Commit | Line | Data |
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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
e2882c85 | 3 | Copyright (C) 2001-2018 Free Software Foundation, Inc. |
3993f6b1 DJ |
4 | |
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
3993f6b1 DJ |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
3993f6b1 DJ |
19 | |
20 | #include "defs.h" | |
21 | #include "inferior.h" | |
45741a9c | 22 | #include "infrun.h" |
3993f6b1 | 23 | #include "target.h" |
96d7229d LM |
24 | #include "nat/linux-nat.h" |
25 | #include "nat/linux-waitpid.h" | |
3993f6b1 | 26 | #include "gdb_wait.h" |
d6b0e80f AC |
27 | #include <unistd.h> |
28 | #include <sys/syscall.h> | |
5826e159 | 29 | #include "nat/gdb_ptrace.h" |
0274a8ce | 30 | #include "linux-nat.h" |
125f8a3d GB |
31 | #include "nat/linux-ptrace.h" |
32 | #include "nat/linux-procfs.h" | |
8cc73a39 | 33 | #include "nat/linux-personality.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" | |
1777feb0 | 42 | #include <sys/procfs.h> /* for elf_gregset etc. */ |
dba24537 AC |
43 | #include "elf-bfd.h" /* for elfcore_write_* */ |
44 | #include "gregset.h" /* for gregset */ | |
45 | #include "gdbcore.h" /* for get_exec_file */ | |
46 | #include <ctype.h> /* for isdigit */ | |
53ce3c39 | 47 | #include <sys/stat.h> /* for struct stat */ |
dba24537 | 48 | #include <fcntl.h> /* for O_RDONLY */ |
b84876c2 PA |
49 | #include "inf-loop.h" |
50 | #include "event-loop.h" | |
51 | #include "event-top.h" | |
07e059b5 VP |
52 | #include <pwd.h> |
53 | #include <sys/types.h> | |
2978b111 | 54 | #include <dirent.h> |
07e059b5 | 55 | #include "xml-support.h" |
efcbbd14 | 56 | #include <sys/vfs.h> |
6c95b8df | 57 | #include "solib.h" |
125f8a3d | 58 | #include "nat/linux-osdata.h" |
6432734d | 59 | #include "linux-tdep.h" |
7dcd53a0 | 60 | #include "symfile.h" |
5808517f YQ |
61 | #include "agent.h" |
62 | #include "tracepoint.h" | |
87b0bb13 | 63 | #include "buffer.h" |
6ecd4729 | 64 | #include "target-descriptions.h" |
614c279d | 65 | #include "filestuff.h" |
77e371c0 | 66 | #include "objfiles.h" |
7a6a1731 GB |
67 | #include "nat/linux-namespaces.h" |
68 | #include "fileio.h" | |
efcbbd14 UW |
69 | |
70 | #ifndef SPUFS_MAGIC | |
71 | #define SPUFS_MAGIC 0x23c9b64e | |
72 | #endif | |
dba24537 | 73 | |
1777feb0 | 74 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
75 | |
76 | Waiting for events in sync mode | |
77 | =============================== | |
78 | ||
4a6ed09b PA |
79 | When waiting for an event in a specific thread, we just use waitpid, |
80 | passing the specific pid, and not passing WNOHANG. | |
81 | ||
82 | When waiting for an event in all threads, waitpid is not quite good: | |
83 | ||
84 | - If the thread group leader exits while other threads in the thread | |
85 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
86 | return an exit status until the other threads in the group are | |
87 | reaped. | |
88 | ||
89 | - When a non-leader thread execs, that thread just vanishes without | |
90 | reporting an exit (so we'd hang if we waited for it explicitly in | |
91 | that case). The exec event is instead reported to the TGID pid. | |
92 | ||
93 | The solution is to always use -1 and WNOHANG, together with | |
94 | sigsuspend. | |
95 | ||
96 | First, we use non-blocking waitpid to check for events. If nothing is | |
97 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
98 | it means something happened to a child process. As soon as we know | |
99 | there's an event, we get back to calling nonblocking waitpid. | |
100 | ||
101 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
102 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
103 | when it's blocked, the signal becomes pending and sigsuspend | |
104 | immediately notices it and returns. | |
105 | ||
106 | Waiting for events in async mode (TARGET_WNOHANG) | |
107 | ================================================= | |
8a77dff3 | 108 | |
7feb7d06 PA |
109 | In async mode, GDB should always be ready to handle both user input |
110 | and target events, so neither blocking waitpid nor sigsuspend are | |
111 | viable options. Instead, we should asynchronously notify the GDB main | |
112 | event loop whenever there's an unprocessed event from the target. We | |
113 | detect asynchronous target events by handling SIGCHLD signals. To | |
114 | notify the event loop about target events, the self-pipe trick is used | |
115 | --- a pipe is registered as waitable event source in the event loop, | |
116 | the event loop select/poll's on the read end of this pipe (as well on | |
117 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
118 | byte to this pipe. This is more portable than relying on | |
119 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
120 | emulates them with select/poll+sigprocmask, and that is racy | |
121 | (a.k.a. plain broken). | |
122 | ||
123 | Obviously, if we fail to notify the event loop if there's a target | |
124 | event, it's bad. OTOH, if we notify the event loop when there's no | |
125 | event from the target, linux_nat_wait will detect that there's no real | |
126 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
127 | This is mostly harmless, but it will waste time and is better avoided. | |
128 | ||
129 | The main design point is that every time GDB is outside linux-nat.c, | |
130 | we have a SIGCHLD handler installed that is called when something | |
131 | happens to the target and notifies the GDB event loop. Whenever GDB | |
132 | core decides to handle the event, and calls into linux-nat.c, we | |
133 | process things as in sync mode, except that the we never block in | |
134 | sigsuspend. | |
135 | ||
136 | While processing an event, we may end up momentarily blocked in | |
137 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
138 | return quickly. E.g., in all-stop mode, before reporting to the core | |
139 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
140 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
141 | Note that this is different from blocking indefinitely waiting for the | |
142 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
143 | |
144 | Use of signals | |
145 | ============== | |
146 | ||
147 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
148 | signal is not entirely significant; we just need for a signal to be delivered, | |
149 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
150 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
151 | be queued once; we do not keep track of other sources of SIGSTOP. | |
152 | ||
153 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
154 | use them, because they have special behavior when the signal is generated - | |
155 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
156 | kills the entire thread group. | |
157 | ||
158 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
159 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
160 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
161 | ||
162 | We could use a real-time signal instead. This would solve those problems; we | |
163 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
164 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
165 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
166 | blocked. |
167 | ||
168 | Exec events | |
169 | =========== | |
170 | ||
171 | The case of a thread group (process) with 3 or more threads, and a | |
172 | thread other than the leader execs is worth detailing: | |
173 | ||
174 | On an exec, the Linux kernel destroys all threads except the execing | |
175 | one in the thread group, and resets the execing thread's tid to the | |
176 | tgid. No exit notification is sent for the execing thread -- from the | |
177 | ptracer's perspective, it appears as though the execing thread just | |
178 | vanishes. Until we reap all other threads except the leader and the | |
179 | execing thread, the leader will be zombie, and the execing thread will | |
180 | be in `D (disc sleep)' state. As soon as all other threads are | |
181 | reaped, the execing thread changes its tid to the tgid, and the | |
182 | previous (zombie) leader vanishes, giving place to the "new" | |
183 | leader. */ | |
a0ef4274 | 184 | |
dba24537 AC |
185 | #ifndef O_LARGEFILE |
186 | #define O_LARGEFILE 0 | |
187 | #endif | |
0274a8ce | 188 | |
f6ac5f3d PA |
189 | struct linux_nat_target *linux_target; |
190 | ||
433bbbf8 | 191 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 192 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 193 | |
9f0bdab8 | 194 | /* The method to call, if any, when a new thread is attached. */ |
7b50312a PA |
195 | static void (*linux_nat_new_thread) (struct lwp_info *); |
196 | ||
466eecee SM |
197 | /* The method to call, if any, when a thread is destroyed. */ |
198 | static void (*linux_nat_delete_thread) (struct arch_lwp_info *); | |
199 | ||
26cb8b7c PA |
200 | /* The method to call, if any, when a new fork is attached. */ |
201 | static linux_nat_new_fork_ftype *linux_nat_new_fork; | |
202 | ||
203 | /* The method to call, if any, when a process is no longer | |
204 | attached. */ | |
205 | static linux_nat_forget_process_ftype *linux_nat_forget_process_hook; | |
206 | ||
7b50312a PA |
207 | /* Hook to call prior to resuming a thread. */ |
208 | static void (*linux_nat_prepare_to_resume) (struct lwp_info *); | |
9f0bdab8 | 209 | |
5b009018 PA |
210 | /* The method to call, if any, when the siginfo object needs to be |
211 | converted between the layout returned by ptrace, and the layout in | |
212 | the architecture of the inferior. */ | |
a5362b9a | 213 | static int (*linux_nat_siginfo_fixup) (siginfo_t *, |
5b009018 PA |
214 | gdb_byte *, |
215 | int); | |
216 | ||
6a3cb8e8 PA |
217 | /* The saved to_close method, inherited from inf-ptrace.c. |
218 | Called by our to_close. */ | |
219 | static void (*super_close) (struct target_ops *); | |
220 | ||
ccce17b0 | 221 | static unsigned int debug_linux_nat; |
920d2a44 AC |
222 | static void |
223 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
224 | struct cmd_list_element *c, const char *value) | |
225 | { | |
226 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
227 | value); | |
228 | } | |
d6b0e80f | 229 | |
ae087d01 DJ |
230 | struct simple_pid_list |
231 | { | |
232 | int pid; | |
3d799a95 | 233 | int status; |
ae087d01 DJ |
234 | struct simple_pid_list *next; |
235 | }; | |
236 | struct simple_pid_list *stopped_pids; | |
237 | ||
aa01bd36 PA |
238 | /* Whether target_thread_events is in effect. */ |
239 | static int report_thread_events; | |
240 | ||
3dd5b83d PA |
241 | /* Async mode support. */ |
242 | ||
b84876c2 PA |
243 | /* The read/write ends of the pipe registered as waitable file in the |
244 | event loop. */ | |
245 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
246 | ||
198297aa PA |
247 | /* True if we're currently in async mode. */ |
248 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
249 | ||
7feb7d06 | 250 | /* Flush the event pipe. */ |
b84876c2 | 251 | |
7feb7d06 PA |
252 | static void |
253 | async_file_flush (void) | |
b84876c2 | 254 | { |
7feb7d06 PA |
255 | int ret; |
256 | char buf; | |
b84876c2 | 257 | |
7feb7d06 | 258 | do |
b84876c2 | 259 | { |
7feb7d06 | 260 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 261 | } |
7feb7d06 | 262 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
263 | } |
264 | ||
7feb7d06 PA |
265 | /* Put something (anything, doesn't matter what, or how much) in event |
266 | pipe, so that the select/poll in the event-loop realizes we have | |
267 | something to process. */ | |
252fbfc8 | 268 | |
b84876c2 | 269 | static void |
7feb7d06 | 270 | async_file_mark (void) |
b84876c2 | 271 | { |
7feb7d06 | 272 | int ret; |
b84876c2 | 273 | |
7feb7d06 PA |
274 | /* It doesn't really matter what the pipe contains, as long we end |
275 | up with something in it. Might as well flush the previous | |
276 | left-overs. */ | |
277 | async_file_flush (); | |
b84876c2 | 278 | |
7feb7d06 | 279 | do |
b84876c2 | 280 | { |
7feb7d06 | 281 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 282 | } |
7feb7d06 | 283 | while (ret == -1 && errno == EINTR); |
b84876c2 | 284 | |
7feb7d06 PA |
285 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
286 | be awakened anyway. */ | |
b84876c2 PA |
287 | } |
288 | ||
7feb7d06 PA |
289 | static int kill_lwp (int lwpid, int signo); |
290 | ||
291 | static int stop_callback (struct lwp_info *lp, void *data); | |
2db9a427 | 292 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
7feb7d06 PA |
293 | |
294 | static void block_child_signals (sigset_t *prev_mask); | |
295 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
296 | |
297 | struct lwp_info; | |
298 | static struct lwp_info *add_lwp (ptid_t ptid); | |
299 | static void purge_lwp_list (int pid); | |
4403d8e9 | 300 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
301 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
302 | ||
8a99810d PA |
303 | static int lwp_status_pending_p (struct lwp_info *lp); |
304 | ||
9c02b525 PA |
305 | static int sigtrap_is_event (int status); |
306 | static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; | |
307 | ||
e7ad2f14 PA |
308 | static void save_stop_reason (struct lwp_info *lp); |
309 | ||
cff068da GB |
310 | \f |
311 | /* LWP accessors. */ | |
312 | ||
313 | /* See nat/linux-nat.h. */ | |
314 | ||
315 | ptid_t | |
316 | ptid_of_lwp (struct lwp_info *lwp) | |
317 | { | |
318 | return lwp->ptid; | |
319 | } | |
320 | ||
321 | /* See nat/linux-nat.h. */ | |
322 | ||
4b134ca1 GB |
323 | void |
324 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
325 | struct arch_lwp_info *info) | |
326 | { | |
327 | lwp->arch_private = info; | |
328 | } | |
329 | ||
330 | /* See nat/linux-nat.h. */ | |
331 | ||
332 | struct arch_lwp_info * | |
333 | lwp_arch_private_info (struct lwp_info *lwp) | |
334 | { | |
335 | return lwp->arch_private; | |
336 | } | |
337 | ||
338 | /* See nat/linux-nat.h. */ | |
339 | ||
cff068da GB |
340 | int |
341 | lwp_is_stopped (struct lwp_info *lwp) | |
342 | { | |
343 | return lwp->stopped; | |
344 | } | |
345 | ||
346 | /* See nat/linux-nat.h. */ | |
347 | ||
348 | enum target_stop_reason | |
349 | lwp_stop_reason (struct lwp_info *lwp) | |
350 | { | |
351 | return lwp->stop_reason; | |
352 | } | |
353 | ||
0e00e962 AA |
354 | /* See nat/linux-nat.h. */ |
355 | ||
356 | int | |
357 | lwp_is_stepping (struct lwp_info *lwp) | |
358 | { | |
359 | return lwp->step; | |
360 | } | |
361 | ||
ae087d01 DJ |
362 | \f |
363 | /* Trivial list manipulation functions to keep track of a list of | |
364 | new stopped processes. */ | |
365 | static void | |
3d799a95 | 366 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 367 | { |
8d749320 | 368 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 369 | |
ae087d01 | 370 | new_pid->pid = pid; |
3d799a95 | 371 | new_pid->status = status; |
ae087d01 DJ |
372 | new_pid->next = *listp; |
373 | *listp = new_pid; | |
374 | } | |
375 | ||
376 | static int | |
46a96992 | 377 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
378 | { |
379 | struct simple_pid_list **p; | |
380 | ||
381 | for (p = listp; *p != NULL; p = &(*p)->next) | |
382 | if ((*p)->pid == pid) | |
383 | { | |
384 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 385 | |
46a96992 | 386 | *statusp = (*p)->status; |
ae087d01 DJ |
387 | xfree (*p); |
388 | *p = next; | |
389 | return 1; | |
390 | } | |
391 | return 0; | |
392 | } | |
393 | ||
de0d863e DB |
394 | /* Return the ptrace options that we want to try to enable. */ |
395 | ||
396 | static int | |
397 | linux_nat_ptrace_options (int attached) | |
398 | { | |
399 | int options = 0; | |
400 | ||
401 | if (!attached) | |
402 | options |= PTRACE_O_EXITKILL; | |
403 | ||
404 | options |= (PTRACE_O_TRACESYSGOOD | |
405 | | PTRACE_O_TRACEVFORKDONE | |
406 | | PTRACE_O_TRACEVFORK | |
407 | | PTRACE_O_TRACEFORK | |
408 | | PTRACE_O_TRACEEXEC); | |
409 | ||
410 | return options; | |
411 | } | |
412 | ||
96d7229d | 413 | /* Initialize ptrace warnings and check for supported ptrace |
beed38b8 JB |
414 | features given PID. |
415 | ||
416 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
417 | |
418 | static void | |
beed38b8 | 419 | linux_init_ptrace (pid_t pid, int attached) |
3993f6b1 | 420 | { |
de0d863e DB |
421 | int options = linux_nat_ptrace_options (attached); |
422 | ||
423 | linux_enable_event_reporting (pid, options); | |
96d7229d | 424 | linux_ptrace_init_warnings (); |
4de4c07c DJ |
425 | } |
426 | ||
f6ac5f3d PA |
427 | linux_nat_target::~linux_nat_target () |
428 | {} | |
429 | ||
430 | void | |
431 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 432 | { |
beed38b8 | 433 | linux_init_ptrace (pid, 1); |
4de4c07c DJ |
434 | } |
435 | ||
f6ac5f3d PA |
436 | void |
437 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 438 | { |
beed38b8 | 439 | linux_init_ptrace (ptid_get_pid (ptid), 0); |
4de4c07c DJ |
440 | } |
441 | ||
4403d8e9 JK |
442 | /* Return the number of known LWPs in the tgid given by PID. */ |
443 | ||
444 | static int | |
445 | num_lwps (int pid) | |
446 | { | |
447 | int count = 0; | |
448 | struct lwp_info *lp; | |
449 | ||
450 | for (lp = lwp_list; lp; lp = lp->next) | |
451 | if (ptid_get_pid (lp->ptid) == pid) | |
452 | count++; | |
453 | ||
454 | return count; | |
455 | } | |
456 | ||
457 | /* Call delete_lwp with prototype compatible for make_cleanup. */ | |
458 | ||
459 | static void | |
460 | delete_lwp_cleanup (void *lp_voidp) | |
461 | { | |
9a3c8263 | 462 | struct lwp_info *lp = (struct lwp_info *) lp_voidp; |
4403d8e9 JK |
463 | |
464 | delete_lwp (lp->ptid); | |
465 | } | |
466 | ||
d83ad864 DB |
467 | /* Target hook for follow_fork. On entry inferior_ptid must be the |
468 | ptid of the followed inferior. At return, inferior_ptid will be | |
469 | unchanged. */ | |
470 | ||
f6ac5f3d PA |
471 | int |
472 | linux_nat_target::follow_fork (int follow_child, int detach_fork) | |
3993f6b1 | 473 | { |
d83ad864 | 474 | if (!follow_child) |
4de4c07c | 475 | { |
6c95b8df | 476 | struct lwp_info *child_lp = NULL; |
d83ad864 | 477 | int status = W_STOPCODE (0); |
d83ad864 | 478 | int has_vforked; |
79639e11 | 479 | ptid_t parent_ptid, child_ptid; |
d83ad864 DB |
480 | int parent_pid, child_pid; |
481 | ||
482 | has_vforked = (inferior_thread ()->pending_follow.kind | |
483 | == TARGET_WAITKIND_VFORKED); | |
79639e11 PA |
484 | parent_ptid = inferior_ptid; |
485 | child_ptid = inferior_thread ()->pending_follow.value.related_pid; | |
486 | parent_pid = ptid_get_lwp (parent_ptid); | |
487 | child_pid = ptid_get_lwp (child_ptid); | |
4de4c07c | 488 | |
1777feb0 | 489 | /* We're already attached to the parent, by default. */ |
2989a365 | 490 | child_lp = add_lwp (child_ptid); |
d83ad864 DB |
491 | child_lp->stopped = 1; |
492 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 493 | |
ac264b3b MS |
494 | /* Detach new forked process? */ |
495 | if (detach_fork) | |
f75c00e4 | 496 | { |
2989a365 TT |
497 | struct cleanup *old_chain = make_cleanup (delete_lwp_cleanup, |
498 | child_lp); | |
4403d8e9 | 499 | |
4403d8e9 JK |
500 | if (linux_nat_prepare_to_resume != NULL) |
501 | linux_nat_prepare_to_resume (child_lp); | |
c077881a HZ |
502 | |
503 | /* When debugging an inferior in an architecture that supports | |
504 | hardware single stepping on a kernel without commit | |
505 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
506 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
507 | set if the parent process had them set. | |
508 | To work around this, single step the child process | |
509 | once before detaching to clear the flags. */ | |
510 | ||
2fd9d7ca PA |
511 | /* Note that we consult the parent's architecture instead of |
512 | the child's because there's no inferior for the child at | |
513 | this point. */ | |
c077881a | 514 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 515 | (parent_ptid))) |
c077881a | 516 | { |
c077881a HZ |
517 | linux_disable_event_reporting (child_pid); |
518 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
519 | perror_with_name (_("Couldn't do single step")); | |
520 | if (my_waitpid (child_pid, &status, 0) < 0) | |
521 | perror_with_name (_("Couldn't wait vfork process")); | |
522 | } | |
523 | ||
524 | if (WIFSTOPPED (status)) | |
9caaaa83 PA |
525 | { |
526 | int signo; | |
527 | ||
528 | signo = WSTOPSIG (status); | |
529 | if (signo != 0 | |
530 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
531 | signo = 0; | |
532 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
533 | } | |
4403d8e9 JK |
534 | |
535 | do_cleanups (old_chain); | |
ac264b3b MS |
536 | } |
537 | else | |
538 | { | |
2989a365 TT |
539 | scoped_restore save_inferior_ptid |
540 | = make_scoped_restore (&inferior_ptid); | |
541 | inferior_ptid = child_ptid; | |
542 | ||
6c95b8df | 543 | /* Let the thread_db layer learn about this new process. */ |
2277426b | 544 | check_for_thread_db (); |
ac264b3b | 545 | } |
9016a515 DJ |
546 | |
547 | if (has_vforked) | |
548 | { | |
3ced3da4 | 549 | struct lwp_info *parent_lp; |
6c95b8df | 550 | |
79639e11 | 551 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 552 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 553 | |
96d7229d | 554 | if (linux_supports_tracevforkdone ()) |
9016a515 | 555 | { |
6c95b8df PA |
556 | if (debug_linux_nat) |
557 | fprintf_unfiltered (gdb_stdlog, | |
558 | "LCFF: waiting for VFORK_DONE on %d\n", | |
559 | parent_pid); | |
3ced3da4 | 560 | parent_lp->stopped = 1; |
9016a515 | 561 | |
6c95b8df PA |
562 | /* We'll handle the VFORK_DONE event like any other |
563 | event, in target_wait. */ | |
9016a515 DJ |
564 | } |
565 | else | |
566 | { | |
567 | /* We can't insert breakpoints until the child has | |
568 | finished with the shared memory region. We need to | |
569 | wait until that happens. Ideal would be to just | |
570 | call: | |
571 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
572 | - waitpid (parent_pid, &status, __WALL); | |
573 | However, most architectures can't handle a syscall | |
574 | being traced on the way out if it wasn't traced on | |
575 | the way in. | |
576 | ||
577 | We might also think to loop, continuing the child | |
578 | until it exits or gets a SIGTRAP. One problem is | |
579 | that the child might call ptrace with PTRACE_TRACEME. | |
580 | ||
581 | There's no simple and reliable way to figure out when | |
582 | the vforked child will be done with its copy of the | |
583 | shared memory. We could step it out of the syscall, | |
584 | two instructions, let it go, and then single-step the | |
585 | parent once. When we have hardware single-step, this | |
586 | would work; with software single-step it could still | |
587 | be made to work but we'd have to be able to insert | |
588 | single-step breakpoints in the child, and we'd have | |
589 | to insert -just- the single-step breakpoint in the | |
590 | parent. Very awkward. | |
591 | ||
