Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
28e7fd62 | 3 | Copyright (C) 2001-2013 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" |
dab06dbe | 39 | #include "inf-child.h" |
10d6c8cd DJ |
40 | #include "inf-ptrace.h" |
41 | #include "auxv.h" | |
dba24537 | 42 | #include <sys/param.h> /* for MAXPATHLEN */ |
1777feb0 | 43 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
44 | #include "elf-bfd.h" /* for elfcore_write_* */ |
45 | #include "gregset.h" /* for gregset */ | |
46 | #include "gdbcore.h" /* for get_exec_file */ | |
47 | #include <ctype.h> /* for isdigit */ | |
1777feb0 | 48 | #include "gdbthread.h" /* for struct thread_info etc. */ |
dba24537 AC |
49 | #include "gdb_stat.h" /* for struct stat */ |
50 | #include <fcntl.h> /* for O_RDONLY */ | |
b84876c2 PA |
51 | #include "inf-loop.h" |
52 | #include "event-loop.h" | |
53 | #include "event-top.h" | |
07e059b5 VP |
54 | #include <pwd.h> |
55 | #include <sys/types.h> | |
56 | #include "gdb_dirent.h" | |
57 | #include "xml-support.h" | |
191c4426 | 58 | #include "terminal.h" |
efcbbd14 | 59 | #include <sys/vfs.h> |
6c95b8df | 60 | #include "solib.h" |
d26e3629 | 61 | #include "linux-osdata.h" |
6432734d | 62 | #include "linux-tdep.h" |
7dcd53a0 | 63 | #include "symfile.h" |
5808517f YQ |
64 | #include "agent.h" |
65 | #include "tracepoint.h" | |
87b0bb13 JK |
66 | #include "exceptions.h" |
67 | #include "linux-ptrace.h" | |
68 | #include "buffer.h" | |
6ecd4729 | 69 | #include "target-descriptions.h" |
efcbbd14 UW |
70 | |
71 | #ifndef SPUFS_MAGIC | |
72 | #define SPUFS_MAGIC 0x23c9b64e | |
73 | #endif | |
dba24537 | 74 | |
10568435 JK |
75 | #ifdef HAVE_PERSONALITY |
76 | # include <sys/personality.h> | |
77 | # if !HAVE_DECL_ADDR_NO_RANDOMIZE | |
78 | # define ADDR_NO_RANDOMIZE 0x0040000 | |
79 | # endif | |
80 | #endif /* HAVE_PERSONALITY */ | |
81 | ||
1777feb0 | 82 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
83 | |
84 | Waiting for events in sync mode | |
85 | =============================== | |
86 | ||
87 | When waiting for an event in a specific thread, we just use waitpid, passing | |
88 | the specific pid, and not passing WNOHANG. | |
89 | ||
1777feb0 | 90 | When waiting for an event in all threads, waitpid is not quite good. Prior to |
8a77dff3 | 91 | version 2.4, Linux can either wait for event in main thread, or in secondary |
1777feb0 | 92 | threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
8a77dff3 VP |
93 | miss an event. The solution is to use non-blocking waitpid, together with |
94 | sigsuspend. First, we use non-blocking waitpid to get an event in the main | |
1777feb0 | 95 | process, if any. Second, we use non-blocking waitpid with the __WCLONED |
8a77dff3 VP |
96 | flag to check for events in cloned processes. If nothing is found, we use |
97 | sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something | |
98 | happened to a child process -- and SIGCHLD will be delivered both for events | |
99 | in main debugged process and in cloned processes. As soon as we know there's | |
3e43a32a MS |
100 | an event, we get back to calling nonblocking waitpid with and without |
101 | __WCLONED. | |
8a77dff3 VP |
102 | |
103 | Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, | |
1777feb0 | 104 | so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
8a77dff3 VP |
105 | blocked, the signal becomes pending and sigsuspend immediately |
106 | notices it and returns. | |
107 | ||
108 | Waiting for events in async mode | |
109 | ================================ | |
110 | ||
7feb7d06 PA |
111 | In async mode, GDB should always be ready to handle both user input |
112 | and target events, so neither blocking waitpid nor sigsuspend are | |
113 | viable options. Instead, we should asynchronously notify the GDB main | |
114 | event loop whenever there's an unprocessed event from the target. We | |
115 | detect asynchronous target events by handling SIGCHLD signals. To | |
116 | notify the event loop about target events, the self-pipe trick is used | |
117 | --- a pipe is registered as waitable event source in the event loop, | |
118 | the event loop select/poll's on the read end of this pipe (as well on | |
119 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
120 | byte to this pipe. This is more portable than relying on | |
121 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
122 | emulates them with select/poll+sigprocmask, and that is racy | |
123 | (a.k.a. plain broken). | |
124 | ||
125 | Obviously, if we fail to notify the event loop if there's a target | |
126 | event, it's bad. OTOH, if we notify the event loop when there's no | |
127 | event from the target, linux_nat_wait will detect that there's no real | |
128 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
129 | This is mostly harmless, but it will waste time and is better avoided. | |
130 | ||
131 | The main design point is that every time GDB is outside linux-nat.c, | |
132 | we have a SIGCHLD handler installed that is called when something | |
133 | happens to the target and notifies the GDB event loop. Whenever GDB | |
134 | core decides to handle the event, and calls into linux-nat.c, we | |
135 | process things as in sync mode, except that the we never block in | |
136 | sigsuspend. | |
137 | ||
138 | While processing an event, we may end up momentarily blocked in | |
139 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
140 | return quickly. E.g., in all-stop mode, before reporting to the core | |
141 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
142 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
143 | Note that this is different from blocking indefinitely waiting for the | |
144 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
145 | |
146 | Use of signals | |
147 | ============== | |
148 | ||
149 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
150 | signal is not entirely significant; we just need for a signal to be delivered, | |
151 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
152 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
153 | be queued once; we do not keep track of other sources of SIGSTOP. | |
154 | ||
155 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
156 | use them, because they have special behavior when the signal is generated - | |
157 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
158 | kills the entire thread group. | |
159 | ||
160 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
161 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
162 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
163 | ||
164 | We could use a real-time signal instead. This would solve those problems; we | |
165 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
166 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
167 | generates it, and there are races with trying to find a signal that is not | |
168 | blocked. */ | |
a0ef4274 | 169 | |
dba24537 AC |
170 | #ifndef O_LARGEFILE |
171 | #define O_LARGEFILE 0 | |
172 | #endif | |
0274a8ce | 173 | |
ca2163eb PA |
174 | /* Unlike other extended result codes, WSTOPSIG (status) on |
175 | PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but | |
176 | instead SIGTRAP with bit 7 set. */ | |
177 | #define SYSCALL_SIGTRAP (SIGTRAP | 0x80) | |
178 | ||
10d6c8cd DJ |
179 | /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
180 | the use of the multi-threaded target. */ | |
181 | static struct target_ops *linux_ops; | |
f973ed9c | 182 | static struct target_ops linux_ops_saved; |
10d6c8cd | 183 | |
9f0bdab8 | 184 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
185 | static void (*linux_nat_new_thread) (struct lwp_info *); |
186 | ||
26cb8b7c PA |
187 | /* The method to call, if any, when a new fork is attached. */ |
188 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
189 | ||
190 | /* The method to call, if any, when a process is no longer | |
191 | attached. */ | |
192 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
193 | ||
7b50312a PA |
194 | /* Hook to call prior to resuming a thread. */ |
195 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 196 | |
5b009018 PA |
197 | /* The method to call, if any, when the siginfo object needs to be |
198 | converted between the layout returned by ptrace, and the layout in | |
199 | the architecture of the inferior. */ | |
a5362b9a | 200 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
201 | gdb_byte *, |
202 | int); | |
203 | ||
ac264b3b MS |
204 | /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
205 | Called by our to_xfer_partial. */ | |
206 | static LONGEST (*super_xfer_partial) (struct target_ops *, | |
207 | enum target_object, | |
208 | const char *, gdb_byte *, | |
209 | const gdb_byte *, | |
10d6c8cd DJ |
210 | ULONGEST, LONGEST); |
211 | ||
ccce17b0 | 212 | static unsigned int debug_linux_nat; |
920d2a44 AC |
213 | static void |
214 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
215 | struct cmd_list_element *c, const char *value) | |
216 | { | |
217 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
218 | value); | |
219 | } | |
d6b0e80f | 220 | |
ae087d01 DJ |
221 | struct simple_pid_list |
222 | { | |
223 | int pid; | |
3d799a95 | 224 | int status; |
ae087d01 DJ |
225 | struct simple_pid_list *next; |
226 | }; | |
227 | struct simple_pid_list *stopped_pids; | |
228 | ||
3993f6b1 DJ |
229 | /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
230 | can not be used, 1 if it can. */ | |
231 | ||
232 | static int linux_supports_tracefork_flag = -1; | |
233 | ||
3e43a32a MS |
234 | /* This variable is a tri-state flag: -1 for unknown, 0 if |
235 | PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */ | |
a96d9b2e SDJ |
236 | |
237 | static int linux_supports_tracesysgood_flag = -1; | |
238 | ||
9016a515 DJ |
239 | /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
240 | PTRACE_O_TRACEVFORKDONE. */ | |
241 | ||
242 | static int linux_supports_tracevforkdone_flag = -1; | |
243 | ||
a96d9b2e SDJ |
244 | /* Stores the current used ptrace() options. */ |
245 | static int current_ptrace_options = 0; | |
246 | ||
3dd5b83d PA |
247 | /* Async mode support. */ |
248 | ||
b84876c2 PA |
249 | /* The read/write ends of the pipe registered as waitable file in the |
250 | event loop. */ | |
251 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
252 | ||
7feb7d06 | 253 | /* Flush the event pipe. */ |
b84876c2 | 254 | |
7feb7d06 PA |
255 | static void |
256 | async_file_flush (void) | |
b84876c2 | 257 | { |
7feb7d06 PA |
258 | int ret; |
259 | char buf; | |
b84876c2 | 260 | |
7feb7d06 | 261 | do |
b84876c2 | 262 | { |
7feb7d06 | 263 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 264 | } |
7feb7d06 | 265 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
266 | } |
267 | ||
7feb7d06 PA |
268 | /* Put something (anything, doesn't matter what, or how much) in event |
269 | pipe, so that the select/poll in the event-loop realizes we have | |
270 | something to process. */ | |
252fbfc8 | 271 | |
b84876c2 | 272 | static void |
7feb7d06 | 273 | async_file_mark (void) |
b84876c2 | 274 | { |
7feb7d06 | 275 | int ret; |
b84876c2 | 276 | |
7feb7d06 PA |
277 | /* It doesn't really matter what the pipe contains, as long we end |
278 | up with something in it. Might as well flush the previous | |
279 | left-overs. */ | |
280 | async_file_flush (); | |
b84876c2 | 281 | |
7feb7d06 | 282 | do |
b84876c2 | 283 | { |
7feb7d06 | 284 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 285 | } |
7feb7d06 | 286 | while (ret == -1 && errno == EINTR); |
b84876c2 | 287 | |
7feb7d06 PA |
288 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
289 | be awakened anyway. */ | |
b84876c2 PA |
290 | } |
291 | ||
7feb7d06 | 292 | static void linux_nat_async (void (*callback) |
3e43a32a MS |
293 | (enum inferior_event_type event_type, |
294 | void *context), | |
7feb7d06 | 295 | void *context); |
7feb7d06 PA |
296 | static int kill_lwp (int lwpid, int signo); |
297 | ||
298 | static int stop_callback (struct lwp_info *lp, void *data); | |
299 | ||
300 | static void block_child_signals (sigset_t *prev_mask); | |
301 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
302 | |
303 | struct lwp_info; | |
304 | static struct lwp_info *add_lwp (ptid_t ptid); | |
305 | static void purge_lwp_list (int pid); | |
4403d8e9 | 306 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
307 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
308 | ||
ae087d01 DJ |
309 | \f |
310 | /* Trivial list manipulation functions to keep track of a list of | |
311 | new stopped processes. */ | |
312 | static void | |
3d799a95 | 313 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 DJ |
314 | { |
315 | struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); | |
e0881a8e | 316 | |
ae087d01 | 317 | new_pid->pid = pid; |
3d799a95 | 318 | new_pid->status = status; |
ae087d01 DJ |
319 | new_pid->next = *listp; |
320 | *listp = new_pid; | |
321 | } | |
322 | ||
84636d28 PA |
323 | static int |
324 | in_pid_list_p (struct simple_pid_list *list, int pid) | |
325 | { | |
326 | struct simple_pid_list *p; | |
327 | ||
328 | for (p = list; p != NULL; p = p->next) | |
329 | if (p->pid == pid) | |
330 | return 1; | |
331 | return 0; | |
332 | } | |
333 | ||
ae087d01 | 334 | static int |
46a96992 | 335 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
336 | { |
337 | struct simple_pid_list **p; | |
338 | ||
339 | for (p = listp; *p != NULL; p = &(*p)->next) | |
340 | if ((*p)->pid == pid) | |
341 | { | |
342 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 343 | |
46a96992 | 344 | *statusp = (*p)->status; |
ae087d01 DJ |
345 | xfree (*p); |
346 | *p = next; | |
347 | return 1; | |
348 | } | |
349 | return 0; | |
350 | } | |
351 | ||
3993f6b1 DJ |
352 | \f |
353 | /* A helper function for linux_test_for_tracefork, called after fork (). */ | |
354 | ||
355 | static void | |
356 | linux_tracefork_child (void) | |
357 | { | |
3993f6b1 DJ |
358 | ptrace (PTRACE_TRACEME, 0, 0, 0); |
359 | kill (getpid (), SIGSTOP); | |
360 | fork (); | |
48bb3cce | 361 | _exit (0); |
3993f6b1 DJ |
362 | } |
363 | ||
7feb7d06 | 364 | /* Wrapper function for waitpid which handles EINTR. */ |
b957e937 DJ |
365 | |
366 | static int | |
46a96992 | 367 | my_waitpid (int pid, int *statusp, int flags) |
b957e937 DJ |
368 | { |
369 | int ret; | |
b84876c2 | 370 | |
b957e937 DJ |
371 | do |
372 | { | |
46a96992 | 373 | ret = waitpid (pid, statusp, flags); |
b957e937 DJ |
374 | } |
375 | while (ret == -1 && errno == EINTR); | |
376 | ||
377 | return ret; | |
378 | } | |
379 | ||
380 | /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. | |
381 | ||
382 | First, we try to enable fork tracing on ORIGINAL_PID. If this fails, | |
383 | we know that the feature is not available. This may change the tracing | |
384 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. | |
385 | ||
386 | However, if it succeeds, we don't know for sure that the feature is | |
387 | available; old versions of PTRACE_SETOPTIONS ignored unknown options. We | |
3993f6b1 | 388 | create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
b957e937 DJ |
389 | fork tracing, and let it fork. If the process exits, we assume that we |
390 | can't use TRACEFORK; if we get the fork notification, and we can extract | |
391 | the new child's PID, then we assume that we can. */ | |
3993f6b1 DJ |
392 | |
393 | static void | |
b957e937 | 394 | linux_test_for_tracefork (int original_pid) |
3993f6b1 DJ |
395 | { |
396 | int child_pid, ret, status; | |
397 | long second_pid; | |
7feb7d06 | 398 | sigset_t prev_mask; |
4c28f408 | 399 | |
7feb7d06 PA |
400 | /* We don't want those ptrace calls to be interrupted. */ |
401 | block_child_signals (&prev_mask); | |
3993f6b1 | 402 | |
b957e937 DJ |
403 | linux_supports_tracefork_flag = 0; |
404 | linux_supports_tracevforkdone_flag = 0; | |
405 | ||
406 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); | |
407 | if (ret != 0) | |
7feb7d06 PA |
408 | { |
409 | restore_child_signals_mask (&prev_mask); | |
410 | return; | |
411 | } | |
b957e937 | 412 | |
3993f6b1 DJ |
413 | child_pid = fork (); |
414 | if (child_pid == -1) | |
e2e0b3e5 | 415 | perror_with_name (("fork")); |
3993f6b1 DJ |
416 | |
417 | if (child_pid == 0) | |
418 | linux_tracefork_child (); | |
419 | ||
b957e937 | 420 | ret = my_waitpid (child_pid, &status, 0); |
3993f6b1 | 421 | if (ret == -1) |
e2e0b3e5 | 422 | perror_with_name (("waitpid")); |
3993f6b1 | 423 | else if (ret != child_pid) |
8a3fe4f8 | 424 | error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
3993f6b1 | 425 | if (! WIFSTOPPED (status)) |
3e43a32a MS |
426 | error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), |
427 | status); | |
3993f6b1 | 428 | |
3993f6b1 DJ |
429 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
430 | if (ret != 0) | |
431 | { | |
b957e937 DJ |
432 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
433 | if (ret != 0) | |
434 | { | |
8a3fe4f8 | 435 | warning (_("linux_test_for_tracefork: failed to kill child")); |
7feb7d06 | 436 | restore_child_signals_mask (&prev_mask); |
b957e937 DJ |
437 | return; |
438 | } | |
439 | ||
440 | ret = my_waitpid (child_pid, &status, 0); | |
441 | if (ret != child_pid) | |
3e43a32a MS |
442 | warning (_("linux_test_for_tracefork: failed " |
443 | "to wait for killed child")); | |
b957e937 | 444 | else if (!WIFSIGNALED (status)) |
3e43a32a MS |
445 | warning (_("linux_test_for_tracefork: unexpected " |
446 | "wait status 0x%x from killed child"), status); | |
b957e937 | 447 | |
7feb7d06 | 448 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
449 | return; |
450 | } | |
451 | ||
9016a515 DJ |
452 | /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
453 | ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, | |
454 | PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); | |
455 | linux_supports_tracevforkdone_flag = (ret == 0); | |
456 | ||
b957e937 DJ |
457 | ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
458 | if (ret != 0) | |
8a3fe4f8 | 459 | warning (_("linux_test_for_tracefork: failed to resume child")); |
b957e937 DJ |
460 | |
461 | ret = my_waitpid (child_pid, &status, 0); | |
462 | ||
3993f6b1 DJ |
463 | if (ret == child_pid && WIFSTOPPED (status) |
464 | && status >> 16 == PTRACE_EVENT_FORK) | |
465 | { | |
466 | second_pid = 0; | |
467 | ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); | |
468 | if (ret == 0 && second_pid != 0) | |
469 | { | |
470 | int second_status; | |
471 | ||
472 | linux_supports_tracefork_flag = 1; | |
b957e937 DJ |
473 | my_waitpid (second_pid, &second_status, 0); |
474 | ret = ptrace (PTRACE_KILL, second_pid, 0, 0); | |
475 | if (ret != 0) | |
3e43a32a MS |
476 | warning (_("linux_test_for_tracefork: " |
477 | "failed to kill second child")); | |
97725dc4 | 478 | my_waitpid (second_pid, &status, 0); |
3993f6b1 DJ |
479 | } |
480 | } | |
b957e937 | 481 | else |
8a3fe4f8 AC |
482 | warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
483 | "(%d, status 0x%x)"), ret, status); | |
3993f6b1 | 484 | |
b957e937 DJ |
485 | ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
486 | if (ret != 0) | |
8a3fe4f8 | 487 | warning (_("linux_test_for_tracefork: failed to kill child")); |
b957e937 | 488 | my_waitpid (child_pid, &status, 0); |
4c28f408 | 489 | |
7feb7d06 | 490 | restore_child_signals_mask (&prev_mask); |
3993f6b1 DJ |
491 | } |
492 | ||
a96d9b2e SDJ |
493 | /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls. |
494 | ||
495 | We try to enable syscall tracing on ORIGINAL_PID. If this fails, | |
496 | we know that the feature is not available. This may change the tracing | |
497 | options for ORIGINAL_PID, but we'll be setting them shortly anyway. */ | |
498 | ||
499 | static void | |
500 | linux_test_for_tracesysgood (int original_pid) | |
501 | { | |
502 | int ret; | |
503 | sigset_t prev_mask; | |
504 | ||
505 | /* We don't want those ptrace calls to be interrupted. */ | |
506 | block_child_signals (&prev_mask); | |
507 | ||
508 | linux_supports_tracesysgood_flag = 0; | |
509 | ||
510 | ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD); | |
511 | if (ret != 0) | |
512 | goto out; | |
513 | ||
514 | linux_supports_tracesysgood_flag = 1; | |
515 | out: | |
516 | restore_child_signals_mask (&prev_mask); | |
517 | } | |
518 | ||
519 | /* Determine wether we support PTRACE_O_TRACESYSGOOD option available. | |
520 | This function also sets linux_supports_tracesysgood_flag. */ | |
521 | ||
522 | static int | |
523 | linux_supports_tracesysgood (int pid) | |
524 | { | |
525 | if (linux_supports_tracesysgood_flag == -1) | |
526 | linux_test_for_tracesysgood (pid); | |
527 | return linux_supports_tracesysgood_flag; | |
528 | } | |
529 | ||
3993f6b1 DJ |
530 | /* Return non-zero iff we have tracefork functionality available. |
531 | This function also sets linux_supports_tracefork_flag. */ | |
532 | ||
533 | static int | |
b957e937 | 534 | linux_supports_tracefork (int pid) |
3993f6b1 DJ |
535 | { |
536 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 537 | linux_test_for_tracefork (pid); |
3993f6b1 DJ |
538 | return linux_supports_tracefork_flag; |
539 | } | |
540 | ||
9016a515 | 541 | static int |
b957e937 | 542 | linux_supports_tracevforkdone (int pid) |
9016a515 DJ |
543 | { |
544 | if (linux_supports_tracefork_flag == -1) | |
b957e937 | 545 | linux_test_for_tracefork (pid); |
9016a515 DJ |
546 | return linux_supports_tracevforkdone_flag; |
547 | } | |
548 | ||
a96d9b2e SDJ |
549 | static void |
550 | linux_enable_tracesysgood (ptid_t ptid) | |
551 | { | |
552 | int pid = ptid_get_lwp (ptid); | |
553 | ||
554 | if (pid == 0) | |
555 | pid = ptid_get_pid (ptid); | |
556 | ||
557 | if (linux_supports_tracesysgood (pid) == 0) | |
558 | return; | |
559 | ||
560 | current_ptrace_options |= PTRACE_O_TRACESYSGOOD; | |
561 | ||
562 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); | |
563 | } | |
564 | ||
3993f6b1 | 565 | \f |
4de4c07c DJ |
566 | void |
567 | linux_enable_event_reporting (ptid_t ptid) | |
568 | { | |
d3587048 | 569 | int pid = ptid_get_lwp (ptid); |
4de4c07c | 570 | |
d3587048 DJ |
571 | if (pid == 0) |
572 | pid = ptid_get_pid (ptid); | |
573 | ||
b957e937 | 574 | if (! linux_supports_tracefork (pid)) |
4de4c07c DJ |
575 | return; |
576 | ||
a96d9b2e SDJ |
577 | current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK |
578 | | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE; | |
579 | ||
b957e937 | 580 | if (linux_supports_tracevforkdone (pid)) |
a96d9b2e | 581 | current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; |
9016a515 DJ |
582 | |
583 | /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support | |
584 | read-only process state. */ | |
4de4c07c | 585 | |
a96d9b2e | 586 | ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
4de4c07c DJ |
587 | } |
588 | ||
6d8fd2b7 UW |
589 | static void |
590 | linux_child_post_attach (int pid) | |
4de4c07c DJ |
591 | { |
592 | linux_enable_event_reporting (pid_to_ptid (pid)); | |
a96d9b2e | 593 | linux_enable_tracesysgood (pid_to_ptid (pid)); |
aa7c7447 | 594 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
595 | } |
596 | ||
10d6c8cd | 597 | static void |
4de4c07c DJ |
598 | linux_child_post_startup_inferior (ptid_t ptid) |
599 | { | |
600 | linux_enable_event_reporting (ptid); | |
a96d9b2e | 601 | linux_enable_tracesysgood (ptid); |
aa7c7447 | 602 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
603 | } |
604 | ||
4403d8e9 JK |
605 | /* Return the number of known LWPs in the tgid given by PID. */ |
606 | ||
607 | static int | |
608 | num_lwps (int pid) | |
609 | { | |
610 | int count = 0; | |
611 | struct lwp_info *lp; | |
612 | ||
613 | for (lp = lwp_list; lp; lp = lp->next) | |
614 | if (ptid_get_pid (lp->ptid) == pid) | |
615 | count++; | |
616 | ||
617 | return count; | |
618 | } | |
619 | ||
620 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
621 | ||
622 | static void | |
623 | delete_lwp_cleanup (void *lp_voidp) | |
624 | { | |
625 | struct lwp_info *lp = lp_voidp; | |
626 | ||
627 | delete_lwp (lp->ptid); | |
628 | } | |
629 | ||
6d8fd2b7 UW |
630 | static int |
631 | linux_child_follow_fork (struct target_ops *ops, int follow_child) | |
3993f6b1 | 632 | { |
7feb7d06 | 633 | sigset_t prev_mask; |
9016a515 | 634 | int has_vforked; |
4de4c07c DJ |
635 | int parent_pid, child_pid; |
636 | ||
7feb7d06 | 637 | block_child_signals (&prev_mask); |
b84876c2 | 638 | |
e58b0e63 PA |
639 | has_vforked = (inferior_thread ()->pending_follow.kind |
640 | == TARGET_WAITKIND_VFORKED); | |
641 | parent_pid = ptid_get_lwp (inferior_ptid); | |
d3587048 | 642 | if (parent_pid == 0) |
e58b0e63 PA |
643 | parent_pid = ptid_get_pid (inferior_ptid); |
644 | child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); | |
4de4c07c | 645 | |
6c95b8df PA |
646 | if (has_vforked |
647 | && !non_stop /* Non-stop always resumes both branches. */ | |
648 | && (!target_is_async_p () || sync_execution) | |
649 | && !(follow_child || detach_fork || sched_multi)) | |
650 | { | |
651 | /* The parent stays blocked inside the vfork syscall until the | |
652 | child execs or exits. If we don't let the child run, then | |
653 | the parent stays blocked. If we're telling the parent to run | |
654 | in the foreground, the user will not be able to ctrl-c to get | |
655 | back the terminal, effectively hanging the debug session. */ | |
ac74f770 MS |
656 | fprintf_filtered (gdb_stderr, _("\ |
657 | Can not resume the parent process over vfork in the foreground while\n\ | |
