Pass inferior down to target_detach and to_detach
[deliverable/binutils-gdb.git] / gdb / linux-nat.c
CommitLineData
3993f6b1 1/* GNU/Linux native-dependent code common to multiple platforms.
dba24537 2
e2882c85 3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
3993f6b1
DJ
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
a9762ec7 9 the Free Software Foundation; either version 3 of the License, or
3993f6b1
DJ
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
a9762ec7 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
3993f6b1
DJ
19
20#include "defs.h"
21#include "inferior.h"
45741a9c 22#include "infrun.h"
3993f6b1 23#include "target.h"
96d7229d
LM
24#include "nat/linux-nat.h"
25#include "nat/linux-waitpid.h"
3993f6b1 26#include "gdb_wait.h"
d6b0e80f
AC
27#include <unistd.h>
28#include <sys/syscall.h>
5826e159 29#include "nat/gdb_ptrace.h"
0274a8ce 30#include "linux-nat.h"
125f8a3d
GB
31#include "nat/linux-ptrace.h"
32#include "nat/linux-procfs.h"
8cc73a39 33#include "nat/linux-personality.h"
ac264b3b 34#include "linux-fork.h"
d6b0e80f
AC
35#include "gdbthread.h"
36#include "gdbcmd.h"
37#include "regcache.h"
4f844a66 38#include "regset.h"
dab06dbe 39#include "inf-child.h"
10d6c8cd
DJ
40#include "inf-ptrace.h"
41#include "auxv.h"
1777feb0 42#include <sys/procfs.h> /* for elf_gregset etc. */
dba24537
AC
43#include "elf-bfd.h" /* for elfcore_write_* */
44#include "gregset.h" /* for gregset */
45#include "gdbcore.h" /* for get_exec_file */
46#include <ctype.h> /* for isdigit */
53ce3c39 47#include <sys/stat.h> /* for struct stat */
dba24537 48#include <fcntl.h> /* for O_RDONLY */
b84876c2
PA
49#include "inf-loop.h"
50#include "event-loop.h"
51#include "event-top.h"
07e059b5
VP
52#include <pwd.h>
53#include <sys/types.h>
2978b111 54#include <dirent.h>
07e059b5 55#include "xml-support.h"
efcbbd14 56#include <sys/vfs.h>
6c95b8df 57#include "solib.h"
125f8a3d 58#include "nat/linux-osdata.h"
6432734d 59#include "linux-tdep.h"
7dcd53a0 60#include "symfile.h"
5808517f
YQ
61#include "agent.h"
62#include "tracepoint.h"
87b0bb13 63#include "buffer.h"
6ecd4729 64#include "target-descriptions.h"
614c279d 65#include "filestuff.h"
77e371c0 66#include "objfiles.h"
7a6a1731
GB
67#include "nat/linux-namespaces.h"
68#include "fileio.h"
efcbbd14
UW
69
70#ifndef SPUFS_MAGIC
71#define SPUFS_MAGIC 0x23c9b64e
72#endif
dba24537 73
1777feb0 74/* This comment documents high-level logic of this file.
8a77dff3
VP
75
76Waiting for events in sync mode
77===============================
78
4a6ed09b
PA
79When waiting for an event in a specific thread, we just use waitpid,
80passing the specific pid, and not passing WNOHANG.
81
82When 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
93The solution is to always use -1 and WNOHANG, together with
94sigsuspend.
95
96First, we use non-blocking waitpid to check for events. If nothing is
97found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98it means something happened to a child process. As soon as we know
99there's an event, we get back to calling nonblocking waitpid.
100
101Note that SIGCHLD should be blocked between waitpid and sigsuspend
102calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103when it's blocked, the signal becomes pending and sigsuspend
104immediately notices it and returns.
105
106Waiting for events in async mode (TARGET_WNOHANG)
107=================================================
8a77dff3 108
7feb7d06
PA
109In async mode, GDB should always be ready to handle both user input
110and target events, so neither blocking waitpid nor sigsuspend are
111viable options. Instead, we should asynchronously notify the GDB main
112event loop whenever there's an unprocessed event from the target. We
113detect asynchronous target events by handling SIGCHLD signals. To
114notify the event loop about target events, the self-pipe trick is used
115--- a pipe is registered as waitable event source in the event loop,
116the event loop select/poll's on the read end of this pipe (as well on
117other event sources, e.g., stdin), and the SIGCHLD handler writes a
118byte to this pipe. This is more portable than relying on
119pselect/ppoll, since on kernels that lack those syscalls, libc
120emulates them with select/poll+sigprocmask, and that is racy
121(a.k.a. plain broken).
122
123Obviously, if we fail to notify the event loop if there's a target
124event, it's bad. OTOH, if we notify the event loop when there's no
125event from the target, linux_nat_wait will detect that there's no real
126event to report, and return event of type TARGET_WAITKIND_IGNORE.
127This is mostly harmless, but it will waste time and is better avoided.
128
129The main design point is that every time GDB is outside linux-nat.c,
130we have a SIGCHLD handler installed that is called when something
131happens to the target and notifies the GDB event loop. Whenever GDB
132core decides to handle the event, and calls into linux-nat.c, we
133process things as in sync mode, except that the we never block in
134sigsuspend.
135
136While processing an event, we may end up momentarily blocked in
137waitpid calls. Those waitpid calls, while blocking, are guarantied to
138return quickly. E.g., in all-stop mode, before reporting to the core
139that an LWP hit a breakpoint, all LWPs are stopped by sending them
140SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141Note that this is different from blocking indefinitely waiting for the
142next event --- here, we're already handling an event.
8a77dff3
VP
143
144Use of signals
145==============
146
147We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148signal is not entirely significant; we just need for a signal to be delivered,
149so that we can intercept it. SIGSTOP's advantage is that it can not be
150blocked. A disadvantage is that it is not a real-time signal, so it can only
151be queued once; we do not keep track of other sources of SIGSTOP.
152
153Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154use them, because they have special behavior when the signal is generated -
155not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156kills the entire thread group.
157
158A delivered SIGSTOP would stop the entire thread group, not just the thread we
159tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160cancel it (by PTRACE_CONT without passing SIGSTOP).
161
162We could use a real-time signal instead. This would solve those problems; we
163could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165generates it, and there are races with trying to find a signal that is not
4a6ed09b
PA
166blocked.
167
168Exec events
169===========
170
171The case of a thread group (process) with 3 or more threads, and a
172thread other than the leader execs is worth detailing:
173
174On an exec, the Linux kernel destroys all threads except the execing
175one in the thread group, and resets the execing thread's tid to the
176tgid. No exit notification is sent for the execing thread -- from the
177ptracer's perspective, it appears as though the execing thread just
178vanishes. Until we reap all other threads except the leader and the
179execing thread, the leader will be zombie, and the execing thread will
180be in `D (disc sleep)' state. As soon as all other threads are
181reaped, the execing thread changes its tid to the tgid, and the
182previous (zombie) leader vanishes, giving place to the "new"
183leader. */
a0ef4274 184
dba24537
AC
185#ifndef O_LARGEFILE
186#define O_LARGEFILE 0
187#endif
0274a8ce 188
433bbbf8 189/* Does the current host support PTRACE_GETREGSET? */
0bdb2f78 190enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN;
433bbbf8 191
10d6c8cd
DJ
192/* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194static struct target_ops *linux_ops;
f973ed9c 195static struct target_ops linux_ops_saved;
10d6c8cd 196
9f0bdab8 197/* The method to call, if any, when a new thread is attached. */
7b50312a
PA
198static void (*linux_nat_new_thread) (struct lwp_info *);
199
466eecee
SM
200/* The method to call, if any, when a thread is destroyed. */
201static void (*linux_nat_delete_thread) (struct arch_lwp_info *);
202
26cb8b7c
PA
203/* The method to call, if any, when a new fork is attached. */
204static linux_nat_new_fork_ftype *linux_nat_new_fork;
205
206/* The method to call, if any, when a process is no longer
207 attached. */
208static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
209
7b50312a
PA
210/* Hook to call prior to resuming a thread. */
211static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
9f0bdab8 212
5b009018
PA
213/* The method to call, if any, when the siginfo object needs to be
214 converted between the layout returned by ptrace, and the layout in
215 the architecture of the inferior. */
a5362b9a 216static int (*linux_nat_siginfo_fixup) (siginfo_t *,
5b009018
PA
217 gdb_byte *,
218 int);
219
ac264b3b
MS
220/* The saved to_xfer_partial method, inherited from inf-ptrace.c.
221 Called by our to_xfer_partial. */
4ac248ca 222static target_xfer_partial_ftype *super_xfer_partial;
10d6c8cd 223
6a3cb8e8
PA
224/* The saved to_close method, inherited from inf-ptrace.c.
225 Called by our to_close. */
226static void (*super_close) (struct target_ops *);
227
ccce17b0 228static unsigned int debug_linux_nat;
920d2a44
AC
229static void
230show_debug_linux_nat (struct ui_file *file, int from_tty,
231 struct cmd_list_element *c, const char *value)
232{
233 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 value);
235}
d6b0e80f 236
ae087d01
DJ
237struct simple_pid_list
238{
239 int pid;
3d799a95 240 int status;
ae087d01
DJ
241 struct simple_pid_list *next;
242};
243struct simple_pid_list *stopped_pids;
244
aa01bd36
PA
245/* Whether target_thread_events is in effect. */
246static int report_thread_events;
247
3dd5b83d
PA
248/* Async mode support. */
249
b84876c2
PA
250/* The read/write ends of the pipe registered as waitable file in the
251 event loop. */
252static int linux_nat_event_pipe[2] = { -1, -1 };
253
198297aa
PA
254/* True if we're currently in async mode. */
255#define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
256
7feb7d06 257/* Flush the event pipe. */
b84876c2 258
7feb7d06
PA
259static void
260async_file_flush (void)
b84876c2 261{
7feb7d06
PA
262 int ret;
263 char buf;
b84876c2 264
7feb7d06 265 do
b84876c2 266 {
7feb7d06 267 ret = read (linux_nat_event_pipe[0], &buf, 1);
b84876c2 268 }
7feb7d06 269 while (ret >= 0 || (ret == -1 && errno == EINTR));
b84876c2
PA
270}
271
7feb7d06
PA
272/* Put something (anything, doesn't matter what, or how much) in event
273 pipe, so that the select/poll in the event-loop realizes we have
274 something to process. */
252fbfc8 275
b84876c2 276static void
7feb7d06 277async_file_mark (void)
b84876c2 278{
7feb7d06 279 int ret;
b84876c2 280
7feb7d06
PA
281 /* It doesn't really matter what the pipe contains, as long we end
282 up with something in it. Might as well flush the previous
283 left-overs. */
284 async_file_flush ();
b84876c2 285
7feb7d06 286 do
b84876c2 287 {
7feb7d06 288 ret = write (linux_nat_event_pipe[1], "+", 1);
b84876c2 289 }
7feb7d06 290 while (ret == -1 && errno == EINTR);
b84876c2 291
7feb7d06
PA
292 /* Ignore EAGAIN. If the pipe is full, the event loop will already
293 be awakened anyway. */
b84876c2
PA
294}
295
7feb7d06
PA
296static int kill_lwp (int lwpid, int signo);
297
298static int stop_callback (struct lwp_info *lp, void *data);
2db9a427 299static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
7feb7d06
PA
300
301static void block_child_signals (sigset_t *prev_mask);
302static void restore_child_signals_mask (sigset_t *prev_mask);
2277426b
PA
303
304struct lwp_info;
305static struct lwp_info *add_lwp (ptid_t ptid);
306static void purge_lwp_list (int pid);
4403d8e9 307static void delete_lwp (ptid_t ptid);
2277426b
PA
308static struct lwp_info *find_lwp_pid (ptid_t ptid);
309
8a99810d
PA
310static int lwp_status_pending_p (struct lwp_info *lp);
311
9c02b525
PA
312static int sigtrap_is_event (int status);
313static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
314
e7ad2f14
PA
315static void save_stop_reason (struct lwp_info *lp);
316
cff068da
GB
317\f
318/* LWP accessors. */
319
320/* See nat/linux-nat.h. */
321
322ptid_t
323ptid_of_lwp (struct lwp_info *lwp)
324{
325 return lwp->ptid;
326}
327
328/* See nat/linux-nat.h. */
329
4b134ca1
GB
330void
331lwp_set_arch_private_info (struct lwp_info *lwp,
332 struct arch_lwp_info *info)
333{
334 lwp->arch_private = info;
335}
336
337/* See nat/linux-nat.h. */
338
339struct arch_lwp_info *
340lwp_arch_private_info (struct lwp_info *lwp)
341{
342 return lwp->arch_private;
343}
344
345/* See nat/linux-nat.h. */
346
cff068da
GB
347int
348lwp_is_stopped (struct lwp_info *lwp)
349{
350 return lwp->stopped;
351}
352
353/* See nat/linux-nat.h. */
354
355enum target_stop_reason
356lwp_stop_reason (struct lwp_info *lwp)
357{
358 return lwp->stop_reason;
359}
360
0e00e962
AA
361/* See nat/linux-nat.h. */
362
363int
364lwp_is_stepping (struct lwp_info *lwp)
365{
366 return lwp->step;
367}
368
ae087d01
DJ
369\f
370/* Trivial list manipulation functions to keep track of a list of
371 new stopped processes. */
372static void
3d799a95 373add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
ae087d01 374{
8d749320 375 struct simple_pid_list *new_pid = XNEW (struct simple_pid_list);
e0881a8e 376
ae087d01 377 new_pid->pid = pid;
3d799a95 378 new_pid->status = status;
ae087d01
DJ
379 new_pid->next = *listp;
380 *listp = new_pid;
381}
382
383static int
46a96992 384pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
ae087d01
DJ
385{
386 struct simple_pid_list **p;
387
388 for (p = listp; *p != NULL; p = &(*p)->next)
389 if ((*p)->pid == pid)
390 {
391 struct simple_pid_list *next = (*p)->next;
e0881a8e 392
46a96992 393 *statusp = (*p)->status;
ae087d01
DJ
394 xfree (*p);
395 *p = next;
396 return 1;
397 }
398 return 0;
399}
400
de0d863e
DB
401/* Return the ptrace options that we want to try to enable. */
402
403static int
404linux_nat_ptrace_options (int attached)
405{
406 int options = 0;
407
408 if (!attached)
409 options |= PTRACE_O_EXITKILL;
410
411 options |= (PTRACE_O_TRACESYSGOOD
412 | PTRACE_O_TRACEVFORKDONE
413 | PTRACE_O_TRACEVFORK
414 | PTRACE_O_TRACEFORK
415 | PTRACE_O_TRACEEXEC);
416
417 return options;
418}
419
96d7229d 420/* Initialize ptrace warnings and check for supported ptrace
beed38b8
JB
421 features given PID.
422
423 ATTACHED should be nonzero iff we attached to the inferior. */
3993f6b1
DJ
424
425static void
beed38b8 426linux_init_ptrace (pid_t pid, int attached)
3993f6b1 427{
de0d863e
DB
428 int options = linux_nat_ptrace_options (attached);
429
430 linux_enable_event_reporting (pid, options);
96d7229d 431 linux_ptrace_init_warnings ();
4de4c07c
DJ
432}
433
6d8fd2b7 434static void
f045800c 435linux_child_post_attach (struct target_ops *self, int pid)
4de4c07c 436{
beed38b8 437 linux_init_ptrace (pid, 1);
4de4c07c
DJ
438}
439
10d6c8cd 440static void
2e97a79e 441linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
4de4c07c 442{
beed38b8 443 linux_init_ptrace (ptid_get_pid (ptid), 0);
4de4c07c
DJ
444}
445
4403d8e9
JK
446/* Return the number of known LWPs in the tgid given by PID. */
447
448static int
449num_lwps (int pid)
450{
451 int count = 0;
452 struct lwp_info *lp;
453
454 for (lp = lwp_list; lp; lp = lp->next)
455 if (ptid_get_pid (lp->ptid) == pid)
456 count++;
457
458 return count;
459}
460
461/* Call delete_lwp with prototype compatible for make_cleanup. */
462
463static void
464delete_lwp_cleanup (void *lp_voidp)
465{
9a3c8263 466 struct lwp_info *lp = (struct lwp_info *) lp_voidp;
4403d8e9
JK
467
468 delete_lwp (lp->ptid);
469}
470
d83ad864
DB
471/* Target hook for follow_fork. On entry inferior_ptid must be the
472 ptid of the followed inferior. At return, inferior_ptid will be
473 unchanged. */
474
6d8fd2b7 475static int
07107ca6
LM
476linux_child_follow_fork (struct target_ops *ops, int follow_child,
477 int detach_fork)
3993f6b1 478{
d83ad864 479 if (!follow_child)
4de4c07c 480 {
6c95b8df 481 struct lwp_info *child_lp = NULL;
d83ad864 482 int status = W_STOPCODE (0);
d83ad864 483 int has_vforked;
79639e11 484 ptid_t parent_ptid, child_ptid;
d83ad864
DB
485 int parent_pid, child_pid;
486
487 has_vforked = (inferior_thread ()->pending_follow.kind
488 == TARGET_WAITKIND_VFORKED);
79639e11
PA
489 parent_ptid = inferior_ptid;
490 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
491 parent_pid = ptid_get_lwp (parent_ptid);
492 child_pid = ptid_get_lwp (child_ptid);
4de4c07c 493
1777feb0 494 /* We're already attached to the parent, by default. */
2989a365 495 child_lp = add_lwp (child_ptid);
d83ad864
DB
496 child_lp->stopped = 1;
497 child_lp->last_resume_kind = resume_stop;
4de4c07c 498
ac264b3b
MS
499 /* Detach new forked process? */
500 if (detach_fork)
f75c00e4 501 {
2989a365
TT
502 struct cleanup *old_chain = make_cleanup (delete_lwp_cleanup,
503 child_lp);
4403d8e9 504
4403d8e9
JK
505 if (linux_nat_prepare_to_resume != NULL)
506 linux_nat_prepare_to_resume (child_lp);
c077881a
HZ
507
508 /* When debugging an inferior in an architecture that supports
509 hardware single stepping on a kernel without commit
510 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
511 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
512 set if the parent process had them set.
513 To work around this, single step the child process
514 once before detaching to clear the flags. */
515
2fd9d7ca
PA
516 /* Note that we consult the parent's architecture instead of
517 the child's because there's no inferior for the child at
518 this point. */
c077881a 519 if (!gdbarch_software_single_step_p (target_thread_architecture
2fd9d7ca 520 (parent_ptid)))
c077881a 521 {
c077881a
HZ
522 linux_disable_event_reporting (child_pid);
523 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
524 perror_with_name (_("Couldn't do single step"));
525 if (my_waitpid (child_pid, &status, 0) < 0)
526 perror_with_name (_("Couldn't wait vfork process"));
527 }
528
529 if (WIFSTOPPED (status))
9caaaa83
PA
530 {
531 int signo;
532
533 signo = WSTOPSIG (status);
534 if (signo != 0
535 && !signal_pass_state (gdb_signal_from_host (signo)))
536 signo = 0;
537 ptrace (PTRACE_DETACH, child_pid, 0, signo);
538 }
4403d8e9
JK
539
540 do_cleanups (old_chain);
ac264b3b
MS
541 }
542 else
543 {
2989a365
TT
544 scoped_restore save_inferior_ptid
545 = make_scoped_restore (&inferior_ptid);
546 inferior_ptid = child_ptid;
547
6c95b8df 548 /* Let the thread_db layer learn about this new process. */
2277426b 549 check_for_thread_db ();
ac264b3b 550 }
9016a515
DJ
551
552 if (has_vforked)
553 {
3ced3da4 554 struct lwp_info *parent_lp;
6c95b8df 555
79639e11 556 parent_lp = find_lwp_pid (parent_ptid);
96d7229d 557 gdb_assert (linux_supports_tracefork () >= 0);
3ced3da4 558
96d7229d 559 if (linux_supports_tracevforkdone ())
9016a515 560 {
6c95b8df
PA
561 if (debug_linux_nat)
562 fprintf_unfiltered (gdb_stdlog,
563 "LCFF: waiting for VFORK_DONE on %d\n",
564 parent_pid);
3ced3da4 565 parent_lp->stopped = 1;
9016a515 566
6c95b8df
PA
567 /* We'll handle the VFORK_DONE event like any other
568 event, in target_wait. */
9016a515
DJ
569 }
570 else
571 {
572 /* We can't insert breakpoints until the child has
573 finished with the shared memory region. We need to
574 wait until that happens. Ideal would be to just
575 call:
576 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
577 - waitpid (parent_pid, &status, __WALL);
578 However, most architectures can't handle a syscall
579 being traced on the way out if it wasn't traced on
580 the way in.
581
582 We might also think to loop, continuing the child
583 until it exits or gets a SIGTRAP. One problem is
584 that the child might call ptrace with PTRACE_TRACEME.
585
586 There's no simple and reliable way to figure out when
587 the vforked child will be done with its copy of the
588 shared memory. We could step it out of the syscall,
589 two instructions, let it go, and then single-step the
590 parent once. When we have hardware single-step, this
591 would work; with software single-step it could still
592 be made to work but we'd have to be able to insert
593 single-step breakpoints in the child, and we'd have
594 to insert -just- the single-step breakpoint in the
595 parent. Very awkward.
596
597 In the end, the best we can do is to make sure it
598 runs for a little while. Hopefully it will be out of
599 range of any breakpoints we reinsert. Usually this
600 is only the single-step breakpoint at vfork's return
601 point. */
602
6c95b8df
PA
603 if (debug_linux_nat)
604 fprintf_unfiltered (gdb_stdlog,
3e43a32a
MS
605 "LCFF: no VFORK_DONE "
606 "support, sleeping a bit\n");
6c95b8df 607
9016a515 608 usleep (10000);
9016a515 609
6c95b8df
PA
610 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
611 and leave it pending. The next linux_nat_resume call
612 will notice a pending event, and bypasses actually
613 resuming the inferior. */
3ced3da4
PA
614 parent_lp->status = 0;
615 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
616 parent_lp->stopped = 1;
6c95b8df
PA
617
618 /* If we're in async mode, need to tell the event loop
619 there's something here to process. */
d9d41e78 620 if (target_is_async_p ())
6c95b8df
PA
621 async_file_mark ();
622 }
9016a515 623 }
4de4c07c 624 }
3993f6b1 625 else
4de4c07c 626 {
3ced3da4 627 struct lwp_info *child_lp;
4de4c07c 628
3ced3da4
PA
629 child_lp = add_lwp (inferior_ptid);
630 child_lp->stopped = 1;
25289eb2 631 child_lp->last_resume_kind = resume_stop;
6c95b8df 632
6c95b8df 633 /* Let the thread_db layer learn about this new process. */
ef29ce1a 634 check_for_thread_db ();
4de4c07c
DJ
635 }
636
637 return 0;
638}
639
4de4c07c 640\f
77b06cd7 641static int
a863b201 642linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
4de4c07c 643{
96d7229d 644 return !linux_supports_tracefork ();
3993f6b1
DJ
645}
646
eb73ad13 647static int
973fc227 648linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
eb73ad13
PA
649{
650 return 0;
651}
652
77b06cd7 653static int
3ecc7da0 654linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
3993f6b1 655{
96d7229d 656 return !linux_supports_tracefork ();
3993f6b1
DJ
657}
658
eb73ad13 659static int
e98cf0cd 660linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
eb73ad13
PA
661{
662 return 0;
663}
664
77b06cd7 665static int
ba025e51 666linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
3993f6b1 667{
96d7229d 668 return !linux_supports_tracefork ();
3993f6b1
DJ
669}
670
eb73ad13 671static int
758e29d2 672linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
eb73ad13
PA
673{
674 return 0;
675}
676
a96d9b2e 677static int
ff214e67 678linux_child_set_syscall_catchpoint (struct target_ops *self,
649a140c
PA
679 int pid, bool needed, int any_count,
680 gdb::array_view<const int> syscall_counts)
a96d9b2e 681{
96d7229d 682 if (!linux_supports_tracesysgood ())
77b06cd7
TJB
683 return 1;
684
a96d9b2e
SDJ
685 /* On GNU/Linux, we ignore the arguments. It means that we only
686 enable the syscall catchpoints, but do not disable them.
