WEXITSTATUS (status); | |
1662 | ||
1663 | target_terminal_ours (); | |
1664 | target_mourn_inferior (); | |
1665 | if (exit_code == 0) | |
1666 | error (_("Unable to attach: program exited normally.")); | |
1667 | else | |
1668 | error (_("Unable to attach: program exited with code %d."), | |
1669 | exit_code); | |
1670 | } | |
1671 | else if (WIFSIGNALED (status)) | |
1672 | { | |
1673 | enum target_signal signo; | |
1674 | ||
1675 | target_terminal_ours (); | |
1676 | target_mourn_inferior (); | |
1677 | ||
1678 | signo = target_signal_from_host (WTERMSIG (status)); | |
1679 | error (_("Unable to attach: program terminated with signal " | |
1680 | "%s, %s."), | |
1681 | target_signal_to_name (signo), | |
1682 | target_signal_to_string (signo)); | |
1683 | } | |
1684 | ||
1685 | internal_error (__FILE__, __LINE__, | |
1686 | _("unexpected status %d for PID %ld"), | |
1687 | status, (long) GET_LWP (ptid)); | |
1688 | } | |
1689 | ||
a0ef4274 | 1690 | lp->stopped = 1; |
9f0bdab8 | 1691 | |
a0ef4274 | 1692 | /* Save the wait status to report later. */ |
d6b0e80f | 1693 | lp->resumed = 1; |
a0ef4274 DJ |
1694 | if (debug_linux_nat) |
1695 | fprintf_unfiltered (gdb_stdlog, | |
1696 | "LNA: waitpid %ld, saving status %s\n", | |
1697 | (long) GET_PID (lp->ptid), status_to_str (status)); | |
710151dd | 1698 | |
7feb7d06 PA |
1699 | lp->status = status; |
1700 | ||
1701 | if (target_can_async_p ()) | |
1702 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1703 | } |
1704 | ||
a0ef4274 DJ |
1705 | /* Get pending status of LP. */ |
1706 | static int | |
1707 | get_pending_status (struct lwp_info *lp, int *status) | |
1708 | { | |
ca2163eb PA |
1709 | enum target_signal signo = TARGET_SIGNAL_0; |
1710 | ||
1711 | /* If we paused threads momentarily, we may have stored pending | |
1712 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1713 | and GDB core hasn't seen any signal for those threads. | |
1714 | Otherwise, the last signal reported to the core is found in the | |
1715 | thread object's stop_signal. | |
1716 | ||
1717 | There's a corner case that isn't handled here at present. Only | |
1718 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1719 | stop_signal make sense as a real signal to pass to the inferior. | |
1720 | Some catchpoint related events, like | |
1721 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
1722 | to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But, | |
1723 | those traps are debug API (ptrace in our case) related and | |
1724 | induced; the inferior wouldn't see them if it wasn't being | |
1725 | traced. Hence, we should never pass them to the inferior, even | |
1726 | when set to pass state. Since this corner case isn't handled by | |
1727 | infrun.c when proceeding with a signal, for consistency, neither | |
1728 | do we handle it here (or elsewhere in the file we check for | |
1729 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1730 | this is really a corner case. */ | |
1731 | ||
1732 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
1733 | signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */ | |
1734 | else if (lp->status) | |
1735 | signo = target_signal_from_host (WSTOPSIG (lp->status)); | |
1736 | else if (non_stop && !is_executing (lp->ptid)) | |
1737 | { | |
1738 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1739 | |
16c381f0 | 1740 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1741 | } |
1742 | else if (!non_stop) | |
a0ef4274 | 1743 | { |
ca2163eb PA |
1744 | struct target_waitstatus last; |
1745 | ptid_t last_ptid; | |
4c28f408 | 1746 | |
ca2163eb | 1747 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1748 | |
ca2163eb PA |
1749 | if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
1750 | { | |
e09875d4 | 1751 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1752 | |
16c381f0 | 1753 | signo = tp->suspend.stop_signal; |
4c28f408 | 1754 | } |
ca2163eb | 1755 | } |
4c28f408 | 1756 | |
ca2163eb | 1757 | *status = 0; |
4c28f408 | 1758 | |
ca2163eb PA |
1759 | if (signo == TARGET_SIGNAL_0) |
1760 | { | |
1761 | if (debug_linux_nat) | |
1762 | fprintf_unfiltered (gdb_stdlog, | |
1763 | "GPT: lwp %s has no pending signal\n", | |
1764 | target_pid_to_str (lp->ptid)); | |
1765 | } | |
1766 | else if (!signal_pass_state (signo)) | |
1767 | { | |
1768 | if (debug_linux_nat) | |
3e43a32a MS |
1769 | fprintf_unfiltered (gdb_stdlog, |
1770 | "GPT: lwp %s had signal %s, " | |
1771 | "but it is in no pass state\n", | |
ca2163eb PA |
1772 | target_pid_to_str (lp->ptid), |
1773 | target_signal_to_string (signo)); | |
a0ef4274 | 1774 | } |
a0ef4274 | 1775 | else |
4c28f408 | 1776 | { |
ca2163eb PA |
1777 | *status = W_STOPCODE (target_signal_to_host (signo)); |
1778 | ||
1779 | if (debug_linux_nat) | |
1780 | fprintf_unfiltered (gdb_stdlog, | |
1781 | "GPT: lwp %s has pending signal %s\n", | |
1782 | target_pid_to_str (lp->ptid), | |
1783 | target_signal_to_string (signo)); | |
4c28f408 | 1784 | } |
a0ef4274 DJ |
1785 | |
1786 | return 0; | |
1787 | } | |
1788 | ||
d6b0e80f AC |
1789 | static int |
1790 | detach_callback (struct lwp_info *lp, void *data) | |
1791 | { | |
1792 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1793 | ||
1794 | if (debug_linux_nat && lp->status) | |
1795 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1796 | strsignal (WSTOPSIG (lp->status)), | |
1797 | target_pid_to_str (lp->ptid)); | |
1798 | ||
a0ef4274 DJ |
1799 | /* If there is a pending SIGSTOP, get rid of it. */ |
1800 | if (lp->signalled) | |
d6b0e80f | 1801 | { |
d6b0e80f AC |
1802 | if (debug_linux_nat) |
1803 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1804 | "DC: Sending SIGCONT to %s\n", |
1805 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1806 | |
a0ef4274 | 1807 | kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
d6b0e80f | 1808 | lp->signalled = 0; |
d6b0e80f AC |
1809 | } |
1810 | ||
1811 | /* We don't actually detach from the LWP that has an id equal to the | |
1812 | overall process id just yet. */ | |
1813 | if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) | |
1814 | { | |
a0ef4274 DJ |
1815 | int status = 0; |
1816 | ||
1817 | /* Pass on any pending signal for this LWP. */ | |
1818 | get_pending_status (lp, &status); | |
1819 | ||
7b50312a PA |
1820 | if (linux_nat_prepare_to_resume != NULL) |
1821 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f AC |
1822 | errno = 0; |
1823 | if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, | |
a0ef4274 | 1824 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1825 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1826 | safe_strerror (errno)); |
1827 | ||
1828 | if (debug_linux_nat) | |
1829 | fprintf_unfiltered (gdb_stdlog, | |
1830 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1831 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1832 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1833 | |
1834 | delete_lwp (lp->ptid); | |
1835 | } | |
1836 | ||
1837 | return 0; | |
1838 | } | |
1839 | ||
1840 | static void | |
136d6dae | 1841 | linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f | 1842 | { |
b84876c2 | 1843 | int pid; |
a0ef4274 | 1844 | int status; |
d90e17a7 PA |
1845 | struct lwp_info *main_lwp; |
1846 | ||
1847 | pid = GET_PID (inferior_ptid); | |
a0ef4274 | 1848 | |
b84876c2 PA |
1849 | if (target_can_async_p ()) |
1850 | linux_nat_async (NULL, 0); | |
1851 | ||
4c28f408 PA |
1852 | /* Stop all threads before detaching. ptrace requires that the |
1853 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1854 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1855 | /* ... and wait until all of them have reported back that |
1856 | they're no longer running. */ | |
d90e17a7 | 1857 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1858 | |
d90e17a7 | 1859 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1860 | |
1861 | /* Only the initial process should be left right now. */ | |
d90e17a7 PA |
1862 | gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
1863 | ||
1864 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1865 | |
a0ef4274 DJ |
1866 | /* Pass on any pending signal for the last LWP. */ |
1867 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1868 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1869 | && WIFSTOPPED (status)) |
1870 | { | |
1871 | /* Put the signal number in ARGS so that inf_ptrace_detach will | |
1872 | pass it along with PTRACE_DETACH. */ | |
1873 | args = alloca (8); | |
1874 | sprintf (args, "%d", (int) WSTOPSIG (status)); | |
ddabfc73 TT |
1875 | if (debug_linux_nat) |
1876 | fprintf_unfiltered (gdb_stdlog, | |
1877 | "LND: Sending signal %s to %s\n", | |
1878 | args, | |
1879 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1880 | } |
1881 | ||
7b50312a PA |
1882 | if (linux_nat_prepare_to_resume != NULL) |
1883 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1884 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1885 | |
7a7d3353 PA |
1886 | if (forks_exist_p ()) |
1887 | { | |
1888 | /* Multi-fork case. The current inferior_ptid is being detached | |
1889 | from, but there are other viable forks to debug. Detach from | |
1890 | the current fork, and context-switch to the first | |
1891 | available. */ | |
1892 | linux_fork_detach (args, from_tty); | |
1893 | ||
1894 | if (non_stop && target_can_async_p ()) | |
1895 | target_async (inferior_event_handler, 0); | |
1896 | } | |
1897 | else | |
1898 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1899 | } |
1900 | ||
1901 | /* Resume LP. */ | |
1902 | ||
25289eb2 PA |
1903 | static void |
1904 | resume_lwp (struct lwp_info *lp, int step) | |
d6b0e80f | 1905 | { |
25289eb2 | 1906 | if (lp->stopped) |
6c95b8df | 1907 | { |
25289eb2 PA |
1908 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
1909 | ||
1910 | if (inf->vfork_child != NULL) | |
1911 | { | |
1912 | if (debug_linux_nat) | |
1913 | fprintf_unfiltered (gdb_stdlog, | |
1914 | "RC: Not resuming %s (vfork parent)\n", | |
1915 | target_pid_to_str (lp->ptid)); | |
1916 | } | |
1917 | else if (lp->status == 0 | |
1918 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1919 | { | |
1920 | if (debug_linux_nat) | |
1921 | fprintf_unfiltered (gdb_stdlog, | |
1922 | "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n", | |
1923 | target_pid_to_str (lp->ptid)); | |
1924 | ||
7b50312a PA |
1925 | if (linux_nat_prepare_to_resume != NULL) |
1926 | linux_nat_prepare_to_resume (lp); | |
25289eb2 PA |
1927 | linux_ops->to_resume (linux_ops, |
1928 | pid_to_ptid (GET_LWP (lp->ptid)), | |
1929 | step, TARGET_SIGNAL_0); | |
25289eb2 PA |
1930 | lp->stopped = 0; |
1931 | lp->step = step; | |
1932 | memset (&lp->siginfo, 0, sizeof (lp->siginfo)); | |
1933 | lp->stopped_by_watchpoint = 0; | |
1934 | } | |
1935 | else | |
1936 | { | |
1937 | if (debug_linux_nat) | |
1938 | fprintf_unfiltered (gdb_stdlog, | |
1939 | "RC: Not resuming sibling %s (has pending)\n", | |
1940 | target_pid_to_str (lp->ptid)); | |
1941 | } | |
6c95b8df | 1942 | } |
25289eb2 | 1943 | else |
d6b0e80f | 1944 | { |
d90e17a7 PA |
1945 | if (debug_linux_nat) |
1946 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1947 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1948 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1949 | } |
25289eb2 | 1950 | } |
d6b0e80f | 1951 | |
25289eb2 PA |
1952 | static int |
1953 | resume_callback (struct lwp_info *lp, void *data) | |
1954 | { | |
1955 | resume_lwp (lp, 0); | |
d6b0e80f AC |
1956 | return 0; |
1957 | } | |
1958 | ||
1959 | static int | |
1960 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1961 | { | |
1962 | lp->resumed = 0; | |
25289eb2 | 1963 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1964 | return 0; |
1965 | } | |
1966 | ||
1967 | static int | |
1968 | resume_set_callback (struct lwp_info *lp, void *data) | |
1969 | { | |
1970 | lp->resumed = 1; | |
25289eb2 | 1971 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1972 | return 0; |
1973 | } | |
1974 | ||
1975 | static void | |
28439f5e PA |
1976 | linux_nat_resume (struct target_ops *ops, |
1977 | ptid_t ptid, int step, enum target_signal signo) | |
d6b0e80f | 1978 | { |
7feb7d06 | 1979 | sigset_t prev_mask; |
d6b0e80f | 1980 | struct lwp_info *lp; |
d90e17a7 | 1981 | int resume_many; |
d6b0e80f | 1982 | |
76f50ad1 DJ |
1983 | if (debug_linux_nat) |
1984 | fprintf_unfiltered (gdb_stdlog, | |
1985 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1986 | step ? "step" : "resume", | |
1987 | target_pid_to_str (ptid), | |
423ec54c JK |
1988 | (signo != TARGET_SIGNAL_0 |
1989 | ? strsignal (target_signal_to_host (signo)) : "0"), | |
76f50ad1 DJ |
1990 | target_pid_to_str (inferior_ptid)); |
1991 | ||
7feb7d06 | 1992 | block_child_signals (&prev_mask); |
b84876c2 | 1993 | |
d6b0e80f | 1994 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1995 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1996 | || ptid_is_pid (ptid)); | |
4c28f408 | 1997 | |
e3e9f5a2 PA |
1998 | /* Mark the lwps we're resuming as resumed. */ |
1999 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 2000 | |
d90e17a7 PA |
2001 | /* See if it's the current inferior that should be handled |
2002 | specially. */ | |
2003 | if (resume_many) | |
2004 | lp = find_lwp_pid (inferior_ptid); | |
2005 | else | |
2006 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 2007 | gdb_assert (lp != NULL); |
d6b0e80f | 2008 | |
9f0bdab8 DJ |
2009 | /* Remember if we're stepping. */ |
2010 | lp->step = step; | |
25289eb2 | 2011 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 2012 | |
9f0bdab8 DJ |
2013 | /* If we have a pending wait status for this thread, there is no |
2014 | point in resuming the process. But first make sure that | |
2015 | linux_nat_wait won't preemptively handle the event - we | |
2016 | should never take this short-circuit if we are going to | |
2017 | leave LP running, since we have skipped resuming all the | |
2018 | other threads. This bit of code needs to be synchronized | |
2019 | with linux_nat_wait. */ | |
76f50ad1 | 2020 | |
9f0bdab8 DJ |
2021 | if (lp->status && WIFSTOPPED (lp->status)) |
2022 | { | |
2455069d UW |
2023 | if (!lp->step |
2024 | && WSTOPSIG (lp->status) | |
2025 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 2026 | { |
9f0bdab8 DJ |
2027 | if (debug_linux_nat) |
2028 | fprintf_unfiltered (gdb_stdlog, | |
2029 | "LLR: Not short circuiting for ignored " | |
2030 | "status 0x%x\n", lp->status); | |
2031 | ||
d6b0e80f AC |
2032 | /* FIXME: What should we do if we are supposed to continue |
2033 | this thread with a signal? */ | |
2034 | gdb_assert (signo == TARGET_SIGNAL_0); | |
2455069d | 2035 | signo = target_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
2036 | lp->status = 0; |
2037 | } | |
2038 | } | |
76f50ad1 | 2039 | |
6c95b8df | 2040 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
2041 | { |
2042 | /* FIXME: What should we do if we are supposed to continue | |
2043 | this thread with a signal? */ | |
2044 | gdb_assert (signo == TARGET_SIGNAL_0); | |
76f50ad1 | 2045 | |
9f0bdab8 DJ |
2046 | if (debug_linux_nat) |
2047 | fprintf_unfiltered (gdb_stdlog, | |
2048 | "LLR: Short circuiting for status 0x%x\n", | |
2049 | lp->status); | |
d6b0e80f | 2050 | |
7feb7d06 PA |
2051 | restore_child_signals_mask (&prev_mask); |
2052 | if (target_can_async_p ()) | |
2053 | { | |
2054 | target_async (inferior_event_handler, 0); | |
2055 | /* Tell the event loop we have something to process. */ | |
2056 | async_file_mark (); | |
2057 | } | |
9f0bdab8 | 2058 | return; |
d6b0e80f AC |
2059 | } |
2060 | ||
9f0bdab8 DJ |
2061 | /* Mark LWP as not stopped to prevent it from being continued by |
2062 | resume_callback. */ | |
2063 | lp->stopped = 0; | |
2064 | ||
d90e17a7 PA |
2065 | if (resume_many) |
2066 | iterate_over_lwps (ptid, resume_callback, NULL); | |
2067 | ||
2068 | /* Convert to something the lower layer understands. */ | |
2069 | ptid = pid_to_ptid (GET_LWP (lp->ptid)); | |
d6b0e80f | 2070 | |
7b50312a PA |
2071 | if (linux_nat_prepare_to_resume != NULL) |
2072 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 2073 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
9f0bdab8 | 2074 | memset (&lp->siginfo, 0, sizeof (lp->siginfo)); |
ebec9a0f | 2075 | lp->stopped_by_watchpoint = 0; |
9f0bdab8 | 2076 | |
d6b0e80f AC |
2077 | if (debug_linux_nat) |
2078 | fprintf_unfiltered (gdb_stdlog, | |
2079 | "LLR: %s %s, %s (resume event thread)\n", | |
2080 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2081 | target_pid_to_str (ptid), | |
423ec54c JK |
2082 | (signo != TARGET_SIGNAL_0 |
2083 | ? strsignal (target_signal_to_host (signo)) : "0")); | |
b84876c2 | 2084 | |
7feb7d06 | 2085 | restore_child_signals_mask (&prev_mask); |
b84876c2 | 2086 | if (target_can_async_p ()) |
8ea051c5 | 2087 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
2088 | } |
2089 | ||
c5f62d5f | 2090 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
2091 | |
2092 | static int | |
2093 | kill_lwp (int lwpid, int signo) | |
2094 | { | |
c5f62d5f DE |
2095 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
2096 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
2097 | |
2098 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
2099 | { |
2100 | static int tkill_failed; | |
2101 | ||
2102 | if (!tkill_failed) | |
2103 | { | |
2104 | int ret; | |
2105 | ||
2106 | errno = 0; | |
2107 | ret = syscall (__NR_tkill, lwpid, signo); | |
2108 | if (errno != ENOSYS) | |
2109 | return ret; | |
2110 | tkill_failed = 1; | |
2111 | } | |
2112 | } | |
d6b0e80f AC |
2113 | #endif |
2114 | ||
2115 | return kill (lwpid, signo); | |
2116 | } | |
2117 | ||
ca2163eb PA |
2118 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
