1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
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
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
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.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
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 */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
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
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.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify 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,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops *linux_ops;
195 static struct target_ops linux_ops_saved;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread) (struct lwp_info *);
200 /* The method to call, if any, when a thread is destroyed. */
201 static void (*linux_nat_delete_thread) (struct arch_lwp_info *);
203 /* The method to call, if any, when a new fork is attached. */
204 static linux_nat_new_fork_ftype *linux_nat_new_fork;
206 /* The method to call, if any, when a process is no longer
208 static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
210 /* Hook to call prior to resuming a thread. */
211 static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
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. */
216 static int (*linux_nat_siginfo_fixup) (siginfo_t *,
220 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
221 Called by our to_xfer_partial. */
222 static target_xfer_partial_ftype *super_xfer_partial;
224 /* The saved to_close method, inherited from inf-ptrace.c.
225 Called by our to_close. */
226 static void (*super_close) (struct target_ops *);
228 static unsigned int debug_linux_nat;
230 show_debug_linux_nat (struct ui_file *file, int from_tty,
231 struct cmd_list_element *c, const char *value)
233 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
237 struct simple_pid_list
241 struct simple_pid_list *next;
243 struct simple_pid_list *stopped_pids;
245 /* Whether target_thread_events is in effect. */
246 static int report_thread_events;
248 /* Async mode support. */
250 /* The read/write ends of the pipe registered as waitable file in the
252 static int linux_nat_event_pipe[2] = { -1, -1 };
254 /* True if we're currently in async mode. */
255 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
257 /* Flush the event pipe. */
260 async_file_flush (void)
267 ret = read (linux_nat_event_pipe[0], &buf, 1);
269 while (ret >= 0 || (ret == -1 && errno == EINTR));
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. */
277 async_file_mark (void)
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
288 ret = write (linux_nat_event_pipe[1], "+", 1);
290 while (ret == -1 && errno == EINTR);
292 /* Ignore EAGAIN. If the pipe is full, the event loop will already
293 be awakened anyway. */
296 static int kill_lwp (int lwpid, int signo);
298 static int stop_callback (struct lwp_info *lp, void *data);
299 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
301 static void block_child_signals (sigset_t *prev_mask);
302 static void restore_child_signals_mask (sigset_t *prev_mask);
305 static struct lwp_info *add_lwp (ptid_t ptid);
306 static void purge_lwp_list (int pid);
307 static void delete_lwp (ptid_t ptid);
308 static struct lwp_info *find_lwp_pid (ptid_t ptid);
310 static int lwp_status_pending_p (struct lwp_info *lp);
312 static int sigtrap_is_event (int status);
313 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
315 static void save_stop_reason (struct lwp_info *lp);
320 /* See nat/linux-nat.h. */
323 ptid_of_lwp (struct lwp_info *lwp)
328 /* See nat/linux-nat.h. */
331 lwp_set_arch_private_info (struct lwp_info *lwp,
332 struct arch_lwp_info *info)
334 lwp->arch_private = info;
337 /* See nat/linux-nat.h. */
339 struct arch_lwp_info *
340 lwp_arch_private_info (struct lwp_info *lwp)
342 return lwp->arch_private;
345 /* See nat/linux-nat.h. */
348 lwp_is_stopped (struct lwp_info *lwp)
353 /* See nat/linux-nat.h. */
355 enum target_stop_reason
356 lwp_stop_reason (struct lwp_info *lwp)
358 return lwp->stop_reason;
361 /* See nat/linux-nat.h. */
364 lwp_is_stepping (struct lwp_info *lwp)
370 /* Trivial list manipulation functions to keep track of a list of
371 new stopped processes. */
373 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
375 struct simple_pid_list *new_pid = XNEW (struct simple_pid_list);
378 new_pid->status = status;
379 new_pid->next = *listp;
384 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
386 struct simple_pid_list **p;
388 for (p = listp; *p != NULL; p = &(*p)->next)
389 if ((*p)->pid == pid)
391 struct simple_pid_list *next = (*p)->next;
393 *statusp = (*p)->status;
401 /* Return the ptrace options that we want to try to enable. */
404 linux_nat_ptrace_options (int attached)
409 options |= PTRACE_O_EXITKILL;
411 options |= (PTRACE_O_TRACESYSGOOD
412 | PTRACE_O_TRACEVFORKDONE
413 | PTRACE_O_TRACEVFORK
415 | PTRACE_O_TRACEEXEC);
420 /* Initialize ptrace warnings and check for supported ptrace
423 ATTACHED should be nonzero iff we attached to the inferior. */
426 linux_init_ptrace (pid_t pid, int attached)
428 int options = linux_nat_ptrace_options (attached);
430 linux_enable_event_reporting (pid, options);
431 linux_ptrace_init_warnings ();
435 linux_child_post_attach (struct target_ops *self, int pid)
437 linux_init_ptrace (pid, 1);
441 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
443 linux_init_ptrace (ptid_get_pid (ptid), 0);
446 /* Return the number of known LWPs in the tgid given by PID. */
454 for (lp = lwp_list; lp; lp = lp->next)
455 if (ptid_get_pid (lp->ptid) == pid)
461 /* Call delete_lwp with prototype compatible for make_cleanup. */
464 delete_lwp_cleanup (void *lp_voidp)
466 struct lwp_info *lp = (struct lwp_info *) lp_voidp;
468 delete_lwp (lp->ptid);
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
476 linux_child_follow_fork (struct target_ops *ops, int follow_child,
481 struct lwp_info *child_lp = NULL;
482 int status = W_STOPCODE (0);
484 ptid_t parent_ptid, child_ptid;
485 int parent_pid, child_pid;
487 has_vforked = (inferior_thread ()->pending_follow.kind
488 == TARGET_WAITKIND_VFORKED);
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);
494 /* We're already attached to the parent, by default. */
495 child_lp = add_lwp (child_ptid);
496 child_lp->stopped = 1;
497 child_lp->last_resume_kind = resume_stop;
499 /* Detach new forked process? */
502 struct cleanup *old_chain = make_cleanup (delete_lwp_cleanup,
505 if (linux_nat_prepare_to_resume != NULL)
506 linux_nat_prepare_to_resume (child_lp);
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. */
516 /* Note that we consult the parent's architecture instead of
517 the child's because there's no inferior for the child at
519 if (!gdbarch_software_single_step_p (target_thread_architecture
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"));
529 if (WIFSTOPPED (status))
533 signo = WSTOPSIG (status);
535 && !signal_pass_state (gdb_signal_from_host (signo)))
537 ptrace (PTRACE_DETACH, child_pid, 0, signo);
540 do_cleanups (old_chain);
544 scoped_restore save_inferior_ptid
545 = make_scoped_restore (&inferior_ptid);
546 inferior_ptid = child_ptid;
548 /* Let the thread_db layer learn about this new process. */
549 check_for_thread_db ();
554 struct lwp_info *parent_lp;
556 parent_lp = find_lwp_pid (parent_ptid);
557 gdb_assert (linux_supports_tracefork () >= 0);
559 if (linux_supports_tracevforkdone ())
562 fprintf_unfiltered (gdb_stdlog,
563 "LCFF: waiting for VFORK_DONE on %d\n",
565 parent_lp->stopped = 1;
567 /* We'll handle the VFORK_DONE event like any other
568 event, in target_wait. */
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
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
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.
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.
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
604 fprintf_unfiltered (gdb_stdlog,
605 "LCFF: no VFORK_DONE "
606 "support, sleeping a bit\n");
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. */
614 parent_lp->status = 0;
615 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
616 parent_lp->stopped = 1;
618 /* If we're in async mode, need to tell the event loop
619 there's something here to process. */
620 if (target_is_async_p ())
627 struct lwp_info *child_lp;
629 child_lp = add_lwp (inferior_ptid);
630 child_lp->stopped = 1;
631 child_lp->last_resume_kind = resume_stop;
633 /* Let the thread_db layer learn about this new process. */
634 check_for_thread_db ();
642 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
644 return !linux_supports_tracefork ();
648 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
654 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
656 return !linux_supports_tracefork ();
660 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
666 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
668 return !linux_supports_tracefork ();
672 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
678 linux_child_set_syscall_catchpoint (struct target_ops *self,
679 int pid, bool needed, int any_count,
680 gdb::array_view<const int> syscall_counts)
682 if (!linux_supports_tracesysgood ())
685 /* On GNU/Linux, we ignore the arguments. It means that we only
686 enable the syscall catchpoints, but do not disable them.