77b06cd7 687
649a140c 688 Also, we do not use the `syscall_counts' information because we do not
a96d9b2e
SDJ
689 filter system calls here. We let GDB do the logic for us. */
690 return 0;
691}
692
774113b0
PA
693/* List of known LWPs, keyed by LWP PID. This speeds up the common
694 case of mapping a PID returned from the kernel to our corresponding
695 lwp_info data structure. */
696static htab_t lwp_lwpid_htab;
697
698/* Calculate a hash from a lwp_info's LWP PID. */
699
700static hashval_t
701lwp_info_hash (const void *ap)
702{
703 const struct lwp_info *lp = (struct lwp_info *) ap;
704 pid_t pid = ptid_get_lwp (lp->ptid);
705
706 return iterative_hash_object (pid, 0);
707}
708
709/* Equality function for the lwp_info hash table. Compares the LWP's
710 PID. */
711
712static int
713lwp_lwpid_htab_eq (const void *a, const void *b)
714{
715 const struct lwp_info *entry = (const struct lwp_info *) a;
716 const struct lwp_info *element = (const struct lwp_info *) b;
717
718 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
719}
720
721/* Create the lwp_lwpid_htab hash table. */
722
723static void
724lwp_lwpid_htab_create (void)
725{
726 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
727}
728
729/* Add LP to the hash table. */
730
731static void
732lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
733{
734 void **slot;
735
736 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
737 gdb_assert (slot != NULL && *slot == NULL);
738 *slot = lp;
739}
740
741/* Head of doubly-linked list of known LWPs. Sorted by reverse
742 creation order. This order is assumed in some cases. E.g.,
743 reaping status after killing alls lwps of a process: the leader LWP
744 must be reaped last. */
9f0bdab8 745struct lwp_info *lwp_list;
774113b0
PA
746
747/* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
748
749static void
750lwp_list_add (struct lwp_info *lp)
751{
752 lp->next = lwp_list;
753 if (lwp_list != NULL)
754 lwp_list->prev = lp;
755 lwp_list = lp;
756}
757
758/* Remove LP from sorted-by-reverse-creation-order doubly-linked
759 list. */
760
761static void
762lwp_list_remove (struct lwp_info *lp)
763{
764 /* Remove from sorted-by-creation-order list. */
765 if (lp->next != NULL)
766 lp->next->prev = lp->prev;
767 if (lp->prev != NULL)
768 lp->prev->next = lp->next;
769 if (lp == lwp_list)
770 lwp_list = lp->next;
771}
772
d6b0e80f
AC
773\f
774
d6b0e80f
AC
775/* Original signal mask. */
776static sigset_t normal_mask;
777
778/* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
779 _initialize_linux_nat. */
780static sigset_t suspend_mask;
781
7feb7d06
PA
782/* Signals to block to make that sigsuspend work. */
783static sigset_t blocked_mask;
784
785/* SIGCHLD action. */
786struct sigaction sigchld_action;
b84876c2 787
7feb7d06
PA
788/* Block child signals (SIGCHLD and linux threads signals), and store
789 the previous mask in PREV_MASK. */
84e46146 790
7feb7d06
PA
791static void
792block_child_signals (sigset_t *prev_mask)
793{
794 /* Make sure SIGCHLD is blocked. */
795 if (!sigismember (&blocked_mask, SIGCHLD))
796 sigaddset (&blocked_mask, SIGCHLD);
797
798 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
799}
800
801/* Restore child signals mask, previously returned by
802 block_child_signals. */
803
804static void
805restore_child_signals_mask (sigset_t *prev_mask)
806{
807 sigprocmask (SIG_SETMASK, prev_mask, NULL);
808}
2455069d
UW
809
810/* Mask of signals to pass directly to the inferior. */
811static sigset_t pass_mask;
812
813/* Update signals to pass to the inferior. */
814static void
94bedb42
TT
815linux_nat_pass_signals (struct target_ops *self,
816 int numsigs, unsigned char *pass_signals)
2455069d
UW
817{
818 int signo;
819
820 sigemptyset (&pass_mask);
821
822 for (signo = 1; signo < NSIG; signo++)
823 {
2ea28649 824 int target_signo = gdb_signal_from_host (signo);
2455069d
UW
825 if (target_signo < numsigs && pass_signals[target_signo])
826 sigaddset (&pass_mask, signo);
827 }
828}
829
d6b0e80f
AC
830\f
831
832/* Prototypes for local functions. */
833static int stop_wait_callback (struct lwp_info *lp, void *data);
8dd27370 834static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
20ba1ce6 835static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
ced2dffb 836static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
710151dd 837
d6b0e80f 838\f
d6b0e80f 839
7b50312a
PA
840/* Destroy and free LP. */
841
842static void
843lwp_free (struct lwp_info *lp)
844{
466eecee
SM
845 /* Let the arch specific bits release arch_lwp_info. */
846 if (linux_nat_delete_thread != NULL)
847 linux_nat_delete_thread (lp->arch_private);
848 else
849 gdb_assert (lp->arch_private == NULL);
850
7b50312a
PA
851 xfree (lp);
852}
853
774113b0 854/* Traversal function for purge_lwp_list. */
d90e17a7 855
774113b0
PA
856static int
857lwp_lwpid_htab_remove_pid (void **slot, void *info)
d90e17a7 858{
774113b0
PA
859 struct lwp_info *lp = (struct lwp_info *) *slot;
860 int pid = *(int *) info;
d90e17a7 861
774113b0 862 if (ptid_get_pid (lp->ptid) == pid)
d90e17a7 863 {
774113b0
PA
864 htab_clear_slot (lwp_lwpid_htab, slot);
865 lwp_list_remove (lp);
866 lwp_free (lp);
867 }
d90e17a7 868
774113b0
PA
869 return 1;
870}
d90e17a7 871
774113b0
PA
872/* Remove all LWPs belong to PID from the lwp list. */
873
874static void
875purge_lwp_list (int pid)
876{
877 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
d90e17a7
PA
878}
879
26cb8b7c
PA
880/* Add the LWP specified by PTID to the list. PTID is the first LWP
881 in the process. Return a pointer to the structure describing the
882 new LWP.
883
884 This differs from add_lwp in that we don't let the arch specific
885 bits know about this new thread. Current clients of this callback
886 take the opportunity to install watchpoints in the new thread, and
887 we shouldn't do that for the first thread. If we're spawning a
888 child ("run"), the thread executes the shell wrapper first, and we
889 shouldn't touch it until it execs the program we want to debug.
890 For "attach", it'd be okay to call the callback, but it's not
891 necessary, because watchpoints can't yet have been inserted into
892 the inferior. */
d6b0e80f
AC
893
894static struct lwp_info *
26cb8b7c 895add_initial_lwp (ptid_t ptid)
d6b0e80f
AC
896{
897 struct lwp_info *lp;
898
dfd4cc63 899 gdb_assert (ptid_lwp_p (ptid));
d6b0e80f 900
8d749320 901 lp = XNEW (struct lwp_info);
d6b0e80f
AC
902
903 memset (lp, 0, sizeof (struct lwp_info));
904
25289eb2 905 lp->last_resume_kind = resume_continue;
d6b0e80f
AC
906 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
907
908 lp->ptid = ptid;
dc146f7c 909 lp->core = -1;
d6b0e80f 910
774113b0
PA
911 /* Add to sorted-by-reverse-creation-order list. */
912 lwp_list_add (lp);
913
914 /* Add to keyed-by-pid htab. */
915 lwp_lwpid_htab_add_lwp (lp);
d6b0e80f 916
26cb8b7c
PA
917 return lp;
918}
919
920/* Add the LWP specified by PID to the list. Return a pointer to the
921 structure describing the new LWP. The LWP should already be
922 stopped. */
923
924static struct lwp_info *
925add_lwp (ptid_t ptid)
926{
927 struct lwp_info *lp;
928
929 lp = add_initial_lwp (ptid);
930
6e012a6c
PA
931 /* Let the arch specific bits know about this new thread. Current
932 clients of this callback take the opportunity to install
26cb8b7c
PA
933 watchpoints in the new thread. We don't do this for the first
934 thread though. See add_initial_lwp. */
935 if (linux_nat_new_thread != NULL)
7b50312a 936 linux_nat_new_thread (lp);
9f0bdab8 937
d6b0e80f
AC
938 return lp;
939}
940
941/* Remove the LWP specified by PID from the list. */
942
943static void
944delete_lwp (ptid_t ptid)
945{
774113b0
PA
946 struct lwp_info *lp;
947 void **slot;
948 struct lwp_info dummy;
d6b0e80f 949
774113b0
PA
950 dummy.ptid = ptid;
951 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
952 if (slot == NULL)
953 return;
d6b0e80f 954
774113b0
PA
955 lp = *(struct lwp_info **) slot;
956 gdb_assert (lp != NULL);
d6b0e80f 957
774113b0 958 htab_clear_slot (lwp_lwpid_htab, slot);
d6b0e80f 959
774113b0
PA
960 /* Remove from sorted-by-creation-order list. */
961 lwp_list_remove (lp);
d6b0e80f 962
774113b0 963 /* Release. */
7b50312a 964 lwp_free (lp);
d6b0e80f
AC
965}
966
967/* Return a pointer to the structure describing the LWP corresponding
968 to PID. If no corresponding LWP could be found, return NULL. */
969
970static struct lwp_info *
971find_lwp_pid (ptid_t ptid)
972{
973 struct lwp_info *lp;
974 int lwp;
774113b0 975 struct lwp_info dummy;
d6b0e80f 976
dfd4cc63
LM
977 if (ptid_lwp_p (ptid))
978 lwp = ptid_get_lwp (ptid);
d6b0e80f 979 else
dfd4cc63 980 lwp = ptid_get_pid (ptid);
d6b0e80f 981
774113b0
PA
982 dummy.ptid = ptid_build (0, lwp, 0);
983 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
984 return lp;
d6b0e80f
AC
985}
986
6d4ee8c6 987/* See nat/linux-nat.h. */
d6b0e80f
AC
988
989struct lwp_info *
d90e17a7 990iterate_over_lwps (ptid_t filter,
6d4ee8c6 991 iterate_over_lwps_ftype callback,
d90e17a7 992 void *data)
d6b0e80f
AC
993{
994 struct lwp_info *lp, *lpnext;
995
996 for (lp = lwp_list; lp; lp = lpnext)
997 {
998 lpnext = lp->next;
d90e17a7
PA
999
1000 if (ptid_match (lp->ptid, filter))
1001 {
6d4ee8c6 1002 if ((*callback) (lp, data) != 0)
d90e17a7
PA
1003 return lp;
1004 }
d6b0e80f
AC
1005 }
1006
1007 return NULL;
1008}
1009
2277426b
PA
1010/* Update our internal state when changing from one checkpoint to
1011 another indicated by NEW_PTID. We can only switch single-threaded
1012 applications, so we only create one new LWP, and the previous list
1013 is discarded. */
f973ed9c
DJ
1014
1015void
1016linux_nat_switch_fork (ptid_t new_ptid)
1017{
1018 struct lwp_info *lp;
1019
dfd4cc63 1020 purge_lwp_list (ptid_get_pid (inferior_ptid));
2277426b 1021
f973ed9c
DJ
1022 lp = add_lwp (new_ptid);
1023 lp->stopped = 1;
e26af52f 1024
2277426b
PA
1025 /* This changes the thread's ptid while preserving the gdb thread
1026 num. Also changes the inferior pid, while preserving the
1027 inferior num. */
1028 thread_change_ptid (inferior_ptid, new_ptid);
1029
1030 /* We've just told GDB core that the thread changed target id, but,
1031 in fact, it really is a different thread, with different register
1032 contents. */
1033 registers_changed ();
e26af52f
DJ
1034}
1035
e26af52f
DJ
1036/* Handle the exit of a single thread LP. */
1037
1038static void
1039exit_lwp (struct lwp_info *lp)
1040{
e09875d4 1041 struct thread_info *th = find_thread_ptid (lp->ptid);
063bfe2e
VP
1042
1043 if (th)
e26af52f 1044 {
17faa917
DJ
1045 if (print_thread_events)
1046 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1047
4f8d22e3 1048 delete_thread (lp->ptid);
e26af52f
DJ
1049 }
1050
1051 delete_lwp (lp->ptid);
1052}
1053
a0ef4274
DJ
1054/* Wait for the LWP specified by LP, which we have just attached to.
1055 Returns a wait status for that LWP, to cache. */
1056
1057static int
22827c51 1058linux_nat_post_attach_wait (ptid_t ptid, int *signalled)
a0ef4274 1059{
dfd4cc63 1060 pid_t new_pid, pid = ptid_get_lwp (ptid);
a0ef4274
DJ
1061 int status;
1062
644cebc9 1063 if (linux_proc_pid_is_stopped (pid))
a0ef4274
DJ
1064 {
1065 if (debug_linux_nat)
1066 fprintf_unfiltered (gdb_stdlog,
1067 "LNPAW: Attaching to a stopped process\n");
1068
1069 /* The process is definitely stopped. It is in a job control
1070 stop, unless the kernel predates the TASK_STOPPED /
1071 TASK_TRACED distinction, in which case it might be in a
1072 ptrace stop. Make sure it is in a ptrace stop; from there we
1073 can kill it, signal it, et cetera.
1074
1075 First make sure there is a pending SIGSTOP. Since we are
1076 already attached, the process can not transition from stopped
1077 to running without a PTRACE_CONT; so we know this signal will
1078 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1079 probably already in the queue (unless this kernel is old
1080 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1081 is not an RT signal, it can only be queued once. */
1082 kill_lwp (pid, SIGSTOP);
1083
1084 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1085 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1086 ptrace (PTRACE_CONT, pid, 0, 0);
1087 }
1088
1089 /* Make sure the initial process is stopped. The user-level threads
1090 layer might want to poke around in the inferior, and that won't
1091 work if things haven't stabilized yet. */
4a6ed09b 1092 new_pid = my_waitpid (pid, &status, __WALL);
dacc9cb2
PP
1093 gdb_assert (pid == new_pid);
1094
1095 if (!WIFSTOPPED (status))
1096 {
1097 /* The pid we tried to attach has apparently just exited. */
1098 if (debug_linux_nat)
1099 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1100 pid, status_to_str (status));
1101 return status;
1102 }
a0ef4274
DJ
1103
1104 if (WSTOPSIG (status) != SIGSTOP)
1105 {
1106 *signalled = 1;
1107 if (debug_linux_nat)
1108 fprintf_unfiltered (gdb_stdlog,
1109 "LNPAW: Received %s after attaching\n",
1110 status_to_str (status));
1111 }
1112
1113 return status;
1114}
1115
b84876c2 1116static void
136d6dae 1117linux_nat_create_inferior (struct target_ops *ops,
7c5ded6a
SDJ
1118 const char *exec_file, const std::string &allargs,
1119 char **env, int from_tty)
b84876c2 1120{
41272101
TT
1121 maybe_disable_address_space_randomization restore_personality
1122 (disable_randomization);
b84876c2
PA
1123
1124 /* The fork_child mechanism is synchronous and calls target_wait, so
1125 we have to mask the async mode. */
1126
2455069d 1127 /* Make sure we report all signals during startup. */
94bedb42 1128 linux_nat_pass_signals (ops, 0, NULL);
2455069d 1129
136d6dae 1130 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
b84876c2
PA
1131}
1132
8784d563
PA
1133/* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1134 already attached. Returns true if a new LWP is found, false
1135 otherwise. */
1136
1137static int
1138attach_proc_task_lwp_callback (ptid_t ptid)
1139{
1140 struct lwp_info *lp;
1141
1142 /* Ignore LWPs we're already attached to. */
1143 lp = find_lwp_pid (ptid);
1144 if (lp == NULL)
1145 {
1146 int lwpid = ptid_get_lwp (ptid);
1147
1148 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1149 {
1150 int err = errno;
1151
1152 /* Be quiet if we simply raced with the thread exiting.
1153 EPERM is returned if the thread's task still exists, and
1154 is marked as exited or zombie, as well as other
1155 conditions, so in that case, confirm the status in
1156 /proc/PID/status. */
1157 if (err == ESRCH
1158 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1159 {
1160 if (debug_linux_nat)
1161 {
1162 fprintf_unfiltered (gdb_stdlog,
1163 "Cannot attach to lwp %d: "
1164 "thread is gone (%d: %s)\n",
1165 lwpid, err, safe_strerror (err));
1166 }
1167 }
1168 else
1169 {
4d9b86e1
SM
1170 std::string reason
1171 = linux_ptrace_attach_fail_reason_string (ptid, err);
1172
f71f0b0d 1173 warning (_("Cannot attach to lwp %d: %s"),
4d9b86e1 1174 lwpid, reason.c_str ());
8784d563
PA
1175 }
1176 }
1177 else
1178 {
1179 if (debug_linux_nat)
1180 fprintf_unfiltered (gdb_stdlog,
1181 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1182 target_pid_to_str (ptid));
1183
1184 lp = add_lwp (ptid);
8784d563
PA
1185
1186 /* The next time we wait for this LWP we'll see a SIGSTOP as
1187 PTRACE_ATTACH brings it to a halt. */
1188 lp->signalled = 1;
1189
1190 /* We need to wait for a stop before being able to make the
1191 next ptrace call on this LWP. */
1192 lp->must_set_ptrace_flags = 1;
026a9174
PA
1193
1194 /* So that wait collects the SIGSTOP. */
1195 lp->resumed = 1;
1196
1197 /* Also add the LWP to gdb's thread list, in case a
1198 matching libthread_db is not found (or the process uses
1199 raw clone). */
1200 add_thread (lp->ptid);
1201 set_running (lp->ptid, 1);
1202 set_executing (lp->ptid, 1);
8784d563
PA
1203 }
1204
1205 return 1;
1206 }
1207 return 0;
1208}
1209
d6b0e80f 1210static void
c0939df1 1211linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
d6b0e80f
AC
1212{
1213 struct lwp_info *lp;
d6b0e80f 1214 int status;
af990527 1215 ptid_t ptid;
d6b0e80f 1216
2455069d 1217 /* Make sure we report all signals during attach. */
94bedb42 1218 linux_nat_pass_signals (ops, 0, NULL);
2455069d 1219
492d29ea 1220 TRY
87b0bb13
JK
1221 {
1222 linux_ops->to_attach (ops, args, from_tty);
1223 }
492d29ea 1224 CATCH (ex, RETURN_MASK_ERROR)
87b0bb13
JK
1225 {
1226 pid_t pid = parse_pid_to_attach (args);
4d9b86e1 1227 std::string reason = linux_ptrace_attach_fail_reason (pid);
87b0bb13 1228
4d9b86e1
SM
1229 if (!reason.empty ())
1230 throw_error (ex.error, "warning: %s\n%s", reason.c_str (), ex.message);
7ae1a6a6 1231 else
a7b2d0fb 1232 throw_error (ex.error, "%s", ex.message);
87b0bb13 1233 }
492d29ea 1234 END_CATCH
d6b0e80f 1235
af990527
PA
1236 /* The ptrace base target adds the main thread with (pid,0,0)
1237 format. Decorate it with lwp info. */
dfd4cc63
LM
1238 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1239 ptid_get_pid (inferior_ptid),
1240 0);
af990527
PA
1241 thread_change_ptid (inferior_ptid, ptid);
1242
9f0bdab8 1243 /* Add the initial process as the first LWP to the list. */
26cb8b7c 1244 lp = add_initial_lwp (ptid);
a0ef4274 1245
22827c51 1246 status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled);
dacc9cb2
PP
1247 if (!WIFSTOPPED (status))
1248 {
1249 if (WIFEXITED (status))
1250 {
1251 int exit_code = WEXITSTATUS (status);
1252
223ffa71 1253 target_terminal::ours ();
bc1e6c81 1254 target_mourn_inferior (inferior_ptid);
dacc9cb2
PP
1255 if (exit_code == 0)
1256 error (_("Unable to attach: program exited normally."));
1257 else
1258 error (_("Unable to attach: program exited with code %d."),
1259 exit_code);
1260 }
1261 else if (WIFSIGNALED (status))
1262 {
2ea28649 1263 enum gdb_signal signo;
dacc9cb2 1264
223ffa71 1265 target_terminal::ours ();
bc1e6c81 1266 target_mourn_inferior (inferior_ptid);
dacc9cb2 1267
2ea28649 1268 signo = gdb_signal_from_host (WTERMSIG (status));
dacc9cb2
PP
1269 error (_("Unable to attach: program terminated with signal "
1270 "%s, %s."),
2ea28649
PA
1271 gdb_signal_to_name (signo),
1272 gdb_signal_to_string (signo));
dacc9cb2
PP
1273 }
1274
1275 internal_error (__FILE__, __LINE__,
1276 _("unexpected status %d for PID %ld"),
dfd4cc63 1277 status, (long) ptid_get_lwp (ptid));
dacc9cb2
PP
1278 }
1279
a0ef4274 1280 lp->stopped = 1;
9f0bdab8 1281
a0ef4274 1282 /* Save the wait status to report later. */
d6b0e80f 1283 lp->resumed = 1;
a0ef4274
DJ
1284 if (debug_linux_nat)
1285 fprintf_unfiltered (gdb_stdlog,
1286 "LNA: waitpid %ld, saving status %s\n",
dfd4cc63 1287 (long) ptid_get_pid (lp->ptid), status_to_str (status));
710151dd 1288
7feb7d06
PA
1289 lp->status = status;
1290
8784d563
PA
1291 /* We must attach to every LWP. If /proc is mounted, use that to
1292 find them now. The inferior may be using raw clone instead of
1293 using pthreads. But even if it is using pthreads, thread_db
1294 walks structures in the inferior's address space to find the list
1295 of threads/LWPs, and those structures may well be corrupted.
