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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
3666a048 | 3 | Copyright (C) 2001-2021 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" | |
268a13a5 | 26 | #include "gdbsupport/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 | 49 | #include "inf-loop.h" |
400b5eca | 50 | #include "gdbsupport/event-loop.h" |
b84876c2 | 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" |
268a13a5 | 61 | #include "gdbsupport/agent.h" |
5808517f | 62 | #include "tracepoint.h" |
268a13a5 | 63 | #include "gdbsupport/buffer.h" |
6ecd4729 | 64 | #include "target-descriptions.h" |
268a13a5 | 65 | #include "gdbsupport/filestuff.h" |
77e371c0 | 66 | #include "objfiles.h" |
7a6a1731 | 67 | #include "nat/linux-namespaces.h" |
268a13a5 TT |
68 | #include "gdbsupport/fileio.h" |
69 | #include "gdbsupport/scope-exit.h" | |
21987b9c | 70 | #include "gdbsupport/gdb-sigmask.h" |
ba988419 | 71 | #include "gdbsupport/common-debug.h" |
efcbbd14 | 72 | |
1777feb0 | 73 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
74 | |
75 | Waiting for events in sync mode | |
76 | =============================== | |
77 | ||
4a6ed09b PA |
78 | When waiting for an event in a specific thread, we just use waitpid, |
79 | passing the specific pid, and not passing WNOHANG. | |
80 | ||
81 | When waiting for an event in all threads, waitpid is not quite good: | |
82 | ||
83 | - If the thread group leader exits while other threads in the thread | |
84 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
85 | return an exit status until the other threads in the group are | |
86 | reaped. | |
87 | ||
88 | - When a non-leader thread execs, that thread just vanishes without | |
89 | reporting an exit (so we'd hang if we waited for it explicitly in | |
90 | that case). The exec event is instead reported to the TGID pid. | |
91 | ||
92 | The solution is to always use -1 and WNOHANG, together with | |
93 | sigsuspend. | |
94 | ||
95 | First, we use non-blocking waitpid to check for events. If nothing is | |
96 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
97 | it means something happened to a child process. As soon as we know | |
98 | there's an event, we get back to calling nonblocking waitpid. | |
99 | ||
100 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
101 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
102 | when it's blocked, the signal becomes pending and sigsuspend | |
103 | immediately notices it and returns. | |
104 | ||
105 | Waiting for events in async mode (TARGET_WNOHANG) | |
106 | ================================================= | |
8a77dff3 | 107 | |
7feb7d06 PA |
108 | In async mode, GDB should always be ready to handle both user input |
109 | and target events, so neither blocking waitpid nor sigsuspend are | |
110 | viable options. Instead, we should asynchronously notify the GDB main | |
111 | event loop whenever there's an unprocessed event from the target. We | |
112 | detect asynchronous target events by handling SIGCHLD signals. To | |
113 | notify the event loop about target events, the self-pipe trick is used | |
114 | --- a pipe is registered as waitable event source in the event loop, | |
115 | the event loop select/poll's on the read end of this pipe (as well on | |
116 | other event sources, e.g., stdin), and the SIGCHLD handler writes a | |
117 | byte to this pipe. This is more portable than relying on | |
118 | pselect/ppoll, since on kernels that lack those syscalls, libc | |
119 | emulates them with select/poll+sigprocmask, and that is racy | |
120 | (a.k.a. plain broken). | |
121 | ||
122 | Obviously, if we fail to notify the event loop if there's a target | |
123 | event, it's bad. OTOH, if we notify the event loop when there's no | |
124 | event from the target, linux_nat_wait will detect that there's no real | |
125 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
126 | This is mostly harmless, but it will waste time and is better avoided. | |
127 | ||
128 | The main design point is that every time GDB is outside linux-nat.c, | |
129 | we have a SIGCHLD handler installed that is called when something | |
130 | happens to the target and notifies the GDB event loop. Whenever GDB | |
131 | core decides to handle the event, and calls into linux-nat.c, we | |
132 | process things as in sync mode, except that the we never block in | |
133 | sigsuspend. | |
134 | ||
135 | While processing an event, we may end up momentarily blocked in | |
136 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
137 | return quickly. E.g., in all-stop mode, before reporting to the core | |
138 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
139 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
140 | Note that this is different from blocking indefinitely waiting for the | |
141 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
142 | |
143 | Use of signals | |
144 | ============== | |
145 | ||
146 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
147 | signal is not entirely significant; we just need for a signal to be delivered, | |
148 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
149 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
150 | be queued once; we do not keep track of other sources of SIGSTOP. | |
151 | ||
152 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
153 | use them, because they have special behavior when the signal is generated - | |
154 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
155 | kills the entire thread group. | |
156 | ||
157 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
158 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
159 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
160 | ||
161 | We could use a real-time signal instead. This would solve those problems; we | |
162 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
163 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
164 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
165 | blocked. |
166 | ||
167 | Exec events | |
168 | =========== | |
169 | ||
170 | The case of a thread group (process) with 3 or more threads, and a | |
171 | thread other than the leader execs is worth detailing: | |
172 | ||
173 | On an exec, the Linux kernel destroys all threads except the execing | |
174 | one in the thread group, and resets the execing thread's tid to the | |
175 | tgid. No exit notification is sent for the execing thread -- from the | |
176 | ptracer's perspective, it appears as though the execing thread just | |
177 | vanishes. Until we reap all other threads except the leader and the | |
178 | execing thread, the leader will be zombie, and the execing thread will | |
179 | be in `D (disc sleep)' state. As soon as all other threads are | |
180 | reaped, the execing thread changes its tid to the tgid, and the | |
181 | previous (zombie) leader vanishes, giving place to the "new" | |
182 | leader. */ | |
a0ef4274 | 183 | |
dba24537 AC |
184 | #ifndef O_LARGEFILE |
185 | #define O_LARGEFILE 0 | |
186 | #endif | |
0274a8ce | 187 | |
f6ac5f3d PA |
188 | struct linux_nat_target *linux_target; |
189 | ||
433bbbf8 | 190 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 191 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 192 | |
ccce17b0 | 193 | static unsigned int debug_linux_nat; |
920d2a44 AC |
194 | static void |
195 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
196 | struct cmd_list_element *c, const char *value) | |
197 | { | |
198 | fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), | |
199 | value); | |
200 | } | |
d6b0e80f | 201 | |
17417fb0 | 202 | /* Print a linux-nat debug statement. */ |
9327494e SM |
203 | |
204 | #define linux_nat_debug_printf(fmt, ...) \ | |
74b773fc | 205 | debug_prefixed_printf_cond (debug_linux_nat, "linux-nat", fmt, ##__VA_ARGS__) |
9327494e | 206 | |
ae087d01 DJ |
207 | struct simple_pid_list |
208 | { | |
209 | int pid; | |
3d799a95 | 210 | int status; |
ae087d01 DJ |
211 | struct simple_pid_list *next; |
212 | }; | |
05c309a8 | 213 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 214 | |
aa01bd36 PA |
215 | /* Whether target_thread_events is in effect. */ |
216 | static int report_thread_events; | |
217 | ||
3dd5b83d PA |
218 | /* Async mode support. */ |
219 | ||
b84876c2 PA |
220 | /* The read/write ends of the pipe registered as waitable file in the |
221 | event loop. */ | |
222 | static int linux_nat_event_pipe[2] = { -1, -1 }; | |
223 | ||
198297aa PA |
224 | /* True if we're currently in async mode. */ |
225 | #define linux_is_async_p() (linux_nat_event_pipe[0] != -1) | |
226 | ||
7feb7d06 | 227 | /* Flush the event pipe. */ |
b84876c2 | 228 | |
7feb7d06 PA |
229 | static void |
230 | async_file_flush (void) | |
b84876c2 | 231 | { |
7feb7d06 PA |
232 | int ret; |
233 | char buf; | |
b84876c2 | 234 | |
7feb7d06 | 235 | do |
b84876c2 | 236 | { |
7feb7d06 | 237 | ret = read (linux_nat_event_pipe[0], &buf, 1); |
b84876c2 | 238 | } |
7feb7d06 | 239 | while (ret >= 0 || (ret == -1 && errno == EINTR)); |
b84876c2 PA |
240 | } |
241 | ||
7feb7d06 PA |
242 | /* Put something (anything, doesn't matter what, or how much) in event |
243 | pipe, so that the select/poll in the event-loop realizes we have | |
244 | something to process. */ | |
252fbfc8 | 245 | |
b84876c2 | 246 | static void |
7feb7d06 | 247 | async_file_mark (void) |
b84876c2 | 248 | { |
7feb7d06 | 249 | int ret; |
b84876c2 | 250 | |
7feb7d06 PA |
251 | /* It doesn't really matter what the pipe contains, as long we end |
252 | up with something in it. Might as well flush the previous | |
253 | left-overs. */ | |
254 | async_file_flush (); | |
b84876c2 | 255 | |
7feb7d06 | 256 | do |
b84876c2 | 257 | { |
7feb7d06 | 258 | ret = write (linux_nat_event_pipe[1], "+", 1); |
b84876c2 | 259 | } |
7feb7d06 | 260 | while (ret == -1 && errno == EINTR); |
b84876c2 | 261 | |
7feb7d06 PA |
262 | /* Ignore EAGAIN. If the pipe is full, the event loop will already |
263 | be awakened anyway. */ | |
b84876c2 PA |
264 | } |
265 | ||
7feb7d06 PA |
266 | static int kill_lwp (int lwpid, int signo); |
267 | ||
d3a70e03 | 268 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
269 | |
270 | static void block_child_signals (sigset_t *prev_mask); | |
271 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
272 | |
273 | struct lwp_info; | |
274 | static struct lwp_info *add_lwp (ptid_t ptid); | |
275 | static void purge_lwp_list (int pid); | |
4403d8e9 | 276 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
277 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
278 | ||
8a99810d PA |
279 | static int lwp_status_pending_p (struct lwp_info *lp); |
280 | ||
e7ad2f14 PA |
281 | static void save_stop_reason (struct lwp_info *lp); |
282 | ||
05c06f31 PA |
283 | static void maybe_close_proc_mem_file (pid_t pid); |
284 | ||
cff068da GB |
285 | \f |
286 | /* LWP accessors. */ | |
287 | ||
288 | /* See nat/linux-nat.h. */ | |
289 | ||
290 | ptid_t | |
291 | ptid_of_lwp (struct lwp_info *lwp) | |
292 | { | |
293 | return lwp->ptid; | |
294 | } | |
295 | ||
296 | /* See nat/linux-nat.h. */ | |
297 | ||
4b134ca1 GB |
298 | void |
299 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
300 | struct arch_lwp_info *info) | |
301 | { | |
302 | lwp->arch_private = info; | |
303 | } | |
304 | ||
305 | /* See nat/linux-nat.h. */ | |
306 | ||
307 | struct arch_lwp_info * | |
308 | lwp_arch_private_info (struct lwp_info *lwp) | |
309 | { | |
310 | return lwp->arch_private; | |
311 | } | |
312 | ||
313 | /* See nat/linux-nat.h. */ | |
314 | ||
cff068da GB |
315 | int |
316 | lwp_is_stopped (struct lwp_info *lwp) | |
317 | { | |
318 | return lwp->stopped; | |
319 | } | |
320 | ||
321 | /* See nat/linux-nat.h. */ | |
322 | ||
323 | enum target_stop_reason | |
324 | lwp_stop_reason (struct lwp_info *lwp) | |
325 | { | |
326 | return lwp->stop_reason; | |
327 | } | |
328 | ||
0e00e962 AA |
329 | /* See nat/linux-nat.h. */ |
330 | ||
331 | int | |
332 | lwp_is_stepping (struct lwp_info *lwp) | |
333 | { | |
334 | return lwp->step; | |
335 | } | |
336 | ||
ae087d01 DJ |
337 | \f |
338 | /* Trivial list manipulation functions to keep track of a list of | |
339 | new stopped processes. */ | |
340 | static void | |
3d799a95 | 341 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 342 | { |
8d749320 | 343 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 344 | |
ae087d01 | 345 | new_pid->pid = pid; |
3d799a95 | 346 | new_pid->status = status; |
ae087d01 DJ |
347 | new_pid->next = *listp; |
348 | *listp = new_pid; | |
349 | } | |
350 | ||
351 | static int | |
46a96992 | 352 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
353 | { |
354 | struct simple_pid_list **p; | |
355 | ||
356 | for (p = listp; *p != NULL; p = &(*p)->next) | |
357 | if ((*p)->pid == pid) | |
358 | { | |
359 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 360 | |
46a96992 | 361 | *statusp = (*p)->status; |
ae087d01 DJ |
362 | xfree (*p); |
363 | *p = next; | |
364 | return 1; | |
365 | } | |
366 | return 0; | |
367 | } | |
368 | ||
de0d863e DB |
369 | /* Return the ptrace options that we want to try to enable. */ |
370 | ||
371 | static int | |
372 | linux_nat_ptrace_options (int attached) | |
373 | { | |
374 | int options = 0; | |
375 | ||
376 | if (!attached) | |
377 | options |= PTRACE_O_EXITKILL; | |
378 | ||
379 | options |= (PTRACE_O_TRACESYSGOOD | |
380 | | PTRACE_O_TRACEVFORKDONE | |
381 | | PTRACE_O_TRACEVFORK | |
382 | | PTRACE_O_TRACEFORK | |
383 | | PTRACE_O_TRACEEXEC); | |
384 | ||
385 | return options; | |
386 | } | |
387 | ||
1b919490 VB |
388 | /* Initialize ptrace and procfs warnings and check for supported |
389 | ptrace features given PID. | |
beed38b8 JB |
390 | |
391 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
392 | |
393 | static void | |
1b919490 | 394 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 395 | { |
de0d863e DB |
396 | int options = linux_nat_ptrace_options (attached); |
397 | ||
398 | linux_enable_event_reporting (pid, options); | |
96d7229d | 399 | linux_ptrace_init_warnings (); |
1b919490 | 400 | linux_proc_init_warnings (); |
4de4c07c DJ |
401 | } |
402 | ||
f6ac5f3d PA |
403 | linux_nat_target::~linux_nat_target () |
404 | {} | |
405 | ||
406 | void | |
407 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 408 | { |
1b919490 | 409 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
410 | } |
411 | ||
f6ac5f3d PA |
412 | void |
413 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 414 | { |
1b919490 | 415 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
416 | } |
417 | ||
4403d8e9 JK |
418 | /* Return the number of known LWPs in the tgid given by PID. */ |
419 | ||
420 | static int | |
421 | num_lwps (int pid) | |
422 | { | |
423 | int count = 0; | |
4403d8e9 | 424 | |
901b9821 | 425 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 426 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
427 | count++; |
428 | ||
429 | return count; | |
430 | } | |
431 | ||
169bb27b | 432 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 433 | |
169bb27b | 434 | struct lwp_deleter |
4403d8e9 | 435 | { |
169bb27b AB |
436 | void operator() (struct lwp_info *lwp) const |
437 | { | |
438 | delete_lwp (lwp->ptid); | |
439 | } | |
440 | }; | |
4403d8e9 | 441 | |
169bb27b AB |
442 | /* A unique_ptr specialisation for lwp_info. */ |
443 | ||
444 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 445 | |
82d1f134 | 446 | /* Target hook for follow_fork. */ |
d83ad864 | 447 | |
e97007b6 | 448 | void |
82d1f134 SM |
449 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
450 | target_waitkind fork_kind, bool follow_child, | |
451 | bool detach_fork) | |
3993f6b1 | 452 | { |
82d1f134 SM |
453 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
454 | follow_child, detach_fork); | |
455 | ||
d83ad864 | 456 | if (!follow_child) |
4de4c07c | 457 | { |
3a849a34 SM |
458 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
459 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
460 | int parent_pid = parent_ptid.lwp (); |
461 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 462 | |
1777feb0 | 463 | /* We're already attached to the parent, by default. */ |
3a849a34 | 464 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
465 | child_lp->stopped = 1; |
466 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 467 | |
ac264b3b MS |
468 | /* Detach new forked process? */ |
469 | if (detach_fork) | |
f75c00e4 | 470 | { |
95347337 AB |
471 | int child_stop_signal = 0; |
472 | bool detach_child = true; | |
4403d8e9 | 473 | |
169bb27b AB |
474 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
475 | to prevent us doing anything stupid with it. */ | |
476 | lwp_info_up child_lp_ptr (child_lp); | |
477 | child_lp = nullptr; | |
478 | ||
479 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
480 | |
481 | /* When debugging an inferior in an architecture that supports | |
482 | hardware single stepping on a kernel without commit | |
483 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
484 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
485 | set if the parent process had them set. | |
486 | To work around this, single step the child process | |
487 | once before detaching to clear the flags. */ | |
488 | ||
2fd9d7ca PA |
489 | /* Note that we consult the parent's architecture instead of |
490 | the child's because there's no inferior for the child at | |
491 | this point. */ | |
c077881a | 492 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 493 | (parent_ptid))) |
c077881a | 494 | { |
95347337 AB |
495 | int status; |
496 | ||
c077881a HZ |
497 | linux_disable_event_reporting (child_pid); |
498 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
499 | perror_with_name (_("Couldn't do single step")); | |
500 | if (my_waitpid (child_pid, &status, 0) < 0) | |
501 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
502 | else |
503 | { | |
504 | detach_child = WIFSTOPPED (status); | |
505 | child_stop_signal = WSTOPSIG (status); | |
506 | } | |
c077881a HZ |
507 | } |
508 | ||
95347337 | 509 | if (detach_child) |
9caaaa83 | 510 | { |
95347337 | 511 | int signo = child_stop_signal; |
9caaaa83 | 512 | |
9caaaa83 PA |
513 | if (signo != 0 |
514 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
515 | signo = 0; | |
516 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
517 | } | |
ac264b3b | 518 | } |
9016a515 DJ |
519 | |
520 | if (has_vforked) | |
521 | { | |
3ced3da4 | 522 | struct lwp_info *parent_lp; |
6c95b8df | 523 | |
79639e11 | 524 | parent_lp = find_lwp_pid (parent_ptid); |
96d7229d | 525 | gdb_assert (linux_supports_tracefork () >= 0); |
3ced3da4 | 526 | |
96d7229d | 527 | if (linux_supports_tracevforkdone ()) |
9016a515 | 528 | { |
9327494e SM |
529 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", |
530 | parent_pid); | |
3ced3da4 | 531 | parent_lp->stopped = 1; |
9016a515 | 532 | |
6c95b8df PA |
533 | /* We'll handle the VFORK_DONE event like any other |
534 | event, in target_wait. */ | |
9016a515 DJ |
535 | } |
536 | else | |
537 | { | |
538 | /* We can't insert breakpoints until the child has | |
539 | finished with the shared memory region. We need to | |
540 | wait until that happens. Ideal would be to just | |
541 | call: | |
542 | - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); | |
543 | - waitpid (parent_pid, &status, __WALL); | |
544 | However, most architectures can't handle a syscall | |
545 | being traced on the way out if it wasn't traced on | |
546 | the way in. | |
547 | ||
548 | We might also think to loop, continuing the child | |
549 | until it exits or gets a SIGTRAP. One problem is | |
550 | that the child might call ptrace with PTRACE_TRACEME. | |
551 | ||
552 | There's no simple and reliable way to figure out when | |
553 | the vforked child will be done with its copy of the | |
554 | shared memory. We could step it out of the syscall, | |
555 | two instructions, let it go, and then single-step the | |
556 | parent once. When we have hardware single-step, this | |
557 | would work; with software single-step it could still | |
558 | be made to work but we'd have to be able to insert | |
559 | single-step breakpoints in the child, and we'd have | |
560 | to insert -just- the single-step breakpoint in the | |
561 | parent. Very awkward. | |
562 | ||
563 | In the end, the best we can do is to make sure it | |
564 | runs for a little while. Hopefully it will be out of | |
565 | range of any breakpoints we reinsert. Usually this | |
566 | is only the single-step breakpoint at vfork's return | |
567 | point. */ | |
568 | ||
9327494e | 569 | linux_nat_debug_printf ("no VFORK_DONE support, sleeping a bit"); |
6c95b8df | 570 | |
9016a515 | 571 | usleep (10000); |
9016a515 | 572 | |
6c95b8df PA |
573 | /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
574 | and leave it pending. The next linux_nat_resume call | |
575 | will notice a pending event, and bypasses actually | |
576 | resuming the inferior. */ | |
3ced3da4 | 577 | parent_lp->status = 0; |
183be222 | 578 | parent_lp->waitstatus.set_vfork_done (); |
3ced3da4 | 579 | parent_lp->stopped = 1; |
6c95b8df PA |
580 | |
581 | /* If we're in async mode, need to tell the event loop | |
582 | there's something here to process. */ | |
d9d41e78 | 583 | if (target_is_async_p ()) |
6c95b8df PA |
584 | async_file_mark (); |
585 | } | |
9016a515 | 586 | } |
4de4c07c | 587 | } |
3993f6b1 | 588 | else |
4de4c07c | 589 | { |
3ced3da4 | 590 | struct lwp_info *child_lp; |
4de4c07c | 591 | |
82d1f134 | 592 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 593 | child_lp->stopped = 1; |
25289eb2 | 594 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 595 | } |
4de4c07c DJ |
596 | } |
597 | ||
4de4c07c | 598 | \f |
f6ac5f3d PA |
599 | int |
600 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 601 | { |
96d7229d | 602 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
