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3993f6b1 | 1 | /* GNU/Linux native-dependent code common to multiple platforms. |
dba24537 | 2 | |
213516ef | 3 | Copyright (C) 2001-2023 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" | |
ef0f16cc TT |
42 | #include <sys/procfs.h> |
43 | #include "elf-bfd.h" | |
44 | #include "gregset.h" | |
45 | #include "gdbcore.h" | |
46 | #include <ctype.h> | |
47 | #include <sys/stat.h> | |
48 | #include <fcntl.h> | |
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" |
6ecd4729 | 63 | #include "target-descriptions.h" |
268a13a5 | 64 | #include "gdbsupport/filestuff.h" |
77e371c0 | 65 | #include "objfiles.h" |
7a6a1731 | 66 | #include "nat/linux-namespaces.h" |
b146ba14 | 67 | #include "gdbsupport/block-signals.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" |
8a89ddbd | 72 | #include <unordered_map> |
efcbbd14 | 73 | |
1777feb0 | 74 | /* This comment documents high-level logic of this file. |
8a77dff3 VP |
75 | |
76 | Waiting for events in sync mode | |
77 | =============================== | |
78 | ||
4a6ed09b PA |
79 | When waiting for an event in a specific thread, we just use waitpid, |
80 | passing the specific pid, and not passing WNOHANG. | |
81 | ||
82 | When waiting for an event in all threads, waitpid is not quite good: | |
83 | ||
84 | - If the thread group leader exits while other threads in the thread | |
85 | group still exist, waitpid(TGID, ...) hangs. That waitpid won't | |
86 | return an exit status until the other threads in the group are | |
87 | reaped. | |
88 | ||
89 | - When a non-leader thread execs, that thread just vanishes without | |
90 | reporting an exit (so we'd hang if we waited for it explicitly in | |
91 | that case). The exec event is instead reported to the TGID pid. | |
92 | ||
93 | The solution is to always use -1 and WNOHANG, together with | |
94 | sigsuspend. | |
95 | ||
96 | First, we use non-blocking waitpid to check for events. If nothing is | |
97 | found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, | |
98 | it means something happened to a child process. As soon as we know | |
99 | there's an event, we get back to calling nonblocking waitpid. | |
100 | ||
101 | Note that SIGCHLD should be blocked between waitpid and sigsuspend | |
102 | calls, so that we don't miss a signal. If SIGCHLD arrives in between, | |
103 | when it's blocked, the signal becomes pending and sigsuspend | |
104 | immediately notices it and returns. | |
105 | ||
106 | Waiting for events in async mode (TARGET_WNOHANG) | |
107 | ================================================= | |
8a77dff3 | 108 | |
7feb7d06 PA |
109 | In async mode, GDB should always be ready to handle both user input |
110 | and target events, so neither blocking waitpid nor sigsuspend are | |
111 | viable options. Instead, we should asynchronously notify the GDB main | |
112 | event loop whenever there's an unprocessed event from the target. We | |
113 | detect asynchronous target events by handling SIGCHLD signals. To | |
c150bdf0 JB |
114 | notify the event loop about target events, an event pipe is used |
115 | --- the pipe is registered as waitable event source in the event loop, | |
7feb7d06 | 116 | the event loop select/poll's on the read end of this pipe (as well on |
c150bdf0 JB |
117 | other event sources, e.g., stdin), and the SIGCHLD handler marks the |
118 | event pipe to raise an event. This is more portable than relying on | |
7feb7d06 PA |
119 | pselect/ppoll, since on kernels that lack those syscalls, libc |
120 | emulates them with select/poll+sigprocmask, and that is racy | |
121 | (a.k.a. plain broken). | |
122 | ||
123 | Obviously, if we fail to notify the event loop if there's a target | |
124 | event, it's bad. OTOH, if we notify the event loop when there's no | |
125 | event from the target, linux_nat_wait will detect that there's no real | |
126 | event to report, and return event of type TARGET_WAITKIND_IGNORE. | |
127 | This is mostly harmless, but it will waste time and is better avoided. | |
128 | ||
129 | The main design point is that every time GDB is outside linux-nat.c, | |
130 | we have a SIGCHLD handler installed that is called when something | |
131 | happens to the target and notifies the GDB event loop. Whenever GDB | |
132 | core decides to handle the event, and calls into linux-nat.c, we | |
133 | process things as in sync mode, except that the we never block in | |
134 | sigsuspend. | |
135 | ||
136 | While processing an event, we may end up momentarily blocked in | |
137 | waitpid calls. Those waitpid calls, while blocking, are guarantied to | |
138 | return quickly. E.g., in all-stop mode, before reporting to the core | |
139 | that an LWP hit a breakpoint, all LWPs are stopped by sending them | |
140 | SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. | |
141 | Note that this is different from blocking indefinitely waiting for the | |
142 | next event --- here, we're already handling an event. | |
8a77dff3 VP |
143 | |
144 | Use of signals | |
145 | ============== | |
146 | ||
147 | We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another | |
148 | signal is not entirely significant; we just need for a signal to be delivered, | |
149 | so that we can intercept it. SIGSTOP's advantage is that it can not be | |
150 | blocked. A disadvantage is that it is not a real-time signal, so it can only | |
151 | be queued once; we do not keep track of other sources of SIGSTOP. | |
152 | ||
153 | Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't | |
154 | use them, because they have special behavior when the signal is generated - | |
155 | not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL | |
156 | kills the entire thread group. | |
157 | ||
158 | A delivered SIGSTOP would stop the entire thread group, not just the thread we | |
159 | tkill'd. But we never let the SIGSTOP be delivered; we always intercept and | |
160 | cancel it (by PTRACE_CONT without passing SIGSTOP). | |
161 | ||
162 | We could use a real-time signal instead. This would solve those problems; we | |
163 | could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. | |
164 | But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH | |
165 | generates it, and there are races with trying to find a signal that is not | |
4a6ed09b PA |
166 | blocked. |
167 | ||
168 | Exec events | |
169 | =========== | |
170 | ||
171 | The case of a thread group (process) with 3 or more threads, and a | |
172 | thread other than the leader execs is worth detailing: | |
173 | ||
174 | On an exec, the Linux kernel destroys all threads except the execing | |
175 | one in the thread group, and resets the execing thread's tid to the | |
176 | tgid. No exit notification is sent for the execing thread -- from the | |
177 | ptracer's perspective, it appears as though the execing thread just | |
178 | vanishes. Until we reap all other threads except the leader and the | |
179 | execing thread, the leader will be zombie, and the execing thread will | |
180 | be in `D (disc sleep)' state. As soon as all other threads are | |
181 | reaped, the execing thread changes its tid to the tgid, and the | |
182 | previous (zombie) leader vanishes, giving place to the "new" | |
183 | leader. */ | |
a0ef4274 | 184 | |
dba24537 AC |
185 | #ifndef O_LARGEFILE |
186 | #define O_LARGEFILE 0 | |
187 | #endif | |
0274a8ce | 188 | |
f6ac5f3d PA |
189 | struct linux_nat_target *linux_target; |
190 | ||
433bbbf8 | 191 | /* Does the current host support PTRACE_GETREGSET? */ |
0bdb2f78 | 192 | enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; |
433bbbf8 | 193 | |
b6e52a0b AB |
194 | /* When true, print debug messages relating to the linux native target. */ |
195 | ||
196 | static bool debug_linux_nat; | |
197 | ||
8864ef42 | 198 | /* Implement 'show debug linux-nat'. */ |
b6e52a0b | 199 | |
920d2a44 AC |
200 | static void |
201 | show_debug_linux_nat (struct ui_file *file, int from_tty, | |
202 | struct cmd_list_element *c, const char *value) | |
203 | { | |
6cb06a8c TT |
204 | gdb_printf (file, _("Debugging of GNU/Linux native targets is %s.\n"), |
205 | value); | |
920d2a44 | 206 | } |
d6b0e80f | 207 | |
17417fb0 | 208 | /* Print a linux-nat debug statement. */ |
9327494e SM |
209 | |
210 | #define linux_nat_debug_printf(fmt, ...) \ | |
74b773fc | 211 | debug_prefixed_printf_cond (debug_linux_nat, "linux-nat", fmt, ##__VA_ARGS__) |
9327494e | 212 | |
b6e52a0b AB |
213 | /* Print "linux-nat" enter/exit debug statements. */ |
214 | ||
215 | #define LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT \ | |
216 | scoped_debug_enter_exit (debug_linux_nat, "linux-nat") | |
217 | ||
ae087d01 DJ |
218 | struct simple_pid_list |
219 | { | |
220 | int pid; | |
3d799a95 | 221 | int status; |
ae087d01 DJ |
222 | struct simple_pid_list *next; |
223 | }; | |
05c309a8 | 224 | static struct simple_pid_list *stopped_pids; |
ae087d01 | 225 | |
aa01bd36 PA |
226 | /* Whether target_thread_events is in effect. */ |
227 | static int report_thread_events; | |
228 | ||
7feb7d06 PA |
229 | static int kill_lwp (int lwpid, int signo); |
230 | ||
d3a70e03 | 231 | static int stop_callback (struct lwp_info *lp); |
7feb7d06 PA |
232 | |
233 | static void block_child_signals (sigset_t *prev_mask); | |
234 | static void restore_child_signals_mask (sigset_t *prev_mask); | |
2277426b PA |
235 | |
236 | struct lwp_info; | |
237 | static struct lwp_info *add_lwp (ptid_t ptid); | |
238 | static void purge_lwp_list (int pid); | |
4403d8e9 | 239 | static void delete_lwp (ptid_t ptid); |
2277426b PA |
240 | static struct lwp_info *find_lwp_pid (ptid_t ptid); |
241 | ||
8a99810d PA |
242 | static int lwp_status_pending_p (struct lwp_info *lp); |
243 | ||
e7ad2f14 PA |
244 | static void save_stop_reason (struct lwp_info *lp); |
245 | ||
1bcb0708 | 246 | static bool proc_mem_file_is_writable (); |
8a89ddbd PA |
247 | static void close_proc_mem_file (pid_t pid); |
248 | static void open_proc_mem_file (ptid_t ptid); | |
05c06f31 | 249 | |
6cf20c46 PA |
250 | /* Return TRUE if LWP is the leader thread of the process. */ |
251 | ||
252 | static bool | |
253 | is_leader (lwp_info *lp) | |
254 | { | |
255 | return lp->ptid.pid () == lp->ptid.lwp (); | |
256 | } | |
257 | ||
57573e54 PA |
258 | /* Convert an LWP's pending status to a std::string. */ |
259 | ||
260 | static std::string | |
261 | pending_status_str (lwp_info *lp) | |
262 | { | |
263 | gdb_assert (lwp_status_pending_p (lp)); | |
264 | ||
265 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) | |
266 | return lp->waitstatus.to_string (); | |
267 | else | |
268 | return status_to_str (lp->status); | |
269 | } | |
270 | ||
a51e14ef PA |
271 | /* Return true if we should report exit events for LP. */ |
272 | ||
273 | static bool | |
274 | report_exit_events_for (lwp_info *lp) | |
275 | { | |
276 | thread_info *thr = linux_target->find_thread (lp->ptid); | |
277 | gdb_assert (thr != nullptr); | |
278 | ||
279 | return (report_thread_events | |
280 | || (thr->thread_options () & GDB_THREAD_OPTION_EXIT) != 0); | |
281 | } | |
282 | ||
cff068da GB |
283 | \f |
284 | /* LWP accessors. */ | |
285 | ||
286 | /* See nat/linux-nat.h. */ | |
287 | ||
288 | ptid_t | |
289 | ptid_of_lwp (struct lwp_info *lwp) | |
290 | { | |
291 | return lwp->ptid; | |
292 | } | |
293 | ||
294 | /* See nat/linux-nat.h. */ | |
295 | ||
4b134ca1 GB |
296 | void |
297 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
298 | struct arch_lwp_info *info) | |
299 | { | |
300 | lwp->arch_private = info; | |
301 | } | |
302 | ||
303 | /* See nat/linux-nat.h. */ | |
304 | ||
305 | struct arch_lwp_info * | |
306 | lwp_arch_private_info (struct lwp_info *lwp) | |
307 | { | |
308 | return lwp->arch_private; | |
309 | } | |
310 | ||
311 | /* See nat/linux-nat.h. */ | |
312 | ||
cff068da GB |
313 | int |
314 | lwp_is_stopped (struct lwp_info *lwp) | |
315 | { | |
316 | return lwp->stopped; | |
317 | } | |
318 | ||
319 | /* See nat/linux-nat.h. */ | |
320 | ||
321 | enum target_stop_reason | |
322 | lwp_stop_reason (struct lwp_info *lwp) | |
323 | { | |
324 | return lwp->stop_reason; | |
325 | } | |
326 | ||
0e00e962 AA |
327 | /* See nat/linux-nat.h. */ |
328 | ||
329 | int | |
330 | lwp_is_stepping (struct lwp_info *lwp) | |
331 | { | |
332 | return lwp->step; | |
333 | } | |
334 | ||
ae087d01 DJ |
335 | \f |
336 | /* Trivial list manipulation functions to keep track of a list of | |
337 | new stopped processes. */ | |
338 | static void | |
3d799a95 | 339 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 340 | { |
8d749320 | 341 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 342 | |
ae087d01 | 343 | new_pid->pid = pid; |
3d799a95 | 344 | new_pid->status = status; |
ae087d01 DJ |
345 | new_pid->next = *listp; |
346 | *listp = new_pid; | |
347 | } | |
348 | ||
349 | static int | |
46a96992 | 350 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
351 | { |
352 | struct simple_pid_list **p; | |
353 | ||
354 | for (p = listp; *p != NULL; p = &(*p)->next) | |
355 | if ((*p)->pid == pid) | |
356 | { | |
357 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 358 | |
46a96992 | 359 | *statusp = (*p)->status; |
ae087d01 DJ |
360 | xfree (*p); |
361 | *p = next; | |
362 | return 1; | |
363 | } | |
364 | return 0; | |
365 | } | |
366 | ||
de0d863e DB |
367 | /* Return the ptrace options that we want to try to enable. */ |
368 | ||
369 | static int | |
370 | linux_nat_ptrace_options (int attached) | |
371 | { | |
372 | int options = 0; | |
373 | ||
374 | if (!attached) | |
375 | options |= PTRACE_O_EXITKILL; | |
376 | ||
377 | options |= (PTRACE_O_TRACESYSGOOD | |
378 | | PTRACE_O_TRACEVFORKDONE | |
379 | | PTRACE_O_TRACEVFORK | |
380 | | PTRACE_O_TRACEFORK | |
381 | | PTRACE_O_TRACEEXEC); | |
382 | ||
383 | return options; | |
384 | } | |
385 | ||
1b919490 VB |
386 | /* Initialize ptrace and procfs warnings and check for supported |
387 | ptrace features given PID. | |
beed38b8 JB |
388 | |
389 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
390 | |
391 | static void | |
1b919490 | 392 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 393 | { |
de0d863e DB |
394 | int options = linux_nat_ptrace_options (attached); |
395 | ||
396 | linux_enable_event_reporting (pid, options); | |
96d7229d | 397 | linux_ptrace_init_warnings (); |
1b919490 | 398 | linux_proc_init_warnings (); |
9dff6a5d | 399 | proc_mem_file_is_writable (); |
4de4c07c DJ |
400 | } |
401 | ||
f6ac5f3d PA |
402 | linux_nat_target::~linux_nat_target () |
403 | {} | |
404 | ||
405 | void | |
406 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 407 | { |
1b919490 | 408 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
409 | } |
410 | ||
200fd287 AB |
411 | /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
412 | ||
f6ac5f3d PA |
413 | void |
414 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 415 | { |
1b919490 | 416 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
417 | } |
418 | ||
4403d8e9 JK |
419 | /* Return the number of known LWPs in the tgid given by PID. */ |
420 | ||
421 | static int | |
422 | num_lwps (int pid) | |
423 | { | |
424 | int count = 0; | |
4403d8e9 | 425 | |
901b9821 | 426 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 427 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
428 | count++; |
429 | ||
430 | return count; | |
431 | } | |
432 | ||
169bb27b | 433 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 434 | |
169bb27b | 435 | struct lwp_deleter |
4403d8e9 | 436 | { |
169bb27b AB |
437 | void operator() (struct lwp_info *lwp) const |
438 | { | |
439 | delete_lwp (lwp->ptid); | |
440 | } | |
441 | }; | |
4403d8e9 | 442 | |
169bb27b AB |
443 | /* A unique_ptr specialisation for lwp_info. */ |
444 | ||
445 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 446 | |
82d1f134 | 447 | /* Target hook for follow_fork. */ |
d83ad864 | 448 | |
e97007b6 | 449 | void |
82d1f134 SM |
450 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
451 | target_waitkind fork_kind, bool follow_child, | |
452 | bool detach_fork) | |
3993f6b1 | 453 | { |
82d1f134 SM |
454 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
455 | follow_child, detach_fork); | |
456 | ||
d83ad864 | 457 | if (!follow_child) |
4de4c07c | 458 | { |
3a849a34 SM |
459 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
460 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
461 | int parent_pid = parent_ptid.lwp (); |
462 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 463 | |
1777feb0 | 464 | /* We're already attached to the parent, by default. */ |
3a849a34 | 465 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
466 | child_lp->stopped = 1; |
467 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 468 | |
ac264b3b MS |
469 | /* Detach new forked process? */ |
470 | if (detach_fork) | |
f75c00e4 | 471 | { |
95347337 AB |
472 | int child_stop_signal = 0; |
473 | bool detach_child = true; | |
4403d8e9 | 474 | |
169bb27b AB |
475 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
476 | to prevent us doing anything stupid with it. */ | |
477 | lwp_info_up child_lp_ptr (child_lp); | |
478 | child_lp = nullptr; | |
479 | ||
480 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
481 | |
482 | /* When debugging an inferior in an architecture that supports | |
483 | hardware single stepping on a kernel without commit | |
484 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
485 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
486 | set if the parent process had them set. | |
487 | To work around this, single step the child process | |
488 | once before detaching to clear the flags. */ | |
489 | ||
2fd9d7ca PA |
490 | /* Note that we consult the parent's architecture instead of |
491 | the child's because there's no inferior for the child at | |
492 | this point. */ | |
c077881a | 493 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 494 | (parent_ptid))) |
c077881a | 495 | { |
95347337 AB |
496 | int status; |
497 | ||
c077881a HZ |
498 | linux_disable_event_reporting (child_pid); |
499 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
500 | perror_with_name (_("Couldn't do single step")); | |
501 | if (my_waitpid (child_pid, &status, 0) < 0) | |
502 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
503 | else |
504 | { | |
505 | detach_child = WIFSTOPPED (status); | |
506 | child_stop_signal = WSTOPSIG (status); | |
507 | } | |
c077881a HZ |
508 | } |
509 | ||
95347337 | 510 | if (detach_child) |
9caaaa83 | 511 | { |
95347337 | 512 | int signo = child_stop_signal; |
9caaaa83 | 513 | |
9caaaa83 PA |
514 | if (signo != 0 |
515 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
516 | signo = 0; | |
517 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
8a89ddbd PA |
518 | |
519 | close_proc_mem_file (child_pid); | |
9caaaa83 | 520 | } |
ac264b3b | 521 | } |
9016a515 DJ |
522 | |
523 | if (has_vforked) | |
524 | { | |
a2885186 SM |
525 | lwp_info *parent_lp = find_lwp_pid (parent_ptid); |
526 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", parent_pid); | |
527 | parent_lp->stopped = 1; | |
6c95b8df | 528 | |
a2885186 SM |
529 | /* We'll handle the VFORK_DONE event like any other |
530 | event, in target_wait. */ | |
9016a515 | 531 | } |
4de4c07c | 532 | } |
3993f6b1 | 533 | else |
4de4c07c | 534 | { |
3ced3da4 | 535 | struct lwp_info *child_lp; |
4de4c07c | 536 | |
82d1f134 | 537 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 538 | child_lp->stopped = 1; |
25289eb2 | 539 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 540 | } |
4de4c07c DJ |
541 | } |
542 | ||
4de4c07c | 543 | \f |
f6ac5f3d PA |
544 | int |
545 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 546 | { |
a2885186 | 547 | return 0; |
3993f6b1 DJ |
548 | } |
549 | ||
f6ac5f3d PA |
550 | int |
551 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
552 | { |
553 | return 0; | |
554 | } | |
555 | ||
f6ac5f3d PA |
556 | int |
557 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 558 | { |
a2885186 | 559 | return 0; |
3993f6b1 DJ |
560 | } |
561 | ||
f6ac5f3d PA |
562 | int |
563 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
564 | { |
565 | return 0; | |
566 | } | |
567 | ||
f6ac5f3d PA |
568 | int |
569 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 570 | { |
a2885186 | 571 | return 0; |
3993f6b1 DJ |
572 | } |
573 | ||
f6ac5f3d PA |
574 | int |
575 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
576 | { |
577 | return 0; | |
578 | } | |
579 | ||
f6ac5f3d PA |
580 | int |
581 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
582 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 583 | { |
a96d9b2e SDJ |
584 | /* On GNU/Linux, we ignore the arguments. It means that we only |
585 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 586 | |
649a140c | 587 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
588 | filter system calls here. We let GDB do the logic for us. */ |
589 | return 0; | |
590 | } | |
591 | ||
774113b0 PA |
592 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
593 | case of mapping a PID returned from the kernel to our corresponding | |
594 | lwp_info data structure. */ | |
595 | static htab_t lwp_lwpid_htab; | |
596 | ||
597 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
598 | ||
599 | static hashval_t | |
600 | lwp_info_hash (const void *ap) | |
601 | { | |
602 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 603 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
604 | |
605 | return iterative_hash_object (pid, 0); | |
606 | } | |
607 | ||
608 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
609 | PID. */ | |
610 | ||
611 | static int | |
612 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
613 | { | |
614 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
615 | const struct lwp_info *element = (const struct lwp_info *) b; | |
616 | ||
e38504b3 | 617 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
618 | } |
619 | ||
620 | /* Create the lwp_lwpid_htab hash table. */ | |
621 | ||
622 | static void | |
623 | lwp_lwpid_htab_create (void) | |
624 | { | |
625 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
626 | } | |
627 | ||
628 | /* Add LP to the hash table. */ | |
629 | ||
630 | static void | |
631 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
632 | { | |
633 | void **slot; | |
634 | ||
635 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
636 | gdb_assert (slot != NULL && *slot == NULL); | |
637 | *slot = lp; | |
638 | } | |
639 | ||
640 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