658 | holding the child stopped. Try \"set detach-on-fork\" or \ | |
659 | \"set schedule-multiple\".\n")); | |
660 | /* FIXME output string > 80 columns. */ | |
6c95b8df PA |
661 | return 1; |
662 | } | |
663 | ||
4de4c07c DJ |
664 | if (! follow_child) |
665 | { | |
6c95b8df | 666 | struct lwp_info *child_lp = NULL; |
4de4c07c | 667 | |
1777feb0 | 668 | /* We're already attached to the parent, by default. */ |
4de4c07c | 669 | |
ac264b3b MS |
670 | /* Detach new forked process? */ |
671 | if (detach_fork) | |
f75c00e4 | 672 | { |
4403d8e9 JK |
673 | struct cleanup *old_chain; |
674 | ||
6c95b8df PA |
675 | /* Before detaching from the child, remove all breakpoints |
676 | from it. If we forked, then this has already been taken | |
677 | care of by infrun.c. If we vforked however, any | |
678 | breakpoint inserted in the parent is visible in the | |
679 | child, even those added while stopped in a vfork | |
680 | catchpoint. This will remove the breakpoints from the | |
681 | parent also, but they'll be reinserted below. */ | |
682 | if (has_vforked) | |
683 | { | |
684 | /* keep breakpoints list in sync. */ | |
685 | remove_breakpoints_pid (GET_PID (inferior_ptid)); | |
686 | } | |
687 | ||
e85a822c | 688 | if (info_verbose || debug_linux_nat) |
ac264b3b MS |
689 | { |
690 | target_terminal_ours (); | |
691 | fprintf_filtered (gdb_stdlog, | |
3e43a32a MS |
692 | "Detaching after fork from " |
693 | "child process %d.\n", | |
ac264b3b MS |
694 | child_pid); |
695 | } | |
4de4c07c | 696 | |
4403d8e9 JK |
697 | old_chain = save_inferior_ptid (); |
698 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
699 | ||
700 | child_lp = add_lwp (inferior_ptid); | |
701 | child_lp->stopped = 1; | |
702 | child_lp->last_resume_kind = resume_stop; | |
703 | make_cleanup (delete_lwp_cleanup, child_lp); | |
704 | ||
4403d8e9 JK |
705 | if (linux_nat_prepare_to_resume != NULL) |
706 | linux_nat_prepare_to_resume (child_lp); | |
ac264b3b | 707 | ptrace (PTRACE_DETACH, child_pid, 0, 0); |
4403d8e9 JK |
708 | |
709 | do_cleanups (old_chain); | |
ac264b3b MS |
710 | } |
711 | else | |
712 | { | |
77435e4c | 713 | struct inferior *parent_inf, *child_inf; |
2277426b | 714 | struct cleanup *old_chain; |
7f9f62ba PA |
715 | |
716 | /* Add process to GDB's tables. */ | |
77435e4c PA |
717 | child_inf = add_inferior (child_pid); |
718 | ||
e58b0e63 | 719 | parent_inf = current_inferior (); |
77435e4c | 720 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 721 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
722 | child_inf->gdbarch = parent_inf->gdbarch; |
723 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7f9f62ba | 724 | |
2277426b | 725 | old_chain = save_inferior_ptid (); |
6c95b8df | 726 | save_current_program_space (); |
2277426b PA |
727 | |
728 | inferior_ptid = ptid_build (child_pid, child_pid, 0); | |
729 | add_thread (inferior_ptid); | |
6c95b8df PA |
730 | child_lp = add_lwp (inferior_ptid); |
731 | child_lp->stopped = 1; | |
25289eb2 | 732 | child_lp->last_resume_kind = resume_stop; |
7dcd53a0 | 733 | child_inf->symfile_flags = SYMFILE_NO_READ; |
2277426b | 734 | |
6c95b8df PA |
735 | /* If this is a vfork child, then the address-space is |
736 | shared with the parent. */ | |
737 | if (has_vforked) | |
738 | { | |
739 | child_inf->pspace = parent_inf->pspace; | |
740 | child_inf->aspace = parent_inf->aspace; | |
741 | ||
742 | /* The parent will be frozen until the child is done | |
743 | with the shared region. Keep track of the | |
744 | parent. */ | |
745 | child_inf->vfork_parent = parent_inf; | |
746 | child_inf->pending_detach = 0; | |
747 | parent_inf->vfork_child = child_inf; | |
748 | parent_inf->pending_detach = 0; | |
749 | } | |
750 | else | |
751 | { | |
752 | child_inf->aspace = new_address_space (); | |
753 | child_inf->pspace = add_program_space (child_inf->aspace); | |
754 | child_inf->removable = 1; | |
755 | set_current_program_space (child_inf->pspace); | |
756 | clone_program_space (child_inf->pspace, parent_inf->pspace); | |
757 | ||
758 | /* Let the shared library layer (solib-svr4) learn about | |
759 | this new process, relocate the cloned exec, pull in | |
760 | shared libraries, and install the solib event | |
761 | breakpoint. If a "cloned-VM" event was propagated | |
762 | better throughout the core, this wouldn't be | |
763 | required. */ | |
268a4a75 | 764 | solib_create_inferior_hook (0); |
6c95b8df PA |
765 | } |
766 | ||
767 | /* Let the thread_db layer learn about this new process. */ | |
2277426b PA |
768 | check_for_thread_db (); |
769 | ||
770 | do_cleanups (old_chain); | |
ac264b3b | 771 | } |
9016a515 DJ |
772 | |
773 | if (has_vforked) | |
774 | { | |
3ced3da4 | 775 | struct lwp_info *parent_lp; |
6c95b8df PA |
776 | struct inferior *parent_inf; |
777 | ||
778 | parent_inf = current_inferior (); | |
779 | ||
780 | /* If we detached from the child, then we have to be careful | |
781 | to not insert breakpoints in the parent until the child | |
782 | is done with the shared memory region. However, if we're | |
783 | staying attached to the child, then we can and should | |
784 | insert breakpoints, so that we can debug it. A | |
785 | subsequent child exec or exit is enough to know when does | |
786 | the child stops using the parent's address space. */ | |
787 | parent_inf->waiting_for_vfork_done = detach_fork; | |
56710373 | 788 | parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
6c95b8df | 789 | |
3ced3da4 | 790 | parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
b957e937 | 791 | gdb_assert (linux_supports_tracefork_flag >= 0); |
3ced3da4 | 792 | |
b957e937 | 793 | if (linux_supports_tracevforkdone (0)) |
9016a515 | 794 | { |
6c95b8df PA |
795 | if (debug_linux_nat) |
796 | fprintf_unfiltered (gdb_stdlog, | |
797 | "LCFF: waiting for VFORK_DONE on %d\n", | |
798 | parent_pid); | |
3ced3da4 | 799 | parent_lp->stopped = 1; |
9016a515 | 800 | |
6c95b8df PA |
801 | /* We'll handle the VFORK_DONE event like any other |
802 | event, in target_wait. */ | |
9016a515 DJ |
803 | } |
804 | else | |
805 | { | |
806 | /* We can't insert breakpoints until the child has | |
807 | finished with the shared memory region. We need to | |
808 | wait until that happens. Ideal would be to just | |
809 | call: | |
810 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
811 | - waitpid (parent_pid, &status, __WALL); | |
812 | However, most architectures can't handle a syscall | |
813 | being traced on the way out if it wasn't traced on | |
814 | the way in. | |
815 | ||
816 | We might also think to loop, continuing the child | |
817 | until it exits or gets a SIGTRAP. One problem is | |
818 | that the child might call ptrace with PTRACE_TRACEME. | |
819 | ||
820 | There's no simple and reliable way to figure out when | |
821 | the vforked child will be done with its copy of the | |
822 | shared memory. We could step it out of the syscall, | |
823 | two instructions, let it go, and then single-step the | |
824 | parent once. When we have hardware single-step, this | |
825 | would work; with software single-step it could still | |
826 | be made to work but we'd have to be able to insert | |
827 | single-step breakpoints in the child, and we'd have | |
828 | to insert -just- the single-step breakpoint in the | |
829 | parent. Very awkward. | |
830 | ||
831 | In the end, the best we can do is to make sure it | |
832 | runs for a little while. Hopefully it will be out of | |
833 | range of any breakpoints we reinsert. Usually this | |
834 | is only the single-step breakpoint at vfork's return | |
835 | point. */ | |
836 | ||
6c95b8df PA |
837 | if (debug_linux_nat) |
838 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
839 | "LCFF: no VFORK_DONE " |
840 | "support, sleeping a bit\n"); | |
6c95b8df | 841 | |
9016a515 | 842 | usleep (10000); |
9016a515 | 843 | |
6c95b8df PA |
844 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
845 | and leave it pending. The next linux_nat_resume call | |
846 | will notice a pending event, and bypasses actually | |
847 | resuming the inferior. */ | |
3ced3da4 PA |
848 | parent_lp->status = 0; |
849 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
850 | parent_lp->stopped = 1; | |
6c95b8df PA |
851 | |
852 | /* If we're in async mode, need to tell the event loop | |
853 | there's something here to process. */ | |
854 | if (target_can_async_p ()) | |
855 | async_file_mark (); | |
856 | } | |
9016a515 | 857 | } |
4de4c07c | 858 | } |
3993f6b1 | 859 | else |
4de4c07c | 860 | { |
77435e4c | 861 | struct inferior *parent_inf, *child_inf; |
3ced3da4 | 862 | struct lwp_info *child_lp; |
6c95b8df | 863 | struct program_space *parent_pspace; |
4de4c07c | 864 | |
e85a822c | 865 | if (info_verbose || debug_linux_nat) |
f75c00e4 DJ |
866 | { |
867 | target_terminal_ours (); | |
6c95b8df | 868 | if (has_vforked) |
3e43a32a MS |
869 | fprintf_filtered (gdb_stdlog, |
870 | _("Attaching after process %d " | |
871 | "vfork to child process %d.\n"), | |
6c95b8df PA |
872 | parent_pid, child_pid); |
873 | else | |
3e43a32a MS |
874 | fprintf_filtered (gdb_stdlog, |
875 | _("Attaching after process %d " | |
876 | "fork to child process %d.\n"), | |
6c95b8df | 877 | parent_pid, child_pid); |
f75c00e4 | 878 | } |
4de4c07c | 879 | |
7a7d3353 PA |
880 | /* Add the new inferior first, so that the target_detach below |
881 | doesn't unpush the target. */ | |
882 | ||
77435e4c PA |
883 | child_inf = add_inferior (child_pid); |
884 | ||
e58b0e63 | 885 | parent_inf = current_inferior (); |
77435e4c | 886 | child_inf->attach_flag = parent_inf->attach_flag; |
191c4426 | 887 | copy_terminal_info (child_inf, parent_inf); |
6ecd4729 PA |
888 | child_inf->gdbarch = parent_inf->gdbarch; |
889 | copy_inferior_target_desc_info (child_inf, parent_inf); | |
7a7d3353 | 890 | |
6c95b8df | 891 | parent_pspace = parent_inf->pspace; |
9016a515 | 892 | |
6c95b8df PA |
893 | /* If we're vforking, we want to hold on to the parent until the |
894 | child exits or execs. At child exec or exit time we can | |
895 | remove the old breakpoints from the parent and detach or | |
896 | resume debugging it. Otherwise, detach the parent now; we'll | |
897 | want to reuse it's program/address spaces, but we can't set | |
898 | them to the child before removing breakpoints from the | |
899 | parent, otherwise, the breakpoints module could decide to | |
900 | remove breakpoints from the wrong process (since they'd be | |
901 | assigned to the same address space). */ | |
9016a515 DJ |
902 | |
903 | if (has_vforked) | |
7f9f62ba | 904 | { |
6c95b8df PA |
905 | gdb_assert (child_inf->vfork_parent == NULL); |
906 | gdb_assert (parent_inf->vfork_child == NULL); | |
907 | child_inf->vfork_parent = parent_inf; | |
908 | child_inf->pending_detach = 0; | |
909 | parent_inf->vfork_child = child_inf; | |
910 | parent_inf->pending_detach = detach_fork; | |
911 | parent_inf->waiting_for_vfork_done = 0; | |
ac264b3b | 912 | } |
2277426b | 913 | else if (detach_fork) |
b84876c2 | 914 | target_detach (NULL, 0); |
4de4c07c | 915 | |
6c95b8df PA |
916 | /* Note that the detach above makes PARENT_INF dangling. */ |
917 | ||
918 | /* Add the child thread to the appropriate lists, and switch to | |
919 | this new thread, before cloning the program space, and | |
920 | informing the solib layer about this new process. */ | |
921 | ||
9f0bdab8 | 922 | inferior_ptid = ptid_build (child_pid, child_pid, 0); |
2277426b | 923 | add_thread (inferior_ptid); |
3ced3da4 PA |
924 | child_lp = add_lwp (inferior_ptid); |
925 | child_lp->stopped = 1; | |
25289eb2 | 926 | child_lp->last_resume_kind = resume_stop; |
6c95b8df PA |
927 | |
928 | /* If this is a vfork child, then the address-space is shared | |
929 | with the parent. If we detached from the parent, then we can | |
930 | reuse the parent's program/address spaces. */ | |
931 | if (has_vforked || detach_fork) | |
932 | { | |
933 | child_inf->pspace = parent_pspace; | |
934 | child_inf->aspace = child_inf->pspace->aspace; | |
935 | } | |
936 | else | |
937 | { | |
938 | child_inf->aspace = new_address_space (); | |
939 | child_inf->pspace = add_program_space (child_inf->aspace); | |
940 | child_inf->removable = 1; | |
7dcd53a0 | 941 | child_inf->symfile_flags = SYMFILE_NO_READ; |
6c95b8df PA |
942 | set_current_program_space (child_inf->pspace); |
943 | clone_program_space (child_inf->pspace, parent_pspace); | |
944 | ||
945 | /* Let the shared library layer (solib-svr4) learn about | |
946 | this new process, relocate the cloned exec, pull in | |
947 | shared libraries, and install the solib event breakpoint. | |
948 | If a "cloned-VM" event was propagated better throughout | |
949 | the core, this wouldn't be required. */ | |
268a4a75 | 950 | solib_create_inferior_hook (0); |
6c95b8df | 951 | } |
ac264b3b | 952 | |
6c95b8df | 953 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 954 | check_for_thread_db (); |
4de4c07c DJ |
955 | } |
956 | ||
7feb7d06 | 957 | restore_child_signals_mask (&prev_mask); |
4de4c07c DJ |
958 | return 0; |
959 | } | |
960 | ||
4de4c07c | 961 | \f |
77b06cd7 | 962 | static int |
6d8fd2b7 | 963 | linux_child_insert_fork_catchpoint (int pid) |
4de4c07c | 964 | { |
77b06cd7 | 965 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
966 | } |
967 | ||
eb73ad13 PA |
968 | static int |
969 | linux_child_remove_fork_catchpoint (int pid) | |
970 | { | |
971 | return 0; | |
972 | } | |
973 | ||
77b06cd7 | 974 | static int |
6d8fd2b7 | 975 | linux_child_insert_vfork_catchpoint (int pid) |
3993f6b1 | 976 | { |
77b06cd7 | 977 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
978 | } |
979 | ||
eb73ad13 PA |
980 | static int |
981 | linux_child_remove_vfork_catchpoint (int pid) | |
982 | { | |
983 | return 0; | |
984 | } | |
985 | ||
77b06cd7 | 986 | static int |
6d8fd2b7 | 987 | linux_child_insert_exec_catchpoint (int pid) |
3993f6b1 | 988 | { |
77b06cd7 | 989 | return !linux_supports_tracefork (pid); |
3993f6b1 DJ |
990 | } |
991 | ||
eb73ad13 PA |
992 | static int |
993 | linux_child_remove_exec_catchpoint (int pid) | |
994 | { | |
995 | return 0; | |
996 | } | |
997 | ||
a96d9b2e SDJ |
998 | static int |
999 | linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, | |
1000 | int table_size, int *table) | |
1001 | { | |
77b06cd7 TJB |
1002 | if (!linux_supports_tracesysgood (pid)) |
1003 | return 1; | |
1004 | ||
a96d9b2e SDJ |
1005 | /* On GNU/Linux, we ignore the arguments. It means that we only |
1006 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 1007 | |
a96d9b2e SDJ |
1008 | Also, we do not use the `table' information because we do not |
1009 | filter system calls here. We let GDB do the logic for us. */ | |
1010 | return 0; | |
1011 | } | |
1012 | ||
d6b0e80f AC |
1013 | /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
1014 | are processes sharing the same VM space. A multi-threaded process | |
1015 | is basically a group of such processes. However, such a grouping | |
1016 | is almost entirely a user-space issue; the kernel doesn't enforce | |
1017 | such a grouping at all (this might change in the future). In | |
1018 | general, we'll rely on the threads library (i.e. the GNU/Linux | |
1019 | Threads library) to provide such a grouping. | |
1020 | ||
1021 | It is perfectly well possible to write a multi-threaded application | |
1022 | without the assistance of a threads library, by using the clone | |
1023 | system call directly. This module should be able to give some | |
1024 | rudimentary support for debugging such applications if developers | |
1025 | specify the CLONE_PTRACE flag in the clone system call, and are | |
1026 | using the Linux kernel 2.4 or above. | |
1027 | ||
1028 | Note that there are some peculiarities in GNU/Linux that affect | |
1029 | this code: | |
1030 | ||
1031 | - In general one should specify the __WCLONE flag to waitpid in | |
1032 | order to make it report events for any of the cloned processes | |
1033 | (and leave it out for the initial process). However, if a cloned | |
1034 | process has exited the exit status is only reported if the | |
1035 | __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but | |
1036 | we cannot use it since GDB must work on older systems too. | |
1037 | ||
1038 | - When a traced, cloned process exits and is waited for by the | |
1039 | debugger, the kernel reassigns it to the original parent and | |
1040 | keeps it around as a "zombie". Somehow, the GNU/Linux Threads | |
1041 | library doesn't notice this, which leads to the "zombie problem": | |
1042 | When debugged a multi-threaded process that spawns a lot of | |
1043 | threads will run out of processes, even if the threads exit, | |
1044 | because the "zombies" stay around. */ | |
1045 | ||
1046 | /* List of known LWPs. */ | |
9f0bdab8 | 1047 | struct lwp_info *lwp_list; |
d6b0e80f AC |
1048 | \f |
1049 | ||
d6b0e80f AC |
1050 | /* Original signal mask. */ |
1051 | static sigset_t normal_mask; | |
1052 | ||
1053 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
1054 | _initialize_linux_nat. */ | |
1055 | static sigset_t suspend_mask; | |
1056 | ||
7feb7d06 PA |
1057 | /* Signals to block to make that sigsuspend work. */ |
1058 | static sigset_t blocked_mask; | |
1059 | ||
1060 | /* SIGCHLD action. */ | |
1061 | struct sigaction sigchld_action; | |
b84876c2 | 1062 | |
7feb7d06 PA |
1063 | /* Block child signals (SIGCHLD and linux threads signals), and store |
1064 | the previous mask in PREV_MASK. */ | |
84e46146 | 1065 | |
7feb7d06 PA |
1066 | static void |
1067 | block_child_signals (sigset_t *prev_mask) | |
1068 | { | |
1069 | /* Make sure SIGCHLD is blocked. */ | |
1070 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
1071 | sigaddset (&blocked_mask, SIGCHLD); | |
1072 | ||
1073 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
1074 | } | |
1075 | ||
1076 | /* Restore child signals mask, previously returned by | |
1077 | block_child_signals. */ | |
1078 | ||
1079 | static void | |
1080 | restore_child_signals_mask (sigset_t *prev_mask) | |
1081 | { | |
1082 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
1083 | } | |
2455069d UW |
1084 | |
1085 | /* Mask of signals to pass directly to the inferior. */ | |
1086 | static sigset_t pass_mask; | |
1087 | ||
1088 | /* Update signals to pass to the inferior. */ | |
1089 | static void | |
1090 | linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) | |
1091 | { | |
1092 | int signo; | |
1093 | ||
1094 | sigemptyset (&pass_mask); | |
1095 | ||
1096 | for (signo = 1; signo < NSIG; signo++) | |
1097 | { | |
2ea28649 | 1098 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
1099 | if (target_signo < numsigs && pass_signals[target_signo]) |
1100 | sigaddset (&pass_mask, signo); | |
1101 | } | |
1102 | } | |
1103 | ||
d6b0e80f AC |
1104 | \f |
1105 | ||
1106 | /* Prototypes for local functions. */ | |
1107 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
28439f5e | 1108 | static int linux_thread_alive (ptid_t ptid); |
6d8fd2b7 | 1109 | static char *linux_child_pid_to_exec_file (int pid); |
710151dd | 1110 | |
d6b0e80f AC |
1111 | \f |
1112 | /* Convert wait status STATUS to a string. Used for printing debug | |
1113 | messages only. */ | |
1114 | ||
1115 | static char * | |
1116 | status_to_str (int status) | |
1117 | { | |
1118 | static char buf[64]; | |
1119 | ||
1120 | if (WIFSTOPPED (status)) | |
206aa767 | 1121 | { |
ca2163eb | 1122 | if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
206aa767 DE |
1123 | snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
1124 | strsignal (SIGTRAP)); | |
1125 | else | |
1126 | snprintf (buf, sizeof (buf), "%s (stopped)", | |
1127 | strsignal (WSTOPSIG (status))); | |
1128 | } | |
d6b0e80f AC |
1129 | else if (WIFSIGNALED (status)) |
1130 | snprintf (buf, sizeof (buf), "%s (terminated)", | |
ba9b2ec3 | 1131 | strsignal (WTERMSIG (status))); |
d6b0e80f AC |
1132 | else |
1133 | snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); | |
1134 | ||
1135 | return buf; | |
1136 | } | |
1137 | ||
7b50312a PA |
1138 | /* Destroy and free LP. */ |
1139 | ||
1140 | static void | |
1141 | lwp_free (struct lwp_info *lp) | |
1142 | { | |
1143 | xfree (lp->arch_private); | |
1144 | xfree (lp); | |
1145 | } | |
1146 | ||
d90e17a7 PA |
1147 | /* Remove all LWPs belong to PID from the lwp list. */ |
1148 | ||
1149 | static void | |
1150 | purge_lwp_list (int pid) | |
1151 | { | |
1152 | struct lwp_info *lp, *lpprev, *lpnext; | |
1153 | ||
1154 | lpprev = NULL; | |
1155 | ||
1156 | for (lp = lwp_list; lp; lp = lpnext) | |
1157 | { | |
1158 | lpnext = lp->next; | |
1159 | ||
1160 | if (ptid_get_pid (lp->ptid) == pid) | |
1161 | { | |
1162 | if (lp == lwp_list) | |
1163 | lwp_list = lp->next; | |
1164 | else | |
1165 | lpprev->next = lp->next; | |
1166 | ||
7b50312a | 1167 | lwp_free (lp); |
d90e17a7 PA |
1168 | } |
1169 | else | |
1170 | lpprev = lp; | |
1171 | } | |
1172 | } | |
1173 | ||
26cb8b7c PA |
1174 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
1175 | in the process. Return a pointer to the structure describing the | |
1176 | new LWP. | |
1177 | ||
1178 | This differs from add_lwp in that we don't let the arch specific | |
1179 | bits know about this new thread. Current clients of this callback | |
1180 | take the opportunity to install watchpoints in the new thread, and | |
1181 | we shouldn't do that for the first thread. If we're spawning a | |
1182 | child ("run"), the thread executes the shell wrapper first, and we | |
1183 | shouldn't touch it until it execs the program we want to debug. | |
1184 | For "attach", it'd be okay to call the callback, but it's not | |
1185 | necessary, because watchpoints can't yet have been inserted into | |
1186 | the inferior. */ | |
d6b0e80f AC |
1187 | |
1188 | static struct lwp_info * | |
26cb8b7c | 1189 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
1190 | { |
1191 | struct lwp_info *lp; | |
1192 | ||
1193 | gdb_assert (is_lwp (ptid)); | |
1194 | ||
1195 | lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); | |
1196 | ||
1197 | memset (lp, 0, sizeof (struct lwp_info)); | |
1198 | ||
25289eb2 | 1199 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1200 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
1201 | ||
1202 | lp->ptid = ptid; | |
dc146f7c | 1203 | lp->core = -1; |
d6b0e80f AC |
1204 | |
1205 | lp->next = lwp_list; | |
1206 | lwp_list = lp; | |
d6b0e80f | 1207 | |
26cb8b7c PA |
1208 | return lp; |
1209 | } | |
1210 | ||
1211 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
1212 | structure describing the new LWP. The LWP should already be | |
1213 | stopped. */ | |
1214 | ||
1215 | static struct lwp_info * | |
1216 | add_lwp (ptid_t ptid) | |
1217 | { | |
1218 | struct lwp_info *lp; | |
1219 | ||
1220 | lp = add_initial_lwp (ptid); | |
1221 | ||
6e012a6c PA |
1222 | /* Let the arch specific bits know about this new thread. Current |
1223 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
1224 | watchpoints in the new thread. We don't do this for the first |
1225 | thread though. See add_initial_lwp. */ | |
1226 | if (linux_nat_new_thread != NULL) | |
7b50312a | 1227 | linux_nat_new_thread (lp); |
9f0bdab8 | 1228 | |
d6b0e80f AC |
1229 | return lp; |
1230 | } | |
1231 | ||
1232 | /* Remove the LWP specified by PID from the list. */ | |
1233 | ||
1234 | static void | |
1235 | delete_lwp (ptid_t ptid) | |
1236 | { | |
1237 | struct lwp_info *lp, *lpprev; | |
1238 | ||
1239 | lpprev = NULL; | |
1240 | ||
1241 | for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) | |
1242 | if (ptid_equal (lp->ptid, ptid)) | |
1243 | break; | |
1244 | ||
1245 | if (!lp) | |
1246 | return; | |
1247 | ||
d6b0e80f AC |
1248 | if (lpprev) |
1249 | lpprev->next = lp->next; | |
1250 | else | |
1251 | lwp_list = lp->next; | |
1252 | ||
7b50312a | 1253 | lwp_free (lp); |
d6b0e80f AC |
1254 | } |
1255 | ||
1256 | /* Return a pointer to the structure describing the LWP corresponding | |
1257 | to PID. If no corresponding LWP could be found, return NULL. */ | |
1258 | ||
1259 | static struct lwp_info * | |
1260 | find_lwp_pid (ptid_t ptid) | |
1261 | { | |
1262 | struct lwp_info *lp; | |
1263 | int lwp; | |
1264 | ||
1265 | if (is_lwp (ptid)) | |
1266 | lwp = GET_LWP (ptid); | |
1267 | else | |
1268 | lwp = GET_PID (ptid); | |
1269 | ||
1270 | for (lp = lwp_list; lp; lp = lp->next) | |
1271 | if (lwp == GET_LWP (lp->ptid)) | |
1272 | return lp; | |
1273 | ||
1274 | return NULL; | |
1275 | } | |
1276 | ||
1277 | /* Call CALLBACK with its second argument set to DATA for every LWP in | |
1278 | the list. If CALLBACK returns 1 for a particular LWP, return a | |
1279 | pointer to the structure describing that LWP immediately. | |
1280 | Otherwise return NULL. */ | |
1281 | ||
1282 | struct lwp_info * | |
d90e17a7 PA |
1283 | iterate_over_lwps (ptid_t filter, |
1284 | int (*callback) (struct lwp_info *, void *), | |
1285 | void *data) | |
d6b0e80f AC |
1286 | { |
1287 | struct lwp_info *lp, *lpnext; | |
1288 | ||
1289 | for (lp = lwp_list; lp; lp = lpnext) | |
1290 | { | |
1291 | lpnext = lp->next; | |
d90e17a7 PA |
1292 | |
1293 | if (ptid_match (lp->ptid, filter)) | |
1294 | { | |
1295 | if ((*callback) (lp, data)) | |
1296 | return lp; | |
1297 | } | |
d6b0e80f AC |
1298 | } |
1299 | ||
1300 | return NULL; | |
1301 | } | |
1302 | ||
2277426b PA |
1303 | /* Update our internal state when changing from one checkpoint to |
1304 | another indicated by NEW_PTID. We can only switch single-threaded | |