2119 | event, check if the core is interested in it: if not, ignore the | |
2120 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
2121 | syscall entry/exit status, since the ptrace event itself doesn't | |
2122 | indicate it, and report the trap to higher layers. */ | |
2123 | ||
2124 | static int | |
2125 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
2126 | { | |
2127 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
2128 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
2129 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
2130 | ||
2131 | if (stopping) | |
2132 | { | |
2133 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
2134 | makes it so that the LWP reports an immediate syscall return, | |
2135 | followed by the SIGSTOP. Skip seeing that "return" using | |
2136 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
2137 | SIGSTOP. Later when the thread is resumed, a new syscall | |
2138 | entry event. If we didn't do this (and returned 0), we'd | |
2139 | leave a syscall entry pending, and our caller, by using | |
2140 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
2141 | itself. Later, when the user re-resumes this LWP, we'd see | |
2142 | another syscall entry event and we'd mistake it for a return. | |
2143 | ||
2144 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
2145 | (leaving immediately with LWP->signalled set, without issuing | |
2146 | a PTRACE_CONT), it would still be problematic to leave this | |
2147 | syscall enter pending, as later when the thread is resumed, | |
2148 | it would then see the same syscall exit mentioned above, | |
2149 | followed by the delayed SIGSTOP, while the syscall didn't | |
2150 | actually get to execute. It seems it would be even more | |
2151 | confusing to the user. */ | |
2152 | ||
2153 | if (debug_linux_nat) | |
2154 | fprintf_unfiltered (gdb_stdlog, | |
2155 | "LHST: ignoring syscall %d " | |
2156 | "for LWP %ld (stopping threads), " | |
2157 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
2158 | syscall_number, | |
2159 | GET_LWP (lp->ptid)); | |
2160 | ||
2161 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2162 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2163 | return 1; | |
2164 | } | |
2165 | ||
2166 | if (catch_syscall_enabled ()) | |
2167 | { | |
2168 | /* Always update the entry/return state, even if this particular | |
2169 | syscall isn't interesting to the core now. In async mode, | |
2170 | the user could install a new catchpoint for this syscall | |
2171 | between syscall enter/return, and we'll need to know to | |
2172 | report a syscall return if that happens. */ | |
2173 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2174 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
2175 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
2176 | ||
2177 | if (catching_syscall_number (syscall_number)) | |
2178 | { | |
2179 | /* Alright, an event to report. */ | |
2180 | ourstatus->kind = lp->syscall_state; | |
2181 | ourstatus->value.syscall_number = syscall_number; | |
2182 | ||
2183 | if (debug_linux_nat) | |
2184 | fprintf_unfiltered (gdb_stdlog, | |
2185 | "LHST: stopping for %s of syscall %d" | |
2186 | " for LWP %ld\n", | |
3e43a32a MS |
2187 | lp->syscall_state |
2188 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
2189 | ? "entry" : "return", |
2190 | syscall_number, | |
2191 | GET_LWP (lp->ptid)); | |
2192 | return 0; | |
2193 | } | |
2194 | ||
2195 | if (debug_linux_nat) | |
2196 | fprintf_unfiltered (gdb_stdlog, | |
2197 | "LHST: ignoring %s of syscall %d " | |
2198 | "for LWP %ld\n", | |
2199 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2200 | ? "entry" : "return", | |
2201 | syscall_number, | |
2202 | GET_LWP (lp->ptid)); | |
2203 | } | |
2204 | else | |
2205 | { | |
2206 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
2207 | before on this LWP, it could happen that the user removes all | |
2208 | syscall catchpoints before we get to process this event. | |
2209 | There are two noteworthy issues here: | |
2210 | ||
2211 | - When stopped at a syscall entry event, resuming with | |
2212 | PT_STEP still resumes executing the syscall and reports a | |
2213 | syscall return. | |
2214 | ||
2215 | - Only PT_SYSCALL catches syscall enters. If we last | |
2216 | single-stepped this thread, then this event can't be a | |
2217 | syscall enter. If we last single-stepped this thread, this | |
2218 | has to be a syscall exit. | |
2219 | ||
2220 | The points above mean that the next resume, be it PT_STEP or | |
2221 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
2222 | if (debug_linux_nat) | |
2223 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2224 | "LHST: caught syscall event " |
2225 | "with no syscall catchpoints." | |
ca2163eb PA |
2226 | " %d for LWP %ld, ignoring\n", |
2227 | syscall_number, | |
2228 | GET_LWP (lp->ptid)); | |
2229 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2230 | } | |
2231 | ||
2232 | /* The core isn't interested in this event. For efficiency, avoid | |
2233 | stopping all threads only to have the core resume them all again. | |
2234 | Since we're not stopping threads, if we're still syscall tracing | |
2235 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
2236 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
2237 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
2238 | ||
2239 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
2240 | fill a regcache. */ | |
2241 | registers_changed (); | |
7b50312a PA |
2242 | if (linux_nat_prepare_to_resume != NULL) |
2243 | linux_nat_prepare_to_resume (lp); | |
ca2163eb PA |
2244 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
2245 | lp->step, TARGET_SIGNAL_0); | |
2246 | return 1; | |
2247 | } | |
2248 | ||
3d799a95 DJ |
2249 | /* Handle a GNU/Linux extended wait response. If we see a clone |
2250 | event, we need to add the new LWP to our list (and not report the | |
2251 | trap to higher layers). This function returns non-zero if the | |
2252 | event should be ignored and we should wait again. If STOPPING is | |
2253 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
2254 | |
2255 | static int | |
3d799a95 DJ |
2256 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
2257 | int stopping) | |
d6b0e80f | 2258 | { |
3d799a95 DJ |
2259 | int pid = GET_LWP (lp->ptid); |
2260 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
3d799a95 | 2261 | int event = status >> 16; |
d6b0e80f | 2262 | |
3d799a95 DJ |
2263 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
2264 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 2265 | { |
3d799a95 DJ |
2266 | unsigned long new_pid; |
2267 | int ret; | |
2268 | ||
2269 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 2270 | |
3d799a95 DJ |
2271 | /* If we haven't already seen the new PID stop, wait for it now. */ |
2272 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2273 | { | |
2274 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2275 | hits the SIGSTOP, but we're already attached. */ | |
2276 | ret = my_waitpid (new_pid, &status, | |
2277 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
2278 | if (ret == -1) | |
2279 | perror_with_name (_("waiting for new child")); | |
2280 | else if (ret != new_pid) | |
2281 | internal_error (__FILE__, __LINE__, | |
2282 | _("wait returned unexpected PID %d"), ret); | |
2283 | else if (!WIFSTOPPED (status)) | |
2284 | internal_error (__FILE__, __LINE__, | |
2285 | _("wait returned unexpected status 0x%x"), status); | |
2286 | } | |
2287 | ||
3a3e9ee3 | 2288 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2289 | |
2277426b PA |
2290 | if (event == PTRACE_EVENT_FORK |
2291 | && linux_fork_checkpointing_p (GET_PID (lp->ptid))) | |
2292 | { | |
2277426b PA |
2293 | /* Handle checkpointing by linux-fork.c here as a special |
2294 | case. We don't want the follow-fork-mode or 'catch fork' | |
2295 | to interfere with this. */ | |
2296 | ||
2297 | /* This won't actually modify the breakpoint list, but will | |
2298 | physically remove the breakpoints from the child. */ | |
2299 | detach_breakpoints (new_pid); | |
2300 | ||
2301 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2302 | if (!find_fork_pid (new_pid)) |
2303 | add_fork (new_pid); | |
2277426b PA |
2304 | |
2305 | /* Report as spurious, so that infrun doesn't want to follow | |
2306 | this fork. We're actually doing an infcall in | |
2307 | linux-fork.c. */ | |
2308 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2309 | linux_enable_event_reporting (pid_to_ptid (new_pid)); | |
2310 | ||
2311 | /* Report the stop to the core. */ | |
2312 | return 0; | |
2313 | } | |
2314 | ||
3d799a95 DJ |
2315 | if (event == PTRACE_EVENT_FORK) |
2316 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2317 | else if (event == PTRACE_EVENT_VFORK) | |
2318 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2319 | else |
3d799a95 | 2320 | { |
78768c4a JK |
2321 | struct lwp_info *new_lp; |
2322 | ||
3d799a95 | 2323 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2324 | |
3c4d7e12 PA |
2325 | if (debug_linux_nat) |
2326 | fprintf_unfiltered (gdb_stdlog, | |
2327 | "LHEW: Got clone event " | |
2328 | "from LWP %d, new child is LWP %ld\n", | |
2329 | pid, new_pid); | |
2330 | ||
d90e17a7 | 2331 | new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
3d799a95 | 2332 | new_lp->cloned = 1; |
4c28f408 | 2333 | new_lp->stopped = 1; |
d6b0e80f | 2334 | |
3d799a95 DJ |
2335 | if (WSTOPSIG (status) != SIGSTOP) |
2336 | { | |
2337 | /* This can happen if someone starts sending signals to | |
2338 | the new thread before it gets a chance to run, which | |
2339 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2340 | This is an unlikely case, and harder to handle for | |
2341 | fork / vfork than for clone, so we do not try - but | |
2342 | we handle it for clone events here. We'll send | |
2343 | the other signal on to the thread below. */ | |
2344 | ||
2345 | new_lp->signalled = 1; | |
2346 | } | |
2347 | else | |
79395f92 PA |
2348 | { |
2349 | struct thread_info *tp; | |
2350 | ||
2351 | /* When we stop for an event in some other thread, and | |
2352 | pull the thread list just as this thread has cloned, | |
2353 | we'll have seen the new thread in the thread_db list | |
2354 | before handling the CLONE event (glibc's | |
2355 | pthread_create adds the new thread to the thread list | |
2356 | before clone'ing, and has the kernel fill in the | |
2357 | thread's tid on the clone call with | |
2358 | CLONE_PARENT_SETTID). If that happened, and the core | |
2359 | had requested the new thread to stop, we'll have | |
2360 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2361 | RT signal, it can only be queued once. We need to be | |
2362 | careful to not resume the LWP if we wanted it to | |
2363 | stop. In that case, we'll leave the SIGSTOP pending. | |
2364 | It will later be reported as TARGET_SIGNAL_0. */ | |
2365 | tp = find_thread_ptid (new_lp->ptid); | |
2366 | if (tp != NULL && tp->stop_requested) | |
2367 | new_lp->last_resume_kind = resume_stop; | |
2368 | else | |
2369 | status = 0; | |
2370 | } | |
d6b0e80f | 2371 | |
4c28f408 | 2372 | if (non_stop) |
3d799a95 | 2373 | { |
4c28f408 PA |
2374 | /* Add the new thread to GDB's lists as soon as possible |
2375 | so that: | |
2376 | ||
2377 | 1) the frontend doesn't have to wait for a stop to | |
2378 | display them, and, | |
2379 | ||
2380 | 2) we tag it with the correct running state. */ | |
2381 | ||
2382 | /* If the thread_db layer is active, let it know about | |
2383 | this new thread, and add it to GDB's list. */ | |
2384 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2385 | { | |
2386 | /* We're not using thread_db. Add it to GDB's | |
2387 | list. */ | |
2388 | target_post_attach (GET_LWP (new_lp->ptid)); | |
2389 | add_thread (new_lp->ptid); | |
2390 | } | |
2391 | ||
2392 | if (!stopping) | |
2393 | { | |
2394 | set_running (new_lp->ptid, 1); | |
2395 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2396 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2397 | resume_stop. */ | |
2398 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2399 | } |
2400 | } | |
2401 | ||
79395f92 PA |
2402 | if (status != 0) |
2403 | { | |
2404 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2405 | gdb_assert (new_lp->status == 0); | |
2406 | ||
2407 | /* Save the wait status to report later. */ | |
2408 | if (debug_linux_nat) | |
2409 | fprintf_unfiltered (gdb_stdlog, | |
2410 | "LHEW: waitpid of new LWP %ld, " | |
2411 | "saving status %s\n", | |
2412 | (long) GET_LWP (new_lp->ptid), | |
2413 | status_to_str (status)); | |
2414 | new_lp->status = status; | |
2415 | } | |
2416 | ||
ca2163eb PA |
2417 | /* Note the need to use the low target ops to resume, to |
2418 | handle resuming with PT_SYSCALL if we have syscall | |
2419 | catchpoints. */ | |
4c28f408 PA |
2420 | if (!stopping) |
2421 | { | |
3d799a95 | 2422 | new_lp->resumed = 1; |
ca2163eb | 2423 | |
79395f92 | 2424 | if (status == 0) |
ad34eb2f | 2425 | { |
e21ffe51 | 2426 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2427 | if (debug_linux_nat) |
2428 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 PA |
2429 | "LHEW: resuming new LWP %ld\n", |
2430 | GET_LWP (new_lp->ptid)); | |
7b50312a PA |
2431 | if (linux_nat_prepare_to_resume != NULL) |
2432 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 PA |
2433 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
2434 | 0, TARGET_SIGNAL_0); | |
2435 | new_lp->stopped = 0; | |
ad34eb2f JK |
2436 | } |
2437 | } | |
d6b0e80f | 2438 | |
3d799a95 DJ |
2439 | if (debug_linux_nat) |
2440 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2441 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
2442 | if (linux_nat_prepare_to_resume != NULL) |
2443 | linux_nat_prepare_to_resume (lp); | |
ca2163eb PA |
2444 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
2445 | 0, TARGET_SIGNAL_0); | |
3d799a95 DJ |
2446 | |
2447 | return 1; | |
2448 | } | |
2449 | ||
2450 | return 0; | |
d6b0e80f AC |
2451 | } |
2452 | ||
3d799a95 DJ |
2453 | if (event == PTRACE_EVENT_EXEC) |
2454 | { | |
a75724bc PA |
2455 | if (debug_linux_nat) |
2456 | fprintf_unfiltered (gdb_stdlog, | |
2457 | "LHEW: Got exec event from LWP %ld\n", | |
2458 | GET_LWP (lp->ptid)); | |
2459 | ||
3d799a95 DJ |
2460 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2461 | ourstatus->value.execd_pathname | |
6d8fd2b7 | 2462 | = xstrdup (linux_child_pid_to_exec_file (pid)); |
3d799a95 | 2463 | |
6c95b8df PA |
2464 | return 0; |
2465 | } | |
2466 | ||
2467 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2468 | { | |
2469 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2470 | { |
6c95b8df | 2471 | if (debug_linux_nat) |
3e43a32a MS |
2472 | fprintf_unfiltered (gdb_stdlog, |
2473 | "LHEW: Got expected PTRACE_EVENT_" | |
2474 | "VFORK_DONE from LWP %ld: stopping\n", | |
6c95b8df | 2475 | GET_LWP (lp->ptid)); |
3d799a95 | 2476 | |
6c95b8df PA |
2477 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2478 | return 0; | |
3d799a95 DJ |
2479 | } |
2480 | ||
6c95b8df | 2481 | if (debug_linux_nat) |
3e43a32a MS |
2482 | fprintf_unfiltered (gdb_stdlog, |
2483 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2484 | "from LWP %ld: resuming\n", | |
6c95b8df PA |
2485 | GET_LWP (lp->ptid)); |
2486 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2487 | return 1; | |
3d799a95 DJ |
2488 | } |
2489 | ||
2490 | internal_error (__FILE__, __LINE__, | |
2491 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2492 | } |
2493 | ||
432b4d03 JK |
2494 | /* Return non-zero if LWP is a zombie. */ |
2495 | ||
2496 | static int | |
2497 | linux_lwp_is_zombie (long lwp) | |
2498 | { | |
2499 | char buffer[MAXPATHLEN]; | |
2500 | FILE *procfile; | |
ea23808b PA |
2501 | int retval; |
2502 | int have_state; | |
432b4d03 | 2503 | |
07e78767 | 2504 | xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp); |
432b4d03 JK |
2505 | procfile = fopen (buffer, "r"); |
2506 | if (procfile == NULL) | |
2507 | { | |
2508 | warning (_("unable to open /proc file '%s'"), buffer); | |
2509 | return 0; | |
2510 | } | |
ea23808b PA |
2511 | |
2512 | have_state = 0; | |
432b4d03 | 2513 | while (fgets (buffer, sizeof (buffer), procfile) != NULL) |
ea23808b | 2514 | if (strncmp (buffer, "State:", 6) == 0) |
432b4d03 | 2515 | { |
ea23808b | 2516 | have_state = 1; |
432b4d03 JK |
2517 | break; |
2518 | } | |
ea23808b PA |
2519 | retval = (have_state |
2520 | && strcmp (buffer, "State:\tZ (zombie)\n") == 0); | |
432b4d03 | 2521 | fclose (procfile); |
432b4d03 JK |
2522 | return retval; |
2523 | } | |
2524 | ||
d6b0e80f AC |
2525 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2526 | exited. */ | |
2527 | ||
2528 | static int | |
2529 | wait_lwp (struct lwp_info *lp) | |
2530 | { | |
2531 | pid_t pid; | |
432b4d03 | 2532 | int status = 0; |
d6b0e80f | 2533 | int thread_dead = 0; |
432b4d03 | 2534 | sigset_t prev_mask; |
d6b0e80f AC |
2535 | |
2536 | gdb_assert (!lp->stopped); | |
2537 | gdb_assert (lp->status == 0); | |
2538 | ||
432b4d03 JK |
2539 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2540 | block_child_signals (&prev_mask); | |
2541 | ||
2542 | for (;;) | |
d6b0e80f | 2543 | { |
432b4d03 JK |
2544 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2545 | was right and we should just call sigsuspend. */ | |
2546 | ||
2547 | pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); | |
d6b0e80f | 2548 | if (pid == -1 && errno == ECHILD) |
432b4d03 | 2549 | pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2550 | if (pid == -1 && errno == ECHILD) |
2551 | { | |
2552 | /* The thread has previously exited. We need to delete it | |