641 | creation order. This order is assumed in some cases. E.g., | |
642 | reaping status after killing alls lwps of a process: the leader LWP | |
643 | must be reaped last. */ | |
901b9821 SM |
644 | |
645 | static intrusive_list<lwp_info> lwp_list; | |
646 | ||
647 | /* See linux-nat.h. */ | |
648 | ||
649 | lwp_info_range | |
650 | all_lwps () | |
651 | { | |
652 | return lwp_info_range (lwp_list.begin ()); | |
653 | } | |
654 | ||
655 | /* See linux-nat.h. */ | |
656 | ||
657 | lwp_info_safe_range | |
658 | all_lwps_safe () | |
659 | { | |
660 | return lwp_info_safe_range (lwp_list.begin ()); | |
661 | } | |
774113b0 PA |
662 | |
663 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
664 | ||
665 | static void | |
666 | lwp_list_add (struct lwp_info *lp) | |
667 | { | |
901b9821 | 668 | lwp_list.push_front (*lp); |
774113b0 PA |
669 | } |
670 | ||
671 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
672 | list. */ | |
673 | ||
674 | static void | |
675 | lwp_list_remove (struct lwp_info *lp) | |
676 | { | |
677 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 678 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
679 | } |
680 | ||
d6b0e80f AC |
681 | \f |
682 | ||
d6b0e80f AC |
683 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
684 | _initialize_linux_nat. */ | |
685 | static sigset_t suspend_mask; | |
686 | ||
7feb7d06 PA |
687 | /* Signals to block to make that sigsuspend work. */ |
688 | static sigset_t blocked_mask; | |
689 | ||
690 | /* SIGCHLD action. */ | |
6bd434d6 | 691 | static struct sigaction sigchld_action; |
b84876c2 | 692 | |
7feb7d06 PA |
693 | /* Block child signals (SIGCHLD and linux threads signals), and store |
694 | the previous mask in PREV_MASK. */ | |
84e46146 | 695 | |
7feb7d06 PA |
696 | static void |
697 | block_child_signals (sigset_t *prev_mask) | |
698 | { | |
699 | /* Make sure SIGCHLD is blocked. */ | |
700 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
701 | sigaddset (&blocked_mask, SIGCHLD); | |
702 | ||
21987b9c | 703 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
704 | } |
705 | ||
706 | /* Restore child signals mask, previously returned by | |
707 | block_child_signals. */ | |
708 | ||
709 | static void | |
710 | restore_child_signals_mask (sigset_t *prev_mask) | |
711 | { | |
21987b9c | 712 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 713 | } |
2455069d UW |
714 | |
715 | /* Mask of signals to pass directly to the inferior. */ | |
716 | static sigset_t pass_mask; | |
717 | ||
718 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 719 | void |
adc6a863 PA |
720 | linux_nat_target::pass_signals |
721 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
722 | { |
723 | int signo; | |
724 | ||
725 | sigemptyset (&pass_mask); | |
726 | ||
727 | for (signo = 1; signo < NSIG; signo++) | |
728 | { | |
2ea28649 | 729 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 730 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 731 | sigaddset (&pass_mask, signo); |
2455069d UW |
732 | } |
733 | } | |
734 | ||
d6b0e80f AC |
735 | \f |
736 | ||
737 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
738 | static int stop_wait_callback (struct lwp_info *lp); |
739 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 740 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 741 | |
d6b0e80f | 742 | \f |
d6b0e80f | 743 | |
7b50312a PA |
744 | /* Destroy and free LP. */ |
745 | ||
676362df | 746 | lwp_info::~lwp_info () |
7b50312a | 747 | { |
466eecee | 748 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 749 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
750 | } |
751 | ||
774113b0 | 752 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 753 | |
774113b0 PA |
754 | static int |
755 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 756 | { |
774113b0 PA |
757 | struct lwp_info *lp = (struct lwp_info *) *slot; |
758 | int pid = *(int *) info; | |
d90e17a7 | 759 | |
e99b03dc | 760 | if (lp->ptid.pid () == pid) |
d90e17a7 | 761 | { |
774113b0 PA |
762 | htab_clear_slot (lwp_lwpid_htab, slot); |
763 | lwp_list_remove (lp); | |
676362df | 764 | delete lp; |
774113b0 | 765 | } |
d90e17a7 | 766 | |
774113b0 PA |
767 | return 1; |
768 | } | |
d90e17a7 | 769 | |
774113b0 PA |
770 | /* Remove all LWPs belong to PID from the lwp list. */ |
771 | ||
772 | static void | |
773 | purge_lwp_list (int pid) | |
774 | { | |
775 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
776 | } |
777 | ||
26cb8b7c PA |
778 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
779 | in the process. Return a pointer to the structure describing the | |
780 | new LWP. | |
781 | ||
782 | This differs from add_lwp in that we don't let the arch specific | |
783 | bits know about this new thread. Current clients of this callback | |
784 | take the opportunity to install watchpoints in the new thread, and | |
785 | we shouldn't do that for the first thread. If we're spawning a | |
786 | child ("run"), the thread executes the shell wrapper first, and we | |
787 | shouldn't touch it until it execs the program we want to debug. | |
788 | For "attach", it'd be okay to call the callback, but it's not | |
789 | necessary, because watchpoints can't yet have been inserted into | |
790 | the inferior. */ | |
d6b0e80f AC |
791 | |
792 | static struct lwp_info * | |
26cb8b7c | 793 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 794 | { |
15a9e13e | 795 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 796 | |
b0f6c8d2 | 797 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 798 | |
d6b0e80f | 799 | |
774113b0 PA |
800 | /* Add to sorted-by-reverse-creation-order list. */ |
801 | lwp_list_add (lp); | |
802 | ||
803 | /* Add to keyed-by-pid htab. */ | |
804 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 805 | |
26cb8b7c PA |
806 | return lp; |
807 | } | |
808 | ||
809 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
810 | structure describing the new LWP. The LWP should already be | |
811 | stopped. */ | |
812 | ||
813 | static struct lwp_info * | |
814 | add_lwp (ptid_t ptid) | |
815 | { | |
816 | struct lwp_info *lp; | |
817 | ||
818 | lp = add_initial_lwp (ptid); | |
819 | ||
6e012a6c PA |
820 | /* Let the arch specific bits know about this new thread. Current |
821 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
822 | watchpoints in the new thread. We don't do this for the first |
823 | thread though. See add_initial_lwp. */ | |
135340af | 824 | linux_target->low_new_thread (lp); |
9f0bdab8 | 825 | |
d6b0e80f AC |
826 | return lp; |
827 | } | |
828 | ||
829 | /* Remove the LWP specified by PID from the list. */ | |
830 | ||
831 | static void | |
832 | delete_lwp (ptid_t ptid) | |
833 | { | |
b0f6c8d2 | 834 | lwp_info dummy (ptid); |
d6b0e80f | 835 | |
b0f6c8d2 | 836 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
837 | if (slot == NULL) |
838 | return; | |
d6b0e80f | 839 | |
b0f6c8d2 | 840 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 841 | gdb_assert (lp != NULL); |
d6b0e80f | 842 | |
774113b0 | 843 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 844 | |
774113b0 PA |
845 | /* Remove from sorted-by-creation-order list. */ |
846 | lwp_list_remove (lp); | |
d6b0e80f | 847 | |
774113b0 | 848 | /* Release. */ |
676362df | 849 | delete lp; |
d6b0e80f AC |
850 | } |
851 | ||
852 | /* Return a pointer to the structure describing the LWP corresponding | |
853 | to PID. If no corresponding LWP could be found, return NULL. */ | |
854 | ||
855 | static struct lwp_info * | |
856 | find_lwp_pid (ptid_t ptid) | |
857 | { | |
d6b0e80f AC |
858 | int lwp; |
859 | ||
15a9e13e | 860 | if (ptid.lwp_p ()) |
e38504b3 | 861 | lwp = ptid.lwp (); |
d6b0e80f | 862 | else |
e99b03dc | 863 | lwp = ptid.pid (); |
d6b0e80f | 864 | |
b0f6c8d2 SM |
865 | lwp_info dummy (ptid_t (0, lwp)); |
866 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
867 | } |
868 | ||
6d4ee8c6 | 869 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
870 | |
871 | struct lwp_info * | |
d90e17a7 | 872 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 873 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 874 | { |
901b9821 | 875 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 876 | { |
26a57c92 | 877 | if (lp->ptid.matches (filter)) |
d90e17a7 | 878 | { |
d3a70e03 | 879 | if (callback (lp) != 0) |
d90e17a7 PA |
880 | return lp; |
881 | } | |
d6b0e80f AC |
882 | } |
883 | ||
884 | return NULL; | |
885 | } | |
886 | ||
2277426b PA |
887 | /* Update our internal state when changing from one checkpoint to |
888 | another indicated by NEW_PTID. We can only switch single-threaded | |
889 | applications, so we only create one new LWP, and the previous list | |
890 | is discarded. */ | |
f973ed9c DJ |
891 | |
892 | void | |
893 | linux_nat_switch_fork (ptid_t new_ptid) | |
894 | { | |
895 | struct lwp_info *lp; | |
896 | ||
e99b03dc | 897 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 898 | |
f973ed9c DJ |
899 | lp = add_lwp (new_ptid); |
900 | lp->stopped = 1; | |
e26af52f | 901 | |
2277426b PA |
902 | /* This changes the thread's ptid while preserving the gdb thread |
903 | num. Also changes the inferior pid, while preserving the | |
904 | inferior num. */ | |
5b6d1e4f | 905 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
906 | |
907 | /* We've just told GDB core that the thread changed target id, but, | |
908 | in fact, it really is a different thread, with different register | |
909 | contents. */ | |
910 | registers_changed (); | |
e26af52f DJ |
911 | } |
912 | ||
7730e5c6 PA |
913 | /* Handle the exit of a single thread LP. If DEL_THREAD is true, |
914 | delete the thread_info associated to LP, if it exists. */ | |
e26af52f DJ |
915 | |
916 | static void | |
7730e5c6 | 917 | exit_lwp (struct lwp_info *lp, bool del_thread = true) |
e26af52f | 918 | { |
9213a6d7 | 919 | struct thread_info *th = linux_target->find_thread (lp->ptid); |
063bfe2e | 920 | |
7730e5c6 | 921 | if (th != nullptr && del_thread) |
9d7d58e7 | 922 | delete_thread (th); |
e26af52f DJ |
923 | |
924 | delete_lwp (lp->ptid); | |
925 | } | |
926 | ||
a0ef4274 DJ |
927 | /* Wait for the LWP specified by LP, which we have just attached to. |
928 | Returns a wait status for that LWP, to cache. */ | |
929 | ||
930 | static int | |
22827c51 | 931 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 932 | { |
e38504b3 | 933 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
934 | int status; |
935 | ||
644cebc9 | 936 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 937 | { |
9327494e | 938 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
939 | |
940 | /* The process is definitely stopped. It is in a job control | |
941 | stop, unless the kernel predates the TASK_STOPPED / | |
942 | TASK_TRACED distinction, in which case it might be in a | |
943 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
944 | can kill it, signal it, et cetera. | |
945 | ||
dda83cd7 | 946 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
947 | already attached, the process can not transition from stopped |
948 | to running without a PTRACE_CONT; so we know this signal will | |
949 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
950 | probably already in the queue (unless this kernel is old | |
951 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
952 | is not an RT signal, it can only be queued once. */ | |
953 | kill_lwp (pid, SIGSTOP); | |
954 | ||
955 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
956 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
957 | ptrace (PTRACE_CONT, pid, 0, 0); | |
958 | } | |
959 | ||
960 | /* Make sure the initial process is stopped. The user-level threads | |
961 | layer might want to poke around in the inferior, and that won't | |
962 | work if things haven't stabilized yet. */ | |
4a6ed09b | 963 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
964 | gdb_assert (pid == new_pid); |
965 | ||
966 | if (!WIFSTOPPED (status)) | |
967 | { | |
968 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 969 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 970 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
971 | return status; |
972 | } | |
a0ef4274 DJ |
973 | |
974 | if (WSTOPSIG (status) != SIGSTOP) | |
975 | { | |
976 | *signalled = 1; | |
9327494e | 977 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 978 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
979 | } |
980 | ||
981 | return status; | |
982 | } | |
983 | ||
f6ac5f3d PA |
984 | void |
985 | linux_nat_target::create_inferior (const char *exec_file, | |
986 | const std::string &allargs, | |
987 | char **env, int from_tty) | |
b84876c2 | 988 | { |
41272101 TT |
989 | maybe_disable_address_space_randomization restore_personality |
990 | (disable_randomization); | |
b84876c2 PA |
991 | |
992 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
993 | we have to mask the async mode. */ | |
994 | ||
2455069d | 995 | /* Make sure we report all signals during startup. */ |
adc6a863 | 996 | pass_signals ({}); |
2455069d | 997 | |
f6ac5f3d | 998 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
8a89ddbd PA |
999 | |
1000 | open_proc_mem_file (inferior_ptid); | |
b84876c2 PA |
1001 | } |
1002 | ||
8784d563 PA |
1003 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
1004 | already attached. Returns true if a new LWP is found, false | |
1005 | otherwise. */ | |
1006 | ||
1007 | static int | |
1008 | attach_proc_task_lwp_callback (ptid_t ptid) | |
1009 | { | |
1010 | struct lwp_info *lp; | |
1011 | ||
1012 | /* Ignore LWPs we're already attached to. */ | |
1013 | lp = find_lwp_pid (ptid); | |
1014 | if (lp == NULL) | |
1015 | { | |
e38504b3 | 1016 | int lwpid = ptid.lwp (); |
8784d563 PA |
1017 | |
1018 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1019 | { | |
1020 | int err = errno; | |
1021 | ||
1022 | /* Be quiet if we simply raced with the thread exiting. | |
1023 | EPERM is returned if the thread's task still exists, and | |
1024 | is marked as exited or zombie, as well as other | |
1025 | conditions, so in that case, confirm the status in | |
1026 | /proc/PID/status. */ | |
1027 | if (err == ESRCH | |
1028 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1029 | { | |
9327494e SM |
1030 | linux_nat_debug_printf |
1031 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1032 | lwpid, err, safe_strerror (err)); | |
1033 | ||
8784d563 PA |
1034 | } |
1035 | else | |
1036 | { | |
4d9b86e1 | 1037 | std::string reason |
50fa3001 | 1038 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1039 | |
f71f0b0d | 1040 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1041 | lwpid, reason.c_str ()); |
8784d563 PA |
1042 | } |
1043 | } | |
1044 | else | |
1045 | { | |
9327494e | 1046 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
e53c95d4 | 1047 | ptid.to_string ().c_str ()); |
8784d563 PA |
1048 | |
1049 | lp = add_lwp (ptid); | |
8784d563 PA |
1050 | |
1051 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1052 | PTRACE_ATTACH brings it to a halt. */ | |
1053 | lp->signalled = 1; | |
1054 | ||
1055 | /* We need to wait for a stop before being able to make the | |
1056 | next ptrace call on this LWP. */ | |
1057 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1058 | |
1059 | /* So that wait collects the SIGSTOP. */ | |
1060 | lp->resumed = 1; | |
1061 | ||
1062 | /* Also add the LWP to gdb's thread list, in case a | |
1063 | matching libthread_db is not found (or the process uses | |
1064 | raw clone). */ | |
5b6d1e4f | 1065 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1066 | set_running (linux_target, lp->ptid, true); |
1067 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1068 | } |
1069 | ||
1070 | return 1; | |
1071 | } | |
1072 | return 0; | |
1073 | } | |
1074 | ||
f6ac5f3d PA |
1075 | void |
1076 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1077 | { |
1078 | struct lwp_info *lp; | |
d6b0e80f | 1079 | int status; |
af990527 | 1080 | ptid_t ptid; |
d6b0e80f | 1081 | |
2455069d | 1082 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1083 | pass_signals ({}); |
2455069d | 1084 | |
a70b8144 | 1085 | try |
87b0bb13 | 1086 | { |
f6ac5f3d | 1087 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1088 | } |
230d2906 | 1089 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1090 | { |
1091 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1092 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1093 | |
4d9b86e1 | 1094 | if (!reason.empty ()) |
3d6e9d23 TT |
1095 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1096 | ex.what ()); | |
7ae1a6a6 | 1097 | else |
3d6e9d23 | 1098 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1099 | } |
d6b0e80f | 1100 | |
af990527 PA |
1101 | /* The ptrace base target adds the main thread with (pid,0,0) |
1102 | format. Decorate it with lwp info. */ | |
e99b03dc | 1103 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1104 | inferior_ptid.pid ()); |
5b6d1e4f | 1105 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1106 | |
9f0bdab8 | 1107 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1108 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1109 | |
22827c51 | 1110 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1111 | if (!WIFSTOPPED (status)) |
1112 | { | |
1113 | if (WIFEXITED (status)) | |
1114 | { | |
1115 | int exit_code = WEXITSTATUS (status); | |
1116 | ||
223ffa71 | 1117 | target_terminal::ours (); |
bc1e6c81 | 1118 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1119 | if (exit_code == 0) |
1120 | error (_("Unable to attach: program exited normally.")); | |
1121 | else | |
1122 | error (_("Unable to attach: program exited with code %d."), | |
1123 | exit_code); | |
1124 | } | |
1125 | else if (WIFSIGNALED (status)) | |
1126 | { | |
2ea28649 | 1127 | enum gdb_signal signo; |
dacc9cb2 | 1128 | |
223ffa71 | 1129 | target_terminal::ours (); |
bc1e6c81 | 1130 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1131 | |
2ea28649 | 1132 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1133 | error (_("Unable to attach: program terminated with signal " |
1134 | "%s, %s."), | |
2ea28649 PA |
1135 | gdb_signal_to_name (signo), |
1136 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1137 | } |
1138 | ||
f34652de | 1139 | internal_error (_("unexpected status %d for PID %ld"), |
e38504b3 | 1140 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1141 | } |
1142 | ||
a0ef4274 | 1143 | lp->stopped = 1; |
9f0bdab8 | 1144 | |
8a89ddbd PA |
1145 | open_proc_mem_file (lp->ptid); |
1146 | ||
a0ef4274 | 1147 | /* Save the wait status to report later. */ |
d6b0e80f | 1148 | lp->resumed = 1; |
9327494e | 1149 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1150 | (long) lp->ptid.pid (), |
1151 | status_to_str (status).c_str ()); | |
710151dd | 1152 | |
7feb7d06 PA |
1153 | lp->status = status; |
1154 | ||
8784d563 PA |
1155 | /* We must attach to every LWP. If /proc is mounted, use that to |
1156 | find them now. The inferior may be using raw clone instead of | |
1157 | using pthreads. But even if it is using pthreads, thread_db | |
1158 | walks structures in the inferior's address space to find the list | |
1159 | of threads/LWPs, and those structures may well be corrupted. | |
1160 | Note that once thread_db is loaded, we'll still use it to list | |
1161 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1162 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 | 1163 | attach_proc_task_lwp_callback); |
d6b0e80f AC |
1164 | } |
1165 | ||
4a3ee32a SM |
1166 | /* Ptrace-detach the thread with pid PID. */ |
1167 | ||
1168 | static void | |
1169 | detach_one_pid (int pid, int signo) | |
1170 | { | |
1171 | if (ptrace (PTRACE_DETACH, pid, 0, signo) < 0) | |
1172 | { | |
1173 | int save_errno = errno; | |
1174 | ||
1175 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1176 | zombie. This can happen if one of the already-detached | |
1177 | threads exits the whole thread group. In that case we're | |
1178 | still attached, and must reap the lwp. */ | |
1179 | if (save_errno == ESRCH) | |
1180 | { | |
1181 | int ret, status; | |
1182 | ||
1183 | ret = my_waitpid (pid, &status, __WALL); | |
1184 | if (ret == -1) | |
1185 | { | |
1186 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1187 | pid, safe_strerror (errno)); | |
1188 | } | |
1189 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1190 | { | |
1191 | warning (_("Reaping LWP %d while detaching " | |
1192 | "returned unexpected status 0x%x"), | |
1193 | pid, status); | |
1194 | } | |
1195 | } | |
1196 | else | |
1197 | error (_("Can't detach %d: %s"), | |
1198 | pid, safe_strerror (save_errno)); | |
1199 | } | |
1200 | else | |
1201 | linux_nat_debug_printf ("PTRACE_DETACH (%d, %s, 0) (OK)", | |
1202 | pid, strsignal (signo)); | |
1203 | } | |
1204 | ||
ced2dffb PA |
1205 | /* Get pending signal of THREAD as a host signal number, for detaching |
1206 | purposes. This is the signal the thread last stopped for, which we | |
1207 | need to deliver to the thread when detaching, otherwise, it'd be | |
1208 | suppressed/lost. */ | |
1209 | ||
a0ef4274 | 1210 | static int |
ced2dffb | 1211 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1212 | { |
a493e3e2 | 1213 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1214 | |
1215 | /* If we paused threads momentarily, we may have stored pending | |
1216 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1217 | and GDB core hasn't seen any signal for those threads. | |
1218 | Otherwise, the last signal reported to the core is found in the | |
1219 | thread object's stop_signal. | |
1220 | ||
1221 | There's a corner case that isn't handled here at present. Only | |
1222 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1223 | stop_signal make sense as a real signal to pass to the inferior. | |
1224 | Some catchpoint related events, like | |
1225 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1226 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1227 | those traps are debug API (ptrace in our case) related and |
1228 | induced; the inferior wouldn't see them if it wasn't being | |
1229 | traced. Hence, we should never pass them to the inferior, even | |
1230 | when set to pass state. Since this corner case isn't handled by | |
1231 | infrun.c when proceeding with a signal, for consistency, neither | |
1232 | do we handle it here (or elsewhere in the file we check for | |
1233 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1234 | this is really a corner case. */ | |
1235 | ||