688 Also, we do not use the `syscall_counts' information because we do not
689 filter system calls here. We let GDB do the logic for us. */
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. */
696 static htab_t lwp_lwpid_htab;
698 /* Calculate a hash from a lwp_info's LWP PID. */
701 lwp_info_hash (const void *ap)
703 const struct lwp_info *lp = (struct lwp_info *) ap;
704 pid_t pid = ptid_get_lwp (lp->ptid);
706 return iterative_hash_object (pid, 0);
709 /* Equality function for the lwp_info hash table. Compares the LWP's
713 lwp_lwpid_htab_eq (const void *a, const void *b)
715 const struct lwp_info *entry = (const struct lwp_info *) a;
716 const struct lwp_info *element = (const struct lwp_info *) b;
718 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
721 /* Create the lwp_lwpid_htab hash table. */
724 lwp_lwpid_htab_create (void)
726 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
729 /* Add LP to the hash table. */
732 lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
736 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
737 gdb_assert (slot != NULL && *slot == NULL);
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. */
745 struct lwp_info *lwp_list;
747 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
750 lwp_list_add (struct lwp_info *lp)
753 if (lwp_list != NULL)
758 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
762 lwp_list_remove (struct lwp_info *lp)
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;
775 /* Original signal mask. */
776 static sigset_t normal_mask;
778 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
779 _initialize_linux_nat. */
780 static sigset_t suspend_mask;
782 /* Signals to block to make that sigsuspend work. */
783 static sigset_t blocked_mask;
785 /* SIGCHLD action. */
786 struct sigaction sigchld_action;
788 /* Block child signals (SIGCHLD and linux threads signals), and store
789 the previous mask in PREV_MASK. */
792 block_child_signals (sigset_t *prev_mask)
794 /* Make sure SIGCHLD is blocked. */
795 if (!sigismember (&blocked_mask, SIGCHLD))
796 sigaddset (&blocked_mask, SIGCHLD);
798 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
801 /* Restore child signals mask, previously returned by
802 block_child_signals. */
805 restore_child_signals_mask (sigset_t *prev_mask)
807 sigprocmask (SIG_SETMASK, prev_mask, NULL);
810 /* Mask of signals to pass directly to the inferior. */
811 static sigset_t pass_mask;
813 /* Update signals to pass to the inferior. */
815 linux_nat_pass_signals (struct target_ops *self,
816 int numsigs, unsigned char *pass_signals)
820 sigemptyset (&pass_mask);
822 for (signo = 1; signo < NSIG; signo++)
824 int target_signo = gdb_signal_from_host (signo);
825 if (target_signo < numsigs && pass_signals[target_signo])
826 sigaddset (&pass_mask, signo);
832 /* Prototypes for local functions. */
833 static int stop_wait_callback (struct lwp_info *lp, void *data);
834 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
835 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
836 static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
840 /* Destroy and free LP. */
843 lwp_free (struct lwp_info *lp)
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);
849 gdb_assert (lp->arch_private == NULL);
854 /* Traversal function for purge_lwp_list. */
857 lwp_lwpid_htab_remove_pid (void **slot, void *info)
859 struct lwp_info *lp = (struct lwp_info *) *slot;
860 int pid = *(int *) info;
862 if (ptid_get_pid (lp->ptid) == pid)
864 htab_clear_slot (lwp_lwpid_htab, slot);
865 lwp_list_remove (lp);
872 /* Remove all LWPs belong to PID from the lwp list. */
875 purge_lwp_list (int pid)
877 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
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
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
894 static struct lwp_info *
895 add_initial_lwp (ptid_t ptid)
899 gdb_assert (ptid_lwp_p (ptid));
901 lp = XNEW (struct lwp_info);
903 memset (lp, 0, sizeof (struct lwp_info));
905 lp->last_resume_kind = resume_continue;
906 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
911 /* Add to sorted-by-reverse-creation-order list. */
914 /* Add to keyed-by-pid htab. */
915 lwp_lwpid_htab_add_lwp (lp);
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
924 static struct lwp_info *
925 add_lwp (ptid_t ptid)
929 lp = add_initial_lwp (ptid);
931 /* Let the arch specific bits know about this new thread. Current
932 clients of this callback take the opportunity to install
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)
936 linux_nat_new_thread (lp);
941 /* Remove the LWP specified by PID from the list. */
944 delete_lwp (ptid_t ptid)
948 struct lwp_info dummy;
951 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
955 lp = *(struct lwp_info **) slot;
956 gdb_assert (lp != NULL);
958 htab_clear_slot (lwp_lwpid_htab, slot);
960 /* Remove from sorted-by-creation-order list. */
961 lwp_list_remove (lp);
967 /* Return a pointer to the structure describing the LWP corresponding
968 to PID. If no corresponding LWP could be found, return NULL. */
970 static struct lwp_info *
971 find_lwp_pid (ptid_t ptid)
975 struct lwp_info dummy;
977 if (ptid_lwp_p (ptid))
978 lwp = ptid_get_lwp (ptid);
980 lwp = ptid_get_pid (ptid);
982 dummy.ptid = ptid_build (0, lwp, 0);
983 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
987 /* See nat/linux-nat.h. */
990 iterate_over_lwps (ptid_t filter,
991 iterate_over_lwps_ftype callback,
994 struct lwp_info *lp, *lpnext;
996 for (lp = lwp_list; lp; lp = lpnext)
1000 if (ptid_match (lp->ptid, filter))
1002 if ((*callback) (lp, data) != 0)
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
1016 linux_nat_switch_fork (ptid_t new_ptid)
1018 struct lwp_info *lp;
1020 purge_lwp_list (ptid_get_pid (inferior_ptid));
1022 lp = add_lwp (new_ptid);
1025 /* This changes the thread's ptid while preserving the gdb thread
1026 num. Also changes the inferior pid, while preserving the
1028 thread_change_ptid (inferior_ptid, new_ptid);
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
1033 registers_changed ();
1036 /* Handle the exit of a single thread LP. */
1039 exit_lwp (struct lwp_info *lp)
1041 struct thread_info *th = find_thread_ptid (lp->ptid);
1045 if (print_thread_events)
1046 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1048 delete_thread (lp->ptid);
1051 delete_lwp (lp->ptid);
1054 /* Wait for the LWP specified by LP, which we have just attached to.
1055 Returns a wait status for that LWP, to cache. */
1058 linux_nat_post_attach_wait (ptid_t ptid, int *signalled)
1060 pid_t new_pid, pid = ptid_get_lwp (ptid);
1063 if (linux_proc_pid_is_stopped (pid))
1065 if (debug_linux_nat)
1066 fprintf_unfiltered (gdb_stdlog,
1067 "LNPAW: Attaching to a stopped process\n");
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.
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);
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);
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. */
1092 new_pid = my_waitpid (pid, &status, __WALL);
1093 gdb_assert (pid == new_pid);
1095 if (!WIFSTOPPED (status))
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));
1104 if (WSTOPSIG (status) != SIGSTOP)
1107 if (debug_linux_nat)
1108 fprintf_unfiltered (gdb_stdlog,
1109 "LNPAW: Received %s after attaching\n",
1110 status_to_str (status));
1117 linux_nat_create_inferior (struct target_ops *ops,
1118 const char *exec_file, const std::string &allargs,
1119 char **env, int from_tty)
1121 maybe_disable_address_space_randomization restore_personality
1122 (disable_randomization);
1124 /* The fork_child mechanism is synchronous and calls target_wait, so
1125 we have to mask the async mode. */
1127 /* Make sure we report all signals during startup. */
1128 linux_nat_pass_signals (ops, 0, NULL);
1130 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
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
1138 attach_proc_task_lwp_callback (ptid_t ptid)
1140 struct lwp_info *lp;
1142 /* Ignore LWPs we're already attached to. */
1143 lp = find_lwp_pid (ptid);
1146 int lwpid = ptid_get_lwp (ptid);
1148 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
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. */
1158 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1160 if (debug_linux_nat)
1162 fprintf_unfiltered (gdb_stdlog,
1163 "Cannot attach to lwp %d: "
1164 "thread is gone (%d: %s)\n",
1165 lwpid, err, safe_strerror (err));
1171 = linux_ptrace_attach_fail_reason_string (ptid, err);
1173 warning (_("Cannot attach to lwp %d: %s"),
1174 lwpid, reason.c_str ());
1179 if (debug_linux_nat)
1180 fprintf_unfiltered (gdb_stdlog,
1181 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1182 target_pid_to_str (ptid));
1184 lp = add_lwp (ptid);
1186 /* The next time we wait for this LWP we'll see a SIGSTOP as
1187 PTRACE_ATTACH brings it to a halt. */
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;
1194 /* So that wait collects the SIGSTOP. */
1197 /* Also add the LWP to gdb's thread list, in case a
1198 matching libthread_db is not found (or the process uses
1200 add_thread (lp->ptid);
1201 set_running (lp->ptid, 1);
1202 set_executing (lp->ptid, 1);
1211 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1213 struct lwp_info *lp;
1217 /* Make sure we report all signals during attach. */
1218 linux_nat_pass_signals (ops, 0, NULL);
1222 linux_ops->to_attach (ops, args, from_tty);
1224 CATCH (ex, RETURN_MASK_ERROR)
1226 pid_t pid = parse_pid_to_attach (args);
1227 std::string reason = linux_ptrace_attach_fail_reason (pid);
1229 if (!reason.empty ())
1230 throw_error (ex.error, "warning: %s\n%s", reason.c_str (), ex.message);
1232 throw_error (ex.error, "%s", ex.message);
1236 /* The ptrace base target adds the main thread with (pid,0,0)
1237 format. Decorate it with lwp info. */
1238 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1239 ptid_get_pid (inferior_ptid),
1241 thread_change_ptid (inferior_ptid, ptid);
1243 /* Add the initial process as the first LWP to the list. */
1244 lp = add_initial_lwp (ptid);
1246 status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled);
1247 if (!WIFSTOPPED (status))
1249 if (WIFEXITED (status))
1251 int exit_code = WEXITSTATUS (status);
1253 target_terminal::ours ();
1254 target_mourn_inferior (inferior_ptid);
1256 error (_("Unable to attach: program exited normally."));
1258 error (_("Unable to attach: program exited with code %d."),
1261 else if (WIFSIGNALED (status))
1263 enum gdb_signal signo;
1265 target_terminal::ours ();
1266 target_mourn_inferior (inferior_ptid);
1268 signo = gdb_signal_from_host (WTERMSIG (status));
1269 error (_("Unable to attach: program terminated with signal "
1271 gdb_signal_to_name (signo),
1272 gdb_signal_to_string (signo));
1275 internal_error (__FILE__, __LINE__,
1276 _("unexpected status %d for PID %ld"),
1277 status, (long) ptid_get_lwp (ptid));
1282 /* Save the wait status to report later. */
1284 if (debug_linux_nat)
1285 fprintf_unfiltered (gdb_stdlog,
1286 "LNA: waitpid %ld, saving status %s\n",
1287 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1289 lp->status = status;
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);
1301 if (target_can_async_p ())
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
1311 get_detach_signal (struct lwp_info *lp)
1313 enum gdb_signal signo = GDB_SIGNAL_0;
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.
