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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 | ||
cff068da GB |
271 | \f |
272 | /* LWP accessors. */ | |
273 | ||
274 | /* See nat/linux-nat.h. */ | |
275 | ||
276 | ptid_t | |
277 | ptid_of_lwp (struct lwp_info *lwp) | |
278 | { | |
279 | return lwp->ptid; | |
280 | } | |
281 | ||
282 | /* See nat/linux-nat.h. */ | |
283 | ||
4b134ca1 GB |
284 | void |
285 | lwp_set_arch_private_info (struct lwp_info *lwp, | |
286 | struct arch_lwp_info *info) | |
287 | { | |
288 | lwp->arch_private = info; | |
289 | } | |
290 | ||
291 | /* See nat/linux-nat.h. */ | |
292 | ||
293 | struct arch_lwp_info * | |
294 | lwp_arch_private_info (struct lwp_info *lwp) | |
295 | { | |
296 | return lwp->arch_private; | |
297 | } | |
298 | ||
299 | /* See nat/linux-nat.h. */ | |
300 | ||
cff068da GB |
301 | int |
302 | lwp_is_stopped (struct lwp_info *lwp) | |
303 | { | |
304 | return lwp->stopped; | |
305 | } | |
306 | ||
307 | /* See nat/linux-nat.h. */ | |
308 | ||
309 | enum target_stop_reason | |
310 | lwp_stop_reason (struct lwp_info *lwp) | |
311 | { | |
312 | return lwp->stop_reason; | |
313 | } | |
314 | ||
0e00e962 AA |
315 | /* See nat/linux-nat.h. */ |
316 | ||
317 | int | |
318 | lwp_is_stepping (struct lwp_info *lwp) | |
319 | { | |
320 | return lwp->step; | |
321 | } | |
322 | ||
ae087d01 DJ |
323 | \f |
324 | /* Trivial list manipulation functions to keep track of a list of | |
325 | new stopped processes. */ | |
326 | static void | |
3d799a95 | 327 | add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
ae087d01 | 328 | { |
8d749320 | 329 | struct simple_pid_list *new_pid = XNEW (struct simple_pid_list); |
e0881a8e | 330 | |
ae087d01 | 331 | new_pid->pid = pid; |
3d799a95 | 332 | new_pid->status = status; |
ae087d01 DJ |
333 | new_pid->next = *listp; |
334 | *listp = new_pid; | |
335 | } | |
336 | ||
337 | static int | |
46a96992 | 338 | pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
ae087d01 DJ |
339 | { |
340 | struct simple_pid_list **p; | |
341 | ||
342 | for (p = listp; *p != NULL; p = &(*p)->next) | |
343 | if ((*p)->pid == pid) | |
344 | { | |
345 | struct simple_pid_list *next = (*p)->next; | |
e0881a8e | 346 | |
46a96992 | 347 | *statusp = (*p)->status; |
ae087d01 DJ |
348 | xfree (*p); |
349 | *p = next; | |
350 | return 1; | |
351 | } | |
352 | return 0; | |
353 | } | |
354 | ||
de0d863e DB |
355 | /* Return the ptrace options that we want to try to enable. */ |
356 | ||
357 | static int | |
358 | linux_nat_ptrace_options (int attached) | |
359 | { | |
360 | int options = 0; | |
361 | ||
362 | if (!attached) | |
363 | options |= PTRACE_O_EXITKILL; | |
364 | ||
365 | options |= (PTRACE_O_TRACESYSGOOD | |
366 | | PTRACE_O_TRACEVFORKDONE | |
367 | | PTRACE_O_TRACEVFORK | |
368 | | PTRACE_O_TRACEFORK | |
369 | | PTRACE_O_TRACEEXEC); | |
370 | ||
371 | return options; | |
372 | } | |
373 | ||
1b919490 VB |
374 | /* Initialize ptrace and procfs warnings and check for supported |
375 | ptrace features given PID. | |
beed38b8 JB |
376 | |
377 | ATTACHED should be nonzero iff we attached to the inferior. */ | |
3993f6b1 DJ |
378 | |
379 | static void | |
1b919490 | 380 | linux_init_ptrace_procfs (pid_t pid, int attached) |
3993f6b1 | 381 | { |
de0d863e DB |
382 | int options = linux_nat_ptrace_options (attached); |
383 | ||
384 | linux_enable_event_reporting (pid, options); | |
96d7229d | 385 | linux_ptrace_init_warnings (); |
1b919490 | 386 | linux_proc_init_warnings (); |
9dff6a5d | 387 | proc_mem_file_is_writable (); |
4de4c07c DJ |
388 | } |
389 | ||
f6ac5f3d PA |
390 | linux_nat_target::~linux_nat_target () |
391 | {} | |
392 | ||
393 | void | |
394 | linux_nat_target::post_attach (int pid) | |
4de4c07c | 395 | { |
1b919490 | 396 | linux_init_ptrace_procfs (pid, 1); |
4de4c07c DJ |
397 | } |
398 | ||
200fd287 AB |
399 | /* Implement the virtual inf_ptrace_target::post_startup_inferior method. */ |
400 | ||
f6ac5f3d PA |
401 | void |
402 | linux_nat_target::post_startup_inferior (ptid_t ptid) | |
4de4c07c | 403 | { |
1b919490 | 404 | linux_init_ptrace_procfs (ptid.pid (), 0); |
4de4c07c DJ |
405 | } |
406 | ||
4403d8e9 JK |
407 | /* Return the number of known LWPs in the tgid given by PID. */ |
408 | ||
409 | static int | |
410 | num_lwps (int pid) | |
411 | { | |
412 | int count = 0; | |
4403d8e9 | 413 | |
901b9821 | 414 | for (const lwp_info *lp ATTRIBUTE_UNUSED : all_lwps ()) |
e99b03dc | 415 | if (lp->ptid.pid () == pid) |
4403d8e9 JK |
416 | count++; |
417 | ||
418 | return count; | |
419 | } | |
420 | ||
169bb27b | 421 | /* Deleter for lwp_info unique_ptr specialisation. */ |
4403d8e9 | 422 | |
169bb27b | 423 | struct lwp_deleter |
4403d8e9 | 424 | { |
169bb27b AB |
425 | void operator() (struct lwp_info *lwp) const |
426 | { | |
427 | delete_lwp (lwp->ptid); | |
428 | } | |
429 | }; | |
4403d8e9 | 430 | |
169bb27b AB |
431 | /* A unique_ptr specialisation for lwp_info. */ |
432 | ||
433 | typedef std::unique_ptr<struct lwp_info, lwp_deleter> lwp_info_up; | |
4403d8e9 | 434 | |
82d1f134 | 435 | /* Target hook for follow_fork. */ |
d83ad864 | 436 | |
e97007b6 | 437 | void |
82d1f134 SM |
438 | linux_nat_target::follow_fork (inferior *child_inf, ptid_t child_ptid, |
439 | target_waitkind fork_kind, bool follow_child, | |
440 | bool detach_fork) | |
3993f6b1 | 441 | { |
82d1f134 SM |
442 | inf_ptrace_target::follow_fork (child_inf, child_ptid, fork_kind, |
443 | follow_child, detach_fork); | |
444 | ||
d83ad864 | 445 | if (!follow_child) |
4de4c07c | 446 | { |
3a849a34 SM |
447 | bool has_vforked = fork_kind == TARGET_WAITKIND_VFORKED; |
448 | ptid_t parent_ptid = inferior_ptid; | |
3a849a34 SM |
449 | int parent_pid = parent_ptid.lwp (); |
450 | int child_pid = child_ptid.lwp (); | |
4de4c07c | 451 | |
1777feb0 | 452 | /* We're already attached to the parent, by default. */ |
3a849a34 | 453 | lwp_info *child_lp = add_lwp (child_ptid); |
d83ad864 DB |
454 | child_lp->stopped = 1; |
455 | child_lp->last_resume_kind = resume_stop; | |
4de4c07c | 456 | |
ac264b3b MS |
457 | /* Detach new forked process? */ |
458 | if (detach_fork) | |
f75c00e4 | 459 | { |
95347337 AB |
460 | int child_stop_signal = 0; |
461 | bool detach_child = true; | |
4403d8e9 | 462 | |
169bb27b AB |
463 | /* Move CHILD_LP into a unique_ptr and clear the source pointer |
464 | to prevent us doing anything stupid with it. */ | |
465 | lwp_info_up child_lp_ptr (child_lp); | |
466 | child_lp = nullptr; | |
467 | ||
468 | linux_target->low_prepare_to_resume (child_lp_ptr.get ()); | |
c077881a HZ |
469 | |
470 | /* When debugging an inferior in an architecture that supports | |
471 | hardware single stepping on a kernel without commit | |
472 | 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child | |
473 | process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits | |
474 | set if the parent process had them set. | |
475 | To work around this, single step the child process | |
476 | once before detaching to clear the flags. */ | |
477 | ||
2fd9d7ca PA |
478 | /* Note that we consult the parent's architecture instead of |
479 | the child's because there's no inferior for the child at | |
480 | this point. */ | |
c077881a | 481 | if (!gdbarch_software_single_step_p (target_thread_architecture |
2fd9d7ca | 482 | (parent_ptid))) |
c077881a | 483 | { |
95347337 AB |
484 | int status; |
485 | ||
c077881a HZ |
486 | linux_disable_event_reporting (child_pid); |
487 | if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0) | |
488 | perror_with_name (_("Couldn't do single step")); | |
489 | if (my_waitpid (child_pid, &status, 0) < 0) | |
490 | perror_with_name (_("Couldn't wait vfork process")); | |
95347337 AB |
491 | else |
492 | { | |
493 | detach_child = WIFSTOPPED (status); | |
494 | child_stop_signal = WSTOPSIG (status); | |
495 | } | |
c077881a HZ |
496 | } |
497 | ||
95347337 | 498 | if (detach_child) |
9caaaa83 | 499 | { |
95347337 | 500 | int signo = child_stop_signal; |
9caaaa83 | 501 | |
9caaaa83 PA |
502 | if (signo != 0 |
503 | && !signal_pass_state (gdb_signal_from_host (signo))) | |
504 | signo = 0; | |
505 | ptrace (PTRACE_DETACH, child_pid, 0, signo); | |
8a89ddbd PA |
506 | |
507 | close_proc_mem_file (child_pid); | |
9caaaa83 | 508 | } |
ac264b3b | 509 | } |
9016a515 DJ |
510 | |
511 | if (has_vforked) | |
512 | { | |
a2885186 SM |
513 | lwp_info *parent_lp = find_lwp_pid (parent_ptid); |
514 | linux_nat_debug_printf ("waiting for VFORK_DONE on %d", parent_pid); | |
515 | parent_lp->stopped = 1; | |
6c95b8df | 516 | |
a2885186 SM |
517 | /* We'll handle the VFORK_DONE event like any other |
518 | event, in target_wait. */ | |
9016a515 | 519 | } |
4de4c07c | 520 | } |
3993f6b1 | 521 | else |
4de4c07c | 522 | { |
3ced3da4 | 523 | struct lwp_info *child_lp; |
4de4c07c | 524 | |
82d1f134 | 525 | child_lp = add_lwp (child_ptid); |
3ced3da4 | 526 | child_lp->stopped = 1; |
25289eb2 | 527 | child_lp->last_resume_kind = resume_stop; |
4de4c07c | 528 | } |
4de4c07c DJ |
529 | } |
530 | ||
4de4c07c | 531 | \f |
f6ac5f3d PA |
532 | int |
533 | linux_nat_target::insert_fork_catchpoint (int pid) | |
4de4c07c | 534 | { |
a2885186 | 535 | return 0; |
3993f6b1 DJ |
536 | } |
537 | ||
f6ac5f3d PA |
538 | int |
539 | linux_nat_target::remove_fork_catchpoint (int pid) | |
eb73ad13 PA |
540 | { |
541 | return 0; | |
542 | } | |
543 | ||
f6ac5f3d PA |
544 | int |
545 | linux_nat_target::insert_vfork_catchpoint (int pid) | |
3993f6b1 | 546 | { |
a2885186 | 547 | return 0; |
3993f6b1 DJ |
548 | } |
549 | ||
f6ac5f3d PA |
550 | int |
551 | linux_nat_target::remove_vfork_catchpoint (int pid) | |
eb73ad13 PA |
552 | { |
553 | return 0; | |
554 | } | |
555 | ||
f6ac5f3d PA |
556 | int |
557 | linux_nat_target::insert_exec_catchpoint (int pid) | |
3993f6b1 | 558 | { |
a2885186 | 559 | return 0; |
3993f6b1 DJ |
560 | } |
561 | ||
f6ac5f3d PA |
562 | int |
563 | linux_nat_target::remove_exec_catchpoint (int pid) | |
eb73ad13 PA |
564 | { |
565 | return 0; | |
566 | } | |
567 | ||
f6ac5f3d PA |
568 | int |
569 | linux_nat_target::set_syscall_catchpoint (int pid, bool needed, int any_count, | |
570 | gdb::array_view<const int> syscall_counts) | |
a96d9b2e | 571 | { |
a96d9b2e SDJ |
572 | /* On GNU/Linux, we ignore the arguments. It means that we only |
573 | enable the syscall catchpoints, but do not disable them. | |
77b06cd7 | 574 | |
649a140c | 575 | Also, we do not use the `syscall_counts' information because we do not |
a96d9b2e SDJ |
576 | filter system calls here. We let GDB do the logic for us. */ |
577 | return 0; | |
578 | } | |
579 | ||
774113b0 PA |
580 | /* List of known LWPs, keyed by LWP PID. This speeds up the common |
581 | case of mapping a PID returned from the kernel to our corresponding | |
582 | lwp_info data structure. */ | |
583 | static htab_t lwp_lwpid_htab; | |
584 | ||
585 | /* Calculate a hash from a lwp_info's LWP PID. */ | |
586 | ||
587 | static hashval_t | |
588 | lwp_info_hash (const void *ap) | |
589 | { | |
590 | const struct lwp_info *lp = (struct lwp_info *) ap; | |
e38504b3 | 591 | pid_t pid = lp->ptid.lwp (); |
774113b0 PA |
592 | |
593 | return iterative_hash_object (pid, 0); | |
594 | } | |
595 | ||
596 | /* Equality function for the lwp_info hash table. Compares the LWP's | |
597 | PID. */ | |
598 | ||
599 | static int | |
600 | lwp_lwpid_htab_eq (const void *a, const void *b) | |
601 | { | |
602 | const struct lwp_info *entry = (const struct lwp_info *) a; | |
603 | const struct lwp_info *element = (const struct lwp_info *) b; | |
604 | ||
e38504b3 | 605 | return entry->ptid.lwp () == element->ptid.lwp (); |
774113b0 PA |
606 | } |
607 | ||
608 | /* Create the lwp_lwpid_htab hash table. */ | |
609 | ||
610 | static void | |
611 | lwp_lwpid_htab_create (void) | |
612 | { | |
613 | lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL); | |
614 | } | |
615 | ||
616 | /* Add LP to the hash table. */ | |
617 | ||
618 | static void | |
619 | lwp_lwpid_htab_add_lwp (struct lwp_info *lp) | |
620 | { | |
621 | void **slot; | |
622 | ||
623 | slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT); | |
624 | gdb_assert (slot != NULL && *slot == NULL); | |
625 | *slot = lp; | |
626 | } | |
627 | ||
628 | /* Head of doubly-linked list of known LWPs. Sorted by reverse | |
629 | creation order. This order is assumed in some cases. E.g., | |
630 | reaping status after killing alls lwps of a process: the leader LWP | |
631 | must be reaped last. */ | |
901b9821 SM |
632 | |
633 | static intrusive_list<lwp_info> lwp_list; | |
634 | ||
635 | /* See linux-nat.h. */ | |
636 | ||
637 | lwp_info_range | |
638 | all_lwps () | |
639 | { | |
640 | return lwp_info_range (lwp_list.begin ()); | |
641 | } | |
642 | ||
643 | /* See linux-nat.h. */ | |
644 | ||
645 | lwp_info_safe_range | |
646 | all_lwps_safe () | |
647 | { | |
648 | return lwp_info_safe_range (lwp_list.begin ()); | |
649 | } | |
774113b0 PA |
650 | |
651 | /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */ | |
652 | ||
653 | static void | |
654 | lwp_list_add (struct lwp_info *lp) | |
655 | { | |
901b9821 | 656 | lwp_list.push_front (*lp); |
774113b0 PA |
657 | } |
658 | ||
659 | /* Remove LP from sorted-by-reverse-creation-order doubly-linked | |
660 | list. */ | |
661 | ||
662 | static void | |
663 | lwp_list_remove (struct lwp_info *lp) | |
664 | { | |
665 | /* Remove from sorted-by-creation-order list. */ | |
901b9821 | 666 | lwp_list.erase (lwp_list.iterator_to (*lp)); |
774113b0 PA |
667 | } |
668 | ||
d6b0e80f AC |
669 | \f |
670 | ||
d6b0e80f AC |
671 | /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
672 | _initialize_linux_nat. */ | |
673 | static sigset_t suspend_mask; | |
674 | ||
7feb7d06 PA |
675 | /* Signals to block to make that sigsuspend work. */ |
676 | static sigset_t blocked_mask; | |
677 | ||
678 | /* SIGCHLD action. */ | |
6bd434d6 | 679 | static struct sigaction sigchld_action; |
b84876c2 | 680 | |
7feb7d06 PA |
681 | /* Block child signals (SIGCHLD and linux threads signals), and store |
682 | the previous mask in PREV_MASK. */ | |
84e46146 | 683 | |
7feb7d06 PA |
684 | static void |
685 | block_child_signals (sigset_t *prev_mask) | |
686 | { | |
687 | /* Make sure SIGCHLD is blocked. */ | |
688 | if (!sigismember (&blocked_mask, SIGCHLD)) | |
689 | sigaddset (&blocked_mask, SIGCHLD); | |
690 | ||
21987b9c | 691 | gdb_sigmask (SIG_BLOCK, &blocked_mask, prev_mask); |
7feb7d06 PA |
692 | } |
693 | ||
694 | /* Restore child signals mask, previously returned by | |
695 | block_child_signals. */ | |
696 | ||
697 | static void | |
698 | restore_child_signals_mask (sigset_t *prev_mask) | |
699 | { | |
21987b9c | 700 | gdb_sigmask (SIG_SETMASK, prev_mask, NULL); |
7feb7d06 | 701 | } |
2455069d UW |
702 | |
703 | /* Mask of signals to pass directly to the inferior. */ | |
704 | static sigset_t pass_mask; | |
705 | ||
706 | /* Update signals to pass to the inferior. */ | |
f6ac5f3d | 707 | void |
adc6a863 PA |
708 | linux_nat_target::pass_signals |
709 | (gdb::array_view<const unsigned char> pass_signals) | |
2455069d UW |
710 | { |
711 | int signo; | |
712 | ||
713 | sigemptyset (&pass_mask); | |
714 | ||
715 | for (signo = 1; signo < NSIG; signo++) | |
716 | { | |
2ea28649 | 717 | int target_signo = gdb_signal_from_host (signo); |
adc6a863 | 718 | if (target_signo < pass_signals.size () && pass_signals[target_signo]) |
dda83cd7 | 719 | sigaddset (&pass_mask, signo); |
2455069d UW |
720 | } |
721 | } | |
722 | ||
d6b0e80f AC |
723 | \f |
724 | ||
725 | /* Prototypes for local functions. */ | |
d3a70e03 TT |
726 | static int stop_wait_callback (struct lwp_info *lp); |
727 | static int resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid); | |
ced2dffb | 728 | static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp); |
710151dd | 729 | |
d6b0e80f | 730 | \f |
d6b0e80f | 731 | |
7b50312a PA |
732 | /* Destroy and free LP. */ |
733 | ||
676362df | 734 | lwp_info::~lwp_info () |
7b50312a | 735 | { |
466eecee | 736 | /* Let the arch specific bits release arch_lwp_info. */ |
676362df | 737 | linux_target->low_delete_thread (this->arch_private); |
7b50312a PA |
738 | } |
739 | ||
774113b0 | 740 | /* Traversal function for purge_lwp_list. */ |
d90e17a7 | 741 | |
774113b0 PA |
742 | static int |
743 | lwp_lwpid_htab_remove_pid (void **slot, void *info) | |
d90e17a7 | 744 | { |
774113b0 PA |
745 | struct lwp_info *lp = (struct lwp_info *) *slot; |
746 | int pid = *(int *) info; | |
d90e17a7 | 747 | |
e99b03dc | 748 | if (lp->ptid.pid () == pid) |
d90e17a7 | 749 | { |
774113b0 PA |
750 | htab_clear_slot (lwp_lwpid_htab, slot); |
751 | lwp_list_remove (lp); | |
676362df | 752 | delete lp; |
774113b0 | 753 | } |
d90e17a7 | 754 | |
774113b0 PA |
755 | return 1; |
756 | } | |
d90e17a7 | 757 | |
774113b0 PA |
758 | /* Remove all LWPs belong to PID from the lwp list. */ |
759 | ||
760 | static void | |
761 | purge_lwp_list (int pid) | |
762 | { | |
763 | htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid); | |
d90e17a7 PA |
764 | } |
765 | ||
26cb8b7c PA |
766 | /* Add the LWP specified by PTID to the list. PTID is the first LWP |
767 | in the process. Return a pointer to the structure describing the | |
768 | new LWP. | |
769 | ||
770 | This differs from add_lwp in that we don't let the arch specific | |
771 | bits know about this new thread. Current clients of this callback | |
772 | take the opportunity to install watchpoints in the new thread, and | |
773 | we shouldn't do that for the first thread. If we're spawning a | |
774 | child ("run"), the thread executes the shell wrapper first, and we | |
775 | shouldn't touch it until it execs the program we want to debug. | |
776 | For "attach", it'd be okay to call the callback, but it's not | |
777 | necessary, because watchpoints can't yet have been inserted into | |
778 | the inferior. */ | |
d6b0e80f AC |
779 | |
780 | static struct lwp_info * | |
26cb8b7c | 781 | add_initial_lwp (ptid_t ptid) |
d6b0e80f | 782 | { |
15a9e13e | 783 | gdb_assert (ptid.lwp_p ()); |
d6b0e80f | 784 | |
b0f6c8d2 | 785 | lwp_info *lp = new lwp_info (ptid); |
d6b0e80f | 786 | |
d6b0e80f | 787 | |
774113b0 PA |
788 | /* Add to sorted-by-reverse-creation-order list. */ |
789 | lwp_list_add (lp); | |
790 | ||
791 | /* Add to keyed-by-pid htab. */ | |
792 | lwp_lwpid_htab_add_lwp (lp); | |
d6b0e80f | 793 | |
26cb8b7c PA |
794 | return lp; |
795 | } | |
796 | ||
797 | /* Add the LWP specified by PID to the list. Return a pointer to the | |
798 | structure describing the new LWP. The LWP should already be | |
799 | stopped. */ | |
800 | ||
801 | static struct lwp_info * | |
802 | add_lwp (ptid_t ptid) | |
803 | { | |
804 | struct lwp_info *lp; | |
805 | ||
806 | lp = add_initial_lwp (ptid); | |
807 | ||
6e012a6c PA |
808 | /* Let the arch specific bits know about this new thread. Current |
809 | clients of this callback take the opportunity to install | |
26cb8b7c PA |
810 | watchpoints in the new thread. We don't do this for the first |
811 | thread though. See add_initial_lwp. */ | |
135340af | 812 | linux_target->low_new_thread (lp); |
9f0bdab8 | 813 | |
d6b0e80f AC |
814 | return lp; |
815 | } | |
816 | ||
817 | /* Remove the LWP specified by PID from the list. */ | |
818 | ||
819 | static void | |
820 | delete_lwp (ptid_t ptid) | |
821 | { | |
b0f6c8d2 | 822 | lwp_info dummy (ptid); |
d6b0e80f | 823 | |
b0f6c8d2 | 824 | void **slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT); |
774113b0 PA |
825 | if (slot == NULL) |
826 | return; | |
d6b0e80f | 827 | |
b0f6c8d2 | 828 | lwp_info *lp = *(struct lwp_info **) slot; |
774113b0 | 829 | gdb_assert (lp != NULL); |
d6b0e80f | 830 | |
774113b0 | 831 | htab_clear_slot (lwp_lwpid_htab, slot); |
d6b0e80f | 832 | |
774113b0 PA |
833 | /* Remove from sorted-by-creation-order list. */ |
834 | lwp_list_remove (lp); | |
d6b0e80f | 835 | |
774113b0 | 836 | /* Release. */ |
676362df | 837 | delete lp; |
d6b0e80f AC |
838 | } |
839 | ||
840 | /* Return a pointer to the structure describing the LWP corresponding | |
841 | to PID. If no corresponding LWP could be found, return NULL. */ | |
842 | ||
843 | static struct lwp_info * | |
844 | find_lwp_pid (ptid_t ptid) | |
845 | { | |
d6b0e80f AC |
846 | int lwp; |
847 | ||
15a9e13e | 848 | if (ptid.lwp_p ()) |
e38504b3 | 849 | lwp = ptid.lwp (); |
d6b0e80f | 850 | else |
e99b03dc | 851 | lwp = ptid.pid (); |
d6b0e80f | 852 | |
b0f6c8d2 SM |
853 | lwp_info dummy (ptid_t (0, lwp)); |
854 | return (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy); | |
d6b0e80f AC |
855 | } |
856 | ||
6d4ee8c6 | 857 | /* See nat/linux-nat.h. */ |
d6b0e80f AC |
858 | |
859 | struct lwp_info * | |
d90e17a7 | 860 | iterate_over_lwps (ptid_t filter, |
d3a70e03 | 861 | gdb::function_view<iterate_over_lwps_ftype> callback) |
d6b0e80f | 862 | { |
901b9821 | 863 | for (lwp_info *lp : all_lwps_safe ()) |
d6b0e80f | 864 | { |
26a57c92 | 865 | if (lp->ptid.matches (filter)) |
d90e17a7 | 866 | { |
d3a70e03 | 867 | if (callback (lp) != 0) |
d90e17a7 PA |
868 | return lp; |
869 | } | |
d6b0e80f AC |
870 | } |
871 | ||
872 | return NULL; | |
873 | } | |
874 | ||
2277426b PA |
875 | /* Update our internal state when changing from one checkpoint to |
876 | another indicated by NEW_PTID. We can only switch single-threaded | |
877 | applications, so we only create one new LWP, and the previous list | |
878 | is discarded. */ | |
f973ed9c DJ |
879 | |