592 | In the end, the best we can do is to make sure it | |
593 | runs for a little while. Hopefully it will be out of | |
594 | range of any breakpoints we reinsert. Usually this | |
595 | is only the single-step breakpoint at vfork's return | |
596 | point. */ | |
597 | ||
6c95b8df PA |
598 | if (debug_linux_nat) |
599 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
600 | "LCFF: no VFORK_DONE " |
601 | "support, sleeping a bit\n"); | |
6c95b8df | 602 | |
9016a515 | 603 | usleep (10000); |
9016a515 | 604 | |
6c95b8df PA |
605 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
606 | and leave it pending. The next linux_nat_resume call | |
607 | will notice a pending event, and bypasses actually | |
608 | resuming the inferior. */ | |
3ced3da4 PA |
609 | parent_lp->status = 0; |
610 | parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; | |
611 | parent_lp->stopped = 1; | |
6c95b8df PA |
612 | |
613 | /* If we're in async mode, need to tell the event loop | |
614 | there's something here to process. */ | |
d9d41e78 | 615 | if (target_is_async_p ()) |
6c95b8df PA |
616 | async_file_mark (); |
617 | } | |
9016a515 | 618 | } |
4de4c07c | 619 | } |
3993f6b1 | 620 | else |
4de4c07c | 621 | { |
3ced3da4 | 622 | struct lwp_info *child_lp; |
4de4c07c | 623 | |
3ced3da4 PA |
624 | child_lp = add_lwp (inferior_ptid); |
625 | child_lp->stopped = 1; | |
25289eb2 | 626 | child_lp->last_resume_kind = resume_stop; |
6c95b8df | 627 | |
6c95b8df | 628 | /* Let the thread_db layer learn about this new process. */ |
ef29ce1a | 629 | check_for_thread_db (); |
4de4c07c DJ |
630 | } |
631 | ||
632 | return 0; | |
633 | } | |
634 | ||
4de4c07c | 635 | \f |
f6ac5f3d PA |
636 | int |
637 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 638 | { |
96d7229d | 639 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
640 | } |
641 | ||
f6ac5f3d PA |
642 | int |
643 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
644 | { |
645 | return 0; | |
646 | } | |
647 | ||
f6ac5f3d PA |
648 | int |
649 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 650 | { |
96d7229d | 651 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
652 | } |
653 | ||
f6ac5f3d PA |
654 | int |
655 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
656 | { |
657 | return 0; | |
658 | } | |
659 | ||
f6ac5f3d PA |
660 | int |
661 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 662 | { |
96d7229d | 663 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
664 | } |
665 | ||
f6ac5f3d PA |
666 | int |
667 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
668 | { |
669 | return 0; | |
670 | } | |
671 | ||
f6ac5f3d PA |
672 | int |
673 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
674 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 675 | { |
96d7229d | 676 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
677 | return 1; |
678 | ||
a96d9b2e SDJ |
679 | /* On GNU/Linux, we ignore the arguments. It means that we only |
680 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 681 | |
649a140c | 682 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
683 | filter system calls here. We let GDB do the logic for us. */ |
684 | return 0; | |
685 | } | |
686 | ||
774113b0 PA |
687 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
688 | case of mapping a PID returned from the kernel to our corresponding | |
689 | lwp_info data structure. */ | |
690 | static htab_t lwp_lwpid_htab; | |
691 | ||
692 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
693 | ||
694 | static hashval_t | |
695 | lwp_info_hash (const void *ap) | |
696 | { | |
697 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
698 | pid_t pid = ptid_get_lwp (lp->ptid); | |
699 | ||
700 | return iterative_hash_object (pid, 0); | |
701 | } | |
702 | ||
703 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
704 | PID. */ | |
705 | ||
706 | static int | |
707 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
708 | { | |
709 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
710 | const struct lwp_info *element = (const struct lwp_info *) b; | |
711 | ||
712 | return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid); | |
713 | } | |
714 | ||
715 | /* Create the lwp_lwpid_htab hash table. */ | |
716 | ||
717 | static void | |
718 | lwp_lwpid_htab_create (void) | |
719 | { | |
720 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
721 | } | |
722 | ||
723 | /* Add LP to the hash table. */ | |
724 | ||
725 | static void | |
726 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
727 | { | |
728 | void **slot; | |
729 | ||
730 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
731 | gdb_assert (slot != NULL && *slot == NULL); | |
732 | *slot = lp; | |
733 | } | |
734 | ||
735 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
736 | creation order. This order is assumed in some cases. E.g., | |
737 | reaping status after killing alls lwps of a process: the leader LWP | |
738 | must be reaped last. */ | |
9f0bdab8 | 739 | struct lwp_info *lwp_list; |
774113b0 PA |
740 | |
741 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
742 | ||
743 | static void | |
744 | lwp_list_add (struct lwp_info *lp) | |
745 | { | |
746 | lp->next = lwp_list; | |
747 | if (lwp_list != NULL) | |
748 | lwp_list->prev = lp; | |
749 | lwp_list = lp; | |
750 | } | |
751 | ||
752 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
753 | list. */ | |
754 | ||
755 | static void | |
756 | lwp_list_remove (struct lwp_info *lp) | |
757 | { | |
758 | /* Remove from sorted-by-creation-order list. */ | |
759 | if (lp->next != NULL) | |
760 | lp->next->prev = lp->prev; | |
761 | if (lp->prev != NULL) | |
762 | lp->prev->next = lp->next; | |
763 | if (lp == lwp_list) | |
764 | lwp_list = lp->next; | |
765 | } | |
766 | ||
d6b0e80f AC |
767 | \f |
768 | ||
d6b0e80f AC |
769 | /* Original signal mask. */ |
770 | static sigset_t normal_mask; | |
771 | ||
772 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in | |
773 | _initialize_linux_nat. */ | |
774 | static sigset_t suspend_mask; | |
775 | ||
7feb7d06 PA |
776 | /* Signals to block to make that sigsuspend work. */ |
777 | static sigset_t blocked_mask; | |
778 | ||
779 | /* SIGCHLD action. */ | |
780 | struct sigaction sigchld_action; | |
b84876c2 | 781 | |
7feb7d06 PA |
782 | /* Block child signals (SIGCHLD and linux threads signals), and store |
783 | the previous mask in PREV_MASK. */ | |
84e46146 | 784 | |
7feb7d06 PA |
785 | static void |
786 | block_child_signals (sigset_t *prev_mask) | |
787 | { | |
788 | /* Make sure SIGCHLD is blocked. */ | |
789 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
790 | sigaddset (&blocked_mask, SIGCHLD); | |
791 | ||
792 | sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); | |
793 | } | |
794 | ||
795 | /* Restore child signals mask, previously returned by | |
796 | block_child_signals. */ | |
797 | ||
798 | static void | |
799 | restore_child_signals_mask (sigset_t *prev_mask) | |
800 | { | |
801 | sigprocmask (SIG_SETMASK, prev_mask, NULL); | |
802 | } | |
2455069d UW |
803 | |
804 | /* Mask of signals to pass directly to the inferior. */ | |
805 | static sigset_t pass_mask; | |
806 | ||
807 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d PA |
808 | void |
809 | linux_nat_target::pass_signals (int numsigs, unsigned char *pass_signals) | |
2455069d UW |
810 | { |
811 | int signo; | |
812 | ||
813 | sigemptyset (&pass_mask); | |
814 | ||
815 | for (signo = 1; signo < NSIG; signo++) | |
816 | { | |
2ea28649 | 817 | int target_signo = gdb_signal_from_host (signo); |
2455069d UW |
818 | if (target_signo < numsigs && pass_signals[target_signo]) |
819 | sigaddset (&pass_mask, signo); | |
820 | } | |
821 | } | |
822 | ||
d6b0e80f AC |
823 | \f |
824 | ||
825 | /* Prototypes for local functions. */ | |
826 | static int stop_wait_callback (struct lwp_info *lp, void *data); | |
20ba1ce6 | 827 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data); |
ced2dffb | 828 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 829 | |
d6b0e80f | 830 | \f |
d6b0e80f | 831 | |
7b50312a PA |
832 | /* Destroy and free LP. */ |
833 | ||
834 | static void | |
835 | lwp_free (struct lwp_info *lp) | |
836 | { | |
466eecee SM |
837 | /* Let the arch specific bits release arch_lwp_info. */ |
838 | if (linux_nat_delete_thread != NULL) | |
839 | linux_nat_delete_thread (lp->arch_private); | |
840 | else | |
841 | gdb_assert (lp->arch_private == NULL); | |
842 | ||
7b50312a PA |
843 | xfree (lp); |
844 | } | |
845 | ||
774113b0 | 846 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 847 | |
774113b0 PA |
848 | static int |
849 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 850 | { |
774113b0 PA |
851 | struct lwp_info *lp = (struct lwp_info *) *slot; |
852 | int pid = *(int *) info; | |
d90e17a7 | 853 | |
774113b0 | 854 | if (ptid_get_pid (lp->ptid) == pid) |
d90e17a7 | 855 | { |
774113b0 PA |
856 | htab_clear_slot (lwp_lwpid_htab, slot); |
857 | lwp_list_remove (lp); | |
858 | lwp_free (lp); | |
859 | } | |
d90e17a7 | 860 | |
774113b0 PA |
861 | return 1; |
862 | } | |
d90e17a7 | 863 | |
774113b0 PA |
864 | /* Remove all LWPs belong to PID from the lwp list. */ |
865 | ||
866 | static void | |
867 | purge_lwp_list (int pid) | |
868 | { | |
869 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
870 | } |
871 | ||
26cb8b7c PA |
872 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
873 | in the process. Return a pointer to the structure describing the | |
874 | new LWP. | |
875 | ||
876 | This differs from add_lwp in that we don't let the arch specific | |
877 | bits know about this new thread. Current clients of this callback | |
878 | take the opportunity to install watchpoints in the new thread, and | |
879 | we shouldn't do that for the first thread. If we're spawning a | |
880 | child ("run"), the thread executes the shell wrapper first, and we | |
881 | shouldn't touch it until it execs the program we want to debug. | |
882 | For "attach", it'd be okay to call the callback, but it's not | |
883 | necessary, because watchpoints can't yet have been inserted into | |
884 | the inferior. */ | |
d6b0e80f AC |
885 | |
886 | static struct lwp_info * | |
26cb8b7c | 887 | add_initial_lwp (ptid_t ptid) |
d6b0e80f AC |
888 | { |
889 | struct lwp_info *lp; | |
890 | ||
dfd4cc63 | 891 | gdb_assert (ptid_lwp_p (ptid)); |
d6b0e80f | 892 | |
8d749320 | 893 | lp = XNEW (struct lwp_info); |
d6b0e80f AC |
894 | |
895 | memset (lp, 0, sizeof (struct lwp_info)); | |
896 | ||
25289eb2 | 897 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
898 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
899 | ||
900 | lp->ptid = ptid; | |
dc146f7c | 901 | lp->core = -1; |
d6b0e80f | 902 | |
774113b0 PA |
903 | /* Add to sorted-by-reverse-creation-order list. */ |
904 | lwp_list_add (lp); | |
905 | ||
906 | /* Add to keyed-by-pid htab. */ | |
907 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 908 | |
26cb8b7c PA |
909 | return lp; |
910 | } | |
911 | ||
912 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
913 | structure describing the new LWP. The LWP should already be | |
914 | stopped. */ | |
915 | ||
916 | static struct lwp_info * | |
917 | add_lwp (ptid_t ptid) | |
918 | { | |
919 | struct lwp_info *lp; | |
920 | ||
921 | lp = add_initial_lwp (ptid); | |
922 | ||
6e012a6c PA |
923 | /* Let the arch specific bits know about this new thread. Current |
924 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
925 | watchpoints in the new thread. We don't do this for the first |
926 | thread though. See add_initial_lwp. */ | |
927 | if (linux_nat_new_thread != NULL) | |
7b50312a | 928 | linux_nat_new_thread (lp); |
9f0bdab8 | 929 | |
d6b0e80f AC |
930 | return lp; |
931 | } | |
932 | ||
933 | /* Remove the LWP specified by PID from the list. */ | |
934 | ||
935 | static void | |
936 | delete_lwp (ptid_t ptid) | |
937 | { | |
774113b0 PA |
938 | struct lwp_info *lp; |
939 | void **slot; | |
940 | struct lwp_info dummy; | |
d6b0e80f | 941 | |
774113b0 PA |
942 | dummy.ptid = ptid; |
943 | slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); | |
944 | if (slot == NULL) | |
945 | return; | |
d6b0e80f | 946 | |
774113b0 PA |
947 | lp = *(struct lwp_info **) slot; |
948 | gdb_assert (lp != NULL); | |
d6b0e80f | 949 | |
774113b0 | 950 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 951 | |
774113b0 PA |
952 | /* Remove from sorted-by-creation-order list. */ |
953 | lwp_list_remove (lp); | |
d6b0e80f | 954 | |
774113b0 | 955 | /* Release. */ |
7b50312a | 956 | lwp_free (lp); |
d6b0e80f AC |
957 | } |
958 | ||
959 | /* Return a pointer to the structure describing the LWP corresponding | |
960 | to PID. If no corresponding LWP could be found, return NULL. */ | |
961 | ||
962 | static struct lwp_info * | |
963 | find_lwp_pid (ptid_t ptid) | |
964 | { | |
965 | struct lwp_info *lp; | |
966 | int lwp; | |
774113b0 | 967 | struct lwp_info dummy; |
d6b0e80f | 968 | |
dfd4cc63 LM |
969 | if (ptid_lwp_p (ptid)) |
970 | lwp = ptid_get_lwp (ptid); | |
d6b0e80f | 971 | else |
dfd4cc63 | 972 | lwp = ptid_get_pid (ptid); |
d6b0e80f | 973 | |
774113b0 PA |
974 | dummy.ptid = ptid_build (0, lwp, 0); |
975 | lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
976 | return lp; | |
d6b0e80f AC |
977 | } |
978 | ||
6d4ee8c6 | 979 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
980 | |
981 | struct lwp_info * | |
d90e17a7 | 982 | iterate_over_lwps (ptid_t filter, |
6d4ee8c6 | 983 | iterate_over_lwps_ftype callback, |
d90e17a7 | 984 | void *data) |
d6b0e80f AC |
985 | { |
986 | struct lwp_info *lp, *lpnext; | |
987 | ||
988 | for (lp = lwp_list; lp; lp = lpnext) | |
989 | { | |
990 | lpnext = lp->next; | |
d90e17a7 PA |
991 | |
992 | if (ptid_match (lp->ptid, filter)) | |
993 | { | |
6d4ee8c6 | 994 | if ((*callback) (lp, data) != 0) |
d90e17a7 PA |
995 | return lp; |
996 | } | |
d6b0e80f AC |
997 | } |
998 | ||
999 | return NULL; | |
1000 | } | |
1001 | ||
2277426b PA |
1002 | /* Update our internal state when changing from one checkpoint to |
1003 | another indicated by NEW_PTID. We can only switch single-threaded | |
1004 | applications, so we only create one new LWP, and the previous list | |
1005 | is discarded. */ | |
f973ed9c DJ |
1006 | |
1007 | void | |
1008 | linux_nat_switch_fork (ptid_t new_ptid) | |
1009 | { | |
1010 | struct lwp_info *lp; | |
1011 | ||
dfd4cc63 | 1012 | purge_lwp_list (ptid_get_pid (inferior_ptid)); |
2277426b | 1013 | |
f973ed9c DJ |
1014 | lp = add_lwp (new_ptid); |
1015 | lp->stopped = 1; | |
e26af52f | 1016 | |
2277426b PA |
1017 | /* This changes the thread's ptid while preserving the gdb thread |
1018 | num. Also changes the inferior pid, while preserving the | |
1019 | inferior num. */ | |
1020 | thread_change_ptid (inferior_ptid, new_ptid); | |
1021 | ||
1022 | /* We've just told GDB core that the thread changed target id, but, | |
1023 | in fact, it really is a different thread, with different register | |
1024 | contents. */ | |
1025 | registers_changed (); | |
e26af52f DJ |
1026 | } |
1027 | ||
e26af52f DJ |
1028 | /* Handle the exit of a single thread LP. */ |
1029 | ||
1030 | static void | |
1031 | exit_lwp (struct lwp_info *lp) | |
1032 | { | |
e09875d4 | 1033 | struct thread_info *th = find_thread_ptid (lp->ptid); |
063bfe2e VP |
1034 | |
1035 | if (th) | |
e26af52f | 1036 | { |
17faa917 DJ |
1037 | if (print_thread_events) |
1038 | printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); | |
1039 | ||
4f8d22e3 | 1040 | delete_thread (lp->ptid); |
e26af52f DJ |
1041 | } |
1042 | ||
1043 | delete_lwp (lp->ptid); | |
1044 | } | |
1045 | ||
a0ef4274 DJ |
1046 | /* Wait for the LWP specified by LP, which we have just attached to. |
1047 | Returns a wait status for that LWP, to cache. */ | |
1048 | ||
1049 | static int | |
22827c51 | 1050 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 1051 | { |
dfd4cc63 | 1052 | pid_t new_pid, pid = ptid_get_lwp (ptid); |
a0ef4274 DJ |
1053 | int status; |
1054 | ||
644cebc9 | 1055 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 DJ |
1056 | { |
1057 | if (debug_linux_nat) | |
1058 | fprintf_unfiltered (gdb_stdlog, | |
1059 | "LNPAW: Attaching to a stopped process\n"); | |
1060 | ||
1061 | /* The process is definitely stopped. It is in a job control | |
1062 | stop, unless the kernel predates the TASK_STOPPED / | |
1063 | TASK_TRACED distinction, in which case it might be in a | |
1064 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1065 | can kill it, signal it, et cetera. | |
1066 | ||
1067 | First make sure there is a pending SIGSTOP. Since we are | |
1068 | already attached, the process can not transition from stopped | |
1069 | to running without a PTRACE_CONT; so we know this signal will | |
1070 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1071 | probably already in the queue (unless this kernel is old | |
1072 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1073 | is not an RT signal, it can only be queued once. */ | |
1074 | kill_lwp (pid, SIGSTOP); | |
1075 | ||
1076 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1077 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1078 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1079 | } | |
1080 | ||
1081 | /* Make sure the initial process is stopped. The user-level threads | |
1082 | layer might want to poke around in the inferior, and that won't | |
1083 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1084 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1085 | gdb_assert (pid == new_pid); |
1086 | ||
1087 | if (!WIFSTOPPED (status)) | |
1088 | { | |
1089 | /* The pid we tried to attach has apparently just exited. */ | |
1090 | if (debug_linux_nat) | |
1091 | fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", | |
1092 | pid, status_to_str (status)); | |
1093 | return status; | |
1094 | } | |
a0ef4274 DJ |
1095 | |
1096 | if (WSTOPSIG (status) != SIGSTOP) | |
1097 | { | |
1098 | *signalled = 1; | |
1099 | if (debug_linux_nat) | |
1100 | fprintf_unfiltered (gdb_stdlog, | |
1101 | "LNPAW: Received %s after attaching\n", | |
1102 | status_to_str (status)); | |
1103 | } | |
1104 | ||
1105 | return status; | |
1106 | } | |
1107 | ||
f6ac5f3d PA |
1108 | void |
1109 | linux_nat_target::create_inferior (const char *exec_file, | |
1110 | const std::string &allargs, | |
1111 | char **env, int from_tty) | |
b84876c2 | 1112 | { |
41272101 TT |
1113 | maybe_disable_address_space_randomization restore_personality |
1114 | (disable_randomization); | |
b84876c2 PA |
1115 | |
1116 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1117 | we have to mask the async mode. */ | |
1118 | ||
2455069d | 1119 | /* Make sure we report all signals during startup. */ |
f6ac5f3d | 1120 | pass_signals (0, NULL); |
2455069d | 1121 | |
f6ac5f3d | 1122 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
b84876c2 PA |
1123 | } |
1124 | ||
8784d563 PA |
1125 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1126 | already attached. Returns true if a new LWP is found, false | |
1127 | otherwise. */ | |
1128 | ||
1129 | static int | |
1130 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1131 | { | |
1132 | struct lwp_info *lp; | |
1133 | ||
1134 | /* Ignore LWPs we're already attached to. */ | |
1135 | lp = find_lwp_pid (ptid); | |
1136 | if (lp == NULL) | |
1137 | { | |
1138 | int lwpid = ptid_get_lwp (ptid); | |
1139 | ||
1140 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1141 | { | |
1142 | int err = errno; | |
1143 | ||
1144 | /* Be quiet if we simply raced with the thread exiting. | |
1145 | EPERM is returned if the thread's task still exists, and | |
1146 | is marked as exited or zombie, as well as other | |
1147 | conditions, so in that case, confirm the status in | |
1148 | /proc/PID/status. */ | |
1149 | if (err == ESRCH | |
1150 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1151 | { | |
1152 | if (debug_linux_nat) | |
1153 | { | |
1154 | fprintf_unfiltered (gdb_stdlog, | |
1155 | "Cannot attach to lwp %d: " | |
1156 | "thread is gone (%d: %s)\n", | |
1157 | lwpid, err, safe_strerror (err)); | |
1158 | } | |
1159 | } | |
1160 | else | |
1161 | { | |
4d9b86e1 SM |
1162 | std::string reason |
1163 | = linux_ptrace_attach_fail_reason_string (ptid, err); | |
1164 | ||
f71f0b0d | 1165 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1166 | lwpid, reason.c_str ()); |
8784d563 PA |
1167 | } |
1168 | } | |
1169 | else | |
1170 | { | |
1171 | if (debug_linux_nat) | |
1172 | fprintf_unfiltered (gdb_stdlog, | |
1173 | "PTRACE_ATTACH %s, 0, 0 (OK)\n", | |
1174 | target_pid_to_str (ptid)); | |
1175 | ||
1176 | lp = add_lwp (ptid); | |
8784d563 PA |
1177 | |
1178 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1179 | PTRACE_ATTACH brings it to a halt. */ | |
1180 | lp->signalled = 1; | |
1181 | ||
1182 | /* We need to wait for a stop before being able to make the | |
1183 | next ptrace call on this LWP. */ | |
1184 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1185 | |
1186 | /* So that wait collects the SIGSTOP. */ | |
1187 | lp->resumed = 1; | |
1188 | ||
1189 | /* Also add the LWP to gdb's thread list, in case a | |
1190 | matching libthread_db is not found (or the process uses | |
1191 | raw clone). */ | |
1192 | add_thread (lp->ptid); | |
1193 | set_running (lp->ptid, 1); | |
1194 | set_executing (lp->ptid, 1); | |
8784d563 PA |
1195 | } |
1196 | ||
1197 | return 1; | |
1198 | } | |
1199 | return 0; | |
1200 | } | |
1201 | ||
f6ac5f3d PA |
1202 | void |
1203 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1204 | { |
1205 | struct lwp_info *lp; | |
d6b0e80f | 1206 | int status; |
af990527 | 1207 | ptid_t ptid; |
d6b0e80f | 1208 | |
2455069d | 1209 | /* Make sure we report all signals during attach. */ |
f6ac5f3d | 1210 | pass_signals (0, NULL); |
2455069d | 1211 | |
492d29ea | 1212 | TRY |
87b0bb13 | 1213 | { |
f6ac5f3d | 1214 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1215 | } |
492d29ea | 1216 | CATCH (ex, RETURN_MASK_ERROR) |
87b0bb13 JK |
1217 | { |
1218 | pid_t pid = parse_pid_to_attach (args); | |
4d9b86e1 | 1219 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1220 | |
4d9b86e1 SM |
1221 | if (!reason.empty ()) |
1222 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), ex.message); | |
7ae1a6a6 | 1223 | else |
a7b2d0fb | 1224 | throw_error (ex.error, "%s", ex.message); |
87b0bb13 | 1225 | } |
492d29ea | 1226 | END_CATCH |
d6b0e80f | 1227 | |
af990527 PA |
1228 | /* The ptrace base target adds the main thread with (pid,0,0) |
1229 | format. Decorate it with lwp info. */ | |
dfd4cc63 LM |
1230 | ptid = ptid_build (ptid_get_pid (inferior_ptid), |
1231 | ptid_get_pid (inferior_ptid), | |
1232 | 0); | |
af990527 PA |
1233 | thread_change_ptid (inferior_ptid, ptid); |
1234 | ||
9f0bdab8 | 1235 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1236 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1237 | |
22827c51 | 1238 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1239 | if (!WIFSTOPPED (status)) |
1240 | { | |
