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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 | ||
ced2dffb PA |
1283 | /* Detach from LP. If SIGNO_P is non-NULL, then it points to the |
1284 | signal number that should be passed to the LWP when detaching. | |
1285 | Otherwise pass any pending signal the LWP may have, if any. */ | |
1286 | ||
1287 | static void | |
1288 | detach_one_lwp (struct lwp_info *lp, int *signo_p) | |
d6b0e80f | 1289 | { |
b26b06dd AB |
1290 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1291 | ||
1292 | linux_nat_debug_printf ("lwp %s (stopped = %d)", | |
1293 | lp->ptid.to_string ().c_str (), lp->stopped); | |
1294 | ||
e38504b3 | 1295 | int lwpid = lp->ptid.lwp (); |
ced2dffb PA |
1296 | int signo; |
1297 | ||
d6b0e80f AC |
1298 | gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
1299 | ||
df5ad102 SM |
1300 | /* If the lwp/thread we are about to detach has a pending fork event, |
1301 | there is a process GDB is attached to that the core of GDB doesn't know | |
1302 | about. Detach from it. */ | |
1303 | ||
1304 | /* Check in lwp_info::status. */ | |
1305 | if (WIFSTOPPED (lp->status) && linux_is_extended_waitstatus (lp->status)) | |
1306 | { | |
1307 | int event = linux_ptrace_get_extended_event (lp->status); | |
1308 | ||
1309 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) | |
1310 | { | |
1311 | unsigned long child_pid; | |
1312 | int ret = ptrace (PTRACE_GETEVENTMSG, lp->ptid.lwp (), 0, &child_pid); | |
1313 | if (ret == 0) | |
1314 | detach_one_pid (child_pid, 0); | |
1315 | else | |
1316 | perror_warning_with_name (_("Failed to detach fork child")); | |
1317 | } | |
1318 | } | |
1319 | ||
1320 | /* Check in lwp_info::waitstatus. */ | |
1321 | if (lp->waitstatus.kind () == TARGET_WAITKIND_VFORKED | |
1322 | || lp->waitstatus.kind () == TARGET_WAITKIND_FORKED) | |
1323 | detach_one_pid (lp->waitstatus.child_ptid ().pid (), 0); | |
1324 | ||
1325 | ||
1326 | /* Check in thread_info::pending_waitstatus. */ | |
9213a6d7 | 1327 | thread_info *tp = linux_target->find_thread (lp->ptid); |
df5ad102 SM |
1328 | if (tp->has_pending_waitstatus ()) |
1329 | { | |
1330 | const target_waitstatus &ws = tp->pending_waitstatus (); | |
1331 | ||
1332 | if (ws.kind () == TARGET_WAITKIND_VFORKED | |
1333 | || ws.kind () == TARGET_WAITKIND_FORKED) | |
1334 | detach_one_pid (ws.child_ptid ().pid (), 0); | |
1335 | } | |
1336 | ||
1337 | /* Check in thread_info::pending_follow. */ | |
1338 | if (tp->pending_follow.kind () == TARGET_WAITKIND_VFORKED | |
1339 | || tp->pending_follow.kind () == TARGET_WAITKIND_FORKED) | |
1340 | detach_one_pid (tp->pending_follow.child_ptid ().pid (), 0); | |
1341 | ||
9327494e SM |
1342 | if (lp->status != 0) |
1343 | linux_nat_debug_printf ("Pending %s for %s on detach.", | |
1344 | strsignal (WSTOPSIG (lp->status)), | |
e53c95d4 | 1345 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1346 | |
a0ef4274 DJ |
1347 | /* If there is a pending SIGSTOP, get rid of it. */ |
1348 | if (lp->signalled) | |
d6b0e80f | 1349 | { |
9327494e | 1350 | linux_nat_debug_printf ("Sending SIGCONT to %s", |
e53c95d4 | 1351 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 1352 | |
ced2dffb | 1353 | kill_lwp (lwpid, SIGCONT); |
d6b0e80f | 1354 | lp->signalled = 0; |
d6b0e80f AC |
1355 | } |
1356 | ||
ced2dffb | 1357 | if (signo_p == NULL) |
d6b0e80f | 1358 | { |
a0ef4274 | 1359 | /* Pass on any pending signal for this LWP. */ |
ced2dffb PA |
1360 | signo = get_detach_signal (lp); |
1361 | } | |
1362 | else | |
1363 | signo = *signo_p; | |
a0ef4274 | 1364 | |
b26b06dd AB |
1365 | linux_nat_debug_printf ("preparing to resume lwp %s (stopped = %d)", |
1366 | lp->ptid.to_string ().c_str (), | |
1367 | lp->stopped); | |
1368 | ||
ced2dffb PA |
1369 | /* Preparing to resume may try to write registers, and fail if the |
1370 | lwp is zombie. If that happens, ignore the error. We'll handle | |
1371 | it below, when detach fails with ESRCH. */ | |
a70b8144 | 1372 | try |
ced2dffb | 1373 | { |
135340af | 1374 | linux_target->low_prepare_to_resume (lp); |
ced2dffb | 1375 | } |
230d2906 | 1376 | catch (const gdb_exception_error &ex) |
ced2dffb PA |
1377 | { |
1378 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1379 | throw; |
ced2dffb | 1380 | } |
d6b0e80f | 1381 | |
4a3ee32a | 1382 | detach_one_pid (lwpid, signo); |
ced2dffb PA |
1383 | |
1384 | delete_lwp (lp->ptid); | |
1385 | } | |
d6b0e80f | 1386 | |
ced2dffb | 1387 | static int |
d3a70e03 | 1388 | detach_callback (struct lwp_info *lp) |
ced2dffb PA |
1389 | { |
1390 | /* We don't actually detach from the thread group leader just yet. | |
1391 | If the thread group exits, we must reap the zombie clone lwps | |
1392 | before we're able to reap the leader. */ | |
e38504b3 | 1393 | if (lp->ptid.lwp () != lp->ptid.pid ()) |
ced2dffb | 1394 | detach_one_lwp (lp, NULL); |
d6b0e80f AC |
1395 | return 0; |
1396 | } | |
1397 | ||
f6ac5f3d PA |
1398 | void |
1399 | linux_nat_target::detach (inferior *inf, int from_tty) | |
d6b0e80f | 1400 | { |
b26b06dd AB |
1401 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
1402 | ||
d90e17a7 | 1403 | struct lwp_info *main_lwp; |
bc09b0c1 | 1404 | int pid = inf->pid; |
a0ef4274 | 1405 | |
ae5e0686 MK |
1406 | /* Don't unregister from the event loop, as there may be other |
1407 | inferiors running. */ | |
b84876c2 | 1408 | |
4c28f408 | 1409 | /* Stop all threads before detaching. ptrace requires that the |
30baf67b | 1410 | thread is stopped to successfully detach. */ |
d3a70e03 | 1411 | iterate_over_lwps (ptid_t (pid), stop_callback); |
4c28f408 PA |
1412 | /* ... and wait until all of them have reported back that |
1413 | they're no longer running. */ | |
d3a70e03 | 1414 | iterate_over_lwps (ptid_t (pid), stop_wait_callback); |
4c28f408 | 1415 | |
e87f0fe8 PA |
1416 | /* We can now safely remove breakpoints. We don't this in earlier |
1417 | in common code because this target doesn't currently support | |
1418 | writing memory while the inferior is running. */ | |
1419 | remove_breakpoints_inf (current_inferior ()); | |
1420 | ||
d3a70e03 | 1421 | iterate_over_lwps (ptid_t (pid), detach_callback); |
d6b0e80f AC |
1422 | |
1423 | /* Only the initial process should be left right now. */ | |
bc09b0c1 | 1424 | gdb_assert (num_lwps (pid) == 1); |
d90e17a7 | 1425 | |
f2907e49 | 1426 | main_lwp = find_lwp_pid (ptid_t (pid)); |
d6b0e80f | 1427 | |
7a7d3353 PA |
1428 | if (forks_exist_p ()) |
1429 | { | |
1430 | /* Multi-fork case. The current inferior_ptid is being detached | |
1431 | from, but there are other viable forks to debug. Detach from | |
1432 | the current fork, and context-switch to the first | |
1433 | available. */ | |
6bd6f3b6 | 1434 | linux_fork_detach (from_tty); |
7a7d3353 PA |
1435 | } |
1436 | else | |
ced2dffb | 1437 | { |
ced2dffb PA |
1438 | target_announce_detach (from_tty); |
1439 | ||
6bd6f3b6 SM |
1440 | /* Pass on any pending signal for the last LWP. */ |
1441 | int signo = get_detach_signal (main_lwp); | |
ced2dffb PA |
1442 | |
1443 | detach_one_lwp (main_lwp, &signo); | |
1444 | ||
f6ac5f3d | 1445 | detach_success (inf); |
ced2dffb | 1446 | } |
05c06f31 | 1447 | |
8a89ddbd | 1448 | close_proc_mem_file (pid); |
d6b0e80f AC |
1449 | } |
1450 | ||
8a99810d PA |
1451 | /* Resume execution of the inferior process. If STEP is nonzero, |
1452 | single-step it. If SIGNAL is nonzero, give it that signal. */ | |
1453 | ||
1454 | static void | |
23f238d3 PA |
1455 | linux_resume_one_lwp_throw (struct lwp_info *lp, int step, |
1456 | enum gdb_signal signo) | |
8a99810d | 1457 | { |
8a99810d | 1458 | lp->step = step; |
9c02b525 PA |
1459 | |
1460 | /* stop_pc doubles as the PC the LWP had when it was last resumed. | |
1461 | We only presently need that if the LWP is stepped though (to | |
1462 | handle the case of stepping a breakpoint instruction). */ | |
1463 | if (step) | |
1464 | { | |
5b6d1e4f | 1465 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
1466 | |
1467 | lp->stop_pc = regcache_read_pc (regcache); | |
1468 | } | |
1469 | else | |
1470 | lp->stop_pc = 0; | |
1471 | ||
135340af | 1472 | linux_target->low_prepare_to_resume (lp); |
f6ac5f3d | 1473 | linux_target->low_resume (lp->ptid, step, signo); |
23f238d3 PA |
1474 | |
1475 | /* Successfully resumed. Clear state that no longer makes sense, | |
1476 | and mark the LWP as running. Must not do this before resuming | |
1477 | otherwise if that fails other code will be confused. E.g., we'd | |
1478 | later try to stop the LWP and hang forever waiting for a stop | |
1479 | status. Note that we must not throw after this is cleared, | |
1480 | otherwise handle_zombie_lwp_error would get confused. */ | |
8a99810d | 1481 | lp->stopped = 0; |
1ad3de98 | 1482 | lp->core = -1; |
23f238d3 | 1483 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; |
5b6d1e4f | 1484 | registers_changed_ptid (linux_target, lp->ptid); |
8a99810d PA |
1485 | } |
1486 | ||
23f238d3 PA |
1487 | /* Called when we try to resume a stopped LWP and that errors out. If |
1488 | the LWP is no longer in ptrace-stopped state (meaning it's zombie, | |
1489 | or about to become), discard the error, clear any pending status | |
1490 | the LWP may have, and return true (we'll collect the exit status | |
1491 | soon enough). Otherwise, return false. */ | |
1492 | ||
1493 | static int | |
1494 | check_ptrace_stopped_lwp_gone (struct lwp_info *lp) | |
1495 | { | |
1496 | /* If we get an error after resuming the LWP successfully, we'd | |
1497 | confuse !T state for the LWP being gone. */ | |
1498 | gdb_assert (lp->stopped); | |
1499 | ||
1500 | /* We can't just check whether the LWP is in 'Z (Zombie)' state, | |
1501 | because even if ptrace failed with ESRCH, the tracee may be "not | |
1502 | yet fully dead", but already refusing ptrace requests. In that | |
1503 | case the tracee has 'R (Running)' state for a little bit | |
1504 | (observed in Linux 3.18). See also the note on ESRCH in the | |
1505 | ptrace(2) man page. Instead, check whether the LWP has any state | |
1506 | other than ptrace-stopped. */ | |
1507 | ||
1508 | /* Don't assume anything if /proc/PID/status can't be read. */ | |
e38504b3 | 1509 | if (linux_proc_pid_is_trace_stopped_nowarn (lp->ptid.lwp ()) == 0) |
23f238d3 PA |
1510 | { |
1511 | lp->stop_reason = TARGET_STOPPED_BY_NO_REASON; | |
1512 | lp->status = 0; | |
183be222 | 1513 | lp->waitstatus.set_ignore (); |
23f238d3 PA |
1514 | return 1; |
1515 | } | |
1516 | return 0; | |
1517 | } | |
1518 | ||
1519 | /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP | |
1520 | disappears while we try to resume it. */ | |
1521 | ||
1522 | static void | |
1523 | linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) | |
1524 | { | |
a70b8144 | 1525 | try |
23f238d3 PA |
1526 | { |
1527 | linux_resume_one_lwp_throw (lp, step, signo); | |
1528 | } | |
230d2906 | 1529 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
1530 | { |
1531 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 1532 | throw; |
23f238d3 | 1533 | } |
23f238d3 PA |
1534 | } |
1535 | ||
d6b0e80f AC |
1536 | /* Resume LP. */ |
1537 | ||
25289eb2 | 1538 | static void |
e5ef252a | 1539 | resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo) |
d6b0e80f | 1540 | { |
25289eb2 | 1541 | if (lp->stopped) |
6c95b8df | 1542 | { |
5b6d1e4f | 1543 | struct inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
25289eb2 PA |
1544 | |
1545 | if (inf->vfork_child != NULL) | |
1546 | { | |
8a9da63e | 1547 | linux_nat_debug_printf ("Not resuming sibling %s (vfork parent)", |
e53c95d4 | 1548 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1549 | } |
8a99810d | 1550 | else if (!lwp_status_pending_p (lp)) |
25289eb2 | 1551 | { |
9327494e | 1552 | linux_nat_debug_printf ("Resuming sibling %s, %s, %s", |
e53c95d4 | 1553 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1554 | (signo != GDB_SIGNAL_0 |
1555 | ? strsignal (gdb_signal_to_host (signo)) | |
1556 | : "0"), | |
1557 | step ? "step" : "resume"); | |
25289eb2 | 1558 | |
8a99810d | 1559 | linux_resume_one_lwp (lp, step, signo); |
25289eb2 PA |
1560 | } |
1561 | else | |
1562 | { | |
9327494e | 1563 | linux_nat_debug_printf ("Not resuming sibling %s (has pending)", |
e53c95d4 | 1564 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1565 | } |
6c95b8df | 1566 | } |
25289eb2 | 1567 | else |
9327494e | 1568 | linux_nat_debug_printf ("Not resuming sibling %s (not stopped)", |
e53c95d4 | 1569 | lp->ptid.to_string ().c_str ()); |
25289eb2 | 1570 | } |
d6b0e80f | 1571 | |
8817a6f2 PA |
1572 | /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing. |
1573 | Resume LWP with the last stop signal, if it is in pass state. */ | |
e5ef252a | 1574 | |
25289eb2 | 1575 | static int |
d3a70e03 | 1576 | linux_nat_resume_callback (struct lwp_info *lp, struct lwp_info *except) |
25289eb2 | 1577 | { |
e5ef252a PA |
1578 | enum gdb_signal signo = GDB_SIGNAL_0; |
1579 | ||
8817a6f2 PA |
1580 | if (lp == except) |
1581 | return 0; | |
1582 | ||
e5ef252a PA |
1583 | if (lp->stopped) |
1584 | { | |
1585 | struct thread_info *thread; | |
1586 | ||
9213a6d7 | 1587 | thread = linux_target->find_thread (lp->ptid); |
e5ef252a PA |
1588 | if (thread != NULL) |
1589 | { | |
1edb66d8 SM |
1590 | signo = thread->stop_signal (); |
1591 | thread->set_stop_signal (GDB_SIGNAL_0); | |
e5ef252a PA |
1592 | } |
1593 | } | |
1594 | ||
1595 | resume_lwp (lp, 0, signo); | |
d6b0e80f AC |
1596 | return 0; |
1597 | } | |
1598 | ||
1599 | static int | |
d3a70e03 | 1600 | resume_clear_callback (struct lwp_info *lp) |
d6b0e80f AC |
1601 | { |
1602 | lp->resumed = 0; | |
25289eb2 | 1603 | lp->last_resume_kind = resume_stop; |
d6b0e80f AC |
1604 | return 0; |
1605 | } | |
1606 | ||
1607 | static int | |
d3a70e03 | 1608 | resume_set_callback (struct lwp_info *lp) |
d6b0e80f AC |
1609 | { |
1610 | lp->resumed = 1; | |
25289eb2 | 1611 | lp->last_resume_kind = resume_continue; |
d6b0e80f AC |
1612 | return 0; |
1613 | } | |
1614 | ||
f6ac5f3d | 1615 | void |
d51926f0 | 1616 | linux_nat_target::resume (ptid_t scope_ptid, int step, enum gdb_signal signo) |
d6b0e80f AC |
1617 | { |
1618 | struct lwp_info *lp; | |
d6b0e80f | 1619 | |
9327494e SM |
1620 | linux_nat_debug_printf ("Preparing to %s %s, %s, inferior_ptid %s", |
1621 | step ? "step" : "resume", | |
d51926f0 | 1622 | scope_ptid.to_string ().c_str (), |
9327494e SM |
1623 | (signo != GDB_SIGNAL_0 |
1624 | ? strsignal (gdb_signal_to_host (signo)) : "0"), | |
e53c95d4 | 1625 | inferior_ptid.to_string ().c_str ()); |
76f50ad1 | 1626 | |
7da6a5b9 LM |
1627 | /* Mark the lwps we're resuming as resumed and update their |
1628 | last_resume_kind to resume_continue. */ | |
d51926f0 | 1629 | iterate_over_lwps (scope_ptid, resume_set_callback); |
d6b0e80f | 1630 | |
d51926f0 | 1631 | lp = find_lwp_pid (inferior_ptid); |
9f0bdab8 | 1632 | gdb_assert (lp != NULL); |
d6b0e80f | 1633 | |
9f0bdab8 | 1634 | /* Remember if we're stepping. */ |
25289eb2 | 1635 | lp->last_resume_kind = step ? resume_step : resume_continue; |
d6b0e80f | 1636 | |
9f0bdab8 DJ |
1637 | /* If we have a pending wait status for this thread, there is no |
1638 | point in resuming the process. But first make sure that | |
1639 | linux_nat_wait won't preemptively handle the event - we | |
1640 | should never take this short-circuit if we are going to | |
1641 | leave LP running, since we have skipped resuming all the | |
1642 | other threads. This bit of code needs to be synchronized | |
1643 | with linux_nat_wait. */ | |
76f50ad1 | 1644 | |
9f0bdab8 DJ |
1645 | if (lp->status && WIFSTOPPED (lp->status)) |
1646 | { | |
2455069d UW |
1647 | if (!lp->step |
1648 | && WSTOPSIG (lp->status) | |
1649 | && sigismember (&pass_mask, WSTOPSIG (lp->status))) | |
d6b0e80f | 1650 | { |
9327494e SM |
1651 | linux_nat_debug_printf |
1652 | ("Not short circuiting for ignored status 0x%x", lp->status); | |
9f0bdab8 | 1653 | |
d6b0e80f AC |
1654 | /* FIXME: What should we do if we are supposed to continue |
1655 | this thread with a signal? */ | |
a493e3e2 | 1656 | gdb_assert (signo == GDB_SIGNAL_0); |
2ea28649 | 1657 | signo = gdb_signal_from_host (WSTOPSIG (lp->status)); |
9f0bdab8 DJ |
1658 | lp->status = 0; |
1659 | } | |
1660 | } | |
76f50ad1 | 1661 | |
8a99810d | 1662 | if (lwp_status_pending_p (lp)) |
9f0bdab8 DJ |
1663 | { |
1664 | /* FIXME: What should we do if we are supposed to continue | |
1665 | this thread with a signal? */ | |
a493e3e2 | 1666 | gdb_assert (signo == GDB_SIGNAL_0); |
76f50ad1 | 1667 | |
57573e54 PA |
1668 | linux_nat_debug_printf ("Short circuiting for status %s", |
1669 | pending_status_str (lp).c_str ()); | |
d6b0e80f | 1670 | |
7feb7d06 PA |
1671 | if (target_can_async_p ()) |
1672 | { | |
4a570176 | 1673 | target_async (true); |
7feb7d06 PA |
1674 | /* Tell the event loop we have something to process. */ |
1675 | async_file_mark (); | |
1676 | } | |
9f0bdab8 | 1677 | return; |
d6b0e80f AC |
1678 | } |
1679 | ||
d51926f0 PA |
1680 | /* No use iterating unless we're resuming other threads. */ |
1681 | if (scope_ptid != lp->ptid) | |
1682 | iterate_over_lwps (scope_ptid, [=] (struct lwp_info *info) | |