1296 Note that once thread_db is loaded, we'll still use it to list
1297 threads and associate pthread info with each LWP. */
1298 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1299 attach_proc_task_lwp_callback);
1300
7feb7d06 1301 if (target_can_async_p ())
6a3753b3 1302 target_async (1);
d6b0e80f
AC
1303}
1304
ced2dffb
PA
1305/* Get pending signal of THREAD as a host signal number, for detaching
1306 purposes. This is the signal the thread last stopped for, which we
1307 need to deliver to the thread when detaching, otherwise, it'd be
1308 suppressed/lost. */
1309
a0ef4274 1310static int
ced2dffb 1311get_detach_signal (struct lwp_info *lp)
a0ef4274 1312{
a493e3e2 1313 enum gdb_signal signo = GDB_SIGNAL_0;
ca2163eb
PA
1314
1315 /* If we paused threads momentarily, we may have stored pending
1316 events in lp->status or lp->waitstatus (see stop_wait_callback),
1317 and GDB core hasn't seen any signal for those threads.
1318 Otherwise, the last signal reported to the core is found in the
1319 thread object's stop_signal.
1320
1321 There's a corner case that isn't handled here at present. Only
1322 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1323 stop_signal make sense as a real signal to pass to the inferior.
1324 Some catchpoint related events, like
1325 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
a493e3e2 1326 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
ca2163eb
PA
1327 those traps are debug API (ptrace in our case) related and
1328 induced; the inferior wouldn't see them if it wasn't being
1329 traced. Hence, we should never pass them to the inferior, even
1330 when set to pass state. Since this corner case isn't handled by
1331 infrun.c when proceeding with a signal, for consistency, neither
1332 do we handle it here (or elsewhere in the file we check for
1333 signal pass state). Normally SIGTRAP isn't set to pass state, so
1334 this is really a corner case. */
1335
1336 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
a493e3e2 1337 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
ca2163eb 1338 else if (lp->status)
2ea28649 1339 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
fbea99ea 1340 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
ca2163eb
PA
1341 {
1342 struct thread_info *tp = find_thread_ptid (lp->ptid);
e0881a8e 1343
72b049d3
PA
1344 if (tp->suspend.waitstatus_pending_p)
1345 signo = tp->suspend.waitstatus.value.sig;
1346 else
1347 signo = tp->suspend.stop_signal;
ca2163eb 1348 }
fbea99ea 1349 else if (!target_is_non_stop_p ())
a0ef4274 1350 {
ca2163eb
PA
1351 struct target_waitstatus last;
1352 ptid_t last_ptid;
4c28f408 1353
ca2163eb 1354 get_last_target_status (&last_ptid, &last);
4c28f408 1355
dfd4cc63 1356 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
ca2163eb 1357 {
e09875d4 1358 struct thread_info *tp = find_thread_ptid (lp->ptid);
e0881a8e 1359
16c381f0 1360 signo = tp->suspend.stop_signal;
4c28f408 1361 }
ca2163eb 1362 }
4c28f408 1363
a493e3e2 1364 if (signo == GDB_SIGNAL_0)
ca2163eb
PA
1365 {
1366 if (debug_linux_nat)
1367 fprintf_unfiltered (gdb_stdlog,
1368 "GPT: lwp %s has no pending signal\n",
1369 target_pid_to_str (lp->ptid));
1370 }
1371 else if (!signal_pass_state (signo))
1372 {
1373 if (debug_linux_nat)
3e43a32a
MS
1374 fprintf_unfiltered (gdb_stdlog,
1375 "GPT: lwp %s had signal %s, "
1376 "but it is in no pass state\n",
ca2163eb 1377 target_pid_to_str (lp->ptid),
2ea28649 1378 gdb_signal_to_string (signo));
a0ef4274 1379 }
a0ef4274 1380 else
4c28f408 1381 {
ca2163eb
PA
1382 if (debug_linux_nat)
1383 fprintf_unfiltered (gdb_stdlog,
1384 "GPT: lwp %s has pending signal %s\n",
1385 target_pid_to_str (lp->ptid),
2ea28649 1386 gdb_signal_to_string (signo));
ced2dffb
PA
1387
1388 return gdb_signal_to_host (signo);
4c28f408 1389 }
a0ef4274
DJ
1390
1391 return 0;
1392}
1393
ced2dffb
PA
1394/* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1395 signal number that should be passed to the LWP when detaching.
1396 Otherwise pass any pending signal the LWP may have, if any. */
1397
1398static void
1399detach_one_lwp (struct lwp_info *lp, int *signo_p)
d6b0e80f 1400{
ced2dffb
PA
1401 int lwpid = ptid_get_lwp (lp->ptid);
1402 int signo;
1403
d6b0e80f
AC
1404 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1405
1406 if (debug_linux_nat && lp->status)
1407 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1408 strsignal (WSTOPSIG (lp->status)),
1409 target_pid_to_str (lp->ptid));
1410
a0ef4274
DJ
1411 /* If there is a pending SIGSTOP, get rid of it. */
1412 if (lp->signalled)
d6b0e80f 1413 {
d6b0e80f
AC
1414 if (debug_linux_nat)
1415 fprintf_unfiltered (gdb_stdlog,
a0ef4274
DJ
1416 "DC: Sending SIGCONT to %s\n",
1417 target_pid_to_str (lp->ptid));
d6b0e80f 1418
ced2dffb 1419 kill_lwp (lwpid, SIGCONT);
d6b0e80f 1420 lp->signalled = 0;
d6b0e80f
AC
1421 }
1422
ced2dffb 1423 if (signo_p == NULL)
d6b0e80f 1424 {
a0ef4274 1425 /* Pass on any pending signal for this LWP. */
ced2dffb
PA
1426 signo = get_detach_signal (lp);
1427 }
1428 else
1429 signo = *signo_p;
a0ef4274 1430
ced2dffb
PA
1431 /* Preparing to resume may try to write registers, and fail if the
1432 lwp is zombie. If that happens, ignore the error. We'll handle
1433 it below, when detach fails with ESRCH. */
1434 TRY
1435 {
7b50312a
PA
1436 if (linux_nat_prepare_to_resume != NULL)
1437 linux_nat_prepare_to_resume (lp);
ced2dffb
PA
1438 }
1439 CATCH (ex, RETURN_MASK_ERROR)
1440 {
1441 if (!check_ptrace_stopped_lwp_gone (lp))
1442 throw_exception (ex);
1443 }
1444 END_CATCH
d6b0e80f 1445
ced2dffb
PA
1446 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1447 {
1448 int save_errno = errno;
1449
1450 /* We know the thread exists, so ESRCH must mean the lwp is
1451 zombie. This can happen if one of the already-detached
1452 threads exits the whole thread group. In that case we're
1453 still attached, and must reap the lwp. */
1454 if (save_errno == ESRCH)
1455 {
1456 int ret, status;
d6b0e80f 1457
ced2dffb
PA
1458 ret = my_waitpid (lwpid, &status, __WALL);
1459 if (ret == -1)
1460 {
1461 warning (_("Couldn't reap LWP %d while detaching: %s"),
1462 lwpid, strerror (errno));
1463 }
1464 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1465 {
1466 warning (_("Reaping LWP %d while detaching "
1467 "returned unexpected status 0x%x"),
1468 lwpid, status);
1469 }
1470 }
1471 else
1472 {
1473 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1474 safe_strerror (save_errno));
1475 }
d6b0e80f 1476 }
ced2dffb
PA
1477 else if (debug_linux_nat)
1478 {
1479 fprintf_unfiltered (gdb_stdlog,
1480 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1481 target_pid_to_str (lp->ptid),
1482 strsignal (signo));
1483 }
1484
1485 delete_lwp (lp->ptid);
1486}
d6b0e80f 1487
ced2dffb
PA
1488static int
1489detach_callback (struct lwp_info *lp, void *data)
1490{
1491 /* We don't actually detach from the thread group leader just yet.
1492 If the thread group exits, we must reap the zombie clone lwps
1493 before we're able to reap the leader. */
1494 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1495 detach_one_lwp (lp, NULL);
d6b0e80f
AC
1496 return 0;
1497}
1498
1499static void
6e1e1966 1500linux_nat_detach (struct target_ops *ops, inferior *inf, int from_tty)
d6b0e80f 1501{
b84876c2 1502 int pid;
d90e17a7
PA
1503 struct lwp_info *main_lwp;
1504
dfd4cc63 1505 pid = ptid_get_pid (inferior_ptid);
a0ef4274 1506
ae5e0686
MK
1507 /* Don't unregister from the event loop, as there may be other
1508 inferiors running. */
b84876c2 1509
4c28f408
PA
1510 /* Stop all threads before detaching. ptrace requires that the
1511 thread is stopped to sucessfully detach. */
d90e17a7 1512 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
4c28f408
PA
1513 /* ... and wait until all of them have reported back that
1514 they're no longer running. */
d90e17a7 1515 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
4c28f408 1516
d90e17a7 1517 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
d6b0e80f
AC
1518
1519 /* Only the initial process should be left right now. */
dfd4cc63 1520 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
d90e17a7
PA
1521
1522 main_lwp = find_lwp_pid (pid_to_ptid (pid));
d6b0e80f 1523
7a7d3353
PA
1524 if (forks_exist_p ())
1525 {
1526 /* Multi-fork case. The current inferior_ptid is being detached
1527 from, but there are other viable forks to debug. Detach from
1528 the current fork, and context-switch to the first
1529 available. */
6bd6f3b6 1530 linux_fork_detach (from_tty);
7a7d3353
PA
1531 }
1532 else
ced2dffb 1533 {
ced2dffb
PA
1534 target_announce_detach (from_tty);
1535
6bd6f3b6
SM
1536 /* Pass on any pending signal for the last LWP. */
1537 int signo = get_detach_signal (main_lwp);
ced2dffb
PA
1538
1539 detach_one_lwp (main_lwp, &signo);
1540
1541 inf_ptrace_detach_success (ops);
1542 }
d6b0e80f
AC
1543}
1544
8a99810d
PA
1545/* Resume execution of the inferior process. If STEP is nonzero,
1546 single-step it. If SIGNAL is nonzero, give it that signal. */
1547
1548static void
23f238d3
PA
1549linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1550 enum gdb_signal signo)
8a99810d 1551{
8a99810d 1552 lp->step = step;
9c02b525
PA
1553
1554 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1555 We only presently need that if the LWP is stepped though (to
1556 handle the case of stepping a breakpoint instruction). */
1557 if (step)
1558 {
1559 struct regcache *regcache = get_thread_regcache (lp->ptid);
1560
1561 lp->stop_pc = regcache_read_pc (regcache);
1562 }
1563 else
1564 lp->stop_pc = 0;
1565
8a99810d
PA
1566 if (linux_nat_prepare_to_resume != NULL)
1567 linux_nat_prepare_to_resume (lp);
90ad5e1d 1568 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
23f238d3
PA
1569
1570 /* Successfully resumed. Clear state that no longer makes sense,
1571 and mark the LWP as running. Must not do this before resuming
1572 otherwise if that fails other code will be confused. E.g., we'd
1573 later try to stop the LWP and hang forever waiting for a stop
1574 status. Note that we must not throw after this is cleared,
1575 otherwise handle_zombie_lwp_error would get confused. */
8a99810d 1576 lp->stopped = 0;
1ad3de98 1577 lp->core = -1;
23f238d3 1578 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
8a99810d
PA
1579 registers_changed_ptid (lp->ptid);
1580}
1581
23f238d3
PA
1582/* Called when we try to resume a stopped LWP and that errors out. If
1583 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1584 or about to become), discard the error, clear any pending status
1585 the LWP may have, and return true (we'll collect the exit status
1586 soon enough). Otherwise, return false. */
1587
1588static int
1589check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1590{
1591 /* If we get an error after resuming the LWP successfully, we'd
1592 confuse !T state for the LWP being gone. */
1593 gdb_assert (lp->stopped);
1594
1595 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1596 because even if ptrace failed with ESRCH, the tracee may be "not
1597 yet fully dead", but already refusing ptrace requests. In that
1598 case the tracee has 'R (Running)' state for a little bit
1599 (observed in Linux 3.18). See also the note on ESRCH in the
1600 ptrace(2) man page. Instead, check whether the LWP has any state
1601 other than ptrace-stopped. */
1602
1603 /* Don't assume anything if /proc/PID/status can't be read. */
1604 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1605 {
1606 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1607 lp->status = 0;
1608 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1609 return 1;
1610 }
1611 return 0;
1612}
1613
1614/* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1615 disappears while we try to resume it. */
1616
1617static void
1618linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1619{
1620 TRY
1621 {
1622 linux_resume_one_lwp_throw (lp, step, signo);
1623 }
1624 CATCH (ex, RETURN_MASK_ERROR)
1625 {
1626 if (!check_ptrace_stopped_lwp_gone (lp))
1627 throw_exception (ex);
1628 }
1629 END_CATCH
1630}
1631
d6b0e80f
AC
1632/* Resume LP. */
1633
25289eb2 1634static void
e5ef252a 1635resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
d6b0e80f 1636{
25289eb2 1637 if (lp->stopped)
6c95b8df 1638 {
c9657e70 1639 struct inferior *inf = find_inferior_ptid (lp->ptid);
25289eb2
PA
1640
1641 if (inf->vfork_child != NULL)
1642 {
1643 if (debug_linux_nat)
1644 fprintf_unfiltered (gdb_stdlog,
1645 "RC: Not resuming %s (vfork parent)\n",
1646 target_pid_to_str (lp->ptid));
1647 }
8a99810d 1648 else if (!lwp_status_pending_p (lp))
25289eb2
PA
1649 {
1650 if (debug_linux_nat)
1651 fprintf_unfiltered (gdb_stdlog,
e5ef252a
PA
1652 "RC: Resuming sibling %s, %s, %s\n",
1653 target_pid_to_str (lp->ptid),
1654 (signo != GDB_SIGNAL_0
1655 ? strsignal (gdb_signal_to_host (signo))
1656 : "0"),
1657 step ? "step" : "resume");
25289eb2 1658
8a99810d 1659 linux_resume_one_lwp (lp, step, signo);
25289eb2
PA
1660 }
1661 else
1662 {
1663 if (debug_linux_nat)
1664 fprintf_unfiltered (gdb_stdlog,
1665 "RC: Not resuming sibling %s (has pending)\n",
1666 target_pid_to_str (lp->ptid));
1667 }
6c95b8df 1668 }
25289eb2 1669 else
d6b0e80f 1670 {
d90e17a7
PA
1671 if (debug_linux_nat)
1672 fprintf_unfiltered (gdb_stdlog,
25289eb2 1673 "RC: Not resuming sibling %s (not stopped)\n",
d6b0e80f 1674 target_pid_to_str (lp->ptid));
d6b0e80f 1675 }
25289eb2 1676}
d6b0e80f 1677
8817a6f2
PA
1678/* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1679 Resume LWP with the last stop signal, if it is in pass state. */
e5ef252a 1680
25289eb2 1681static int
8817a6f2 1682linux_nat_resume_callback (struct lwp_info *lp, void *except)
25289eb2 1683{
e5ef252a
PA
1684 enum gdb_signal signo = GDB_SIGNAL_0;
1685
8817a6f2
PA
1686 if (lp == except)
1687 return 0;
1688
e5ef252a
PA
1689 if (lp->stopped)
1690 {
1691 struct thread_info *thread;
1692
1693 thread = find_thread_ptid (lp->ptid);
1694 if (thread != NULL)
1695 {
70509625 1696 signo = thread->suspend.stop_signal;
e5ef252a
PA
1697 thread->suspend.stop_signal = GDB_SIGNAL_0;
1698 }
1699 }
1700
1701 resume_lwp (lp, 0, signo);
d6b0e80f
AC
1702 return 0;
1703}
1704
1705static int
1706resume_clear_callback (struct lwp_info *lp, void *data)
1707{
1708 lp->resumed = 0;
25289eb2 1709 lp->last_resume_kind = resume_stop;
d6b0e80f
AC
1710 return 0;
1711}
1712
1713static int
1714resume_set_callback (struct lwp_info *lp, void *data)
1715{
1716 lp->resumed = 1;
25289eb2 1717 lp->last_resume_kind = resume_continue;
d6b0e80f
AC
1718 return 0;
1719}
1720
1721static void
28439f5e 1722linux_nat_resume (struct target_ops *ops,
2ea28649 1723 ptid_t ptid, int step, enum gdb_signal signo)
d6b0e80f
AC
1724{
1725 struct lwp_info *lp;
d90e17a7 1726 int resume_many;
d6b0e80f 1727
76f50ad1
DJ
1728 if (debug_linux_nat)
1729 fprintf_unfiltered (gdb_stdlog,
1730 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1731 step ? "step" : "resume",
1732 target_pid_to_str (ptid),
a493e3e2 1733 (signo != GDB_SIGNAL_0
2ea28649 1734 ? strsignal (gdb_signal_to_host (signo)) : "0"),
76f50ad1
DJ
1735 target_pid_to_str (inferior_ptid));
1736
d6b0e80f 1737 /* A specific PTID means `step only this process id'. */
d90e17a7
PA
1738 resume_many = (ptid_equal (minus_one_ptid, ptid)
1739 || ptid_is_pid (ptid));
4c28f408 1740
e3e9f5a2
PA
1741 /* Mark the lwps we're resuming as resumed. */
1742 iterate_over_lwps (ptid, resume_set_callback, NULL);
d6b0e80f 1743
d90e17a7
PA
1744 /* See if it's the current inferior that should be handled
1745 specially. */
1746 if (resume_many)
1747 lp = find_lwp_pid (inferior_ptid);
1748 else
1749 lp = find_lwp_pid (ptid);
9f0bdab8 1750 gdb_assert (lp != NULL);
d6b0e80f 1751
9f0bdab8 1752 /* Remember if we're stepping. */
25289eb2 1753 lp->last_resume_kind = step ? resume_step : resume_continue;
d6b0e80f 1754
9f0bdab8
DJ
1755 /* If we have a pending wait status for this thread, there is no
1756 point in resuming the process. But first make sure that
1757 linux_nat_wait won't preemptively handle the event - we
1758 should never take this short-circuit if we are going to
1759 leave LP running, since we have skipped resuming all the
1760 other threads. This bit of code needs to be synchronized
1761 with linux_nat_wait. */
76f50ad1 1762
9f0bdab8
DJ
1763 if (lp->status && WIFSTOPPED (lp->status))
1764 {
2455069d
UW
1765 if (!lp->step
1766 && WSTOPSIG (lp->status)
1767 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
d6b0e80f 1768 {
9f0bdab8
DJ
1769 if (debug_linux_nat)
1770 fprintf_unfiltered (gdb_stdlog,
1771 "LLR: Not short circuiting for ignored "
1772 "status 0x%x\n", lp->status);
1773
d6b0e80f
AC
1774 /* FIXME: What should we do if we are supposed to continue
1775 this thread with a signal? */
a493e3e2 1776 gdb_assert (signo == GDB_SIGNAL_0);
2ea28649 1777 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
9f0bdab8
DJ
1778 lp->status = 0;
1779 }
1780 }
76f50ad1 1781
8a99810d 1782 if (lwp_status_pending_p (lp))
9f0bdab8
DJ
1783 {
1784 /* FIXME: What should we do if we are supposed to continue
1785 this thread with a signal? */
a493e3e2 1786 gdb_assert (signo == GDB_SIGNAL_0);
76f50ad1 1787
9f0bdab8
DJ
1788 if (debug_linux_nat)
1789 fprintf_unfiltered (gdb_stdlog,
1790 "LLR: Short circuiting for status 0x%x\n",
1791 lp->status);
d6b0e80f 1792
7feb7d06
PA
1793 if (target_can_async_p ())
1794 {
6a3753b3 1795 target_async (1);
7feb7d06
PA
1796 /* Tell the event loop we have something to process. */
1797 async_file_mark ();
1798 }
9f0bdab8 1799 return;
d6b0e80f
AC
1800 }
1801
d90e17a7 1802 if (resume_many)
8817a6f2 1803 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
d90e17a7 1804
d6b0e80f
AC
1805 if (debug_linux_nat)
1806 fprintf_unfiltered (gdb_stdlog,
1807 "LLR: %s %s, %s (resume event thread)\n",
1808 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2bf6fb9d 1809 target_pid_to_str (lp->ptid),
a493e3e2 1810 (signo != GDB_SIGNAL_0
2ea28649 1811 ? strsignal (gdb_signal_to_host (signo)) : "0"));
b84876c2 1812
2bf6fb9d
PA
1813 linux_resume_one_lwp (lp, step, signo);
1814
b84876c2 1815 if (target_can_async_p ())
6a3753b3 1816 target_async (1);
d6b0e80f
AC
1817}
1818
c5f62d5f 1819/* Send a signal to an LWP. */
d6b0e80f
AC
1820
1821static int
1822kill_lwp (int lwpid, int signo)
1823{
4a6ed09b 1824 int ret;
d6b0e80f 1825
4a6ed09b
PA
1826 errno = 0;
1827 ret = syscall (__NR_tkill, lwpid, signo);
1828 if (errno == ENOSYS)
1829 {
1830 /* If tkill fails, then we are not using nptl threads, a
1831 configuration we no longer support. */
1832 perror_with_name (("tkill"));
1833 }
1834 return ret;
d6b0e80f
AC
1835}
1836
ca2163eb
PA
1837/* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1838 event, check if the core is interested in it: if not, ignore the
1839 event, and keep waiting; otherwise, we need to toggle the LWP's
1840 syscall entry/exit status, since the ptrace event itself doesn't
1841 indicate it, and report the trap to higher layers. */
1842
1843static int
1844linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1845{
1846 struct target_waitstatus *ourstatus = &lp->waitstatus;
1847 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1848 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1849
1850 if (stopping)
1851 {
1852 /* If we're stopping threads, there's a SIGSTOP pending, which
1853 makes it so that the LWP reports an immediate syscall return,
1854 followed by the SIGSTOP. Skip seeing that "return" using
1855 PTRACE_CONT directly, and let stop_wait_callback collect the
1856 SIGSTOP. Later when the thread is resumed, a new syscall
1857 entry event. If we didn't do this (and returned 0), we'd
1858 leave a syscall entry pending, and our caller, by using
1859 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1860 itself. Later, when the user re-resumes this LWP, we'd see
1861 another syscall entry event and we'd mistake it for a return.