1305 | applications, so we only create one new LWP, and the previous list | |
1306 | is discarded. */ | |
f973ed9c DJ |
1307 | |
1308 | void | |
1309 | linux_nat_switch_fork (ptid_t new_ptid) | |
1310 | { | |
1311 | struct lwp_info *lp; | |
1312 | ||
2277426b PA |
1313 | purge_lwp_list (GET_PID (inferior_ptid)); |
1314 | ||
f973ed9c DJ |
1315 | lp = add_lwp (new_ptid); |
1316 | lp->stopped = 1; | |
e26af52f | 1317 | |
2277426b PA |
1318 | /* This changes the thread's ptid while preserving the gdb thread |
1319 | num. Also changes the inferior pid, while preserving the | |
1320 | inferior num. */ | |
1321 | thread_change_ptid (inferior_ptid, new_ptid); | |
1322 | ||
1323 | /* We've just told GDB core that the thread changed target id, but, | |
1324 | in fact, it really is a different thread, with different register | |
1325 | contents. */ | |
1326 | registers_changed (); | |
e26af52f DJ |
1327 | } |
1328 | ||
e26af52f DJ |
1329 | /* Handle the exit of a single thread LP. */ |
1330 | ||
1331 | static void | |
1332 | exit_lwp (struct lwp_info *lp) | |
1333 | { | |
e09875d4 | 1334 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1335 | |
1336 | if (th) | |
e26af52f | 1337 | { |
17faa917 DJ |
1338 | if (print_thread_events) |
1339 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1340 | ||
4f8d22e3 | 1341 | delete_thread (lp->ptid); |
e26af52f DJ |
1342 | } |
1343 | ||
1344 | delete_lwp (lp->ptid); | |
1345 | } | |
1346 | ||
a0ef4274 DJ |
1347 | /* Wait for the LWP specified by LP, which we have just attached to. |
1348 | Returns a wait status for that LWP, to cache. */ | |
1349 | ||
1350 | static int | |
1351 | linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, | |
1352 | int *signalled) | |
1353 | { | |
1354 | pid_t new_pid, pid = GET_LWP (ptid); | |
1355 | int status; | |
1356 | ||
644cebc9 | 1357 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1358 | { |
1359 | if (debug_linux_nat) | |
1360 | fprintf_unfiltered (gdb_stdlog, | |
1361 | "LNPAW: Attaching to a stopped process\n"); | |
1362 | ||
1363 | /* The process is definitely stopped. It is in a job control | |
1364 | stop, unless the kernel predates the TASK_STOPPED / | |
1365 | TASK_TRACED distinction, in which case it might be in a | |
1366 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1367 | can kill it, signal it, et cetera. | |
1368 | ||
1369 | First make sure there is a pending SIGSTOP. Since we are | |
1370 | already attached, the process can not transition from stopped | |
1371 | to running without a PTRACE_CONT; so we know this signal will | |
1372 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1373 | probably already in the queue (unless this kernel is old | |
1374 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1375 | is not an RT signal, it can only be queued once. */ | |
1376 | kill_lwp (pid, SIGSTOP); | |
1377 | ||
1378 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1379 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1380 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1381 | } | |
1382 | ||
1383 | /* Make sure the initial process is stopped. The user-level threads | |
1384 | layer might want to poke around in the inferior, and that won't | |
1385 | work if things haven't stabilized yet. */ | |
1386 | new_pid = my_waitpid (pid, &status, 0); | |
1387 | if (new_pid == -1 && errno == ECHILD) | |
1388 | { | |
1389 | if (first) | |
1390 | warning (_("%s is a cloned process"), target_pid_to_str (ptid)); | |
1391 | ||
1392 | /* Try again with __WCLONE to check cloned processes. */ | |
1393 | new_pid = my_waitpid (pid, &status, __WCLONE); | |
1394 | *cloned = 1; | |
1395 | } | |
1396 | ||
dacc9cb2 PP |
1397 | gdb_assert (pid == new_pid); |
1398 | ||
1399 | if (!WIFSTOPPED (status)) | |
1400 | { | |
1401 | /* The pid we tried to attach has apparently just exited. */ | |
1402 | if (debug_linux_nat) | |
1403 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1404 | pid, status_to_str (status)); | |
1405 | return status; | |
1406 | } | |
a0ef4274 DJ |
1407 | |
1408 | if (WSTOPSIG (status) != SIGSTOP) | |
1409 | { | |
1410 | *signalled = 1; | |
1411 | if (debug_linux_nat) | |
1412 | fprintf_unfiltered (gdb_stdlog, | |
1413 | "LNPAW: Received %s after attaching\n", | |
1414 | status_to_str (status)); | |
1415 | } | |
1416 | ||
1417 | return status; | |
1418 | } | |
1419 | ||
84636d28 PA |
1420 | /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
1421 | the new LWP could not be attached, or 1 if we're already auto | |
1422 | attached to this thread, but haven't processed the | |
1423 | PTRACE_EVENT_CLONE event of its parent thread, so we just ignore | |
1424 | its existance, without considering it an error. */ | |
d6b0e80f | 1425 | |
9ee57c33 | 1426 | int |
93815fbf | 1427 | lin_lwp_attach_lwp (ptid_t ptid) |
d6b0e80f | 1428 | { |
9ee57c33 | 1429 | struct lwp_info *lp; |
7feb7d06 | 1430 | sigset_t prev_mask; |
84636d28 | 1431 | int lwpid; |
d6b0e80f AC |
1432 | |
1433 | gdb_assert (is_lwp (ptid)); | |
1434 | ||
7feb7d06 | 1435 | block_child_signals (&prev_mask); |
d6b0e80f | 1436 | |
9ee57c33 | 1437 | lp = find_lwp_pid (ptid); |
84636d28 | 1438 | lwpid = GET_LWP (ptid); |
d6b0e80f AC |
1439 | |
1440 | /* We assume that we're already attached to any LWP that has an id | |
1441 | equal to the overall process id, and to any LWP that is already | |
1442 | in our list of LWPs. If we're not seeing exit events from threads | |
1443 | and we've had PID wraparound since we last tried to stop all threads, | |
1444 | this assumption might be wrong; fortunately, this is very unlikely | |
1445 | to happen. */ | |
84636d28 | 1446 | if (lwpid != GET_PID (ptid) && lp == NULL) |
d6b0e80f | 1447 | { |
a0ef4274 | 1448 | int status, cloned = 0, signalled = 0; |
d6b0e80f | 1449 | |
84636d28 | 1450 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
9ee57c33 | 1451 | { |
84636d28 PA |
1452 | if (linux_supports_tracefork_flag) |
1453 | { | |
1454 | /* If we haven't stopped all threads when we get here, | |
1455 | we may have seen a thread listed in thread_db's list, | |
1456 | but not processed the PTRACE_EVENT_CLONE yet. If | |
1457 | that's the case, ignore this new thread, and let | |
1458 | normal event handling discover it later. */ | |
1459 | if (in_pid_list_p (stopped_pids, lwpid)) | |
1460 | { | |
1461 | /* We've already seen this thread stop, but we | |
1462 | haven't seen the PTRACE_EVENT_CLONE extended | |
1463 | event yet. */ | |
1464 | restore_child_signals_mask (&prev_mask); | |
1465 | return 0; | |
1466 | } | |
1467 | else | |
1468 | { | |
1469 | int new_pid; | |
1470 | int status; | |
1471 | ||
1472 | /* See if we've got a stop for this new child | |
1473 | pending. If so, we're already attached. */ | |
1474 | new_pid = my_waitpid (lwpid, &status, WNOHANG); | |
1475 | if (new_pid == -1 && errno == ECHILD) | |
1476 | new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); | |
1477 | if (new_pid != -1) | |
1478 | { | |
1479 | if (WIFSTOPPED (status)) | |
1480 | add_to_pid_list (&stopped_pids, lwpid, status); | |
1481 | ||
1482 | restore_child_signals_mask (&prev_mask); | |
1483 | return 1; | |
1484 | } | |
1485 | } | |
1486 | } | |
1487 | ||
9ee57c33 DJ |
1488 | /* If we fail to attach to the thread, issue a warning, |
1489 | but continue. One way this can happen is if thread | |
e9efe249 | 1490 | creation is interrupted; as of Linux kernel 2.6.19, a |
9ee57c33 DJ |
1491 | bug may place threads in the thread list and then fail |
1492 | to create them. */ | |
1493 | warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), | |
1494 | safe_strerror (errno)); | |
7feb7d06 | 1495 | restore_child_signals_mask (&prev_mask); |
9ee57c33 DJ |
1496 | return -1; |
1497 | } | |
1498 | ||
d6b0e80f AC |
1499 | if (debug_linux_nat) |
1500 | fprintf_unfiltered (gdb_stdlog, | |
1501 | "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1502 | target_pid_to_str (ptid)); | |
1503 | ||
a0ef4274 | 1504 | status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
dacc9cb2 | 1505 | if (!WIFSTOPPED (status)) |
673c2bbe DE |
1506 | { |
1507 | restore_child_signals_mask (&prev_mask); | |
f687d035 | 1508 | return 1; |
673c2bbe | 1509 | } |
dacc9cb2 | 1510 | |
a0ef4274 DJ |
1511 | lp = add_lwp (ptid); |
1512 | lp->stopped = 1; | |
1513 | lp->cloned = cloned; | |
1514 | lp->signalled = signalled; | |
1515 | if (WSTOPSIG (status) != SIGSTOP) | |
d6b0e80f | 1516 | { |
a0ef4274 DJ |
1517 | lp->resumed = 1; |
1518 | lp->status = status; | |
d6b0e80f AC |
1519 | } |
1520 | ||
a0ef4274 | 1521 | target_post_attach (GET_LWP (lp->ptid)); |
d6b0e80f AC |
1522 | |
1523 | if (debug_linux_nat) | |
1524 | { | |
1525 | fprintf_unfiltered (gdb_stdlog, | |
1526 | "LLAL: waitpid %s received %s\n", | |
1527 | target_pid_to_str (ptid), | |
1528 | status_to_str (status)); | |
1529 | } | |
1530 | } | |
1531 | else | |
1532 | { | |
1533 | /* We assume that the LWP representing the original process is | |
1534 | already stopped. Mark it as stopped in the data structure | |
155bd5d1 AC |
1535 | that the GNU/linux ptrace layer uses to keep track of |
1536 | threads. Note that this won't have already been done since | |
1537 | the main thread will have, we assume, been stopped by an | |
1538 | attach from a different layer. */ | |
9ee57c33 DJ |
1539 | if (lp == NULL) |
1540 | lp = add_lwp (ptid); | |
d6b0e80f AC |
1541 | lp->stopped = 1; |
1542 | } | |
9ee57c33 | 1543 | |
25289eb2 | 1544 | lp->last_resume_kind = resume_stop; |
7feb7d06 | 1545 | restore_child_signals_mask (&prev_mask); |
9ee57c33 | 1546 | return 0; |
d6b0e80f AC |
1547 | } |
1548 | ||
b84876c2 | 1549 | static void |
136d6dae VP |
1550 | linux_nat_create_inferior (struct target_ops *ops, |
1551 | char *exec_file, char *allargs, char **env, | |
b84876c2 PA |
1552 | int from_tty) |
1553 | { | |
10568435 JK |
1554 | #ifdef HAVE_PERSONALITY |
1555 | int personality_orig = 0, personality_set = 0; | |
1556 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1557 | |
1558 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1559 | we have to mask the async mode. */ | |
1560 | ||
10568435 JK |
1561 | #ifdef HAVE_PERSONALITY |
1562 | if (disable_randomization) | |
1563 | { | |
1564 | errno = 0; | |
1565 | personality_orig = personality (0xffffffff); | |
1566 | if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) | |
1567 | { | |
1568 | personality_set = 1; | |
1569 | personality (personality_orig | ADDR_NO_RANDOMIZE); | |
1570 | } | |
1571 | if (errno != 0 || (personality_set | |
1572 | && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) | |
1573 | warning (_("Error disabling address space randomization: %s"), | |
1574 | safe_strerror (errno)); | |
1575 | } | |
1576 | #endif /* HAVE_PERSONALITY */ | |
1577 | ||
2455069d UW |
1578 | /* Make sure we report all signals during startup. */ |
1579 | linux_nat_pass_signals (0, NULL); | |
1580 | ||
136d6dae | 1581 | linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
b84876c2 | 1582 | |
10568435 JK |
1583 | #ifdef HAVE_PERSONALITY |
1584 | if (personality_set) | |
1585 | { | |
1586 | errno = 0; | |
1587 | personality (personality_orig); | |
1588 | if (errno != 0) | |
1589 | warning (_("Error restoring address space randomization: %s"), | |
1590 | safe_strerror (errno)); | |
1591 | } | |
1592 | #endif /* HAVE_PERSONALITY */ | |
b84876c2 PA |
1593 | } |
1594 | ||
d6b0e80f | 1595 | static void |
136d6dae | 1596 | linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f AC |
1597 | { |
1598 | struct lwp_info *lp; | |
d6b0e80f | 1599 | int status; |
af990527 | 1600 | ptid_t ptid; |
87b0bb13 | 1601 | volatile struct gdb_exception ex; |
d6b0e80f | 1602 | |
2455069d UW |
1603 | /* Make sure we report all signals during attach. */ |
1604 | linux_nat_pass_signals (0, NULL); | |
1605 | ||
87b0bb13 JK |
1606 | TRY_CATCH (ex, RETURN_MASK_ERROR) |
1607 | { | |
1608 | linux_ops->to_attach (ops, args, from_tty); | |
1609 | } | |
1610 | if (ex.reason < 0) | |
1611 | { | |
1612 | pid_t pid = parse_pid_to_attach (args); | |
1613 | struct buffer buffer; | |
1614 | char *message, *buffer_s; | |
1615 | ||
1616 | message = xstrdup (ex.message); | |
1617 | make_cleanup (xfree, message); | |
1618 | ||
1619 | buffer_init (&buffer); | |
1620 | linux_ptrace_attach_warnings (pid, &buffer); | |
1621 | ||
1622 | buffer_grow_str0 (&buffer, ""); | |
1623 | buffer_s = buffer_finish (&buffer); | |
1624 | make_cleanup (xfree, buffer_s); | |
1625 | ||
1626 | throw_error (ex.error, "%s%s", buffer_s, message); | |
1627 | } | |
d6b0e80f | 1628 | |
af990527 PA |
1629 | /* The ptrace base target adds the main thread with (pid,0,0) |
1630 | format. Decorate it with lwp info. */ | |
1631 | ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); | |
1632 | thread_change_ptid (inferior_ptid, ptid); | |
1633 | ||
9f0bdab8 | 1634 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1635 | lp = add_initial_lwp (ptid); |
a0ef4274 DJ |
1636 | |
1637 | status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, | |
1638 | &lp->signalled); | |
dacc9cb2 PP |
1639 | if (!WIFSTOPPED (status)) |
1640 | { | |
1641 | if (WIFEXITED (status)) | |
1642 | { | |
1643 | int exit_code = WEXITSTATUS (status); | |
1644 | ||
1645 | target_terminal_ours (); | |
1646 | target_mourn_inferior (); | |
1647 | if (exit_code == 0) | |
1648 | error (_("Unable to attach: program exited normally.")); | |
1649 | else | |
1650 | error (_("Unable to attach: program exited with code %d."), | |
1651 | exit_code); | |
1652 | } | |
1653 | else if (WIFSIGNALED (status)) | |
1654 | { | |
2ea28649 | 1655 | enum gdb_signal signo; |
dacc9cb2 PP |
1656 | |
1657 | target_terminal_ours (); | |
1658 | target_mourn_inferior (); | |
1659 | ||
2ea28649 | 1660 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1661 | error (_("Unable to attach: program terminated with signal " |
1662 | "%s, %s."), | |
2ea28649 PA |
1663 | gdb_signal_to_name (signo), |
1664 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1665 | } |
1666 | ||
1667 | internal_error (__FILE__, __LINE__, | |
1668 | _("unexpected status %d for PID %ld"), | |
1669 | status, (long) GET_LWP (ptid)); | |
1670 | } | |
1671 | ||
a0ef4274 | 1672 | lp->stopped = 1; |
9f0bdab8 | 1673 | |
a0ef4274 | 1674 | /* Save the wait status to report later. */ |
d6b0e80f | 1675 | lp->resumed = 1; |
a0ef4274 DJ |
1676 | if (debug_linux_nat) |
1677 | fprintf_unfiltered (gdb_stdlog, | |
1678 | "LNA: waitpid %ld, saving status %s\n", | |
1679 | (long) GET_PID (lp->ptid), status_to_str (status)); | |
710151dd | 1680 | |
7feb7d06 PA |
1681 | lp->status = status; |
1682 | ||
1683 | if (target_can_async_p ()) | |
1684 | target_async (inferior_event_handler, 0); | |
d6b0e80f AC |
1685 | } |
1686 | ||
a0ef4274 DJ |
1687 | /* Get pending status of LP. */ |
1688 | static int | |
1689 | get_pending_status (struct lwp_info *lp, int *status) | |
1690 | { | |
a493e3e2 | 1691 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1692 | |
1693 | /* If we paused threads momentarily, we may have stored pending | |
1694 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1695 | and GDB core hasn't seen any signal for those threads. | |
1696 | Otherwise, the last signal reported to the core is found in the | |
1697 | thread object's stop_signal. | |
1698 | ||
1699 | There's a corner case that isn't handled here at present. Only | |
1700 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1701 | stop_signal make sense as a real signal to pass to the inferior. | |
1702 | Some catchpoint related events, like | |
1703 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1704 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1705 | those traps are debug API (ptrace in our case) related and |
1706 | induced; the inferior wouldn't see them if it wasn't being | |
1707 | traced. Hence, we should never pass them to the inferior, even | |
1708 | when set to pass state. Since this corner case isn't handled by | |
1709 | infrun.c when proceeding with a signal, for consistency, neither | |
1710 | do we handle it here (or elsewhere in the file we check for | |
1711 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1712 | this is really a corner case. */ | |
1713 | ||
1714 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1715 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1716 | else if (lp->status) |
2ea28649 | 1717 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
ca2163eb PA |
1718 | else if (non_stop && !is_executing (lp->ptid)) |
1719 | { | |
1720 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1721 | |
16c381f0 | 1722 | signo = tp->suspend.stop_signal; |
ca2163eb PA |
1723 | } |
1724 | else if (!non_stop) | |
a0ef4274 | 1725 | { |
ca2163eb PA |
1726 | struct target_waitstatus last; |
1727 | ptid_t last_ptid; | |
4c28f408 | 1728 | |
ca2163eb | 1729 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1730 | |
ca2163eb PA |
1731 | if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
1732 | { | |
e09875d4 | 1733 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1734 | |
16c381f0 | 1735 | signo = tp->suspend.stop_signal; |
4c28f408 | 1736 | } |
ca2163eb | 1737 | } |
4c28f408 | 1738 | |
ca2163eb | 1739 | *status = 0; |
4c28f408 | 1740 | |
a493e3e2 | 1741 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1742 | { |
1743 | if (debug_linux_nat) | |
1744 | fprintf_unfiltered (gdb_stdlog, | |
1745 | "GPT: lwp %s has no pending signal\n", | |
1746 | target_pid_to_str (lp->ptid)); | |
1747 | } | |
1748 | else if (!signal_pass_state (signo)) | |
1749 | { | |
1750 | if (debug_linux_nat) | |
3e43a32a MS |
1751 | fprintf_unfiltered (gdb_stdlog, |
1752 | "GPT: lwp %s had signal %s, " | |
1753 | "but it is in no pass state\n", | |
ca2163eb | 1754 | target_pid_to_str (lp->ptid), |
2ea28649 | 1755 | gdb_signal_to_string (signo)); |
a0ef4274 | 1756 | } |
a0ef4274 | 1757 | else |
4c28f408 | 1758 | { |
2ea28649 | 1759 | *status = W_STOPCODE (gdb_signal_to_host (signo)); |
ca2163eb PA |
1760 | |
1761 | if (debug_linux_nat) | |
1762 | fprintf_unfiltered (gdb_stdlog, | |
1763 | "GPT: lwp %s has pending signal %s\n", | |
1764 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1765 | gdb_signal_to_string (signo)); |
4c28f408 | 1766 | } |
a0ef4274 DJ |
1767 | |
1768 | return 0; | |
1769 | } | |
1770 | ||
d6b0e80f AC |
1771 | static int |
1772 | detach_callback (struct lwp_info *lp, void *data) | |
1773 | { | |
1774 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); | |
1775 | ||
1776 | if (debug_linux_nat && lp->status) | |
1777 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1778 | strsignal (WSTOPSIG (lp->status)), | |
1779 | target_pid_to_str (lp->ptid)); | |
1780 | ||
a0ef4274 DJ |
1781 | /* If there is a pending SIGSTOP, get rid of it. */ |
1782 | if (lp->signalled) | |
d6b0e80f | 1783 | { |
d6b0e80f AC |
1784 | if (debug_linux_nat) |
1785 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1786 | "DC: Sending SIGCONT to %s\n", |
1787 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1788 | |
a0ef4274 | 1789 | kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
d6b0e80f | 1790 | lp->signalled = 0; |
d6b0e80f AC |
1791 | } |
1792 | ||
1793 | /* We don't actually detach from the LWP that has an id equal to the | |
1794 | overall process id just yet. */ | |
1795 | if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) | |
1796 | { | |
a0ef4274 DJ |
1797 | int status = 0; |
1798 | ||
1799 | /* Pass on any pending signal for this LWP. */ | |
1800 | get_pending_status (lp, &status); | |
1801 | ||
7b50312a PA |
1802 | if (linux_nat_prepare_to_resume != NULL) |
1803 | linux_nat_prepare_to_resume (lp); | |
d6b0e80f AC |
1804 | errno = 0; |
1805 | if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, | |
a0ef4274 | 1806 | WSTOPSIG (status)) < 0) |
8a3fe4f8 | 1807 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
d6b0e80f AC |
1808 | safe_strerror (errno)); |
1809 | ||
1810 | if (debug_linux_nat) | |
1811 | fprintf_unfiltered (gdb_stdlog, | |
1812 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1813 | target_pid_to_str (lp->ptid), | |
7feb7d06 | 1814 | strsignal (WSTOPSIG (status))); |
d6b0e80f AC |
1815 | |
1816 | delete_lwp (lp->ptid); | |
1817 | } | |
1818 | ||
1819 | return 0; | |
1820 | } | |
1821 | ||
1822 | static void | |
136d6dae | 1823 | linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
d6b0e80f | 1824 | { |
b84876c2 | 1825 | int pid; |
a0ef4274 | 1826 | int status; |
d90e17a7 PA |
1827 | struct lwp_info *main_lwp; |
1828 | ||
1829 | pid = GET_PID (inferior_ptid); | |
a0ef4274 | 1830 | |
ae5e0686 MK |
1831 | /* Don't unregister from the event loop, as there may be other |
1832 | inferiors running. */ | |
b84876c2 | 1833 | |
4c28f408 PA |
1834 | /* Stop all threads before detaching. ptrace requires that the |
1835 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1836 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1837 | /* ... and wait until all of them have reported back that |
1838 | they're no longer running. */ | |
d90e17a7 | 1839 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1840 | |
d90e17a7 | 1841 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1842 | |
1843 | /* Only the initial process should be left right now. */ | |
d90e17a7 PA |
1844 | gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
1845 | ||
1846 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1847 | |
a0ef4274 DJ |
1848 | /* Pass on any pending signal for the last LWP. */ |
1849 | if ((args == NULL || *args == '\0') | |
d90e17a7 | 1850 | && get_pending_status (main_lwp, &status) != -1 |
a0ef4274 DJ |
1851 | && WIFSTOPPED (status)) |
1852 | { | |
1853 | /* Put the signal number in ARGS so that inf_ptrace_detach will | |
1854 | pass it along with PTRACE_DETACH. */ | |
1855 | args = alloca (8); | |
1856 | sprintf (args, "%d", (int) WSTOPSIG (status)); | |
ddabfc73 TT |
1857 | if (debug_linux_nat) |
1858 | fprintf_unfiltered (gdb_stdlog, | |
1859 | "LND: Sending signal %s to %s\n", | |
1860 | args, | |
1861 | target_pid_to_str (main_lwp->ptid)); | |
a0ef4274 DJ |
1862 | } |
1863 | ||
7b50312a PA |
1864 | if (linux_nat_prepare_to_resume != NULL) |
1865 | linux_nat_prepare_to_resume (main_lwp); | |
d90e17a7 | 1866 | delete_lwp (main_lwp->ptid); |
b84876c2 | 1867 | |
7a7d3353 PA |
1868 | if (forks_exist_p ()) |
1869 | { | |
1870 | /* Multi-fork case. The current inferior_ptid is being detached | |
1871 | from, but there are other viable forks to debug. Detach from | |
1872 | the current fork, and context-switch to the first | |
1873 | available. */ | |
1874 | linux_fork_detach (args, from_tty); | |
7a7d3353 PA |
1875 | } |
1876 | else | |
1877 | linux_ops->to_detach (ops, args, from_tty); | |
d6b0e80f AC |
1878 | } |
1879 | ||
1880 | /* Resume LP. */ | |
1881 | ||
25289eb2 | 1882 | static void |
e5ef252a | 1883 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1884 | { |
25289eb2 | 1885 | if (lp->stopped) |
6c95b8df | 1886 | { |
25289eb2 PA |
1887 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
1888 | ||
1889 | if (inf->vfork_child != NULL) | |
1890 | { | |
1891 | if (debug_linux_nat) | |
1892 | fprintf_unfiltered (gdb_stdlog, | |
1893 | "RC: Not resuming %s (vfork parent)\n", | |
1894 | target_pid_to_str (lp->ptid)); | |
1895 | } | |
1896 | else if (lp->status == 0 | |
1897 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
1898 | { | |
1899 | if (debug_linux_nat) | |
1900 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1901 | "RC: Resuming sibling %s, %s, %s\n", |
1902 | target_pid_to_str (lp->ptid), | |
1903 | (signo != GDB_SIGNAL_0 | |
1904 | ? strsignal (gdb_signal_to_host (signo)) | |
1905 | : "0"), | |
1906 | step ? "step" : "resume"); | |
25289eb2 | 1907 | |
7b50312a PA |
1908 | if (linux_nat_prepare_to_resume != NULL) |
1909 | linux_nat_prepare_to_resume (lp); | |
25289eb2 PA |
1910 | linux_ops->to_resume (linux_ops, |
1911 | pid_to_ptid (GET_LWP (lp->ptid)), | |
e5ef252a | 1912 | step, signo); |
25289eb2 PA |
1913 | lp->stopped = 0; |
1914 | lp->step = step; | |
25289eb2 PA |
1915 | lp->stopped_by_watchpoint = 0; |
1916 | } | |
1917 | else | |
1918 | { | |
1919 | if (debug_linux_nat) | |
1920 | fprintf_unfiltered (gdb_stdlog, | |
1921 | "RC: Not resuming sibling %s (has pending)\n", | |
1922 | target_pid_to_str (lp->ptid)); | |
1923 | } | |
6c95b8df | 1924 | } |
25289eb2 | 1925 | else |
d6b0e80f | 1926 | { |
d90e17a7 PA |
1927 | if (debug_linux_nat) |
1928 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1929 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1930 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1931 | } |
25289eb2 | 1932 | } |
d6b0e80f | 1933 | |
e5ef252a PA |
1934 | /* Resume LWP, with the last stop signal, if it is in pass state. */ |
1935 | ||
25289eb2 | 1936 | static int |
e5ef252a | 1937 | linux_nat_resume_callback (struct lwp_info *lp, void *data) |
25289eb2 | 1938 | { |
e5ef252a PA |
1939 | enum gdb_signal signo = GDB_SIGNAL_0; |
1940 | ||
1941 | if (lp->stopped) | |
1942 | { | |
1943 | struct thread_info *thread; | |
1944 | ||
1945 | thread = find_thread_ptid (lp->ptid); | |
1946 | if (thread != NULL) | |
1947 | { | |
1948 | if (signal_pass_state (thread->suspend.stop_signal)) | |
1949 | signo = thread->suspend.stop_signal; | |
1950 | thread->suspend.stop_signal = GDB_SIGNAL_0; | |
1951 | } | |
1952 | } | |
1953 | ||
1954 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1955 | return 0; |
1956 | } | |
1957 | ||
1958 | static int | |
1959 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1960 | { | |
1961 | lp->resumed = 0; | |