1683 | { | |
1684 | return linux_nat_resume_callback (info, lp); | |
1685 | }); | |
d90e17a7 | 1686 | |
9327494e SM |
1687 | linux_nat_debug_printf ("%s %s, %s (resume event thread)", |
1688 | step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 1689 | lp->ptid.to_string ().c_str (), |
9327494e SM |
1690 | (signo != GDB_SIGNAL_0 |
1691 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
b84876c2 | 1692 | |
2bf6fb9d | 1693 | linux_resume_one_lwp (lp, step, signo); |
d6b0e80f AC |
1694 | } |
1695 | ||
c5f62d5f | 1696 | /* Send a signal to an LWP. */ |
d6b0e80f AC |
1697 | |
1698 | static int | |
1699 | kill_lwp (int lwpid, int signo) | |
1700 | { | |
4a6ed09b | 1701 | int ret; |
d6b0e80f | 1702 | |
4a6ed09b PA |
1703 | errno = 0; |
1704 | ret = syscall (__NR_tkill, lwpid, signo); | |
1705 | if (errno == ENOSYS) | |
1706 | { | |
1707 | /* If tkill fails, then we are not using nptl threads, a | |
1708 | configuration we no longer support. */ | |
1709 | perror_with_name (("tkill")); | |
1710 | } | |
1711 | return ret; | |
d6b0e80f AC |
1712 | } |
1713 | ||
ca2163eb PA |
1714 | /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
1715 | event, check if the core is interested in it: if not, ignore the | |
1716 | event, and keep waiting; otherwise, we need to toggle the LWP's | |
1717 | syscall entry/exit status, since the ptrace event itself doesn't | |
1718 | indicate it, and report the trap to higher layers. */ | |
1719 | ||
1720 | static int | |
1721 | linux_handle_syscall_trap (struct lwp_info *lp, int stopping) | |
1722 | { | |
1723 | struct target_waitstatus *ourstatus = &lp->waitstatus; | |
1724 | struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); | |
9213a6d7 | 1725 | thread_info *thread = linux_target->find_thread (lp->ptid); |
00431a78 | 1726 | int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, thread); |
ca2163eb PA |
1727 | |
1728 | if (stopping) | |
1729 | { | |
1730 | /* If we're stopping threads, there's a SIGSTOP pending, which | |
1731 | makes it so that the LWP reports an immediate syscall return, | |
1732 | followed by the SIGSTOP. Skip seeing that "return" using | |
1733 | PTRACE_CONT directly, and let stop_wait_callback collect the | |
1734 | SIGSTOP. Later when the thread is resumed, a new syscall | |
1735 | entry event. If we didn't do this (and returned 0), we'd | |
1736 | leave a syscall entry pending, and our caller, by using | |
1737 | PTRACE_CONT to collect the SIGSTOP, skips the syscall return | |
1738 | itself. Later, when the user re-resumes this LWP, we'd see | |
1739 | another syscall entry event and we'd mistake it for a return. | |
1740 | ||
1741 | If stop_wait_callback didn't force the SIGSTOP out of the LWP | |
1742 | (leaving immediately with LWP->signalled set, without issuing | |
1743 | a PTRACE_CONT), it would still be problematic to leave this | |
1744 | syscall enter pending, as later when the thread is resumed, | |
1745 | it would then see the same syscall exit mentioned above, | |
1746 | followed by the delayed SIGSTOP, while the syscall didn't | |
1747 | actually get to execute. It seems it would be even more | |
1748 | confusing to the user. */ | |
1749 | ||
9327494e SM |
1750 | linux_nat_debug_printf |
1751 | ("ignoring syscall %d for LWP %ld (stopping threads), resuming with " | |
1752 | "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1753 | |
1754 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
e38504b3 | 1755 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 1756 | lp->stopped = 0; |
ca2163eb PA |
1757 | return 1; |
1758 | } | |
1759 | ||
bfd09d20 JS |
1760 | /* Always update the entry/return state, even if this particular |
1761 | syscall isn't interesting to the core now. In async mode, | |
1762 | the user could install a new catchpoint for this syscall | |
1763 | between syscall enter/return, and we'll need to know to | |
1764 | report a syscall return if that happens. */ | |
1765 | lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1766 | ? TARGET_WAITKIND_SYSCALL_RETURN | |
1767 | : TARGET_WAITKIND_SYSCALL_ENTRY); | |
1768 | ||
ca2163eb PA |
1769 | if (catch_syscall_enabled ()) |
1770 | { | |
ca2163eb PA |
1771 | if (catching_syscall_number (syscall_number)) |
1772 | { | |
1773 | /* Alright, an event to report. */ | |
183be222 SM |
1774 | if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY) |
1775 | ourstatus->set_syscall_entry (syscall_number); | |
1776 | else if (lp->syscall_state == TARGET_WAITKIND_SYSCALL_RETURN) | |
1777 | ourstatus->set_syscall_return (syscall_number); | |
1778 | else | |
1779 | gdb_assert_not_reached ("unexpected syscall state"); | |
ca2163eb | 1780 | |
9327494e SM |
1781 | linux_nat_debug_printf |
1782 | ("stopping for %s of syscall %d for LWP %ld", | |
1783 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1784 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
1785 | ||
ca2163eb PA |
1786 | return 0; |
1787 | } | |
1788 | ||
9327494e SM |
1789 | linux_nat_debug_printf |
1790 | ("ignoring %s of syscall %d for LWP %ld", | |
1791 | (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY | |
1792 | ? "entry" : "return"), syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1793 | } |
1794 | else | |
1795 | { | |
1796 | /* If we had been syscall tracing, and hence used PT_SYSCALL | |
1797 | before on this LWP, it could happen that the user removes all | |
1798 | syscall catchpoints before we get to process this event. | |
1799 | There are two noteworthy issues here: | |
1800 | ||
1801 | - When stopped at a syscall entry event, resuming with | |
1802 | PT_STEP still resumes executing the syscall and reports a | |
1803 | syscall return. | |
1804 | ||
1805 | - Only PT_SYSCALL catches syscall enters. If we last | |
1806 | single-stepped this thread, then this event can't be a | |
1807 | syscall enter. If we last single-stepped this thread, this | |
1808 | has to be a syscall exit. | |
1809 | ||
1810 | The points above mean that the next resume, be it PT_STEP or | |
1811 | PT_CONTINUE, can not trigger a syscall trace event. */ | |
9327494e SM |
1812 | linux_nat_debug_printf |
1813 | ("caught syscall event with no syscall catchpoints. %d for LWP %ld, " | |
1814 | "ignoring", syscall_number, lp->ptid.lwp ()); | |
ca2163eb PA |
1815 | lp->syscall_state = TARGET_WAITKIND_IGNORE; |
1816 | } | |
1817 | ||
1818 | /* The core isn't interested in this event. For efficiency, avoid | |
1819 | stopping all threads only to have the core resume them all again. | |
1820 | Since we're not stopping threads, if we're still syscall tracing | |
1821 | and not stepping, we can't use PTRACE_CONT here, as we'd miss any | |
1822 | subsequent syscall. Simply resume using the inf-ptrace layer, | |
1823 | which knows when to use PT_SYSCALL or PT_CONTINUE. */ | |
1824 | ||
8a99810d | 1825 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
ca2163eb PA |
1826 | return 1; |
1827 | } | |
1828 | ||
3d799a95 DJ |
1829 | /* Handle a GNU/Linux extended wait response. If we see a clone |
1830 | event, we need to add the new LWP to our list (and not report the | |
1831 | trap to higher layers). This function returns non-zero if the | |
1832 | event should be ignored and we should wait again. If STOPPING is | |
1833 | true, the new LWP remains stopped, otherwise it is continued. */ | |
d6b0e80f AC |
1834 | |
1835 | static int | |
4dd63d48 | 1836 | linux_handle_extended_wait (struct lwp_info *lp, int status) |
d6b0e80f | 1837 | { |
e38504b3 | 1838 | int pid = lp->ptid.lwp (); |
3d799a95 | 1839 | struct target_waitstatus *ourstatus = &lp->waitstatus; |
89a5711c | 1840 | int event = linux_ptrace_get_extended_event (status); |
d6b0e80f | 1841 | |
bfd09d20 JS |
1842 | /* All extended events we currently use are mid-syscall. Only |
1843 | PTRACE_EVENT_STOP is delivered more like a signal-stop, but | |
1844 | you have to be using PTRACE_SEIZE to get that. */ | |
1845 | lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY; | |
1846 | ||
3d799a95 DJ |
1847 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
1848 | || event == PTRACE_EVENT_CLONE) | |
d6b0e80f | 1849 | { |
3d799a95 DJ |
1850 | unsigned long new_pid; |
1851 | int ret; | |
1852 | ||
1853 | ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); | |
6fc19103 | 1854 | |
3d799a95 DJ |
1855 | /* If we haven't already seen the new PID stop, wait for it now. */ |
1856 | if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) | |
1857 | { | |
1858 | /* The new child has a pending SIGSTOP. We can't affect it until it | |
1859 | hits the SIGSTOP, but we're already attached. */ | |
4a6ed09b | 1860 | ret = my_waitpid (new_pid, &status, __WALL); |
3d799a95 DJ |
1861 | if (ret == -1) |
1862 | perror_with_name (_("waiting for new child")); | |
1863 | else if (ret != new_pid) | |
f34652de | 1864 | internal_error (_("wait returned unexpected PID %d"), ret); |
3d799a95 | 1865 | else if (!WIFSTOPPED (status)) |
f34652de | 1866 | internal_error (_("wait returned unexpected status 0x%x"), status); |
3d799a95 DJ |
1867 | } |
1868 | ||
183be222 | 1869 | ptid_t child_ptid (new_pid, new_pid); |
3d799a95 | 1870 | |
26cb8b7c PA |
1871 | if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK) |
1872 | { | |
8a89ddbd PA |
1873 | open_proc_mem_file (child_ptid); |
1874 | ||
26cb8b7c PA |
1875 | /* The arch-specific native code may need to know about new |
1876 | forks even if those end up never mapped to an | |
1877 | inferior. */ | |
135340af | 1878 | linux_target->low_new_fork (lp, new_pid); |
26cb8b7c | 1879 | } |
1310c1b0 PFC |
1880 | else if (event == PTRACE_EVENT_CLONE) |
1881 | { | |
1882 | linux_target->low_new_clone (lp, new_pid); | |
1883 | } | |
26cb8b7c | 1884 | |
2277426b | 1885 | if (event == PTRACE_EVENT_FORK |
e99b03dc | 1886 | && linux_fork_checkpointing_p (lp->ptid.pid ())) |
2277426b | 1887 | { |
2277426b PA |
1888 | /* Handle checkpointing by linux-fork.c here as a special |
1889 | case. We don't want the follow-fork-mode or 'catch fork' | |
1890 | to interfere with this. */ | |
1891 | ||
1892 | /* This won't actually modify the breakpoint list, but will | |
1893 | physically remove the breakpoints from the child. */ | |
184ea2f7 | 1894 | detach_breakpoints (ptid_t (new_pid, new_pid)); |
2277426b PA |
1895 | |
1896 | /* Retain child fork in ptrace (stopped) state. */ | |
14571dad MS |
1897 | if (!find_fork_pid (new_pid)) |
1898 | add_fork (new_pid); | |
2277426b PA |
1899 | |
1900 | /* Report as spurious, so that infrun doesn't want to follow | |
1901 | this fork. We're actually doing an infcall in | |
1902 | linux-fork.c. */ | |
183be222 | 1903 | ourstatus->set_spurious (); |
2277426b PA |
1904 | |
1905 | /* Report the stop to the core. */ | |
1906 | return 0; | |
1907 | } | |
1908 | ||
3d799a95 | 1909 | if (event == PTRACE_EVENT_FORK) |
183be222 | 1910 | ourstatus->set_forked (child_ptid); |
3d799a95 | 1911 | else if (event == PTRACE_EVENT_VFORK) |
183be222 | 1912 | ourstatus->set_vforked (child_ptid); |
4dd63d48 | 1913 | else if (event == PTRACE_EVENT_CLONE) |
3d799a95 | 1914 | { |
78768c4a JK |
1915 | struct lwp_info *new_lp; |
1916 | ||
183be222 | 1917 | ourstatus->set_ignore (); |
78768c4a | 1918 | |
9327494e SM |
1919 | linux_nat_debug_printf |
1920 | ("Got clone event from LWP %d, new child is LWP %ld", pid, new_pid); | |
3c4d7e12 | 1921 | |
184ea2f7 | 1922 | new_lp = add_lwp (ptid_t (lp->ptid.pid (), new_pid)); |
4c28f408 | 1923 | new_lp->stopped = 1; |
4dd63d48 | 1924 | new_lp->resumed = 1; |
d6b0e80f | 1925 | |
2db9a427 PA |
1926 | /* If the thread_db layer is active, let it record the user |
1927 | level thread id and status, and add the thread to GDB's | |
1928 | list. */ | |
1929 | if (!thread_db_notice_clone (lp->ptid, new_lp->ptid)) | |
3d799a95 | 1930 | { |
2db9a427 PA |
1931 | /* The process is not using thread_db. Add the LWP to |
1932 | GDB's list. */ | |
5b6d1e4f | 1933 | add_thread (linux_target, new_lp->ptid); |
2db9a427 | 1934 | } |
4c28f408 | 1935 | |
2ee52aa4 | 1936 | /* Even if we're stopping the thread for some reason |
4dd63d48 PA |
1937 | internal to this module, from the perspective of infrun |
1938 | and the user/frontend, this new thread is running until | |
1939 | it next reports a stop. */ | |
719546c4 SM |
1940 | set_running (linux_target, new_lp->ptid, true); |
1941 | set_executing (linux_target, new_lp->ptid, true); | |
4c28f408 | 1942 | |
4dd63d48 | 1943 | if (WSTOPSIG (status) != SIGSTOP) |
79395f92 | 1944 | { |
4dd63d48 PA |
1945 | /* This can happen if someone starts sending signals to |
1946 | the new thread before it gets a chance to run, which | |
1947 | have a lower number than SIGSTOP (e.g. SIGUSR1). | |
1948 | This is an unlikely case, and harder to handle for | |
1949 | fork / vfork than for clone, so we do not try - but | |
1950 | we handle it for clone events here. */ | |
1951 | ||
1952 | new_lp->signalled = 1; | |
1953 | ||
79395f92 PA |
1954 | /* We created NEW_LP so it cannot yet contain STATUS. */ |
1955 | gdb_assert (new_lp->status == 0); | |
1956 | ||
1957 | /* Save the wait status to report later. */ | |
9327494e SM |
1958 | linux_nat_debug_printf |
1959 | ("waitpid of new LWP %ld, saving status %s", | |
8d06918f | 1960 | (long) new_lp->ptid.lwp (), status_to_str (status).c_str ()); |
79395f92 PA |
1961 | new_lp->status = status; |
1962 | } | |
aa01bd36 PA |
1963 | else if (report_thread_events) |
1964 | { | |
183be222 | 1965 | new_lp->waitstatus.set_thread_created (); |
aa01bd36 PA |
1966 | new_lp->status = status; |
1967 | } | |
79395f92 | 1968 | |
3d799a95 DJ |
1969 | return 1; |
1970 | } | |
1971 | ||
1972 | return 0; | |
d6b0e80f AC |
1973 | } |
1974 | ||
3d799a95 DJ |
1975 | if (event == PTRACE_EVENT_EXEC) |
1976 | { | |
9327494e | 1977 | linux_nat_debug_printf ("Got exec event from LWP %ld", lp->ptid.lwp ()); |
a75724bc | 1978 | |
8a89ddbd PA |
1979 | /* Close the previous /proc/PID/mem file for this inferior, |
1980 | which was using the address space which is now gone. | |
1981 | Reading/writing from this file would return 0/EOF. */ | |
1982 | close_proc_mem_file (lp->ptid.pid ()); | |
1983 | ||
1984 | /* Open a new file for the new address space. */ | |
1985 | open_proc_mem_file (lp->ptid); | |
05c06f31 | 1986 | |
183be222 SM |
1987 | ourstatus->set_execd |
1988 | (make_unique_xstrdup (linux_proc_pid_to_exec_file (pid))); | |
3d799a95 | 1989 | |
8af756ef PA |
1990 | /* The thread that execed must have been resumed, but, when a |
1991 | thread execs, it changes its tid to the tgid, and the old | |
1992 | tgid thread might have not been resumed. */ | |
1993 | lp->resumed = 1; | |
6c95b8df PA |
1994 | return 0; |
1995 | } | |
1996 | ||
1997 | if (event == PTRACE_EVENT_VFORK_DONE) | |
1998 | { | |
9327494e | 1999 | linux_nat_debug_printf |
5a0c4a06 SM |
2000 | ("Got PTRACE_EVENT_VFORK_DONE from LWP %ld", |
2001 | lp->ptid.lwp ()); | |
2002 | ourstatus->set_vfork_done (); | |
2003 | return 0; | |
3d799a95 DJ |
2004 | } |
2005 | ||
f34652de | 2006 | internal_error (_("unknown ptrace event %d"), event); |
d6b0e80f AC |
2007 | } |
2008 | ||
9c3a5d93 PA |
2009 | /* Suspend waiting for a signal. We're mostly interested in |
2010 | SIGCHLD/SIGINT. */ | |
2011 | ||
2012 | static void | |
2013 | wait_for_signal () | |
2014 | { | |
9327494e | 2015 | linux_nat_debug_printf ("about to sigsuspend"); |
9c3a5d93 PA |
2016 | sigsuspend (&suspend_mask); |
2017 | ||
2018 | /* If the quit flag is set, it means that the user pressed Ctrl-C | |
2019 | and we're debugging a process that is running on a separate | |
2020 | terminal, so we must forward the Ctrl-C to the inferior. (If the | |
2021 | inferior is sharing GDB's terminal, then the Ctrl-C reaches the | |
2022 | inferior directly.) We must do this here because functions that | |
2023 | need to block waiting for a signal loop forever until there's an | |
2024 | event to report before returning back to the event loop. */ | |
2025 | if (!target_terminal::is_ours ()) | |
2026 | { | |
2027 | if (check_quit_flag ()) | |
2028 | target_pass_ctrlc (); | |
2029 | } | |
2030 | } | |
2031 | ||
d6b0e80f AC |
2032 | /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
2033 | exited. */ | |
2034 | ||
2035 | static int | |
2036 | wait_lwp (struct lwp_info *lp) | |
2037 | { | |
2038 | pid_t pid; | |
432b4d03 | 2039 | int status = 0; |
d6b0e80f | 2040 | int thread_dead = 0; |
432b4d03 | 2041 | sigset_t prev_mask; |
d6b0e80f AC |
2042 | |
2043 | gdb_assert (!lp->stopped); | |
2044 | gdb_assert (lp->status == 0); | |
2045 | ||
432b4d03 JK |
2046 | /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
2047 | block_child_signals (&prev_mask); | |
2048 | ||
2049 | for (;;) | |
d6b0e80f | 2050 | { |
e38504b3 | 2051 | pid = my_waitpid (lp->ptid.lwp (), &status, __WALL | WNOHANG); |
a9f4bb21 PA |
2052 | if (pid == -1 && errno == ECHILD) |
2053 | { | |
2054 | /* The thread has previously exited. We need to delete it | |
4a6ed09b PA |
2055 | now because if this was a non-leader thread execing, we |
2056 | won't get an exit event. See comments on exec events at | |
2057 | the top of the file. */ | |