1241 | if (WIFEXITED (status)) | |
1242 | { | |
1243 | int exit_code = WEXITSTATUS (status); | |
1244 | ||
223ffa71 | 1245 | target_terminal::ours (); |
bc1e6c81 | 1246 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1247 | if (exit_code == 0) |
1248 | error (_("Unable to attach: program exited normally.")); | |
1249 | else | |
1250 | error (_("Unable to attach: program exited with code %d."), | |
1251 | exit_code); | |
1252 | } | |
1253 | else if (WIFSIGNALED (status)) | |
1254 | { | |
2ea28649 | 1255 | enum gdb_signal signo; |
dacc9cb2 | 1256 | |
223ffa71 | 1257 | target_terminal::ours (); |
bc1e6c81 | 1258 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1259 | |
2ea28649 | 1260 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1261 | error (_("Unable to attach: program terminated with signal " |
1262 | "%s, %s."), | |
2ea28649 PA |
1263 | gdb_signal_to_name (signo), |
1264 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1265 | } |
1266 | ||
1267 | internal_error (__FILE__, __LINE__, | |
1268 | _("unexpected status %d for PID %ld"), | |
dfd4cc63 | 1269 | status, (long) ptid_get_lwp (ptid)); |
dacc9cb2 PP |
1270 | } |
1271 | ||
a0ef4274 | 1272 | lp->stopped = 1; |
9f0bdab8 | 1273 | |
a0ef4274 | 1274 | /* Save the wait status to report later. */ |
d6b0e80f | 1275 | lp->resumed = 1; |
a0ef4274 DJ |
1276 | if (debug_linux_nat) |
1277 | fprintf_unfiltered (gdb_stdlog, | |
1278 | "LNA: waitpid %ld, saving status %s\n", | |
dfd4cc63 | 1279 | (long) ptid_get_pid (lp->ptid), status_to_str (status)); |
710151dd | 1280 | |
7feb7d06 PA |
1281 | lp->status = status; |
1282 | ||
8784d563 PA |
1283 | /* We must attach to every LWP. If /proc is mounted, use that to |
1284 | find them now. The inferior may be using raw clone instead of | |
1285 | using pthreads. But even if it is using pthreads, thread_db | |
1286 | walks structures in the inferior's address space to find the list | |
1287 | of threads/LWPs, and those structures may well be corrupted. | |
1288 | Note that once thread_db is loaded, we'll still use it to list | |
1289 | threads and associate pthread info with each LWP. */ | |
1290 | linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid), | |
1291 | attach_proc_task_lwp_callback); | |
1292 | ||
7feb7d06 | 1293 | if (target_can_async_p ()) |
6a3753b3 | 1294 | target_async (1); |
d6b0e80f AC |
1295 | } |
1296 | ||
ced2dffb PA |
1297 | /* Get pending signal of THREAD as a host signal number, for detaching |
1298 | purposes. This is the signal the thread last stopped for, which we | |
1299 | need to deliver to the thread when detaching, otherwise, it'd be | |
1300 | suppressed/lost. */ | |
1301 | ||
a0ef4274 | 1302 | static int |
ced2dffb | 1303 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1304 | { |
a493e3e2 | 1305 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1306 | |
1307 | /* If we paused threads momentarily, we may have stored pending | |
1308 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1309 | and GDB core hasn't seen any signal for those threads. | |
1310 | Otherwise, the last signal reported to the core is found in the | |
1311 | thread object's stop_signal. | |
1312 | ||
1313 | There's a corner case that isn't handled here at present. Only | |
1314 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1315 | stop_signal make sense as a real signal to pass to the inferior. | |
1316 | Some catchpoint related events, like | |
1317 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1318 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1319 | those traps are debug API (ptrace in our case) related and |
1320 | induced; the inferior wouldn't see them if it wasn't being | |
1321 | traced. Hence, we should never pass them to the inferior, even | |
1322 | when set to pass state. Since this corner case isn't handled by | |
1323 | infrun.c when proceeding with a signal, for consistency, neither | |
1324 | do we handle it here (or elsewhere in the file we check for | |
1325 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1326 | this is really a corner case. */ | |
1327 | ||
1328 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
a493e3e2 | 1329 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1330 | else if (lp->status) |
2ea28649 | 1331 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
fbea99ea | 1332 | else if (target_is_non_stop_p () && !is_executing (lp->ptid)) |
ca2163eb PA |
1333 | { |
1334 | struct thread_info *tp = find_thread_ptid (lp->ptid); | |
e0881a8e | 1335 | |
72b049d3 PA |
1336 | if (tp->suspend.waitstatus_pending_p) |
1337 | signo = tp->suspend.waitstatus.value.sig; | |
1338 | else | |
1339 | signo = tp->suspend.stop_signal; | |
ca2163eb | 1340 | } |
fbea99ea | 1341 | else if (!target_is_non_stop_p ()) |
a0ef4274 | 1342 | { |
ca2163eb PA |
1343 | struct target_waitstatus last; |
1344 | ptid_t last_ptid; | |
4c28f408 | 1345 | |
ca2163eb | 1346 | get_last_target_status (&last_ptid, &last); |
4c28f408 | 1347 | |
dfd4cc63 | 1348 | if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid)) |
ca2163eb | 1349 | { |
e09875d4 | 1350 | struct thread_info *tp = find_thread_ptid (lp->ptid); |
e0881a8e | 1351 | |
16c381f0 | 1352 | signo = tp->suspend.stop_signal; |
4c28f408 | 1353 | } |
ca2163eb | 1354 | } |
4c28f408 | 1355 | |
a493e3e2 | 1356 | if (signo == GDB_SIGNAL_0) |
ca2163eb PA |
1357 | { |
1358 | if (debug_linux_nat) | |
1359 | fprintf_unfiltered (gdb_stdlog, | |
1360 | "GPT: lwp %s has no pending signal\n", | |
1361 | target_pid_to_str (lp->ptid)); | |
1362 | } | |
1363 | else if (!signal_pass_state (signo)) | |
1364 | { | |
1365 | if (debug_linux_nat) | |
3e43a32a MS |
1366 | fprintf_unfiltered (gdb_stdlog, |
1367 | "GPT: lwp %s had signal %s, " | |
1368 | "but it is in no pass state\n", | |
ca2163eb | 1369 | target_pid_to_str (lp->ptid), |
2ea28649 | 1370 | gdb_signal_to_string (signo)); |
a0ef4274 | 1371 | } |
a0ef4274 | 1372 | else |
4c28f408 | 1373 | { |
ca2163eb PA |
1374 | if (debug_linux_nat) |
1375 | fprintf_unfiltered (gdb_stdlog, | |
1376 | "GPT: lwp %s has pending signal %s\n", | |
1377 | target_pid_to_str (lp->ptid), | |
2ea28649 | 1378 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1379 | |
1380 | return gdb_signal_to_host (signo); | |
4c28f408 | 1381 | } |
a0ef4274 DJ |
1382 | |
1383 | return 0; | |
1384 | } | |
1385 | ||
ced2dffb PA |
1386 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1387 | signal number that should be passed to the LWP when detaching. | |
1388 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1389 | ||
1390 | static void | |
1391 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1392 | { |
ced2dffb PA |
1393 | int lwpid = ptid_get_lwp (lp->ptid); |
1394 | int signo; | |
1395 | ||
d6b0e80f AC |
1396 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1397 | ||
1398 | if (debug_linux_nat && lp->status) | |
1399 | fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", | |
1400 | strsignal (WSTOPSIG (lp->status)), | |
1401 | target_pid_to_str (lp->ptid)); | |
1402 | ||
a0ef4274 DJ |
1403 | /* If there is a pending SIGSTOP, get rid of it. */ |
1404 | if (lp->signalled) | |
d6b0e80f | 1405 | { |
d6b0e80f AC |
1406 | if (debug_linux_nat) |
1407 | fprintf_unfiltered (gdb_stdlog, | |
a0ef4274 DJ |
1408 | "DC: Sending SIGCONT to %s\n", |
1409 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 1410 | |
ced2dffb | 1411 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1412 | lp->signalled = 0; |
d6b0e80f AC |
1413 | } |
1414 | ||
ced2dffb | 1415 | if (signo_p == NULL) |
d6b0e80f | 1416 | { |
a0ef4274 | 1417 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1418 | signo = get_detach_signal (lp); |
1419 | } | |
1420 | else | |
1421 | signo = *signo_p; | |
a0ef4274 | 1422 | |
ced2dffb PA |
1423 | /* Preparing to resume may try to write registers, and fail if the |
1424 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1425 | it below, when detach fails with ESRCH. */ | |
1426 | TRY | |
1427 | { | |
7b50312a PA |
1428 | if (linux_nat_prepare_to_resume != NULL) |
1429 | linux_nat_prepare_to_resume (lp); | |
ced2dffb PA |
1430 | } |
1431 | CATCH (ex, RETURN_MASK_ERROR) | |
1432 | { | |
1433 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
1434 | throw_exception (ex); | |
1435 | } | |
1436 | END_CATCH | |
d6b0e80f | 1437 | |
ced2dffb PA |
1438 | if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0) |
1439 | { | |
1440 | int save_errno = errno; | |
1441 | ||
1442 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1443 | zombie. This can happen if one of the already-detached | |
1444 | threads exits the whole thread group. In that case we're | |
1445 | still attached, and must reap the lwp. */ | |
1446 | if (save_errno == ESRCH) | |
1447 | { | |
1448 | int ret, status; | |
d6b0e80f | 1449 | |
ced2dffb PA |
1450 | ret = my_waitpid (lwpid, &status, __WALL); |
1451 | if (ret == -1) | |
1452 | { | |
1453 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1454 | lwpid, strerror (errno)); | |
1455 | } | |
1456 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1457 | { | |
1458 | warning (_("Reaping LWP %d while detaching " | |
1459 | "returned unexpected status 0x%x"), | |
1460 | lwpid, status); | |
1461 | } | |
1462 | } | |
1463 | else | |
1464 | { | |
1465 | error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), | |
1466 | safe_strerror (save_errno)); | |
1467 | } | |
d6b0e80f | 1468 | } |
ced2dffb PA |
1469 | else if (debug_linux_nat) |
1470 | { | |
1471 | fprintf_unfiltered (gdb_stdlog, | |
1472 | "PTRACE_DETACH (%s, %s, 0) (OK)\n", | |
1473 | target_pid_to_str (lp->ptid), | |
1474 | strsignal (signo)); | |
1475 | } | |
1476 | ||
1477 | delete_lwp (lp->ptid); | |
1478 | } | |
d6b0e80f | 1479 | |
ced2dffb PA |
1480 | static int |
1481 | detach_callback (struct lwp_info *lp, void *data) | |
1482 | { | |
1483 | /* We don't actually detach from the thread group leader just yet. | |
1484 | If the thread group exits, we must reap the zombie clone lwps | |
1485 | before we're able to reap the leader. */ | |
1486 | if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid)) | |
1487 | detach_one_lwp (lp, NULL); | |
d6b0e80f AC |
1488 | return 0; |
1489 | } | |
1490 | ||
f6ac5f3d PA |
1491 | void |
1492 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1493 | { |
d90e17a7 | 1494 | struct lwp_info *main_lwp; |
bc09b0c1 | 1495 | int pid = inf->pid; |
a0ef4274 | 1496 | |
ae5e0686 MK |
1497 | /* Don't unregister from the event loop, as there may be other |
1498 | inferiors running. */ | |
b84876c2 | 1499 | |
4c28f408 PA |
1500 | /* Stop all threads before detaching. ptrace requires that the |
1501 | thread is stopped to sucessfully detach. */ | |
d90e17a7 | 1502 | iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
4c28f408 PA |
1503 | /* ... and wait until all of them have reported back that |
1504 | they're no longer running. */ | |
d90e17a7 | 1505 | iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
4c28f408 | 1506 | |
d90e17a7 | 1507 | iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
d6b0e80f AC |
1508 | |
1509 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1510 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 PA |
1511 | |
1512 | main_lwp = find_lwp_pid (pid_to_ptid (pid)); | |
d6b0e80f | 1513 | |
7a7d3353 PA |
1514 | if (forks_exist_p ()) |
1515 | { | |
1516 | /* Multi-fork case. The current inferior_ptid is being detached | |
1517 | from, but there are other viable forks to debug. Detach from | |
1518 | the current fork, and context-switch to the first | |
1519 | available. */ | |
6bd6f3b6 | 1520 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1521 | } |
1522 | else | |
ced2dffb | 1523 | { |
ced2dffb PA |
1524 | target_announce_detach (from_tty); |
1525 | ||
6bd6f3b6 SM |
1526 | /* Pass on any pending signal for the last LWP. */ |
1527 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1528 | |
1529 | detach_one_lwp (main_lwp, &signo); | |
1530 | ||
f6ac5f3d | 1531 | detach_success (inf); |
ced2dffb | 1532 | } |
d6b0e80f AC |
1533 | } |
1534 | ||
8a99810d PA |
1535 | /* Resume execution of the inferior process. If STEP is nonzero, |
1536 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1537 | ||
1538 | static void | |
23f238d3 PA |
1539 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1540 | enum gdb_signal signo) | |
8a99810d | 1541 | { |
8a99810d | 1542 | lp->step = step; |
9c02b525 PA |
1543 | |
1544 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1545 | We only presently need that if the LWP is stepped though (to | |
1546 | handle the case of stepping a breakpoint instruction). */ | |
1547 | if (step) | |
1548 | { | |
1549 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
1550 | ||
1551 | lp->stop_pc = regcache_read_pc (regcache); | |
1552 | } | |
1553 | else | |
1554 | lp->stop_pc = 0; | |
1555 | ||
8a99810d PA |
1556 | if (linux_nat_prepare_to_resume != NULL) |
1557 | linux_nat_prepare_to_resume (lp); | |
f6ac5f3d | 1558 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1559 | |
1560 | /* Successfully resumed. Clear state that no longer makes sense, | |
1561 | and mark the LWP as running. Must not do this before resuming | |
1562 | otherwise if that fails other code will be confused. E.g., we'd | |
1563 | later try to stop the LWP and hang forever waiting for a stop | |
1564 | status. Note that we must not throw after this is cleared, | |
1565 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1566 | lp->stopped = 0; |
1ad3de98 | 1567 | lp->core = -1; |
23f238d3 | 1568 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
8a99810d PA |
1569 | registers_changed_ptid (lp->ptid); |
1570 | } | |
1571 | ||
23f238d3 PA |
1572 | /* Called when we try to resume a stopped LWP and that errors out. If |
1573 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1574 | or about to become), discard the error, clear any pending status | |
1575 | the LWP may have, and return true (we'll collect the exit status | |
1576 | soon enough). Otherwise, return false. */ | |
1577 | ||
1578 | static int | |
1579 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1580 | { | |
1581 | /* If we get an error after resuming the LWP successfully, we'd | |
1582 | confuse !T state for the LWP being gone. */ | |
1583 | gdb_assert (lp->stopped); | |
1584 | ||
1585 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1586 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1587 | yet fully dead", but already refusing ptrace requests. In that | |
1588 | case the tracee has 'R (Running)' state for a little bit | |
1589 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1590 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1591 | other than ptrace-stopped. */ | |
1592 | ||
1593 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
1594 | if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0) | |
1595 | { | |
1596 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1597 | lp->status = 0; | |
1598 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
1599 | return 1; | |
1600 | } | |
1601 | return 0; | |
1602 | } | |
1603 | ||
1604 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1605 | disappears while we try to resume it. */ | |
1606 | ||
1607 | static void | |
1608 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1609 | { | |
1610 | TRY | |
1611 | { | |
1612 | linux_resume_one_lwp_throw (lp, step, signo); | |
1613 | } | |
1614 | CATCH (ex, RETURN_MASK_ERROR) | |
1615 | { | |
1616 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
1617 | throw_exception (ex); | |
1618 | } | |
1619 | END_CATCH | |
1620 | } | |
1621 | ||
d6b0e80f AC |
1622 | /* Resume LP. */ |
1623 | ||
25289eb2 | 1624 | static void |
e5ef252a | 1625 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1626 | { |
25289eb2 | 1627 | if (lp->stopped) |
6c95b8df | 1628 | { |
c9657e70 | 1629 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
25289eb2 PA |
1630 | |
1631 | if (inf->vfork_child != NULL) | |
1632 | { | |
1633 | if (debug_linux_nat) | |
1634 | fprintf_unfiltered (gdb_stdlog, | |
1635 | "RC: Not resuming %s (vfork parent)\n", | |
1636 | target_pid_to_str (lp->ptid)); | |
1637 | } | |
8a99810d | 1638 | else if (!lwp_status_pending_p (lp)) |
25289eb2 PA |
1639 | { |
1640 | if (debug_linux_nat) | |
1641 | fprintf_unfiltered (gdb_stdlog, | |
e5ef252a PA |
1642 | "RC: Resuming sibling %s, %s, %s\n", |
1643 | target_pid_to_str (lp->ptid), | |
1644 | (signo != GDB_SIGNAL_0 | |
1645 | ? strsignal (gdb_signal_to_host (signo)) | |
1646 | : "0"), | |
1647 | step ? "step" : "resume"); | |
25289eb2 | 1648 | |
8a99810d | 1649 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1650 | } |
1651 | else | |
1652 | { | |
1653 | if (debug_linux_nat) | |
1654 | fprintf_unfiltered (gdb_stdlog, | |
1655 | "RC: Not resuming sibling %s (has pending)\n", | |
1656 | target_pid_to_str (lp->ptid)); | |
1657 | } | |
6c95b8df | 1658 | } |
25289eb2 | 1659 | else |
d6b0e80f | 1660 | { |
d90e17a7 PA |
1661 | if (debug_linux_nat) |
1662 | fprintf_unfiltered (gdb_stdlog, | |
25289eb2 | 1663 | "RC: Not resuming sibling %s (not stopped)\n", |
d6b0e80f | 1664 | target_pid_to_str (lp->ptid)); |
d6b0e80f | 1665 | } |
25289eb2 | 1666 | } |
d6b0e80f | 1667 | |
8817a6f2 PA |
1668 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1669 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1670 | |
25289eb2 | 1671 | static int |
8817a6f2 | 1672 | linux_nat_resume_callback (struct lwp_info *lp, void *except) |
25289eb2 | 1673 | { |
e5ef252a PA |
1674 | enum gdb_signal signo = GDB_SIGNAL_0; |
1675 | ||
8817a6f2 PA |
1676 | if (lp == except) |
1677 | return 0; | |
1678 | ||
e5ef252a PA |
1679 | if (lp->stopped) |
1680 | { | |
1681 | struct thread_info *thread; | |
1682 | ||
1683 | thread = find_thread_ptid (lp->ptid); | |
1684 | if (thread != NULL) | |
1685 | { | |
70509625 | 1686 | signo = thread->suspend.stop_signal; |
e5ef252a PA |
1687 | thread->suspend.stop_signal = GDB_SIGNAL_0; |
1688 | } | |
1689 | } | |
1690 | ||
1691 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1692 | return 0; |
1693 | } | |
1694 | ||
1695 | static int | |
1696 | resume_clear_callback (struct lwp_info *lp, void *data) | |
1697 | { | |
1698 | lp->resumed = 0; | |
25289eb2 | 1699 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1700 | return 0; |
1701 | } | |
1702 | ||
1703 | static int | |
1704 | resume_set_callback (struct lwp_info *lp, void *data) | |
1705 | { | |
1706 | lp->resumed = 1; | |
25289eb2 | 1707 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1708 | return 0; |
1709 | } | |
1710 | ||
f6ac5f3d PA |
1711 | void |
1712 | linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) | |
d6b0e80f AC |
1713 | { |
1714 | struct lwp_info *lp; | |
d90e17a7 | 1715 | int resume_many; |
d6b0e80f | 1716 | |
76f50ad1 DJ |
1717 | if (debug_linux_nat) |
1718 | fprintf_unfiltered (gdb_stdlog, | |
1719 | "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", | |
1720 | step ? "step" : "resume", | |
1721 | target_pid_to_str (ptid), | |
a493e3e2 | 1722 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1723 | ? strsignal (gdb_signal_to_host (signo)) : "0"), |
76f50ad1 DJ |
1724 | target_pid_to_str (inferior_ptid)); |
1725 | ||
d6b0e80f | 1726 | /* A specific PTID means `step only this process id'. */ |
d90e17a7 PA |
1727 | resume_many = (ptid_equal (minus_one_ptid, ptid) |
1728 | || ptid_is_pid (ptid)); | |
4c28f408 | 1729 | |
e3e9f5a2 PA |
1730 | /* Mark the lwps we're resuming as resumed. */ |
1731 | iterate_over_lwps (ptid, resume_set_callback, NULL); | |
d6b0e80f | 1732 | |
d90e17a7 PA |
1733 | /* See if it's the current inferior that should be handled |
1734 | specially. */ | |
1735 | if (resume_many) | |
1736 | lp = find_lwp_pid (inferior_ptid); | |
1737 | else | |
1738 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1739 | gdb_assert (lp != NULL); |
d6b0e80f | 1740 | |
9f0bdab8 | 1741 | /* Remember if we're stepping. */ |
25289eb2 | 1742 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1743 | |
9f0bdab8 DJ |
1744 | /* If we have a pending wait status for this thread, there is no |
1745 | point in resuming the process. But first make sure that | |
1746 | linux_nat_wait won't preemptively handle the event - we | |
1747 | should never take this short-circuit if we are going to | |
1748 | leave LP running, since we have skipped resuming all the | |
1749 | other threads. This bit of code needs to be synchronized | |
1750 | with linux_nat_wait. */ | |
76f50ad1 | 1751 | |
9f0bdab8 DJ |
1752 | if (lp->status && WIFSTOPPED (lp->status)) |
1753 | { | |
2455069d UW |
1754 | if (!lp->step |
1755 | && WSTOPSIG (lp->status) | |
1756 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1757 | { |
9f0bdab8 DJ |
1758 | if (debug_linux_nat) |
1759 | fprintf_unfiltered (gdb_stdlog, | |
1760 | "LLR: Not short circuiting for ignored " | |
1761 | "status 0x%x\n", lp->status); | |
1762 | ||
d6b0e80f AC |
1763 | /* FIXME: What should we do if we are supposed to continue |
1764 | this thread with a signal? */ | |
a493e3e2 | 1765 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1766 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1767 | lp->status = 0; |
1768 | } | |
1769 | } | |
76f50ad1 | 1770 | |
8a99810d | 1771 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1772 | { |
1773 | /* FIXME: What should we do if we are supposed to continue | |
1774 | this thread with a signal? */ | |
a493e3e2 | 1775 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1776 | |
9f0bdab8 DJ |
1777 | if (debug_linux_nat) |
1778 | fprintf_unfiltered (gdb_stdlog, | |
1779 | "LLR: Short circuiting for status 0x%x\n", | |
1780 | lp->status); | |
d6b0e80f | 1781 | |
7feb7d06 PA |
1782 | if (target_can_async_p ()) |
1783 | { | |
6a3753b3 | 1784 | target_async (1); |
7feb7d06 PA |
1785 | /* Tell the event loop we have something to process. */ |
1786 | async_file_mark (); | |
1787 | } | |
9f0bdab8 | 1788 | return; |
d6b0e80f AC |
1789 | } |
1790 | ||
d90e17a7 | 1791 | if (resume_many) |
8817a6f2 | 1792 | iterate_over_lwps (ptid, linux_nat_resume_callback, lp); |
d90e17a7 | 1793 | |
d6b0e80f AC |
1794 | if (debug_linux_nat) |
1795 | fprintf_unfiltered (gdb_stdlog, | |
1796 | "LLR: %s %s, %s (resume event thread)\n", | |
1797 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2bf6fb9d | 1798 | target_pid_to_str (lp->ptid), |
a493e3e2 | 1799 | (signo != GDB_SIGNAL_0 |
2ea28649 | 1800 | ? strsignal (gdb_signal_to_host (signo)) : "0")); |
b84876c2 | 1801 | |
2bf6fb9d PA |
1802 | linux_resume_one_lwp (lp, step, signo); |
1803 | ||
b84876c2 | 1804 | if (target_can_async_p ()) |
6a3753b3 | 1805 | target_async (1); |
d6b0e80f AC |
1806 | } |
1807 | ||
c5f62d5f | 1808 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1809 | |
1810 | static int | |
1811 | kill_lwp (int lwpid, int signo) | |
1812 | { | |
4a6ed09b | 1813 | int ret; |
d6b0e80f | 1814 | |
4a6ed09b PA |
1815 | errno = 0; |
1816 | ret = syscall (__NR_tkill, lwpid, signo); | |
1817 | if (errno == ENOSYS) | |
1818 | { | |