603 | } |
604 | ||
f6ac5f3d PA |
605 | int |
606 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
607 | { |
608 | return 0; | |
609 | } | |
610 | ||
f6ac5f3d PA |
611 | int |
612 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 613 | { |
96d7229d | 614 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
615 | } |
616 | ||
f6ac5f3d PA |
617 | int |
618 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
619 | { |
620 | return 0; | |
621 | } | |
622 | ||
f6ac5f3d PA |
623 | int |
624 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 625 | { |
96d7229d | 626 | return !linux_supports_tracefork (); |
3993f6b1 DJ |
627 | } |
628 | ||
f6ac5f3d PA |
629 | int |
630 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
631 | { |
632 | return 0; | |
633 | } | |
634 | ||
f6ac5f3d PA |
635 | int |
636 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
637 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 638 | { |
96d7229d | 639 | if (!linux_supports_tracesysgood ()) |
77b06cd7 TJB |
640 | return 1; |
641 | ||
a96d9b2e SDJ |
642 | /* On GNU/Linux, we ignore the arguments. It means that we only |
643 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 644 | |
649a140c | 645 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
646 | filter system calls here. We let GDB do the logic for us. */ |
647 | return 0; | |
648 | } | |
649 | ||
774113b0 PA |
650 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
651 | case of mapping a PID returned from the kernel to our corresponding | |
652 | lwp_info data structure. */ | |
653 | static htab_t lwp_lwpid_htab; | |
654 | ||
655 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
656 | ||
657 | static hashval_t | |
658 | lwp_info_hash (const void *ap) | |
659 | { | |
660 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 661 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
662 | |
663 | return iterative_hash_object (pid, 0); | |
664 | } | |
665 | ||
666 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
667 | PID. */ | |
668 | ||
669 | static int | |
670 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
671 | { | |
672 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
673 | const struct lwp_info *element = (const struct lwp_info *) b; | |
674 | ||
e38504b3 | 675 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
676 | } |
677 | ||
678 | /* Create the lwp_lwpid_htab hash table. */ | |
679 | ||
680 | static void | |
681 | lwp_lwpid_htab_create (void) | |
682 | { | |
683 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
684 | } | |
685 | ||
686 | /* Add LP to the hash table. */ | |
687 | ||
688 | static void | |
689 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
690 | { | |
691 | void **slot; | |
692 | ||
693 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
694 | gdb_assert (slot != NULL && *slot == NULL); | |
695 | *slot = lp; | |
696 | } | |
697 | ||
698 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
699 | creation order. This order is assumed in some cases. E.g., | |
700 | reaping status after killing alls lwps of a process: the leader LWP | |
701 | must be reaped last. */ | |
901b9821 SM |
702 | |
703 | static intrusive_list<lwp_info> lwp_list; | |
704 | ||
705 | /* See linux-nat.h. */ | |
706 | ||
707 | lwp_info_range | |
708 | all_lwps () | |
709 | { | |
710 | return lwp_info_range (lwp_list.begin ()); | |
711 | } | |
712 | ||
713 | /* See linux-nat.h. */ | |
714 | ||
715 | lwp_info_safe_range | |
716 | all_lwps_safe () | |
717 | { | |
718 | return lwp_info_safe_range (lwp_list.begin ()); | |
719 | } | |
774113b0 PA |
720 | |
721 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
722 | ||
723 | static void | |
724 | lwp_list_add (struct lwp_info *lp) | |
725 | { | |
901b9821 | 726 | lwp_list.push_front (*lp); |
774113b0 PA |
727 | } |
728 | ||
729 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
730 | list. */ | |
731 | ||
732 | static void | |
733 | lwp_list_remove (struct lwp_info *lp) | |
734 | { | |
735 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 736 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
737 | } |
738 | ||
d6b0e80f AC |
739 | \f |
740 | ||
d6b0e80f AC |
741 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
742 | _initialize_linux_nat. */ | |
743 | static sigset_t suspend_mask; | |
744 | ||
7feb7d06 PA |
745 | /* Signals to block to make that sigsuspend work. */ |
746 | static sigset_t blocked_mask; | |
747 | ||
748 | /* SIGCHLD action. */ | |
6bd434d6 | 749 | static struct sigaction sigchld_action; |
b84876c2 | 750 | |
7feb7d06 PA |
751 | /* Block child signals (SIGCHLD and linux threads signals), and store |
752 | the previous mask in PREV_MASK. */ | |
84e46146 | 753 | |
7feb7d06 PA |
754 | static void |
755 | block_child_signals (sigset_t *prev_mask) | |
756 | { | |
757 | /* Make sure SIGCHLD is blocked. */ | |
758 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
759 | sigaddset (&blocked_mask, SIGCHLD); | |
760 | ||
21987b9c | 761 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
762 | } |
763 | ||
764 | /* Restore child signals mask, previously returned by | |
765 | block_child_signals. */ | |
766 | ||
767 | static void | |
768 | restore_child_signals_mask (sigset_t *prev_mask) | |
769 | { | |
21987b9c | 770 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 771 | } |
2455069d UW |
772 | |
773 | /* Mask of signals to pass directly to the inferior. */ | |
774 | static sigset_t pass_mask; | |
775 | ||
776 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 777 | void |
adc6a863 PA |
778 | linux_nat_target::pass_signals |
779 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
780 | { |
781 | int signo; | |
782 | ||
783 | sigemptyset (&pass_mask); | |
784 | ||
785 | for (signo = 1; signo < NSIG; signo++) | |
786 | { | |
2ea28649 | 787 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 788 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 789 | sigaddset (&pass_mask, signo); |
2455069d UW |
790 | } |
791 | } | |
792 | ||
d6b0e80f AC |
793 | \f |
794 | ||
795 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
796 | static int stop_wait_callback (struct lwp_info *lp); |
797 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 798 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 799 | |
d6b0e80f | 800 | \f |
d6b0e80f | 801 | |
7b50312a PA |
802 | /* Destroy and free LP. */ |
803 | ||
676362df | 804 | lwp_info::~lwp_info () |
7b50312a | 805 | { |
466eecee | 806 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 807 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
808 | } |
809 | ||
774113b0 | 810 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 811 | |
774113b0 PA |
812 | static int |
813 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 814 | { |
774113b0 PA |
815 | struct lwp_info *lp = (struct lwp_info *) *slot; |
816 | int pid = *(int *) info; | |
d90e17a7 | 817 | |
e99b03dc | 818 | if (lp->ptid.pid () == pid) |
d90e17a7 | 819 | { |
774113b0 PA |
820 | htab_clear_slot (lwp_lwpid_htab, slot); |
821 | lwp_list_remove (lp); | |
676362df | 822 | delete lp; |
774113b0 | 823 | } |
d90e17a7 | 824 | |
774113b0 PA |
825 | return 1; |
826 | } | |
d90e17a7 | 827 | |
774113b0 PA |
828 | /* Remove all LWPs belong to PID from the lwp list. */ |
829 | ||
830 | static void | |
831 | purge_lwp_list (int pid) | |
832 | { | |
833 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
834 | } |
835 | ||
26cb8b7c PA |
836 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
837 | in the process. Return a pointer to the structure describing the | |
838 | new LWP. | |
839 | ||
840 | This differs from add_lwp in that we don't let the arch specific | |
841 | bits know about this new thread. Current clients of this callback | |
842 | take the opportunity to install watchpoints in the new thread, and | |
843 | we shouldn't do that for the first thread. If we're spawning a | |
844 | child ("run"), the thread executes the shell wrapper first, and we | |
845 | shouldn't touch it until it execs the program we want to debug. | |
846 | For "attach", it'd be okay to call the callback, but it's not | |
847 | necessary, because watchpoints can't yet have been inserted into | |
848 | the inferior. */ | |
d6b0e80f AC |
849 | |
850 | static struct lwp_info * | |
26cb8b7c | 851 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 852 | { |
15a9e13e | 853 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 854 | |
b0f6c8d2 | 855 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 856 | |
d6b0e80f | 857 | |
774113b0 PA |
858 | /* Add to sorted-by-reverse-creation-order list. */ |
859 | lwp_list_add (lp); | |
860 | ||
861 | /* Add to keyed-by-pid htab. */ | |
862 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 863 | |
26cb8b7c PA |
864 | return lp; |
865 | } | |
866 | ||
867 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
868 | structure describing the new LWP. The LWP should already be | |
869 | stopped. */ | |
870 | ||
871 | static struct lwp_info * | |
872 | add_lwp (ptid_t ptid) | |
873 | { | |
874 | struct lwp_info *lp; | |
875 | ||
876 | lp = add_initial_lwp (ptid); | |
877 | ||
6e012a6c PA |
878 | /* Let the arch specific bits know about this new thread. Current |
879 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
880 | watchpoints in the new thread. We don't do this for the first |
881 | thread though. See add_initial_lwp. */ | |
135340af | 882 | linux_target->low_new_thread (lp); |
9f0bdab8 | 883 | |
d6b0e80f AC |
884 | return lp; |
885 | } | |
886 | ||
887 | /* Remove the LWP specified by PID from the list. */ | |
888 | ||
889 | static void | |
890 | delete_lwp (ptid_t ptid) | |
891 | { | |
b0f6c8d2 | 892 | lwp_info dummy (ptid); |
d6b0e80f | 893 | |
b0f6c8d2 | 894 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
895 | if (slot == NULL) |
896 | return; | |
d6b0e80f | 897 | |
b0f6c8d2 | 898 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 899 | gdb_assert (lp != NULL); |
d6b0e80f | 900 | |
774113b0 | 901 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 902 | |
774113b0 PA |
903 | /* Remove from sorted-by-creation-order list. */ |
904 | lwp_list_remove (lp); | |
d6b0e80f | 905 | |
774113b0 | 906 | /* Release. */ |
676362df | 907 | delete lp; |
d6b0e80f AC |
908 | } |
909 | ||
910 | /* Return a pointer to the structure describing the LWP corresponding | |
911 | to PID. If no corresponding LWP could be found, return NULL. */ | |
912 | ||
913 | static struct lwp_info * | |
914 | find_lwp_pid (ptid_t ptid) | |
915 | { | |
d6b0e80f AC |
916 | int lwp; |
917 | ||
15a9e13e | 918 | if (ptid.lwp_p ()) |
e38504b3 | 919 | lwp = ptid.lwp (); |
d6b0e80f | 920 | else |
e99b03dc | 921 | lwp = ptid.pid (); |
d6b0e80f | 922 | |
b0f6c8d2 SM |
923 | lwp_info dummy (ptid_t (0, lwp)); |
924 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
925 | } |
926 | ||
6d4ee8c6 | 927 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
928 | |
929 | struct lwp_info * | |
d90e17a7 | 930 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 931 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 932 | { |
901b9821 | 933 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 934 | { |
26a57c92 | 935 | if (lp->ptid.matches (filter)) |
d90e17a7 | 936 | { |
d3a70e03 | 937 | if (callback (lp) != 0) |
d90e17a7 PA |
938 | return lp; |
939 | } | |
d6b0e80f AC |
940 | } |
941 | ||
942 | return NULL; | |
943 | } | |
944 | ||
2277426b PA |
945 | /* Update our internal state when changing from one checkpoint to |
946 | another indicated by NEW_PTID. We can only switch single-threaded | |
947 | applications, so we only create one new LWP, and the previous list | |
948 | is discarded. */ | |
f973ed9c DJ |
949 | |
950 | void | |
951 | linux_nat_switch_fork (ptid_t new_ptid) | |
952 | { | |
953 | struct lwp_info *lp; | |
954 | ||
e99b03dc | 955 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 956 | |
f973ed9c DJ |
957 | lp = add_lwp (new_ptid); |
958 | lp->stopped = 1; | |
e26af52f | 959 | |
2277426b PA |
960 | /* This changes the thread's ptid while preserving the gdb thread |
961 | num. Also changes the inferior pid, while preserving the | |
962 | inferior num. */ | |
5b6d1e4f | 963 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
964 | |
965 | /* We've just told GDB core that the thread changed target id, but, | |
966 | in fact, it really is a different thread, with different register | |
967 | contents. */ | |
968 | registers_changed (); | |
e26af52f DJ |
969 | } |
970 | ||
e26af52f DJ |
971 | /* Handle the exit of a single thread LP. */ |
972 | ||
973 | static void | |
974 | exit_lwp (struct lwp_info *lp) | |
975 | { | |
5b6d1e4f | 976 | struct thread_info *th = find_thread_ptid (linux_target, lp->ptid); |
063bfe2e VP |
977 | |
978 | if (th) | |
e26af52f | 979 | { |
17faa917 | 980 | if (print_thread_events) |
a068643d TT |
981 | printf_unfiltered (_("[%s exited]\n"), |
982 | target_pid_to_str (lp->ptid).c_str ()); | |
17faa917 | 983 | |
00431a78 | 984 | delete_thread (th); |
e26af52f DJ |
985 | } |
986 | ||
987 | delete_lwp (lp->ptid); | |
988 | } | |
989 | ||
a0ef4274 DJ |
990 | /* Wait for the LWP specified by LP, which we have just attached to. |
991 | Returns a wait status for that LWP, to cache. */ | |
992 | ||
993 | static int | |
22827c51 | 994 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 995 | { |
e38504b3 | 996 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
997 | int status; |
998 | ||
644cebc9 | 999 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 1000 | { |
9327494e | 1001 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
1002 | |
1003 | /* The process is definitely stopped. It is in a job control | |
1004 | stop, unless the kernel predates the TASK_STOPPED / | |
1005 | TASK_TRACED distinction, in which case it might be in a | |
1006 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
1007 | can kill it, signal it, et cetera. | |
1008 | ||
dda83cd7 | 1009 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
1010 | already attached, the process can not transition from stopped |
1011 | to running without a PTRACE_CONT; so we know this signal will | |
1012 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
1013 | probably already in the queue (unless this kernel is old | |
1014 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
1015 | is not an RT signal, it can only be queued once. */ | |
1016 | kill_lwp (pid, SIGSTOP); | |
1017 | ||
1018 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
1019 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
1020 | ptrace (PTRACE_CONT, pid, 0, 0); | |
1021 | } | |
1022 | ||
1023 | /* Make sure the initial process is stopped. The user-level threads | |
1024 | layer might want to poke around in the inferior, and that won't | |
1025 | work if things haven't stabilized yet. */ | |
4a6ed09b | 1026 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
1027 | gdb_assert (pid == new_pid); |
1028 | ||
1029 | if (!WIFSTOPPED (status)) | |
1030 | { | |
1031 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 1032 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 1033 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
1034 | return status; |
1035 | } | |
a0ef4274 DJ |
1036 | |
1037 | if (WSTOPSIG (status) != SIGSTOP) | |
1038 | { | |
1039 | *signalled = 1; | |
9327494e | 1040 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 1041 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
1042 | } |
1043 | ||
1044 | return status; | |
1045 | } | |
1046 | ||
f6ac5f3d PA |
1047 | void |
1048 | linux_nat_target::create_inferior (const char *exec_file, | |
1049 | const std::string &allargs, | |
1050 | char **env, int from_tty) | |
b84876c2 | 1051 | { |
41272101 TT |
1052 | maybe_disable_address_space_randomization restore_personality |
1053 | (disable_randomization); | |
b84876c2 PA |
1054 | |
1055 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
1056 | we have to mask the async mode. */ | |
1057 | ||
2455069d | 1058 | /* Make sure we report all signals during startup. */ |
adc6a863 | 1059 | pass_signals ({}); |
2455069d | 1060 | |
f6ac5f3d | 1061 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
b84876c2 PA |
1062 | } |
1063 | ||
8784d563 PA |
1064 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1065 | already attached. Returns true if a new LWP is found, false | |
1066 | otherwise. */ | |
1067 | ||
1068 | static int | |
1069 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1070 | { | |
1071 | struct lwp_info *lp; | |
1072 | ||
1073 | /* Ignore LWPs we're already attached to. */ | |
1074 | lp = find_lwp_pid (ptid); | |
1075 | if (lp == NULL) | |
1076 | { | |
e38504b3 | 1077 | int lwpid = ptid.lwp (); |
8784d563 PA |
1078 | |
1079 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1080 | { | |
1081 | int err = errno; | |
1082 | ||
1083 | /* Be quiet if we simply raced with the thread exiting. | |
1084 | EPERM is returned if the thread's task still exists, and | |
1085 | is marked as exited or zombie, as well as other | |
1086 | conditions, so in that case, confirm the status in | |
1087 | /proc/PID/status. */ | |
1088 | if (err == ESRCH | |
1089 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1090 | { | |
9327494e SM |
1091 | linux_nat_debug_printf |
1092 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1093 | lwpid, err, safe_strerror (err)); | |
1094 | ||
8784d563 PA |
1095 | } |
1096 | else | |
1097 | { | |
4d9b86e1 | 1098 | std::string reason |
50fa3001 | 1099 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1100 | |
f71f0b0d | 1101 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1102 | lwpid, reason.c_str ()); |
8784d563 PA |
1103 | } |
1104 | } | |
1105 | else | |
1106 | { | |
9327494e SM |
1107 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
1108 | target_pid_to_str (ptid).c_str ()); | |
8784d563 PA |
1109 | |
1110 | lp = add_lwp (ptid); | |
8784d563 PA |
1111 | |
1112 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1113 | PTRACE_ATTACH brings it to a halt. */ | |
1114 | lp->signalled = 1; | |
1115 | ||
1116 | /* We need to wait for a stop before being able to make the | |
1117 | next ptrace call on this LWP. */ | |
1118 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1119 | |
1120 | /* So that wait collects the SIGSTOP. */ | |
1121 | lp->resumed = 1; | |
1122 | ||
1123 | /* Also add the LWP to gdb's thread list, in case a | |
1124 | matching libthread_db is not found (or the process uses | |
1125 | raw clone). */ | |
5b6d1e4f | 1126 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1127 | set_running (linux_target, lp->ptid, true); |
1128 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1129 | } |
1130 | ||
1131 | return 1; | |
1132 | } | |
1133 | return 0; | |
1134 | } | |
1135 | ||
f6ac5f3d PA |
1136 | void |
1137 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1138 | { |
1139 | struct lwp_info *lp; | |
d6b0e80f | 1140 | int status; |
af990527 | 1141 | ptid_t ptid; |
d6b0e80f | 1142 | |
2455069d | 1143 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1144 | pass_signals ({}); |
2455069d | 1145 | |
a70b8144 | 1146 | try |
87b0bb13 | 1147 | { |
f6ac5f3d | 1148 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1149 | } |
230d2906 | 1150 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1151 | { |
1152 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1153 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1154 | |
4d9b86e1 | 1155 | if (!reason.empty ()) |
3d6e9d23 TT |
1156 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1157 | ex.what ()); | |
7ae1a6a6 | 1158 | else |
3d6e9d23 | 1159 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1160 | } |
d6b0e80f | 1161 | |
af990527 PA |
1162 | /* The ptrace base target adds the main thread with (pid,0,0) |
1163 | format. Decorate it with lwp info. */ | |
e99b03dc | 1164 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1165 | inferior_ptid.pid ()); |
5b6d1e4f | 1166 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1167 | |
9f0bdab8 | 1168 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1169 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1170 | |
22827c51 | 1171 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1172 | if (!WIFSTOPPED (status)) |
1173 | { | |
1174 | if (WIFEXITED (status)) | |
1175 | { | |
1176 | int exit_code = WEXITSTATUS (status); | |
1177 | ||
223ffa71 | 1178 | target_terminal::ours (); |
bc1e6c81 | 1179 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1180 | if (exit_code == 0) |
1181 | error (_("Unable to attach: program exited normally.")); | |
1182 | else | |
1183 | error (_("Unable to attach: program exited with code %d."), | |
1184 | exit_code); | |
1185 | } | |
1186 | else if (WIFSIGNALED (status)) | |
1187 | { | |
2ea28649 | 1188 | enum gdb_signal signo; |
dacc9cb2 | 1189 | |
223ffa71 | 1190 | target_terminal::ours (); |
bc1e6c81 | 1191 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1192 | |
2ea28649 | 1193 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1194 | error (_("Unable to attach: program terminated with signal " |
1195 | "%s, %s."), | |
2ea28649 PA |
1196 | gdb_signal_to_name (signo), |
1197 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1198 | } |
1199 | ||
1200 | internal_error (__FILE__, __LINE__, | |
1201 | _("unexpected status %d for PID %ld"), | |
e38504b3 | 1202 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1203 | } |
1204 | ||
a0ef4274 | 1205 | lp->stopped = 1; |
9f0bdab8 | 1206 | |
a0ef4274 | 1207 | /* Save the wait status to report later. */ |
d6b0e80f | 1208 | lp->resumed = 1; |
9327494e | 1209 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1210 | (long) lp->ptid.pid (), |
1211 | status_to_str (status).c_str ()); | |
710151dd | 1212 | |
7feb7d06 PA |
1213 | lp->status = status; |
1214 | ||
8784d563 PA |
1215 | /* We must attach to every LWP. If /proc is mounted, use that to |