a9f4bb21 | 2058 | thread_dead = 1; |
9327494e | 2059 | linux_nat_debug_printf ("%s vanished.", |
e53c95d4 | 2060 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2061 | } |
432b4d03 JK |
2062 | if (pid != 0) |
2063 | break; | |
2064 | ||
2065 | /* Bugs 10970, 12702. | |
2066 | Thread group leader may have exited in which case we'll lock up in | |
2067 | waitpid if there are other threads, even if they are all zombies too. | |
2068 | Basically, we're not supposed to use waitpid this way. | |
4a6ed09b PA |
2069 | tkill(pid,0) cannot be used here as it gets ESRCH for both |
2070 | for zombie and running processes. | |
432b4d03 JK |
2071 | |
2072 | As a workaround, check if we're waiting for the thread group leader and | |
2073 | if it's a zombie, and avoid calling waitpid if it is. | |
2074 | ||
2075 | This is racy, what if the tgl becomes a zombie right after we check? | |
2076 | Therefore always use WNOHANG with sigsuspend - it is equivalent to | |
5f572dec | 2077 | waiting waitpid but linux_proc_pid_is_zombie is safe this way. */ |
432b4d03 | 2078 | |
e38504b3 TT |
2079 | if (lp->ptid.pid () == lp->ptid.lwp () |
2080 | && linux_proc_pid_is_zombie (lp->ptid.lwp ())) | |
d6b0e80f | 2081 | { |
d6b0e80f | 2082 | thread_dead = 1; |
9327494e | 2083 | linux_nat_debug_printf ("Thread group leader %s vanished.", |
e53c95d4 | 2084 | lp->ptid.to_string ().c_str ()); |
432b4d03 | 2085 | break; |
d6b0e80f | 2086 | } |
432b4d03 JK |
2087 | |
2088 | /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers | |
2089 | get invoked despite our caller had them intentionally blocked by | |
2090 | block_child_signals. This is sensitive only to the loop of | |
2091 | linux_nat_wait_1 and there if we get called my_waitpid gets called | |
2092 | again before it gets to sigsuspend so we can safely let the handlers | |
2093 | get executed here. */ | |
9c3a5d93 | 2094 | wait_for_signal (); |
432b4d03 JK |
2095 | } |
2096 | ||
2097 | restore_child_signals_mask (&prev_mask); | |
2098 | ||
d6b0e80f AC |
2099 | if (!thread_dead) |
2100 | { | |
e38504b3 | 2101 | gdb_assert (pid == lp->ptid.lwp ()); |
d6b0e80f | 2102 | |
9327494e | 2103 | linux_nat_debug_printf ("waitpid %s received %s", |
e53c95d4 | 2104 | lp->ptid.to_string ().c_str (), |
8d06918f | 2105 | status_to_str (status).c_str ()); |
d6b0e80f | 2106 | |
a9f4bb21 PA |
2107 | /* Check if the thread has exited. */ |
2108 | if (WIFEXITED (status) || WIFSIGNALED (status)) | |
2109 | { | |
aa01bd36 | 2110 | if (report_thread_events |
e38504b3 | 2111 | || lp->ptid.pid () == lp->ptid.lwp ()) |
69dde7dc | 2112 | { |
9327494e | 2113 | linux_nat_debug_printf ("LWP %d exited.", lp->ptid.pid ()); |
69dde7dc | 2114 | |
aa01bd36 | 2115 | /* If this is the leader exiting, it means the whole |
69dde7dc PA |
2116 | process is gone. Store the status to report to the |
2117 | core. Store it in lp->waitstatus, because lp->status | |
2118 | would be ambiguous (W_EXITCODE(0,0) == 0). */ | |
7509b829 | 2119 | lp->waitstatus = host_status_to_waitstatus (status); |
69dde7dc PA |
2120 | return 0; |
2121 | } | |
2122 | ||
a9f4bb21 | 2123 | thread_dead = 1; |
9327494e | 2124 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2125 | lp->ptid.to_string ().c_str ()); |
a9f4bb21 | 2126 | } |
d6b0e80f AC |
2127 | } |
2128 | ||
2129 | if (thread_dead) | |
2130 | { | |
e26af52f | 2131 | exit_lwp (lp); |
d6b0e80f AC |
2132 | return 0; |
2133 | } | |
2134 | ||
2135 | gdb_assert (WIFSTOPPED (status)); | |
8817a6f2 | 2136 | lp->stopped = 1; |
d6b0e80f | 2137 | |
8784d563 PA |
2138 | if (lp->must_set_ptrace_flags) |
2139 | { | |
5b6d1e4f | 2140 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2141 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2142 | |
e38504b3 | 2143 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2144 | lp->must_set_ptrace_flags = 0; |
2145 | } | |
2146 | ||
ca2163eb PA |
2147 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2148 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2149 | { | |
2150 | /* No longer need the sysgood bit. The ptrace event ends up | |
2151 | recorded in lp->waitstatus if we care for it. We can carry | |
2152 | on handling the event like a regular SIGTRAP from here | |
2153 | on. */ | |
2154 | status = W_STOPCODE (SIGTRAP); | |
2155 | if (linux_handle_syscall_trap (lp, 1)) | |
2156 | return wait_lwp (lp); | |
2157 | } | |
bfd09d20 JS |
2158 | else |
2159 | { | |
2160 | /* Almost all other ptrace-stops are known to be outside of system | |
2161 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2162 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2163 | } | |
ca2163eb | 2164 | |
d6b0e80f | 2165 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2166 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2167 | && linux_is_extended_waitstatus (status)) | |
d6b0e80f | 2168 | { |
9327494e | 2169 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
4dd63d48 | 2170 | linux_handle_extended_wait (lp, status); |
20ba1ce6 | 2171 | return 0; |
d6b0e80f AC |
2172 | } |
2173 | ||
2174 | return status; | |
2175 | } | |
2176 | ||
2177 | /* Send a SIGSTOP to LP. */ | |
2178 | ||
2179 | static int | |
d3a70e03 | 2180 | stop_callback (struct lwp_info *lp) |
d6b0e80f AC |
2181 | { |
2182 | if (!lp->stopped && !lp->signalled) | |
2183 | { | |
2184 | int ret; | |
2185 | ||
9327494e | 2186 | linux_nat_debug_printf ("kill %s **<SIGSTOP>**", |
e53c95d4 | 2187 | lp->ptid.to_string ().c_str ()); |
9327494e | 2188 | |
d6b0e80f | 2189 | errno = 0; |
e38504b3 | 2190 | ret = kill_lwp (lp->ptid.lwp (), SIGSTOP); |
9327494e | 2191 | linux_nat_debug_printf ("lwp kill %d %s", ret, |
d6b0e80f | 2192 | errno ? safe_strerror (errno) : "ERRNO-OK"); |
d6b0e80f AC |
2193 | |
2194 | lp->signalled = 1; | |
2195 | gdb_assert (lp->status == 0); | |
2196 | } | |
2197 | ||
2198 | return 0; | |
2199 | } | |
2200 | ||
7b50312a PA |
2201 | /* Request a stop on LWP. */ |
2202 | ||
2203 | void | |
2204 | linux_stop_lwp (struct lwp_info *lwp) | |
2205 | { | |
d3a70e03 | 2206 | stop_callback (lwp); |
7b50312a PA |
2207 | } |
2208 | ||
2db9a427 PA |
2209 | /* See linux-nat.h */ |
2210 | ||
2211 | void | |
2212 | linux_stop_and_wait_all_lwps (void) | |
2213 | { | |
2214 | /* Stop all LWP's ... */ | |
d3a70e03 | 2215 | iterate_over_lwps (minus_one_ptid, stop_callback); |
2db9a427 PA |
2216 | |
2217 | /* ... and wait until all of them have reported back that | |
2218 | they're no longer running. */ | |
d3a70e03 | 2219 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
2db9a427 PA |
2220 | } |
2221 | ||
2222 | /* See linux-nat.h */ | |
2223 | ||
2224 | void | |
2225 | linux_unstop_all_lwps (void) | |
2226 | { | |
2227 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
2228 | [] (struct lwp_info *info) |
2229 | { | |
2230 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
2231 | }); | |
2db9a427 PA |
2232 | } |
2233 | ||
57380f4e | 2234 | /* Return non-zero if LWP PID has a pending SIGINT. */ |
d6b0e80f AC |
2235 | |
2236 | static int | |
57380f4e DJ |
2237 | linux_nat_has_pending_sigint (int pid) |
2238 | { | |
2239 | sigset_t pending, blocked, ignored; | |
57380f4e DJ |
2240 | |
2241 | linux_proc_pending_signals (pid, &pending, &blocked, &ignored); | |
2242 | ||
2243 | if (sigismember (&pending, SIGINT) | |
2244 | && !sigismember (&ignored, SIGINT)) | |
2245 | return 1; | |
2246 | ||
2247 | return 0; | |
2248 | } | |
2249 | ||
2250 | /* Set a flag in LP indicating that we should ignore its next SIGINT. */ | |
2251 | ||
2252 | static int | |
d3a70e03 | 2253 | set_ignore_sigint (struct lwp_info *lp) |
d6b0e80f | 2254 | { |
57380f4e DJ |
2255 | /* If a thread has a pending SIGINT, consume it; otherwise, set a |
2256 | flag to consume the next one. */ | |
2257 | if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) | |
2258 | && WSTOPSIG (lp->status) == SIGINT) | |
2259 | lp->status = 0; | |
2260 | else | |
2261 | lp->ignore_sigint = 1; | |
2262 | ||
2263 | return 0; | |
2264 | } | |
2265 | ||
2266 | /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. | |
2267 | This function is called after we know the LWP has stopped; if the LWP | |
2268 | stopped before the expected SIGINT was delivered, then it will never have | |
2269 | arrived. Also, if the signal was delivered to a shared queue and consumed | |
2270 | by a different thread, it will never be delivered to this LWP. */ | |
d6b0e80f | 2271 | |
57380f4e DJ |
2272 | static void |
2273 | maybe_clear_ignore_sigint (struct lwp_info *lp) | |
2274 | { | |
2275 | if (!lp->ignore_sigint) | |
2276 | return; | |
2277 | ||
e38504b3 | 2278 | if (!linux_nat_has_pending_sigint (lp->ptid.lwp ())) |
57380f4e | 2279 | { |
9327494e | 2280 | linux_nat_debug_printf ("Clearing bogus flag for %s", |
e53c95d4 | 2281 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2282 | lp->ignore_sigint = 0; |
2283 | } | |
2284 | } | |
2285 | ||
ebec9a0f PA |
2286 | /* Fetch the possible triggered data watchpoint info and store it in |
2287 | LP. | |
2288 | ||
2289 | On some archs, like x86, that use debug registers to set | |
2290 | watchpoints, it's possible that the way to know which watched | |
2291 | address trapped, is to check the register that is used to select | |
2292 | which address to watch. Problem is, between setting the watchpoint | |
2293 | and reading back which data address trapped, the user may change | |
2294 | the set of watchpoints, and, as a consequence, GDB changes the | |
2295 | debug registers in the inferior. To avoid reading back a stale | |
2296 | stopped-data-address when that happens, we cache in LP the fact | |
2297 | that a watchpoint trapped, and the corresponding data address, as | |
2298 | soon as we see LP stop with a SIGTRAP. If GDB changes the debug | |
2299 | registers meanwhile, we have the cached data we can rely on. */ | |
2300 | ||
9c02b525 PA |
2301 | static int |
2302 | check_stopped_by_watchpoint (struct lwp_info *lp) | |
ebec9a0f | 2303 | { |
2989a365 | 2304 | scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); |
ebec9a0f PA |
2305 | inferior_ptid = lp->ptid; |
2306 | ||
f6ac5f3d | 2307 | if (linux_target->low_stopped_by_watchpoint ()) |
ebec9a0f | 2308 | { |
15c66dd6 | 2309 | lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT; |
f6ac5f3d PA |
2310 | lp->stopped_data_address_p |
2311 | = linux_target->low_stopped_data_address (&lp->stopped_data_address); | |
ebec9a0f PA |
2312 | } |
2313 | ||
15c66dd6 | 2314 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
9c02b525 PA |
2315 | } |
2316 | ||
9c02b525 | 2317 | /* Returns true if the LWP had stopped for a watchpoint. */ |
ebec9a0f | 2318 | |
57810aa7 | 2319 | bool |
f6ac5f3d | 2320 | linux_nat_target::stopped_by_watchpoint () |
ebec9a0f PA |
2321 | { |
2322 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2323 | ||
2324 | gdb_assert (lp != NULL); | |
2325 | ||
15c66dd6 | 2326 | return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT; |
ebec9a0f PA |
2327 | } |
2328 | ||
57810aa7 | 2329 | bool |
f6ac5f3d | 2330 | linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) |
ebec9a0f PA |
2331 | { |
2332 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2333 | ||
2334 | gdb_assert (lp != NULL); | |
2335 | ||
2336 | *addr_p = lp->stopped_data_address; | |
2337 | ||
2338 | return lp->stopped_data_address_p; | |
2339 | } | |
2340 | ||
26ab7092 JK |
2341 | /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
2342 | ||
135340af PA |
2343 | bool |
2344 | linux_nat_target::low_status_is_event (int status) | |
26ab7092 JK |
2345 | { |
2346 | return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; | |
2347 | } | |
2348 | ||
57380f4e DJ |
2349 | /* Wait until LP is stopped. */ |
2350 | ||
2351 | static int | |
d3a70e03 | 2352 | stop_wait_callback (struct lwp_info *lp) |
57380f4e | 2353 | { |
5b6d1e4f | 2354 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
6c95b8df PA |
2355 | |
2356 | /* If this is a vfork parent, bail out, it is not going to report | |
2357 | any SIGSTOP until the vfork is done with. */ | |
2358 | if (inf->vfork_child != NULL) | |
2359 | return 0; | |
2360 | ||
d6b0e80f AC |
2361 | if (!lp->stopped) |
2362 | { | |
2363 | int status; | |
2364 | ||
2365 | status = wait_lwp (lp); | |
2366 | if (status == 0) | |
2367 | return 0; | |
2368 | ||
57380f4e DJ |
2369 | if (lp->ignore_sigint && WIFSTOPPED (status) |
2370 | && WSTOPSIG (status) == SIGINT) | |
d6b0e80f | 2371 | { |
57380f4e | 2372 | lp->ignore_sigint = 0; |
d6b0e80f AC |
2373 | |
2374 | errno = 0; | |
e38504b3 | 2375 | ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0); |
8817a6f2 | 2376 | lp->stopped = 0; |
9327494e SM |
2377 | linux_nat_debug_printf |
2378 | ("PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)", | |
e53c95d4 | 2379 | lp->ptid.to_string ().c_str (), |
9327494e | 2380 | errno ? safe_strerror (errno) : "OK"); |
d6b0e80f | 2381 | |
d3a70e03 | 2382 | return stop_wait_callback (lp); |
d6b0e80f AC |
2383 | } |
2384 | ||
57380f4e DJ |
2385 | maybe_clear_ignore_sigint (lp); |
2386 | ||
d6b0e80f AC |
2387 | if (WSTOPSIG (status) != SIGSTOP) |
2388 | { | |
e5ef252a | 2389 | /* The thread was stopped with a signal other than SIGSTOP. */ |
7feb7d06 | 2390 | |
9327494e | 2391 | linux_nat_debug_printf ("Pending event %s in %s", |
8d06918f | 2392 | status_to_str ((int) status).c_str (), |
e53c95d4 | 2393 | lp->ptid.to_string ().c_str ()); |
e5ef252a PA |
2394 | |
2395 | /* Save the sigtrap event. */ | |
2396 | lp->status = status; | |
e5ef252a | 2397 | gdb_assert (lp->signalled); |
e7ad2f14 | 2398 | save_stop_reason (lp); |
d6b0e80f AC |
2399 | } |
2400 | else | |
2401 | { | |
7010835a | 2402 | /* We caught the SIGSTOP that we intended to catch. */ |
e5ef252a | 2403 | |
9327494e | 2404 | linux_nat_debug_printf ("Expected SIGSTOP caught for %s.", |
e53c95d4 | 2405 | lp->ptid.to_string ().c_str ()); |
e5ef252a | 2406 | |
d6b0e80f | 2407 | lp->signalled = 0; |
7010835a AB |
2408 | |
2409 | /* If we are waiting for this stop so we can report the thread | |
2410 | stopped then we need to record this status. Otherwise, we can | |
2411 | now discard this stop event. */ | |
2412 | if (lp->last_resume_kind == resume_stop) | |
2413 | { | |
2414 | lp->status = status; | |
2415 | save_stop_reason (lp); | |
2416 | } | |
d6b0e80f AC |
2417 | } |
2418 | } | |
2419 | ||
2420 | return 0; | |
2421 | } | |
2422 | ||
9c02b525 PA |
2423 | /* Return non-zero if LP has a wait status pending. Discard the |
2424 | pending event and resume the LWP if the event that originally | |
2425 | caused the stop became uninteresting. */ | |
d6b0e80f AC |
2426 | |
2427 | static int | |
d3a70e03 | 2428 | status_callback (struct lwp_info *lp) |
d6b0e80f AC |
2429 | { |
2430 | /* Only report a pending wait status if we pretend that this has | |
2431 | indeed been resumed. */ | |
ca2163eb PA |
2432 | if (!lp->resumed) |
2433 | return 0; | |
2434 | ||
eb54c8bf PA |
2435 | if (!lwp_status_pending_p (lp)) |
2436 | return 0; | |
2437 | ||
15c66dd6 PA |
2438 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT |
2439 | || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) | |
9c02b525 | 2440 | { |
5b6d1e4f | 2441 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
9c02b525 PA |
2442 | CORE_ADDR pc; |
2443 | int discard = 0; | |
2444 | ||
9c02b525 PA |
2445 | pc = regcache_read_pc (regcache); |
2446 | ||
2447 | if (pc != lp->stop_pc) | |
2448 | { | |
9327494e | 2449 | linux_nat_debug_printf ("PC of %s changed. was=%s, now=%s", |
e53c95d4 | 2450 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2451 | paddress (current_inferior ()->arch (), |
2452 | lp->stop_pc), | |
2453 | paddress (current_inferior ()->arch (), pc)); | |
9c02b525 PA |
2454 | discard = 1; |
2455 | } | |
faf09f01 PA |
2456 | |
2457 | #if !USE_SIGTRAP_SIGINFO | |
a01bda52 | 2458 | else if (!breakpoint_inserted_here_p (regcache->aspace (), pc)) |
9c02b525 | 2459 | { |
9327494e | 2460 | linux_nat_debug_printf ("previous breakpoint of %s, at %s gone", |
e53c95d4 | 2461 | lp->ptid.to_string ().c_str (), |
99d9c3b9 SM |
2462 | paddress (current_inferior ()->arch (), |
2463 | lp->stop_pc)); | |
9c02b525 PA |
2464 | |
2465 | discard = 1; | |
2466 | } | |
faf09f01 | 2467 | #endif |
9c02b525 PA |
2468 | |
2469 | if (discard) | |
2470 | { | |
9327494e | 2471 | linux_nat_debug_printf ("pending event of %s cancelled.", |
e53c95d4 | 2472 | lp->ptid.to_string ().c_str ()); |
9c02b525 PA |
2473 | |
2474 | lp->status = 0; | |
2475 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); | |
2476 | return 0; | |
2477 | } | |
9c02b525 PA |
2478 | } |
2479 | ||
eb54c8bf | 2480 | return 1; |
d6b0e80f AC |
2481 | } |
2482 | ||
d6b0e80f AC |
2483 | /* Count the LWP's that have had events. */ |
2484 | ||
2485 | static int | |
d3a70e03 | 2486 | count_events_callback (struct lwp_info *lp, int *count) |
d6b0e80f | 2487 | { |
d6b0e80f AC |
2488 | gdb_assert (count != NULL); |
2489 | ||
9c02b525 PA |
2490 | /* Select only resumed LWPs that have an event pending. */ |
2491 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2492 | (*count)++; |
2493 | ||
2494 | return 0; | |
2495 | } | |
2496 | ||