25289eb2 | 1962 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1963 | return 0; |
1964 | } | |
1965 | ||
1966 | static int | |
1967 | resume_set_callback (struct lwp_info *lp, void *data) | |
1968 | { | |
1969 | lp->resumed = 1; | |
25289eb2 | 1970 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1971 | return 0; |
1972 | } | |
1973 | ||
1974 | static void | |
28439f5e | 1975 | linux_nat_resume (struct target_ops *ops, |
2ea28649 | 1976 | ptid_t ptid, int step, enum gdb_signal signo) |
d6b0e80f | 1977 | { |
7feb7d06 | 1978 | sigset_t prev_mask; |
d6b0e80f | 1979 | struct lwp_info *lp; |
d90e17a7 | 1980 | int resume_many; |
d6b0e80f | 1981 | |
76f50ad1 DJ |
1982 | if (debug_linux_nat) |
1983 | fprintf_unfiltered (gdb_stdlog, | |
1984 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1985 | step ? "step" : "resume", | |
1986 | target_pid_to_str (ptid), | |
a493e3e2 | 1987 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1988 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1989 | target_pid_to_str (inferior_ptid)); |
1990 | ||
7feb7d06 | 1991 | block_child_signals (&prev_mask); |
b84876c2 | 1992 | |
d6b0e80f | 1993 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1994 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1995 | || ptid_is_pid (ptid)); | |
4c28f408 | 1996 | |
e3e9f5a2 PA |
1997 | /* Mark the lwps we're resuming as resumed. */ |
1998 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1999 | |
d90e17a7 PA |
2000 | /* See if it's the current inferior that should be handled |
2001 | specially. */ | |
2002 | if (resume_many) | |
2003 | lp = find_lwp_pid (inferior_ptid); | |
2004 | else | |
2005 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 2006 | gdb_assert (lp != NULL); |
d6b0e80f | 2007 | |
9f0bdab8 DJ |
2008 | /* Remember if we're stepping. */ |
2009 | lp->step = step; | |
25289eb2 | 2010 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 2011 | |
9f0bdab8 DJ |
2012 | /* If we have a pending wait status for this thread, there is no |
2013 | point in resuming the process. But first make sure that | |
2014 | linux_nat_wait won't preemptively handle the event - we | |
2015 | should never take this short-circuit if we are going to | |
2016 | leave LP running, since we have skipped resuming all the | |
2017 | other threads. This bit of code needs to be synchronized | |
2018 | with linux_nat_wait. */ | |
76f50ad1 | 2019 | |
9f0bdab8 DJ |
2020 | if (lp->status && WIFSTOPPED (lp->status)) |
2021 | { | |
2455069d UW |
2022 | if (!lp->step |
2023 | && WSTOPSIG (lp->status) | |
2024 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 2025 | { |
9f0bdab8 DJ |
2026 | if (debug_linux_nat) |
2027 | fprintf_unfiltered (gdb_stdlog, | |
2028 | "LLR: Not short circuiting for ignored " | |
2029 | "status 0x%x\n", lp->status); | |
2030 | ||
d6b0e80f AC |
2031 | /* FIXME: What should we do if we are supposed to continue |
2032 | this thread with a signal? */ | |
a493e3e2 | 2033 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 2034 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
2035 | lp->status = 0; |
2036 | } | |
2037 | } | |
76f50ad1 | 2038 | |
6c95b8df | 2039 | if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
9f0bdab8 DJ |
2040 | { |
2041 | /* FIXME: What should we do if we are supposed to continue | |
2042 | this thread with a signal? */ | |
a493e3e2 | 2043 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 2044 | |
9f0bdab8 DJ |
2045 | if (debug_linux_nat) |
2046 | fprintf_unfiltered (gdb_stdlog, | |
2047 | "LLR: Short circuiting for status 0x%x\n", | |
2048 | lp->status); | |
d6b0e80f | 2049 | |
7feb7d06 PA |
2050 | restore_child_signals_mask (&prev_mask); |
2051 | if (target_can_async_p ()) | |
2052 | { | |
2053 | target_async (inferior_event_handler, 0); | |
2054 | /* Tell the event loop we have something to process. */ | |
2055 | async_file_mark (); | |
2056 | } | |
9f0bdab8 | 2057 | return; |
d6b0e80f AC |
2058 | } |
2059 | ||
9f0bdab8 | 2060 | /* Mark LWP as not stopped to prevent it from being continued by |
e5ef252a | 2061 | linux_nat_resume_callback. */ |
9f0bdab8 DJ |
2062 | lp->stopped = 0; |
2063 | ||
d90e17a7 | 2064 | if (resume_many) |
e5ef252a | 2065 | iterate_over_lwps (ptid, linux_nat_resume_callback, NULL); |
d90e17a7 PA |
2066 | |
2067 | /* Convert to something the lower layer understands. */ | |
2068 | ptid = pid_to_ptid (GET_LWP (lp->ptid)); | |
d6b0e80f | 2069 | |
7b50312a PA |
2070 | if (linux_nat_prepare_to_resume != NULL) |
2071 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 2072 | linux_ops->to_resume (linux_ops, ptid, step, signo); |
ebec9a0f | 2073 | lp->stopped_by_watchpoint = 0; |
9f0bdab8 | 2074 | |
d6b0e80f AC |
2075 | if (debug_linux_nat) |
2076 | fprintf_unfiltered (gdb_stdlog, | |
2077 | "LLR: %s %s, %s (resume event thread)\n", | |
2078 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2079 | target_pid_to_str (ptid), | |
a493e3e2 | 2080 | (signo != GDB_SIGNAL_0 |
2ea28649 | 2081 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 2082 | |
7feb7d06 | 2083 | restore_child_signals_mask (&prev_mask); |
b84876c2 | 2084 | if (target_can_async_p ()) |
8ea051c5 | 2085 | target_async (inferior_event_handler, 0); |
d6b0e80f AC |
2086 | } |
2087 | ||
c5f62d5f | 2088 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
2089 | |
2090 | static int | |
2091 | kill_lwp (int lwpid, int signo) | |
2092 | { | |
c5f62d5f DE |
2093 | /* Use tkill, if possible, in case we are using nptl threads. If tkill |
2094 | fails, then we are not using nptl threads and we should be using kill. */ | |
d6b0e80f AC |
2095 | |
2096 | #ifdef HAVE_TKILL_SYSCALL | |
c5f62d5f DE |
2097 | { |
2098 | static int tkill_failed; | |
2099 | ||
2100 | if (!tkill_failed) | |
2101 | { | |
2102 | int ret; | |
2103 | ||
2104 | errno = 0; | |
2105 | ret = syscall (__NR_tkill, lwpid, signo); | |
2106 | if (errno != ENOSYS) | |
2107 | return ret; | |
2108 | tkill_failed = 1; | |
2109 | } | |
2110 | } | |
d6b0e80f AC |
2111 | #endif |
2112 | ||
2113 | return kill (lwpid, signo); | |
2114 | } | |
2115 | ||
ca2163eb PA |
2116 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
2117 | event, check if the core is interested in it: if not, ignore the | |
2118 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
2119 | syscall entry/exit status, since the ptrace event itself doesn't | |
2120 | indicate it, and report the trap to higher layers. */ | |
2121 | ||
2122 | static int | |
2123 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
2124 | { | |
2125 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
2126 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
2127 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
2128 | ||
2129 | if (stopping) | |
2130 | { | |
2131 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
2132 | makes it so that the LWP reports an immediate syscall return, | |
2133 | followed by the SIGSTOP. Skip seeing that "return" using | |
2134 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
2135 | SIGSTOP. Later when the thread is resumed, a new syscall | |
2136 | entry event. If we didn't do this (and returned 0), we'd | |
2137 | leave a syscall entry pending, and our caller, by using | |
2138 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
2139 | itself. Later, when the user re-resumes this LWP, we'd see | |
2140 | another syscall entry event and we'd mistake it for a return. | |
2141 | ||
2142 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
2143 | (leaving immediately with LWP->signalled set, without issuing | |
2144 | a PTRACE_CONT), it would still be problematic to leave this | |
2145 | syscall enter pending, as later when the thread is resumed, | |
2146 | it would then see the same syscall exit mentioned above, | |
2147 | followed by the delayed SIGSTOP, while the syscall didn't | |
2148 | actually get to execute. It seems it would be even more | |
2149 | confusing to the user. */ | |
2150 | ||
2151 | if (debug_linux_nat) | |
2152 | fprintf_unfiltered (gdb_stdlog, | |
2153 | "LHST: ignoring syscall %d " | |
2154 | "for LWP %ld (stopping threads), " | |
2155 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
2156 | syscall_number, | |
2157 | GET_LWP (lp->ptid)); | |
2158 | ||
2159 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2160 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2161 | return 1; | |
2162 | } | |
2163 | ||
2164 | if (catch_syscall_enabled ()) | |
2165 | { | |
2166 | /* Always update the entry/return state, even if this particular | |
2167 | syscall isn't interesting to the core now. In async mode, | |
2168 | the user could install a new catchpoint for this syscall | |
2169 | between syscall enter/return, and we'll need to know to | |
2170 | report a syscall return if that happens. */ | |
2171 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2172 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
2173 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
2174 | ||
2175 | if (catching_syscall_number (syscall_number)) | |
2176 | { | |
2177 | /* Alright, an event to report. */ | |
2178 | ourstatus->kind = lp->syscall_state; | |
2179 | ourstatus->value.syscall_number = syscall_number; | |
2180 | ||
2181 | if (debug_linux_nat) | |
2182 | fprintf_unfiltered (gdb_stdlog, | |
2183 | "LHST: stopping for %s of syscall %d" | |
2184 | " for LWP %ld\n", | |
3e43a32a MS |
2185 | lp->syscall_state |
2186 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
2187 | ? "entry" : "return", |
2188 | syscall_number, | |
2189 | GET_LWP (lp->ptid)); | |
2190 | return 0; | |
2191 | } | |
2192 | ||
2193 | if (debug_linux_nat) | |
2194 | fprintf_unfiltered (gdb_stdlog, | |
2195 | "LHST: ignoring %s of syscall %d " | |
2196 | "for LWP %ld\n", | |
2197 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
2198 | ? "entry" : "return", | |
2199 | syscall_number, | |
2200 | GET_LWP (lp->ptid)); | |
2201 | } | |
2202 | else | |
2203 | { | |
2204 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
2205 | before on this LWP, it could happen that the user removes all | |
2206 | syscall catchpoints before we get to process this event. | |
2207 | There are two noteworthy issues here: | |
2208 | ||
2209 | - When stopped at a syscall entry event, resuming with | |
2210 | PT_STEP still resumes executing the syscall and reports a | |
2211 | syscall return. | |
2212 | ||
2213 | - Only PT_SYSCALL catches syscall enters. If we last | |
2214 | single-stepped this thread, then this event can't be a | |
2215 | syscall enter. If we last single-stepped this thread, this | |
2216 | has to be a syscall exit. | |
2217 | ||
2218 | The points above mean that the next resume, be it PT_STEP or | |
2219 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
2220 | if (debug_linux_nat) | |
2221 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2222 | "LHST: caught syscall event " |
2223 | "with no syscall catchpoints." | |
ca2163eb PA |
2224 | " %d for LWP %ld, ignoring\n", |
2225 | syscall_number, | |
2226 | GET_LWP (lp->ptid)); | |
2227 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2228 | } | |
2229 | ||
2230 | /* The core isn't interested in this event. For efficiency, avoid | |
2231 | stopping all threads only to have the core resume them all again. | |
2232 | Since we're not stopping threads, if we're still syscall tracing | |
2233 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
2234 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
2235 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
2236 | ||
2237 | /* Note that gdbarch_get_syscall_number may access registers, hence | |
2238 | fill a regcache. */ | |
2239 | registers_changed (); | |
7b50312a PA |
2240 | if (linux_nat_prepare_to_resume != NULL) |
2241 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2242 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2243 | lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
2244 | return 1; |
2245 | } | |
2246 | ||
3d799a95 DJ |
2247 | /* Handle a GNU/Linux extended wait response. If we see a clone |
2248 | event, we need to add the new LWP to our list (and not report the | |
2249 | trap to higher layers). This function returns non-zero if the | |
2250 | event should be ignored and we should wait again. If STOPPING is | |
2251 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
2252 | |
2253 | static int | |
3d799a95 DJ |
2254 | linux_handle_extended_wait (struct lwp_info *lp, int status, |
2255 | int stopping) | |
d6b0e80f | 2256 | { |
3d799a95 DJ |
2257 | int pid = GET_LWP (lp->ptid); |
2258 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
3d799a95 | 2259 | int event = status >> 16; |
d6b0e80f | 2260 | |
3d799a95 DJ |
2261 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
2262 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 2263 | { |
3d799a95 DJ |
2264 | unsigned long new_pid; |
2265 | int ret; | |
2266 | ||
2267 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 2268 | |
3d799a95 DJ |
2269 | /* If we haven't already seen the new PID stop, wait for it now. */ |
2270 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
2271 | { | |
2272 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
2273 | hits the SIGSTOP, but we're already attached. */ | |
2274 | ret = my_waitpid (new_pid, &status, | |
2275 | (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); | |
2276 | if (ret == -1) | |
2277 | perror_with_name (_("waiting for new child")); | |
2278 | else if (ret != new_pid) | |
2279 | internal_error (__FILE__, __LINE__, | |
2280 | _("wait returned unexpected PID %d"), ret); | |
2281 | else if (!WIFSTOPPED (status)) | |
2282 | internal_error (__FILE__, __LINE__, | |
2283 | _("wait returned unexpected status 0x%x"), status); | |
2284 | } | |
2285 | ||
3a3e9ee3 | 2286 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 2287 | |
26cb8b7c PA |
2288 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
2289 | { | |
2290 | /* The arch-specific native code may need to know about new | |
2291 | forks even if those end up never mapped to an | |
2292 | inferior. */ | |
2293 | if (linux_nat_new_fork != NULL) | |
2294 | linux_nat_new_fork (lp, new_pid); | |
2295 | } | |
2296 | ||
2277426b PA |
2297 | if (event == PTRACE_EVENT_FORK |
2298 | && linux_fork_checkpointing_p (GET_PID (lp->ptid))) | |
2299 | { | |
2277426b PA |
2300 | /* Handle checkpointing by linux-fork.c here as a special |
2301 | case. We don't want the follow-fork-mode or 'catch fork' | |
2302 | to interfere with this. */ | |
2303 | ||
2304 | /* This won't actually modify the breakpoint list, but will | |
2305 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2306 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2307 | |
2308 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2309 | if (!find_fork_pid (new_pid)) |
2310 | add_fork (new_pid); | |
2277426b PA |
2311 | |
2312 | /* Report as spurious, so that infrun doesn't want to follow | |
2313 | this fork. We're actually doing an infcall in | |
2314 | linux-fork.c. */ | |
2315 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2316 | |
2317 | /* Report the stop to the core. */ | |
2318 | return 0; | |
2319 | } | |
2320 | ||
3d799a95 DJ |
2321 | if (event == PTRACE_EVENT_FORK) |
2322 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2323 | else if (event == PTRACE_EVENT_VFORK) | |
2324 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
6fc19103 | 2325 | else |
3d799a95 | 2326 | { |
78768c4a JK |
2327 | struct lwp_info *new_lp; |
2328 | ||
3d799a95 | 2329 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2330 | |
3c4d7e12 PA |
2331 | if (debug_linux_nat) |
2332 | fprintf_unfiltered (gdb_stdlog, | |
2333 | "LHEW: Got clone event " | |
2334 | "from LWP %d, new child is LWP %ld\n", | |
2335 | pid, new_pid); | |
2336 | ||
d90e17a7 | 2337 | new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
3d799a95 | 2338 | new_lp->cloned = 1; |
4c28f408 | 2339 | new_lp->stopped = 1; |
d6b0e80f | 2340 | |
3d799a95 DJ |
2341 | if (WSTOPSIG (status) != SIGSTOP) |
2342 | { | |
2343 | /* This can happen if someone starts sending signals to | |
2344 | the new thread before it gets a chance to run, which | |
2345 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2346 | This is an unlikely case, and harder to handle for | |
2347 | fork / vfork than for clone, so we do not try - but | |
2348 | we handle it for clone events here. We'll send | |
2349 | the other signal on to the thread below. */ | |
2350 | ||
2351 | new_lp->signalled = 1; | |
2352 | } | |
2353 | else | |
79395f92 PA |
2354 | { |
2355 | struct thread_info *tp; | |
2356 | ||
2357 | /* When we stop for an event in some other thread, and | |
2358 | pull the thread list just as this thread has cloned, | |
2359 | we'll have seen the new thread in the thread_db list | |
2360 | before handling the CLONE event (glibc's | |
2361 | pthread_create adds the new thread to the thread list | |
2362 | before clone'ing, and has the kernel fill in the | |
2363 | thread's tid on the clone call with | |
2364 | CLONE_PARENT_SETTID). If that happened, and the core | |
2365 | had requested the new thread to stop, we'll have | |
2366 | killed it with SIGSTOP. But since SIGSTOP is not an | |
2367 | RT signal, it can only be queued once. We need to be | |
2368 | careful to not resume the LWP if we wanted it to | |
2369 | stop. In that case, we'll leave the SIGSTOP pending. | |
a493e3e2 | 2370 | It will later be reported as GDB_SIGNAL_0. */ |
79395f92 PA |
2371 | tp = find_thread_ptid (new_lp->ptid); |
2372 | if (tp != NULL && tp->stop_requested) | |
2373 | new_lp->last_resume_kind = resume_stop; | |
2374 | else | |
2375 | status = 0; | |
2376 | } | |
d6b0e80f | 2377 | |
4c28f408 | 2378 | if (non_stop) |
3d799a95 | 2379 | { |
4c28f408 PA |
2380 | /* Add the new thread to GDB's lists as soon as possible |
2381 | so that: | |
2382 | ||
2383 | 1) the frontend doesn't have to wait for a stop to | |
2384 | display them, and, | |
2385 | ||
2386 | 2) we tag it with the correct running state. */ | |
2387 | ||
2388 | /* If the thread_db layer is active, let it know about | |
2389 | this new thread, and add it to GDB's list. */ | |
2390 | if (!thread_db_attach_lwp (new_lp->ptid)) | |
2391 | { | |
2392 | /* We're not using thread_db. Add it to GDB's | |
2393 | list. */ | |
2394 | target_post_attach (GET_LWP (new_lp->ptid)); | |
2395 | add_thread (new_lp->ptid); | |
2396 | } | |
2397 | ||
2398 | if (!stopping) | |
2399 | { | |
2400 | set_running (new_lp->ptid, 1); | |
2401 | set_executing (new_lp->ptid, 1); | |
e21ffe51 PA |
2402 | /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
2403 | resume_stop. */ | |
2404 | new_lp->last_resume_kind = resume_continue; | |
4c28f408 PA |
2405 | } |
2406 | } | |
2407 | ||
79395f92 PA |
2408 | if (status != 0) |
2409 | { | |
2410 | /* We created NEW_LP so it cannot yet contain STATUS. */ | |
2411 | gdb_assert (new_lp->status == 0); | |
2412 | ||
2413 | /* Save the wait status to report later. */ | |
2414 | if (debug_linux_nat) | |
2415 | fprintf_unfiltered (gdb_stdlog, | |
2416 | "LHEW: waitpid of new LWP %ld, " | |
2417 | "saving status %s\n", | |
2418 | (long) GET_LWP (new_lp->ptid), | |
2419 | status_to_str (status)); | |
2420 | new_lp->status = status; | |
2421 | } | |
2422 | ||
ca2163eb PA |
2423 | /* Note the need to use the low target ops to resume, to |
2424 | handle resuming with PT_SYSCALL if we have syscall | |
2425 | catchpoints. */ | |
4c28f408 PA |
2426 | if (!stopping) |
2427 | { | |
3d799a95 | 2428 | new_lp->resumed = 1; |
ca2163eb | 2429 | |
79395f92 | 2430 | if (status == 0) |
ad34eb2f | 2431 | { |
e21ffe51 | 2432 | gdb_assert (new_lp->last_resume_kind == resume_continue); |
ad34eb2f JK |
2433 | if (debug_linux_nat) |
2434 | fprintf_unfiltered (gdb_stdlog, | |
79395f92 PA |
2435 | "LHEW: resuming new LWP %ld\n", |
2436 | GET_LWP (new_lp->ptid)); | |
7b50312a PA |
2437 | if (linux_nat_prepare_to_resume != NULL) |
2438 | linux_nat_prepare_to_resume (new_lp); | |
79395f92 | 2439 | linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
a493e3e2 | 2440 | 0, GDB_SIGNAL_0); |
79395f92 | 2441 | new_lp->stopped = 0; |
ad34eb2f JK |
2442 | } |
2443 | } | |
d6b0e80f | 2444 | |
3d799a95 DJ |
2445 | if (debug_linux_nat) |
2446 | fprintf_unfiltered (gdb_stdlog, | |
3c4d7e12 | 2447 | "LHEW: resuming parent LWP %d\n", pid); |
7b50312a PA |
2448 | if (linux_nat_prepare_to_resume != NULL) |
2449 | linux_nat_prepare_to_resume (lp); | |
ca2163eb | 2450 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 2451 | 0, GDB_SIGNAL_0); |
3d799a95 DJ |
2452 | |
2453 | return 1; | |
2454 | } | |
2455 | ||
2456 | return 0; | |
d6b0e80f AC |
2457 | } |
2458 | ||
3d799a95 DJ |
2459 | if (event == PTRACE_EVENT_EXEC) |
2460 | { | |
a75724bc PA |
2461 | if (debug_linux_nat) |
2462 | fprintf_unfiltered (gdb_stdlog, | |
2463 | "LHEW: Got exec event from LWP %ld\n", | |
2464 | GET_LWP (lp->ptid)); | |
2465 | ||
3d799a95 DJ |
2466 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2467 | ourstatus->value.execd_pathname | |
6d8fd2b7 | 2468 | = xstrdup (linux_child_pid_to_exec_file (pid)); |
3d799a95 | 2469 | |
6c95b8df PA |
2470 | return 0; |
2471 | } | |
2472 | ||
2473 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2474 | { | |
2475 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2476 | { |
6c95b8df | 2477 | if (debug_linux_nat) |
3e43a32a MS |
2478 | fprintf_unfiltered (gdb_stdlog, |
2479 | "LHEW: Got expected PTRACE_EVENT_" | |
2480 | "VFORK_DONE from LWP %ld: stopping\n", | |
6c95b8df | 2481 | GET_LWP (lp->ptid)); |
3d799a95 | 2482 | |
6c95b8df PA |
2483 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2484 | return 0; | |
3d799a95 DJ |
2485 | } |
2486 | ||
6c95b8df | 2487 | if (debug_linux_nat) |
3e43a32a MS |
2488 | fprintf_unfiltered (gdb_stdlog, |
2489 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
2490 | "from LWP %ld: resuming\n", | |
6c95b8df PA |
2491 | GET_LWP (lp->ptid)); |
2492 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2493 | return 1; | |
3d799a95 DJ |
2494 | } |
2495 | ||
2496 | internal_error (__FILE__, __LINE__, | |
2497 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2498 | } |
2499 | ||
2500 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has | |
2501 | exited. */ | |
2502 | ||
2503 | static int | |
2504 | wait_lwp (struct lwp_info *lp) | |
2505 | { | |
2506 | pid_t pid; | |
432b4d03 | 2507 | int status = 0; |
d6b0e80f | 2508 | int thread_dead = 0; |
432b4d03 | 2509 | sigset_t prev_mask; |
d6b0e80f AC |
2510 | |
2511 | gdb_assert (!lp->stopped); | |
2512 | gdb_assert (lp->status == 0); | |
2513 | ||
432b4d03 JK |
2514 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2515 | block_child_signals (&prev_mask); | |
2516 | ||
2517 | for (;;) | |
d6b0e80f | 2518 | { |
432b4d03 JK |
2519 | /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
2520 | was right and we should just call sigsuspend. */ | |
2521 | ||
2522 | pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); | |
d6b0e80f | 2523 | if (pid == -1 && errno == ECHILD) |
432b4d03 | 2524 | pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
a9f4bb21 PA |
2525 | if (pid == -1 && errno == ECHILD) |
2526 | { | |
2527 | /* The thread has previously exited. We need to delete it | |
2528 | now because, for some vendor 2.4 kernels with NPTL | |
2529 | support backported, there won't be an exit event unless | |
2530 | it is the main thread. 2.6 kernels will report an exit | |
2531 | event for each thread that exits, as expected. */ | |
2532 | thread_dead = 1; | |
2533 | if (debug_linux_nat) | |
2534 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2535 | target_pid_to_str (lp->ptid)); | |
2536 | } | |
432b4d03 JK |
2537 | if (pid != 0) |
2538 | break; | |
2539 | ||
2540 | /* Bugs 10970, 12702. | |
2541 | Thread group leader may have exited in which case we'll lock up in | |
2542 | waitpid if there are other threads, even if they are all zombies too. | |
2543 | Basically, we're not supposed to use waitpid this way. | |
2544 | __WCLONE is not applicable for the leader so we can't use that. | |
2545 | LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED | |
2546 | process; it gets ESRCH both for the zombie and for running processes. | |
2547 | ||
2548 | As a workaround, check if we're waiting for the thread group leader and | |
2549 | if it's a zombie, and avoid calling waitpid if it is. | |
2550 | ||
2551 | This is racy, what if the tgl becomes a zombie right after we check? | |
2552 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2553 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 JK |
2554 | |
2555 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) | |
5f572dec | 2556 | && linux_proc_pid_is_zombie (GET_LWP (lp->ptid))) |
d6b0e80f | 2557 | { |
d6b0e80f AC |
2558 | thread_dead = 1; |
2559 | if (debug_linux_nat) | |
432b4d03 JK |
2560 | fprintf_unfiltered (gdb_stdlog, |
2561 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2562 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2563 | break; |
d6b0e80f | 2564 | } |
432b4d03 JK |
2565 | |
2566 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2567 | get invoked despite our caller had them intentionally blocked by | |
2568 | block_child_signals. This is sensitive only to the loop of | |
2569 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2570 | again before it gets to sigsuspend so we can safely let the handlers | |
2571 | get executed here. */ | |
2572 | ||
2573 | sigsuspend (&suspend_mask); | |
2574 | } | |
2575 | ||
2576 | restore_child_signals_mask (&prev_mask); | |