1819 | /* If tkill fails, then we are not using nptl threads, a | |
1820 | configuration we no longer support. */ | |
1821 | perror_with_name (("tkill")); | |
1822 | } | |
1823 | return ret; | |
d6b0e80f AC |
1824 | } |
1825 | ||
ca2163eb PA |
1826 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1827 | event, check if the core is interested in it: if not, ignore the | |
1828 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1829 | syscall entry/exit status, since the ptrace event itself doesn't | |
1830 | indicate it, and report the trap to higher layers. */ | |
1831 | ||
1832 | static int | |
1833 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1834 | { | |
1835 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1836 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
1837 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); | |
1838 | ||
1839 | if (stopping) | |
1840 | { | |
1841 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1842 | makes it so that the LWP reports an immediate syscall return, | |
1843 | followed by the SIGSTOP. Skip seeing that "return" using | |
1844 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1845 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1846 | entry event. If we didn't do this (and returned 0), we'd | |
1847 | leave a syscall entry pending, and our caller, by using | |
1848 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1849 | itself. Later, when the user re-resumes this LWP, we'd see | |
1850 | another syscall entry event and we'd mistake it for a return. | |
1851 | ||
1852 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1853 | (leaving immediately with LWP->signalled set, without issuing | |
1854 | a PTRACE_CONT), it would still be problematic to leave this | |
1855 | syscall enter pending, as later when the thread is resumed, | |
1856 | it would then see the same syscall exit mentioned above, | |
1857 | followed by the delayed SIGSTOP, while the syscall didn't | |
1858 | actually get to execute. It seems it would be even more | |
1859 | confusing to the user. */ | |
1860 | ||
1861 | if (debug_linux_nat) | |
1862 | fprintf_unfiltered (gdb_stdlog, | |
1863 | "LHST: ignoring syscall %d " | |
1864 | "for LWP %ld (stopping threads), " | |
1865 | "resuming with PTRACE_CONT for SIGSTOP\n", | |
1866 | syscall_number, | |
dfd4cc63 | 1867 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1868 | |
1869 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
dfd4cc63 | 1870 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 1871 | lp->stopped = 0; |
ca2163eb PA |
1872 | return 1; |
1873 | } | |
1874 | ||
bfd09d20 JS |
1875 | /* Always update the entry/return state, even if this particular |
1876 | syscall isn't interesting to the core now. In async mode, | |
1877 | the user could install a new catchpoint for this syscall | |
1878 | between syscall enter/return, and we'll need to know to | |
1879 | report a syscall return if that happens. */ | |
1880 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1881 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1882 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1883 | ||
ca2163eb PA |
1884 | if (catch_syscall_enabled ()) |
1885 | { | |
ca2163eb PA |
1886 | if (catching_syscall_number (syscall_number)) |
1887 | { | |
1888 | /* Alright, an event to report. */ | |
1889 | ourstatus->kind = lp->syscall_state; | |
1890 | ourstatus->value.syscall_number = syscall_number; | |
1891 | ||
1892 | if (debug_linux_nat) | |
1893 | fprintf_unfiltered (gdb_stdlog, | |
1894 | "LHST: stopping for %s of syscall %d" | |
1895 | " for LWP %ld\n", | |
3e43a32a MS |
1896 | lp->syscall_state |
1897 | == TARGET_WAITKIND_SYSCALL_ENTRY | |
ca2163eb PA |
1898 | ? "entry" : "return", |
1899 | syscall_number, | |
dfd4cc63 | 1900 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1901 | return 0; |
1902 | } | |
1903 | ||
1904 | if (debug_linux_nat) | |
1905 | fprintf_unfiltered (gdb_stdlog, | |
1906 | "LHST: ignoring %s of syscall %d " | |
1907 | "for LWP %ld\n", | |
1908 | lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1909 | ? "entry" : "return", | |
1910 | syscall_number, | |
dfd4cc63 | 1911 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1912 | } |
1913 | else | |
1914 | { | |
1915 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1916 | before on this LWP, it could happen that the user removes all | |
1917 | syscall catchpoints before we get to process this event. | |
1918 | There are two noteworthy issues here: | |
1919 | ||
1920 | - When stopped at a syscall entry event, resuming with | |
1921 | PT_STEP still resumes executing the syscall and reports a | |
1922 | syscall return. | |
1923 | ||
1924 | - Only PT_SYSCALL catches syscall enters. If we last | |
1925 | single-stepped this thread, then this event can't be a | |
1926 | syscall enter. If we last single-stepped this thread, this | |
1927 | has to be a syscall exit. | |
1928 | ||
1929 | The points above mean that the next resume, be it PT_STEP or | |
1930 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
1931 | if (debug_linux_nat) | |
1932 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
1933 | "LHST: caught syscall event " |
1934 | "with no syscall catchpoints." | |
ca2163eb PA |
1935 | " %d for LWP %ld, ignoring\n", |
1936 | syscall_number, | |
dfd4cc63 | 1937 | ptid_get_lwp (lp->ptid)); |
ca2163eb PA |
1938 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1939 | } | |
1940 | ||
1941 | /* The core isn't interested in this event. For efficiency, avoid | |
1942 | stopping all threads only to have the core resume them all again. | |
1943 | Since we're not stopping threads, if we're still syscall tracing | |
1944 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1945 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1946 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1947 | ||
8a99810d | 1948 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1949 | return 1; |
1950 | } | |
1951 | ||
3d799a95 DJ |
1952 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1953 | event, we need to add the new LWP to our list (and not report the | |
1954 | trap to higher layers). This function returns non-zero if the | |
1955 | event should be ignored and we should wait again. If STOPPING is | |
1956 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1957 | |
1958 | static int | |
4dd63d48 | 1959 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1960 | { |
dfd4cc63 | 1961 | int pid = ptid_get_lwp (lp->ptid); |
3d799a95 | 1962 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1963 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1964 | |
bfd09d20 JS |
1965 | /* All extended events we currently use are mid-syscall. Only |
1966 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1967 | you have to be using PTRACE_SEIZE to get that. */ | |
1968 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1969 | ||
3d799a95 DJ |
1970 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1971 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1972 | { |
3d799a95 DJ |
1973 | unsigned long new_pid; |
1974 | int ret; | |
1975 | ||
1976 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1977 | |
3d799a95 DJ |
1978 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1979 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1980 | { | |
1981 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1982 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1983 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1984 | if (ret == -1) |
1985 | perror_with_name (_("waiting for new child")); | |
1986 | else if (ret != new_pid) | |
1987 | internal_error (__FILE__, __LINE__, | |
1988 | _("wait returned unexpected PID %d"), ret); | |
1989 | else if (!WIFSTOPPED (status)) | |
1990 | internal_error (__FILE__, __LINE__, | |
1991 | _("wait returned unexpected status 0x%x"), status); | |
1992 | } | |
1993 | ||
3a3e9ee3 | 1994 | ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
3d799a95 | 1995 | |
26cb8b7c PA |
1996 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1997 | { | |
1998 | /* The arch-specific native code may need to know about new | |
1999 | forks even if those end up never mapped to an | |
2000 | inferior. */ | |
2001 | if (linux_nat_new_fork != NULL) | |
2002 | linux_nat_new_fork (lp, new_pid); | |
2003 | } | |
2004 | ||
2277426b | 2005 | if (event == PTRACE_EVENT_FORK |
dfd4cc63 | 2006 | && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid))) |
2277426b | 2007 | { |
2277426b PA |
2008 | /* Handle checkpointing by linux-fork.c here as a special |
2009 | case. We don't want the follow-fork-mode or 'catch fork' | |
2010 | to interfere with this. */ | |
2011 | ||
2012 | /* This won't actually modify the breakpoint list, but will | |
2013 | physically remove the breakpoints from the child. */ | |
d80ee84f | 2014 | detach_breakpoints (ptid_build (new_pid, new_pid, 0)); |
2277426b PA |
2015 | |
2016 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
2017 | if (!find_fork_pid (new_pid)) |
2018 | add_fork (new_pid); | |
2277426b PA |
2019 | |
2020 | /* Report as spurious, so that infrun doesn't want to follow | |
2021 | this fork. We're actually doing an infcall in | |
2022 | linux-fork.c. */ | |
2023 | ourstatus->kind = TARGET_WAITKIND_SPURIOUS; | |
2277426b PA |
2024 | |
2025 | /* Report the stop to the core. */ | |
2026 | return 0; | |
2027 | } | |
2028 | ||
3d799a95 DJ |
2029 | if (event == PTRACE_EVENT_FORK) |
2030 | ourstatus->kind = TARGET_WAITKIND_FORKED; | |
2031 | else if (event == PTRACE_EVENT_VFORK) | |
2032 | ourstatus->kind = TARGET_WAITKIND_VFORKED; | |
4dd63d48 | 2033 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 2034 | { |
78768c4a JK |
2035 | struct lwp_info *new_lp; |
2036 | ||
3d799a95 | 2037 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
78768c4a | 2038 | |
3c4d7e12 PA |
2039 | if (debug_linux_nat) |
2040 | fprintf_unfiltered (gdb_stdlog, | |
2041 | "LHEW: Got clone event " | |
2042 | "from LWP %d, new child is LWP %ld\n", | |
2043 | pid, new_pid); | |
2044 | ||
dfd4cc63 | 2045 | new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); |
4c28f408 | 2046 | new_lp->stopped = 1; |
4dd63d48 | 2047 | new_lp->resumed = 1; |
d6b0e80f | 2048 | |
2db9a427 PA |
2049 | /* If the thread_db layer is active, let it record the user |
2050 | level thread id and status, and add the thread to GDB's | |
2051 | list. */ | |
2052 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 2053 | { |
2db9a427 PA |
2054 | /* The process is not using thread_db. Add the LWP to |
2055 | GDB's list. */ | |
2056 | target_post_attach (ptid_get_lwp (new_lp->ptid)); | |
2057 | add_thread (new_lp->ptid); | |
2058 | } | |
4c28f408 | 2059 | |
2ee52aa4 | 2060 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
2061 | internal to this module, from the perspective of infrun |
2062 | and the user/frontend, this new thread is running until | |
2063 | it next reports a stop. */ | |
2ee52aa4 | 2064 | set_running (new_lp->ptid, 1); |
4dd63d48 | 2065 | set_executing (new_lp->ptid, 1); |
4c28f408 | 2066 | |
4dd63d48 | 2067 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 2068 | { |
4dd63d48 PA |
2069 | /* This can happen if someone starts sending signals to |
2070 | the new thread before it gets a chance to run, which | |
2071 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
2072 | This is an unlikely case, and harder to handle for | |
2073 | fork / vfork than for clone, so we do not try - but | |
2074 | we handle it for clone events here. */ | |
2075 | ||
2076 | new_lp->signalled = 1; | |
2077 | ||
79395f92 PA |
2078 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
2079 | gdb_assert (new_lp->status == 0); | |
2080 | ||
2081 | /* Save the wait status to report later. */ | |
2082 | if (debug_linux_nat) | |
2083 | fprintf_unfiltered (gdb_stdlog, | |
2084 | "LHEW: waitpid of new LWP %ld, " | |
2085 | "saving status %s\n", | |
dfd4cc63 | 2086 | (long) ptid_get_lwp (new_lp->ptid), |
79395f92 PA |
2087 | status_to_str (status)); |
2088 | new_lp->status = status; | |
2089 | } | |
aa01bd36 PA |
2090 | else if (report_thread_events) |
2091 | { | |
2092 | new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED; | |
2093 | new_lp->status = status; | |
2094 | } | |
79395f92 | 2095 | |
3d799a95 DJ |
2096 | return 1; |
2097 | } | |
2098 | ||
2099 | return 0; | |
d6b0e80f AC |
2100 | } |
2101 | ||
3d799a95 DJ |
2102 | if (event == PTRACE_EVENT_EXEC) |
2103 | { | |
a75724bc PA |
2104 | if (debug_linux_nat) |
2105 | fprintf_unfiltered (gdb_stdlog, | |
2106 | "LHEW: Got exec event from LWP %ld\n", | |
dfd4cc63 | 2107 | ptid_get_lwp (lp->ptid)); |
a75724bc | 2108 | |
3d799a95 DJ |
2109 | ourstatus->kind = TARGET_WAITKIND_EXECD; |
2110 | ourstatus->value.execd_pathname | |
f6ac5f3d | 2111 | = xstrdup (linux_proc_pid_to_exec_file (pid)); |
3d799a95 | 2112 | |
8af756ef PA |
2113 | /* The thread that execed must have been resumed, but, when a |
2114 | thread execs, it changes its tid to the tgid, and the old | |
2115 | tgid thread might have not been resumed. */ | |
2116 | lp->resumed = 1; | |
6c95b8df PA |
2117 | return 0; |
2118 | } | |
2119 | ||
2120 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2121 | { | |
2122 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2123 | { |
6c95b8df | 2124 | if (debug_linux_nat) |
3e43a32a MS |
2125 | fprintf_unfiltered (gdb_stdlog, |
2126 | "LHEW: Got expected PTRACE_EVENT_" | |
2127 | "VFORK_DONE from LWP %ld: stopping\n", | |
dfd4cc63 | 2128 | ptid_get_lwp (lp->ptid)); |
3d799a95 | 2129 | |
6c95b8df PA |
2130 | ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
2131 | return 0; | |
3d799a95 DJ |
2132 | } |
2133 | ||
6c95b8df | 2134 | if (debug_linux_nat) |
3e43a32a MS |
2135 | fprintf_unfiltered (gdb_stdlog, |
2136 | "LHEW: Got PTRACE_EVENT_VFORK_DONE " | |
20ba1ce6 | 2137 | "from LWP %ld: ignoring\n", |
dfd4cc63 | 2138 | ptid_get_lwp (lp->ptid)); |
6c95b8df | 2139 | return 1; |
3d799a95 DJ |
2140 | } |
2141 | ||
2142 | internal_error (__FILE__, __LINE__, | |
2143 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2144 | } |
2145 | ||
9c3a5d93 PA |
2146 | /* Suspend waiting for a signal. We're mostly interested in |
2147 | SIGCHLD/SIGINT. */ | |
2148 | ||
2149 | static void | |
2150 | wait_for_signal () | |
2151 | { | |
2152 | if (debug_linux_nat) | |
2153 | fprintf_unfiltered (gdb_stdlog, "linux-nat: about to sigsuspend\n"); | |
2154 | sigsuspend (&suspend_mask); | |
2155 | ||
2156 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2157 | and we're debugging a process that is running on a separate | |
2158 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2159 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2160 | inferior directly.) We must do this here because functions that | |
2161 | need to block waiting for a signal loop forever until there's an | |
2162 | event to report before returning back to the event loop. */ | |
2163 | if (!target_terminal::is_ours ()) | |
2164 | { | |
2165 | if (check_quit_flag ()) | |
2166 | target_pass_ctrlc (); | |
2167 | } | |
2168 | } | |
2169 | ||
d6b0e80f AC |
2170 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2171 | exited. */ | |
2172 | ||
2173 | static int | |
2174 | wait_lwp (struct lwp_info *lp) | |
2175 | { | |
2176 | pid_t pid; | |
432b4d03 | 2177 | int status = 0; |
d6b0e80f | 2178 | int thread_dead = 0; |
432b4d03 | 2179 | sigset_t prev_mask; |
d6b0e80f AC |
2180 | |
2181 | gdb_assert (!lp->stopped); | |
2182 | gdb_assert (lp->status == 0); | |
2183 | ||
432b4d03 JK |
2184 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2185 | block_child_signals (&prev_mask); | |
2186 | ||
2187 | for (;;) | |
d6b0e80f | 2188 | { |
4a6ed09b | 2189 | pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2190 | if (pid == -1 && errno == ECHILD) |
2191 | { | |
2192 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2193 | now because if this was a non-leader thread execing, we |
2194 | won't get an exit event. See comments on exec events at | |
2195 | the top of the file. */ | |
a9f4bb21 PA |
2196 | thread_dead = 1; |
2197 | if (debug_linux_nat) | |
2198 | fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", | |
2199 | target_pid_to_str (lp->ptid)); | |
2200 | } | |
432b4d03 JK |
2201 | if (pid != 0) |
2202 | break; | |
2203 | ||
2204 | /* Bugs 10970, 12702. | |
2205 | Thread group leader may have exited in which case we'll lock up in | |
2206 | waitpid if there are other threads, even if they are all zombies too. | |
2207 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2208 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2209 | for zombie and running processes. | |
432b4d03 JK |
2210 | |
2211 | As a workaround, check if we're waiting for the thread group leader and | |
2212 | if it's a zombie, and avoid calling waitpid if it is. | |
2213 | ||
2214 | This is racy, what if the tgl becomes a zombie right after we check? | |
2215 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2216 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2217 | |
dfd4cc63 LM |
2218 | if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid) |
2219 | && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid))) | |
d6b0e80f | 2220 | { |
d6b0e80f AC |
2221 | thread_dead = 1; |
2222 | if (debug_linux_nat) | |
432b4d03 JK |
2223 | fprintf_unfiltered (gdb_stdlog, |
2224 | "WL: Thread group leader %s vanished.\n", | |
d6b0e80f | 2225 | target_pid_to_str (lp->ptid)); |
432b4d03 | 2226 | break; |
d6b0e80f | 2227 | } |
432b4d03 JK |
2228 | |
2229 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2230 | get invoked despite our caller had them intentionally blocked by | |
2231 | block_child_signals. This is sensitive only to the loop of | |
2232 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2233 | again before it gets to sigsuspend so we can safely let the handlers | |
2234 | get executed here. */ | |
9c3a5d93 | 2235 | wait_for_signal (); |
432b4d03 JK |
2236 | } |
2237 | ||
2238 | restore_child_signals_mask (&prev_mask); | |
2239 | ||
d6b0e80f AC |
2240 | if (!thread_dead) |
2241 | { | |
dfd4cc63 | 2242 | gdb_assert (pid == ptid_get_lwp (lp->ptid)); |
d6b0e80f AC |
2243 | |
2244 | if (debug_linux_nat) | |
2245 | { | |
2246 | fprintf_unfiltered (gdb_stdlog, | |
2247 | "WL: waitpid %s received %s\n", | |
2248 | target_pid_to_str (lp->ptid), | |
2249 | status_to_str (status)); | |
2250 | } | |
d6b0e80f | 2251 | |
a9f4bb21 PA |
2252 | /* Check if the thread has exited. */ |
2253 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2254 | { | |
aa01bd36 PA |
2255 | if (report_thread_events |
2256 | || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)) | |
69dde7dc PA |
2257 | { |
2258 | if (debug_linux_nat) | |
aa01bd36 | 2259 | fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n", |
69dde7dc PA |
2260 | ptid_get_pid (lp->ptid)); |
2261 | ||
aa01bd36 | 2262 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2263 | process is gone. Store the status to report to the |
2264 | core. Store it in lp->waitstatus, because lp->status | |
2265 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
2266 | store_waitstatus (&lp->waitstatus, status); | |
2267 | return 0; | |
2268 | } | |
2269 | ||
a9f4bb21 PA |
2270 | thread_dead = 1; |
2271 | if (debug_linux_nat) | |
2272 | fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", | |
2273 | target_pid_to_str (lp->ptid)); | |
2274 | } | |
d6b0e80f AC |
2275 | } |
2276 | ||
2277 | if (thread_dead) | |
2278 | { | |
e26af52f | 2279 | exit_lwp (lp); |
d6b0e80f AC |
2280 | return 0; |
2281 | } | |
2282 | ||
2283 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2284 | lp->stopped = 1; |
d6b0e80f | 2285 | |
8784d563 PA |
2286 | if (lp->must_set_ptrace_flags) |
2287 | { | |
2288 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
de0d863e | 2289 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2290 | |
de0d863e | 2291 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options); |
8784d563 PA |
2292 | lp->must_set_ptrace_flags = 0; |
2293 | } | |
2294 | ||
ca2163eb PA |
2295 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2296 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2297 | { | |
2298 | /* No longer need the sysgood bit. The ptrace event ends up | |
2299 | recorded in lp->waitstatus if we care for it. We can carry | |
2300 | on handling the event like a regular SIGTRAP from here | |
2301 | on. */ | |
2302 | status = W_STOPCODE (SIGTRAP); | |
2303 | if (linux_handle_syscall_trap (lp, 1)) | |
2304 | return wait_lwp (lp); | |
2305 | } | |
bfd09d20 JS |
2306 | else |
2307 | { | |
2308 | /* Almost all other ptrace-stops are known to be outside of system | |
2309 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2310 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2311 | } | |
ca2163eb | 2312 | |
d6b0e80f | 2313 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2314 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2315 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f AC |
2316 | { |
2317 | if (debug_linux_nat) | |
2318 | fprintf_unfiltered (gdb_stdlog, | |
2319 | "WL: Handling extended status 0x%06x\n", | |
2320 | status); | |
4dd63d48 | 2321 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2322 | return 0; |
d6b0e80f AC |
2323 | } |
2324 | ||
2325 | return status; | |
2326 | } | |
2327 | ||
2328 | /* Send a SIGSTOP to LP. */ | |
2329 | ||
2330 | static int | |
2331 | stop_callback (struct lwp_info *lp, void *data) | |
2332 | { | |
2333 | if (!lp->stopped && !lp->signalled) | |
2334 | { | |
2335 | int ret; | |
2336 | ||
2337 | if (debug_linux_nat) | |
2338 | { | |
2339 | fprintf_unfiltered (gdb_stdlog, | |
2340 | "SC: kill %s **<SIGSTOP>**\n", | |
2341 | target_pid_to_str (lp->ptid)); | |
2342 | } | |
2343 | errno = 0; | |
dfd4cc63 | 2344 | ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP); |
d6b0e80f AC |
2345 | if (debug_linux_nat) |
2346 | { | |
2347 | fprintf_unfiltered (gdb_stdlog, | |
2348 | "SC: lwp kill %d %s\n", | |
2349 | ret, | |
2350 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
2351 | } | |
2352 | ||
2353 | lp->signalled = 1; | |
2354 | gdb_assert (lp->status == 0); | |
2355 | } | |
2356 | ||
2357 | return 0; | |
2358 | } | |
2359 | ||
7b50312a PA |
2360 | /* Request a stop on LWP. */ |
2361 | ||
2362 | void | |
2363 | linux_stop_lwp (struct lwp_info *lwp) | |
2364 | { | |
2365 | stop_callback (lwp, NULL); | |
2366 | } | |
2367 | ||
2db9a427 PA |
2368 | /* See linux-nat.h */ |
2369 | ||
2370 | void | |
2371 | linux_stop_and_wait_all_lwps (void) | |
2372 | { | |
2373 | /* Stop all LWP's ... */ | |
2374 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); | |
2375 | ||
2376 | /* ... and wait until all of them have reported back that | |
2377 | they're no longer running. */ | |
2378 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); | |
2379 | } | |
2380 | ||
2381 | /* See linux-nat.h */ | |
2382 | ||
2383 | void | |
2384 | linux_unstop_all_lwps (void) | |
2385 | { | |