1216 | find them now. The inferior may be using raw clone instead of | |
1217 | using pthreads. But even if it is using pthreads, thread_db | |
1218 | walks structures in the inferior's address space to find the list | |
1219 | of threads/LWPs, and those structures may well be corrupted. | |
1220 | Note that once thread_db is loaded, we'll still use it to list | |
1221 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1222 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 PA |
1223 | attach_proc_task_lwp_callback); |
1224 | ||
7feb7d06 | 1225 | if (target_can_async_p ()) |
6a3753b3 | 1226 | target_async (1); |
d6b0e80f AC |
1227 | } |
1228 | ||
ced2dffb PA |
1229 | /* Get pending signal of THREAD as a host signal number, for detaching |
1230 | purposes. This is the signal the thread last stopped for, which we | |
1231 | need to deliver to the thread when detaching, otherwise, it'd be | |
1232 | suppressed/lost. */ | |
1233 | ||
a0ef4274 | 1234 | static int |
ced2dffb | 1235 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1236 | { |
a493e3e2 | 1237 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1238 | |
1239 | /* If we paused threads momentarily, we may have stored pending | |
1240 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1241 | and GDB core hasn't seen any signal for those threads. | |
1242 | Otherwise, the last signal reported to the core is found in the | |
1243 | thread object's stop_signal. | |
1244 | ||
1245 | There's a corner case that isn't handled here at present. Only | |
1246 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1247 | stop_signal make sense as a real signal to pass to the inferior. | |
1248 | Some catchpoint related events, like | |
1249 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1250 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1251 | those traps are debug API (ptrace in our case) related and |
1252 | induced; the inferior wouldn't see them if it wasn't being | |
1253 | traced. Hence, we should never pass them to the inferior, even | |
1254 | when set to pass state. Since this corner case isn't handled by | |
1255 | infrun.c when proceeding with a signal, for consistency, neither | |
1256 | do we handle it here (or elsewhere in the file we check for | |
1257 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1258 | this is really a corner case. */ | |
1259 | ||
183be222 | 1260 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1261 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1262 | else if (lp->status) |
2ea28649 | 1263 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1264 | else |
ca2163eb | 1265 | { |
5b6d1e4f | 1266 | struct thread_info *tp = find_thread_ptid (linux_target, lp->ptid); |
e0881a8e | 1267 | |
611841bb | 1268 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1269 | { |
1edb66d8 | 1270 | if (tp->has_pending_waitstatus ()) |
183be222 | 1271 | signo = tp->pending_waitstatus ().sig (); |
00431a78 | 1272 | else |
1edb66d8 | 1273 | signo = tp->stop_signal (); |
00431a78 PA |
1274 | } |
1275 | else if (!target_is_non_stop_p ()) | |
1276 | { | |
00431a78 | 1277 | ptid_t last_ptid; |
5b6d1e4f | 1278 | process_stratum_target *last_target; |
00431a78 | 1279 | |
5b6d1e4f | 1280 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1281 | |
5b6d1e4f PA |
1282 | if (last_target == linux_target |
1283 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1284 | signo = tp->stop_signal (); |
4c28f408 | 1285 | } |
ca2163eb | 1286 | } |
4c28f408 | 1287 | |
a493e3e2 | 1288 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1289 | { |
9327494e SM |
1290 | linux_nat_debug_printf ("lwp %s has no pending signal", |
1291 | target_pid_to_str (lp->ptid).c_str ()); | |
ca2163eb PA |
1292 | } |
1293 | else if (!signal_pass_state (signo)) | |
1294 | { | |
9327494e SM |
1295 | linux_nat_debug_printf |
1296 | ("lwp %s had signal %s but it is in no pass state", | |
1297 | target_pid_to_str (lp->ptid).c_str (), gdb_signal_to_string (signo)); | |
a0ef4274 | 1298 | } |
a0ef4274 | 1299 | else |
4c28f408 | 1300 | { |
9327494e SM |
1301 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
1302 | target_pid_to_str (lp->ptid).c_str (), | |
1303 | gdb_signal_to_string (signo)); | |
ced2dffb PA |
1304 | |
1305 | return gdb_signal_to_host (signo); | |
4c28f408 | 1306 | } |
a0ef4274 DJ |
1307 | |
1308 | return 0; | |
1309 | } | |
1310 | ||
ced2dffb PA |
1311 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1312 | signal number that should be passed to the LWP when detaching. | |
1313 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1314 | ||
1315 | static void | |
1316 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1317 | { |
e38504b3 | 1318 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1319 | int signo; |
1320 | ||
d6b0e80f AC |
1321 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1322 | ||
9327494e SM |
1323 | if (lp->status != 0) |
1324 | linux_nat_debug_printf ("Pending %s for %s on detach.", | |
1325 | strsignal (WSTOPSIG (lp->status)), | |
1326 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1327 | |
a0ef4274 DJ |
1328 | /* If there is a pending SIGSTOP, get rid of it. */ |
1329 | if (lp->signalled) | |
d6b0e80f | 1330 | { |
9327494e SM |
1331 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
1332 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 1333 | |
ced2dffb | 1334 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1335 | lp->signalled = 0; |
d6b0e80f AC |
1336 | } |
1337 | ||
ced2dffb | 1338 | if (signo_p == NULL) |
d6b0e80f | 1339 | { |
a0ef4274 | 1340 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1341 | signo = get_detach_signal (lp); |
1342 | } | |
1343 | else | |
1344 | signo = *signo_p; | |
a0ef4274 | 1345 | |
ced2dffb PA |
1346 | /* Preparing to resume may try to write registers, and fail if the |
1347 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1348 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1349 | try |
ced2dffb | 1350 | { |
135340af | 1351 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1352 | } |
230d2906 | 1353 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1354 | { |
1355 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1356 | throw; |
ced2dffb | 1357 | } |
d6b0e80f | 1358 | |
ced2dffb PA |
1359 | if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0) |
1360 | { | |
1361 | int save_errno = errno; | |
1362 | ||
1363 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1364 | zombie. This can happen if one of the already-detached | |
1365 | threads exits the whole thread group. In that case we're | |
1366 | still attached, and must reap the lwp. */ | |
1367 | if (save_errno == ESRCH) | |
1368 | { | |
1369 | int ret, status; | |
d6b0e80f | 1370 | |
ced2dffb PA |
1371 | ret = my_waitpid (lwpid, &status, __WALL); |
1372 | if (ret == -1) | |
1373 | { | |
1374 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
6d91ce9a | 1375 | lwpid, safe_strerror (errno)); |
ced2dffb PA |
1376 | } |
1377 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1378 | { | |
1379 | warning (_("Reaping LWP %d while detaching " | |
1380 | "returned unexpected status 0x%x"), | |
1381 | lwpid, status); | |
1382 | } | |
1383 | } | |
1384 | else | |
1385 | { | |
a068643d TT |
1386 | error (_("Can't detach %s: %s"), |
1387 | target_pid_to_str (lp->ptid).c_str (), | |
ced2dffb PA |
1388 | safe_strerror (save_errno)); |
1389 | } | |
d6b0e80f | 1390 | } |
9327494e SM |
1391 | else |
1392 | linux_nat_debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)", | |
1393 | target_pid_to_str (lp->ptid).c_str (), | |
1394 | strsignal (signo)); | |
ced2dffb PA |
1395 | |
1396 | delete_lwp (lp->ptid); | |
1397 | } | |
d6b0e80f | 1398 | |
ced2dffb | 1399 | static int |
d3a70e03 | 1400 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1401 | { |
1402 | /* We don't actually detach from the thread group leader just yet. | |
1403 | If the thread group exits, we must reap the zombie clone lwps | |
1404 | before we're able to reap the leader. */ | |
e38504b3 | 1405 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1406 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1407 | return 0; |
1408 | } | |
1409 | ||
f6ac5f3d PA |
1410 | void |
1411 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1412 | { |
d90e17a7 | 1413 | struct lwp_info *main_lwp; |
bc09b0c1 | 1414 | int pid = inf->pid; |
a0ef4274 | 1415 | |
ae5e0686 MK |
1416 | /* Don't unregister from the event loop, as there may be other |
1417 | inferiors running. */ | |
b84876c2 | 1418 | |
4c28f408 | 1419 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1420 | thread is stopped to successfully detach. */ |
d3a70e03 | 1421 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1422 | /* ... and wait until all of them have reported back that |
1423 | they're no longer running. */ | |
d3a70e03 | 1424 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1425 | |
e87f0fe8 PA |
1426 | /* We can now safely remove breakpoints. We don't this in earlier |
1427 | in common code because this target doesn't currently support | |
1428 | writing memory while the inferior is running. */ | |
1429 | remove_breakpoints_inf (current_inferior ()); | |
1430 | ||
d3a70e03 | 1431 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1432 | |
1433 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1434 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1435 | |
f2907e49 | 1436 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1437 | |
7a7d3353 PA |
1438 | if (forks_exist_p ()) |
1439 | { | |
1440 | /* Multi-fork case. The current inferior_ptid is being detached | |
1441 | from, but there are other viable forks to debug. Detach from | |
1442 | the current fork, and context-switch to the first | |
1443 | available. */ | |
6bd6f3b6 | 1444 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1445 | } |
1446 | else | |
ced2dffb | 1447 | { |
ced2dffb PA |
1448 | target_announce_detach (from_tty); |
1449 | ||
6bd6f3b6 SM |
1450 | /* Pass on any pending signal for the last LWP. */ |
1451 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1452 | |
1453 | detach_one_lwp (main_lwp, &signo); | |
1454 | ||
f6ac5f3d | 1455 | detach_success (inf); |
ced2dffb | 1456 | } |
05c06f31 PA |
1457 | |
1458 | maybe_close_proc_mem_file (pid); | |
d6b0e80f AC |
1459 | } |
1460 | ||
8a99810d PA |
1461 | /* Resume execution of the inferior process. If STEP is nonzero, |
1462 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1463 | ||
1464 | static void | |
23f238d3 PA |
1465 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1466 | enum gdb_signal signo) | |
8a99810d | 1467 | { |
8a99810d | 1468 | lp->step = step; |
9c02b525 PA |
1469 | |
1470 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1471 | We only presently need that if the LWP is stepped though (to | |
1472 | handle the case of stepping a breakpoint instruction). */ | |
1473 | if (step) | |
1474 | { | |
5b6d1e4f | 1475 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1476 | |
1477 | lp->stop_pc = regcache_read_pc (regcache); | |
1478 | } | |
1479 | else | |
1480 | lp->stop_pc = 0; | |
1481 | ||
135340af | 1482 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1483 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1484 | |
1485 | /* Successfully resumed. Clear state that no longer makes sense, | |
1486 | and mark the LWP as running. Must not do this before resuming | |
1487 | otherwise if that fails other code will be confused. E.g., we'd | |
1488 | later try to stop the LWP and hang forever waiting for a stop | |
1489 | status. Note that we must not throw after this is cleared, | |
1490 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1491 | lp->stopped = 0; |
1ad3de98 | 1492 | lp->core = -1; |
23f238d3 | 1493 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1494 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1495 | } |
1496 | ||
23f238d3 PA |
1497 | /* Called when we try to resume a stopped LWP and that errors out. If |
1498 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1499 | or about to become), discard the error, clear any pending status | |
1500 | the LWP may have, and return true (we'll collect the exit status | |
1501 | soon enough). Otherwise, return false. */ | |
1502 | ||
1503 | static int | |
1504 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1505 | { | |
1506 | /* If we get an error after resuming the LWP successfully, we'd | |
1507 | confuse !T state for the LWP being gone. */ | |
1508 | gdb_assert (lp->stopped); | |
1509 | ||
1510 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1511 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1512 | yet fully dead", but already refusing ptrace requests. In that | |
1513 | case the tracee has 'R (Running)' state for a little bit | |
1514 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1515 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1516 | other than ptrace-stopped. */ | |
1517 | ||
1518 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1519 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1520 | { |
1521 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1522 | lp->status = 0; | |
183be222 | 1523 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1524 | return 1; |
1525 | } | |
1526 | return 0; | |
1527 | } | |
1528 | ||
1529 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1530 | disappears while we try to resume it. */ | |
1531 | ||
1532 | static void | |
1533 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1534 | { | |
a70b8144 | 1535 | try |
23f238d3 PA |
1536 | { |
1537 | linux_resume_one_lwp_throw (lp, step, signo); | |
1538 | } | |
230d2906 | 1539 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1540 | { |
1541 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1542 | throw; |
23f238d3 | 1543 | } |
23f238d3 PA |
1544 | } |
1545 | ||
d6b0e80f AC |
1546 | /* Resume LP. */ |
1547 | ||
25289eb2 | 1548 | static void |
e5ef252a | 1549 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1550 | { |
25289eb2 | 1551 | if (lp->stopped) |
6c95b8df | 1552 | { |
5b6d1e4f | 1553 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1554 | |
1555 | if (inf->vfork_child != NULL) | |
1556 | { | |
9327494e SM |
1557 | linux_nat_debug_printf ("Not resuming %s (vfork parent)", |
1558 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1559 | } |
8a99810d | 1560 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1561 | { |
9327494e SM |
1562 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
1563 | target_pid_to_str (lp->ptid).c_str (), | |
1564 | (signo != GDB_SIGNAL_0 | |
1565 | ? strsignal (gdb_signal_to_host (signo)) | |
1566 | : "0"), | |
1567 | step ? "step" : "resume"); | |
25289eb2 | 1568 | |
8a99810d | 1569 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1570 | } |
1571 | else | |
1572 | { | |
9327494e SM |
1573 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
1574 | target_pid_to_str (lp->ptid).c_str ()); | |
25289eb2 | 1575 | } |
6c95b8df | 1576 | } |
25289eb2 | 1577 | else |
9327494e | 1578 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
a068643d | 1579 | target_pid_to_str (lp->ptid).c_str ()); |
25289eb2 | 1580 | } |
d6b0e80f | 1581 | |
8817a6f2 PA |
1582 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1583 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1584 | |
25289eb2 | 1585 | static int |
d3a70e03 | 1586 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1587 | { |
e5ef252a PA |
1588 | enum gdb_signal signo = GDB_SIGNAL_0; |
1589 | ||
8817a6f2 PA |
1590 | if (lp == except) |
1591 | return 0; | |
1592 | ||
e5ef252a PA |
1593 | if (lp->stopped) |
1594 | { | |
1595 | struct thread_info *thread; | |
1596 | ||
5b6d1e4f | 1597 | thread = find_thread_ptid (linux_target, lp->ptid); |
e5ef252a PA |
1598 | if (thread != NULL) |
1599 | { | |
1edb66d8 SM |
1600 | signo = thread->stop_signal (); |
1601 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1602 | } |
1603 | } | |
1604 | ||
1605 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1606 | return 0; |
1607 | } | |
1608 | ||
1609 | static int | |
d3a70e03 | 1610 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1611 | { |
1612 | lp->resumed = 0; | |
25289eb2 | 1613 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1614 | return 0; |
1615 | } | |
1616 | ||
1617 | static int | |
d3a70e03 | 1618 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1619 | { |
1620 | lp->resumed = 1; | |
25289eb2 | 1621 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1622 | return 0; |
1623 | } | |
1624 | ||
f6ac5f3d PA |
1625 | void |
1626 | linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) | |
d6b0e80f AC |
1627 | { |
1628 | struct lwp_info *lp; | |
d90e17a7 | 1629 | int resume_many; |
d6b0e80f | 1630 | |
9327494e SM |
1631 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1632 | step ? "step" : "resume", | |
1633 | target_pid_to_str (ptid).c_str (), | |
1634 | (signo != GDB_SIGNAL_0 | |
1635 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
1636 | target_pid_to_str (inferior_ptid).c_str ()); | |
76f50ad1 | 1637 | |
d6b0e80f | 1638 | /* A specific PTID means `step only this process id'. */ |
d7e15655 | 1639 | resume_many = (minus_one_ptid == ptid |
0e998d96 | 1640 | || ptid.is_pid ()); |
4c28f408 | 1641 | |
7da6a5b9 LM |
1642 | /* Mark the lwps we're resuming as resumed and update their |
1643 | last_resume_kind to resume_continue. */ | |
d3a70e03 | 1644 | iterate_over_lwps (ptid, resume_set_callback); |
d6b0e80f | 1645 | |
d90e17a7 PA |
1646 | /* See if it's the current inferior that should be handled |
1647 | specially. */ | |
1648 | if (resume_many) | |
1649 | lp = find_lwp_pid (inferior_ptid); | |
1650 | else | |
1651 | lp = find_lwp_pid (ptid); | |
9f0bdab8 | 1652 | gdb_assert (lp != NULL); |
d6b0e80f | 1653 | |
9f0bdab8 | 1654 | /* Remember if we're stepping. */ |
25289eb2 | 1655 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1656 | |
9f0bdab8 DJ |
1657 | /* If we have a pending wait status for this thread, there is no |
1658 | point in resuming the process. But first make sure that | |
1659 | linux_nat_wait won't preemptively handle the event - we | |
1660 | should never take this short-circuit if we are going to | |
1661 | leave LP running, since we have skipped resuming all the | |
1662 | other threads. This bit of code needs to be synchronized | |
1663 | with linux_nat_wait. */ | |
76f50ad1 | 1664 | |
9f0bdab8 DJ |
1665 | if (lp->status && WIFSTOPPED (lp->status)) |
1666 | { | |
2455069d UW |
1667 | if (!lp->step |
1668 | && WSTOPSIG (lp->status) | |
1669 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1670 | { |
9327494e SM |
1671 | linux_nat_debug_printf |
1672 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1673 | |
d6b0e80f AC |
1674 | /* FIXME: What should we do if we are supposed to continue |
1675 | this thread with a signal? */ | |
a493e3e2 | 1676 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1677 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1678 | lp->status = 0; |
1679 | } | |
1680 | } | |
76f50ad1 | 1681 | |
8a99810d | 1682 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1683 | { |
1684 | /* FIXME: What should we do if we are supposed to continue | |
1685 | this thread with a signal? */ | |
a493e3e2 | 1686 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1687 | |
9327494e SM |
1688 | linux_nat_debug_printf ("Short circuiting for status 0x%x", |
1689 | lp->status); | |
d6b0e80f | 1690 | |
7feb7d06 PA |
1691 | if (target_can_async_p ()) |
1692 | { | |
6a3753b3 | 1693 | target_async (1); |
7feb7d06 PA |
1694 | /* Tell the event loop we have something to process. */ |
1695 | async_file_mark (); | |
1696 | } | |
9f0bdab8 | 1697 | return; |
d6b0e80f AC |
1698 | } |
1699 | ||
d90e17a7 | 1700 | if (resume_many) |
d3a70e03 TT |
1701 | iterate_over_lwps (ptid, [=] (struct lwp_info *info) |
1702 | { | |
1703 | return linux_nat_resume_callback (info, lp); | |
1704 | }); | |
d90e17a7 | 1705 | |
9327494e SM |
1706 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1707 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
1708 | target_pid_to_str (lp->ptid).c_str (), | |
1709 | (signo != GDB_SIGNAL_0 | |
1710 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1711 | |
2bf6fb9d PA |
1712 | linux_resume_one_lwp (lp, step, signo); |
1713 | ||
b84876c2 | 1714 | if (target_can_async_p ()) |
6a3753b3 | 1715 | target_async (1); |
d6b0e80f AC |
1716 | } |
1717 | ||
c5f62d5f | 1718 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1719 | |
1720 | static int | |
1721 | kill_lwp (int lwpid, int signo) | |
1722 | { | |
4a6ed09b | 1723 | int ret; |
d6b0e80f | 1724 | |
4a6ed09b PA |
1725 | errno = 0; |
1726 | ret = syscall (__NR_tkill, lwpid, signo); | |
1727 | if (errno == ENOSYS) | |
1728 | { | |
1729 | /* If tkill fails, then we are not using nptl threads, a | |
1730 | configuration we no longer support. */ | |
1731 | perror_with_name (("tkill")); | |
1732 | } | |
1733 | return ret; | |
d6b0e80f AC |
1734 | } |
1735 | ||
ca2163eb PA |
1736 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1737 | event, check if the core is interested in it: if not, ignore the | |
1738 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1739 | syscall entry/exit status, since the ptrace event itself doesn't | |
1740 | indicate it, and report the trap to higher layers. */ | |
1741 | ||
1742 | static int | |
1743 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1744 | { | |
1745 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1746 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
5b6d1e4f | 1747 | thread_info *thread = find_thread_ptid (linux_target, lp->ptid); |
00431a78 | 1748 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1749 | |
1750 | if (stopping) | |
1751 | { | |
1752 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1753 | makes it so that the LWP reports an immediate syscall return, | |
1754 | followed by the SIGSTOP. Skip seeing that "return" using | |