2577 | ||
d6b0e80f AC |
2578 | if (!thread_dead) |
2579 | { | |
2580 | gdb_assert (pid == GET_LWP (lp->ptid)); | |
2581 | ||
2582 | if (debug_linux_nat) | |
2583 | { | |
2584 | fprintf_unfiltered (gdb_stdlog, | |
2585 | "WL: waitpid %s received %s\n", | |
2586 | target_pid_to_str (lp->ptid), | |
2587 | status_to_str (status)); | |
2588 | } | |
d6b0e80f | 2589 | |
a9f4bb21 PA |
2590 | /* Check if the thread has exited. */ |
2591 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2592 | { | |
2593 | thread_dead = 1; | |
2594 | if (debug_linux_nat) | |
2595 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2596 | target_pid_to_str (lp->ptid)); | |
2597 | } | |
d6b0e80f AC |
2598 | } |
2599 | ||
2600 | if (thread_dead) | |
2601 | { | |
e26af52f | 2602 | exit_lwp (lp); |
d6b0e80f AC |
2603 | return 0; |
2604 | } | |
2605 | ||
2606 | gdb_assert (WIFSTOPPED (status)); | |
2607 | ||
ca2163eb PA |
2608 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2609 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2610 | { | |
2611 | /* No longer need the sysgood bit. The ptrace event ends up | |
2612 | recorded in lp->waitstatus if we care for it. We can carry | |
2613 | on handling the event like a regular SIGTRAP from here | |
2614 | on. */ | |
2615 | status = W_STOPCODE (SIGTRAP); | |
2616 | if (linux_handle_syscall_trap (lp, 1)) | |
2617 | return wait_lwp (lp); | |
2618 | } | |
2619 | ||
d6b0e80f AC |
2620 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
2621 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
2622 | { | |
2623 | if (debug_linux_nat) | |
2624 | fprintf_unfiltered (gdb_stdlog, | |
2625 | "WL: Handling extended status 0x%06x\n", | |
2626 | status); | |
3d799a95 | 2627 | if (linux_handle_extended_wait (lp, status, 1)) |
d6b0e80f AC |
2628 | return wait_lwp (lp); |
2629 | } | |
2630 | ||
2631 | return status; | |
2632 | } | |
2633 | ||
2634 | /* Send a SIGSTOP to LP. */ | |
2635 | ||
2636 | static int | |
2637 | stop_callback (struct lwp_info *lp, void *data) | |
2638 | { | |
2639 | if (!lp->stopped && !lp->signalled) | |
2640 | { | |
2641 | int ret; | |
2642 | ||
2643 | if (debug_linux_nat) | |
2644 | { | |
2645 | fprintf_unfiltered (gdb_stdlog, | |
2646 | "SC: kill %s **<SIGSTOP>**\n", | |
2647 | target_pid_to_str (lp->ptid)); | |
2648 | } | |
2649 | errno = 0; | |
2650 | ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); | |
2651 | if (debug_linux_nat) | |
2652 | { | |
2653 | fprintf_unfiltered (gdb_stdlog, | |
2654 | "SC: lwp kill %d %s\n", | |
2655 | ret, | |
2656 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2657 | } | |
2658 | ||
2659 | lp->signalled = 1; | |
2660 | gdb_assert (lp->status == 0); | |
2661 | } | |
2662 | ||
2663 | return 0; | |
2664 | } | |
2665 | ||
7b50312a PA |
2666 | /* Request a stop on LWP. */ |
2667 | ||
2668 | void | |
2669 | linux_stop_lwp (struct lwp_info *lwp) | |
2670 | { | |
2671 | stop_callback (lwp, NULL); | |
2672 | } | |
2673 | ||
57380f4e | 2674 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2675 | |
2676 | static int | |
57380f4e DJ |
2677 | linux_nat_has_pending_sigint (int pid) |
2678 | { | |
2679 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2680 | |
2681 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2682 | ||
2683 | if (sigismember (&pending, SIGINT) | |
2684 | && !sigismember (&ignored, SIGINT)) | |
2685 | return 1; | |
2686 | ||
2687 | return 0; | |
2688 | } | |
2689 | ||
2690 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2691 | ||
2692 | static int | |
2693 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2694 | { |
57380f4e DJ |
2695 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2696 | flag to consume the next one. */ | |
2697 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2698 | && WSTOPSIG (lp->status) == SIGINT) | |
2699 | lp->status = 0; | |
2700 | else | |
2701 | lp->ignore_sigint = 1; | |
2702 | ||
2703 | return 0; | |
2704 | } | |
2705 | ||
2706 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2707 | This function is called after we know the LWP has stopped; if the LWP | |
2708 | stopped before the expected SIGINT was delivered, then it will never have | |
2709 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2710 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2711 | |
57380f4e DJ |
2712 | static void |
2713 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2714 | { | |
2715 | if (!lp->ignore_sigint) | |
2716 | return; | |
2717 | ||
2718 | if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) | |
2719 | { | |
2720 | if (debug_linux_nat) | |
2721 | fprintf_unfiltered (gdb_stdlog, | |
2722 | "MCIS: Clearing bogus flag for %s\n", | |
2723 | target_pid_to_str (lp->ptid)); | |
2724 | lp->ignore_sigint = 0; | |
2725 | } | |
2726 | } | |
2727 | ||
ebec9a0f PA |
2728 | /* Fetch the possible triggered data watchpoint info and store it in |
2729 | LP. | |
2730 | ||
2731 | On some archs, like x86, that use debug registers to set | |
2732 | watchpoints, it's possible that the way to know which watched | |
2733 | address trapped, is to check the register that is used to select | |
2734 | which address to watch. Problem is, between setting the watchpoint | |
2735 | and reading back which data address trapped, the user may change | |
2736 | the set of watchpoints, and, as a consequence, GDB changes the | |
2737 | debug registers in the inferior. To avoid reading back a stale | |
2738 | stopped-data-address when that happens, we cache in LP the fact | |
2739 | that a watchpoint trapped, and the corresponding data address, as | |
2740 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2741 | registers meanwhile, we have the cached data we can rely on. */ | |
2742 | ||
2743 | static void | |
2744 | save_sigtrap (struct lwp_info *lp) | |
2745 | { | |
2746 | struct cleanup *old_chain; | |
2747 | ||
2748 | if (linux_ops->to_stopped_by_watchpoint == NULL) | |
2749 | { | |
2750 | lp->stopped_by_watchpoint = 0; | |
2751 | return; | |
2752 | } | |
2753 | ||
2754 | old_chain = save_inferior_ptid (); | |
2755 | inferior_ptid = lp->ptid; | |
2756 | ||
2757 | lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); | |
2758 | ||
2759 | if (lp->stopped_by_watchpoint) | |
2760 | { | |
2761 | if (linux_ops->to_stopped_data_address != NULL) | |
2762 | lp->stopped_data_address_p = | |
2763 | linux_ops->to_stopped_data_address (¤t_target, | |
2764 | &lp->stopped_data_address); | |
2765 | else | |
2766 | lp->stopped_data_address_p = 0; | |
2767 | } | |
2768 | ||
2769 | do_cleanups (old_chain); | |
2770 | } | |
2771 | ||
2772 | /* See save_sigtrap. */ | |
2773 | ||
2774 | static int | |
2775 | linux_nat_stopped_by_watchpoint (void) | |
2776 | { | |
2777 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2778 | ||
2779 | gdb_assert (lp != NULL); | |
2780 | ||
2781 | return lp->stopped_by_watchpoint; | |
2782 | } | |
2783 | ||
2784 | static int | |
2785 | linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) | |
2786 | { | |
2787 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2788 | ||
2789 | gdb_assert (lp != NULL); | |
2790 | ||
2791 | *addr_p = lp->stopped_data_address; | |
2792 | ||
2793 | return lp->stopped_data_address_p; | |
2794 | } | |
2795 | ||
26ab7092 JK |
2796 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2797 | ||
2798 | static int | |
2799 | sigtrap_is_event (int status) | |
2800 | { | |
2801 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2802 | } | |
2803 | ||
2804 | /* SIGTRAP-like events recognizer. */ | |
2805 | ||
2806 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
2807 | ||
00390b84 JK |
2808 | /* Check for SIGTRAP-like events in LP. */ |
2809 | ||
2810 | static int | |
2811 | linux_nat_lp_status_is_event (struct lwp_info *lp) | |
2812 | { | |
2813 | /* We check for lp->waitstatus in addition to lp->status, because we can | |
2814 | have pending process exits recorded in lp->status | |
2815 | and W_EXITCODE(0,0) == 0. We should probably have an additional | |
2816 | lp->status_p flag. */ | |
2817 | ||
2818 | return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE | |
2819 | && linux_nat_status_is_event (lp->status)); | |
2820 | } | |
2821 | ||
26ab7092 JK |
2822 | /* Set alternative SIGTRAP-like events recognizer. If |
2823 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2824 | applied. */ | |
2825 | ||
2826 | void | |
2827 | linux_nat_set_status_is_event (struct target_ops *t, | |
2828 | int (*status_is_event) (int status)) | |
2829 | { | |
2830 | linux_nat_status_is_event = status_is_event; | |
2831 | } | |
2832 | ||
57380f4e DJ |
2833 | /* Wait until LP is stopped. */ |
2834 | ||
2835 | static int | |
2836 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2837 | { | |
6c95b8df PA |
2838 | struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
2839 | ||
2840 | /* If this is a vfork parent, bail out, it is not going to report | |
2841 | any SIGSTOP until the vfork is done with. */ | |
2842 | if (inf->vfork_child != NULL) | |
2843 | return 0; | |
2844 | ||
d6b0e80f AC |
2845 | if (!lp->stopped) |
2846 | { | |
2847 | int status; | |
2848 | ||
2849 | status = wait_lwp (lp); | |
2850 | if (status == 0) | |
2851 | return 0; | |
2852 | ||
57380f4e DJ |
2853 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2854 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2855 | { |
57380f4e | 2856 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2857 | |
2858 | errno = 0; | |
2859 | ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); | |
2860 | if (debug_linux_nat) | |
2861 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2862 | "PTRACE_CONT %s, 0, 0 (%s) " |
2863 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2864 | target_pid_to_str (lp->ptid), |
2865 | errno ? safe_strerror (errno) : "OK"); | |
2866 | ||
57380f4e | 2867 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2868 | } |
2869 | ||
57380f4e DJ |
2870 | maybe_clear_ignore_sigint (lp); |
2871 | ||
d6b0e80f AC |
2872 | if (WSTOPSIG (status) != SIGSTOP) |
2873 | { | |
e5ef252a | 2874 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2875 | |
e5ef252a PA |
2876 | save_sigtrap (lp); |
2877 | ||
2878 | if (debug_linux_nat) | |
2879 | fprintf_unfiltered (gdb_stdlog, | |
2880 | "SWC: Pending event %s in %s\n", | |
2881 | status_to_str ((int) status), | |
2882 | target_pid_to_str (lp->ptid)); | |
2883 | ||
2884 | /* Save the sigtrap event. */ | |
2885 | lp->status = status; | |
2886 | gdb_assert (!lp->stopped); | |
2887 | gdb_assert (lp->signalled); | |
2888 | lp->stopped = 1; | |
d6b0e80f AC |
2889 | } |
2890 | else | |
2891 | { | |
2892 | /* We caught the SIGSTOP that we intended to catch, so | |
2893 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2894 | |
2895 | if (debug_linux_nat) | |
2896 | fprintf_unfiltered (gdb_stdlog, | |
2897 | "SWC: Delayed SIGSTOP caught for %s.\n", | |
2898 | target_pid_to_str (lp->ptid)); | |
2899 | ||
d6b0e80f | 2900 | lp->stopped = 1; |
e5ef252a PA |
2901 | |
2902 | /* Reset SIGNALLED only after the stop_wait_callback call | |
2903 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2904 | lp->signalled = 0; |
2905 | } | |
2906 | } | |
2907 | ||
2908 | return 0; | |
2909 | } | |
2910 | ||
d6b0e80f AC |
2911 | /* Return non-zero if LP has a wait status pending. */ |
2912 | ||
2913 | static int | |
2914 | status_callback (struct lwp_info *lp, void *data) | |
2915 | { | |
2916 | /* Only report a pending wait status if we pretend that this has | |
2917 | indeed been resumed. */ | |
ca2163eb PA |
2918 | if (!lp->resumed) |
2919 | return 0; | |
2920 | ||
2921 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2922 | { | |
2923 | /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, | |
766062f6 | 2924 | or a pending process exit. Note that `W_EXITCODE(0,0) == |
ca2163eb PA |
2925 | 0', so a clean process exit can not be stored pending in |
2926 | lp->status, it is indistinguishable from | |
2927 | no-pending-status. */ | |
2928 | return 1; | |
2929 | } | |
2930 | ||
2931 | if (lp->status != 0) | |
2932 | return 1; | |
2933 | ||
2934 | return 0; | |
d6b0e80f AC |
2935 | } |
2936 | ||
2937 | /* Return non-zero if LP isn't stopped. */ | |
2938 | ||
2939 | static int | |
2940 | running_callback (struct lwp_info *lp, void *data) | |
2941 | { | |
25289eb2 PA |
2942 | return (!lp->stopped |
2943 | || ((lp->status != 0 | |
2944 | || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
2945 | && lp->resumed)); | |
d6b0e80f AC |
2946 | } |
2947 | ||
2948 | /* Count the LWP's that have had events. */ | |
2949 | ||
2950 | static int | |
2951 | count_events_callback (struct lwp_info *lp, void *data) | |
2952 | { | |
2953 | int *count = data; | |
2954 | ||
2955 | gdb_assert (count != NULL); | |
2956 | ||
e09490f1 | 2957 | /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2958 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2959 | (*count)++; |
2960 | ||
2961 | return 0; | |
2962 | } | |
2963 | ||
2964 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2965 | ||
2966 | static int | |
2967 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2968 | { | |
25289eb2 PA |
2969 | if (lp->last_resume_kind == resume_step |
2970 | && lp->status != 0) | |
d6b0e80f AC |
2971 | return 1; |
2972 | else | |
2973 | return 0; | |
2974 | } | |
2975 | ||
2976 | /* Select the Nth LWP that has had a SIGTRAP event. */ | |
2977 | ||
2978 | static int | |
2979 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2980 | { | |
2981 | int *selector = data; | |
2982 | ||
2983 | gdb_assert (selector != NULL); | |
2984 | ||
1777feb0 | 2985 | /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
00390b84 | 2986 | if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
d6b0e80f AC |
2987 | if ((*selector)-- == 0) |
2988 | return 1; | |
2989 | ||
2990 | return 0; | |
2991 | } | |
2992 | ||
710151dd PA |
2993 | static int |
2994 | cancel_breakpoint (struct lwp_info *lp) | |
2995 | { | |
2996 | /* Arrange for a breakpoint to be hit again later. We don't keep | |
2997 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
2998 | LWP. We will handle the current event, eventually we will resume | |
2999 | this LWP, and this breakpoint will trap again. | |
3000 | ||
3001 | If we do not do this, then we run the risk that the user will | |
3002 | delete or disable the breakpoint, but the LWP will have already | |
3003 | tripped on it. */ | |
3004 | ||
515630c5 UW |
3005 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3006 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3007 | CORE_ADDR pc; | |
3008 | ||
3009 | pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); | |
6c95b8df | 3010 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
710151dd PA |
3011 | { |
3012 | if (debug_linux_nat) | |
3013 | fprintf_unfiltered (gdb_stdlog, | |
3014 | "CB: Push back breakpoint for %s\n", | |
3015 | target_pid_to_str (lp->ptid)); | |
3016 | ||
3017 | /* Back up the PC if necessary. */ | |
515630c5 UW |
3018 | if (gdbarch_decr_pc_after_break (gdbarch)) |
3019 | regcache_write_pc (regcache, pc); | |
3020 | ||
710151dd PA |
3021 | return 1; |
3022 | } | |
3023 | return 0; | |
3024 | } | |
3025 | ||
d6b0e80f AC |
3026 | static int |
3027 | cancel_breakpoints_callback (struct lwp_info *lp, void *data) | |
3028 | { | |
3029 | struct lwp_info *event_lp = data; | |
3030 | ||
3031 | /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ | |
3032 | if (lp == event_lp) | |
3033 | return 0; | |
3034 | ||
3035 | /* If a LWP other than the LWP that we're reporting an event for has | |
3036 | hit a GDB breakpoint (as opposed to some random trap signal), | |
3037 | then just arrange for it to hit it again later. We don't keep | |
3038 | the SIGTRAP status and don't forward the SIGTRAP signal to the | |
3039 | LWP. We will handle the current event, eventually we will resume | |
3040 | all LWPs, and this one will get its breakpoint trap again. | |
3041 | ||
3042 | If we do not do this, then we run the risk that the user will | |
3043 | delete or disable the breakpoint, but the LWP will have already | |
3044 | tripped on it. */ | |
3045 | ||
00390b84 | 3046 | if (linux_nat_lp_status_is_event (lp) |
710151dd PA |
3047 | && cancel_breakpoint (lp)) |
3048 | /* Throw away the SIGTRAP. */ | |
3049 | lp->status = 0; | |
d6b0e80f AC |
3050 | |
3051 | return 0; | |
3052 | } | |
3053 | ||
3054 | /* Select one LWP out of those that have events pending. */ | |
3055 | ||
3056 | static void | |
d90e17a7 | 3057 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
3058 | { |
3059 | int num_events = 0; | |
3060 | int random_selector; | |
3061 | struct lwp_info *event_lp; | |
3062 | ||
ac264b3b | 3063 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
3064 | (*orig_lp)->status = *status; |
3065 | ||
3066 | /* Give preference to any LWP that is being single-stepped. */ | |
d90e17a7 PA |
3067 | event_lp = iterate_over_lwps (filter, |
3068 | select_singlestep_lwp_callback, NULL); | |
d6b0e80f AC |
3069 | if (event_lp != NULL) |
3070 | { | |
3071 | if (debug_linux_nat) | |
3072 | fprintf_unfiltered (gdb_stdlog, | |
3073 | "SEL: Select single-step %s\n", | |
3074 | target_pid_to_str (event_lp->ptid)); | |
3075 | } | |
3076 | else | |
3077 | { | |
3078 | /* No single-stepping LWP. Select one at random, out of those | |
3079 | which have had SIGTRAP events. */ | |
3080 | ||
3081 | /* First see how many SIGTRAP events we have. */ | |
d90e17a7 | 3082 | iterate_over_lwps (filter, count_events_callback, &num_events); |
d6b0e80f AC |
3083 | |
3084 | /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ | |
3085 | random_selector = (int) | |
3086 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
3087 | ||
3088 | if (debug_linux_nat && num_events > 1) | |
3089 | fprintf_unfiltered (gdb_stdlog, | |
3090 | "SEL: Found %d SIGTRAP events, selecting #%d\n", | |
3091 | num_events, random_selector); | |
3092 | ||
d90e17a7 PA |
3093 | event_lp = iterate_over_lwps (filter, |
3094 | select_event_lwp_callback, | |
d6b0e80f AC |
3095 | &random_selector); |
3096 | } | |
3097 | ||
3098 | if (event_lp != NULL) | |
3099 | { | |
3100 | /* Switch the event LWP. */ | |
3101 | *orig_lp = event_lp; | |
3102 | *status = event_lp->status; | |
3103 | } | |
3104 | ||
3105 | /* Flush the wait status for the event LWP. */ | |
3106 | (*orig_lp)->status = 0; | |
3107 | } | |
3108 | ||
3109 | /* Return non-zero if LP has been resumed. */ | |
3110 | ||
3111 | static int | |
3112 | resumed_callback (struct lwp_info *lp, void *data) | |
3113 | { | |
3114 | return lp->resumed; | |
3115 | } | |
3116 | ||
12d9289a PA |
3117 | /* Stop an active thread, verify it still exists, then resume it. If |
3118 | the thread ends up with a pending status, then it is not resumed, | |
3119 | and *DATA (really a pointer to int), is set. */ | |
d6b0e80f AC |
3120 | |
3121 | static int | |
3122 | stop_and_resume_callback (struct lwp_info *lp, void *data) | |
3123 | { | |
12d9289a PA |
3124 | int *new_pending_p = data; |
3125 | ||
25289eb2 | 3126 | if (!lp->stopped) |
d6b0e80f | 3127 | { |
25289eb2 PA |
3128 | ptid_t ptid = lp->ptid; |
3129 | ||
d6b0e80f AC |
3130 | stop_callback (lp, NULL); |
3131 | stop_wait_callback (lp, NULL); | |
25289eb2 PA |
3132 | |
3133 | /* Resume if the lwp still exists, and the core wanted it | |
3134 | running. */ | |
12d9289a PA |
3135 | lp = find_lwp_pid (ptid); |
3136 | if (lp != NULL) | |
25289eb2 | 3137 | { |
12d9289a PA |
3138 | if (lp->last_resume_kind == resume_stop |
3139 | && lp->status == 0) | |
3140 | { | |
3141 | /* The core wanted the LWP to stop. Even if it stopped | |
3142 | cleanly (with SIGSTOP), leave the event pending. */ | |
3143 | if (debug_linux_nat) | |
3144 | fprintf_unfiltered (gdb_stdlog, | |
3145 | "SARC: core wanted LWP %ld stopped " | |
3146 | "(leaving SIGSTOP pending)\n", | |
3147 | GET_LWP (lp->ptid)); | |
3148 | lp->status = W_STOPCODE (SIGSTOP); | |
3149 | } | |
3150 | ||
3151 | if (lp->status == 0) | |
3152 | { | |
3153 | if (debug_linux_nat) | |
3154 | fprintf_unfiltered (gdb_stdlog, | |
3155 | "SARC: re-resuming LWP %ld\n", | |
3156 | GET_LWP (lp->ptid)); | |
e5ef252a | 3157 | resume_lwp (lp, lp->step, GDB_SIGNAL_0); |
12d9289a PA |
3158 | } |
3159 | else | |
3160 | { | |
3161 | if (debug_linux_nat) | |
3162 | fprintf_unfiltered (gdb_stdlog, | |
3163 | "SARC: not re-resuming LWP %ld " | |
3164 | "(has pending)\n", | |
3165 | GET_LWP (lp->ptid)); | |
3166 | if (new_pending_p) | |
3167 | *new_pending_p = 1; | |
3168 | } | |
25289eb2 | 3169 | } |
d6b0e80f AC |
3170 | } |
3171 | return 0; | |
3172 | } | |
3173 | ||
02f3fc28 | 3174 | /* Check if we should go on and pass this event to common code. |
12d9289a PA |
3175 | Return the affected lwp if we are, or NULL otherwise. If we stop |
3176 | all lwps temporarily, we may end up with new pending events in some | |
3177 | other lwp. In that case set *NEW_PENDING_P to true. */ | |
3178 | ||
02f3fc28 | 3179 | static struct lwp_info * |
0e5bf2a8 | 3180 | linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
02f3fc28 PA |
3181 | { |
3182 | struct lwp_info *lp; | |
3183 | ||
12d9289a PA |
3184 | *new_pending_p = 0; |
3185 | ||
02f3fc28 PA |
3186 | lp = find_lwp_pid (pid_to_ptid (lwpid)); |
3187 | ||
3188 | /* Check for stop events reported by a process we didn't already | |
3189 | know about - anything not already in our LWP list. | |
3190 | ||
3191 | If we're expecting to receive stopped processes after | |
3192 | fork, vfork, and clone events, then we'll just add the | |
3193 | new one to our list and go back to waiting for the event | |
3194 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
3195 | from waitpid before or after the event is. |
3196 | ||
3197 | But note the case of a non-leader thread exec'ing after the | |
3198 | leader having exited, and gone from our lists. The non-leader | |
3199 | thread changes its tid to the tgid. */ | |
3200 | ||
3201 | if (WIFSTOPPED (status) && lp == NULL | |
3202 | && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) | |
3203 | { | |
3204 | /* A multi-thread exec after we had seen the leader exiting. */ | |
3205 | if (debug_linux_nat) | |
3206 | fprintf_unfiltered (gdb_stdlog, | |
3207 | "LLW: Re-adding thread group leader LWP %d.\n", | |
3208 | lwpid); | |
3209 | ||
3210 | lp = add_lwp (BUILD_LWP (lwpid, lwpid)); | |
3211 | lp->stopped = 1; | |
3212 | lp->resumed = 1; | |
3213 | add_thread (lp->ptid); | |
3214 | } | |
3215 | ||
02f3fc28 PA |
3216 | if (WIFSTOPPED (status) && !lp) |
3217 | { | |
84636d28 | 3218 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
3219 | return NULL; |
3220 | } | |
3221 | ||
3222 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3223 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3224 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3225 | exits. */ |
3226 | if (!WIFSTOPPED (status) && !lp) | |
3227 | return NULL; | |
3228 | ||
ca2163eb PA |
3229 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3230 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3231 | { | |
3232 | /* No longer need the sysgood bit. The ptrace event ends up | |
3233 | recorded in lp->waitstatus if we care for it. We can carry | |
3234 | on handling the event like a regular SIGTRAP from here | |
3235 | on. */ | |
3236 | status = W_STOPCODE (SIGTRAP); | |
3237 | if (linux_handle_syscall_trap (lp, 0)) | |
3238 | return NULL; | |
3239 | } | |
02f3fc28 | 3240 | |
ca2163eb PA |
3241 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
3242 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) | |
02f3fc28 PA |
3243 | { |
3244 | if (debug_linux_nat) | |
3245 | fprintf_unfiltered (gdb_stdlog, | |
3246 | "LLW: Handling extended status 0x%06x\n", | |
3247 | status); | |
3248 | if (linux_handle_extended_wait (lp, status, 0)) | |
3249 | return NULL; | |
3250 | } | |
3251 | ||
26ab7092 | 3252 | if (linux_nat_status_is_event (status)) |
da559b09 | 3253 | save_sigtrap (lp); |
ca2163eb | 3254 | |
02f3fc28 | 3255 | /* Check if the thread has exited. */ |
d90e17a7 PA |
3256 | if ((WIFEXITED (status) || WIFSIGNALED (status)) |
3257 | && num_lwps (GET_PID (lp->ptid)) > 1) | |
02f3fc28 | 3258 | { |
9db03742 JB |
3259 | /* If this is the main thread, we must stop all threads and verify |
3260 | if they are still alive. This is because in the nptl thread model | |
3261 | on Linux 2.4, there is no signal issued for exiting LWPs | |
02f3fc28 PA |
3262 | other than the main thread. We only get the main thread exit |
3263 | signal once all child threads have already exited. If we | |
3264 | stop all the threads and use the stop_wait_callback to check | |
3265 | if they have exited we can determine whether this signal | |
3266 | should be ignored or whether it means the end of the debugged | |
3267 | application, regardless of which threading model is being | |
5d3b6af6 | 3268 | used. */ |
02f3fc28 PA |
3269 | if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
3270 | { | |
3271 | lp->stopped = 1; | |
d90e17a7 | 3272 | iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
12d9289a | 3273 | stop_and_resume_callback, new_pending_p); |
02f3fc28 PA |
3274 | } |
3275 | ||
3276 | if (debug_linux_nat) | |
3277 | fprintf_unfiltered (gdb_stdlog, | |
3278 | "LLW: %s exited.\n", | |
3279 | target_pid_to_str (lp->ptid)); | |
3280 | ||
d90e17a7 | 3281 | if (num_lwps (GET_PID (lp->ptid)) > 1) |
9db03742 JB |
3282 | { |
3283 | /* If there is at least one more LWP, then the exit signal | |
3284 | was not the end of the debugged application and should be | |
3285 | ignored. */ | |
3286 | exit_lwp (lp); | |
3287 | return NULL; | |