183be222 | 1236 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1237 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1238 | else if (lp->status) |
2ea28649 | 1239 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1240 | else |
ca2163eb | 1241 | { |
9213a6d7 | 1242 | thread_info *tp = linux_target->find_thread (lp->ptid); |
e0881a8e | 1243 | |
611841bb | 1244 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1245 | { |
1edb66d8 | 1246 | if (tp->has_pending_waitstatus ()) |
df5ad102 SM |
1247 | { |
1248 | /* If the thread has a pending event, and it was stopped with a | |
287de656 | 1249 | signal, use that signal to resume it. If it has a pending |
df5ad102 SM |
1250 | event of another kind, it was not stopped with a signal, so |
1251 | resume it without a signal. */ | |
1252 | if (tp->pending_waitstatus ().kind () == TARGET_WAITKIND_STOPPED) | |
1253 | signo = tp->pending_waitstatus ().sig (); | |
1254 | else | |
1255 | signo = GDB_SIGNAL_0; | |
1256 | } | |
00431a78 | 1257 | else |
1edb66d8 | 1258 | signo = tp->stop_signal (); |
00431a78 PA |
1259 | } |
1260 | else if (!target_is_non_stop_p ()) | |
1261 | { | |
00431a78 | 1262 | ptid_t last_ptid; |
5b6d1e4f | 1263 | process_stratum_target *last_target; |
00431a78 | 1264 | |
5b6d1e4f | 1265 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1266 | |
5b6d1e4f PA |
1267 | if (last_target == linux_target |
1268 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1269 | signo = tp->stop_signal (); |
4c28f408 | 1270 | } |
ca2163eb | 1271 | } |
4c28f408 | 1272 | |
a493e3e2 | 1273 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1274 | { |
9327494e | 1275 | linux_nat_debug_printf ("lwp %s has no pending signal", |
e53c95d4 | 1276 | lp->ptid.to_string ().c_str ()); |
ca2163eb PA |
1277 | } |
1278 | else if (!signal_pass_state (signo)) | |
1279 | { | |
9327494e SM |
1280 | linux_nat_debug_printf |
1281 | ("lwp %s had signal %s but it is in no pass state", | |
e53c95d4 | 1282 | lp->ptid.to_string ().c_str (), gdb_signal_to_string (signo)); |
a0ef4274 | 1283 | } |
a0ef4274 | 1284 | else |
4c28f408 | 1285 | { |
9327494e | 1286 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
e53c95d4 | 1287 | lp->ptid.to_string ().c_str (), |
9327494e | 1288 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1289 | |
1290 | return gdb_signal_to_host (signo); | |
4c28f408 | 1291 | } |
a0ef4274 DJ |
1292 | |
1293 | return 0; | |
1294 | } | |
1295 | ||
0d36baa9 | 1296 | /* If LP has a pending fork/vfork/clone status, return it. */ |
ced2dffb | 1297 | |
6b09f134 | 1298 | static std::optional<target_waitstatus> |
0d36baa9 | 1299 | get_pending_child_status (lwp_info *lp) |
d6b0e80f | 1300 | { |
b26b06dd AB |
1301 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1302 | ||
1303 | linux_nat_debug_printf ("lwp %s (stopped = %d)", | |
1304 | lp->ptid.to_string ().c_str (), lp->stopped); | |
1305 | ||
df5ad102 SM |
1306 | /* Check in lwp_info::status. */ |
1307 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1308 | { | |
1309 | int event = linux_ptrace_get_extended_event (lp->status); | |
1310 | ||
0d36baa9 PA |
1311 | if (event == PTRACE_EVENT_FORK |
1312 | || event == PTRACE_EVENT_VFORK | |
1313 | || event == PTRACE_EVENT_CLONE) | |
df5ad102 SM |
1314 | { |
1315 | unsigned long child_pid; | |
1316 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1317 | if (ret == 0) | |
0d36baa9 PA |
1318 | { |
1319 | target_waitstatus ws; | |
1320 | ||
1321 | if (event == PTRACE_EVENT_FORK) | |
1322 | ws.set_forked (ptid_t (child_pid, child_pid)); | |
1323 | else if (event == PTRACE_EVENT_VFORK) | |
1324 | ws.set_vforked (ptid_t (child_pid, child_pid)); | |
1325 | else if (event == PTRACE_EVENT_CLONE) | |
1326 | ws.set_thread_cloned (ptid_t (lp->ptid.pid (), child_pid)); | |
1327 | else | |
1328 | gdb_assert_not_reached ("unhandled"); | |
1329 | ||
1330 | return ws; | |
1331 | } | |
df5ad102 | 1332 | else |
0d36baa9 PA |
1333 | { |
1334 | perror_warning_with_name (_("Failed to retrieve event msg")); | |
1335 | return {}; | |
1336 | } | |
df5ad102 SM |
1337 | } |
1338 | } | |
1339 | ||
1340 | /* Check in lwp_info::waitstatus. */ | |
0d36baa9 PA |
1341 | if (is_new_child_status (lp->waitstatus.kind ())) |
1342 | return lp->waitstatus; | |
df5ad102 | 1343 | |
9213a6d7 | 1344 | thread_info *tp = linux_target->find_thread (lp->ptid); |
df5ad102 | 1345 | |
0d36baa9 PA |
1346 | /* Check in thread_info::pending_waitstatus. */ |
1347 | if (tp->has_pending_waitstatus () | |
1348 | && is_new_child_status (tp->pending_waitstatus ().kind ())) | |
1349 | return tp->pending_waitstatus (); | |
df5ad102 SM |
1350 | |
1351 | /* Check in thread_info::pending_follow. */ | |
0d36baa9 PA |
1352 | if (is_new_child_status (tp->pending_follow.kind ())) |
1353 | return tp->pending_follow; | |
df5ad102 | 1354 | |
0d36baa9 PA |
1355 | return {}; |
1356 | } | |
1357 | ||
1358 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the | |
1359 | signal number that should be passed to the LWP when detaching. | |
1360 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1361 | ||
1362 | static void | |
1363 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
1364 | { | |
1365 | int lwpid = lp->ptid.lwp (); | |
1366 | int signo; | |
1367 | ||
1368 | /* If the lwp/thread we are about to detach has a pending fork/clone | |
1369 | event, there is a process/thread GDB is attached to that the core | |
1370 | of GDB doesn't know about. Detach from it. */ | |
1371 | ||
6b09f134 | 1372 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 PA |
1373 | if (ws.has_value ()) |
1374 | detach_one_pid (ws->child_ptid ().lwp (), 0); | |
d6b0e80f | 1375 | |
a0ef4274 DJ |
1376 | /* If there is a pending SIGSTOP, get rid of it. */ |
1377 | if (lp->signalled) | |
d6b0e80f | 1378 | { |
9327494e | 1379 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1380 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1381 | |
ced2dffb | 1382 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1383 | lp->signalled = 0; |
d6b0e80f AC |
1384 | } |
1385 | ||
ced2dffb | 1386 | if (signo_p == NULL) |
d6b0e80f | 1387 | { |
a0ef4274 | 1388 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1389 | signo = get_detach_signal (lp); |
1390 | } | |
1391 | else | |
1392 | signo = *signo_p; | |
a0ef4274 | 1393 | |
b26b06dd AB |
1394 | linux_nat_debug_printf ("preparing to resume lwp %s (stopped = %d)", |
1395 | lp->ptid.to_string ().c_str (), | |
1396 | lp->stopped); | |
1397 | ||
ced2dffb PA |
1398 | /* Preparing to resume may try to write registers, and fail if the |
1399 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1400 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1401 | try |
ced2dffb | 1402 | { |
135340af | 1403 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1404 | } |
230d2906 | 1405 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1406 | { |
1407 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1408 | throw; |
ced2dffb | 1409 | } |
d6b0e80f | 1410 | |
4a3ee32a | 1411 | detach_one_pid (lwpid, signo); |
ced2dffb PA |
1412 | |
1413 | delete_lwp (lp->ptid); | |
1414 | } | |
d6b0e80f | 1415 | |
ced2dffb | 1416 | static int |
d3a70e03 | 1417 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1418 | { |
1419 | /* We don't actually detach from the thread group leader just yet. | |
1420 | If the thread group exits, we must reap the zombie clone lwps | |
1421 | before we're able to reap the leader. */ | |
e38504b3 | 1422 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1423 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1424 | return 0; |
1425 | } | |
1426 | ||
f6ac5f3d PA |
1427 | void |
1428 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1429 | { |
b26b06dd AB |
1430 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1431 | ||
d90e17a7 | 1432 | struct lwp_info *main_lwp; |
bc09b0c1 | 1433 | int pid = inf->pid; |
a0ef4274 | 1434 | |
ae5e0686 MK |
1435 | /* Don't unregister from the event loop, as there may be other |
1436 | inferiors running. */ | |
b84876c2 | 1437 | |
4c28f408 | 1438 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1439 | thread is stopped to successfully detach. */ |
d3a70e03 | 1440 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1441 | /* ... and wait until all of them have reported back that |
1442 | they're no longer running. */ | |
d3a70e03 | 1443 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1444 | |
e87f0fe8 PA |
1445 | /* We can now safely remove breakpoints. We don't this in earlier |
1446 | in common code because this target doesn't currently support | |
1447 | writing memory while the inferior is running. */ | |
1448 | remove_breakpoints_inf (current_inferior ()); | |
1449 | ||
d3a70e03 | 1450 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f | 1451 | |
fd492bf1 AB |
1452 | /* We have detached from everything except the main thread now, so |
1453 | should only have one thread left. However, in non-stop mode the | |
1454 | main thread might have exited, in which case we'll have no threads | |
1455 | left. */ | |
1456 | gdb_assert (num_lwps (pid) == 1 | |
1457 | || (target_is_non_stop_p () && num_lwps (pid) == 0)); | |
d6b0e80f | 1458 | |
7a7d3353 PA |
1459 | if (forks_exist_p ()) |
1460 | { | |
1461 | /* Multi-fork case. The current inferior_ptid is being detached | |
1462 | from, but there are other viable forks to debug. Detach from | |
1463 | the current fork, and context-switch to the first | |
1464 | available. */ | |
6bd6f3b6 | 1465 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1466 | } |
1467 | else | |
ced2dffb | 1468 | { |
ced2dffb PA |
1469 | target_announce_detach (from_tty); |
1470 | ||
fd492bf1 AB |
1471 | /* In non-stop mode it is possible that the main thread has exited, |
1472 | in which case we don't try to detach. */ | |
1473 | main_lwp = find_lwp_pid (ptid_t (pid)); | |
1474 | if (main_lwp != nullptr) | |
1475 | { | |
1476 | /* Pass on any pending signal for the last LWP. */ | |
1477 | int signo = get_detach_signal (main_lwp); | |
ced2dffb | 1478 | |
fd492bf1 AB |
1479 | detach_one_lwp (main_lwp, &signo); |
1480 | } | |
1481 | else | |
1482 | gdb_assert (target_is_non_stop_p ()); | |
ced2dffb | 1483 | |
f6ac5f3d | 1484 | detach_success (inf); |
ced2dffb | 1485 | } |
05c06f31 | 1486 | |
8a89ddbd | 1487 | close_proc_mem_file (pid); |
d6b0e80f AC |
1488 | } |
1489 | ||
8a99810d PA |
1490 | /* Resume execution of the inferior process. If STEP is nonzero, |
1491 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1492 | ||
1493 | static void | |
23f238d3 PA |
1494 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1495 | enum gdb_signal signo) | |
8a99810d | 1496 | { |
8a99810d | 1497 | lp->step = step; |
9c02b525 PA |
1498 | |
1499 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1500 | We only presently need that if the LWP is stepped though (to | |
1501 | handle the case of stepping a breakpoint instruction). */ | |
1502 | if (step) | |
1503 | { | |
5b6d1e4f | 1504 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1505 | |
1506 | lp->stop_pc = regcache_read_pc (regcache); | |
1507 | } | |
1508 | else | |
1509 | lp->stop_pc = 0; | |
1510 | ||
135340af | 1511 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1512 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1513 | |
1514 | /* Successfully resumed. Clear state that no longer makes sense, | |
1515 | and mark the LWP as running. Must not do this before resuming | |
1516 | otherwise if that fails other code will be confused. E.g., we'd | |
1517 | later try to stop the LWP and hang forever waiting for a stop | |
1518 | status. Note that we must not throw after this is cleared, | |
1519 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1520 | lp->stopped = 0; |
1ad3de98 | 1521 | lp->core = -1; |
23f238d3 | 1522 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1523 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1524 | } |
1525 | ||
23f238d3 PA |
1526 | /* Called when we try to resume a stopped LWP and that errors out. If |
1527 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1528 | or about to become), discard the error, clear any pending status | |
1529 | the LWP may have, and return true (we'll collect the exit status | |
1530 | soon enough). Otherwise, return false. */ | |
1531 | ||
1532 | static int | |
1533 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1534 | { | |
1535 | /* If we get an error after resuming the LWP successfully, we'd | |
1536 | confuse !T state for the LWP being gone. */ | |
1537 | gdb_assert (lp->stopped); | |
1538 | ||
1539 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1540 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1541 | yet fully dead", but already refusing ptrace requests. In that | |
1542 | case the tracee has 'R (Running)' state for a little bit | |
1543 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1544 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1545 | other than ptrace-stopped. */ | |
1546 | ||
1547 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1548 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1549 | { |
1550 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1551 | lp->status = 0; | |
183be222 | 1552 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1553 | return 1; |
1554 | } | |
1555 | return 0; | |
1556 | } | |
1557 | ||
1558 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1559 | disappears while we try to resume it. */ | |
1560 | ||
1561 | static void | |
1562 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1563 | { | |
a70b8144 | 1564 | try |
23f238d3 PA |
1565 | { |
1566 | linux_resume_one_lwp_throw (lp, step, signo); | |
1567 | } | |
230d2906 | 1568 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1569 | { |
1570 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1571 | throw; |
23f238d3 | 1572 | } |
23f238d3 PA |
1573 | } |
1574 | ||
d6b0e80f AC |
1575 | /* Resume LP. */ |
1576 | ||
25289eb2 | 1577 | static void |
e5ef252a | 1578 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1579 | { |
25289eb2 | 1580 | if (lp->stopped) |
6c95b8df | 1581 | { |
5b6d1e4f | 1582 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1583 | |
1584 | if (inf->vfork_child != NULL) | |
1585 | { | |
8a9da63e | 1586 | linux_nat_debug_printf ("Not resuming sibling %s (vfork parent)", |
e53c95d4 | 1587 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1588 | } |
8a99810d | 1589 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1590 | { |
9327494e | 1591 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
e53c95d4 | 1592 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1593 | (signo != GDB_SIGNAL_0 |
1594 | ? strsignal (gdb_signal_to_host (signo)) | |
1595 | : "0"), | |
1596 | step ? "step" : "resume"); | |
25289eb2 | 1597 | |
8a99810d | 1598 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1599 | } |
1600 | else | |
1601 | { | |
9327494e | 1602 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
e53c95d4 | 1603 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1604 | } |
6c95b8df | 1605 | } |
25289eb2 | 1606 | else |
9327494e | 1607 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
e53c95d4 | 1608 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1609 | } |
d6b0e80f | 1610 | |
8817a6f2 PA |
1611 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1612 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1613 | |
25289eb2 | 1614 | static int |
d3a70e03 | 1615 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1616 | { |
e5ef252a PA |
1617 | enum gdb_signal signo = GDB_SIGNAL_0; |
1618 | ||
8817a6f2 PA |
1619 | if (lp == except) |
1620 | return 0; | |
1621 | ||
e5ef252a PA |
1622 | if (lp->stopped) |
1623 | { | |
1624 | struct thread_info *thread; | |
1625 | ||
9213a6d7 | 1626 | thread = linux_target->find_thread (lp->ptid); |
e5ef252a PA |
1627 | if (thread != NULL) |
1628 | { | |
1edb66d8 SM |
1629 | signo = thread->stop_signal (); |
1630 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1631 | } |
1632 | } | |
1633 | ||
1634 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1635 | return 0; |
1636 | } | |
1637 | ||
1638 | static int | |
d3a70e03 | 1639 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1640 | { |
1641 | lp->resumed = 0; | |
25289eb2 | 1642 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1643 | return 0; |
1644 | } | |
1645 | ||
1646 | static int | |
d3a70e03 | 1647 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1648 | { |
1649 | lp->resumed = 1; | |
25289eb2 | 1650 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1651 | return 0; |
1652 | } | |
1653 | ||
f6ac5f3d | 1654 | void |
d51926f0 | 1655 | linux_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1656 | { |
1657 | struct lwp_info *lp; | |
d6b0e80f | 1658 | |
9327494e SM |
1659 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1660 | step ? "step" : "resume", | |
d51926f0 | 1661 | scope_ptid.to_string ().c_str (), |
9327494e SM |
1662 | (signo != GDB_SIGNAL_0 |
1663 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
e53c95d4 | 1664 | inferior_ptid.to_string ().c_str ()); |
76f50ad1 | 1665 | |
7da6a5b9 LM |
1666 | /* Mark the lwps we're resuming as resumed and update their |
1667 | last_resume_kind to resume_continue. */ | |
d51926f0 | 1668 | iterate_over_lwps (scope_ptid, resume_set_callback); |
d6b0e80f | 1669 | |
d51926f0 | 1670 | lp = find_lwp_pid (inferior_ptid); |
9f0bdab8 | 1671 | gdb_assert (lp != NULL); |
d6b0e80f | 1672 | |
9f0bdab8 | 1673 | /* Remember if we're stepping. */ |
25289eb2 | 1674 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1675 | |
9f0bdab8 DJ |
1676 | /* If we have a pending wait status for this thread, there is no |
1677 | point in resuming the process. But first make sure that | |
1678 | linux_nat_wait won't preemptively handle the event - we | |
1679 | should never take this short-circuit if we are going to | |
1680 | leave LP running, since we have skipped resuming all the | |
1681 | other threads. This bit of code needs to be synchronized | |
1682 | with linux_nat_wait. */ | |
76f50ad1 | 1683 | |
9f0bdab8 DJ |
1684 | if (lp->status && WIFSTOPPED (lp->status)) |
1685 | { | |
2455069d UW |
1686 | if (!lp->step |
1687 | && WSTOPSIG (lp->status) | |
1688 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1689 | { |
9327494e SM |
1690 | linux_nat_debug_printf |
1691 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1692 | |
d6b0e80f AC |
1693 | /* FIXME: What should we do if we are supposed to continue |
1694 | this thread with a signal? */ | |
a493e3e2 | 1695 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1696 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1697 | lp->status = 0; |
1698 | } | |
1699 | } | |
76f50ad1 | 1700 | |
8a99810d | 1701 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1702 | { |
1703 | /* FIXME: What should we do if we are supposed to continue | |
1704 | this thread with a signal? */ | |
a493e3e2 | 1705 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1706 | |
57573e54 PA |
1707 | linux_nat_debug_printf ("Short circuiting for status %s", |
1708 | pending_status_str (lp).c_str ()); | |
d6b0e80f | 1709 | |
7feb7d06 PA |
1710 | if (target_can_async_p ()) |
1711 | { | |
4a570176 | 1712 | target_async (true); |
7feb7d06 PA |
1713 | /* Tell the event loop we have something to process. */ |
1714 | async_file_mark (); | |
1715 | } | |
9f0bdab8 | 1716 | return; |
d6b0e80f AC |
1717 | } |
1718 | ||
d51926f0 PA |
1719 | /* No use iterating unless we're resuming other threads. */ |
1720 | if (scope_ptid != lp->ptid) | |
1721 | iterate_over_lwps (scope_ptid, [=] (struct lwp_info *info) | |
1722 | { | |
1723 | return linux_nat_resume_callback (info, lp); | |
1724 | }); | |
d90e17a7 | 1725 | |
9327494e SM |
1726 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1727 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 1728 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1729 | (signo != GDB_SIGNAL_0 |
1730 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1731 | |
2bf6fb9d | 1732 | linux_resume_one_lwp (lp, step, signo); |
d6b0e80f AC |
1733 | } |
1734 | ||
c5f62d5f | 1735 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1736 | |
1737 | static int | |
1738 | kill_lwp (int lwpid, int signo) | |
1739 | { | |
4a6ed09b | 1740 | int ret; |
d6b0e80f | 1741 | |
4a6ed09b PA |
1742 | errno = 0; |
1743 | ret = syscall (__NR_tkill, lwpid, signo); | |
1744 | if (errno == ENOSYS) | |
1745 | { | |
1746 | /* If tkill fails, then we are not using nptl threads, a | |
1747 | configuration we no longer support. */ | |
1748 | perror_with_name (("tkill")); | |
1749 | } | |
1750 | return ret; | |
d6b0e80f AC |
1751 | } |
1752 | ||
ca2163eb PA |
1753 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1754 | event, check if the core is interested in it: if not, ignore the | |
1755 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1756 | syscall entry/exit status, since the ptrace event itself doesn't | |
1757 | indicate it, and report the trap to higher layers. */ | |
1758 | ||
1759 | static int | |
1760 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1761 | { | |
1762 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1763 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
9213a6d7 | 1764 | thread_info *thread = linux_target->find_thread (lp->ptid); |
00431a78 | 1765 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1766 | |
1767 | if (stopping) | |
1768 | { | |
1769 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1770 | makes it so that the LWP reports an immediate syscall return, | |
1771 | followed by the SIGSTOP. Skip seeing that "return" using | |
1772 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1773 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1774 | entry event. If we didn't do this (and returned 0), we'd | |
1775 | leave a syscall entry pending, and our caller, by using | |
1776 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1777 | itself. Later, when the user re-resumes this LWP, we'd see | |
1778 | another syscall entry event and we'd mistake it for a return. | |
1779 | ||
1780 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1781 | (leaving immediately with LWP->signalled set, without issuing | |
1782 | a PTRACE_CONT), it would still be problematic to leave this | |
1783 | syscall enter pending, as later when the thread is resumed, | |
1784 | it would then see the same syscall exit mentioned above, | |
1785 | followed by the delayed SIGSTOP, while the syscall didn't | |
1786 | actually get to execute. It seems it would be even more | |