2553 | now because, for some vendor 2.4 kernels with NPTL | |
2554 | support backported, there won't be an exit event unless | |
2555 | it is the main thread. 2.6 kernels will report an exit | |
2556 | event for each thread that exits, as expected. */ | |
2557 | thread_dead = 1; | |
2558 | if (debug_linux_nat) | |
2559 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2560 | target_pid_to_str (lp->ptid)); | |
2561 | } | |
432b4d03 JK |
2562 | if (pid != 0) |
2563 | break; | |
2564 | ||
2565 | /* Bugs 10970, 12702. | |
2566 | Thread group leader may have exited in which case we'll lock up in | |
2567 | waitpid if there are other threads, even if they are all zombies too. | |
2568 | Basically, we're not supposed to use waitpid this way. | |
2569 | __WCLONE is not applicable for the leader so we can't use that. | |
2570 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2571 | process; it gets ESRCH both for the zombie and for running processes. | |
2572 | ||
2573 | As a workaround, check if we're waiting for the thread group leader and | |
2574 | if it's a zombie, and avoid calling waitpid if it is. | |
2575 | ||
2576 | This is racy, what if the tgl becomes a zombie right after we check? | |
2577 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
2578 | waiting waitpid but the linux_lwp_is_zombie is safe this way. */ | |
2579 | ||
2580 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) | |
2581 | && linux_lwp_is_zombie (GET_LWP (lp->ptid))) | |
d6b0e80f | 2582 | { |
d6b0e80f AC |
2583 | thread_dead = 1; |
2584 | if (debug_linux_nat) | |
432b4d03 JK |
2585 | fprintf_unfiltered (gdb_stdlog, |
2586 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2587 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2588 | break; |
d6b0e80f | 2589 | } |
432b4d03 JK |
2590 | |
2591 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2592 | get invoked despite our caller had them intentionally blocked by | |
2593 | block_child_signals. This is sensitive only to the loop of | |
2594 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2595 | again before it gets to sigsuspend so we can safely let the handlers | |
2596 | get executed here. */ | |
2597 | ||
2598 | sigsuspend (&suspend_mask); | |
2599 | } | |
2600 | ||
2601 | restore_child_signals_mask (&prev_mask); | |
2602 | ||
d6b0e80f AC |
2603 | if (!thread_dead) |
2604 | { | |
2605 | gdb_assert (pid == GET_LWP (lp->ptid)); | |
2606 | ||
2607 | if (debug_linux_nat) | |
2608 | { | |
2609 | fprintf_unfiltered (gdb_stdlog, | |
2610 | "WL: waitpid %s received %s\n", | |
2611 | target_pid_to_str (lp->ptid), | |
2612 | status_to_str (status)); | |
2613 | } | |
d6b0e80f | 2614 | |
a9f4bb21 PA |
2615 | /* Check if the thread has exited. */ |
2616 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2617 | { | |
2618 | thread_dead = 1; | |
2619 | if (debug_linux_nat) | |
2620 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2621 | target_pid_to_str (lp->ptid)); | |
2622 | } | |
d6b0e80f AC |
2623 | } |
2624 | ||
2625 | if (thread_dead) | |
2626 | { | |
e26af52f | 2627 | exit_lwp (lp); |
d6b0e80f AC |
2628 | return 0; |
2629 | } | |
2630 | ||
2631 | gdb_assert (WIFSTOPPED (status)); | |
2632 | ||
ca2163eb PA |
2633 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2634 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2635 | { | |
2636 | /* No longer need the sysgood bit. The ptrace event ends up | |
2637 | recorded in lp->waitstatus if we care for it. We can carry | |
2638 | on handling the event like a regular SIGTRAP from here | |
2639 | on. */ | |
2640 | status = W_STOPCODE (SIGTRAP); | |
2641 | if (linux_handle_syscall_trap (lp, 1)) | |
2642 | return wait_lwp (lp); | |
2643 | } | |
2644 | ||
d6b0e80f AC |
2645 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2646 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
2647 | { | |
2648 | if (debug_linux_nat) | |
2649 | fprintf_unfiltered (gdb_stdlog, | |
2650 | "WL: Handling extended status 0x%06x\n", | |
2651 | status); | |
3d799a95 | 2652 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2653 | return wait_lwp (lp); |
2654 | } | |
2655 | ||
2656 | return status; | |
2657 | } | |
2658 | ||
9f0bdab8 DJ |
2659 | /* Save the most recent siginfo for LP. This is currently only called |
2660 | for SIGTRAP; some ports use the si_addr field for | |
2661 | target_stopped_data_address. In the future, it may also be used to | |
2662 | restore the siginfo of requeued signals. */ | |
2663 | ||
2664 | static void | |
2665 | save_siginfo (struct lwp_info *lp) | |
2666 | { | |
2667 | errno = 0; | |
2668 | ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid), | |
2669 | (PTRACE_TYPE_ARG3) 0, &lp->siginfo); | |
2670 | ||
2671 | if (errno != 0) | |
2672 | memset (&lp->siginfo, 0, sizeof (lp->siginfo)); | |
2673 | } | |
2674 | ||
d6b0e80f AC |
2675 | /* Send a SIGSTOP to LP. */ |
2676 | ||
2677 | static int | |
2678 | stop_callback (struct lwp_info *lp, void *data) | |
2679 | { | |
2680 | if (!lp->stopped && !lp->signalled) | |
2681 | { | |
2682 | int ret; | |
2683 | ||
2684 | if (debug_linux_nat) | |
2685 | { | |
2686 | fprintf_unfiltered (gdb_stdlog, | |
2687 | "SC: kill %s **<SIGSTOP>**\n", | |
2688 | target_pid_to_str (lp->ptid)); | |
2689 | } | |
2690 | errno = 0; | |
2691 | ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); | |
2692 | if (debug_linux_nat) | |
2693 | { | |
2694 | fprintf_unfiltered (gdb_stdlog, | |
2695 | "SC: lwp kill %d %s\n", | |
2696 | ret, | |
2697 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2698 | } | |
2699 | ||
2700 | lp->signalled = 1; | |
2701 | gdb_assert (lp->status == 0); | |
2702 | } | |
2703 | ||
2704 | return 0; | |
2705 | } | |
2706 | ||
7b50312a PA |
2707 | /* Request a stop on LWP. */ |
2708 | ||
2709 | void | |
2710 | linux_stop_lwp (struct lwp_info *lwp) | |
2711 | { | |
2712 | stop_callback (lwp, NULL); | |
2713 | } | |
2714 | ||
57380f4e | 2715 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2716 | |
2717 | static int | |
57380f4e DJ |
2718 | linux_nat_has_pending_sigint (int pid) |
2719 | { | |
2720 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2721 | |
2722 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2723 | ||
2724 | if (sigismember (&pending, SIGINT) | |
2725 | && !sigismember (&ignored, SIGINT)) | |
2726 | return 1; | |
2727 | ||
2728 | return 0; | |
2729 | } | |
2730 | ||
2731 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2732 | ||
2733 | static int | |
2734 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2735 | { |
57380f4e DJ |
2736 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2737 | flag to consume the next one. */ | |
2738 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2739 | && WSTOPSIG (lp->status) == SIGINT) | |
2740 | lp->status = 0; | |
2741 | else | |
2742 | lp->ignore_sigint = 1; | |
2743 | ||
2744 | return 0; | |
2745 | } | |
2746 | ||
2747 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2748 | This function is called after we know the LWP has stopped; if the LWP | |
2749 | stopped before the expected SIGINT was delivered, then it will never have | |
2750 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2751 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2752 | |
57380f4e DJ |
2753 | static void |
2754 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2755 | { | |
2756 | if (!lp->ignore_sigint) | |
2757 | return; | |
2758 | ||
2759 | if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) | |
2760 | { | |
2761 | if (debug_linux_nat) | |
2762 | fprintf_unfiltered (gdb_stdlog, | |
2763 | "MCIS: Clearing bogus flag for %s\n", | |
2764 | target_pid_to_str (lp->ptid)); | |
2765 | lp->ignore_sigint = 0; | |
2766 | } | |
2767 | } | |
2768 | ||
ebec9a0f PA |
2769 | /* Fetch the possible triggered data watchpoint info and store it in |
2770 | LP. | |
2771 | ||
2772 | On some archs, like x86, that use debug registers to set | |
2773 | watchpoints, it's possible that the way to know which watched | |
2774 | address trapped, is to check the register that is used to select | |
2775 | which address to watch. Problem is, between setting the watchpoint | |
2776 | and reading back which data address trapped, the user may change | |
2777 | the set of watchpoints, and, as a consequence, GDB changes the | |
2778 | debug registers in the inferior. To avoid reading back a stale | |
2779 | stopped-data-address when that happens, we cache in LP the fact | |
2780 | that a watchpoint trapped, and the corresponding data address, as | |
2781 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2782 | registers meanwhile, we have the cached data we can rely on. */ | |
2783 | ||
2784 | static void | |
2785 | save_sigtrap (struct lwp_info *lp) | |
2786 | { | |
2787 | struct cleanup *old_chain; | |
2788 | ||
2789 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2790 | { | |
2791 | lp->stopped_by_watchpoint = 0; | |
2792 | return; | |
2793 | } | |
2794 | ||
2795 | old_chain = save_inferior_ptid (); | |
2796 | inferior_ptid = lp->ptid; | |
2797 | ||
2798 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); | |
2799 | ||
2800 | if (lp->stopped_by_watchpoint) | |
2801 | { | |
2802 | if (linux_ops->to_stopped_data_address != NULL) | |
2803 | lp->stopped_data_address_p = | |
2804 | linux_ops->to_stopped_data_address (¤t_target, | |
2805 | &lp->stopped_data_address); | |
2806 | else | |
2807 | lp->stopped_data_address_p = 0; | |
2808 | } | |
2809 | ||
2810 | do_cleanups (old_chain); | |
2811 | } | |
2812 | ||
2813 | /* See save_sigtrap. */ | |
2814 | ||
2815 | static int | |
2816 | linux_nat_stopped_by_watchpoint (void) | |
2817 | { | |
2818 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2819 | ||
2820 | gdb_assert (lp != NULL); | |
2821 | ||
2822 | return lp->stopped_by_watchpoint; | |
2823 | } | |
2824 | ||
2825 | static int | |
2826 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2827 | { | |
2828 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2829 | ||
2830 | gdb_assert (lp != NULL); | |
2831 | ||
2832 | *addr_p = lp->stopped_data_address; | |
2833 | ||
2834 | return lp->stopped_data_address_p; | |
2835 | } | |
2836 | ||
26ab7092 JK |
2837 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2838 | ||
2839 | static int | |
2840 | sigtrap_is_event (int status) | |
2841 | { | |
2842 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2843 | } | |
2844 | ||
2845 | /* SIGTRAP-like events recognizer. */ | |
2846 | ||
2847 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2848 | ||
00390b84 JK |
2849 | /* Check for SIGTRAP-like events in LP. */ |
2850 | ||
2851 | static int | |
2852 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2853 | { | |
2854 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2855 | have pending process exits recorded in lp->status | |
2856 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2857 | lp->status_p flag. */ | |
2858 | ||
2859 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2860 | && linux_nat_status_is_event (lp->status)); | |
2861 | } | |
2862 | ||
26ab7092 JK |
2863 | /* Set alternative SIGTRAP-like events recognizer. If |
2864 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2865 | applied. */ | |
2866 | ||
2867 | void | |
2868 | linux_nat_set_status_is_event (struct target_ops *t, | |
2869 | int (*status_is_event) (int status)) | |
2870 | { | |
2871 | linux_nat_status_is_event = status_is_event; | |
2872 | } | |
2873 | ||
57380f4e DJ |
2874 | /* Wait until LP is stopped. */ |
2875 | ||
2876 | static int | |
2877 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2878 | { | |
6c95b8df PA |
2879 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
2880 | ||
2881 | /* If this is a vfork parent, bail out, it is not going to report | |
2882 | any SIGSTOP until the vfork is done with. */ | |
2883 | if (inf->vfork_child != NULL) | |
2884 | return 0; | |
2885 | ||
d6b0e80f AC |
2886 | if (!lp->stopped) |
2887 | { | |
2888 | int status; | |
2889 | ||
2890 | status = wait_lwp (lp); | |
2891 | if (status == 0) | |
2892 | return 0; | |
2893 | ||
57380f4e DJ |
2894 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2895 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2896 | { |
57380f4e | 2897 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2898 | |
2899 | errno = 0; | |
2900 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2901 | if (debug_linux_nat) | |
2902 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2903 | "PTRACE_CONT %s, 0, 0 (%s) " |
2904 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2905 | target_pid_to_str (lp->ptid), |
2906 | errno ? safe_strerror (errno) : "OK"); | |
2907 | ||
57380f4e | 2908 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2909 | } |
2910 | ||
57380f4e DJ |
2911 | maybe_clear_ignore_sigint (lp); |
2912 | ||
d6b0e80f AC |
2913 | if (WSTOPSIG (status) != SIGSTOP) |
2914 | { | |
26ab7092 | 2915 | if (linux_nat_status_is_event (status)) |
d6b0e80f AC |
2916 | { |
2917 | /* If a LWP other than the LWP that we're reporting an | |
2918 | event for has hit a GDB breakpoint (as opposed to | |
2919 | some random trap signal), then just arrange for it to | |
2920 | hit it again later. We don't keep the SIGTRAP status | |
2921 | and don't forward the SIGTRAP signal to the LWP. We | |
2922 | will handle the current event, eventually we will | |
2923 | resume all LWPs, and this one will get its breakpoint | |
2924 | trap again. | |
2925 | ||
2926 | If we do not do this, then we run the risk that the | |
2927 | user will delete or disable the breakpoint, but the | |
2928 | thread will have already tripped on it. */ | |
2929 | ||
9f0bdab8 DJ |
2930 | /* Save the trap's siginfo in case we need it later. */ |
2931 | save_siginfo (lp); | |
2932 | ||
ebec9a0f PA |
2933 | save_sigtrap (lp); |
2934 | ||
1777feb0 | 2935 | /* Now resume this LWP and get the SIGSTOP event. */ |
d6b0e80f AC |
2936 | errno = 0; |
2937 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2938 | if (debug_linux_nat) | |
2939 | { | |
2940 | fprintf_unfiltered (gdb_stdlog, | |
2941 | "PTRACE_CONT %s, 0, 0 (%s)\n", | |
2942 | target_pid_to_str (lp->ptid), | |
2943 | errno ? safe_strerror (errno) : "OK"); | |
2944 | ||
2945 | fprintf_unfiltered (gdb_stdlog, | |
2946 | "SWC: Candidate SIGTRAP event in %s\n", | |
2947 | target_pid_to_str (lp->ptid)); | |
2948 | } | |
710151dd | 2949 | /* Hold this event/waitstatus while we check to see if |
1777feb0 | 2950 | there are any more (we still want to get that SIGSTOP). */ |
57380f4e | 2951 | stop_wait_callback (lp, NULL); |
710151dd | 2952 | |
7feb7d06 PA |
2953 | /* Hold the SIGTRAP for handling by linux_nat_wait. If |
2954 | there's another event, throw it back into the | |
1777feb0 | 2955 | queue. */ |
7feb7d06 | 2956 | if (lp->status) |
710151dd | 2957 | { |
7feb7d06 PA |
2958 | if (debug_linux_nat) |
2959 | fprintf_unfiltered (gdb_stdlog, | |
2960 | "SWC: kill %s, %s\n", | |
2961 | target_pid_to_str (lp->ptid), | |
2962 | status_to_str ((int) status)); | |
2963 | kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status)); | |
d6b0e80f | 2964 | } |
7feb7d06 | 2965 | |
1777feb0 | 2966 | /* Save the sigtrap event. */ |
7feb7d06 | 2967 | lp->status = status; |
d6b0e80f AC |
2968 | return 0; |
2969 | } | |
2970 | else | |
2971 | { | |
2972 | /* The thread was stopped with a signal other than | |
1777feb0 | 2973 | SIGSTOP, and didn't accidentally trip a breakpoint. */ |
d6b0e80f AC |
2974 | |
2975 | if (debug_linux_nat) | |
2976 | { | |
2977 | fprintf_unfiltered (gdb_stdlog, | |
2978 | "SWC: Pending event %s in %s\n", | |
2979 | status_to_str ((int) status), | |
2980 | target_pid_to_str (lp->ptid)); | |
2981 | } | |
1777feb0 | 2982 | /* Now resume this LWP and get the SIGSTOP event. */ |
d6b0e80f AC |
2983 | errno = 0; |
2984 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2985 | if (debug_linux_nat) | |
2986 | fprintf_unfiltered (gdb_stdlog, | |
2987 | "SWC: PTRACE_CONT %s, 0, 0 (%s)\n", | |
2988 | target_pid_to_str (lp->ptid), | |
2989 | errno ? safe_strerror (errno) : "OK"); | |
2990 | ||
2991 | /* Hold this event/waitstatus while we check to see if | |
1777feb0 | 2992 | there are any more (we still want to get that SIGSTOP). */ |
57380f4e | 2993 | stop_wait_callback (lp, NULL); |
710151dd PA |
2994 | |
2995 | /* If the lp->status field is still empty, use it to | |
2996 | hold this event. If not, then this event must be | |
2997 | returned to the event queue of the LWP. */ | |
7feb7d06 | 2998 | if (lp->status) |
d6b0e80f AC |
2999 | { |
3000 | if (debug_linux_nat) | |
3001 | { | |
3002 | fprintf_unfiltered (gdb_stdlog, | |
3003 | "SWC: kill %s, %s\n", | |
3004 | target_pid_to_str (lp->ptid), | |
3005 | status_to_str ((int) status)); | |
3006 | } | |
3007 | kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status)); | |
3008 | } | |
710151dd PA |
3009 | else |
3010 | lp->status = status; | |
d6b0e80f AC |
3011 | return 0; |
3012 | } | |
3013 | } | |
3014 | else | |
3015 | { | |
3016 | /* We caught the SIGSTOP that we intended to catch, so | |
3017 | there's no SIGSTOP pending. */ | |
3018 | lp->stopped = 1; | |
3019 | lp->signalled = 0; | |
3020 | } | |
3021 | } | |
3022 | ||
3023 | return 0; | |
3024 | } | |
3025 | ||
d6b0e80f AC |
3026 | /* Return non-zero if LP has a wait status pending. */ |
3027 | ||
3028 | static int | |
3029 | status_callback (struct lwp_info *lp, void *data) | |
3030 | { | |
3031 | /* Only report a pending wait status if we pretend that this has | |
3032 | indeed been resumed. */ | |
ca2163eb PA |
3033 | if (!lp->resumed) |
3034 | return 0; | |
3035 | ||
3036 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3037 | { | |
3038 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 3039 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