2497 | /* Select the LWP (if any) that is currently being single-stepped. */ | |
2498 | ||
2499 | static int | |
d3a70e03 | 2500 | select_singlestep_lwp_callback (struct lwp_info *lp) |
d6b0e80f | 2501 | { |
25289eb2 PA |
2502 | if (lp->last_resume_kind == resume_step |
2503 | && lp->status != 0) | |
d6b0e80f AC |
2504 | return 1; |
2505 | else | |
2506 | return 0; | |
2507 | } | |
2508 | ||
8a99810d PA |
2509 | /* Returns true if LP has a status pending. */ |
2510 | ||
2511 | static int | |
2512 | lwp_status_pending_p (struct lwp_info *lp) | |
2513 | { | |
2514 | /* We check for lp->waitstatus in addition to lp->status, because we | |
2515 | can have pending process exits recorded in lp->status and | |
2516 | W_EXITCODE(0,0) happens to be 0. */ | |
183be222 | 2517 | return lp->status != 0 || lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE; |
8a99810d PA |
2518 | } |
2519 | ||
b90fc188 | 2520 | /* Select the Nth LWP that has had an event. */ |
d6b0e80f AC |
2521 | |
2522 | static int | |
d3a70e03 | 2523 | select_event_lwp_callback (struct lwp_info *lp, int *selector) |
d6b0e80f | 2524 | { |
d6b0e80f AC |
2525 | gdb_assert (selector != NULL); |
2526 | ||
9c02b525 PA |
2527 | /* Select only resumed LWPs that have an event pending. */ |
2528 | if (lp->resumed && lwp_status_pending_p (lp)) | |
d6b0e80f AC |
2529 | if ((*selector)-- == 0) |
2530 | return 1; | |
2531 | ||
2532 | return 0; | |
2533 | } | |
2534 | ||
e7ad2f14 PA |
2535 | /* Called when the LWP stopped for a signal/trap. If it stopped for a |
2536 | trap check what caused it (breakpoint, watchpoint, trace, etc.), | |
2537 | and save the result in the LWP's stop_reason field. If it stopped | |
2538 | for a breakpoint, decrement the PC if necessary on the lwp's | |
2539 | architecture. */ | |
9c02b525 | 2540 | |
e7ad2f14 PA |
2541 | static void |
2542 | save_stop_reason (struct lwp_info *lp) | |
710151dd | 2543 | { |
e7ad2f14 PA |
2544 | struct regcache *regcache; |
2545 | struct gdbarch *gdbarch; | |
515630c5 | 2546 | CORE_ADDR pc; |
9c02b525 | 2547 | CORE_ADDR sw_bp_pc; |
faf09f01 PA |
2548 | #if USE_SIGTRAP_SIGINFO |
2549 | siginfo_t siginfo; | |
2550 | #endif | |
9c02b525 | 2551 | |
e7ad2f14 PA |
2552 | gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON); |
2553 | gdb_assert (lp->status != 0); | |
2554 | ||
135340af | 2555 | if (!linux_target->low_status_is_event (lp->status)) |
e7ad2f14 PA |
2556 | return; |
2557 | ||
a9deee17 PA |
2558 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
2559 | if (inf->starting_up) | |
2560 | return; | |
2561 | ||
5b6d1e4f | 2562 | regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 2563 | gdbarch = regcache->arch (); |
e7ad2f14 | 2564 | |
9c02b525 | 2565 | pc = regcache_read_pc (regcache); |
527a273a | 2566 | sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch); |
515630c5 | 2567 | |
faf09f01 PA |
2568 | #if USE_SIGTRAP_SIGINFO |
2569 | if (linux_nat_get_siginfo (lp->ptid, &siginfo)) | |
2570 | { | |
2571 | if (siginfo.si_signo == SIGTRAP) | |
2572 | { | |
e7ad2f14 PA |
2573 | if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code) |
2574 | && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) | |
faf09f01 | 2575 | { |
e7ad2f14 PA |
2576 | /* The si_code is ambiguous on this arch -- check debug |
2577 | registers. */ | |
2578 | if (!check_stopped_by_watchpoint (lp)) | |
2579 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2580 | } | |
2581 | else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)) | |
2582 | { | |
2583 | /* If we determine the LWP stopped for a SW breakpoint, | |
2584 | trust it. Particularly don't check watchpoint | |
7da6a5b9 | 2585 | registers, because, at least on s390, we'd find |
e7ad2f14 PA |
2586 | stopped-by-watchpoint as long as there's a watchpoint |
2587 | set. */ | |
faf09f01 | 2588 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
faf09f01 | 2589 | } |
e7ad2f14 | 2590 | else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code)) |
faf09f01 | 2591 | { |
e7ad2f14 PA |
2592 | /* This can indicate either a hardware breakpoint or |
2593 | hardware watchpoint. Check debug registers. */ | |
2594 | if (!check_stopped_by_watchpoint (lp)) | |
2595 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; | |
faf09f01 | 2596 | } |
2bf6fb9d PA |
2597 | else if (siginfo.si_code == TRAP_TRACE) |
2598 | { | |
9327494e | 2599 | linux_nat_debug_printf ("%s stopped by trace", |
e53c95d4 | 2600 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2601 | |
2602 | /* We may have single stepped an instruction that | |
2603 | triggered a watchpoint. In that case, on some | |
2604 | architectures (such as x86), instead of TRAP_HWBKPT, | |
2605 | si_code indicates TRAP_TRACE, and we need to check | |
2606 | the debug registers separately. */ | |
2607 | check_stopped_by_watchpoint (lp); | |
2bf6fb9d | 2608 | } |
faf09f01 PA |
2609 | } |
2610 | } | |
2611 | #else | |
9c02b525 | 2612 | if ((!lp->step || lp->stop_pc == sw_bp_pc) |
a01bda52 | 2613 | && software_breakpoint_inserted_here_p (regcache->aspace (), |
9c02b525 | 2614 | sw_bp_pc)) |
710151dd | 2615 | { |
9c02b525 PA |
2616 | /* The LWP was either continued, or stepped a software |
2617 | breakpoint instruction. */ | |
e7ad2f14 PA |
2618 | lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT; |
2619 | } | |
2620 | ||
a01bda52 | 2621 | if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc)) |
e7ad2f14 PA |
2622 | lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT; |
2623 | ||
2624 | if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON) | |
2625 | check_stopped_by_watchpoint (lp); | |
2626 | #endif | |
2627 | ||
2628 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT) | |
2629 | { | |
9327494e | 2630 | linux_nat_debug_printf ("%s stopped by software breakpoint", |
e53c95d4 | 2631 | lp->ptid.to_string ().c_str ()); |
710151dd PA |
2632 | |
2633 | /* Back up the PC if necessary. */ | |
9c02b525 PA |
2634 | if (pc != sw_bp_pc) |
2635 | regcache_write_pc (regcache, sw_bp_pc); | |
515630c5 | 2636 | |
e7ad2f14 PA |
2637 | /* Update this so we record the correct stop PC below. */ |
2638 | pc = sw_bp_pc; | |
710151dd | 2639 | } |
e7ad2f14 | 2640 | else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT) |
9c02b525 | 2641 | { |
9327494e | 2642 | linux_nat_debug_printf ("%s stopped by hardware breakpoint", |
e53c95d4 | 2643 | lp->ptid.to_string ().c_str ()); |
e7ad2f14 PA |
2644 | } |
2645 | else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT) | |
2646 | { | |
9327494e | 2647 | linux_nat_debug_printf ("%s stopped by hardware watchpoint", |
e53c95d4 | 2648 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2649 | } |
d6b0e80f | 2650 | |
e7ad2f14 | 2651 | lp->stop_pc = pc; |
d6b0e80f AC |
2652 | } |
2653 | ||
faf09f01 PA |
2654 | |
2655 | /* Returns true if the LWP had stopped for a software breakpoint. */ | |
2656 | ||
57810aa7 | 2657 | bool |
f6ac5f3d | 2658 | linux_nat_target::stopped_by_sw_breakpoint () |
faf09f01 PA |
2659 | { |
2660 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2661 | ||
2662 | gdb_assert (lp != NULL); | |
2663 | ||
2664 | return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT; | |
2665 | } | |
2666 | ||
2667 | /* Implement the supports_stopped_by_sw_breakpoint method. */ | |
2668 | ||
57810aa7 | 2669 | bool |
f6ac5f3d | 2670 | linux_nat_target::supports_stopped_by_sw_breakpoint () |
faf09f01 PA |
2671 | { |
2672 | return USE_SIGTRAP_SIGINFO; | |
2673 | } | |
2674 | ||
2675 | /* Returns true if the LWP had stopped for a hardware | |
2676 | breakpoint/watchpoint. */ | |
2677 | ||
57810aa7 | 2678 | bool |
f6ac5f3d | 2679 | linux_nat_target::stopped_by_hw_breakpoint () |
faf09f01 PA |
2680 | { |
2681 | struct lwp_info *lp = find_lwp_pid (inferior_ptid); | |
2682 | ||
2683 | gdb_assert (lp != NULL); | |
2684 | ||
2685 | return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT; | |
2686 | } | |
2687 | ||
2688 | /* Implement the supports_stopped_by_hw_breakpoint method. */ | |
2689 | ||
57810aa7 | 2690 | bool |
f6ac5f3d | 2691 | linux_nat_target::supports_stopped_by_hw_breakpoint () |
faf09f01 PA |
2692 | { |
2693 | return USE_SIGTRAP_SIGINFO; | |
2694 | } | |
2695 | ||
d6b0e80f AC |
2696 | /* Select one LWP out of those that have events pending. */ |
2697 | ||
2698 | static void | |
d90e17a7 | 2699 | select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
d6b0e80f AC |
2700 | { |
2701 | int num_events = 0; | |
2702 | int random_selector; | |
9c02b525 | 2703 | struct lwp_info *event_lp = NULL; |
d6b0e80f | 2704 | |
ac264b3b | 2705 | /* Record the wait status for the original LWP. */ |
d6b0e80f AC |
2706 | (*orig_lp)->status = *status; |
2707 | ||
9c02b525 PA |
2708 | /* In all-stop, give preference to the LWP that is being |
2709 | single-stepped. There will be at most one, and it will be the | |
2710 | LWP that the core is most interested in. If we didn't do this, | |
2711 | then we'd have to handle pending step SIGTRAPs somehow in case | |
2712 | the core later continues the previously-stepped thread, as | |
2713 | otherwise we'd report the pending SIGTRAP then, and the core, not | |
2714 | having stepped the thread, wouldn't understand what the trap was | |
2715 | for, and therefore would report it to the user as a random | |
2716 | signal. */ | |
fbea99ea | 2717 | if (!target_is_non_stop_p ()) |
d6b0e80f | 2718 | { |
d3a70e03 | 2719 | event_lp = iterate_over_lwps (filter, select_singlestep_lwp_callback); |
9c02b525 PA |
2720 | if (event_lp != NULL) |
2721 | { | |
9327494e | 2722 | linux_nat_debug_printf ("Select single-step %s", |
e53c95d4 | 2723 | event_lp->ptid.to_string ().c_str ()); |
9c02b525 | 2724 | } |
d6b0e80f | 2725 | } |
9c02b525 PA |
2726 | |
2727 | if (event_lp == NULL) | |
d6b0e80f | 2728 | { |
9c02b525 | 2729 | /* Pick one at random, out of those which have had events. */ |
d6b0e80f | 2730 | |
9c02b525 | 2731 | /* First see how many events we have. */ |
d3a70e03 TT |
2732 | iterate_over_lwps (filter, |
2733 | [&] (struct lwp_info *info) | |
2734 | { | |
2735 | return count_events_callback (info, &num_events); | |
2736 | }); | |
8bf3b159 | 2737 | gdb_assert (num_events > 0); |
d6b0e80f | 2738 | |
9c02b525 PA |
2739 | /* Now randomly pick a LWP out of those that have had |
2740 | events. */ | |
d6b0e80f AC |
2741 | random_selector = (int) |
2742 | ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); | |
2743 | ||
9327494e SM |
2744 | if (num_events > 1) |
2745 | linux_nat_debug_printf ("Found %d events, selecting #%d", | |
2746 | num_events, random_selector); | |
d6b0e80f | 2747 | |
d3a70e03 TT |
2748 | event_lp |
2749 | = (iterate_over_lwps | |
2750 | (filter, | |
2751 | [&] (struct lwp_info *info) | |
2752 | { | |
2753 | return select_event_lwp_callback (info, | |
2754 | &random_selector); | |
2755 | })); | |
d6b0e80f AC |
2756 | } |
2757 | ||
2758 | if (event_lp != NULL) | |
2759 | { | |
2760 | /* Switch the event LWP. */ | |
2761 | *orig_lp = event_lp; | |
2762 | *status = event_lp->status; | |
2763 | } | |
2764 | ||
2765 | /* Flush the wait status for the event LWP. */ | |
2766 | (*orig_lp)->status = 0; | |
2767 | } | |
2768 | ||
2769 | /* Return non-zero if LP has been resumed. */ | |
2770 | ||
2771 | static int | |
d3a70e03 | 2772 | resumed_callback (struct lwp_info *lp) |
d6b0e80f AC |
2773 | { |
2774 | return lp->resumed; | |
2775 | } | |
2776 | ||
02f3fc28 | 2777 | /* Check if we should go on and pass this event to common code. |
12d9289a | 2778 | |
897608ed SM |
2779 | If so, save the status to the lwp_info structure associated to LWPID. */ |
2780 | ||
2781 | static void | |
9c02b525 | 2782 | linux_nat_filter_event (int lwpid, int status) |
02f3fc28 PA |
2783 | { |
2784 | struct lwp_info *lp; | |
89a5711c | 2785 | int event = linux_ptrace_get_extended_event (status); |
02f3fc28 | 2786 | |
f2907e49 | 2787 | lp = find_lwp_pid (ptid_t (lwpid)); |
02f3fc28 | 2788 | |
1abeb1e9 PA |
2789 | /* Check for events reported by anything not in our LWP list. */ |
2790 | if (lp == nullptr) | |
0e5bf2a8 | 2791 | { |
1abeb1e9 PA |
2792 | if (WIFSTOPPED (status)) |
2793 | { | |
2794 | if (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC) | |
2795 | { | |
2796 | /* A non-leader thread exec'ed after we've seen the | |
2797 | leader zombie, and removed it from our lists (in | |
2798 | check_zombie_leaders). The non-leader thread changes | |
2799 | its tid to the tgid. */ | |
2800 | linux_nat_debug_printf | |
2801 | ("Re-adding thread group leader LWP %d after exec.", | |
2802 | lwpid); | |
0e5bf2a8 | 2803 | |
1abeb1e9 PA |
2804 | lp = add_lwp (ptid_t (lwpid, lwpid)); |
2805 | lp->stopped = 1; | |
2806 | lp->resumed = 1; | |
2807 | add_thread (linux_target, lp->ptid); | |
2808 | } | |
2809 | else | |
2810 | { | |
2811 | /* A process we are controlling has forked and the new | |
2812 | child's stop was reported to us by the kernel. Save | |
2813 | its PID and go back to waiting for the fork event to | |
2814 | be reported - the stopped process might be returned | |
2815 | from waitpid before or after the fork event is. */ | |
2816 | linux_nat_debug_printf | |
2817 | ("Saving LWP %d status %s in stopped_pids list", | |
2818 | lwpid, status_to_str (status).c_str ()); | |
2819 | add_to_pid_list (&stopped_pids, lwpid, status); | |
2820 | } | |
2821 | } | |
2822 | else | |
2823 | { | |
2824 | /* Don't report an event for the exit of an LWP not in our | |
2825 | list, i.e. not part of any inferior we're debugging. | |
2826 | This can happen if we detach from a program we originally | |
6cf20c46 PA |
2827 | forked and then it exits. However, note that we may have |
2828 | earlier deleted a leader of an inferior we're debugging, | |
2829 | in check_zombie_leaders. Re-add it back here if so. */ | |
2830 | for (inferior *inf : all_inferiors (linux_target)) | |
2831 | { | |
2832 | if (inf->pid == lwpid) | |
2833 | { | |
2834 | linux_nat_debug_printf | |
2835 | ("Re-adding thread group leader LWP %d after exit.", | |
2836 | lwpid); | |
2837 | ||
2838 | lp = add_lwp (ptid_t (lwpid, lwpid)); | |
2839 | lp->resumed = 1; | |
2840 | add_thread (linux_target, lp->ptid); | |
2841 | break; | |
2842 | } | |
2843 | } | |
1abeb1e9 | 2844 | } |
0e5bf2a8 | 2845 | |
1abeb1e9 PA |
2846 | if (lp == nullptr) |
2847 | return; | |
02f3fc28 PA |
2848 | } |
2849 | ||
8817a6f2 PA |
2850 | /* This LWP is stopped now. (And if dead, this prevents it from |
2851 | ever being continued.) */ | |
2852 | lp->stopped = 1; | |
2853 | ||
8784d563 PA |
2854 | if (WIFSTOPPED (status) && lp->must_set_ptrace_flags) |
2855 | { | |
5b6d1e4f | 2856 | inferior *inf = find_inferior_pid (linux_target, lp->ptid.pid ()); |
de0d863e | 2857 | int options = linux_nat_ptrace_options (inf->attach_flag); |
8784d563 | 2858 | |
e38504b3 | 2859 | linux_enable_event_reporting (lp->ptid.lwp (), options); |
8784d563 PA |
2860 | lp->must_set_ptrace_flags = 0; |
2861 | } | |
2862 | ||
ca2163eb PA |
2863 | /* Handle GNU/Linux's syscall SIGTRAPs. */ |
2864 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) | |
2865 | { | |
2866 | /* No longer need the sysgood bit. The ptrace event ends up | |
2867 | recorded in lp->waitstatus if we care for it. We can carry | |
2868 | on handling the event like a regular SIGTRAP from here | |
2869 | on. */ | |
2870 | status = W_STOPCODE (SIGTRAP); | |
2871 | if (linux_handle_syscall_trap (lp, 0)) | |
897608ed | 2872 | return; |
ca2163eb | 2873 | } |
bfd09d20 JS |
2874 | else |
2875 | { | |
2876 | /* Almost all other ptrace-stops are known to be outside of system | |
2877 | calls, with further exceptions in linux_handle_extended_wait. */ | |
2878 | lp->syscall_state = TARGET_WAITKIND_IGNORE; | |
2879 | } | |
02f3fc28 | 2880 | |
ca2163eb | 2881 | /* Handle GNU/Linux's extended waitstatus for trace events. */ |
89a5711c DB |
2882 | if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP |
2883 | && linux_is_extended_waitstatus (status)) | |
02f3fc28 | 2884 | { |
9327494e SM |
2885 | linux_nat_debug_printf ("Handling extended status 0x%06x", status); |
2886 | ||
4dd63d48 | 2887 | if (linux_handle_extended_wait (lp, status)) |
897608ed | 2888 | return; |
02f3fc28 PA |
2889 | } |
2890 | ||
2891 | /* Check if the thread has exited. */ | |
9c02b525 PA |
2892 | if (WIFEXITED (status) || WIFSIGNALED (status)) |
2893 | { | |
6cf20c46 | 2894 | if (!report_thread_events && !is_leader (lp)) |
02f3fc28 | 2895 | { |
9327494e | 2896 | linux_nat_debug_printf ("%s exited.", |
e53c95d4 | 2897 | lp->ptid.to_string ().c_str ()); |
9c02b525 | 2898 | |
6cf20c46 | 2899 | /* If this was not the leader exiting, then the exit signal |
4a6ed09b PA |
2900 | was not the end of the debugged application and should be |
2901 | ignored. */ | |
2902 | exit_lwp (lp); | |
897608ed | 2903 | return; |
02f3fc28 PA |
2904 | } |
2905 | ||
77598427 PA |
2906 | /* Note that even if the leader was ptrace-stopped, it can still |
2907 | exit, if e.g., some other thread brings down the whole | |
2908 | process (calls `exit'). So don't assert that the lwp is | |
2909 | resumed. */ | |
9327494e SM |
2910 | linux_nat_debug_printf ("LWP %ld exited (resumed=%d)", |