3288 | } | |
02f3fc28 PA |
3289 | } |
3290 | ||
3291 | /* Check if the current LWP has previously exited. In the nptl | |
3292 | thread model, LWPs other than the main thread do not issue | |
3293 | signals when they exit so we must check whenever the thread has | |
3294 | stopped. A similar check is made in stop_wait_callback(). */ | |
d90e17a7 | 3295 | if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
02f3fc28 | 3296 | { |
d90e17a7 PA |
3297 | ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
3298 | ||
02f3fc28 PA |
3299 | if (debug_linux_nat) |
3300 | fprintf_unfiltered (gdb_stdlog, | |
3301 | "LLW: %s exited.\n", | |
3302 | target_pid_to_str (lp->ptid)); | |
3303 | ||
3304 | exit_lwp (lp); | |
3305 | ||
3306 | /* Make sure there is at least one thread running. */ | |
d90e17a7 | 3307 | gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
02f3fc28 PA |
3308 | |
3309 | /* Discard the event. */ | |
3310 | return NULL; | |
3311 | } | |
3312 | ||
3313 | /* Make sure we don't report a SIGSTOP that we sent ourselves in | |
3314 | an attempt to stop an LWP. */ | |
3315 | if (lp->signalled | |
3316 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3317 | { | |
3318 | if (debug_linux_nat) | |
3319 | fprintf_unfiltered (gdb_stdlog, | |
3320 | "LLW: Delayed SIGSTOP caught for %s.\n", | |
3321 | target_pid_to_str (lp->ptid)); | |
3322 | ||
02f3fc28 PA |
3323 | lp->signalled = 0; |
3324 | ||
25289eb2 PA |
3325 | if (lp->last_resume_kind != resume_stop) |
3326 | { | |
3327 | /* This is a delayed SIGSTOP. */ | |
02f3fc28 | 3328 | |
25289eb2 PA |
3329 | registers_changed (); |
3330 | ||
7b50312a PA |
3331 | if (linux_nat_prepare_to_resume != NULL) |
3332 | linux_nat_prepare_to_resume (lp); | |
25289eb2 | 3333 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3334 | lp->step, GDB_SIGNAL_0); |
25289eb2 PA |
3335 | if (debug_linux_nat) |
3336 | fprintf_unfiltered (gdb_stdlog, | |
3337 | "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", | |
3338 | lp->step ? | |
3339 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3340 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3341 | |
25289eb2 PA |
3342 | lp->stopped = 0; |
3343 | gdb_assert (lp->resumed); | |
02f3fc28 | 3344 | |
25289eb2 PA |
3345 | /* Discard the event. */ |
3346 | return NULL; | |
3347 | } | |
02f3fc28 PA |
3348 | } |
3349 | ||
57380f4e DJ |
3350 | /* Make sure we don't report a SIGINT that we have already displayed |
3351 | for another thread. */ | |
3352 | if (lp->ignore_sigint | |
3353 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3354 | { | |
3355 | if (debug_linux_nat) | |
3356 | fprintf_unfiltered (gdb_stdlog, | |
3357 | "LLW: Delayed SIGINT caught for %s.\n", | |
3358 | target_pid_to_str (lp->ptid)); | |
3359 | ||
3360 | /* This is a delayed SIGINT. */ | |
3361 | lp->ignore_sigint = 0; | |
3362 | ||
3363 | registers_changed (); | |
7b50312a PA |
3364 | if (linux_nat_prepare_to_resume != NULL) |
3365 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3366 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3367 | lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3368 | if (debug_linux_nat) |
3369 | fprintf_unfiltered (gdb_stdlog, | |
3370 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3371 | lp->step ? | |
3372 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3373 | target_pid_to_str (lp->ptid)); | |
3374 | ||
3375 | lp->stopped = 0; | |
3376 | gdb_assert (lp->resumed); | |
3377 | ||
3378 | /* Discard the event. */ | |
3379 | return NULL; | |
3380 | } | |
3381 | ||
02f3fc28 PA |
3382 | /* An interesting event. */ |
3383 | gdb_assert (lp); | |
ca2163eb | 3384 | lp->status = status; |
02f3fc28 PA |
3385 | return lp; |
3386 | } | |
3387 | ||
0e5bf2a8 PA |
3388 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3389 | their exits until all other threads in the group have exited. */ | |
3390 | ||
3391 | static void | |
3392 | check_zombie_leaders (void) | |
3393 | { | |
3394 | struct inferior *inf; | |
3395 | ||
3396 | ALL_INFERIORS (inf) | |
3397 | { | |
3398 | struct lwp_info *leader_lp; | |
3399 | ||
3400 | if (inf->pid == 0) | |
3401 | continue; | |
3402 | ||
3403 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3404 | if (leader_lp != NULL | |
3405 | /* Check if there are other threads in the group, as we may | |
3406 | have raced with the inferior simply exiting. */ | |
3407 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3408 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3409 | { |
3410 | if (debug_linux_nat) | |
3411 | fprintf_unfiltered (gdb_stdlog, | |
3412 | "CZL: Thread group leader %d zombie " | |
3413 | "(it exited, or another thread execd).\n", | |
3414 | inf->pid); | |
3415 | ||
3416 | /* A leader zombie can mean one of two things: | |
3417 | ||
3418 | - It exited, and there's an exit status pending | |
3419 | available, or only the leader exited (not the whole | |
3420 | program). In the latter case, we can't waitpid the | |
3421 | leader's exit status until all other threads are gone. | |
3422 | ||
3423 | - There are 3 or more threads in the group, and a thread | |
3424 | other than the leader exec'd. On an exec, the Linux | |
3425 | kernel destroys all other threads (except the execing | |
3426 | one) in the thread group, and resets the execing thread's | |
3427 | tid to the tgid. No exit notification is sent for the | |
3428 | execing thread -- from the ptracer's perspective, it | |
3429 | appears as though the execing thread just vanishes. | |
3430 | Until we reap all other threads except the leader and the | |
3431 | execing thread, the leader will be zombie, and the | |
3432 | execing thread will be in `D (disc sleep)'. As soon as | |
3433 | all other threads are reaped, the execing thread changes | |
3434 | it's tid to the tgid, and the previous (zombie) leader | |
3435 | vanishes, giving place to the "new" leader. We could try | |
3436 | distinguishing the exit and exec cases, by waiting once | |
3437 | more, and seeing if something comes out, but it doesn't | |
3438 | sound useful. The previous leader _does_ go away, and | |
3439 | we'll re-add the new one once we see the exec event | |
3440 | (which is just the same as what would happen if the | |
3441 | previous leader did exit voluntarily before some other | |
3442 | thread execs). */ | |
3443 | ||
3444 | if (debug_linux_nat) | |
3445 | fprintf_unfiltered (gdb_stdlog, | |
3446 | "CZL: Thread group leader %d vanished.\n", | |
3447 | inf->pid); | |
3448 | exit_lwp (leader_lp); | |
3449 | } | |
3450 | } | |
3451 | } | |
3452 | ||
d6b0e80f | 3453 | static ptid_t |
7feb7d06 | 3454 | linux_nat_wait_1 (struct target_ops *ops, |
47608cb1 PA |
3455 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3456 | int target_options) | |
d6b0e80f | 3457 | { |
7feb7d06 | 3458 | static sigset_t prev_mask; |
4b60df3d | 3459 | enum resume_kind last_resume_kind; |
12d9289a | 3460 | struct lwp_info *lp; |
12d9289a | 3461 | int status; |
d6b0e80f | 3462 | |
01124a23 | 3463 | if (debug_linux_nat) |
b84876c2 PA |
3464 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3465 | ||
f973ed9c DJ |
3466 | /* The first time we get here after starting a new inferior, we may |
3467 | not have added it to the LWP list yet - this is the earliest | |
3468 | moment at which we know its PID. */ | |
d90e17a7 | 3469 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3470 | { |
27c9d204 PA |
3471 | /* Upgrade the main thread's ptid. */ |
3472 | thread_change_ptid (inferior_ptid, | |
3473 | BUILD_LWP (GET_PID (inferior_ptid), | |
3474 | GET_PID (inferior_ptid))); | |
3475 | ||
26cb8b7c | 3476 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3477 | lp->resumed = 1; |
3478 | } | |
3479 | ||
7feb7d06 PA |
3480 | /* Make sure SIGCHLD is blocked. */ |
3481 | block_child_signals (&prev_mask); | |
d6b0e80f AC |
3482 | |
3483 | retry: | |
d90e17a7 PA |
3484 | lp = NULL; |
3485 | status = 0; | |
d6b0e80f AC |
3486 | |
3487 | /* First check if there is a LWP with a wait status pending. */ | |
0e5bf2a8 | 3488 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d6b0e80f | 3489 | { |
0e5bf2a8 | 3490 | /* Any LWP in the PTID group that's been resumed will do. */ |
d90e17a7 | 3491 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
d6b0e80f AC |
3492 | if (lp) |
3493 | { | |
ca2163eb | 3494 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3495 | fprintf_unfiltered (gdb_stdlog, |
3496 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3497 | status_to_str (lp->status), |
d6b0e80f AC |
3498 | target_pid_to_str (lp->ptid)); |
3499 | } | |
d6b0e80f AC |
3500 | } |
3501 | else if (is_lwp (ptid)) | |
3502 | { | |
3503 | if (debug_linux_nat) | |
3504 | fprintf_unfiltered (gdb_stdlog, | |
3505 | "LLW: Waiting for specific LWP %s.\n", | |
3506 | target_pid_to_str (ptid)); | |
3507 | ||
3508 | /* We have a specific LWP to check. */ | |
3509 | lp = find_lwp_pid (ptid); | |
3510 | gdb_assert (lp); | |
d6b0e80f | 3511 | |
ca2163eb | 3512 | if (debug_linux_nat && lp->status) |
d6b0e80f AC |
3513 | fprintf_unfiltered (gdb_stdlog, |
3514 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3515 | status_to_str (lp->status), |
d6b0e80f AC |
3516 | target_pid_to_str (lp->ptid)); |
3517 | ||
d90e17a7 PA |
3518 | /* We check for lp->waitstatus in addition to lp->status, |
3519 | because we can have pending process exits recorded in | |
3520 | lp->status and W_EXITCODE(0,0) == 0. We should probably have | |
3521 | an additional lp->status_p flag. */ | |
ca2163eb | 3522 | if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
d90e17a7 | 3523 | lp = NULL; |
d6b0e80f AC |
3524 | } |
3525 | ||
b84876c2 PA |
3526 | if (!target_can_async_p ()) |
3527 | { | |
3528 | /* Causes SIGINT to be passed on to the attached process. */ | |
3529 | set_sigint_trap (); | |
b84876c2 | 3530 | } |
d6b0e80f | 3531 | |
0e5bf2a8 | 3532 | /* But if we don't find a pending event, we'll have to wait. */ |
7feb7d06 | 3533 | |
d90e17a7 | 3534 | while (lp == NULL) |
d6b0e80f AC |
3535 | { |
3536 | pid_t lwpid; | |
3537 | ||
0e5bf2a8 PA |
3538 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3539 | quirks: | |
3540 | ||
3541 | - If the thread group leader exits while other threads in the | |
3542 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3543 | waitpid won't return an exit status until the other threads | |
3544 | in the group are reapped. | |
3545 | ||
3546 | - When a non-leader thread execs, that thread just vanishes | |
3547 | without reporting an exit (so we'd hang if we waited for it | |
3548 | explicitly in that case). The exec event is reported to | |
3549 | the TGID pid. */ | |
3550 | ||
3551 | errno = 0; | |
3552 | lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); | |
3553 | if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) | |
3554 | lwpid = my_waitpid (-1, &status, WNOHANG); | |
3555 | ||
3556 | if (debug_linux_nat) | |
3557 | fprintf_unfiltered (gdb_stdlog, | |
3558 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3559 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3560 | |
d6b0e80f AC |
3561 | if (lwpid > 0) |
3562 | { | |
12d9289a PA |
3563 | /* If this is true, then we paused LWPs momentarily, and may |
3564 | now have pending events to handle. */ | |
3565 | int new_pending; | |
3566 | ||
d6b0e80f AC |
3567 | if (debug_linux_nat) |
3568 | { | |
3569 | fprintf_unfiltered (gdb_stdlog, | |
3570 | "LLW: waitpid %ld received %s\n", | |
3571 | (long) lwpid, status_to_str (status)); | |
3572 | } | |
3573 | ||
0e5bf2a8 | 3574 | lp = linux_nat_filter_event (lwpid, status, &new_pending); |
d90e17a7 | 3575 | |
33355866 JK |
3576 | /* STATUS is now no longer valid, use LP->STATUS instead. */ |
3577 | status = 0; | |
3578 | ||
0e5bf2a8 | 3579 | if (lp && !ptid_match (lp->ptid, ptid)) |
d6b0e80f | 3580 | { |
e3e9f5a2 PA |
3581 | gdb_assert (lp->resumed); |
3582 | ||
d90e17a7 | 3583 | if (debug_linux_nat) |
3e43a32a MS |
3584 | fprintf (stderr, |
3585 | "LWP %ld got an event %06x, leaving pending.\n", | |
33355866 | 3586 | ptid_get_lwp (lp->ptid), lp->status); |
d90e17a7 | 3587 | |
ca2163eb | 3588 | if (WIFSTOPPED (lp->status)) |
d90e17a7 | 3589 | { |
ca2163eb | 3590 | if (WSTOPSIG (lp->status) != SIGSTOP) |
d90e17a7 | 3591 | { |
e3e9f5a2 PA |
3592 | /* Cancel breakpoint hits. The breakpoint may |
3593 | be removed before we fetch events from this | |
3594 | process to report to the core. It is best | |
3595 | not to assume the moribund breakpoints | |
3596 | heuristic always handles these cases --- it | |
3597 | could be too many events go through to the | |
3598 | core before this one is handled. All-stop | |
3599 | always cancels breakpoint hits in all | |
3600 | threads. */ | |
3601 | if (non_stop | |
00390b84 | 3602 | && linux_nat_lp_status_is_event (lp) |
e3e9f5a2 PA |
3603 | && cancel_breakpoint (lp)) |
3604 | { | |
3605 | /* Throw away the SIGTRAP. */ | |
3606 | lp->status = 0; | |
3607 | ||
3608 | if (debug_linux_nat) | |
3609 | fprintf (stderr, | |
3e43a32a MS |
3610 | "LLW: LWP %ld hit a breakpoint while" |
3611 | " waiting for another process;" | |
3612 | " cancelled it\n", | |
e3e9f5a2 PA |
3613 | ptid_get_lwp (lp->ptid)); |
3614 | } | |
3615 | lp->stopped = 1; | |
d90e17a7 PA |
3616 | } |
3617 | else | |
3618 | { | |
3619 | lp->stopped = 1; | |
3620 | lp->signalled = 0; | |
3621 | } | |
3622 | } | |
33355866 | 3623 | else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
d90e17a7 PA |
3624 | { |
3625 | if (debug_linux_nat) | |
3e43a32a MS |
3626 | fprintf (stderr, |
3627 | "Process %ld exited while stopping LWPs\n", | |
d90e17a7 PA |
3628 | ptid_get_lwp (lp->ptid)); |
3629 | ||
3630 | /* This was the last lwp in the process. Since | |
3631 | events are serialized to GDB core, and we can't | |
3632 | report this one right now, but GDB core and the | |
3633 | other target layers will want to be notified | |
3634 | about the exit code/signal, leave the status | |
3635 | pending for the next time we're able to report | |
3636 | it. */ | |
d90e17a7 PA |
3637 | |
3638 | /* Prevent trying to stop this thread again. We'll | |
3639 | never try to resume it because it has a pending | |
3640 | status. */ | |
3641 | lp->stopped = 1; | |
3642 | ||
3643 | /* Dead LWP's aren't expected to reported a pending | |
3644 | sigstop. */ | |
3645 | lp->signalled = 0; | |
3646 | ||
3647 | /* Store the pending event in the waitstatus as | |
3648 | well, because W_EXITCODE(0,0) == 0. */ | |
ca2163eb | 3649 | store_waitstatus (&lp->waitstatus, lp->status); |
d90e17a7 PA |
3650 | } |
3651 | ||
3652 | /* Keep looking. */ | |
3653 | lp = NULL; | |
d6b0e80f AC |
3654 | } |
3655 | ||
0e5bf2a8 | 3656 | if (new_pending) |
d90e17a7 | 3657 | { |
0e5bf2a8 PA |
3658 | /* Some LWP now has a pending event. Go all the way |
3659 | back to check it. */ | |
3660 | goto retry; | |
3661 | } | |
12d9289a | 3662 | |
0e5bf2a8 PA |
3663 | if (lp) |
3664 | { | |
3665 | /* We got an event to report to the core. */ | |
3666 | break; | |
d90e17a7 | 3667 | } |
0e5bf2a8 PA |
3668 | |
3669 | /* Retry until nothing comes out of waitpid. A single | |
3670 | SIGCHLD can indicate more than one child stopped. */ | |
3671 | continue; | |
d6b0e80f AC |
3672 | } |
3673 | ||
0e5bf2a8 PA |
3674 | /* Check for zombie thread group leaders. Those can't be reaped |
3675 | until all other threads in the thread group are. */ | |
3676 | check_zombie_leaders (); | |
d6b0e80f | 3677 | |
0e5bf2a8 PA |
3678 | /* If there are no resumed children left, bail. We'd be stuck |
3679 | forever in the sigsuspend call below otherwise. */ | |
3680 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3681 | { | |
3682 | if (debug_linux_nat) | |
3683 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3684 | |
0e5bf2a8 | 3685 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3686 | |
0e5bf2a8 PA |
3687 | if (!target_can_async_p ()) |
3688 | clear_sigint_trap (); | |
b84876c2 | 3689 | |
0e5bf2a8 PA |
3690 | restore_child_signals_mask (&prev_mask); |
3691 | return minus_one_ptid; | |
d6b0e80f | 3692 | } |
28736962 | 3693 | |
0e5bf2a8 PA |
3694 | /* No interesting event to report to the core. */ |
3695 | ||
3696 | if (target_options & TARGET_WNOHANG) | |
3697 | { | |
01124a23 | 3698 | if (debug_linux_nat) |
28736962 PA |
3699 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3700 | ||
0e5bf2a8 | 3701 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3702 | restore_child_signals_mask (&prev_mask); |
3703 | return minus_one_ptid; | |
3704 | } | |
d6b0e80f AC |
3705 | |
3706 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3707 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3708 | |
3709 | /* Block until we get an event reported with SIGCHLD. */ | |
3710 | sigsuspend (&suspend_mask); | |
d6b0e80f AC |
3711 | } |
3712 | ||
b84876c2 | 3713 | if (!target_can_async_p ()) |
d26b5354 | 3714 | clear_sigint_trap (); |
d6b0e80f AC |
3715 | |
3716 | gdb_assert (lp); | |
3717 | ||
ca2163eb PA |
3718 | status = lp->status; |
3719 | lp->status = 0; | |
3720 | ||
d6b0e80f AC |
3721 | /* Don't report signals that GDB isn't interested in, such as |
3722 | signals that are neither printed nor stopped upon. Stopping all | |
3723 | threads can be a bit time-consuming so if we want decent | |
3724 | performance with heavily multi-threaded programs, especially when | |
3725 | they're using a high frequency timer, we'd better avoid it if we | |
3726 | can. */ | |
3727 | ||
3728 | if (WIFSTOPPED (status)) | |
3729 | { | |
2ea28649 | 3730 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); |
d6b0e80f | 3731 | |
2455069d UW |
3732 | /* When using hardware single-step, we need to report every signal. |
3733 | Otherwise, signals in pass_mask may be short-circuited. */ | |
d539ed7e | 3734 | if (!lp->step |
2455069d | 3735 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
d6b0e80f AC |
3736 | { |
3737 | /* FIMXE: kettenis/2001-06-06: Should we resume all threads | |
3738 | here? It is not clear we should. GDB may not expect | |
3739 | other threads to run. On the other hand, not resuming | |
3740 | newly attached threads may cause an unwanted delay in | |
3741 | getting them running. */ | |
3742 | registers_changed (); | |
7b50312a PA |
3743 | if (linux_nat_prepare_to_resume != NULL) |
3744 | linux_nat_prepare_to_resume (lp); | |
28439f5e | 3745 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
10d6c8cd | 3746 | lp->step, signo); |
d6b0e80f AC |
3747 | if (debug_linux_nat) |
3748 | fprintf_unfiltered (gdb_stdlog, | |
3749 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3750 | lp->step ? | |
3751 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3752 | target_pid_to_str (lp->ptid), | |
a493e3e2 | 3753 | (signo != GDB_SIGNAL_0 |
2ea28649 | 3754 | ? strsignal (gdb_signal_to_host (signo)) |
423ec54c | 3755 | : "0")); |
d6b0e80f | 3756 | lp->stopped = 0; |
d6b0e80f AC |
3757 | goto retry; |
3758 | } | |
3759 | ||
1ad15515 | 3760 | if (!non_stop) |
d6b0e80f | 3761 | { |
1ad15515 PA |
3762 | /* Only do the below in all-stop, as we currently use SIGINT |
3763 | to implement target_stop (see linux_nat_stop) in | |
3764 | non-stop. */ | |
a493e3e2 | 3765 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) |
1ad15515 PA |
3766 | { |
3767 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3768 | forwarded to the entire process group, that is, all LWPs | |
3769 | will receive it - unless they're using CLONE_THREAD to | |
3770 | share signals. Since we only want to report it once, we | |
3771 | mark it as ignored for all LWPs except this one. */ | |
d90e17a7 PA |
3772 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
3773 | set_ignore_sigint, NULL); | |
1ad15515 PA |
3774 | lp->ignore_sigint = 0; |
3775 | } | |
3776 | else | |
3777 | maybe_clear_ignore_sigint (lp); | |
d6b0e80f AC |
3778 | } |
3779 | } | |
3780 | ||
3781 | /* This LWP is stopped now. */ | |
3782 | lp->stopped = 1; | |
3783 | ||
3784 | if (debug_linux_nat) | |
3785 | fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", | |
3786 | status_to_str (status), target_pid_to_str (lp->ptid)); | |
3787 | ||
4c28f408 PA |
3788 | if (!non_stop) |
3789 | { | |
3790 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3791 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3792 | |
3793 | /* ... and wait until all of them have reported back that | |
3794 | they're no longer running. */ | |
d90e17a7 | 3795 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
4c28f408 PA |
3796 | |
3797 | /* If we're not waiting for a specific LWP, choose an event LWP | |
3798 | from among those that have had events. Giving equal priority | |
3799 | to all LWPs that have had events helps prevent | |
3800 | starvation. */ | |
0e5bf2a8 | 3801 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
d90e17a7 | 3802 | select_event_lwp (ptid, &lp, &status); |
d6b0e80f | 3803 | |
e3e9f5a2 PA |
3804 | /* Now that we've selected our final event LWP, cancel any |
3805 | breakpoints in other LWPs that have hit a GDB breakpoint. | |
3806 | See the comment in cancel_breakpoints_callback to find out | |
3807 | why. */ | |
3808 | iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); | |
3809 | ||
4b60df3d PA |
3810 | /* We'll need this to determine whether to report a SIGSTOP as |
3811 | TARGET_WAITKIND_0. Need to take a copy because | |
3812 | resume_clear_callback clears it. */ | |
3813 | last_resume_kind = lp->last_resume_kind; | |
3814 | ||
e3e9f5a2 PA |
3815 | /* In all-stop, from the core's perspective, all LWPs are now |
3816 | stopped until a new resume action is sent over. */ | |
3817 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3818 | } | |
3819 | else | |
25289eb2 | 3820 | { |
4b60df3d PA |
3821 | /* See above. */ |
3822 | last_resume_kind = lp->last_resume_kind; | |
3823 | resume_clear_callback (lp, NULL); | |
25289eb2 | 3824 | } |
d6b0e80f | 3825 | |
26ab7092 | 3826 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3827 | { |
d6b0e80f AC |
3828 | if (debug_linux_nat) |
3829 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3830 | "LLW: trap ptid is %s.\n", |
3831 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3832 | } |
d6b0e80f AC |
3833 | |
3834 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3835 | { | |
3836 | *ourstatus = lp->waitstatus; | |
3837 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3838 | } | |
3839 | else | |
3840 | store_waitstatus (ourstatus, status); | |
3841 | ||
01124a23 | 3842 | if (debug_linux_nat) |
b84876c2 PA |
3843 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3844 | ||
7feb7d06 | 3845 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3846 | |
4b60df3d | 3847 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3848 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3849 | && WSTOPSIG (status) == SIGSTOP) | |
3850 | { | |
3851 | /* A thread that has been requested to stop by GDB with | |
3852 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3853 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3854 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3855 | } |
3856 | ||
1e225492 JK |
3857 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3858 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3859 | lp->core = -1; | |
3860 | else | |
2e794194 | 3861 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3862 | |
f973ed9c | 3863 | return lp->ptid; |
d6b0e80f AC |
3864 | } |
3865 | ||
e3e9f5a2 PA |
3866 | /* Resume LWPs that are currently stopped without any pending status |
3867 | to report, but are resumed from the core's perspective. */ | |
3868 | ||
3869 | static int | |
3870 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3871 | { | |
3872 | ptid_t *wait_ptid_p = data; | |
3873 | ||
3874 | if (lp->stopped | |
3875 | && lp->resumed | |
3876 | && lp->status == 0 | |
3877 | && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) | |
3878 | { | |
336060f3 PA |
3879 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
3880 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
3881 | CORE_ADDR pc = regcache_read_pc (regcache); | |
3882 | ||
e3e9f5a2 PA |
3883 | gdb_assert (is_executing (lp->ptid)); |
3884 | ||
3885 | /* Don't bother if there's a breakpoint at PC that we'd hit | |
3886 | immediately, and we're not waiting for this LWP. */ | |
3887 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3888 | { | |
e3e9f5a2 PA |
3889 | if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
3890 | return 0; | |
3891 | } | |
3892 | ||
3893 | if (debug_linux_nat) | |
3894 | fprintf_unfiltered (gdb_stdlog, | |
336060f3 PA |
3895 | "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
3896 | target_pid_to_str (lp->ptid), | |
3897 | paddress (gdbarch, pc), | |
3898 | lp->step); | |
e3e9f5a2 | 3899 | |
336060f3 | 3900 | registers_changed (); |
7b50312a PA |
3901 | if (linux_nat_prepare_to_resume != NULL) |
3902 | linux_nat_prepare_to_resume (lp); | |
e3e9f5a2 | 3903 | linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
a493e3e2 | 3904 | lp->step, GDB_SIGNAL_0); |
e3e9f5a2 | 3905 | lp->stopped = 0; |
e3e9f5a2 PA |
3906 | lp->stopped_by_watchpoint = 0; |
3907 | } | |
3908 | ||
3909 | return 0; | |
3910 | } | |
3911 | ||
7feb7d06 PA |
3912 | static ptid_t |
3913 | linux_nat_wait (struct target_ops *ops, | |
47608cb1 PA |
3914 | ptid_t ptid, struct target_waitstatus *ourstatus, |
3915 | int target_options) | |
7feb7d06 PA |
3916 | { |
3917 | ptid_t event_ptid; | |
3918 | ||
3919 | if (debug_linux_nat) | |
09826ec5 PA |
3920 | { |
3921 | char *options_string; | |
3922 | ||
3923 | options_string = target_options_to_string (target_options); | |