3040 | 0', so a clean process exit can not be stored pending in |
3041 | lp->status, it is indistinguishable from | |
3042 | no-pending-status. */ | |
3043 | return 1; | |
3044 | } | |
3045 | ||
3046 | if (lp->status != 0) | |
3047 | return 1; | |
3048 | ||
3049 | return 0; | |
d6b0e80f AC |
3050 | } |
3051 | ||
3052 | /* Return non-zero if LP isn't stopped. */ | |
3053 | ||
3054 | static int | |
3055 | running_callback (struct lwp_info *lp, void *data) | |
3056 | { | |
25289eb2 PA |
3057 | return (!lp->stopped |
3058 | || ((lp->status != 0 | |
3059 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3060 | && lp->resumed)); | |
d6b0e80f AC |
3061 | } |
3062 | ||
3063 | /* Count the LWP's that have had events. */ | |
3064 | ||
3065 | static int | |
3066 | count_events_callback (struct lwp_info *lp, void *data) | |
3067 | { | |
3068 | int *count = data; | |
3069 | ||
3070 | gdb_assert (count != NULL); | |
3071 | ||
e09490f1 | 3072 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 3073 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
3074 | (*count)++; |
3075 | ||
3076 | return 0; | |
3077 | } | |
3078 | ||
3079 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
3080 | ||
3081 | static int | |
3082 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
3083 | { | |
25289eb2 PA |
3084 | if (lp->last_resume_kind == resume_step |
3085 | && lp->status != 0) | |
d6b0e80f AC |
3086 | return 1; |
3087 | else | |
3088 | return 0; | |
3089 | } | |
3090 | ||
3091 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
3092 | ||
3093 | static int | |
3094 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
3095 | { | |
3096 | int *selector = data; | |
3097 | ||
3098 | gdb_assert (selector != NULL); | |
3099 | ||
1777feb0 | 3100 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 3101 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
3102 | if ((*selector)-- == 0) |
3103 | return 1; | |
3104 | ||
3105 | return 0; | |
3106 | } | |
3107 | ||
710151dd PA |
3108 | static int |
3109 | cancel_breakpoint (struct lwp_info *lp) | |
3110 | { | |
3111 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
3112 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3113 | LWP. We will handle the current event, eventually we will resume | |
3114 | this LWP, and this breakpoint will trap again. | |
3115 | ||
3116 | If we do not do this, then we run the risk that the user will | |
3117 | delete or disable the breakpoint, but the LWP will have already | |
3118 | tripped on it. */ | |
3119 | ||
515630c5 UW |
3120 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3121 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3122 | CORE_ADDR pc; | |
3123 | ||
3124 | pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); | |
6c95b8df | 3125 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
3126 | { |
3127 | if (debug_linux_nat) | |
3128 | fprintf_unfiltered (gdb_stdlog, | |
3129 | "CB: Push back breakpoint for %s\n", | |
3130 | target_pid_to_str (lp->ptid)); | |
3131 | ||
3132 | /* Back up the PC if necessary. */ | |
515630c5 UW |
3133 | if (gdbarch_decr_pc_after_break (gdbarch)) |
3134 | regcache_write_pc (regcache, pc); | |
3135 | ||
710151dd PA |
3136 | return 1; |
3137 | } | |
3138 | return 0; | |
3139 | } | |
3140 | ||
d6b0e80f AC |
3141 | static int |
3142 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
3143 | { | |
3144 | struct lwp_info *event_lp = data; | |
3145 | ||
3146 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
3147 | if (lp == event_lp) | |
3148 | return 0; | |
3149 | ||
3150 | /* If a LWP other than the LWP that we're reporting an event for has | |
3151 | hit a GDB breakpoint (as opposed to some random trap signal), | |
3152 | then just arrange for it to hit it again later. We don't keep | |
3153 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3154 | LWP. We will handle the current event, eventually we will resume | |
3155 | all LWPs, and this one will get its breakpoint trap again. | |
3156 | ||
3157 | If we do not do this, then we run the risk that the user will | |
3158 | delete or disable the breakpoint, but the LWP will have already | |
3159 | tripped on it. */ | |
3160 | ||
00390b84 | 3161 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
3162 | && cancel_breakpoint (lp)) |
3163 | /* Throw away the SIGTRAP. */ | |
3164 | lp->status = 0; | |
d6b0e80f AC |
3165 | |
3166 | return 0; | |
3167 | } | |
3168 | ||
3169 | /* Select one LWP out of those that have events pending. */ | |
3170 | ||
3171 | static void | |
d90e17a7 | 3172 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
3173 | { |
3174 | int num_events = 0; | |
3175 | int random_selector; | |
3176 | struct lwp_info *event_lp; | |
3177 | ||
ac264b3b | 3178 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
3179 | (*orig_lp)->status = *status; |
3180 | ||
3181 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
3182 | event_lp = iterate_over_lwps (filter, |
3183 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
3184 | if (event_lp != NULL) |
3185 | { | |
3186 | if (debug_linux_nat) | |
3187 | fprintf_unfiltered (gdb_stdlog, | |
3188 | "SEL: Select single-step %s\n", | |
3189 | target_pid_to_str (event_lp->ptid)); | |
3190 | } | |
3191 | else | |
3192 | { | |
3193 | /* No single-stepping LWP. Select one at random, out of those | |
3194 | which have had SIGTRAP events. */ | |
3195 | ||
3196 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 3197 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
3198 | |
3199 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
3200 | random_selector = (int) | |
3201 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
3202 | ||
3203 | if (debug_linux_nat && num_events > 1) | |
3204 | fprintf_unfiltered (gdb_stdlog, | |
3205 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
3206 | num_events, random_selector); | |
3207 | ||
d90e17a7 PA |
3208 | event_lp = iterate_over_lwps (filter, |
3209 | select_event_lwp_callback, | |
d6b0e80f AC |
3210 | &random_selector); |
3211 | } | |
3212 | ||
3213 | if (event_lp != NULL) | |
3214 | { | |
3215 | /* Switch the event LWP. */ | |
3216 | *orig_lp = event_lp; | |
3217 | *status = event_lp->status; | |
3218 | } | |
3219 | ||
3220 | /* Flush the wait status for the event LWP. */ | |
3221 | (*orig_lp)->status = 0; | |
3222 | } | |
3223 | ||
3224 | /* Return non-zero if LP has been resumed. */ | |
3225 | ||
3226 | static int | |
3227 | resumed_callback (struct lwp_info *lp, void *data) | |
3228 | { | |
3229 | return lp->resumed; | |
3230 | } | |
3231 | ||
12d9289a PA |
3232 | /* Stop an active thread, verify it still exists, then resume it. If |
3233 | the thread ends up with a pending status, then it is not resumed, | |
3234 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
3235 | |
3236 | static int | |
3237 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
3238 | { | |
12d9289a PA |
3239 | int *new_pending_p = data; |
3240 | ||
25289eb2 | 3241 | if (!lp->stopped) |
d6b0e80f | 3242 | { |
25289eb2 PA |
3243 | ptid_t ptid = lp->ptid; |
3244 | ||
d6b0e80f AC |
3245 | stop_callback (lp, NULL); |
3246 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
3247 | |
3248 | /* Resume if the lwp still exists, and the core wanted it | |
3249 | running. */ | |
12d9289a PA |
3250 | lp = find_lwp_pid (ptid); |
3251 | if (lp != NULL) | |
25289eb2 | 3252 | { |
12d9289a PA |
3253 | if (lp->last_resume_kind == resume_stop |
3254 | && lp->status == 0) | |
3255 | { | |
3256 | /* The core wanted the LWP to stop. Even if it stopped | |
3257 | cleanly (with SIGSTOP), leave the event pending. */ | |
3258 | if (debug_linux_nat) | |
3259 | fprintf_unfiltered (gdb_stdlog, | |
3260 | "SARC: core wanted LWP %ld stopped " | |
3261 | "(leaving SIGSTOP pending)\n", | |
3262 | GET_LWP (lp->ptid)); | |
3263 | lp->status = W_STOPCODE (SIGSTOP); | |
3264 | } | |
3265 | ||
3266 | if (lp->status == 0) | |
3267 | { | |
3268 | if (debug_linux_nat) | |
3269 | fprintf_unfiltered (gdb_stdlog, | |
3270 | "SARC: re-resuming LWP %ld\n", | |
3271 | GET_LWP (lp->ptid)); | |
3272 | resume_lwp (lp, lp->step); | |
3273 | } | |
3274 | else | |
3275 | { | |
3276 | if (debug_linux_nat) | |
3277 | fprintf_unfiltered (gdb_stdlog, | |
3278 | "SARC: not re-resuming LWP %ld " | |
3279 | "(has pending)\n", | |
3280 | GET_LWP (lp->ptid)); | |
3281 | if (new_pending_p) | |
3282 | *new_pending_p = 1; | |
3283 | } | |
25289eb2 | 3284 | } |
d6b0e80f AC |
3285 | } |
3286 | return 0; | |
3287 | } | |
3288 | ||
02f3fc28 | 3289 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
3290 | Return the affected lwp if we are, or NULL otherwise. If we stop |
3291 | all lwps temporarily, we may end up with new pending events in some | |
3292 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
3293 | ||
02f3fc28 | 3294 | static struct lwp_info * |
0e5bf2a8 | 3295 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
3296 | { |
3297 | struct lwp_info *lp; | |
3298 | ||
12d9289a PA |
3299 | *new_pending_p = 0; |
3300 | ||
02f3fc28 PA |
3301 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
3302 | ||
3303 | /* Check for stop events reported by a process we didn't already | |
3304 | know about - anything not already in our LWP list. | |
3305 | ||
3306 | If we're expecting to receive stopped processes after | |
3307 | fork, vfork, and clone events, then we'll just add the | |
3308 | new one to our list and go back to waiting for the event | |
3309 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
3310 | from waitpid before or after the event is. |
3311 | ||
3312 | But note the case of a non-leader thread exec'ing after the | |
3313 | leader having exited, and gone from our lists. The non-leader | |
3314 | thread changes its tid to the tgid. */ | |
3315 | ||
3316 | if (WIFSTOPPED (status) && lp == NULL | |
3317 | && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) | |
3318 | { | |
3319 | /* A multi-thread exec after we had seen the leader exiting. */ | |
3320 | if (debug_linux_nat) | |
3321 | fprintf_unfiltered (gdb_stdlog, | |
3322 | "LLW: Re-adding thread group leader LWP %d.\n", | |
3323 | lwpid); | |
3324 | ||
3325 | lp = add_lwp (BUILD_LWP (lwpid, lwpid)); | |
3326 | lp->stopped = 1; | |
3327 | lp->resumed = 1; | |
3328 | add_thread (lp->ptid); | |
3329 | } | |
3330 | ||
02f3fc28 PA |
3331 | if (WIFSTOPPED (status) && !lp) |
3332 | { | |
84636d28 | 3333 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
3334 | return NULL; |
3335 | } | |
3336 | ||
3337 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3338 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3339 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3340 | exits. */ |
3341 | if (!WIFSTOPPED (status) && !lp) | |
3342 | return NULL; | |
3343 | ||
ca2163eb PA |
3344 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3345 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3346 | { | |
3347 | /* No longer need the sysgood bit. The ptrace event ends up | |
3348 | recorded in lp->waitstatus if we care for it. We can carry | |
3349 | on handling the event like a regular SIGTRAP from here | |
3350 | on. */ | |
3351 | status = W_STOPCODE (SIGTRAP); | |
3352 | if (linux_handle_syscall_trap (lp, 0)) | |
3353 | return NULL; | |
3354 | } | |
02f3fc28 | 3355 | |
ca2163eb PA |
3356 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
3357 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
02f3fc28 PA |
3358 | { |
3359 | if (debug_linux_nat) | |
3360 | fprintf_unfiltered (gdb_stdlog, | |
3361 | "LLW: Handling extended status 0x%06x\n", | |
3362 | status); | |
3363 | if (linux_handle_extended_wait (lp, status, 0)) | |
3364 | return NULL; | |
3365 | } | |
3366 | ||
26ab7092 | 3367 | if (linux_nat_status_is_event (status)) |
ebec9a0f PA |
3368 | { |
3369 | /* Save the trap's siginfo in case we need it later. */ | |
3370 | save_siginfo (lp); | |
3371 | ||
3372 | save_sigtrap (lp); | |
3373 | } | |
ca2163eb | 3374 | |
02f3fc28 | 3375 | /* Check if the thread has exited. */ |
d90e17a7 PA |
3376 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
3377 | && num_lwps (GET_PID (lp->ptid)) > 1) | |
02f3fc28 | 3378 | { |
9db03742 JB |
3379 | /* If this is the main thread, we must stop all threads and verify |
3380 | if they are still alive. This is because in the nptl thread model | |
3381 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
3382 | other than the main thread. We only get the main thread exit |
3383 | signal once all child threads have already exited. If we | |
3384 | stop all the threads and use the stop_wait_callback to check | |
3385 | if they have exited we can determine whether this signal | |
3386 | should be ignored or whether it means the end of the debugged | |
3387 | application, regardless of which threading model is being | |
5d3b6af6 | 3388 | used. */ |
02f3fc28 PA |
3389 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
3390 | { | |
3391 | lp->stopped = 1; | |
d90e17a7 | 3392 | iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
12d9289a | 3393 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
3394 | } |
3395 | ||
3396 | if (debug_linux_nat) | |
3397 | fprintf_unfiltered (gdb_stdlog, | |
3398 | "LLW: %s exited.\n", | |
3399 | target_pid_to_str (lp->ptid)); | |
3400 | ||
d90e17a7 | 3401 | if (num_lwps (GET_PID (lp->ptid)) > 1) |
9db03742 JB |
3402 | { |
3403 | /* If there is at least one more LWP, then the exit signal | |
3404 | was not the end of the debugged application and should be | |
3405 | ignored. */ | |
3406 | exit_lwp (lp); | |
3407 | return NULL; | |
3408 | } | |
02f3fc28 PA |
3409 | } |
3410 | ||
3411 | /* Check if the current LWP has previously exited. In the nptl | |
3412 | thread model, LWPs other than the main thread do not issue | |
3413 | signals when they exit so we must check whenever the thread has | |
3414 | stopped. A similar check is made in stop_wait_callback(). */ | |
d90e17a7 | 3415 | if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3416 | { |
d90e17a7 PA |
3417 | ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
3418 | ||
02f3fc28 PA |
3419 | if (debug_linux_nat) |
3420 | fprintf_unfiltered (gdb_stdlog, | |
3421 | "LLW: %s exited.\n", | |
3422 | target_pid_to_str (lp->ptid)); | |
3423 | ||
3424 | exit_lwp (lp); | |
3425 | ||
3426 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3427 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3428 | |
3429 | /* Discard the event. */ | |
3430 | return NULL; | |
3431 | } | |
3432 | ||
3433 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3434 | an attempt to stop an LWP. */ | |
3435 | if (lp->signalled | |
3436 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3437 | { | |
3438 | if (debug_linux_nat) | |
3439 | fprintf_unfiltered (gdb_stdlog, | |
3440 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3441 | target_pid_to_str (lp->ptid)); | |
3442 | ||
02f3fc28 PA |
3443 | lp->signalled = 0; |
3444 | ||
25289eb2 PA |
3445 | if (lp->last_resume_kind != resume_stop) |
3446 | { | |
3447 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3448 | |
25289eb2 PA |
3449 | registers_changed (); |
3450 | ||
7b50312a PA |
3451 | if (linux_nat_prepare_to_resume != NULL) |
3452 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 3453 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
02f3fc28 | 3454 | lp->step, TARGET_SIGNAL_0); |
25289eb2 PA |
3455 | if (debug_linux_nat) |
3456 | fprintf_unfiltered (gdb_stdlog, | |
3457 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3458 | lp->step ? | |
3459 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3460 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3461 | |
25289eb2 PA |
3462 | lp->stopped = 0; |
3463 | gdb_assert (lp->resumed); | |
02f3fc28 | 3464 | |
25289eb2 PA |
3465 | /* Discard the event. */ |
3466 | return NULL; | |
3467 | } | |
02f3fc28 PA |
3468 | } |
3469 | ||
57380f4e DJ |
3470 | /* Make sure we don't report a SIGINT that we have already displayed |
3471 | for another thread. */ | |
3472 | if (lp->ignore_sigint | |
3473 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3474 | { | |
3475 | if (debug_linux_nat) | |
3476 | fprintf_unfiltered (gdb_stdlog, | |
3477 | "LLW: Delayed SIGINT caught for %s.\n", | |
3478 | target_pid_to_str (lp->ptid)); | |
3479 | ||
3480 | /* This is a delayed SIGINT. */ | |
3481 | lp->ignore_sigint = 0; | |
3482 | ||
3483 | registers_changed (); | |
7b50312a PA |
3484 | if (linux_nat_prepare_to_resume != NULL) |
3485 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3486 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
57380f4e DJ |
3487 | lp->step, TARGET_SIGNAL_0); |
3488 | if (debug_linux_nat) | |
3489 | fprintf_unfiltered (gdb_stdlog, | |
3490 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3491 | lp->step ? | |
3492 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3493 | target_pid_to_str (lp->ptid)); | |
3494 | ||
3495 | lp->stopped = 0; | |
3496 | gdb_assert (lp->resumed); | |
3497 | ||
3498 | /* Discard the event. */ | |
3499 | return NULL; | |
3500 | } | |
3501 | ||
02f3fc28 PA |
3502 | /* An interesting event. */ |
3503 | gdb_assert (lp); | |
ca2163eb | 3504 | lp->status = status; |
02f3fc28 PA |
3505 | return lp; |
3506 | } | |
3507 | ||
0e5bf2a8 PA |
3508 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3509 | their exits until all other threads in the group have exited. */ | |
3510 | ||
3511 | static void | |
3512 | check_zombie_leaders (void) | |
3513 | { | |
3514 | struct inferior *inf; | |
3515 | ||
3516 | ALL_INFERIORS (inf) | |
3517 | { | |
3518 | struct lwp_info *leader_lp; | |
3519 | ||
3520 | if (inf->pid == 0) | |
3521 | continue; | |
3522 | ||
3523 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3524 | if (leader_lp != NULL | |