2911 | lp->ptid.lwp (), lp->resumed); | |
02f3fc28 | 2912 | |
9c02b525 PA |
2913 | /* Dead LWP's aren't expected to reported a pending sigstop. */ |
2914 | lp->signalled = 0; | |
2915 | ||
2916 | /* Store the pending event in the waitstatus, because | |
2917 | W_EXITCODE(0,0) == 0. */ | |
7509b829 | 2918 | lp->waitstatus = host_status_to_waitstatus (status); |
897608ed | 2919 | return; |
02f3fc28 PA |
2920 | } |
2921 | ||
02f3fc28 PA |
2922 | /* Make sure we don't report a SIGSTOP that we sent ourselves in |
2923 | an attempt to stop an LWP. */ | |
2924 | if (lp->signalled | |
2925 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) | |
2926 | { | |
02f3fc28 PA |
2927 | lp->signalled = 0; |
2928 | ||
2bf6fb9d | 2929 | if (lp->last_resume_kind == resume_stop) |
25289eb2 | 2930 | { |
9327494e | 2931 | linux_nat_debug_printf ("resume_stop SIGSTOP caught for %s.", |
e53c95d4 | 2932 | lp->ptid.to_string ().c_str ()); |
2bf6fb9d PA |
2933 | } |
2934 | else | |
2935 | { | |
2936 | /* This is a delayed SIGSTOP. Filter out the event. */ | |
02f3fc28 | 2937 | |
9327494e SM |
2938 | linux_nat_debug_printf |
2939 | ("%s %s, 0, 0 (discard delayed SIGSTOP)", | |
2940 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2941 | lp->ptid.to_string ().c_str ()); |
02f3fc28 | 2942 | |
2bf6fb9d | 2943 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
25289eb2 | 2944 | gdb_assert (lp->resumed); |
897608ed | 2945 | return; |
25289eb2 | 2946 | } |
02f3fc28 PA |
2947 | } |
2948 | ||
57380f4e DJ |
2949 | /* Make sure we don't report a SIGINT that we have already displayed |
2950 | for another thread. */ | |
2951 | if (lp->ignore_sigint | |
2952 | && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) | |
2953 | { | |
9327494e | 2954 | linux_nat_debug_printf ("Delayed SIGINT caught for %s.", |
e53c95d4 | 2955 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2956 | |
2957 | /* This is a delayed SIGINT. */ | |
2958 | lp->ignore_sigint = 0; | |
2959 | ||
8a99810d | 2960 | linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0); |
9327494e SM |
2961 | linux_nat_debug_printf ("%s %s, 0, 0 (discard SIGINT)", |
2962 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 2963 | lp->ptid.to_string ().c_str ()); |
57380f4e DJ |
2964 | gdb_assert (lp->resumed); |
2965 | ||
2966 | /* Discard the event. */ | |
897608ed | 2967 | return; |
57380f4e DJ |
2968 | } |
2969 | ||
9c02b525 PA |
2970 | /* Don't report signals that GDB isn't interested in, such as |
2971 | signals that are neither printed nor stopped upon. Stopping all | |
7da6a5b9 | 2972 | threads can be a bit time-consuming, so if we want decent |
9c02b525 PA |
2973 | performance with heavily multi-threaded programs, especially when |
2974 | they're using a high frequency timer, we'd better avoid it if we | |
2975 | can. */ | |
2976 | if (WIFSTOPPED (status)) | |
2977 | { | |
2978 | enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status)); | |
2979 | ||
fbea99ea | 2980 | if (!target_is_non_stop_p ()) |
9c02b525 PA |
2981 | { |
2982 | /* Only do the below in all-stop, as we currently use SIGSTOP | |
2983 | to implement target_stop (see linux_nat_stop) in | |
2984 | non-stop. */ | |
2985 | if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0) | |
2986 | { | |
2987 | /* If ^C/BREAK is typed at the tty/console, SIGINT gets | |
2988 | forwarded to the entire process group, that is, all LWPs | |
2989 | will receive it - unless they're using CLONE_THREAD to | |
2990 | share signals. Since we only want to report it once, we | |
2991 | mark it as ignored for all LWPs except this one. */ | |
d3a70e03 | 2992 | iterate_over_lwps (ptid_t (lp->ptid.pid ()), set_ignore_sigint); |
9c02b525 PA |
2993 | lp->ignore_sigint = 0; |
2994 | } | |
2995 | else | |
2996 | maybe_clear_ignore_sigint (lp); | |
2997 | } | |
2998 | ||
2999 | /* When using hardware single-step, we need to report every signal. | |
c9587f88 | 3000 | Otherwise, signals in pass_mask may be short-circuited |
d8c06f22 AB |
3001 | except signals that might be caused by a breakpoint, or SIGSTOP |
3002 | if we sent the SIGSTOP and are waiting for it to arrive. */ | |
9c02b525 | 3003 | if (!lp->step |
c9587f88 | 3004 | && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)) |
d8c06f22 | 3005 | && (WSTOPSIG (status) != SIGSTOP |
9213a6d7 | 3006 | || !linux_target->find_thread (lp->ptid)->stop_requested) |
c9587f88 | 3007 | && !linux_wstatus_maybe_breakpoint (status)) |
9c02b525 PA |
3008 | { |
3009 | linux_resume_one_lwp (lp, lp->step, signo); | |
9327494e SM |
3010 | linux_nat_debug_printf |
3011 | ("%s %s, %s (preempt 'handle')", | |
3012 | lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", | |
e53c95d4 | 3013 | lp->ptid.to_string ().c_str (), |
9327494e SM |
3014 | (signo != GDB_SIGNAL_0 |
3015 | ? strsignal (gdb_signal_to_host (signo)) : "0")); | |
897608ed | 3016 | return; |
9c02b525 PA |
3017 | } |
3018 | } | |
3019 | ||
02f3fc28 PA |
3020 | /* An interesting event. */ |
3021 | gdb_assert (lp); | |
ca2163eb | 3022 | lp->status = status; |
e7ad2f14 | 3023 | save_stop_reason (lp); |
02f3fc28 PA |
3024 | } |
3025 | ||
0e5bf2a8 PA |
3026 | /* Detect zombie thread group leaders, and "exit" them. We can't reap |
3027 | their exits until all other threads in the group have exited. */ | |
3028 | ||
3029 | static void | |
3030 | check_zombie_leaders (void) | |
3031 | { | |
08036331 | 3032 | for (inferior *inf : all_inferiors ()) |
0e5bf2a8 PA |
3033 | { |
3034 | struct lwp_info *leader_lp; | |
3035 | ||
3036 | if (inf->pid == 0) | |
3037 | continue; | |
3038 | ||
f2907e49 | 3039 | leader_lp = find_lwp_pid (ptid_t (inf->pid)); |
0e5bf2a8 PA |
3040 | if (leader_lp != NULL |
3041 | /* Check if there are other threads in the group, as we may | |
6cf20c46 PA |
3042 | have raced with the inferior simply exiting. Note this |
3043 | isn't a watertight check. If the inferior is | |
3044 | multi-threaded and is exiting, it may be we see the | |
3045 | leader as zombie before we reap all the non-leader | |
3046 | threads. See comments below. */ | |
0e5bf2a8 | 3047 | && num_lwps (inf->pid) > 1 |
5f572dec | 3048 | && linux_proc_pid_is_zombie (inf->pid)) |
0e5bf2a8 | 3049 | { |
6cf20c46 PA |
3050 | /* A zombie leader in a multi-threaded program can mean one |
3051 | of three things: | |
3052 | ||
3053 | #1 - Only the leader exited, not the whole program, e.g., | |
3054 | with pthread_exit. Since we can't reap the leader's exit | |
3055 | status until all other threads are gone and reaped too, | |
3056 | we want to delete the zombie leader right away, as it | |
3057 | can't be debugged, we can't read its registers, etc. | |
3058 | This is the main reason we check for zombie leaders | |
3059 | disappearing. | |
3060 | ||
3061 | #2 - The whole thread-group/process exited (a group exit, | |
3062 | via e.g. exit(3), and there is (or will be shortly) an | |
3063 | exit reported for each thread in the process, and then | |
3064 | finally an exit for the leader once the non-leaders are | |
3065 | reaped. | |
3066 | ||
3067 | #3 - There are 3 or more threads in the group, and a | |
3068 | thread other than the leader exec'd. See comments on | |
3069 | exec events at the top of the file. | |
3070 | ||
3071 | Ideally we would never delete the leader for case #2. | |
3072 | Instead, we want to collect the exit status of each | |
3073 | non-leader thread, and then finally collect the exit | |
3074 | status of the leader as normal and use its exit code as | |
3075 | whole-process exit code. Unfortunately, there's no | |
3076 | race-free way to distinguish cases #1 and #2. We can't | |
3077 | assume the exit events for the non-leaders threads are | |
3078 | already pending in the kernel, nor can we assume the | |
3079 | non-leader threads are in zombie state already. Between | |
3080 | the leader becoming zombie and the non-leaders exiting | |
3081 | and becoming zombie themselves, there's a small time | |
3082 | window, so such a check would be racy. Temporarily | |
3083 | pausing all threads and checking to see if all threads | |
3084 | exit or not before re-resuming them would work in the | |
3085 | case that all threads are running right now, but it | |
3086 | wouldn't work if some thread is currently already | |
3087 | ptrace-stopped, e.g., due to scheduler-locking. | |
3088 | ||
3089 | So what we do is we delete the leader anyhow, and then | |
3090 | later on when we see its exit status, we re-add it back. | |
3091 | We also make sure that we only report a whole-process | |
3092 | exit when we see the leader exiting, as opposed to when | |
3093 | the last LWP in the LWP list exits, which can be a | |
3094 | non-leader if we deleted the leader here. */ | |
9327494e | 3095 | linux_nat_debug_printf ("Thread group leader %d zombie " |
6cf20c46 PA |
3096 | "(it exited, or another thread execd), " |
3097 | "deleting it.", | |
9327494e | 3098 | inf->pid); |
0e5bf2a8 PA |
3099 | exit_lwp (leader_lp); |
3100 | } | |
3101 | } | |
3102 | } | |
3103 | ||
aa01bd36 PA |
3104 | /* Convenience function that is called when the kernel reports an exit |
3105 | event. This decides whether to report the event to GDB as a | |
3106 | process exit event, a thread exit event, or to suppress the | |
3107 | event. */ | |
3108 | ||
3109 | static ptid_t | |
3110 | filter_exit_event (struct lwp_info *event_child, | |
3111 | struct target_waitstatus *ourstatus) | |
3112 | { | |
3113 | ptid_t ptid = event_child->ptid; | |
3114 | ||
6cf20c46 | 3115 | if (!is_leader (event_child)) |
aa01bd36 PA |
3116 | { |
3117 | if (report_thread_events) | |
183be222 | 3118 | ourstatus->set_thread_exited (0); |
aa01bd36 | 3119 | else |
183be222 | 3120 | ourstatus->set_ignore (); |
aa01bd36 PA |
3121 | |
3122 | exit_lwp (event_child); | |
3123 | } | |
3124 | ||
3125 | return ptid; | |
3126 | } | |
3127 | ||
d6b0e80f | 3128 | static ptid_t |
f6ac5f3d | 3129 | linux_nat_wait_1 (ptid_t ptid, struct target_waitstatus *ourstatus, |
b60cea74 | 3130 | target_wait_flags target_options) |
d6b0e80f | 3131 | { |
b26b06dd AB |
3132 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3133 | ||
fc9b8e47 | 3134 | sigset_t prev_mask; |
4b60df3d | 3135 | enum resume_kind last_resume_kind; |
12d9289a | 3136 | struct lwp_info *lp; |
12d9289a | 3137 | int status; |
d6b0e80f | 3138 | |
f973ed9c DJ |
3139 | /* The first time we get here after starting a new inferior, we may |
3140 | not have added it to the LWP list yet - this is the earliest | |
3141 | moment at which we know its PID. */ | |
677c92fe | 3142 | if (ptid.is_pid () && find_lwp_pid (ptid) == nullptr) |
f973ed9c | 3143 | { |
677c92fe | 3144 | ptid_t lwp_ptid (ptid.pid (), ptid.pid ()); |
27c9d204 | 3145 | |
677c92fe SM |
3146 | /* Upgrade the main thread's ptid. */ |
3147 | thread_change_ptid (linux_target, ptid, lwp_ptid); | |
3148 | lp = add_initial_lwp (lwp_ptid); | |
f973ed9c DJ |
3149 | lp->resumed = 1; |
3150 | } | |
3151 | ||
12696c10 | 3152 | /* Make sure SIGCHLD is blocked until the sigsuspend below. */ |
7feb7d06 | 3153 | block_child_signals (&prev_mask); |
d6b0e80f | 3154 | |
d6b0e80f | 3155 | /* First check if there is a LWP with a wait status pending. */ |
d3a70e03 | 3156 | lp = iterate_over_lwps (ptid, status_callback); |
8a99810d | 3157 | if (lp != NULL) |
d6b0e80f | 3158 | { |
9327494e | 3159 | linux_nat_debug_printf ("Using pending wait status %s for %s.", |
57573e54 | 3160 | pending_status_str (lp).c_str (), |
e53c95d4 | 3161 | lp->ptid.to_string ().c_str ()); |
d6b0e80f AC |
3162 | } |
3163 | ||
9c02b525 PA |
3164 | /* But if we don't find a pending event, we'll have to wait. Always |
3165 | pull all events out of the kernel. We'll randomly select an | |
3166 | event LWP out of all that have events, to prevent starvation. */ | |
7feb7d06 | 3167 | |
d90e17a7 | 3168 | while (lp == NULL) |
d6b0e80f AC |
3169 | { |
3170 | pid_t lwpid; | |
3171 | ||
0e5bf2a8 PA |
3172 | /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
3173 | quirks: | |
3174 | ||
3175 | - If the thread group leader exits while other threads in the | |
3176 | thread group still exist, waitpid(TGID, ...) hangs. That | |
3177 | waitpid won't return an exit status until the other threads | |
85102364 | 3178 | in the group are reaped. |
0e5bf2a8 PA |
3179 | |
3180 | - When a non-leader thread execs, that thread just vanishes | |
3181 | without reporting an exit (so we'd hang if we waited for it | |
3182 | explicitly in that case). The exec event is reported to | |
3183 | the TGID pid. */ | |
3184 | ||
3185 | errno = 0; | |
4a6ed09b | 3186 | lwpid = my_waitpid (-1, &status, __WALL | WNOHANG); |
0e5bf2a8 | 3187 | |
9327494e SM |
3188 | linux_nat_debug_printf ("waitpid(-1, ...) returned %d, %s", |
3189 | lwpid, | |
3190 | errno ? safe_strerror (errno) : "ERRNO-OK"); | |
b84876c2 | 3191 | |
d6b0e80f AC |
3192 | if (lwpid > 0) |
3193 | { | |
9327494e | 3194 | linux_nat_debug_printf ("waitpid %ld received %s", |
8d06918f SM |
3195 | (long) lwpid, |
3196 | status_to_str (status).c_str ()); | |
d6b0e80f | 3197 | |
9c02b525 | 3198 | linux_nat_filter_event (lwpid, status); |
0e5bf2a8 PA |
3199 | /* Retry until nothing comes out of waitpid. A single |
3200 | SIGCHLD can indicate more than one child stopped. */ | |
3201 | continue; | |
d6b0e80f AC |
3202 | } |
3203 | ||
20ba1ce6 PA |
3204 | /* Now that we've pulled all events out of the kernel, resume |
3205 | LWPs that don't have an interesting event to report. */ | |
3206 | iterate_over_lwps (minus_one_ptid, | |
d3a70e03 TT |
3207 | [] (struct lwp_info *info) |
3208 | { | |
3209 | return resume_stopped_resumed_lwps (info, minus_one_ptid); | |
3210 | }); | |
20ba1ce6 PA |
3211 | |
3212 | /* ... and find an LWP with a status to report to the core, if | |
3213 | any. */ | |
d3a70e03 | 3214 | lp = iterate_over_lwps (ptid, status_callback); |
9c02b525 PA |
3215 | if (lp != NULL) |
3216 | break; | |
3217 | ||
0e5bf2a8 PA |
3218 | /* Check for zombie thread group leaders. Those can't be reaped |
3219 | until all other threads in the thread group are. */ | |
3220 | check_zombie_leaders (); | |
d6b0e80f | 3221 | |
0e5bf2a8 PA |
3222 | /* If there are no resumed children left, bail. We'd be stuck |
3223 | forever in the sigsuspend call below otherwise. */ | |
d3a70e03 | 3224 | if (iterate_over_lwps (ptid, resumed_callback) == NULL) |
0e5bf2a8 | 3225 | { |
9327494e | 3226 | linux_nat_debug_printf ("exit (no resumed LWP)"); |
b84876c2 | 3227 | |
183be222 | 3228 | ourstatus->set_no_resumed (); |
b84876c2 | 3229 | |
0e5bf2a8 PA |
3230 | restore_child_signals_mask (&prev_mask); |
3231 | return minus_one_ptid; | |
d6b0e80f | 3232 | } |
28736962 | 3233 | |
0e5bf2a8 PA |
3234 | /* No interesting event to report to the core. */ |
3235 | ||
3236 | if (target_options & TARGET_WNOHANG) | |
3237 | { | |
b26b06dd | 3238 | linux_nat_debug_printf ("no interesting events found"); |
28736962 | 3239 | |
183be222 | 3240 | ourstatus->set_ignore (); |
28736962 PA |
3241 | restore_child_signals_mask (&prev_mask); |
3242 | return minus_one_ptid; | |
3243 | } | |
d6b0e80f AC |
3244 | |
3245 | /* We shouldn't end up here unless we want to try again. */ | |
d90e17a7 | 3246 | gdb_assert (lp == NULL); |
0e5bf2a8 PA |
3247 | |
3248 | /* Block until we get an event reported with SIGCHLD. */ | |
9c3a5d93 | 3249 | wait_for_signal (); |
d6b0e80f AC |
3250 | } |
3251 | ||
d6b0e80f AC |
3252 | gdb_assert (lp); |
3253 | ||
ca2163eb PA |
3254 | status = lp->status; |
3255 | lp->status = 0; | |
3256 | ||
fbea99ea | 3257 | if (!target_is_non_stop_p ()) |
4c28f408 PA |
3258 | { |
3259 | /* Now stop all other LWP's ... */ | |
d3a70e03 | 3260 | iterate_over_lwps (minus_one_ptid, stop_callback); |
4c28f408 PA |
3261 | |
3262 | /* ... and wait until all of them have reported back that | |
3263 | they're no longer running. */ | |
d3a70e03 | 3264 | iterate_over_lwps (minus_one_ptid, stop_wait_callback); |
9c02b525 PA |
3265 | } |
3266 | ||
3267 | /* If we're not waiting for a specific LWP, choose an event LWP from | |
3268 | among those that have had events. Giving equal priority to all | |
3269 | LWPs that have had events helps prevent starvation. */ | |
d7e15655 | 3270 | if (ptid == minus_one_ptid || ptid.is_pid ()) |
9c02b525 PA |
3271 | select_event_lwp (ptid, &lp, &status); |
3272 | ||
3273 | gdb_assert (lp != NULL); | |
3274 | ||
3275 | /* Now that we've selected our final event LWP, un-adjust its PC if | |
faf09f01 PA |
3276 | it was a software breakpoint, and we can't reliably support the |
3277 | "stopped by software breakpoint" stop reason. */ | |
3278 | if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT | |
3279 | && !USE_SIGTRAP_SIGINFO) | |
9c02b525 | 3280 | { |
5b6d1e4f | 3281 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3282 | struct gdbarch *gdbarch = regcache->arch (); |
527a273a | 3283 | int decr_pc = gdbarch_decr_pc_after_break (gdbarch); |
4c28f408 | 3284 | |
9c02b525 PA |
3285 | if (decr_pc != 0) |
3286 | { | |
3287 | CORE_ADDR pc; | |
d6b0e80f | 3288 | |
9c02b525 PA |
3289 | pc = regcache_read_pc (regcache); |
3290 | regcache_write_pc (regcache, pc + decr_pc); | |
3291 | } | |
3292 | } | |
e3e9f5a2 | 3293 | |