1787 | confusing to the user. */ | |
1788 | ||
9327494e SM |
1789 | linux_nat_debug_printf |
1790 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1791 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1792 | |
1793 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1794 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1795 | lp->stopped = 0; |
ca2163eb PA |
1796 | return 1; |
1797 | } | |
1798 | ||
bfd09d20 JS |
1799 | /* Always update the entry/return state, even if this particular |
1800 | syscall isn't interesting to the core now. In async mode, | |
1801 | the user could install a new catchpoint for this syscall | |
1802 | between syscall enter/return, and we'll need to know to | |
1803 | report a syscall return if that happens. */ | |
1804 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1805 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1806 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1807 | ||
ca2163eb PA |
1808 | if (catch_syscall_enabled ()) |
1809 | { | |
ca2163eb PA |
1810 | if (catching_syscall_number (syscall_number)) |
1811 | { | |
1812 | /* Alright, an event to report. */ | |
183be222 SM |
1813 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1814 | ourstatus->set_syscall_entry (syscall_number); | |
1815 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1816 | ourstatus->set_syscall_return (syscall_number); | |
1817 | else | |
1818 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1819 | |
9327494e SM |
1820 | linux_nat_debug_printf |
1821 | ("stopping for %s of syscall %d for LWP %ld", | |
1822 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1823 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1824 | ||
ca2163eb PA |
1825 | return 0; |
1826 | } | |
1827 | ||
9327494e SM |
1828 | linux_nat_debug_printf |
1829 | ("ignoring %s of syscall %d for LWP %ld", | |
1830 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1831 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1832 | } |
1833 | else | |
1834 | { | |
1835 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1836 | before on this LWP, it could happen that the user removes all | |
1837 | syscall catchpoints before we get to process this event. | |
1838 | There are two noteworthy issues here: | |
1839 | ||
1840 | - When stopped at a syscall entry event, resuming with | |
1841 | PT_STEP still resumes executing the syscall and reports a | |
1842 | syscall return. | |
1843 | ||
1844 | - Only PT_SYSCALL catches syscall enters. If we last | |
1845 | single-stepped this thread, then this event can't be a | |
1846 | syscall enter. If we last single-stepped this thread, this | |
1847 | has to be a syscall exit. | |
1848 | ||
1849 | The points above mean that the next resume, be it PT_STEP or | |
1850 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1851 | linux_nat_debug_printf |
1852 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1853 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1854 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1855 | } | |
1856 | ||
1857 | /* The core isn't interested in this event. For efficiency, avoid | |
1858 | stopping all threads only to have the core resume them all again. | |
1859 | Since we're not stopping threads, if we're still syscall tracing | |
1860 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1861 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1862 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1863 | ||
8a99810d | 1864 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1865 | return 1; |
1866 | } | |
1867 | ||
0d36baa9 PA |
1868 | /* See target.h. */ |
1869 | ||
1870 | void | |
1871 | linux_nat_target::follow_clone (ptid_t child_ptid) | |
1872 | { | |
1873 | lwp_info *new_lp = add_lwp (child_ptid); | |
1874 | new_lp->stopped = 1; | |
1875 | ||
1876 | /* If the thread_db layer is active, let it record the user | |
1877 | level thread id and status, and add the thread to GDB's | |
1878 | list. */ | |
1879 | if (!thread_db_notice_clone (inferior_ptid, new_lp->ptid)) | |
1880 | { | |
1881 | /* The process is not using thread_db. Add the LWP to | |
1882 | GDB's list. */ | |
1883 | add_thread (linux_target, new_lp->ptid); | |
1884 | } | |
1885 | ||
1886 | /* We just created NEW_LP so it cannot yet contain STATUS. */ | |
1887 | gdb_assert (new_lp->status == 0); | |
1888 | ||
1889 | if (!pull_pid_from_list (&stopped_pids, child_ptid.lwp (), &new_lp->status)) | |
1890 | internal_error (_("no saved status for clone lwp")); | |
1891 | ||
1892 | if (WSTOPSIG (new_lp->status) != SIGSTOP) | |
1893 | { | |
1894 | /* This can happen if someone starts sending signals to | |
1895 | the new thread before it gets a chance to run, which | |
1896 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1897 | This is an unlikely case, and harder to handle for | |
1898 | fork / vfork than for clone, so we do not try - but | |
1899 | we handle it for clone events here. */ | |
1900 | ||
1901 | new_lp->signalled = 1; | |
1902 | ||
1903 | /* Save the wait status to report later. */ | |
1904 | linux_nat_debug_printf | |
1905 | ("waitpid of new LWP %ld, saving status %s", | |
1906 | (long) new_lp->ptid.lwp (), status_to_str (new_lp->status).c_str ()); | |
1907 | } | |
1908 | else | |
1909 | { | |
1910 | new_lp->status = 0; | |
1911 | ||
1912 | if (report_thread_events) | |
1913 | new_lp->waitstatus.set_thread_created (); | |
1914 | } | |
1915 | } | |
1916 | ||
3d799a95 DJ |
1917 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1918 | event, we need to add the new LWP to our list (and not report the | |
1919 | trap to higher layers). This function returns non-zero if the | |
1920 | event should be ignored and we should wait again. If STOPPING is | |
1921 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1922 | |
1923 | static int | |
4dd63d48 | 1924 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1925 | { |
e38504b3 | 1926 | int pid = lp->ptid.lwp (); |
3d799a95 | 1927 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1928 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1929 | |
bfd09d20 JS |
1930 | /* All extended events we currently use are mid-syscall. Only |
1931 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1932 | you have to be using PTRACE_SEIZE to get that. */ | |
1933 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1934 | ||
3d799a95 DJ |
1935 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1936 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1937 | { |
3d799a95 DJ |
1938 | unsigned long new_pid; |
1939 | int ret; | |
1940 | ||
1941 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1942 | |
3d799a95 DJ |
1943 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1944 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1945 | { | |
1946 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1947 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1948 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1949 | if (ret == -1) |
1950 | perror_with_name (_("waiting for new child")); | |
1951 | else if (ret != new_pid) | |
f34652de | 1952 | internal_error (_("wait returned unexpected PID %d"), ret); |
3d799a95 | 1953 | else if (!WIFSTOPPED (status)) |
f34652de | 1954 | internal_error (_("wait returned unexpected status 0x%x"), status); |
3d799a95 DJ |
1955 | } |
1956 | ||
26cb8b7c PA |
1957 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1958 | { | |
0d36baa9 | 1959 | open_proc_mem_file (ptid_t (new_pid, new_pid)); |
8a89ddbd | 1960 | |
26cb8b7c PA |
1961 | /* The arch-specific native code may need to know about new |
1962 | forks even if those end up never mapped to an | |
1963 | inferior. */ | |
135340af | 1964 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1965 | } |
1310c1b0 PFC |
1966 | else if (event == PTRACE_EVENT_CLONE) |
1967 | { | |
1968 | linux_target->low_new_clone (lp, new_pid); | |
1969 | } | |
26cb8b7c | 1970 | |
2277426b | 1971 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1972 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1973 | { |
2277426b PA |
1974 | /* Handle checkpointing by linux-fork.c here as a special |
1975 | case. We don't want the follow-fork-mode or 'catch fork' | |
1976 | to interfere with this. */ | |
1977 | ||
1978 | /* This won't actually modify the breakpoint list, but will | |
1979 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 1980 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
1981 | |
1982 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1983 | if (!find_fork_pid (new_pid)) |
1984 | add_fork (new_pid); | |
2277426b PA |
1985 | |
1986 | /* Report as spurious, so that infrun doesn't want to follow | |
1987 | this fork. We're actually doing an infcall in | |
1988 | linux-fork.c. */ | |
183be222 | 1989 | ourstatus->set_spurious (); |
2277426b PA |
1990 | |
1991 | /* Report the stop to the core. */ | |
1992 | return 0; | |
1993 | } | |
1994 | ||
3d799a95 | 1995 | if (event == PTRACE_EVENT_FORK) |
0d36baa9 | 1996 | ourstatus->set_forked (ptid_t (new_pid, new_pid)); |
3d799a95 | 1997 | else if (event == PTRACE_EVENT_VFORK) |
0d36baa9 | 1998 | ourstatus->set_vforked (ptid_t (new_pid, new_pid)); |
4dd63d48 | 1999 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 2000 | { |
9327494e SM |
2001 | linux_nat_debug_printf |
2002 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 2003 | |
0d36baa9 PA |
2004 | /* Save the status again, we'll use it in follow_clone. */ |
2005 | add_to_pid_list (&stopped_pids, new_pid, status); | |
4dd63d48 | 2006 | |
0d36baa9 | 2007 | ourstatus->set_thread_cloned (ptid_t (lp->ptid.pid (), new_pid)); |
3d799a95 DJ |
2008 | } |
2009 | ||
2010 | return 0; | |
d6b0e80f AC |
2011 | } |
2012 | ||
3d799a95 DJ |
2013 | if (event == PTRACE_EVENT_EXEC) |
2014 | { | |
9327494e | 2015 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2016 | |
8a89ddbd PA |
2017 | /* Close the previous /proc/PID/mem file for this inferior, |
2018 | which was using the address space which is now gone. | |
2019 | Reading/writing from this file would return 0/EOF. */ | |
2020 | close_proc_mem_file (lp->ptid.pid ()); | |
2021 | ||
2022 | /* Open a new file for the new address space. */ | |
2023 | open_proc_mem_file (lp->ptid); | |
05c06f31 | 2024 | |
183be222 SM |
2025 | ourstatus->set_execd |
2026 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 2027 | |
8af756ef PA |
2028 | /* The thread that execed must have been resumed, but, when a |
2029 | thread execs, it changes its tid to the tgid, and the old | |
2030 | tgid thread might have not been resumed. */ | |
2031 | lp->resumed = 1; | |
6a534f85 PA |
2032 | |
2033 | /* All other LWPs are gone now. We'll have received a thread | |
2034 | exit notification for all threads other the execing one. | |
2035 | That one, if it wasn't the leader, just silently changes its | |
2036 | tid to the tgid, and the previous leader vanishes. Since | |
2037 | Linux 3.0, the former thread ID can be retrieved with | |
2038 | PTRACE_GETEVENTMSG, but since we support older kernels, don't | |
2039 | bother with it, and just walk the LWP list. Even with | |
2040 | PTRACE_GETEVENTMSG, we'd still need to lookup the | |
2041 | corresponding LWP object, and it would be an extra ptrace | |
2042 | syscall, so this way may even be more efficient. */ | |
2043 | for (lwp_info *other_lp : all_lwps_safe ()) | |
2044 | if (other_lp != lp && other_lp->ptid.pid () == lp->ptid.pid ()) | |
2045 | exit_lwp (other_lp); | |
2046 | ||
6c95b8df PA |
2047 | return 0; |
2048 | } | |
2049 | ||
2050 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2051 | { | |
9327494e | 2052 | linux_nat_debug_printf |
5a0c4a06 SM |
2053 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", |
2054 | lp->ptid.lwp ()); | |
2055 | ourstatus->set_vfork_done (); | |
2056 | return 0; | |
3d799a95 DJ |
2057 | } |
2058 | ||
f34652de | 2059 | internal_error (_("unknown ptrace event %d"), event); |
d6b0e80f AC |
2060 | } |
2061 | ||
9c3a5d93 PA |
2062 | /* Suspend waiting for a signal. We're mostly interested in |
2063 | SIGCHLD/SIGINT. */ | |
2064 | ||
2065 | static void | |
2066 | wait_for_signal () | |
2067 | { | |
9327494e | 2068 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2069 | sigsuspend (&suspend_mask); |
2070 | ||
2071 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2072 | and we're debugging a process that is running on a separate | |
2073 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2074 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2075 | inferior directly.) We must do this here because functions that | |
2076 | need to block waiting for a signal loop forever until there's an | |
2077 | event to report before returning back to the event loop. */ | |
2078 | if (!target_terminal::is_ours ()) | |
2079 | { | |
2080 | if (check_quit_flag ()) | |
2081 | target_pass_ctrlc (); | |
2082 | } | |
2083 | } | |
2084 | ||
d6b0e80f AC |
2085 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2086 | exited. */ | |
2087 | ||
2088 | static int | |
2089 | wait_lwp (struct lwp_info *lp) | |
2090 | { | |
2091 | pid_t pid; | |
432b4d03 | 2092 | int status = 0; |
d6b0e80f | 2093 | int thread_dead = 0; |
432b4d03 | 2094 | sigset_t prev_mask; |
d6b0e80f AC |
2095 | |
2096 | gdb_assert (!lp->stopped); | |
2097 | gdb_assert (lp->status == 0); | |
2098 | ||
432b4d03 JK |
2099 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2100 | block_child_signals (&prev_mask); | |
2101 | ||
2102 | for (;;) | |
d6b0e80f | 2103 | { |
e38504b3 | 2104 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2105 | if (pid == -1 && errno == ECHILD) |
2106 | { | |
2107 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2108 | now because if this was a non-leader thread execing, we |
2109 | won't get an exit event. See comments on exec events at | |
2110 | the top of the file. */ | |
a9f4bb21 | 2111 | thread_dead = 1; |
9327494e | 2112 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2113 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2114 | } |
432b4d03 JK |
2115 | if (pid != 0) |
2116 | break; | |
2117 | ||
2118 | /* Bugs 10970, 12702. | |
2119 | Thread group leader may have exited in which case we'll lock up in | |
2120 | waitpid if there are other threads, even if they are all zombies too. | |
2121 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2122 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2123 | for zombie and running processes. | |
432b4d03 JK |
2124 | |
2125 | As a workaround, check if we're waiting for the thread group leader and | |
2126 | if it's a zombie, and avoid calling waitpid if it is. | |
2127 | ||
2128 | This is racy, what if the tgl becomes a zombie right after we check? | |
2129 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2130 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2131 | |
e38504b3 TT |
2132 | if (lp->ptid.pid () == lp->ptid.lwp () |
2133 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2134 | { |
d6b0e80f | 2135 | thread_dead = 1; |
9327494e | 2136 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2137 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2138 | break; |
d6b0e80f | 2139 | } |
432b4d03 JK |
2140 | |
2141 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2142 | get invoked despite our caller had them intentionally blocked by | |
2143 | block_child_signals. This is sensitive only to the loop of | |
2144 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2145 | again before it gets to sigsuspend so we can safely let the handlers | |
2146 | get executed here. */ | |
9c3a5d93 | 2147 | wait_for_signal (); |
432b4d03 JK |
2148 | } |
2149 | ||
2150 | restore_child_signals_mask (&prev_mask); | |
2151 | ||
d6b0e80f AC |
2152 | if (!thread_dead) |
2153 | { | |
e38504b3 | 2154 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2155 | |
9327494e | 2156 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2157 | lp->ptid.to_string ().c_str (), |
8d06918f | 2158 | status_to_str (status).c_str ()); |
d6b0e80f | 2159 | |
a9f4bb21 PA |
2160 | /* Check if the thread has exited. */ |
2161 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2162 | { | |
a51e14ef | 2163 | if (report_exit_events_for (lp) || is_leader (lp)) |
69dde7dc | 2164 | { |
9327494e | 2165 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2166 | |
aa01bd36 | 2167 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2168 | process is gone. Store the status to report to the |
2169 | core. Store it in lp->waitstatus, because lp->status | |
2170 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
7509b829 | 2171 | lp->waitstatus = host_status_to_waitstatus (status); |
69dde7dc PA |
2172 | return 0; |
2173 | } | |
2174 | ||
a9f4bb21 | 2175 | thread_dead = 1; |
9327494e | 2176 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2177 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2178 | } |
d6b0e80f AC |
2179 | } |
2180 | ||
2181 | if (thread_dead) | |
2182 | { | |
e26af52f | 2183 | exit_lwp (lp); |
d6b0e80f AC |
2184 | return 0; |
2185 | } | |
2186 | ||
2187 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2188 | lp->stopped = 1; |
d6b0e80f | 2189 | |
8784d563 PA |
2190 | if (lp->must_set_ptrace_flags) |
2191 | { | |
5b6d1e4f | 2192 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2193 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2194 | |
e38504b3 | 2195 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2196 | lp->must_set_ptrace_flags = 0; |
2197 | } | |
2198 | ||
ca2163eb PA |
2199 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2200 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2201 | { | |
2202 | /* No longer need the sysgood bit. The ptrace event ends up | |
2203 | recorded in lp->waitstatus if we care for it. We can carry | |
2204 | on handling the event like a regular SIGTRAP from here | |
2205 | on. */ | |
2206 | status = W_STOPCODE (SIGTRAP); | |
2207 | if (linux_handle_syscall_trap (lp, 1)) | |
2208 | return wait_lwp (lp); | |
2209 | } | |
bfd09d20 JS |
2210 | else |
2211 | { | |
2212 | /* Almost all other ptrace-stops are known to be outside of system | |
2213 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2214 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2215 | } | |
ca2163eb | 2216 | |
d6b0e80f | 2217 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2218 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2219 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2220 | { |
9327494e | 2221 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2222 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2223 | return 0; |
d6b0e80f AC |
2224 | } |
2225 | ||
2226 | return status; | |
2227 | } | |
2228 | ||
2229 | /* Send a SIGSTOP to LP. */ | |
2230 | ||
2231 | static int | |
d3a70e03 | 2232 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2233 | { |
2234 | if (!lp->stopped && !lp->signalled) | |
2235 | { | |
2236 | int ret; | |
2237 | ||
9327494e | 2238 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2239 | lp->ptid.to_string ().c_str ()); |
9327494e | 2240 | |
d6b0e80f | 2241 | errno = 0; |
e38504b3 | 2242 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2243 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2244 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2245 | |
2246 | lp->signalled = 1; | |
2247 | gdb_assert (lp->status == 0); | |
2248 | } | |
2249 | ||
2250 | return 0; | |
2251 | } | |
2252 | ||
7b50312a PA |
2253 | /* Request a stop on LWP. */ |
2254 | ||
2255 | void | |
2256 | linux_stop_lwp (struct lwp_info *lwp) | |
2257 | { | |
d3a70e03 | 2258 | stop_callback (lwp); |
7b50312a PA |
2259 | } |
2260 | ||
2db9a427 PA |
2261 | /* See linux-nat.h */ |
2262 | ||
2263 | void | |
2264 | linux_stop_and_wait_all_lwps (void) | |
2265 | { | |
2266 | /* Stop all LWP's ... */ | |
d3a70e03 | 2267 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2268 | |
2269 | /* ... and wait until all of them have reported back that | |
2270 | they're no longer running. */ | |
d3a70e03 | 2271 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2272 | } |
2273 | ||
2274 | /* See linux-nat.h */ | |
2275 | ||
2276 | void | |
2277 | linux_unstop_all_lwps (void) | |
2278 | { | |
2279 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2280 | [] (struct lwp_info *info) |
2281 | { | |
2282 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2283 | }); | |
2db9a427 PA |
2284 | } |
2285 | ||
57380f4e | 2286 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2287 | |
2288 | static int | |
57380f4e DJ |
2289 | linux_nat_has_pending_sigint (int pid) |
2290 | { | |
2291 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2292 | |
2293 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2294 | ||
2295 | if (sigismember (&pending, SIGINT) | |
2296 | && !sigismember (&ignored, SIGINT)) | |
2297 | return 1; | |
2298 | ||
2299 | return 0; | |
2300 | } | |
2301 | ||
2302 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2303 | ||
2304 | static int | |
d3a70e03 | 2305 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2306 | { |
57380f4e DJ |
2307 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2308 | flag to consume the next one. */ | |
2309 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2310 | && WSTOPSIG (lp->status) == SIGINT) | |
2311 | lp->status = 0; | |
2312 | else | |
2313 | lp->ignore_sigint = 1; | |
2314 | ||
2315 | return 0; | |
2316 | } | |
2317 | ||
2318 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2319 | This function is called after we know the LWP has stopped; if the LWP | |
2320 | stopped before the expected SIGINT was delivered, then it will never have | |
2321 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2322 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2323 | |
57380f4e DJ |
2324 | static void |
2325 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2326 | { | |
2327 | if (!lp->ignore_sigint) | |
2328 | return; | |
2329 | ||
e38504b3 | 2330 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2331 | { |
9327494e | 2332 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2333 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2334 | lp->ignore_sigint = 0; |
2335 | } | |
2336 | } | |
2337 | ||
ebec9a0f PA |
2338 | /* Fetch the possible triggered data watchpoint info and store it in |
2339 | LP. | |
2340 | ||
2341 | On some archs, like x86, that use debug registers to set | |
2342 | watchpoints, it's possible that the way to know which watched | |
2343 | address trapped, is to check the register that is used to select | |
2344 | which address to watch. Problem is, between setting the watchpoint | |