3525 | /* Check if there are other threads in the group, as we may | |
3526 | have raced with the inferior simply exiting. */ | |
3527 | && num_lwps (inf->pid) > 1 | |
3528 | && linux_lwp_is_zombie (inf->pid)) | |
3529 | { | |
3530 | if (debug_linux_nat) | |
3531 | fprintf_unfiltered (gdb_stdlog, | |
3532 | "CZL: Thread group leader %d zombie " | |
3533 | "(it exited, or another thread execd).\n", | |
3534 | inf->pid); | |
3535 | ||
3536 | /* A leader zombie can mean one of two things: | |
3537 | ||
3538 | - It exited, and there's an exit status pending | |
3539 | available, or only the leader exited (not the whole | |
3540 | program). In the latter case, we can't waitpid the | |
3541 | leader's exit status until all other threads are gone. | |
3542 | ||
3543 | - There are 3 or more threads in the group, and a thread | |
3544 | other than the leader exec'd. On an exec, the Linux | |
3545 | kernel destroys all other threads (except the execing | |
3546 | one) in the thread group, and resets the execing thread's | |
3547 | tid to the tgid. No exit notification is sent for the | |
3548 | execing thread -- from the ptracer's perspective, it | |
3549 | appears as though the execing thread just vanishes. | |
3550 | Until we reap all other threads except the leader and the | |
3551 | execing thread, the leader will be zombie, and the | |
3552 | execing thread will be in `D (disc sleep)'. As soon as | |
3553 | all other threads are reaped, the execing thread changes | |
3554 | it's tid to the tgid, and the previous (zombie) leader | |
3555 | vanishes, giving place to the "new" leader. We could try | |
3556 | distinguishing the exit and exec cases, by waiting once | |
3557 | more, and seeing if something comes out, but it doesn't | |
3558 | sound useful. The previous leader _does_ go away, and | |
3559 | we'll re-add the new one once we see the exec event | |
3560 | (which is just the same as what would happen if the | |
3561 | previous leader did exit voluntarily before some other | |
3562 | thread execs). */ | |
3563 | ||
3564 | if (debug_linux_nat) | |
3565 | fprintf_unfiltered (gdb_stdlog, | |
3566 | "CZL: Thread group leader %d vanished.\n", | |
3567 | inf->pid); | |
3568 | exit_lwp (leader_lp); | |
3569 | } | |
3570 | } | |
3571 | } | |
3572 | ||
d6b0e80f | 3573 | static ptid_t |
7feb7d06 | 3574 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3575 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3576 | int target_options) | |
d6b0e80f | 3577 | { |
7feb7d06 | 3578 | static sigset_t prev_mask; |
4b60df3d | 3579 | enum resume_kind last_resume_kind; |
12d9289a | 3580 | struct lwp_info *lp; |
12d9289a | 3581 | int status; |
d6b0e80f | 3582 | |
01124a23 | 3583 | if (debug_linux_nat) |
b84876c2 PA |
3584 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3585 | ||
f973ed9c DJ |
3586 | /* The first time we get here after starting a new inferior, we may |
3587 | not have added it to the LWP list yet - this is the earliest | |
3588 | moment at which we know its PID. */ | |
d90e17a7 | 3589 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3590 | { |
27c9d204 PA |
3591 | /* Upgrade the main thread's ptid. */ |
3592 | thread_change_ptid (inferior_ptid, | |
3593 | BUILD_LWP (GET_PID (inferior_ptid), | |
3594 | GET_PID (inferior_ptid))); | |
3595 | ||
f973ed9c DJ |
3596 | lp = add_lwp (inferior_ptid); |
3597 | lp->resumed = 1; | |
3598 | } | |
3599 | ||
7feb7d06 PA |
3600 | /* Make sure SIGCHLD is blocked. */ |
3601 | block_child_signals (&prev_mask); | |
d6b0e80f AC |
3602 | |
3603 | retry: | |
d90e17a7 PA |
3604 | lp = NULL; |
3605 | status = 0; | |
d6b0e80f AC |
3606 | |
3607 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3608 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3609 | { |
0e5bf2a8 | 3610 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3611 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3612 | if (lp) |
3613 | { | |
ca2163eb | 3614 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3615 | fprintf_unfiltered (gdb_stdlog, |
3616 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3617 | status_to_str (lp->status), |
d6b0e80f AC |
3618 | target_pid_to_str (lp->ptid)); |
3619 | } | |
d6b0e80f AC |
3620 | } |
3621 | else if (is_lwp (ptid)) | |
3622 | { | |
3623 | if (debug_linux_nat) | |
3624 | fprintf_unfiltered (gdb_stdlog, | |
3625 | "LLW: Waiting for specific LWP %s.\n", | |
3626 | target_pid_to_str (ptid)); | |
3627 | ||
3628 | /* We have a specific LWP to check. */ | |
3629 | lp = find_lwp_pid (ptid); | |
3630 | gdb_assert (lp); | |
d6b0e80f | 3631 | |
ca2163eb | 3632 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3633 | fprintf_unfiltered (gdb_stdlog, |
3634 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3635 | status_to_str (lp->status), |
d6b0e80f AC |
3636 | target_pid_to_str (lp->ptid)); |
3637 | ||
d90e17a7 PA |
3638 | /* We check for lp->waitstatus in addition to lp->status, |
3639 | because we can have pending process exits recorded in | |
3640 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3641 | an additional lp->status_p flag. */ | |
ca2163eb | 3642 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3643 | lp = NULL; |
d6b0e80f AC |
3644 | } |
3645 | ||
25289eb2 | 3646 | if (lp && lp->signalled && lp->last_resume_kind != resume_stop) |
d6b0e80f AC |
3647 | { |
3648 | /* A pending SIGSTOP may interfere with the normal stream of | |
3649 | events. In a typical case where interference is a problem, | |
3650 | we have a SIGSTOP signal pending for LWP A while | |
3651 | single-stepping it, encounter an event in LWP B, and take the | |
3652 | pending SIGSTOP while trying to stop LWP A. After processing | |
3653 | the event in LWP B, LWP A is continued, and we'll never see | |
3654 | the SIGTRAP associated with the last time we were | |
3655 | single-stepping LWP A. */ | |
3656 | ||
3657 | /* Resume the thread. It should halt immediately returning the | |
3658 | pending SIGSTOP. */ | |
3659 | registers_changed (); | |
7b50312a PA |
3660 | if (linux_nat_prepare_to_resume != NULL) |
3661 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3662 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3663 | lp->step, TARGET_SIGNAL_0); |
d6b0e80f AC |
3664 | if (debug_linux_nat) |
3665 | fprintf_unfiltered (gdb_stdlog, | |
3666 | "LLW: %s %s, 0, 0 (expect SIGSTOP)\n", | |
3667 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3668 | target_pid_to_str (lp->ptid)); | |
3669 | lp->stopped = 0; | |
3670 | gdb_assert (lp->resumed); | |
3671 | ||
ca2163eb PA |
3672 | /* Catch the pending SIGSTOP. */ |
3673 | status = lp->status; | |
3674 | lp->status = 0; | |
3675 | ||
d6b0e80f | 3676 | stop_wait_callback (lp, NULL); |
ca2163eb PA |
3677 | |
3678 | /* If the lp->status field isn't empty, we caught another signal | |
3679 | while flushing the SIGSTOP. Return it back to the event | |
3680 | queue of the LWP, as we already have an event to handle. */ | |
3681 | if (lp->status) | |
3682 | { | |
3683 | if (debug_linux_nat) | |
3684 | fprintf_unfiltered (gdb_stdlog, | |
3685 | "LLW: kill %s, %s\n", | |
3686 | target_pid_to_str (lp->ptid), | |
3687 | status_to_str (lp->status)); | |
3688 | kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status)); | |
3689 | } | |
3690 | ||
3691 | lp->status = status; | |
d6b0e80f AC |
3692 | } |
3693 | ||
b84876c2 PA |
3694 | if (!target_can_async_p ()) |
3695 | { | |
3696 | /* Causes SIGINT to be passed on to the attached process. */ | |
3697 | set_sigint_trap (); | |
b84876c2 | 3698 | } |
d6b0e80f | 3699 | |
0e5bf2a8 | 3700 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3701 | |
d90e17a7 | 3702 | while (lp == NULL) |
d6b0e80f AC |
3703 | { |
3704 | pid_t lwpid; | |
3705 | ||
0e5bf2a8 PA |
3706 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3707 | quirks: | |
3708 | ||
3709 | - If the thread group leader exits while other threads in the | |
3710 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3711 | waitpid won't return an exit status until the other threads | |
3712 | in the group are reapped. | |
3713 | ||
3714 | - When a non-leader thread execs, that thread just vanishes | |
3715 | without reporting an exit (so we'd hang if we waited for it | |
3716 | explicitly in that case). The exec event is reported to | |
3717 | the TGID pid. */ | |
3718 | ||
3719 | errno = 0; | |
3720 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3721 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3722 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3723 | ||
3724 | if (debug_linux_nat) | |
3725 | fprintf_unfiltered (gdb_stdlog, | |
3726 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3727 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3728 | |
d6b0e80f AC |
3729 | if (lwpid > 0) |
3730 | { | |
12d9289a PA |
3731 | /* If this is true, then we paused LWPs momentarily, and may |
3732 | now have pending events to handle. */ | |
3733 | int new_pending; | |
3734 | ||
d6b0e80f AC |
3735 | if (debug_linux_nat) |
3736 | { | |
3737 | fprintf_unfiltered (gdb_stdlog, | |
3738 | "LLW: waitpid %ld received %s\n", | |
3739 | (long) lwpid, status_to_str (status)); | |
3740 | } | |
3741 | ||
0e5bf2a8 | 3742 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3743 | |
33355866 JK |
3744 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3745 | status = 0; | |
3746 | ||
0e5bf2a8 | 3747 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3748 | { |
e3e9f5a2 PA |
3749 | gdb_assert (lp->resumed); |
3750 | ||
d90e17a7 | 3751 | if (debug_linux_nat) |
3e43a32a MS |
3752 | fprintf (stderr, |
3753 | "LWP %ld got an event %06x, leaving pending.\n", | |
33355866 | 3754 | ptid_get_lwp (lp->ptid), lp->status); |
d90e17a7 | 3755 | |
ca2163eb | 3756 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3757 | { |
ca2163eb | 3758 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3759 | { |
e3e9f5a2 PA |
3760 | /* Cancel breakpoint hits. The breakpoint may |
3761 | be removed before we fetch events from this | |
3762 | process to report to the core. It is best | |
3763 | not to assume the moribund breakpoints | |
3764 | heuristic always handles these cases --- it | |
3765 | could be too many events go through to the | |
3766 | core before this one is handled. All-stop | |
3767 | always cancels breakpoint hits in all | |
3768 | threads. */ | |
3769 | if (non_stop | |
00390b84 | 3770 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3771 | && cancel_breakpoint (lp)) |
3772 | { | |
3773 | /* Throw away the SIGTRAP. */ | |
3774 | lp->status = 0; | |
3775 | ||
3776 | if (debug_linux_nat) | |
3777 | fprintf (stderr, | |
3e43a32a MS |
3778 | "LLW: LWP %ld hit a breakpoint while" |
3779 | " waiting for another process;" | |
3780 | " cancelled it\n", | |
e3e9f5a2 PA |
3781 | ptid_get_lwp (lp->ptid)); |
3782 | } | |
3783 | lp->stopped = 1; | |
d90e17a7 PA |
3784 | } |
3785 | else | |
3786 | { | |
3787 | lp->stopped = 1; | |
3788 | lp->signalled = 0; | |
3789 | } | |
3790 | } | |
33355866 | 3791 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3792 | { |
3793 | if (debug_linux_nat) | |
3e43a32a MS |
3794 | fprintf (stderr, |
3795 | "Process %ld exited while stopping LWPs\n", | |
d90e17a7 PA |
3796 | ptid_get_lwp (lp->ptid)); |
3797 | ||
3798 | /* This was the last lwp in the process. Since | |
3799 | events are serialized to GDB core, and we can't | |
3800 | report this one right now, but GDB core and the | |
3801 | other target layers will want to be notified | |
3802 | about the exit code/signal, leave the status | |
3803 | pending for the next time we're able to report | |
3804 | it. */ | |
d90e17a7 PA |
3805 | |
3806 | /* Prevent trying to stop this thread again. We'll | |
3807 | never try to resume it because it has a pending | |
3808 | status. */ | |
3809 | lp->stopped = 1; | |
3810 | ||
3811 | /* Dead LWP's aren't expected to reported a pending | |
3812 | sigstop. */ | |
3813 | lp->signalled = 0; | |
3814 | ||
3815 | /* Store the pending event in the waitstatus as | |
3816 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3817 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3818 | } |
3819 | ||
3820 | /* Keep looking. */ | |
3821 | lp = NULL; | |
d6b0e80f AC |
3822 | } |
3823 | ||
0e5bf2a8 | 3824 | if (new_pending) |
d90e17a7 | 3825 | { |
0e5bf2a8 PA |
3826 | /* Some LWP now has a pending event. Go all the way |
3827 | back to check it. */ | |
3828 | goto retry; | |
3829 | } | |
12d9289a | 3830 | |
0e5bf2a8 PA |
3831 | if (lp) |
3832 | { | |
3833 | /* We got an event to report to the core. */ | |
3834 | break; | |
d90e17a7 | 3835 | } |
0e5bf2a8 PA |
3836 | |
3837 | /* Retry until nothing comes out of waitpid. A single | |
3838 | SIGCHLD can indicate more than one child stopped. */ | |
3839 | continue; | |
d6b0e80f AC |
3840 | } |
3841 | ||
0e5bf2a8 PA |
3842 | /* Check for zombie thread group leaders. Those can't be reaped |
3843 | until all other threads in the thread group are. */ | |
3844 | check_zombie_leaders (); | |
d6b0e80f | 3845 | |
0e5bf2a8 PA |
3846 | /* If there are no resumed children left, bail. We'd be stuck |
3847 | forever in the sigsuspend call below otherwise. */ | |
3848 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3849 | { | |
3850 | if (debug_linux_nat) | |
3851 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3852 | |
0e5bf2a8 | 3853 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3854 | |
0e5bf2a8 PA |
3855 | if (!target_can_async_p ()) |
3856 | clear_sigint_trap (); | |
b84876c2 | 3857 | |
0e5bf2a8 PA |
3858 | restore_child_signals_mask (&prev_mask); |
3859 | return minus_one_ptid; | |
d6b0e80f | 3860 | } |
28736962 | 3861 | |
0e5bf2a8 PA |
3862 | /* No interesting event to report to the core. */ |
3863 | ||
3864 | if (target_options & TARGET_WNOHANG) | |
3865 | { | |
01124a23 | 3866 | if (debug_linux_nat) |
28736962 PA |
3867 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3868 | ||
0e5bf2a8 | 3869 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3870 | restore_child_signals_mask (&prev_mask); |
3871 | return minus_one_ptid; | |
3872 | } | |
d6b0e80f AC |
3873 | |
3874 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3875 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3876 | |
3877 | /* Block until we get an event reported with SIGCHLD. */ | |
3878 | sigsuspend (&suspend_mask); | |
d6b0e80f AC |
3879 | } |
3880 | ||
b84876c2 | 3881 | if (!target_can_async_p ()) |
d26b5354 | 3882 | clear_sigint_trap (); |
d6b0e80f AC |
3883 | |
3884 | gdb_assert (lp); | |
3885 | ||
ca2163eb PA |
3886 | status = lp->status; |
3887 | lp->status = 0; | |
3888 | ||
d6b0e80f AC |
3889 | /* Don't report signals that GDB isn't interested in, such as |
3890 | signals that are neither printed nor stopped upon. Stopping all | |
3891 | threads can be a bit time-consuming so if we want decent | |
3892 | performance with heavily multi-threaded programs, especially when | |
3893 | they're using a high frequency timer, we'd better avoid it if we | |
3894 | can. */ | |
3895 | ||
3896 | if (WIFSTOPPED (status)) | |
3897 | { | |
423ec54c | 3898 | enum target_signal signo = target_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3899 | |
2455069d UW |
3900 | /* When using hardware single-step, we need to report every signal. |
3901 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3902 | if (!lp->step |
2455069d | 3903 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3904 | { |
3905 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3906 | here? It is not clear we should. GDB may not expect | |
3907 | other threads to run. On the other hand, not resuming | |
3908 | newly attached threads may cause an unwanted delay in | |
3909 | getting them running. */ | |
3910 | registers_changed (); | |
7b50312a PA |
3911 | if (linux_nat_prepare_to_resume != NULL) |
3912 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3913 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3914 | lp->step, signo); |
d6b0e80f AC |
3915 | if (debug_linux_nat) |
3916 | fprintf_unfiltered (gdb_stdlog, | |
3917 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3918 | lp->step ? | |
3919 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3920 | target_pid_to_str (lp->ptid), | |
423ec54c JK |
3921 | (signo != TARGET_SIGNAL_0 |
3922 | ? strsignal (target_signal_to_host (signo)) | |
3923 | : "0")); | |
d6b0e80f | 3924 | lp->stopped = 0; |
d6b0e80f AC |
3925 | goto retry; |
3926 | } | |
3927 | ||
1ad15515 | 3928 | if (!non_stop) |
d6b0e80f | 3929 | { |
1ad15515 PA |
3930 | /* Only do the below in all-stop, as we currently use SIGINT |
3931 | to implement target_stop (see linux_nat_stop) in | |
3932 | non-stop. */ | |
3933 | if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3934 | { | |
3935 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3936 | forwarded to the entire process group, that is, all LWPs | |
3937 | will receive it - unless they're using CLONE_THREAD to | |
3938 | share signals. Since we only want to report it once, we | |
3939 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3940 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3941 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3942 | lp->ignore_sigint = 0; |
3943 | } | |
3944 | else | |
3945 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3946 | } |
3947 | } | |
3948 | ||
3949 | /* This LWP is stopped now. */ | |
3950 | lp->stopped = 1; | |
3951 | ||
3952 | if (debug_linux_nat) | |
3953 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3954 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3955 | ||
4c28f408 PA |
3956 | if (!non_stop) |
3957 | { | |
3958 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3959 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3960 | |