3924 | fprintf_unfiltered (gdb_stdlog, | |
3925 | "linux_nat_wait: [%s], [%s]\n", | |
3926 | target_pid_to_str (ptid), | |
3927 | options_string); | |
3928 | xfree (options_string); | |
3929 | } | |
7feb7d06 PA |
3930 | |
3931 | /* Flush the async file first. */ | |
3932 | if (target_can_async_p ()) | |
3933 | async_file_flush (); | |
3934 | ||
e3e9f5a2 PA |
3935 | /* Resume LWPs that are currently stopped without any pending status |
3936 | to report, but are resumed from the core's perspective. LWPs get | |
3937 | in this state if we find them stopping at a time we're not | |
3938 | interested in reporting the event (target_wait on a | |
3939 | specific_process, for example, see linux_nat_wait_1), and | |
3940 | meanwhile the event became uninteresting. Don't bother resuming | |
3941 | LWPs we're not going to wait for if they'd stop immediately. */ | |
3942 | if (non_stop) | |
3943 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); | |
3944 | ||
47608cb1 | 3945 | event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
7feb7d06 PA |
3946 | |
3947 | /* If we requested any event, and something came out, assume there | |
3948 | may be more. If we requested a specific lwp or process, also | |
3949 | assume there may be more. */ | |
3950 | if (target_can_async_p () | |
6953d224 PA |
3951 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3952 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3953 | || !ptid_equal (ptid, minus_one_ptid))) |
3954 | async_file_mark (); | |
3955 | ||
3956 | /* Get ready for the next event. */ | |
3957 | if (target_can_async_p ()) | |
3958 | target_async (inferior_event_handler, 0); | |
3959 | ||
3960 | return event_ptid; | |
3961 | } | |
3962 | ||
d6b0e80f AC |
3963 | static int |
3964 | kill_callback (struct lwp_info *lp, void *data) | |
3965 | { | |
ed731959 JK |
3966 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3967 | ||
3968 | errno = 0; | |
3969 | kill (GET_LWP (lp->ptid), SIGKILL); | |
3970 | if (debug_linux_nat) | |
3971 | fprintf_unfiltered (gdb_stdlog, | |
3972 | "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", | |
3973 | target_pid_to_str (lp->ptid), | |
3974 | errno ? safe_strerror (errno) : "OK"); | |
3975 | ||
3976 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3977 | ||
d6b0e80f AC |
3978 | errno = 0; |
3979 | ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); | |
3980 | if (debug_linux_nat) | |
3981 | fprintf_unfiltered (gdb_stdlog, | |
3982 | "KC: PTRACE_KILL %s, 0, 0 (%s)\n", | |
3983 | target_pid_to_str (lp->ptid), | |
3984 | errno ? safe_strerror (errno) : "OK"); | |
3985 | ||
3986 | return 0; | |
3987 | } | |
3988 | ||
3989 | static int | |
3990 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3991 | { | |
3992 | pid_t pid; | |
3993 | ||
3994 | /* We must make sure that there are no pending events (delayed | |
3995 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3996 | program doesn't interfere with any following debugging session. */ | |
3997 | ||
3998 | /* For cloned processes we must check both with __WCLONE and | |
3999 | without, since the exit status of a cloned process isn't reported | |
4000 | with __WCLONE. */ | |
4001 | if (lp->cloned) | |
4002 | { | |
4003 | do | |
4004 | { | |
58aecb61 | 4005 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
e85a822c | 4006 | if (pid != (pid_t) -1) |
d6b0e80f | 4007 | { |
e85a822c DJ |
4008 | if (debug_linux_nat) |
4009 | fprintf_unfiltered (gdb_stdlog, | |
4010 | "KWC: wait %s received unknown.\n", | |
4011 | target_pid_to_str (lp->ptid)); | |
4012 | /* The Linux kernel sometimes fails to kill a thread | |
4013 | completely after PTRACE_KILL; that goes from the stop | |
4014 | point in do_fork out to the one in | |
4015 | get_signal_to_deliever and waits again. So kill it | |
4016 | again. */ | |
4017 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4018 | } |
4019 | } | |
4020 | while (pid == GET_LWP (lp->ptid)); | |
4021 | ||
4022 | gdb_assert (pid == -1 && errno == ECHILD); | |
4023 | } | |
4024 | ||
4025 | do | |
4026 | { | |
58aecb61 | 4027 | pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
e85a822c | 4028 | if (pid != (pid_t) -1) |
d6b0e80f | 4029 | { |
e85a822c DJ |
4030 | if (debug_linux_nat) |
4031 | fprintf_unfiltered (gdb_stdlog, | |
4032 | "KWC: wait %s received unk.\n", | |
4033 | target_pid_to_str (lp->ptid)); | |
4034 | /* See the call to kill_callback above. */ | |
4035 | kill_callback (lp, NULL); | |
d6b0e80f AC |
4036 | } |
4037 | } | |
4038 | while (pid == GET_LWP (lp->ptid)); | |
4039 | ||
4040 | gdb_assert (pid == -1 && errno == ECHILD); | |
4041 | return 0; | |
4042 | } | |
4043 | ||
4044 | static void | |
7d85a9c0 | 4045 | linux_nat_kill (struct target_ops *ops) |
d6b0e80f | 4046 | { |
f973ed9c DJ |
4047 | struct target_waitstatus last; |
4048 | ptid_t last_ptid; | |
4049 | int status; | |
d6b0e80f | 4050 | |
f973ed9c DJ |
4051 | /* If we're stopped while forking and we haven't followed yet, |
4052 | kill the other task. We need to do this first because the | |
4053 | parent will be sleeping if this is a vfork. */ | |
d6b0e80f | 4054 | |
f973ed9c | 4055 | get_last_target_status (&last_ptid, &last); |
d6b0e80f | 4056 | |
f973ed9c DJ |
4057 | if (last.kind == TARGET_WAITKIND_FORKED |
4058 | || last.kind == TARGET_WAITKIND_VFORKED) | |
4059 | { | |
3a3e9ee3 | 4060 | ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
f973ed9c | 4061 | wait (&status); |
26cb8b7c PA |
4062 | |
4063 | /* Let the arch-specific native code know this process is | |
4064 | gone. */ | |
4065 | linux_nat_forget_process (PIDGET (last.value.related_pid)); | |
f973ed9c DJ |
4066 | } |
4067 | ||
4068 | if (forks_exist_p ()) | |
7feb7d06 | 4069 | linux_fork_killall (); |
f973ed9c DJ |
4070 | else |
4071 | { | |
d90e17a7 | 4072 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 4073 | |
4c28f408 PA |
4074 | /* Stop all threads before killing them, since ptrace requires |
4075 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 4076 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
4077 | /* ... and wait until all of them have reported back that |
4078 | they're no longer running. */ | |
d90e17a7 | 4079 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 4080 | |
f973ed9c | 4081 | /* Kill all LWP's ... */ |
d90e17a7 | 4082 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
4083 | |
4084 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 4085 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
4086 | } |
4087 | ||
4088 | target_mourn_inferior (); | |
d6b0e80f AC |
4089 | } |
4090 | ||
4091 | static void | |
136d6dae | 4092 | linux_nat_mourn_inferior (struct target_ops *ops) |
d6b0e80f | 4093 | { |
26cb8b7c PA |
4094 | int pid = ptid_get_pid (inferior_ptid); |
4095 | ||
4096 | purge_lwp_list (pid); | |
d6b0e80f | 4097 | |
f973ed9c | 4098 | if (! forks_exist_p ()) |
d90e17a7 PA |
4099 | /* Normal case, no other forks available. */ |
4100 | linux_ops->to_mourn_inferior (ops); | |
f973ed9c DJ |
4101 | else |
4102 | /* Multi-fork case. The current inferior_ptid has exited, but | |
4103 | there are other viable forks to debug. Delete the exiting | |
4104 | one and context-switch to the first available. */ | |
4105 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
4106 | |
4107 | /* Let the arch-specific native code know this process is gone. */ | |
4108 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
4109 | } |
4110 | ||
5b009018 PA |
4111 | /* Convert a native/host siginfo object, into/from the siginfo in the |
4112 | layout of the inferiors' architecture. */ | |
4113 | ||
4114 | static void | |
a5362b9a | 4115 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
4116 | { |
4117 | int done = 0; | |
4118 | ||
4119 | if (linux_nat_siginfo_fixup != NULL) | |
4120 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
4121 | ||
4122 | /* If there was no callback, or the callback didn't do anything, | |
4123 | then just do a straight memcpy. */ | |
4124 | if (!done) | |
4125 | { | |
4126 | if (direction == 1) | |
a5362b9a | 4127 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 4128 | else |
a5362b9a | 4129 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
4130 | } |
4131 | } | |
4132 | ||
4aa995e1 PA |
4133 | static LONGEST |
4134 | linux_xfer_siginfo (struct target_ops *ops, enum target_object object, | |
4135 | const char *annex, gdb_byte *readbuf, | |
4136 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4137 | { | |
4aa995e1 | 4138 | int pid; |
a5362b9a TS |
4139 | siginfo_t siginfo; |
4140 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
4141 | |
4142 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
4143 | gdb_assert (readbuf || writebuf); | |
4144 | ||
4145 | pid = GET_LWP (inferior_ptid); | |
4146 | if (pid == 0) | |
4147 | pid = GET_PID (inferior_ptid); | |
4148 | ||
4149 | if (offset > sizeof (siginfo)) | |
4150 | return -1; | |
4151 | ||
4152 | errno = 0; | |
4153 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4154 | if (errno != 0) | |
4155 | return -1; | |
4156 | ||
5b009018 PA |
4157 | /* When GDB is built as a 64-bit application, ptrace writes into |
4158 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
4159 | inferior with a 64-bit GDB should look the same as debugging it | |
4160 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
4161 | the converted layout, so any read/write will have to be done | |
4162 | post-conversion. */ | |
4163 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
4164 | ||
4aa995e1 PA |
4165 | if (offset + len > sizeof (siginfo)) |
4166 | len = sizeof (siginfo) - offset; | |
4167 | ||
4168 | if (readbuf != NULL) | |
5b009018 | 4169 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
4170 | else |
4171 | { | |
5b009018 PA |
4172 | memcpy (inf_siginfo + offset, writebuf, len); |
4173 | ||
4174 | /* Convert back to ptrace layout before flushing it out. */ | |
4175 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
4176 | ||
4aa995e1 PA |
4177 | errno = 0; |
4178 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
4179 | if (errno != 0) | |
4180 | return -1; | |
4181 | } | |
4182 | ||
4183 | return len; | |
4184 | } | |
4185 | ||
10d6c8cd DJ |
4186 | static LONGEST |
4187 | linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, | |
4188 | const char *annex, gdb_byte *readbuf, | |
4189 | const gdb_byte *writebuf, | |
4190 | ULONGEST offset, LONGEST len) | |
d6b0e80f | 4191 | { |
4aa995e1 | 4192 | struct cleanup *old_chain; |
10d6c8cd | 4193 | LONGEST xfer; |
d6b0e80f | 4194 | |
4aa995e1 PA |
4195 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
4196 | return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, | |
4197 | offset, len); | |
4198 | ||
c35b1492 PA |
4199 | /* The target is connected but no live inferior is selected. Pass |
4200 | this request down to a lower stratum (e.g., the executable | |
4201 | file). */ | |
4202 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
4203 | return 0; | |
4204 | ||
4aa995e1 PA |
4205 | old_chain = save_inferior_ptid (); |
4206 | ||
d6b0e80f AC |
4207 | if (is_lwp (inferior_ptid)) |
4208 | inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); | |
4209 | ||
10d6c8cd DJ |
4210 | xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
4211 | offset, len); | |
d6b0e80f AC |
4212 | |
4213 | do_cleanups (old_chain); | |
4214 | return xfer; | |
4215 | } | |
4216 | ||
4217 | static int | |
28439f5e | 4218 | linux_thread_alive (ptid_t ptid) |
d6b0e80f | 4219 | { |
8c6a60d1 | 4220 | int err, tmp_errno; |
4c28f408 | 4221 | |
d6b0e80f AC |
4222 | gdb_assert (is_lwp (ptid)); |
4223 | ||
4c28f408 PA |
4224 | /* Send signal 0 instead of anything ptrace, because ptracing a |
4225 | running thread errors out claiming that the thread doesn't | |
4226 | exist. */ | |
4227 | err = kill_lwp (GET_LWP (ptid), 0); | |
8c6a60d1 | 4228 | tmp_errno = errno; |
d6b0e80f AC |
4229 | if (debug_linux_nat) |
4230 | fprintf_unfiltered (gdb_stdlog, | |
4c28f408 | 4231 | "LLTA: KILL(SIG0) %s (%s)\n", |
d6b0e80f | 4232 | target_pid_to_str (ptid), |
8c6a60d1 | 4233 | err ? safe_strerror (tmp_errno) : "OK"); |
9c0dd46b | 4234 | |
4c28f408 | 4235 | if (err != 0) |
d6b0e80f AC |
4236 | return 0; |
4237 | ||
4238 | return 1; | |
4239 | } | |
4240 | ||
28439f5e PA |
4241 | static int |
4242 | linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) | |
4243 | { | |
4244 | return linux_thread_alive (ptid); | |
4245 | } | |
4246 | ||
d6b0e80f | 4247 | static char * |
117de6a9 | 4248 | linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
d6b0e80f AC |
4249 | { |
4250 | static char buf[64]; | |
4251 | ||
a0ef4274 | 4252 | if (is_lwp (ptid) |
d90e17a7 PA |
4253 | && (GET_PID (ptid) != GET_LWP (ptid) |
4254 | || num_lwps (GET_PID (ptid)) > 1)) | |
d6b0e80f AC |
4255 | { |
4256 | snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); | |
4257 | return buf; | |
4258 | } | |
4259 | ||
4260 | return normal_pid_to_str (ptid); | |
4261 | } | |
4262 | ||
4694da01 TT |
4263 | static char * |
4264 | linux_nat_thread_name (struct thread_info *thr) | |
4265 | { | |
4266 | int pid = ptid_get_pid (thr->ptid); | |
4267 | long lwp = ptid_get_lwp (thr->ptid); | |
4268 | #define FORMAT "/proc/%d/task/%ld/comm" | |
4269 | char buf[sizeof (FORMAT) + 30]; | |
4270 | FILE *comm_file; | |
4271 | char *result = NULL; | |
4272 | ||
4273 | snprintf (buf, sizeof (buf), FORMAT, pid, lwp); | |
4274 | comm_file = fopen (buf, "r"); | |
4275 | if (comm_file) | |
4276 | { | |
4277 | /* Not exported by the kernel, so we define it here. */ | |
4278 | #define COMM_LEN 16 | |
4279 | static char line[COMM_LEN + 1]; | |
4280 | ||
4281 | if (fgets (line, sizeof (line), comm_file)) | |
4282 | { | |
4283 | char *nl = strchr (line, '\n'); | |
4284 | ||
4285 | if (nl) | |
4286 | *nl = '\0'; | |
4287 | if (*line != '\0') | |
4288 | result = line; | |
4289 | } | |
4290 | ||
4291 | fclose (comm_file); | |
4292 | } | |
4293 | ||
4294 | #undef COMM_LEN | |
4295 | #undef FORMAT | |
4296 | ||
4297 | return result; | |
4298 | } | |
4299 | ||
dba24537 AC |
4300 | /* Accepts an integer PID; Returns a string representing a file that |
4301 | can be opened to get the symbols for the child process. */ | |
4302 | ||
6d8fd2b7 UW |
4303 | static char * |
4304 | linux_child_pid_to_exec_file (int pid) | |
dba24537 AC |
4305 | { |
4306 | char *name1, *name2; | |
4307 | ||
4308 | name1 = xmalloc (MAXPATHLEN); | |
4309 | name2 = xmalloc (MAXPATHLEN); | |
4310 | make_cleanup (xfree, name1); | |
4311 | make_cleanup (xfree, name2); | |
4312 | memset (name2, 0, MAXPATHLEN); | |
4313 | ||
4314 | sprintf (name1, "/proc/%d/exe", pid); | |
0270a750 | 4315 | if (readlink (name1, name2, MAXPATHLEN - 1) > 0) |
dba24537 AC |
4316 | return name2; |
4317 | else | |
4318 | return name1; | |
4319 | } | |
4320 | ||
dba24537 AC |
4321 | /* Records the thread's register state for the corefile note |
4322 | section. */ | |
4323 | ||
4324 | static char * | |
6432734d UW |
4325 | linux_nat_collect_thread_registers (const struct regcache *regcache, |
4326 | ptid_t ptid, bfd *obfd, | |
4327 | char *note_data, int *note_size, | |
2ea28649 | 4328 | enum gdb_signal stop_signal) |
dba24537 | 4329 | { |
6432734d | 4330 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
4f844a66 | 4331 | const struct regset *regset; |
55e969c1 | 4332 | int core_regset_p; |
6432734d UW |
4333 | gdb_gregset_t gregs; |
4334 | gdb_fpregset_t fpregs; | |
4f844a66 DM |
4335 | |
4336 | core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); | |
dba24537 | 4337 | |
6432734d UW |
4338 | if (core_regset_p |
4339 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", | |
4340 | sizeof (gregs))) | |
4341 | != NULL && regset->collect_regset != NULL) | |
4342 | regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs)); | |
4f844a66 | 4343 | else |
6432734d | 4344 | fill_gregset (regcache, &gregs, -1); |
2f2241f1 | 4345 | |
6432734d UW |
4346 | note_data = (char *) elfcore_write_prstatus |
4347 | (obfd, note_data, note_size, ptid_get_lwp (ptid), | |
2ea28649 | 4348 | gdb_signal_to_host (stop_signal), &gregs); |
2f2241f1 | 4349 | |
6432734d UW |
4350 | if (core_regset_p |
4351 | && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", | |
4352 | sizeof (fpregs))) | |
3e43a32a | 4353 | != NULL && regset->collect_regset != NULL) |
6432734d UW |
4354 | regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs)); |
4355 | else | |
4356 | fill_fpregset (regcache, &fpregs, -1); | |
17ea7499 | 4357 | |
6432734d UW |
4358 | note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size, |
4359 | &fpregs, sizeof (fpregs)); | |
4f844a66 | 4360 | |
dba24537 AC |
4361 | return note_data; |
4362 | } | |
4363 | ||
dba24537 AC |
4364 | /* Fills the "to_make_corefile_note" target vector. Builds the note |
4365 | section for a corefile, and returns it in a malloc buffer. */ | |
4366 | ||
4367 | static char * | |
4368 | linux_nat_make_corefile_notes (bfd *obfd, int *note_size) | |
4369 | { | |
6432734d UW |
4370 | /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been |
4371 | converted to gdbarch_core_regset_sections, this function can go away. */ | |
f5656ead | 4372 | return linux_make_corefile_notes (target_gdbarch (), obfd, note_size, |
6432734d | 4373 | linux_nat_collect_thread_registers); |
dba24537 AC |
4374 | } |
4375 | ||
10d6c8cd DJ |
4376 | /* Implement the to_xfer_partial interface for memory reads using the /proc |
4377 | filesystem. Because we can use a single read() call for /proc, this | |
4378 | can be much more efficient than banging away at PTRACE_PEEKTEXT, | |
4379 | but it doesn't support writes. */ | |
4380 | ||
4381 | static LONGEST | |
4382 | linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, | |
4383 | const char *annex, gdb_byte *readbuf, | |
4384 | const gdb_byte *writebuf, | |
4385 | ULONGEST offset, LONGEST len) | |
dba24537 | 4386 | { |
10d6c8cd DJ |
4387 | LONGEST ret; |
4388 | int fd; | |
dba24537 AC |
4389 | char filename[64]; |
4390 | ||
10d6c8cd | 4391 | if (object != TARGET_OBJECT_MEMORY || !readbuf) |
dba24537 AC |
4392 | return 0; |
4393 | ||
4394 | /* Don't bother for one word. */ | |
4395 | if (len < 3 * sizeof (long)) | |
4396 | return 0; | |
4397 | ||
4398 | /* We could keep this file open and cache it - possibly one per | |
4399 | thread. That requires some juggling, but is even faster. */ | |
4400 | sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); | |
4401 | fd = open (filename, O_RDONLY | O_LARGEFILE); | |
4402 | if (fd == -1) | |
4403 | return 0; | |
4404 | ||
4405 | /* If pread64 is available, use it. It's faster if the kernel | |
4406 | supports it (only one syscall), and it's 64-bit safe even on | |
4407 | 32-bit platforms (for instance, SPARC debugging a SPARC64 | |
4408 | application). */ | |
4409 | #ifdef HAVE_PREAD64 | |
10d6c8cd | 4410 | if (pread64 (fd, readbuf, len, offset) != len) |
dba24537 | 4411 | #else |
10d6c8cd | 4412 | if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
dba24537 AC |
4413 | #endif |
4414 | ret = 0; | |
4415 | else | |
4416 | ret = len; | |
4417 | ||
4418 | close (fd); | |
4419 | return ret; | |
4420 | } | |
4421 | ||
efcbbd14 UW |
4422 | |
4423 | /* Enumerate spufs IDs for process PID. */ | |
4424 | static LONGEST | |
4425 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) | |
4426 | { | |
f5656ead | 4427 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4428 | LONGEST pos = 0; |
4429 | LONGEST written = 0; | |
4430 | char path[128]; | |
4431 | DIR *dir; | |
4432 | struct dirent *entry; | |
4433 | ||
4434 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4435 | dir = opendir (path); | |
4436 | if (!dir) | |
4437 | return -1; | |
4438 | ||
4439 | rewinddir (dir); | |
4440 | while ((entry = readdir (dir)) != NULL) | |
4441 | { | |
4442 | struct stat st; | |
4443 | struct statfs stfs; | |
4444 | int fd; | |
4445 | ||
4446 | fd = atoi (entry->d_name); | |
4447 | if (!fd) | |
4448 | continue; | |
4449 | ||
4450 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4451 | if (stat (path, &st) != 0) | |
4452 | continue; | |
4453 | if (!S_ISDIR (st.st_mode)) | |
4454 | continue; | |
4455 | ||
4456 | if (statfs (path, &stfs) != 0) | |
4457 | continue; | |
4458 | if (stfs.f_type != SPUFS_MAGIC) | |
4459 | continue; | |
4460 | ||
4461 | if (pos >= offset && pos + 4 <= offset + len) | |
4462 | { | |
4463 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4464 | written += 4; | |
4465 | } | |
4466 | pos += 4; | |
4467 | } | |
4468 | ||
4469 | closedir (dir); | |
4470 | return written; | |
4471 | } | |
4472 | ||
4473 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4474 | object type, using the /proc file system. */ | |
4475 | static LONGEST | |
4476 | linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, | |
4477 | const char *annex, gdb_byte *readbuf, | |
4478 | const gdb_byte *writebuf, | |
4479 | ULONGEST offset, LONGEST len) | |
4480 | { | |
4481 | char buf[128]; | |
4482 | int fd = 0; | |
4483 | int ret = -1; | |
4484 | int pid = PIDGET (inferior_ptid); | |
4485 | ||
4486 | if (!annex) | |
4487 | { | |
4488 | if (!readbuf) | |
4489 | return -1; | |
4490 | else | |
4491 | return spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4492 | } | |
4493 | ||
4494 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
4495 | fd = open (buf, writebuf? O_WRONLY : O_RDONLY); | |
4496 | if (fd <= 0) | |
4497 | return -1; | |
4498 | ||
4499 | if (offset != 0 | |
4500 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4501 | { | |
4502 | close (fd); | |
4503 | return 0; | |
4504 | } | |
4505 | ||
4506 | if (writebuf) | |
4507 | ret = write (fd, writebuf, (size_t) len); | |
4508 | else if (readbuf) | |
4509 | ret = read (fd, readbuf, (size_t) len); | |
4510 | ||
4511 | close (fd); | |
4512 | return ret; | |
4513 | } | |
4514 | ||
4515 | ||
dba24537 AC |
4516 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4517 | ||
4518 | static void | |
4519 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4520 | { | |
4521 | int len = strlen (line) - 1; | |
4522 | const char *p; | |
4523 | int signum; | |
4524 | ||
4525 | if (line[len] != '\n') | |
8a3fe4f8 | 4526 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4527 | |
4528 | p = line; | |
4529 | signum = len * 4; | |
4530 | while (len-- > 0) | |
4531 | { | |
4532 | int digit; | |
4533 | ||
4534 | if (*p >= '0' && *p <= '9') | |
4535 | digit = *p - '0'; | |
4536 | else if (*p >= 'a' && *p <= 'f') | |
4537 | digit = *p - 'a' + 10; | |
4538 | else | |
8a3fe4f8 | 4539 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4540 | |
4541 | signum -= 4; | |
4542 | ||
4543 | if (digit & 1) | |
4544 | sigaddset (sigs, signum + 1); | |
4545 | if (digit & 2) | |
4546 | sigaddset (sigs, signum + 2); | |
4547 | if (digit & 4) | |
4548 | sigaddset (sigs, signum + 3); | |
4549 | if (digit & 8) | |
4550 | sigaddset (sigs, signum + 4); | |
4551 | ||
4552 | p++; | |
4553 | } | |
4554 | } | |
4555 | ||
4556 | /* Find process PID's pending signals from /proc/pid/status and set | |
4557 | SIGS to match. */ | |
4558 | ||
4559 | void | |
3e43a32a MS |
4560 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4561 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 AC |
4562 | { |
4563 | FILE *procfile; | |
4564 | char buffer[MAXPATHLEN], fname[MAXPATHLEN]; | |
7c8a8b04 | 4565 | struct cleanup *cleanup; |
dba24537 AC |
4566 | |
4567 | sigemptyset (pending); | |
4568 | sigemptyset (blocked); | |
4569 | sigemptyset (ignored); | |
4570 | sprintf (fname, "/proc/%d/status", pid); | |
4571 | procfile = fopen (fname, "r"); | |
4572 | if (procfile == NULL) | |
8a3fe4f8 | 4573 | error (_("Could not open %s"), fname); |
7c8a8b04 | 4574 | cleanup = make_cleanup_fclose (procfile); |
dba24537 AC |
4575 | |
4576 | while (fgets (buffer, MAXPATHLEN, procfile) != NULL) | |
4577 | { | |
4578 | /* Normal queued signals are on the SigPnd line in the status | |
4579 | file. However, 2.6 kernels also have a "shared" pending | |
4580 | queue for delivering signals to a thread group, so check for | |
4581 | a ShdPnd line also. | |
4582 | ||
4583 | Unfortunately some Red Hat kernels include the shared pending | |
4584 | queue but not the ShdPnd status field. */ | |
4585 | ||
4586 | if (strncmp (buffer, "SigPnd:\t", 8) == 0) | |
4587 | add_line_to_sigset (buffer + 8, pending); | |
4588 | else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) | |
4589 | add_line_to_sigset (buffer + 8, pending); | |
4590 | else if (strncmp (buffer, "SigBlk:\t", 8) == 0) | |
4591 | add_line_to_sigset (buffer + 8, blocked); | |
4592 | else if (strncmp (buffer, "SigIgn:\t", 8) == 0) | |
4593 | add_line_to_sigset (buffer + 8, ignored); | |
4594 | } | |
4595 | ||
7c8a8b04 | 4596 | do_cleanups (cleanup); |
dba24537 AC |
4597 | } |
4598 | ||
07e059b5 VP |
4599 | static LONGEST |
4600 | linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, | |
e0881a8e MS |
4601 | const char *annex, gdb_byte *readbuf, |
4602 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
07e059b5 | 4603 | { |
07e059b5 VP |
4604 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4605 | ||
d26e3629 | 4606 | return linux_common_xfer_osdata (annex, readbuf, offset, len); |
07e059b5 VP |
4607 | } |
4608 | ||
10d6c8cd DJ |
4609 | static LONGEST |
4610 | linux_xfer_partial (struct target_ops *ops, enum target_object object, | |
4611 | const char *annex, gdb_byte *readbuf, | |
4612 | const gdb_byte *writebuf, ULONGEST offset, LONGEST len) | |
4613 | { | |
4614 | LONGEST xfer; | |
4615 | ||
4616 | if (object == TARGET_OBJECT_AUXV) | |