880 | void | |
881 | linux_nat_switch_fork (ptid_t new_ptid) | |
882 | { | |
883 | struct lwp_info *lp; | |
884 | ||
e99b03dc | 885 | purge_lwp_list (inferior_ptid.pid ()); |
2277426b | 886 | |
f973ed9c DJ |
887 | lp = add_lwp (new_ptid); |
888 | lp->stopped = 1; | |
e26af52f | 889 | |
2277426b PA |
890 | /* This changes the thread's ptid while preserving the gdb thread |
891 | num. Also changes the inferior pid, while preserving the | |
892 | inferior num. */ | |
5b6d1e4f | 893 | thread_change_ptid (linux_target, inferior_ptid, new_ptid); |
2277426b PA |
894 | |
895 | /* We've just told GDB core that the thread changed target id, but, | |
896 | in fact, it really is a different thread, with different register | |
897 | contents. */ | |
898 | registers_changed (); | |
e26af52f DJ |
899 | } |
900 | ||
e26af52f DJ |
901 | /* Handle the exit of a single thread LP. */ |
902 | ||
903 | static void | |
904 | exit_lwp (struct lwp_info *lp) | |
905 | { | |
9213a6d7 | 906 | struct thread_info *th = linux_target->find_thread (lp->ptid); |
063bfe2e VP |
907 | |
908 | if (th) | |
9d7d58e7 | 909 | delete_thread (th); |
e26af52f DJ |
910 | |
911 | delete_lwp (lp->ptid); | |
912 | } | |
913 | ||
a0ef4274 DJ |
914 | /* Wait for the LWP specified by LP, which we have just attached to. |
915 | Returns a wait status for that LWP, to cache. */ | |
916 | ||
917 | static int | |
22827c51 | 918 | linux_nat_post_attach_wait (ptid_t ptid, int *signalled) |
a0ef4274 | 919 | { |
e38504b3 | 920 | pid_t new_pid, pid = ptid.lwp (); |
a0ef4274 DJ |
921 | int status; |
922 | ||
644cebc9 | 923 | if (linux_proc_pid_is_stopped (pid)) |
a0ef4274 | 924 | { |
9327494e | 925 | linux_nat_debug_printf ("Attaching to a stopped process"); |
a0ef4274 DJ |
926 | |
927 | /* The process is definitely stopped. It is in a job control | |
928 | stop, unless the kernel predates the TASK_STOPPED / | |
929 | TASK_TRACED distinction, in which case it might be in a | |
930 | ptrace stop. Make sure it is in a ptrace stop; from there we | |
931 | can kill it, signal it, et cetera. | |
932 | ||
dda83cd7 | 933 | First make sure there is a pending SIGSTOP. Since we are |
a0ef4274 DJ |
934 | already attached, the process can not transition from stopped |
935 | to running without a PTRACE_CONT; so we know this signal will | |
936 | go into the queue. The SIGSTOP generated by PTRACE_ATTACH is | |
937 | probably already in the queue (unless this kernel is old | |
938 | enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP | |
939 | is not an RT signal, it can only be queued once. */ | |
940 | kill_lwp (pid, SIGSTOP); | |
941 | ||
942 | /* Finally, resume the stopped process. This will deliver the SIGSTOP | |
943 | (or a higher priority signal, just like normal PTRACE_ATTACH). */ | |
944 | ptrace (PTRACE_CONT, pid, 0, 0); | |
945 | } | |
946 | ||
947 | /* Make sure the initial process is stopped. The user-level threads | |
948 | layer might want to poke around in the inferior, and that won't | |
949 | work if things haven't stabilized yet. */ | |
4a6ed09b | 950 | new_pid = my_waitpid (pid, &status, __WALL); |
dacc9cb2 PP |
951 | gdb_assert (pid == new_pid); |
952 | ||
953 | if (!WIFSTOPPED (status)) | |
954 | { | |
955 | /* The pid we tried to attach has apparently just exited. */ | |
9327494e | 956 | linux_nat_debug_printf ("Failed to stop %d: %s", pid, |
8d06918f | 957 | status_to_str (status).c_str ()); |
dacc9cb2 PP |
958 | return status; |
959 | } | |
a0ef4274 DJ |
960 | |
961 | if (WSTOPSIG (status) != SIGSTOP) | |
962 | { | |
963 | *signalled = 1; | |
9327494e | 964 | linux_nat_debug_printf ("Received %s after attaching", |
8d06918f | 965 | status_to_str (status).c_str ()); |
a0ef4274 DJ |
966 | } |
967 | ||
968 | return status; | |
969 | } | |
970 | ||
f6ac5f3d PA |
971 | void |
972 | linux_nat_target::create_inferior (const char *exec_file, | |
973 | const std::string &allargs, | |
974 | char **env, int from_tty) | |
b84876c2 | 975 | { |
41272101 TT |
976 | maybe_disable_address_space_randomization restore_personality |
977 | (disable_randomization); | |
b84876c2 PA |
978 | |
979 | /* The fork_child mechanism is synchronous and calls target_wait, so | |
980 | we have to mask the async mode. */ | |
981 | ||
2455069d | 982 | /* Make sure we report all signals during startup. */ |
adc6a863 | 983 | pass_signals ({}); |
2455069d | 984 | |
f6ac5f3d | 985 | inf_ptrace_target::create_inferior (exec_file, allargs, env, from_tty); |
8a89ddbd PA |
986 | |
987 | open_proc_mem_file (inferior_ptid); | |
b84876c2 PA |
988 | } |
989 | ||
8784d563 PA |
990 | /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not |
991 | already attached. Returns true if a new LWP is found, false | |
992 | otherwise. */ | |
993 | ||
994 | static int | |
995 | attach_proc_task_lwp_callback (ptid_t ptid) | |
996 | { | |
997 | struct lwp_info *lp; | |
998 | ||
999 | /* Ignore LWPs we're already attached to. */ | |
1000 | lp = find_lwp_pid (ptid); | |
1001 | if (lp == NULL) | |
1002 | { | |
e38504b3 | 1003 | int lwpid = ptid.lwp (); |
8784d563 PA |
1004 | |
1005 | if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) | |
1006 | { | |
1007 | int err = errno; | |
1008 | ||
1009 | /* Be quiet if we simply raced with the thread exiting. | |
1010 | EPERM is returned if the thread's task still exists, and | |
1011 | is marked as exited or zombie, as well as other | |
1012 | conditions, so in that case, confirm the status in | |
1013 | /proc/PID/status. */ | |
1014 | if (err == ESRCH | |
1015 | || (err == EPERM && linux_proc_pid_is_gone (lwpid))) | |
1016 | { | |
9327494e SM |
1017 | linux_nat_debug_printf |
1018 | ("Cannot attach to lwp %d: thread is gone (%d: %s)", | |
1019 | lwpid, err, safe_strerror (err)); | |
1020 | ||
8784d563 PA |
1021 | } |
1022 | else | |
1023 | { | |
4d9b86e1 | 1024 | std::string reason |
50fa3001 | 1025 | = linux_ptrace_attach_fail_reason_string (ptid, err); |
4d9b86e1 | 1026 | |
f71f0b0d | 1027 | warning (_("Cannot attach to lwp %d: %s"), |
4d9b86e1 | 1028 | lwpid, reason.c_str ()); |
8784d563 PA |
1029 | } |
1030 | } | |
1031 | else | |
1032 | { | |
9327494e | 1033 | linux_nat_debug_printf ("PTRACE_ATTACH %s, 0, 0 (OK)", |
e53c95d4 | 1034 | ptid.to_string ().c_str ()); |
8784d563 PA |
1035 | |
1036 | lp = add_lwp (ptid); | |
8784d563 PA |
1037 | |
1038 | /* The next time we wait for this LWP we'll see a SIGSTOP as | |
1039 | PTRACE_ATTACH brings it to a halt. */ | |
1040 | lp->signalled = 1; | |
1041 | ||
1042 | /* We need to wait for a stop before being able to make the | |
1043 | next ptrace call on this LWP. */ | |
1044 | lp->must_set_ptrace_flags = 1; | |
026a9174 PA |
1045 | |
1046 | /* So that wait collects the SIGSTOP. */ | |
1047 | lp->resumed = 1; | |
1048 | ||
1049 | /* Also add the LWP to gdb's thread list, in case a | |
1050 | matching libthread_db is not found (or the process uses | |
1051 | raw clone). */ | |
5b6d1e4f | 1052 | add_thread (linux_target, lp->ptid); |
719546c4 SM |
1053 | set_running (linux_target, lp->ptid, true); |
1054 | set_executing (linux_target, lp->ptid, true); | |
8784d563 PA |
1055 | } |
1056 | ||
1057 | return 1; | |
1058 | } | |
1059 | return 0; | |
1060 | } | |
1061 | ||
f6ac5f3d PA |
1062 | void |
1063 | linux_nat_target::attach (const char *args, int from_tty) | |
d6b0e80f AC |
1064 | { |
1065 | struct lwp_info *lp; | |
d6b0e80f | 1066 | int status; |
af990527 | 1067 | ptid_t ptid; |
d6b0e80f | 1068 | |
2455069d | 1069 | /* Make sure we report all signals during attach. */ |
adc6a863 | 1070 | pass_signals ({}); |
2455069d | 1071 | |
a70b8144 | 1072 | try |
87b0bb13 | 1073 | { |
f6ac5f3d | 1074 | inf_ptrace_target::attach (args, from_tty); |
87b0bb13 | 1075 | } |
230d2906 | 1076 | catch (const gdb_exception_error &ex) |
87b0bb13 JK |
1077 | { |
1078 | pid_t pid = parse_pid_to_attach (args); | |
50fa3001 | 1079 | std::string reason = linux_ptrace_attach_fail_reason (pid); |
87b0bb13 | 1080 | |
4d9b86e1 | 1081 | if (!reason.empty ()) |
3d6e9d23 TT |
1082 | throw_error (ex.error, "warning: %s\n%s", reason.c_str (), |
1083 | ex.what ()); | |
7ae1a6a6 | 1084 | else |
3d6e9d23 | 1085 | throw_error (ex.error, "%s", ex.what ()); |
87b0bb13 | 1086 | } |
d6b0e80f | 1087 | |
af990527 PA |
1088 | /* The ptrace base target adds the main thread with (pid,0,0) |
1089 | format. Decorate it with lwp info. */ | |
e99b03dc | 1090 | ptid = ptid_t (inferior_ptid.pid (), |
184ea2f7 | 1091 | inferior_ptid.pid ()); |
5b6d1e4f | 1092 | thread_change_ptid (linux_target, inferior_ptid, ptid); |
af990527 | 1093 | |
9f0bdab8 | 1094 | /* Add the initial process as the first LWP to the list. */ |
26cb8b7c | 1095 | lp = add_initial_lwp (ptid); |
a0ef4274 | 1096 | |
22827c51 | 1097 | status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled); |
dacc9cb2 PP |
1098 | if (!WIFSTOPPED (status)) |
1099 | { | |
1100 | if (WIFEXITED (status)) | |
1101 | { | |
1102 | int exit_code = WEXITSTATUS (status); | |
1103 | ||
223ffa71 | 1104 | target_terminal::ours (); |
bc1e6c81 | 1105 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 PP |
1106 | if (exit_code == 0) |
1107 | error (_("Unable to attach: program exited normally.")); | |
1108 | else | |
1109 | error (_("Unable to attach: program exited with code %d."), | |
1110 | exit_code); | |
1111 | } | |
1112 | else if (WIFSIGNALED (status)) | |
1113 | { | |
2ea28649 | 1114 | enum gdb_signal signo; |
dacc9cb2 | 1115 | |
223ffa71 | 1116 | target_terminal::ours (); |
bc1e6c81 | 1117 | target_mourn_inferior (inferior_ptid); |
dacc9cb2 | 1118 | |
2ea28649 | 1119 | signo = gdb_signal_from_host (WTERMSIG (status)); |
dacc9cb2 PP |
1120 | error (_("Unable to attach: program terminated with signal " |
1121 | "%s, %s."), | |
2ea28649 PA |
1122 | gdb_signal_to_name (signo), |
1123 | gdb_signal_to_string (signo)); | |
dacc9cb2 PP |
1124 | } |
1125 | ||
f34652de | 1126 | internal_error (_("unexpected status %d for PID %ld"), |
e38504b3 | 1127 | status, (long) ptid.lwp ()); |
dacc9cb2 PP |
1128 | } |
1129 | ||
a0ef4274 | 1130 | lp->stopped = 1; |
9f0bdab8 | 1131 | |
8a89ddbd PA |
1132 | open_proc_mem_file (lp->ptid); |
1133 | ||
a0ef4274 | 1134 | /* Save the wait status to report later. */ |
d6b0e80f | 1135 | lp->resumed = 1; |
9327494e | 1136 | linux_nat_debug_printf ("waitpid %ld, saving status %s", |
8d06918f SM |
1137 | (long) lp->ptid.pid (), |
1138 | status_to_str (status).c_str ()); | |
710151dd | 1139 | |
7feb7d06 PA |
1140 | lp->status = status; |
1141 | ||
8784d563 PA |
1142 | /* We must attach to every LWP. If /proc is mounted, use that to |
1143 | find them now. The inferior may be using raw clone instead of | |
1144 | using pthreads. But even if it is using pthreads, thread_db | |
1145 | walks structures in the inferior's address space to find the list | |
1146 | of threads/LWPs, and those structures may well be corrupted. | |
1147 | Note that once thread_db is loaded, we'll still use it to list | |
1148 | threads and associate pthread info with each LWP. */ | |
e99b03dc | 1149 | linux_proc_attach_tgid_threads (lp->ptid.pid (), |
8784d563 | 1150 | attach_proc_task_lwp_callback); |
d6b0e80f AC |
1151 | } |
1152 | ||
4a3ee32a SM |
1153 | /* Ptrace-detach the thread with pid PID. */ |
1154 | ||
1155 | static void | |
1156 | detach_one_pid (int pid, int signo) | |
1157 | { | |
1158 | if (ptrace (PTRACE_DETACH, pid, 0, signo) < 0) | |
1159 | { | |
1160 | int save_errno = errno; | |
1161 | ||
1162 | /* We know the thread exists, so ESRCH must mean the lwp is | |
1163 | zombie. This can happen if one of the already-detached | |
1164 | threads exits the whole thread group. In that case we're | |
1165 | still attached, and must reap the lwp. */ | |
1166 | if (save_errno == ESRCH) | |
1167 | { | |
1168 | int ret, status; | |
1169 | ||
1170 | ret = my_waitpid (pid, &status, __WALL); | |
1171 | if (ret == -1) | |
1172 | { | |
1173 | warning (_("Couldn't reap LWP %d while detaching: %s"), | |
1174 | pid, safe_strerror (errno)); | |
1175 | } | |
1176 | else if (!WIFEXITED (status) && !WIFSIGNALED (status)) | |
1177 | { | |
1178 | warning (_("Reaping LWP %d while detaching " | |
1179 | "returned unexpected status 0x%x"), | |
1180 | pid, status); | |
1181 | } | |
1182 | } | |
1183 | else | |
1184 | error (_("Can't detach %d: %s"), | |
1185 | pid, safe_strerror (save_errno)); | |
1186 | } | |
1187 | else | |
1188 | linux_nat_debug_printf ("PTRACE_DETACH (%d, %s, 0) (OK)", | |
1189 | pid, strsignal (signo)); | |
1190 | } | |
1191 | ||
ced2dffb PA |
1192 | /* Get pending signal of THREAD as a host signal number, for detaching |
1193 | purposes. This is the signal the thread last stopped for, which we | |
1194 | need to deliver to the thread when detaching, otherwise, it'd be | |
1195 | suppressed/lost. */ | |
1196 | ||
a0ef4274 | 1197 | static int |
ced2dffb | 1198 | get_detach_signal (struct lwp_info *lp) |
a0ef4274 | 1199 | { |
a493e3e2 | 1200 | enum gdb_signal signo = GDB_SIGNAL_0; |
ca2163eb PA |
1201 | |
1202 | /* If we paused threads momentarily, we may have stored pending | |
1203 | events in lp->status or lp->waitstatus (see stop_wait_callback), | |
1204 | and GDB core hasn't seen any signal for those threads. | |
1205 | Otherwise, the last signal reported to the core is found in the | |
1206 | thread object's stop_signal. | |
1207 | ||
1208 | There's a corner case that isn't handled here at present. Only | |
1209 | if the thread stopped with a TARGET_WAITKIND_STOPPED does | |
1210 | stop_signal make sense as a real signal to pass to the inferior. | |
1211 | Some catchpoint related events, like | |
1212 | TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set | |
a493e3e2 | 1213 | to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
ca2163eb PA |
1214 | those traps are debug API (ptrace in our case) related and |
1215 | induced; the inferior wouldn't see them if it wasn't being | |
1216 | traced. Hence, we should never pass them to the inferior, even | |
1217 | when set to pass state. Since this corner case isn't handled by | |
1218 | infrun.c when proceeding with a signal, for consistency, neither | |
1219 | do we handle it here (or elsewhere in the file we check for | |
1220 | signal pass state). Normally SIGTRAP isn't set to pass state, so | |
1221 | this is really a corner case. */ | |
1222 | ||
183be222 | 1223 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
a493e3e2 | 1224 | signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
ca2163eb | 1225 | else if (lp->status) |
2ea28649 | 1226 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
00431a78 | 1227 | else |
ca2163eb | 1228 | { |
9213a6d7 | 1229 | thread_info *tp = linux_target->find_thread (lp->ptid); |
e0881a8e | 1230 | |
611841bb | 1231 | if (target_is_non_stop_p () && !tp->executing ()) |
ca2163eb | 1232 | { |
1edb66d8 | 1233 | if (tp->has_pending_waitstatus ()) |
df5ad102 SM |
1234 | { |
1235 | /* If the thread has a pending event, and it was stopped with a | |
287de656 | 1236 | signal, use that signal to resume it. If it has a pending |
df5ad102 SM |
1237 | event of another kind, it was not stopped with a signal, so |
1238 | resume it without a signal. */ | |
1239 | if (tp->pending_waitstatus ().kind () == TARGET_WAITKIND_STOPPED) | |
1240 | signo = tp->pending_waitstatus ().sig (); | |
1241 | else | |
1242 | signo = GDB_SIGNAL_0; | |
1243 | } | |
00431a78 | 1244 | else |
1edb66d8 | 1245 | signo = tp->stop_signal (); |
00431a78 PA |
1246 | } |
1247 | else if (!target_is_non_stop_p ()) | |
1248 | { | |
00431a78 | 1249 | ptid_t last_ptid; |
5b6d1e4f | 1250 | process_stratum_target *last_target; |
00431a78 | 1251 | |
5b6d1e4f | 1252 | get_last_target_status (&last_target, &last_ptid, nullptr); |
e0881a8e | 1253 | |
5b6d1e4f PA |
1254 | if (last_target == linux_target |
1255 | && lp->ptid.lwp () == last_ptid.lwp ()) | |
1edb66d8 | 1256 | signo = tp->stop_signal (); |
4c28f408 | 1257 | } |
ca2163eb | 1258 | } |
4c28f408 | 1259 | |
a493e3e2 | 1260 | if (signo == GDB_SIGNAL_0) |
ca2163eb | 1261 | { |
9327494e | 1262 | linux_nat_debug_printf ("lwp %s has no pending signal", |
e53c95d4 | 1263 | lp->ptid.to_string ().c_str ()); |
ca2163eb PA |
1264 | } |
1265 | else if (!signal_pass_state (signo)) | |
1266 | { | |
9327494e SM |
1267 | linux_nat_debug_printf |
1268 | ("lwp %s had signal %s but it is in no pass state", | |
e53c95d4 | 1269 | lp->ptid.to_string ().c_str (), gdb_signal_to_string (signo)); |
a0ef4274 | 1270 | } |
a0ef4274 | 1271 | else |
4c28f408 | 1272 | { |
9327494e | 1273 | linux_nat_debug_printf ("lwp %s has pending signal %s", |
e53c95d4 | 1274 | lp->ptid.to_string ().c_str (), |
9327494e | 1275 | gdb_signal_to_string (signo)); |
ced2dffb PA |
1276 | |
1277 | return gdb_signal_to_host (signo); | |
4c28f408 | 1278 | } |
a0ef4274 DJ |
1279 | |
1280 | return 0; | |
1281 | } | |
1282 | ||
0d36baa9 | 1283 | /* If LP has a pending fork/vfork/clone status, return it. */ |
ced2dffb | 1284 | |
0d36baa9 PA |
1285 | static gdb::optional<target_waitstatus> |
1286 | get_pending_child_status (lwp_info *lp) | |
d6b0e80f | 1287 | { |
b26b06dd AB |
1288 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1289 | ||
1290 | linux_nat_debug_printf ("lwp %s (stopped = %d)", | |
1291 | lp->ptid.to_string ().c_str (), lp->stopped); | |
1292 | ||
df5ad102 SM |
1293 | /* Check in lwp_info::status. */ |
1294 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1295 | { | |
1296 | int event = linux_ptrace_get_extended_event (lp->status); | |
1297 | ||
0d36baa9 PA |
1298 | if (event == PTRACE_EVENT_FORK |
1299 | || event == PTRACE_EVENT_VFORK | |
1300 | || event == PTRACE_EVENT_CLONE) | |
df5ad102 SM |
1301 | { |
1302 | unsigned long child_pid; | |
1303 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1304 | if (ret == 0) | |
0d36baa9 PA |
1305 | { |
1306 | target_waitstatus ws; | |
1307 | ||
1308 | if (event == PTRACE_EVENT_FORK) | |
1309 | ws.set_forked (ptid_t (child_pid, child_pid)); | |
1310 | else if (event == PTRACE_EVENT_VFORK) | |
1311 | ws.set_vforked (ptid_t (child_pid, child_pid)); | |
1312 | else if (event == PTRACE_EVENT_CLONE) | |
1313 | ws.set_thread_cloned (ptid_t (lp->ptid.pid (), child_pid)); | |
1314 | else | |
1315 | gdb_assert_not_reached ("unhandled"); | |
1316 | ||
1317 | return ws; | |
1318 | } | |
df5ad102 | 1319 | else |
0d36baa9 PA |
1320 | { |
1321 | perror_warning_with_name (_("Failed to retrieve event msg")); | |
1322 | return {}; | |
1323 | } | |
df5ad102 SM |
1324 | } |
1325 | } | |
1326 | ||
1327 | /* Check in lwp_info::waitstatus. */ | |
0d36baa9 PA |
1328 | if (is_new_child_status (lp->waitstatus.kind ())) |
1329 | return lp->waitstatus; | |
df5ad102 | 1330 | |
9213a6d7 | 1331 | thread_info *tp = linux_target->find_thread (lp->ptid); |
df5ad102 | 1332 | |
0d36baa9 PA |
1333 | /* Check in thread_info::pending_waitstatus. */ |
1334 | if (tp->has_pending_waitstatus () | |
1335 | && is_new_child_status (tp->pending_waitstatus ().kind ())) | |
1336 | return tp->pending_waitstatus (); | |
df5ad102 SM |
1337 | |
1338 | /* Check in thread_info::pending_follow. */ | |
0d36baa9 PA |
1339 | if (is_new_child_status (tp->pending_follow.kind ())) |
1340 | return tp->pending_follow; | |
df5ad102 | 1341 | |
0d36baa9 PA |
1342 | return {}; |
1343 | } | |
1344 | ||
1345 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the | |
1346 | signal number that should be passed to the LWP when detaching. | |
1347 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1348 | ||
1349 | static void | |
1350 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
1351 | { | |
1352 | int lwpid = lp->ptid.lwp (); | |
1353 | int signo; | |
1354 | ||
1355 | /* If the lwp/thread we are about to detach has a pending fork/clone | |
1356 | event, there is a process/thread GDB is attached to that the core | |
1357 | of GDB doesn't know about. Detach from it. */ | |
1358 | ||
1359 | gdb::optional<target_waitstatus> ws = get_pending_child_status (lp); | |
1360 | if (ws.has_value ()) | |
1361 | detach_one_pid (ws->child_ptid ().lwp (), 0); | |
d6b0e80f | 1362 | |
a0ef4274 DJ |
1363 | /* If there is a pending SIGSTOP, get rid of it. */ |
1364 | if (lp->signalled) | |
d6b0e80f | 1365 | { |
9327494e | 1366 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1367 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1368 | |
ced2dffb | 1369 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1370 | lp->signalled = 0; |
d6b0e80f AC |
1371 | } |
1372 | ||
ced2dffb | 1373 | if (signo_p == NULL) |
d6b0e80f | 1374 | { |
a0ef4274 | 1375 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1376 | signo = get_detach_signal (lp); |
1377 | } | |
1378 | else | |
1379 | signo = *signo_p; | |
a0ef4274 | 1380 | |
b26b06dd AB |
1381 | linux_nat_debug_printf ("preparing to resume lwp %s (stopped = %d)", |
1382 | lp->ptid.to_string ().c_str (), | |
1383 | lp->stopped); | |
1384 | ||
ced2dffb PA |
1385 | /* Preparing to resume may try to write registers, and fail if the |
1386 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1387 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1388 | try |
ced2dffb | 1389 | { |
135340af | 1390 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1391 | } |
230d2906 | 1392 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1393 | { |
1394 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1395 | throw; |
ced2dffb | 1396 | } |
d6b0e80f | 1397 | |
4a3ee32a | 1398 | detach_one_pid (lwpid, signo); |
ced2dffb PA |