1755 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1756 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1757 | entry event. If we didn't do this (and returned 0), we'd | |
1758 | leave a syscall entry pending, and our caller, by using | |
1759 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1760 | itself. Later, when the user re-resumes this LWP, we'd see | |
1761 | another syscall entry event and we'd mistake it for a return. | |
1762 | ||
1763 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1764 | (leaving immediately with LWP->signalled set, without issuing | |
1765 | a PTRACE_CONT), it would still be problematic to leave this | |
1766 | syscall enter pending, as later when the thread is resumed, | |
1767 | it would then see the same syscall exit mentioned above, | |
1768 | followed by the delayed SIGSTOP, while the syscall didn't | |
1769 | actually get to execute. It seems it would be even more | |
1770 | confusing to the user. */ | |
1771 | ||
9327494e SM |
1772 | linux_nat_debug_printf |
1773 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1774 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1775 | |
1776 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1777 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1778 | lp->stopped = 0; |
ca2163eb PA |
1779 | return 1; |
1780 | } | |
1781 | ||
bfd09d20 JS |
1782 | /* Always update the entry/return state, even if this particular |
1783 | syscall isn't interesting to the core now. In async mode, | |
1784 | the user could install a new catchpoint for this syscall | |
1785 | between syscall enter/return, and we'll need to know to | |
1786 | report a syscall return if that happens. */ | |
1787 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1788 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1789 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1790 | ||
ca2163eb PA |
1791 | if (catch_syscall_enabled ()) |
1792 | { | |
ca2163eb PA |
1793 | if (catching_syscall_number (syscall_number)) |
1794 | { | |
1795 | /* Alright, an event to report. */ | |
183be222 SM |
1796 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1797 | ourstatus->set_syscall_entry (syscall_number); | |
1798 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1799 | ourstatus->set_syscall_return (syscall_number); | |
1800 | else | |
1801 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1802 | |
9327494e SM |
1803 | linux_nat_debug_printf |
1804 | ("stopping for %s of syscall %d for LWP %ld", | |
1805 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1806 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1807 | ||
ca2163eb PA |
1808 | return 0; |
1809 | } | |
1810 | ||
9327494e SM |
1811 | linux_nat_debug_printf |
1812 | ("ignoring %s of syscall %d for LWP %ld", | |
1813 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1814 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1815 | } |
1816 | else | |
1817 | { | |
1818 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1819 | before on this LWP, it could happen that the user removes all | |
1820 | syscall catchpoints before we get to process this event. | |
1821 | There are two noteworthy issues here: | |
1822 | ||
1823 | - When stopped at a syscall entry event, resuming with | |
1824 | PT_STEP still resumes executing the syscall and reports a | |
1825 | syscall return. | |
1826 | ||
1827 | - Only PT_SYSCALL catches syscall enters. If we last | |
1828 | single-stepped this thread, then this event can't be a | |
1829 | syscall enter. If we last single-stepped this thread, this | |
1830 | has to be a syscall exit. | |
1831 | ||
1832 | The points above mean that the next resume, be it PT_STEP or | |
1833 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1834 | linux_nat_debug_printf |
1835 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1836 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1837 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1838 | } | |
1839 | ||
1840 | /* The core isn't interested in this event. For efficiency, avoid | |
1841 | stopping all threads only to have the core resume them all again. | |
1842 | Since we're not stopping threads, if we're still syscall tracing | |
1843 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1844 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1845 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1846 | ||
8a99810d | 1847 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1848 | return 1; |
1849 | } | |
1850 | ||
3d799a95 DJ |
1851 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1852 | event, we need to add the new LWP to our list (and not report the | |
1853 | trap to higher layers). This function returns non-zero if the | |
1854 | event should be ignored and we should wait again. If STOPPING is | |
1855 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1856 | |
1857 | static int | |
4dd63d48 | 1858 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1859 | { |
e38504b3 | 1860 | int pid = lp->ptid.lwp (); |
3d799a95 | 1861 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1862 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1863 | |
bfd09d20 JS |
1864 | /* All extended events we currently use are mid-syscall. Only |
1865 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1866 | you have to be using PTRACE_SEIZE to get that. */ | |
1867 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1868 | ||
3d799a95 DJ |
1869 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1870 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1871 | { |
3d799a95 DJ |
1872 | unsigned long new_pid; |
1873 | int ret; | |
1874 | ||
1875 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1876 | |
3d799a95 DJ |
1877 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1878 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1879 | { | |
1880 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1881 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1882 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1883 | if (ret == -1) |
1884 | perror_with_name (_("waiting for new child")); | |
1885 | else if (ret != new_pid) | |
1886 | internal_error (__FILE__, __LINE__, | |
1887 | _("wait returned unexpected PID %d"), ret); | |
1888 | else if (!WIFSTOPPED (status)) | |
1889 | internal_error (__FILE__, __LINE__, | |
1890 | _("wait returned unexpected status 0x%x"), status); | |
1891 | } | |
1892 | ||
183be222 | 1893 | ptid_t child_ptid (new_pid, new_pid); |
3d799a95 | 1894 | |
26cb8b7c PA |
1895 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1896 | { | |
1897 | /* The arch-specific native code may need to know about new | |
1898 | forks even if those end up never mapped to an | |
1899 | inferior. */ | |
135340af | 1900 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1901 | } |
1310c1b0 PFC |
1902 | else if (event == PTRACE_EVENT_CLONE) |
1903 | { | |
1904 | linux_target->low_new_clone (lp, new_pid); | |
1905 | } | |
26cb8b7c | 1906 | |
2277426b | 1907 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1908 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1909 | { |
2277426b PA |
1910 | /* Handle checkpointing by linux-fork.c here as a special |
1911 | case. We don't want the follow-fork-mode or 'catch fork' | |
1912 | to interfere with this. */ | |
1913 | ||
1914 | /* This won't actually modify the breakpoint list, but will | |
1915 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 1916 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
1917 | |
1918 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1919 | if (!find_fork_pid (new_pid)) |
1920 | add_fork (new_pid); | |
2277426b PA |
1921 | |
1922 | /* Report as spurious, so that infrun doesn't want to follow | |
1923 | this fork. We're actually doing an infcall in | |
1924 | linux-fork.c. */ | |
183be222 | 1925 | ourstatus->set_spurious (); |
2277426b PA |
1926 | |
1927 | /* Report the stop to the core. */ | |
1928 | return 0; | |
1929 | } | |
1930 | ||
3d799a95 | 1931 | if (event == PTRACE_EVENT_FORK) |
183be222 | 1932 | ourstatus->set_forked (child_ptid); |
3d799a95 | 1933 | else if (event == PTRACE_EVENT_VFORK) |
183be222 | 1934 | ourstatus->set_vforked (child_ptid); |
4dd63d48 | 1935 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1936 | { |
78768c4a JK |
1937 | struct lwp_info *new_lp; |
1938 | ||
183be222 | 1939 | ourstatus->set_ignore (); |
78768c4a | 1940 | |
9327494e SM |
1941 | linux_nat_debug_printf |
1942 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1943 | |
184ea2f7 | 1944 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid)); |
4c28f408 | 1945 | new_lp->stopped = 1; |
4dd63d48 | 1946 | new_lp->resumed = 1; |
d6b0e80f | 1947 | |
2db9a427 PA |
1948 | /* If the thread_db layer is active, let it record the user |
1949 | level thread id and status, and add the thread to GDB's | |
1950 | list. */ | |
1951 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 1952 | { |
2db9a427 PA |
1953 | /* The process is not using thread_db. Add the LWP to |
1954 | GDB's list. */ | |
e38504b3 | 1955 | target_post_attach (new_lp->ptid.lwp ()); |
5b6d1e4f | 1956 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 1957 | } |
4c28f408 | 1958 | |
2ee52aa4 | 1959 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
1960 | internal to this module, from the perspective of infrun |
1961 | and the user/frontend, this new thread is running until | |
1962 | it next reports a stop. */ | |
719546c4 SM |
1963 | set_running (linux_target, new_lp->ptid, true); |
1964 | set_executing (linux_target, new_lp->ptid, true); | |
4c28f408 | 1965 | |
4dd63d48 | 1966 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 1967 | { |
4dd63d48 PA |
1968 | /* This can happen if someone starts sending signals to |
1969 | the new thread before it gets a chance to run, which | |
1970 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1971 | This is an unlikely case, and harder to handle for | |
1972 | fork / vfork than for clone, so we do not try - but | |
1973 | we handle it for clone events here. */ | |
1974 | ||
1975 | new_lp->signalled = 1; | |
1976 | ||
79395f92 PA |
1977 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
1978 | gdb_assert (new_lp->status == 0); | |
1979 | ||
1980 | /* Save the wait status to report later. */ | |
9327494e SM |
1981 | linux_nat_debug_printf |
1982 | ("waitpid of new LWP %ld, saving status %s", | |
8d06918f | 1983 | (long) new_lp->ptid.lwp (), status_to_str (status).c_str ()); |
79395f92 PA |
1984 | new_lp->status = status; |
1985 | } | |
aa01bd36 PA |
1986 | else if (report_thread_events) |
1987 | { | |
183be222 | 1988 | new_lp->waitstatus.set_thread_created (); |
aa01bd36 PA |
1989 | new_lp->status = status; |
1990 | } | |
79395f92 | 1991 | |
3d799a95 DJ |
1992 | return 1; |
1993 | } | |
1994 | ||
1995 | return 0; | |
d6b0e80f AC |
1996 | } |
1997 | ||
3d799a95 DJ |
1998 | if (event == PTRACE_EVENT_EXEC) |
1999 | { | |
9327494e | 2000 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2001 | |
05c06f31 PA |
2002 | /* Close the /proc/<pid>/mem file if it was open for this |
2003 | inferior. */ | |
2004 | maybe_close_proc_mem_file (lp->ptid.pid ()); | |
2005 | ||
183be222 SM |
2006 | ourstatus->set_execd |
2007 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 2008 | |
8af756ef PA |
2009 | /* The thread that execed must have been resumed, but, when a |
2010 | thread execs, it changes its tid to the tgid, and the old | |
2011 | tgid thread might have not been resumed. */ | |
2012 | lp->resumed = 1; | |
6c95b8df PA |
2013 | return 0; |
2014 | } | |
2015 | ||
2016 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2017 | { | |
2018 | if (current_inferior ()->waiting_for_vfork_done) | |
3d799a95 | 2019 | { |
9327494e SM |
2020 | linux_nat_debug_printf |
2021 | ("Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping", | |
2022 | lp->ptid.lwp ()); | |
3d799a95 | 2023 | |
183be222 | 2024 | ourstatus->set_vfork_done (); |
6c95b8df | 2025 | return 0; |
3d799a95 DJ |
2026 | } |
2027 | ||
9327494e SM |
2028 | linux_nat_debug_printf |
2029 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld: ignoring", lp->ptid.lwp ()); | |
2030 | ||
6c95b8df | 2031 | return 1; |
3d799a95 DJ |
2032 | } |
2033 | ||
2034 | internal_error (__FILE__, __LINE__, | |
2035 | _("unknown ptrace event %d"), event); | |
d6b0e80f AC |
2036 | } |
2037 | ||
9c3a5d93 PA |
2038 | /* Suspend waiting for a signal. We're mostly interested in |
2039 | SIGCHLD/SIGINT. */ | |
2040 | ||
2041 | static void | |
2042 | wait_for_signal () | |
2043 | { | |
9327494e | 2044 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2045 | sigsuspend (&suspend_mask); |
2046 | ||
2047 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2048 | and we're debugging a process that is running on a separate | |
2049 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2050 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2051 | inferior directly.) We must do this here because functions that | |
2052 | need to block waiting for a signal loop forever until there's an | |
2053 | event to report before returning back to the event loop. */ | |
2054 | if (!target_terminal::is_ours ()) | |
2055 | { | |
2056 | if (check_quit_flag ()) | |
2057 | target_pass_ctrlc (); | |
2058 | } | |
2059 | } | |
2060 | ||
d6b0e80f AC |
2061 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2062 | exited. */ | |
2063 | ||
2064 | static int | |
2065 | wait_lwp (struct lwp_info *lp) | |
2066 | { | |
2067 | pid_t pid; | |
432b4d03 | 2068 | int status = 0; |
d6b0e80f | 2069 | int thread_dead = 0; |
432b4d03 | 2070 | sigset_t prev_mask; |
d6b0e80f AC |
2071 | |
2072 | gdb_assert (!lp->stopped); | |
2073 | gdb_assert (lp->status == 0); | |
2074 | ||
432b4d03 JK |
2075 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2076 | block_child_signals (&prev_mask); | |
2077 | ||
2078 | for (;;) | |
d6b0e80f | 2079 | { |
e38504b3 | 2080 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2081 | if (pid == -1 && errno == ECHILD) |
2082 | { | |
2083 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2084 | now because if this was a non-leader thread execing, we |
2085 | won't get an exit event. See comments on exec events at | |
2086 | the top of the file. */ | |
a9f4bb21 | 2087 | thread_dead = 1; |
9327494e SM |
2088 | linux_nat_debug_printf ("%s vanished.", |
2089 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2090 | } |
432b4d03 JK |
2091 | if (pid != 0) |
2092 | break; | |
2093 | ||
2094 | /* Bugs 10970, 12702. | |
2095 | Thread group leader may have exited in which case we'll lock up in | |
2096 | waitpid if there are other threads, even if they are all zombies too. | |
2097 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2098 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2099 | for zombie and running processes. | |
432b4d03 JK |
2100 | |
2101 | As a workaround, check if we're waiting for the thread group leader and | |
2102 | if it's a zombie, and avoid calling waitpid if it is. | |
2103 | ||
2104 | This is racy, what if the tgl becomes a zombie right after we check? | |
2105 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2106 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2107 | |
e38504b3 TT |
2108 | if (lp->ptid.pid () == lp->ptid.lwp () |
2109 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2110 | { |
d6b0e80f | 2111 | thread_dead = 1; |
9327494e SM |
2112 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
2113 | target_pid_to_str (lp->ptid).c_str ()); | |
432b4d03 | 2114 | break; |
d6b0e80f | 2115 | } |
432b4d03 JK |
2116 | |
2117 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2118 | get invoked despite our caller had them intentionally blocked by | |
2119 | block_child_signals. This is sensitive only to the loop of | |
2120 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2121 | again before it gets to sigsuspend so we can safely let the handlers | |
2122 | get executed here. */ | |
9c3a5d93 | 2123 | wait_for_signal (); |
432b4d03 JK |
2124 | } |
2125 | ||
2126 | restore_child_signals_mask (&prev_mask); | |
2127 | ||
d6b0e80f AC |
2128 | if (!thread_dead) |
2129 | { | |
e38504b3 | 2130 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2131 | |
9327494e | 2132 | linux_nat_debug_printf ("waitpid %s received %s", |
a068643d | 2133 | target_pid_to_str (lp->ptid).c_str (), |
8d06918f | 2134 | status_to_str (status).c_str ()); |
d6b0e80f | 2135 | |
a9f4bb21 PA |
2136 | /* Check if the thread has exited. */ |
2137 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2138 | { | |
aa01bd36 | 2139 | if (report_thread_events |
e38504b3 | 2140 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2141 | { |
9327494e | 2142 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2143 | |
aa01bd36 | 2144 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2145 | process is gone. Store the status to report to the |
2146 | core. Store it in lp->waitstatus, because lp->status | |
2147 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
2148 | store_waitstatus (&lp->waitstatus, status); | |
2149 | return 0; | |
2150 | } | |
2151 | ||
a9f4bb21 | 2152 | thread_dead = 1; |
9327494e SM |
2153 | linux_nat_debug_printf ("%s exited.", |
2154 | target_pid_to_str (lp->ptid).c_str ()); | |
a9f4bb21 | 2155 | } |
d6b0e80f AC |
2156 | } |
2157 | ||
2158 | if (thread_dead) | |
2159 | { | |
e26af52f | 2160 | exit_lwp (lp); |
d6b0e80f AC |
2161 | return 0; |
2162 | } | |
2163 | ||
2164 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2165 | lp->stopped = 1; |
d6b0e80f | 2166 | |
8784d563 PA |
2167 | if (lp->must_set_ptrace_flags) |
2168 | { | |
5b6d1e4f | 2169 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2170 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2171 | |
e38504b3 | 2172 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2173 | lp->must_set_ptrace_flags = 0; |
2174 | } | |
2175 | ||
ca2163eb PA |
2176 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2177 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2178 | { | |
2179 | /* No longer need the sysgood bit. The ptrace event ends up | |
2180 | recorded in lp->waitstatus if we care for it. We can carry | |
2181 | on handling the event like a regular SIGTRAP from here | |
2182 | on. */ | |
2183 | status = W_STOPCODE (SIGTRAP); | |
2184 | if (linux_handle_syscall_trap (lp, 1)) | |
2185 | return wait_lwp (lp); | |
2186 | } | |
bfd09d20 JS |
2187 | else |
2188 | { | |
2189 | /* Almost all other ptrace-stops are known to be outside of system | |
2190 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2191 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2192 | } | |
ca2163eb | 2193 | |
d6b0e80f | 2194 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2195 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2196 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2197 | { |
9327494e | 2198 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2199 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2200 | return 0; |
d6b0e80f AC |
2201 | } |
2202 | ||
2203 | return status; | |
2204 | } | |
2205 | ||
2206 | /* Send a SIGSTOP to LP. */ | |
2207 | ||
2208 | static int | |
d3a70e03 | 2209 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2210 | { |
2211 | if (!lp->stopped && !lp->signalled) | |
2212 | { | |
2213 | int ret; | |
2214 | ||
9327494e | 2215 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
a068643d | 2216 | target_pid_to_str (lp->ptid).c_str ()); |
9327494e | 2217 | |
d6b0e80f | 2218 | errno = 0; |
e38504b3 | 2219 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2220 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2221 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2222 | |
2223 | lp->signalled = 1; | |
2224 | gdb_assert (lp->status == 0); | |
2225 | } | |
2226 | ||
2227 | return 0; | |
2228 | } | |
2229 | ||
7b50312a PA |
2230 | /* Request a stop on LWP. */ |
2231 | ||
2232 | void | |
2233 | linux_stop_lwp (struct lwp_info *lwp) | |
2234 | { | |
d3a70e03 | 2235 | stop_callback (lwp); |
7b50312a PA |
2236 | } |
2237 | ||
2db9a427 PA |
2238 | /* See linux-nat.h */ |
2239 | ||
2240 | void | |
2241 | linux_stop_and_wait_all_lwps (void) | |
2242 | { | |
2243 | /* Stop all LWP's ... */ | |
d3a70e03 | 2244 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2245 | |
2246 | /* ... and wait until all of them have reported back that | |
2247 | they're no longer running. */ | |
d3a70e03 | 2248 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2249 | } |
2250 | ||
2251 | /* See linux-nat.h */ | |
2252 | ||
2253 | void | |
2254 | linux_unstop_all_lwps (void) | |
2255 | { | |
2256 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2257 | [] (struct lwp_info *info) |
2258 | { | |
2259 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2260 | }); | |
2db9a427 PA |
2261 | } |
2262 | ||
57380f4e | 2263 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2264 | |
2265 | static int | |
57380f4e DJ |
2266 | linux_nat_has_pending_sigint (int pid) |
2267 | { | |
2268 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2269 | |
2270 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2271 | ||
2272 | if (sigismember (&pending, SIGINT) | |
2273 | && !sigismember (&ignored, SIGINT)) | |
2274 | return 1; | |
2275 | ||
2276 | return 0; | |
2277 | } | |
2278 | ||
2279 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2280 | ||
2281 | static int | |
d3a70e03 | 2282 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2283 | { |
57380f4e DJ |
2284 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2285 | flag to consume the next one. */ | |
2286 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2287 | && WSTOPSIG (lp->status) == SIGINT) | |
2288 | lp->status = 0; | |
2289 | else | |
2290 | lp->ignore_sigint = 1; | |
2291 | ||
2292 | return 0; | |
2293 | } | |
2294 | ||