1862
1863 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1864 (leaving immediately with LWP->signalled set, without issuing
1865 a PTRACE_CONT), it would still be problematic to leave this
1866 syscall enter pending, as later when the thread is resumed,
1867 it would then see the same syscall exit mentioned above,
1868 followed by the delayed SIGSTOP, while the syscall didn't
1869 actually get to execute. It seems it would be even more
1870 confusing to the user. */
1871
1872 if (debug_linux_nat)
1873 fprintf_unfiltered (gdb_stdlog,
1874 "LHST: ignoring syscall %d "
1875 "for LWP %ld (stopping threads), "
1876 "resuming with PTRACE_CONT for SIGSTOP\n",
1877 syscall_number,
dfd4cc63 1878 ptid_get_lwp (lp->ptid));
ca2163eb
PA
1879
1880 lp->syscall_state = TARGET_WAITKIND_IGNORE;
dfd4cc63 1881 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
8817a6f2 1882 lp->stopped = 0;
ca2163eb
PA
1883 return 1;
1884 }
1885
bfd09d20
JS
1886 /* Always update the entry/return state, even if this particular
1887 syscall isn't interesting to the core now. In async mode,
1888 the user could install a new catchpoint for this syscall
1889 between syscall enter/return, and we'll need to know to
1890 report a syscall return if that happens. */
1891 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1892 ? TARGET_WAITKIND_SYSCALL_RETURN
1893 : TARGET_WAITKIND_SYSCALL_ENTRY);
1894
ca2163eb
PA
1895 if (catch_syscall_enabled ())
1896 {
ca2163eb
PA
1897 if (catching_syscall_number (syscall_number))
1898 {
1899 /* Alright, an event to report. */
1900 ourstatus->kind = lp->syscall_state;
1901 ourstatus->value.syscall_number = syscall_number;
1902
1903 if (debug_linux_nat)
1904 fprintf_unfiltered (gdb_stdlog,
1905 "LHST: stopping for %s of syscall %d"
1906 " for LWP %ld\n",
3e43a32a
MS
1907 lp->syscall_state
1908 == TARGET_WAITKIND_SYSCALL_ENTRY
ca2163eb
PA
1909 ? "entry" : "return",
1910 syscall_number,
dfd4cc63 1911 ptid_get_lwp (lp->ptid));
ca2163eb
PA
1912 return 0;
1913 }
1914
1915 if (debug_linux_nat)
1916 fprintf_unfiltered (gdb_stdlog,
1917 "LHST: ignoring %s of syscall %d "
1918 "for LWP %ld\n",
1919 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1920 ? "entry" : "return",
1921 syscall_number,
dfd4cc63 1922 ptid_get_lwp (lp->ptid));
ca2163eb
PA
1923 }
1924 else
1925 {
1926 /* If we had been syscall tracing, and hence used PT_SYSCALL
1927 before on this LWP, it could happen that the user removes all
1928 syscall catchpoints before we get to process this event.
1929 There are two noteworthy issues here:
1930
1931 - When stopped at a syscall entry event, resuming with
1932 PT_STEP still resumes executing the syscall and reports a
1933 syscall return.
1934
1935 - Only PT_SYSCALL catches syscall enters. If we last
1936 single-stepped this thread, then this event can't be a
1937 syscall enter. If we last single-stepped this thread, this
1938 has to be a syscall exit.
1939
1940 The points above mean that the next resume, be it PT_STEP or
1941 PT_CONTINUE, can not trigger a syscall trace event. */
1942 if (debug_linux_nat)
1943 fprintf_unfiltered (gdb_stdlog,
3e43a32a
MS
1944 "LHST: caught syscall event "
1945 "with no syscall catchpoints."
ca2163eb
PA
1946 " %d for LWP %ld, ignoring\n",
1947 syscall_number,
dfd4cc63 1948 ptid_get_lwp (lp->ptid));
ca2163eb
PA
1949 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1950 }
1951
1952 /* The core isn't interested in this event. For efficiency, avoid
1953 stopping all threads only to have the core resume them all again.
1954 Since we're not stopping threads, if we're still syscall tracing
1955 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1956 subsequent syscall. Simply resume using the inf-ptrace layer,
1957 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1958
8a99810d 1959 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
ca2163eb
PA
1960 return 1;
1961}
1962
3d799a95
DJ
1963/* Handle a GNU/Linux extended wait response. If we see a clone
1964 event, we need to add the new LWP to our list (and not report the
1965 trap to higher layers). This function returns non-zero if the
1966 event should be ignored and we should wait again. If STOPPING is
1967 true, the new LWP remains stopped, otherwise it is continued. */
d6b0e80f
AC
1968
1969static int
4dd63d48 1970linux_handle_extended_wait (struct lwp_info *lp, int status)
d6b0e80f 1971{
dfd4cc63 1972 int pid = ptid_get_lwp (lp->ptid);
3d799a95 1973 struct target_waitstatus *ourstatus = &lp->waitstatus;
89a5711c 1974 int event = linux_ptrace_get_extended_event (status);
d6b0e80f 1975
bfd09d20
JS
1976 /* All extended events we currently use are mid-syscall. Only
1977 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1978 you have to be using PTRACE_SEIZE to get that. */
1979 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1980
3d799a95
DJ
1981 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1982 || event == PTRACE_EVENT_CLONE)
d6b0e80f 1983 {
3d799a95
DJ
1984 unsigned long new_pid;
1985 int ret;
1986
1987 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
6fc19103 1988
3d799a95
DJ
1989 /* If we haven't already seen the new PID stop, wait for it now. */
1990 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1991 {
1992 /* The new child has a pending SIGSTOP. We can't affect it until it
1993 hits the SIGSTOP, but we're already attached. */
4a6ed09b 1994 ret = my_waitpid (new_pid, &status, __WALL);
3d799a95
DJ
1995 if (ret == -1)
1996 perror_with_name (_("waiting for new child"));
1997 else if (ret != new_pid)
1998 internal_error (__FILE__, __LINE__,
1999 _("wait returned unexpected PID %d"), ret);
2000 else if (!WIFSTOPPED (status))
2001 internal_error (__FILE__, __LINE__,
2002 _("wait returned unexpected status 0x%x"), status);
2003 }
2004
3a3e9ee3 2005 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
3d799a95 2006
26cb8b7c
PA
2007 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2008 {
2009 /* The arch-specific native code may need to know about new
2010 forks even if those end up never mapped to an
2011 inferior. */
2012 if (linux_nat_new_fork != NULL)
2013 linux_nat_new_fork (lp, new_pid);
2014 }
2015
2277426b 2016 if (event == PTRACE_EVENT_FORK
dfd4cc63 2017 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2277426b 2018 {
2277426b
PA
2019 /* Handle checkpointing by linux-fork.c here as a special
2020 case. We don't want the follow-fork-mode or 'catch fork'
2021 to interfere with this. */
2022
2023 /* This won't actually modify the breakpoint list, but will
2024 physically remove the breakpoints from the child. */
d80ee84f 2025 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2277426b
PA
2026
2027 /* Retain child fork in ptrace (stopped) state. */
14571dad
MS
2028 if (!find_fork_pid (new_pid))
2029 add_fork (new_pid);
2277426b
PA
2030
2031 /* Report as spurious, so that infrun doesn't want to follow
2032 this fork. We're actually doing an infcall in
2033 linux-fork.c. */
2034 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2277426b
PA
2035
2036 /* Report the stop to the core. */
2037 return 0;
2038 }
2039
3d799a95
DJ
2040 if (event == PTRACE_EVENT_FORK)
2041 ourstatus->kind = TARGET_WAITKIND_FORKED;
2042 else if (event == PTRACE_EVENT_VFORK)
2043 ourstatus->kind = TARGET_WAITKIND_VFORKED;
4dd63d48 2044 else if (event == PTRACE_EVENT_CLONE)
3d799a95 2045 {
78768c4a
JK
2046 struct lwp_info *new_lp;
2047
3d799a95 2048 ourstatus->kind = TARGET_WAITKIND_IGNORE;
78768c4a 2049
3c4d7e12
PA
2050 if (debug_linux_nat)
2051 fprintf_unfiltered (gdb_stdlog,
2052 "LHEW: Got clone event "
2053 "from LWP %d, new child is LWP %ld\n",
2054 pid, new_pid);
2055
dfd4cc63 2056 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
4c28f408 2057 new_lp->stopped = 1;
4dd63d48 2058 new_lp->resumed = 1;
d6b0e80f 2059
2db9a427
PA
2060 /* If the thread_db layer is active, let it record the user
2061 level thread id and status, and add the thread to GDB's
2062 list. */
2063 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
3d799a95 2064 {
2db9a427
PA
2065 /* The process is not using thread_db. Add the LWP to
2066 GDB's list. */
2067 target_post_attach (ptid_get_lwp (new_lp->ptid));
2068 add_thread (new_lp->ptid);
2069 }
4c28f408 2070
2ee52aa4 2071 /* Even if we're stopping the thread for some reason
4dd63d48
PA
2072 internal to this module, from the perspective of infrun
2073 and the user/frontend, this new thread is running until
2074 it next reports a stop. */
2ee52aa4 2075 set_running (new_lp->ptid, 1);
4dd63d48 2076 set_executing (new_lp->ptid, 1);
4c28f408 2077
4dd63d48 2078 if (WSTOPSIG (status) != SIGSTOP)
79395f92 2079 {
4dd63d48
PA
2080 /* This can happen if someone starts sending signals to
2081 the new thread before it gets a chance to run, which
2082 have a lower number than SIGSTOP (e.g. SIGUSR1).
2083 This is an unlikely case, and harder to handle for
2084 fork / vfork than for clone, so we do not try - but
2085 we handle it for clone events here. */
2086
2087 new_lp->signalled = 1;
2088
79395f92
PA
2089 /* We created NEW_LP so it cannot yet contain STATUS. */
2090 gdb_assert (new_lp->status == 0);
2091
2092 /* Save the wait status to report later. */
2093 if (debug_linux_nat)
2094 fprintf_unfiltered (gdb_stdlog,
2095 "LHEW: waitpid of new LWP %ld, "
2096 "saving status %s\n",
dfd4cc63 2097 (long) ptid_get_lwp (new_lp->ptid),
79395f92
PA
2098 status_to_str (status));
2099 new_lp->status = status;
2100 }
aa01bd36
PA
2101 else if (report_thread_events)
2102 {
2103 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2104 new_lp->status = status;
2105 }
79395f92 2106
3d799a95
DJ
2107 return 1;
2108 }
2109
2110 return 0;
d6b0e80f
AC
2111 }
2112
3d799a95
DJ
2113 if (event == PTRACE_EVENT_EXEC)
2114 {
a75724bc
PA
2115 if (debug_linux_nat)
2116 fprintf_unfiltered (gdb_stdlog,
2117 "LHEW: Got exec event from LWP %ld\n",
dfd4cc63 2118 ptid_get_lwp (lp->ptid));
a75724bc 2119
3d799a95
DJ
2120 ourstatus->kind = TARGET_WAITKIND_EXECD;
2121 ourstatus->value.execd_pathname
8dd27370 2122 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
3d799a95 2123
8af756ef
PA
2124 /* The thread that execed must have been resumed, but, when a
2125 thread execs, it changes its tid to the tgid, and the old
2126 tgid thread might have not been resumed. */
2127 lp->resumed = 1;
6c95b8df
PA
2128 return 0;
2129 }
2130
2131 if (event == PTRACE_EVENT_VFORK_DONE)
2132 {
2133 if (current_inferior ()->waiting_for_vfork_done)
3d799a95 2134 {
6c95b8df 2135 if (debug_linux_nat)
3e43a32a
MS
2136 fprintf_unfiltered (gdb_stdlog,
2137 "LHEW: Got expected PTRACE_EVENT_"
2138 "VFORK_DONE from LWP %ld: stopping\n",
dfd4cc63 2139 ptid_get_lwp (lp->ptid));
3d799a95 2140
6c95b8df
PA
2141 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2142 return 0;
3d799a95
DJ
2143 }
2144
6c95b8df 2145 if (debug_linux_nat)
3e43a32a
MS
2146 fprintf_unfiltered (gdb_stdlog,
2147 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
20ba1ce6 2148 "from LWP %ld: ignoring\n",
dfd4cc63 2149 ptid_get_lwp (lp->ptid));
6c95b8df 2150 return 1;
3d799a95
DJ
2151 }
2152
2153 internal_error (__FILE__, __LINE__,
2154 _("unknown ptrace event %d"), event);
d6b0e80f
AC
2155}
2156
2157/* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2158 exited. */
2159
2160static int
2161wait_lwp (struct lwp_info *lp)
2162{
2163 pid_t pid;
432b4d03 2164 int status = 0;
d6b0e80f 2165 int thread_dead = 0;
432b4d03 2166 sigset_t prev_mask;
d6b0e80f
AC
2167
2168 gdb_assert (!lp->stopped);
2169 gdb_assert (lp->status == 0);
2170
432b4d03
JK
2171 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2172 block_child_signals (&prev_mask);
2173
2174 for (;;)
d6b0e80f 2175 {
4a6ed09b 2176 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
a9f4bb21
PA
2177 if (pid == -1 && errno == ECHILD)
2178 {
2179 /* The thread has previously exited. We need to delete it
4a6ed09b
PA
2180 now because if this was a non-leader thread execing, we
2181 won't get an exit event. See comments on exec events at
2182 the top of the file. */
a9f4bb21
PA
2183 thread_dead = 1;
2184 if (debug_linux_nat)
2185 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2186 target_pid_to_str (lp->ptid));
2187 }
432b4d03
JK
2188 if (pid != 0)
2189 break;
2190
2191 /* Bugs 10970, 12702.
2192 Thread group leader may have exited in which case we'll lock up in
2193 waitpid if there are other threads, even if they are all zombies too.
2194 Basically, we're not supposed to use waitpid this way.
4a6ed09b
PA
2195 tkill(pid,0) cannot be used here as it gets ESRCH for both
2196 for zombie and running processes.
432b4d03
JK
2197
2198 As a workaround, check if we're waiting for the thread group leader and
2199 if it's a zombie, and avoid calling waitpid if it is.
2200
2201 This is racy, what if the tgl becomes a zombie right after we check?
2202 Therefore always use WNOHANG with sigsuspend - it is equivalent to
5f572dec 2203 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
432b4d03 2204
dfd4cc63
LM
2205 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2206 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
d6b0e80f 2207 {
d6b0e80f
AC
2208 thread_dead = 1;
2209 if (debug_linux_nat)
432b4d03
JK
2210 fprintf_unfiltered (gdb_stdlog,
2211 "WL: Thread group leader %s vanished.\n",
d6b0e80f 2212 target_pid_to_str (lp->ptid));
432b4d03 2213 break;
d6b0e80f 2214 }
432b4d03
JK
2215
2216 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2217 get invoked despite our caller had them intentionally blocked by
2218 block_child_signals. This is sensitive only to the loop of
2219 linux_nat_wait_1 and there if we get called my_waitpid gets called
2220 again before it gets to sigsuspend so we can safely let the handlers
2221 get executed here. */
2222
d36bf488
DE
2223 if (debug_linux_nat)
2224 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
432b4d03
JK
2225 sigsuspend (&suspend_mask);
2226 }
2227
2228 restore_child_signals_mask (&prev_mask);
2229
d6b0e80f
AC
2230 if (!thread_dead)
2231 {
dfd4cc63 2232 gdb_assert (pid == ptid_get_lwp (lp->ptid));
d6b0e80f
AC
2233
2234 if (debug_linux_nat)
2235 {
2236 fprintf_unfiltered (gdb_stdlog,
2237 "WL: waitpid %s received %s\n",
2238 target_pid_to_str (lp->ptid),
2239 status_to_str (status));
2240 }
d6b0e80f 2241
a9f4bb21
PA
2242 /* Check if the thread has exited. */
2243 if (WIFEXITED (status) || WIFSIGNALED (status))
2244 {
aa01bd36
PA
2245 if (report_thread_events
2246 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
69dde7dc
PA
2247 {
2248 if (debug_linux_nat)
aa01bd36 2249 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
69dde7dc
PA
2250 ptid_get_pid (lp->ptid));
2251
aa01bd36 2252 /* If this is the leader exiting, it means the whole
69dde7dc
PA
2253 process is gone. Store the status to report to the
2254 core. Store it in lp->waitstatus, because lp->status
2255 would be ambiguous (W_EXITCODE(0,0) == 0). */
2256 store_waitstatus (&lp->waitstatus, status);
2257 return 0;
2258 }
2259
a9f4bb21
PA
2260 thread_dead = 1;
2261 if (debug_linux_nat)
2262 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2263 target_pid_to_str (lp->ptid));
2264 }
d6b0e80f
AC
2265 }
2266
2267 if (thread_dead)
2268 {
e26af52f 2269 exit_lwp (lp);
d6b0e80f
AC
2270 return 0;
2271 }
2272
2273 gdb_assert (WIFSTOPPED (status));
8817a6f2 2274 lp->stopped = 1;
d6b0e80f 2275
8784d563
PA
2276 if (lp->must_set_ptrace_flags)
2277 {
2278 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
de0d863e 2279 int options = linux_nat_ptrace_options (inf->attach_flag);
8784d563 2280
de0d863e 2281 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
8784d563
PA
2282 lp->must_set_ptrace_flags = 0;
2283 }
2284
ca2163eb
PA
2285 /* Handle GNU/Linux's syscall SIGTRAPs. */
2286 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2287 {
2288 /* No longer need the sysgood bit. The ptrace event ends up
2289 recorded in lp->waitstatus if we care for it. We can carry
2290 on handling the event like a regular SIGTRAP from here
2291 on. */
2292 status = W_STOPCODE (SIGTRAP);
2293 if (linux_handle_syscall_trap (lp, 1))
2294 return wait_lwp (lp);
2295 }
bfd09d20
JS
2296 else
2297 {
2298 /* Almost all other ptrace-stops are known to be outside of system
2299 calls, with further exceptions in linux_handle_extended_wait. */
2300 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2301 }
ca2163eb 2302
d6b0e80f 2303 /* Handle GNU/Linux's extended waitstatus for trace events. */
89a5711c
DB
2304 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2305 && linux_is_extended_waitstatus (status))
d6b0e80f
AC
2306 {
2307 if (debug_linux_nat)
2308 fprintf_unfiltered (gdb_stdlog,
2309 "WL: Handling extended status 0x%06x\n",
2310 status);
4dd63d48 2311 linux_handle_extended_wait (lp, status);
20ba1ce6 2312 return 0;
d6b0e80f
AC
2313 }
2314
2315 return status;
2316}
2317
2318/* Send a SIGSTOP to LP. */
2319
2320static int
2321stop_callback (struct lwp_info *lp, void *data)
2322{
2323 if (!lp->stopped && !lp->signalled)
2324 {
2325 int ret;
2326
2327 if (debug_linux_nat)
2328 {
2329 fprintf_unfiltered (gdb_stdlog,
2330 "SC: kill %s **<SIGSTOP>**\n",
2331 target_pid_to_str (lp->ptid));
2332 }
2333 errno = 0;
dfd4cc63 2334 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
d6b0e80f
AC
2335 if (debug_linux_nat)
2336 {
2337 fprintf_unfiltered (gdb_stdlog,
2338 "SC: lwp kill %d %s\n",
2339 ret,
2340 errno ? safe_strerror (errno) : "ERRNO-OK");
2341 }
2342
2343 lp->signalled = 1;
2344 gdb_assert (lp->status == 0);
2345 }
2346
2347 return 0;
2348}
2349
7b50312a
PA
2350/* Request a stop on LWP. */
2351
2352void
2353linux_stop_lwp (struct lwp_info *lwp)
2354{
2355 stop_callback (lwp, NULL);
2356}
2357
2db9a427
PA
2358/* See linux-nat.h */
2359
2360void
2361linux_stop_and_wait_all_lwps (void)
2362{
2363 /* Stop all LWP's ... */
2364 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2365
2366 /* ... and wait until all of them have reported back that
2367 they're no longer running. */
2368 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2369}
2370
2371/* See linux-nat.h */
2372
2373void
2374linux_unstop_all_lwps (void)
2375{
2376 iterate_over_lwps (minus_one_ptid,
2377 resume_stopped_resumed_lwps, &minus_one_ptid);
2378}
2379
57380f4e 2380/* Return non-zero if LWP PID has a pending SIGINT. */
d6b0e80f
AC
2381
2382static int
57380f4e
DJ
2383linux_nat_has_pending_sigint (int pid)
2384{
2385 sigset_t pending, blocked, ignored;
57380f4e
DJ
2386
2387 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2388
2389 if (sigismember (&pending, SIGINT)
2390 && !sigismember (&ignored, SIGINT))
2391 return 1;
2392
2393 return 0;
2394}
2395
2396/* Set a flag in LP indicating that we should ignore its next SIGINT. */
2397
2398static int
2399set_ignore_sigint (struct lwp_info *lp, void *data)
d6b0e80f 2400{
57380f4e
DJ
2401 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2402 flag to consume the next one. */
2403 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2404 && WSTOPSIG (lp->status) == SIGINT)
2405 lp->status = 0;
2406 else
2407 lp->ignore_sigint = 1;
2408
2409 return 0;
2410}
2411
2412/* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2413 This function is called after we know the LWP has stopped; if the LWP
2414 stopped before the expected SIGINT was delivered, then it will never have
2415 arrived. Also, if the signal was delivered to a shared queue and consumed
2416 by a different thread, it will never be delivered to this LWP. */
d6b0e80f 2417
57380f4e
DJ
2418static void
2419maybe_clear_ignore_sigint (struct lwp_info *lp)
2420{
2421 if (!lp->ignore_sigint)
2422 return;
2423
dfd4cc63 2424 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
57380f4e
DJ
2425 {
2426 if (debug_linux_nat)
2427 fprintf_unfiltered (gdb_stdlog,
2428 "MCIS: Clearing bogus flag for %s\n",
2429 target_pid_to_str (lp->ptid));
2430 lp->ignore_sigint = 0;