2386 | iterate_over_lwps (minus_one_ptid, | |
2387 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
2388 | } | |
2389 | ||
57380f4e | 2390 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2391 | |
2392 | static int | |
57380f4e DJ |
2393 | linux_nat_has_pending_sigint (int pid) |
2394 | { | |
2395 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2396 | |
2397 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2398 | ||
2399 | if (sigismember (&pending, SIGINT) | |
2400 | && !sigismember (&ignored, SIGINT)) | |
2401 | return 1; | |
2402 | ||
2403 | return 0; | |
2404 | } | |
2405 | ||
2406 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2407 | ||
2408 | static int | |
2409 | set_ignore_sigint (struct lwp_info *lp, void *data) | |
d6b0e80f | 2410 | { |
57380f4e DJ |
2411 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2412 | flag to consume the next one. */ | |
2413 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2414 | && WSTOPSIG (lp->status) == SIGINT) | |
2415 | lp->status = 0; | |
2416 | else | |
2417 | lp->ignore_sigint = 1; | |
2418 | ||
2419 | return 0; | |
2420 | } | |
2421 | ||
2422 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2423 | This function is called after we know the LWP has stopped; if the LWP | |
2424 | stopped before the expected SIGINT was delivered, then it will never have | |
2425 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2426 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2427 | |
57380f4e DJ |
2428 | static void |
2429 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2430 | { | |
2431 | if (!lp->ignore_sigint) | |
2432 | return; | |
2433 | ||
dfd4cc63 | 2434 | if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid))) |
57380f4e DJ |
2435 | { |
2436 | if (debug_linux_nat) | |
2437 | fprintf_unfiltered (gdb_stdlog, | |
2438 | "MCIS: Clearing bogus flag for %s\n", | |
2439 | target_pid_to_str (lp->ptid)); | |
2440 | lp->ignore_sigint = 0; | |
2441 | } | |
2442 | } | |
2443 | ||
ebec9a0f PA |
2444 | /* Fetch the possible triggered data watchpoint info and store it in |
2445 | LP. | |
2446 | ||
2447 | On some archs, like x86, that use debug registers to set | |
2448 | watchpoints, it's possible that the way to know which watched | |
2449 | address trapped, is to check the register that is used to select | |
2450 | which address to watch. Problem is, between setting the watchpoint | |
2451 | and reading back which data address trapped, the user may change | |
2452 | the set of watchpoints, and, as a consequence, GDB changes the | |
2453 | debug registers in the inferior. To avoid reading back a stale | |
2454 | stopped-data-address when that happens, we cache in LP the fact | |
2455 | that a watchpoint trapped, and the corresponding data address, as | |
2456 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2457 | registers meanwhile, we have the cached data we can rely on. */ | |
2458 | ||
9c02b525 PA |
2459 | static int |
2460 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2461 | { |
2989a365 | 2462 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2463 | inferior_ptid = lp->ptid; |
2464 | ||
f6ac5f3d | 2465 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2466 | { |
15c66dd6 | 2467 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2468 | lp->stopped_data_address_p |
2469 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2470 | } |
2471 | ||
15c66dd6 | 2472 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2473 | } |
2474 | ||
9c02b525 | 2475 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2476 | |
57810aa7 | 2477 | bool |
f6ac5f3d | 2478 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2479 | { |
2480 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2481 | ||
2482 | gdb_assert (lp != NULL); | |
2483 | ||
15c66dd6 | 2484 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2485 | } |
2486 | ||
57810aa7 | 2487 | bool |
f6ac5f3d | 2488 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2489 | { |
2490 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2491 | ||
2492 | gdb_assert (lp != NULL); | |
2493 | ||
2494 | *addr_p = lp->stopped_data_address; | |
2495 | ||
2496 | return lp->stopped_data_address_p; | |
2497 | } | |
2498 | ||
26ab7092 JK |
2499 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2500 | ||
2501 | static int | |
2502 | sigtrap_is_event (int status) | |
2503 | { | |
2504 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2505 | } | |
2506 | ||
26ab7092 JK |
2507 | /* Set alternative SIGTRAP-like events recognizer. If |
2508 | breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be | |
2509 | applied. */ | |
2510 | ||
2511 | void | |
2512 | linux_nat_set_status_is_event (struct target_ops *t, | |
2513 | int (*status_is_event) (int status)) | |
2514 | { | |
2515 | linux_nat_status_is_event = status_is_event; | |
2516 | } | |
2517 | ||
57380f4e DJ |
2518 | /* Wait until LP is stopped. */ |
2519 | ||
2520 | static int | |
2521 | stop_wait_callback (struct lwp_info *lp, void *data) | |
2522 | { | |
c9657e70 | 2523 | struct inferior *inf = find_inferior_ptid (lp->ptid); |
6c95b8df PA |
2524 | |
2525 | /* If this is a vfork parent, bail out, it is not going to report | |
2526 | any SIGSTOP until the vfork is done with. */ | |
2527 | if (inf->vfork_child != NULL) | |
2528 | return 0; | |
2529 | ||
d6b0e80f AC |
2530 | if (!lp->stopped) |
2531 | { | |
2532 | int status; | |
2533 | ||
2534 | status = wait_lwp (lp); | |
2535 | if (status == 0) | |
2536 | return 0; | |
2537 | ||
57380f4e DJ |
2538 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2539 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2540 | { |
57380f4e | 2541 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2542 | |
2543 | errno = 0; | |
dfd4cc63 | 2544 | ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0); |
8817a6f2 | 2545 | lp->stopped = 0; |
d6b0e80f AC |
2546 | if (debug_linux_nat) |
2547 | fprintf_unfiltered (gdb_stdlog, | |
3e43a32a MS |
2548 | "PTRACE_CONT %s, 0, 0 (%s) " |
2549 | "(discarding SIGINT)\n", | |
d6b0e80f AC |
2550 | target_pid_to_str (lp->ptid), |
2551 | errno ? safe_strerror (errno) : "OK"); | |
2552 | ||
57380f4e | 2553 | return stop_wait_callback (lp, NULL); |
d6b0e80f AC |
2554 | } |
2555 | ||
57380f4e DJ |
2556 | maybe_clear_ignore_sigint (lp); |
2557 | ||
d6b0e80f AC |
2558 | if (WSTOPSIG (status) != SIGSTOP) |
2559 | { | |
e5ef252a | 2560 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2561 | |
e5ef252a PA |
2562 | if (debug_linux_nat) |
2563 | fprintf_unfiltered (gdb_stdlog, | |
2564 | "SWC: Pending event %s in %s\n", | |
2565 | status_to_str ((int) status), | |
2566 | target_pid_to_str (lp->ptid)); | |
2567 | ||
2568 | /* Save the sigtrap event. */ | |
2569 | lp->status = status; | |
e5ef252a | 2570 | gdb_assert (lp->signalled); |
e7ad2f14 | 2571 | save_stop_reason (lp); |
d6b0e80f AC |
2572 | } |
2573 | else | |
2574 | { | |
2575 | /* We caught the SIGSTOP that we intended to catch, so | |
2576 | there's no SIGSTOP pending. */ | |
e5ef252a PA |
2577 | |
2578 | if (debug_linux_nat) | |
2579 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2580 | "SWC: Expected SIGSTOP caught for %s.\n", |
e5ef252a PA |
2581 | target_pid_to_str (lp->ptid)); |
2582 | ||
e5ef252a PA |
2583 | /* Reset SIGNALLED only after the stop_wait_callback call |
2584 | above as it does gdb_assert on SIGNALLED. */ | |
d6b0e80f AC |
2585 | lp->signalled = 0; |
2586 | } | |
2587 | } | |
2588 | ||
2589 | return 0; | |
2590 | } | |
2591 | ||
9c02b525 PA |
2592 | /* Return non-zero if LP has a wait status pending. Discard the |
2593 | pending event and resume the LWP if the event that originally | |
2594 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2595 | |
2596 | static int | |
2597 | status_callback (struct lwp_info *lp, void *data) | |
2598 | { | |
2599 | /* Only report a pending wait status if we pretend that this has | |
2600 | indeed been resumed. */ | |
ca2163eb PA |
2601 | if (!lp->resumed) |
2602 | return 0; | |
2603 | ||
eb54c8bf PA |
2604 | if (!lwp_status_pending_p (lp)) |
2605 | return 0; | |
2606 | ||
15c66dd6 PA |
2607 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2608 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 PA |
2609 | { |
2610 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
9c02b525 PA |
2611 | CORE_ADDR pc; |
2612 | int discard = 0; | |
2613 | ||
9c02b525 PA |
2614 | pc = regcache_read_pc (regcache); |
2615 | ||
2616 | if (pc != lp->stop_pc) | |
2617 | { | |
2618 | if (debug_linux_nat) | |
2619 | fprintf_unfiltered (gdb_stdlog, | |
2620 | "SC: PC of %s changed. was=%s, now=%s\n", | |
2621 | target_pid_to_str (lp->ptid), | |
2622 | paddress (target_gdbarch (), lp->stop_pc), | |
2623 | paddress (target_gdbarch (), pc)); | |
2624 | discard = 1; | |
2625 | } | |
faf09f01 PA |
2626 | |
2627 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2628 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 PA |
2629 | { |
2630 | if (debug_linux_nat) | |
2631 | fprintf_unfiltered (gdb_stdlog, | |
2632 | "SC: previous breakpoint of %s, at %s gone\n", | |
2633 | target_pid_to_str (lp->ptid), | |
2634 | paddress (target_gdbarch (), lp->stop_pc)); | |
2635 | ||
2636 | discard = 1; | |
2637 | } | |
faf09f01 | 2638 | #endif |
9c02b525 PA |
2639 | |
2640 | if (discard) | |
2641 | { | |
2642 | if (debug_linux_nat) | |
2643 | fprintf_unfiltered (gdb_stdlog, | |
2644 | "SC: pending event of %s cancelled.\n", | |
2645 | target_pid_to_str (lp->ptid)); | |
2646 | ||
2647 | lp->status = 0; | |
2648 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2649 | return 0; | |
2650 | } | |
9c02b525 PA |
2651 | } |
2652 | ||
eb54c8bf | 2653 | return 1; |
d6b0e80f AC |
2654 | } |
2655 | ||
d6b0e80f AC |
2656 | /* Count the LWP's that have had events. */ |
2657 | ||
2658 | static int | |
2659 | count_events_callback (struct lwp_info *lp, void *data) | |
2660 | { | |
9a3c8263 | 2661 | int *count = (int *) data; |
d6b0e80f AC |
2662 | |
2663 | gdb_assert (count != NULL); | |
2664 | ||
9c02b525 PA |
2665 | /* Select only resumed LWPs that have an event pending. */ |
2666 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2667 | (*count)++; |
2668 | ||
2669 | return 0; | |
2670 | } | |
2671 | ||
2672 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2673 | ||
2674 | static int | |
2675 | select_singlestep_lwp_callback (struct lwp_info *lp, void *data) | |
2676 | { | |
25289eb2 PA |
2677 | if (lp->last_resume_kind == resume_step |
2678 | && lp->status != 0) | |
d6b0e80f AC |
2679 | return 1; |
2680 | else | |
2681 | return 0; | |
2682 | } | |
2683 | ||
8a99810d PA |
2684 | /* Returns true if LP has a status pending. */ |
2685 | ||
2686 | static int | |
2687 | lwp_status_pending_p (struct lwp_info *lp) | |
2688 | { | |
2689 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2690 | can have pending process exits recorded in lp->status and | |
2691 | W_EXITCODE(0,0) happens to be 0. */ | |
2692 | return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE; | |
2693 | } | |
2694 | ||
b90fc188 | 2695 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2696 | |
2697 | static int | |
2698 | select_event_lwp_callback (struct lwp_info *lp, void *data) | |
2699 | { | |
9a3c8263 | 2700 | int *selector = (int *) data; |
d6b0e80f AC |
2701 | |
2702 | gdb_assert (selector != NULL); | |
2703 | ||
9c02b525 PA |
2704 | /* Select only resumed LWPs that have an event pending. */ |
2705 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2706 | if ((*selector)-- == 0) |
2707 | return 1; | |
2708 | ||
2709 | return 0; | |
2710 | } | |
2711 | ||
e7ad2f14 PA |
2712 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2713 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2714 | and save the result in the LWP's stop_reason field. If it stopped | |
2715 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2716 | architecture. */ | |
9c02b525 | 2717 | |
e7ad2f14 PA |
2718 | static void |
2719 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2720 | { |
e7ad2f14 PA |
2721 | struct regcache *regcache; |
2722 | struct gdbarch *gdbarch; | |
515630c5 | 2723 | CORE_ADDR pc; |
9c02b525 | 2724 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2725 | #if USE_SIGTRAP_SIGINFO |
2726 | siginfo_t siginfo; | |
2727 | #endif | |
9c02b525 | 2728 | |
e7ad2f14 PA |
2729 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2730 | gdb_assert (lp->status != 0); | |
2731 | ||
2732 | if (!linux_nat_status_is_event (lp->status)) | |
2733 | return; | |
2734 | ||
2735 | regcache = get_thread_regcache (lp->ptid); | |
ac7936df | 2736 | gdbarch = regcache->arch (); |
e7ad2f14 | 2737 | |
9c02b525 | 2738 | pc = regcache_read_pc (regcache); |
527a273a | 2739 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2740 | |
faf09f01 PA |
2741 | #if USE_SIGTRAP_SIGINFO |
2742 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2743 | { | |
2744 | if (siginfo.si_signo == SIGTRAP) | |
2745 | { | |
e7ad2f14 PA |
2746 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2747 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2748 | { |
e7ad2f14 PA |
2749 | /* The si_code is ambiguous on this arch -- check debug |
2750 | registers. */ | |
2751 | if (!check_stopped_by_watchpoint (lp)) | |
2752 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2753 | } | |
2754 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2755 | { | |
2756 | /* If we determine the LWP stopped for a SW breakpoint, | |
2757 | trust it. Particularly don't check watchpoint | |
2758 | registers, because at least on s390, we'd find | |
2759 | stopped-by-watchpoint as long as there's a watchpoint | |
2760 | set. */ | |
faf09f01 | 2761 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2762 | } |
e7ad2f14 | 2763 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2764 | { |
e7ad2f14 PA |
2765 | /* This can indicate either a hardware breakpoint or |
2766 | hardware watchpoint. Check debug registers. */ | |
2767 | if (!check_stopped_by_watchpoint (lp)) | |
2768 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2769 | } |
2bf6fb9d PA |
2770 | else if (siginfo.si_code == TRAP_TRACE) |
2771 | { | |
2772 | if (debug_linux_nat) | |
2773 | fprintf_unfiltered (gdb_stdlog, | |
2774 | "CSBB: %s stopped by trace\n", | |
2775 | target_pid_to_str (lp->ptid)); | |
e7ad2f14 PA |
2776 | |
2777 | /* We may have single stepped an instruction that | |
2778 | triggered a watchpoint. In that case, on some | |
2779 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2780 | si_code indicates TRAP_TRACE, and we need to check | |
2781 | the debug registers separately. */ | |
2782 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2783 | } |
faf09f01 PA |
2784 | } |
2785 | } | |
2786 | #else | |
9c02b525 | 2787 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2788 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2789 | sw_bp_pc)) |
710151dd | 2790 | { |
9c02b525 PA |
2791 | /* The LWP was either continued, or stepped a software |
2792 | breakpoint instruction. */ | |
e7ad2f14 PA |
2793 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2794 | } | |
2795 | ||
a01bda52 | 2796 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2797 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2798 | ||
2799 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2800 | check_stopped_by_watchpoint (lp); | |
2801 | #endif | |
2802 | ||
2803 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2804 | { | |
710151dd PA |
2805 | if (debug_linux_nat) |
2806 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 2807 | "CSBB: %s stopped by software breakpoint\n", |
710151dd PA |
2808 | target_pid_to_str (lp->ptid)); |
2809 | ||
2810 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2811 | if (pc != sw_bp_pc) |
2812 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2813 | |
e7ad2f14 PA |
2814 | /* Update this so we record the correct stop PC below. */ |
2815 | pc = sw_bp_pc; | |
710151dd | 2816 | } |
e7ad2f14 | 2817 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 PA |
2818 | { |
2819 | if (debug_linux_nat) | |
2820 | fprintf_unfiltered (gdb_stdlog, | |
e7ad2f14 PA |
2821 | "CSBB: %s stopped by hardware breakpoint\n", |
2822 | target_pid_to_str (lp->ptid)); | |
2823 | } | |
2824 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2825 | { | |
2826 | if (debug_linux_nat) | |
2827 | fprintf_unfiltered (gdb_stdlog, | |
2828 | "CSBB: %s stopped by hardware watchpoint\n", | |
9c02b525 | 2829 | target_pid_to_str (lp->ptid)); |
9c02b525 | 2830 | } |
d6b0e80f | 2831 | |
e7ad2f14 | 2832 | lp->stop_pc = pc; |
d6b0e80f AC |
2833 | } |
2834 | ||
faf09f01 PA |
2835 | |
2836 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2837 | ||
57810aa7 | 2838 | bool |
f6ac5f3d | 2839 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2840 | { |
2841 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2842 | ||
2843 | gdb_assert (lp != NULL); | |
2844 | ||
2845 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2846 | } | |
2847 | ||
2848 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2849 | ||
57810aa7 | 2850 | bool |
f6ac5f3d | 2851 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2852 | { |
2853 | return USE_SIGTRAP_SIGINFO; | |
2854 | } | |
2855 | ||
2856 | /* Returns true if the LWP had stopped for a hardware | |
2857 | breakpoint/watchpoint. */ | |
2858 | ||
57810aa7 | 2859 | bool |
f6ac5f3d | 2860 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2861 | { |
2862 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2863 | ||
2864 | gdb_assert (lp != NULL); | |
2865 | ||
2866 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2867 | } | |
2868 | ||
2869 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2870 | ||
57810aa7 | 2871 | bool |
f6ac5f3d | 2872 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2873 | { |
2874 | return USE_SIGTRAP_SIGINFO; | |
2875 | } | |
2876 | ||
d6b0e80f AC |
2877 | /* Select one LWP out of those that have events pending. */ |
2878 | ||
2879 | static void | |
d90e17a7 | 2880 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2881 | { |
2882 | int num_events = 0; | |
2883 | int random_selector; | |
9c02b525 | 2884 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2885 | |
ac264b3b | 2886 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2887 | (*orig_lp)->status = *status; |
2888 | ||
9c02b525 PA |
2889 | /* In all-stop, give preference to the LWP that is being |
2890 | single-stepped. There will be at most one, and it will be the | |
2891 | LWP that the core is most interested in. If we didn't do this, | |
2892 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2893 | the core later continues the previously-stepped thread, as | |
2894 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2895 | having stepped the thread, wouldn't understand what the trap was | |
2896 | for, and therefore would report it to the user as a random | |
2897 | signal. */ | |
fbea99ea | 2898 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2899 | { |
9c02b525 PA |
2900 | event_lp = iterate_over_lwps (filter, |
2901 | select_singlestep_lwp_callback, NULL); | |
2902 | if (event_lp != NULL) | |
2903 | { | |
2904 | if (debug_linux_nat) | |
2905 | fprintf_unfiltered (gdb_stdlog, | |
2906 | "SEL: Select single-step %s\n", | |
2907 | target_pid_to_str (event_lp->ptid)); | |
2908 | } | |
d6b0e80f | 2909 | } |
9c02b525 PA |
2910 | |
2911 | if (event_lp == NULL) | |
d6b0e80f | 2912 | { |
9c02b525 | 2913 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2914 | |
9c02b525 | 2915 | /* First see how many events we have. */ |
d90e17a7 | 2916 | iterate_over_lwps (filter, count_events_callback, &num_events); |
8bf3b159 | 2917 | gdb_assert (num_events > 0); |
d6b0e80f | 2918 | |
9c02b525 PA |
2919 | /* Now randomly pick a LWP out of those that have had |
2920 | events. */ | |
d6b0e80f AC |
2921 | random_selector = (int) |
2922 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2923 | ||
2924 | if (debug_linux_nat && num_events > 1) | |
2925 | fprintf_unfiltered (gdb_stdlog, | |
9c02b525 | 2926 | "SEL: Found %d events, selecting #%d\n", |
d6b0e80f AC |
2927 | num_events, random_selector); |
2928 | ||
d90e17a7 PA |
2929 | event_lp = iterate_over_lwps (filter, |
2930 | select_event_lwp_callback, | |
d6b0e80f AC |
2931 | &random_selector); |
2932 | } | |
2933 | ||
2934 | if (event_lp != NULL) | |
2935 | { | |
2936 | /* Switch the event LWP. */ | |
2937 | *orig_lp = event_lp; | |
2938 | *status = event_lp->status; | |
2939 | } | |
2940 | ||
2941 | /* Flush the wait status for the event LWP. */ | |
2942 | (*orig_lp)->status = 0; | |
2943 | } | |
2944 | ||
2945 | /* Return non-zero if LP has been resumed. */ | |
2946 | ||
2947 | static int | |
2948 | resumed_callback (struct lwp_info *lp, void *data) | |
2949 | { | |
2950 | return lp->resumed; | |
2951 | } | |
2952 | ||
02f3fc28 | 2953 | /* Check if we should go on and pass this event to common code. |
9c02b525 | 2954 | Return the affected lwp if we are, or NULL otherwise. */ |
12d9289a | 2955 | |
02f3fc28 | 2956 | static struct lwp_info * |
9c02b525 | 2957 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2958 | { |
2959 | struct lwp_info *lp; | |
89a5711c | 2960 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 PA |
2961 | |
2962 | lp = find_lwp_pid (pid_to_ptid (lwpid)); | |
2963 | ||
2964 | /* Check for stop events reported by a process we didn't already | |
2965 | know about - anything not already in our LWP list. | |
2966 | ||
2967 | If we're expecting to receive stopped processes after | |
2968 | fork, vfork, and clone events, then we'll just add the | |
2969 | new one to our list and go back to waiting for the event | |
2970 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2971 | from waitpid before or after the event is. |
2972 | ||
2973 | But note the case of a non-leader thread exec'ing after the | |
2974 | leader having exited, and gone from our lists. The non-leader | |
2975 | thread changes its tid to the tgid. */ | |
2976 | ||
2977 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2978 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2979 | { |
2980 | /* A multi-thread exec after we had seen the leader exiting. */ | |
2981 | if (debug_linux_nat) | |
2982 | fprintf_unfiltered (gdb_stdlog, | |
2983 | "LLW: Re-adding thread group leader LWP %d.\n", | |
2984 | lwpid); | |
2985 | ||
dfd4cc63 | 2986 | lp = add_lwp (ptid_build (lwpid, lwpid, 0)); |
0e5bf2a8 PA |
2987 | lp->stopped = 1; |
2988 | lp->resumed = 1; | |
2989 | add_thread (lp->ptid); | |
2990 | } | |
2991 | ||
02f3fc28 PA |
2992 | if (WIFSTOPPED (status) && !lp) |
2993 | { | |
3b27ef47 PA |
2994 | if (debug_linux_nat) |
2995 | fprintf_unfiltered (gdb_stdlog, | |
2996 | "LHEW: saving LWP %ld status %s in stopped_pids list\n", | |
2997 | (long) lwpid, status_to_str (status)); | |
84636d28 | 2998 | add_to_pid_list (&stopped_pids, lwpid, status); |
02f3fc28 PA |
2999 | return NULL; |
3000 | } | |
3001 | ||