2295 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2296 | This function is called after we know the LWP has stopped; if the LWP | |
2297 | stopped before the expected SIGINT was delivered, then it will never have | |
2298 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2299 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2300 | |
57380f4e DJ |
2301 | static void |
2302 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2303 | { | |
2304 | if (!lp->ignore_sigint) | |
2305 | return; | |
2306 | ||
e38504b3 | 2307 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2308 | { |
9327494e SM |
2309 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
2310 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2311 | lp->ignore_sigint = 0; |
2312 | } | |
2313 | } | |
2314 | ||
ebec9a0f PA |
2315 | /* Fetch the possible triggered data watchpoint info and store it in |
2316 | LP. | |
2317 | ||
2318 | On some archs, like x86, that use debug registers to set | |
2319 | watchpoints, it's possible that the way to know which watched | |
2320 | address trapped, is to check the register that is used to select | |
2321 | which address to watch. Problem is, between setting the watchpoint | |
2322 | and reading back which data address trapped, the user may change | |
2323 | the set of watchpoints, and, as a consequence, GDB changes the | |
2324 | debug registers in the inferior. To avoid reading back a stale | |
2325 | stopped-data-address when that happens, we cache in LP the fact | |
2326 | that a watchpoint trapped, and the corresponding data address, as | |
2327 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2328 | registers meanwhile, we have the cached data we can rely on. */ | |
2329 | ||
9c02b525 PA |
2330 | static int |
2331 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2332 | { |
2989a365 | 2333 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2334 | inferior_ptid = lp->ptid; |
2335 | ||
f6ac5f3d | 2336 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2337 | { |
15c66dd6 | 2338 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2339 | lp->stopped_data_address_p |
2340 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2341 | } |
2342 | ||
15c66dd6 | 2343 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2344 | } |
2345 | ||
9c02b525 | 2346 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2347 | |
57810aa7 | 2348 | bool |
f6ac5f3d | 2349 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2350 | { |
2351 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2352 | ||
2353 | gdb_assert (lp != NULL); | |
2354 | ||
15c66dd6 | 2355 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2356 | } |
2357 | ||
57810aa7 | 2358 | bool |
f6ac5f3d | 2359 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2360 | { |
2361 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2362 | ||
2363 | gdb_assert (lp != NULL); | |
2364 | ||
2365 | *addr_p = lp->stopped_data_address; | |
2366 | ||
2367 | return lp->stopped_data_address_p; | |
2368 | } | |
2369 | ||
26ab7092 JK |
2370 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2371 | ||
135340af PA |
2372 | bool |
2373 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2374 | { |
2375 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2376 | } | |
2377 | ||
57380f4e DJ |
2378 | /* Wait until LP is stopped. */ |
2379 | ||
2380 | static int | |
d3a70e03 | 2381 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2382 | { |
5b6d1e4f | 2383 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2384 | |
2385 | /* If this is a vfork parent, bail out, it is not going to report | |
2386 | any SIGSTOP until the vfork is done with. */ | |
2387 | if (inf->vfork_child != NULL) | |
2388 | return 0; | |
2389 | ||
d6b0e80f AC |
2390 | if (!lp->stopped) |
2391 | { | |
2392 | int status; | |
2393 | ||
2394 | status = wait_lwp (lp); | |
2395 | if (status == 0) | |
2396 | return 0; | |
2397 | ||
57380f4e DJ |
2398 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2399 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2400 | { |
57380f4e | 2401 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2402 | |
2403 | errno = 0; | |
e38504b3 | 2404 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2405 | lp->stopped = 0; |
9327494e SM |
2406 | linux_nat_debug_printf |
2407 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
2408 | target_pid_to_str (lp->ptid).c_str (), | |
2409 | errno ? safe_strerror (errno) : "OK"); | |
d6b0e80f | 2410 | |
d3a70e03 | 2411 | return stop_wait_callback (lp); |
d6b0e80f AC |
2412 | } |
2413 | ||
57380f4e DJ |
2414 | maybe_clear_ignore_sigint (lp); |
2415 | ||
d6b0e80f AC |
2416 | if (WSTOPSIG (status) != SIGSTOP) |
2417 | { | |
e5ef252a | 2418 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2419 | |
9327494e | 2420 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2421 | status_to_str ((int) status).c_str (), |
9327494e | 2422 | target_pid_to_str (lp->ptid).c_str ()); |
e5ef252a PA |
2423 | |
2424 | /* Save the sigtrap event. */ | |
2425 | lp->status = status; | |
e5ef252a | 2426 | gdb_assert (lp->signalled); |
e7ad2f14 | 2427 | save_stop_reason (lp); |
d6b0e80f AC |
2428 | } |
2429 | else | |
2430 | { | |
7010835a | 2431 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2432 | |
9327494e SM |
2433 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
2434 | target_pid_to_str (lp->ptid).c_str ()); | |
e5ef252a | 2435 | |
d6b0e80f | 2436 | lp->signalled = 0; |
7010835a AB |
2437 | |
2438 | /* If we are waiting for this stop so we can report the thread | |
2439 | stopped then we need to record this status. Otherwise, we can | |
2440 | now discard this stop event. */ | |
2441 | if (lp->last_resume_kind == resume_stop) | |
2442 | { | |
2443 | lp->status = status; | |
2444 | save_stop_reason (lp); | |
2445 | } | |
d6b0e80f AC |
2446 | } |
2447 | } | |
2448 | ||
2449 | return 0; | |
2450 | } | |
2451 | ||
9c02b525 PA |
2452 | /* Return non-zero if LP has a wait status pending. Discard the |
2453 | pending event and resume the LWP if the event that originally | |
2454 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2455 | |
2456 | static int | |
d3a70e03 | 2457 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2458 | { |
2459 | /* Only report a pending wait status if we pretend that this has | |
2460 | indeed been resumed. */ | |
ca2163eb PA |
2461 | if (!lp->resumed) |
2462 | return 0; | |
2463 | ||
eb54c8bf PA |
2464 | if (!lwp_status_pending_p (lp)) |
2465 | return 0; | |
2466 | ||
15c66dd6 PA |
2467 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2468 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2469 | { |
5b6d1e4f | 2470 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2471 | CORE_ADDR pc; |
2472 | int discard = 0; | |
2473 | ||
9c02b525 PA |
2474 | pc = regcache_read_pc (regcache); |
2475 | ||
2476 | if (pc != lp->stop_pc) | |
2477 | { | |
9327494e SM |
2478 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
2479 | target_pid_to_str (lp->ptid).c_str (), | |
2480 | paddress (target_gdbarch (), lp->stop_pc), | |
2481 | paddress (target_gdbarch (), pc)); | |
9c02b525 PA |
2482 | discard = 1; |
2483 | } | |
faf09f01 PA |
2484 | |
2485 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2486 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2487 | { |
9327494e SM |
2488 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
2489 | target_pid_to_str (lp->ptid).c_str (), | |
2490 | paddress (target_gdbarch (), lp->stop_pc)); | |
9c02b525 PA |
2491 | |
2492 | discard = 1; | |
2493 | } | |
faf09f01 | 2494 | #endif |
9c02b525 PA |
2495 | |
2496 | if (discard) | |
2497 | { | |
9327494e SM |
2498 | linux_nat_debug_printf ("pending event of %s cancelled.", |
2499 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 PA |
2500 | |
2501 | lp->status = 0; | |
2502 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2503 | return 0; | |
2504 | } | |
9c02b525 PA |
2505 | } |
2506 | ||
eb54c8bf | 2507 | return 1; |
d6b0e80f AC |
2508 | } |
2509 | ||
d6b0e80f AC |
2510 | /* Count the LWP's that have had events. */ |
2511 | ||
2512 | static int | |
d3a70e03 | 2513 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2514 | { |
d6b0e80f AC |
2515 | gdb_assert (count != NULL); |
2516 | ||
9c02b525 PA |
2517 | /* Select only resumed LWPs that have an event pending. */ |
2518 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2519 | (*count)++; |
2520 | ||
2521 | return 0; | |
2522 | } | |
2523 | ||
2524 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2525 | ||
2526 | static int | |
d3a70e03 | 2527 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2528 | { |
25289eb2 PA |
2529 | if (lp->last_resume_kind == resume_step |
2530 | && lp->status != 0) | |
d6b0e80f AC |
2531 | return 1; |
2532 | else | |
2533 | return 0; | |
2534 | } | |
2535 | ||
8a99810d PA |
2536 | /* Returns true if LP has a status pending. */ |
2537 | ||
2538 | static int | |
2539 | lwp_status_pending_p (struct lwp_info *lp) | |
2540 | { | |
2541 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2542 | can have pending process exits recorded in lp->status and | |
2543 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2544 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2545 | } |
2546 | ||
b90fc188 | 2547 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2548 | |
2549 | static int | |
d3a70e03 | 2550 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2551 | { |
d6b0e80f AC |
2552 | gdb_assert (selector != NULL); |
2553 | ||
9c02b525 PA |
2554 | /* Select only resumed LWPs that have an event pending. */ |
2555 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2556 | if ((*selector)-- == 0) |
2557 | return 1; | |
2558 | ||
2559 | return 0; | |
2560 | } | |
2561 | ||
e7ad2f14 PA |
2562 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2563 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2564 | and save the result in the LWP's stop_reason field. If it stopped | |
2565 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2566 | architecture. */ | |
9c02b525 | 2567 | |
e7ad2f14 PA |
2568 | static void |
2569 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2570 | { |
e7ad2f14 PA |
2571 | struct regcache *regcache; |
2572 | struct gdbarch *gdbarch; | |
515630c5 | 2573 | CORE_ADDR pc; |
9c02b525 | 2574 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2575 | #if USE_SIGTRAP_SIGINFO |
2576 | siginfo_t siginfo; | |
2577 | #endif | |
9c02b525 | 2578 | |
e7ad2f14 PA |
2579 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2580 | gdb_assert (lp->status != 0); | |
2581 | ||
135340af | 2582 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2583 | return; |
2584 | ||
5b6d1e4f | 2585 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2586 | gdbarch = regcache->arch (); |
e7ad2f14 | 2587 | |
9c02b525 | 2588 | pc = regcache_read_pc (regcache); |
527a273a | 2589 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2590 | |
faf09f01 PA |
2591 | #if USE_SIGTRAP_SIGINFO |
2592 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2593 | { | |
2594 | if (siginfo.si_signo == SIGTRAP) | |
2595 | { | |
e7ad2f14 PA |
2596 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2597 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2598 | { |
e7ad2f14 PA |
2599 | /* The si_code is ambiguous on this arch -- check debug |
2600 | registers. */ | |
2601 | if (!check_stopped_by_watchpoint (lp)) | |
2602 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2603 | } | |
2604 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2605 | { | |
2606 | /* If we determine the LWP stopped for a SW breakpoint, | |
2607 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2608 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2609 | stopped-by-watchpoint as long as there's a watchpoint |
2610 | set. */ | |
faf09f01 | 2611 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2612 | } |
e7ad2f14 | 2613 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2614 | { |
e7ad2f14 PA |
2615 | /* This can indicate either a hardware breakpoint or |
2616 | hardware watchpoint. Check debug registers. */ | |
2617 | if (!check_stopped_by_watchpoint (lp)) | |
2618 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2619 | } |
2bf6fb9d PA |
2620 | else if (siginfo.si_code == TRAP_TRACE) |
2621 | { | |
9327494e SM |
2622 | linux_nat_debug_printf ("%s stopped by trace", |
2623 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2624 | |
2625 | /* We may have single stepped an instruction that | |
2626 | triggered a watchpoint. In that case, on some | |
2627 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2628 | si_code indicates TRAP_TRACE, and we need to check | |
2629 | the debug registers separately. */ | |
2630 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2631 | } |
faf09f01 PA |
2632 | } |
2633 | } | |
2634 | #else | |
9c02b525 | 2635 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2636 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2637 | sw_bp_pc)) |
710151dd | 2638 | { |
9c02b525 PA |
2639 | /* The LWP was either continued, or stepped a software |
2640 | breakpoint instruction. */ | |
e7ad2f14 PA |
2641 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2642 | } | |
2643 | ||
a01bda52 | 2644 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2645 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2646 | ||
2647 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2648 | check_stopped_by_watchpoint (lp); | |
2649 | #endif | |
2650 | ||
2651 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2652 | { | |
9327494e SM |
2653 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
2654 | target_pid_to_str (lp->ptid).c_str ()); | |
710151dd PA |
2655 | |
2656 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2657 | if (pc != sw_bp_pc) |
2658 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2659 | |
e7ad2f14 PA |
2660 | /* Update this so we record the correct stop PC below. */ |
2661 | pc = sw_bp_pc; | |
710151dd | 2662 | } |
e7ad2f14 | 2663 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2664 | { |
9327494e SM |
2665 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
2666 | target_pid_to_str (lp->ptid).c_str ()); | |
e7ad2f14 PA |
2667 | } |
2668 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2669 | { | |
9327494e SM |
2670 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
2671 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2672 | } |
d6b0e80f | 2673 | |
e7ad2f14 | 2674 | lp->stop_pc = pc; |
d6b0e80f AC |
2675 | } |
2676 | ||
faf09f01 PA |
2677 | |
2678 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2679 | ||
57810aa7 | 2680 | bool |
f6ac5f3d | 2681 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2682 | { |
2683 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2684 | ||
2685 | gdb_assert (lp != NULL); | |
2686 | ||
2687 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2688 | } | |
2689 | ||
2690 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2691 | ||
57810aa7 | 2692 | bool |
f6ac5f3d | 2693 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2694 | { |
2695 | return USE_SIGTRAP_SIGINFO; | |
2696 | } | |
2697 | ||
2698 | /* Returns true if the LWP had stopped for a hardware | |
2699 | breakpoint/watchpoint. */ | |
2700 | ||
57810aa7 | 2701 | bool |
f6ac5f3d | 2702 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2703 | { |
2704 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2705 | ||
2706 | gdb_assert (lp != NULL); | |
2707 | ||
2708 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2709 | } | |
2710 | ||
2711 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2712 | ||
57810aa7 | 2713 | bool |
f6ac5f3d | 2714 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2715 | { |
2716 | return USE_SIGTRAP_SIGINFO; | |
2717 | } | |
2718 | ||
d6b0e80f AC |
2719 | /* Select one LWP out of those that have events pending. */ |
2720 | ||
2721 | static void | |
d90e17a7 | 2722 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2723 | { |
2724 | int num_events = 0; | |
2725 | int random_selector; | |
9c02b525 | 2726 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2727 | |
ac264b3b | 2728 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2729 | (*orig_lp)->status = *status; |
2730 | ||
9c02b525 PA |
2731 | /* In all-stop, give preference to the LWP that is being |
2732 | single-stepped. There will be at most one, and it will be the | |
2733 | LWP that the core is most interested in. If we didn't do this, | |
2734 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2735 | the core later continues the previously-stepped thread, as | |
2736 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2737 | having stepped the thread, wouldn't understand what the trap was | |
2738 | for, and therefore would report it to the user as a random | |
2739 | signal. */ | |
fbea99ea | 2740 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2741 | { |
d3a70e03 | 2742 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2743 | if (event_lp != NULL) |
2744 | { | |
9327494e SM |
2745 | linux_nat_debug_printf ("Select single-step %s", |
2746 | target_pid_to_str (event_lp->ptid).c_str ()); | |
9c02b525 | 2747 | } |
d6b0e80f | 2748 | } |
9c02b525 PA |
2749 | |
2750 | if (event_lp == NULL) | |
d6b0e80f | 2751 | { |
9c02b525 | 2752 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2753 | |
9c02b525 | 2754 | /* First see how many events we have. */ |
d3a70e03 TT |
2755 | iterate_over_lwps (filter, |
2756 | [&] (struct lwp_info *info) | |
2757 | { | |
2758 | return count_events_callback (info, &num_events); | |
2759 | }); | |
8bf3b159 | 2760 | gdb_assert (num_events > 0); |
d6b0e80f | 2761 | |
9c02b525 PA |
2762 | /* Now randomly pick a LWP out of those that have had |
2763 | events. */ | |
d6b0e80f AC |
2764 | random_selector = (int) |
2765 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2766 | ||
9327494e SM |
2767 | if (num_events > 1) |
2768 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2769 | num_events, random_selector); | |
d6b0e80f | 2770 | |
d3a70e03 TT |
2771 | event_lp |
2772 | = (iterate_over_lwps | |
2773 | (filter, | |
2774 | [&] (struct lwp_info *info) | |
2775 | { | |
2776 | return select_event_lwp_callback (info, | |
2777 | &random_selector); | |
2778 | })); | |
d6b0e80f AC |
2779 | } |
2780 | ||
2781 | if (event_lp != NULL) | |
2782 | { | |
2783 | /* Switch the event LWP. */ | |
2784 | *orig_lp = event_lp; | |
2785 | *status = event_lp->status; | |
2786 | } | |
2787 | ||
2788 | /* Flush the wait status for the event LWP. */ | |
2789 | (*orig_lp)->status = 0; | |
2790 | } | |
2791 | ||
2792 | /* Return non-zero if LP has been resumed. */ | |
2793 | ||
2794 | static int | |
d3a70e03 | 2795 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2796 | { |
2797 | return lp->resumed; | |
2798 | } | |
2799 | ||
02f3fc28 | 2800 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2801 | |
897608ed SM |
2802 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2803 | ||
2804 | static void | |
9c02b525 | 2805 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2806 | { |
2807 | struct lwp_info *lp; | |
89a5711c | 2808 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2809 | |
f2907e49 | 2810 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 PA |
2811 | |
2812 | /* Check for stop events reported by a process we didn't already | |
2813 | know about - anything not already in our LWP list. | |
2814 | ||
2815 | If we're expecting to receive stopped processes after | |
2816 | fork, vfork, and clone events, then we'll just add the | |
2817 | new one to our list and go back to waiting for the event | |
2818 | to be reported - the stopped process might be returned | |
0e5bf2a8 PA |
2819 | from waitpid before or after the event is. |
2820 | ||
2821 | But note the case of a non-leader thread exec'ing after the | |
2822 | leader having exited, and gone from our lists. The non-leader | |
2823 | thread changes its tid to the tgid. */ | |
2824 | ||
2825 | if (WIFSTOPPED (status) && lp == NULL | |
89a5711c | 2826 | && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC)) |
0e5bf2a8 PA |
2827 | { |
2828 | /* A multi-thread exec after we had seen the leader exiting. */ | |
9327494e | 2829 | linux_nat_debug_printf ("Re-adding thread group leader LWP %d.", lwpid); |
0e5bf2a8 | 2830 | |
184ea2f7 | 2831 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
0e5bf2a8 PA |
2832 | lp->stopped = 1; |
2833 | lp->resumed = 1; | |
5b6d1e4f | 2834 | add_thread (linux_target, lp->ptid); |
0e5bf2a8 PA |
2835 | } |
2836 | ||
02f3fc28 PA |
2837 | if (WIFSTOPPED (status) && !lp) |
2838 | { | |
9327494e | 2839 | linux_nat_debug_printf ("saving LWP %ld status %s in stopped_pids list", |
8d06918f | 2840 | (long) lwpid, status_to_str (status).c_str ()); |
84636d28 | 2841 | add_to_pid_list (&stopped_pids, lwpid, status); |
897608ed | 2842 | return; |
02f3fc28 PA |
2843 | } |
2844 | ||
2845 | /* Make sure we don't report an event for the exit of an LWP not in | |
1777feb0 | 2846 | our list, i.e. not part of the current process. This can happen |
fd62cb89 | 2847 | if we detach from a program we originally forked and then it |
02f3fc28 PA |
2848 | exits. */ |
2849 | if (!WIFSTOPPED (status) && !lp) | |
897608ed | 2850 | return; |
02f3fc28 | 2851 | |
8817a6f2 PA |
2852 | /* This LWP is stopped now. (And if dead, this prevents it from |
2853 | ever being continued.) */ | |
2854 | lp->stopped = 1; | |
2855 | ||
8784d563 PA |
2856 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2857 | { | |
5b6d1e4f | 2858 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2859 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2860 | |
e38504b3 | 2861 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2862 | lp->must_set_ptrace_flags = 0; |
2863 | } | |
2864 | ||
ca2163eb PA |
2865 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2866 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2867 | { | |