1399 | |
1400 | delete_lwp (lp->ptid); | |
1401 | } | |
d6b0e80f | 1402 | |
ced2dffb | 1403 | static int |
d3a70e03 | 1404 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1405 | { |
1406 | /* We don't actually detach from the thread group leader just yet. | |
1407 | If the thread group exits, we must reap the zombie clone lwps | |
1408 | before we're able to reap the leader. */ | |
e38504b3 | 1409 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1410 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1411 | return 0; |
1412 | } | |
1413 | ||
f6ac5f3d PA |
1414 | void |
1415 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1416 | { |
b26b06dd AB |
1417 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1418 | ||
d90e17a7 | 1419 | struct lwp_info *main_lwp; |
bc09b0c1 | 1420 | int pid = inf->pid; |
a0ef4274 | 1421 | |
ae5e0686 MK |
1422 | /* Don't unregister from the event loop, as there may be other |
1423 | inferiors running. */ | |
b84876c2 | 1424 | |
4c28f408 | 1425 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1426 | thread is stopped to successfully detach. */ |
d3a70e03 | 1427 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1428 | /* ... and wait until all of them have reported back that |
1429 | they're no longer running. */ | |
d3a70e03 | 1430 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1431 | |
e87f0fe8 PA |
1432 | /* We can now safely remove breakpoints. We don't this in earlier |
1433 | in common code because this target doesn't currently support | |
1434 | writing memory while the inferior is running. */ | |
1435 | remove_breakpoints_inf (current_inferior ()); | |
1436 | ||
d3a70e03 | 1437 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f | 1438 | |
fd492bf1 AB |
1439 | /* We have detached from everything except the main thread now, so |
1440 | should only have one thread left. However, in non-stop mode the | |
1441 | main thread might have exited, in which case we'll have no threads | |
1442 | left. */ | |
1443 | gdb_assert (num_lwps (pid) == 1 | |
1444 | || (target_is_non_stop_p () && num_lwps (pid) == 0)); | |
d6b0e80f | 1445 | |
7a7d3353 PA |
1446 | if (forks_exist_p ()) |
1447 | { | |
1448 | /* Multi-fork case. The current inferior_ptid is being detached | |
1449 | from, but there are other viable forks to debug. Detach from | |
1450 | the current fork, and context-switch to the first | |
1451 | available. */ | |
6bd6f3b6 | 1452 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1453 | } |
1454 | else | |
ced2dffb | 1455 | { |
ced2dffb PA |
1456 | target_announce_detach (from_tty); |
1457 | ||
fd492bf1 AB |
1458 | /* In non-stop mode it is possible that the main thread has exited, |
1459 | in which case we don't try to detach. */ | |
1460 | main_lwp = find_lwp_pid (ptid_t (pid)); | |
1461 | if (main_lwp != nullptr) | |
1462 | { | |
1463 | /* Pass on any pending signal for the last LWP. */ | |
1464 | int signo = get_detach_signal (main_lwp); | |
ced2dffb | 1465 | |
fd492bf1 AB |
1466 | detach_one_lwp (main_lwp, &signo); |
1467 | } | |
1468 | else | |
1469 | gdb_assert (target_is_non_stop_p ()); | |
ced2dffb | 1470 | |
f6ac5f3d | 1471 | detach_success (inf); |
ced2dffb | 1472 | } |
05c06f31 | 1473 | |
8a89ddbd | 1474 | close_proc_mem_file (pid); |
d6b0e80f AC |
1475 | } |
1476 | ||
8a99810d PA |
1477 | /* Resume execution of the inferior process. If STEP is nonzero, |
1478 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1479 | ||
1480 | static void | |
23f238d3 PA |
1481 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1482 | enum gdb_signal signo) | |
8a99810d | 1483 | { |
8a99810d | 1484 | lp->step = step; |
9c02b525 PA |
1485 | |
1486 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1487 | We only presently need that if the LWP is stepped though (to | |
1488 | handle the case of stepping a breakpoint instruction). */ | |
1489 | if (step) | |
1490 | { | |
5b6d1e4f | 1491 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1492 | |
1493 | lp->stop_pc = regcache_read_pc (regcache); | |
1494 | } | |
1495 | else | |
1496 | lp->stop_pc = 0; | |
1497 | ||
135340af | 1498 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1499 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1500 | |
1501 | /* Successfully resumed. Clear state that no longer makes sense, | |
1502 | and mark the LWP as running. Must not do this before resuming | |
1503 | otherwise if that fails other code will be confused. E.g., we'd | |
1504 | later try to stop the LWP and hang forever waiting for a stop | |
1505 | status. Note that we must not throw after this is cleared, | |
1506 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1507 | lp->stopped = 0; |
1ad3de98 | 1508 | lp->core = -1; |
23f238d3 | 1509 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1510 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1511 | } |
1512 | ||
23f238d3 PA |
1513 | /* Called when we try to resume a stopped LWP and that errors out. If |
1514 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1515 | or about to become), discard the error, clear any pending status | |
1516 | the LWP may have, and return true (we'll collect the exit status | |
1517 | soon enough). Otherwise, return false. */ | |
1518 | ||
1519 | static int | |
1520 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1521 | { | |
1522 | /* If we get an error after resuming the LWP successfully, we'd | |
1523 | confuse !T state for the LWP being gone. */ | |
1524 | gdb_assert (lp->stopped); | |
1525 | ||
1526 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1527 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1528 | yet fully dead", but already refusing ptrace requests. In that | |
1529 | case the tracee has 'R (Running)' state for a little bit | |
1530 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1531 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1532 | other than ptrace-stopped. */ | |
1533 | ||
1534 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1535 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1536 | { |
1537 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1538 | lp->status = 0; | |
183be222 | 1539 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1540 | return 1; |
1541 | } | |
1542 | return 0; | |
1543 | } | |
1544 | ||
1545 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1546 | disappears while we try to resume it. */ | |
1547 | ||
1548 | static void | |
1549 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1550 | { | |
a70b8144 | 1551 | try |
23f238d3 PA |
1552 | { |
1553 | linux_resume_one_lwp_throw (lp, step, signo); | |
1554 | } | |
230d2906 | 1555 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1556 | { |
1557 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1558 | throw; |
23f238d3 | 1559 | } |
23f238d3 PA |
1560 | } |
1561 | ||
d6b0e80f AC |
1562 | /* Resume LP. */ |
1563 | ||
25289eb2 | 1564 | static void |
e5ef252a | 1565 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1566 | { |
25289eb2 | 1567 | if (lp->stopped) |
6c95b8df | 1568 | { |
5b6d1e4f | 1569 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1570 | |
1571 | if (inf->vfork_child != NULL) | |
1572 | { | |
8a9da63e | 1573 | linux_nat_debug_printf ("Not resuming sibling %s (vfork parent)", |
e53c95d4 | 1574 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1575 | } |
8a99810d | 1576 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1577 | { |
9327494e | 1578 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
e53c95d4 | 1579 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1580 | (signo != GDB_SIGNAL_0 |
1581 | ? strsignal (gdb_signal_to_host (signo)) | |
1582 | : "0"), | |
1583 | step ? "step" : "resume"); | |
25289eb2 | 1584 | |
8a99810d | 1585 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1586 | } |
1587 | else | |
1588 | { | |
9327494e | 1589 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
e53c95d4 | 1590 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1591 | } |
6c95b8df | 1592 | } |
25289eb2 | 1593 | else |
9327494e | 1594 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
e53c95d4 | 1595 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1596 | } |
d6b0e80f | 1597 | |
8817a6f2 PA |
1598 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1599 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1600 | |
25289eb2 | 1601 | static int |
d3a70e03 | 1602 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1603 | { |
e5ef252a PA |
1604 | enum gdb_signal signo = GDB_SIGNAL_0; |
1605 | ||
8817a6f2 PA |
1606 | if (lp == except) |
1607 | return 0; | |
1608 | ||
e5ef252a PA |
1609 | if (lp->stopped) |
1610 | { | |
1611 | struct thread_info *thread; | |
1612 | ||
9213a6d7 | 1613 | thread = linux_target->find_thread (lp->ptid); |
e5ef252a PA |
1614 | if (thread != NULL) |
1615 | { | |
1edb66d8 SM |
1616 | signo = thread->stop_signal (); |
1617 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1618 | } |
1619 | } | |
1620 | ||
1621 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1622 | return 0; |
1623 | } | |
1624 | ||
1625 | static int | |
d3a70e03 | 1626 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1627 | { |
1628 | lp->resumed = 0; | |
25289eb2 | 1629 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1630 | return 0; |
1631 | } | |
1632 | ||
1633 | static int | |
d3a70e03 | 1634 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1635 | { |
1636 | lp->resumed = 1; | |
25289eb2 | 1637 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1638 | return 0; |
1639 | } | |
1640 | ||
f6ac5f3d | 1641 | void |
d51926f0 | 1642 | linux_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1643 | { |
1644 | struct lwp_info *lp; | |
d6b0e80f | 1645 | |
9327494e SM |
1646 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1647 | step ? "step" : "resume", | |
d51926f0 | 1648 | scope_ptid.to_string ().c_str (), |
9327494e SM |
1649 | (signo != GDB_SIGNAL_0 |
1650 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
e53c95d4 | 1651 | inferior_ptid.to_string ().c_str ()); |
76f50ad1 | 1652 | |
7da6a5b9 LM |
1653 | /* Mark the lwps we're resuming as resumed and update their |
1654 | last_resume_kind to resume_continue. */ | |
d51926f0 | 1655 | iterate_over_lwps (scope_ptid, resume_set_callback); |
d6b0e80f | 1656 | |
d51926f0 | 1657 | lp = find_lwp_pid (inferior_ptid); |
9f0bdab8 | 1658 | gdb_assert (lp != NULL); |
d6b0e80f | 1659 | |
9f0bdab8 | 1660 | /* Remember if we're stepping. */ |
25289eb2 | 1661 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1662 | |
9f0bdab8 DJ |
1663 | /* If we have a pending wait status for this thread, there is no |
1664 | point in resuming the process. But first make sure that | |
1665 | linux_nat_wait won't preemptively handle the event - we | |
1666 | should never take this short-circuit if we are going to | |
1667 | leave LP running, since we have skipped resuming all the | |
1668 | other threads. This bit of code needs to be synchronized | |
1669 | with linux_nat_wait. */ | |
76f50ad1 | 1670 | |
9f0bdab8 DJ |
1671 | if (lp->status && WIFSTOPPED (lp->status)) |
1672 | { | |
2455069d UW |
1673 | if (!lp->step |
1674 | && WSTOPSIG (lp->status) | |
1675 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1676 | { |
9327494e SM |
1677 | linux_nat_debug_printf |
1678 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1679 | |
d6b0e80f AC |
1680 | /* FIXME: What should we do if we are supposed to continue |
1681 | this thread with a signal? */ | |
a493e3e2 | 1682 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1683 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1684 | lp->status = 0; |
1685 | } | |
1686 | } | |
76f50ad1 | 1687 | |
8a99810d | 1688 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1689 | { |
1690 | /* FIXME: What should we do if we are supposed to continue | |
1691 | this thread with a signal? */ | |
a493e3e2 | 1692 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1693 | |
57573e54 PA |
1694 | linux_nat_debug_printf ("Short circuiting for status %s", |
1695 | pending_status_str (lp).c_str ()); | |
d6b0e80f | 1696 | |
7feb7d06 PA |
1697 | if (target_can_async_p ()) |
1698 | { | |
4a570176 | 1699 | target_async (true); |
7feb7d06 PA |
1700 | /* Tell the event loop we have something to process. */ |
1701 | async_file_mark (); | |
1702 | } | |
9f0bdab8 | 1703 | return; |
d6b0e80f AC |
1704 | } |
1705 | ||
d51926f0 PA |
1706 | /* No use iterating unless we're resuming other threads. */ |
1707 | if (scope_ptid != lp->ptid) | |
1708 | iterate_over_lwps (scope_ptid, [=] (struct lwp_info *info) | |
1709 | { | |
1710 | return linux_nat_resume_callback (info, lp); | |
1711 | }); | |
d90e17a7 | 1712 | |
9327494e SM |
1713 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1714 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 1715 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1716 | (signo != GDB_SIGNAL_0 |
1717 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1718 | |
2bf6fb9d | 1719 | linux_resume_one_lwp (lp, step, signo); |
d6b0e80f AC |
1720 | } |
1721 | ||
c5f62d5f | 1722 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1723 | |
1724 | static int | |
1725 | kill_lwp (int lwpid, int signo) | |
1726 | { | |
4a6ed09b | 1727 | int ret; |
d6b0e80f | 1728 | |
4a6ed09b PA |
1729 | errno = 0; |
1730 | ret = syscall (__NR_tkill, lwpid, signo); | |
1731 | if (errno == ENOSYS) | |
1732 | { | |
1733 | /* If tkill fails, then we are not using nptl threads, a | |
1734 | configuration we no longer support. */ | |
1735 | perror_with_name (("tkill")); | |
1736 | } | |
1737 | return ret; | |
d6b0e80f AC |
1738 | } |
1739 | ||
ca2163eb PA |
1740 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1741 | event, check if the core is interested in it: if not, ignore the | |
1742 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1743 | syscall entry/exit status, since the ptrace event itself doesn't | |
1744 | indicate it, and report the trap to higher layers. */ | |
1745 | ||
1746 | static int | |
1747 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1748 | { | |
1749 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1750 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
9213a6d7 | 1751 | thread_info *thread = linux_target->find_thread (lp->ptid); |
00431a78 | 1752 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1753 | |
1754 | if (stopping) | |
1755 | { | |
1756 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1757 | makes it so that the LWP reports an immediate syscall return, | |
1758 | followed by the SIGSTOP. Skip seeing that "return" using | |
1759 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1760 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1761 | entry event. If we didn't do this (and returned 0), we'd | |
1762 | leave a syscall entry pending, and our caller, by using | |
1763 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1764 | itself. Later, when the user re-resumes this LWP, we'd see | |
1765 | another syscall entry event and we'd mistake it for a return. | |
1766 | ||
1767 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1768 | (leaving immediately with LWP->signalled set, without issuing | |
1769 | a PTRACE_CONT), it would still be problematic to leave this | |
1770 | syscall enter pending, as later when the thread is resumed, | |
1771 | it would then see the same syscall exit mentioned above, | |
1772 | followed by the delayed SIGSTOP, while the syscall didn't | |
1773 | actually get to execute. It seems it would be even more | |
1774 | confusing to the user. */ | |
1775 | ||
9327494e SM |
1776 | linux_nat_debug_printf |
1777 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1778 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1779 | |
1780 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1781 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1782 | lp->stopped = 0; |
ca2163eb PA |
1783 | return 1; |
1784 | } | |
1785 | ||
bfd09d20 JS |
1786 | /* Always update the entry/return state, even if this particular |
1787 | syscall isn't interesting to the core now. In async mode, | |
1788 | the user could install a new catchpoint for this syscall | |
1789 | between syscall enter/return, and we'll need to know to | |
1790 | report a syscall return if that happens. */ | |
1791 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1792 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1793 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1794 | ||
ca2163eb PA |
1795 | if (catch_syscall_enabled ()) |
1796 | { | |
ca2163eb PA |
1797 | if (catching_syscall_number (syscall_number)) |
1798 | { | |
1799 | /* Alright, an event to report. */ | |
183be222 SM |
1800 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1801 | ourstatus->set_syscall_entry (syscall_number); | |
1802 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1803 | ourstatus->set_syscall_return (syscall_number); | |
1804 | else | |
1805 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1806 | |
9327494e SM |
1807 | linux_nat_debug_printf |
1808 | ("stopping for %s of syscall %d for LWP %ld", | |
1809 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1810 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1811 | ||
ca2163eb PA |
1812 | return 0; |
1813 | } | |
1814 | ||
9327494e SM |
1815 | linux_nat_debug_printf |
1816 | ("ignoring %s of syscall %d for LWP %ld", | |
1817 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1818 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1819 | } |
1820 | else | |
1821 | { | |
1822 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1823 | before on this LWP, it could happen that the user removes all | |
1824 | syscall catchpoints before we get to process this event. | |
1825 | There are two noteworthy issues here: | |
1826 | ||
1827 | - When stopped at a syscall entry event, resuming with | |
1828 | PT_STEP still resumes executing the syscall and reports a | |
1829 | syscall return. | |
1830 | ||
1831 | - Only PT_SYSCALL catches syscall enters. If we last | |
1832 | single-stepped this thread, then this event can't be a | |
1833 | syscall enter. If we last single-stepped this thread, this | |
1834 | has to be a syscall exit. | |
1835 | ||
1836 | The points above mean that the next resume, be it PT_STEP or | |
1837 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1838 | linux_nat_debug_printf |
1839 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1840 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1841 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1842 | } | |
1843 | ||
1844 | /* The core isn't interested in this event. For efficiency, avoid | |
1845 | stopping all threads only to have the core resume them all again. | |
1846 | Since we're not stopping threads, if we're still syscall tracing | |
1847 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1848 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1849 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1850 | ||
8a99810d | 1851 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1852 | return 1; |
1853 | } | |
1854 | ||
0d36baa9 PA |
1855 | /* See target.h. */ |
1856 | ||
1857 | void | |
1858 | linux_nat_target::follow_clone (ptid_t child_ptid) | |
1859 | { | |
1860 | lwp_info *new_lp = add_lwp (child_ptid); | |
1861 | new_lp->stopped = 1; | |
1862 | ||
1863 | /* If the thread_db layer is active, let it record the user | |
1864 | level thread id and status, and add the thread to GDB's | |
1865 | list. */ | |
1866 | if (!thread_db_notice_clone (inferior_ptid, new_lp->ptid)) | |
1867 | { | |
1868 | /* The process is not using thread_db. Add the LWP to | |
1869 | GDB's list. */ | |
1870 | add_thread (linux_target, new_lp->ptid); | |
1871 | } | |
1872 | ||
1873 | /* We just created NEW_LP so it cannot yet contain STATUS. */ | |
1874 | gdb_assert (new_lp->status == 0); | |
1875 | ||
1876 | if (!pull_pid_from_list (&stopped_pids, child_ptid.lwp (), &new_lp->status)) | |
1877 | internal_error (_("no saved status for clone lwp")); | |
1878 | ||
1879 | if (WSTOPSIG (new_lp->status) != SIGSTOP) | |
1880 | { | |
1881 | /* This can happen if someone starts sending signals to | |
1882 | the new thread before it gets a chance to run, which | |
1883 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1884 | This is an unlikely case, and harder to handle for | |
1885 | fork / vfork than for clone, so we do not try - but | |
1886 | we handle it for clone events here. */ | |
1887 | ||
1888 | new_lp->signalled = 1; | |
1889 | ||
1890 | /* Save the wait status to report later. */ | |
1891 | linux_nat_debug_printf | |
1892 | ("waitpid of new LWP %ld, saving status %s", | |
1893 | (long) new_lp->ptid.lwp (), status_to_str (new_lp->status).c_str ()); | |
1894 | } | |
1895 | else | |
1896 | { | |
1897 | new_lp->status = 0; | |
1898 | ||
1899 | if (report_thread_events) | |
1900 | new_lp->waitstatus.set_thread_created (); | |
1901 | } | |
1902 | } | |
1903 | ||
3d799a95 DJ |
1904 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1905 | event, we need to add the new LWP to our list (and not report the | |
1906 | trap to higher layers). This function returns non-zero if the | |
1907 | event should be ignored and we should wait again. If STOPPING is | |
1908 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1909 | |
1910 | static int | |
4dd63d48 | 1911 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1912 | { |