3002 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 3003 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 3004 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
3005 | exits. */ |
3006 | if (!WIFSTOPPED (status) && !lp) | |
3007 | return NULL; | |
3008 | ||
8817a6f2 PA |
3009 | /* This LWP is stopped now. (And if dead, this prevents it from |
3010 | ever being continued.) */ | |
3011 | lp->stopped = 1; | |
3012 | ||
8784d563 PA |
3013 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
3014 | { | |
3015 | struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid)); | |
de0d863e | 3016 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 3017 | |
de0d863e | 3018 | linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options); |
8784d563 PA |
3019 | lp->must_set_ptrace_flags = 0; |
3020 | } | |
3021 | ||
ca2163eb PA |
3022 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
3023 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
3024 | { | |
3025 | /* No longer need the sysgood bit. The ptrace event ends up | |
3026 | recorded in lp->waitstatus if we care for it. We can carry | |
3027 | on handling the event like a regular SIGTRAP from here | |
3028 | on. */ | |
3029 | status = W_STOPCODE (SIGTRAP); | |
3030 | if (linux_handle_syscall_trap (lp, 0)) | |
3031 | return NULL; | |
3032 | } | |
bfd09d20 JS |
3033 | else |
3034 | { | |
3035 | /* Almost all other ptrace-stops are known to be outside of system | |
3036 | calls, with further exceptions in linux_handle_extended_wait. */ | |
3037 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
3038 | } | |
02f3fc28 | 3039 | |
ca2163eb | 3040 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
3041 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
3042 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 PA |
3043 | { |
3044 | if (debug_linux_nat) | |
3045 | fprintf_unfiltered (gdb_stdlog, | |
3046 | "LLW: Handling extended status 0x%06x\n", | |
3047 | status); | |
4dd63d48 | 3048 | if (linux_handle_extended_wait (lp, status)) |
02f3fc28 PA |
3049 | return NULL; |
3050 | } | |
3051 | ||
3052 | /* Check if the thread has exited. */ | |
9c02b525 PA |
3053 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
3054 | { | |
aa01bd36 PA |
3055 | if (!report_thread_events |
3056 | && num_lwps (ptid_get_pid (lp->ptid)) > 1) | |
02f3fc28 | 3057 | { |
9c02b525 PA |
3058 | if (debug_linux_nat) |
3059 | fprintf_unfiltered (gdb_stdlog, | |
3060 | "LLW: %s exited.\n", | |
3061 | target_pid_to_str (lp->ptid)); | |
3062 | ||
4a6ed09b PA |
3063 | /* If there is at least one more LWP, then the exit signal |
3064 | was not the end of the debugged application and should be | |
3065 | ignored. */ | |
3066 | exit_lwp (lp); | |
3067 | return NULL; | |
02f3fc28 PA |
3068 | } |
3069 | ||
77598427 PA |
3070 | /* Note that even if the leader was ptrace-stopped, it can still |
3071 | exit, if e.g., some other thread brings down the whole | |
3072 | process (calls `exit'). So don't assert that the lwp is | |
3073 | resumed. */ | |
02f3fc28 PA |
3074 | if (debug_linux_nat) |
3075 | fprintf_unfiltered (gdb_stdlog, | |
aa01bd36 | 3076 | "LWP %ld exited (resumed=%d)\n", |
77598427 | 3077 | ptid_get_lwp (lp->ptid), lp->resumed); |
02f3fc28 | 3078 | |
9c02b525 PA |
3079 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
3080 | lp->signalled = 0; | |
3081 | ||
3082 | /* Store the pending event in the waitstatus, because | |
3083 | W_EXITCODE(0,0) == 0. */ | |
3084 | store_waitstatus (&lp->waitstatus, status); | |
3085 | return lp; | |
02f3fc28 PA |
3086 | } |
3087 | ||
02f3fc28 PA |
3088 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
3089 | an attempt to stop an LWP. */ | |
3090 | if (lp->signalled | |
3091 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
3092 | { | |
02f3fc28 PA |
3093 | lp->signalled = 0; |
3094 | ||
2bf6fb9d | 3095 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 3096 | { |
2bf6fb9d PA |
3097 | if (debug_linux_nat) |
3098 | fprintf_unfiltered (gdb_stdlog, | |
3099 | "LLW: resume_stop SIGSTOP caught for %s.\n", | |
3100 | target_pid_to_str (lp->ptid)); | |
3101 | } | |
3102 | else | |
3103 | { | |
3104 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 3105 | |
25289eb2 PA |
3106 | if (debug_linux_nat) |
3107 | fprintf_unfiltered (gdb_stdlog, | |
2bf6fb9d | 3108 | "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n", |
25289eb2 PA |
3109 | lp->step ? |
3110 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3111 | target_pid_to_str (lp->ptid)); | |
02f3fc28 | 3112 | |
2bf6fb9d | 3113 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3114 | gdb_assert (lp->resumed); |
25289eb2 PA |
3115 | return NULL; |
3116 | } | |
02f3fc28 PA |
3117 | } |
3118 | ||
57380f4e DJ |
3119 | /* Make sure we don't report a SIGINT that we have already displayed |
3120 | for another thread. */ | |
3121 | if (lp->ignore_sigint | |
3122 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3123 | { | |
3124 | if (debug_linux_nat) | |
3125 | fprintf_unfiltered (gdb_stdlog, | |
3126 | "LLW: Delayed SIGINT caught for %s.\n", | |
3127 | target_pid_to_str (lp->ptid)); | |
3128 | ||
3129 | /* This is a delayed SIGINT. */ | |
3130 | lp->ignore_sigint = 0; | |
3131 | ||
8a99810d | 3132 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
57380f4e DJ |
3133 | if (debug_linux_nat) |
3134 | fprintf_unfiltered (gdb_stdlog, | |
3135 | "LLW: %s %s, 0, 0 (discard SIGINT)\n", | |
3136 | lp->step ? | |
3137 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3138 | target_pid_to_str (lp->ptid)); | |
57380f4e DJ |
3139 | gdb_assert (lp->resumed); |
3140 | ||
3141 | /* Discard the event. */ | |
3142 | return NULL; | |
3143 | } | |
3144 | ||
9c02b525 PA |
3145 | /* Don't report signals that GDB isn't interested in, such as |
3146 | signals that are neither printed nor stopped upon. Stopping all | |
3147 | threads can be a bit time-consuming so if we want decent | |
3148 | performance with heavily multi-threaded programs, especially when | |
3149 | they're using a high frequency timer, we'd better avoid it if we | |
3150 | can. */ | |
3151 | if (WIFSTOPPED (status)) | |
3152 | { | |
3153 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3154 | ||
fbea99ea | 3155 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3156 | { |
3157 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3158 | to implement target_stop (see linux_nat_stop) in | |
3159 | non-stop. */ | |
3160 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3161 | { | |
3162 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3163 | forwarded to the entire process group, that is, all LWPs | |
3164 | will receive it - unless they're using CLONE_THREAD to | |
3165 | share signals. Since we only want to report it once, we | |
3166 | mark it as ignored for all LWPs except this one. */ | |
3167 | iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)), | |
3168 | set_ignore_sigint, NULL); | |
3169 | lp->ignore_sigint = 0; | |
3170 | } | |
3171 | else | |
3172 | maybe_clear_ignore_sigint (lp); | |
3173 | } | |
3174 | ||
3175 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 AT |
3176 | Otherwise, signals in pass_mask may be short-circuited |
3177 | except signals that might be caused by a breakpoint. */ | |
9c02b525 | 3178 | if (!lp->step |
c9587f88 AT |
3179 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
3180 | && !linux_wstatus_maybe_breakpoint (status)) | |
9c02b525 PA |
3181 | { |
3182 | linux_resume_one_lwp (lp, lp->step, signo); | |
3183 | if (debug_linux_nat) | |
3184 | fprintf_unfiltered (gdb_stdlog, | |
3185 | "LLW: %s %s, %s (preempt 'handle')\n", | |
3186 | lp->step ? | |
3187 | "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3188 | target_pid_to_str (lp->ptid), | |
3189 | (signo != GDB_SIGNAL_0 | |
3190 | ? strsignal (gdb_signal_to_host (signo)) | |
3191 | : "0")); | |
3192 | return NULL; | |
3193 | } | |
3194 | } | |
3195 | ||
02f3fc28 PA |
3196 | /* An interesting event. */ |
3197 | gdb_assert (lp); | |
ca2163eb | 3198 | lp->status = status; |
e7ad2f14 | 3199 | save_stop_reason (lp); |
02f3fc28 PA |
3200 | return lp; |
3201 | } | |
3202 | ||
0e5bf2a8 PA |
3203 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3204 | their exits until all other threads in the group have exited. */ | |
3205 | ||
3206 | static void | |
3207 | check_zombie_leaders (void) | |
3208 | { | |
3209 | struct inferior *inf; | |
3210 | ||
3211 | ALL_INFERIORS (inf) | |
3212 | { | |
3213 | struct lwp_info *leader_lp; | |
3214 | ||
3215 | if (inf->pid == 0) | |
3216 | continue; | |
3217 | ||
3218 | leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); | |
3219 | if (leader_lp != NULL | |
3220 | /* Check if there are other threads in the group, as we may | |
3221 | have raced with the inferior simply exiting. */ | |
3222 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3223 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 PA |
3224 | { |
3225 | if (debug_linux_nat) | |
3226 | fprintf_unfiltered (gdb_stdlog, | |
3227 | "CZL: Thread group leader %d zombie " | |
3228 | "(it exited, or another thread execd).\n", | |
3229 | inf->pid); | |
3230 | ||
3231 | /* A leader zombie can mean one of two things: | |
3232 | ||
3233 | - It exited, and there's an exit status pending | |
3234 | available, or only the leader exited (not the whole | |
3235 | program). In the latter case, we can't waitpid the | |
3236 | leader's exit status until all other threads are gone. | |
3237 | ||
3238 | - There are 3 or more threads in the group, and a thread | |
4a6ed09b PA |
3239 | other than the leader exec'd. See comments on exec |
3240 | events at the top of the file. We could try | |
0e5bf2a8 PA |
3241 | distinguishing the exit and exec cases, by waiting once |
3242 | more, and seeing if something comes out, but it doesn't | |
3243 | sound useful. The previous leader _does_ go away, and | |
3244 | we'll re-add the new one once we see the exec event | |
3245 | (which is just the same as what would happen if the | |
3246 | previous leader did exit voluntarily before some other | |
3247 | thread execs). */ | |
3248 | ||
3249 | if (debug_linux_nat) | |
3250 | fprintf_unfiltered (gdb_stdlog, | |
3251 | "CZL: Thread group leader %d vanished.\n", | |
3252 | inf->pid); | |
3253 | exit_lwp (leader_lp); | |
3254 | } | |
3255 | } | |
3256 | } | |
3257 | ||
aa01bd36 PA |
3258 | /* Convenience function that is called when the kernel reports an exit |
3259 | event. This decides whether to report the event to GDB as a | |
3260 | process exit event, a thread exit event, or to suppress the | |
3261 | event. */ | |
3262 | ||
3263 | static ptid_t | |
3264 | filter_exit_event (struct lwp_info *event_child, | |
3265 | struct target_waitstatus *ourstatus) | |
3266 | { | |
3267 | ptid_t ptid = event_child->ptid; | |
3268 | ||
3269 | if (num_lwps (ptid_get_pid (ptid)) > 1) | |
3270 | { | |
3271 | if (report_thread_events) | |
3272 | ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED; | |
3273 | else | |
3274 | ourstatus->kind = TARGET_WAITKIND_IGNORE; | |
3275 | ||
3276 | exit_lwp (event_child); | |
3277 | } | |
3278 | ||
3279 | return ptid; | |
3280 | } | |
3281 | ||
d6b0e80f | 3282 | static ptid_t |
f6ac5f3d | 3283 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
47608cb1 | 3284 | int target_options) |
d6b0e80f | 3285 | { |
fc9b8e47 | 3286 | sigset_t prev_mask; |
4b60df3d | 3287 | enum resume_kind last_resume_kind; |
12d9289a | 3288 | struct lwp_info *lp; |
12d9289a | 3289 | int status; |
d6b0e80f | 3290 | |
01124a23 | 3291 | if (debug_linux_nat) |
b84876c2 PA |
3292 | fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
3293 | ||
f973ed9c DJ |
3294 | /* The first time we get here after starting a new inferior, we may |
3295 | not have added it to the LWP list yet - this is the earliest | |
3296 | moment at which we know its PID. */ | |
d90e17a7 | 3297 | if (ptid_is_pid (inferior_ptid)) |
f973ed9c | 3298 | { |
27c9d204 PA |
3299 | /* Upgrade the main thread's ptid. */ |
3300 | thread_change_ptid (inferior_ptid, | |
dfd4cc63 LM |
3301 | ptid_build (ptid_get_pid (inferior_ptid), |
3302 | ptid_get_pid (inferior_ptid), 0)); | |
27c9d204 | 3303 | |
26cb8b7c | 3304 | lp = add_initial_lwp (inferior_ptid); |
f973ed9c DJ |
3305 | lp->resumed = 1; |
3306 | } | |
3307 | ||
12696c10 | 3308 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3309 | block_child_signals (&prev_mask); |
d6b0e80f | 3310 | |
d6b0e80f | 3311 | /* First check if there is a LWP with a wait status pending. */ |
8a99810d PA |
3312 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3313 | if (lp != NULL) | |
d6b0e80f AC |
3314 | { |
3315 | if (debug_linux_nat) | |
d6b0e80f AC |
3316 | fprintf_unfiltered (gdb_stdlog, |
3317 | "LLW: Using pending wait status %s for %s.\n", | |
ca2163eb | 3318 | status_to_str (lp->status), |
d6b0e80f | 3319 | target_pid_to_str (lp->ptid)); |
d6b0e80f AC |
3320 | } |
3321 | ||
9c02b525 PA |
3322 | /* But if we don't find a pending event, we'll have to wait. Always |
3323 | pull all events out of the kernel. We'll randomly select an | |
3324 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3325 | |
d90e17a7 | 3326 | while (lp == NULL) |
d6b0e80f AC |
3327 | { |
3328 | pid_t lwpid; | |
3329 | ||
0e5bf2a8 PA |
3330 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3331 | quirks: | |
3332 | ||
3333 | - If the thread group leader exits while other threads in the | |
3334 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3335 | waitpid won't return an exit status until the other threads | |
3336 | in the group are reapped. | |
3337 | ||
3338 | - When a non-leader thread execs, that thread just vanishes | |
3339 | without reporting an exit (so we'd hang if we waited for it | |
3340 | explicitly in that case). The exec event is reported to | |
3341 | the TGID pid. */ | |
3342 | ||
3343 | errno = 0; | |
4a6ed09b | 3344 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 PA |
3345 | |
3346 | if (debug_linux_nat) | |
3347 | fprintf_unfiltered (gdb_stdlog, | |
3348 | "LNW: waitpid(-1, ...) returned %d, %s\n", | |
3349 | lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3350 | |
d6b0e80f AC |
3351 | if (lwpid > 0) |
3352 | { | |
d6b0e80f AC |
3353 | if (debug_linux_nat) |
3354 | { | |
3355 | fprintf_unfiltered (gdb_stdlog, | |
3356 | "LLW: waitpid %ld received %s\n", | |
3357 | (long) lwpid, status_to_str (status)); | |
3358 | } | |
3359 | ||
9c02b525 | 3360 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3361 | /* Retry until nothing comes out of waitpid. A single |
3362 | SIGCHLD can indicate more than one child stopped. */ | |
3363 | continue; | |
d6b0e80f AC |
3364 | } |
3365 | ||
20ba1ce6 PA |
3366 | /* Now that we've pulled all events out of the kernel, resume |
3367 | LWPs that don't have an interesting event to report. */ | |
3368 | iterate_over_lwps (minus_one_ptid, | |
3369 | resume_stopped_resumed_lwps, &minus_one_ptid); | |
3370 | ||
3371 | /* ... and find an LWP with a status to report to the core, if | |
3372 | any. */ | |
9c02b525 PA |
3373 | lp = iterate_over_lwps (ptid, status_callback, NULL); |
3374 | if (lp != NULL) | |
3375 | break; | |
3376 | ||
0e5bf2a8 PA |
3377 | /* Check for zombie thread group leaders. Those can't be reaped |
3378 | until all other threads in the thread group are. */ | |
3379 | check_zombie_leaders (); | |
d6b0e80f | 3380 | |
0e5bf2a8 PA |
3381 | /* If there are no resumed children left, bail. We'd be stuck |
3382 | forever in the sigsuspend call below otherwise. */ | |
3383 | if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) | |
3384 | { | |
3385 | if (debug_linux_nat) | |
3386 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); | |
b84876c2 | 3387 | |
0e5bf2a8 | 3388 | ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
b84876c2 | 3389 | |
0e5bf2a8 PA |
3390 | restore_child_signals_mask (&prev_mask); |
3391 | return minus_one_ptid; | |
d6b0e80f | 3392 | } |
28736962 | 3393 | |
0e5bf2a8 PA |
3394 | /* No interesting event to report to the core. */ |
3395 | ||
3396 | if (target_options & TARGET_WNOHANG) | |
3397 | { | |
01124a23 | 3398 | if (debug_linux_nat) |
28736962 PA |
3399 | fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
3400 | ||
0e5bf2a8 | 3401 | ourstatus->kind = TARGET_WAITKIND_IGNORE; |
28736962 PA |
3402 | restore_child_signals_mask (&prev_mask); |
3403 | return minus_one_ptid; | |
3404 | } | |
d6b0e80f AC |
3405 | |
3406 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3407 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3408 | |
3409 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3410 | wait_for_signal (); |
d6b0e80f AC |
3411 | } |
3412 | ||
d6b0e80f AC |
3413 | gdb_assert (lp); |
3414 | ||
ca2163eb PA |
3415 | status = lp->status; |
3416 | lp->status = 0; | |
3417 | ||
fbea99ea | 3418 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3419 | { |
3420 | /* Now stop all other LWP's ... */ | |
d90e17a7 | 3421 | iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
4c28f408 PA |
3422 | |
3423 | /* ... and wait until all of them have reported back that | |
3424 | they're no longer running. */ | |
d90e17a7 | 3425 | iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
9c02b525 PA |
3426 | } |
3427 | ||
3428 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3429 | among those that have had events. Giving equal priority to all | |
3430 | LWPs that have had events helps prevent starvation. */ | |
3431 | if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) | |
3432 | select_event_lwp (ptid, &lp, &status); | |
3433 | ||
3434 | gdb_assert (lp != NULL); | |
3435 | ||
3436 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3437 | it was a software breakpoint, and we can't reliably support the |
3438 | "stopped by software breakpoint" stop reason. */ | |
3439 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3440 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 PA |
3441 | { |
3442 | struct regcache *regcache = get_thread_regcache (lp->ptid); | |
ac7936df | 3443 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3444 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3445 | |
9c02b525 PA |
3446 | if (decr_pc != 0) |
3447 | { | |
3448 | CORE_ADDR pc; | |
d6b0e80f | 3449 | |
9c02b525 PA |
3450 | pc = regcache_read_pc (regcache); |
3451 | regcache_write_pc (regcache, pc + decr_pc); | |
3452 | } | |
3453 | } | |
e3e9f5a2 | 3454 | |
9c02b525 PA |
3455 | /* We'll need this to determine whether to report a SIGSTOP as |
3456 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3457 | clears it. */ | |
3458 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3459 | |
fbea99ea | 3460 | if (!target_is_non_stop_p ()) |
9c02b525 | 3461 | { |
e3e9f5a2 PA |
3462 | /* In all-stop, from the core's perspective, all LWPs are now |
3463 | stopped until a new resume action is sent over. */ | |
3464 | iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); | |
3465 | } | |
3466 | else | |
25289eb2 | 3467 | { |
4b60df3d | 3468 | resume_clear_callback (lp, NULL); |
25289eb2 | 3469 | } |
d6b0e80f | 3470 | |
26ab7092 | 3471 | if (linux_nat_status_is_event (status)) |
d6b0e80f | 3472 | { |
d6b0e80f AC |
3473 | if (debug_linux_nat) |
3474 | fprintf_unfiltered (gdb_stdlog, | |
4fdebdd0 PA |
3475 | "LLW: trap ptid is %s.\n", |
3476 | target_pid_to_str (lp->ptid)); | |
d6b0e80f | 3477 | } |
d6b0e80f AC |
3478 | |
3479 | if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) | |
3480 | { | |
3481 | *ourstatus = lp->waitstatus; | |
3482 | lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; | |
3483 | } | |
3484 | else | |
3485 | store_waitstatus (ourstatus, status); | |
3486 | ||
01124a23 | 3487 | if (debug_linux_nat) |
b84876c2 PA |
3488 | fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
3489 | ||
7feb7d06 | 3490 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3491 | |
4b60df3d | 3492 | if (last_resume_kind == resume_stop |
25289eb2 PA |
3493 | && ourstatus->kind == TARGET_WAITKIND_STOPPED |
3494 | && WSTOPSIG (status) == SIGSTOP) | |
3495 | { | |
3496 | /* A thread that has been requested to stop by GDB with | |
3497 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3498 | use of SIGSTOP is an implementation detail. */ | |
a493e3e2 | 3499 | ourstatus->value.sig = GDB_SIGNAL_0; |
25289eb2 PA |
3500 | } |
3501 | ||
1e225492 JK |
3502 | if (ourstatus->kind == TARGET_WAITKIND_EXITED |
3503 | || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) | |
3504 | lp->core = -1; | |
3505 | else | |
2e794194 | 3506 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3507 | |
aa01bd36 PA |
3508 | if (ourstatus->kind == TARGET_WAITKIND_EXITED) |
3509 | return filter_exit_event (lp, ourstatus); | |
3510 | ||
f973ed9c | 3511 | return lp->ptid; |
d6b0e80f AC |
3512 | } |
3513 | ||
e3e9f5a2 PA |
3514 | /* Resume LWPs that are currently stopped without any pending status |
3515 | to report, but are resumed from the core's perspective. */ | |
3516 | ||
3517 | static int | |
3518 | resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) | |
3519 | { | |
9a3c8263 | 3520 | ptid_t *wait_ptid_p = (ptid_t *) data; |
e3e9f5a2 | 3521 | |
4dd63d48 PA |
3522 | if (!lp->stopped) |
3523 | { | |
3524 | if (debug_linux_nat) | |
3525 | fprintf_unfiltered (gdb_stdlog, | |
3526 | "RSRL: NOT resuming LWP %s, not stopped\n", | |
3527 | target_pid_to_str (lp->ptid)); | |
3528 | } | |
3529 | else if (!lp->resumed) | |
3530 | { | |
3531 | if (debug_linux_nat) | |
3532 | fprintf_unfiltered (gdb_stdlog, | |
3533 | "RSRL: NOT resuming LWP %s, not resumed\n", | |
3534 | target_pid_to_str (lp->ptid)); | |
3535 | } | |
3536 | else if (lwp_status_pending_p (lp)) | |
3537 | { | |
3538 | if (debug_linux_nat) | |
3539 | fprintf_unfiltered (gdb_stdlog, | |
3540 | "RSRL: NOT resuming LWP %s, has pending status\n", | |
3541 | target_pid_to_str (lp->ptid)); | |
3542 | } | |
3543 | else | |
e3e9f5a2 | 3544 | { |
336060f3 | 3545 | struct regcache *regcache = get_thread_regcache (lp->ptid); |
ac7936df | 3546 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3547 | |
23f238d3 | 3548 | TRY |
e3e9f5a2 | 3549 | { |
23f238d3 PA |
3550 | CORE_ADDR pc = regcache_read_pc (regcache); |
3551 | int leave_stopped = 0; | |
e3e9f5a2 | 3552 | |
23f238d3 PA |
3553 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3554 | immediately, and we're not waiting for this LWP. */ | |
3555 | if (!ptid_match (lp->ptid, *wait_ptid_p)) | |
3556 | { | |
a01bda52 | 3557 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3558 | leave_stopped = 1; |
3559 | } | |
e3e9f5a2 | 3560 | |
23f238d3 PA |
3561 | if (!leave_stopped) |
3562 | { | |
3563 | if (debug_linux_nat) | |
3564 | fprintf_unfiltered (gdb_stdlog, | |
3565 | "RSRL: resuming stopped-resumed LWP %s at " | |
3566 | "%s: step=%d\n", | |
3567 | target_pid_to_str (lp->ptid), | |
3568 | paddress (gdbarch, pc), | |
3569 | lp->step); | |
3570 | ||
3571 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3572 | } | |
3573 | } | |
3574 | CATCH (ex, RETURN_MASK_ERROR) | |
3575 | { | |
3576 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