3961 | /* ... and wait until all of them have reported back that | |
3962 | they're no longer running. */ | |
d90e17a7 | 3963 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3964 | |
3965 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3966 | from among those that have had events. Giving equal priority | |
3967 | to all LWPs that have had events helps prevent | |
3968 | starvation. */ | |
0e5bf2a8 | 3969 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3970 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3971 | |
e3e9f5a2 PA |
3972 | /* Now that we've selected our final event LWP, cancel any |
3973 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3974 | See the comment in cancel_breakpoints_callback to find out | |
3975 | why. */ | |
3976 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3977 | ||
4b60df3d PA |
3978 | /* We'll need this to determine whether to report a SIGSTOP as |
3979 | TARGET_WAITKIND_0. Need to take a copy because | |
3980 | resume_clear_callback clears it. */ | |
3981 | last_resume_kind = lp->last_resume_kind; | |
3982 | ||
e3e9f5a2 PA |
3983 | /* In all-stop, from the core's perspective, all LWPs are now |
3984 | stopped until a new resume action is sent over. */ | |
3985 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3986 | } | |
3987 | else | |
25289eb2 | 3988 | { |
4b60df3d PA |
3989 | /* See above. */ |
3990 | last_resume_kind = lp->last_resume_kind; | |
3991 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3992 | } |
d6b0e80f | 3993 | |
26ab7092 | 3994 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3995 | { |
d6b0e80f AC |
3996 | if (debug_linux_nat) |
3997 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3998 | "LLW: trap ptid is %s.\n", |
3999 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 4000 | } |
d6b0e80f AC |
4001 | |
4002 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
4003 | { | |
4004 | *ourstatus = lp->waitstatus; | |
4005 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
4006 | } | |
4007 | else | |
4008 | store_waitstatus (ourstatus, status); | |
4009 | ||
01124a23 | 4010 | if (debug_linux_nat) |
b84876c2 PA |
4011 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
4012 | ||
7feb7d06 | 4013 | restore_child_signals_mask (&prev_mask); |
1e225492 | 4014 | |
4b60df3d | 4015 | if (last_resume_kind == resume_stop |
25289eb2 PA |
4016 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
4017 | && WSTOPSIG (status) == SIGSTOP) | |
4018 | { | |
4019 | /* A thread that has been requested to stop by GDB with | |
4020 | target_stop, and it stopped cleanly, so report as SIG0. The | |
4021 | use of SIGSTOP is an implementation detail. */ | |
4022 | ourstatus->value.sig = TARGET_SIGNAL_0; | |
4023 | } | |
4024 | ||
1e225492 JK |
4025 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
4026 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
4027 | lp->core = -1; | |
4028 | else | |
4029 | lp->core = linux_nat_core_of_thread_1 (lp->ptid); | |
4030 | ||
f973ed9c | 4031 | return lp->ptid; |
d6b0e80f AC |
4032 | } |
4033 | ||
e3e9f5a2 PA |
4034 | /* Resume LWPs that are currently stopped without any pending status |
4035 | to report, but are resumed from the core's perspective. */ | |
4036 | ||
4037 | static int | |
4038 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
4039 | { | |
4040 | ptid_t *wait_ptid_p = data; | |
4041 | ||
4042 | if (lp->stopped | |
4043 | && lp->resumed | |
4044 | && lp->status == 0 | |
4045 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
4046 | { | |
336060f3 PA |
4047 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
4048 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
4049 | CORE_ADDR pc = regcache_read_pc (regcache); | |
4050 | ||
e3e9f5a2 PA |
4051 | gdb_assert (is_executing (lp->ptid)); |
4052 | ||
4053 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
4054 | immediately, and we're not waiting for this LWP. */ | |
4055 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
4056 | { | |
e3e9f5a2 PA |
4057 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
4058 | return 0; | |
4059 | } | |
4060 | ||
4061 | if (debug_linux_nat) | |
4062 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
4063 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
4064 | target_pid_to_str (lp->ptid), | |
4065 | paddress (gdbarch, pc), | |
4066 | lp->step); | |
e3e9f5a2 | 4067 | |
336060f3 | 4068 | registers_changed (); |
7b50312a PA |
4069 | if (linux_nat_prepare_to_resume != NULL) |
4070 | linux_nat_prepare_to_resume (lp); | |
e3e9f5a2 PA |
4071 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
4072 | lp->step, TARGET_SIGNAL_0); | |
4073 | lp->stopped = 0; | |
4074 | memset (&lp->siginfo, 0, sizeof (lp->siginfo)); | |
4075 | lp->stopped_by_watchpoint = 0; | |
4076 | } | |
4077 | ||
4078 | return 0; | |
4079 | } | |
4080 | ||
7feb7d06 PA |
4081 | static ptid_t |
4082 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
4083 | ptid_t ptid, struct target_waitstatus *ourstatus, |
4084 | int target_options) | |
7feb7d06 PA |
4085 | { |
4086 | ptid_t event_ptid; | |
4087 | ||
4088 | if (debug_linux_nat) | |
3e43a32a MS |
4089 | fprintf_unfiltered (gdb_stdlog, |
4090 | "linux_nat_wait: [%s]\n", target_pid_to_str (ptid)); | |
7feb7d06 PA |
4091 | |
4092 | /* Flush the async file first. */ | |
4093 | if (target_can_async_p ()) | |
4094 | async_file_flush (); | |
4095 | ||
e3e9f5a2 PA |
4096 | /* Resume LWPs that are currently stopped without any pending status |
4097 | to report, but are resumed from the core's perspective. LWPs get | |
4098 | in this state if we find them stopping at a time we're not | |
4099 | interested in reporting the event (target_wait on a | |
4100 | specific_process, for example, see linux_nat_wait_1), and | |
4101 | meanwhile the event became uninteresting. Don't bother resuming | |
4102 | LWPs we're not going to wait for if they'd stop immediately. */ | |
4103 | if (non_stop) | |
4104 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
4105 | ||
47608cb1 | 4106 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
4107 | |
4108 | /* If we requested any event, and something came out, assume there | |
4109 | may be more. If we requested a specific lwp or process, also | |
4110 | assume there may be more. */ | |
4111 | if (target_can_async_p () | |
6953d224 PA |
4112 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
4113 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
4114 | || !ptid_equal (ptid, minus_one_ptid))) |
4115 | async_file_mark (); | |
4116 | ||
4117 | /* Get ready for the next event. */ | |
4118 | if (target_can_async_p ()) | |
4119 | target_async (inferior_event_handler, 0); | |
4120 | ||
4121 | return event_ptid; | |
4122 | } | |
4123 | ||
d6b0e80f AC |
4124 | static int |
4125 | kill_callback (struct lwp_info *lp, void *data) | |
4126 | { | |
ed731959 JK |
4127 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
4128 | ||
4129 | errno = 0; | |
4130 | kill (GET_LWP (lp->ptid), SIGKILL); | |
4131 | if (debug_linux_nat) | |
4132 | fprintf_unfiltered (gdb_stdlog, | |
4133 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
4134 | target_pid_to_str (lp->ptid), | |
4135 | errno ? safe_strerror (errno) : "OK"); | |
4136 | ||
4137 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
4138 | ||
d6b0e80f AC |
4139 | errno = 0; |
4140 | ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); | |
4141 | if (debug_linux_nat) | |
4142 | fprintf_unfiltered (gdb_stdlog, | |
4143 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
4144 | target_pid_to_str (lp->ptid), | |
4145 | errno ? safe_strerror (errno) : "OK"); | |
4146 | ||
4147 | return 0; | |
4148 | } | |
4149 | ||
4150 | static int | |
4151 | kill_wait_callback (struct lwp_info *lp, void *data) | |
4152 | { | |
4153 | pid_t pid; | |
4154 | ||
4155 | /* We must make sure that there are no pending events (delayed | |
4156 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
4157 | program doesn't interfere with any following debugging session. */ | |
4158 | ||
4159 | /* For cloned processes we must check both with __WCLONE and | |
4160 | without, since the exit status of a cloned process isn't reported | |
4161 | with __WCLONE. */ | |
4162 | if (lp->cloned) | |
4163 | { | |
4164 | do | |
4165 | { | |
58aecb61 | 4166 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
e85a822c | 4167 | if (pid != (pid_t) -1) |
d6b0e80f | 4168 | { |
e85a822c DJ |
4169 | if (debug_linux_nat) |
4170 | fprintf_unfiltered (gdb_stdlog, | |
4171 | "KWC: wait %s received unknown.\n", | |
4172 | target_pid_to_str (lp->ptid)); | |
4173 | /* The Linux kernel sometimes fails to kill a thread | |
4174 | completely after PTRACE_KILL; that goes from the stop | |
4175 | point in do_fork out to the one in | |
4176 | get_signal_to_deliever and waits again. So kill it | |
4177 | again. */ | |
4178 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4179 | } |
4180 | } | |
4181 | while (pid == GET_LWP (lp->ptid)); | |
4182 | ||
4183 | gdb_assert (pid == -1 && errno == ECHILD); | |
4184 | } | |
4185 | ||
4186 | do | |
4187 | { | |
58aecb61 | 4188 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
e85a822c | 4189 | if (pid != (pid_t) -1) |
d6b0e80f | 4190 | { |
e85a822c DJ |
4191 | if (debug_linux_nat) |
4192 | fprintf_unfiltered (gdb_stdlog, | |
4193 | "KWC: wait %s received unk.\n", | |
4194 | target_pid_to_str (lp->ptid)); | |
4195 | /* See the call to kill_callback above. */ | |
4196 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4197 | } |
4198 | } | |
4199 | while (pid == GET_LWP (lp->ptid)); | |
4200 | ||
4201 | gdb_assert (pid == -1 && errno == ECHILD); | |
4202 | return 0; | |
4203 | } | |
4204 | ||
4205 | static void | |
7d85a9c0 | 4206 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 4207 | { |
f973ed9c DJ |
4208 | struct target_waitstatus last; |
4209 | ptid_t last_ptid; | |
4210 | int status; | |
d6b0e80f | 4211 | |
f973ed9c DJ |
4212 | /* If we're stopped while forking and we haven't followed yet, |
4213 | kill the other task. We need to do this first because the | |
4214 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 4215 | |
f973ed9c | 4216 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 4217 | |
f973ed9c DJ |
4218 | if (last.kind == TARGET_WAITKIND_FORKED |
4219 | || last.kind == TARGET_WAITKIND_VFORKED) | |
4220 | { | |
3a3e9ee3 | 4221 | ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
f973ed9c DJ |
4222 | wait (&status); |
4223 | } | |
4224 | ||
4225 | if (forks_exist_p ()) | |
7feb7d06 | 4226 | linux_fork_killall (); |
f973ed9c DJ |
4227 | else |
4228 | { | |
d90e17a7 | 4229 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 4230 | |
4c28f408 PA |
4231 | /* Stop all threads before killing them, since ptrace requires |
4232 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 4233 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
4234 | /* ... and wait until all of them have reported back that |
4235 | they're no longer running. */ | |
d90e17a7 | 4236 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 4237 | |
f973ed9c | 4238 | /* Kill all LWP's ... */ |
d90e17a7 | 4239 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
4240 | |
4241 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 4242 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
4243 | } |
4244 | ||
4245 | target_mourn_inferior (); | |
d6b0e80f AC |
4246 | } |
4247 | ||
4248 | static void | |
136d6dae | 4249 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 4250 | { |
d90e17a7 | 4251 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
d6b0e80f | 4252 | |
f973ed9c | 4253 | if (! forks_exist_p ()) |
d90e17a7 PA |
4254 | /* Normal case, no other forks available. */ |
4255 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
4256 | else |
4257 | /* Multi-fork case. The current inferior_ptid has exited, but | |
4258 | there are other viable forks to debug. Delete the exiting | |
4259 | one and context-switch to the first available. */ | |
4260 | linux_fork_mourn_inferior (); | |
d6b0e80f AC |
4261 | } |
4262 | ||
5b009018 PA |
4263 | /* Convert a native/host siginfo object, into/from the siginfo in the |
4264 | layout of the inferiors' architecture. */ | |
4265 | ||
4266 | static void | |
4267 | siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction) | |
4268 | { | |
4269 | int done = 0; | |
4270 | ||
4271 | if (linux_nat_siginfo_fixup != NULL) | |
4272 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
4273 | ||
4274 | /* If there was no callback, or the callback didn't do anything, | |
4275 | then just do a straight memcpy. */ | |
4276 | if (!done) | |
4277 | { | |
4278 | if (direction == 1) | |
4279 | memcpy (siginfo, inf_siginfo, sizeof (struct siginfo)); | |
4280 | else | |
4281 | memcpy (inf_siginfo, siginfo, sizeof (struct siginfo)); | |
4282 | } | |
4283 | } | |
4284 | ||
4aa995e1 PA |
4285 | static LONGEST |
4286 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, | |
4287 | const char *annex, gdb_byte *readbuf, | |
4288 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4289 | { | |
4aa995e1 PA |
4290 | int pid; |
4291 | struct siginfo siginfo; | |
5b009018 | 4292 | gdb_byte inf_siginfo[sizeof (struct siginfo)]; |
4aa995e1 PA |
4293 | |
4294 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
4295 | gdb_assert (readbuf || writebuf); | |
4296 | ||
4297 | pid = GET_LWP (inferior_ptid); | |
4298 | if (pid == 0) | |
4299 | pid = GET_PID (inferior_ptid); | |
4300 | ||
4301 | if (offset > sizeof (siginfo)) | |
4302 | return -1; | |
4303 | ||
4304 | errno = 0; | |
4305 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4306 | if (errno != 0) | |
4307 | return -1; | |
4308 | ||
5b009018 PA |
4309 | /* When GDB is built as a 64-bit application, ptrace writes into |
4310 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
4311 | inferior with a 64-bit GDB should look the same as debugging it | |
4312 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
4313 | the converted layout, so any read/write will have to be done | |
4314 | post-conversion. */ | |
4315 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
4316 | ||
4aa995e1 PA |
4317 | if (offset + len > sizeof (siginfo)) |
4318 | len = sizeof (siginfo) - offset; | |
4319 | ||
4320 | if (readbuf != NULL) | |
5b009018 | 4321 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
4322 | else |
4323 | { | |
5b009018 PA |
4324 | memcpy (inf_siginfo + offset, writebuf, len); |
4325 | ||
4326 | /* Convert back to ptrace layout before flushing it out. */ | |
4327 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
4328 | ||
4aa995e1 PA |
4329 | errno = 0; |
4330 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4331 | if (errno != 0) | |
4332 | return -1; | |
4333 | } | |
4334 | ||
4335 | return len; | |
4336 | } | |
4337 | ||
10d6c8cd DJ |
4338 | static LONGEST |
4339 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, | |
4340 | const char *annex, gdb_byte *readbuf, | |
4341 | const gdb_byte *writebuf, | |
4342 | ULONGEST offset, LONGEST len) | |
d6b0e80f | 4343 | { |
4aa995e1 | 4344 | struct cleanup *old_chain; |
10d6c8cd | 4345 | LONGEST xfer; |
d6b0e80f | 4346 | |
4aa995e1 PA |
4347 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
4348 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
4349 | offset, len); | |
4350 | ||
c35b1492 PA |
4351 | /* The target is connected but no live inferior is selected. Pass |
4352 | this request down to a lower stratum (e.g., the executable | |
4353 | file). */ | |
4354 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
4355 | return 0; | |
4356 | ||
4aa995e1 PA |
4357 | old_chain = save_inferior_ptid (); |
4358 | ||
d6b0e80f AC |
4359 | if (is_lwp (inferior_ptid)) |
4360 | inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); | |
4361 | ||
10d6c8cd DJ |
4362 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
4363 | offset, len); | |
d6b0e80f AC |
4364 | |
4365 | do_cleanups (old_chain); | |
4366 | return xfer; | |
4367 | } | |
4368 | ||
4369 | static int | |
28439f5e | 4370 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 4371 | { |
8c6a60d1 | 4372 | int err, tmp_errno; |
4c28f408 | 4373 | |
d6b0e80f AC |
4374 | gdb_assert (is_lwp (ptid)); |
4375 | ||
4c28f408 PA |
4376 | /* Send signal 0 instead of anything ptrace, because ptracing a |
4377 | running thread errors out claiming that the thread doesn't | |
4378 | exist. */ | |
4379 | err = kill_lwp (GET_LWP (ptid), 0); | |
8c6a60d1 | 4380 | tmp_errno = errno; |
d6b0e80f AC |
4381 | if (debug_linux_nat) |
4382 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 4383 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 4384 | target_pid_to_str (ptid), |
8c6a60d1 | 4385 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 4386 | |
4c28f408 | 4387 | if (err != 0) |
d6b0e80f AC |
4388 | return 0; |
4389 | ||
4390 | return 1; | |
4391 | } | |
4392 | ||
28439f5e PA |
4393 | static int |
4394 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
4395 | { | |
4396 | return linux_thread_alive (ptid); | |
4397 | } | |
4398 | ||
d6b0e80f | 4399 | static char * |
117de6a9 | 4400 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
4401 | { |
4402 | static char buf[64]; | |
4403 | ||
a0ef4274 | 4404 | if (is_lwp (ptid) |
d90e17a7 PA |
4405 | && (GET_PID (ptid) != GET_LWP (ptid) |
4406 | || num_lwps (GET_PID (ptid)) > 1)) | |
d6b0e80f AC |
4407 | { |
4408 | snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); | |
4409 | return buf; | |
4410 | } | |
4411 | ||
4412 | return normal_pid_to_str (ptid); | |
4413 | } | |
4414 | ||
4694da01 TT |
4415 | static char * |
4416 | linux_nat_thread_name (struct thread_info *thr) | |
4417 | { | |
4418 | int pid = ptid_get_pid (thr->ptid); | |
4419 | long lwp = ptid_get_lwp (thr->ptid); | |