e38504b3 | 1913 | int pid = lp->ptid.lwp (); |
3d799a95 | 1914 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1915 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1916 | |
bfd09d20 JS |
1917 | /* All extended events we currently use are mid-syscall. Only |
1918 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1919 | you have to be using PTRACE_SEIZE to get that. */ | |
1920 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1921 | ||
3d799a95 DJ |
1922 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1923 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1924 | { |
3d799a95 DJ |
1925 | unsigned long new_pid; |
1926 | int ret; | |
1927 | ||
1928 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1929 | |
3d799a95 DJ |
1930 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1931 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1932 | { | |
1933 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1934 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1935 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1936 | if (ret == -1) |
1937 | perror_with_name (_("waiting for new child")); | |
1938 | else if (ret != new_pid) | |
f34652de | 1939 | internal_error (_("wait returned unexpected PID %d"), ret); |
3d799a95 | 1940 | else if (!WIFSTOPPED (status)) |
f34652de | 1941 | internal_error (_("wait returned unexpected status 0x%x"), status); |
3d799a95 DJ |
1942 | } |
1943 | ||
26cb8b7c PA |
1944 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1945 | { | |
0d36baa9 | 1946 | open_proc_mem_file (ptid_t (new_pid, new_pid)); |
8a89ddbd | 1947 | |
26cb8b7c PA |
1948 | /* The arch-specific native code may need to know about new |
1949 | forks even if those end up never mapped to an | |
1950 | inferior. */ | |
135340af | 1951 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1952 | } |
1310c1b0 PFC |
1953 | else if (event == PTRACE_EVENT_CLONE) |
1954 | { | |
1955 | linux_target->low_new_clone (lp, new_pid); | |
1956 | } | |
26cb8b7c | 1957 | |
2277426b | 1958 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1959 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1960 | { |
2277426b PA |
1961 | /* Handle checkpointing by linux-fork.c here as a special |
1962 | case. We don't want the follow-fork-mode or 'catch fork' | |
1963 | to interfere with this. */ | |
1964 | ||
1965 | /* This won't actually modify the breakpoint list, but will | |
1966 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 1967 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
1968 | |
1969 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1970 | if (!find_fork_pid (new_pid)) |
1971 | add_fork (new_pid); | |
2277426b PA |
1972 | |
1973 | /* Report as spurious, so that infrun doesn't want to follow | |
1974 | this fork. We're actually doing an infcall in | |
1975 | linux-fork.c. */ | |
183be222 | 1976 | ourstatus->set_spurious (); |
2277426b PA |
1977 | |
1978 | /* Report the stop to the core. */ | |
1979 | return 0; | |
1980 | } | |
1981 | ||
3d799a95 | 1982 | if (event == PTRACE_EVENT_FORK) |
0d36baa9 | 1983 | ourstatus->set_forked (ptid_t (new_pid, new_pid)); |
3d799a95 | 1984 | else if (event == PTRACE_EVENT_VFORK) |
0d36baa9 | 1985 | ourstatus->set_vforked (ptid_t (new_pid, new_pid)); |
4dd63d48 | 1986 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1987 | { |
9327494e SM |
1988 | linux_nat_debug_printf |
1989 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1990 | |
0d36baa9 PA |
1991 | /* Save the status again, we'll use it in follow_clone. */ |
1992 | add_to_pid_list (&stopped_pids, new_pid, status); | |
4dd63d48 | 1993 | |
0d36baa9 | 1994 | ourstatus->set_thread_cloned (ptid_t (lp->ptid.pid (), new_pid)); |
3d799a95 DJ |
1995 | } |
1996 | ||
1997 | return 0; | |
d6b0e80f AC |
1998 | } |
1999 | ||
3d799a95 DJ |
2000 | if (event == PTRACE_EVENT_EXEC) |
2001 | { | |
9327494e | 2002 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 2003 | |
8a89ddbd PA |
2004 | /* Close the previous /proc/PID/mem file for this inferior, |
2005 | which was using the address space which is now gone. | |
2006 | Reading/writing from this file would return 0/EOF. */ | |
2007 | close_proc_mem_file (lp->ptid.pid ()); | |
2008 | ||
2009 | /* Open a new file for the new address space. */ | |
2010 | open_proc_mem_file (lp->ptid); | |
05c06f31 | 2011 | |
183be222 SM |
2012 | ourstatus->set_execd |
2013 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 2014 | |
8af756ef PA |
2015 | /* The thread that execed must have been resumed, but, when a |
2016 | thread execs, it changes its tid to the tgid, and the old | |
2017 | tgid thread might have not been resumed. */ | |
2018 | lp->resumed = 1; | |
6a534f85 PA |
2019 | |
2020 | /* All other LWPs are gone now. We'll have received a thread | |
2021 | exit notification for all threads other the execing one. | |
2022 | That one, if it wasn't the leader, just silently changes its | |
2023 | tid to the tgid, and the previous leader vanishes. Since | |
2024 | Linux 3.0, the former thread ID can be retrieved with | |
2025 | PTRACE_GETEVENTMSG, but since we support older kernels, don't | |
2026 | bother with it, and just walk the LWP list. Even with | |
2027 | PTRACE_GETEVENTMSG, we'd still need to lookup the | |
2028 | corresponding LWP object, and it would be an extra ptrace | |
2029 | syscall, so this way may even be more efficient. */ | |
2030 | for (lwp_info *other_lp : all_lwps_safe ()) | |
2031 | if (other_lp != lp && other_lp->ptid.pid () == lp->ptid.pid ()) | |
2032 | exit_lwp (other_lp); | |
2033 | ||
6c95b8df PA |
2034 | return 0; |
2035 | } | |
2036 | ||
2037 | if (event == PTRACE_EVENT_VFORK_DONE) | |
2038 | { | |
9327494e | 2039 | linux_nat_debug_printf |
5a0c4a06 SM |
2040 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", |
2041 | lp->ptid.lwp ()); | |
2042 | ourstatus->set_vfork_done (); | |
2043 | return 0; | |
3d799a95 DJ |
2044 | } |
2045 | ||
f34652de | 2046 | internal_error (_("unknown ptrace event %d"), event); |
d6b0e80f AC |
2047 | } |
2048 | ||
9c3a5d93 PA |
2049 | /* Suspend waiting for a signal. We're mostly interested in |
2050 | SIGCHLD/SIGINT. */ | |
2051 | ||
2052 | static void | |
2053 | wait_for_signal () | |
2054 | { | |
9327494e | 2055 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2056 | sigsuspend (&suspend_mask); |
2057 | ||
2058 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2059 | and we're debugging a process that is running on a separate | |
2060 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2061 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2062 | inferior directly.) We must do this here because functions that | |
2063 | need to block waiting for a signal loop forever until there's an | |
2064 | event to report before returning back to the event loop. */ | |
2065 | if (!target_terminal::is_ours ()) | |
2066 | { | |
2067 | if (check_quit_flag ()) | |
2068 | target_pass_ctrlc (); | |
2069 | } | |
2070 | } | |
2071 | ||
d6b0e80f AC |
2072 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2073 | exited. */ | |
2074 | ||
2075 | static int | |
2076 | wait_lwp (struct lwp_info *lp) | |
2077 | { | |
2078 | pid_t pid; | |
432b4d03 | 2079 | int status = 0; |
d6b0e80f | 2080 | int thread_dead = 0; |
432b4d03 | 2081 | sigset_t prev_mask; |
d6b0e80f AC |
2082 | |
2083 | gdb_assert (!lp->stopped); | |
2084 | gdb_assert (lp->status == 0); | |
2085 | ||
432b4d03 JK |
2086 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2087 | block_child_signals (&prev_mask); | |
2088 | ||
2089 | for (;;) | |
d6b0e80f | 2090 | { |
e38504b3 | 2091 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2092 | if (pid == -1 && errno == ECHILD) |
2093 | { | |
2094 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2095 | now because if this was a non-leader thread execing, we |
2096 | won't get an exit event. See comments on exec events at | |
2097 | the top of the file. */ | |
a9f4bb21 | 2098 | thread_dead = 1; |
9327494e | 2099 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2100 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2101 | } |
432b4d03 JK |
2102 | if (pid != 0) |
2103 | break; | |
2104 | ||
2105 | /* Bugs 10970, 12702. | |
2106 | Thread group leader may have exited in which case we'll lock up in | |
2107 | waitpid if there are other threads, even if they are all zombies too. | |
2108 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2109 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2110 | for zombie and running processes. | |
432b4d03 JK |
2111 | |
2112 | As a workaround, check if we're waiting for the thread group leader and | |
2113 | if it's a zombie, and avoid calling waitpid if it is. | |
2114 | ||
2115 | This is racy, what if the tgl becomes a zombie right after we check? | |
2116 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2117 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2118 | |
e38504b3 TT |
2119 | if (lp->ptid.pid () == lp->ptid.lwp () |
2120 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2121 | { |
d6b0e80f | 2122 | thread_dead = 1; |
9327494e | 2123 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2124 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2125 | break; |
d6b0e80f | 2126 | } |
432b4d03 JK |
2127 | |
2128 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2129 | get invoked despite our caller had them intentionally blocked by | |
2130 | block_child_signals. This is sensitive only to the loop of | |
2131 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2132 | again before it gets to sigsuspend so we can safely let the handlers | |
2133 | get executed here. */ | |
9c3a5d93 | 2134 | wait_for_signal (); |
432b4d03 JK |
2135 | } |
2136 | ||
2137 | restore_child_signals_mask (&prev_mask); | |
2138 | ||
d6b0e80f AC |
2139 | if (!thread_dead) |
2140 | { | |
e38504b3 | 2141 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2142 | |
9327494e | 2143 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2144 | lp->ptid.to_string ().c_str (), |
8d06918f | 2145 | status_to_str (status).c_str ()); |
d6b0e80f | 2146 | |
a9f4bb21 PA |
2147 | /* Check if the thread has exited. */ |
2148 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2149 | { | |
aa01bd36 | 2150 | if (report_thread_events |
e38504b3 | 2151 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2152 | { |
9327494e | 2153 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2154 | |
aa01bd36 | 2155 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2156 | process is gone. Store the status to report to the |
2157 | core. Store it in lp->waitstatus, because lp->status | |
2158 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
7509b829 | 2159 | lp->waitstatus = host_status_to_waitstatus (status); |
69dde7dc PA |
2160 | return 0; |
2161 | } | |
2162 | ||
a9f4bb21 | 2163 | thread_dead = 1; |
9327494e | 2164 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2165 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2166 | } |
d6b0e80f AC |
2167 | } |
2168 | ||
2169 | if (thread_dead) | |
2170 | { | |
e26af52f | 2171 | exit_lwp (lp); |
d6b0e80f AC |
2172 | return 0; |
2173 | } | |
2174 | ||
2175 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2176 | lp->stopped = 1; |
d6b0e80f | 2177 | |
8784d563 PA |
2178 | if (lp->must_set_ptrace_flags) |
2179 | { | |
5b6d1e4f | 2180 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2181 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2182 | |
e38504b3 | 2183 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2184 | lp->must_set_ptrace_flags = 0; |
2185 | } | |
2186 | ||
ca2163eb PA |
2187 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2188 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2189 | { | |
2190 | /* No longer need the sysgood bit. The ptrace event ends up | |
2191 | recorded in lp->waitstatus if we care for it. We can carry | |
2192 | on handling the event like a regular SIGTRAP from here | |
2193 | on. */ | |
2194 | status = W_STOPCODE (SIGTRAP); | |
2195 | if (linux_handle_syscall_trap (lp, 1)) | |
2196 | return wait_lwp (lp); | |
2197 | } | |
bfd09d20 JS |
2198 | else |
2199 | { | |
2200 | /* Almost all other ptrace-stops are known to be outside of system | |
2201 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2202 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2203 | } | |
ca2163eb | 2204 | |
d6b0e80f | 2205 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2206 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2207 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2208 | { |
9327494e | 2209 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2210 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2211 | return 0; |
d6b0e80f AC |
2212 | } |
2213 | ||
2214 | return status; | |
2215 | } | |
2216 | ||
2217 | /* Send a SIGSTOP to LP. */ | |
2218 | ||
2219 | static int | |
d3a70e03 | 2220 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2221 | { |
2222 | if (!lp->stopped && !lp->signalled) | |
2223 | { | |
2224 | int ret; | |
2225 | ||
9327494e | 2226 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2227 | lp->ptid.to_string ().c_str ()); |
9327494e | 2228 | |
d6b0e80f | 2229 | errno = 0; |
e38504b3 | 2230 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2231 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2232 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2233 | |
2234 | lp->signalled = 1; | |
2235 | gdb_assert (lp->status == 0); | |
2236 | } | |
2237 | ||
2238 | return 0; | |
2239 | } | |
2240 | ||
7b50312a PA |
2241 | /* Request a stop on LWP. */ |
2242 | ||
2243 | void | |
2244 | linux_stop_lwp (struct lwp_info *lwp) | |
2245 | { | |
d3a70e03 | 2246 | stop_callback (lwp); |
7b50312a PA |
2247 | } |
2248 | ||
2db9a427 PA |
2249 | /* See linux-nat.h */ |
2250 | ||
2251 | void | |
2252 | linux_stop_and_wait_all_lwps (void) | |
2253 | { | |
2254 | /* Stop all LWP's ... */ | |
d3a70e03 | 2255 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2256 | |
2257 | /* ... and wait until all of them have reported back that | |
2258 | they're no longer running. */ | |
d3a70e03 | 2259 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2260 | } |
2261 | ||
2262 | /* See linux-nat.h */ | |
2263 | ||
2264 | void | |
2265 | linux_unstop_all_lwps (void) | |
2266 | { | |
2267 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2268 | [] (struct lwp_info *info) |
2269 | { | |
2270 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2271 | }); | |
2db9a427 PA |
2272 | } |
2273 | ||
57380f4e | 2274 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2275 | |
2276 | static int | |
57380f4e DJ |
2277 | linux_nat_has_pending_sigint (int pid) |
2278 | { | |
2279 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2280 | |
2281 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2282 | ||
2283 | if (sigismember (&pending, SIGINT) | |
2284 | && !sigismember (&ignored, SIGINT)) | |
2285 | return 1; | |
2286 | ||
2287 | return 0; | |
2288 | } | |
2289 | ||
2290 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2291 | ||
2292 | static int | |
d3a70e03 | 2293 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2294 | { |
57380f4e DJ |
2295 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2296 | flag to consume the next one. */ | |
2297 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2298 | && WSTOPSIG (lp->status) == SIGINT) | |
2299 | lp->status = 0; | |
2300 | else | |
2301 | lp->ignore_sigint = 1; | |
2302 | ||
2303 | return 0; | |
2304 | } | |
2305 | ||
2306 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2307 | This function is called after we know the LWP has stopped; if the LWP | |
2308 | stopped before the expected SIGINT was delivered, then it will never have | |
2309 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2310 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2311 | |
57380f4e DJ |
2312 | static void |
2313 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2314 | { | |
2315 | if (!lp->ignore_sigint) | |
2316 | return; | |
2317 | ||
e38504b3 | 2318 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2319 | { |
9327494e | 2320 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2321 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2322 | lp->ignore_sigint = 0; |
2323 | } | |
2324 | } | |
2325 | ||
ebec9a0f PA |
2326 | /* Fetch the possible triggered data watchpoint info and store it in |
2327 | LP. | |
2328 | ||
2329 | On some archs, like x86, that use debug registers to set | |
2330 | watchpoints, it's possible that the way to know which watched | |
2331 | address trapped, is to check the register that is used to select | |
2332 | which address to watch. Problem is, between setting the watchpoint | |
2333 | and reading back which data address trapped, the user may change | |
2334 | the set of watchpoints, and, as a consequence, GDB changes the | |
2335 | debug registers in the inferior. To avoid reading back a stale | |
2336 | stopped-data-address when that happens, we cache in LP the fact | |
2337 | that a watchpoint trapped, and the corresponding data address, as | |
2338 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2339 | registers meanwhile, we have the cached data we can rely on. */ | |
2340 | ||
9c02b525 PA |
2341 | static int |
2342 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2343 | { |
2989a365 | 2344 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2345 | inferior_ptid = lp->ptid; |
2346 | ||
f6ac5f3d | 2347 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2348 | { |
15c66dd6 | 2349 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2350 | lp->stopped_data_address_p |
2351 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2352 | } |
2353 | ||
15c66dd6 | 2354 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2355 | } |
2356 | ||
9c02b525 | 2357 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2358 | |
57810aa7 | 2359 | bool |
f6ac5f3d | 2360 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2361 | { |
2362 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2363 | ||
2364 | gdb_assert (lp != NULL); | |
2365 | ||
15c66dd6 | 2366 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2367 | } |
2368 | ||
57810aa7 | 2369 | bool |
f6ac5f3d | 2370 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2371 | { |
2372 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2373 | ||
2374 | gdb_assert (lp != NULL); | |
2375 | ||
2376 | *addr_p = lp->stopped_data_address; | |
2377 | ||
2378 | return lp->stopped_data_address_p; | |
2379 | } | |
2380 | ||
26ab7092 JK |
2381 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2382 | ||
135340af PA |
2383 | bool |
2384 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2385 | { |
2386 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2387 | } | |
2388 | ||
57380f4e DJ |
2389 | /* Wait until LP is stopped. */ |
2390 | ||
2391 | static int | |
d3a70e03 | 2392 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2393 | { |
5b6d1e4f | 2394 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2395 | |
2396 | /* If this is a vfork parent, bail out, it is not going to report | |
2397 | any SIGSTOP until the vfork is done with. */ | |
2398 | if (inf->vfork_child != NULL) | |
2399 | return 0; | |
2400 | ||
d6b0e80f AC |
2401 | if (!lp->stopped) |
2402 | { | |
2403 | int status; | |
2404 | ||
2405 | status = wait_lwp (lp); | |
2406 | if (status == 0) | |
2407 | return 0; | |
2408 | ||
57380f4e DJ |
2409 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2410 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2411 | { |
57380f4e | 2412 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2413 | |
2414 | errno = 0; | |
e38504b3 | 2415 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2416 | lp->stopped = 0; |
9327494e SM |
2417 | linux_nat_debug_printf |
2418 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2419 | lp->ptid.to_string ().c_str (), |
9327494e | 2420 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2421 | |
d3a70e03 | 2422 | return stop_wait_callback (lp); |
d6b0e80f AC |
2423 | } |
2424 | ||
57380f4e DJ |
2425 | maybe_clear_ignore_sigint (lp); |
2426 | ||
d6b0e80f AC |
2427 | if (WSTOPSIG (status) != SIGSTOP) |
2428 | { | |
e5ef252a | 2429 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2430 | |
9327494e | 2431 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2432 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2433 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2434 | |
2435 | /* Save the sigtrap event. */ | |
2436 | lp->status = status; | |
e5ef252a | 2437 | gdb_assert (lp->signalled); |
e7ad2f14 | 2438 | save_stop_reason (lp); |
d6b0e80f AC |
2439 | } |
2440 | else | |
2441 | { | |
7010835a | 2442 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2443 | |
9327494e | 2444 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2445 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2446 | |
d6b0e80f | 2447 | lp->signalled = 0; |
7010835a AB |
2448 | |
2449 | /* If we are waiting for this stop so we can report the thread | |
2450 | stopped then we need to record this status. Otherwise, we can | |
2451 | now discard this stop event. */ | |
2452 | if (lp->last_resume_kind == resume_stop) | |
2453 | { | |
2454 | lp->status = status; | |
2455 | save_stop_reason (lp); | |
2456 | } | |
d6b0e80f AC |
2457 | } |
2458 | } | |
2459 | ||