3577 | throw_exception (ex); | |
3578 | } | |
3579 | END_CATCH | |
e3e9f5a2 PA |
3580 | } |
3581 | ||
3582 | return 0; | |
3583 | } | |
3584 | ||
f6ac5f3d PA |
3585 | ptid_t |
3586 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
3587 | int target_options) | |
7feb7d06 PA |
3588 | { |
3589 | ptid_t event_ptid; | |
3590 | ||
3591 | if (debug_linux_nat) | |
09826ec5 PA |
3592 | { |
3593 | char *options_string; | |
3594 | ||
3595 | options_string = target_options_to_string (target_options); | |
3596 | fprintf_unfiltered (gdb_stdlog, | |
3597 | "linux_nat_wait: [%s], [%s]\n", | |
3598 | target_pid_to_str (ptid), | |
3599 | options_string); | |
3600 | xfree (options_string); | |
3601 | } | |
7feb7d06 PA |
3602 | |
3603 | /* Flush the async file first. */ | |
d9d41e78 | 3604 | if (target_is_async_p ()) |
7feb7d06 PA |
3605 | async_file_flush (); |
3606 | ||
e3e9f5a2 PA |
3607 | /* Resume LWPs that are currently stopped without any pending status |
3608 | to report, but are resumed from the core's perspective. LWPs get | |
3609 | in this state if we find them stopping at a time we're not | |
3610 | interested in reporting the event (target_wait on a | |
3611 | specific_process, for example, see linux_nat_wait_1), and | |
3612 | meanwhile the event became uninteresting. Don't bother resuming | |
3613 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3614 | if (target_is_non_stop_p ()) |
e3e9f5a2 PA |
3615 | iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); |
3616 | ||
f6ac5f3d | 3617 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3618 | |
3619 | /* If we requested any event, and something came out, assume there | |
3620 | may be more. If we requested a specific lwp or process, also | |
3621 | assume there may be more. */ | |
d9d41e78 | 3622 | if (target_is_async_p () |
6953d224 PA |
3623 | && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
3624 | && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) | |
7feb7d06 PA |
3625 | || !ptid_equal (ptid, minus_one_ptid))) |
3626 | async_file_mark (); | |
3627 | ||
7feb7d06 PA |
3628 | return event_ptid; |
3629 | } | |
3630 | ||
1d2736d4 PA |
3631 | /* Kill one LWP. */ |
3632 | ||
3633 | static void | |
3634 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3635 | { |
ed731959 JK |
3636 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3637 | ||
3638 | errno = 0; | |
1d2736d4 | 3639 | kill_lwp (pid, SIGKILL); |
ed731959 | 3640 | if (debug_linux_nat) |
57745c90 PA |
3641 | { |
3642 | int save_errno = errno; | |
3643 | ||
3644 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 | 3645 | "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid, |
57745c90 PA |
3646 | save_errno ? safe_strerror (save_errno) : "OK"); |
3647 | } | |
ed731959 JK |
3648 | |
3649 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3650 | ||
d6b0e80f | 3651 | errno = 0; |
1d2736d4 | 3652 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3653 | if (debug_linux_nat) |
57745c90 PA |
3654 | { |
3655 | int save_errno = errno; | |
3656 | ||
3657 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 | 3658 | "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid, |
57745c90 PA |
3659 | save_errno ? safe_strerror (save_errno) : "OK"); |
3660 | } | |
d6b0e80f AC |
3661 | } |
3662 | ||
1d2736d4 PA |
3663 | /* Wait for an LWP to die. */ |
3664 | ||
3665 | static void | |
3666 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3667 | { |
1d2736d4 | 3668 | pid_t res; |
d6b0e80f AC |
3669 | |
3670 | /* We must make sure that there are no pending events (delayed | |
3671 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3672 | program doesn't interfere with any following debugging session. */ | |
3673 | ||
d6b0e80f AC |
3674 | do |
3675 | { | |
1d2736d4 PA |
3676 | res = my_waitpid (pid, NULL, __WALL); |
3677 | if (res != (pid_t) -1) | |
d6b0e80f | 3678 | { |
e85a822c DJ |
3679 | if (debug_linux_nat) |
3680 | fprintf_unfiltered (gdb_stdlog, | |
1d2736d4 PA |
3681 | "KWC: wait %ld received unknown.\n", |
3682 | (long) pid); | |
4a6ed09b PA |
3683 | /* The Linux kernel sometimes fails to kill a thread |
3684 | completely after PTRACE_KILL; that goes from the stop | |
3685 | point in do_fork out to the one in get_signal_to_deliver | |
3686 | and waits again. So kill it again. */ | |
1d2736d4 | 3687 | kill_one_lwp (pid); |
d6b0e80f AC |
3688 | } |
3689 | } | |
1d2736d4 PA |
3690 | while (res == pid); |
3691 | ||
3692 | gdb_assert (res == -1 && errno == ECHILD); | |
3693 | } | |
3694 | ||
3695 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3696 | |
1d2736d4 PA |
3697 | static int |
3698 | kill_callback (struct lwp_info *lp, void *data) | |
3699 | { | |
3700 | kill_one_lwp (ptid_get_lwp (lp->ptid)); | |
d6b0e80f AC |
3701 | return 0; |
3702 | } | |
3703 | ||
1d2736d4 PA |
3704 | /* Callback for iterate_over_lwps. */ |
3705 | ||
3706 | static int | |
3707 | kill_wait_callback (struct lwp_info *lp, void *data) | |
3708 | { | |
3709 | kill_wait_one_lwp (ptid_get_lwp (lp->ptid)); | |
3710 | return 0; | |
3711 | } | |
3712 | ||
3713 | /* Kill the fork children of any threads of inferior INF that are | |
3714 | stopped at a fork event. */ | |
3715 | ||
3716 | static void | |
3717 | kill_unfollowed_fork_children (struct inferior *inf) | |
3718 | { | |
3719 | struct thread_info *thread; | |
3720 | ||
3721 | ALL_NON_EXITED_THREADS (thread) | |
3722 | if (thread->inf == inf) | |
3723 | { | |
3724 | struct target_waitstatus *ws = &thread->pending_follow; | |
3725 | ||
3726 | if (ws->kind == TARGET_WAITKIND_FORKED | |
3727 | || ws->kind == TARGET_WAITKIND_VFORKED) | |
3728 | { | |
3729 | ptid_t child_ptid = ws->value.related_pid; | |
3730 | int child_pid = ptid_get_pid (child_ptid); | |
3731 | int child_lwp = ptid_get_lwp (child_ptid); | |
1d2736d4 PA |
3732 | |
3733 | kill_one_lwp (child_lwp); | |
3734 | kill_wait_one_lwp (child_lwp); | |
3735 | ||
3736 | /* Let the arch-specific native code know this process is | |
3737 | gone. */ | |
3738 | linux_nat_forget_process (child_pid); | |
3739 | } | |
3740 | } | |
3741 | } | |
3742 | ||
f6ac5f3d PA |
3743 | void |
3744 | linux_nat_target::kill () | |
d6b0e80f | 3745 | { |
f973ed9c DJ |
3746 | /* If we're stopped while forking and we haven't followed yet, |
3747 | kill the other task. We need to do this first because the | |
3748 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3749 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3750 | |
3751 | if (forks_exist_p ()) | |
7feb7d06 | 3752 | linux_fork_killall (); |
f973ed9c DJ |
3753 | else |
3754 | { | |
d90e17a7 | 3755 | ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
e0881a8e | 3756 | |
4c28f408 PA |
3757 | /* Stop all threads before killing them, since ptrace requires |
3758 | that the thread is stopped to sucessfully PTRACE_KILL. */ | |
d90e17a7 | 3759 | iterate_over_lwps (ptid, stop_callback, NULL); |
4c28f408 PA |
3760 | /* ... and wait until all of them have reported back that |
3761 | they're no longer running. */ | |
d90e17a7 | 3762 | iterate_over_lwps (ptid, stop_wait_callback, NULL); |
4c28f408 | 3763 | |
f973ed9c | 3764 | /* Kill all LWP's ... */ |
d90e17a7 | 3765 | iterate_over_lwps (ptid, kill_callback, NULL); |
f973ed9c DJ |
3766 | |
3767 | /* ... and wait until we've flushed all events. */ | |
d90e17a7 | 3768 | iterate_over_lwps (ptid, kill_wait_callback, NULL); |
f973ed9c DJ |
3769 | } |
3770 | ||
bc1e6c81 | 3771 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3772 | } |
3773 | ||
f6ac5f3d PA |
3774 | void |
3775 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3776 | { |
26cb8b7c PA |
3777 | int pid = ptid_get_pid (inferior_ptid); |
3778 | ||
3779 | purge_lwp_list (pid); | |
d6b0e80f | 3780 | |
f973ed9c | 3781 | if (! forks_exist_p ()) |
d90e17a7 | 3782 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3783 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3784 | else |
3785 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3786 | there are other viable forks to debug. Delete the exiting | |
3787 | one and context-switch to the first available. */ | |
3788 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3789 | |
3790 | /* Let the arch-specific native code know this process is gone. */ | |
3791 | linux_nat_forget_process (pid); | |
d6b0e80f AC |
3792 | } |
3793 | ||
5b009018 PA |
3794 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3795 | layout of the inferiors' architecture. */ | |
3796 | ||
3797 | static void | |
a5362b9a | 3798 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 PA |
3799 | { |
3800 | int done = 0; | |
3801 | ||
3802 | if (linux_nat_siginfo_fixup != NULL) | |
3803 | done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); | |
3804 | ||
3805 | /* If there was no callback, or the callback didn't do anything, | |
3806 | then just do a straight memcpy. */ | |
3807 | if (!done) | |
3808 | { | |
3809 | if (direction == 1) | |
a5362b9a | 3810 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3811 | else |
a5362b9a | 3812 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3813 | } |
3814 | } | |
3815 | ||
9b409511 | 3816 | static enum target_xfer_status |
f6ac5f3d | 3817 | linux_xfer_siginfo (enum target_object object, |
4aa995e1 | 3818 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3819 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3820 | ULONGEST *xfered_len) | |
4aa995e1 | 3821 | { |
4aa995e1 | 3822 | int pid; |
a5362b9a TS |
3823 | siginfo_t siginfo; |
3824 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3825 | |
3826 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3827 | gdb_assert (readbuf || writebuf); | |
3828 | ||
dfd4cc63 | 3829 | pid = ptid_get_lwp (inferior_ptid); |
4aa995e1 | 3830 | if (pid == 0) |
dfd4cc63 | 3831 | pid = ptid_get_pid (inferior_ptid); |
4aa995e1 PA |
3832 | |
3833 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3834 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3835 | |
3836 | errno = 0; | |
3837 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3838 | if (errno != 0) | |
2ed4b548 | 3839 | return TARGET_XFER_E_IO; |
4aa995e1 | 3840 | |
5b009018 PA |
3841 | /* When GDB is built as a 64-bit application, ptrace writes into |
3842 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3843 | inferior with a 64-bit GDB should look the same as debugging it | |
3844 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3845 | the converted layout, so any read/write will have to be done | |
3846 | post-conversion. */ | |
3847 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3848 | ||
4aa995e1 PA |
3849 | if (offset + len > sizeof (siginfo)) |
3850 | len = sizeof (siginfo) - offset; | |
3851 | ||
3852 | if (readbuf != NULL) | |
5b009018 | 3853 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3854 | else |
3855 | { | |
5b009018 PA |
3856 | memcpy (inf_siginfo + offset, writebuf, len); |
3857 | ||
3858 | /* Convert back to ptrace layout before flushing it out. */ | |
3859 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3860 | ||
4aa995e1 PA |
3861 | errno = 0; |
3862 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3863 | if (errno != 0) | |
2ed4b548 | 3864 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3865 | } |
3866 | ||
9b409511 YQ |
3867 | *xfered_len = len; |
3868 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3869 | } |
3870 | ||
9b409511 | 3871 | static enum target_xfer_status |
f6ac5f3d PA |
3872 | linux_nat_xfer_osdata (enum target_object object, |
3873 | const char *annex, gdb_byte *readbuf, | |
3874 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3875 | ULONGEST *xfered_len); | |
3876 | ||
3877 | static enum target_xfer_status | |
3878 | linux_proc_xfer_spu (enum target_object object, | |
3879 | const char *annex, gdb_byte *readbuf, | |
3880 | const gdb_byte *writebuf, | |
3881 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len); | |
3882 | ||
3883 | static enum target_xfer_status | |
3884 | linux_proc_xfer_partial (enum target_object object, | |
3885 | const char *annex, gdb_byte *readbuf, | |
3886 | const gdb_byte *writebuf, | |
3887 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
3888 | ||
3889 | enum target_xfer_status | |
3890 | linux_nat_target::xfer_partial (enum target_object object, | |
3891 | const char *annex, gdb_byte *readbuf, | |
3892 | const gdb_byte *writebuf, | |
3893 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3894 | { |
9b409511 | 3895 | enum target_xfer_status xfer; |
d6b0e80f | 3896 | |
4aa995e1 | 3897 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3898 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3899 | offset, len, xfered_len); |
4aa995e1 | 3900 | |
c35b1492 PA |
3901 | /* The target is connected but no live inferior is selected. Pass |
3902 | this request down to a lower stratum (e.g., the executable | |
3903 | file). */ | |
3904 | if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) | |
9b409511 | 3905 | return TARGET_XFER_EOF; |
c35b1492 | 3906 | |
f6ac5f3d PA |
3907 | if (object == TARGET_OBJECT_AUXV) |
3908 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3909 | offset, len, xfered_len); | |
3910 | ||
3911 | if (object == TARGET_OBJECT_OSDATA) | |
3912 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3913 | offset, len, xfered_len); | |
d6b0e80f | 3914 | |
f6ac5f3d PA |
3915 | if (object == TARGET_OBJECT_SPU) |
3916 | return linux_proc_xfer_spu (object, annex, readbuf, writebuf, | |
3917 | offset, len, xfered_len); | |
3918 | ||
3919 | /* GDB calculates all addresses in the largest possible address | |
3920 | width. | |
3921 | The address width must be masked before its final use - either by | |
3922 | linux_proc_xfer_partial or inf_ptrace_target::xfer_partial. | |
3923 | ||
3924 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
3925 | ||
3926 | if (object == TARGET_OBJECT_MEMORY) | |
3927 | { | |
3928 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); | |
3929 | ||
3930 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3931 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
3932 | } | |
3933 | ||
3934 | xfer = linux_proc_xfer_partial (object, annex, readbuf, writebuf, | |
3935 | offset, len, xfered_len); | |
3936 | if (xfer != TARGET_XFER_EOF) | |
3937 | return xfer; | |
3938 | ||
3939 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3940 | offset, len, xfered_len); | |
d6b0e80f AC |
3941 | } |
3942 | ||
57810aa7 | 3943 | bool |
f6ac5f3d | 3944 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3945 | { |
4a6ed09b PA |
3946 | /* As long as a PTID is in lwp list, consider it alive. */ |
3947 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3948 | } |
3949 | ||
8a06aea7 PA |
3950 | /* Implement the to_update_thread_list target method for this |
3951 | target. */ | |
3952 | ||
f6ac5f3d PA |
3953 | void |
3954 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3955 | { |
a6904d5a PA |
3956 | struct lwp_info *lwp; |
3957 | ||
4a6ed09b PA |
3958 | /* We add/delete threads from the list as clone/exit events are |
3959 | processed, so just try deleting exited threads still in the | |
3960 | thread list. */ | |
3961 | delete_exited_threads (); | |
a6904d5a PA |
3962 | |
3963 | /* Update the processor core that each lwp/thread was last seen | |
3964 | running on. */ | |
3965 | ALL_LWPS (lwp) | |
1ad3de98 PA |
3966 | { |
3967 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3968 | time we fetched the thread's core. Accessing /proc becomes | |
3969 | noticeably expensive when we have thousands of LWPs. */ | |
3970 | if (lwp->core == -1) | |
3971 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3972 | } | |
8a06aea7 PA |
3973 | } |
3974 | ||
f6ac5f3d PA |
3975 | const char * |
3976 | linux_nat_target::pid_to_str (ptid_t ptid) | |
d6b0e80f AC |
3977 | { |
3978 | static char buf[64]; | |
3979 | ||
dfd4cc63 LM |
3980 | if (ptid_lwp_p (ptid) |
3981 | && (ptid_get_pid (ptid) != ptid_get_lwp (ptid) | |
3982 | || num_lwps (ptid_get_pid (ptid)) > 1)) | |
d6b0e80f | 3983 | { |
dfd4cc63 | 3984 | snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid)); |
d6b0e80f AC |
3985 | return buf; |
3986 | } | |
3987 | ||
3988 | return normal_pid_to_str (ptid); | |
3989 | } | |
3990 | ||
f6ac5f3d PA |
3991 | const char * |
3992 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3993 | { |
79efa585 | 3994 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3995 | } |
3996 | ||
dba24537 AC |
3997 | /* Accepts an integer PID; Returns a string representing a file that |
3998 | can be opened to get the symbols for the child process. */ | |
3999 | ||
f6ac5f3d PA |
4000 | char * |
4001 | linux_nat_target::pid_to_exec_file (int pid) | |
dba24537 | 4002 | { |
e0d86d2c | 4003 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
4004 | } |
4005 | ||
a379284a AA |
4006 | /* Implement the to_xfer_partial target method using /proc/<pid>/mem. |
4007 | Because we can use a single read/write call, this can be much more | |
4008 | efficient than banging away at PTRACE_PEEKTEXT. */ | |
10d6c8cd | 4009 | |
9b409511 | 4010 | static enum target_xfer_status |
f6ac5f3d | 4011 | linux_proc_xfer_partial (enum target_object object, |
10d6c8cd DJ |
4012 | const char *annex, gdb_byte *readbuf, |
4013 | const gdb_byte *writebuf, | |
9b409511 | 4014 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len) |
dba24537 | 4015 | { |
10d6c8cd DJ |
4016 | LONGEST ret; |
4017 | int fd; | |
dba24537 AC |
4018 | char filename[64]; |
4019 | ||
a379284a | 4020 | if (object != TARGET_OBJECT_MEMORY) |
f486487f | 4021 | return TARGET_XFER_EOF; |
dba24537 AC |
4022 | |
4023 | /* Don't bother for one word. */ | |
4024 | if (len < 3 * sizeof (long)) | |
9b409511 | 4025 | return TARGET_XFER_EOF; |
dba24537 AC |
4026 | |
4027 | /* We could keep this file open and cache it - possibly one per | |
4028 | thread. That requires some juggling, but is even faster. */ | |
b67aeab0 SM |
4029 | xsnprintf (filename, sizeof filename, "/proc/%ld/mem", |
4030 | ptid_get_lwp (inferior_ptid)); | |
a379284a AA |
4031 | fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY) |
4032 | | O_LARGEFILE), 0); | |
dba24537 | 4033 | if (fd == -1) |
9b409511 | 4034 | return TARGET_XFER_EOF; |
dba24537 | 4035 | |
a379284a AA |
4036 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
4037 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
4038 | debugging a SPARC64 application). */ | |
dba24537 | 4039 | #ifdef HAVE_PREAD64 |
a379284a AA |
4040 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
4041 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 4042 | #else |
a379284a AA |
4043 | ret = lseek (fd, offset, SEEK_SET); |
4044 | if (ret != -1) | |
4045 | ret = (readbuf ? read (fd, readbuf, len) | |
4046 | : write (fd, writebuf, len)); | |
dba24537 | 4047 | #endif |
dba24537 AC |
4048 | |
4049 | close (fd); | |
9b409511 | 4050 | |
a379284a | 4051 | if (ret == -1 || ret == 0) |
9b409511 YQ |
4052 | return TARGET_XFER_EOF; |
4053 | else | |
4054 | { | |
4055 | *xfered_len = ret; | |
4056 | return TARGET_XFER_OK; | |
4057 | } | |
dba24537 AC |
4058 | } |
4059 | ||
efcbbd14 UW |
4060 | |
4061 | /* Enumerate spufs IDs for process PID. */ | |
4062 | static LONGEST | |
b55e14c7 | 4063 | spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len) |
efcbbd14 | 4064 | { |
f5656ead | 4065 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
efcbbd14 UW |
4066 | LONGEST pos = 0; |
4067 | LONGEST written = 0; | |
4068 | char path[128]; | |
4069 | DIR *dir; | |
4070 | struct dirent *entry; | |
4071 | ||
4072 | xsnprintf (path, sizeof path, "/proc/%d/fd", pid); | |
4073 | dir = opendir (path); | |
4074 | if (!dir) | |
4075 | return -1; | |
4076 | ||
4077 | rewinddir (dir); | |
4078 | while ((entry = readdir (dir)) != NULL) | |
4079 | { | |
4080 | struct stat st; | |
4081 | struct statfs stfs; | |
4082 | int fd; | |
4083 | ||
4084 | fd = atoi (entry->d_name); | |
4085 | if (!fd) | |
4086 | continue; | |
4087 | ||
4088 | xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); | |
4089 | if (stat (path, &st) != 0) | |
4090 | continue; | |
4091 | if (!S_ISDIR (st.st_mode)) | |
4092 | continue; | |
4093 | ||
4094 | if (statfs (path, &stfs) != 0) | |
4095 | continue; | |
4096 | if (stfs.f_type != SPUFS_MAGIC) | |
4097 | continue; | |
4098 | ||
4099 | if (pos >= offset && pos + 4 <= offset + len) | |
4100 | { | |
4101 | store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); | |
4102 | written += 4; | |
4103 | } | |
4104 | pos += 4; | |
4105 | } | |
4106 | ||
4107 | closedir (dir); | |
4108 | return written; | |
4109 | } | |
4110 | ||
4111 | /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU | |
4112 | object type, using the /proc file system. */ | |
9b409511 YQ |
4113 | |
4114 | static enum target_xfer_status | |
f6ac5f3d | 4115 | linux_proc_xfer_spu (enum target_object object, |
efcbbd14 UW |
4116 | const char *annex, gdb_byte *readbuf, |
4117 | const gdb_byte *writebuf, | |
9b409511 | 4118 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
efcbbd14 UW |
4119 | { |
4120 | char buf[128]; | |
4121 | int fd = 0; | |
4122 | int ret = -1; | |
b67aeab0 | 4123 | int pid = ptid_get_lwp (inferior_ptid); |
efcbbd14 UW |
4124 | |
4125 | if (!annex) | |
4126 | { | |
4127 | if (!readbuf) | |
2ed4b548 | 4128 | return TARGET_XFER_E_IO; |
efcbbd14 | 4129 | else |
9b409511 YQ |
4130 | { |
4131 | LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len); | |
4132 | ||
4133 | if (l < 0) | |
4134 | return TARGET_XFER_E_IO; | |
4135 | else if (l == 0) | |
4136 | return TARGET_XFER_EOF; | |
4137 | else | |
4138 | { | |
4139 | *xfered_len = (ULONGEST) l; | |
4140 | return TARGET_XFER_OK; | |
4141 | } | |
4142 | } | |
efcbbd14 UW |
4143 | } |
4144 | ||
4145 | xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); | |
614c279d | 4146 | fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0); |
efcbbd14 | 4147 | if (fd <= 0) |
2ed4b548 | 4148 | return TARGET_XFER_E_IO; |
efcbbd14 UW |
4149 | |
4150 | if (offset != 0 | |
4151 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
4152 | { | |
4153 | close (fd); | |
9b409511 | 4154 | return TARGET_XFER_EOF; |
efcbbd14 UW |
4155 | } |
4156 | ||
4157 | if (writebuf) | |
4158 | ret = write (fd, writebuf, (size_t) len); | |
4159 | else if (readbuf) | |
4160 | ret = read (fd, readbuf, (size_t) len); | |
4161 | ||
4162 | close (fd); | |
9b409511 YQ |
4163 | |
4164 | if (ret < 0) | |
4165 | return TARGET_XFER_E_IO; | |
4166 | else if (ret == 0) | |
4167 | return TARGET_XFER_EOF; | |
4168 | else | |
4169 | { | |
4170 | *xfered_len = (ULONGEST) ret; | |
4171 | return TARGET_XFER_OK; | |
4172 | } | |
efcbbd14 UW |
4173 | } |
4174 | ||
4175 | ||
dba24537 AC |
4176 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4177 | ||
4178 | static void | |
4179 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4180 | { | |
4181 | int len = strlen (line) - 1; | |
4182 | const char *p; | |
4183 | int signum; | |
4184 | ||
4185 | if (line[len] != '\n') | |
8a3fe4f8 | 4186 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4187 | |