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
1326 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
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. */
1336 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1337 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1338 else if (lp->status)
1339 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1340 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1342 struct thread_info *tp = find_thread_ptid (lp->ptid);
1344 if (tp->suspend.waitstatus_pending_p)
1345 signo = tp->suspend.waitstatus.value.sig;
1347 signo = tp->suspend.stop_signal;
1349 else if (!target_is_non_stop_p ())
1351 struct target_waitstatus last;
1354 get_last_target_status (&last_ptid, &last);
1356 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1358 struct thread_info *tp = find_thread_ptid (lp->ptid);
1360 signo = tp->suspend.stop_signal;
1364 if (signo == GDB_SIGNAL_0)
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));
1371 else if (!signal_pass_state (signo))
1373 if (debug_linux_nat)
1374 fprintf_unfiltered (gdb_stdlog,
1375 "GPT: lwp %s had signal %s, "
1376 "but it is in no pass state\n",
1377 target_pid_to_str (lp->ptid),
1378 gdb_signal_to_string (signo));
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),
1386 gdb_signal_to_string (signo));
1388 return gdb_signal_to_host (signo);
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. */
1399 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1401 int lwpid = ptid_get_lwp (lp->ptid);
1404 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
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));
1411 /* If there is a pending SIGSTOP, get rid of it. */
1414 if (debug_linux_nat)
1415 fprintf_unfiltered (gdb_stdlog,
1416 "DC: Sending SIGCONT to %s\n",
1417 target_pid_to_str (lp->ptid));
1419 kill_lwp (lwpid, SIGCONT);
1423 if (signo_p == NULL)
1425 /* Pass on any pending signal for this LWP. */
1426 signo = get_detach_signal (lp);
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. */
1436 if (linux_nat_prepare_to_resume != NULL)
1437 linux_nat_prepare_to_resume (lp);
1439 CATCH (ex, RETURN_MASK_ERROR)
1441 if (!check_ptrace_stopped_lwp_gone (lp))
1442 throw_exception (ex);
1446 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1448 int save_errno = errno;
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)
1458 ret = my_waitpid (lwpid, &status, __WALL);
1461 warning (_("Couldn't reap LWP %d while detaching: %s"),
1462 lwpid, strerror (errno));
1464 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1466 warning (_("Reaping LWP %d while detaching "
1467 "returned unexpected status 0x%x"),
1473 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1474 safe_strerror (save_errno));
1477 else if (debug_linux_nat)
1479 fprintf_unfiltered (gdb_stdlog,
1480 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1481 target_pid_to_str (lp->ptid),
1485 delete_lwp (lp->ptid);
1489 detach_callback (struct lwp_info *lp, void *data)
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);
1500 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1503 struct lwp_info *main_lwp;
1505 pid = ptid_get_pid (inferior_ptid);
1507 /* Don't unregister from the event loop, as there may be other
1508 inferiors running. */
1510 /* Stop all threads before detaching. ptrace requires that the
1511 thread is stopped to sucessfully detach. */
1512 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1513 /* ... and wait until all of them have reported back that
1514 they're no longer running. */
1515 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1517 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1519 /* Only the initial process should be left right now. */
1520 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1522 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1524 if (forks_exist_p ())
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
1530 linux_fork_detach (args, from_tty);
1536 target_announce_detach (from_tty);
1538 /* Pass on any pending signal for the last LWP, unless the user
1539 requested detaching with a different signal (most likely 0,
1540 meaning, discard the signal). */
1542 signo = atoi (args);
1544 signo = get_detach_signal (main_lwp);
1546 detach_one_lwp (main_lwp, &signo);
1548 inf_ptrace_detach_success (ops);
1552 /* Resume execution of the inferior process. If STEP is nonzero,
1553 single-step it. If SIGNAL is nonzero, give it that signal. */
1556 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1557 enum gdb_signal signo)
1561 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1562 We only presently need that if the LWP is stepped though (to
1563 handle the case of stepping a breakpoint instruction). */
1566 struct regcache *regcache = get_thread_regcache (lp->ptid);
1568 lp->stop_pc = regcache_read_pc (regcache);
1573 if (linux_nat_prepare_to_resume != NULL)
1574 linux_nat_prepare_to_resume (lp);
1575 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1577 /* Successfully resumed. Clear state that no longer makes sense,
1578 and mark the LWP as running. Must not do this before resuming
1579 otherwise if that fails other code will be confused. E.g., we'd
1580 later try to stop the LWP and hang forever waiting for a stop
1581 status. Note that we must not throw after this is cleared,
1582 otherwise handle_zombie_lwp_error would get confused. */
1585 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1586 registers_changed_ptid (lp->ptid);
1589 /* Called when we try to resume a stopped LWP and that errors out. If
1590 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1591 or about to become), discard the error, clear any pending status
1592 the LWP may have, and return true (we'll collect the exit status
1593 soon enough). Otherwise, return false. */
1596 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1598 /* If we get an error after resuming the LWP successfully, we'd
1599 confuse !T state for the LWP being gone. */
1600 gdb_assert (lp->stopped);
1602 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1603 because even if ptrace failed with ESRCH, the tracee may be "not
1604 yet fully dead", but already refusing ptrace requests. In that
1605 case the tracee has 'R (Running)' state for a little bit
1606 (observed in Linux 3.18). See also the note on ESRCH in the
1607 ptrace(2) man page. Instead, check whether the LWP has any state
1608 other than ptrace-stopped. */
1610 /* Don't assume anything if /proc/PID/status can't be read. */
1611 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1613 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1615 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1621 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1622 disappears while we try to resume it. */
1625 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1629 linux_resume_one_lwp_throw (lp, step, signo);
1631 CATCH (ex, RETURN_MASK_ERROR)
1633 if (!check_ptrace_stopped_lwp_gone (lp))
1634 throw_exception (ex);
1642 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1646 struct inferior *inf = find_inferior_ptid (lp->ptid);
1648 if (inf->vfork_child != NULL)
1650 if (debug_linux_nat)
1651 fprintf_unfiltered (gdb_stdlog,
1652 "RC: Not resuming %s (vfork parent)\n",
1653 target_pid_to_str (lp->ptid));
1655 else if (!lwp_status_pending_p (lp))
1657 if (debug_linux_nat)
1658 fprintf_unfiltered (gdb_stdlog,
1659 "RC: Resuming sibling %s, %s, %s\n",
1660 target_pid_to_str (lp->ptid),
1661 (signo != GDB_SIGNAL_0
1662 ? strsignal (gdb_signal_to_host (signo))
1664 step ? "step" : "resume");
1666 linux_resume_one_lwp (lp, step, signo);
1670 if (debug_linux_nat)
1671 fprintf_unfiltered (gdb_stdlog,
1672 "RC: Not resuming sibling %s (has pending)\n",
1673 target_pid_to_str (lp->ptid));
1678 if (debug_linux_nat)
1679 fprintf_unfiltered (gdb_stdlog,
1680 "RC: Not resuming sibling %s (not stopped)\n",
1681 target_pid_to_str (lp->ptid));
1685 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1686 Resume LWP with the last stop signal, if it is in pass state. */
1689 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1691 enum gdb_signal signo = GDB_SIGNAL_0;
1698 struct thread_info *thread;
1700 thread = find_thread_ptid (lp->ptid);
1703 signo = thread->suspend.stop_signal;
1704 thread->suspend.stop_signal = GDB_SIGNAL_0;
1708 resume_lwp (lp, 0, signo);
1713 resume_clear_callback (struct lwp_info *lp, void *data)
1716 lp->last_resume_kind = resume_stop;
1721 resume_set_callback (struct lwp_info *lp, void *data)
1724 lp->last_resume_kind = resume_continue;
1729 linux_nat_resume (struct target_ops *ops,
1730 ptid_t ptid, int step, enum gdb_signal signo)
1732 struct lwp_info *lp;
1735 if (debug_linux_nat)
1736 fprintf_unfiltered (gdb_stdlog,
1737 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1738 step ? "step" : "resume",
1739 target_pid_to_str (ptid),
1740 (signo != GDB_SIGNAL_0
1741 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1742 target_pid_to_str (inferior_ptid));
1744 /* A specific PTID means `step only this process id'. */
1745 resume_many = (ptid_equal (minus_one_ptid, ptid)
1746 || ptid_is_pid (ptid));
1748 /* Mark the lwps we're resuming as resumed. */
1749 iterate_over_lwps (ptid, resume_set_callback, NULL);
1751 /* See if it's the current inferior that should be handled
1754 lp = find_lwp_pid (inferior_ptid);
1756 lp = find_lwp_pid (ptid);
1757 gdb_assert (lp != NULL);
1759 /* Remember if we're stepping. */
1760 lp->last_resume_kind = step ? resume_step : resume_continue;
1762 /* If we have a pending wait status for this thread, there is no
1763 point in resuming the process. But first make sure that
1764 linux_nat_wait won't preemptively handle the event - we
1765 should never take this short-circuit if we are going to
1766 leave LP running, since we have skipped resuming all the
1767 other threads. This bit of code needs to be synchronized
1768 with linux_nat_wait. */
1770 if (lp->status && WIFSTOPPED (lp->status))
1773 && WSTOPSIG (lp->status)
1774 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1776 if (debug_linux_nat)
1777 fprintf_unfiltered (gdb_stdlog,
1778 "LLR: Not short circuiting for ignored "
1779 "status 0x%x\n", lp->status);
1781 /* FIXME: What should we do if we are supposed to continue
1782 this thread with a signal? */
1783 gdb_assert (signo == GDB_SIGNAL_0);
1784 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1789 if (lwp_status_pending_p (lp))
1791 /* FIXME: What should we do if we are supposed to continue
1792 this thread with a signal? */
1793 gdb_assert (signo == GDB_SIGNAL_0);
1795 if (debug_linux_nat)
1796 fprintf_unfiltered (gdb_stdlog,
1797 "LLR: Short circuiting for status 0x%x\n",
1800 if (target_can_async_p ())
1803 /* Tell the event loop we have something to process. */
1810 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1812 if (debug_linux_nat)
1813 fprintf_unfiltered (gdb_stdlog,
1814 "LLR: %s %s, %s (resume event thread)\n",
1815 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1816 target_pid_to_str (lp->ptid),
1817 (signo != GDB_SIGNAL_0
1818 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1820 linux_resume_one_lwp (lp, step, signo);
1822 if (target_can_async_p ())
1826 /* Send a signal to an LWP. */
1829 kill_lwp (int lwpid, int signo)
1834 ret = syscall (__NR_tkill, lwpid, signo);
1835 if (errno == ENOSYS)
1837 /* If tkill fails, then we are not using nptl threads, a
1838 configuration we no longer support. */
1839 perror_with_name (("tkill"));
1844 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1845 event, check if the core is interested in it: if not, ignore the
1846 event, and keep waiting; otherwise, we need to toggle the LWP's
1847 syscall entry/exit status, since the ptrace event itself doesn't
1848 indicate it, and report the trap to higher layers. */
1851 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1853 struct target_waitstatus *ourstatus = &lp->waitstatus;
1854 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1855 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1859 /* If we're stopping threads, there's a SIGSTOP pending, which
1860 makes it so that the LWP reports an immediate syscall return,
1861 followed by the SIGSTOP. Skip seeing that "return" using
1862 PTRACE_CONT directly, and let stop_wait_callback collect the
1863 SIGSTOP. Later when the thread is resumed, a new syscall
1864 entry event. If we didn't do this (and returned 0), we'd
1865 leave a syscall entry pending, and our caller, by using
1866 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1867 itself. Later, when the user re-resumes this LWP, we'd see
1868 another syscall entry event and we'd mistake it for a return.