9f2982ff | 4617 | return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
10d6c8cd DJ |
4618 | offset, len); |
4619 | ||
07e059b5 VP |
4620 | if (object == TARGET_OBJECT_OSDATA) |
4621 | return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, | |
4622 | offset, len); | |
4623 | ||
efcbbd14 UW |
4624 | if (object == TARGET_OBJECT_SPU) |
4625 | return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, | |
4626 | offset, len); | |
4627 | ||
8f313923 JK |
4628 | /* GDB calculates all the addresses in possibly larget width of the address. |
4629 | Address width needs to be masked before its final use - either by | |
4630 | linux_proc_xfer_partial or inf_ptrace_xfer_partial. | |
4631 | ||
4632 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
4633 | ||
4634 | if (object == TARGET_OBJECT_MEMORY) | |
4635 | { | |
f5656ead | 4636 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
8f313923 JK |
4637 | |
4638 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
4639 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
4640 | } | |
4641 | ||
10d6c8cd DJ |
4642 | xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
4643 | offset, len); | |
4644 | if (xfer != 0) | |
4645 | return xfer; | |
4646 | ||
4647 | return super_xfer_partial (ops, object, annex, readbuf, writebuf, | |
4648 | offset, len); | |
4649 | } | |
4650 | ||
5808517f YQ |
4651 | static void |
4652 | cleanup_target_stop (void *arg) | |
4653 | { | |
4654 | ptid_t *ptid = (ptid_t *) arg; | |
4655 | ||
4656 | gdb_assert (arg != NULL); | |
4657 | ||
4658 | /* Unpause all */ | |
a493e3e2 | 4659 | target_resume (*ptid, 0, GDB_SIGNAL_0); |
5808517f YQ |
4660 | } |
4661 | ||
4662 | static VEC(static_tracepoint_marker_p) * | |
4663 | linux_child_static_tracepoint_markers_by_strid (const char *strid) | |
4664 | { | |
4665 | char s[IPA_CMD_BUF_SIZE]; | |
4666 | struct cleanup *old_chain; | |
4667 | int pid = ptid_get_pid (inferior_ptid); | |
4668 | VEC(static_tracepoint_marker_p) *markers = NULL; | |
4669 | struct static_tracepoint_marker *marker = NULL; | |
4670 | char *p = s; | |
4671 | ptid_t ptid = ptid_build (pid, 0, 0); | |
4672 | ||
4673 | /* Pause all */ | |
4674 | target_stop (ptid); | |
4675 | ||
4676 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4677 | s[sizeof ("qTfSTM")] = 0; | |
4678 | ||
42476b70 | 4679 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4680 | |
4681 | old_chain = make_cleanup (free_current_marker, &marker); | |
4682 | make_cleanup (cleanup_target_stop, &ptid); | |
4683 | ||
4684 | while (*p++ == 'm') | |
4685 | { | |
4686 | if (marker == NULL) | |
4687 | marker = XCNEW (struct static_tracepoint_marker); | |
4688 | ||
4689 | do | |
4690 | { | |
4691 | parse_static_tracepoint_marker_definition (p, &p, marker); | |
4692 | ||
4693 | if (strid == NULL || strcmp (strid, marker->str_id) == 0) | |
4694 | { | |
4695 | VEC_safe_push (static_tracepoint_marker_p, | |
4696 | markers, marker); | |
4697 | marker = NULL; | |
4698 | } | |
4699 | else | |
4700 | { | |
4701 | release_static_tracepoint_marker (marker); | |
4702 | memset (marker, 0, sizeof (*marker)); | |
4703 | } | |
4704 | } | |
4705 | while (*p++ == ','); /* comma-separated list */ | |
4706 | ||
4707 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4708 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4709 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4710 | p = s; |
4711 | } | |
4712 | ||
4713 | do_cleanups (old_chain); | |
4714 | ||
4715 | return markers; | |
4716 | } | |
4717 | ||
e9efe249 | 4718 | /* Create a prototype generic GNU/Linux target. The client can override |
10d6c8cd DJ |
4719 | it with local methods. */ |
4720 | ||
910122bf UW |
4721 | static void |
4722 | linux_target_install_ops (struct target_ops *t) | |
10d6c8cd | 4723 | { |
6d8fd2b7 | 4724 | t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
eb73ad13 | 4725 | t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
6d8fd2b7 | 4726 | t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
eb73ad13 | 4727 | t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
6d8fd2b7 | 4728 | t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
eb73ad13 | 4729 | t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
a96d9b2e | 4730 | t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
6d8fd2b7 | 4731 | t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
10d6c8cd | 4732 | t->to_post_startup_inferior = linux_child_post_startup_inferior; |
6d8fd2b7 UW |
4733 | t->to_post_attach = linux_child_post_attach; |
4734 | t->to_follow_fork = linux_child_follow_fork; | |
10d6c8cd DJ |
4735 | t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
4736 | ||
4737 | super_xfer_partial = t->to_xfer_partial; | |
4738 | t->to_xfer_partial = linux_xfer_partial; | |
5808517f YQ |
4739 | |
4740 | t->to_static_tracepoint_markers_by_strid | |
4741 | = linux_child_static_tracepoint_markers_by_strid; | |
910122bf UW |
4742 | } |
4743 | ||
4744 | struct target_ops * | |
4745 | linux_target (void) | |
4746 | { | |
4747 | struct target_ops *t; | |
4748 | ||
4749 | t = inf_ptrace_target (); | |
4750 | linux_target_install_ops (t); | |
4751 | ||
4752 | return t; | |
4753 | } | |
4754 | ||
4755 | struct target_ops * | |
7714d83a | 4756 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
910122bf UW |
4757 | { |
4758 | struct target_ops *t; | |
4759 | ||
4760 | t = inf_ptrace_trad_target (register_u_offset); | |
4761 | linux_target_install_ops (t); | |
10d6c8cd | 4762 | |
10d6c8cd DJ |
4763 | return t; |
4764 | } | |
4765 | ||
b84876c2 PA |
4766 | /* target_is_async_p implementation. */ |
4767 | ||
4768 | static int | |
4769 | linux_nat_is_async_p (void) | |
4770 | { | |
4771 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4772 | it explicitly with the "set target-async" command. |
b84876c2 | 4773 | Someday, linux will always be async. */ |
3dd5b83d | 4774 | return target_async_permitted; |
b84876c2 PA |
4775 | } |
4776 | ||
4777 | /* target_can_async_p implementation. */ | |
4778 | ||
4779 | static int | |
4780 | linux_nat_can_async_p (void) | |
4781 | { | |
4782 | /* NOTE: palves 2008-03-21: We're only async when the user requests | |
7feb7d06 | 4783 | it explicitly with the "set target-async" command. |
b84876c2 | 4784 | Someday, linux will always be async. */ |
3dd5b83d | 4785 | return target_async_permitted; |
b84876c2 PA |
4786 | } |
4787 | ||
9908b566 VP |
4788 | static int |
4789 | linux_nat_supports_non_stop (void) | |
4790 | { | |
4791 | return 1; | |
4792 | } | |
4793 | ||
d90e17a7 PA |
4794 | /* True if we want to support multi-process. To be removed when GDB |
4795 | supports multi-exec. */ | |
4796 | ||
2277426b | 4797 | int linux_multi_process = 1; |
d90e17a7 PA |
4798 | |
4799 | static int | |
4800 | linux_nat_supports_multi_process (void) | |
4801 | { | |
4802 | return linux_multi_process; | |
4803 | } | |
4804 | ||
03583c20 UW |
4805 | static int |
4806 | linux_nat_supports_disable_randomization (void) | |
4807 | { | |
4808 | #ifdef HAVE_PERSONALITY | |
4809 | return 1; | |
4810 | #else | |
4811 | return 0; | |
4812 | #endif | |
4813 | } | |
4814 | ||
b84876c2 PA |
4815 | static int async_terminal_is_ours = 1; |
4816 | ||
4817 | /* target_terminal_inferior implementation. */ | |
4818 | ||
4819 | static void | |
4820 | linux_nat_terminal_inferior (void) | |
4821 | { | |
4822 | if (!target_is_async_p ()) | |
4823 | { | |
4824 | /* Async mode is disabled. */ | |
4825 | terminal_inferior (); | |
4826 | return; | |
4827 | } | |
4828 | ||
b84876c2 PA |
4829 | terminal_inferior (); |
4830 | ||
d9d2d8b6 | 4831 | /* Calls to target_terminal_*() are meant to be idempotent. */ |
b84876c2 PA |
4832 | if (!async_terminal_is_ours) |
4833 | return; | |
4834 | ||
4835 | delete_file_handler (input_fd); | |
4836 | async_terminal_is_ours = 0; | |
4837 | set_sigint_trap (); | |
4838 | } | |
4839 | ||
4840 | /* target_terminal_ours implementation. */ | |
4841 | ||
2c0b251b | 4842 | static void |
b84876c2 PA |
4843 | linux_nat_terminal_ours (void) |
4844 | { | |
4845 | if (!target_is_async_p ()) | |
4846 | { | |
4847 | /* Async mode is disabled. */ | |
4848 | terminal_ours (); | |
4849 | return; | |
4850 | } | |
4851 | ||
4852 | /* GDB should never give the terminal to the inferior if the | |
4853 | inferior is running in the background (run&, continue&, etc.), | |
4854 | but claiming it sure should. */ | |
4855 | terminal_ours (); | |
4856 | ||
b84876c2 PA |
4857 | if (async_terminal_is_ours) |
4858 | return; | |
4859 | ||
4860 | clear_sigint_trap (); | |
4861 | add_file_handler (input_fd, stdin_event_handler, 0); | |
4862 | async_terminal_is_ours = 1; | |
4863 | } | |
4864 | ||
4865 | static void (*async_client_callback) (enum inferior_event_type event_type, | |
4866 | void *context); | |
4867 | static void *async_client_context; | |
4868 | ||
7feb7d06 PA |
4869 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4870 | so we notice when any child changes state, and notify the | |
4871 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4872 | above to wait for the arrival of a SIGCHLD. */ | |
4873 | ||
b84876c2 | 4874 | static void |
7feb7d06 | 4875 | sigchld_handler (int signo) |
b84876c2 | 4876 | { |
7feb7d06 PA |
4877 | int old_errno = errno; |
4878 | ||
01124a23 DE |
4879 | if (debug_linux_nat) |
4880 | ui_file_write_async_safe (gdb_stdlog, | |
4881 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4882 | |
4883 | if (signo == SIGCHLD | |
4884 | && linux_nat_event_pipe[0] != -1) | |
4885 | async_file_mark (); /* Let the event loop know that there are | |
4886 | events to handle. */ | |
4887 | ||
4888 | errno = old_errno; | |
4889 | } | |
4890 | ||
4891 | /* Callback registered with the target events file descriptor. */ | |
4892 | ||
4893 | static void | |
4894 | handle_target_event (int error, gdb_client_data client_data) | |
4895 | { | |
4896 | (*async_client_callback) (INF_REG_EVENT, async_client_context); | |
4897 | } | |
4898 | ||
4899 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4900 | ||
4901 | static int | |
4902 | linux_async_pipe (int enable) | |
4903 | { | |
4904 | int previous = (linux_nat_event_pipe[0] != -1); | |
4905 | ||
4906 | if (previous != enable) | |
4907 | { | |
4908 | sigset_t prev_mask; | |
4909 | ||
4910 | block_child_signals (&prev_mask); | |
4911 | ||
4912 | if (enable) | |
4913 | { | |
4914 | if (pipe (linux_nat_event_pipe) == -1) | |
4915 | internal_error (__FILE__, __LINE__, | |
4916 | "creating event pipe failed."); | |
4917 | ||
4918 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4919 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4920 | } | |
4921 | else | |
4922 | { | |
4923 | close (linux_nat_event_pipe[0]); | |
4924 | close (linux_nat_event_pipe[1]); | |
4925 | linux_nat_event_pipe[0] = -1; | |
4926 | linux_nat_event_pipe[1] = -1; | |
4927 | } | |
4928 | ||
4929 | restore_child_signals_mask (&prev_mask); | |
4930 | } | |
4931 | ||
4932 | return previous; | |
b84876c2 PA |
4933 | } |
4934 | ||
4935 | /* target_async implementation. */ | |
4936 | ||
4937 | static void | |
4938 | linux_nat_async (void (*callback) (enum inferior_event_type event_type, | |
4939 | void *context), void *context) | |
4940 | { | |
b84876c2 PA |
4941 | if (callback != NULL) |
4942 | { | |
4943 | async_client_callback = callback; | |
4944 | async_client_context = context; | |
7feb7d06 PA |
4945 | if (!linux_async_pipe (1)) |
4946 | { | |
4947 | add_file_handler (linux_nat_event_pipe[0], | |
4948 | handle_target_event, NULL); | |
4949 | /* There may be pending events to handle. Tell the event loop | |
4950 | to poll them. */ | |
4951 | async_file_mark (); | |
4952 | } | |
b84876c2 PA |
4953 | } |
4954 | else | |
4955 | { | |
4956 | async_client_callback = callback; | |
4957 | async_client_context = context; | |
b84876c2 | 4958 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4959 | linux_async_pipe (0); |
b84876c2 PA |
4960 | } |
4961 | return; | |
4962 | } | |
4963 | ||
a493e3e2 | 4964 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4965 | event came out. */ |
4966 | ||
4c28f408 | 4967 | static int |
252fbfc8 | 4968 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4969 | { |
d90e17a7 | 4970 | if (!lwp->stopped) |
252fbfc8 | 4971 | { |
d90e17a7 PA |
4972 | if (debug_linux_nat) |
4973 | fprintf_unfiltered (gdb_stdlog, | |
4974 | "LNSL: running -> suspending %s\n", | |
4975 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4976 | |
252fbfc8 | 4977 | |
25289eb2 PA |
4978 | if (lwp->last_resume_kind == resume_stop) |
4979 | { | |
4980 | if (debug_linux_nat) | |
4981 | fprintf_unfiltered (gdb_stdlog, | |
4982 | "linux-nat: already stopping LWP %ld at " | |
4983 | "GDB's request\n", | |
4984 | ptid_get_lwp (lwp->ptid)); | |
4985 | return 0; | |
4986 | } | |
252fbfc8 | 4987 | |
25289eb2 PA |
4988 | stop_callback (lwp, NULL); |
4989 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4990 | } |
4991 | else | |
4992 | { | |
4993 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4994 | |
d90e17a7 PA |
4995 | if (debug_linux_nat) |
4996 | { | |
e09875d4 | 4997 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4998 | fprintf_unfiltered (gdb_stdlog, |
4999 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
5000 | target_pid_to_str (lwp->ptid)); |
5001 | else | |
3e43a32a MS |
5002 | fprintf_unfiltered (gdb_stdlog, |
5003 | "LNSL: already stopped/no " | |
5004 | "stop_requested yet %s\n", | |
d90e17a7 | 5005 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
5006 | } |
5007 | } | |
4c28f408 PA |
5008 | return 0; |
5009 | } | |
5010 | ||
5011 | static void | |
5012 | linux_nat_stop (ptid_t ptid) | |
5013 | { | |
5014 | if (non_stop) | |
d90e17a7 | 5015 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4c28f408 PA |
5016 | else |
5017 | linux_ops->to_stop (ptid); | |
5018 | } | |
5019 | ||
d90e17a7 | 5020 | static void |
460014f5 | 5021 | linux_nat_close (void) |
d90e17a7 PA |
5022 | { |
5023 | /* Unregister from the event loop. */ | |
305436e0 PA |
5024 | if (linux_nat_is_async_p ()) |
5025 | linux_nat_async (NULL, 0); | |
d90e17a7 | 5026 | |
d90e17a7 | 5027 | if (linux_ops->to_close) |
460014f5 | 5028 | linux_ops->to_close (); |
d90e17a7 PA |
5029 | } |
5030 | ||
c0694254 PA |
5031 | /* When requests are passed down from the linux-nat layer to the |
5032 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
5033 | used. The address space pointer is stored in the inferior object, | |
5034 | but the common code that is passed such ptid can't tell whether | |
5035 | lwpid is a "main" process id or not (it assumes so). We reverse | |
5036 | look up the "main" process id from the lwp here. */ | |
5037 | ||
70221824 | 5038 | static struct address_space * |
c0694254 PA |
5039 | linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
5040 | { | |
5041 | struct lwp_info *lwp; | |
5042 | struct inferior *inf; | |
5043 | int pid; | |
5044 | ||
5045 | pid = GET_LWP (ptid); | |
5046 | if (GET_LWP (ptid) == 0) | |
5047 | { | |
5048 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
5049 | tgid. */ | |
5050 | lwp = find_lwp_pid (ptid); | |
5051 | pid = GET_PID (lwp->ptid); | |
5052 | } | |
5053 | else | |
5054 | { | |
5055 | /* A (pid,lwpid,0) ptid. */ | |
5056 | pid = GET_PID (ptid); | |
5057 | } | |
5058 | ||
5059 | inf = find_inferior_pid (pid); | |
5060 | gdb_assert (inf != NULL); | |
5061 | return inf->aspace; | |
5062 | } | |
5063 | ||
dc146f7c VP |
5064 | /* Return the cached value of the processor core for thread PTID. */ |
5065 | ||
70221824 | 5066 | static int |
dc146f7c VP |
5067 | linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
5068 | { | |
5069 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 5070 | |
dc146f7c VP |
5071 | if (info) |
5072 | return info->core; | |
5073 | return -1; | |
5074 | } | |
5075 | ||
f973ed9c DJ |
5076 | void |
5077 | linux_nat_add_target (struct target_ops *t) | |
5078 | { | |
f973ed9c DJ |
5079 | /* Save the provided single-threaded target. We save this in a separate |
5080 | variable because another target we've inherited from (e.g. inf-ptrace) | |
5081 | may have saved a pointer to T; we want to use it for the final | |
5082 | process stratum target. */ | |
5083 | linux_ops_saved = *t; | |
5084 | linux_ops = &linux_ops_saved; | |
5085 | ||
5086 | /* Override some methods for multithreading. */ | |
b84876c2 | 5087 | t->to_create_inferior = linux_nat_create_inferior; |
f973ed9c DJ |
5088 | t->to_attach = linux_nat_attach; |
5089 | t->to_detach = linux_nat_detach; | |
5090 | t->to_resume = linux_nat_resume; | |
5091 | t->to_wait = linux_nat_wait; | |
2455069d | 5092 | t->to_pass_signals = linux_nat_pass_signals; |
f973ed9c DJ |
5093 | t->to_xfer_partial = linux_nat_xfer_partial; |
5094 | t->to_kill = linux_nat_kill; | |
5095 | t->to_mourn_inferior = linux_nat_mourn_inferior; | |
5096 | t->to_thread_alive = linux_nat_thread_alive; | |
5097 | t->to_pid_to_str = linux_nat_pid_to_str; | |
4694da01 | 5098 | t->to_thread_name = linux_nat_thread_name; |
f973ed9c | 5099 | t->to_has_thread_control = tc_schedlock; |
c0694254 | 5100 | t->to_thread_address_space = linux_nat_thread_address_space; |
ebec9a0f PA |
5101 | t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
5102 | t->to_stopped_data_address = linux_nat_stopped_data_address; | |
f973ed9c | 5103 | |
b84876c2 PA |
5104 | t->to_can_async_p = linux_nat_can_async_p; |
5105 | t->to_is_async_p = linux_nat_is_async_p; | |
9908b566 | 5106 | t->to_supports_non_stop = linux_nat_supports_non_stop; |
b84876c2 | 5107 | t->to_async = linux_nat_async; |
b84876c2 PA |
5108 | t->to_terminal_inferior = linux_nat_terminal_inferior; |
5109 | t->to_terminal_ours = linux_nat_terminal_ours; | |
d90e17a7 | 5110 | t->to_close = linux_nat_close; |
b84876c2 | 5111 | |
4c28f408 PA |
5112 | /* Methods for non-stop support. */ |
5113 | t->to_stop = linux_nat_stop; | |
5114 | ||
d90e17a7 PA |
5115 | t->to_supports_multi_process = linux_nat_supports_multi_process; |
5116 | ||
03583c20 UW |
5117 | t->to_supports_disable_randomization |
5118 | = linux_nat_supports_disable_randomization; | |
5119 | ||
dc146f7c VP |
5120 | t->to_core_of_thread = linux_nat_core_of_thread; |
5121 | ||
f973ed9c DJ |
5122 | /* We don't change the stratum; this target will sit at |
5123 | process_stratum and thread_db will set at thread_stratum. This | |
5124 | is a little strange, since this is a multi-threaded-capable | |
5125 | target, but we want to be on the stack below thread_db, and we | |
5126 | also want to be used for single-threaded processes. */ | |
5127 | ||
5128 | add_target (t); | |
f973ed9c DJ |
5129 | } |
5130 | ||
9f0bdab8 DJ |
5131 | /* Register a method to call whenever a new thread is attached. */ |
5132 | void | |
7b50312a PA |
5133 | linux_nat_set_new_thread (struct target_ops *t, |
5134 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
5135 | { |
5136 | /* Save the pointer. We only support a single registered instance | |
5137 | of the GNU/Linux native target, so we do not need to map this to | |
5138 | T. */ | |
5139 | linux_nat_new_thread = new_thread; | |
5140 | } | |
5141 | ||
26cb8b7c PA |
5142 | /* See declaration in linux-nat.h. */ |
5143 | ||
5144 | void | |
5145 | linux_nat_set_new_fork (struct target_ops *t, | |
5146 | linux_nat_new_fork_ftype *new_fork) | |
5147 | { | |
5148 | /* Save the pointer. */ | |
5149 | linux_nat_new_fork = new_fork; | |
5150 | } | |
5151 | ||
5152 | /* See declaration in linux-nat.h. */ | |
5153 | ||
5154 | void | |
5155 | linux_nat_set_forget_process (struct target_ops *t, | |
5156 | linux_nat_forget_process_ftype *fn) | |
5157 | { | |
5158 | /* Save the pointer. */ | |
5159 | linux_nat_forget_process_hook = fn; | |
5160 | } | |
5161 | ||
5162 | /* See declaration in linux-nat.h. */ | |
5163 | ||
5164 | void | |
5165 | linux_nat_forget_process (pid_t pid) | |
5166 | { | |
5167 | if (linux_nat_forget_process_hook != NULL) | |
5168 | linux_nat_forget_process_hook (pid); | |
5169 | } | |
5170 | ||
5b009018 PA |
5171 | /* Register a method that converts a siginfo object between the layout |
5172 | that ptrace returns, and the layout in the architecture of the | |
5173 | inferior. */ | |
5174 | void | |
5175 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 5176 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
5177 | gdb_byte *, |
5178 | int)) | |
5179 | { | |
5180 | /* Save the pointer. */ | |
5181 | linux_nat_siginfo_fixup = siginfo_fixup; | |
5182 | } | |
5183 | ||
7b50312a PA |
5184 | /* Register a method to call prior to resuming a thread. */ |
5185 | ||
5186 | void | |
5187 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
5188 | void (*prepare_to_resume) (struct lwp_info *)) | |
5189 | { | |
5190 | /* Save the pointer. */ | |
5191 | linux_nat_prepare_to_resume = prepare_to_resume; | |
5192 | } | |
5193 | ||
f865ee35 JK |
5194 | /* See linux-nat.h. */ |
5195 | ||
5196 | int | |
5197 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 5198 | { |
da559b09 | 5199 | int pid; |
9f0bdab8 | 5200 | |
da559b09 JK |
5201 | pid = GET_LWP (ptid); |
5202 | if (pid == 0) | |
5203 | pid = GET_PID (ptid); | |
f865ee35 | 5204 | |
da559b09 JK |
5205 | errno = 0; |
5206 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
5207 | if (errno != 0) | |
5208 | { | |
5209 | memset (siginfo, 0, sizeof (*siginfo)); | |
5210 | return 0; | |
5211 | } | |
f865ee35 | 5212 | return 1; |
9f0bdab8 DJ |
5213 | } |
5214 | ||
2c0b251b PA |
5215 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
5216 | extern initialize_file_ftype _initialize_linux_nat; | |
5217 | ||
d6b0e80f AC |
5218 | void |
5219 | _initialize_linux_nat (void) | |
5220 | { | |
ccce17b0 YQ |
5221 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
5222 | &debug_linux_nat, _("\ | |
b84876c2 PA |
5223 | Set debugging of GNU/Linux lwp module."), _("\ |
5224 | Show debugging of GNU/Linux lwp module."), _("\ | |
5225 | Enables printf debugging output."), | |
ccce17b0 YQ |
5226 | NULL, |
5227 | show_debug_linux_nat, | |
5228 | &setdebuglist, &showdebuglist); | |
b84876c2 | 5229 | |
b84876c2 | 5230 | /* Save this mask as the default. */ |
d6b0e80f AC |
5231 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
5232 | ||
7feb7d06 PA |
5233 | /* Install a SIGCHLD handler. */ |
5234 | sigchld_action.sa_handler = sigchld_handler; | |
5235 | sigemptyset (&sigchld_action.sa_mask); | |
5236 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
5237 | |
5238 | /* Make it the default. */ | |
7feb7d06 | 5239 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
5240 | |
5241 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
5242 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
5243 | sigdelset (&suspend_mask, SIGCHLD); | |
5244 | ||
7feb7d06 | 5245 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5246 | } |
5247 | \f | |
5248 | ||
5249 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
5250 | the GNU/Linux Threads library and therefore doesn't really belong | |
5251 | here. */ | |
5252 | ||
5253 | /* Read variable NAME in the target and return its value if found. | |
5254 | Otherwise return zero. It is assumed that the type of the variable | |
5255 | is `int'. */ | |
5256 | ||
5257 | static int | |
5258 | get_signo (const char *name) | |
5259 | { | |
5260 | struct minimal_symbol *ms; | |
5261 | int signo; | |
5262 | ||
5263 | ms = lookup_minimal_symbol (name, NULL, NULL); | |
5264 | if (ms == NULL) | |
5265 | return 0; | |
5266 | ||
8e70166d | 5267 | if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
d6b0e80f AC |
5268 | sizeof (signo)) != 0) |
5269 | return 0; | |
5270 | ||
5271 | return signo; | |
5272 | } | |
5273 | ||
5274 | /* Return the set of signals used by the threads library in *SET. */ | |
5275 | ||
5276 | void | |
5277 | lin_thread_get_thread_signals (sigset_t *set) | |
5278 | { | |
5279 | struct sigaction action; | |
5280 | int restart, cancel; | |
5281 | ||
b84876c2 | 5282 | sigemptyset (&blocked_mask); |
d6b0e80f AC |
5283 | sigemptyset (set); |
5284 | ||
5285 | restart = get_signo ("__pthread_sig_restart"); | |
17fbb0bd DJ |
5286 | cancel = get_signo ("__pthread_sig_cancel"); |
5287 | ||
5288 | /* LinuxThreads normally uses the first two RT signals, but in some legacy | |
5289 | cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does | |
5290 | not provide any way for the debugger to query the signal numbers - | |
5291 | fortunately they don't change! */ | |
5292 | ||
d6b0e80f | 5293 | if (restart == 0) |
17fbb0bd | 5294 | restart = __SIGRTMIN; |
d6b0e80f | 5295 | |
d6b0e80f | 5296 | if (cancel == 0) |
17fbb0bd | 5297 | cancel = __SIGRTMIN + 1; |
d6b0e80f AC |
5298 | |
5299 | sigaddset (set, restart); | |
5300 | sigaddset (set, cancel); | |
5301 | ||
5302 | /* The GNU/Linux Threads library makes terminating threads send a | |
5303 | special "cancel" signal instead of SIGCHLD. Make sure we catch | |
5304 | those (to prevent them from terminating GDB itself, which is | |
5305 | likely to be their default action) and treat them the same way as | |
5306 | SIGCHLD. */ | |
5307 | ||
5308 | action.sa_handler = sigchld_handler; | |
5309 | sigemptyset (&action.sa_mask); | |
58aecb61 | 5310 | action.sa_flags = SA_RESTART; |
d6b0e80f AC |
5311 | sigaction (cancel, &action, NULL); |
5312 | ||
5313 | /* We block the "cancel" signal throughout this code ... */ | |
5314 | sigaddset (&blocked_mask, cancel); | |
5315 | sigprocmask (SIG_BLOCK, &blocked_mask, NULL); | |
5316 | ||
5317 | /* ... except during a sigsuspend. */ | |
5318 | sigdelset (&suspend_mask, cancel); | |
5319 | } |