2868 | /* No longer need the sysgood bit. The ptrace event ends up | |
2869 | recorded in lp->waitstatus if we care for it. We can carry | |
2870 | on handling the event like a regular SIGTRAP from here | |
2871 | on. */ | |
2872 | status = W_STOPCODE (SIGTRAP); | |
2873 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2874 | return; |
ca2163eb | 2875 | } |
bfd09d20 JS |
2876 | else |
2877 | { | |
2878 | /* Almost all other ptrace-stops are known to be outside of system | |
2879 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2880 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2881 | } | |
02f3fc28 | 2882 | |
ca2163eb | 2883 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2884 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2885 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2886 | { |
9327494e SM |
2887 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2888 | ||
4dd63d48 | 2889 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2890 | return; |
02f3fc28 PA |
2891 | } |
2892 | ||
2893 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2894 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2895 | { | |
aa01bd36 | 2896 | if (!report_thread_events |
e99b03dc | 2897 | && num_lwps (lp->ptid.pid ()) > 1) |
02f3fc28 | 2898 | { |
9327494e SM |
2899 | linux_nat_debug_printf ("%s exited.", |
2900 | target_pid_to_str (lp->ptid).c_str ()); | |
9c02b525 | 2901 | |
4a6ed09b PA |
2902 | /* If there is at least one more LWP, then the exit signal |
2903 | was not the end of the debugged application and should be | |
2904 | ignored. */ | |
2905 | exit_lwp (lp); | |
897608ed | 2906 | return; |
02f3fc28 PA |
2907 | } |
2908 | ||
77598427 PA |
2909 | /* Note that even if the leader was ptrace-stopped, it can still |
2910 | exit, if e.g., some other thread brings down the whole | |
2911 | process (calls `exit'). So don't assert that the lwp is | |
2912 | resumed. */ | |
9327494e SM |
2913 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2914 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2915 | |
9c02b525 PA |
2916 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2917 | lp->signalled = 0; | |
2918 | ||
2919 | /* Store the pending event in the waitstatus, because | |
2920 | W_EXITCODE(0,0) == 0. */ | |
2921 | store_waitstatus (&lp->waitstatus, status); | |
897608ed | 2922 | return; |
02f3fc28 PA |
2923 | } |
2924 | ||
02f3fc28 PA |
2925 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2926 | an attempt to stop an LWP. */ | |
2927 | if (lp->signalled | |
2928 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2929 | { | |
02f3fc28 PA |
2930 | lp->signalled = 0; |
2931 | ||
2bf6fb9d | 2932 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2933 | { |
9327494e SM |
2934 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
2935 | target_pid_to_str (lp->ptid).c_str ()); | |
2bf6fb9d PA |
2936 | } |
2937 | else | |
2938 | { | |
2939 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2940 | |
9327494e SM |
2941 | linux_nat_debug_printf |
2942 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2943 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2944 | target_pid_to_str (lp->ptid).c_str ()); | |
02f3fc28 | 2945 | |
2bf6fb9d | 2946 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2947 | gdb_assert (lp->resumed); |
897608ed | 2948 | return; |
25289eb2 | 2949 | } |
02f3fc28 PA |
2950 | } |
2951 | ||
57380f4e DJ |
2952 | /* Make sure we don't report a SIGINT that we have already displayed |
2953 | for another thread. */ | |
2954 | if (lp->ignore_sigint | |
2955 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2956 | { | |
9327494e SM |
2957 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
2958 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2959 | |
2960 | /* This is a delayed SIGINT. */ | |
2961 | lp->ignore_sigint = 0; | |
2962 | ||
8a99810d | 2963 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
2964 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
2965 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
2966 | target_pid_to_str (lp->ptid).c_str ()); | |
57380f4e DJ |
2967 | gdb_assert (lp->resumed); |
2968 | ||
2969 | /* Discard the event. */ | |
897608ed | 2970 | return; |
57380f4e DJ |
2971 | } |
2972 | ||
9c02b525 PA |
2973 | /* Don't report signals that GDB isn't interested in, such as |
2974 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 2975 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
2976 | performance with heavily multi-threaded programs, especially when |
2977 | they're using a high frequency timer, we'd better avoid it if we | |
2978 | can. */ | |
2979 | if (WIFSTOPPED (status)) | |
2980 | { | |
2981 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
2982 | ||
fbea99ea | 2983 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
2984 | { |
2985 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
2986 | to implement target_stop (see linux_nat_stop) in | |
2987 | non-stop. */ | |
2988 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
2989 | { | |
2990 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
2991 | forwarded to the entire process group, that is, all LWPs | |
2992 | will receive it - unless they're using CLONE_THREAD to | |
2993 | share signals. Since we only want to report it once, we | |
2994 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 2995 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
2996 | lp->ignore_sigint = 0; |
2997 | } | |
2998 | else | |
2999 | maybe_clear_ignore_sigint (lp); | |
3000 | } | |
3001 | ||
3002 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3003 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3004 | except signals that might be caused by a breakpoint, or SIGSTOP |
3005 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3006 | if (!lp->step |
c9587f88 | 3007 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3008 | && (WSTOPSIG (status) != SIGSTOP |
5b6d1e4f | 3009 | || !find_thread_ptid (linux_target, lp->ptid)->stop_requested) |
c9587f88 | 3010 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3011 | { |
3012 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3013 | linux_nat_debug_printf |
3014 | ("%s %s, %s (preempt 'handle')", | |
3015 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
3016 | target_pid_to_str (lp->ptid).c_str (), | |
3017 | (signo != GDB_SIGNAL_0 | |
3018 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3019 | return; |
9c02b525 PA |
3020 | } |
3021 | } | |
3022 | ||
02f3fc28 PA |
3023 | /* An interesting event. */ |
3024 | gdb_assert (lp); | |
ca2163eb | 3025 | lp->status = status; |
e7ad2f14 | 3026 | save_stop_reason (lp); |
02f3fc28 PA |
3027 | } |
3028 | ||
0e5bf2a8 PA |
3029 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3030 | their exits until all other threads in the group have exited. */ | |
3031 | ||
3032 | static void | |
3033 | check_zombie_leaders (void) | |
3034 | { | |
08036331 | 3035 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3036 | { |
3037 | struct lwp_info *leader_lp; | |
3038 | ||
3039 | if (inf->pid == 0) | |
3040 | continue; | |
3041 | ||
f2907e49 | 3042 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3043 | if (leader_lp != NULL |
3044 | /* Check if there are other threads in the group, as we may | |
3045 | have raced with the inferior simply exiting. */ | |
3046 | && num_lwps (inf->pid) > 1 | |
5f572dec | 3047 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3048 | { |
9327494e SM |
3049 | linux_nat_debug_printf ("Thread group leader %d zombie " |
3050 | "(it exited, or another thread execd).", | |
3051 | inf->pid); | |
0e5bf2a8 PA |
3052 | |
3053 | /* A leader zombie can mean one of two things: | |
3054 | ||
3055 | - It exited, and there's an exit status pending | |
3056 | available, or only the leader exited (not the whole | |
3057 | program). In the latter case, we can't waitpid the | |
3058 | leader's exit status until all other threads are gone. | |
3059 | ||
3060 | - There are 3 or more threads in the group, and a thread | |
4a6ed09b PA |
3061 | other than the leader exec'd. See comments on exec |
3062 | events at the top of the file. We could try | |
0e5bf2a8 PA |
3063 | distinguishing the exit and exec cases, by waiting once |
3064 | more, and seeing if something comes out, but it doesn't | |
3065 | sound useful. The previous leader _does_ go away, and | |
3066 | we'll re-add the new one once we see the exec event | |
3067 | (which is just the same as what would happen if the | |
3068 | previous leader did exit voluntarily before some other | |
3069 | thread execs). */ | |
3070 | ||
9327494e | 3071 | linux_nat_debug_printf ("Thread group leader %d vanished.", inf->pid); |
0e5bf2a8 PA |
3072 | exit_lwp (leader_lp); |
3073 | } | |
3074 | } | |
3075 | } | |
3076 | ||
aa01bd36 PA |
3077 | /* Convenience function that is called when the kernel reports an exit |
3078 | event. This decides whether to report the event to GDB as a | |
3079 | process exit event, a thread exit event, or to suppress the | |
3080 | event. */ | |
3081 | ||
3082 | static ptid_t | |
3083 | filter_exit_event (struct lwp_info *event_child, | |
3084 | struct target_waitstatus *ourstatus) | |
3085 | { | |
3086 | ptid_t ptid = event_child->ptid; | |
3087 | ||
e99b03dc | 3088 | if (num_lwps (ptid.pid ()) > 1) |
aa01bd36 PA |
3089 | { |
3090 | if (report_thread_events) | |
183be222 | 3091 | ourstatus->set_thread_exited (0); |
aa01bd36 | 3092 | else |
183be222 | 3093 | ourstatus->set_ignore (); |
aa01bd36 PA |
3094 | |
3095 | exit_lwp (event_child); | |
3096 | } | |
3097 | ||
3098 | return ptid; | |
3099 | } | |
3100 | ||
d6b0e80f | 3101 | static ptid_t |
f6ac5f3d | 3102 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3103 | target_wait_flags target_options) |
d6b0e80f | 3104 | { |
fc9b8e47 | 3105 | sigset_t prev_mask; |
4b60df3d | 3106 | enum resume_kind last_resume_kind; |
12d9289a | 3107 | struct lwp_info *lp; |
12d9289a | 3108 | int status; |
d6b0e80f | 3109 | |
9327494e | 3110 | linux_nat_debug_printf ("enter"); |
b84876c2 | 3111 | |
f973ed9c DJ |
3112 | /* The first time we get here after starting a new inferior, we may |
3113 | not have added it to the LWP list yet - this is the earliest | |
3114 | moment at which we know its PID. */ | |
677c92fe | 3115 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3116 | { |
677c92fe | 3117 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3118 | |
677c92fe SM |
3119 | /* Upgrade the main thread's ptid. */ |
3120 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3121 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3122 | lp->resumed = 1; |
3123 | } | |
3124 | ||
12696c10 | 3125 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3126 | block_child_signals (&prev_mask); |
d6b0e80f | 3127 | |
d6b0e80f | 3128 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3129 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3130 | if (lp != NULL) |
d6b0e80f | 3131 | { |
9327494e | 3132 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
8d06918f | 3133 | status_to_str (lp->status).c_str (), |
9327494e | 3134 | target_pid_to_str (lp->ptid).c_str ()); |
d6b0e80f AC |
3135 | } |
3136 | ||
9c02b525 PA |
3137 | /* But if we don't find a pending event, we'll have to wait. Always |
3138 | pull all events out of the kernel. We'll randomly select an | |
3139 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3140 | |
d90e17a7 | 3141 | while (lp == NULL) |
d6b0e80f AC |
3142 | { |
3143 | pid_t lwpid; | |
3144 | ||
0e5bf2a8 PA |
3145 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3146 | quirks: | |
3147 | ||
3148 | - If the thread group leader exits while other threads in the | |
3149 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3150 | waitpid won't return an exit status until the other threads | |
85102364 | 3151 | in the group are reaped. |
0e5bf2a8 PA |
3152 | |
3153 | - When a non-leader thread execs, that thread just vanishes | |
3154 | without reporting an exit (so we'd hang if we waited for it | |
3155 | explicitly in that case). The exec event is reported to | |
3156 | the TGID pid. */ | |
3157 | ||
3158 | errno = 0; | |
4a6ed09b | 3159 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3160 | |
9327494e SM |
3161 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3162 | lwpid, | |
3163 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3164 | |
d6b0e80f AC |
3165 | if (lwpid > 0) |
3166 | { | |
9327494e | 3167 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3168 | (long) lwpid, |
3169 | status_to_str (status).c_str ()); | |
d6b0e80f | 3170 | |
9c02b525 | 3171 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3172 | /* Retry until nothing comes out of waitpid. A single |
3173 | SIGCHLD can indicate more than one child stopped. */ | |
3174 | continue; | |
d6b0e80f AC |
3175 | } |
3176 | ||
20ba1ce6 PA |
3177 | /* Now that we've pulled all events out of the kernel, resume |
3178 | LWPs that don't have an interesting event to report. */ | |
3179 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3180 | [] (struct lwp_info *info) |
3181 | { | |
3182 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3183 | }); | |
20ba1ce6 PA |
3184 | |
3185 | /* ... and find an LWP with a status to report to the core, if | |
3186 | any. */ | |
d3a70e03 | 3187 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3188 | if (lp != NULL) |
3189 | break; | |
3190 | ||
0e5bf2a8 PA |
3191 | /* Check for zombie thread group leaders. Those can't be reaped |
3192 | until all other threads in the thread group are. */ | |
3193 | check_zombie_leaders (); | |
d6b0e80f | 3194 | |
0e5bf2a8 PA |
3195 | /* If there are no resumed children left, bail. We'd be stuck |
3196 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3197 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3198 | { |
9327494e | 3199 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3200 | |
183be222 | 3201 | ourstatus->set_no_resumed (); |
b84876c2 | 3202 | |
0e5bf2a8 PA |
3203 | restore_child_signals_mask (&prev_mask); |
3204 | return minus_one_ptid; | |
d6b0e80f | 3205 | } |
28736962 | 3206 | |
0e5bf2a8 PA |
3207 | /* No interesting event to report to the core. */ |
3208 | ||
3209 | if (target_options & TARGET_WNOHANG) | |
3210 | { | |
9327494e | 3211 | linux_nat_debug_printf ("exit (ignore)"); |
28736962 | 3212 | |
183be222 | 3213 | ourstatus->set_ignore (); |
28736962 PA |
3214 | restore_child_signals_mask (&prev_mask); |
3215 | return minus_one_ptid; | |
3216 | } | |
d6b0e80f AC |
3217 | |
3218 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3219 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3220 | |
3221 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3222 | wait_for_signal (); |
d6b0e80f AC |
3223 | } |
3224 | ||
d6b0e80f AC |
3225 | gdb_assert (lp); |
3226 | ||
ca2163eb PA |
3227 | status = lp->status; |
3228 | lp->status = 0; | |
3229 | ||
fbea99ea | 3230 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3231 | { |
3232 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3233 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3234 | |
3235 | /* ... and wait until all of them have reported back that | |
3236 | they're no longer running. */ | |
d3a70e03 | 3237 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3238 | } |
3239 | ||
3240 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3241 | among those that have had events. Giving equal priority to all | |
3242 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3243 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3244 | select_event_lwp (ptid, &lp, &status); |
3245 | ||
3246 | gdb_assert (lp != NULL); | |
3247 | ||
3248 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3249 | it was a software breakpoint, and we can't reliably support the |
3250 | "stopped by software breakpoint" stop reason. */ | |
3251 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3252 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3253 | { |
5b6d1e4f | 3254 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3255 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3256 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3257 | |
9c02b525 PA |
3258 | if (decr_pc != 0) |
3259 | { | |
3260 | CORE_ADDR pc; | |
d6b0e80f | 3261 | |
9c02b525 PA |
3262 | pc = regcache_read_pc (regcache); |
3263 | regcache_write_pc (regcache, pc + decr_pc); | |
3264 | } | |
3265 | } | |
e3e9f5a2 | 3266 | |
9c02b525 PA |
3267 | /* We'll need this to determine whether to report a SIGSTOP as |
3268 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3269 | clears it. */ | |
3270 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3271 | |
fbea99ea | 3272 | if (!target_is_non_stop_p ()) |
9c02b525 | 3273 | { |
e3e9f5a2 PA |
3274 | /* In all-stop, from the core's perspective, all LWPs are now |
3275 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3276 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3277 | } |
3278 | else | |
25289eb2 | 3279 | { |
d3a70e03 | 3280 | resume_clear_callback (lp); |
25289eb2 | 3281 | } |
d6b0e80f | 3282 | |
135340af | 3283 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3284 | { |
9327494e SM |
3285 | linux_nat_debug_printf ("trap ptid is %s.", |
3286 | target_pid_to_str (lp->ptid).c_str ()); | |
d6b0e80f | 3287 | } |
d6b0e80f | 3288 | |
183be222 | 3289 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3290 | { |
3291 | *ourstatus = lp->waitstatus; | |
183be222 | 3292 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3293 | } |
3294 | else | |
3295 | store_waitstatus (ourstatus, status); | |
3296 | ||
9327494e | 3297 | linux_nat_debug_printf ("exit"); |
b84876c2 | 3298 | |
7feb7d06 | 3299 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3300 | |
4b60df3d | 3301 | if (last_resume_kind == resume_stop |
183be222 | 3302 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3303 | && WSTOPSIG (status) == SIGSTOP) |
3304 | { | |
3305 | /* A thread that has been requested to stop by GDB with | |
3306 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3307 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3308 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3309 | } |
3310 | ||
183be222 SM |
3311 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3312 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3313 | lp->core = -1; |
3314 | else | |
2e794194 | 3315 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3316 | |
183be222 | 3317 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED) |
aa01bd36 PA |
3318 | return filter_exit_event (lp, ourstatus); |
3319 | ||
f973ed9c | 3320 | return lp->ptid; |
d6b0e80f AC |
3321 | } |
3322 | ||
e3e9f5a2 PA |
3323 | /* Resume LWPs that are currently stopped without any pending status |
3324 | to report, but are resumed from the core's perspective. */ | |
3325 | ||
3326 | static int | |
d3a70e03 | 3327 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3328 | { |
4dd63d48 PA |
3329 | if (!lp->stopped) |
3330 | { | |
9327494e SM |
3331 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
3332 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3333 | } |
3334 | else if (!lp->resumed) | |
3335 | { | |
9327494e SM |
3336 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
3337 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3338 | } |
3339 | else if (lwp_status_pending_p (lp)) | |
3340 | { | |
9327494e SM |
3341 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
3342 | target_pid_to_str (lp->ptid).c_str ()); | |
4dd63d48 PA |
3343 | } |
3344 | else | |
e3e9f5a2 | 3345 | { |
5b6d1e4f | 3346 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3347 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3348 | |
a70b8144 | 3349 | try |
e3e9f5a2 | 3350 | { |
23f238d3 PA |
3351 | CORE_ADDR pc = regcache_read_pc (regcache); |
3352 | int leave_stopped = 0; | |
e3e9f5a2 | 3353 | |
23f238d3 PA |
3354 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3355 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3356 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3357 | { |
a01bda52 | 3358 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3359 | leave_stopped = 1; |
3360 | } | |
e3e9f5a2 | 3361 | |
23f238d3 PA |
3362 | if (!leave_stopped) |
3363 | { | |
9327494e SM |
3364 | linux_nat_debug_printf |
3365 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
3366 | target_pid_to_str (lp->ptid).c_str (), paddress (gdbarch, pc), | |
3367 | lp->step); | |
23f238d3 PA |
3368 | |
3369 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3370 | } | |
3371 | } | |
230d2906 | 3372 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3373 | { |
3374 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3375 | throw; |
23f238d3 | 3376 | } |
e3e9f5a2 PA |
3377 | } |
3378 | ||
3379 | return 0; | |
3380 | } | |
3381 | ||
f6ac5f3d PA |
3382 | ptid_t |
3383 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3384 | target_wait_flags target_options) |
7feb7d06 PA |
3385 | { |
3386 | ptid_t event_ptid; | |
3387 | ||
9327494e SM |
3388 | linux_nat_debug_printf ("[%s], [%s]", target_pid_to_str (ptid).c_str (), |
3389 | target_options_to_string (target_options).c_str ()); | |
7feb7d06 PA |
3390 | |
3391 | /* Flush the async file first. */ | |
d9d41e78 | 3392 | if (target_is_async_p ()) |
7feb7d06 PA |
3393 | async_file_flush (); |
3394 | ||
e3e9f5a2 PA |
3395 | /* Resume LWPs that are currently stopped without any pending status |
3396 | to report, but are resumed from the core's perspective. LWPs get | |
3397 | in this state if we find them stopping at a time we're not | |
3398 | interested in reporting the event (target_wait on a | |
3399 | specific_process, for example, see linux_nat_wait_1), and | |
3400 | meanwhile the event became uninteresting. Don't bother resuming | |
3401 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3402 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3403 | iterate_over_lwps (minus_one_ptid, |