2345 | and reading back which data address trapped, the user may change | |
2346 | the set of watchpoints, and, as a consequence, GDB changes the | |
2347 | debug registers in the inferior. To avoid reading back a stale | |
2348 | stopped-data-address when that happens, we cache in LP the fact | |
2349 | that a watchpoint trapped, and the corresponding data address, as | |
2350 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2351 | registers meanwhile, we have the cached data we can rely on. */ | |
2352 | ||
9c02b525 PA |
2353 | static int |
2354 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2355 | { |
2989a365 | 2356 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2357 | inferior_ptid = lp->ptid; |
2358 | ||
f6ac5f3d | 2359 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2360 | { |
15c66dd6 | 2361 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2362 | lp->stopped_data_address_p |
2363 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2364 | } |
2365 | ||
15c66dd6 | 2366 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2367 | } |
2368 | ||
9c02b525 | 2369 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2370 | |
57810aa7 | 2371 | bool |
f6ac5f3d | 2372 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2373 | { |
2374 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2375 | ||
2376 | gdb_assert (lp != NULL); | |
2377 | ||
15c66dd6 | 2378 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2379 | } |
2380 | ||
57810aa7 | 2381 | bool |
f6ac5f3d | 2382 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2383 | { |
2384 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2385 | ||
2386 | gdb_assert (lp != NULL); | |
2387 | ||
2388 | *addr_p = lp->stopped_data_address; | |
2389 | ||
2390 | return lp->stopped_data_address_p; | |
2391 | } | |
2392 | ||
26ab7092 JK |
2393 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2394 | ||
135340af PA |
2395 | bool |
2396 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2397 | { |
2398 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2399 | } | |
2400 | ||
57380f4e DJ |
2401 | /* Wait until LP is stopped. */ |
2402 | ||
2403 | static int | |
d3a70e03 | 2404 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2405 | { |
5b6d1e4f | 2406 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2407 | |
2408 | /* If this is a vfork parent, bail out, it is not going to report | |
2409 | any SIGSTOP until the vfork is done with. */ | |
2410 | if (inf->vfork_child != NULL) | |
2411 | return 0; | |
2412 | ||
d6b0e80f AC |
2413 | if (!lp->stopped) |
2414 | { | |
2415 | int status; | |
2416 | ||
2417 | status = wait_lwp (lp); | |
2418 | if (status == 0) | |
2419 | return 0; | |
2420 | ||
57380f4e DJ |
2421 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2422 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2423 | { |
57380f4e | 2424 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2425 | |
2426 | errno = 0; | |
e38504b3 | 2427 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2428 | lp->stopped = 0; |
9327494e SM |
2429 | linux_nat_debug_printf |
2430 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2431 | lp->ptid.to_string ().c_str (), |
9327494e | 2432 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2433 | |
d3a70e03 | 2434 | return stop_wait_callback (lp); |
d6b0e80f AC |
2435 | } |
2436 | ||
57380f4e DJ |
2437 | maybe_clear_ignore_sigint (lp); |
2438 | ||
d6b0e80f AC |
2439 | if (WSTOPSIG (status) != SIGSTOP) |
2440 | { | |
e5ef252a | 2441 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2442 | |
9327494e | 2443 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2444 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2445 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2446 | |
2447 | /* Save the sigtrap event. */ | |
2448 | lp->status = status; | |
e5ef252a | 2449 | gdb_assert (lp->signalled); |
e7ad2f14 | 2450 | save_stop_reason (lp); |
d6b0e80f AC |
2451 | } |
2452 | else | |
2453 | { | |
7010835a | 2454 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2455 | |
9327494e | 2456 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2457 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2458 | |
d6b0e80f | 2459 | lp->signalled = 0; |
7010835a AB |
2460 | |
2461 | /* If we are waiting for this stop so we can report the thread | |
2462 | stopped then we need to record this status. Otherwise, we can | |
2463 | now discard this stop event. */ | |
2464 | if (lp->last_resume_kind == resume_stop) | |
2465 | { | |
2466 | lp->status = status; | |
2467 | save_stop_reason (lp); | |
2468 | } | |
d6b0e80f AC |
2469 | } |
2470 | } | |
2471 | ||
2472 | return 0; | |
2473 | } | |
2474 | ||
74387712 SM |
2475 | /* Get the inferior associated to LWP. Must be called with an LWP that has |
2476 | an associated inferior. Always return non-nullptr. */ | |
2477 | ||
2478 | static inferior * | |
2479 | lwp_inferior (const lwp_info *lwp) | |
2480 | { | |
2481 | inferior *inf = find_inferior_ptid (linux_target, lwp->ptid); | |
2482 | gdb_assert (inf != nullptr); | |
2483 | return inf; | |
2484 | } | |
2485 | ||
9c02b525 PA |
2486 | /* Return non-zero if LP has a wait status pending. Discard the |
2487 | pending event and resume the LWP if the event that originally | |
2488 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2489 | |
2490 | static int | |
d3a70e03 | 2491 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2492 | { |
2493 | /* Only report a pending wait status if we pretend that this has | |
2494 | indeed been resumed. */ | |
ca2163eb PA |
2495 | if (!lp->resumed) |
2496 | return 0; | |
2497 | ||
eb54c8bf PA |
2498 | if (!lwp_status_pending_p (lp)) |
2499 | return 0; | |
2500 | ||
15c66dd6 PA |
2501 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2502 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2503 | { |
5b6d1e4f | 2504 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2505 | CORE_ADDR pc; |
2506 | int discard = 0; | |
2507 | ||
9c02b525 PA |
2508 | pc = regcache_read_pc (regcache); |
2509 | ||
2510 | if (pc != lp->stop_pc) | |
2511 | { | |
9327494e | 2512 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2513 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2514 | paddress (current_inferior ()->arch (), |
2515 | lp->stop_pc), | |
2516 | paddress (current_inferior ()->arch (), pc)); | |
9c02b525 PA |
2517 | discard = 1; |
2518 | } | |
faf09f01 PA |
2519 | |
2520 | #if !USE_SIGTRAP_SIGINFO | |
74387712 | 2521 | else if (!breakpoint_inserted_here_p (lwp_inferior (lp)->aspace, pc)) |
9c02b525 | 2522 | { |
9327494e | 2523 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
e53c95d4 | 2524 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2525 | paddress (current_inferior ()->arch (), |
2526 | lp->stop_pc)); | |
9c02b525 PA |
2527 | |
2528 | discard = 1; | |
2529 | } | |
faf09f01 | 2530 | #endif |
9c02b525 PA |
2531 | |
2532 | if (discard) | |
2533 | { | |
9327494e | 2534 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2535 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2536 | |
2537 | lp->status = 0; | |
2538 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2539 | return 0; | |
2540 | } | |
9c02b525 PA |
2541 | } |
2542 | ||
eb54c8bf | 2543 | return 1; |
d6b0e80f AC |
2544 | } |
2545 | ||
d6b0e80f AC |
2546 | /* Count the LWP's that have had events. */ |
2547 | ||
2548 | static int | |
d3a70e03 | 2549 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2550 | { |
d6b0e80f AC |
2551 | gdb_assert (count != NULL); |
2552 | ||
9c02b525 PA |
2553 | /* Select only resumed LWPs that have an event pending. */ |
2554 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2555 | (*count)++; |
2556 | ||
2557 | return 0; | |
2558 | } | |
2559 | ||
2560 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2561 | ||
2562 | static int | |
d3a70e03 | 2563 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2564 | { |
25289eb2 PA |
2565 | if (lp->last_resume_kind == resume_step |
2566 | && lp->status != 0) | |
d6b0e80f AC |
2567 | return 1; |
2568 | else | |
2569 | return 0; | |
2570 | } | |
2571 | ||
8a99810d PA |
2572 | /* Returns true if LP has a status pending. */ |
2573 | ||
2574 | static int | |
2575 | lwp_status_pending_p (struct lwp_info *lp) | |
2576 | { | |
2577 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2578 | can have pending process exits recorded in lp->status and | |
2579 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2580 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2581 | } |
2582 | ||
b90fc188 | 2583 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2584 | |
2585 | static int | |
d3a70e03 | 2586 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2587 | { |
d6b0e80f AC |
2588 | gdb_assert (selector != NULL); |
2589 | ||
9c02b525 PA |
2590 | /* Select only resumed LWPs that have an event pending. */ |
2591 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2592 | if ((*selector)-- == 0) |
2593 | return 1; | |
2594 | ||
2595 | return 0; | |
2596 | } | |
2597 | ||
e7ad2f14 PA |
2598 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2599 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2600 | and save the result in the LWP's stop_reason field. If it stopped | |
2601 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2602 | architecture. */ | |
9c02b525 | 2603 | |
e7ad2f14 PA |
2604 | static void |
2605 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2606 | { |
e7ad2f14 PA |
2607 | struct regcache *regcache; |
2608 | struct gdbarch *gdbarch; | |
515630c5 | 2609 | CORE_ADDR pc; |
9c02b525 | 2610 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2611 | #if USE_SIGTRAP_SIGINFO |
2612 | siginfo_t siginfo; | |
2613 | #endif | |
9c02b525 | 2614 | |
e7ad2f14 PA |
2615 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2616 | gdb_assert (lp->status != 0); | |
2617 | ||
135340af | 2618 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2619 | return; |
2620 | ||
74387712 | 2621 | inferior *inf = lwp_inferior (lp); |
a9deee17 PA |
2622 | if (inf->starting_up) |
2623 | return; | |
2624 | ||
5b6d1e4f | 2625 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2626 | gdbarch = regcache->arch (); |
e7ad2f14 | 2627 | |
9c02b525 | 2628 | pc = regcache_read_pc (regcache); |
527a273a | 2629 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2630 | |
faf09f01 PA |
2631 | #if USE_SIGTRAP_SIGINFO |
2632 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2633 | { | |
2634 | if (siginfo.si_signo == SIGTRAP) | |
2635 | { | |
e7ad2f14 PA |
2636 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2637 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2638 | { |
e7ad2f14 PA |
2639 | /* The si_code is ambiguous on this arch -- check debug |
2640 | registers. */ | |
2641 | if (!check_stopped_by_watchpoint (lp)) | |
2642 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2643 | } | |
2644 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2645 | { | |
2646 | /* If we determine the LWP stopped for a SW breakpoint, | |
2647 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2648 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2649 | stopped-by-watchpoint as long as there's a watchpoint |
2650 | set. */ | |
faf09f01 | 2651 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2652 | } |
e7ad2f14 | 2653 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2654 | { |
e7ad2f14 PA |
2655 | /* This can indicate either a hardware breakpoint or |
2656 | hardware watchpoint. Check debug registers. */ | |
2657 | if (!check_stopped_by_watchpoint (lp)) | |
2658 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2659 | } |
2bf6fb9d PA |
2660 | else if (siginfo.si_code == TRAP_TRACE) |
2661 | { | |
9327494e | 2662 | linux_nat_debug_printf ("%s stopped by trace", |
e53c95d4 | 2663 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2664 | |
2665 | /* We may have single stepped an instruction that | |
2666 | triggered a watchpoint. In that case, on some | |
2667 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2668 | si_code indicates TRAP_TRACE, and we need to check | |
2669 | the debug registers separately. */ | |
2670 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2671 | } |
faf09f01 PA |
2672 | } |
2673 | } | |
2674 | #else | |
9c02b525 | 2675 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
74387712 | 2676 | && software_breakpoint_inserted_here_p (inf->aspace, sw_bp_pc)) |
710151dd | 2677 | { |
9c02b525 PA |
2678 | /* The LWP was either continued, or stepped a software |
2679 | breakpoint instruction. */ | |
e7ad2f14 PA |
2680 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2681 | } | |
2682 | ||
74387712 | 2683 | if (hardware_breakpoint_inserted_here_p (inf->aspace, pc)) |
e7ad2f14 PA |
2684 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2685 | ||
2686 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2687 | check_stopped_by_watchpoint (lp); | |
2688 | #endif | |
2689 | ||
2690 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2691 | { | |
9327494e | 2692 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2693 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2694 | |
2695 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2696 | if (pc != sw_bp_pc) |
2697 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2698 | |
e7ad2f14 PA |
2699 | /* Update this so we record the correct stop PC below. */ |
2700 | pc = sw_bp_pc; | |
710151dd | 2701 | } |
e7ad2f14 | 2702 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2703 | { |
9327494e | 2704 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2705 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2706 | } |
2707 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2708 | { | |
9327494e | 2709 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2710 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2711 | } |
d6b0e80f | 2712 | |
e7ad2f14 | 2713 | lp->stop_pc = pc; |
d6b0e80f AC |
2714 | } |
2715 | ||
faf09f01 PA |
2716 | |
2717 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2718 | ||
57810aa7 | 2719 | bool |
f6ac5f3d | 2720 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2721 | { |
2722 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2723 | ||
2724 | gdb_assert (lp != NULL); | |
2725 | ||
2726 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2727 | } | |
2728 | ||
2729 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2730 | ||
57810aa7 | 2731 | bool |
f6ac5f3d | 2732 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2733 | { |
2734 | return USE_SIGTRAP_SIGINFO; | |
2735 | } | |
2736 | ||
2737 | /* Returns true if the LWP had stopped for a hardware | |
2738 | breakpoint/watchpoint. */ | |
2739 | ||
57810aa7 | 2740 | bool |
f6ac5f3d | 2741 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2742 | { |
2743 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2744 | ||
2745 | gdb_assert (lp != NULL); | |
2746 | ||
2747 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2748 | } | |
2749 | ||
2750 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2751 | ||
57810aa7 | 2752 | bool |
f6ac5f3d | 2753 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2754 | { |
2755 | return USE_SIGTRAP_SIGINFO; | |
2756 | } | |
2757 | ||
d6b0e80f AC |
2758 | /* Select one LWP out of those that have events pending. */ |
2759 | ||
2760 | static void | |
d90e17a7 | 2761 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2762 | { |
2763 | int num_events = 0; | |
2764 | int random_selector; | |
9c02b525 | 2765 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2766 | |
ac264b3b | 2767 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2768 | (*orig_lp)->status = *status; |
2769 | ||
9c02b525 PA |
2770 | /* In all-stop, give preference to the LWP that is being |
2771 | single-stepped. There will be at most one, and it will be the | |
2772 | LWP that the core is most interested in. If we didn't do this, | |
2773 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2774 | the core later continues the previously-stepped thread, as | |
2775 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2776 | having stepped the thread, wouldn't understand what the trap was | |
2777 | for, and therefore would report it to the user as a random | |
2778 | signal. */ | |
fbea99ea | 2779 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2780 | { |
d3a70e03 | 2781 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2782 | if (event_lp != NULL) |
2783 | { | |
9327494e | 2784 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2785 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2786 | } |
d6b0e80f | 2787 | } |
9c02b525 PA |
2788 | |
2789 | if (event_lp == NULL) | |
d6b0e80f | 2790 | { |
9c02b525 | 2791 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2792 | |
9c02b525 | 2793 | /* First see how many events we have. */ |
d3a70e03 TT |
2794 | iterate_over_lwps (filter, |
2795 | [&] (struct lwp_info *info) | |
2796 | { | |
2797 | return count_events_callback (info, &num_events); | |
2798 | }); | |
8bf3b159 | 2799 | gdb_assert (num_events > 0); |
d6b0e80f | 2800 | |
9c02b525 PA |
2801 | /* Now randomly pick a LWP out of those that have had |
2802 | events. */ | |
d6b0e80f AC |
2803 | random_selector = (int) |
2804 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2805 | ||
9327494e SM |
2806 | if (num_events > 1) |
2807 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2808 | num_events, random_selector); | |
d6b0e80f | 2809 | |
d3a70e03 TT |
2810 | event_lp |
2811 | = (iterate_over_lwps | |
2812 | (filter, | |
2813 | [&] (struct lwp_info *info) | |
2814 | { | |
2815 | return select_event_lwp_callback (info, | |
2816 | &random_selector); | |
2817 | })); | |
d6b0e80f AC |
2818 | } |
2819 | ||
2820 | if (event_lp != NULL) | |
2821 | { | |
2822 | /* Switch the event LWP. */ | |
2823 | *orig_lp = event_lp; | |
2824 | *status = event_lp->status; | |
2825 | } | |
2826 | ||
2827 | /* Flush the wait status for the event LWP. */ | |
2828 | (*orig_lp)->status = 0; | |
2829 | } | |
2830 | ||
2831 | /* Return non-zero if LP has been resumed. */ | |
2832 | ||
2833 | static int | |
d3a70e03 | 2834 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2835 | { |
2836 | return lp->resumed; | |
2837 | } | |
2838 | ||
02f3fc28 | 2839 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2840 | |
897608ed SM |
2841 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2842 | ||
2843 | static void | |
9c02b525 | 2844 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2845 | { |
2846 | struct lwp_info *lp; | |
89a5711c | 2847 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2848 | |
f2907e49 | 2849 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2850 | |
1abeb1e9 PA |
2851 | /* Check for events reported by anything not in our LWP list. */ |
2852 | if (lp == nullptr) | |
0e5bf2a8 | 2853 | { |
1abeb1e9 PA |
2854 | if (WIFSTOPPED (status)) |
2855 | { | |
2856 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2857 | { | |
2858 | /* A non-leader thread exec'ed after we've seen the | |
2859 | leader zombie, and removed it from our lists (in | |
2860 | check_zombie_leaders). The non-leader thread changes | |
2861 | its tid to the tgid. */ | |
2862 | linux_nat_debug_printf | |
2863 | ("Re-adding thread group leader LWP %d after exec.", | |
2864 | lwpid); | |
0e5bf2a8 | 2865 | |
1abeb1e9 PA |
2866 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2867 | lp->stopped = 1; | |
2868 | lp->resumed = 1; | |
2869 | add_thread (linux_target, lp->ptid); | |
2870 | } | |
2871 | else | |
2872 | { | |
2873 | /* A process we are controlling has forked and the new | |
2874 | child's stop was reported to us by the kernel. Save | |
2875 | its PID and go back to waiting for the fork event to | |
2876 | be reported - the stopped process might be returned | |
2877 | from waitpid before or after the fork event is. */ | |
2878 | linux_nat_debug_printf | |
2879 | ("Saving LWP %d status %s in stopped_pids list", | |
2880 | lwpid, status_to_str (status).c_str ()); | |
2881 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2882 | } | |
2883 | } | |
2884 | else | |
2885 | { | |
2886 | /* Don't report an event for the exit of an LWP not in our | |
2887 | list, i.e. not part of any inferior we're debugging. | |
2888 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
2889 | forked and then it exits. However, note that we may have |
2890 | earlier deleted a leader of an inferior we're debugging, | |
2891 | in check_zombie_leaders. Re-add it back here if so. */ | |
2892 | for (inferior *inf : all_inferiors (linux_target)) | |
2893 | { | |
2894 | if (inf->pid == lwpid) | |
2895 | { | |
2896 | linux_nat_debug_printf | |
2897 | ("Re-adding thread group leader LWP %d after exit.", | |
2898 | lwpid); | |
2899 | ||
2900 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
2901 | lp->resumed = 1; | |
2902 | add_thread (linux_target, lp->ptid); | |
2903 | break; | |
2904 | } | |
2905 | } | |
1abeb1e9 | 2906 | } |
0e5bf2a8 | 2907 | |
1abeb1e9 PA |
2908 | if (lp == nullptr) |
2909 | return; | |
02f3fc28 PA |
2910 | } |
2911 | ||
8817a6f2 PA |
2912 | /* This LWP is stopped now. (And if dead, this prevents it from |
2913 | ever being continued.) */ | |
2914 | lp->stopped = 1; | |
2915 | ||
8784d563 PA |
2916 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2917 | { | |
5b6d1e4f | 2918 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2919 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2920 | |
e38504b3 | 2921 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2922 | lp->must_set_ptrace_flags = 0; |
2923 | } | |
2924 | ||
ca2163eb PA |
2925 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2926 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2927 | { | |
2928 | /* No longer need the sysgood bit. The ptrace event ends up | |
2929 | recorded in lp->waitstatus if we care for it. We can carry | |
2930 | on handling the event like a regular SIGTRAP from here | |
2931 | on. */ | |
2932 | status = W_STOPCODE (SIGTRAP); | |
2933 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2934 | return; |
ca2163eb | 2935 | } |
bfd09d20 JS |
2936 | else |
2937 | { | |
2938 | /* Almost all other ptrace-stops are known to be outside of system | |
2939 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2940 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2941 | } | |
02f3fc28 | 2942 | |
ca2163eb | 2943 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2944 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2945 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2946 | { |