9c02b525 PA |
3294 | /* We'll need this to determine whether to report a SIGSTOP as |
3295 | GDB_SIGNAL_0. Need to take a copy because resume_clear_callback | |
3296 | clears it. */ | |
3297 | last_resume_kind = lp->last_resume_kind; | |
4b60df3d | 3298 | |
fbea99ea | 3299 | if (!target_is_non_stop_p ()) |
9c02b525 | 3300 | { |
e3e9f5a2 PA |
3301 | /* In all-stop, from the core's perspective, all LWPs are now |
3302 | stopped until a new resume action is sent over. */ | |
d3a70e03 | 3303 | iterate_over_lwps (minus_one_ptid, resume_clear_callback); |
e3e9f5a2 PA |
3304 | } |
3305 | else | |
25289eb2 | 3306 | { |
d3a70e03 | 3307 | resume_clear_callback (lp); |
25289eb2 | 3308 | } |
d6b0e80f | 3309 | |
135340af | 3310 | if (linux_target->low_status_is_event (status)) |
d6b0e80f | 3311 | { |
9327494e | 3312 | linux_nat_debug_printf ("trap ptid is %s.", |
e53c95d4 | 3313 | lp->ptid.to_string ().c_str ()); |
d6b0e80f | 3314 | } |
d6b0e80f | 3315 | |
183be222 | 3316 | if (lp->waitstatus.kind () != TARGET_WAITKIND_IGNORE) |
d6b0e80f AC |
3317 | { |
3318 | *ourstatus = lp->waitstatus; | |
183be222 | 3319 | lp->waitstatus.set_ignore (); |
d6b0e80f AC |
3320 | } |
3321 | else | |
7509b829 | 3322 | *ourstatus = host_status_to_waitstatus (status); |
d6b0e80f | 3323 | |
b26b06dd | 3324 | linux_nat_debug_printf ("event found"); |
b84876c2 | 3325 | |
7feb7d06 | 3326 | restore_child_signals_mask (&prev_mask); |
1e225492 | 3327 | |
4b60df3d | 3328 | if (last_resume_kind == resume_stop |
183be222 | 3329 | && ourstatus->kind () == TARGET_WAITKIND_STOPPED |
25289eb2 PA |
3330 | && WSTOPSIG (status) == SIGSTOP) |
3331 | { | |
3332 | /* A thread that has been requested to stop by GDB with | |
3333 | target_stop, and it stopped cleanly, so report as SIG0. The | |
3334 | use of SIGSTOP is an implementation detail. */ | |
183be222 | 3335 | ourstatus->set_stopped (GDB_SIGNAL_0); |
25289eb2 PA |
3336 | } |
3337 | ||
183be222 SM |
3338 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED |
3339 | || ourstatus->kind () == TARGET_WAITKIND_SIGNALLED) | |
1e225492 JK |
3340 | lp->core = -1; |
3341 | else | |
2e794194 | 3342 | lp->core = linux_common_core_of_thread (lp->ptid); |
1e225492 | 3343 | |
183be222 | 3344 | if (ourstatus->kind () == TARGET_WAITKIND_EXITED) |
aa01bd36 PA |
3345 | return filter_exit_event (lp, ourstatus); |
3346 | ||
f973ed9c | 3347 | return lp->ptid; |
d6b0e80f AC |
3348 | } |
3349 | ||
e3e9f5a2 PA |
3350 | /* Resume LWPs that are currently stopped without any pending status |
3351 | to report, but are resumed from the core's perspective. */ | |
3352 | ||
3353 | static int | |
d3a70e03 | 3354 | resume_stopped_resumed_lwps (struct lwp_info *lp, const ptid_t wait_ptid) |
e3e9f5a2 | 3355 | { |
14ec4172 AB |
3356 | inferior *inf = find_inferior_ptid (linux_target, lp->ptid); |
3357 | ||
8a9da63e | 3358 | if (!lp->stopped) |
4dd63d48 | 3359 | { |
9327494e | 3360 | linux_nat_debug_printf ("NOT resuming LWP %s, not stopped", |
e53c95d4 | 3361 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3362 | } |
3363 | else if (!lp->resumed) | |
3364 | { | |
9327494e | 3365 | linux_nat_debug_printf ("NOT resuming LWP %s, not resumed", |
e53c95d4 | 3366 | lp->ptid.to_string ().c_str ()); |
4dd63d48 PA |
3367 | } |
3368 | else if (lwp_status_pending_p (lp)) | |
3369 | { | |
9327494e | 3370 | linux_nat_debug_printf ("NOT resuming LWP %s, has pending status", |
e53c95d4 | 3371 | lp->ptid.to_string ().c_str ()); |
4dd63d48 | 3372 | } |
8a9da63e AB |
3373 | else if (inf->vfork_child != nullptr) |
3374 | { | |
3375 | linux_nat_debug_printf ("NOT resuming LWP %s (vfork parent)", | |
3376 | lp->ptid.to_string ().c_str ()); | |
3377 | } | |
4dd63d48 | 3378 | else |
e3e9f5a2 | 3379 | { |
5b6d1e4f | 3380 | struct regcache *regcache = get_thread_regcache (linux_target, lp->ptid); |
ac7936df | 3381 | struct gdbarch *gdbarch = regcache->arch (); |
336060f3 | 3382 | |
a70b8144 | 3383 | try |
e3e9f5a2 | 3384 | { |
23f238d3 PA |
3385 | CORE_ADDR pc = regcache_read_pc (regcache); |
3386 | int leave_stopped = 0; | |
e3e9f5a2 | 3387 | |
23f238d3 PA |
3388 | /* Don't bother if there's a breakpoint at PC that we'd hit |
3389 | immediately, and we're not waiting for this LWP. */ | |
d3a70e03 | 3390 | if (!lp->ptid.matches (wait_ptid)) |
23f238d3 | 3391 | { |
a01bda52 | 3392 | if (breakpoint_inserted_here_p (regcache->aspace (), pc)) |
23f238d3 PA |
3393 | leave_stopped = 1; |
3394 | } | |
e3e9f5a2 | 3395 | |
23f238d3 PA |
3396 | if (!leave_stopped) |
3397 | { | |
9327494e SM |
3398 | linux_nat_debug_printf |
3399 | ("resuming stopped-resumed LWP %s at %s: step=%d", | |
e53c95d4 | 3400 | lp->ptid.to_string ().c_str (), paddress (gdbarch, pc), |
9327494e | 3401 | lp->step); |
23f238d3 PA |
3402 | |
3403 | linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0); | |
3404 | } | |
3405 | } | |
230d2906 | 3406 | catch (const gdb_exception_error &ex) |
23f238d3 PA |
3407 | { |
3408 | if (!check_ptrace_stopped_lwp_gone (lp)) | |
eedc3f4f | 3409 | throw; |
23f238d3 | 3410 | } |
e3e9f5a2 PA |
3411 | } |
3412 | ||
3413 | return 0; | |
3414 | } | |
3415 | ||
f6ac5f3d PA |
3416 | ptid_t |
3417 | linux_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, | |
b60cea74 | 3418 | target_wait_flags target_options) |
7feb7d06 | 3419 | { |
b26b06dd AB |
3420 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3421 | ||
7feb7d06 PA |
3422 | ptid_t event_ptid; |
3423 | ||
e53c95d4 | 3424 | linux_nat_debug_printf ("[%s], [%s]", ptid.to_string ().c_str (), |
9327494e | 3425 | target_options_to_string (target_options).c_str ()); |
7feb7d06 PA |
3426 | |
3427 | /* Flush the async file first. */ | |
d9d41e78 | 3428 | if (target_is_async_p ()) |
7feb7d06 PA |
3429 | async_file_flush (); |
3430 | ||
e3e9f5a2 PA |
3431 | /* Resume LWPs that are currently stopped without any pending status |
3432 | to report, but are resumed from the core's perspective. LWPs get | |
3433 | in this state if we find them stopping at a time we're not | |
3434 | interested in reporting the event (target_wait on a | |
3435 | specific_process, for example, see linux_nat_wait_1), and | |
3436 | meanwhile the event became uninteresting. Don't bother resuming | |
3437 | LWPs we're not going to wait for if they'd stop immediately. */ | |
fbea99ea | 3438 | if (target_is_non_stop_p ()) |
d3a70e03 TT |
3439 | iterate_over_lwps (minus_one_ptid, |
3440 | [=] (struct lwp_info *info) | |
3441 | { | |
3442 | return resume_stopped_resumed_lwps (info, ptid); | |
3443 | }); | |
e3e9f5a2 | 3444 | |
f6ac5f3d | 3445 | event_ptid = linux_nat_wait_1 (ptid, ourstatus, target_options); |
7feb7d06 PA |
3446 | |
3447 | /* If we requested any event, and something came out, assume there | |
3448 | may be more. If we requested a specific lwp or process, also | |
3449 | assume there may be more. */ | |
d9d41e78 | 3450 | if (target_is_async_p () |
183be222 SM |
3451 | && ((ourstatus->kind () != TARGET_WAITKIND_IGNORE |
3452 | && ourstatus->kind () != TARGET_WAITKIND_NO_RESUMED) | |
d7e15655 | 3453 | || ptid != minus_one_ptid)) |
7feb7d06 PA |
3454 | async_file_mark (); |
3455 | ||
7feb7d06 PA |
3456 | return event_ptid; |
3457 | } | |
3458 | ||
1d2736d4 PA |
3459 | /* Kill one LWP. */ |
3460 | ||
3461 | static void | |
3462 | kill_one_lwp (pid_t pid) | |
d6b0e80f | 3463 | { |
ed731959 JK |
3464 | /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
3465 | ||
3466 | errno = 0; | |
1d2736d4 | 3467 | kill_lwp (pid, SIGKILL); |
9327494e | 3468 | |
ed731959 | 3469 | if (debug_linux_nat) |
57745c90 PA |
3470 | { |
3471 | int save_errno = errno; | |
3472 | ||
9327494e SM |
3473 | linux_nat_debug_printf |
3474 | ("kill (SIGKILL) %ld, 0, 0 (%s)", (long) pid, | |
3475 | save_errno != 0 ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3476 | } |
ed731959 JK |
3477 | |
3478 | /* Some kernels ignore even SIGKILL for processes under ptrace. */ | |
3479 | ||
d6b0e80f | 3480 | errno = 0; |
1d2736d4 | 3481 | ptrace (PTRACE_KILL, pid, 0, 0); |
d6b0e80f | 3482 | if (debug_linux_nat) |
57745c90 PA |
3483 | { |
3484 | int save_errno = errno; | |
3485 | ||
9327494e SM |
3486 | linux_nat_debug_printf |
3487 | ("PTRACE_KILL %ld, 0, 0 (%s)", (long) pid, | |
3488 | save_errno ? safe_strerror (save_errno) : "OK"); | |
57745c90 | 3489 | } |
d6b0e80f AC |
3490 | } |
3491 | ||
1d2736d4 PA |
3492 | /* Wait for an LWP to die. */ |
3493 | ||
3494 | static void | |
3495 | kill_wait_one_lwp (pid_t pid) | |
d6b0e80f | 3496 | { |
1d2736d4 | 3497 | pid_t res; |
d6b0e80f AC |
3498 | |
3499 | /* We must make sure that there are no pending events (delayed | |
3500 | SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current | |
3501 | program doesn't interfere with any following debugging session. */ | |
3502 | ||
d6b0e80f AC |
3503 | do |
3504 | { | |
1d2736d4 PA |
3505 | res = my_waitpid (pid, NULL, __WALL); |
3506 | if (res != (pid_t) -1) | |
d6b0e80f | 3507 | { |
9327494e SM |
3508 | linux_nat_debug_printf ("wait %ld received unknown.", (long) pid); |
3509 | ||
4a6ed09b PA |
3510 | /* The Linux kernel sometimes fails to kill a thread |
3511 | completely after PTRACE_KILL; that goes from the stop | |
3512 | point in do_fork out to the one in get_signal_to_deliver | |
3513 | and waits again. So kill it again. */ | |
1d2736d4 | 3514 | kill_one_lwp (pid); |
d6b0e80f AC |
3515 | } |
3516 | } | |
1d2736d4 PA |
3517 | while (res == pid); |
3518 | ||
3519 | gdb_assert (res == -1 && errno == ECHILD); | |
3520 | } | |
3521 | ||
3522 | /* Callback for iterate_over_lwps. */ | |
d6b0e80f | 3523 | |
1d2736d4 | 3524 | static int |
d3a70e03 | 3525 | kill_callback (struct lwp_info *lp) |
1d2736d4 | 3526 | { |
e38504b3 | 3527 | kill_one_lwp (lp->ptid.lwp ()); |
d6b0e80f AC |
3528 | return 0; |
3529 | } | |
3530 | ||
1d2736d4 PA |
3531 | /* Callback for iterate_over_lwps. */ |
3532 | ||
3533 | static int | |
d3a70e03 | 3534 | kill_wait_callback (struct lwp_info *lp) |
1d2736d4 | 3535 | { |
e38504b3 | 3536 | kill_wait_one_lwp (lp->ptid.lwp ()); |
1d2736d4 PA |
3537 | return 0; |
3538 | } | |
3539 | ||
3540 | /* Kill the fork children of any threads of inferior INF that are | |
3541 | stopped at a fork event. */ | |
3542 | ||
3543 | static void | |
3544 | kill_unfollowed_fork_children (struct inferior *inf) | |
3545 | { | |
08036331 PA |
3546 | for (thread_info *thread : inf->non_exited_threads ()) |
3547 | { | |
3548 | struct target_waitstatus *ws = &thread->pending_follow; | |
1d2736d4 | 3549 | |
183be222 SM |
3550 | if (ws->kind () == TARGET_WAITKIND_FORKED |
3551 | || ws->kind () == TARGET_WAITKIND_VFORKED) | |
08036331 | 3552 | { |
183be222 | 3553 | ptid_t child_ptid = ws->child_ptid (); |
08036331 PA |
3554 | int child_pid = child_ptid.pid (); |
3555 | int child_lwp = child_ptid.lwp (); | |
3556 | ||
3557 | kill_one_lwp (child_lwp); | |
3558 | kill_wait_one_lwp (child_lwp); | |
3559 | ||
3560 | /* Let the arch-specific native code know this process is | |
3561 | gone. */ | |
3562 | linux_target->low_forget_process (child_pid); | |
3563 | } | |
3564 | } | |
1d2736d4 PA |
3565 | } |
3566 | ||
f6ac5f3d PA |
3567 | void |
3568 | linux_nat_target::kill () | |
d6b0e80f | 3569 | { |
f973ed9c DJ |
3570 | /* If we're stopped while forking and we haven't followed yet, |
3571 | kill the other task. We need to do this first because the | |
3572 | parent will be sleeping if this is a vfork. */ | |
1d2736d4 | 3573 | kill_unfollowed_fork_children (current_inferior ()); |
f973ed9c DJ |
3574 | |
3575 | if (forks_exist_p ()) | |
7feb7d06 | 3576 | linux_fork_killall (); |
f973ed9c DJ |
3577 | else |
3578 | { | |
e99b03dc | 3579 | ptid_t ptid = ptid_t (inferior_ptid.pid ()); |
e0881a8e | 3580 | |
4c28f408 | 3581 | /* Stop all threads before killing them, since ptrace requires |
30baf67b | 3582 | that the thread is stopped to successfully PTRACE_KILL. */ |
d3a70e03 | 3583 | iterate_over_lwps (ptid, stop_callback); |
4c28f408 PA |
3584 | /* ... and wait until all of them have reported back that |
3585 | they're no longer running. */ | |
d3a70e03 | 3586 | iterate_over_lwps (ptid, stop_wait_callback); |
4c28f408 | 3587 | |
f973ed9c | 3588 | /* Kill all LWP's ... */ |
d3a70e03 | 3589 | iterate_over_lwps (ptid, kill_callback); |
f973ed9c DJ |
3590 | |
3591 | /* ... and wait until we've flushed all events. */ | |
d3a70e03 | 3592 | iterate_over_lwps (ptid, kill_wait_callback); |
f973ed9c DJ |
3593 | } |
3594 | ||
bc1e6c81 | 3595 | target_mourn_inferior (inferior_ptid); |
d6b0e80f AC |
3596 | } |
3597 | ||
f6ac5f3d PA |
3598 | void |
3599 | linux_nat_target::mourn_inferior () | |
d6b0e80f | 3600 | { |
b26b06dd AB |
3601 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
3602 | ||
e99b03dc | 3603 | int pid = inferior_ptid.pid (); |
26cb8b7c PA |
3604 | |
3605 | purge_lwp_list (pid); | |
d6b0e80f | 3606 | |
8a89ddbd | 3607 | close_proc_mem_file (pid); |
05c06f31 | 3608 | |
f973ed9c | 3609 | if (! forks_exist_p ()) |
d90e17a7 | 3610 | /* Normal case, no other forks available. */ |
f6ac5f3d | 3611 | inf_ptrace_target::mourn_inferior (); |
f973ed9c DJ |
3612 | else |
3613 | /* Multi-fork case. The current inferior_ptid has exited, but | |
3614 | there are other viable forks to debug. Delete the exiting | |
3615 | one and context-switch to the first available. */ | |
3616 | linux_fork_mourn_inferior (); | |
26cb8b7c PA |
3617 | |
3618 | /* Let the arch-specific native code know this process is gone. */ | |
135340af | 3619 | linux_target->low_forget_process (pid); |
d6b0e80f AC |
3620 | } |
3621 | ||
5b009018 PA |
3622 | /* Convert a native/host siginfo object, into/from the siginfo in the |
3623 | layout of the inferiors' architecture. */ | |
3624 | ||
3625 | static void | |
a5362b9a | 3626 | siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction) |
5b009018 | 3627 | { |
135340af PA |
3628 | /* If the low target didn't do anything, then just do a straight |
3629 | memcpy. */ | |
3630 | if (!linux_target->low_siginfo_fixup (siginfo, inf_siginfo, direction)) | |
5b009018 PA |
3631 | { |
3632 | if (direction == 1) | |
a5362b9a | 3633 | memcpy (siginfo, inf_siginfo, sizeof (siginfo_t)); |
5b009018 | 3634 | else |
a5362b9a | 3635 | memcpy (inf_siginfo, siginfo, sizeof (siginfo_t)); |
5b009018 PA |
3636 | } |
3637 | } | |
3638 | ||
9b409511 | 3639 | static enum target_xfer_status |
7154e786 | 3640 | linux_xfer_siginfo (ptid_t ptid, enum target_object object, |
dda83cd7 | 3641 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
3642 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
3643 | ULONGEST *xfered_len) | |
4aa995e1 | 3644 | { |
a5362b9a TS |
3645 | siginfo_t siginfo; |
3646 | gdb_byte inf_siginfo[sizeof (siginfo_t)]; | |
4aa995e1 PA |
3647 | |
3648 | gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); | |
3649 | gdb_assert (readbuf || writebuf); | |
3650 | ||
4aa995e1 | 3651 | if (offset > sizeof (siginfo)) |
2ed4b548 | 3652 | return TARGET_XFER_E_IO; |
4aa995e1 | 3653 | |
7154e786 | 3654 | if (!linux_nat_get_siginfo (ptid, &siginfo)) |
2ed4b548 | 3655 | return TARGET_XFER_E_IO; |
4aa995e1 | 3656 | |
5b009018 PA |
3657 | /* When GDB is built as a 64-bit application, ptrace writes into |
3658 | SIGINFO an object with 64-bit layout. Since debugging a 32-bit | |
3659 | inferior with a 64-bit GDB should look the same as debugging it | |
3660 | with a 32-bit GDB, we need to convert it. GDB core always sees | |
3661 | the converted layout, so any read/write will have to be done | |
3662 | post-conversion. */ | |
3663 | siginfo_fixup (&siginfo, inf_siginfo, 0); | |
3664 | ||
4aa995e1 PA |
3665 | if (offset + len > sizeof (siginfo)) |
3666 | len = sizeof (siginfo) - offset; | |
3667 | ||
3668 | if (readbuf != NULL) | |
5b009018 | 3669 | memcpy (readbuf, inf_siginfo + offset, len); |
4aa995e1 PA |
3670 | else |
3671 | { | |
5b009018 PA |
3672 | memcpy (inf_siginfo + offset, writebuf, len); |
3673 | ||
3674 | /* Convert back to ptrace layout before flushing it out. */ | |
3675 | siginfo_fixup (&siginfo, inf_siginfo, 1); | |
3676 | ||
7154e786 | 3677 | int pid = get_ptrace_pid (ptid); |
4aa995e1 PA |
3678 | errno = 0; |
3679 | ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); | |
3680 | if (errno != 0) | |
2ed4b548 | 3681 | return TARGET_XFER_E_IO; |
4aa995e1 PA |
3682 | } |
3683 | ||
9b409511 YQ |
3684 | *xfered_len = len; |
3685 | return TARGET_XFER_OK; | |
4aa995e1 PA |
3686 | } |
3687 | ||
9b409511 | 3688 | static enum target_xfer_status |
f6ac5f3d PA |
3689 | linux_nat_xfer_osdata (enum target_object object, |
3690 | const char *annex, gdb_byte *readbuf, | |
3691 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, | |
3692 | ULONGEST *xfered_len); | |
3693 | ||
f6ac5f3d | 3694 | static enum target_xfer_status |
f9f593dd SM |
3695 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3696 | const gdb_byte *writebuf, ULONGEST offset, | |
3697 | LONGEST len, ULONGEST *xfered_len); | |
f6ac5f3d PA |
3698 | |
3699 | enum target_xfer_status | |
3700 | linux_nat_target::xfer_partial (enum target_object object, | |
3701 | const char *annex, gdb_byte *readbuf, | |
3702 | const gdb_byte *writebuf, | |