4188 | p = line; | |
4189 | signum = len * 4; | |
4190 | while (len-- > 0) | |
4191 | { | |
4192 | int digit; | |
4193 | ||
4194 | if (*p >= '0' && *p <= '9') | |
4195 | digit = *p - '0'; | |
4196 | else if (*p >= 'a' && *p <= 'f') | |
4197 | digit = *p - 'a' + 10; | |
4198 | else | |
8a3fe4f8 | 4199 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4200 | |
4201 | signum -= 4; | |
4202 | ||
4203 | if (digit & 1) | |
4204 | sigaddset (sigs, signum + 1); | |
4205 | if (digit & 2) | |
4206 | sigaddset (sigs, signum + 2); | |
4207 | if (digit & 4) | |
4208 | sigaddset (sigs, signum + 3); | |
4209 | if (digit & 8) | |
4210 | sigaddset (sigs, signum + 4); | |
4211 | ||
4212 | p++; | |
4213 | } | |
4214 | } | |
4215 | ||
4216 | /* Find process PID's pending signals from /proc/pid/status and set | |
4217 | SIGS to match. */ | |
4218 | ||
4219 | void | |
3e43a32a MS |
4220 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4221 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4222 | { |
d8d2a3ee | 4223 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4224 | |
4225 | sigemptyset (pending); | |
4226 | sigemptyset (blocked); | |
4227 | sigemptyset (ignored); | |
cde33bf1 | 4228 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4229 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4230 | if (procfile == NULL) |
8a3fe4f8 | 4231 | error (_("Could not open %s"), fname); |
dba24537 | 4232 | |
d419f42d | 4233 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4234 | { |
4235 | /* Normal queued signals are on the SigPnd line in the status | |
4236 | file. However, 2.6 kernels also have a "shared" pending | |
4237 | queue for delivering signals to a thread group, so check for | |
4238 | a ShdPnd line also. | |
4239 | ||
4240 | Unfortunately some Red Hat kernels include the shared pending | |
4241 | queue but not the ShdPnd status field. */ | |
4242 | ||
61012eef | 4243 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4244 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4245 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4246 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4247 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4248 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4249 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4250 | add_line_to_sigset (buffer + 8, ignored); |
4251 | } | |
dba24537 AC |
4252 | } |
4253 | ||
9b409511 | 4254 | static enum target_xfer_status |
f6ac5f3d | 4255 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4256 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4257 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4258 | ULONGEST *xfered_len) | |
07e059b5 | 4259 | { |
07e059b5 VP |
4260 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4261 | ||
9b409511 YQ |
4262 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4263 | if (*xfered_len == 0) | |
4264 | return TARGET_XFER_EOF; | |
4265 | else | |
4266 | return TARGET_XFER_OK; | |
07e059b5 VP |
4267 | } |
4268 | ||
5808517f YQ |
4269 | static void |
4270 | cleanup_target_stop (void *arg) | |
4271 | { | |
4272 | ptid_t *ptid = (ptid_t *) arg; | |
4273 | ||
4274 | gdb_assert (arg != NULL); | |
4275 | ||
4276 | /* Unpause all */ | |
049a8570 | 4277 | target_continue_no_signal (*ptid); |
5808517f YQ |
4278 | } |
4279 | ||
f6ac5f3d PA |
4280 | std::vector<static_tracepoint_marker> |
4281 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4282 | { |
4283 | char s[IPA_CMD_BUF_SIZE]; | |
4284 | struct cleanup *old_chain; | |
4285 | int pid = ptid_get_pid (inferior_ptid); | |
5d9310c4 | 4286 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4287 | const char *p = s; |
5808517f | 4288 | ptid_t ptid = ptid_build (pid, 0, 0); |
5d9310c4 | 4289 | static_tracepoint_marker marker; |
5808517f YQ |
4290 | |
4291 | /* Pause all */ | |
4292 | target_stop (ptid); | |
4293 | ||
4294 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4295 | s[sizeof ("qTfSTM")] = 0; | |
4296 | ||
42476b70 | 4297 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4298 | |
5d9310c4 | 4299 | old_chain = make_cleanup (cleanup_target_stop, &ptid); |
5808517f YQ |
4300 | |
4301 | while (*p++ == 'm') | |
4302 | { | |
5808517f YQ |
4303 | do |
4304 | { | |
5d9310c4 | 4305 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4306 | |
5d9310c4 SM |
4307 | if (strid == NULL || marker.str_id == strid) |
4308 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4309 | } |
4310 | while (*p++ == ','); /* comma-separated list */ | |
4311 | ||
4312 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4313 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4314 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4315 | p = s; |
4316 | } | |
4317 | ||
4318 | do_cleanups (old_chain); | |
4319 | ||
4320 | return markers; | |
4321 | } | |
4322 | ||
b84876c2 PA |
4323 | /* target_is_async_p implementation. */ |
4324 | ||
57810aa7 | 4325 | bool |
f6ac5f3d | 4326 | linux_nat_target::is_async_p () |
b84876c2 | 4327 | { |
198297aa | 4328 | return linux_is_async_p (); |
b84876c2 PA |
4329 | } |
4330 | ||
4331 | /* target_can_async_p implementation. */ | |
4332 | ||
57810aa7 | 4333 | bool |
f6ac5f3d | 4334 | linux_nat_target::can_async_p () |
b84876c2 | 4335 | { |
fde1b17d SM |
4336 | /* We're always async, unless the user explicitly prevented it with the |
4337 | "maint set target-async" command. */ | |
3dd5b83d | 4338 | return target_async_permitted; |
b84876c2 PA |
4339 | } |
4340 | ||
57810aa7 | 4341 | bool |
f6ac5f3d | 4342 | linux_nat_target::supports_non_stop () |
9908b566 VP |
4343 | { |
4344 | return 1; | |
4345 | } | |
4346 | ||
fbea99ea PA |
4347 | /* to_always_non_stop_p implementation. */ |
4348 | ||
57810aa7 | 4349 | bool |
f6ac5f3d | 4350 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4351 | { |
f12899e9 | 4352 | return 1; |
fbea99ea PA |
4353 | } |
4354 | ||
d90e17a7 PA |
4355 | /* True if we want to support multi-process. To be removed when GDB |
4356 | supports multi-exec. */ | |
4357 | ||
2277426b | 4358 | int linux_multi_process = 1; |
d90e17a7 | 4359 | |
57810aa7 | 4360 | bool |
f6ac5f3d | 4361 | linux_nat_target::supports_multi_process () |
d90e17a7 PA |
4362 | { |
4363 | return linux_multi_process; | |
4364 | } | |
4365 | ||
57810aa7 | 4366 | bool |
f6ac5f3d | 4367 | linux_nat_target::supports_disable_randomization () |
03583c20 UW |
4368 | { |
4369 | #ifdef HAVE_PERSONALITY | |
4370 | return 1; | |
4371 | #else | |
4372 | return 0; | |
4373 | #endif | |
4374 | } | |
4375 | ||
7feb7d06 PA |
4376 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4377 | so we notice when any child changes state, and notify the | |
4378 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4379 | above to wait for the arrival of a SIGCHLD. */ | |
4380 | ||
b84876c2 | 4381 | static void |
7feb7d06 | 4382 | sigchld_handler (int signo) |
b84876c2 | 4383 | { |
7feb7d06 PA |
4384 | int old_errno = errno; |
4385 | ||
01124a23 DE |
4386 | if (debug_linux_nat) |
4387 | ui_file_write_async_safe (gdb_stdlog, | |
4388 | "sigchld\n", sizeof ("sigchld\n") - 1); | |
7feb7d06 PA |
4389 | |
4390 | if (signo == SIGCHLD | |
4391 | && linux_nat_event_pipe[0] != -1) | |
4392 | async_file_mark (); /* Let the event loop know that there are | |
4393 | events to handle. */ | |
4394 | ||
4395 | errno = old_errno; | |
4396 | } | |
4397 | ||
4398 | /* Callback registered with the target events file descriptor. */ | |
4399 | ||
4400 | static void | |
4401 | handle_target_event (int error, gdb_client_data client_data) | |
4402 | { | |
6a3753b3 | 4403 | inferior_event_handler (INF_REG_EVENT, NULL); |
7feb7d06 PA |
4404 | } |
4405 | ||
4406 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4407 | ||
4408 | static int | |
4409 | linux_async_pipe (int enable) | |
4410 | { | |
198297aa | 4411 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4412 | |
4413 | if (previous != enable) | |
4414 | { | |
4415 | sigset_t prev_mask; | |
4416 | ||
12696c10 PA |
4417 | /* Block child signals while we create/destroy the pipe, as |
4418 | their handler writes to it. */ | |
7feb7d06 PA |
4419 | block_child_signals (&prev_mask); |
4420 | ||
4421 | if (enable) | |
4422 | { | |
614c279d | 4423 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4424 | internal_error (__FILE__, __LINE__, |
4425 | "creating event pipe failed."); | |
4426 | ||
4427 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4428 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4429 | } | |
4430 | else | |
4431 | { | |
4432 | close (linux_nat_event_pipe[0]); | |
4433 | close (linux_nat_event_pipe[1]); | |
4434 | linux_nat_event_pipe[0] = -1; | |
4435 | linux_nat_event_pipe[1] = -1; | |
4436 | } | |
4437 | ||
4438 | restore_child_signals_mask (&prev_mask); | |
4439 | } | |
4440 | ||
4441 | return previous; | |
b84876c2 PA |
4442 | } |
4443 | ||
4444 | /* target_async implementation. */ | |
4445 | ||
f6ac5f3d PA |
4446 | void |
4447 | linux_nat_target::async (int enable) | |
b84876c2 | 4448 | { |
6a3753b3 | 4449 | if (enable) |
b84876c2 | 4450 | { |
7feb7d06 PA |
4451 | if (!linux_async_pipe (1)) |
4452 | { | |
4453 | add_file_handler (linux_nat_event_pipe[0], | |
4454 | handle_target_event, NULL); | |
4455 | /* There may be pending events to handle. Tell the event loop | |
4456 | to poll them. */ | |
4457 | async_file_mark (); | |
4458 | } | |
b84876c2 PA |
4459 | } |
4460 | else | |
4461 | { | |
b84876c2 | 4462 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4463 | linux_async_pipe (0); |
b84876c2 PA |
4464 | } |
4465 | return; | |
4466 | } | |
4467 | ||
a493e3e2 | 4468 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4469 | event came out. */ |
4470 | ||
4c28f408 | 4471 | static int |
252fbfc8 | 4472 | linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
4c28f408 | 4473 | { |
d90e17a7 | 4474 | if (!lwp->stopped) |
252fbfc8 | 4475 | { |
d90e17a7 PA |
4476 | if (debug_linux_nat) |
4477 | fprintf_unfiltered (gdb_stdlog, | |
4478 | "LNSL: running -> suspending %s\n", | |
4479 | target_pid_to_str (lwp->ptid)); | |
252fbfc8 | 4480 | |
252fbfc8 | 4481 | |
25289eb2 PA |
4482 | if (lwp->last_resume_kind == resume_stop) |
4483 | { | |
4484 | if (debug_linux_nat) | |
4485 | fprintf_unfiltered (gdb_stdlog, | |
4486 | "linux-nat: already stopping LWP %ld at " | |
4487 | "GDB's request\n", | |
4488 | ptid_get_lwp (lwp->ptid)); | |
4489 | return 0; | |
4490 | } | |
252fbfc8 | 4491 | |
25289eb2 PA |
4492 | stop_callback (lwp, NULL); |
4493 | lwp->last_resume_kind = resume_stop; | |
d90e17a7 PA |
4494 | } |
4495 | else | |
4496 | { | |
4497 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4498 | |
d90e17a7 PA |
4499 | if (debug_linux_nat) |
4500 | { | |
e09875d4 | 4501 | if (find_thread_ptid (lwp->ptid)->stop_requested) |
3e43a32a MS |
4502 | fprintf_unfiltered (gdb_stdlog, |
4503 | "LNSL: already stopped/stop_requested %s\n", | |
d90e17a7 PA |
4504 | target_pid_to_str (lwp->ptid)); |
4505 | else | |
3e43a32a MS |
4506 | fprintf_unfiltered (gdb_stdlog, |
4507 | "LNSL: already stopped/no " | |
4508 | "stop_requested yet %s\n", | |
d90e17a7 | 4509 | target_pid_to_str (lwp->ptid)); |
252fbfc8 PA |
4510 | } |
4511 | } | |
4c28f408 PA |
4512 | return 0; |
4513 | } | |
4514 | ||
f6ac5f3d PA |
4515 | void |
4516 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4517 | { |
bfedc46a PA |
4518 | iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
4519 | } | |
4520 | ||
f6ac5f3d PA |
4521 | void |
4522 | linux_nat_target::close () | |
d90e17a7 PA |
4523 | { |
4524 | /* Unregister from the event loop. */ | |
f6ac5f3d PA |
4525 | if (is_async_p ()) |
4526 | async (0); | |
d90e17a7 | 4527 | |
f6ac5f3d | 4528 | inf_ptrace_target::close (); |
d90e17a7 PA |
4529 | } |
4530 | ||
c0694254 PA |
4531 | /* When requests are passed down from the linux-nat layer to the |
4532 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4533 | used. The address space pointer is stored in the inferior object, | |
4534 | but the common code that is passed such ptid can't tell whether | |
4535 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4536 | look up the "main" process id from the lwp here. */ | |
4537 | ||
f6ac5f3d PA |
4538 | struct address_space * |
4539 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4540 | { |
4541 | struct lwp_info *lwp; | |
4542 | struct inferior *inf; | |
4543 | int pid; | |
4544 | ||
dfd4cc63 | 4545 | if (ptid_get_lwp (ptid) == 0) |
c0694254 PA |
4546 | { |
4547 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4548 | tgid. */ | |
4549 | lwp = find_lwp_pid (ptid); | |
dfd4cc63 | 4550 | pid = ptid_get_pid (lwp->ptid); |
c0694254 PA |
4551 | } |
4552 | else | |
4553 | { | |
4554 | /* A (pid,lwpid,0) ptid. */ | |
dfd4cc63 | 4555 | pid = ptid_get_pid (ptid); |
c0694254 PA |
4556 | } |
4557 | ||
4558 | inf = find_inferior_pid (pid); | |
4559 | gdb_assert (inf != NULL); | |
4560 | return inf->aspace; | |
4561 | } | |
4562 | ||
dc146f7c VP |
4563 | /* Return the cached value of the processor core for thread PTID. */ |
4564 | ||
f6ac5f3d PA |
4565 | int |
4566 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4567 | { |
4568 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4569 | |
dc146f7c VP |
4570 | if (info) |
4571 | return info->core; | |
4572 | return -1; | |
4573 | } | |
4574 | ||
7a6a1731 GB |
4575 | /* Implementation of to_filesystem_is_local. */ |
4576 | ||
57810aa7 | 4577 | bool |
f6ac5f3d | 4578 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4579 | { |
4580 | struct inferior *inf = current_inferior (); | |
4581 | ||
4582 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4583 | return true; |
7a6a1731 GB |
4584 | |
4585 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4586 | } | |
4587 | ||
4588 | /* Convert the INF argument passed to a to_fileio_* method | |
4589 | to a process ID suitable for passing to its corresponding | |
4590 | linux_mntns_* function. If INF is non-NULL then the | |
4591 | caller is requesting the filesystem seen by INF. If INF | |
4592 | is NULL then the caller is requesting the filesystem seen | |
4593 | by the GDB. We fall back to GDB's filesystem in the case | |
4594 | that INF is non-NULL but its PID is unknown. */ | |
4595 | ||
4596 | static pid_t | |
4597 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4598 | { | |
4599 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4600 | return getpid (); | |
4601 | else | |
4602 | return inf->pid; | |
4603 | } | |
4604 | ||
4605 | /* Implementation of to_fileio_open. */ | |
4606 | ||
f6ac5f3d PA |
4607 | int |
4608 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4609 | int flags, int mode, int warn_if_slow, | |
4610 | int *target_errno) | |
7a6a1731 GB |
4611 | { |
4612 | int nat_flags; | |
4613 | mode_t nat_mode; | |
4614 | int fd; | |
4615 | ||
4616 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4617 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4618 | { | |
4619 | *target_errno = FILEIO_EINVAL; | |
4620 | return -1; | |
4621 | } | |
4622 | ||
4623 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4624 | filename, nat_flags, nat_mode); | |
4625 | if (fd == -1) | |
4626 | *target_errno = host_to_fileio_error (errno); | |
4627 | ||
4628 | return fd; | |
4629 | } | |
4630 | ||
4631 | /* Implementation of to_fileio_readlink. */ | |
4632 | ||
f6ac5f3d PA |
4633 | gdb::optional<std::string> |
4634 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
4635 | int *target_errno) | |
7a6a1731 GB |
4636 | { |
4637 | char buf[PATH_MAX]; | |
4638 | int len; | |
7a6a1731 GB |
4639 | |
4640 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4641 | filename, buf, sizeof (buf)); | |
4642 | if (len < 0) | |
4643 | { | |
4644 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4645 | return {}; |
7a6a1731 GB |
4646 | } |
4647 | ||
e0d3522b | 4648 | return std::string (buf, len); |
7a6a1731 GB |
4649 | } |
4650 | ||
4651 | /* Implementation of to_fileio_unlink. */ | |
4652 | ||
f6ac5f3d PA |
4653 | int |
4654 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
4655 | int *target_errno) | |
7a6a1731 GB |
4656 | { |
4657 | int ret; | |
4658 | ||
4659 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4660 | filename); | |
4661 | if (ret == -1) | |
4662 | *target_errno = host_to_fileio_error (errno); | |
4663 | ||
4664 | return ret; | |
4665 | } | |
4666 | ||
aa01bd36 PA |
4667 | /* Implementation of the to_thread_events method. */ |
4668 | ||
f6ac5f3d PA |
4669 | void |
4670 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4671 | { |
4672 | report_thread_events = enable; | |
4673 | } | |
4674 | ||
f6ac5f3d PA |
4675 | linux_nat_target::linux_nat_target () |
4676 | { | |
f973ed9c DJ |
4677 | /* We don't change the stratum; this target will sit at |
4678 | process_stratum and thread_db will set at thread_stratum. This | |
4679 | is a little strange, since this is a multi-threaded-capable | |
4680 | target, but we want to be on the stack below thread_db, and we | |
4681 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4682 | } |
4683 | ||
9f0bdab8 DJ |
4684 | /* Register a method to call whenever a new thread is attached. */ |
4685 | void | |
7b50312a PA |
4686 | linux_nat_set_new_thread (struct target_ops *t, |
4687 | void (*new_thread) (struct lwp_info *)) | |
9f0bdab8 DJ |
4688 | { |
4689 | /* Save the pointer. We only support a single registered instance | |
4690 | of the GNU/Linux native target, so we do not need to map this to | |
4691 | T. */ | |
4692 | linux_nat_new_thread = new_thread; | |
4693 | } | |
4694 | ||
466eecee SM |
4695 | /* Register a method to call whenever a new thread is attached. */ |
4696 | void | |
4697 | linux_nat_set_delete_thread (struct target_ops *t, | |
4698 | void (*delete_thread) (struct arch_lwp_info *)) | |
4699 | { | |
4700 | /* Save the pointer. We only support a single registered instance | |
4701 | of the GNU/Linux native target, so we do not need to map this to | |
4702 | T. */ | |
4703 | linux_nat_delete_thread = delete_thread; | |
4704 | } | |
4705 | ||
26cb8b7c PA |
4706 | /* See declaration in linux-nat.h. */ |
4707 | ||
4708 | void | |
4709 | linux_nat_set_new_fork (struct target_ops *t, | |
4710 | linux_nat_new_fork_ftype *new_fork) | |
4711 | { | |
4712 | /* Save the pointer. */ | |
4713 | linux_nat_new_fork = new_fork; | |
4714 | } | |
4715 | ||
4716 | /* See declaration in linux-nat.h. */ | |
4717 | ||
4718 | void | |
4719 | linux_nat_set_forget_process (struct target_ops *t, | |
4720 | linux_nat_forget_process_ftype *fn) | |
4721 | { | |
4722 | /* Save the pointer. */ | |
4723 | linux_nat_forget_process_hook = fn; | |
4724 | } | |
4725 | ||
4726 | /* See declaration in linux-nat.h. */ | |
4727 | ||
4728 | void | |
4729 | linux_nat_forget_process (pid_t pid) | |
4730 | { | |
4731 | if (linux_nat_forget_process_hook != NULL) | |
4732 | linux_nat_forget_process_hook (pid); | |
4733 | } | |
4734 | ||
5b009018 PA |
4735 | /* Register a method that converts a siginfo object between the layout |
4736 | that ptrace returns, and the layout in the architecture of the | |
4737 | inferior. */ | |
4738 | void | |
4739 | linux_nat_set_siginfo_fixup (struct target_ops *t, | |
a5362b9a | 4740 | int (*siginfo_fixup) (siginfo_t *, |
5b009018 PA |
4741 | gdb_byte *, |
4742 | int)) | |
4743 | { | |
4744 | /* Save the pointer. */ | |
4745 | linux_nat_siginfo_fixup = siginfo_fixup; | |
4746 | } | |
4747 | ||
7b50312a PA |
4748 | /* Register a method to call prior to resuming a thread. */ |
4749 | ||
4750 | void | |
4751 | linux_nat_set_prepare_to_resume (struct target_ops *t, | |
4752 | void (*prepare_to_resume) (struct lwp_info *)) | |
4753 | { | |
4754 | /* Save the pointer. */ | |
4755 | linux_nat_prepare_to_resume = prepare_to_resume; | |
4756 | } | |
4757 | ||
f865ee35 JK |
4758 | /* See linux-nat.h. */ |
4759 | ||
4760 | int | |
4761 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4762 | { |
da559b09 | 4763 | int pid; |
9f0bdab8 | 4764 | |
dfd4cc63 | 4765 | pid = ptid_get_lwp (ptid); |
da559b09 | 4766 | if (pid == 0) |
dfd4cc63 | 4767 | pid = ptid_get_pid (ptid); |
f865ee35 | 4768 | |
da559b09 JK |
4769 | errno = 0; |
4770 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4771 | if (errno != 0) | |
4772 | { | |
4773 | memset (siginfo, 0, sizeof (*siginfo)); | |
4774 | return 0; | |
4775 | } | |
f865ee35 | 4776 | return 1; |
9f0bdab8 DJ |
4777 | } |
4778 | ||
7b669087 GB |
4779 | /* See nat/linux-nat.h. */ |
4780 | ||
4781 | ptid_t | |
4782 | current_lwp_ptid (void) | |
4783 | { | |
4784 | gdb_assert (ptid_lwp_p (inferior_ptid)); | |
4785 | return inferior_ptid; | |
4786 | } | |
4787 | ||
d6b0e80f AC |
4788 | void |
4789 | _initialize_linux_nat (void) | |
4790 | { | |
ccce17b0 YQ |
4791 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4792 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4793 | Set debugging of GNU/Linux lwp module."), _("\ |
4794 | Show debugging of GNU/Linux lwp module."), _("\ | |
4795 | Enables printf debugging output."), | |
ccce17b0 YQ |
4796 | NULL, |
4797 | show_debug_linux_nat, | |
4798 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4799 | |
7a6a1731 GB |
4800 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4801 | &debug_linux_namespaces, _("\ | |
4802 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4803 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4804 | Enables printf debugging output."), | |
4805 | NULL, | |
4806 | NULL, | |
4807 | &setdebuglist, &showdebuglist); | |
4808 | ||
b84876c2 | 4809 | /* Save this mask as the default. */ |
d6b0e80f AC |
4810 | sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
4811 | ||
7feb7d06 PA |
4812 | /* Install a SIGCHLD handler. */ |
4813 | sigchld_action.sa_handler = sigchld_handler; | |
4814 | sigemptyset (&sigchld_action.sa_mask); | |
4815 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4816 | |
4817 | /* Make it the default. */ | |
7feb7d06 | 4818 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4819 | |
4820 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
4821 | sigprocmask (SIG_SETMASK, NULL, &suspend_mask); | |
4822 | sigdelset (&suspend_mask, SIGCHLD); | |
4823 | ||
7feb7d06 | 4824 | sigemptyset (&blocked_mask); |
774113b0 PA |
4825 | |
4826 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4827 | } |
4828 | \f | |
4829 | ||
4830 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4831 | the GNU/Linux Threads library and therefore doesn't really belong | |
4832 | here. */ | |
4833 | ||
d6b0e80f AC |
4834 | /* Return the set of signals used by the threads library in *SET. */ |
4835 | ||
4836 | void | |
4837 | lin_thread_get_thread_signals (sigset_t *set) | |
4838 | { | |
d6b0e80f AC |
4839 | sigemptyset (set); |
4840 | ||
4a6ed09b PA |
4841 | /* NPTL reserves the first two RT signals, but does not provide any |
4842 | way for the debugger to query the signal numbers - fortunately | |
4843 | they don't change. */ | |
4844 | sigaddset (set, __SIGRTMIN); | |
4845 | sigaddset (set, __SIGRTMIN + 1); | |
d6b0e80f | 4846 | } |