2431 }
2432}
2433
ebec9a0f
PA
2434/* Fetch the possible triggered data watchpoint info and store it in
2435 LP.
2436
2437 On some archs, like x86, that use debug registers to set
2438 watchpoints, it's possible that the way to know which watched
2439 address trapped, is to check the register that is used to select
2440 which address to watch. Problem is, between setting the watchpoint
2441 and reading back which data address trapped, the user may change
2442 the set of watchpoints, and, as a consequence, GDB changes the
2443 debug registers in the inferior. To avoid reading back a stale
2444 stopped-data-address when that happens, we cache in LP the fact
2445 that a watchpoint trapped, and the corresponding data address, as
2446 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2447 registers meanwhile, we have the cached data we can rely on. */
2448
9c02b525
PA
2449static int
2450check_stopped_by_watchpoint (struct lwp_info *lp)
ebec9a0f 2451{
ebec9a0f 2452 if (linux_ops->to_stopped_by_watchpoint == NULL)
9c02b525 2453 return 0;
ebec9a0f 2454
2989a365 2455 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
ebec9a0f
PA
2456 inferior_ptid = lp->ptid;
2457
9c02b525 2458 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
ebec9a0f 2459 {
15c66dd6 2460 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
9c02b525 2461
ebec9a0f
PA
2462 if (linux_ops->to_stopped_data_address != NULL)
2463 lp->stopped_data_address_p =
2464 linux_ops->to_stopped_data_address (&current_target,
2465 &lp->stopped_data_address);
2466 else
2467 lp->stopped_data_address_p = 0;
2468 }
2469
15c66dd6 2470 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
9c02b525
PA
2471}
2472
9c02b525 2473/* Returns true if the LWP had stopped for a watchpoint. */
ebec9a0f
PA
2474
2475static int
6a109b6b 2476linux_nat_stopped_by_watchpoint (struct target_ops *ops)
ebec9a0f
PA
2477{
2478 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2479
2480 gdb_assert (lp != NULL);
2481
15c66dd6 2482 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
ebec9a0f
PA
2483}
2484
2485static int
2486linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2487{
2488 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2489
2490 gdb_assert (lp != NULL);
2491
2492 *addr_p = lp->stopped_data_address;
2493
2494 return lp->stopped_data_address_p;
2495}
2496
26ab7092
JK
2497/* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2498
2499static int
2500sigtrap_is_event (int status)
2501{
2502 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2503}
2504
26ab7092
JK
2505/* Set alternative SIGTRAP-like events recognizer. If
2506 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2507 applied. */
2508
2509void
2510linux_nat_set_status_is_event (struct target_ops *t,
2511 int (*status_is_event) (int status))
2512{
2513 linux_nat_status_is_event = status_is_event;
2514}
2515
57380f4e
DJ
2516/* Wait until LP is stopped. */
2517
2518static int
2519stop_wait_callback (struct lwp_info *lp, void *data)
2520{
c9657e70 2521 struct inferior *inf = find_inferior_ptid (lp->ptid);
6c95b8df
PA
2522
2523 /* If this is a vfork parent, bail out, it is not going to report
2524 any SIGSTOP until the vfork is done with. */
2525 if (inf->vfork_child != NULL)
2526 return 0;
2527
d6b0e80f
AC
2528 if (!lp->stopped)
2529 {
2530 int status;
2531
2532 status = wait_lwp (lp);
2533 if (status == 0)
2534 return 0;
2535
57380f4e
DJ
2536 if (lp->ignore_sigint && WIFSTOPPED (status)
2537 && WSTOPSIG (status) == SIGINT)
d6b0e80f 2538 {
57380f4e 2539 lp->ignore_sigint = 0;
d6b0e80f
AC
2540
2541 errno = 0;
dfd4cc63 2542 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
8817a6f2 2543 lp->stopped = 0;
d6b0e80f
AC
2544 if (debug_linux_nat)
2545 fprintf_unfiltered (gdb_stdlog,
3e43a32a
MS
2546 "PTRACE_CONT %s, 0, 0 (%s) "
2547 "(discarding SIGINT)\n",
d6b0e80f
AC
2548 target_pid_to_str (lp->ptid),
2549 errno ? safe_strerror (errno) : "OK");
2550
57380f4e 2551 return stop_wait_callback (lp, NULL);
d6b0e80f
AC
2552 }
2553
57380f4e
DJ
2554 maybe_clear_ignore_sigint (lp);
2555
d6b0e80f
AC
2556 if (WSTOPSIG (status) != SIGSTOP)
2557 {
e5ef252a 2558 /* The thread was stopped with a signal other than SIGSTOP. */
7feb7d06 2559
e5ef252a
PA
2560 if (debug_linux_nat)
2561 fprintf_unfiltered (gdb_stdlog,
2562 "SWC: Pending event %s in %s\n",
2563 status_to_str ((int) status),
2564 target_pid_to_str (lp->ptid));
2565
2566 /* Save the sigtrap event. */
2567 lp->status = status;
e5ef252a 2568 gdb_assert (lp->signalled);
e7ad2f14 2569 save_stop_reason (lp);
d6b0e80f
AC
2570 }
2571 else
2572 {
2573 /* We caught the SIGSTOP that we intended to catch, so
2574 there's no SIGSTOP pending. */
e5ef252a
PA
2575
2576 if (debug_linux_nat)
2577 fprintf_unfiltered (gdb_stdlog,
2bf6fb9d 2578 "SWC: Expected SIGSTOP caught for %s.\n",
e5ef252a
PA
2579 target_pid_to_str (lp->ptid));
2580
e5ef252a
PA
2581 /* Reset SIGNALLED only after the stop_wait_callback call
2582 above as it does gdb_assert on SIGNALLED. */
d6b0e80f
AC
2583 lp->signalled = 0;
2584 }
2585 }
2586
2587 return 0;
2588}
2589
9c02b525
PA
2590/* Return non-zero if LP has a wait status pending. Discard the
2591 pending event and resume the LWP if the event that originally
2592 caused the stop became uninteresting. */
d6b0e80f
AC
2593
2594static int
2595status_callback (struct lwp_info *lp, void *data)
2596{
2597 /* Only report a pending wait status if we pretend that this has
2598 indeed been resumed. */
ca2163eb
PA
2599 if (!lp->resumed)
2600 return 0;
2601
eb54c8bf
PA
2602 if (!lwp_status_pending_p (lp))
2603 return 0;
2604
15c66dd6
PA
2605 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2606 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
9c02b525
PA
2607 {
2608 struct regcache *regcache = get_thread_regcache (lp->ptid);
9c02b525
PA
2609 CORE_ADDR pc;
2610 int discard = 0;
2611
9c02b525
PA
2612 pc = regcache_read_pc (regcache);
2613
2614 if (pc != lp->stop_pc)
2615 {
2616 if (debug_linux_nat)
2617 fprintf_unfiltered (gdb_stdlog,
2618 "SC: PC of %s changed. was=%s, now=%s\n",
2619 target_pid_to_str (lp->ptid),
2620 paddress (target_gdbarch (), lp->stop_pc),
2621 paddress (target_gdbarch (), pc));
2622 discard = 1;
2623 }
faf09f01
PA
2624
2625#if !USE_SIGTRAP_SIGINFO
a01bda52 2626 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
9c02b525
PA
2627 {
2628 if (debug_linux_nat)
2629 fprintf_unfiltered (gdb_stdlog,
2630 "SC: previous breakpoint of %s, at %s gone\n",
2631 target_pid_to_str (lp->ptid),
2632 paddress (target_gdbarch (), lp->stop_pc));
2633
2634 discard = 1;
2635 }
faf09f01 2636#endif
9c02b525
PA
2637
2638 if (discard)
2639 {
2640 if (debug_linux_nat)
2641 fprintf_unfiltered (gdb_stdlog,
2642 "SC: pending event of %s cancelled.\n",
2643 target_pid_to_str (lp->ptid));
2644
2645 lp->status = 0;
2646 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2647 return 0;
2648 }
9c02b525
PA
2649 }
2650
eb54c8bf 2651 return 1;
d6b0e80f
AC
2652}
2653
d6b0e80f
AC
2654/* Count the LWP's that have had events. */
2655
2656static int
2657count_events_callback (struct lwp_info *lp, void *data)
2658{
9a3c8263 2659 int *count = (int *) data;
d6b0e80f
AC
2660
2661 gdb_assert (count != NULL);
2662
9c02b525
PA
2663 /* Select only resumed LWPs that have an event pending. */
2664 if (lp->resumed && lwp_status_pending_p (lp))
d6b0e80f
AC
2665 (*count)++;
2666
2667 return 0;
2668}
2669
2670/* Select the LWP (if any) that is currently being single-stepped. */
2671
2672static int
2673select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2674{
25289eb2
PA
2675 if (lp->last_resume_kind == resume_step
2676 && lp->status != 0)
d6b0e80f
AC
2677 return 1;
2678 else
2679 return 0;
2680}
2681
8a99810d
PA
2682/* Returns true if LP has a status pending. */
2683
2684static int
2685lwp_status_pending_p (struct lwp_info *lp)
2686{
2687 /* We check for lp->waitstatus in addition to lp->status, because we
2688 can have pending process exits recorded in lp->status and
2689 W_EXITCODE(0,0) happens to be 0. */
2690 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2691}
2692
b90fc188 2693/* Select the Nth LWP that has had an event. */
d6b0e80f
AC
2694
2695static int
2696select_event_lwp_callback (struct lwp_info *lp, void *data)
2697{
9a3c8263 2698 int *selector = (int *) data;
d6b0e80f
AC
2699
2700 gdb_assert (selector != NULL);
2701
9c02b525
PA
2702 /* Select only resumed LWPs that have an event pending. */
2703 if (lp->resumed && lwp_status_pending_p (lp))
d6b0e80f
AC
2704 if ((*selector)-- == 0)
2705 return 1;
2706
2707 return 0;
2708}
2709
e7ad2f14
PA
2710/* Called when the LWP stopped for a signal/trap. If it stopped for a
2711 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2712 and save the result in the LWP's stop_reason field. If it stopped
2713 for a breakpoint, decrement the PC if necessary on the lwp's
2714 architecture. */
9c02b525 2715
e7ad2f14
PA
2716static void
2717save_stop_reason (struct lwp_info *lp)
710151dd 2718{
e7ad2f14
PA
2719 struct regcache *regcache;
2720 struct gdbarch *gdbarch;
515630c5 2721 CORE_ADDR pc;
9c02b525 2722 CORE_ADDR sw_bp_pc;
faf09f01
PA
2723#if USE_SIGTRAP_SIGINFO
2724 siginfo_t siginfo;
2725#endif
9c02b525 2726
e7ad2f14
PA
2727 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2728 gdb_assert (lp->status != 0);
2729
2730 if (!linux_nat_status_is_event (lp->status))
2731 return;
2732
2733 regcache = get_thread_regcache (lp->ptid);
ac7936df 2734 gdbarch = regcache->arch ();
e7ad2f14 2735
9c02b525 2736 pc = regcache_read_pc (regcache);
527a273a 2737 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
515630c5 2738
faf09f01
PA
2739#if USE_SIGTRAP_SIGINFO
2740 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2741 {
2742 if (siginfo.si_signo == SIGTRAP)
2743 {
e7ad2f14
PA
2744 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2745 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
faf09f01 2746 {
e7ad2f14
PA
2747 /* The si_code is ambiguous on this arch -- check debug
2748 registers. */
2749 if (!check_stopped_by_watchpoint (lp))
2750 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2751 }
2752 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2753 {
2754 /* If we determine the LWP stopped for a SW breakpoint,
2755 trust it. Particularly don't check watchpoint
2756 registers, because at least on s390, we'd find
2757 stopped-by-watchpoint as long as there's a watchpoint
2758 set. */
faf09f01 2759 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
faf09f01 2760 }
e7ad2f14 2761 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
faf09f01 2762 {
e7ad2f14
PA
2763 /* This can indicate either a hardware breakpoint or
2764 hardware watchpoint. Check debug registers. */
2765 if (!check_stopped_by_watchpoint (lp))
2766 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
faf09f01 2767 }
2bf6fb9d
PA
2768 else if (siginfo.si_code == TRAP_TRACE)
2769 {
2770 if (debug_linux_nat)
2771 fprintf_unfiltered (gdb_stdlog,
2772 "CSBB: %s stopped by trace\n",
2773 target_pid_to_str (lp->ptid));
e7ad2f14
PA
2774
2775 /* We may have single stepped an instruction that
2776 triggered a watchpoint. In that case, on some
2777 architectures (such as x86), instead of TRAP_HWBKPT,
2778 si_code indicates TRAP_TRACE, and we need to check
2779 the debug registers separately. */
2780 check_stopped_by_watchpoint (lp);
2bf6fb9d 2781 }
faf09f01
PA
2782 }
2783 }
2784#else
9c02b525 2785 if ((!lp->step || lp->stop_pc == sw_bp_pc)
a01bda52 2786 && software_breakpoint_inserted_here_p (regcache->aspace (),
9c02b525 2787 sw_bp_pc))
710151dd 2788 {
9c02b525
PA
2789 /* The LWP was either continued, or stepped a software
2790 breakpoint instruction. */
e7ad2f14
PA
2791 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2792 }
2793
a01bda52 2794 if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc))
e7ad2f14
PA
2795 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2796
2797 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2798 check_stopped_by_watchpoint (lp);
2799#endif
2800
2801 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2802 {
710151dd
PA
2803 if (debug_linux_nat)
2804 fprintf_unfiltered (gdb_stdlog,
2bf6fb9d 2805 "CSBB: %s stopped by software breakpoint\n",
710151dd
PA
2806 target_pid_to_str (lp->ptid));
2807
2808 /* Back up the PC if necessary. */
9c02b525
PA
2809 if (pc != sw_bp_pc)
2810 regcache_write_pc (regcache, sw_bp_pc);
515630c5 2811
e7ad2f14
PA
2812 /* Update this so we record the correct stop PC below. */
2813 pc = sw_bp_pc;
710151dd 2814 }
e7ad2f14 2815 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
9c02b525
PA
2816 {
2817 if (debug_linux_nat)
2818 fprintf_unfiltered (gdb_stdlog,
e7ad2f14
PA
2819 "CSBB: %s stopped by hardware breakpoint\n",
2820 target_pid_to_str (lp->ptid));
2821 }
2822 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2823 {
2824 if (debug_linux_nat)
2825 fprintf_unfiltered (gdb_stdlog,
2826 "CSBB: %s stopped by hardware watchpoint\n",
9c02b525 2827 target_pid_to_str (lp->ptid));
9c02b525 2828 }
d6b0e80f 2829
e7ad2f14 2830 lp->stop_pc = pc;
d6b0e80f
AC
2831}
2832
faf09f01
PA
2833
2834/* Returns true if the LWP had stopped for a software breakpoint. */
2835
2836static int
2837linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2838{
2839 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2840
2841 gdb_assert (lp != NULL);
2842
2843 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2844}
2845
2846/* Implement the supports_stopped_by_sw_breakpoint method. */
2847
2848static int
2849linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2850{
2851 return USE_SIGTRAP_SIGINFO;
2852}
2853
2854/* Returns true if the LWP had stopped for a hardware
2855 breakpoint/watchpoint. */
2856
2857static int
2858linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2859{
2860 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2861
2862 gdb_assert (lp != NULL);
2863
2864 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2865}
2866
2867/* Implement the supports_stopped_by_hw_breakpoint method. */
2868
2869static int
2870linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2871{
2872 return USE_SIGTRAP_SIGINFO;
2873}
2874
d6b0e80f
AC
2875/* Select one LWP out of those that have events pending. */
2876
2877static void
d90e17a7 2878select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
d6b0e80f
AC
2879{
2880 int num_events = 0;
2881 int random_selector;
9c02b525 2882 struct lwp_info *event_lp = NULL;
d6b0e80f 2883
ac264b3b 2884 /* Record the wait status for the original LWP. */
d6b0e80f
AC
2885 (*orig_lp)->status = *status;
2886
9c02b525
PA
2887 /* In all-stop, give preference to the LWP that is being
2888 single-stepped. There will be at most one, and it will be the
2889 LWP that the core is most interested in. If we didn't do this,
2890 then we'd have to handle pending step SIGTRAPs somehow in case
2891 the core later continues the previously-stepped thread, as
2892 otherwise we'd report the pending SIGTRAP then, and the core, not
2893 having stepped the thread, wouldn't understand what the trap was
2894 for, and therefore would report it to the user as a random
2895 signal. */
fbea99ea 2896 if (!target_is_non_stop_p ())
d6b0e80f 2897 {
9c02b525
PA
2898 event_lp = iterate_over_lwps (filter,
2899 select_singlestep_lwp_callback, NULL);
2900 if (event_lp != NULL)
2901 {
2902 if (debug_linux_nat)
2903 fprintf_unfiltered (gdb_stdlog,
2904 "SEL: Select single-step %s\n",
2905 target_pid_to_str (event_lp->ptid));
2906 }
d6b0e80f 2907 }
9c02b525
PA
2908
2909 if (event_lp == NULL)
d6b0e80f 2910 {
9c02b525 2911 /* Pick one at random, out of those which have had events. */
d6b0e80f 2912
9c02b525 2913 /* First see how many events we have. */
d90e17a7 2914 iterate_over_lwps (filter, count_events_callback, &num_events);
8bf3b159 2915 gdb_assert (num_events > 0);
d6b0e80f 2916
9c02b525
PA
2917 /* Now randomly pick a LWP out of those that have had
2918 events. */
d6b0e80f
AC
2919 random_selector = (int)
2920 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2921
2922 if (debug_linux_nat && num_events > 1)
2923 fprintf_unfiltered (gdb_stdlog,
9c02b525 2924 "SEL: Found %d events, selecting #%d\n",
d6b0e80f
AC
2925 num_events, random_selector);
2926
d90e17a7
PA
2927 event_lp = iterate_over_lwps (filter,
2928 select_event_lwp_callback,
d6b0e80f
AC
2929 &random_selector);
2930 }
2931
2932 if (event_lp != NULL)
2933 {
2934 /* Switch the event LWP. */
2935 *orig_lp = event_lp;
2936 *status = event_lp->status;
2937 }
2938
2939 /* Flush the wait status for the event LWP. */
2940 (*orig_lp)->status = 0;
2941}
2942
2943/* Return non-zero if LP has been resumed. */
2944
2945static int
2946resumed_callback (struct lwp_info *lp, void *data)
2947{
2948 return lp->resumed;
2949}
2950
02f3fc28 2951/* Check if we should go on and pass this event to common code.
9c02b525 2952 Return the affected lwp if we are, or NULL otherwise. */
12d9289a 2953
02f3fc28 2954static struct lwp_info *
9c02b525 2955linux_nat_filter_event (int lwpid, int status)
02f3fc28
PA
2956{
2957 struct lwp_info *lp;
89a5711c 2958 int event = linux_ptrace_get_extended_event (status);
02f3fc28
PA
2959
2960 lp = find_lwp_pid (pid_to_ptid (lwpid));
2961
2962 /* Check for stop events reported by a process we didn't already
2963 know about - anything not already in our LWP list.
2964
2965 If we're expecting to receive stopped processes after
2966 fork, vfork, and clone events, then we'll just add the
2967 new one to our list and go back to waiting for the event
2968 to be reported - the stopped process might be returned
0e5bf2a8
PA
2969 from waitpid before or after the event is.
2970
2971 But note the case of a non-leader thread exec'ing after the
2972 leader having exited, and gone from our lists. The non-leader
2973 thread changes its tid to the tgid. */
2974
2975 if (WIFSTOPPED (status) && lp == NULL
89a5711c 2976 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
0e5bf2a8
PA
2977 {
2978 /* A multi-thread exec after we had seen the leader exiting. */
2979 if (debug_linux_nat)
2980 fprintf_unfiltered (gdb_stdlog,
2981 "LLW: Re-adding thread group leader LWP %d.\n",
2982 lwpid);
2983
dfd4cc63 2984 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
0e5bf2a8
PA
2985 lp->stopped = 1;
2986 lp->resumed = 1;
2987 add_thread (lp->ptid);
2988 }
2989
02f3fc28
PA
2990 if (WIFSTOPPED (status) && !lp)
2991 {
3b27ef47
PA
2992 if (debug_linux_nat)
2993 fprintf_unfiltered (gdb_stdlog,
2994 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2995 (long) lwpid, status_to_str (status));
84636d28 2996 add_to_pid_list (&stopped_pids, lwpid, status);
02f3fc28
PA
2997 return NULL;
2998 }
2999
3000 /* Make sure we don't report an event for the exit of an LWP not in
1777feb0 3001 our list, i.e. not part of the current process. This can happen
fd62cb89 3002 if we detach from a program we originally forked and then it
02f3fc28
PA
3003 exits. */
3004 if (!WIFSTOPPED (status) && !lp)
3005 return NULL;
3006
8817a6f2
PA
3007 /* This LWP is stopped now. (And if dead, this prevents it from
3008 ever being continued.) */
3009 lp->stopped = 1;
3010
8784d563
PA
3011 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3012 {
3013 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
de0d863e 3014 int options = linux_nat_ptrace_options (inf->attach_flag);
8784d563 3015
de0d863e 3016 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
8784d563
PA
3017 lp->must_set_ptrace_flags = 0;
3018 }
3019
ca2163eb
PA
3020 /* Handle GNU/Linux's syscall SIGTRAPs. */
3021 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3022 {
3023 /* No longer need the sysgood bit. The ptrace event ends up
3024 recorded in lp->waitstatus if we care for it. We can carry
3025 on handling the event like a regular SIGTRAP from here
3026 on. */
3027 status = W_STOPCODE (SIGTRAP);
3028 if (linux_handle_syscall_trap (lp, 0))
3029 return NULL;
3030 }
bfd09d20
JS
3031 else
3032 {
3033 /* Almost all other ptrace-stops are known to be outside of system
3034 calls, with further exceptions in linux_handle_extended_wait. */
3035 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3036 }
02f3fc28 3037
ca2163eb 3038 /* Handle GNU/Linux's extended waitstatus for trace events. */
89a5711c
DB
3039 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3040 && linux_is_extended_waitstatus (status))
02f3fc28
PA
3041 {
3042 if (debug_linux_nat)
3043 fprintf_unfiltered (gdb_stdlog,
3044 "LLW: Handling extended status 0x%06x\n",
3045 status);
4dd63d48 3046 if (linux_handle_extended_wait (lp, status))
02f3fc28
PA
3047 return NULL;
3048 }
3049
3050 /* Check if the thread has exited. */
9c02b525
PA
3051 if (WIFEXITED (status) || WIFSIGNALED (status))
3052 {
aa01bd36
PA
3053 if (!report_thread_events
3054 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
02f3fc28 3055 {
9c02b525
PA
3056 if (debug_linux_nat)
3057 fprintf_unfiltered (gdb_stdlog,
3058 "LLW: %s exited.\n",
3059 target_pid_to_str (lp->ptid));
3060
4a6ed09b
PA
3061 /* If there is at least one more LWP, then the exit signal
3062 was not the end of the debugged application and should be
3063 ignored. */
3064 exit_lwp (lp);
3065 return NULL;
02f3fc28
PA
3066 }
3067
77598427
PA
3068 /* Note that even if the leader was ptrace-stopped, it can still
3069 exit, if e.g., some other thread brings down the whole
3070 process (calls `exit'). So don't assert that the lwp is
3071 resumed. */
02f3fc28
PA
3072 if (debug_linux_nat)
3073 fprintf_unfiltered (gdb_stdlog,
aa01bd36 3074 "LWP %ld exited (resumed=%d)\n",
77598427 3075 ptid_get_lwp (lp->ptid), lp->resumed);
02f3fc28 3076
9c02b525
PA
3077 /* Dead LWP's aren't expected to reported a pending sigstop. */
3078 lp->signalled = 0;
3079
3080 /* Store the pending event in the waitstatus, because
3081 W_EXITCODE(0,0) == 0. */
3082 store_waitstatus (&lp->waitstatus, status);
3083 return lp;
02f3fc28
PA
3084 }
3085
02f3fc28
PA
3086 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3087 an attempt to stop an LWP. */
3088 if (lp->signalled
3089 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3090 {
02f3fc28
PA
3091 lp->signalled = 0;
3092
2bf6fb9d 3093 if (lp->last_resume_kind == resume_stop)
25289eb2 3094 {
2bf6fb9d
PA
3095 if (debug_linux_nat)
3096 fprintf_unfiltered (gdb_stdlog,
3097 "LLW: resume_stop SIGSTOP caught for %s.\n",
3098 target_pid_to_str (lp->ptid));
3099 }
3100 else
3101 {
3102 /* This is a delayed SIGSTOP. Filter out the event. */
02f3fc28 3103
25289eb2
PA
3104 if (debug_linux_nat)
3105 fprintf_unfiltered (gdb_stdlog,
2bf6fb9d 3106 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
25289eb2
PA
3107 lp->step ?