3404 | [=] (struct lwp_info *info) | |
3405 | { | |
3406 | return resume_stopped_resumed_lwps (info, ptid); | |
3407 | }); | |
e3e9f5a2 | 3408 | |
f6ac5f3d | 3409 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3410 | |
3411 | /* If we requested any event, and something came out, assume there | |
3412 | may be more. If we requested a specific lwp or process, also | |
3413 | assume there may be more. */ | |
d9d41e78 | 3414 | if (target_is_async_p () |
183be222 SM |
3415 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3416 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3417 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3418 | async_file_mark (); |
3419 | ||
7feb7d06 PA |
3420 | return event_ptid; |
3421 | } | |
3422 | ||
1d2736d4 PA |
3423 | /* Kill one LWP. */ |
3424 | ||
3425 | static void | |
3426 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3427 | { |
ed731959 JK |
3428 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3429 | ||
3430 | errno = 0; | |
1d2736d4 | 3431 | kill_lwp (pid, SIGKILL); |
9327494e | 3432 | |
ed731959 | 3433 | if (debug_linux_nat) |
57745c90 PA |
3434 | { |
3435 | int save_errno = errno; | |
3436 | ||
9327494e SM |
3437 | linux_nat_debug_printf |
3438 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3439 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3440 | } |
ed731959 JK |
3441 | |
3442 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3443 | ||
d6b0e80f | 3444 | errno = 0; |
1d2736d4 | 3445 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3446 | if (debug_linux_nat) |
57745c90 PA |
3447 | { |
3448 | int save_errno = errno; | |
3449 | ||
9327494e SM |
3450 | linux_nat_debug_printf |
3451 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3452 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3453 | } |
d6b0e80f AC |
3454 | } |
3455 | ||
1d2736d4 PA |
3456 | /* Wait for an LWP to die. */ |
3457 | ||
3458 | static void | |
3459 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3460 | { |
1d2736d4 | 3461 | pid_t res; |
d6b0e80f AC |
3462 | |
3463 | /* We must make sure that there are no pending events (delayed | |
3464 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3465 | program doesn't interfere with any following debugging session. */ | |
3466 | ||
d6b0e80f AC |
3467 | do |
3468 | { | |
1d2736d4 PA |
3469 | res = my_waitpid (pid, NULL, __WALL); |
3470 | if (res != (pid_t) -1) | |
d6b0e80f | 3471 | { |
9327494e SM |
3472 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3473 | ||
4a6ed09b PA |
3474 | /* The Linux kernel sometimes fails to kill a thread |
3475 | completely after PTRACE_KILL; that goes from the stop | |
3476 | point in do_fork out to the one in get_signal_to_deliver | |
3477 | and waits again. So kill it again. */ | |
1d2736d4 | 3478 | kill_one_lwp (pid); |
d6b0e80f AC |
3479 | } |
3480 | } | |
1d2736d4 PA |
3481 | while (res == pid); |
3482 | ||
3483 | gdb_assert (res == -1 && errno == ECHILD); | |
3484 | } | |
3485 | ||
3486 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3487 | |
1d2736d4 | 3488 | static int |
d3a70e03 | 3489 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3490 | { |
e38504b3 | 3491 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3492 | return 0; |
3493 | } | |
3494 | ||
1d2736d4 PA |
3495 | /* Callback for iterate_over_lwps. */ |
3496 | ||
3497 | static int | |
d3a70e03 | 3498 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3499 | { |
e38504b3 | 3500 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3501 | return 0; |
3502 | } | |
3503 | ||
3504 | /* Kill the fork children of any threads of inferior INF that are | |
3505 | stopped at a fork event. */ | |
3506 | ||
3507 | static void | |
3508 | kill_unfollowed_fork_children (struct inferior *inf) | |
3509 | { | |
08036331 PA |
3510 | for (thread_info *thread : inf->non_exited_threads ()) |
3511 | { | |
3512 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3513 | |
183be222 SM |
3514 | if (ws->kind () == TARGET_WAITKIND_FORKED |
3515 | || ws->kind () == TARGET_WAITKIND_VFORKED) | |
08036331 | 3516 | { |
183be222 | 3517 | ptid_t child_ptid = ws->child_ptid (); |
08036331 PA |
3518 | int child_pid = child_ptid.pid (); |
3519 | int child_lwp = child_ptid.lwp (); | |
3520 | ||
3521 | kill_one_lwp (child_lwp); | |
3522 | kill_wait_one_lwp (child_lwp); | |
3523 | ||
3524 | /* Let the arch-specific native code know this process is | |
3525 | gone. */ | |
3526 | linux_target->low_forget_process (child_pid); | |
3527 | } | |
3528 | } | |
1d2736d4 PA |
3529 | } |
3530 | ||
f6ac5f3d PA |
3531 | void |
3532 | linux_nat_target::kill () | |
d6b0e80f | 3533 | { |
f973ed9c DJ |
3534 | /* If we're stopped while forking and we haven't followed yet, |
3535 | kill the other task. We need to do this first because the | |
3536 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3537 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3538 | |
3539 | if (forks_exist_p ()) | |
7feb7d06 | 3540 | linux_fork_killall (); |
f973ed9c DJ |
3541 | else |
3542 | { | |
e99b03dc | 3543 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3544 | |
4c28f408 | 3545 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3546 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3547 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3548 | /* ... and wait until all of them have reported back that |
3549 | they're no longer running. */ | |
d3a70e03 | 3550 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3551 | |
f973ed9c | 3552 | /* Kill all LWP's ... */ |
d3a70e03 | 3553 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3554 | |
3555 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3556 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3557 | } |
3558 | ||
bc1e6c81 | 3559 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3560 | } |
3561 | ||
f6ac5f3d PA |
3562 | void |
3563 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3564 | { |
e99b03dc | 3565 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3566 | |
3567 | purge_lwp_list (pid); | |
d6b0e80f | 3568 | |
05c06f31 PA |
3569 | /* Close the /proc/<pid>/mem file if it was open for this |
3570 | inferior. */ | |
3571 | maybe_close_proc_mem_file (pid); | |
3572 | ||
f973ed9c | 3573 | if (! forks_exist_p ()) |
d90e17a7 | 3574 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3575 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3576 | else |
3577 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3578 | there are other viable forks to debug. Delete the exiting | |
3579 | one and context-switch to the first available. */ | |
3580 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3581 | |
3582 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3583 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3584 | } |
3585 | ||
5b009018 PA |
3586 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3587 | layout of the inferiors' architecture. */ | |
3588 | ||
3589 | static void | |
a5362b9a | 3590 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3591 | { |
135340af PA |
3592 | /* If the low target didn't do anything, then just do a straight |
3593 | memcpy. */ | |
3594 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3595 | { |
3596 | if (direction == 1) | |
a5362b9a | 3597 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3598 | else |
a5362b9a | 3599 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3600 | } |
3601 | } | |
3602 | ||
9b409511 | 3603 | static enum target_xfer_status |
f6ac5f3d | 3604 | linux_xfer_siginfo (enum target_object object, |
dda83cd7 | 3605 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3606 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3607 | ULONGEST *xfered_len) | |
4aa995e1 | 3608 | { |
4aa995e1 | 3609 | int pid; |
a5362b9a TS |
3610 | siginfo_t siginfo; |
3611 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3612 | |
3613 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3614 | gdb_assert (readbuf || writebuf); | |
3615 | ||
e38504b3 | 3616 | pid = inferior_ptid.lwp (); |
4aa995e1 | 3617 | if (pid == 0) |
e99b03dc | 3618 | pid = inferior_ptid.pid (); |
4aa995e1 PA |
3619 | |
3620 | if (offset > sizeof (siginfo)) | |
2ed4b548 | 3621 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3622 | |
3623 | errno = 0; | |
3624 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3625 | if (errno != 0) | |
2ed4b548 | 3626 | return TARGET_XFER_E_IO; |
4aa995e1 | 3627 | |
5b009018 PA |
3628 | /* When GDB is built as a 64-bit application, ptrace writes into |
3629 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3630 | inferior with a 64-bit GDB should look the same as debugging it | |
3631 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3632 | the converted layout, so any read/write will have to be done | |
3633 | post-conversion. */ | |
3634 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3635 | ||
4aa995e1 PA |
3636 | if (offset + len > sizeof (siginfo)) |
3637 | len = sizeof (siginfo) - offset; | |
3638 | ||
3639 | if (readbuf != NULL) | |
5b009018 | 3640 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3641 | else |
3642 | { | |
5b009018 PA |
3643 | memcpy (inf_siginfo + offset, writebuf, len); |
3644 | ||
3645 | /* Convert back to ptrace layout before flushing it out. */ | |
3646 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3647 | ||
4aa995e1 PA |
3648 | errno = 0; |
3649 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3650 | if (errno != 0) | |
2ed4b548 | 3651 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3652 | } |
3653 | ||
9b409511 YQ |
3654 | *xfered_len = len; |
3655 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3656 | } |
3657 | ||
9b409511 | 3658 | static enum target_xfer_status |
f6ac5f3d PA |
3659 | linux_nat_xfer_osdata (enum target_object object, |
3660 | const char *annex, gdb_byte *readbuf, | |
3661 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3662 | ULONGEST *xfered_len); | |
3663 | ||
f6ac5f3d | 3664 | static enum target_xfer_status |
05c06f31 PA |
3665 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, |
3666 | ULONGEST offset, LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3667 | |
3668 | enum target_xfer_status | |
3669 | linux_nat_target::xfer_partial (enum target_object object, | |
3670 | const char *annex, gdb_byte *readbuf, | |
3671 | const gdb_byte *writebuf, | |
3672 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3673 | { |
4aa995e1 | 3674 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
f6ac5f3d | 3675 | return linux_xfer_siginfo (object, annex, readbuf, writebuf, |
9b409511 | 3676 | offset, len, xfered_len); |
4aa995e1 | 3677 | |
c35b1492 PA |
3678 | /* The target is connected but no live inferior is selected. Pass |
3679 | this request down to a lower stratum (e.g., the executable | |
3680 | file). */ | |
d7e15655 | 3681 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3682 | return TARGET_XFER_EOF; |
c35b1492 | 3683 | |
f6ac5f3d PA |
3684 | if (object == TARGET_OBJECT_AUXV) |
3685 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3686 | offset, len, xfered_len); | |
3687 | ||
3688 | if (object == TARGET_OBJECT_OSDATA) | |
3689 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3690 | offset, len, xfered_len); | |
d6b0e80f | 3691 | |
f6ac5f3d PA |
3692 | if (object == TARGET_OBJECT_MEMORY) |
3693 | { | |
05c06f31 PA |
3694 | /* GDB calculates all addresses in the largest possible address |
3695 | width. The address width must be masked before its final use | |
3696 | by linux_proc_xfer_partial. | |
3697 | ||
3698 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
f6ac5f3d PA |
3699 | int addr_bit = gdbarch_addr_bit (target_gdbarch ()); |
3700 | ||
3701 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3702 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3703 | |
05c06f31 PA |
3704 | return linux_proc_xfer_memory_partial (readbuf, writebuf, |
3705 | offset, len, xfered_len); | |
3706 | } | |
f6ac5f3d PA |
3707 | |
3708 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3709 | offset, len, xfered_len); | |
d6b0e80f AC |
3710 | } |
3711 | ||
57810aa7 | 3712 | bool |
f6ac5f3d | 3713 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3714 | { |
4a6ed09b PA |
3715 | /* As long as a PTID is in lwp list, consider it alive. */ |
3716 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3717 | } |
3718 | ||
8a06aea7 PA |
3719 | /* Implement the to_update_thread_list target method for this |
3720 | target. */ | |
3721 | ||
f6ac5f3d PA |
3722 | void |
3723 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3724 | { |
4a6ed09b PA |
3725 | /* We add/delete threads from the list as clone/exit events are |
3726 | processed, so just try deleting exited threads still in the | |
3727 | thread list. */ | |
3728 | delete_exited_threads (); | |
a6904d5a PA |
3729 | |
3730 | /* Update the processor core that each lwp/thread was last seen | |
3731 | running on. */ | |
901b9821 | 3732 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3733 | { |
3734 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3735 | time we fetched the thread's core. Accessing /proc becomes | |
3736 | noticeably expensive when we have thousands of LWPs. */ | |
3737 | if (lwp->core == -1) | |
3738 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3739 | } | |
8a06aea7 PA |
3740 | } |
3741 | ||
a068643d | 3742 | std::string |
f6ac5f3d | 3743 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3744 | { |
15a9e13e | 3745 | if (ptid.lwp_p () |
e38504b3 | 3746 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3747 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3748 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3749 | |
3750 | return normal_pid_to_str (ptid); | |
3751 | } | |
3752 | ||
f6ac5f3d PA |
3753 | const char * |
3754 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3755 | { |
79efa585 | 3756 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3757 | } |
3758 | ||
dba24537 AC |
3759 | /* Accepts an integer PID; Returns a string representing a file that |
3760 | can be opened to get the symbols for the child process. */ | |
3761 | ||
f6ac5f3d PA |
3762 | char * |
3763 | linux_nat_target::pid_to_exec_file (int pid) | |
dba24537 | 3764 | { |
e0d86d2c | 3765 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3766 | } |
3767 | ||
05c06f31 PA |
3768 | /* Keep the /proc/<pid>/mem file open between memory accesses, as a |
3769 | cache to avoid constantly closing/opening the file in the common | |
3770 | case of multiple memory reads/writes from/to the same inferior. | |
3771 | Note we don't keep a file open per inferior to avoid keeping too | |
3772 | many file descriptors open, which can run into resource limits. */ | |
3773 | static struct | |
3774 | { | |
3775 | /* The LWP this open file is for. Note that after opening the file, | |
3776 | even if the thread subsequently exits, the open file is still | |
3777 | usable for accessing memory. It's only when the whole process | |
3778 | exits or execs that the file becomes invalid (at which point | |
3779 | reads/writes return EOF). */ | |
3780 | ptid_t ptid; | |
10d6c8cd | 3781 | |
05c06f31 PA |
3782 | /* The file descriptor. -1 if file is not open. */ |
3783 | int fd = -1; | |
3784 | ||
3785 | /* Close FD and clear it to -1. */ | |
3786 | void close () | |
3787 | { | |
89662f69 | 3788 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
05c06f31 PA |
3789 | fd, ptid.pid (), ptid.lwp ()); |
3790 | ::close (fd); | |
3791 | fd = -1; | |
3792 | } | |
3793 | } last_proc_mem_file; | |
3794 | ||
3795 | /* Close the /proc/<pid>/mem file if its LWP matches PTID. */ | |
3796 | ||
3797 | static void | |
3798 | maybe_close_proc_mem_file (pid_t pid) | |
dba24537 | 3799 | { |
05c06f31 PA |
3800 | if (last_proc_mem_file.ptid.pid () == pid) |
3801 | last_proc_mem_file.close (); | |
3802 | } | |
dba24537 | 3803 | |
05c06f31 PA |
3804 | /* Helper for linux_proc_xfer_memory_partial. Accesses /proc via |
3805 | PTID. Returns -1 on error, with errno set. Returns number of | |
3806 | read/written bytes otherwise. Returns 0 on EOF, which indicates | |
3807 | the address space is gone (because the process exited or | |
3808 | execed). */ | |
dba24537 | 3809 | |
05c06f31 PA |
3810 | static ssize_t |
3811 | linux_proc_xfer_memory_partial_pid (ptid_t ptid, | |
3812 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3813 | ULONGEST offset, LONGEST len) | |
3814 | { | |
3815 | ssize_t ret; | |
dba24537 | 3816 | |
05c06f31 PA |
3817 | /* As long as we're hitting the same inferior, the previously open |
3818 | file is good, even if the thread it was open for exits. */ | |
3819 | if (last_proc_mem_file.fd != -1 | |
3820 | && last_proc_mem_file.ptid.pid () != ptid.pid ()) | |
3821 | last_proc_mem_file.close (); | |
3822 | ||
3823 | if (last_proc_mem_file.fd == -1) | |
3824 | { | |
3825 | /* Actually use /proc/<pid>/task/<lwp>/mem instead of | |
3826 | /proc/<lwp>/mem to avoid PID-reuse races, as we may be trying | |
3827 | to read memory via a thread which we've already reaped. | |
3828 | /proc/<lwp>/mem could open a file for the wrong process. If | |
3829 | the LWPID is reused for the same process it's OK, we can read | |
3830 | memory through it just fine. If the LWPID is reused for a | |
3831 | different process, then the open will fail because the path | |
3832 | won't exist. */ | |
3833 | char filename[64]; | |
3834 | xsnprintf (filename, sizeof filename, | |
3835 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3836 | ||
3837 | last_proc_mem_file.fd | |
13084383 | 3838 | = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); |
05c06f31 PA |
3839 | |
3840 | if (last_proc_mem_file.fd == -1) | |
3841 | { | |
3842 | linux_nat_debug_printf ("opening %s failed: %s (%d)\n", | |
3843 | filename, safe_strerror (errno), errno); | |
3844 | return -1; | |
3845 | } | |
3846 | last_proc_mem_file.ptid = ptid; | |
3847 | ||
89662f69 | 3848 | linux_nat_debug_printf ("opened fd %d for %s", |
05c06f31 PA |
3849 | last_proc_mem_file.fd, filename); |
3850 | } | |
3851 | ||
3852 | int fd = last_proc_mem_file.fd; | |
dba24537 | 3853 | |
a379284a AA |
3854 | /* Use pread64/pwrite64 if available, since they save a syscall and can |
3855 | handle 64-bit offsets even on 32-bit platforms (for instance, SPARC | |
3856 | debugging a SPARC64 application). */ | |
dba24537 | 3857 | #ifdef HAVE_PREAD64 |
a379284a AA |
3858 | ret = (readbuf ? pread64 (fd, readbuf, len, offset) |
3859 | : pwrite64 (fd, writebuf, len, offset)); | |
dba24537 | 3860 | #else |
a379284a AA |
3861 | ret = lseek (fd, offset, SEEK_SET); |
3862 | if (ret != -1) | |
3863 | ret = (readbuf ? read (fd, readbuf, len) | |
3864 | : write (fd, writebuf, len)); | |
dba24537 | 3865 | #endif |
dba24537 | 3866 | |
05c06f31 PA |
3867 | if (ret == -1) |
3868 | { | |
3869 | linux_nat_debug_printf ("accessing fd %d for pid %ld failed: %s (%d)\n", | |
3870 | fd, ptid.lwp (), | |
3871 | safe_strerror (errno), errno); | |
3872 | } | |
3873 | else if (ret == 0) | |
3874 | { | |
3875 | linux_nat_debug_printf ("accessing fd %d for pid %ld got EOF\n", | |
3876 | fd, ptid.lwp ()); | |
3877 | } | |
9b409511 | 3878 | |
05c06f31 PA |
3879 | return ret; |
3880 | } | |
3881 | ||
3882 | /* Implement the to_xfer_partial target method using /proc/<pid>/mem. | |
3883 | Because we can use a single read/write call, this can be much more | |
3884 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
3885 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
3886 | threads. */ | |
3887 | ||
3888 | static enum target_xfer_status | |
3889 | linux_proc_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf, | |
3890 | ULONGEST offset, LONGEST len, | |
3891 | ULONGEST *xfered_len) | |
3892 | { | |
3893 | /* Unlike PTRACE_PEEKTEXT/PTRACE_POKETEXT, reading/writing from/to | |
3894 | /proc/<pid>/mem works with running threads, and even exited | |
3895 | threads if the file was already open. If we need to open or | |
3896 | reopen the /proc file though, we may get an EACCES error | |
3897 | ("Permission denied"), meaning the thread is gone but its exit | |
3898 | status isn't reaped yet, or ENOENT if the thread is gone and | |
3899 | already reaped. In that case, just try opening the file for | |
3900 | another thread in the process. If all threads fail, then it must | |
3901 | mean the whole process exited, in which case there's nothing else | |
3902 | to do and we just fail the memory access. | |
3903 | ||
3904 | Note we don't simply always access via the leader thread because | |
3905 | the leader may exit without exiting the whole process. See | |
3906 | gdb.threads/leader-exit.exp, for example. */ | |
3907 | ||
3908 | /* It's frequently the case that the selected thread is stopped, and | |
3909 | is thus not likely to exit (unless something kills the process | |
3910 | outside our control, with e.g., SIGKILL). Give that one a try | |
3911 | first. | |
3912 | ||
3913 | Also, inferior_ptid may actually point at an LWP not in lwp_list. | |
3914 | This happens when we're detaching from a fork child that we don't | |
3915 | want to debug ("set detach-on-fork on"), and the breakpoints | |
3916 | module uninstalls breakpoints from the fork child. Which process | |
3917 | to access is given by inferior_ptid. */ | |
3918 | int res = linux_proc_xfer_memory_partial_pid (inferior_ptid, | |
3919 | readbuf, writebuf, | |
3920 | offset, len); | |
3921 | if (res == 0) | |
3922 | { | |
3923 | /* EOF means the address space is gone, the whole | |
3924 | process exited or execed. */ | |
3925 | return TARGET_XFER_EOF; | |
3926 | } | |
3927 | else if (res != -1) | |
3928 | { | |
3929 | *xfered_len = res; | |
3930 | return TARGET_XFER_OK; | |
3931 | } | |
9b409511 YQ |
3932 | else |
3933 | { | |
05c06f31 PA |
3934 | /* If we simply raced with the thread exiting (EACCES), or the |
3935 | current thread is THREAD_EXITED (ENOENT), try some other | |
3936 | thread. It's easier to handle an ENOENT failure than check | |