3703 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) | |
d6b0e80f | 3704 | { |
4aa995e1 | 3705 | if (object == TARGET_OBJECT_SIGNAL_INFO) |
7154e786 | 3706 | return linux_xfer_siginfo (inferior_ptid, object, annex, readbuf, writebuf, |
9b409511 | 3707 | offset, len, xfered_len); |
4aa995e1 | 3708 | |
c35b1492 PA |
3709 | /* The target is connected but no live inferior is selected. Pass |
3710 | this request down to a lower stratum (e.g., the executable | |
3711 | file). */ | |
d7e15655 | 3712 | if (object == TARGET_OBJECT_MEMORY && inferior_ptid == null_ptid) |
9b409511 | 3713 | return TARGET_XFER_EOF; |
c35b1492 | 3714 | |
f6ac5f3d PA |
3715 | if (object == TARGET_OBJECT_AUXV) |
3716 | return memory_xfer_auxv (this, object, annex, readbuf, writebuf, | |
3717 | offset, len, xfered_len); | |
3718 | ||
3719 | if (object == TARGET_OBJECT_OSDATA) | |
3720 | return linux_nat_xfer_osdata (object, annex, readbuf, writebuf, | |
3721 | offset, len, xfered_len); | |
d6b0e80f | 3722 | |
f6ac5f3d PA |
3723 | if (object == TARGET_OBJECT_MEMORY) |
3724 | { | |
05c06f31 PA |
3725 | /* GDB calculates all addresses in the largest possible address |
3726 | width. The address width must be masked before its final use | |
3727 | by linux_proc_xfer_partial. | |
3728 | ||
3729 | Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ | |
99d9c3b9 | 3730 | int addr_bit = gdbarch_addr_bit (current_inferior ()->arch ()); |
f6ac5f3d PA |
3731 | |
3732 | if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) | |
3733 | offset &= ((ULONGEST) 1 << addr_bit) - 1; | |
f6ac5f3d | 3734 | |
dd09fe0d KS |
3735 | /* If /proc/pid/mem is writable, don't fallback to ptrace. If |
3736 | the write via /proc/pid/mem fails because the inferior execed | |
3737 | (and we haven't seen the exec event yet), a subsequent ptrace | |
3738 | poke would incorrectly write memory to the post-exec address | |
3739 | space, while the core was trying to write to the pre-exec | |
3740 | address space. */ | |
3741 | if (proc_mem_file_is_writable ()) | |
f9f593dd SM |
3742 | return linux_proc_xfer_memory_partial (inferior_ptid.pid (), readbuf, |
3743 | writebuf, offset, len, | |
3744 | xfered_len); | |
05c06f31 | 3745 | } |
f6ac5f3d PA |
3746 | |
3747 | return inf_ptrace_target::xfer_partial (object, annex, readbuf, writebuf, | |
3748 | offset, len, xfered_len); | |
d6b0e80f AC |
3749 | } |
3750 | ||
57810aa7 | 3751 | bool |
f6ac5f3d | 3752 | linux_nat_target::thread_alive (ptid_t ptid) |
28439f5e | 3753 | { |
4a6ed09b PA |
3754 | /* As long as a PTID is in lwp list, consider it alive. */ |
3755 | return find_lwp_pid (ptid) != NULL; | |
28439f5e PA |
3756 | } |
3757 | ||
8a06aea7 PA |
3758 | /* Implement the to_update_thread_list target method for this |
3759 | target. */ | |
3760 | ||
f6ac5f3d PA |
3761 | void |
3762 | linux_nat_target::update_thread_list () | |
8a06aea7 | 3763 | { |
4a6ed09b PA |
3764 | /* We add/delete threads from the list as clone/exit events are |
3765 | processed, so just try deleting exited threads still in the | |
3766 | thread list. */ | |
3767 | delete_exited_threads (); | |
a6904d5a PA |
3768 | |
3769 | /* Update the processor core that each lwp/thread was last seen | |
3770 | running on. */ | |
901b9821 | 3771 | for (lwp_info *lwp : all_lwps ()) |
1ad3de98 PA |
3772 | { |
3773 | /* Avoid accessing /proc if the thread hasn't run since we last | |
3774 | time we fetched the thread's core. Accessing /proc becomes | |
3775 | noticeably expensive when we have thousands of LWPs. */ | |
3776 | if (lwp->core == -1) | |
3777 | lwp->core = linux_common_core_of_thread (lwp->ptid); | |
3778 | } | |
8a06aea7 PA |
3779 | } |
3780 | ||
a068643d | 3781 | std::string |
f6ac5f3d | 3782 | linux_nat_target::pid_to_str (ptid_t ptid) |
d6b0e80f | 3783 | { |
15a9e13e | 3784 | if (ptid.lwp_p () |
e38504b3 | 3785 | && (ptid.pid () != ptid.lwp () |
e99b03dc | 3786 | || num_lwps (ptid.pid ()) > 1)) |
a068643d | 3787 | return string_printf ("LWP %ld", ptid.lwp ()); |
d6b0e80f AC |
3788 | |
3789 | return normal_pid_to_str (ptid); | |
3790 | } | |
3791 | ||
f6ac5f3d PA |
3792 | const char * |
3793 | linux_nat_target::thread_name (struct thread_info *thr) | |
4694da01 | 3794 | { |
79efa585 | 3795 | return linux_proc_tid_get_name (thr->ptid); |
4694da01 TT |
3796 | } |
3797 | ||
dba24537 AC |
3798 | /* Accepts an integer PID; Returns a string representing a file that |
3799 | can be opened to get the symbols for the child process. */ | |
3800 | ||
0e90c441 | 3801 | const char * |
f6ac5f3d | 3802 | linux_nat_target::pid_to_exec_file (int pid) |
dba24537 | 3803 | { |
e0d86d2c | 3804 | return linux_proc_pid_to_exec_file (pid); |
dba24537 AC |
3805 | } |
3806 | ||
8a89ddbd PA |
3807 | /* Object representing an /proc/PID/mem open file. We keep one such |
3808 | file open per inferior. | |
3809 | ||
3810 | It might be tempting to think about only ever opening one file at | |
3811 | most for all inferiors, closing/reopening the file as we access | |
3812 | memory of different inferiors, to minimize number of file | |
3813 | descriptors open, which can otherwise run into resource limits. | |
3814 | However, that does not work correctly -- if the inferior execs and | |
3815 | we haven't processed the exec event yet, and, we opened a | |
3816 | /proc/PID/mem file, we will get a mem file accessing the post-exec | |
3817 | address space, thinking we're opening it for the pre-exec address | |
3818 | space. That is dangerous as we can poke memory (e.g. clearing | |
3819 | breakpoints) in the post-exec memory by mistake, corrupting the | |
3820 | inferior. For that reason, we open the mem file as early as | |
3821 | possible, right after spawning, forking or attaching to the | |
3822 | inferior, when the inferior is stopped and thus before it has a | |
3823 | chance of execing. | |
3824 | ||
3825 | Note that after opening the file, even if the thread we opened it | |
3826 | for subsequently exits, the open file is still usable for accessing | |
3827 | memory. It's only when the whole process exits or execs that the | |
3828 | file becomes invalid, at which point reads/writes return EOF. */ | |
3829 | ||
3830 | class proc_mem_file | |
3831 | { | |
3832 | public: | |
3833 | proc_mem_file (ptid_t ptid, int fd) | |
3834 | : m_ptid (ptid), m_fd (fd) | |
3835 | { | |
3836 | gdb_assert (m_fd != -1); | |
3837 | } | |
05c06f31 | 3838 | |
8a89ddbd | 3839 | ~proc_mem_file () |
05c06f31 | 3840 | { |
89662f69 | 3841 | linux_nat_debug_printf ("closing fd %d for /proc/%d/task/%ld/mem", |
8a89ddbd PA |
3842 | m_fd, m_ptid.pid (), m_ptid.lwp ()); |
3843 | close (m_fd); | |
05c06f31 | 3844 | } |
05c06f31 | 3845 | |
8a89ddbd PA |
3846 | DISABLE_COPY_AND_ASSIGN (proc_mem_file); |
3847 | ||
3848 | int fd () | |
3849 | { | |
3850 | return m_fd; | |
3851 | } | |
3852 | ||
3853 | private: | |
3854 | /* The LWP this file was opened for. Just for debugging | |
3855 | purposes. */ | |
3856 | ptid_t m_ptid; | |
3857 | ||
3858 | /* The file descriptor. */ | |
3859 | int m_fd = -1; | |
3860 | }; | |
3861 | ||
3862 | /* The map between an inferior process id, and the open /proc/PID/mem | |
3863 | file. This is stored in a map instead of in a per-inferior | |
3864 | structure because we need to be able to access memory of processes | |
3865 | which don't have a corresponding struct inferior object. E.g., | |
3866 | with "detach-on-fork on" (the default), and "follow-fork parent" | |
3867 | (also default), we don't create an inferior for the fork child, but | |
3868 | we still need to remove breakpoints from the fork child's | |
3869 | memory. */ | |
3870 | static std::unordered_map<int, proc_mem_file> proc_mem_file_map; | |
3871 | ||
3872 | /* Close the /proc/PID/mem file for PID. */ | |
05c06f31 PA |
3873 | |
3874 | static void | |
8a89ddbd | 3875 | close_proc_mem_file (pid_t pid) |
dba24537 | 3876 | { |
8a89ddbd | 3877 | proc_mem_file_map.erase (pid); |
05c06f31 | 3878 | } |
dba24537 | 3879 | |
8a89ddbd PA |
3880 | /* Open the /proc/PID/mem file for the process (thread group) of PTID. |
3881 | We actually open /proc/PID/task/LWP/mem, as that's the LWP we know | |
3882 | exists and is stopped right now. We prefer the | |
3883 | /proc/PID/task/LWP/mem form over /proc/LWP/mem to avoid tid-reuse | |
3884 | races, just in case this is ever called on an already-waited | |
3885 | LWP. */ | |
dba24537 | 3886 | |
8a89ddbd PA |
3887 | static void |
3888 | open_proc_mem_file (ptid_t ptid) | |
05c06f31 | 3889 | { |
8a89ddbd PA |
3890 | auto iter = proc_mem_file_map.find (ptid.pid ()); |
3891 | gdb_assert (iter == proc_mem_file_map.end ()); | |
dba24537 | 3892 | |
8a89ddbd PA |
3893 | char filename[64]; |
3894 | xsnprintf (filename, sizeof filename, | |
3895 | "/proc/%d/task/%ld/mem", ptid.pid (), ptid.lwp ()); | |
3896 | ||
3897 | int fd = gdb_open_cloexec (filename, O_RDWR | O_LARGEFILE, 0).release (); | |
05c06f31 | 3898 | |
8a89ddbd PA |
3899 | if (fd == -1) |
3900 | { | |
3901 | warning (_("opening /proc/PID/mem file for lwp %d.%ld failed: %s (%d)"), | |
3902 | ptid.pid (), ptid.lwp (), | |
3903 | safe_strerror (errno), errno); | |
3904 | return; | |
05c06f31 PA |
3905 | } |
3906 | ||
8a89ddbd PA |
3907 | proc_mem_file_map.emplace (std::piecewise_construct, |
3908 | std::forward_as_tuple (ptid.pid ()), | |
3909 | std::forward_as_tuple (ptid, fd)); | |
3910 | ||
9221923c | 3911 | linux_nat_debug_printf ("opened fd %d for lwp %d.%ld", |
8a89ddbd PA |
3912 | fd, ptid.pid (), ptid.lwp ()); |
3913 | } | |
3914 | ||
1bcb0708 PA |
3915 | /* Helper for linux_proc_xfer_memory_partial and |
3916 | proc_mem_file_is_writable. FD is the already opened /proc/pid/mem | |
3917 | file, and PID is the pid of the corresponding process. The rest of | |
3918 | the arguments are like linux_proc_xfer_memory_partial's. */ | |
8a89ddbd PA |
3919 | |
3920 | static enum target_xfer_status | |
1bcb0708 PA |
3921 | linux_proc_xfer_memory_partial_fd (int fd, int pid, |
3922 | gdb_byte *readbuf, const gdb_byte *writebuf, | |
3923 | ULONGEST offset, LONGEST len, | |
3924 | ULONGEST *xfered_len) | |
8a89ddbd PA |
3925 | { |
3926 | ssize_t ret; | |
3927 | ||
8a89ddbd | 3928 | gdb_assert (fd != -1); |
dba24537 | 3929 | |
31a56a22 PA |
3930 | /* Use pread64/pwrite64 if available, since they save a syscall and |
3931 | can handle 64-bit offsets even on 32-bit platforms (for instance, | |
3932 | SPARC debugging a SPARC64 application). But only use them if the | |
3933 | offset isn't so high that when cast to off_t it'd be negative, as | |
3934 | seen on SPARC64. pread64/pwrite64 outright reject such offsets. | |
3935 | lseek does not. */ | |
dba24537 | 3936 | #ifdef HAVE_PREAD64 |
31a56a22 PA |
3937 | if ((off_t) offset >= 0) |
3938 | ret = (readbuf != nullptr | |
3939 | ? pread64 (fd, readbuf, len, offset) | |
3940 | : pwrite64 (fd, writebuf, len, offset)); | |
3941 | else | |
dba24537 | 3942 | #endif |
31a56a22 PA |
3943 | { |
3944 | ret = lseek (fd, offset, SEEK_SET); | |
3945 | if (ret != -1) | |
3946 | ret = (readbuf != nullptr | |
3947 | ? read (fd, readbuf, len) | |
3948 | : write (fd, writebuf, len)); | |
3949 | } | |
dba24537 | 3950 | |
05c06f31 PA |
3951 | if (ret == -1) |
3952 | { | |
9221923c | 3953 | linux_nat_debug_printf ("accessing fd %d for pid %d failed: %s (%d)", |
1bcb0708 | 3954 | fd, pid, safe_strerror (errno), errno); |
284b6bb5 | 3955 | return TARGET_XFER_E_IO; |
05c06f31 PA |
3956 | } |
3957 | else if (ret == 0) | |
3958 | { | |
8a89ddbd PA |
3959 | /* EOF means the address space is gone, the whole process exited |
3960 | or execed. */ | |
9221923c | 3961 | linux_nat_debug_printf ("accessing fd %d for pid %d got EOF", |
1bcb0708 | 3962 | fd, pid); |
05c06f31 PA |
3963 | return TARGET_XFER_EOF; |
3964 | } | |
9b409511 YQ |
3965 | else |
3966 | { | |
8a89ddbd | 3967 | *xfered_len = ret; |
9b409511 YQ |
3968 | return TARGET_XFER_OK; |
3969 | } | |
05c06f31 | 3970 | } |
efcbbd14 | 3971 | |
1bcb0708 PA |
3972 | /* Implement the to_xfer_partial target method using /proc/PID/mem. |
3973 | Because we can use a single read/write call, this can be much more | |
3974 | efficient than banging away at PTRACE_PEEKTEXT. Also, unlike | |
3975 | PTRACE_PEEKTEXT/PTRACE_POKETEXT, this works with running | |
3976 | threads. */ | |
3977 | ||
3978 | static enum target_xfer_status | |
f9f593dd SM |
3979 | linux_proc_xfer_memory_partial (int pid, gdb_byte *readbuf, |
3980 | const gdb_byte *writebuf, ULONGEST offset, | |
3981 | LONGEST len, ULONGEST *xfered_len) | |
1bcb0708 | 3982 | { |
1bcb0708 PA |
3983 | auto iter = proc_mem_file_map.find (pid); |
3984 | if (iter == proc_mem_file_map.end ()) | |
3985 | return TARGET_XFER_EOF; | |
3986 | ||
3987 | int fd = iter->second.fd (); | |
3988 | ||
3989 | return linux_proc_xfer_memory_partial_fd (fd, pid, readbuf, writebuf, offset, | |
3990 | len, xfered_len); | |
3991 | } | |
3992 | ||
3993 | /* Check whether /proc/pid/mem is writable in the current kernel, and | |
3994 | return true if so. It wasn't writable before Linux 2.6.39, but | |
3995 | there's no way to know whether the feature was backported to older | |
3996 | kernels. So we check to see if it works. The result is cached, | |
3bfdcabb | 3997 | and this is guaranteed to be called once early during inferior |
9dff6a5d PA |
3998 | startup, so that any warning is printed out consistently between |
3999 | GDB invocations. Note we don't call it during GDB startup instead | |
4000 | though, because then we might warn with e.g. just "gdb --version" | |
4001 | on sandboxed systems. See PR gdb/29907. */ | |
1bcb0708 PA |
4002 | |
4003 | static bool | |
4004 | proc_mem_file_is_writable () | |
4005 | { | |
4006 | static gdb::optional<bool> writable; | |
4007 | ||
4008 | if (writable.has_value ()) | |
4009 | return *writable; | |
4010 | ||
4011 | writable.emplace (false); | |
4012 | ||
4013 | /* We check whether /proc/pid/mem is writable by trying to write to | |
4014 | one of our variables via /proc/self/mem. */ | |
4015 | ||
4016 | int fd = gdb_open_cloexec ("/proc/self/mem", O_RDWR | O_LARGEFILE, 0).release (); | |
4017 | ||
4018 | if (fd == -1) | |
4019 | { | |
4020 | warning (_("opening /proc/self/mem file failed: %s (%d)"), | |
4021 | safe_strerror (errno), errno); | |
4022 | return *writable; | |
4023 | } | |
4024 | ||
4025 | SCOPE_EXIT { close (fd); }; | |
4026 | ||
4027 | /* This is the variable we try to write to. Note OFFSET below. */ | |
4028 | volatile gdb_byte test_var = 0; | |
4029 | ||
4030 | gdb_byte writebuf[] = {0x55}; | |
4031 | ULONGEST offset = (uintptr_t) &test_var; | |
4032 | ULONGEST xfered_len; | |
4033 | ||
4034 | enum target_xfer_status res | |
4035 | = linux_proc_xfer_memory_partial_fd (fd, getpid (), nullptr, writebuf, | |
4036 | offset, 1, &xfered_len); | |
4037 | ||
4038 | if (res == TARGET_XFER_OK) | |
4039 | { | |
4040 | gdb_assert (xfered_len == 1); | |
4041 | gdb_assert (test_var == 0x55); | |
4042 | /* Success. */ | |
4043 | *writable = true; | |
4044 | } | |
4045 | ||
4046 | return *writable; | |
4047 | } | |
4048 | ||
dba24537 AC |
4049 | /* Parse LINE as a signal set and add its set bits to SIGS. */ |
4050 | ||
4051 | static void | |
4052 | add_line_to_sigset (const char *line, sigset_t *sigs) | |
4053 | { | |
4054 | int len = strlen (line) - 1; | |
4055 | const char *p; | |
4056 | int signum; | |
4057 | ||
4058 | if (line[len] != '\n') | |
8a3fe4f8 | 4059 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4060 | |
4061 | p = line; | |
4062 | signum = len * 4; | |
4063 | while (len-- > 0) | |
4064 | { | |
4065 | int digit; | |
4066 | ||
4067 | if (*p >= '0' && *p <= '9') | |
4068 | digit = *p - '0'; | |
4069 | else if (*p >= 'a' && *p <= 'f') | |
4070 | digit = *p - 'a' + 10; | |
4071 | else | |
8a3fe4f8 | 4072 | error (_("Could not parse signal set: %s"), line); |
dba24537 AC |
4073 | |
4074 | signum -= 4; | |
4075 | ||
4076 | if (digit & 1) | |
4077 | sigaddset (sigs, signum + 1); | |
4078 | if (digit & 2) | |
4079 | sigaddset (sigs, signum + 2); | |
4080 | if (digit & 4) | |
4081 | sigaddset (sigs, signum + 3); | |
4082 | if (digit & 8) | |
4083 | sigaddset (sigs, signum + 4); | |
4084 | ||
4085 | p++; | |
4086 | } | |
4087 | } | |
4088 | ||
4089 | /* Find process PID's pending signals from /proc/pid/status and set | |
4090 | SIGS to match. */ | |
4091 | ||
4092 | void | |
3e43a32a MS |
4093 | linux_proc_pending_signals (int pid, sigset_t *pending, |
4094 | sigset_t *blocked, sigset_t *ignored) | |
dba24537 | 4095 | { |
d8d2a3ee | 4096 | char buffer[PATH_MAX], fname[PATH_MAX]; |
dba24537 AC |
4097 | |
4098 | sigemptyset (pending); | |
4099 | sigemptyset (blocked); | |
4100 | sigemptyset (ignored); | |
cde33bf1 | 4101 | xsnprintf (fname, sizeof fname, "/proc/%d/status", pid); |
d419f42d | 4102 | gdb_file_up procfile = gdb_fopen_cloexec (fname, "r"); |
dba24537 | 4103 | if (procfile == NULL) |
8a3fe4f8 | 4104 | error (_("Could not open %s"), fname); |
dba24537 | 4105 | |
d419f42d | 4106 | while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL) |
dba24537 AC |
4107 | { |
4108 | /* Normal queued signals are on the SigPnd line in the status | |
4109 | file. However, 2.6 kernels also have a "shared" pending | |