9327494e SM |
2947 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2948 | ||
4dd63d48 | 2949 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2950 | return; |
02f3fc28 PA |
2951 | } |
2952 | ||
2953 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2954 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2955 | { | |
a51e14ef | 2956 | if (!report_exit_events_for (lp) && !is_leader (lp)) |
02f3fc28 | 2957 | { |
9327494e | 2958 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2959 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2960 | |
6cf20c46 | 2961 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
2962 | was not the end of the debugged application and should be |
2963 | ignored. */ | |
2964 | exit_lwp (lp); | |
897608ed | 2965 | return; |
02f3fc28 PA |
2966 | } |
2967 | ||
77598427 PA |
2968 | /* Note that even if the leader was ptrace-stopped, it can still |
2969 | exit, if e.g., some other thread brings down the whole | |
2970 | process (calls `exit'). So don't assert that the lwp is | |
2971 | resumed. */ | |
9327494e SM |
2972 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2973 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2974 | |
9c02b525 PA |
2975 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2976 | lp->signalled = 0; | |
2977 | ||
2978 | /* Store the pending event in the waitstatus, because | |
2979 | W_EXITCODE(0,0) == 0. */ | |
7509b829 | 2980 | lp->waitstatus = host_status_to_waitstatus (status); |
897608ed | 2981 | return; |
02f3fc28 PA |
2982 | } |
2983 | ||
02f3fc28 PA |
2984 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2985 | an attempt to stop an LWP. */ | |
2986 | if (lp->signalled | |
2987 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2988 | { | |
02f3fc28 PA |
2989 | lp->signalled = 0; |
2990 | ||
2bf6fb9d | 2991 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2992 | { |
9327494e | 2993 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 2994 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
2995 | } |
2996 | else | |
2997 | { | |
2998 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2999 | |
9327494e SM |
3000 | linux_nat_debug_printf |
3001 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
3002 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3003 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 3004 | |
2bf6fb9d | 3005 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 3006 | gdb_assert (lp->resumed); |
897608ed | 3007 | return; |
25289eb2 | 3008 | } |
02f3fc28 PA |
3009 | } |
3010 | ||
57380f4e DJ |
3011 | /* Make sure we don't report a SIGINT that we have already displayed |
3012 | for another thread. */ | |
3013 | if (lp->ignore_sigint | |
3014 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
3015 | { | |
9327494e | 3016 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 3017 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3018 | |
3019 | /* This is a delayed SIGINT. */ | |
3020 | lp->ignore_sigint = 0; | |
3021 | ||
8a99810d | 3022 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
3023 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
3024 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3025 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3026 | gdb_assert (lp->resumed); |
3027 | ||
3028 | /* Discard the event. */ | |
897608ed | 3029 | return; |
57380f4e DJ |
3030 | } |
3031 | ||
9c02b525 PA |
3032 | /* Don't report signals that GDB isn't interested in, such as |
3033 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3034 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3035 | performance with heavily multi-threaded programs, especially when |
3036 | they're using a high frequency timer, we'd better avoid it if we | |
3037 | can. */ | |
3038 | if (WIFSTOPPED (status)) | |
3039 | { | |
3040 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3041 | ||
fbea99ea | 3042 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3043 | { |
3044 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3045 | to implement target_stop (see linux_nat_stop) in | |
3046 | non-stop. */ | |
3047 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3048 | { | |
3049 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3050 | forwarded to the entire process group, that is, all LWPs | |
3051 | will receive it - unless they're using CLONE_THREAD to | |
3052 | share signals. Since we only want to report it once, we | |
3053 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3054 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3055 | lp->ignore_sigint = 0; |
3056 | } | |
3057 | else | |
3058 | maybe_clear_ignore_sigint (lp); | |
3059 | } | |
3060 | ||
3061 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3062 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3063 | except signals that might be caused by a breakpoint, or SIGSTOP |
3064 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3065 | if (!lp->step |
c9587f88 | 3066 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3067 | && (WSTOPSIG (status) != SIGSTOP |
9213a6d7 | 3068 | || !linux_target->find_thread (lp->ptid)->stop_requested) |
c9587f88 | 3069 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3070 | { |
3071 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3072 | linux_nat_debug_printf |
3073 | ("%s %s, %s (preempt 'handle')", | |
3074 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3075 | lp->ptid.to_string ().c_str (), |
9327494e SM |
3076 | (signo != GDB_SIGNAL_0 |
3077 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3078 | return; |
9c02b525 PA |
3079 | } |
3080 | } | |
3081 | ||
02f3fc28 PA |
3082 | /* An interesting event. */ |
3083 | gdb_assert (lp); | |
ca2163eb | 3084 | lp->status = status; |
e7ad2f14 | 3085 | save_stop_reason (lp); |
02f3fc28 PA |
3086 | } |
3087 | ||
0e5bf2a8 PA |
3088 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3089 | their exits until all other threads in the group have exited. */ | |
3090 | ||
3091 | static void | |
3092 | check_zombie_leaders (void) | |
3093 | { | |
08036331 | 3094 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3095 | { |
3096 | struct lwp_info *leader_lp; | |
3097 | ||
3098 | if (inf->pid == 0) | |
3099 | continue; | |
3100 | ||
f2907e49 | 3101 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3102 | if (leader_lp != NULL |
3103 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3104 | have raced with the inferior simply exiting. Note this |
3105 | isn't a watertight check. If the inferior is | |
3106 | multi-threaded and is exiting, it may be we see the | |
3107 | leader as zombie before we reap all the non-leader | |
3108 | threads. See comments below. */ | |
0e5bf2a8 | 3109 | && num_lwps (inf->pid) > 1 |
5f572dec | 3110 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3111 | { |
6cf20c46 PA |
3112 | /* A zombie leader in a multi-threaded program can mean one |
3113 | of three things: | |
3114 | ||
3115 | #1 - Only the leader exited, not the whole program, e.g., | |
3116 | with pthread_exit. Since we can't reap the leader's exit | |
3117 | status until all other threads are gone and reaped too, | |
3118 | we want to delete the zombie leader right away, as it | |
3119 | can't be debugged, we can't read its registers, etc. | |
3120 | This is the main reason we check for zombie leaders | |
3121 | disappearing. | |
3122 | ||
3123 | #2 - The whole thread-group/process exited (a group exit, | |
3124 | via e.g. exit(3), and there is (or will be shortly) an | |
3125 | exit reported for each thread in the process, and then | |
3126 | finally an exit for the leader once the non-leaders are | |
3127 | reaped. | |
3128 | ||
3129 | #3 - There are 3 or more threads in the group, and a | |
3130 | thread other than the leader exec'd. See comments on | |
3131 | exec events at the top of the file. | |
3132 | ||
3133 | Ideally we would never delete the leader for case #2. | |
3134 | Instead, we want to collect the exit status of each | |
3135 | non-leader thread, and then finally collect the exit | |
3136 | status of the leader as normal and use its exit code as | |
3137 | whole-process exit code. Unfortunately, there's no | |
3138 | race-free way to distinguish cases #1 and #2. We can't | |
3139 | assume the exit events for the non-leaders threads are | |
3140 | already pending in the kernel, nor can we assume the | |
3141 | non-leader threads are in zombie state already. Between | |
3142 | the leader becoming zombie and the non-leaders exiting | |
3143 | and becoming zombie themselves, there's a small time | |
3144 | window, so such a check would be racy. Temporarily | |
3145 | pausing all threads and checking to see if all threads | |
3146 | exit or not before re-resuming them would work in the | |
3147 | case that all threads are running right now, but it | |
3148 | wouldn't work if some thread is currently already | |
3149 | ptrace-stopped, e.g., due to scheduler-locking. | |
3150 | ||
3151 | So what we do is we delete the leader anyhow, and then | |
3152 | later on when we see its exit status, we re-add it back. | |
3153 | We also make sure that we only report a whole-process | |
3154 | exit when we see the leader exiting, as opposed to when | |
3155 | the last LWP in the LWP list exits, which can be a | |
3156 | non-leader if we deleted the leader here. */ | |
9327494e | 3157 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3158 | "(it exited, or another thread execd), " |
3159 | "deleting it.", | |
9327494e | 3160 | inf->pid); |
0e5bf2a8 PA |
3161 | exit_lwp (leader_lp); |
3162 | } | |
3163 | } | |
3164 | } | |
3165 | ||
a51e14ef PA |
3166 | /* Convenience function that is called when we're about to return an |
3167 | event to the core. If the event is an exit or signalled event, | |
3168 | then this decides whether to report it as process-wide event, as a | |
3169 | thread exit event, or to suppress it. All other event kinds are | |
3170 | passed through unmodified. */ | |
aa01bd36 PA |
3171 | |
3172 | static ptid_t | |
3173 | filter_exit_event (struct lwp_info *event_child, | |
3174 | struct target_waitstatus *ourstatus) | |
3175 | { | |
3176 | ptid_t ptid = event_child->ptid; | |
3177 | ||
a51e14ef PA |
3178 | /* Note we must filter TARGET_WAITKIND_SIGNALLED as well, otherwise |
3179 | if a non-leader thread exits with a signal, we'd report it to the | |
3180 | core which would interpret it as the whole-process exiting. | |
3181 | There is no TARGET_WAITKIND_THREAD_SIGNALLED event kind. */ | |
3182 | if (ourstatus->kind () != TARGET_WAITKIND_EXITED | |
3183 | && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) | |
3184 | return ptid; | |
3185 | ||
6cf20c46 | 3186 | if (!is_leader (event_child)) |
aa01bd36 | 3187 | { |
a51e14ef | 3188 | if (report_exit_events_for (event_child)) |
7730e5c6 PA |
3189 | { |
3190 | ourstatus->set_thread_exited (0); | |
3191 | /* Delete lwp, but not thread_info, infrun will need it to | |
3192 | process the event. */ | |
3193 | exit_lwp (event_child, false); | |
3194 | } | |
aa01bd36 | 3195 | else |
7730e5c6 PA |
3196 | { |
3197 | ourstatus->set_ignore (); | |
3198 | exit_lwp (event_child); | |
3199 | } | |
aa01bd36 PA |
3200 | } |
3201 | ||
3202 | return ptid; | |
3203 | } | |
3204 | ||
d6b0e80f | 3205 | static ptid_t |
f6ac5f3d | 3206 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3207 | target_wait_flags target_options) |
d6b0e80f | 3208 | { |
b26b06dd AB |
3209 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3210 | ||
fc9b8e47 | 3211 | sigset_t prev_mask; |
4b60df3d | 3212 | enum resume_kind last_resume_kind; |
12d9289a | 3213 | struct lwp_info *lp; |
12d9289a | 3214 | int status; |
d6b0e80f | 3215 | |
f973ed9c DJ |
3216 | /* The first time we get here after starting a new inferior, we may |
3217 | not have added it to the LWP list yet - this is the earliest | |
3218 | moment at which we know its PID. */ | |
677c92fe | 3219 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3220 | { |
677c92fe | 3221 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3222 | |
677c92fe SM |
3223 | /* Upgrade the main thread's ptid. */ |
3224 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3225 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3226 | lp->resumed = 1; |
3227 | } | |
3228 | ||
12696c10 | 3229 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3230 | block_child_signals (&prev_mask); |
d6b0e80f | 3231 | |
d6b0e80f | 3232 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3233 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3234 | if (lp != NULL) |
d6b0e80f | 3235 | { |
9327494e | 3236 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
57573e54 | 3237 | pending_status_str (lp).c_str (), |
e53c95d4 | 3238 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3239 | } |
3240 | ||
9c02b525 PA |
3241 | /* But if we don't find a pending event, we'll have to wait. Always |
3242 | pull all events out of the kernel. We'll randomly select an | |
3243 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3244 | |
d90e17a7 | 3245 | while (lp == NULL) |
d6b0e80f AC |
3246 | { |
3247 | pid_t lwpid; | |
3248 | ||
0e5bf2a8 PA |
3249 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3250 | quirks: | |
3251 | ||
3252 | - If the thread group leader exits while other threads in the | |
3253 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3254 | waitpid won't return an exit status until the other threads | |
85102364 | 3255 | in the group are reaped. |
0e5bf2a8 PA |
3256 | |
3257 | - When a non-leader thread execs, that thread just vanishes | |
3258 | without reporting an exit (so we'd hang if we waited for it | |
3259 | explicitly in that case). The exec event is reported to | |
3260 | the TGID pid. */ | |
3261 | ||
3262 | errno = 0; | |
4a6ed09b | 3263 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3264 | |
9327494e SM |
3265 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3266 | lwpid, | |
3267 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3268 | |
d6b0e80f AC |
3269 | if (lwpid > 0) |
3270 | { | |
9327494e | 3271 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3272 | (long) lwpid, |
3273 | status_to_str (status).c_str ()); | |
d6b0e80f | 3274 | |
9c02b525 | 3275 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3276 | /* Retry until nothing comes out of waitpid. A single |
3277 | SIGCHLD can indicate more than one child stopped. */ | |
3278 | continue; | |
d6b0e80f AC |
3279 | } |
3280 | ||
20ba1ce6 PA |
3281 | /* Now that we've pulled all events out of the kernel, resume |
3282 | LWPs that don't have an interesting event to report. */ | |
3283 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3284 | [] (struct lwp_info *info) |
3285 | { | |
3286 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3287 | }); | |
20ba1ce6 PA |
3288 | |
3289 | /* ... and find an LWP with a status to report to the core, if | |
3290 | any. */ | |
d3a70e03 | 3291 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3292 | if (lp != NULL) |
3293 | break; | |
3294 | ||
0e5bf2a8 PA |
3295 | /* Check for zombie thread group leaders. Those can't be reaped |
3296 | until all other threads in the thread group are. */ | |
3297 | check_zombie_leaders (); | |
d6b0e80f | 3298 | |
0e5bf2a8 PA |
3299 | /* If there are no resumed children left, bail. We'd be stuck |
3300 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3301 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3302 | { |
9327494e | 3303 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3304 | |
183be222 | 3305 | ourstatus->set_no_resumed (); |
b84876c2 | 3306 | |
0e5bf2a8 PA |
3307 | restore_child_signals_mask (&prev_mask); |
3308 | return minus_one_ptid; | |
d6b0e80f | 3309 | } |
28736962 | 3310 | |
0e5bf2a8 PA |
3311 | /* No interesting event to report to the core. */ |
3312 | ||
3313 | if (target_options & TARGET_WNOHANG) | |
3314 | { | |
b26b06dd | 3315 | linux_nat_debug_printf ("no interesting events found"); |
28736962 | 3316 | |
183be222 | 3317 | ourstatus->set_ignore (); |
28736962 PA |
3318 | restore_child_signals_mask (&prev_mask); |
3319 | return minus_one_ptid; | |
3320 | } | |
d6b0e80f AC |
3321 | |
3322 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3323 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3324 | |
3325 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3326 | wait_for_signal (); |
d6b0e80f AC |
3327 | } |
3328 | ||
d6b0e80f AC |
3329 | gdb_assert (lp); |
3330 | ||
ca2163eb PA |
3331 | status = lp->status; |
3332 | lp->status = 0; | |
3333 | ||
fbea99ea | 3334 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3335 | { |
3336 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3337 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3338 | |
3339 | /* ... and wait until all of them have reported back that | |
3340 | they're no longer running. */ | |
d3a70e03 | 3341 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3342 | } |
3343 | ||
3344 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3345 | among those that have had events. Giving equal priority to all | |
3346 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3347 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3348 | select_event_lwp (ptid, &lp, &status); |
3349 | ||
3350 | gdb_assert (lp != NULL); | |
3351 | ||
3352 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3353 | it was a software breakpoint, and we can't reliably support the |
3354 | "stopped by software breakpoint" stop reason. */ | |
3355 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3356 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3357 | { |
5b6d1e4f | 3358 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3359 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3360 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3361 | |
9c02b525 PA |
3362 | if (decr_pc != 0) |
3363 | { | |
3364 | CORE_ADDR pc; | |
d6b0e80f | 3365 | |
9c02b525 PA |
3366 | pc = regcache_read_pc (regcache); |
3367 | regcache_write_pc (regcache, pc + decr_pc); | |
3368 | } | |
3369 | } | |
e3e9f5a2 | 3370 | |
9c02b525 PA |
3371 | /* We'll need this to determine whether to report a SIGSTOP as |
3372 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3373 | clears it. */ | |
3374 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3375 | |
fbea99ea | 3376 | if (!target_is_non_stop_p ()) |
9c02b525 | 3377 | { |
e3e9f5a2 PA |
3378 | /* In all-stop, from the core's perspective, all LWPs are now |
3379 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3380 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3381 | } |
3382 | else | |
25289eb2 | 3383 | { |
d3a70e03 | 3384 | resume_clear_callback (lp); |
25289eb2 | 3385 | } |
d6b0e80f | 3386 | |
135340af | 3387 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3388 | { |
9327494e | 3389 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3390 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3391 | } |
d6b0e80f | 3392 | |
183be222 | 3393 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3394 | { |
3395 | *ourstatus = lp->waitstatus; | |
183be222 | 3396 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3397 | } |
3398 | else | |
7509b829 | 3399 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3400 | |
b26b06dd | 3401 | linux_nat_debug_printf ("event found"); |
b84876c2 | 3402 | |
7feb7d06 | 3403 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3404 | |
4b60df3d | 3405 | if (last_resume_kind == resume_stop |
183be222 | 3406 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3407 | && WSTOPSIG (status) == SIGSTOP) |
3408 | { | |
3409 | /* A thread that has been requested to stop by GDB with | |
3410 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3411 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3412 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3413 | } |
3414 | ||
183be222 SM |
3415 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3416 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3417 | lp->core = -1; |
3418 | else | |
2e794194 | 3419 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3420 | |
a51e14ef | 3421 | return filter_exit_event (lp, ourstatus); |
d6b0e80f AC |
3422 | } |
3423 | ||
e3e9f5a2 PA |
3424 | /* Resume LWPs that are currently stopped without any pending status |
3425 | to report, but are resumed from the core's perspective. */ | |
3426 | ||
3427 | static int | |
d3a70e03 | 3428 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3429 | { |
74387712 | 3430 | inferior *inf = lwp_inferior (lp); |
14ec4172 | 3431 | |
8a9da63e | 3432 | if (!lp->stopped) |
4dd63d48 | 3433 | { |
9327494e | 3434 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3435 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3436 | } |
3437 | else if (!lp->resumed) | |
3438 | { | |
9327494e | 3439 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3440 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3441 | } |
3442 | else if (lwp_status_pending_p (lp)) | |
3443 | { | |
9327494e | 3444 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3445 | lp->ptid.to_string ().c_str ()); |
4dd63d48 | 3446 | } |
8a9da63e AB |
3447 | else if (inf->vfork_child != nullptr) |
3448 | { | |
3449 | linux_nat_debug_printf ("NOT resuming LWP %s (vfork parent)", | |
3450 | lp->ptid.to_string ().c_str ()); | |
3451 | } | |
4dd63d48 | 3452 | else |
e3e9f5a2 | 3453 | { |
5b6d1e4f | 3454 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3455 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3456 | |
a70b8144 | 3457 | try |
e3e9f5a2 | 3458 | { |
23f238d3 PA |
3459 | CORE_ADDR pc = regcache_read_pc (regcache); |
3460 | int leave_stopped = 0; | |
e3e9f5a2 | 3461 | |
23f238d3 PA |
3462 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3463 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3464 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3465 | { |
f9582a22 | 3466 | if (breakpoint_inserted_here_p (inf->aspace.get (), pc)) |
23f238d3 PA |
3467 | leave_stopped = 1; |
3468 | } | |
e3e9f5a2 | 3469 | |
23f238d3 PA |
3470 | if (!leave_stopped) |
3471 | { | |
9327494e SM |
3472 | linux_nat_debug_printf |
3473 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3474 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3475 | lp->step); |
23f238d3 PA |
3476 | |
3477 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3478 | } | |
3479 | } | |
230d2906 | 3480 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3481 | { |
3482 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3483 | throw; |
23f238d3 | 3484 | } |
e3e9f5a2 PA |
3485 | } |
3486 | ||