2460 | return 0; | |
2461 | } | |
2462 | ||
9c02b525 PA |
2463 | /* Return non-zero if LP has a wait status pending. Discard the |
2464 | pending event and resume the LWP if the event that originally | |
2465 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2466 | |
2467 | static int | |
d3a70e03 | 2468 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2469 | { |
2470 | /* Only report a pending wait status if we pretend that this has | |
2471 | indeed been resumed. */ | |
ca2163eb PA |
2472 | if (!lp->resumed) |
2473 | return 0; | |
2474 | ||
eb54c8bf PA |
2475 | if (!lwp_status_pending_p (lp)) |
2476 | return 0; | |
2477 | ||
15c66dd6 PA |
2478 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2479 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2480 | { |
5b6d1e4f | 2481 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2482 | CORE_ADDR pc; |
2483 | int discard = 0; | |
2484 | ||
9c02b525 PA |
2485 | pc = regcache_read_pc (regcache); |
2486 | ||
2487 | if (pc != lp->stop_pc) | |
2488 | { | |
9327494e | 2489 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2490 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2491 | paddress (current_inferior ()->arch (), |
2492 | lp->stop_pc), | |
2493 | paddress (current_inferior ()->arch (), pc)); | |
9c02b525 PA |
2494 | discard = 1; |
2495 | } | |
faf09f01 PA |
2496 | |
2497 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2498 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2499 | { |
9327494e | 2500 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
e53c95d4 | 2501 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2502 | paddress (current_inferior ()->arch (), |
2503 | lp->stop_pc)); | |
9c02b525 PA |
2504 | |
2505 | discard = 1; | |
2506 | } | |
faf09f01 | 2507 | #endif |
9c02b525 PA |
2508 | |
2509 | if (discard) | |
2510 | { | |
9327494e | 2511 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2512 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2513 | |
2514 | lp->status = 0; | |
2515 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2516 | return 0; | |
2517 | } | |
9c02b525 PA |
2518 | } |
2519 | ||
eb54c8bf | 2520 | return 1; |
d6b0e80f AC |
2521 | } |
2522 | ||
d6b0e80f AC |
2523 | /* Count the LWP's that have had events. */ |
2524 | ||
2525 | static int | |
d3a70e03 | 2526 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2527 | { |
d6b0e80f AC |
2528 | gdb_assert (count != NULL); |
2529 | ||
9c02b525 PA |
2530 | /* Select only resumed LWPs that have an event pending. */ |
2531 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2532 | (*count)++; |
2533 | ||
2534 | return 0; | |
2535 | } | |
2536 | ||
2537 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2538 | ||
2539 | static int | |
d3a70e03 | 2540 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2541 | { |
25289eb2 PA |
2542 | if (lp->last_resume_kind == resume_step |
2543 | && lp->status != 0) | |
d6b0e80f AC |
2544 | return 1; |
2545 | else | |
2546 | return 0; | |
2547 | } | |
2548 | ||
8a99810d PA |
2549 | /* Returns true if LP has a status pending. */ |
2550 | ||
2551 | static int | |
2552 | lwp_status_pending_p (struct lwp_info *lp) | |
2553 | { | |
2554 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2555 | can have pending process exits recorded in lp->status and | |
2556 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2557 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2558 | } |
2559 | ||
b90fc188 | 2560 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2561 | |
2562 | static int | |
d3a70e03 | 2563 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2564 | { |
d6b0e80f AC |
2565 | gdb_assert (selector != NULL); |
2566 | ||
9c02b525 PA |
2567 | /* Select only resumed LWPs that have an event pending. */ |
2568 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2569 | if ((*selector)-- == 0) |
2570 | return 1; | |
2571 | ||
2572 | return 0; | |
2573 | } | |
2574 | ||
e7ad2f14 PA |
2575 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2576 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2577 | and save the result in the LWP's stop_reason field. If it stopped | |
2578 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2579 | architecture. */ | |
9c02b525 | 2580 | |
e7ad2f14 PA |
2581 | static void |
2582 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2583 | { |
e7ad2f14 PA |
2584 | struct regcache *regcache; |
2585 | struct gdbarch *gdbarch; | |
515630c5 | 2586 | CORE_ADDR pc; |
9c02b525 | 2587 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2588 | #if USE_SIGTRAP_SIGINFO |
2589 | siginfo_t siginfo; | |
2590 | #endif | |
9c02b525 | 2591 | |
e7ad2f14 PA |
2592 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2593 | gdb_assert (lp->status != 0); | |
2594 | ||
135340af | 2595 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2596 | return; |
2597 | ||
a9deee17 PA |
2598 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
2599 | if (inf->starting_up) | |
2600 | return; | |
2601 | ||
5b6d1e4f | 2602 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2603 | gdbarch = regcache->arch (); |
e7ad2f14 | 2604 | |
9c02b525 | 2605 | pc = regcache_read_pc (regcache); |
527a273a | 2606 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2607 | |
faf09f01 PA |
2608 | #if USE_SIGTRAP_SIGINFO |
2609 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2610 | { | |
2611 | if (siginfo.si_signo == SIGTRAP) | |
2612 | { | |
e7ad2f14 PA |
2613 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2614 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2615 | { |
e7ad2f14 PA |
2616 | /* The si_code is ambiguous on this arch -- check debug |
2617 | registers. */ | |
2618 | if (!check_stopped_by_watchpoint (lp)) | |
2619 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2620 | } | |
2621 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2622 | { | |
2623 | /* If we determine the LWP stopped for a SW breakpoint, | |
2624 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2625 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2626 | stopped-by-watchpoint as long as there's a watchpoint |
2627 | set. */ | |
faf09f01 | 2628 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2629 | } |
e7ad2f14 | 2630 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2631 | { |
e7ad2f14 PA |
2632 | /* This can indicate either a hardware breakpoint or |
2633 | hardware watchpoint. Check debug registers. */ | |
2634 | if (!check_stopped_by_watchpoint (lp)) | |
2635 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2636 | } |
2bf6fb9d PA |
2637 | else if (siginfo.si_code == TRAP_TRACE) |
2638 | { | |
9327494e | 2639 | linux_nat_debug_printf ("%s stopped by trace", |
e53c95d4 | 2640 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2641 | |
2642 | /* We may have single stepped an instruction that | |
2643 | triggered a watchpoint. In that case, on some | |
2644 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2645 | si_code indicates TRAP_TRACE, and we need to check | |
2646 | the debug registers separately. */ | |
2647 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2648 | } |
faf09f01 PA |
2649 | } |
2650 | } | |
2651 | #else | |
9c02b525 | 2652 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2653 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2654 | sw_bp_pc)) |
710151dd | 2655 | { |
9c02b525 PA |
2656 | /* The LWP was either continued, or stepped a software |
2657 | breakpoint instruction. */ | |
e7ad2f14 PA |
2658 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2659 | } | |
2660 | ||
a01bda52 | 2661 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2662 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2663 | ||
2664 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2665 | check_stopped_by_watchpoint (lp); | |
2666 | #endif | |
2667 | ||
2668 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2669 | { | |
9327494e | 2670 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2671 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2672 | |
2673 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2674 | if (pc != sw_bp_pc) |
2675 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2676 | |
e7ad2f14 PA |
2677 | /* Update this so we record the correct stop PC below. */ |
2678 | pc = sw_bp_pc; | |
710151dd | 2679 | } |
e7ad2f14 | 2680 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2681 | { |
9327494e | 2682 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2683 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2684 | } |
2685 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2686 | { | |
9327494e | 2687 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2688 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2689 | } |
d6b0e80f | 2690 | |
e7ad2f14 | 2691 | lp->stop_pc = pc; |
d6b0e80f AC |
2692 | } |
2693 | ||
faf09f01 PA |
2694 | |
2695 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2696 | ||
57810aa7 | 2697 | bool |
f6ac5f3d | 2698 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2699 | { |
2700 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2701 | ||
2702 | gdb_assert (lp != NULL); | |
2703 | ||
2704 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2705 | } | |
2706 | ||
2707 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2708 | ||
57810aa7 | 2709 | bool |
f6ac5f3d | 2710 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2711 | { |
2712 | return USE_SIGTRAP_SIGINFO; | |
2713 | } | |
2714 | ||
2715 | /* Returns true if the LWP had stopped for a hardware | |
2716 | breakpoint/watchpoint. */ | |
2717 | ||
57810aa7 | 2718 | bool |
f6ac5f3d | 2719 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2720 | { |
2721 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2722 | ||
2723 | gdb_assert (lp != NULL); | |
2724 | ||
2725 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2726 | } | |
2727 | ||
2728 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2729 | ||
57810aa7 | 2730 | bool |
f6ac5f3d | 2731 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2732 | { |
2733 | return USE_SIGTRAP_SIGINFO; | |
2734 | } | |
2735 | ||
d6b0e80f AC |
2736 | /* Select one LWP out of those that have events pending. */ |
2737 | ||
2738 | static void | |
d90e17a7 | 2739 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2740 | { |
2741 | int num_events = 0; | |
2742 | int random_selector; | |
9c02b525 | 2743 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2744 | |
ac264b3b | 2745 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2746 | (*orig_lp)->status = *status; |
2747 | ||
9c02b525 PA |
2748 | /* In all-stop, give preference to the LWP that is being |
2749 | single-stepped. There will be at most one, and it will be the | |
2750 | LWP that the core is most interested in. If we didn't do this, | |
2751 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2752 | the core later continues the previously-stepped thread, as | |
2753 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2754 | having stepped the thread, wouldn't understand what the trap was | |
2755 | for, and therefore would report it to the user as a random | |
2756 | signal. */ | |
fbea99ea | 2757 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2758 | { |
d3a70e03 | 2759 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2760 | if (event_lp != NULL) |
2761 | { | |
9327494e | 2762 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2763 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2764 | } |
d6b0e80f | 2765 | } |
9c02b525 PA |
2766 | |
2767 | if (event_lp == NULL) | |
d6b0e80f | 2768 | { |
9c02b525 | 2769 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2770 | |
9c02b525 | 2771 | /* First see how many events we have. */ |
d3a70e03 TT |
2772 | iterate_over_lwps (filter, |
2773 | [&] (struct lwp_info *info) | |
2774 | { | |
2775 | return count_events_callback (info, &num_events); | |
2776 | }); | |
8bf3b159 | 2777 | gdb_assert (num_events > 0); |
d6b0e80f | 2778 | |
9c02b525 PA |
2779 | /* Now randomly pick a LWP out of those that have had |
2780 | events. */ | |
d6b0e80f AC |
2781 | random_selector = (int) |
2782 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2783 | ||
9327494e SM |
2784 | if (num_events > 1) |
2785 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2786 | num_events, random_selector); | |
d6b0e80f | 2787 | |
d3a70e03 TT |
2788 | event_lp |
2789 | = (iterate_over_lwps | |
2790 | (filter, | |
2791 | [&] (struct lwp_info *info) | |
2792 | { | |
2793 | return select_event_lwp_callback (info, | |
2794 | &random_selector); | |
2795 | })); | |
d6b0e80f AC |
2796 | } |
2797 | ||
2798 | if (event_lp != NULL) | |
2799 | { | |
2800 | /* Switch the event LWP. */ | |
2801 | *orig_lp = event_lp; | |
2802 | *status = event_lp->status; | |
2803 | } | |
2804 | ||
2805 | /* Flush the wait status for the event LWP. */ | |
2806 | (*orig_lp)->status = 0; | |
2807 | } | |
2808 | ||
2809 | /* Return non-zero if LP has been resumed. */ | |
2810 | ||
2811 | static int | |
d3a70e03 | 2812 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2813 | { |
2814 | return lp->resumed; | |
2815 | } | |
2816 | ||
02f3fc28 | 2817 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2818 | |
897608ed SM |
2819 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2820 | ||
2821 | static void | |
9c02b525 | 2822 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2823 | { |
2824 | struct lwp_info *lp; | |
89a5711c | 2825 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2826 | |
f2907e49 | 2827 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2828 | |
1abeb1e9 PA |
2829 | /* Check for events reported by anything not in our LWP list. */ |
2830 | if (lp == nullptr) | |
0e5bf2a8 | 2831 | { |
1abeb1e9 PA |
2832 | if (WIFSTOPPED (status)) |
2833 | { | |
2834 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2835 | { | |
2836 | /* A non-leader thread exec'ed after we've seen the | |
2837 | leader zombie, and removed it from our lists (in | |
2838 | check_zombie_leaders). The non-leader thread changes | |
2839 | its tid to the tgid. */ | |
2840 | linux_nat_debug_printf | |
2841 | ("Re-adding thread group leader LWP %d after exec.", | |
2842 | lwpid); | |
0e5bf2a8 | 2843 | |
1abeb1e9 PA |
2844 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2845 | lp->stopped = 1; | |
2846 | lp->resumed = 1; | |
2847 | add_thread (linux_target, lp->ptid); | |
2848 | } | |
2849 | else | |
2850 | { | |
2851 | /* A process we are controlling has forked and the new | |
2852 | child's stop was reported to us by the kernel. Save | |
2853 | its PID and go back to waiting for the fork event to | |
2854 | be reported - the stopped process might be returned | |
2855 | from waitpid before or after the fork event is. */ | |
2856 | linux_nat_debug_printf | |
2857 | ("Saving LWP %d status %s in stopped_pids list", | |
2858 | lwpid, status_to_str (status).c_str ()); | |
2859 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2860 | } | |
2861 | } | |
2862 | else | |
2863 | { | |
2864 | /* Don't report an event for the exit of an LWP not in our | |
2865 | list, i.e. not part of any inferior we're debugging. | |
2866 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
2867 | forked and then it exits. However, note that we may have |
2868 | earlier deleted a leader of an inferior we're debugging, | |
2869 | in check_zombie_leaders. Re-add it back here if so. */ | |
2870 | for (inferior *inf : all_inferiors (linux_target)) | |
2871 | { | |
2872 | if (inf->pid == lwpid) | |
2873 | { | |
2874 | linux_nat_debug_printf | |
2875 | ("Re-adding thread group leader LWP %d after exit.", | |
2876 | lwpid); | |
2877 | ||
2878 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
2879 | lp->resumed = 1; | |
2880 | add_thread (linux_target, lp->ptid); | |
2881 | break; | |
2882 | } | |
2883 | } | |
1abeb1e9 | 2884 | } |
0e5bf2a8 | 2885 | |
1abeb1e9 PA |
2886 | if (lp == nullptr) |
2887 | return; | |
02f3fc28 PA |
2888 | } |
2889 | ||
8817a6f2 PA |
2890 | /* This LWP is stopped now. (And if dead, this prevents it from |
2891 | ever being continued.) */ | |
2892 | lp->stopped = 1; | |
2893 | ||
8784d563 PA |
2894 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2895 | { | |
5b6d1e4f | 2896 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2897 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2898 | |
e38504b3 | 2899 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2900 | lp->must_set_ptrace_flags = 0; |
2901 | } | |
2902 | ||
ca2163eb PA |
2903 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2904 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2905 | { | |
2906 | /* No longer need the sysgood bit. The ptrace event ends up | |
2907 | recorded in lp->waitstatus if we care for it. We can carry | |
2908 | on handling the event like a regular SIGTRAP from here | |
2909 | on. */ | |
2910 | status = W_STOPCODE (SIGTRAP); | |
2911 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2912 | return; |
ca2163eb | 2913 | } |
bfd09d20 JS |
2914 | else |
2915 | { | |
2916 | /* Almost all other ptrace-stops are known to be outside of system | |
2917 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2918 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2919 | } | |
02f3fc28 | 2920 | |
ca2163eb | 2921 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2922 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2923 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2924 | { |
9327494e SM |
2925 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2926 | ||
4dd63d48 | 2927 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2928 | return; |
02f3fc28 PA |
2929 | } |
2930 | ||
2931 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2932 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2933 | { | |
6cf20c46 | 2934 | if (!report_thread_events && !is_leader (lp)) |
02f3fc28 | 2935 | { |
9327494e | 2936 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2937 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2938 | |
6cf20c46 | 2939 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
2940 | was not the end of the debugged application and should be |
2941 | ignored. */ | |
2942 | exit_lwp (lp); | |
897608ed | 2943 | return; |
02f3fc28 PA |
2944 | } |
2945 | ||
77598427 PA |
2946 | /* Note that even if the leader was ptrace-stopped, it can still |
2947 | exit, if e.g., some other thread brings down the whole | |
2948 | process (calls `exit'). So don't assert that the lwp is | |
2949 | resumed. */ | |
9327494e SM |
2950 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2951 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2952 | |
9c02b525 PA |
2953 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2954 | lp->signalled = 0; | |
2955 | ||
2956 | /* Store the pending event in the waitstatus, because | |
2957 | W_EXITCODE(0,0) == 0. */ | |
7509b829 | 2958 | lp->waitstatus = host_status_to_waitstatus (status); |
897608ed | 2959 | return; |
02f3fc28 PA |
2960 | } |
2961 | ||
02f3fc28 PA |
2962 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2963 | an attempt to stop an LWP. */ | |
2964 | if (lp->signalled | |
2965 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2966 | { | |
02f3fc28 PA |
2967 | lp->signalled = 0; |
2968 | ||
2bf6fb9d | 2969 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2970 | { |
9327494e | 2971 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 2972 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
2973 | } |
2974 | else | |
2975 | { | |
2976 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2977 | |
9327494e SM |
2978 | linux_nat_debug_printf |
2979 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2980 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2981 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 2982 | |
2bf6fb9d | 2983 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2984 | gdb_assert (lp->resumed); |
897608ed | 2985 | return; |
25289eb2 | 2986 | } |
02f3fc28 PA |
2987 | } |
2988 | ||
57380f4e DJ |
2989 | /* Make sure we don't report a SIGINT that we have already displayed |
2990 | for another thread. */ | |
2991 | if (lp->ignore_sigint | |
2992 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2993 | { | |
9327494e | 2994 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 2995 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2996 | |
2997 | /* This is a delayed SIGINT. */ | |
2998 | lp->ignore_sigint = 0; | |
2999 | ||
8a99810d | 3000 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
3001 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
3002 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3003 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
3004 | gdb_assert (lp->resumed); |
3005 | ||
3006 | /* Discard the event. */ | |
897608ed | 3007 | return; |
57380f4e DJ |
3008 | } |
3009 | ||
9c02b525 PA |
3010 | /* Don't report signals that GDB isn't interested in, such as |
3011 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 3012 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
3013 | performance with heavily multi-threaded programs, especially when |
3014 | they're using a high frequency timer, we'd better avoid it if we | |
3015 | can. */ | |
3016 | if (WIFSTOPPED (status)) | |
3017 | { | |
3018 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
3019 | ||
fbea99ea | 3020 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