1870 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1871 (leaving immediately with LWP->signalled set, without issuing
1872 a PTRACE_CONT), it would still be problematic to leave this
1873 syscall enter pending, as later when the thread is resumed,
1874 it would then see the same syscall exit mentioned above,
1875 followed by the delayed SIGSTOP, while the syscall didn't
1876 actually get to execute. It seems it would be even more
1877 confusing to the user. */
1879 if (debug_linux_nat)
1880 fprintf_unfiltered (gdb_stdlog,
1881 "LHST: ignoring syscall %d "
1882 "for LWP %ld (stopping threads), "
1883 "resuming with PTRACE_CONT for SIGSTOP\n",
1885 ptid_get_lwp (lp->ptid));
1887 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1888 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1893 /* Always update the entry/return state, even if this particular
1894 syscall isn't interesting to the core now. In async mode,
1895 the user could install a new catchpoint for this syscall
1896 between syscall enter/return, and we'll need to know to
1897 report a syscall return if that happens. */
1898 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1899 ? TARGET_WAITKIND_SYSCALL_RETURN
1900 : TARGET_WAITKIND_SYSCALL_ENTRY);
1902 if (catch_syscall_enabled ())
1904 if (catching_syscall_number (syscall_number))
1906 /* Alright, an event to report. */
1907 ourstatus->kind = lp->syscall_state;
1908 ourstatus->value.syscall_number = syscall_number;
1910 if (debug_linux_nat)
1911 fprintf_unfiltered (gdb_stdlog,
1912 "LHST: stopping for %s of syscall %d"
1915 == TARGET_WAITKIND_SYSCALL_ENTRY
1916 ? "entry" : "return",
1918 ptid_get_lwp (lp->ptid));
1922 if (debug_linux_nat)
1923 fprintf_unfiltered (gdb_stdlog,
1924 "LHST: ignoring %s of syscall %d "
1926 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1927 ? "entry" : "return",
1929 ptid_get_lwp (lp->ptid));
1933 /* If we had been syscall tracing, and hence used PT_SYSCALL
1934 before on this LWP, it could happen that the user removes all
1935 syscall catchpoints before we get to process this event.
1936 There are two noteworthy issues here:
1938 - When stopped at a syscall entry event, resuming with
1939 PT_STEP still resumes executing the syscall and reports a
1942 - Only PT_SYSCALL catches syscall enters. If we last
1943 single-stepped this thread, then this event can't be a
1944 syscall enter. If we last single-stepped this thread, this
1945 has to be a syscall exit.
1947 The points above mean that the next resume, be it PT_STEP or
1948 PT_CONTINUE, can not trigger a syscall trace event. */
1949 if (debug_linux_nat)
1950 fprintf_unfiltered (gdb_stdlog,
1951 "LHST: caught syscall event "
1952 "with no syscall catchpoints."
1953 " %d for LWP %ld, ignoring\n",
1955 ptid_get_lwp (lp->ptid));
1956 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1959 /* The core isn't interested in this event. For efficiency, avoid
1960 stopping all threads only to have the core resume them all again.
1961 Since we're not stopping threads, if we're still syscall tracing
1962 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1963 subsequent syscall. Simply resume using the inf-ptrace layer,
1964 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1966 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1970 /* Handle a GNU/Linux extended wait response. If we see a clone
1971 event, we need to add the new LWP to our list (and not report the
1972 trap to higher layers). This function returns non-zero if the
1973 event should be ignored and we should wait again. If STOPPING is
1974 true, the new LWP remains stopped, otherwise it is continued. */
1977 linux_handle_extended_wait (struct lwp_info *lp, int status)
1979 int pid = ptid_get_lwp (lp->ptid);
1980 struct target_waitstatus *ourstatus = &lp->waitstatus;
1981 int event = linux_ptrace_get_extended_event (status);
1983 /* All extended events we currently use are mid-syscall. Only
1984 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1985 you have to be using PTRACE_SEIZE to get that. */
1986 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1988 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1989 || event == PTRACE_EVENT_CLONE)
1991 unsigned long new_pid;
1994 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1996 /* If we haven't already seen the new PID stop, wait for it now. */
1997 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1999 /* The new child has a pending SIGSTOP. We can't affect it until it
2000 hits the SIGSTOP, but we're already attached. */
2001 ret = my_waitpid (new_pid, &status, __WALL);
2003 perror_with_name (_("waiting for new child"));
2004 else if (ret != new_pid)
2005 internal_error (__FILE__, __LINE__,
2006 _("wait returned unexpected PID %d"), ret);
2007 else if (!WIFSTOPPED (status))
2008 internal_error (__FILE__, __LINE__,
2009 _("wait returned unexpected status 0x%x"), status);
2012 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2014 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2016 /* The arch-specific native code may need to know about new
2017 forks even if those end up never mapped to an
2019 if (linux_nat_new_fork != NULL)
2020 linux_nat_new_fork (lp, new_pid);
2023 if (event == PTRACE_EVENT_FORK
2024 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2026 /* Handle checkpointing by linux-fork.c here as a special
2027 case. We don't want the follow-fork-mode or 'catch fork'
2028 to interfere with this. */
2030 /* This won't actually modify the breakpoint list, but will
2031 physically remove the breakpoints from the child. */
2032 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2034 /* Retain child fork in ptrace (stopped) state. */
2035 if (!find_fork_pid (new_pid))
2038 /* Report as spurious, so that infrun doesn't want to follow
2039 this fork. We're actually doing an infcall in
2041 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2043 /* Report the stop to the core. */
2047 if (event == PTRACE_EVENT_FORK)
2048 ourstatus->kind = TARGET_WAITKIND_FORKED;
2049 else if (event == PTRACE_EVENT_VFORK)
2050 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2051 else if (event == PTRACE_EVENT_CLONE)
2053 struct lwp_info *new_lp;
2055 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2057 if (debug_linux_nat)
2058 fprintf_unfiltered (gdb_stdlog,
2059 "LHEW: Got clone event "
2060 "from LWP %d, new child is LWP %ld\n",
2063 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2064 new_lp->stopped = 1;
2065 new_lp->resumed = 1;
2067 /* If the thread_db layer is active, let it record the user
2068 level thread id and status, and add the thread to GDB's
2070 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2072 /* The process is not using thread_db. Add the LWP to
2074 target_post_attach (ptid_get_lwp (new_lp->ptid));
2075 add_thread (new_lp->ptid);
2078 /* Even if we're stopping the thread for some reason
2079 internal to this module, from the perspective of infrun
2080 and the user/frontend, this new thread is running until
2081 it next reports a stop. */
2082 set_running (new_lp->ptid, 1);
2083 set_executing (new_lp->ptid, 1);
2085 if (WSTOPSIG (status) != SIGSTOP)
2087 /* This can happen if someone starts sending signals to
2088 the new thread before it gets a chance to run, which
2089 have a lower number than SIGSTOP (e.g. SIGUSR1).