3487 | return 0; | |
3488 | } | |
3489 | ||
f6ac5f3d PA |
3490 | ptid_t |
3491 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3492 | target_wait_flags target_options) |
7feb7d06 | 3493 | { |
b26b06dd AB |
3494 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3495 | ||
7feb7d06 PA |
3496 | ptid_t event_ptid; |
3497 | ||
e53c95d4 | 3498 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3499 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3500 | |
3501 | /* Flush the async file first. */ | |
d9d41e78 | 3502 | if (target_is_async_p ()) |
7feb7d06 PA |
3503 | async_file_flush (); |
3504 | ||
e3e9f5a2 PA |
3505 | /* Resume LWPs that are currently stopped without any pending status |
3506 | to report, but are resumed from the core's perspective. LWPs get | |
3507 | in this state if we find them stopping at a time we're not | |
3508 | interested in reporting the event (target_wait on a | |
3509 | specific_process, for example, see linux_nat_wait_1), and | |
3510 | meanwhile the event became uninteresting. Don't bother resuming | |
3511 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3512 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3513 | iterate_over_lwps (minus_one_ptid, |
3514 | [=] (struct lwp_info *info) | |
3515 | { | |
3516 | return resume_stopped_resumed_lwps (info, ptid); | |
3517 | }); | |
e3e9f5a2 | 3518 | |
f6ac5f3d | 3519 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3520 | |
3521 | /* If we requested any event, and something came out, assume there | |
3522 | may be more. If we requested a specific lwp or process, also | |
3523 | assume there may be more. */ | |
d9d41e78 | 3524 | if (target_is_async_p () |
183be222 SM |
3525 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3526 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3527 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3528 | async_file_mark (); |
3529 | ||
7feb7d06 PA |
3530 | return event_ptid; |
3531 | } | |
3532 | ||
1d2736d4 PA |
3533 | /* Kill one LWP. */ |
3534 | ||
3535 | static void | |
3536 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3537 | { |
ed731959 JK |
3538 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3539 | ||
3540 | errno = 0; | |
1d2736d4 | 3541 | kill_lwp (pid, SIGKILL); |
9327494e | 3542 | |
ed731959 | 3543 | if (debug_linux_nat) |
57745c90 PA |
3544 | { |
3545 | int save_errno = errno; | |
3546 | ||
9327494e SM |
3547 | linux_nat_debug_printf |
3548 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3549 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3550 | } |
ed731959 JK |
3551 | |
3552 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3553 | ||
d6b0e80f | 3554 | errno = 0; |
1d2736d4 | 3555 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3556 | if (debug_linux_nat) |
57745c90 PA |
3557 | { |
3558 | int save_errno = errno; | |
3559 | ||
9327494e SM |
3560 | linux_nat_debug_printf |
3561 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3562 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3563 | } |
d6b0e80f AC |
3564 | } |
3565 | ||
1d2736d4 PA |
3566 | /* Wait for an LWP to die. */ |
3567 | ||
3568 | static void | |
3569 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3570 | { |
1d2736d4 | 3571 | pid_t res; |
d6b0e80f AC |
3572 | |
3573 | /* We must make sure that there are no pending events (delayed | |
3574 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3575 | program doesn't interfere with any following debugging session. */ | |
3576 | ||
d6b0e80f AC |
3577 | do |
3578 | { | |
1d2736d4 PA |
3579 | res = my_waitpid (pid, NULL, __WALL); |
3580 | if (res != (pid_t) -1) | |
d6b0e80f | 3581 | { |
9327494e SM |
3582 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3583 | ||
4a6ed09b PA |
3584 | /* The Linux kernel sometimes fails to kill a thread |
3585 | completely after PTRACE_KILL; that goes from the stop | |
3586 | point in do_fork out to the one in get_signal_to_deliver | |
3587 | and waits again. So kill it again. */ | |
1d2736d4 | 3588 | kill_one_lwp (pid); |
d6b0e80f AC |
3589 | } |
3590 | } | |
1d2736d4 PA |
3591 | while (res == pid); |
3592 | ||
3593 | gdb_assert (res == -1 && errno == ECHILD); | |
3594 | } | |
3595 | ||
3596 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3597 | |
1d2736d4 | 3598 | static int |
d3a70e03 | 3599 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3600 | { |
e38504b3 | 3601 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3602 | return 0; |
3603 | } | |
3604 | ||
1d2736d4 PA |
3605 | /* Callback for iterate_over_lwps. */ |
3606 | ||
3607 | static int | |
d3a70e03 | 3608 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3609 | { |
e38504b3 | 3610 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3611 | return 0; |
3612 | } | |
3613 | ||
0d36baa9 | 3614 | /* Kill the fork/clone child of LP if it has an unfollowed child. */ |
1d2736d4 | 3615 | |
0d36baa9 PA |
3616 | static int |
3617 | kill_unfollowed_child_callback (lwp_info *lp) | |
1d2736d4 | 3618 | { |
6b09f134 | 3619 | std::optional<target_waitstatus> ws = get_pending_child_status (lp); |
0d36baa9 | 3620 | if (ws.has_value ()) |
08036331 | 3621 | { |
0d36baa9 PA |
3622 | ptid_t child_ptid = ws->child_ptid (); |
3623 | int child_pid = child_ptid.pid (); | |
3624 | int child_lwp = child_ptid.lwp (); | |
08036331 | 3625 | |
0d36baa9 PA |
3626 | kill_one_lwp (child_lwp); |
3627 | kill_wait_one_lwp (child_lwp); | |
08036331 | 3628 | |
0d36baa9 PA |
3629 | /* Let the arch-specific native code know this process is |
3630 | gone. */ | |
3631 | if (ws->kind () != TARGET_WAITKIND_THREAD_CLONED) | |
3632 | linux_target->low_forget_process (child_pid); | |
08036331 | 3633 | } |
0d36baa9 PA |
3634 | |
3635 | return 0; | |
1d2736d4 PA |
3636 | } |
3637 | ||
f6ac5f3d PA |
3638 | void |
3639 | linux_nat_target::kill () | |
d6b0e80f | 3640 | { |
0d36baa9 PA |
3641 | ptid_t pid_ptid (inferior_ptid.pid ()); |
3642 | ||
3643 | /* If we're stopped while forking/cloning and we haven't followed | |
3644 | yet, kill the child task. We need to do this first because the | |
f973ed9c | 3645 | parent will be sleeping if this is a vfork. */ |
0d36baa9 | 3646 | iterate_over_lwps (pid_ptid, kill_unfollowed_child_callback); |
f973ed9c DJ |
3647 | |
3648 | if (forks_exist_p ()) | |
7feb7d06 | 3649 | linux_fork_killall (); |
f973ed9c DJ |
3650 | else |
3651 | { | |
4c28f408 | 3652 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3653 | that the thread is stopped to successfully PTRACE_KILL. */ |
0d36baa9 | 3654 | iterate_over_lwps (pid_ptid, stop_callback); |
4c28f408 PA |
3655 | /* ... and wait until all of them have reported back that |
3656 | they're no longer running. */ | |
0d36baa9 | 3657 | iterate_over_lwps (pid_ptid, stop_wait_callback); |
4c28f408 | 3658 | |
f973ed9c | 3659 | /* Kill all LWP's ... */ |
0d36baa9 | 3660 | iterate_over_lwps (pid_ptid, kill_callback); |
f973ed9c DJ |
3661 | |
3662 | /* ... and wait until we've flushed all events. */ | |
0d36baa9 | 3663 | iterate_over_lwps (pid_ptid, kill_wait_callback); |
f973ed9c DJ |
3664 | } |
3665 | ||
bc1e6c81 | 3666 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3667 | } |
3668 | ||
f6ac5f3d PA |
3669 | void |
3670 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3671 | { |
b26b06dd AB |
3672 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3673 | ||
e99b03dc | 3674 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3675 | |
3676 | purge_lwp_list (pid); | |
d6b0e80f | 3677 | |
8a89ddbd | 3678 | close_proc_mem_file (pid); |
05c06f31 | 3679 | |
f973ed9c | 3680 | if (! forks_exist_p ()) |
d90e17a7 | 3681 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3682 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3683 | else |
3684 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3685 | there are other viable forks to debug. Delete the exiting | |
3686 | one and context-switch to the first available. */ | |
3687 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3688 | |
3689 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3690 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3691 | } |
3692 | ||
5b009018 PA |
3693 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3694 | layout of the inferiors' architecture. */ | |
3695 | ||
3696 | static void | |
a5362b9a | 3697 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3698 | { |
135340af PA |
3699 | /* If the low target didn't do anything, then just do a straight |
3700 | memcpy. */ | |
3701 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3702 | { |
3703 | if (direction == 1) | |
a5362b9a | 3704 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3705 | else |
a5362b9a | 3706 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3707 | } |
3708 | } | |
3709 | ||
9b409511 | 3710 | static enum target_xfer_status |
7154e786 | 3711 | linux_xfer_siginfo (ptid_t ptid, enum target_object object, |
dda83cd7 | 3712 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3713 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3714 | ULONGEST *xfered_len) | |
4aa995e1 | 3715 | { |
a5362b9a TS |
3716 | siginfo_t siginfo; |
3717 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3718 | |
3719 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3720 | gdb_assert (readbuf || writebuf); | |
3721 | ||
4aa995e1 | 3722 | if (offset > sizeof (siginfo)) |
2ed4b548 | 3723 | return TARGET_XFER_E_IO; |
4aa995e1 | 3724 | |
7154e786 | 3725 | if (!linux_nat_get_siginfo (ptid, &siginfo)) |
2ed4b548 | 3726 | return TARGET_XFER_E_IO; |
4aa995e1 | 3727 | |
5b009018 PA |
3728 | /* When GDB is built as a 64-bit application, ptrace writes into |
3729 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3730 | inferior with a 64-bit GDB should look the same as debugging it | |
3731 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3732 | the converted layout, so any read/write will have to be done | |
3733 | post-conversion. */ | |
3734 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3735 | ||
4aa995e1 PA |
3736 | if (offset + len > sizeof (siginfo)) |
3737 | len = sizeof (siginfo) - offset; | |
3738 | ||
3739 | if (readbuf != NULL) | |
5b009018 | 3740 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3741 | else |
3742 | { | |
5b009018 PA |
3743 | memcpy (inf_siginfo + offset, writebuf, len); |
3744 | ||
3745 | /* Convert back to ptrace layout before flushing it out. */ | |
3746 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3747 | ||
7154e786 | 3748 | int pid = get_ptrace_pid (ptid); |
4aa995e1 PA |
3749 | errno = 0; |
3750 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3751 | if (errno != 0) | |
2ed4b548 | 3752 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3753 | } |
3754 | ||
9b409511 YQ |
3755 | *xfered_len = len; |
3756 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3757 | } |
3758 | ||
9b409511 | 3759 | static enum target_xfer_status |
f6ac5f3d PA |
3760 | linux_nat_xfer_osdata (enum target_object object, |
3761 | const char *annex, gdb_byte *readbuf, | |
3762 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3763 | ULONGEST *xfered_len); | |
3764 | ||
f6ac5f3d | 3765 | static enum target_xfer_status |
f9f593dd SM |
3766 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3767 | const gdb_byte *writebuf, ULONGEST offset, | |
3768 | LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3769 | |
3770 | enum target_xfer_status | |
3771 | linux_nat_target::xfer_partial (enum target_object object, | |
3772 | const char *annex, gdb_byte *readbuf, | |
3773 | const gdb_byte *writebuf, | |
3774 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3775 | { |
4aa995e1 | 3776 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
7154e786 | 3777 | return linux_xfer_siginfo (inferior_ptid, object, annex, readbuf, writebuf, |
9b409511 | 3778 | offset, len, xfered_len); |
4aa995e1 | 3779 | |
c35b1492 PA |
3780 | /* The target is connected but no live inferior is selected. Pass |
3781 | this request down to a lower stratum (e.g., the executable | |
3782 | file). */ | |
d7e15655 | 3783 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3784 | return TARGET_XFER_EOF; |
c35b1492 | 3785 | |
f6ac5f3d PA |
3786 | if (object == TARGET_OBJECT_AUXV) |
3787 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3788 | offset, len, xfered_len); | |
3789 | ||
3790 | if (object == TARGET_OBJECT_OSDATA) | |
3791 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3792 | offset, len, xfered_len); | |
d6b0e80f | 3793 | |
f6ac5f3d PA |
3794 | if (object == TARGET_OBJECT_MEMORY) |
3795 | { | |
05c06f31 PA |
3796 | /* GDB calculates all addresses in the largest possible address |
3797 | width. The address width must be masked before its final use | |
3798 | by linux_proc_xfer_partial. | |
3799 | ||
3800 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
99d9c3b9 | 3801 | int addr_bit = gdbarch_addr_bit (current_inferior ()->arch ()); |
f6ac5f3d PA |
3802 | |
3803 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3804 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3805 | |
dd09fe0d KS |
3806 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3807 | the write via /proc/pid/mem fails because the inferior execed | |
3808 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3809 | poke would incorrectly write memory to the post-exec address | |
3810 | space, while the core was trying to write to the pre-exec | |
3811 | address space. */ | |
3812 | if (proc_mem_file_is_writable ()) | |
f9f593dd SM |
3813 | return linux_proc_xfer_memory_partial (inferior_ptid.pid (), readbuf, |
3814 | writebuf, offset, len, | |
3815 | xfered_len); | |
05c06f31 | 3816 | } |
f6ac5f3d PA |
3817 | |
3818 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3819 | offset, len, xfered_len); | |
d6b0e80f AC |
3820 | } |
3821 | ||
57810aa7 | 3822 | bool |
f6ac5f3d | 3823 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3824 | { |
4a6ed09b PA |
3825 | /* As long as a PTID is in lwp list, consider it alive. */ |
3826 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3827 | } |
3828 | ||
8a06aea7 PA |
3829 | /* Implement the to_update_thread_list target method for this |
3830 | target. */ | |
3831 | ||
f6ac5f3d PA |
3832 | void |
3833 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3834 | { |
4a6ed09b PA |
3835 | /* We add/delete threads from the list as clone/exit events are |
3836 | processed, so just try deleting exited threads still in the | |
3837 | thread list. */ | |
3838 | delete_exited_threads (); | |
a6904d5a PA |
3839 | |
3840 | /* Update the processor core that each lwp/thread was last seen | |
3841 | running on. */ | |
901b9821 | 3842 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3843 | { |
3844 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3845 | time we fetched the thread's core. Accessing /proc becomes | |
3846 | noticeably expensive when we have thousands of LWPs. */ | |
3847 | if (lwp->core == -1) | |
3848 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3849 | } | |
8a06aea7 PA |
3850 | } |
3851 | ||
a068643d | 3852 | std::string |
f6ac5f3d | 3853 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3854 | { |
15a9e13e | 3855 | if (ptid.lwp_p () |
e38504b3 | 3856 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3857 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3858 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3859 | |
3860 | return normal_pid_to_str (ptid); | |
3861 | } | |
3862 | ||
f6ac5f3d PA |
3863 | const char * |
3864 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3865 | { |
79efa585 | 3866 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3867 | } |
3868 | ||
dba24537 AC |
3869 | /* Accepts an integer PID; Returns a string representing a file that |
3870 | can be opened to get the symbols for the child process. */ | |
3871 | ||
0e90c441 | 3872 | const char * |
f6ac5f3d | 3873 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3874 | { |
e0d86d2c | 3875 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3876 | } |
3877 | ||
8a89ddbd PA |
3878 | /* Object representing an /proc/PID/mem open file. We keep one such |
3879 | file open per inferior. | |
3880 | ||
3881 | It might be tempting to think about only ever opening one file at | |
3882 | most for all inferiors, closing/reopening the file as we access | |
3883 | memory of different inferiors, to minimize number of file | |
3884 | descriptors open, which can otherwise run into resource limits. | |
3885 | However, that does not work correctly -- if the inferior execs and | |
3886 | we haven't processed the exec event yet, and, we opened a | |
3887 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
3888 | address space, thinking we're opening it for the pre-exec address | |
3889 | space. That is dangerous as we can poke memory (e.g. clearing | |
3890 | breakpoints) in the post-exec memory by mistake, corrupting the | |
3891 | inferior. For that reason, we open the mem file as early as | |
3892 | possible, right after spawning, forking or attaching to the | |
3893 | inferior, when the inferior is stopped and thus before it has a | |
3894 | chance of execing. | |
3895 | ||
3896 | Note that after opening the file, even if the thread we opened it | |
3897 | for subsequently exits, the open file is still usable for accessing | |
3898 | memory. It's only when the whole process exits or execs that the | |
3899 | file becomes invalid, at which point reads/writes return EOF. */ | |
3900 | ||
3901 | class proc_mem_file | |
3902 | { | |
3903 | public: | |
3904 | proc_mem_file (ptid_t ptid, int fd) | |
3905 | : m_ptid (ptid), m_fd (fd) | |
3906 | { | |
3907 | gdb_assert (m_fd != -1); | |
3908 | } | |
05c06f31 | 3909 | |
8a89ddbd | 3910 | ~proc_mem_file () |
05c06f31 | 3911 | { |
89662f69 | 3912 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
3913 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
3914 | close (m_fd); | |
05c06f31 | 3915 | } |
05c06f31 | 3916 | |
8a89ddbd PA |
3917 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
3918 | ||
3919 | int fd () | |
3920 | { | |
3921 | return m_fd; | |
3922 | } | |
3923 | ||
3924 | private: | |
3925 | /* The LWP this file was opened for. Just for debugging | |
3926 | purposes. */ | |
3927 | ptid_t m_ptid; | |
3928 | ||
3929 | /* The file descriptor. */ | |
3930 | int m_fd = -1; | |
3931 | }; | |
3932 | ||
3933 | /* The map between an inferior process id, and the open /proc/PID/mem | |
3934 | file. This is stored in a map instead of in a per-inferior | |
3935 | structure because we need to be able to access memory of processes | |
3936 | which don't have a corresponding struct inferior object. E.g., | |
3937 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
3938 | (also default), we don't create an inferior for the fork child, but | |
3939 | we still need to remove breakpoints from the fork child's | |
3940 | memory. */ | |
3941 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
3942 | ||
3943 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
3944 | |
3945 | static void | |
8a89ddbd | 3946 | close_proc_mem_file (pid_t pid) |
dba24537 | 3947 | { |
8a89ddbd | 3948 | proc_mem_file_map.erase (pid); |
05c06f31 | 3949 | } |
dba24537 | 3950 | |
8a89ddbd PA |
3951 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
3952 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
3953 | exists and is stopped right now. We prefer the | |
3954 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
3955 | races, just in case this is ever called on an already-waited | |
3956 | LWP. */ | |
dba24537 | 3957 | |
8a89ddbd PA |
3958 | static void |
3959 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 3960 | { |
8a89ddbd PA |
3961 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
3962 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 3963 | |
8a89ddbd PA |
3964 | char filename[64]; |
3965 | xsnprintf (filename, sizeof filename, | |
3966 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3967 | ||
3968 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 3969 | |
8a89ddbd PA |
3970 | if (fd == -1) |
3971 | { | |
3972 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
3973 | ptid.pid (), ptid.lwp (), | |
3974 | safe_strerror (errno), errno); | |
3975 | return; | |
05c06f31 PA |
3976 | } |
3977 | ||
8a89ddbd PA |
3978 | proc_mem_file_map.emplace (std::piecewise_construct, |
3979 | std::forward_as_tuple (ptid.pid ()), | |
3980 | std::forward_as_tuple (ptid, fd)); | |
3981 | ||
9221923c | 3982 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
3983 | fd, ptid.pid (), ptid.lwp ()); |
3984 | } | |
3985 | ||
1bcb0708 PA |
3986 | /* Helper for linux_proc_xfer_memory_partial and |
3987 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
3988 | file, and PID is the pid of the corresponding process. The rest of | |
3989 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
3990 | |
3991 | static enum target_xfer_status | |
1bcb0708 PA |
3992 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
3993 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3994 | ULONGEST offset, LONGEST len, | |
3995 | ULONGEST *xfered_len) | |
8a89ddbd PA |
3996 | { |
3997 | ssize_t ret; | |
3998 | ||
8a89ddbd | 3999 | gdb_assert (fd != -1); |
dba24537 | 4000 | |
31a56a22 PA |
4001 | /* Use pread64/pwrite64 if available, since they save a syscall and |
4002 | can handle 64-bit offsets even on 32-bit platforms (for instance, | |
4003 | SPARC debugging a SPARC64 application). But only use them if the | |
4004 | offset isn't so high that when cast to off_t it'd be negative, as | |
4005 | seen on SPARC64. pread64/pwrite64 outright reject such offsets. | |
4006 | lseek does not. */ | |
dba24537 | 4007 | #ifdef HAVE_PREAD64 |
31a56a22 PA |
4008 | if ((off_t) offset >= 0) |
4009 | ret = (readbuf != nullptr | |
4010 | ? pread64 (fd, readbuf, len, offset) | |
4011 | : pwrite64 (fd, writebuf, len, offset)); | |
4012 | else | |
dba24537 | 4013 | #endif |
31a56a22 PA |
4014 | { |
4015 | ret = lseek (fd, offset, SEEK_SET); | |
4016 | if (ret != -1) | |
4017 | ret = (readbuf != nullptr | |
4018 | ? read (fd, readbuf, len) | |
4019 | : write (fd, writebuf, len)); | |
4020 | } | |
dba24537 | 4021 | |
05c06f31 PA |
4022 | if (ret == -1) |
4023 | { | |
9221923c | 4024 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 4025 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 4026 | return TARGET_XFER_E_IO; |
05c06f31 PA |
4027 | } |
4028 | else if (ret == 0) | |
4029 | { | |
8a89ddbd PA |
4030 | /* EOF means the address space is gone, the whole process exited |
4031 | or execed. */ | |