3021 | { |
3022 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
3023 | to implement target_stop (see linux_nat_stop) in | |
3024 | non-stop. */ | |
3025 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
3026 | { | |
3027 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
3028 | forwarded to the entire process group, that is, all LWPs | |
3029 | will receive it - unless they're using CLONE_THREAD to | |
3030 | share signals. Since we only want to report it once, we | |
3031 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 3032 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
3033 | lp->ignore_sigint = 0; |
3034 | } | |
3035 | else | |
3036 | maybe_clear_ignore_sigint (lp); | |
3037 | } | |
3038 | ||
3039 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3040 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3041 | except signals that might be caused by a breakpoint, or SIGSTOP |
3042 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3043 | if (!lp->step |
c9587f88 | 3044 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3045 | && (WSTOPSIG (status) != SIGSTOP |
9213a6d7 | 3046 | || !linux_target->find_thread (lp->ptid)->stop_requested) |
c9587f88 | 3047 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3048 | { |
3049 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3050 | linux_nat_debug_printf |
3051 | ("%s %s, %s (preempt 'handle')", | |
3052 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3053 | lp->ptid.to_string ().c_str (), |
9327494e SM |
3054 | (signo != GDB_SIGNAL_0 |
3055 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3056 | return; |
9c02b525 PA |
3057 | } |
3058 | } | |
3059 | ||
02f3fc28 PA |
3060 | /* An interesting event. */ |
3061 | gdb_assert (lp); | |
ca2163eb | 3062 | lp->status = status; |
e7ad2f14 | 3063 | save_stop_reason (lp); |
02f3fc28 PA |
3064 | } |
3065 | ||
0e5bf2a8 PA |
3066 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3067 | their exits until all other threads in the group have exited. */ | |
3068 | ||
3069 | static void | |
3070 | check_zombie_leaders (void) | |
3071 | { | |
08036331 | 3072 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3073 | { |
3074 | struct lwp_info *leader_lp; | |
3075 | ||
3076 | if (inf->pid == 0) | |
3077 | continue; | |
3078 | ||
f2907e49 | 3079 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3080 | if (leader_lp != NULL |
3081 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3082 | have raced with the inferior simply exiting. Note this |
3083 | isn't a watertight check. If the inferior is | |
3084 | multi-threaded and is exiting, it may be we see the | |
3085 | leader as zombie before we reap all the non-leader | |
3086 | threads. See comments below. */ | |
0e5bf2a8 | 3087 | && num_lwps (inf->pid) > 1 |
5f572dec | 3088 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3089 | { |
6cf20c46 PA |
3090 | /* A zombie leader in a multi-threaded program can mean one |
3091 | of three things: | |
3092 | ||
3093 | #1 - Only the leader exited, not the whole program, e.g., | |
3094 | with pthread_exit. Since we can't reap the leader's exit | |
3095 | status until all other threads are gone and reaped too, | |
3096 | we want to delete the zombie leader right away, as it | |
3097 | can't be debugged, we can't read its registers, etc. | |
3098 | This is the main reason we check for zombie leaders | |
3099 | disappearing. | |
3100 | ||
3101 | #2 - The whole thread-group/process exited (a group exit, | |
3102 | via e.g. exit(3), and there is (or will be shortly) an | |
3103 | exit reported for each thread in the process, and then | |
3104 | finally an exit for the leader once the non-leaders are | |
3105 | reaped. | |
3106 | ||
3107 | #3 - There are 3 or more threads in the group, and a | |
3108 | thread other than the leader exec'd. See comments on | |
3109 | exec events at the top of the file. | |
3110 | ||
3111 | Ideally we would never delete the leader for case #2. | |
3112 | Instead, we want to collect the exit status of each | |
3113 | non-leader thread, and then finally collect the exit | |
3114 | status of the leader as normal and use its exit code as | |
3115 | whole-process exit code. Unfortunately, there's no | |
3116 | race-free way to distinguish cases #1 and #2. We can't | |
3117 | assume the exit events for the non-leaders threads are | |
3118 | already pending in the kernel, nor can we assume the | |
3119 | non-leader threads are in zombie state already. Between | |
3120 | the leader becoming zombie and the non-leaders exiting | |
3121 | and becoming zombie themselves, there's a small time | |
3122 | window, so such a check would be racy. Temporarily | |
3123 | pausing all threads and checking to see if all threads | |
3124 | exit or not before re-resuming them would work in the | |
3125 | case that all threads are running right now, but it | |
3126 | wouldn't work if some thread is currently already | |
3127 | ptrace-stopped, e.g., due to scheduler-locking. | |
3128 | ||
3129 | So what we do is we delete the leader anyhow, and then | |
3130 | later on when we see its exit status, we re-add it back. | |
3131 | We also make sure that we only report a whole-process | |
3132 | exit when we see the leader exiting, as opposed to when | |
3133 | the last LWP in the LWP list exits, which can be a | |
3134 | non-leader if we deleted the leader here. */ | |
9327494e | 3135 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3136 | "(it exited, or another thread execd), " |
3137 | "deleting it.", | |
9327494e | 3138 | inf->pid); |
0e5bf2a8 PA |
3139 | exit_lwp (leader_lp); |
3140 | } | |
3141 | } | |
3142 | } | |
3143 | ||
aa01bd36 PA |
3144 | /* Convenience function that is called when the kernel reports an exit |
3145 | event. This decides whether to report the event to GDB as a | |
3146 | process exit event, a thread exit event, or to suppress the | |
3147 | event. */ | |
3148 | ||
3149 | static ptid_t | |
3150 | filter_exit_event (struct lwp_info *event_child, | |
3151 | struct target_waitstatus *ourstatus) | |
3152 | { | |
3153 | ptid_t ptid = event_child->ptid; | |
3154 | ||
6cf20c46 | 3155 | if (!is_leader (event_child)) |
aa01bd36 PA |
3156 | { |
3157 | if (report_thread_events) | |
183be222 | 3158 | ourstatus->set_thread_exited (0); |
aa01bd36 | 3159 | else |
183be222 | 3160 | ourstatus->set_ignore (); |
aa01bd36 PA |
3161 | |
3162 | exit_lwp (event_child); | |
3163 | } | |
3164 | ||
3165 | return ptid; | |
3166 | } | |
3167 | ||
d6b0e80f | 3168 | static ptid_t |
f6ac5f3d | 3169 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3170 | target_wait_flags target_options) |
d6b0e80f | 3171 | { |
b26b06dd AB |
3172 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3173 | ||
fc9b8e47 | 3174 | sigset_t prev_mask; |
4b60df3d | 3175 | enum resume_kind last_resume_kind; |
12d9289a | 3176 | struct lwp_info *lp; |
12d9289a | 3177 | int status; |
d6b0e80f | 3178 | |
f973ed9c DJ |
3179 | /* The first time we get here after starting a new inferior, we may |
3180 | not have added it to the LWP list yet - this is the earliest | |
3181 | moment at which we know its PID. */ | |
677c92fe | 3182 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3183 | { |
677c92fe | 3184 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3185 | |
677c92fe SM |
3186 | /* Upgrade the main thread's ptid. */ |
3187 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3188 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3189 | lp->resumed = 1; |
3190 | } | |
3191 | ||
12696c10 | 3192 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3193 | block_child_signals (&prev_mask); |
d6b0e80f | 3194 | |
d6b0e80f | 3195 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3196 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3197 | if (lp != NULL) |
d6b0e80f | 3198 | { |
9327494e | 3199 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
57573e54 | 3200 | pending_status_str (lp).c_str (), |
e53c95d4 | 3201 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3202 | } |
3203 | ||
9c02b525 PA |
3204 | /* But if we don't find a pending event, we'll have to wait. Always |
3205 | pull all events out of the kernel. We'll randomly select an | |
3206 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3207 | |
d90e17a7 | 3208 | while (lp == NULL) |
d6b0e80f AC |
3209 | { |
3210 | pid_t lwpid; | |
3211 | ||
0e5bf2a8 PA |
3212 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3213 | quirks: | |
3214 | ||
3215 | - If the thread group leader exits while other threads in the | |
3216 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3217 | waitpid won't return an exit status until the other threads | |
85102364 | 3218 | in the group are reaped. |
0e5bf2a8 PA |
3219 | |
3220 | - When a non-leader thread execs, that thread just vanishes | |
3221 | without reporting an exit (so we'd hang if we waited for it | |
3222 | explicitly in that case). The exec event is reported to | |
3223 | the TGID pid. */ | |
3224 | ||
3225 | errno = 0; | |
4a6ed09b | 3226 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3227 | |
9327494e SM |
3228 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3229 | lwpid, | |
3230 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3231 | |
d6b0e80f AC |
3232 | if (lwpid > 0) |
3233 | { | |
9327494e | 3234 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3235 | (long) lwpid, |
3236 | status_to_str (status).c_str ()); | |
d6b0e80f | 3237 | |
9c02b525 | 3238 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3239 | /* Retry until nothing comes out of waitpid. A single |
3240 | SIGCHLD can indicate more than one child stopped. */ | |
3241 | continue; | |
d6b0e80f AC |
3242 | } |
3243 | ||
20ba1ce6 PA |
3244 | /* Now that we've pulled all events out of the kernel, resume |
3245 | LWPs that don't have an interesting event to report. */ | |
3246 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3247 | [] (struct lwp_info *info) |
3248 | { | |
3249 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3250 | }); | |
20ba1ce6 PA |
3251 | |
3252 | /* ... and find an LWP with a status to report to the core, if | |
3253 | any. */ | |
d3a70e03 | 3254 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3255 | if (lp != NULL) |
3256 | break; | |
3257 | ||
0e5bf2a8 PA |
3258 | /* Check for zombie thread group leaders. Those can't be reaped |
3259 | until all other threads in the thread group are. */ | |
3260 | check_zombie_leaders (); | |
d6b0e80f | 3261 | |
0e5bf2a8 PA |
3262 | /* If there are no resumed children left, bail. We'd be stuck |
3263 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3264 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3265 | { |
9327494e | 3266 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3267 | |
183be222 | 3268 | ourstatus->set_no_resumed (); |
b84876c2 | 3269 | |
0e5bf2a8 PA |
3270 | restore_child_signals_mask (&prev_mask); |
3271 | return minus_one_ptid; | |
d6b0e80f | 3272 | } |
28736962 | 3273 | |
0e5bf2a8 PA |
3274 | /* No interesting event to report to the core. */ |
3275 | ||
3276 | if (target_options & TARGET_WNOHANG) | |
3277 | { | |
b26b06dd | 3278 | linux_nat_debug_printf ("no interesting events found"); |
28736962 | 3279 | |
183be222 | 3280 | ourstatus->set_ignore (); |
28736962 PA |
3281 | restore_child_signals_mask (&prev_mask); |
3282 | return minus_one_ptid; | |
3283 | } | |
d6b0e80f AC |
3284 | |
3285 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3286 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3287 | |
3288 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3289 | wait_for_signal (); |
d6b0e80f AC |
3290 | } |
3291 | ||
d6b0e80f AC |
3292 | gdb_assert (lp); |
3293 | ||
ca2163eb PA |
3294 | status = lp->status; |
3295 | lp->status = 0; | |
3296 | ||
fbea99ea | 3297 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3298 | { |
3299 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3300 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3301 | |
3302 | /* ... and wait until all of them have reported back that | |
3303 | they're no longer running. */ | |
d3a70e03 | 3304 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3305 | } |
3306 | ||
3307 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3308 | among those that have had events. Giving equal priority to all | |
3309 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3310 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3311 | select_event_lwp (ptid, &lp, &status); |
3312 | ||
3313 | gdb_assert (lp != NULL); | |
3314 | ||
3315 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3316 | it was a software breakpoint, and we can't reliably support the |
3317 | "stopped by software breakpoint" stop reason. */ | |
3318 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3319 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3320 | { |
5b6d1e4f | 3321 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3322 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3323 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3324 | |
9c02b525 PA |
3325 | if (decr_pc != 0) |
3326 | { | |
3327 | CORE_ADDR pc; | |
d6b0e80f | 3328 | |
9c02b525 PA |
3329 | pc = regcache_read_pc (regcache); |
3330 | regcache_write_pc (regcache, pc + decr_pc); | |
3331 | } | |
3332 | } | |
e3e9f5a2 | 3333 | |
9c02b525 PA |
3334 | /* We'll need this to determine whether to report a SIGSTOP as |
3335 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3336 | clears it. */ | |
3337 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3338 | |
fbea99ea | 3339 | if (!target_is_non_stop_p ()) |
9c02b525 | 3340 | { |
e3e9f5a2 PA |
3341 | /* In all-stop, from the core's perspective, all LWPs are now |
3342 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3343 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3344 | } |
3345 | else | |
25289eb2 | 3346 | { |
d3a70e03 | 3347 | resume_clear_callback (lp); |
25289eb2 | 3348 | } |
d6b0e80f | 3349 | |
135340af | 3350 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3351 | { |
9327494e | 3352 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3353 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3354 | } |
d6b0e80f | 3355 | |
183be222 | 3356 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3357 | { |
3358 | *ourstatus = lp->waitstatus; | |
183be222 | 3359 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3360 | } |
3361 | else | |
7509b829 | 3362 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3363 | |
b26b06dd | 3364 | linux_nat_debug_printf ("event found"); |
b84876c2 | 3365 | |
7feb7d06 | 3366 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3367 | |
4b60df3d | 3368 | if (last_resume_kind == resume_stop |
183be222 | 3369 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3370 | && WSTOPSIG (status) == SIGSTOP) |
3371 | { | |
3372 | /* A thread that has been requested to stop by GDB with | |
3373 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3374 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3375 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3376 | } |
3377 | ||
183be222 SM |
3378 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3379 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3380 | lp->core = -1; |
3381 | else | |
2e794194 | 3382 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3383 | |
183be222 | 3384 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED) |
aa01bd36 PA |
3385 | return filter_exit_event (lp, ourstatus); |
3386 | ||
f973ed9c | 3387 | return lp->ptid; |
d6b0e80f AC |
3388 | } |
3389 | ||
e3e9f5a2 PA |
3390 | /* Resume LWPs that are currently stopped without any pending status |
3391 | to report, but are resumed from the core's perspective. */ | |
3392 | ||
3393 | static int | |
d3a70e03 | 3394 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3395 | { |
14ec4172 AB |
3396 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
3397 | ||
8a9da63e | 3398 | if (!lp->stopped) |
4dd63d48 | 3399 | { |
9327494e | 3400 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3401 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3402 | } |
3403 | else if (!lp->resumed) | |
3404 | { | |
9327494e | 3405 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3406 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3407 | } |
3408 | else if (lwp_status_pending_p (lp)) | |
3409 | { | |
9327494e | 3410 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3411 | lp->ptid.to_string ().c_str ()); |
4dd63d48 | 3412 | } |
8a9da63e AB |
3413 | else if (inf->vfork_child != nullptr) |
3414 | { | |
3415 | linux_nat_debug_printf ("NOT resuming LWP %s (vfork parent)", | |
3416 | lp->ptid.to_string ().c_str ()); | |
3417 | } | |
4dd63d48 | 3418 | else |
e3e9f5a2 | 3419 | { |
5b6d1e4f | 3420 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3421 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3422 | |
a70b8144 | 3423 | try |
e3e9f5a2 | 3424 | { |
23f238d3 PA |
3425 | CORE_ADDR pc = regcache_read_pc (regcache); |
3426 | int leave_stopped = 0; | |
e3e9f5a2 | 3427 | |
23f238d3 PA |
3428 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3429 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3430 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3431 | { |
a01bda52 | 3432 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3433 | leave_stopped = 1; |
3434 | } | |
e3e9f5a2 | 3435 | |
23f238d3 PA |
3436 | if (!leave_stopped) |
3437 | { | |
9327494e SM |
3438 | linux_nat_debug_printf |
3439 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3440 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3441 | lp->step); |
23f238d3 PA |
3442 | |
3443 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3444 | } | |
3445 | } | |
230d2906 | 3446 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3447 | { |
3448 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3449 | throw; |
23f238d3 | 3450 | } |
e3e9f5a2 PA |
3451 | } |
3452 | ||
3453 | return 0; | |
3454 | } | |
3455 | ||
f6ac5f3d PA |
3456 | ptid_t |
3457 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3458 | target_wait_flags target_options) |
7feb7d06 | 3459 | { |
b26b06dd AB |
3460 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3461 | ||
7feb7d06 PA |
3462 | ptid_t event_ptid; |
3463 | ||
e53c95d4 | 3464 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3465 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3466 | |
3467 | /* Flush the async file first. */ | |
d9d41e78 | 3468 | if (target_is_async_p ()) |
7feb7d06 PA |
3469 | async_file_flush (); |
3470 | ||
e3e9f5a2 PA |
3471 | /* Resume LWPs that are currently stopped without any pending status |
3472 | to report, but are resumed from the core's perspective. LWPs get | |
3473 | in this state if we find them stopping at a time we're not | |
3474 | interested in reporting the event (target_wait on a | |
3475 | specific_process, for example, see linux_nat_wait_1), and | |
3476 | meanwhile the event became uninteresting. Don't bother resuming | |
3477 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3478 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3479 | iterate_over_lwps (minus_one_ptid, |
3480 | [=] (struct lwp_info *info) | |
3481 | { | |
3482 | return resume_stopped_resumed_lwps (info, ptid); | |
3483 | }); | |
e3e9f5a2 | 3484 | |
f6ac5f3d | 3485 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3486 | |
3487 | /* If we requested any event, and something came out, assume there | |
3488 | may be more. If we requested a specific lwp or process, also | |
3489 | assume there may be more. */ | |
d9d41e78 | 3490 | if (target_is_async_p () |
183be222 SM |
3491 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3492 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3493 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3494 | async_file_mark (); |
3495 | ||
7feb7d06 PA |
3496 | return event_ptid; |
3497 | } | |
3498 | ||
1d2736d4 PA |
3499 | /* Kill one LWP. */ |
3500 | ||
3501 | static void | |
3502 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3503 | { |
ed731959 JK |
3504 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3505 | ||
3506 | errno = 0; | |
1d2736d4 | 3507 | kill_lwp (pid, SIGKILL); |
9327494e | 3508 | |
ed731959 | 3509 | if (debug_linux_nat) |
57745c90 PA |
3510 | { |
3511 | int save_errno = errno; | |
3512 | ||
9327494e SM |
3513 | linux_nat_debug_printf |
3514 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3515 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3516 | } |
ed731959 JK |
3517 | |
3518 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3519 | ||
d6b0e80f | 3520 | errno = 0; |
1d2736d4 | 3521 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3522 | if (debug_linux_nat) |
57745c90 PA |
3523 | { |
3524 | int save_errno = errno; | |
3525 | ||
9327494e SM |
3526 | linux_nat_debug_printf |
3527 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3528 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3529 | } |
d6b0e80f AC |
3530 | } |
3531 | ||
1d2736d4 PA |
3532 | /* Wait for an LWP to die. */ |
3533 | ||
3534 | static void | |
3535 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3536 | { |
1d2736d4 | 3537 | pid_t res; |
d6b0e80f AC |
3538 | |
3539 | /* We must make sure that there are no pending events (delayed | |
3540 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3541 | program doesn't interfere with any following debugging session. */ | |