2090 This is an unlikely case, and harder to handle for
2091 fork / vfork than for clone, so we do not try - but
2092 we handle it for clone events here. */
2094 new_lp->signalled = 1;
2096 /* We created NEW_LP so it cannot yet contain STATUS. */
2097 gdb_assert (new_lp->status == 0);
2099 /* Save the wait status to report later. */
2100 if (debug_linux_nat)
2101 fprintf_unfiltered (gdb_stdlog,
2102 "LHEW: waitpid of new LWP %ld, "
2103 "saving status %s\n",
2104 (long) ptid_get_lwp (new_lp->ptid),
2105 status_to_str (status));
2106 new_lp->status = status;
2108 else if (report_thread_events)
2110 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2111 new_lp->status = status;
2120 if (event == PTRACE_EVENT_EXEC)
2122 if (debug_linux_nat)
2123 fprintf_unfiltered (gdb_stdlog,
2124 "LHEW: Got exec event from LWP %ld\n",
2125 ptid_get_lwp (lp->ptid));
2127 ourstatus->kind = TARGET_WAITKIND_EXECD;
2128 ourstatus->value.execd_pathname
2129 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2131 /* The thread that execed must have been resumed, but, when a
2132 thread execs, it changes its tid to the tgid, and the old
2133 tgid thread might have not been resumed. */
2138 if (event == PTRACE_EVENT_VFORK_DONE)
2140 if (current_inferior ()->waiting_for_vfork_done)
2142 if (debug_linux_nat)
2143 fprintf_unfiltered (gdb_stdlog,
2144 "LHEW: Got expected PTRACE_EVENT_"
2145 "VFORK_DONE from LWP %ld: stopping\n",
2146 ptid_get_lwp (lp->ptid));
2148 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2152 if (debug_linux_nat)
2153 fprintf_unfiltered (gdb_stdlog,
2154 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2155 "from LWP %ld: ignoring\n",
2156 ptid_get_lwp (lp->ptid));
2160 internal_error (__FILE__, __LINE__,
2161 _("unknown ptrace event %d"), event);
2164 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2168 wait_lwp (struct lwp_info *lp)
2172 int thread_dead = 0;
2175 gdb_assert (!lp->stopped);
2176 gdb_assert (lp->status == 0);
2178 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2179 block_child_signals (&prev_mask);
2183 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2184 if (pid == -1 && errno == ECHILD)
2186 /* The thread has previously exited. We need to delete it
2187 now because if this was a non-leader thread execing, we
2188 won't get an exit event. See comments on exec events at
2189 the top of the file. */
2191 if (debug_linux_nat)
2192 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2193 target_pid_to_str (lp->ptid));
2198 /* Bugs 10970, 12702.
2199 Thread group leader may have exited in which case we'll lock up in
2200 waitpid if there are other threads, even if they are all zombies too.
2201 Basically, we're not supposed to use waitpid this way.
2202 tkill(pid,0) cannot be used here as it gets ESRCH for both
2203 for zombie and running processes.
2205 As a workaround, check if we're waiting for the thread group leader and
2206 if it's a zombie, and avoid calling waitpid if it is.
2208 This is racy, what if the tgl becomes a zombie right after we check?
2209 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2210 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2212 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2213 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2216 if (debug_linux_nat)
2217 fprintf_unfiltered (gdb_stdlog,
2218 "WL: Thread group leader %s vanished.\n",
2219 target_pid_to_str (lp->ptid));
2223 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2224 get invoked despite our caller had them intentionally blocked by
2225 block_child_signals. This is sensitive only to the loop of
2226 linux_nat_wait_1 and there if we get called my_waitpid gets called
2227 again before it gets to sigsuspend so we can safely let the handlers
2228 get executed here. */
2230 if (debug_linux_nat)
2231 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2232 sigsuspend (&suspend_mask);
2235 restore_child_signals_mask (&prev_mask);
2239 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2241 if (debug_linux_nat)
2243 fprintf_unfiltered (gdb_stdlog,
2244 "WL: waitpid %s received %s\n",
2245 target_pid_to_str (lp->ptid),
2246 status_to_str (status));
2249 /* Check if the thread has exited. */
2250 if (WIFEXITED (status) || WIFSIGNALED (status))
2252 if (report_thread_events
2253 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2255 if (debug_linux_nat)
2256 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2257 ptid_get_pid (lp->ptid));
2259 /* If this is the leader exiting, it means the whole
2260 process is gone. Store the status to report to the
2261 core. Store it in lp->waitstatus, because lp->status
2262 would be ambiguous (W_EXITCODE(0,0) == 0). */
2263 store_waitstatus (&lp->waitstatus, status);
2268 if (debug_linux_nat)
2269 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2270 target_pid_to_str (lp->ptid));
2280 gdb_assert (WIFSTOPPED (status));
2283 if (lp->must_set_ptrace_flags)
2285 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2286 int options = linux_nat_ptrace_options (inf->attach_flag);
2288 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2289 lp->must_set_ptrace_flags = 0;
2292 /* Handle GNU/Linux's syscall SIGTRAPs. */
2293 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2295 /* No longer need the sysgood bit. The ptrace event ends up
2296 recorded in lp->waitstatus if we care for it. We can carry
2297 on handling the event like a regular SIGTRAP from here
2299 status = W_STOPCODE (SIGTRAP);
2300 if (linux_handle_syscall_trap (lp, 1))
2301 return wait_lwp (lp);
2305 /* Almost all other ptrace-stops are known to be outside of system
2306 calls, with further exceptions in linux_handle_extended_wait. */
2307 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2310 /* Handle GNU/Linux's extended waitstatus for trace events. */
2311 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2312 && linux_is_extended_waitstatus (status))
2314 if (debug_linux_nat)
2315 fprintf_unfiltered (gdb_stdlog,
2316 "WL: Handling extended status 0x%06x\n",
2318 linux_handle_extended_wait (lp, status);
2325 /* Send a SIGSTOP to LP. */
2328 stop_callback (struct lwp_info *lp, void *data)
2330 if (!lp->stopped && !lp->signalled)
2334 if (debug_linux_nat)
2336 fprintf_unfiltered (gdb_stdlog,
2337 "SC: kill %s **<SIGSTOP>**\n",
2338 target_pid_to_str (lp->ptid));
2341 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2342 if (debug_linux_nat)
2344 fprintf_unfiltered (gdb_stdlog,
2345 "SC: lwp kill %d %s\n",
2347 errno ? safe_strerror (errno) : "ERRNO-OK");
2351 gdb_assert (lp->status == 0);
2357 /* Request a stop on LWP. */
2360 linux_stop_lwp (struct lwp_info *lwp)
2362 stop_callback (lwp, NULL);
2365 /* See linux-nat.h */
2368 linux_stop_and_wait_all_lwps (void)
2370 /* Stop all LWP's ... */
2371 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2373 /* ... and wait until all of them have reported back that
2374 they're no longer running. */
2375 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2378 /* See linux-nat.h */
2381 linux_unstop_all_lwps (void)
2383 iterate_over_lwps (minus_one_ptid,
2384 resume_stopped_resumed_lwps, &minus_one_ptid);
2387 /* Return non-zero if LWP PID has a pending SIGINT. */
2390 linux_nat_has_pending_sigint (int pid)
2392 sigset_t pending, blocked, ignored;
2394 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2396 if (sigismember (&pending, SIGINT)
2397 && !sigismember (&ignored, SIGINT))
2403 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2406 set_ignore_sigint (struct lwp_info *lp, void *data)
2408 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2409 flag to consume the next one. */
2410 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2411 && WSTOPSIG (lp->status) == SIGINT)
2414 lp->ignore_sigint = 1;
2419 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2420 This function is called after we know the LWP has stopped; if the LWP
2421 stopped before the expected SIGINT was delivered, then it will never have
2422 arrived. Also, if the signal was delivered to a shared queue and consumed
2423 by a different thread, it will never be delivered to this LWP. */
2426 maybe_clear_ignore_sigint (struct lwp_info *lp)
2428 if (!lp->ignore_sigint)
2431 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2433 if (debug_linux_nat)
2434 fprintf_unfiltered (gdb_stdlog,
2435 "MCIS: Clearing bogus flag for %s\n",
2436 target_pid_to_str (lp->ptid));
2437 lp->ignore_sigint = 0;
2441 /* Fetch the possible triggered data watchpoint info and store it in
2444 On some archs, like x86, that use debug registers to set
2445 watchpoints, it's possible that the way to know which watched
2446 address trapped, is to check the register that is used to select
2447 which address to watch. Problem is, between setting the watchpoint
2448 and reading back which data address trapped, the user may change
2449 the set of watchpoints, and, as a consequence, GDB changes the
2450 debug registers in the inferior. To avoid reading back a stale
2451 stopped-data-address when that happens, we cache in LP the fact
2452 that a watchpoint trapped, and the corresponding data address, as
2453 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2454 registers meanwhile, we have the cached data we can rely on. */
2457 check_stopped_by_watchpoint (struct lwp_info *lp)
2459 if (linux_ops->to_stopped_by_watchpoint == NULL)
2462 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
2463 inferior_ptid = lp->ptid;
2465 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2467 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2469 if (linux_ops->to_stopped_data_address != NULL)
2470 lp->stopped_data_address_p =
2471 linux_ops->to_stopped_data_address (¤t_target,
2472 &lp->stopped_data_address);
2474 lp->stopped_data_address_p = 0;
2477 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2480 /* Returns true if the LWP had stopped for a watchpoint. */
2483 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2485 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2487 gdb_assert (lp != NULL);
2489 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2493 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2495 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2497 gdb_assert (lp != NULL);
2499 *addr_p = lp->stopped_data_address;
2501 return lp->stopped_data_address_p;
2504 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2507 sigtrap_is_event (int status)
2509 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2512 /* Set alternative SIGTRAP-like events recognizer. If
2513 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2517 linux_nat_set_status_is_event (struct target_ops *t,