3108 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3109 target_pid_to_str (lp->ptid));
02f3fc28 3110
2bf6fb9d 3111 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
25289eb2 3112 gdb_assert (lp->resumed);
25289eb2
PA
3113 return NULL;
3114 }
02f3fc28
PA
3115 }
3116
57380f4e
DJ
3117 /* Make sure we don't report a SIGINT that we have already displayed
3118 for another thread. */
3119 if (lp->ignore_sigint
3120 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3121 {
3122 if (debug_linux_nat)
3123 fprintf_unfiltered (gdb_stdlog,
3124 "LLW: Delayed SIGINT caught for %s.\n",
3125 target_pid_to_str (lp->ptid));
3126
3127 /* This is a delayed SIGINT. */
3128 lp->ignore_sigint = 0;
3129
8a99810d 3130 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
57380f4e
DJ
3131 if (debug_linux_nat)
3132 fprintf_unfiltered (gdb_stdlog,
3133 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3134 lp->step ?
3135 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3136 target_pid_to_str (lp->ptid));
57380f4e
DJ
3137 gdb_assert (lp->resumed);
3138
3139 /* Discard the event. */
3140 return NULL;
3141 }
3142
9c02b525
PA
3143 /* Don't report signals that GDB isn't interested in, such as
3144 signals that are neither printed nor stopped upon. Stopping all
3145 threads can be a bit time-consuming so if we want decent
3146 performance with heavily multi-threaded programs, especially when
3147 they're using a high frequency timer, we'd better avoid it if we
3148 can. */
3149 if (WIFSTOPPED (status))
3150 {
3151 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3152
fbea99ea 3153 if (!target_is_non_stop_p ())
9c02b525
PA
3154 {
3155 /* Only do the below in all-stop, as we currently use SIGSTOP
3156 to implement target_stop (see linux_nat_stop) in
3157 non-stop. */
3158 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3159 {
3160 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3161 forwarded to the entire process group, that is, all LWPs
3162 will receive it - unless they're using CLONE_THREAD to
3163 share signals. Since we only want to report it once, we
3164 mark it as ignored for all LWPs except this one. */
3165 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3166 set_ignore_sigint, NULL);
3167 lp->ignore_sigint = 0;
3168 }
3169 else
3170 maybe_clear_ignore_sigint (lp);
3171 }
3172
3173 /* When using hardware single-step, we need to report every signal.
c9587f88
AT
3174 Otherwise, signals in pass_mask may be short-circuited
3175 except signals that might be caused by a breakpoint. */
9c02b525 3176 if (!lp->step
c9587f88
AT
3177 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3178 && !linux_wstatus_maybe_breakpoint (status))
9c02b525
PA
3179 {
3180 linux_resume_one_lwp (lp, lp->step, signo);
3181 if (debug_linux_nat)
3182 fprintf_unfiltered (gdb_stdlog,
3183 "LLW: %s %s, %s (preempt 'handle')\n",
3184 lp->step ?
3185 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3186 target_pid_to_str (lp->ptid),
3187 (signo != GDB_SIGNAL_0
3188 ? strsignal (gdb_signal_to_host (signo))
3189 : "0"));
3190 return NULL;
3191 }
3192 }
3193
02f3fc28
PA
3194 /* An interesting event. */
3195 gdb_assert (lp);
ca2163eb 3196 lp->status = status;
e7ad2f14 3197 save_stop_reason (lp);
02f3fc28
PA
3198 return lp;
3199}
3200
0e5bf2a8
PA
3201/* Detect zombie thread group leaders, and "exit" them. We can't reap
3202 their exits until all other threads in the group have exited. */
3203
3204static void
3205check_zombie_leaders (void)
3206{
3207 struct inferior *inf;
3208
3209 ALL_INFERIORS (inf)
3210 {
3211 struct lwp_info *leader_lp;
3212
3213 if (inf->pid == 0)
3214 continue;
3215
3216 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3217 if (leader_lp != NULL
3218 /* Check if there are other threads in the group, as we may
3219 have raced with the inferior simply exiting. */
3220 && num_lwps (inf->pid) > 1
5f572dec 3221 && linux_proc_pid_is_zombie (inf->pid))
0e5bf2a8
PA
3222 {
3223 if (debug_linux_nat)
3224 fprintf_unfiltered (gdb_stdlog,
3225 "CZL: Thread group leader %d zombie "
3226 "(it exited, or another thread execd).\n",
3227 inf->pid);
3228
3229 /* A leader zombie can mean one of two things:
3230
3231 - It exited, and there's an exit status pending
3232 available, or only the leader exited (not the whole
3233 program). In the latter case, we can't waitpid the
3234 leader's exit status until all other threads are gone.
3235
3236 - There are 3 or more threads in the group, and a thread
4a6ed09b
PA
3237 other than the leader exec'd. See comments on exec
3238 events at the top of the file. We could try
0e5bf2a8
PA
3239 distinguishing the exit and exec cases, by waiting once
3240 more, and seeing if something comes out, but it doesn't
3241 sound useful. The previous leader _does_ go away, and
3242 we'll re-add the new one once we see the exec event
3243 (which is just the same as what would happen if the
3244 previous leader did exit voluntarily before some other
3245 thread execs). */
3246
3247 if (debug_linux_nat)
3248 fprintf_unfiltered (gdb_stdlog,
3249 "CZL: Thread group leader %d vanished.\n",
3250 inf->pid);
3251 exit_lwp (leader_lp);
3252 }
3253 }
3254}
3255
aa01bd36
PA
3256/* Convenience function that is called when the kernel reports an exit
3257 event. This decides whether to report the event to GDB as a
3258 process exit event, a thread exit event, or to suppress the
3259 event. */
3260
3261static ptid_t
3262filter_exit_event (struct lwp_info *event_child,
3263 struct target_waitstatus *ourstatus)
3264{
3265 ptid_t ptid = event_child->ptid;
3266
3267 if (num_lwps (ptid_get_pid (ptid)) > 1)
3268 {
3269 if (report_thread_events)
3270 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3271 else
3272 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3273
3274 exit_lwp (event_child);
3275 }
3276
3277 return ptid;
3278}
3279
d6b0e80f 3280static ptid_t
7feb7d06 3281linux_nat_wait_1 (struct target_ops *ops,
47608cb1
PA
3282 ptid_t ptid, struct target_waitstatus *ourstatus,
3283 int target_options)
d6b0e80f 3284{
fc9b8e47 3285 sigset_t prev_mask;
4b60df3d 3286 enum resume_kind last_resume_kind;
12d9289a 3287 struct lwp_info *lp;
12d9289a 3288 int status;
d6b0e80f 3289
01124a23 3290 if (debug_linux_nat)
b84876c2
PA
3291 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3292
f973ed9c
DJ
3293 /* The first time we get here after starting a new inferior, we may
3294 not have added it to the LWP list yet - this is the earliest
3295 moment at which we know its PID. */
d90e17a7 3296 if (ptid_is_pid (inferior_ptid))
f973ed9c 3297 {
27c9d204
PA
3298 /* Upgrade the main thread's ptid. */
3299 thread_change_ptid (inferior_ptid,
dfd4cc63
LM
3300 ptid_build (ptid_get_pid (inferior_ptid),
3301 ptid_get_pid (inferior_ptid), 0));
27c9d204 3302
26cb8b7c 3303 lp = add_initial_lwp (inferior_ptid);
f973ed9c
DJ
3304 lp->resumed = 1;
3305 }
3306
12696c10 3307 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
7feb7d06 3308 block_child_signals (&prev_mask);
d6b0e80f 3309
d6b0e80f 3310 /* First check if there is a LWP with a wait status pending. */
8a99810d
PA
3311 lp = iterate_over_lwps (ptid, status_callback, NULL);
3312 if (lp != NULL)
d6b0e80f
AC
3313 {
3314 if (debug_linux_nat)
d6b0e80f
AC
3315 fprintf_unfiltered (gdb_stdlog,
3316 "LLW: Using pending wait status %s for %s.\n",
ca2163eb 3317 status_to_str (lp->status),
d6b0e80f 3318 target_pid_to_str (lp->ptid));
d6b0e80f
AC
3319 }
3320
9c02b525
PA
3321 /* But if we don't find a pending event, we'll have to wait. Always
3322 pull all events out of the kernel. We'll randomly select an
3323 event LWP out of all that have events, to prevent starvation. */
7feb7d06 3324
d90e17a7 3325 while (lp == NULL)
d6b0e80f
AC
3326 {
3327 pid_t lwpid;
3328
0e5bf2a8
PA
3329 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3330 quirks:
3331
3332 - If the thread group leader exits while other threads in the
3333 thread group still exist, waitpid(TGID, ...) hangs. That
3334 waitpid won't return an exit status until the other threads
3335 in the group are reapped.
3336
3337 - When a non-leader thread execs, that thread just vanishes
3338 without reporting an exit (so we'd hang if we waited for it
3339 explicitly in that case). The exec event is reported to
3340 the TGID pid. */
3341
3342 errno = 0;
4a6ed09b 3343 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
0e5bf2a8
PA
3344
3345 if (debug_linux_nat)
3346 fprintf_unfiltered (gdb_stdlog,
3347 "LNW: waitpid(-1, ...) returned %d, %s\n",
3348 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
b84876c2 3349
d6b0e80f
AC
3350 if (lwpid > 0)
3351 {
d6b0e80f
AC
3352 if (debug_linux_nat)
3353 {
3354 fprintf_unfiltered (gdb_stdlog,
3355 "LLW: waitpid %ld received %s\n",
3356 (long) lwpid, status_to_str (status));
3357 }
3358
9c02b525 3359 linux_nat_filter_event (lwpid, status);
0e5bf2a8
PA
3360 /* Retry until nothing comes out of waitpid. A single
3361 SIGCHLD can indicate more than one child stopped. */
3362 continue;
d6b0e80f
AC
3363 }
3364
20ba1ce6
PA
3365 /* Now that we've pulled all events out of the kernel, resume
3366 LWPs that don't have an interesting event to report. */
3367 iterate_over_lwps (minus_one_ptid,
3368 resume_stopped_resumed_lwps, &minus_one_ptid);
3369
3370 /* ... and find an LWP with a status to report to the core, if
3371 any. */
9c02b525
PA
3372 lp = iterate_over_lwps (ptid, status_callback, NULL);
3373 if (lp != NULL)
3374 break;
3375
0e5bf2a8
PA
3376 /* Check for zombie thread group leaders. Those can't be reaped
3377 until all other threads in the thread group are. */
3378 check_zombie_leaders ();
d6b0e80f 3379
0e5bf2a8
PA
3380 /* If there are no resumed children left, bail. We'd be stuck
3381 forever in the sigsuspend call below otherwise. */
3382 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3383 {
3384 if (debug_linux_nat)
3385 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
b84876c2 3386
0e5bf2a8 3387 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
b84876c2 3388
0e5bf2a8
PA
3389 restore_child_signals_mask (&prev_mask);
3390 return minus_one_ptid;
d6b0e80f 3391 }
28736962 3392
0e5bf2a8
PA
3393 /* No interesting event to report to the core. */
3394
3395 if (target_options & TARGET_WNOHANG)
3396 {
01124a23 3397 if (debug_linux_nat)
28736962
PA
3398 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3399
0e5bf2a8 3400 ourstatus->kind = TARGET_WAITKIND_IGNORE;
28736962
PA
3401 restore_child_signals_mask (&prev_mask);
3402 return minus_one_ptid;
3403 }
d6b0e80f
AC
3404
3405 /* We shouldn't end up here unless we want to try again. */
d90e17a7 3406 gdb_assert (lp == NULL);
0e5bf2a8
PA
3407
3408 /* Block until we get an event reported with SIGCHLD. */
d36bf488
DE
3409 if (debug_linux_nat)
3410 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
0e5bf2a8 3411 sigsuspend (&suspend_mask);
d6b0e80f
AC
3412 }
3413
d6b0e80f
AC
3414 gdb_assert (lp);
3415
ca2163eb
PA
3416 status = lp->status;
3417 lp->status = 0;
3418
fbea99ea 3419 if (!target_is_non_stop_p ())
4c28f408
PA
3420 {
3421 /* Now stop all other LWP's ... */
d90e17a7 3422 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
4c28f408
PA
3423
3424 /* ... and wait until all of them have reported back that
3425 they're no longer running. */
d90e17a7 3426 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
9c02b525
PA
3427 }
3428
3429 /* If we're not waiting for a specific LWP, choose an event LWP from
3430 among those that have had events. Giving equal priority to all
3431 LWPs that have had events helps prevent starvation. */
3432 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3433 select_event_lwp (ptid, &lp, &status);
3434
3435 gdb_assert (lp != NULL);
3436
3437 /* Now that we've selected our final event LWP, un-adjust its PC if
faf09f01
PA
3438 it was a software breakpoint, and we can't reliably support the
3439 "stopped by software breakpoint" stop reason. */
3440 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3441 && !USE_SIGTRAP_SIGINFO)
9c02b525
PA
3442 {
3443 struct regcache *regcache = get_thread_regcache (lp->ptid);
ac7936df 3444 struct gdbarch *gdbarch = regcache->arch ();
527a273a 3445 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4c28f408 3446
9c02b525
PA
3447 if (decr_pc != 0)
3448 {
3449 CORE_ADDR pc;
d6b0e80f 3450
9c02b525
PA
3451 pc = regcache_read_pc (regcache);
3452 regcache_write_pc (regcache, pc + decr_pc);
3453 }
3454 }
e3e9f5a2 3455
9c02b525
PA
3456 /* We'll need this to determine whether to report a SIGSTOP as
3457 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3458 clears it. */
3459 last_resume_kind = lp->last_resume_kind;
4b60df3d 3460
fbea99ea 3461 if (!target_is_non_stop_p ())
9c02b525 3462 {
e3e9f5a2
PA
3463 /* In all-stop, from the core's perspective, all LWPs are now
3464 stopped until a new resume action is sent over. */
3465 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3466 }
3467 else
25289eb2 3468 {
4b60df3d 3469 resume_clear_callback (lp, NULL);
25289eb2 3470 }
d6b0e80f 3471
26ab7092 3472 if (linux_nat_status_is_event (status))
d6b0e80f 3473 {
d6b0e80f
AC
3474 if (debug_linux_nat)
3475 fprintf_unfiltered (gdb_stdlog,
4fdebdd0
PA
3476 "LLW: trap ptid is %s.\n",
3477 target_pid_to_str (lp->ptid));
d6b0e80f 3478 }
d6b0e80f
AC
3479
3480 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3481 {
3482 *ourstatus = lp->waitstatus;
3483 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3484 }
3485 else
3486 store_waitstatus (ourstatus, status);
3487
01124a23 3488 if (debug_linux_nat)
b84876c2
PA
3489 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3490
7feb7d06 3491 restore_child_signals_mask (&prev_mask);
1e225492 3492
4b60df3d 3493 if (last_resume_kind == resume_stop
25289eb2
PA
3494 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3495 && WSTOPSIG (status) == SIGSTOP)
3496 {
3497 /* A thread that has been requested to stop by GDB with
3498 target_stop, and it stopped cleanly, so report as SIG0. The
3499 use of SIGSTOP is an implementation detail. */
a493e3e2 3500 ourstatus->value.sig = GDB_SIGNAL_0;
25289eb2
PA
3501 }
3502
1e225492
JK
3503 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3504 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3505 lp->core = -1;
3506 else
2e794194 3507 lp->core = linux_common_core_of_thread (lp->ptid);
1e225492 3508
aa01bd36
PA
3509 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3510 return filter_exit_event (lp, ourstatus);
3511
f973ed9c 3512 return lp->ptid;
d6b0e80f
AC
3513}
3514
e3e9f5a2
PA
3515/* Resume LWPs that are currently stopped without any pending status
3516 to report, but are resumed from the core's perspective. */
3517
3518static int
3519resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3520{
9a3c8263 3521 ptid_t *wait_ptid_p = (ptid_t *) data;
e3e9f5a2 3522
4dd63d48
PA
3523 if (!lp->stopped)
3524 {
3525 if (debug_linux_nat)
3526 fprintf_unfiltered (gdb_stdlog,
3527 "RSRL: NOT resuming LWP %s, not stopped\n",
3528 target_pid_to_str (lp->ptid));
3529 }
3530 else if (!lp->resumed)
3531 {
3532 if (debug_linux_nat)
3533 fprintf_unfiltered (gdb_stdlog,
3534 "RSRL: NOT resuming LWP %s, not resumed\n",
3535 target_pid_to_str (lp->ptid));
3536 }
3537 else if (lwp_status_pending_p (lp))
3538 {
3539 if (debug_linux_nat)
3540 fprintf_unfiltered (gdb_stdlog,
3541 "RSRL: NOT resuming LWP %s, has pending status\n",
3542 target_pid_to_str (lp->ptid));
3543 }
3544 else
e3e9f5a2 3545 {
336060f3 3546 struct regcache *regcache = get_thread_regcache (lp->ptid);
ac7936df 3547 struct gdbarch *gdbarch = regcache->arch ();
336060f3 3548
23f238d3 3549 TRY
e3e9f5a2 3550 {
23f238d3
PA
3551 CORE_ADDR pc = regcache_read_pc (regcache);
3552 int leave_stopped = 0;
e3e9f5a2 3553
23f238d3
PA
3554 /* Don't bother if there's a breakpoint at PC that we'd hit
3555 immediately, and we're not waiting for this LWP. */
3556 if (!ptid_match (lp->ptid, *wait_ptid_p))
3557 {
a01bda52 3558 if (breakpoint_inserted_here_p (regcache->aspace (), pc))
23f238d3
PA
3559 leave_stopped = 1;
3560 }
e3e9f5a2 3561
23f238d3
PA
3562 if (!leave_stopped)
3563 {
3564 if (debug_linux_nat)
3565 fprintf_unfiltered (gdb_stdlog,
3566 "RSRL: resuming stopped-resumed LWP %s at "
3567 "%s: step=%d\n",
3568 target_pid_to_str (lp->ptid),
3569 paddress (gdbarch, pc),
3570 lp->step);
3571
3572 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3573 }
3574 }
3575 CATCH (ex, RETURN_MASK_ERROR)
3576 {
3577 if (!check_ptrace_stopped_lwp_gone (lp))
3578 throw_exception (ex);
3579 }
3580 END_CATCH
e3e9f5a2
PA
3581 }
3582
3583 return 0;
3584}
3585
7feb7d06
PA
3586static ptid_t
3587linux_nat_wait (struct target_ops *ops,
47608cb1
PA
3588 ptid_t ptid, struct target_waitstatus *ourstatus,
3589 int target_options)
7feb7d06
PA
3590{
3591 ptid_t event_ptid;
3592
3593 if (debug_linux_nat)
09826ec5
PA
3594 {
3595 char *options_string;
3596
3597 options_string = target_options_to_string (target_options);
3598 fprintf_unfiltered (gdb_stdlog,
3599 "linux_nat_wait: [%s], [%s]\n",
3600 target_pid_to_str (ptid),
3601 options_string);
3602 xfree (options_string);
3603 }
7feb7d06
PA
3604
3605 /* Flush the async file first. */
d9d41e78 3606 if (target_is_async_p ())
7feb7d06
PA
3607 async_file_flush ();
3608
e3e9f5a2
PA
3609 /* Resume LWPs that are currently stopped without any pending status
3610 to report, but are resumed from the core's perspective. LWPs get
3611 in this state if we find them stopping at a time we're not
3612 interested in reporting the event (target_wait on a
3613 specific_process, for example, see linux_nat_wait_1), and
3614 meanwhile the event became uninteresting. Don't bother resuming
3615 LWPs we're not going to wait for if they'd stop immediately. */
fbea99ea 3616 if (target_is_non_stop_p ())
e3e9f5a2
PA
3617 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3618
47608cb1 3619 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
7feb7d06
PA
3620
3621 /* If we requested any event, and something came out, assume there
3622 may be more. If we requested a specific lwp or process, also
3623 assume there may be more. */
d9d41e78 3624 if (target_is_async_p ()
6953d224
PA
3625 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3626 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
7feb7d06
PA
3627 || !ptid_equal (ptid, minus_one_ptid)))
3628 async_file_mark ();
3629
7feb7d06
PA
3630 return event_ptid;
3631}
3632
1d2736d4
PA
3633/* Kill one LWP. */
3634
3635static void
3636kill_one_lwp (pid_t pid)
d6b0e80f 3637{
ed731959
JK
3638 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3639
3640 errno = 0;
1d2736d4 3641 kill_lwp (pid, SIGKILL);
ed731959 3642 if (debug_linux_nat)
57745c90
PA
3643 {
3644 int save_errno = errno;
3645
3646 fprintf_unfiltered (gdb_stdlog,
1d2736d4 3647 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
57745c90
PA
3648 save_errno ? safe_strerror (save_errno) : "OK");
3649 }
ed731959
JK
3650
3651 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3652
d6b0e80f 3653 errno = 0;
1d2736d4 3654 ptrace (PTRACE_KILL, pid, 0, 0);
d6b0e80f 3655 if (debug_linux_nat)
57745c90
PA
3656 {
3657 int save_errno = errno;
3658
3659 fprintf_unfiltered (gdb_stdlog,
1d2736d4 3660 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
57745c90
PA
3661 save_errno ? safe_strerror (save_errno) : "OK");
3662 }
d6b0e80f
AC
3663}
3664
1d2736d4
PA
3665/* Wait for an LWP to die. */
3666
3667static void
3668kill_wait_one_lwp (pid_t pid)
d6b0e80f 3669{
1d2736d4 3670 pid_t res;
d6b0e80f
AC
3671
3672 /* We must make sure that there are no pending events (delayed
3673 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3674 program doesn't interfere with any following debugging session. */
3675
d6b0e80f
AC
3676 do
3677 {
1d2736d4
PA
3678 res = my_waitpid (pid, NULL, __WALL);
3679 if (res != (pid_t) -1)
d6b0e80f 3680 {
e85a822c
DJ
3681 if (debug_linux_nat)
3682 fprintf_unfiltered (gdb_stdlog,
1d2736d4
PA
3683 "KWC: wait %ld received unknown.\n",
3684 (long) pid);
4a6ed09b
PA
3685 /* The Linux kernel sometimes fails to kill a thread
3686 completely after PTRACE_KILL; that goes from the stop
3687 point in do_fork out to the one in get_signal_to_deliver
3688 and waits again. So kill it again. */
1d2736d4 3689 kill_one_lwp (pid);
d6b0e80f
AC
3690 }
3691 }
1d2736d4
PA
3692 while (res == pid);
3693
3694 gdb_assert (res == -1 && errno == ECHILD);
3695}
3696
3697/* Callback for iterate_over_lwps. */
d6b0e80f 3698
1d2736d4
PA
3699static int
3700kill_callback (struct lwp_info *lp, void *data)
3701{
3702 kill_one_lwp (ptid_get_lwp (lp->ptid));
d6b0e80f
AC
3703 return 0;
3704}
3705
1d2736d4
PA
3706/* Callback for iterate_over_lwps. */
3707
3708static int
3709kill_wait_callback (struct lwp_info *lp, void *data)
3710{
3711 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3712 return 0;
3713}
3714
3715/* Kill the fork children of any threads of inferior INF that are
3716 stopped at a fork event. */
3717
3718static void
3719kill_unfollowed_fork_children (struct inferior *inf)
3720{
3721 struct thread_info *thread;
3722
3723 ALL_NON_EXITED_THREADS (thread)
3724 if (thread->inf == inf)
3725 {
3726 struct target_waitstatus *ws = &thread->pending_follow;
3727
3728 if (ws->kind == TARGET_WAITKIND_FORKED
3729 || ws->kind == TARGET_WAITKIND_VFORKED)
3730 {
3731 ptid_t child_ptid = ws->value.related_pid;
3732 int child_pid = ptid_get_pid (child_ptid);
3733 int child_lwp = ptid_get_lwp (child_ptid);
1d2736d4
PA
3734
3735 kill_one_lwp (child_lwp);
3736 kill_wait_one_lwp (child_lwp);
3737
3738 /* Let the arch-specific native code know this process is
3739 gone. */
3740 linux_nat_forget_process (child_pid);
3741 }
3742 }
3743}
3744
d6b0e80f 3745static void
7d85a9c0 3746linux_nat_kill (struct target_ops *ops)
d6b0e80f 3747{
f973ed9c
DJ
3748 /* If we're stopped while forking and we haven't followed yet,
3749 kill the other task. We need to do this first because the
3750 parent will be sleeping if this is a vfork. */
1d2736d4 3751 kill_unfollowed_fork_children (current_inferior ());
f973ed9c
DJ
3752