3542 | ||
d6b0e80f AC |
3543 | do |
3544 | { | |
1d2736d4 PA |
3545 | res = my_waitpid (pid, NULL, __WALL); |
3546 | if (res != (pid_t) -1) | |
d6b0e80f | 3547 | { |
9327494e SM |
3548 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3549 | ||
4a6ed09b PA |
3550 | /* The Linux kernel sometimes fails to kill a thread |
3551 | completely after PTRACE_KILL; that goes from the stop | |
3552 | point in do_fork out to the one in get_signal_to_deliver | |
3553 | and waits again. So kill it again. */ | |
1d2736d4 | 3554 | kill_one_lwp (pid); |
d6b0e80f AC |
3555 | } |
3556 | } | |
1d2736d4 PA |
3557 | while (res == pid); |
3558 | ||
3559 | gdb_assert (res == -1 && errno == ECHILD); | |
3560 | } | |
3561 | ||
3562 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3563 | |
1d2736d4 | 3564 | static int |
d3a70e03 | 3565 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3566 | { |
e38504b3 | 3567 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3568 | return 0; |
3569 | } | |
3570 | ||
1d2736d4 PA |
3571 | /* Callback for iterate_over_lwps. */ |
3572 | ||
3573 | static int | |
d3a70e03 | 3574 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3575 | { |
e38504b3 | 3576 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3577 | return 0; |
3578 | } | |
3579 | ||
0d36baa9 | 3580 | /* Kill the fork/clone child of LP if it has an unfollowed child. */ |
1d2736d4 | 3581 | |
0d36baa9 PA |
3582 | static int |
3583 | kill_unfollowed_child_callback (lwp_info *lp) | |
1d2736d4 | 3584 | { |
0d36baa9 PA |
3585 | gdb::optional<target_waitstatus> ws = get_pending_child_status (lp); |
3586 | if (ws.has_value ()) | |
08036331 | 3587 | { |
0d36baa9 PA |
3588 | ptid_t child_ptid = ws->child_ptid (); |
3589 | int child_pid = child_ptid.pid (); | |
3590 | int child_lwp = child_ptid.lwp (); | |
08036331 | 3591 | |
0d36baa9 PA |
3592 | kill_one_lwp (child_lwp); |
3593 | kill_wait_one_lwp (child_lwp); | |
08036331 | 3594 | |
0d36baa9 PA |
3595 | /* Let the arch-specific native code know this process is |
3596 | gone. */ | |
3597 | if (ws->kind () != TARGET_WAITKIND_THREAD_CLONED) | |
3598 | linux_target->low_forget_process (child_pid); | |
08036331 | 3599 | } |
0d36baa9 PA |
3600 | |
3601 | return 0; | |
1d2736d4 PA |
3602 | } |
3603 | ||
f6ac5f3d PA |
3604 | void |
3605 | linux_nat_target::kill () | |
d6b0e80f | 3606 | { |
0d36baa9 PA |
3607 | ptid_t pid_ptid (inferior_ptid.pid ()); |
3608 | ||
3609 | /* If we're stopped while forking/cloning and we haven't followed | |
3610 | yet, kill the child task. We need to do this first because the | |
f973ed9c | 3611 | parent will be sleeping if this is a vfork. */ |
0d36baa9 | 3612 | iterate_over_lwps (pid_ptid, kill_unfollowed_child_callback); |
f973ed9c DJ |
3613 | |
3614 | if (forks_exist_p ()) | |
7feb7d06 | 3615 | linux_fork_killall (); |
f973ed9c DJ |
3616 | else |
3617 | { | |
4c28f408 | 3618 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3619 | that the thread is stopped to successfully PTRACE_KILL. */ |
0d36baa9 | 3620 | iterate_over_lwps (pid_ptid, stop_callback); |
4c28f408 PA |
3621 | /* ... and wait until all of them have reported back that |
3622 | they're no longer running. */ | |
0d36baa9 | 3623 | iterate_over_lwps (pid_ptid, stop_wait_callback); |
4c28f408 | 3624 | |
f973ed9c | 3625 | /* Kill all LWP's ... */ |
0d36baa9 | 3626 | iterate_over_lwps (pid_ptid, kill_callback); |
f973ed9c DJ |
3627 | |
3628 | /* ... and wait until we've flushed all events. */ | |
0d36baa9 | 3629 | iterate_over_lwps (pid_ptid, kill_wait_callback); |
f973ed9c DJ |
3630 | } |
3631 | ||
bc1e6c81 | 3632 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3633 | } |
3634 | ||
f6ac5f3d PA |
3635 | void |
3636 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3637 | { |
b26b06dd AB |
3638 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3639 | ||
e99b03dc | 3640 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3641 | |
3642 | purge_lwp_list (pid); | |
d6b0e80f | 3643 | |
8a89ddbd | 3644 | close_proc_mem_file (pid); |
05c06f31 | 3645 | |
f973ed9c | 3646 | if (! forks_exist_p ()) |
d90e17a7 | 3647 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3648 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3649 | else |
3650 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3651 | there are other viable forks to debug. Delete the exiting | |
3652 | one and context-switch to the first available. */ | |
3653 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3654 | |
3655 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3656 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3657 | } |
3658 | ||
5b009018 PA |
3659 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3660 | layout of the inferiors' architecture. */ | |
3661 | ||
3662 | static void | |
a5362b9a | 3663 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3664 | { |
135340af PA |
3665 | /* If the low target didn't do anything, then just do a straight |
3666 | memcpy. */ | |
3667 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3668 | { |
3669 | if (direction == 1) | |
a5362b9a | 3670 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3671 | else |
a5362b9a | 3672 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3673 | } |
3674 | } | |
3675 | ||
9b409511 | 3676 | static enum target_xfer_status |
7154e786 | 3677 | linux_xfer_siginfo (ptid_t ptid, enum target_object object, |
dda83cd7 | 3678 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3679 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3680 | ULONGEST *xfered_len) | |
4aa995e1 | 3681 | { |
a5362b9a TS |
3682 | siginfo_t siginfo; |
3683 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3684 | |
3685 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3686 | gdb_assert (readbuf || writebuf); | |
3687 | ||
4aa995e1 | 3688 | if (offset > sizeof (siginfo)) |
2ed4b548 | 3689 | return TARGET_XFER_E_IO; |
4aa995e1 | 3690 | |
7154e786 | 3691 | if (!linux_nat_get_siginfo (ptid, &siginfo)) |
2ed4b548 | 3692 | return TARGET_XFER_E_IO; |
4aa995e1 | 3693 | |
5b009018 PA |
3694 | /* When GDB is built as a 64-bit application, ptrace writes into |
3695 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3696 | inferior with a 64-bit GDB should look the same as debugging it | |
3697 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3698 | the converted layout, so any read/write will have to be done | |
3699 | post-conversion. */ | |
3700 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3701 | ||
4aa995e1 PA |
3702 | if (offset + len > sizeof (siginfo)) |
3703 | len = sizeof (siginfo) - offset; | |
3704 | ||
3705 | if (readbuf != NULL) | |
5b009018 | 3706 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3707 | else |
3708 | { | |
5b009018 PA |
3709 | memcpy (inf_siginfo + offset, writebuf, len); |
3710 | ||
3711 | /* Convert back to ptrace layout before flushing it out. */ | |
3712 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3713 | ||
7154e786 | 3714 | int pid = get_ptrace_pid (ptid); |
4aa995e1 PA |
3715 | errno = 0; |
3716 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3717 | if (errno != 0) | |
2ed4b548 | 3718 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3719 | } |
3720 | ||
9b409511 YQ |
3721 | *xfered_len = len; |
3722 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3723 | } |
3724 | ||
9b409511 | 3725 | static enum target_xfer_status |
f6ac5f3d PA |
3726 | linux_nat_xfer_osdata (enum target_object object, |
3727 | const char *annex, gdb_byte *readbuf, | |
3728 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3729 | ULONGEST *xfered_len); | |
3730 | ||
f6ac5f3d | 3731 | static enum target_xfer_status |
f9f593dd SM |
3732 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3733 | const gdb_byte *writebuf, ULONGEST offset, | |
3734 | LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3735 | |
3736 | enum target_xfer_status | |
3737 | linux_nat_target::xfer_partial (enum target_object object, | |
3738 | const char *annex, gdb_byte *readbuf, | |
3739 | const gdb_byte *writebuf, | |
3740 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3741 | { |
4aa995e1 | 3742 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
7154e786 | 3743 | return linux_xfer_siginfo (inferior_ptid, object, annex, readbuf, writebuf, |
9b409511 | 3744 | offset, len, xfered_len); |
4aa995e1 | 3745 | |
c35b1492 PA |
3746 | /* The target is connected but no live inferior is selected. Pass |
3747 | this request down to a lower stratum (e.g., the executable | |
3748 | file). */ | |
d7e15655 | 3749 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3750 | return TARGET_XFER_EOF; |
c35b1492 | 3751 | |
f6ac5f3d PA |
3752 | if (object == TARGET_OBJECT_AUXV) |
3753 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3754 | offset, len, xfered_len); | |
3755 | ||
3756 | if (object == TARGET_OBJECT_OSDATA) | |
3757 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3758 | offset, len, xfered_len); | |
d6b0e80f | 3759 | |
f6ac5f3d PA |
3760 | if (object == TARGET_OBJECT_MEMORY) |
3761 | { | |
05c06f31 PA |
3762 | /* GDB calculates all addresses in the largest possible address |
3763 | width. The address width must be masked before its final use | |
3764 | by linux_proc_xfer_partial. | |
3765 | ||
3766 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
99d9c3b9 | 3767 | int addr_bit = gdbarch_addr_bit (current_inferior ()->arch ()); |
f6ac5f3d PA |
3768 | |
3769 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3770 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3771 | |
dd09fe0d KS |
3772 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3773 | the write via /proc/pid/mem fails because the inferior execed | |
3774 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3775 | poke would incorrectly write memory to the post-exec address | |
3776 | space, while the core was trying to write to the pre-exec | |
3777 | address space. */ | |
3778 | if (proc_mem_file_is_writable ()) | |
f9f593dd SM |
3779 | return linux_proc_xfer_memory_partial (inferior_ptid.pid (), readbuf, |
3780 | writebuf, offset, len, | |
3781 | xfered_len); | |
05c06f31 | 3782 | } |
f6ac5f3d PA |
3783 | |
3784 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3785 | offset, len, xfered_len); | |
d6b0e80f AC |
3786 | } |
3787 | ||
57810aa7 | 3788 | bool |
f6ac5f3d | 3789 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3790 | { |
4a6ed09b PA |
3791 | /* As long as a PTID is in lwp list, consider it alive. */ |
3792 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3793 | } |
3794 | ||
8a06aea7 PA |
3795 | /* Implement the to_update_thread_list target method for this |
3796 | target. */ | |
3797 | ||
f6ac5f3d PA |
3798 | void |
3799 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3800 | { |
4a6ed09b PA |
3801 | /* We add/delete threads from the list as clone/exit events are |
3802 | processed, so just try deleting exited threads still in the | |
3803 | thread list. */ | |
3804 | delete_exited_threads (); | |
a6904d5a PA |
3805 | |
3806 | /* Update the processor core that each lwp/thread was last seen | |
3807 | running on. */ | |
901b9821 | 3808 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3809 | { |
3810 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3811 | time we fetched the thread's core. Accessing /proc becomes | |
3812 | noticeably expensive when we have thousands of LWPs. */ | |
3813 | if (lwp->core == -1) | |
3814 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3815 | } | |
8a06aea7 PA |
3816 | } |
3817 | ||
a068643d | 3818 | std::string |
f6ac5f3d | 3819 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3820 | { |
15a9e13e | 3821 | if (ptid.lwp_p () |
e38504b3 | 3822 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3823 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3824 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3825 | |
3826 | return normal_pid_to_str (ptid); | |
3827 | } | |
3828 | ||
f6ac5f3d PA |
3829 | const char * |
3830 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3831 | { |
79efa585 | 3832 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3833 | } |
3834 | ||
dba24537 AC |
3835 | /* Accepts an integer PID; Returns a string representing a file that |
3836 | can be opened to get the symbols for the child process. */ | |
3837 | ||
0e90c441 | 3838 | const char * |
f6ac5f3d | 3839 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3840 | { |
e0d86d2c | 3841 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3842 | } |
3843 | ||
8a89ddbd PA |
3844 | /* Object representing an /proc/PID/mem open file. We keep one such |
3845 | file open per inferior. | |
3846 | ||
3847 | It might be tempting to think about only ever opening one file at | |
3848 | most for all inferiors, closing/reopening the file as we access | |
3849 | memory of different inferiors, to minimize number of file | |
3850 | descriptors open, which can otherwise run into resource limits. | |
3851 | However, that does not work correctly -- if the inferior execs and | |
3852 | we haven't processed the exec event yet, and, we opened a | |
3853 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
3854 | address space, thinking we're opening it for the pre-exec address | |
3855 | space. That is dangerous as we can poke memory (e.g. clearing | |
3856 | breakpoints) in the post-exec memory by mistake, corrupting the | |
3857 | inferior. For that reason, we open the mem file as early as | |
3858 | possible, right after spawning, forking or attaching to the | |
3859 | inferior, when the inferior is stopped and thus before it has a | |
3860 | chance of execing. | |
3861 | ||
3862 | Note that after opening the file, even if the thread we opened it | |
3863 | for subsequently exits, the open file is still usable for accessing | |
3864 | memory. It's only when the whole process exits or execs that the | |
3865 | file becomes invalid, at which point reads/writes return EOF. */ | |
3866 | ||
3867 | class proc_mem_file | |
3868 | { | |
3869 | public: | |
3870 | proc_mem_file (ptid_t ptid, int fd) | |
3871 | : m_ptid (ptid), m_fd (fd) | |
3872 | { | |
3873 | gdb_assert (m_fd != -1); | |
3874 | } | |
05c06f31 | 3875 | |
8a89ddbd | 3876 | ~proc_mem_file () |
05c06f31 | 3877 | { |
89662f69 | 3878 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
3879 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
3880 | close (m_fd); | |
05c06f31 | 3881 | } |
05c06f31 | 3882 | |
8a89ddbd PA |
3883 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
3884 | ||
3885 | int fd () | |
3886 | { | |
3887 | return m_fd; | |
3888 | } | |
3889 | ||
3890 | private: | |
3891 | /* The LWP this file was opened for. Just for debugging | |
3892 | purposes. */ | |
3893 | ptid_t m_ptid; | |
3894 | ||
3895 | /* The file descriptor. */ | |
3896 | int m_fd = -1; | |
3897 | }; | |
3898 | ||
3899 | /* The map between an inferior process id, and the open /proc/PID/mem | |
3900 | file. This is stored in a map instead of in a per-inferior | |
3901 | structure because we need to be able to access memory of processes | |
3902 | which don't have a corresponding struct inferior object. E.g., | |
3903 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
3904 | (also default), we don't create an inferior for the fork child, but | |
3905 | we still need to remove breakpoints from the fork child's | |
3906 | memory. */ | |
3907 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
3908 | ||
3909 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
3910 | |
3911 | static void | |
8a89ddbd | 3912 | close_proc_mem_file (pid_t pid) |
dba24537 | 3913 | { |
8a89ddbd | 3914 | proc_mem_file_map.erase (pid); |
05c06f31 | 3915 | } |
dba24537 | 3916 | |
8a89ddbd PA |
3917 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
3918 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
3919 | exists and is stopped right now. We prefer the | |
3920 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
3921 | races, just in case this is ever called on an already-waited | |
3922 | LWP. */ | |
dba24537 | 3923 | |
8a89ddbd PA |
3924 | static void |
3925 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 3926 | { |
8a89ddbd PA |
3927 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
3928 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 3929 | |
8a89ddbd PA |
3930 | char filename[64]; |
3931 | xsnprintf (filename, sizeof filename, | |
3932 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3933 | ||
3934 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 3935 | |
8a89ddbd PA |
3936 | if (fd == -1) |
3937 | { | |
3938 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
3939 | ptid.pid (), ptid.lwp (), | |
3940 | safe_strerror (errno), errno); | |
3941 | return; | |
05c06f31 PA |
3942 | } |
3943 | ||
8a89ddbd PA |
3944 | proc_mem_file_map.emplace (std::piecewise_construct, |
3945 | std::forward_as_tuple (ptid.pid ()), | |
3946 | std::forward_as_tuple (ptid, fd)); | |
3947 | ||
9221923c | 3948 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
3949 | fd, ptid.pid (), ptid.lwp ()); |
3950 | } | |
3951 | ||
1bcb0708 PA |
3952 | /* Helper for linux_proc_xfer_memory_partial and |
3953 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
3954 | file, and PID is the pid of the corresponding process. The rest of | |
3955 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
3956 | |
3957 | static enum target_xfer_status | |
1bcb0708 PA |
3958 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
3959 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3960 | ULONGEST offset, LONGEST len, | |
3961 | ULONGEST *xfered_len) | |
8a89ddbd PA |
3962 | { |
3963 | ssize_t ret; | |
3964 | ||
8a89ddbd | 3965 | gdb_assert (fd != -1); |
dba24537 | 3966 | |
31a56a22 PA |
3967 | /* Use pread64/pwrite64 if available, since they save a syscall and |
3968 | can handle 64-bit offsets even on 32-bit platforms (for instance, | |
3969 | SPARC debugging a SPARC64 application). But only use them if the | |
3970 | offset isn't so high that when cast to off_t it'd be negative, as | |
3971 | seen on SPARC64. pread64/pwrite64 outright reject such offsets. | |
3972 | lseek does not. */ | |
dba24537 | 3973 | #ifdef HAVE_PREAD64 |
31a56a22 PA |
3974 | if ((off_t) offset >= 0) |
3975 | ret = (readbuf != nullptr | |
3976 | ? pread64 (fd, readbuf, len, offset) | |
3977 | : pwrite64 (fd, writebuf, len, offset)); | |
3978 | else | |
dba24537 | 3979 | #endif |
31a56a22 PA |
3980 | { |
3981 | ret = lseek (fd, offset, SEEK_SET); | |
3982 | if (ret != -1) | |
3983 | ret = (readbuf != nullptr | |
3984 | ? read (fd, readbuf, len) | |
3985 | : write (fd, writebuf, len)); | |
3986 | } | |
dba24537 | 3987 | |
05c06f31 PA |
3988 | if (ret == -1) |
3989 | { | |
9221923c | 3990 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 3991 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 3992 | return TARGET_XFER_E_IO; |
05c06f31 PA |
3993 | } |
3994 | else if (ret == 0) | |
3995 | { | |
8a89ddbd PA |
3996 | /* EOF means the address space is gone, the whole process exited |
3997 | or execed. */ | |
9221923c | 3998 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 3999 | fd, pid); |
05c06f31 PA |
4000 | return TARGET_XFER_EOF; |
4001 | } | |
9b409511 YQ |
4002 | else |
4003 | { | |
8a89ddbd | 4004 | *xfered_len = ret; |
9b409511 YQ |
4005 | return TARGET_XFER_OK; |
4006 | } | |
05c06f31 | 4007 | } |
efcbbd14 | 4008 | |
1bcb0708 PA |
4009 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
4010 | Because we can use a single read/write call, this can be much more | |
4011 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
4012 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
4013 | threads. */ | |
4014 | ||
4015 | static enum target_xfer_status | |
f9f593dd SM |
4016 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
4017 | const gdb_byte *writebuf, ULONGEST offset, | |
4018 | LONGEST len, ULONGEST *xfered_len) | |
1bcb0708 | 4019 | { |
1bcb0708 PA |
4020 | auto iter = proc_mem_file_map.find (pid); |
4021 | if (iter == proc_mem_file_map.end ()) | |
4022 | return TARGET_XFER_EOF; | |
4023 | ||
4024 | int fd = iter->second.fd (); | |
4025 | ||
4026 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
4027 | len, xfered_len); | |
4028 | } | |
4029 | ||
4030 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
4031 | return true if so. It wasn't writable before Linux 2.6.39, but | |
4032 | there's no way to know whether the feature was backported to older | |
4033 | kernels. So we check to see if it works. The result is cached, | |
3bfdcabb | 4034 | and this is guaranteed to be called once early during inferior |
9dff6a5d PA |
4035 | startup, so that any warning is printed out consistently between |
4036 | GDB invocations. Note we don't call it during GDB startup instead | |
4037 | though, because then we might warn with e.g. just "gdb --version" | |
4038 | on sandboxed systems. See PR gdb/29907. */ | |
1bcb0708 PA |
4039 | |
4040 | static bool | |
4041 | proc_mem_file_is_writable () | |
4042 | { | |
4043 | static gdb::optional<bool> writable; | |
4044 | ||
4045 | if (writable.has_value ()) | |
4046 | return *writable; | |
4047 | ||
4048 | writable.emplace (false); | |
4049 | ||
4050 | /* We check whether /proc/pid/mem is writable by trying to write to | |
4051 | one of our variables via /proc/self/mem. */ | |
4052 | ||
4053 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