3937 | for THREAD_EXIT upfront because this function is called | |
3938 | before a thread for inferior_ptid is added to the thread | |
3939 | list. */ | |
3940 | if (errno != EACCES && errno != ENOENT) | |
3941 | return TARGET_XFER_EOF; | |
3942 | } | |
3943 | ||
3944 | int cur_pid = current_inferior ()->pid; | |
3945 | ||
3946 | if (inferior_ptid.pid () != cur_pid) | |
3947 | { | |
3948 | /* We're accessing a fork child, and the access above failed. | |
3949 | Don't bother iterating the LWP list, since there's no other | |
3950 | LWP for this process. */ | |
3951 | return TARGET_XFER_EOF; | |
3952 | } | |
3953 | ||
3954 | /* Iterate over LWPs of the current inferior, trying to access | |
3955 | memory through one of them. */ | |
901b9821 | 3956 | for (lwp_info *lp : all_lwps ()) |
05c06f31 PA |
3957 | { |
3958 | if (lp->ptid.pid () != cur_pid) | |
3959 | continue; | |
3960 | ||
3961 | res = linux_proc_xfer_memory_partial_pid (lp->ptid, | |
3962 | readbuf, writebuf, | |
3963 | offset, len); | |
3964 | ||
3965 | if (res == 0) | |
3966 | { | |
3967 | /* EOF means the address space is gone, the whole process | |
3968 | exited or execed. */ | |
3969 | return TARGET_XFER_EOF; | |
3970 | } | |
3971 | else if (res == -1) | |
3972 | { | |
3973 | if (errno == EACCES) | |
3974 | { | |
3975 | /* This LWP is gone, try another one. */ | |
3976 | continue; | |
3977 | } | |
3978 | ||
3979 | return TARGET_XFER_EOF; | |
3980 | } | |
3981 | ||
3982 | *xfered_len = res; | |
9b409511 YQ |
3983 | return TARGET_XFER_OK; |
3984 | } | |
dba24537 | 3985 | |
05c06f31 PA |
3986 | /* No luck. */ |
3987 | return TARGET_XFER_EOF; | |
3988 | } | |
efcbbd14 | 3989 | |
dba24537 AC |
3990 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
3991 | ||
3992 | static void | |
3993 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
3994 | { | |
3995 | int len = strlen (line) - 1; | |
3996 | const char *p; | |
3997 | int signum; | |
3998 | ||
3999 | if (line[len] != '\n') | |
8a3fe4f8 | 4000 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4001 | |
4002 | p = line; | |
4003 | signum = len * 4; | |
4004 | while (len-- > 0) | |
4005 | { | |
4006 | int digit; | |
4007 | ||
4008 | if (*p >= '0' && *p <= '9') | |
4009 | digit = *p - '0'; | |
4010 | else if (*p >= 'a' && *p <= 'f') | |
4011 | digit = *p - 'a' + 10; | |
4012 | else | |
8a3fe4f8 | 4013 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4014 | |
4015 | signum -= 4; | |
4016 | ||
4017 | if (digit & 1) | |
4018 | sigaddset (sigs, signum + 1); | |
4019 | if (digit & 2) | |
4020 | sigaddset (sigs, signum + 2); | |
4021 | if (digit & 4) | |
4022 | sigaddset (sigs, signum + 3); | |
4023 | if (digit & 8) | |
4024 | sigaddset (sigs, signum + 4); | |
4025 | ||
4026 | p++; | |
4027 | } | |
4028 | } | |
4029 | ||
4030 | /* Find process PID's pending signals from /proc/pid/status and set | |
4031 | SIGS to match. */ | |
4032 | ||
4033 | void | |
3e43a32a MS |
4034 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4035 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4036 | { |
d8d2a3ee | 4037 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4038 | |
4039 | sigemptyset (pending); | |
4040 | sigemptyset (blocked); | |
4041 | sigemptyset (ignored); | |
cde33bf1 | 4042 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4043 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4044 | if (procfile == NULL) |
8a3fe4f8 | 4045 | error (_("Could not open %s"), fname); |
dba24537 | 4046 | |
d419f42d | 4047 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4048 | { |
4049 | /* Normal queued signals are on the SigPnd line in the status | |
4050 | file. However, 2.6 kernels also have a "shared" pending | |
4051 | queue for delivering signals to a thread group, so check for | |
4052 | a ShdPnd line also. | |
4053 | ||
4054 | Unfortunately some Red Hat kernels include the shared pending | |
4055 | queue but not the ShdPnd status field. */ | |
4056 | ||
61012eef | 4057 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4058 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4059 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4060 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4061 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4062 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4063 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4064 | add_line_to_sigset (buffer + 8, ignored); |
4065 | } | |
dba24537 AC |
4066 | } |
4067 | ||
9b409511 | 4068 | static enum target_xfer_status |
f6ac5f3d | 4069 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4070 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4071 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4072 | ULONGEST *xfered_len) | |
07e059b5 | 4073 | { |
07e059b5 VP |
4074 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4075 | ||
9b409511 YQ |
4076 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4077 | if (*xfered_len == 0) | |
4078 | return TARGET_XFER_EOF; | |
4079 | else | |
4080 | return TARGET_XFER_OK; | |
07e059b5 VP |
4081 | } |
4082 | ||
f6ac5f3d PA |
4083 | std::vector<static_tracepoint_marker> |
4084 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4085 | { |
4086 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4087 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4088 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4089 | const char *p = s; |
184ea2f7 | 4090 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4091 | static_tracepoint_marker marker; |
5808517f YQ |
4092 | |
4093 | /* Pause all */ | |
4094 | target_stop (ptid); | |
4095 | ||
4096 | memcpy (s, "qTfSTM", sizeof ("qTfSTM")); | |
4097 | s[sizeof ("qTfSTM")] = 0; | |
4098 | ||
42476b70 | 4099 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4100 | |
1db93f14 TT |
4101 | /* Unpause all. */ |
4102 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4103 | |
4104 | while (*p++ == 'm') | |
4105 | { | |
5808517f YQ |
4106 | do |
4107 | { | |
5d9310c4 | 4108 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4109 | |
5d9310c4 SM |
4110 | if (strid == NULL || marker.str_id == strid) |
4111 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4112 | } |
4113 | while (*p++ == ','); /* comma-separated list */ | |
4114 | ||
4115 | memcpy (s, "qTsSTM", sizeof ("qTsSTM")); | |
4116 | s[sizeof ("qTsSTM")] = 0; | |
42476b70 | 4117 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4118 | p = s; |
4119 | } | |
4120 | ||
5808517f YQ |
4121 | return markers; |
4122 | } | |
4123 | ||
b84876c2 PA |
4124 | /* target_is_async_p implementation. */ |
4125 | ||
57810aa7 | 4126 | bool |
f6ac5f3d | 4127 | linux_nat_target::is_async_p () |
b84876c2 | 4128 | { |
198297aa | 4129 | return linux_is_async_p (); |
b84876c2 PA |
4130 | } |
4131 | ||
4132 | /* target_can_async_p implementation. */ | |
4133 | ||
57810aa7 | 4134 | bool |
f6ac5f3d | 4135 | linux_nat_target::can_async_p () |
b84876c2 | 4136 | { |
fde1b17d SM |
4137 | /* We're always async, unless the user explicitly prevented it with the |
4138 | "maint set target-async" command. */ | |
3dd5b83d | 4139 | return target_async_permitted; |
b84876c2 PA |
4140 | } |
4141 | ||
57810aa7 | 4142 | bool |
f6ac5f3d | 4143 | linux_nat_target::supports_non_stop () |
9908b566 | 4144 | { |
f80c8ec4 | 4145 | return true; |
9908b566 VP |
4146 | } |
4147 | ||
fbea99ea PA |
4148 | /* to_always_non_stop_p implementation. */ |
4149 | ||
57810aa7 | 4150 | bool |
f6ac5f3d | 4151 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4152 | { |
f80c8ec4 | 4153 | return true; |
fbea99ea PA |
4154 | } |
4155 | ||
57810aa7 | 4156 | bool |
f6ac5f3d | 4157 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4158 | { |
aee91db3 | 4159 | return true; |
d90e17a7 PA |
4160 | } |
4161 | ||
57810aa7 | 4162 | bool |
f6ac5f3d | 4163 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4164 | { |
f80c8ec4 | 4165 | return true; |
03583c20 UW |
4166 | } |
4167 | ||
7feb7d06 PA |
4168 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4169 | so we notice when any child changes state, and notify the | |
4170 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4171 | above to wait for the arrival of a SIGCHLD. */ | |
4172 | ||
b84876c2 | 4173 | static void |
7feb7d06 | 4174 | sigchld_handler (int signo) |
b84876c2 | 4175 | { |
7feb7d06 PA |
4176 | int old_errno = errno; |
4177 | ||
01124a23 | 4178 | if (debug_linux_nat) |
da5bd37e | 4179 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 PA |
4180 | |
4181 | if (signo == SIGCHLD | |
4182 | && linux_nat_event_pipe[0] != -1) | |
4183 | async_file_mark (); /* Let the event loop know that there are | |
4184 | events to handle. */ | |
4185 | ||
4186 | errno = old_errno; | |
4187 | } | |
4188 | ||
4189 | /* Callback registered with the target events file descriptor. */ | |
4190 | ||
4191 | static void | |
4192 | handle_target_event (int error, gdb_client_data client_data) | |
4193 | { | |
b1a35af2 | 4194 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4195 | } |
4196 | ||
4197 | /* Create/destroy the target events pipe. Returns previous state. */ | |
4198 | ||
4199 | static int | |
4200 | linux_async_pipe (int enable) | |
4201 | { | |
198297aa | 4202 | int previous = linux_is_async_p (); |
7feb7d06 PA |
4203 | |
4204 | if (previous != enable) | |
4205 | { | |
4206 | sigset_t prev_mask; | |
4207 | ||
12696c10 PA |
4208 | /* Block child signals while we create/destroy the pipe, as |
4209 | their handler writes to it. */ | |
7feb7d06 PA |
4210 | block_child_signals (&prev_mask); |
4211 | ||
4212 | if (enable) | |
4213 | { | |
614c279d | 4214 | if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1) |
7feb7d06 PA |
4215 | internal_error (__FILE__, __LINE__, |
4216 | "creating event pipe failed."); | |
4217 | ||
4218 | fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); | |
4219 | fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); | |
4220 | } | |
4221 | else | |
4222 | { | |
4223 | close (linux_nat_event_pipe[0]); | |
4224 | close (linux_nat_event_pipe[1]); | |
4225 | linux_nat_event_pipe[0] = -1; | |
4226 | linux_nat_event_pipe[1] = -1; | |
4227 | } | |
4228 | ||
4229 | restore_child_signals_mask (&prev_mask); | |
4230 | } | |
4231 | ||
4232 | return previous; | |
b84876c2 PA |
4233 | } |
4234 | ||
5b6d1e4f PA |
4235 | int |
4236 | linux_nat_target::async_wait_fd () | |
4237 | { | |
4238 | return linux_nat_event_pipe[0]; | |
4239 | } | |
4240 | ||
b84876c2 PA |
4241 | /* target_async implementation. */ |
4242 | ||
f6ac5f3d PA |
4243 | void |
4244 | linux_nat_target::async (int enable) | |
b84876c2 | 4245 | { |
6a3753b3 | 4246 | if (enable) |
b84876c2 | 4247 | { |
7feb7d06 PA |
4248 | if (!linux_async_pipe (1)) |
4249 | { | |
4250 | add_file_handler (linux_nat_event_pipe[0], | |
2554f6f5 SM |
4251 | handle_target_event, NULL, |
4252 | "linux-nat"); | |
7feb7d06 PA |
4253 | /* There may be pending events to handle. Tell the event loop |
4254 | to poll them. */ | |
4255 | async_file_mark (); | |
4256 | } | |
b84876c2 PA |
4257 | } |
4258 | else | |
4259 | { | |
b84876c2 | 4260 | delete_file_handler (linux_nat_event_pipe[0]); |
7feb7d06 | 4261 | linux_async_pipe (0); |
b84876c2 PA |
4262 | } |
4263 | return; | |
4264 | } | |
4265 | ||
a493e3e2 | 4266 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4267 | event came out. */ |
4268 | ||
4c28f408 | 4269 | static int |
d3a70e03 | 4270 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4271 | { |
d90e17a7 | 4272 | if (!lwp->stopped) |
252fbfc8 | 4273 | { |
9327494e SM |
4274 | linux_nat_debug_printf ("running -> suspending %s", |
4275 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 | 4276 | |
252fbfc8 | 4277 | |
25289eb2 PA |
4278 | if (lwp->last_resume_kind == resume_stop) |
4279 | { | |
9327494e SM |
4280 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4281 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4282 | return 0; |
4283 | } | |
252fbfc8 | 4284 | |
d3a70e03 | 4285 | stop_callback (lwp); |
25289eb2 | 4286 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4287 | } |
4288 | else | |
4289 | { | |
4290 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4291 | |
d90e17a7 PA |
4292 | if (debug_linux_nat) |
4293 | { | |
5b6d1e4f | 4294 | if (find_thread_ptid (linux_target, lwp->ptid)->stop_requested) |
9327494e SM |
4295 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
4296 | target_pid_to_str (lwp->ptid).c_str ()); | |
d90e17a7 | 4297 | else |
9327494e SM |
4298 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
4299 | target_pid_to_str (lwp->ptid).c_str ()); | |
252fbfc8 PA |
4300 | } |
4301 | } | |
4c28f408 PA |
4302 | return 0; |
4303 | } | |
4304 | ||
f6ac5f3d PA |
4305 | void |
4306 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4307 | { |
d3a70e03 | 4308 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4309 | } |
4310 | ||
f6ac5f3d PA |
4311 | void |
4312 | linux_nat_target::close () | |
d90e17a7 PA |
4313 | { |
4314 | /* Unregister from the event loop. */ | |
f6ac5f3d PA |
4315 | if (is_async_p ()) |
4316 | async (0); | |
d90e17a7 | 4317 | |
f6ac5f3d | 4318 | inf_ptrace_target::close (); |
d90e17a7 PA |
4319 | } |
4320 | ||
c0694254 PA |
4321 | /* When requests are passed down from the linux-nat layer to the |
4322 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4323 | used. The address space pointer is stored in the inferior object, | |
4324 | but the common code that is passed such ptid can't tell whether | |
4325 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4326 | look up the "main" process id from the lwp here. */ | |
4327 | ||
f6ac5f3d PA |
4328 | struct address_space * |
4329 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4330 | { |
4331 | struct lwp_info *lwp; | |
4332 | struct inferior *inf; | |
4333 | int pid; | |
4334 | ||
e38504b3 | 4335 | if (ptid.lwp () == 0) |
c0694254 PA |
4336 | { |
4337 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4338 | tgid. */ | |
4339 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4340 | pid = lwp->ptid.pid (); |
c0694254 PA |
4341 | } |
4342 | else | |
4343 | { | |
4344 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4345 | pid = ptid.pid (); |
c0694254 PA |
4346 | } |
4347 | ||
5b6d1e4f | 4348 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4349 | gdb_assert (inf != NULL); |
4350 | return inf->aspace; | |
4351 | } | |
4352 | ||
dc146f7c VP |
4353 | /* Return the cached value of the processor core for thread PTID. */ |
4354 | ||
f6ac5f3d PA |
4355 | int |
4356 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4357 | { |
4358 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4359 | |
dc146f7c VP |
4360 | if (info) |
4361 | return info->core; | |
4362 | return -1; | |
4363 | } | |
4364 | ||
7a6a1731 GB |
4365 | /* Implementation of to_filesystem_is_local. */ |
4366 | ||
57810aa7 | 4367 | bool |
f6ac5f3d | 4368 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4369 | { |
4370 | struct inferior *inf = current_inferior (); | |
4371 | ||
4372 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4373 | return true; |
7a6a1731 GB |
4374 | |
4375 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4376 | } | |
4377 | ||
4378 | /* Convert the INF argument passed to a to_fileio_* method | |
4379 | to a process ID suitable for passing to its corresponding | |
4380 | linux_mntns_* function. If INF is non-NULL then the | |
4381 | caller is requesting the filesystem seen by INF. If INF | |
4382 | is NULL then the caller is requesting the filesystem seen | |
4383 | by the GDB. We fall back to GDB's filesystem in the case | |
4384 | that INF is non-NULL but its PID is unknown. */ | |
4385 | ||
4386 | static pid_t | |
4387 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4388 | { | |
4389 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4390 | return getpid (); | |
4391 | else | |
4392 | return inf->pid; | |
4393 | } | |
4394 | ||
4395 | /* Implementation of to_fileio_open. */ | |
4396 | ||
f6ac5f3d PA |
4397 | int |
4398 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4399 | int flags, int mode, int warn_if_slow, | |
4400 | int *target_errno) | |
7a6a1731 GB |
4401 | { |
4402 | int nat_flags; | |
4403 | mode_t nat_mode; | |
4404 | int fd; | |
4405 | ||
4406 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4407 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4408 | { | |
4409 | *target_errno = FILEIO_EINVAL; | |
4410 | return -1; | |
4411 | } | |
4412 | ||
4413 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4414 | filename, nat_flags, nat_mode); | |
4415 | if (fd == -1) | |
4416 | *target_errno = host_to_fileio_error (errno); | |
4417 | ||
4418 | return fd; | |
4419 | } | |
4420 | ||
4421 | /* Implementation of to_fileio_readlink. */ | |
4422 | ||
f6ac5f3d PA |
4423 | gdb::optional<std::string> |
4424 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
4425 | int *target_errno) | |
7a6a1731 GB |
4426 | { |
4427 | char buf[PATH_MAX]; | |
4428 | int len; | |
7a6a1731 GB |
4429 | |
4430 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4431 | filename, buf, sizeof (buf)); | |
4432 | if (len < 0) | |
4433 | { | |
4434 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4435 | return {}; |
7a6a1731 GB |
4436 | } |
4437 | ||
e0d3522b | 4438 | return std::string (buf, len); |
7a6a1731 GB |
4439 | } |
4440 | ||
4441 | /* Implementation of to_fileio_unlink. */ | |
4442 | ||
f6ac5f3d PA |
4443 | int |
4444 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
4445 | int *target_errno) | |
7a6a1731 GB |
4446 | { |
4447 | int ret; | |
4448 | ||
4449 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4450 | filename); | |
4451 | if (ret == -1) | |
4452 | *target_errno = host_to_fileio_error (errno); | |
4453 | ||
4454 | return ret; | |
4455 | } | |
4456 | ||
aa01bd36 PA |
4457 | /* Implementation of the to_thread_events method. */ |
4458 | ||
f6ac5f3d PA |
4459 | void |
4460 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4461 | { |
4462 | report_thread_events = enable; | |
4463 | } | |
4464 | ||
f6ac5f3d PA |
4465 | linux_nat_target::linux_nat_target () |
4466 | { | |
f973ed9c DJ |
4467 | /* We don't change the stratum; this target will sit at |
4468 | process_stratum and thread_db will set at thread_stratum. This | |
4469 | is a little strange, since this is a multi-threaded-capable | |
4470 | target, but we want to be on the stack below thread_db, and we | |
4471 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4472 | } |
4473 | ||
f865ee35 JK |
4474 | /* See linux-nat.h. */ |
4475 | ||
4476 | int | |
4477 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) | |
9f0bdab8 | 4478 | { |
da559b09 | 4479 | int pid; |
9f0bdab8 | 4480 | |
e38504b3 | 4481 | pid = ptid.lwp (); |
da559b09 | 4482 | if (pid == 0) |
e99b03dc | 4483 | pid = ptid.pid (); |
f865ee35 | 4484 | |
da559b09 JK |
4485 | errno = 0; |
4486 | ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo); | |
4487 | if (errno != 0) | |
4488 | { | |
4489 | memset (siginfo, 0, sizeof (*siginfo)); | |
4490 | return 0; | |
4491 | } | |
f865ee35 | 4492 | return 1; |
9f0bdab8 DJ |
4493 | } |
4494 | ||
7b669087 GB |
4495 | /* See nat/linux-nat.h. */ |
4496 | ||
4497 | ptid_t | |
4498 | current_lwp_ptid (void) | |
4499 | { | |
15a9e13e | 4500 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4501 | return inferior_ptid; |
4502 | } | |
4503 | ||
6c265988 | 4504 | void _initialize_linux_nat (); |
d6b0e80f | 4505 | void |
6c265988 | 4506 | _initialize_linux_nat () |
d6b0e80f | 4507 | { |
ccce17b0 YQ |
4508 | add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance, |
4509 | &debug_linux_nat, _("\ | |
b84876c2 PA |
4510 | Set debugging of GNU/Linux lwp module."), _("\ |
4511 | Show debugging of GNU/Linux lwp module."), _("\ | |
4512 | Enables printf debugging output."), | |
ccce17b0 YQ |
4513 | NULL, |
4514 | show_debug_linux_nat, | |
4515 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4516 | |
7a6a1731 GB |
4517 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4518 | &debug_linux_namespaces, _("\ | |
4519 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4520 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4521 | Enables printf debugging output."), | |
4522 | NULL, | |
4523 | NULL, | |
4524 | &setdebuglist, &showdebuglist); | |
4525 | ||
7feb7d06 PA |
4526 | /* Install a SIGCHLD handler. */ |
4527 | sigchld_action.sa_handler = sigchld_handler; | |
4528 | sigemptyset (&sigchld_action.sa_mask); | |
4529 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4530 | |
4531 | /* Make it the default. */ | |
7feb7d06 | 4532 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4533 | |
4534 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4535 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4536 | sigdelset (&suspend_mask, SIGCHLD); |
4537 | ||
7feb7d06 | 4538 | sigemptyset (&blocked_mask); |
774113b0 PA |
4539 | |
4540 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4541 | } |
4542 | \f | |
4543 | ||
4544 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4545 | the GNU/Linux Threads library and therefore doesn't really belong | |
4546 | here. */ | |
4547 | ||
089436f7 TV |
4548 | /* NPTL reserves the first two RT signals, but does not provide any |
4549 | way for the debugger to query the signal numbers - fortunately | |
4550 | they don't change. */ | |
4551 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4552 | |
089436f7 TV |
4553 | /* See linux-nat.h. */ |
4554 | ||
4555 | unsigned int | |
4556 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4557 | { |
089436f7 TV |
4558 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4559 | } | |
d6b0e80f | 4560 | |
089436f7 TV |
4561 | /* See linux-nat.h. */ |
4562 | ||
4563 | int | |
4564 | lin_thread_get_thread_signal (unsigned int i) | |
4565 | { | |
4566 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4567 | return lin_thread_signals[i]; | |
d6b0e80f | 4568 | } |