3753 if (forks_exist_p ())
7feb7d06 3754 linux_fork_killall ();
f973ed9c
DJ
3755 else
3756 {
d90e17a7 3757 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
e0881a8e 3758
4c28f408
PA
3759 /* Stop all threads before killing them, since ptrace requires
3760 that the thread is stopped to sucessfully PTRACE_KILL. */
d90e17a7 3761 iterate_over_lwps (ptid, stop_callback, NULL);
4c28f408
PA
3762 /* ... and wait until all of them have reported back that
3763 they're no longer running. */
d90e17a7 3764 iterate_over_lwps (ptid, stop_wait_callback, NULL);
4c28f408 3765
f973ed9c 3766 /* Kill all LWP's ... */
d90e17a7 3767 iterate_over_lwps (ptid, kill_callback, NULL);
f973ed9c
DJ
3768
3769 /* ... and wait until we've flushed all events. */
d90e17a7 3770 iterate_over_lwps (ptid, kill_wait_callback, NULL);
f973ed9c
DJ
3771 }
3772
bc1e6c81 3773 target_mourn_inferior (inferior_ptid);
d6b0e80f
AC
3774}
3775
3776static void
136d6dae 3777linux_nat_mourn_inferior (struct target_ops *ops)
d6b0e80f 3778{
26cb8b7c
PA
3779 int pid = ptid_get_pid (inferior_ptid);
3780
3781 purge_lwp_list (pid);
d6b0e80f 3782
f973ed9c 3783 if (! forks_exist_p ())
d90e17a7
PA
3784 /* Normal case, no other forks available. */
3785 linux_ops->to_mourn_inferior (ops);
f973ed9c
DJ
3786 else
3787 /* Multi-fork case. The current inferior_ptid has exited, but
3788 there are other viable forks to debug. Delete the exiting
3789 one and context-switch to the first available. */
3790 linux_fork_mourn_inferior ();
26cb8b7c
PA
3791
3792 /* Let the arch-specific native code know this process is gone. */
3793 linux_nat_forget_process (pid);
d6b0e80f
AC
3794}
3795
5b009018
PA
3796/* Convert a native/host siginfo object, into/from the siginfo in the
3797 layout of the inferiors' architecture. */
3798
3799static void
a5362b9a 3800siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
5b009018
PA
3801{
3802 int done = 0;
3803
3804 if (linux_nat_siginfo_fixup != NULL)
3805 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3806
3807 /* If there was no callback, or the callback didn't do anything,
3808 then just do a straight memcpy. */
3809 if (!done)
3810 {
3811 if (direction == 1)
a5362b9a 3812 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
5b009018 3813 else
a5362b9a 3814 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
5b009018
PA
3815 }
3816}
3817
9b409511 3818static enum target_xfer_status
4aa995e1
PA
3819linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3820 const char *annex, gdb_byte *readbuf,
9b409511
YQ
3821 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3822 ULONGEST *xfered_len)
4aa995e1 3823{
4aa995e1 3824 int pid;
a5362b9a
TS
3825 siginfo_t siginfo;
3826 gdb_byte inf_siginfo[sizeof (siginfo_t)];
4aa995e1
PA
3827
3828 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3829 gdb_assert (readbuf || writebuf);
3830
dfd4cc63 3831 pid = ptid_get_lwp (inferior_ptid);
4aa995e1 3832 if (pid == 0)
dfd4cc63 3833 pid = ptid_get_pid (inferior_ptid);
4aa995e1
PA
3834
3835 if (offset > sizeof (siginfo))
2ed4b548 3836 return TARGET_XFER_E_IO;
4aa995e1
PA
3837
3838 errno = 0;
3839 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3840 if (errno != 0)
2ed4b548 3841 return TARGET_XFER_E_IO;
4aa995e1 3842
5b009018
PA
3843 /* When GDB is built as a 64-bit application, ptrace writes into
3844 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3845 inferior with a 64-bit GDB should look the same as debugging it
3846 with a 32-bit GDB, we need to convert it. GDB core always sees
3847 the converted layout, so any read/write will have to be done
3848 post-conversion. */
3849 siginfo_fixup (&siginfo, inf_siginfo, 0);
3850
4aa995e1
PA
3851 if (offset + len > sizeof (siginfo))
3852 len = sizeof (siginfo) - offset;
3853
3854 if (readbuf != NULL)
5b009018 3855 memcpy (readbuf, inf_siginfo + offset, len);
4aa995e1
PA
3856 else
3857 {
5b009018
PA
3858 memcpy (inf_siginfo + offset, writebuf, len);
3859
3860 /* Convert back to ptrace layout before flushing it out. */
3861 siginfo_fixup (&siginfo, inf_siginfo, 1);
3862
4aa995e1
PA
3863 errno = 0;
3864 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3865 if (errno != 0)
2ed4b548 3866 return TARGET_XFER_E_IO;
4aa995e1
PA
3867 }
3868
9b409511
YQ
3869 *xfered_len = len;
3870 return TARGET_XFER_OK;
4aa995e1
PA
3871}
3872
9b409511 3873static enum target_xfer_status
10d6c8cd
DJ
3874linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3875 const char *annex, gdb_byte *readbuf,
3876 const gdb_byte *writebuf,
9b409511 3877 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
d6b0e80f 3878{
9b409511 3879 enum target_xfer_status xfer;
d6b0e80f 3880
4aa995e1
PA
3881 if (object == TARGET_OBJECT_SIGNAL_INFO)
3882 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
9b409511 3883 offset, len, xfered_len);
4aa995e1 3884
c35b1492
PA
3885 /* The target is connected but no live inferior is selected. Pass
3886 this request down to a lower stratum (e.g., the executable
3887 file). */
3888 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
9b409511 3889 return TARGET_XFER_EOF;
c35b1492 3890
10d6c8cd 3891 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
9b409511 3892 offset, len, xfered_len);
d6b0e80f 3893
d6b0e80f
AC
3894 return xfer;
3895}
3896
28439f5e
PA
3897static int
3898linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3899{
4a6ed09b
PA
3900 /* As long as a PTID is in lwp list, consider it alive. */
3901 return find_lwp_pid (ptid) != NULL;
28439f5e
PA
3902}
3903
8a06aea7
PA
3904/* Implement the to_update_thread_list target method for this
3905 target. */
3906
3907static void
3908linux_nat_update_thread_list (struct target_ops *ops)
3909{
a6904d5a
PA
3910 struct lwp_info *lwp;
3911
4a6ed09b
PA
3912 /* We add/delete threads from the list as clone/exit events are
3913 processed, so just try deleting exited threads still in the
3914 thread list. */
3915 delete_exited_threads ();
a6904d5a
PA
3916
3917 /* Update the processor core that each lwp/thread was last seen
3918 running on. */
3919 ALL_LWPS (lwp)
1ad3de98
PA
3920 {
3921 /* Avoid accessing /proc if the thread hasn't run since we last
3922 time we fetched the thread's core. Accessing /proc becomes
3923 noticeably expensive when we have thousands of LWPs. */
3924 if (lwp->core == -1)
3925 lwp->core = linux_common_core_of_thread (lwp->ptid);
3926 }
8a06aea7
PA
3927}
3928
7a114964 3929static const char *
117de6a9 3930linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
d6b0e80f
AC
3931{
3932 static char buf[64];
3933
dfd4cc63
LM
3934 if (ptid_lwp_p (ptid)
3935 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3936 || num_lwps (ptid_get_pid (ptid)) > 1))
d6b0e80f 3937 {
dfd4cc63 3938 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
d6b0e80f
AC
3939 return buf;
3940 }
3941
3942 return normal_pid_to_str (ptid);
3943}
3944
73ede765 3945static const char *
503a628d 3946linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
4694da01 3947{
79efa585 3948 return linux_proc_tid_get_name (thr->ptid);
4694da01
TT
3949}
3950
dba24537
AC
3951/* Accepts an integer PID; Returns a string representing a file that
3952 can be opened to get the symbols for the child process. */
3953
6d8fd2b7 3954static char *
8dd27370 3955linux_child_pid_to_exec_file (struct target_ops *self, int pid)
dba24537 3956{
e0d86d2c 3957 return linux_proc_pid_to_exec_file (pid);
dba24537
AC
3958}
3959
a379284a
AA
3960/* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3961 Because we can use a single read/write call, this can be much more
3962 efficient than banging away at PTRACE_PEEKTEXT. */
10d6c8cd 3963
9b409511 3964static enum target_xfer_status
10d6c8cd
DJ
3965linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3966 const char *annex, gdb_byte *readbuf,
3967 const gdb_byte *writebuf,
9b409511 3968 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
dba24537 3969{
10d6c8cd
DJ
3970 LONGEST ret;
3971 int fd;
dba24537
AC
3972 char filename[64];
3973
a379284a 3974 if (object != TARGET_OBJECT_MEMORY)
f486487f 3975 return TARGET_XFER_EOF;
dba24537
AC
3976
3977 /* Don't bother for one word. */
3978 if (len < 3 * sizeof (long))
9b409511 3979 return TARGET_XFER_EOF;
dba24537
AC
3980
3981 /* We could keep this file open and cache it - possibly one per
3982 thread. That requires some juggling, but is even faster. */
b67aeab0
SM
3983 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3984 ptid_get_lwp (inferior_ptid));
a379284a
AA
3985 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
3986 | O_LARGEFILE), 0);
dba24537 3987 if (fd == -1)
9b409511 3988 return TARGET_XFER_EOF;
dba24537 3989
a379284a
AA
3990 /* Use pread64/pwrite64 if available, since they save a syscall and can
3991 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
3992 debugging a SPARC64 application). */
dba24537 3993#ifdef HAVE_PREAD64
a379284a
AA
3994 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
3995 : pwrite64 (fd, writebuf, len, offset));
dba24537 3996#else
a379284a
AA
3997 ret = lseek (fd, offset, SEEK_SET);
3998 if (ret != -1)
3999 ret = (readbuf ? read (fd, readbuf, len)
4000 : write (fd, writebuf, len));
dba24537 4001#endif
dba24537
AC
4002
4003 close (fd);
9b409511 4004
a379284a 4005 if (ret == -1 || ret == 0)
9b409511
YQ
4006 return TARGET_XFER_EOF;
4007 else
4008 {
4009 *xfered_len = ret;
4010 return TARGET_XFER_OK;
4011 }
dba24537
AC
4012}
4013
efcbbd14
UW
4014
4015/* Enumerate spufs IDs for process PID. */
4016static LONGEST
b55e14c7 4017spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
efcbbd14 4018{
f5656ead 4019 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
efcbbd14
UW
4020 LONGEST pos = 0;
4021 LONGEST written = 0;
4022 char path[128];
4023 DIR *dir;
4024 struct dirent *entry;
4025
4026 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4027 dir = opendir (path);
4028 if (!dir)
4029 return -1;
4030
4031 rewinddir (dir);
4032 while ((entry = readdir (dir)) != NULL)
4033 {
4034 struct stat st;
4035 struct statfs stfs;
4036 int fd;
4037
4038 fd = atoi (entry->d_name);
4039 if (!fd)
4040 continue;
4041
4042 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4043 if (stat (path, &st) != 0)
4044 continue;
4045 if (!S_ISDIR (st.st_mode))
4046 continue;
4047
4048 if (statfs (path, &stfs) != 0)
4049 continue;
4050 if (stfs.f_type != SPUFS_MAGIC)
4051 continue;
4052
4053 if (pos >= offset && pos + 4 <= offset + len)
4054 {
4055 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4056 written += 4;
4057 }
4058 pos += 4;
4059 }
4060
4061 closedir (dir);
4062 return written;
4063}
4064
4065/* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4066 object type, using the /proc file system. */
9b409511
YQ
4067
4068static enum target_xfer_status
efcbbd14
UW
4069linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4070 const char *annex, gdb_byte *readbuf,
4071 const gdb_byte *writebuf,
9b409511 4072 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
efcbbd14
UW
4073{
4074 char buf[128];
4075 int fd = 0;
4076 int ret = -1;
b67aeab0 4077 int pid = ptid_get_lwp (inferior_ptid);
efcbbd14
UW
4078
4079 if (!annex)
4080 {
4081 if (!readbuf)
2ed4b548 4082 return TARGET_XFER_E_IO;
efcbbd14 4083 else
9b409511
YQ
4084 {
4085 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4086
4087 if (l < 0)
4088 return TARGET_XFER_E_IO;
4089 else if (l == 0)
4090 return TARGET_XFER_EOF;
4091 else
4092 {
4093 *xfered_len = (ULONGEST) l;
4094 return TARGET_XFER_OK;
4095 }
4096 }
efcbbd14
UW
4097 }
4098
4099 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
614c279d 4100 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
efcbbd14 4101 if (fd <= 0)
2ed4b548 4102 return TARGET_XFER_E_IO;
efcbbd14
UW
4103
4104 if (offset != 0
4105 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4106 {
4107 close (fd);
9b409511 4108 return TARGET_XFER_EOF;
efcbbd14
UW
4109 }
4110
4111 if (writebuf)
4112 ret = write (fd, writebuf, (size_t) len);
4113 else if (readbuf)
4114 ret = read (fd, readbuf, (size_t) len);
4115
4116 close (fd);
9b409511
YQ
4117
4118 if (ret < 0)
4119 return TARGET_XFER_E_IO;
4120 else if (ret == 0)
4121 return TARGET_XFER_EOF;
4122 else
4123 {
4124 *xfered_len = (ULONGEST) ret;
4125 return TARGET_XFER_OK;
4126 }
efcbbd14
UW
4127}
4128
4129
dba24537
AC
4130/* Parse LINE as a signal set and add its set bits to SIGS. */
4131
4132static void
4133add_line_to_sigset (const char *line, sigset_t *sigs)
4134{
4135 int len = strlen (line) - 1;
4136 const char *p;
4137 int signum;
4138
4139 if (line[len] != '\n')
8a3fe4f8 4140 error (_("Could not parse signal set: %s"), line);
dba24537
AC
4141
4142 p = line;
4143 signum = len * 4;
4144 while (len-- > 0)
4145 {
4146 int digit;
4147
4148 if (*p >= '0' && *p <= '9')
4149 digit = *p - '0';
4150 else if (*p >= 'a' && *p <= 'f')
4151 digit = *p - 'a' + 10;
4152 else
8a3fe4f8 4153 error (_("Could not parse signal set: %s"), line);
dba24537
AC
4154
4155 signum -= 4;
4156
4157 if (digit & 1)
4158 sigaddset (sigs, signum + 1);
4159 if (digit & 2)
4160 sigaddset (sigs, signum + 2);
4161 if (digit & 4)
4162 sigaddset (sigs, signum + 3);
4163 if (digit & 8)
4164 sigaddset (sigs, signum + 4);
4165
4166 p++;
4167 }
4168}
4169
4170/* Find process PID's pending signals from /proc/pid/status and set
4171 SIGS to match. */
4172
4173void
3e43a32a
MS
4174linux_proc_pending_signals (int pid, sigset_t *pending,
4175 sigset_t *blocked, sigset_t *ignored)
dba24537 4176{
d8d2a3ee 4177 char buffer[PATH_MAX], fname[PATH_MAX];
dba24537
AC
4178
4179 sigemptyset (pending);
4180 sigemptyset (blocked);
4181 sigemptyset (ignored);
cde33bf1 4182 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
d419f42d 4183 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
dba24537 4184 if (procfile == NULL)
8a3fe4f8 4185 error (_("Could not open %s"), fname);
dba24537 4186
d419f42d 4187 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
dba24537
AC
4188 {
4189 /* Normal queued signals are on the SigPnd line in the status
4190 file. However, 2.6 kernels also have a "shared" pending
4191 queue for delivering signals to a thread group, so check for
4192 a ShdPnd line also.
4193
4194 Unfortunately some Red Hat kernels include the shared pending
4195 queue but not the ShdPnd status field. */
4196
61012eef 4197 if (startswith (buffer, "SigPnd:\t"))
dba24537 4198 add_line_to_sigset (buffer + 8, pending);
61012eef 4199 else if (startswith (buffer, "ShdPnd:\t"))
dba24537 4200 add_line_to_sigset (buffer + 8, pending);
61012eef 4201 else if (startswith (buffer, "SigBlk:\t"))
dba24537 4202 add_line_to_sigset (buffer + 8, blocked);
61012eef 4203 else if (startswith (buffer, "SigIgn:\t"))
dba24537
AC
4204 add_line_to_sigset (buffer + 8, ignored);
4205 }
dba24537
AC
4206}
4207
9b409511 4208static enum target_xfer_status
07e059b5 4209linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
e0881a8e 4210 const char *annex, gdb_byte *readbuf,
9b409511
YQ
4211 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4212 ULONGEST *xfered_len)
07e059b5 4213{
07e059b5
VP
4214 gdb_assert (object == TARGET_OBJECT_OSDATA);
4215
9b409511
YQ
4216 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4217 if (*xfered_len == 0)
4218 return TARGET_XFER_EOF;
4219 else
4220 return TARGET_XFER_OK;
07e059b5
VP
4221}
4222
9b409511 4223static enum target_xfer_status
10d6c8cd
DJ
4224linux_xfer_partial (struct target_ops *ops, enum target_object object,
4225 const char *annex, gdb_byte *readbuf,
9b409511
YQ
4226 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4227 ULONGEST *xfered_len)
10d6c8cd 4228{
9b409511 4229 enum target_xfer_status xfer;
10d6c8cd
DJ
4230
4231 if (object == TARGET_OBJECT_AUXV)
9f2982ff 4232 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
9b409511 4233 offset, len, xfered_len);
10d6c8cd 4234
07e059b5
VP
4235 if (object == TARGET_OBJECT_OSDATA)
4236 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
9b409511 4237 offset, len, xfered_len);
07e059b5 4238
efcbbd14
UW
4239 if (object == TARGET_OBJECT_SPU)
4240 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
9b409511 4241 offset, len, xfered_len);
efcbbd14 4242
8f313923
JK
4243 /* GDB calculates all the addresses in possibly larget width of the address.
4244 Address width needs to be masked before its final use - either by
4245 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4246
4247 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4248
4249 if (object == TARGET_OBJECT_MEMORY)
4250 {
f5656ead 4251 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
8f313923
JK
4252
4253 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4254 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4255 }
4256
10d6c8cd 4257 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
9b409511
YQ
4258 offset, len, xfered_len);
4259 if (xfer != TARGET_XFER_EOF)
10d6c8cd
DJ
4260 return xfer;
4261
4262 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
9b409511 4263 offset, len, xfered_len);
10d6c8cd
DJ
4264}
4265
5808517f
YQ
4266static void
4267cleanup_target_stop (void *arg)
4268{
4269 ptid_t *ptid = (ptid_t *) arg;
4270
4271 gdb_assert (arg != NULL);
4272
4273 /* Unpause all */
049a8570 4274 target_continue_no_signal (*ptid);
5808517f
YQ
4275}
4276
4277static VEC(static_tracepoint_marker_p) *
c686c57f
TT
4278linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4279 const char *strid)
5808517f
YQ
4280{
4281 char s[IPA_CMD_BUF_SIZE];
4282 struct cleanup *old_chain;
4283 int pid = ptid_get_pid (inferior_ptid);
4284 VEC(static_tracepoint_marker_p) *markers = NULL;
4285 struct static_tracepoint_marker *marker = NULL;
256642e8 4286 const char *p = s;
5808517f
YQ
4287 ptid_t ptid = ptid_build (pid, 0, 0);
4288
4289 /* Pause all */
4290 target_stop (ptid);
4291
4292 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4293 s[sizeof ("qTfSTM")] = 0;
4294
42476b70 4295 agent_run_command (pid, s, strlen (s) + 1);
5808517f
YQ
4296
4297 old_chain = make_cleanup (free_current_marker, &marker);
4298 make_cleanup (cleanup_target_stop, &ptid);
4299
4300 while (*p++ == 'm')
4301 {
4302 if (marker == NULL)
4303 marker = XCNEW (struct static_tracepoint_marker);
4304
4305 do
4306 {
4307 parse_static_tracepoint_marker_definition (p, &p, marker);
4308
4309 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4310 {
4311 VEC_safe_push (static_tracepoint_marker_p,
4312 markers, marker);
4313 marker = NULL;
4314 }
4315 else
4316 {
4317 release_static_tracepoint_marker (marker);
4318 memset (marker, 0, sizeof (*marker));
4319 }
4320 }
4321 while (*p++ == ','); /* comma-separated list */
4322
4323 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4324 s[sizeof ("qTsSTM")] = 0;
42476b70 4325 agent_run_command (pid, s, strlen (s) + 1);
5808517f
YQ
4326 p = s;
4327 }
4328
4329 do_cleanups (old_chain);
4330
4331 return markers;
4332}
4333
e9efe249 4334/* Create a prototype generic GNU/Linux target. The client can override
10d6c8cd
DJ
4335 it with local methods. */
4336
910122bf
UW
4337static void
4338linux_target_install_ops (struct target_ops *t)
10d6c8cd 4339{
6d8fd2b7 4340 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
eb73ad13 4341 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
6d8fd2b7 4342 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
eb73ad13 4343 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
6d8fd2b7 4344 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
eb73ad13 4345 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
a96d9b2e 4346 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
6d8fd2b7 4347 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
10d6c8cd 4348 t->to_post_startup_inferior = linux_child_post_startup_inferior;
6d8fd2b7
UW
4349 t->to_post_attach = linux_child_post_attach;
4350 t->to_follow_fork = linux_child_follow_fork;
10d6c8cd
DJ
4351
4352 super_xfer_partial = t->to_xfer_partial;
4353 t->to_xfer_partial = linux_xfer_partial;
5808517f
YQ
4354
4355 t->to_static_tracepoint_markers_by_strid
4356 = linux_child_static_tracepoint_markers_by_strid;
910122bf
UW
4357}
4358
4359struct target_ops *
4360linux_target (void)
4361{
4362 struct target_ops *t;
4363
4364 t = inf_ptrace_target ();
4365 linux_target_install_ops (t);
4366
4367 return t;
4368}
4369
4370struct target_ops *
7714d83a 4371linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
910122bf
UW
4372{
4373 struct target_ops *t;
4374
4375 t = inf_ptrace_trad_target (register_u_offset);
4376 linux_target_install_ops (t);
10d6c8cd 4377
10d6c8cd
DJ
4378 return t;
4379}
4380
b84876c2
PA
4381/* target_is_async_p implementation. */
4382
4383static int
6a109b6b 4384linux_nat_is_async_p (struct target_ops *ops)
b84876c2 4385{
198297aa 4386 return linux_is_async_p ();
b84876c2
PA
4387}
4388
4389/* target_can_async_p implementation. */
4390
4391static int
6a109b6b 4392linux_nat_can_async_p (struct target_ops *ops)
b84876c2 4393{
fde1b17d
SM
4394 /* We're always async, unless the user explicitly prevented it with the
4395 "maint set target-async" command. */
3dd5b83d 4396 return target_async_permitted;
b84876c2
PA
4397}
4398
9908b566 4399static int
2a9a2795 4400linux_nat_supports_non_stop (struct target_ops *self)
9908b566
VP
4401{
4402 return 1;
4403}
4404
fbea99ea
PA
4405/* to_always_non_stop_p implementation. */
4406
4407static int
4408linux_nat_always_non_stop_p (struct target_ops *self)
4409{
f12899e9 4410 return 1;
fbea99ea
PA
4411}
4412
d90e17a7
PA
4413/* True if we want to support multi-process. To be removed when GDB
4414 supports multi-exec. */
4415
2277426b 4416int linux_multi_process = 1;
d90e17a7
PA
4417
4418static int
86ce2668 4419linux_nat_supports_multi_process (struct target_ops *self)
d90e17a7
PA
4420{
4421 return linux_multi_process;
4422}
4423
03583c20 4424static int
2bfc0540 4425linux_nat_supports_disable_randomization (struct target_ops *self)
03583c20
UW
4426{
4427#ifdef HAVE_PERSONALITY
4428 return 1;
4429#else
4430 return 0;
4431#endif
4432}
4433
b84876c2
PA
4434static int async_terminal_is_ours = 1;
4435
4d4ca2a1
DE
4436/* target_terminal_inferior implementation.