4110 | queue for delivering signals to a thread group, so check for | |
4111 | a ShdPnd line also. | |
4112 | ||
4113 | Unfortunately some Red Hat kernels include the shared pending | |
4114 | queue but not the ShdPnd status field. */ | |
4115 | ||
61012eef | 4116 | if (startswith (buffer, "SigPnd:\t")) |
dba24537 | 4117 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4118 | else if (startswith (buffer, "ShdPnd:\t")) |
dba24537 | 4119 | add_line_to_sigset (buffer + 8, pending); |
61012eef | 4120 | else if (startswith (buffer, "SigBlk:\t")) |
dba24537 | 4121 | add_line_to_sigset (buffer + 8, blocked); |
61012eef | 4122 | else if (startswith (buffer, "SigIgn:\t")) |
dba24537 AC |
4123 | add_line_to_sigset (buffer + 8, ignored); |
4124 | } | |
dba24537 AC |
4125 | } |
4126 | ||
9b409511 | 4127 | static enum target_xfer_status |
f6ac5f3d | 4128 | linux_nat_xfer_osdata (enum target_object object, |
e0881a8e | 4129 | const char *annex, gdb_byte *readbuf, |
9b409511 YQ |
4130 | const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, |
4131 | ULONGEST *xfered_len) | |
07e059b5 | 4132 | { |
07e059b5 VP |
4133 | gdb_assert (object == TARGET_OBJECT_OSDATA); |
4134 | ||
9b409511 YQ |
4135 | *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len); |
4136 | if (*xfered_len == 0) | |
4137 | return TARGET_XFER_EOF; | |
4138 | else | |
4139 | return TARGET_XFER_OK; | |
07e059b5 VP |
4140 | } |
4141 | ||
f6ac5f3d PA |
4142 | std::vector<static_tracepoint_marker> |
4143 | linux_nat_target::static_tracepoint_markers_by_strid (const char *strid) | |
5808517f YQ |
4144 | { |
4145 | char s[IPA_CMD_BUF_SIZE]; | |
e99b03dc | 4146 | int pid = inferior_ptid.pid (); |
5d9310c4 | 4147 | std::vector<static_tracepoint_marker> markers; |
256642e8 | 4148 | const char *p = s; |
184ea2f7 | 4149 | ptid_t ptid = ptid_t (pid, 0); |
5d9310c4 | 4150 | static_tracepoint_marker marker; |
5808517f YQ |
4151 | |
4152 | /* Pause all */ | |
4153 | target_stop (ptid); | |
4154 | ||
81aa19c3 | 4155 | strcpy (s, "qTfSTM"); |
42476b70 | 4156 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f | 4157 | |
1db93f14 TT |
4158 | /* Unpause all. */ |
4159 | SCOPE_EXIT { target_continue_no_signal (ptid); }; | |
5808517f YQ |
4160 | |
4161 | while (*p++ == 'm') | |
4162 | { | |
5808517f YQ |
4163 | do |
4164 | { | |
5d9310c4 | 4165 | parse_static_tracepoint_marker_definition (p, &p, &marker); |
5808517f | 4166 | |
5d9310c4 SM |
4167 | if (strid == NULL || marker.str_id == strid) |
4168 | markers.push_back (std::move (marker)); | |
5808517f YQ |
4169 | } |
4170 | while (*p++ == ','); /* comma-separated list */ | |
4171 | ||
81aa19c3 | 4172 | strcpy (s, "qTsSTM"); |
42476b70 | 4173 | agent_run_command (pid, s, strlen (s) + 1); |
5808517f YQ |
4174 | p = s; |
4175 | } | |
4176 | ||
5808517f YQ |
4177 | return markers; |
4178 | } | |
4179 | ||
b84876c2 PA |
4180 | /* target_can_async_p implementation. */ |
4181 | ||
57810aa7 | 4182 | bool |
f6ac5f3d | 4183 | linux_nat_target::can_async_p () |
b84876c2 | 4184 | { |
fce6cd34 AB |
4185 | /* This flag should be checked in the common target.c code. */ |
4186 | gdb_assert (target_async_permitted); | |
4187 | ||
4188 | /* Otherwise, this targets is always able to support async mode. */ | |
4189 | return true; | |
b84876c2 PA |
4190 | } |
4191 | ||
57810aa7 | 4192 | bool |
f6ac5f3d | 4193 | linux_nat_target::supports_non_stop () |
9908b566 | 4194 | { |
f80c8ec4 | 4195 | return true; |
9908b566 VP |
4196 | } |
4197 | ||
fbea99ea PA |
4198 | /* to_always_non_stop_p implementation. */ |
4199 | ||
57810aa7 | 4200 | bool |
f6ac5f3d | 4201 | linux_nat_target::always_non_stop_p () |
fbea99ea | 4202 | { |
f80c8ec4 | 4203 | return true; |
fbea99ea PA |
4204 | } |
4205 | ||
57810aa7 | 4206 | bool |
f6ac5f3d | 4207 | linux_nat_target::supports_multi_process () |
d90e17a7 | 4208 | { |
aee91db3 | 4209 | return true; |
d90e17a7 PA |
4210 | } |
4211 | ||
57810aa7 | 4212 | bool |
f6ac5f3d | 4213 | linux_nat_target::supports_disable_randomization () |
03583c20 | 4214 | { |
f80c8ec4 | 4215 | return true; |
03583c20 UW |
4216 | } |
4217 | ||
7feb7d06 PA |
4218 | /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
4219 | so we notice when any child changes state, and notify the | |
4220 | event-loop; it allows us to use sigsuspend in linux_nat_wait_1 | |
4221 | above to wait for the arrival of a SIGCHLD. */ | |
4222 | ||
b84876c2 | 4223 | static void |
7feb7d06 | 4224 | sigchld_handler (int signo) |
b84876c2 | 4225 | { |
7feb7d06 PA |
4226 | int old_errno = errno; |
4227 | ||
01124a23 | 4228 | if (debug_linux_nat) |
da5bd37e | 4229 | gdb_stdlog->write_async_safe ("sigchld\n", sizeof ("sigchld\n") - 1); |
7feb7d06 | 4230 | |
b146ba14 JB |
4231 | if (signo == SIGCHLD) |
4232 | { | |
4233 | /* Let the event loop know that there are events to handle. */ | |
4234 | linux_nat_target::async_file_mark_if_open (); | |
4235 | } | |
7feb7d06 PA |
4236 | |
4237 | errno = old_errno; | |
4238 | } | |
4239 | ||
4240 | /* Callback registered with the target events file descriptor. */ | |
4241 | ||
4242 | static void | |
4243 | handle_target_event (int error, gdb_client_data client_data) | |
4244 | { | |
b1a35af2 | 4245 | inferior_event_handler (INF_REG_EVENT); |
7feb7d06 PA |
4246 | } |
4247 | ||
b84876c2 PA |
4248 | /* target_async implementation. */ |
4249 | ||
f6ac5f3d | 4250 | void |
4a570176 | 4251 | linux_nat_target::async (bool enable) |
b84876c2 | 4252 | { |
4a570176 | 4253 | if (enable == is_async_p ()) |
b146ba14 JB |
4254 | return; |
4255 | ||
4256 | /* Block child signals while we create/destroy the pipe, as their | |
4257 | handler writes to it. */ | |
4258 | gdb::block_signals blocker; | |
4259 | ||
6a3753b3 | 4260 | if (enable) |
b84876c2 | 4261 | { |
b146ba14 | 4262 | if (!async_file_open ()) |
f34652de | 4263 | internal_error ("creating event pipe failed."); |
b146ba14 JB |
4264 | |
4265 | add_file_handler (async_wait_fd (), handle_target_event, NULL, | |
4266 | "linux-nat"); | |
4267 | ||
4268 | /* There may be pending events to handle. Tell the event loop | |
4269 | to poll them. */ | |
4270 | async_file_mark (); | |
b84876c2 PA |
4271 | } |
4272 | else | |
4273 | { | |
b146ba14 JB |
4274 | delete_file_handler (async_wait_fd ()); |
4275 | async_file_close (); | |
b84876c2 | 4276 | } |
b84876c2 PA |
4277 | } |
4278 | ||
a493e3e2 | 4279 | /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other |
252fbfc8 PA |
4280 | event came out. */ |
4281 | ||
4c28f408 | 4282 | static int |
d3a70e03 | 4283 | linux_nat_stop_lwp (struct lwp_info *lwp) |
4c28f408 | 4284 | { |
d90e17a7 | 4285 | if (!lwp->stopped) |
252fbfc8 | 4286 | { |
9327494e | 4287 | linux_nat_debug_printf ("running -> suspending %s", |
e53c95d4 | 4288 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 | 4289 | |
252fbfc8 | 4290 | |
25289eb2 PA |
4291 | if (lwp->last_resume_kind == resume_stop) |
4292 | { | |
9327494e SM |
4293 | linux_nat_debug_printf ("already stopping LWP %ld at GDB's request", |
4294 | lwp->ptid.lwp ()); | |
25289eb2 PA |
4295 | return 0; |
4296 | } | |
252fbfc8 | 4297 | |
d3a70e03 | 4298 | stop_callback (lwp); |
25289eb2 | 4299 | lwp->last_resume_kind = resume_stop; |
d90e17a7 PA |
4300 | } |
4301 | else | |
4302 | { | |
4303 | /* Already known to be stopped; do nothing. */ | |
252fbfc8 | 4304 | |
d90e17a7 PA |
4305 | if (debug_linux_nat) |
4306 | { | |
9213a6d7 | 4307 | if (linux_target->find_thread (lwp->ptid)->stop_requested) |
9327494e | 4308 | linux_nat_debug_printf ("already stopped/stop_requested %s", |
e53c95d4 | 4309 | lwp->ptid.to_string ().c_str ()); |
d90e17a7 | 4310 | else |
9327494e | 4311 | linux_nat_debug_printf ("already stopped/no stop_requested yet %s", |
e53c95d4 | 4312 | lwp->ptid.to_string ().c_str ()); |
252fbfc8 PA |
4313 | } |
4314 | } | |
4c28f408 PA |
4315 | return 0; |
4316 | } | |
4317 | ||
f6ac5f3d PA |
4318 | void |
4319 | linux_nat_target::stop (ptid_t ptid) | |
4c28f408 | 4320 | { |
b6e52a0b | 4321 | LINUX_NAT_SCOPED_DEBUG_ENTER_EXIT; |
d3a70e03 | 4322 | iterate_over_lwps (ptid, linux_nat_stop_lwp); |
bfedc46a PA |
4323 | } |
4324 | ||
c0694254 PA |
4325 | /* When requests are passed down from the linux-nat layer to the |
4326 | single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are | |
4327 | used. The address space pointer is stored in the inferior object, | |
4328 | but the common code that is passed such ptid can't tell whether | |
4329 | lwpid is a "main" process id or not (it assumes so). We reverse | |
4330 | look up the "main" process id from the lwp here. */ | |
4331 | ||
f6ac5f3d PA |
4332 | struct address_space * |
4333 | linux_nat_target::thread_address_space (ptid_t ptid) | |
c0694254 PA |
4334 | { |
4335 | struct lwp_info *lwp; | |
4336 | struct inferior *inf; | |
4337 | int pid; | |
4338 | ||
e38504b3 | 4339 | if (ptid.lwp () == 0) |
c0694254 PA |
4340 | { |
4341 | /* An (lwpid,0,0) ptid. Look up the lwp object to get at the | |
4342 | tgid. */ | |
4343 | lwp = find_lwp_pid (ptid); | |
e99b03dc | 4344 | pid = lwp->ptid.pid (); |
c0694254 PA |
4345 | } |
4346 | else | |
4347 | { | |
4348 | /* A (pid,lwpid,0) ptid. */ | |
e99b03dc | 4349 | pid = ptid.pid (); |
c0694254 PA |
4350 | } |
4351 | ||
5b6d1e4f | 4352 | inf = find_inferior_pid (this, pid); |
c0694254 PA |
4353 | gdb_assert (inf != NULL); |
4354 | return inf->aspace; | |
4355 | } | |
4356 | ||
dc146f7c VP |
4357 | /* Return the cached value of the processor core for thread PTID. */ |
4358 | ||
f6ac5f3d PA |
4359 | int |
4360 | linux_nat_target::core_of_thread (ptid_t ptid) | |
dc146f7c VP |
4361 | { |
4362 | struct lwp_info *info = find_lwp_pid (ptid); | |
e0881a8e | 4363 | |
dc146f7c VP |
4364 | if (info) |
4365 | return info->core; | |
4366 | return -1; | |
4367 | } | |
4368 | ||
7a6a1731 GB |
4369 | /* Implementation of to_filesystem_is_local. */ |
4370 | ||
57810aa7 | 4371 | bool |
f6ac5f3d | 4372 | linux_nat_target::filesystem_is_local () |
7a6a1731 GB |
4373 | { |
4374 | struct inferior *inf = current_inferior (); | |
4375 | ||
4376 | if (inf->fake_pid_p || inf->pid == 0) | |
57810aa7 | 4377 | return true; |
7a6a1731 GB |
4378 | |
4379 | return linux_ns_same (inf->pid, LINUX_NS_MNT); | |
4380 | } | |
4381 | ||
4382 | /* Convert the INF argument passed to a to_fileio_* method | |
4383 | to a process ID suitable for passing to its corresponding | |
4384 | linux_mntns_* function. If INF is non-NULL then the | |
4385 | caller is requesting the filesystem seen by INF. If INF | |
4386 | is NULL then the caller is requesting the filesystem seen | |
4387 | by the GDB. We fall back to GDB's filesystem in the case | |
4388 | that INF is non-NULL but its PID is unknown. */ | |
4389 | ||
4390 | static pid_t | |
4391 | linux_nat_fileio_pid_of (struct inferior *inf) | |
4392 | { | |
4393 | if (inf == NULL || inf->fake_pid_p || inf->pid == 0) | |
4394 | return getpid (); | |
4395 | else | |
4396 | return inf->pid; | |
4397 | } | |
4398 | ||
4399 | /* Implementation of to_fileio_open. */ | |
4400 | ||
f6ac5f3d PA |
4401 | int |
4402 | linux_nat_target::fileio_open (struct inferior *inf, const char *filename, | |
4403 | int flags, int mode, int warn_if_slow, | |
b872057a | 4404 | fileio_error *target_errno) |
7a6a1731 GB |
4405 | { |
4406 | int nat_flags; | |
4407 | mode_t nat_mode; | |
4408 | int fd; | |
4409 | ||
4410 | if (fileio_to_host_openflags (flags, &nat_flags) == -1 | |
4411 | || fileio_to_host_mode (mode, &nat_mode) == -1) | |
4412 | { | |
4413 | *target_errno = FILEIO_EINVAL; | |
4414 | return -1; | |
4415 | } | |
4416 | ||
4417 | fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf), | |
4418 | filename, nat_flags, nat_mode); | |
4419 | if (fd == -1) | |
4420 | *target_errno = host_to_fileio_error (errno); | |
4421 | ||
4422 | return fd; | |
4423 | } | |
4424 | ||
4425 | /* Implementation of to_fileio_readlink. */ | |
4426 | ||
f6ac5f3d PA |
4427 | gdb::optional<std::string> |
4428 | linux_nat_target::fileio_readlink (struct inferior *inf, const char *filename, | |
b872057a | 4429 | fileio_error *target_errno) |
7a6a1731 GB |
4430 | { |
4431 | char buf[PATH_MAX]; | |
4432 | int len; | |
7a6a1731 GB |
4433 | |
4434 | len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf), | |
4435 | filename, buf, sizeof (buf)); | |
4436 | if (len < 0) | |
4437 | { | |
4438 | *target_errno = host_to_fileio_error (errno); | |
e0d3522b | 4439 | return {}; |
7a6a1731 GB |
4440 | } |
4441 | ||
e0d3522b | 4442 | return std::string (buf, len); |
7a6a1731 GB |
4443 | } |
4444 | ||
4445 | /* Implementation of to_fileio_unlink. */ | |
4446 | ||
f6ac5f3d PA |
4447 | int |
4448 | linux_nat_target::fileio_unlink (struct inferior *inf, const char *filename, | |
b872057a | 4449 | fileio_error *target_errno) |
7a6a1731 GB |
4450 | { |
4451 | int ret; | |
4452 | ||
4453 | ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf), | |
4454 | filename); | |
4455 | if (ret == -1) | |
4456 | *target_errno = host_to_fileio_error (errno); | |
4457 | ||
4458 | return ret; | |
4459 | } | |
4460 | ||
aa01bd36 PA |
4461 | /* Implementation of the to_thread_events method. */ |
4462 | ||
f6ac5f3d PA |
4463 | void |
4464 | linux_nat_target::thread_events (int enable) | |
aa01bd36 PA |
4465 | { |
4466 | report_thread_events = enable; | |
4467 | } | |
4468 | ||
f6ac5f3d PA |
4469 | linux_nat_target::linux_nat_target () |
4470 | { | |
f973ed9c DJ |
4471 | /* We don't change the stratum; this target will sit at |
4472 | process_stratum and thread_db will set at thread_stratum. This | |
4473 | is a little strange, since this is a multi-threaded-capable | |
4474 | target, but we want to be on the stack below thread_db, and we | |
4475 | also want to be used for single-threaded processes. */ | |
f973ed9c DJ |
4476 | } |
4477 | ||
f865ee35 JK |
4478 | /* See linux-nat.h. */ |
4479 | ||
ef632b4b | 4480 | bool |
f865ee35 | 4481 | linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo) |
9f0bdab8 | 4482 | { |
0acd1110 | 4483 | int pid = get_ptrace_pid (ptid); |
7cc662bc | 4484 | return ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo) == 0; |
9f0bdab8 DJ |
4485 | } |
4486 | ||
7b669087 GB |
4487 | /* See nat/linux-nat.h. */ |
4488 | ||
4489 | ptid_t | |
4490 | current_lwp_ptid (void) | |
4491 | { | |
15a9e13e | 4492 | gdb_assert (inferior_ptid.lwp_p ()); |
7b669087 GB |
4493 | return inferior_ptid; |
4494 | } | |
4495 | ||
6c265988 | 4496 | void _initialize_linux_nat (); |
d6b0e80f | 4497 | void |
6c265988 | 4498 | _initialize_linux_nat () |
d6b0e80f | 4499 | { |
8864ef42 | 4500 | add_setshow_boolean_cmd ("linux-nat", class_maintenance, |
b6e52a0b AB |
4501 | &debug_linux_nat, _("\ |
4502 | Set debugging of GNU/Linux native target."), _(" \ | |
4503 | Show debugging of GNU/Linux native target."), _(" \ | |
4504 | When on, print debug messages relating to the GNU/Linux native target."), | |
4505 | nullptr, | |
4506 | show_debug_linux_nat, | |
4507 | &setdebuglist, &showdebuglist); | |
b84876c2 | 4508 | |
7a6a1731 GB |
4509 | add_setshow_boolean_cmd ("linux-namespaces", class_maintenance, |
4510 | &debug_linux_namespaces, _("\ | |
4511 | Set debugging of GNU/Linux namespaces module."), _("\ | |
4512 | Show debugging of GNU/Linux namespaces module."), _("\ | |
4513 | Enables printf debugging output."), | |
4514 | NULL, | |
4515 | NULL, | |
4516 | &setdebuglist, &showdebuglist); | |
4517 | ||
7feb7d06 PA |
4518 | /* Install a SIGCHLD handler. */ |
4519 | sigchld_action.sa_handler = sigchld_handler; | |
4520 | sigemptyset (&sigchld_action.sa_mask); | |
4521 | sigchld_action.sa_flags = SA_RESTART; | |
b84876c2 PA |
4522 | |
4523 | /* Make it the default. */ | |
7feb7d06 | 4524 | sigaction (SIGCHLD, &sigchld_action, NULL); |
d6b0e80f AC |
4525 | |
4526 | /* Make sure we don't block SIGCHLD during a sigsuspend. */ | |
21987b9c | 4527 | gdb_sigmask (SIG_SETMASK, NULL, &suspend_mask); |
d6b0e80f AC |
4528 | sigdelset (&suspend_mask, SIGCHLD); |
4529 | ||
7feb7d06 | 4530 | sigemptyset (&blocked_mask); |
774113b0 PA |
4531 | |
4532 | lwp_lwpid_htab_create (); | |
d6b0e80f AC |
4533 | } |
4534 | \f | |
4535 | ||
4536 | /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to | |
4537 | the GNU/Linux Threads library and therefore doesn't really belong | |
4538 | here. */ | |
4539 | ||
089436f7 TV |
4540 | /* NPTL reserves the first two RT signals, but does not provide any |
4541 | way for the debugger to query the signal numbers - fortunately | |
4542 | they don't change. */ | |
4543 | static int lin_thread_signals[] = { __SIGRTMIN, __SIGRTMIN + 1 }; | |
d6b0e80f | 4544 | |
089436f7 TV |
4545 | /* See linux-nat.h. */ |
4546 | ||
4547 | unsigned int | |
4548 | lin_thread_get_thread_signal_num (void) | |
d6b0e80f | 4549 | { |
089436f7 TV |
4550 | return sizeof (lin_thread_signals) / sizeof (lin_thread_signals[0]); |
4551 | } | |
d6b0e80f | 4552 | |
089436f7 TV |
4553 | /* See linux-nat.h. */ |
4554 | ||
4555 | int | |
4556 | lin_thread_get_thread_signal (unsigned int i) | |
4557 | { | |
4558 | gdb_assert (i < lin_thread_get_thread_signal_num ()); | |
4559 | return lin_thread_signals[i]; | |
d6b0e80f | 4560 | } |