2518 int (*status_is_event) (int status))
2520 linux_nat_status_is_event = status_is_event;
2523 /* Wait until LP is stopped. */
2526 stop_wait_callback (struct lwp_info *lp, void *data)
2528 struct inferior *inf = find_inferior_ptid (lp->ptid);
2530 /* If this is a vfork parent, bail out, it is not going to report
2531 any SIGSTOP until the vfork is done with. */
2532 if (inf->vfork_child != NULL)
2539 status = wait_lwp (lp);
2543 if (lp->ignore_sigint && WIFSTOPPED (status)
2544 && WSTOPSIG (status) == SIGINT)
2546 lp->ignore_sigint = 0;
2549 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2551 if (debug_linux_nat)
2552 fprintf_unfiltered (gdb_stdlog,
2553 "PTRACE_CONT %s, 0, 0 (%s) "
2554 "(discarding SIGINT)\n",
2555 target_pid_to_str (lp->ptid),
2556 errno ? safe_strerror (errno) : "OK");
2558 return stop_wait_callback (lp, NULL);
2561 maybe_clear_ignore_sigint (lp);
2563 if (WSTOPSIG (status) != SIGSTOP)
2565 /* The thread was stopped with a signal other than SIGSTOP. */
2567 if (debug_linux_nat)
2568 fprintf_unfiltered (gdb_stdlog,
2569 "SWC: Pending event %s in %s\n",
2570 status_to_str ((int) status),
2571 target_pid_to_str (lp->ptid));
2573 /* Save the sigtrap event. */
2574 lp->status = status;
2575 gdb_assert (lp->signalled);
2576 save_stop_reason (lp);
2580 /* We caught the SIGSTOP that we intended to catch, so
2581 there's no SIGSTOP pending. */
2583 if (debug_linux_nat)
2584 fprintf_unfiltered (gdb_stdlog,
2585 "SWC: Expected SIGSTOP caught for %s.\n",
2586 target_pid_to_str (lp->ptid));
2588 /* Reset SIGNALLED only after the stop_wait_callback call
2589 above as it does gdb_assert on SIGNALLED. */
2597 /* Return non-zero if LP has a wait status pending. Discard the
2598 pending event and resume the LWP if the event that originally
2599 caused the stop became uninteresting. */
2602 status_callback (struct lwp_info *lp, void *data)
2604 /* Only report a pending wait status if we pretend that this has
2605 indeed been resumed. */
2609 if (!lwp_status_pending_p (lp))
2612 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2613 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2615 struct regcache *regcache = get_thread_regcache (lp->ptid);
2619 pc = regcache_read_pc (regcache);
2621 if (pc != lp->stop_pc)
2623 if (debug_linux_nat)
2624 fprintf_unfiltered (gdb_stdlog,
2625 "SC: PC of %s changed. was=%s, now=%s\n",
2626 target_pid_to_str (lp->ptid),
2627 paddress (target_gdbarch (), lp->stop_pc),
2628 paddress (target_gdbarch (), pc));
2632 #if !USE_SIGTRAP_SIGINFO
2633 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
2635 if (debug_linux_nat)
2636 fprintf_unfiltered (gdb_stdlog,
2637 "SC: previous breakpoint of %s, at %s gone\n",
2638 target_pid_to_str (lp->ptid),
2639 paddress (target_gdbarch (), lp->stop_pc));
2647 if (debug_linux_nat)
2648 fprintf_unfiltered (gdb_stdlog,
2649 "SC: pending event of %s cancelled.\n",
2650 target_pid_to_str (lp->ptid));
2653 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2661 /* Count the LWP's that have had events. */
2664 count_events_callback (struct lwp_info *lp, void *data)
2666 int *count = (int *) data;
2668 gdb_assert (count != NULL);
2670 /* Select only resumed LWPs that have an event pending. */
2671 if (lp->resumed && lwp_status_pending_p (lp))
2677 /* Select the LWP (if any) that is currently being single-stepped. */
2680 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2682 if (lp->last_resume_kind == resume_step
2689 /* Returns true if LP has a status pending. */
2692 lwp_status_pending_p (struct lwp_info *lp)
2694 /* We check for lp->waitstatus in addition to lp->status, because we
2695 can have pending process exits recorded in lp->status and
2696 W_EXITCODE(0,0) happens to be 0. */
2697 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2700 /* Select the Nth LWP that has had an event. */
2703 select_event_lwp_callback (struct lwp_info *lp, void *data)
2705 int *selector = (int *) data;
2707 gdb_assert (selector != NULL);
2709 /* Select only resumed LWPs that have an event pending. */
2710 if (lp->resumed && lwp_status_pending_p (lp))
2711 if ((*selector)-- == 0)
2717 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2718 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2719 and save the result in the LWP's stop_reason field. If it stopped
2720 for a breakpoint, decrement the PC if necessary on the lwp's
2724 save_stop_reason (struct lwp_info *lp)
2726 struct regcache *regcache;
2727 struct gdbarch *gdbarch;
2730 #if USE_SIGTRAP_SIGINFO
2734 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2735 gdb_assert (lp->status != 0);
2737 if (!linux_nat_status_is_event (lp->status))
2740 regcache = get_thread_regcache (lp->ptid);
2741 gdbarch = regcache->arch ();
2743 pc = regcache_read_pc (regcache);
2744 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2746 #if USE_SIGTRAP_SIGINFO
2747 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2749 if (siginfo.si_signo == SIGTRAP)
2751 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2752 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2754 /* The si_code is ambiguous on this arch -- check debug
2756 if (!check_stopped_by_watchpoint (lp))
2757 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2759 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2761 /* If we determine the LWP stopped for a SW breakpoint,
2762 trust it. Particularly don't check watchpoint
2763 registers, because at least on s390, we'd find
2764 stopped-by-watchpoint as long as there's a watchpoint
2766 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2768 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2770 /* This can indicate either a hardware breakpoint or
2771 hardware watchpoint. Check debug registers. */
2772 if (!check_stopped_by_watchpoint (lp))
2773 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2775 else if (siginfo.si_code == TRAP_TRACE)
2777 if (debug_linux_nat)
2778 fprintf_unfiltered (gdb_stdlog,
2779 "CSBB: %s stopped by trace\n",
2780 target_pid_to_str (lp->ptid));
2782 /* We may have single stepped an instruction that
2783 triggered a watchpoint. In that case, on some
2784 architectures (such as x86), instead of TRAP_HWBKPT,
2785 si_code indicates TRAP_TRACE, and we need to check
2786 the debug registers separately. */
2787 check_stopped_by_watchpoint (lp);
2792 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2793 && software_breakpoint_inserted_here_p (regcache->aspace (),
2796 /* The LWP was either continued, or stepped a software
2797 breakpoint instruction. */
2798 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2801 if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc))
2802 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2804 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2805 check_stopped_by_watchpoint (lp);
2808 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2810 if (debug_linux_nat)
2811 fprintf_unfiltered (gdb_stdlog,
2812 "CSBB: %s stopped by software breakpoint\n",
2813 target_pid_to_str (lp->ptid));
2815 /* Back up the PC if necessary. */
2817 regcache_write_pc (regcache, sw_bp_pc);
2819 /* Update this so we record the correct stop PC below. */
2822 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2824 if (debug_linux_nat)
2825 fprintf_unfiltered (gdb_stdlog,
2826 "CSBB: %s stopped by hardware breakpoint\n",
2827 target_pid_to_str (lp->ptid));
2829 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2831 if (debug_linux_nat)
2832 fprintf_unfiltered (gdb_stdlog,
2833 "CSBB: %s stopped by hardware watchpoint\n",
2834 target_pid_to_str (lp->ptid));
2841 /* Returns true if the LWP had stopped for a software breakpoint. */
2844 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2846 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2848 gdb_assert (lp != NULL);
2850 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2853 /* Implement the supports_stopped_by_sw_breakpoint method. */
2856 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2858 return USE_SIGTRAP_SIGINFO;
2861 /* Returns true if the LWP had stopped for a hardware
2862 breakpoint/watchpoint. */
2865 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2867 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2869 gdb_assert (lp != NULL);
2871 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2874 /* Implement the supports_stopped_by_hw_breakpoint method. */
2877 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2879 return USE_SIGTRAP_SIGINFO;
2882 /* Select one LWP out of those that have events pending. */
2885 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2888 int random_selector;
2889 struct lwp_info *event_lp = NULL;
2891 /* Record the wait status for the original LWP. */
2892 (*orig_lp)->status = *status;
2894 /* In all-stop, give preference to the LWP that is being
2895 single-stepped. There will be at most one, and it will be the
2896 LWP that the core is most interested in. If we didn't do this,
2897 then we'd have to handle pending step SIGTRAPs somehow in case
2898 the core later continues the previously-stepped thread, as
2899 otherwise we'd report the pending SIGTRAP then, and the core, not
2900 having stepped the thread, wouldn't understand what the trap was
2901 for, and therefore would report it to the user as a random
2903 if (!target_is_non_stop_p ())
2905 event_lp = iterate_over_lwps (filter,
2906 select_singlestep_lwp_callback, NULL);
2907 if (event_lp != NULL)
2909 if (debug_linux_nat)
2910 fprintf_unfiltered (gdb_stdlog,
2911 "SEL: Select single-step %s\n",
2912 target_pid_to_str (event_lp->ptid));
2916 if (event_lp == NULL)
2918 /* Pick one at random, out of those which have had events. */
2920 /* First see how many events we have. */
2921 iterate_over_lwps (filter, count_events_callback, &num_events);
2922 gdb_assert (num_events > 0);
2924 /* Now randomly pick a LWP out of those that have had
2926 random_selector = (int)
2927 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2929 if (debug_linux_nat && num_events > 1)
2930 fprintf_unfiltered (gdb_stdlog,
2931 "SEL: Found %d events, selecting #%d\n",
2932 num_events, random_selector);
2934 event_lp = iterate_over_lwps (filter,
2935 select_event_lwp_callback,
2939 if (event_lp != NULL)
2941 /* Switch the event LWP. */
2942 *orig_lp = event_lp;
2943 *status = event_lp->status;
2946 /* Flush the wait status for the event LWP. */
2947 (*orig_lp)->status = 0;
2950 /* Return non-zero if LP has been resumed. */
2953 resumed_callback (struct lwp_info *lp, void *data)
2958 /* Check if we should go on and pass this event to common code.