4437
4438 This is a wrapper around child_terminal_inferior to add async support. */
b84876c2
PA
4439
4440static void
d2f640d4 4441linux_nat_terminal_inferior (struct target_ops *self)
b84876c2 4442{
d6b64346 4443 child_terminal_inferior (self);
b84876c2 4444
d9d2d8b6 4445 /* Calls to target_terminal_*() are meant to be idempotent. */
b84876c2
PA
4446 if (!async_terminal_is_ours)
4447 return;
4448
b84876c2
PA
4449 async_terminal_is_ours = 0;
4450 set_sigint_trap ();
4451}
4452
223ffa71 4453/* target_terminal::ours implementation.
4d4ca2a1
DE
4454
4455 This is a wrapper around child_terminal_ours to add async support (and
223ffa71 4456 implement the target_terminal::ours vs target_terminal::ours_for_output
4d4ca2a1
DE
4457 distinction). child_terminal_ours is currently no different than
4458 child_terminal_ours_for_output.
223ffa71 4459 We leave target_terminal::ours_for_output alone, leaving it to
4d4ca2a1 4460 child_terminal_ours_for_output. */
b84876c2 4461
2c0b251b 4462static void
e3594fd1 4463linux_nat_terminal_ours (struct target_ops *self)
b84876c2 4464{
b84876c2
PA
4465 /* GDB should never give the terminal to the inferior if the
4466 inferior is running in the background (run&, continue&, etc.),
4467 but claiming it sure should. */
d6b64346 4468 child_terminal_ours (self);
b84876c2 4469
b84876c2
PA
4470 if (async_terminal_is_ours)
4471 return;
4472
4473 clear_sigint_trap ();
b84876c2
PA
4474 async_terminal_is_ours = 1;
4475}
4476
7feb7d06
PA
4477/* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4478 so we notice when any child changes state, and notify the
4479 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4480 above to wait for the arrival of a SIGCHLD. */
4481
b84876c2 4482static void
7feb7d06 4483sigchld_handler (int signo)
b84876c2 4484{
7feb7d06
PA
4485 int old_errno = errno;
4486
01124a23
DE
4487 if (debug_linux_nat)
4488 ui_file_write_async_safe (gdb_stdlog,
4489 "sigchld\n", sizeof ("sigchld\n") - 1);
7feb7d06
PA
4490
4491 if (signo == SIGCHLD
4492 && linux_nat_event_pipe[0] != -1)
4493 async_file_mark (); /* Let the event loop know that there are
4494 events to handle. */
4495
4496 errno = old_errno;
4497}
4498
4499/* Callback registered with the target events file descriptor. */
4500
4501static void
4502handle_target_event (int error, gdb_client_data client_data)
4503{
6a3753b3 4504 inferior_event_handler (INF_REG_EVENT, NULL);
7feb7d06
PA
4505}
4506
4507/* Create/destroy the target events pipe. Returns previous state. */
4508
4509static int
4510linux_async_pipe (int enable)
4511{
198297aa 4512 int previous = linux_is_async_p ();
7feb7d06
PA
4513
4514 if (previous != enable)
4515 {
4516 sigset_t prev_mask;
4517
12696c10
PA
4518 /* Block child signals while we create/destroy the pipe, as
4519 their handler writes to it. */
7feb7d06
PA
4520 block_child_signals (&prev_mask);
4521
4522 if (enable)
4523 {
614c279d 4524 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
7feb7d06
PA
4525 internal_error (__FILE__, __LINE__,
4526 "creating event pipe failed.");
4527
4528 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4529 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4530 }
4531 else
4532 {
4533 close (linux_nat_event_pipe[0]);
4534 close (linux_nat_event_pipe[1]);
4535 linux_nat_event_pipe[0] = -1;
4536 linux_nat_event_pipe[1] = -1;
4537 }
4538
4539 restore_child_signals_mask (&prev_mask);
4540 }
4541
4542 return previous;
b84876c2
PA
4543}
4544
4545/* target_async implementation. */
4546
4547static void
6a3753b3 4548linux_nat_async (struct target_ops *ops, int enable)
b84876c2 4549{
6a3753b3 4550 if (enable)
b84876c2 4551 {
7feb7d06
PA
4552 if (!linux_async_pipe (1))
4553 {
4554 add_file_handler (linux_nat_event_pipe[0],
4555 handle_target_event, NULL);
4556 /* There may be pending events to handle. Tell the event loop
4557 to poll them. */
4558 async_file_mark ();
4559 }
b84876c2
PA
4560 }
4561 else
4562 {
b84876c2 4563 delete_file_handler (linux_nat_event_pipe[0]);
7feb7d06 4564 linux_async_pipe (0);
b84876c2
PA
4565 }
4566 return;
4567}
4568
a493e3e2 4569/* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
252fbfc8
PA
4570 event came out. */
4571
4c28f408 4572static int
252fbfc8 4573linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4c28f408 4574{
d90e17a7 4575 if (!lwp->stopped)
252fbfc8 4576 {
d90e17a7
PA
4577 if (debug_linux_nat)
4578 fprintf_unfiltered (gdb_stdlog,
4579 "LNSL: running -> suspending %s\n",
4580 target_pid_to_str (lwp->ptid));
252fbfc8 4581
252fbfc8 4582
25289eb2
PA
4583 if (lwp->last_resume_kind == resume_stop)
4584 {
4585 if (debug_linux_nat)
4586 fprintf_unfiltered (gdb_stdlog,
4587 "linux-nat: already stopping LWP %ld at "
4588 "GDB's request\n",
4589 ptid_get_lwp (lwp->ptid));
4590 return 0;
4591 }
252fbfc8 4592
25289eb2
PA
4593 stop_callback (lwp, NULL);
4594 lwp->last_resume_kind = resume_stop;
d90e17a7
PA
4595 }
4596 else
4597 {
4598 /* Already known to be stopped; do nothing. */
252fbfc8 4599
d90e17a7
PA
4600 if (debug_linux_nat)
4601 {
e09875d4 4602 if (find_thread_ptid (lwp->ptid)->stop_requested)
3e43a32a
MS
4603 fprintf_unfiltered (gdb_stdlog,
4604 "LNSL: already stopped/stop_requested %s\n",
d90e17a7
PA
4605 target_pid_to_str (lwp->ptid));
4606 else
3e43a32a
MS
4607 fprintf_unfiltered (gdb_stdlog,
4608 "LNSL: already stopped/no "
4609 "stop_requested yet %s\n",
d90e17a7 4610 target_pid_to_str (lwp->ptid));
252fbfc8
PA
4611 }
4612 }
4c28f408
PA
4613 return 0;
4614}
4615
4616static void
1eab8a48 4617linux_nat_stop (struct target_ops *self, ptid_t ptid)
4c28f408 4618{
bfedc46a
PA
4619 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4620}
4621
d90e17a7 4622static void
de90e03d 4623linux_nat_close (struct target_ops *self)
d90e17a7
PA
4624{
4625 /* Unregister from the event loop. */
9debeba0 4626 if (linux_nat_is_async_p (self))
6a3753b3 4627 linux_nat_async (self, 0);
d90e17a7 4628
d90e17a7 4629 if (linux_ops->to_close)
de90e03d 4630 linux_ops->to_close (linux_ops);
6a3cb8e8
PA
4631
4632 super_close (self);
d90e17a7
PA
4633}
4634
c0694254
PA
4635/* When requests are passed down from the linux-nat layer to the
4636 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4637 used. The address space pointer is stored in the inferior object,
4638 but the common code that is passed such ptid can't tell whether
4639 lwpid is a "main" process id or not (it assumes so). We reverse
4640 look up the "main" process id from the lwp here. */
4641
70221824 4642static struct address_space *
c0694254
PA
4643linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4644{
4645 struct lwp_info *lwp;
4646 struct inferior *inf;
4647 int pid;
4648
dfd4cc63 4649 if (ptid_get_lwp (ptid) == 0)
c0694254
PA
4650 {
4651 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4652 tgid. */
4653 lwp = find_lwp_pid (ptid);
dfd4cc63 4654 pid = ptid_get_pid (lwp->ptid);
c0694254
PA
4655 }
4656 else
4657 {
4658 /* A (pid,lwpid,0) ptid. */
dfd4cc63 4659 pid = ptid_get_pid (ptid);
c0694254
PA
4660 }
4661
4662 inf = find_inferior_pid (pid);
4663 gdb_assert (inf != NULL);
4664 return inf->aspace;
4665}
4666
dc146f7c
VP
4667/* Return the cached value of the processor core for thread PTID. */
4668
70221824 4669static int
dc146f7c
VP
4670linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4671{
4672 struct lwp_info *info = find_lwp_pid (ptid);
e0881a8e 4673
dc146f7c
VP
4674 if (info)
4675 return info->core;
4676 return -1;
4677}
4678
7a6a1731
GB
4679/* Implementation of to_filesystem_is_local. */
4680
4681static int
4682linux_nat_filesystem_is_local (struct target_ops *ops)
4683{
4684 struct inferior *inf = current_inferior ();
4685
4686 if (inf->fake_pid_p || inf->pid == 0)
4687 return 1;
4688
4689 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4690}
4691
4692/* Convert the INF argument passed to a to_fileio_* method
4693 to a process ID suitable for passing to its corresponding
4694 linux_mntns_* function. If INF is non-NULL then the
4695 caller is requesting the filesystem seen by INF. If INF
4696 is NULL then the caller is requesting the filesystem seen
4697 by the GDB. We fall back to GDB's filesystem in the case
4698 that INF is non-NULL but its PID is unknown. */
4699
4700static pid_t
4701linux_nat_fileio_pid_of (struct inferior *inf)
4702{
4703 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4704 return getpid ();
4705 else
4706 return inf->pid;
4707}
4708
4709/* Implementation of to_fileio_open. */
4710
4711static int
4712linux_nat_fileio_open (struct target_ops *self,
4713 struct inferior *inf, const char *filename,
4313b8c0
GB
4714 int flags, int mode, int warn_if_slow,
4715 int *target_errno)
7a6a1731
GB
4716{
4717 int nat_flags;
4718 mode_t nat_mode;
4719 int fd;
4720
4721 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4722 || fileio_to_host_mode (mode, &nat_mode) == -1)
4723 {
4724 *target_errno = FILEIO_EINVAL;
4725 return -1;
4726 }
4727
4728 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4729 filename, nat_flags, nat_mode);
4730 if (fd == -1)
4731 *target_errno = host_to_fileio_error (errno);
4732
4733 return fd;
4734}
4735
4736/* Implementation of to_fileio_readlink. */
4737
4738static char *
4739linux_nat_fileio_readlink (struct target_ops *self,
4740 struct inferior *inf, const char *filename,
4741 int *target_errno)
4742{
4743 char buf[PATH_MAX];
4744 int len;
4745 char *ret;
4746
4747 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4748 filename, buf, sizeof (buf));
4749 if (len < 0)
4750 {
4751 *target_errno = host_to_fileio_error (errno);
4752 return NULL;
4753 }
4754
224c3ddb 4755 ret = (char *) xmalloc (len + 1);
7a6a1731
GB
4756 memcpy (ret, buf, len);
4757 ret[len] = '\0';
4758 return ret;
4759}
4760
4761/* Implementation of to_fileio_unlink. */
4762
4763static int
4764linux_nat_fileio_unlink (struct target_ops *self,
4765 struct inferior *inf, const char *filename,
4766 int *target_errno)
4767{
4768 int ret;
4769
4770 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4771 filename);
4772 if (ret == -1)
4773 *target_errno = host_to_fileio_error (errno);
4774
4775 return ret;
4776}
4777
aa01bd36
PA
4778/* Implementation of the to_thread_events method. */
4779
4780static void
4781linux_nat_thread_events (struct target_ops *ops, int enable)
4782{
4783 report_thread_events = enable;
4784}
4785
f973ed9c
DJ
4786void
4787linux_nat_add_target (struct target_ops *t)
4788{
f973ed9c
DJ
4789 /* Save the provided single-threaded target. We save this in a separate
4790 variable because another target we've inherited from (e.g. inf-ptrace)
4791 may have saved a pointer to T; we want to use it for the final
4792 process stratum target. */
4793 linux_ops_saved = *t;
4794 linux_ops = &linux_ops_saved;
4795
4796 /* Override some methods for multithreading. */
b84876c2 4797 t->to_create_inferior = linux_nat_create_inferior;
f973ed9c
DJ
4798 t->to_attach = linux_nat_attach;
4799 t->to_detach = linux_nat_detach;
4800 t->to_resume = linux_nat_resume;
4801 t->to_wait = linux_nat_wait;
2455069d 4802 t->to_pass_signals = linux_nat_pass_signals;
f973ed9c
DJ
4803 t->to_xfer_partial = linux_nat_xfer_partial;
4804 t->to_kill = linux_nat_kill;
4805 t->to_mourn_inferior = linux_nat_mourn_inferior;
4806 t->to_thread_alive = linux_nat_thread_alive;
8a06aea7 4807 t->to_update_thread_list = linux_nat_update_thread_list;
f973ed9c 4808 t->to_pid_to_str = linux_nat_pid_to_str;
4694da01 4809 t->to_thread_name = linux_nat_thread_name;
f973ed9c 4810 t->to_has_thread_control = tc_schedlock;
c0694254 4811 t->to_thread_address_space = linux_nat_thread_address_space;
ebec9a0f
PA
4812 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4813 t->to_stopped_data_address = linux_nat_stopped_data_address;
faf09f01
PA
4814 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4815 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4816 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4817 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
aa01bd36 4818 t->to_thread_events = linux_nat_thread_events;
f973ed9c 4819
b84876c2
PA
4820 t->to_can_async_p = linux_nat_can_async_p;
4821 t->to_is_async_p = linux_nat_is_async_p;
9908b566 4822 t->to_supports_non_stop = linux_nat_supports_non_stop;
fbea99ea 4823 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
b84876c2 4824 t->to_async = linux_nat_async;
b84876c2
PA
4825 t->to_terminal_inferior = linux_nat_terminal_inferior;
4826 t->to_terminal_ours = linux_nat_terminal_ours;
6a3cb8e8
PA
4827
4828 super_close = t->to_close;
d90e17a7 4829 t->to_close = linux_nat_close;
b84876c2 4830
4c28f408
PA
4831 t->to_stop = linux_nat_stop;
4832
d90e17a7
PA
4833 t->to_supports_multi_process = linux_nat_supports_multi_process;
4834
03583c20
UW
4835 t->to_supports_disable_randomization
4836 = linux_nat_supports_disable_randomization;
4837
dc146f7c
VP
4838 t->to_core_of_thread = linux_nat_core_of_thread;
4839
7a6a1731
GB
4840 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4841 t->to_fileio_open = linux_nat_fileio_open;
4842 t->to_fileio_readlink = linux_nat_fileio_readlink;
4843 t->to_fileio_unlink = linux_nat_fileio_unlink;
4844
f973ed9c
DJ
4845 /* We don't change the stratum; this target will sit at
4846 process_stratum and thread_db will set at thread_stratum. This
4847 is a little strange, since this is a multi-threaded-capable
4848 target, but we want to be on the stack below thread_db, and we
4849 also want to be used for single-threaded processes. */
4850
4851 add_target (t);
f973ed9c
DJ
4852}
4853
9f0bdab8
DJ
4854/* Register a method to call whenever a new thread is attached. */
4855void
7b50312a
PA
4856linux_nat_set_new_thread (struct target_ops *t,
4857 void (*new_thread) (struct lwp_info *))
9f0bdab8
DJ
4858{
4859 /* Save the pointer. We only support a single registered instance
4860 of the GNU/Linux native target, so we do not need to map this to
4861 T. */
4862 linux_nat_new_thread = new_thread;
4863}
4864
466eecee
SM
4865/* Register a method to call whenever a new thread is attached. */
4866void
4867linux_nat_set_delete_thread (struct target_ops *t,
4868 void (*delete_thread) (struct arch_lwp_info *))
4869{
4870 /* Save the pointer. We only support a single registered instance
4871 of the GNU/Linux native target, so we do not need to map this to
4872 T. */
4873 linux_nat_delete_thread = delete_thread;
4874}
4875
26cb8b7c
PA
4876/* See declaration in linux-nat.h. */
4877
4878void
4879linux_nat_set_new_fork (struct target_ops *t,
4880 linux_nat_new_fork_ftype *new_fork)
4881{
4882 /* Save the pointer. */
4883 linux_nat_new_fork = new_fork;
4884}
4885
4886/* See declaration in linux-nat.h. */
4887
4888void
4889linux_nat_set_forget_process (struct target_ops *t,
4890 linux_nat_forget_process_ftype *fn)
4891{
4892 /* Save the pointer. */
4893 linux_nat_forget_process_hook = fn;
4894}
4895
4896/* See declaration in linux-nat.h. */
4897
4898void
4899linux_nat_forget_process (pid_t pid)
4900{
4901 if (linux_nat_forget_process_hook != NULL)
4902 linux_nat_forget_process_hook (pid);
4903}
4904
5b009018
PA
4905/* Register a method that converts a siginfo object between the layout
4906 that ptrace returns, and the layout in the architecture of the
4907 inferior. */
4908void
4909linux_nat_set_siginfo_fixup (struct target_ops *t,
a5362b9a 4910 int (*siginfo_fixup) (siginfo_t *,
5b009018
PA
4911 gdb_byte *,
4912 int))
4913{
4914 /* Save the pointer. */
4915 linux_nat_siginfo_fixup = siginfo_fixup;
4916}
4917
7b50312a
PA
4918/* Register a method to call prior to resuming a thread. */
4919
4920void
4921linux_nat_set_prepare_to_resume (struct target_ops *t,
4922 void (*prepare_to_resume) (struct lwp_info *))
4923{
4924 /* Save the pointer. */
4925 linux_nat_prepare_to_resume = prepare_to_resume;
4926}
4927
f865ee35
JK
4928/* See linux-nat.h. */
4929
4930int
4931linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
9f0bdab8 4932{
da559b09 4933 int pid;
9f0bdab8 4934
dfd4cc63 4935 pid = ptid_get_lwp (ptid);
da559b09 4936 if (pid == 0)
dfd4cc63 4937 pid = ptid_get_pid (ptid);
f865ee35 4938
da559b09
JK
4939 errno = 0;
4940 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4941 if (errno != 0)
4942 {
4943 memset (siginfo, 0, sizeof (*siginfo));
4944 return 0;
4945 }
f865ee35 4946 return 1;
9f0bdab8
DJ
4947}
4948
7b669087
GB
4949/* See nat/linux-nat.h. */
4950
4951ptid_t
4952current_lwp_ptid (void)
4953{
4954 gdb_assert (ptid_lwp_p (inferior_ptid));
4955 return inferior_ptid;
4956}
4957
d6b0e80f
AC
4958void
4959_initialize_linux_nat (void)
4960{
ccce17b0
YQ
4961 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4962 &debug_linux_nat, _("\
b84876c2
PA
4963Set debugging of GNU/Linux lwp module."), _("\
4964Show debugging of GNU/Linux lwp module."), _("\
4965Enables printf debugging output."),
ccce17b0
YQ
4966 NULL,
4967 show_debug_linux_nat,
4968 &setdebuglist, &showdebuglist);
b84876c2 4969
7a6a1731
GB
4970 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4971 &debug_linux_namespaces, _("\
4972Set debugging of GNU/Linux namespaces module."), _("\
4973Show debugging of GNU/Linux namespaces module."), _("\
4974Enables printf debugging output."),
4975 NULL,
4976 NULL,
4977 &setdebuglist, &showdebuglist);
4978
b84876c2 4979 /* Save this mask as the default. */
d6b0e80f
AC
4980 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4981
7feb7d06
PA
4982 /* Install a SIGCHLD handler. */
4983 sigchld_action.sa_handler = sigchld_handler;
4984 sigemptyset (&sigchld_action.sa_mask);
4985 sigchld_action.sa_flags = SA_RESTART;
b84876c2
PA
4986
4987 /* Make it the default. */
7feb7d06 4988 sigaction (SIGCHLD, &sigchld_action, NULL);
d6b0e80f
AC
4989
4990 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4991 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4992 sigdelset (&suspend_mask, SIGCHLD);
4993
7feb7d06 4994 sigemptyset (&blocked_mask);
774113b0
PA
4995
4996 lwp_lwpid_htab_create ();
d6b0e80f
AC
4997}
4998\f
4999
5000/* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5001 the GNU/Linux Threads library and therefore doesn't really belong
5002 here. */
5003
d6b0e80f
AC
5004/* Return the set of signals used by the threads library in *SET. */
5005
5006void
5007lin_thread_get_thread_signals (sigset_t *set)
5008{
d6b0e80f
AC
5009 sigemptyset (set);
5010
4a6ed09b
PA
5011 /* NPTL reserves the first two RT signals, but does not provide any
5012 way for the debugger to query the signal numbers - fortunately
5013 they don't change. */
5014 sigaddset (set, __SIGRTMIN);
5015 sigaddset (set, __SIGRTMIN + 1);
d6b0e80f 5016}
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