4420 | #define FORMAT "/proc/%d/task/%ld/comm" | |
4421 | char buf[sizeof (FORMAT) + 30]; | |
4422 | FILE *comm_file; | |
4423 | char *result = NULL; | |
4424 | ||
4425 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
4426 | comm_file = fopen (buf, "r"); | |
4427 | if (comm_file) | |
4428 | { | |
4429 | /* Not exported by the kernel, so we define it here. */ | |
4430 | #define COMM_LEN 16 | |
4431 | static char line[COMM_LEN + 1]; | |
4432 | ||
4433 | if (fgets (line, sizeof (line), comm_file)) | |
4434 | { | |
4435 | char *nl = strchr (line, '\n'); | |
4436 | ||
4437 | if (nl) | |
4438 | *nl = '\0'; | |
4439 | if (*line != '\0') | |
4440 | result = line; | |
4441 | } | |
4442 | ||
4443 | fclose (comm_file); | |
4444 | } | |
4445 | ||
4446 | #undef COMM_LEN | |
4447 | #undef FORMAT | |
4448 | ||
4449 | return result; | |
4450 | } | |
4451 | ||
dba24537 AC |
4452 | /* Accepts an integer PID; Returns a string representing a file that |
4453 | can be opened to get the symbols for the child process. */ | |
4454 | ||
6d8fd2b7 UW |
4455 | static char * |
4456 | linux_child_pid_to_exec_file (int pid) | |
dba24537 AC |
4457 | { |
4458 | char *name1, *name2; | |
4459 | ||
4460 | name1 = xmalloc (MAXPATHLEN); | |
4461 | name2 = xmalloc (MAXPATHLEN); | |
4462 | make_cleanup (xfree, name1); | |
4463 | make_cleanup (xfree, name2); | |
4464 | memset (name2, 0, MAXPATHLEN); | |
4465 | ||
4466 | sprintf (name1, "/proc/%d/exe", pid); | |
4467 | if (readlink (name1, name2, MAXPATHLEN) > 0) | |
4468 | return name2; | |
4469 | else | |
4470 | return name1; | |
4471 | } | |
4472 | ||
dba24537 AC |
4473 | /* Records the thread's register state for the corefile note |
4474 | section. */ | |
4475 | ||
4476 | static char * | |
6432734d UW |
4477 | linux_nat_collect_thread_registers (const struct regcache *regcache, |
4478 | ptid_t ptid, bfd *obfd, | |
4479 | char *note_data, int *note_size, | |
4480 | enum target_signal stop_signal) | |
dba24537 | 4481 | { |
6432734d | 4482 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
4f844a66 | 4483 | const struct regset *regset; |
55e969c1 | 4484 | int core_regset_p; |
6432734d UW |
4485 | gdb_gregset_t gregs; |
4486 | gdb_fpregset_t fpregs; | |
4f844a66 DM |
4487 | |
4488 | core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); | |
dba24537 | 4489 | |
6432734d UW |
4490 | if (core_regset_p |
4491 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", | |
4492 | sizeof (gregs))) | |
4493 | != NULL && regset->collect_regset != NULL) | |
4494 | regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs)); | |
4f844a66 | 4495 | else |
6432734d | 4496 | fill_gregset (regcache, &gregs, -1); |
2f2241f1 | 4497 | |
6432734d UW |
4498 | note_data = (char *) elfcore_write_prstatus |
4499 | (obfd, note_data, note_size, ptid_get_lwp (ptid), | |
4500 | target_signal_to_host (stop_signal), &gregs); | |
2f2241f1 | 4501 | |
6432734d UW |
4502 | if (core_regset_p |
4503 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", | |
4504 | sizeof (fpregs))) | |
3e43a32a | 4505 | != NULL && regset->collect_regset != NULL) |
6432734d UW |
4506 | regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs)); |
4507 | else | |
4508 | fill_fpregset (regcache, &fpregs, -1); | |
17ea7499 | 4509 | |
6432734d UW |
4510 | note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size, |
4511 | &fpregs, sizeof (fpregs)); | |
4f844a66 | 4512 | |
dba24537 AC |
4513 | return note_data; |
4514 | } | |
4515 | ||
dba24537 AC |
4516 | /* Fills the "to_make_corefile_note" target vector. Builds the note |
4517 | section for a corefile, and returns it in a malloc buffer. */ | |
4518 | ||
4519 | static char * | |
4520 | linux_nat_make_corefile_notes (bfd *obfd, int *note_size) | |
4521 | { | |
6432734d UW |
4522 | /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been |
4523 | converted to gdbarch_core_regset_sections, this function can go away. */ | |
4524 | return linux_make_corefile_notes (target_gdbarch, obfd, note_size, | |
4525 | linux_nat_collect_thread_registers); | |
dba24537 AC |
4526 | } |
4527 | ||
10d6c8cd DJ |
4528 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4529 | filesystem. Because we can use a single read() call for /proc, this | |
4530 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4531 | but it doesn't support writes. */ | |
4532 | ||
4533 | static LONGEST | |
4534 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, | |
4535 | const char *annex, gdb_byte *readbuf, | |
4536 | const gdb_byte *writebuf, | |
4537 | ULONGEST offset, LONGEST len) | |
dba24537 | 4538 | { |
10d6c8cd DJ |
4539 | LONGEST ret; |
4540 | int fd; | |
dba24537 AC |
4541 | char filename[64]; |
4542 | ||
10d6c8cd | 4543 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4544 | return 0; |
4545 | ||
4546 | /* Don't bother for one word. */ | |
4547 | if (len < 3 * sizeof (long)) | |
4548 | return 0; | |
4549 | ||
4550 | /* We could keep this file open and cache it - possibly one per | |
4551 | thread. That requires some juggling, but is even faster. */ | |
4552 | sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); | |
4553 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
4554 | if (fd == -1) | |
4555 | return 0; | |
4556 | ||
4557 | /* If pread64 is available, use it. It's faster if the kernel | |
4558 | supports it (only one syscall), and it's 64-bit safe even on | |
4559 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4560 | application). */ | |
4561 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4562 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4563 | #else |
10d6c8cd | 4564 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4565 | #endif |
4566 | ret = 0; | |
4567 | else | |
4568 | ret = len; | |
4569 | ||
4570 | close (fd); | |
4571 | return ret; | |
4572 | } | |
4573 | ||
efcbbd14 UW |
4574 | |
4575 | /* Enumerate spufs IDs for process PID. */ | |
4576 | static LONGEST | |
4577 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) | |
4578 | { | |
4579 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); | |
4580 | LONGEST pos = 0; | |
4581 | LONGEST written = 0; | |
4582 | char path[128]; | |
4583 | DIR *dir; | |
4584 | struct dirent *entry; | |
4585 | ||
4586 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4587 | dir = opendir (path); | |
4588 | if (!dir) | |
4589 | return -1; | |
4590 | ||
4591 | rewinddir (dir); | |
4592 | while ((entry = readdir (dir)) != NULL) | |
4593 | { | |
4594 | struct stat st; | |
4595 | struct statfs stfs; | |
4596 | int fd; | |
4597 | ||
4598 | fd = atoi (entry->d_name); | |
4599 | if (!fd) | |
4600 | continue; | |
4601 | ||
4602 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4603 | if (stat (path, &st) != 0) | |
4604 | continue; | |
4605 | if (!S_ISDIR (st.st_mode)) | |
4606 | continue; | |
4607 | ||
4608 | if (statfs (path, &stfs) != 0) | |
4609 | continue; | |
4610 | if (stfs.f_type != SPUFS_MAGIC) | |
4611 | continue; | |
4612 | ||
4613 | if (pos >= offset && pos + 4 <= offset + len) | |
4614 | { | |
4615 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4616 | written += 4; | |
4617 | } | |
4618 | pos += 4; | |
4619 | } | |
4620 | ||
4621 | closedir (dir); | |
4622 | return written; | |
4623 | } | |
4624 | ||
4625 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4626 | object type, using the /proc file system. */ | |
4627 | static LONGEST | |
4628 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, | |
4629 | const char *annex, gdb_byte *readbuf, | |
4630 | const gdb_byte *writebuf, | |
4631 | ULONGEST offset, LONGEST len) | |
4632 | { | |
4633 | char buf[128]; | |
4634 | int fd = 0; | |
4635 | int ret = -1; | |
4636 | int pid = PIDGET (inferior_ptid); | |
4637 | ||
4638 | if (!annex) | |
4639 | { | |
4640 | if (!readbuf) | |
4641 | return -1; | |
4642 | else | |
4643 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4644 | } | |
4645 | ||
4646 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
4647 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); | |
4648 | if (fd <= 0) | |
4649 | return -1; | |
4650 | ||
4651 | if (offset != 0 | |
4652 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4653 | { | |
4654 | close (fd); | |
4655 | return 0; | |
4656 | } | |
4657 | ||
4658 | if (writebuf) | |
4659 | ret = write (fd, writebuf, (size_t) len); | |
4660 | else if (readbuf) | |
4661 | ret = read (fd, readbuf, (size_t) len); | |
4662 | ||
4663 | close (fd); | |
4664 | return ret; | |
4665 | } | |
4666 | ||
4667 | ||
dba24537 AC |
4668 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4669 | ||
4670 | static void | |
4671 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4672 | { | |
4673 | int len = strlen (line) - 1; | |
4674 | const char *p; | |
4675 | int signum; | |
4676 | ||
4677 | if (line[len] != '\n') | |
8a3fe4f8 | 4678 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4679 | |
4680 | p = line; | |
4681 | signum = len * 4; | |
4682 | while (len-- > 0) | |
4683 | { | |
4684 | int digit; | |
4685 | ||
4686 | if (*p >= '0' && *p <= '9') | |
4687 | digit = *p - '0'; | |
4688 | else if (*p >= 'a' && *p <= 'f') | |
4689 | digit = *p - 'a' + 10; | |
4690 | else | |
8a3fe4f8 | 4691 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4692 | |
4693 | signum -= 4; | |
4694 | ||
4695 | if (digit & 1) | |
4696 | sigaddset (sigs, signum + 1); | |
4697 | if (digit & 2) | |
4698 | sigaddset (sigs, signum + 2); | |
4699 | if (digit & 4) | |
4700 | sigaddset (sigs, signum + 3); | |
4701 | if (digit & 8) | |
4702 | sigaddset (sigs, signum + 4); | |
4703 | ||
4704 | p++; | |
4705 | } | |
4706 | } | |
4707 | ||
4708 | /* Find process PID's pending signals from /proc/pid/status and set | |
4709 | SIGS to match. */ | |
4710 | ||
4711 | void | |
3e43a32a MS |
4712 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4713 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4714 | { |
4715 | FILE *procfile; | |
4716 | char buffer[MAXPATHLEN], fname[MAXPATHLEN]; | |
7c8a8b04 | 4717 | struct cleanup *cleanup; |
dba24537 AC |
4718 | |
4719 | sigemptyset (pending); | |
4720 | sigemptyset (blocked); | |
4721 | sigemptyset (ignored); | |
4722 | sprintf (fname, "/proc/%d/status", pid); | |
4723 | procfile = fopen (fname, "r"); | |
4724 | if (procfile == NULL) | |
8a3fe4f8 | 4725 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4726 | cleanup = make_cleanup_fclose (procfile); |
dba24537 AC |
4727 | |
4728 | while (fgets (buffer, MAXPATHLEN, procfile) != NULL) | |
4729 | { | |
4730 | /* Normal queued signals are on the SigPnd line in the status | |
4731 | file. However, 2.6 kernels also have a "shared" pending | |
4732 | queue for delivering signals to a thread group, so check for | |
4733 | a ShdPnd line also. | |
4734 | ||
4735 | Unfortunately some Red Hat kernels include the shared pending | |
4736 | queue but not the ShdPnd status field. */ | |
4737 | ||
4738 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4739 | add_line_to_sigset (buffer + 8, pending); | |
4740 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4741 | add_line_to_sigset (buffer + 8, pending); | |
4742 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4743 | add_line_to_sigset (buffer + 8, blocked); | |
4744 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4745 | add_line_to_sigset (buffer + 8, ignored); | |
4746 | } | |
4747 | ||
7c8a8b04 | 4748 | do_cleanups (cleanup); |
dba24537 AC |
4749 | } |
4750 | ||
07e059b5 VP |
4751 | static LONGEST |
4752 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, | |
e0881a8e MS |
4753 | const char *annex, gdb_byte *readbuf, |
4754 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
07e059b5 | 4755 | { |
07e059b5 VP |
4756 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4757 | ||
d26e3629 | 4758 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
07e059b5 VP |
4759 | } |
4760 | ||
10d6c8cd DJ |
4761 | static LONGEST |
4762 | linux_xfer_partial (struct target_ops *ops, enum target_object object, | |
4763 | const char *annex, gdb_byte *readbuf, | |
4764 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4765 | { | |
4766 | LONGEST xfer; | |
4767 | ||
4768 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4769 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
10d6c8cd DJ |
4770 | offset, len); |
4771 | ||
07e059b5 VP |
4772 | if (object == TARGET_OBJECT_OSDATA) |
4773 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
4774 | offset, len); | |
4775 | ||
efcbbd14 UW |
4776 | if (object == TARGET_OBJECT_SPU) |
4777 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
4778 | offset, len); | |
4779 | ||
8f313923 JK |
4780 | /* GDB calculates all the addresses in possibly larget width of the address. |
4781 | Address width needs to be masked before its final use - either by | |
4782 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4783 | ||
4784 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4785 | ||
4786 | if (object == TARGET_OBJECT_MEMORY) | |
4787 | { | |
4788 | int addr_bit = gdbarch_addr_bit (target_gdbarch); | |
4789 | ||
4790 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4791 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4792 | } | |
4793 | ||
10d6c8cd DJ |
4794 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
4795 | offset, len); | |
4796 | if (xfer != 0) | |
4797 | return xfer; | |
4798 | ||
4799 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
4800 | offset, len); | |
4801 | } | |
4802 | ||
e9efe249 | 4803 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4804 | it with local methods. */ |
4805 | ||
910122bf UW |
4806 | static void |
4807 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4808 | { |
6d8fd2b7 | 4809 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4810 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4811 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4812 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4813 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4814 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4815 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4816 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4817 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4818 | t->to_post_attach = linux_child_post_attach; |
4819 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4820 | t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
4821 | ||
4822 | super_xfer_partial = t->to_xfer_partial; | |
4823 | t->to_xfer_partial = linux_xfer_partial; | |
910122bf UW |
4824 | } |
4825 | ||
4826 | struct target_ops * | |
4827 | linux_target (void) | |
4828 | { | |
4829 | struct target_ops *t; | |
4830 | ||
4831 | t = inf_ptrace_target (); | |
4832 | linux_target_install_ops (t); | |
4833 | ||
4834 | return t; | |
4835 | } | |
4836 | ||
4837 | struct target_ops * | |
7714d83a | 4838 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4839 | { |
4840 | struct target_ops *t; | |
4841 | ||
4842 | t = inf_ptrace_trad_target (register_u_offset); | |
4843 | linux_target_install_ops (t); | |
10d6c8cd | 4844 | |
10d6c8cd DJ |
4845 | return t; |
4846 | } | |
4847 | ||
b84876c2 PA |
4848 | /* target_is_async_p implementation. */ |
4849 | ||
4850 | static int | |
4851 | linux_nat_is_async_p (void) | |
4852 | { | |
4853 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4854 | it explicitly with the "set target-async" command. |
b84876c2 | 4855 | Someday, linux will always be async. */ |
3dd5b83d | 4856 | return target_async_permitted; |
b84876c2 PA |
4857 | } |
4858 | ||
4859 | /* target_can_async_p implementation. */ | |
4860 | ||
4861 | static int | |
4862 | linux_nat_can_async_p (void) | |
4863 | { | |
4864 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4865 | it explicitly with the "set target-async" command. |
b84876c2 | 4866 | Someday, linux will always be async. */ |
3dd5b83d | 4867 | return target_async_permitted; |
b84876c2 PA |
4868 | } |
4869 | ||
9908b566 VP |
4870 | static int |
4871 | linux_nat_supports_non_stop (void) | |
4872 | { | |
4873 | return 1; | |
4874 | } | |
4875 | ||
d90e17a7 PA |
4876 | /* True if we want to support multi-process. To be removed when GDB |
4877 | supports multi-exec. */ | |
4878 | ||
2277426b | 4879 | int linux_multi_process = 1; |
d90e17a7 PA |
4880 | |
4881 | static int | |
4882 | linux_nat_supports_multi_process (void) | |
4883 | { | |
4884 | return linux_multi_process; | |
4885 | } | |
4886 | ||
03583c20 UW |
4887 | static int |
4888 | linux_nat_supports_disable_randomization (void) | |
4889 | { | |
4890 | #ifdef HAVE_PERSONALITY | |
4891 | return 1; | |
4892 | #else | |
4893 | return 0; | |
4894 | #endif | |
4895 | } | |
4896 | ||
b84876c2 PA |
4897 | static int async_terminal_is_ours = 1; |
4898 | ||
4899 | /* target_terminal_inferior implementation. */ | |
4900 | ||
4901 | static void | |
4902 | linux_nat_terminal_inferior (void) | |
4903 | { | |
4904 | if (!target_is_async_p ()) | |
4905 | { | |
4906 | /* Async mode is disabled. */ | |
4907 | terminal_inferior (); | |
4908 | return; | |
4909 | } | |
4910 | ||
b84876c2 PA |
4911 | terminal_inferior (); |
4912 | ||
d9d2d8b6 | 4913 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4914 | if (!async_terminal_is_ours) |
4915 | return; | |
4916 | ||
4917 | delete_file_handler (input_fd); | |
4918 | async_terminal_is_ours = 0; | |
4919 | set_sigint_trap (); | |
4920 | } | |
4921 | ||
4922 | /* target_terminal_ours implementation. */ | |
4923 | ||
2c0b251b | 4924 | static void |
b84876c2 PA |
4925 | linux_nat_terminal_ours (void) |
4926 | { | |
4927 | if (!target_is_async_p ()) | |
4928 | { | |
4929 | /* Async mode is disabled. */ | |
4930 | terminal_ours (); | |
4931 | return; | |
4932 | } | |
4933 | ||
4934 | /* GDB should never give the terminal to the inferior if the | |