2959 Return the affected lwp if we are, or NULL otherwise. */
2961 static struct lwp_info *
2962 linux_nat_filter_event (int lwpid, int status)
2964 struct lwp_info *lp;
2965 int event = linux_ptrace_get_extended_event (status);
2967 lp = find_lwp_pid (pid_to_ptid (lwpid));
2969 /* Check for stop events reported by a process we didn't already
2970 know about - anything not already in our LWP list.
2972 If we're expecting to receive stopped processes after
2973 fork, vfork, and clone events, then we'll just add the
2974 new one to our list and go back to waiting for the event
2975 to be reported - the stopped process might be returned
2976 from waitpid before or after the event is.
2978 But note the case of a non-leader thread exec'ing after the
2979 leader having exited, and gone from our lists. The non-leader
2980 thread changes its tid to the tgid. */
2982 if (WIFSTOPPED (status) && lp == NULL
2983 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2985 /* A multi-thread exec after we had seen the leader exiting. */
2986 if (debug_linux_nat)
2987 fprintf_unfiltered (gdb_stdlog,
2988 "LLW: Re-adding thread group leader LWP %d.\n",
2991 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
2994 add_thread (lp->ptid);
2997 if (WIFSTOPPED (status) && !lp)
2999 if (debug_linux_nat)
3000 fprintf_unfiltered (gdb_stdlog,
3001 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3002 (long) lwpid, status_to_str (status));
3003 add_to_pid_list (&stopped_pids, lwpid, status);
3007 /* Make sure we don't report an event for the exit of an LWP not in
3008 our list, i.e. not part of the current process. This can happen
3009 if we detach from a program we originally forked and then it
3011 if (!WIFSTOPPED (status) && !lp)
3014 /* This LWP is stopped now. (And if dead, this prevents it from
3015 ever being continued.) */
3018 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3020 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3021 int options = linux_nat_ptrace_options (inf->attach_flag);
3023 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3024 lp->must_set_ptrace_flags = 0;
3027 /* Handle GNU/Linux's syscall SIGTRAPs. */
3028 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3030 /* No longer need the sysgood bit. The ptrace event ends up
3031 recorded in lp->waitstatus if we care for it. We can carry
3032 on handling the event like a regular SIGTRAP from here
3034 status = W_STOPCODE (SIGTRAP);
3035 if (linux_handle_syscall_trap (lp, 0))
3040 /* Almost all other ptrace-stops are known to be outside of system
3041 calls, with further exceptions in linux_handle_extended_wait. */
3042 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3045 /* Handle GNU/Linux's extended waitstatus for trace events. */
3046 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3047 && linux_is_extended_waitstatus (status))
3049 if (debug_linux_nat)
3050 fprintf_unfiltered (gdb_stdlog,
3051 "LLW: Handling extended status 0x%06x\n",
3053 if (linux_handle_extended_wait (lp, status))
3057 /* Check if the thread has exited. */
3058 if (WIFEXITED (status) || WIFSIGNALED (status))
3060 if (!report_thread_events
3061 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3063 if (debug_linux_nat)
3064 fprintf_unfiltered (gdb_stdlog,
3065 "LLW: %s exited.\n",
3066 target_pid_to_str (lp->ptid));
3068 /* If there is at least one more LWP, then the exit signal
3069 was not the end of the debugged application and should be
3075 /* Note that even if the leader was ptrace-stopped, it can still
3076 exit, if e.g., some other thread brings down the whole
3077 process (calls `exit'). So don't assert that the lwp is
3079 if (debug_linux_nat)
3080 fprintf_unfiltered (gdb_stdlog,
3081 "LWP %ld exited (resumed=%d)\n",
3082 ptid_get_lwp (lp->ptid), lp->resumed);
3084 /* Dead LWP's aren't expected to reported a pending sigstop. */
3087 /* Store the pending event in the waitstatus, because
3088 W_EXITCODE(0,0) == 0. */
3089 store_waitstatus (&lp->waitstatus, status);
3093 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3094 an attempt to stop an LWP. */
3096 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3100 if (lp->last_resume_kind == resume_stop)
3102 if (debug_linux_nat)
3103 fprintf_unfiltered (gdb_stdlog,
3104 "LLW: resume_stop SIGSTOP caught for %s.\n",
3105 target_pid_to_str (lp->ptid));
3109 /* This is a delayed SIGSTOP. Filter out the event. */
3111 if (debug_linux_nat)
3112 fprintf_unfiltered (gdb_stdlog,
3113 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3115 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3116 target_pid_to_str (lp->ptid));
3118 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3119 gdb_assert (lp->resumed);
3124 /* Make sure we don't report a SIGINT that we have already displayed
3125 for another thread. */
3126 if (lp->ignore_sigint
3127 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3129 if (debug_linux_nat)
3130 fprintf_unfiltered (gdb_stdlog,
3131 "LLW: Delayed SIGINT caught for %s.\n",
3132 target_pid_to_str (lp->ptid));
3134 /* This is a delayed SIGINT. */
3135 lp->ignore_sigint = 0;
3137 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3138 if (debug_linux_nat)
3139 fprintf_unfiltered (gdb_stdlog,
3140 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3142 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3143 target_pid_to_str (lp->ptid));
3144 gdb_assert (lp->resumed);
3146 /* Discard the event. */
3150 /* Don't report signals that GDB isn't interested in, such as
3151 signals that are neither printed nor stopped upon. Stopping all
3152 threads can be a bit time-consuming so if we want decent
3153 performance with heavily multi-threaded programs, especially when
3154 they're using a high frequency timer, we'd better avoid it if we
3156 if (WIFSTOPPED (status))
3158 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3160 if (!target_is_non_stop_p ())
3162 /* Only do the below in all-stop, as we currently use SIGSTOP
3163 to implement target_stop (see linux_nat_stop) in
3165 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3167 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3168 forwarded to the entire process group, that is, all LWPs
3169 will receive it - unless they're using CLONE_THREAD to
3170 share signals. Since we only want to report it once, we
3171 mark it as ignored for all LWPs except this one. */
3172 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3173 set_ignore_sigint, NULL);
3174 lp->ignore_sigint = 0;
3177 maybe_clear_ignore_sigint (lp);
3180 /* When using hardware single-step, we need to report every signal.
3181 Otherwise, signals in pass_mask may be short-circuited
3182 except signals that might be caused by a breakpoint. */
3184 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3185 && !linux_wstatus_maybe_breakpoint (status))
3187 linux_resume_one_lwp (lp, lp->step, signo);
3188 if (debug_linux_nat)
3189 fprintf_unfiltered (gdb_stdlog,
3190 "LLW: %s %s, %s (preempt 'handle')\n",
3192 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3193 target_pid_to_str (lp->ptid),
3194 (signo != GDB_SIGNAL_0
3195 ? strsignal (gdb_signal_to_host (signo))
3201 /* An interesting event. */
3203 lp->status = status;
3204 save_stop_reason (lp);
3208 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3209 their exits until all other threads in the group have exited. */
3212 check_zombie_leaders (void)
3214 struct inferior *inf;
3218 struct lwp_info *leader_lp;
3223 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3224 if (leader_lp != NULL
3225 /* Check if there are other threads in the group, as we may
3226 have raced with the inferior simply exiting. */
3227 && num_lwps (inf->pid) > 1
3228 && linux_proc_pid_is_zombie (inf->pid))
3230 if (debug_linux_nat)
3231 fprintf_unfiltered (gdb_stdlog,
3232 "CZL: Thread group leader %d zombie "
3233 "(it exited, or another thread execd).\n",
3236 /* A leader zombie can mean one of two things:
3238 - It exited, and there's an exit status pending
3239 available, or only the leader exited (not the whole
3240 program). In the latter case, we can't waitpid the
3241 leader's exit status until all other threads are gone.
3243 - There are 3 or more threads in the group, and a thread
3244 other than the leader exec'd. See comments on exec
3245 events at the top of the file. We could try
3246 distinguishing the exit and exec cases, by waiting once
3247 more, and seeing if something comes out, but it doesn't
3248 sound useful. The previous leader _does_ go away, and
3249 we'll re-add the new one once we see the exec event
3250 (which is just the same as what would happen if the
3251 previous leader did exit voluntarily before some other
3254 if (debug_linux_nat)
3255 fprintf_unfiltered (gdb_stdlog,
3256 "CZL: Thread group leader %d vanished.\n",
3258 exit_lwp (leader_lp);
3263 /* Convenience function that is called when the kernel reports an exit
3264 event. This decides whether to report the event to GDB as a
3265 process exit event, a thread exit event, or to suppress the
3269 filter_exit_event (struct lwp_info *event_child,
3270 struct target_waitstatus *ourstatus)
3272 ptid_t ptid = event_child->ptid;
3274 if (num_lwps (ptid_get_pid (ptid)) > 1)
3276 if (report_thread_events)
3277 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3279 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3281 exit_lwp (event_child);
3288 linux_nat_wait_1 (struct target_ops *ops,
3289 ptid_t ptid, struct target_waitstatus *ourstatus,
3293 enum resume_kind last_resume_kind;
3294 struct lwp_info *lp;
3297 if (debug_linux_nat)
3298 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3300 /* The first time we get here after starting a new inferior, we may
3301 not have added it to the LWP list yet - this is the earliest
3302 moment at which we know its PID. */
3303 if (ptid_is_pid (inferior_ptid))
3305 /* Upgrade the main thread's ptid. */
3306 thread_change_ptid (inferior_ptid,
3307 ptid_build (ptid_get_pid (inferior_ptid),
3308 ptid_get_pid (inferior_ptid), 0));
3310 lp = add_initial_lwp (inferior_ptid);
3314 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3315 block_child_signals (&prev_mask);
3317 /* First check if there is a LWP with a wait status pending. */
3318 lp = iterate_over_lwps (ptid, status_callback, NULL);
3321 if (debug_linux_nat)
3322 fprintf_unfiltered (gdb_stdlog,
3323 "LLW: Using pending wait status %s for %s.\n",
3324 status_to_str (lp->status),
3325 target_pid_to_str (lp->ptid));
3328 /* But if we don't find a pending event, we'll have to wait. Always
3329 pull all events out of the kernel. We'll randomly select an
3330 event LWP out of all that have events, to prevent starvation. */
3336 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3339 - If the thread group leader exits while other threads in the
3340 thread group still exist, waitpid(TGID, ...) hangs. That
3341 waitpid won't return an exit status until the other threads
3342 in the group are reapped.