4054 | ||
4055 | if (fd == -1) | |
4056 | { | |
4057 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
4058 | safe_strerror (errno), errno); | |
4059 | return *writable; | |
4060 | } | |
4061 | ||
4062 | SCOPE_EXIT { close (fd); }; | |
4063 | ||
4064 | /* This is the variable we try to write to. Note OFFSET below. */ | |
4065 | volatile gdb_byte test_var = 0; | |
4066 | ||
4067 | gdb_byte writebuf[] = {0x55}; | |
4068 | ULONGEST offset = (uintptr_t) &test_var; | |
4069 | ULONGEST xfered_len; | |
4070 | ||
4071 | enum target_xfer_status res | |
4072 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
4073 | offset, 1, &xfered_len); | |
4074 | ||
4075 | if (res == TARGET_XFER_OK) | |
4076 | { | |
4077 | gdb_assert (xfered_len == 1); | |
4078 | gdb_assert (test_var == 0x55); | |
4079 | /* Success. */ | |
4080 | *writable = true; | |
4081 | } | |
4082 | ||
4083 | return *writable; | |
4084 | } | |
4085 | ||
dba24537 AC |
4086 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4087 | ||
4088 | static void | |
4089 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4090 | { | |
4091 | int len = strlen (line) - 1; | |
4092 | const char *p; | |
4093 | int signum; | |
4094 | ||
4095 | if (line[len] != '\n') | |
8a3fe4f8 | 4096 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4097 | |
4098 | p = line; | |
4099 | signum = len * 4; | |
4100 | while (len-- > 0) | |
4101 | { | |
4102 | int digit; | |
4103 | ||
4104 | if (*p >= '0' && *p <= '9') | |
4105 | digit = *p - '0'; | |
4106 | else if (*p >= 'a' && *p <= 'f') | |
4107 | digit = *p - 'a' + 10; | |
4108 | else | |
8a3fe4f8 | 4109 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4110 | |
4111 | signum -= 4; | |
4112 | ||
4113 | if (digit & 1) | |
4114 | sigaddset (sigs, signum + 1); | |
4115 | if (digit & 2) | |
4116 | sigaddset (sigs, signum + 2); | |
4117 | if (digit & 4) | |
4118 | sigaddset (sigs, signum + 3); | |
4119 | if (digit & 8) | |
4120 | sigaddset (sigs, signum + 4); | |
4121 | ||
4122 | p++; | |
4123 | } | |
4124 | } | |
4125 | ||
4126 | /* Find process PID's pending signals from /proc/pid/status and set | |
4127 | SIGS to match. */ | |
4128 | ||
4129 | void | |
3e43a32a MS |
4130 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4131 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4132 | { |
d8d2a3ee | 4133 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4134 | |
4135 | sigemptyset (pending); | |
4136 | sigemptyset (blocked); | |
4137 | sigemptyset (ignored); | |
cde33bf1 | 4138 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4139 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4140 | if (procfile == NULL) |
8a3fe4f8 | 4141 | error (_("Could not open %s"), fname); |
dba24537 | 4142 | |
d419f42d | 4143 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4144 | { |
4145 | /* Normal queued signals are on the SigPnd line in the status | |
4146 | file. However, 2.6 kernels also have a "shared" pending | |
4147 | queue for delivering signals to a thread group, so check for | |
4148 | a ShdPnd line also. | |
4149 | ||
4150 | Unfortunately some Red Hat kernels include the shared pending | |
4151 | queue but not the ShdPnd status field. */ | |
4152 | ||
61012eef | 4153 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4154 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4155 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4156 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4157 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4158 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4159 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4160 | add_line_to_sigset (buffer + 8, ignored); |
4161 | } | |
dba24537 AC |
4162 | } |
4163 | ||
9b409511 | 4164 | static enum target_xfer_status |
f6ac5f3d | 4165 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4166 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4167 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4168 | ULONGEST *xfered_len) | |
07e059b5 | 4169 | { |
07e059b5 VP |
4170 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4171 | ||
9b409511 YQ |
4172 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4173 | if (*xfered_len == 0) | |
4174 | return TARGET_XFER_EOF; | |
4175 | else | |
4176 | return TARGET_XFER_OK; | |
07e059b5 VP |
4177 | } |
4178 | ||
f6ac5f3d PA |
4179 | std::vector<static_tracepoint_marker> |
4180 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4181 | { |
4182 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4183 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4184 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4185 | const char *p = s; |
184ea2f7 | 4186 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4187 | static_tracepoint_marker marker; |
5808517f YQ |
4188 | |
4189 | /* Pause all */ | |
4190 | target_stop (ptid); | |
4191 | ||
81aa19c3 | 4192 | strcpy (s, "qTfSTM"); |
42476b70 | 4193 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4194 | |
1db93f14 TT |
4195 | /* Unpause all. */ |
4196 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4197 | |
4198 | while (*p++ == 'm') | |
4199 | { | |
5808517f YQ |
4200 | do |
4201 | { | |
5d9310c4 | 4202 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4203 | |
5d9310c4 SM |
4204 | if (strid == NULL || marker.str_id == strid) |
4205 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4206 | } |
4207 | while (*p++ == ','); /* comma-separated list */ | |
4208 | ||
81aa19c3 | 4209 | strcpy (s, "qTsSTM"); |
42476b70 | 4210 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4211 | p = s; |
4212 | } | |
4213 | ||
5808517f YQ |
4214 | return markers; |
4215 | } | |
4216 | ||
b84876c2 PA |
4217 | /* target_can_async_p implementation. */ |
4218 | ||
57810aa7 | 4219 | bool |
f6ac5f3d | 4220 | linux_nat_target::can_async_p () |
b84876c2 | 4221 | { |
fce6cd34 AB |
4222 | /* This flag should be checked in the common target.c code. */ |
4223 | gdb_assert (target_async_permitted); | |
4224 | ||
4225 | /* Otherwise, this targets is always able to support async mode. */ | |
4226 | return true; | |
b84876c2 PA |
4227 | } |
4228 | ||
57810aa7 | 4229 | bool |
f6ac5f3d | 4230 | linux_nat_target::supports_non_stop () |
9908b566 | 4231 | { |
f80c8ec4 | 4232 | return true; |
9908b566 VP |
4233 | } |
4234 | ||
fbea99ea PA |
4235 | /* to_always_non_stop_p implementation. */ |
4236 | ||
57810aa7 | 4237 | bool |
f6ac5f3d | 4238 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4239 | { |
f80c8ec4 | 4240 | return true; |
fbea99ea PA |
4241 | } |
4242 | ||
57810aa7 | 4243 | bool |
f6ac5f3d | 4244 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4245 | { |
aee91db3 | 4246 | return true; |
d90e17a7 PA |
4247 | } |
4248 | ||
57810aa7 | 4249 | bool |
f6ac5f3d | 4250 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4251 | { |
f80c8ec4 | 4252 | return true; |
03583c20 UW |
4253 | } |
4254 | ||
7feb7d06 PA |
4255 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4256 | so we notice when any child changes state, and notify the | |
4257 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4258 | above to wait for the arrival of a SIGCHLD. */ | |
4259 | ||
b84876c2 | 4260 | static void |
7feb7d06 | 4261 | sigchld_handler (int signo) |
b84876c2 | 4262 | { |
7feb7d06 PA |
4263 | int old_errno = errno; |
4264 | ||
01124a23 | 4265 | if (debug_linux_nat) |
da5bd37e | 4266 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4267 | |
b146ba14 JB |
4268 | if (signo == SIGCHLD) |
4269 | { | |
4270 | /* Let the event loop know that there are events to handle. */ | |
4271 | linux_nat_target::async_file_mark_if_open (); | |
4272 | } | |
7feb7d06 PA |
4273 | |
4274 | errno = old_errno; | |
4275 | } | |
4276 | ||
4277 | /* Callback registered with the target events file descriptor. */ | |
4278 | ||
4279 | static void | |
4280 | handle_target_event (int error, gdb_client_data client_data) | |
4281 | { | |
b1a35af2 | 4282 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4283 | } |
4284 | ||
b84876c2 PA |
4285 | /* target_async implementation. */ |
4286 | ||
f6ac5f3d | 4287 | void |
4a570176 | 4288 | linux_nat_target::async (bool enable) |
b84876c2 | 4289 | { |
4a570176 | 4290 | if (enable == is_async_p ()) |
b146ba14 JB |
4291 | return; |
4292 | ||
4293 | /* Block child signals while we create/destroy the pipe, as their | |
4294 | handler writes to it. */ | |
4295 | gdb::block_signals blocker; | |
4296 | ||
6a3753b3 | 4297 | if (enable) |
b84876c2 | 4298 | { |
b146ba14 | 4299 | if (!async_file_open ()) |
f34652de | 4300 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4301 | |
4302 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4303 | "linux-nat"); | |
4304 | ||
4305 | /* There may be pending events to handle. Tell the event loop | |
4306 | to poll them. */ | |
4307 | async_file_mark (); | |
b84876c2 PA |
4308 | } |
4309 | else | |
4310 | { | |
b146ba14 JB |
4311 | delete_file_handler (async_wait_fd ()); |
4312 | async_file_close (); | |
b84876c2 | 4313 | } |
b84876c2 PA |
4314 | } |
4315 | ||
a493e3e2 | 4316 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4317 | event came out. */ |
4318 | ||
4c28f408 | 4319 | static int |
d3a70e03 | 4320 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4321 | { |
d90e17a7 | 4322 | if (!lwp->stopped) |
252fbfc8 | 4323 | { |
9327494e | 4324 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4325 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4326 | |
252fbfc8 | 4327 | |
25289eb2 PA |
4328 | if (lwp->last_resume_kind == resume_stop) |
4329 | { | |
9327494e SM |
4330 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4331 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4332 | return 0; |
4333 | } | |
252fbfc8 | 4334 | |
d3a70e03 | 4335 | stop_callback (lwp); |
25289eb2 | 4336 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4337 | } |
4338 | else | |
4339 | { | |
4340 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4341 | |
d90e17a7 PA |
4342 | if (debug_linux_nat) |
4343 | { | |
9213a6d7 | 4344 | if (linux_target->find_thread (lwp->ptid)->stop_requested) |
9327494e | 4345 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4346 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4347 | else |
9327494e | 4348 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4349 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4350 | } |
4351 | } | |
4c28f408 PA |
4352 | return 0; |
4353 | } | |
4354 | ||
f6ac5f3d PA |
4355 | void |
4356 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4357 | { |
b6e52a0b | 4358 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4359 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4360 | } |
4361 | ||
c0694254 PA |
4362 | /* When requests are passed down from the linux-nat layer to the |
4363 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4364 | used. The address space pointer is stored in the inferior object, | |
4365 | but the common code that is passed such ptid can't tell whether | |
4366 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4367 | look up the "main" process id from the lwp here. */ | |
4368 | ||
f6ac5f3d PA |
4369 | struct address_space * |
4370 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4371 | { |
4372 | struct lwp_info *lwp; | |
4373 | struct inferior *inf; | |
4374 | int pid; | |
4375 | ||
e38504b3 | 4376 | if (ptid.lwp () == 0) |
c0694254 PA |
4377 | { |
4378 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4379 | tgid. */ | |
4380 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4381 | pid = lwp->ptid.pid (); |
c0694254 PA |
4382 | } |
4383 | else | |
4384 | { | |
4385 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4386 | pid = ptid.pid (); |
c0694254 PA |
4387 | } |
4388 | ||
5b6d1e4f | 4389 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4390 | gdb_assert (inf != NULL); |
4391 | return inf->aspace; | |
4392 | } | |
4393 | ||
dc146f7c VP |
4394 | /* Return the cached value of the processor core for thread PTID. */ |
4395 | ||
f6ac5f3d PA |
4396 | int |
4397 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4398 | { |
4399 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4400 | |
dc146f7c VP |
4401 | if (info) |
4402 | return info->core; | |
4403 | return -1; | |
4404 | } | |
4405 | ||
7a6a1731 GB |
4406 | /* Implementation of to_filesystem_is_local. */ |
4407 | ||
57810aa7 | 4408 | bool |
f6ac5f3d | 4409 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4410 | { |
4411 | struct inferior *inf = current_inferior (); | |
4412 | ||
4413 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4414 | return true; |
7a6a1731 GB |
4415 | |
4416 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4417 | } | |
4418 | ||
4419 | /* Convert the INF argument passed to a to_fileio_* method | |
4420 | to a process ID suitable for passing to its corresponding | |
4421 | linux_mntns_* function. If INF is non-NULL then the | |
4422 | caller is requesting the filesystem seen by INF. If INF | |
4423 | is NULL then the caller is requesting the filesystem seen | |
4424 | by the GDB. We fall back to GDB's filesystem in the case | |
4425 | that INF is non-NULL but its PID is unknown. */ | |
4426 | ||
4427 | static pid_t | |
4428 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4429 | { | |
4430 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4431 | return getpid (); | |
4432 | else | |
4433 | return inf->pid; | |
4434 | } | |
4435 | ||
4436 | /* Implementation of to_fileio_open. */ | |
4437 | ||
f6ac5f3d PA |
4438 | int |
4439 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4440 | int flags, int mode, int warn_if_slow, | |
b872057a | 4441 | fileio_error *target_errno) |
7a6a1731 GB |
4442 | { |
4443 | int nat_flags; | |
4444 | mode_t nat_mode; | |
4445 | int fd; | |
4446 | ||
4447 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4448 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4449 | { | |
4450 | *target_errno = FILEIO_EINVAL; | |
4451 | return -1; | |
4452 | } | |
4453 | ||
4454 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4455 | filename, nat_flags, nat_mode); | |
4456 | if (fd == -1) | |
4457 | *target_errno = host_to_fileio_error (errno); | |
4458 | ||
4459 | return fd; | |
4460 | } | |
4461 | ||
4462 | /* Implementation of to_fileio_readlink. */ | |
4463 | ||
f6ac5f3d PA |
4464 | gdb::optional<std::string> |
4465 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
b872057a | 4466 | fileio_error *target_errno) |
7a6a1731 GB |
4467 | { |
4468 | char buf[PATH_MAX]; | |
4469 | int len; | |
7a6a1731 GB |
4470 | |
4471 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4472 | filename, buf, sizeof (buf)); | |
4473 | if (len < 0) | |
4474 | { | |
4475 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4476 | return {}; |
7a6a1731 GB |
4477 | } |
4478 | ||
e0d3522b | 4479 | return std::string (buf, len); |
7a6a1731 GB |
4480 | } |
4481 | ||
4482 | /* Implementation of to_fileio_unlink. */ | |
4483 | ||
f6ac5f3d PA |
4484 | int |
4485 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4486 | fileio_error *target_errno) |
7a6a1731 GB |
4487 | { |
4488 | int ret; | |
4489 | ||
4490 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4491 | filename); | |
4492 | if (ret == -1) | |
4493 | *target_errno = host_to_fileio_error (errno); | |
4494 | ||
4495 | return ret; | |
4496 | } | |
4497 | ||
aa01bd36 PA |
4498 | /* Implementation of the to_thread_events method. */ |
4499 | ||
f6ac5f3d PA |
4500 | void |
4501 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4502 | { |
4503 | report_thread_events = enable; | |
4504 | } | |
4505 | ||
25b16bc9 PA |
4506 | bool |
4507 | linux_nat_target::supports_set_thread_options (gdb_thread_options options) | |
4508 | { | |
4509 | constexpr gdb_thread_options supported_options = GDB_THREAD_OPTION_CLONE; | |
4510 | return ((options & supported_options) == options); | |
4511 | } | |
4512 | ||
f6ac5f3d PA |
4513 | linux_nat_target::linux_nat_target () |
4514 | { | |
f973ed9c DJ |
4515 | /* We don't change the stratum; this target will sit at |
4516 | process_stratum and thread_db will set at thread_stratum. This | |
4517 | is a little strange, since this is a multi-threaded-capable | |
4518 | target, but we want to be on the stack below thread_db, and we | |
4519 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4520 | } |
4521 | ||
f865ee35 JK |
4522 | /* See linux-nat.h. */ |
4523 | ||
ef632b4b | 4524 | bool |
f865ee35 | 4525 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) |
9f0bdab8 | 4526 | { |
0acd1110 | 4527 | int pid = get_ptrace_pid (ptid); |
7cc662bc | 4528 | return ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo) == 0; |
9f0bdab8 DJ |
4529 | } |
4530 | ||
7b669087 GB |
4531 | /* See nat/linux-nat.h. */ |
4532 | ||
4533 | ptid_t | |
4534 | current_lwp_ptid (void) | |
4535 | { | |
15a9e13e | 4536 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4537 | return inferior_ptid; |
4538 | } | |
4539 | ||
0ae5b8fa AB |
4540 | /* Implement 'maintenance info linux-lwps'. Displays some basic |
4541 | information about all the current lwp_info objects. */ | |
4542 | ||
4543 | static void | |
4544 | maintenance_info_lwps (const char *arg, int from_tty) | |
4545 | { | |
4546 | if (all_lwps ().size () == 0) | |
4547 | { | |
4548 | gdb_printf ("No Linux LWPs\n"); | |
4549 | return; | |
4550 | } | |
4551 | ||
4552 | /* Start the width at 8 to match the column heading below, then | |
4553 | figure out the widest ptid string. We'll use this to build our | |
4554 | output table below. */ | |
4555 | size_t ptid_width = 8; | |
4556 | for (lwp_info *lp : all_lwps ()) | |
4557 | ptid_width = std::max (ptid_width, lp->ptid.to_string ().size ()); | |
4558 | ||
4559 | /* Setup the table headers. */ | |
4560 | struct ui_out *uiout = current_uiout; | |
4561 | ui_out_emit_table table_emitter (uiout, 2, -1, "linux-lwps"); | |
4562 | uiout->table_header (ptid_width, ui_left, "lwp-ptid", _("LWP Ptid")); | |
4563 | uiout->table_header (9, ui_left, "thread-info", _("Thread ID")); | |
4564 | uiout->table_body (); | |
4565 | ||
4566 | /* Display one table row for each lwp_info. */ | |
4567 | for (lwp_info *lp : all_lwps ()) | |
4568 | { | |
4569 | ui_out_emit_tuple tuple_emitter (uiout, "lwp-entry"); | |
4570 | ||
4571 | thread_info *th = linux_target->find_thread (lp->ptid); | |
4572 | ||
4573 | uiout->field_string ("lwp-ptid", lp->ptid.to_string ().c_str ()); | |
4574 | if (th == nullptr) | |
4575 | uiout->field_string ("thread-info", "None"); | |
4576 | else | |
4577 | uiout->field_string ("thread-info", print_full_thread_id (th)); | |
4578 | ||
4579 | uiout->message ("\n"); | |
4580 | } | |
4581 | } | |
4582 | ||
6c265988 | 4583 | void _initialize_linux_nat (); |
d6b0e80f | 4584 | void |
6c265988 | 4585 | _initialize_linux_nat () |
d6b0e80f | 4586 | { |
8864ef42 | 4587 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b AB |
4588 | &debug_linux_nat, _("\ |
4589 | Set debugging of GNU/Linux native target."), _(" \ | |
4590 | Show debugging of GNU/Linux native target."), _(" \ | |
4591 | When on, print debug messages relating to the GNU/Linux native target."), | |
4592 | nullptr, | |
4593 | show_debug_linux_nat, | |
4594 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4595 | |
7a6a1731 GB |
4596 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4597 | &debug_linux_namespaces, _("\ | |
4598 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4599 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4600 | Enables printf debugging output."), | |
4601 | NULL, | |
4602 | NULL, | |
4603 | &setdebuglist, &showdebuglist); | |
4604 | ||
7feb7d06 PA |
4605 | /* Install a SIGCHLD handler. */ |
4606 | sigchld_action.sa_handler = sigchld_handler; | |
4607 | sigemptyset (&sigchld_action.sa_mask); | |
4608 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4609 | |
4610 | /* Make it the default. */ | |
7feb7d06 | 4611 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4612 | |
4613 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4614 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4615 | sigdelset (&suspend_mask, SIGCHLD); |
4616 | ||
7feb7d06 | 4617 | sigemptyset (&blocked_mask); |
774113b0 PA |
4618 | |
4619 | lwp_lwpid_htab_create (); | |
0ae5b8fa AB |
4620 | |
4621 | add_cmd ("linux-lwps", class_maintenance, maintenance_info_lwps, | |
4622 | _("List the Linux LWPS."), &maintenanceinfolist); | |
d6b0e80f AC |
4623 | } |
4624 | \f | |
4625 | ||
4626 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4627 | the GNU/Linux Threads library and therefore doesn't really belong | |
4628 | here. */ | |
4629 | ||
089436f7 TV |
4630 | /* NPTL reserves the first two RT signals, but does not provide any |
4631 | way for the debugger to query the signal numbers - fortunately | |
4632 | they don't change. */ | |
4633 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4634 | |
089436f7 TV |
4635 | /* See linux-nat.h. */ |
4636 | ||
4637 | unsigned int | |
4638 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4639 | { |
089436f7 TV |
4640 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4641 | } | |
d6b0e80f | 4642 | |
089436f7 TV |
4643 | /* See linux-nat.h. */ |
4644 | ||
4645 | int | |
4646 | lin_thread_get_thread_signal (unsigned int i) | |
4647 | { | |
4648 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4649 | return lin_thread_signals[i]; | |
d6b0e80f | 4650 | } |