4935 | inferior is running in the background (run&, continue&, etc.), | |
4936 | but claiming it sure should. */ | |
4937 | terminal_ours (); | |
4938 | ||
b84876c2 PA |
4939 | if (async_terminal_is_ours) |
4940 | return; | |
4941 | ||
4942 | clear_sigint_trap (); | |
4943 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4944 | async_terminal_is_ours = 1; | |
4945 | } | |
4946 | ||
4947 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4948 | void *context); | |
4949 | static void *async_client_context; | |
4950 | ||
7feb7d06 PA |
4951 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4952 | so we notice when any child changes state, and notify the | |
4953 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4954 | above to wait for the arrival of a SIGCHLD. */ | |
4955 | ||
b84876c2 | 4956 | static void |
7feb7d06 | 4957 | sigchld_handler (int signo) |
b84876c2 | 4958 | { |
7feb7d06 PA |
4959 | int old_errno = errno; |
4960 | ||
01124a23 DE |
4961 | if (debug_linux_nat) |
4962 | ui_file_write_async_safe (gdb_stdlog, | |
4963 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4964 | |
4965 | if (signo == SIGCHLD | |
4966 | && linux_nat_event_pipe[0] != -1) | |
4967 | async_file_mark (); /* Let the event loop know that there are | |
4968 | events to handle. */ | |
4969 | ||
4970 | errno = old_errno; | |
4971 | } | |
4972 | ||
4973 | /* Callback registered with the target events file descriptor. */ | |
4974 | ||
4975 | static void | |
4976 | handle_target_event (int error, gdb_client_data client_data) | |
4977 | { | |
4978 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4979 | } | |
4980 | ||
4981 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4982 | ||
4983 | static int | |
4984 | linux_async_pipe (int enable) | |
4985 | { | |
4986 | int previous = (linux_nat_event_pipe[0] != -1); | |
4987 | ||
4988 | if (previous != enable) | |
4989 | { | |
4990 | sigset_t prev_mask; | |
4991 | ||
4992 | block_child_signals (&prev_mask); | |
4993 | ||
4994 | if (enable) | |
4995 | { | |
4996 | if (pipe (linux_nat_event_pipe) == -1) | |
4997 | internal_error (__FILE__, __LINE__, | |
4998 | "creating event pipe failed."); | |
4999 | ||
5000 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
5001 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
5002 | } | |
5003 | else | |
5004 | { | |
5005 | close (linux_nat_event_pipe[0]); | |
5006 | close (linux_nat_event_pipe[1]); | |
5007 | linux_nat_event_pipe[0] = -1; | |
5008 | linux_nat_event_pipe[1] = -1; | |
5009 | } | |
5010 | ||
5011 | restore_child_signals_mask (&prev_mask); | |
5012 | } | |
5013 | ||
5014 | return previous; | |
b84876c2 PA |
5015 | } |
5016 | ||
5017 | /* target_async implementation. */ | |
5018 | ||
5019 | static void | |
5020 | linux_nat_async (void (*callback) (enum inferior_event_type event_type, | |
5021 | void *context), void *context) | |
5022 | { | |
b84876c2 PA |
5023 | if (callback != NULL) |
5024 | { | |
5025 | async_client_callback = callback; | |
5026 | async_client_context = context; | |
7feb7d06 PA |
5027 | if (!linux_async_pipe (1)) |
5028 | { | |
5029 | add_file_handler (linux_nat_event_pipe[0], | |
5030 | handle_target_event, NULL); | |
5031 | /* There may be pending events to handle. Tell the event loop | |
5032 | to poll them. */ | |
5033 | async_file_mark (); | |
5034 | } | |
b84876c2 PA |
5035 | } |
5036 | else | |
5037 | { | |
5038 | async_client_callback = callback; | |
5039 | async_client_context = context; | |
b84876c2 | 5040 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 5041 | linux_async_pipe (0); |
b84876c2 PA |
5042 | } |
5043 | return; | |
5044 | } | |
5045 | ||
252fbfc8 PA |
5046 | /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other |
5047 | event came out. */ | |
5048 | ||
4c28f408 | 5049 | static int |
252fbfc8 | 5050 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 5051 | { |
d90e17a7 | 5052 | if (!lwp->stopped) |
252fbfc8 | 5053 | { |
d90e17a7 | 5054 | ptid_t ptid = lwp->ptid; |
252fbfc8 | 5055 | |
d90e17a7 PA |
5056 | if (debug_linux_nat) |
5057 | fprintf_unfiltered (gdb_stdlog, | |
5058 | "LNSL: running -> suspending %s\n", | |
5059 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 5060 | |
252fbfc8 | 5061 | |
25289eb2 PA |
5062 | if (lwp->last_resume_kind == resume_stop) |
5063 | { | |
5064 | if (debug_linux_nat) | |
5065 | fprintf_unfiltered (gdb_stdlog, | |
5066 | "linux-nat: already stopping LWP %ld at " | |
5067 | "GDB's request\n", | |
5068 | ptid_get_lwp (lwp->ptid)); | |
5069 | return 0; | |
5070 | } | |
252fbfc8 | 5071 | |
25289eb2 PA |
5072 | stop_callback (lwp, NULL); |
5073 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
5074 | } |
5075 | else | |
5076 | { | |
5077 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 5078 | |
d90e17a7 PA |
5079 | if (debug_linux_nat) |
5080 | { | |
e09875d4 | 5081 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
5082 | fprintf_unfiltered (gdb_stdlog, |
5083 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
5084 | target_pid_to_str (lwp->ptid)); |
5085 | else | |
3e43a32a MS |
5086 | fprintf_unfiltered (gdb_stdlog, |
5087 | "LNSL: already stopped/no " | |
5088 | "stop_requested yet %s\n", | |
d90e17a7 | 5089 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
5090 | } |
5091 | } | |
4c28f408 PA |
5092 | return 0; |
5093 | } | |
5094 | ||
5095 | static void | |
5096 | linux_nat_stop (ptid_t ptid) | |
5097 | { | |
5098 | if (non_stop) | |
d90e17a7 | 5099 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 PA |
5100 | else |
5101 | linux_ops->to_stop (ptid); | |
5102 | } | |
5103 | ||
d90e17a7 PA |
5104 | static void |
5105 | linux_nat_close (int quitting) | |
5106 | { | |
5107 | /* Unregister from the event loop. */ | |
305436e0 PA |
5108 | if (linux_nat_is_async_p ()) |
5109 | linux_nat_async (NULL, 0); | |
d90e17a7 | 5110 | |
d90e17a7 PA |
5111 | if (linux_ops->to_close) |
5112 | linux_ops->to_close (quitting); | |
5113 | } | |
5114 | ||
c0694254 PA |
5115 | /* When requests are passed down from the linux-nat layer to the |
5116 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
5117 | used. The address space pointer is stored in the inferior object, | |
5118 | but the common code that is passed such ptid can't tell whether | |
5119 | lwpid is a "main" process id or not (it assumes so). We reverse | |
5120 | look up the "main" process id from the lwp here. */ | |
5121 | ||
5122 | struct address_space * | |
5123 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) | |
5124 | { | |
5125 | struct lwp_info *lwp; | |
5126 | struct inferior *inf; | |
5127 | int pid; | |
5128 | ||
5129 | pid = GET_LWP (ptid); | |
5130 | if (GET_LWP (ptid) == 0) | |
5131 | { | |
5132 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
5133 | tgid. */ | |
5134 | lwp = find_lwp_pid (ptid); | |
5135 | pid = GET_PID (lwp->ptid); | |
5136 | } | |
5137 | else | |
5138 | { | |
5139 | /* A (pid,lwpid,0) ptid. */ | |
5140 | pid = GET_PID (ptid); | |
5141 | } | |
5142 | ||
5143 | inf = find_inferior_pid (pid); | |
5144 | gdb_assert (inf != NULL); | |
5145 | return inf->aspace; | |
5146 | } | |
5147 | ||
dc146f7c VP |
5148 | int |
5149 | linux_nat_core_of_thread_1 (ptid_t ptid) | |
5150 | { | |
5151 | struct cleanup *back_to; | |
5152 | char *filename; | |
5153 | FILE *f; | |
5154 | char *content = NULL; | |
5155 | char *p; | |
5156 | char *ts = 0; | |
5157 | int content_read = 0; | |
5158 | int i; | |
5159 | int core; | |
5160 | ||
5161 | filename = xstrprintf ("/proc/%d/task/%ld/stat", | |
5162 | GET_PID (ptid), GET_LWP (ptid)); | |
5163 | back_to = make_cleanup (xfree, filename); | |
5164 | ||
5165 | f = fopen (filename, "r"); | |
5166 | if (!f) | |
5167 | { | |
5168 | do_cleanups (back_to); | |
5169 | return -1; | |
5170 | } | |
5171 | ||
5172 | make_cleanup_fclose (f); | |
5173 | ||
5174 | for (;;) | |
5175 | { | |
5176 | int n; | |
e0881a8e | 5177 | |
dc146f7c VP |
5178 | content = xrealloc (content, content_read + 1024); |
5179 | n = fread (content + content_read, 1, 1024, f); | |
5180 | content_read += n; | |
5181 | if (n < 1024) | |
5182 | { | |
5183 | content[content_read] = '\0'; | |
5184 | break; | |
5185 | } | |
5186 | } | |
5187 | ||
5188 | make_cleanup (xfree, content); | |
5189 | ||
5190 | p = strchr (content, '('); | |
ca2a87a0 JK |
5191 | |
5192 | /* Skip ")". */ | |
5193 | if (p != NULL) | |
5194 | p = strchr (p, ')'); | |
5195 | if (p != NULL) | |
5196 | p++; | |
dc146f7c VP |
5197 | |
5198 | /* If the first field after program name has index 0, then core number is | |
5199 | the field with index 36. There's no constant for that anywhere. */ | |
ca2a87a0 JK |
5200 | if (p != NULL) |
5201 | p = strtok_r (p, " ", &ts); | |
5202 | for (i = 0; p != NULL && i != 36; ++i) | |
dc146f7c VP |
5203 | p = strtok_r (NULL, " ", &ts); |
5204 | ||
ca2a87a0 | 5205 | if (p == NULL || sscanf (p, "%d", &core) == 0) |
dc146f7c VP |
5206 | core = -1; |
5207 | ||
5208 | do_cleanups (back_to); | |
5209 | ||
5210 | return core; | |
5211 | } | |
5212 | ||
5213 | /* Return the cached value of the processor core for thread PTID. */ | |
5214 | ||
5215 | int | |
5216 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) | |
5217 | { | |
5218 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 5219 | |
dc146f7c VP |
5220 | if (info) |
5221 | return info->core; | |
5222 | return -1; | |
5223 | } | |
5224 | ||
f973ed9c DJ |
5225 | void |
5226 | linux_nat_add_target (struct target_ops *t) | |
5227 | { | |
f973ed9c DJ |
5228 | /* Save the provided single-threaded target. We save this in a separate |
5229 | variable because another target we've inherited from (e.g. inf-ptrace) | |
5230 | may have saved a pointer to T; we want to use it for the final | |
5231 | process stratum target. */ | |
5232 | linux_ops_saved = *t; | |
5233 | linux_ops = &linux_ops_saved; | |
5234 | ||
5235 | /* Override some methods for multithreading. */ | |
b84876c2 | 5236 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
5237 | t->to_attach = linux_nat_attach; |
5238 | t->to_detach = linux_nat_detach; | |
5239 | t->to_resume = linux_nat_resume; | |
5240 | t->to_wait = linux_nat_wait; | |
2455069d | 5241 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
5242 | t->to_xfer_partial = linux_nat_xfer_partial; |
5243 | t->to_kill = linux_nat_kill; | |
5244 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
5245 | t->to_thread_alive = linux_nat_thread_alive; | |
5246 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 5247 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 5248 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 5249 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
5250 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
5251 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 5252 | |
b84876c2 PA |
5253 | t->to_can_async_p = linux_nat_can_async_p; |
5254 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 5255 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 5256 | t->to_async = linux_nat_async; |
b84876c2 PA |
5257 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
5258 | t->to_terminal_ours = linux_nat_terminal_ours; | |
d90e17a7 | 5259 | t->to_close = linux_nat_close; |
b84876c2 | 5260 | |
4c28f408 PA |
5261 | /* Methods for non-stop support. */ |
5262 | t->to_stop = linux_nat_stop; | |
5263 | ||
d90e17a7 PA |
5264 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
5265 | ||
03583c20 UW |
5266 | t->to_supports_disable_randomization |
5267 | = linux_nat_supports_disable_randomization; | |
5268 | ||
dc146f7c VP |
5269 | t->to_core_of_thread = linux_nat_core_of_thread; |
5270 | ||
f973ed9c DJ |
5271 | /* We don't change the stratum; this target will sit at |
5272 | process_stratum and thread_db will set at thread_stratum. This | |
5273 | is a little strange, since this is a multi-threaded-capable | |
5274 | target, but we want to be on the stack below thread_db, and we | |
5275 | also want to be used for single-threaded processes. */ | |
5276 | ||
5277 | add_target (t); | |
f973ed9c DJ |
5278 | } |
5279 | ||
9f0bdab8 DJ |
5280 | /* Register a method to call whenever a new thread is attached. */ |
5281 | void | |
7b50312a PA |
5282 | linux_nat_set_new_thread (struct target_ops *t, |
5283 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
5284 | { |
5285 | /* Save the pointer. We only support a single registered instance | |
5286 | of the GNU/Linux native target, so we do not need to map this to | |
5287 | T. */ | |
5288 | linux_nat_new_thread = new_thread; | |
5289 | } | |
5290 | ||
5b009018 PA |
5291 | /* Register a method that converts a siginfo object between the layout |
5292 | that ptrace returns, and the layout in the architecture of the | |
5293 | inferior. */ | |
5294 | void | |
5295 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
5296 | int (*siginfo_fixup) (struct siginfo *, | |
5297 | gdb_byte *, | |
5298 | int)) | |
5299 | { | |
5300 | /* Save the pointer. */ | |
5301 | linux_nat_siginfo_fixup = siginfo_fixup; | |
5302 | } | |
5303 | ||
7b50312a PA |
5304 | /* Register a method to call prior to resuming a thread. */ |
5305 | ||
5306 | void | |
5307 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
5308 | void (*prepare_to_resume) (struct lwp_info *)) | |
5309 | { | |
5310 | /* Save the pointer. */ | |
5311 | linux_nat_prepare_to_resume = prepare_to_resume; | |
5312 | } | |
5313 | ||
9f0bdab8 DJ |
5314 | /* Return the saved siginfo associated with PTID. */ |
5315 | struct siginfo * | |
5316 | linux_nat_get_siginfo (ptid_t ptid) | |
5317 | { | |
5318 | struct lwp_info *lp = find_lwp_pid (ptid); | |
5319 | ||
5320 | gdb_assert (lp != NULL); | |
5321 | ||
5322 | return &lp->siginfo; | |
5323 | } | |
5324 | ||
2c0b251b PA |
5325 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
5326 | extern initialize_file_ftype _initialize_linux_nat; | |
5327 | ||
d6b0e80f AC |
5328 | void |
5329 | _initialize_linux_nat (void) | |
5330 | { | |
b84876c2 PA |
5331 | add_setshow_zinteger_cmd ("lin-lwp", class_maintenance, |
5332 | &debug_linux_nat, _("\ | |
5333 | Set debugging of GNU/Linux lwp module."), _("\ | |
5334 | Show debugging of GNU/Linux lwp module."), _("\ | |
5335 | Enables printf debugging output."), | |
5336 | NULL, | |
5337 | show_debug_linux_nat, | |
5338 | &setdebuglist, &showdebuglist); | |
5339 | ||
b84876c2 | 5340 | /* Save this mask as the default. */ |
d6b0e80f AC |
5341 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
5342 | ||
7feb7d06 PA |
5343 | /* Install a SIGCHLD handler. */ |
5344 | sigchld_action.sa_handler = sigchld_handler; | |
5345 | sigemptyset (&sigchld_action.sa_mask); | |
5346 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
5347 | |
5348 | /* Make it the default. */ | |
7feb7d06 | 5349 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
5350 | |
5351 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
5352 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
5353 | sigdelset (&suspend_mask, SIGCHLD); | |
5354 | ||
7feb7d06 | 5355 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5356 | } |
5357 | \f | |
5358 | ||
5359 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
5360 | the GNU/Linux Threads library and therefore doesn't really belong | |
5361 | here. */ | |
5362 | ||
5363 | /* Read variable NAME in the target and return its value if found. | |
5364 | Otherwise return zero. It is assumed that the type of the variable | |
5365 | is `int'. */ | |
5366 | ||
5367 | static int | |
5368 | get_signo (const char *name) | |
5369 | { | |
5370 | struct minimal_symbol *ms; | |
5371 | int signo; | |
5372 | ||
5373 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
5374 | if (ms == NULL) | |
5375 | return 0; | |
5376 | ||
8e70166d | 5377 | if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
5378 | sizeof (signo)) != 0) |
5379 | return 0; | |
5380 | ||
5381 | return signo; | |
5382 | } | |
5383 | ||
5384 | /* Return the set of signals used by the threads library in *SET. */ | |
5385 | ||
5386 | void | |
5387 | lin_thread_get_thread_signals (sigset_t *set) | |
5388 | { | |
5389 | struct sigaction action; | |
5390 | int restart, cancel; | |
5391 | ||
b84876c2 | 5392 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5393 | sigemptyset (set); |
5394 | ||
5395 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5396 | cancel = get_signo ("__pthread_sig_cancel"); |
5397 | ||
5398 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5399 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5400 | not provide any way for the debugger to query the signal numbers - | |
5401 | fortunately they don't change! */ | |
5402 | ||
d6b0e80f | 5403 | if (restart == 0) |
17fbb0bd | 5404 | restart = __SIGRTMIN; |
d6b0e80f | 5405 | |
d6b0e80f | 5406 | if (cancel == 0) |
17fbb0bd | 5407 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5408 | |
5409 | sigaddset (set, restart); | |
5410 | sigaddset (set, cancel); | |
5411 | ||
5412 | /* The GNU/Linux Threads library makes terminating threads send a | |
5413 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5414 | those (to prevent them from terminating GDB itself, which is | |
5415 | likely to be their default action) and treat them the same way as | |
5416 | SIGCHLD. */ | |
5417 | ||
5418 | action.sa_handler = sigchld_handler; | |
5419 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5420 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5421 | sigaction (cancel, &action, NULL); |
5422 | ||
5423 | /* We block the "cancel" signal throughout this code ... */ | |
5424 | sigaddset (&blocked_mask, cancel); | |
5425 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5426 | ||
5427 | /* ... except during a sigsuspend. */ | |
5428 | sigdelset (&suspend_mask, cancel); | |
5429 | } |