9221923c | 4032 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 4033 | fd, pid); |
05c06f31 PA |
4034 | return TARGET_XFER_EOF; |
4035 | } | |
9b409511 YQ |
4036 | else |
4037 | { | |
8a89ddbd | 4038 | *xfered_len = ret; |
9b409511 YQ |
4039 | return TARGET_XFER_OK; |
4040 | } | |
05c06f31 | 4041 | } |
efcbbd14 | 4042 | |
1bcb0708 PA |
4043 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
4044 | Because we can use a single read/write call, this can be much more | |
4045 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
4046 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
4047 | threads. */ | |
4048 | ||
4049 | static enum target_xfer_status | |
f9f593dd SM |
4050 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
4051 | const gdb_byte *writebuf, ULONGEST offset, | |
4052 | LONGEST len, ULONGEST *xfered_len) | |
1bcb0708 | 4053 | { |
1bcb0708 PA |
4054 | auto iter = proc_mem_file_map.find (pid); |
4055 | if (iter == proc_mem_file_map.end ()) | |
4056 | return TARGET_XFER_EOF; | |
4057 | ||
4058 | int fd = iter->second.fd (); | |
4059 | ||
4060 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
4061 | len, xfered_len); | |
4062 | } | |
4063 | ||
4064 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
4065 | return true if so. It wasn't writable before Linux 2.6.39, but | |
4066 | there's no way to know whether the feature was backported to older | |
4067 | kernels. So we check to see if it works. The result is cached, | |
3bfdcabb | 4068 | and this is guaranteed to be called once early during inferior |
9dff6a5d PA |
4069 | startup, so that any warning is printed out consistently between |
4070 | GDB invocations. Note we don't call it during GDB startup instead | |
4071 | though, because then we might warn with e.g. just "gdb --version" | |
4072 | on sandboxed systems. See PR gdb/29907. */ | |
1bcb0708 PA |
4073 | |
4074 | static bool | |
4075 | proc_mem_file_is_writable () | |
4076 | { | |
6b09f134 | 4077 | static std::optional<bool> writable; |
1bcb0708 PA |
4078 | |
4079 | if (writable.has_value ()) | |
4080 | return *writable; | |
4081 | ||
4082 | writable.emplace (false); | |
4083 | ||
4084 | /* We check whether /proc/pid/mem is writable by trying to write to | |
4085 | one of our variables via /proc/self/mem. */ | |
4086 | ||
4087 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
4088 | ||
4089 | if (fd == -1) | |
4090 | { | |
4091 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
4092 | safe_strerror (errno), errno); | |
4093 | return *writable; | |
4094 | } | |
4095 | ||
4096 | SCOPE_EXIT { close (fd); }; | |
4097 | ||
4098 | /* This is the variable we try to write to. Note OFFSET below. */ | |
4099 | volatile gdb_byte test_var = 0; | |
4100 | ||
4101 | gdb_byte writebuf[] = {0x55}; | |
4102 | ULONGEST offset = (uintptr_t) &test_var; | |
4103 | ULONGEST xfered_len; | |
4104 | ||
4105 | enum target_xfer_status res | |
4106 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
4107 | offset, 1, &xfered_len); | |
4108 | ||
4109 | if (res == TARGET_XFER_OK) | |
4110 | { | |
4111 | gdb_assert (xfered_len == 1); | |
4112 | gdb_assert (test_var == 0x55); | |
4113 | /* Success. */ | |
4114 | *writable = true; | |
4115 | } | |
4116 | ||
4117 | return *writable; | |
4118 | } | |
4119 | ||
dba24537 AC |
4120 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4121 | ||
4122 | static void | |
4123 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4124 | { | |
4125 | int len = strlen (line) - 1; | |
4126 | const char *p; | |
4127 | int signum; | |
4128 | ||
4129 | if (line[len] != '\n') | |
8a3fe4f8 | 4130 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4131 | |
4132 | p = line; | |
4133 | signum = len * 4; | |
4134 | while (len-- > 0) | |
4135 | { | |
4136 | int digit; | |
4137 | ||
4138 | if (*p >= '0' && *p <= '9') | |
4139 | digit = *p - '0'; | |
4140 | else if (*p >= 'a' && *p <= 'f') | |
4141 | digit = *p - 'a' + 10; | |
4142 | else | |
8a3fe4f8 | 4143 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4144 | |
4145 | signum -= 4; | |
4146 | ||
4147 | if (digit & 1) | |
4148 | sigaddset (sigs, signum + 1); | |
4149 | if (digit & 2) | |
4150 | sigaddset (sigs, signum + 2); | |
4151 | if (digit & 4) | |
4152 | sigaddset (sigs, signum + 3); | |
4153 | if (digit & 8) | |
4154 | sigaddset (sigs, signum + 4); | |
4155 | ||
4156 | p++; | |
4157 | } | |
4158 | } | |
4159 | ||
4160 | /* Find process PID's pending signals from /proc/pid/status and set | |
4161 | SIGS to match. */ | |
4162 | ||
4163 | void | |
3e43a32a MS |
4164 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4165 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4166 | { |
d8d2a3ee | 4167 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4168 | |
4169 | sigemptyset (pending); | |
4170 | sigemptyset (blocked); | |
4171 | sigemptyset (ignored); | |
cde33bf1 | 4172 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4173 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4174 | if (procfile == NULL) |
8a3fe4f8 | 4175 | error (_("Could not open %s"), fname); |
dba24537 | 4176 | |
d419f42d | 4177 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4178 | { |
4179 | /* Normal queued signals are on the SigPnd line in the status | |
4180 | file. However, 2.6 kernels also have a "shared" pending | |
4181 | queue for delivering signals to a thread group, so check for | |
4182 | a ShdPnd line also. | |
4183 | ||
4184 | Unfortunately some Red Hat kernels include the shared pending | |
4185 | queue but not the ShdPnd status field. */ | |
4186 | ||
61012eef | 4187 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4188 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4189 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4190 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4191 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4192 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4193 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4194 | add_line_to_sigset (buffer + 8, ignored); |
4195 | } | |
dba24537 AC |
4196 | } |
4197 | ||
9b409511 | 4198 | static enum target_xfer_status |
f6ac5f3d | 4199 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4200 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4201 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4202 | ULONGEST *xfered_len) | |
07e059b5 | 4203 | { |
07e059b5 VP |
4204 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4205 | ||
9b409511 YQ |
4206 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4207 | if (*xfered_len == 0) | |
4208 | return TARGET_XFER_EOF; | |
4209 | else | |
4210 | return TARGET_XFER_OK; | |
07e059b5 VP |
4211 | } |
4212 | ||
f6ac5f3d PA |
4213 | std::vector<static_tracepoint_marker> |
4214 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4215 | { |
4216 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4217 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4218 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4219 | const char *p = s; |
184ea2f7 | 4220 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4221 | static_tracepoint_marker marker; |
5808517f YQ |
4222 | |
4223 | /* Pause all */ | |
4224 | target_stop (ptid); | |
4225 | ||
81aa19c3 | 4226 | strcpy (s, "qTfSTM"); |
42476b70 | 4227 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4228 | |
1db93f14 TT |
4229 | /* Unpause all. */ |
4230 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4231 | |
4232 | while (*p++ == 'm') | |
4233 | { | |
5808517f YQ |
4234 | do |
4235 | { | |
5d9310c4 | 4236 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4237 | |
5d9310c4 SM |
4238 | if (strid == NULL || marker.str_id == strid) |
4239 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4240 | } |
4241 | while (*p++ == ','); /* comma-separated list */ | |
4242 | ||
81aa19c3 | 4243 | strcpy (s, "qTsSTM"); |
42476b70 | 4244 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4245 | p = s; |
4246 | } | |
4247 | ||
5808517f YQ |
4248 | return markers; |
4249 | } | |
4250 | ||
b84876c2 PA |
4251 | /* target_can_async_p implementation. */ |
4252 | ||
57810aa7 | 4253 | bool |
f6ac5f3d | 4254 | linux_nat_target::can_async_p () |
b84876c2 | 4255 | { |
fce6cd34 AB |
4256 | /* This flag should be checked in the common target.c code. */ |
4257 | gdb_assert (target_async_permitted); | |
4258 | ||
4259 | /* Otherwise, this targets is always able to support async mode. */ | |
4260 | return true; | |
b84876c2 PA |
4261 | } |
4262 | ||
57810aa7 | 4263 | bool |
f6ac5f3d | 4264 | linux_nat_target::supports_non_stop () |
9908b566 | 4265 | { |
f80c8ec4 | 4266 | return true; |
9908b566 VP |
4267 | } |
4268 | ||
fbea99ea PA |
4269 | /* to_always_non_stop_p implementation. */ |
4270 | ||
57810aa7 | 4271 | bool |
f6ac5f3d | 4272 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4273 | { |
f80c8ec4 | 4274 | return true; |
fbea99ea PA |
4275 | } |
4276 | ||
57810aa7 | 4277 | bool |
f6ac5f3d | 4278 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4279 | { |
aee91db3 | 4280 | return true; |
d90e17a7 PA |
4281 | } |
4282 | ||
57810aa7 | 4283 | bool |
f6ac5f3d | 4284 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4285 | { |
f80c8ec4 | 4286 | return true; |
03583c20 UW |
4287 | } |
4288 | ||
7feb7d06 PA |
4289 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4290 | so we notice when any child changes state, and notify the | |
4291 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4292 | above to wait for the arrival of a SIGCHLD. */ | |
4293 | ||
b84876c2 | 4294 | static void |
7feb7d06 | 4295 | sigchld_handler (int signo) |
b84876c2 | 4296 | { |
7feb7d06 PA |
4297 | int old_errno = errno; |
4298 | ||
01124a23 | 4299 | if (debug_linux_nat) |
da5bd37e | 4300 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4301 | |
b146ba14 JB |
4302 | if (signo == SIGCHLD) |
4303 | { | |
4304 | /* Let the event loop know that there are events to handle. */ | |
4305 | linux_nat_target::async_file_mark_if_open (); | |
4306 | } | |
7feb7d06 PA |
4307 | |
4308 | errno = old_errno; | |
4309 | } | |
4310 | ||
4311 | /* Callback registered with the target events file descriptor. */ | |
4312 | ||
4313 | static void | |
4314 | handle_target_event (int error, gdb_client_data client_data) | |
4315 | { | |
b1a35af2 | 4316 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4317 | } |
4318 | ||
b84876c2 PA |
4319 | /* target_async implementation. */ |
4320 | ||
f6ac5f3d | 4321 | void |
4a570176 | 4322 | linux_nat_target::async (bool enable) |
b84876c2 | 4323 | { |
4a570176 | 4324 | if (enable == is_async_p ()) |
b146ba14 JB |
4325 | return; |
4326 | ||
4327 | /* Block child signals while we create/destroy the pipe, as their | |
4328 | handler writes to it. */ | |
4329 | gdb::block_signals blocker; | |
4330 | ||
6a3753b3 | 4331 | if (enable) |
b84876c2 | 4332 | { |
b146ba14 | 4333 | if (!async_file_open ()) |
f34652de | 4334 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4335 | |
4336 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4337 | "linux-nat"); | |
4338 | ||
4339 | /* There may be pending events to handle. Tell the event loop | |
4340 | to poll them. */ | |
4341 | async_file_mark (); | |
b84876c2 PA |
4342 | } |
4343 | else | |
4344 | { | |
b146ba14 JB |
4345 | delete_file_handler (async_wait_fd ()); |
4346 | async_file_close (); | |
b84876c2 | 4347 | } |
b84876c2 PA |
4348 | } |
4349 | ||
a493e3e2 | 4350 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4351 | event came out. */ |
4352 | ||
4c28f408 | 4353 | static int |
d3a70e03 | 4354 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4355 | { |
d90e17a7 | 4356 | if (!lwp->stopped) |
252fbfc8 | 4357 | { |
9327494e | 4358 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4359 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4360 | |
252fbfc8 | 4361 | |
25289eb2 PA |
4362 | if (lwp->last_resume_kind == resume_stop) |
4363 | { | |
9327494e SM |
4364 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4365 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4366 | return 0; |
4367 | } | |
252fbfc8 | 4368 | |
d3a70e03 | 4369 | stop_callback (lwp); |
25289eb2 | 4370 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4371 | } |
4372 | else | |
4373 | { | |
4374 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4375 | |
d90e17a7 PA |
4376 | if (debug_linux_nat) |
4377 | { | |
9213a6d7 | 4378 | if (linux_target->find_thread (lwp->ptid)->stop_requested) |
9327494e | 4379 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4380 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4381 | else |
9327494e | 4382 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4383 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4384 | } |
4385 | } | |
4c28f408 PA |
4386 | return 0; |
4387 | } | |
4388 | ||
f6ac5f3d PA |
4389 | void |
4390 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4391 | { |
b6e52a0b | 4392 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4393 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4394 | } |
4395 | ||
dc146f7c VP |
4396 | /* Return the cached value of the processor core for thread PTID. */ |
4397 | ||
f6ac5f3d PA |
4398 | int |
4399 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4400 | { |
4401 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4402 | |
dc146f7c VP |
4403 | if (info) |
4404 | return info->core; | |
4405 | return -1; | |
4406 | } | |
4407 | ||
7a6a1731 GB |
4408 | /* Implementation of to_filesystem_is_local. */ |
4409 | ||
57810aa7 | 4410 | bool |
f6ac5f3d | 4411 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4412 | { |
4413 | struct inferior *inf = current_inferior (); | |
4414 | ||
4415 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4416 | return true; |
7a6a1731 GB |
4417 | |
4418 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4419 | } | |
4420 | ||
4421 | /* Convert the INF argument passed to a to_fileio_* method | |
4422 | to a process ID suitable for passing to its corresponding | |
4423 | linux_mntns_* function. If INF is non-NULL then the | |
4424 | caller is requesting the filesystem seen by INF. If INF | |
4425 | is NULL then the caller is requesting the filesystem seen | |
4426 | by the GDB. We fall back to GDB's filesystem in the case | |
4427 | that INF is non-NULL but its PID is unknown. */ | |
4428 | ||
4429 | static pid_t | |
4430 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4431 | { | |
4432 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4433 | return getpid (); | |
4434 | else | |
4435 | return inf->pid; | |
4436 | } | |
4437 | ||
4438 | /* Implementation of to_fileio_open. */ | |
4439 | ||
f6ac5f3d PA |
4440 | int |
4441 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4442 | int flags, int mode, int warn_if_slow, | |
b872057a | 4443 | fileio_error *target_errno) |
7a6a1731 GB |
4444 | { |
4445 | int nat_flags; | |
4446 | mode_t nat_mode; | |
4447 | int fd; | |
4448 | ||
4449 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4450 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4451 | { | |
4452 | *target_errno = FILEIO_EINVAL; | |
4453 | return -1; | |
4454 | } | |
4455 | ||
4456 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4457 | filename, nat_flags, nat_mode); | |
4458 | if (fd == -1) | |
4459 | *target_errno = host_to_fileio_error (errno); | |
4460 | ||
4461 | return fd; | |
4462 | } | |
4463 | ||
4464 | /* Implementation of to_fileio_readlink. */ | |
4465 | ||
6b09f134 | 4466 | std::optional<std::string> |
f6ac5f3d | 4467 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, |
b872057a | 4468 | fileio_error *target_errno) |
7a6a1731 GB |
4469 | { |
4470 | char buf[PATH_MAX]; | |
4471 | int len; | |
7a6a1731 GB |
4472 | |
4473 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4474 | filename, buf, sizeof (buf)); | |
4475 | if (len < 0) | |
4476 | { | |
4477 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4478 | return {}; |
7a6a1731 GB |
4479 | } |
4480 | ||
e0d3522b | 4481 | return std::string (buf, len); |
7a6a1731 GB |
4482 | } |
4483 | ||
4484 | /* Implementation of to_fileio_unlink. */ | |
4485 | ||
f6ac5f3d PA |
4486 | int |
4487 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4488 | fileio_error *target_errno) |
7a6a1731 GB |
4489 | { |
4490 | int ret; | |
4491 | ||
4492 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4493 | filename); | |
4494 | if (ret == -1) | |
4495 | *target_errno = host_to_fileio_error (errno); | |
4496 | ||
4497 | return ret; | |
4498 | } | |
4499 | ||
aa01bd36 PA |
4500 | /* Implementation of the to_thread_events method. */ |
4501 | ||
f6ac5f3d PA |
4502 | void |
4503 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4504 | { |
4505 | report_thread_events = enable; | |
4506 | } | |
4507 | ||
25b16bc9 PA |
4508 | bool |
4509 | linux_nat_target::supports_set_thread_options (gdb_thread_options options) | |
4510 | { | |
a51e14ef PA |
4511 | constexpr gdb_thread_options supported_options |
4512 | = GDB_THREAD_OPTION_CLONE | GDB_THREAD_OPTION_EXIT; | |
25b16bc9 PA |
4513 | return ((options & supported_options) == options); |
4514 | } | |
4515 | ||
f6ac5f3d PA |
4516 | linux_nat_target::linux_nat_target () |
4517 | { | |
f973ed9c DJ |
4518 | /* We don't change the stratum; this target will sit at |
4519 | process_stratum and thread_db will set at thread_stratum. This | |
4520 | is a little strange, since this is a multi-threaded-capable | |
4521 | target, but we want to be on the stack below thread_db, and we | |
4522 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4523 | } |
4524 | ||
f865ee35 JK |
4525 | /* See linux-nat.h. */ |
4526 | ||
ef632b4b | 4527 | bool |
f865ee35 | 4528 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) |
9f0bdab8 | 4529 | { |
0acd1110 | 4530 | int pid = get_ptrace_pid (ptid); |
7cc662bc | 4531 | return ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo) == 0; |
9f0bdab8 DJ |
4532 | } |
4533 | ||
7b669087 GB |
4534 | /* See nat/linux-nat.h. */ |
4535 | ||
4536 | ptid_t | |
4537 | current_lwp_ptid (void) | |
4538 | { | |
15a9e13e | 4539 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4540 | return inferior_ptid; |
4541 | } | |
4542 | ||
0ae5b8fa AB |
4543 | /* Implement 'maintenance info linux-lwps'. Displays some basic |
4544 | information about all the current lwp_info objects. */ | |
4545 | ||
4546 | static void | |
4547 | maintenance_info_lwps (const char *arg, int from_tty) | |
4548 | { | |
4549 | if (all_lwps ().size () == 0) | |
4550 | { | |
4551 | gdb_printf ("No Linux LWPs\n"); | |
4552 | return; | |
4553 | } | |
4554 | ||
4555 | /* Start the width at 8 to match the column heading below, then | |
4556 | figure out the widest ptid string. We'll use this to build our | |
4557 | output table below. */ | |
4558 | size_t ptid_width = 8; | |
4559 | for (lwp_info *lp : all_lwps ()) | |
4560 | ptid_width = std::max (ptid_width, lp->ptid.to_string ().size ()); | |
4561 | ||
4562 | /* Setup the table headers. */ | |
4563 | struct ui_out *uiout = current_uiout; | |
4564 | ui_out_emit_table table_emitter (uiout, 2, -1, "linux-lwps"); | |
4565 | uiout->table_header (ptid_width, ui_left, "lwp-ptid", _("LWP Ptid")); | |
4566 | uiout->table_header (9, ui_left, "thread-info", _("Thread ID")); | |
4567 | uiout->table_body (); | |
4568 | ||
4569 | /* Display one table row for each lwp_info. */ | |
4570 | for (lwp_info *lp : all_lwps ()) | |
4571 | { | |
4572 | ui_out_emit_tuple tuple_emitter (uiout, "lwp-entry"); | |
4573 | ||
4574 | thread_info *th = linux_target->find_thread (lp->ptid); | |
4575 | ||
4576 | uiout->field_string ("lwp-ptid", lp->ptid.to_string ().c_str ()); | |
4577 | if (th == nullptr) | |
4578 | uiout->field_string ("thread-info", "None"); | |
4579 | else | |
4580 | uiout->field_string ("thread-info", print_full_thread_id (th)); | |
4581 | ||
4582 | uiout->message ("\n"); | |
4583 | } | |
4584 | } | |
4585 | ||
6c265988 | 4586 | void _initialize_linux_nat (); |
d6b0e80f | 4587 | void |
6c265988 | 4588 | _initialize_linux_nat () |
d6b0e80f | 4589 | { |
8864ef42 | 4590 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b AB |
4591 | &debug_linux_nat, _("\ |
4592 | Set debugging of GNU/Linux native target."), _(" \ | |
4593 | Show debugging of GNU/Linux native target."), _(" \ | |
4594 | When on, print debug messages relating to the GNU/Linux native target."), | |
4595 | nullptr, | |
4596 | show_debug_linux_nat, | |
4597 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4598 | |
7a6a1731 GB |
4599 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4600 | &debug_linux_namespaces, _("\ | |
4601 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4602 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4603 | Enables printf debugging output."), | |
4604 | NULL, | |
4605 | NULL, | |
4606 | &setdebuglist, &showdebuglist); | |
4607 | ||
7feb7d06 PA |
4608 | /* Install a SIGCHLD handler. */ |
4609 | sigchld_action.sa_handler = sigchld_handler; | |
4610 | sigemptyset (&sigchld_action.sa_mask); | |
4611 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4612 | |
4613 | /* Make it the default. */ | |
7feb7d06 | 4614 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4615 | |
4616 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4617 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4618 | sigdelset (&suspend_mask, SIGCHLD); |
4619 | ||
7feb7d06 | 4620 | sigemptyset (&blocked_mask); |
774113b0 PA |
4621 | |
4622 | lwp_lwpid_htab_create (); | |
0ae5b8fa AB |
4623 | |
4624 | add_cmd ("linux-lwps", class_maintenance, maintenance_info_lwps, | |
4625 | _("List the Linux LWPS."), &maintenanceinfolist); | |
d6b0e80f AC |
4626 | } |
4627 | \f | |
4628 | ||
4629 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4630 | the GNU/Linux Threads library and therefore doesn't really belong | |
4631 | here. */ | |
4632 | ||
089436f7 TV |
4633 | /* NPTL reserves the first two RT signals, but does not provide any |
4634 | way for the debugger to query the signal numbers - fortunately | |
4635 | they don't change. */ | |
4636 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4637 | |
089436f7 TV |
4638 | /* See linux-nat.h. */ |
4639 | ||
4640 | unsigned int | |
4641 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4642 | { |
089436f7 TV |
4643 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4644 | } | |
d6b0e80f | 4645 | |
089436f7 TV |
4646 | /* See linux-nat.h. */ |
4647 | ||
4648 | int | |
4649 | lin_thread_get_thread_signal (unsigned int i) | |
4650 | { | |
4651 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4652 | return lin_thread_signals[i]; | |
d6b0e80f | 4653 | } |