3344 - When a non-leader thread execs, that thread just vanishes
3345 without reporting an exit (so we'd hang if we waited for it
3346 explicitly in that case). The exec event is reported to
3350 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3352 if (debug_linux_nat)
3353 fprintf_unfiltered (gdb_stdlog,
3354 "LNW: waitpid(-1, ...) returned %d, %s\n",
3355 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3359 if (debug_linux_nat)
3361 fprintf_unfiltered (gdb_stdlog,
3362 "LLW: waitpid %ld received %s\n",
3363 (long) lwpid, status_to_str (status));
3366 linux_nat_filter_event (lwpid, status);
3367 /* Retry until nothing comes out of waitpid. A single
3368 SIGCHLD can indicate more than one child stopped. */
3372 /* Now that we've pulled all events out of the kernel, resume
3373 LWPs that don't have an interesting event to report. */
3374 iterate_over_lwps (minus_one_ptid,
3375 resume_stopped_resumed_lwps, &minus_one_ptid);
3377 /* ... and find an LWP with a status to report to the core, if
3379 lp = iterate_over_lwps (ptid, status_callback, NULL);
3383 /* Check for zombie thread group leaders. Those can't be reaped
3384 until all other threads in the thread group are. */
3385 check_zombie_leaders ();
3387 /* If there are no resumed children left, bail. We'd be stuck
3388 forever in the sigsuspend call below otherwise. */
3389 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3391 if (debug_linux_nat)
3392 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3394 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3396 restore_child_signals_mask (&prev_mask);
3397 return minus_one_ptid;
3400 /* No interesting event to report to the core. */
3402 if (target_options & TARGET_WNOHANG)
3404 if (debug_linux_nat)
3405 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3407 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3408 restore_child_signals_mask (&prev_mask);
3409 return minus_one_ptid;
3412 /* We shouldn't end up here unless we want to try again. */
3413 gdb_assert (lp == NULL);
3415 /* Block until we get an event reported with SIGCHLD. */
3416 if (debug_linux_nat)
3417 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3418 sigsuspend (&suspend_mask);
3423 status = lp->status;
3426 if (!target_is_non_stop_p ())
3428 /* Now stop all other LWP's ... */
3429 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3431 /* ... and wait until all of them have reported back that
3432 they're no longer running. */
3433 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3436 /* If we're not waiting for a specific LWP, choose an event LWP from
3437 among those that have had events. Giving equal priority to all
3438 LWPs that have had events helps prevent starvation. */
3439 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3440 select_event_lwp (ptid, &lp, &status);
3442 gdb_assert (lp != NULL);
3444 /* Now that we've selected our final event LWP, un-adjust its PC if
3445 it was a software breakpoint, and we can't reliably support the
3446 "stopped by software breakpoint" stop reason. */
3447 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3448 && !USE_SIGTRAP_SIGINFO)
3450 struct regcache *regcache = get_thread_regcache (lp->ptid);
3451 struct gdbarch *gdbarch = regcache->arch ();
3452 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3458 pc = regcache_read_pc (regcache);
3459 regcache_write_pc (regcache, pc + decr_pc);
3463 /* We'll need this to determine whether to report a SIGSTOP as
3464 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3466 last_resume_kind = lp->last_resume_kind;
3468 if (!target_is_non_stop_p ())
3470 /* In all-stop, from the core's perspective, all LWPs are now
3471 stopped until a new resume action is sent over. */
3472 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3476 resume_clear_callback (lp, NULL);
3479 if (linux_nat_status_is_event (status))
3481 if (debug_linux_nat)
3482 fprintf_unfiltered (gdb_stdlog,
3483 "LLW: trap ptid is %s.\n",
3484 target_pid_to_str (lp->ptid));
3487 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3489 *ourstatus = lp->waitstatus;
3490 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3493 store_waitstatus (ourstatus, status);
3495 if (debug_linux_nat)
3496 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3498 restore_child_signals_mask (&prev_mask);
3500 if (last_resume_kind == resume_stop
3501 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3502 && WSTOPSIG (status) == SIGSTOP)
3504 /* A thread that has been requested to stop by GDB with
3505 target_stop, and it stopped cleanly, so report as SIG0. The
3506 use of SIGSTOP is an implementation detail. */
3507 ourstatus->value.sig = GDB_SIGNAL_0;
3510 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3511 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3514 lp->core = linux_common_core_of_thread (lp->ptid);
3516 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3517 return filter_exit_event (lp, ourstatus);
3522 /* Resume LWPs that are currently stopped without any pending status
3523 to report, but are resumed from the core's perspective. */
3526 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3528 ptid_t *wait_ptid_p = (ptid_t *) data;
3532 if (debug_linux_nat)
3533 fprintf_unfiltered (gdb_stdlog,
3534 "RSRL: NOT resuming LWP %s, not stopped\n",
3535 target_pid_to_str (lp->ptid));
3537 else if (!lp->resumed)
3539 if (debug_linux_nat)
3540 fprintf_unfiltered (gdb_stdlog,
3541 "RSRL: NOT resuming LWP %s, not resumed\n",
3542 target_pid_to_str (lp->ptid));
3544 else if (lwp_status_pending_p (lp))
3546 if (debug_linux_nat)
3547 fprintf_unfiltered (gdb_stdlog,
3548 "RSRL: NOT resuming LWP %s, has pending status\n",
3549 target_pid_to_str (lp->ptid));
3553 struct regcache *regcache = get_thread_regcache (lp->ptid);
3554 struct gdbarch *gdbarch = regcache->arch ();
3558 CORE_ADDR pc = regcache_read_pc (regcache);
3559 int leave_stopped = 0;
3561 /* Don't bother if there's a breakpoint at PC that we'd hit
3562 immediately, and we're not waiting for this LWP. */
3563 if (!ptid_match (lp->ptid, *wait_ptid_p))
3565 if (breakpoint_inserted_here_p (regcache->aspace (), pc))
3571 if (debug_linux_nat)
3572 fprintf_unfiltered (gdb_stdlog,
3573 "RSRL: resuming stopped-resumed LWP %s at "
3575 target_pid_to_str (lp->ptid),
3576 paddress (gdbarch, pc),
3579 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3582 CATCH (ex, RETURN_MASK_ERROR)
3584 if (!check_ptrace_stopped_lwp_gone (lp))
3585 throw_exception (ex);
3594 linux_nat_wait (struct target_ops *ops,
3595 ptid_t ptid, struct target_waitstatus *ourstatus,
3600 if (debug_linux_nat)
3602 char *options_string;
3604 options_string = target_options_to_string (target_options);
3605 fprintf_unfiltered (gdb_stdlog,
3606 "linux_nat_wait: [%s], [%s]\n",
3607 target_pid_to_str (ptid),
3609 xfree (options_string);
3612 /* Flush the async file first. */
3613 if (target_is_async_p ())
3614 async_file_flush ();
3616 /* Resume LWPs that are currently stopped without any pending status
3617 to report, but are resumed from the core's perspective. LWPs get
3618 in this state if we find them stopping at a time we're not
3619 interested in reporting the event (target_wait on a
3620 specific_process, for example, see linux_nat_wait_1), and
3621 meanwhile the event became uninteresting. Don't bother resuming
3622 LWPs we're not going to wait for if they'd stop immediately. */
3623 if (target_is_non_stop_p ())
3624 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3626 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3628 /* If we requested any event, and something came out, assume there
3629 may be more. If we requested a specific lwp or process, also
3630 assume there may be more. */
3631 if (target_is_async_p ()
3632 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3633 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3634 || !ptid_equal (ptid, minus_one_ptid)))
3643 kill_one_lwp (pid_t pid)
3645 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3648 kill_lwp (pid, SIGKILL);
3649 if (debug_linux_nat)
3651 int save_errno = errno;
3653 fprintf_unfiltered (gdb_stdlog,
3654 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3655 save_errno ? safe_strerror (save_errno) : "OK");
3658 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3661 ptrace (PTRACE_KILL, pid, 0, 0);
3662 if (debug_linux_nat)
3664 int save_errno = errno;
3666 fprintf_unfiltered (gdb_stdlog,
3667 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3668 save_errno ? safe_strerror (save_errno) : "OK");
3672 /* Wait for an LWP to die. */
3675 kill_wait_one_lwp (pid_t pid)
3679 /* We must make sure that there are no pending events (delayed
3680 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3681 program doesn't interfere with any following debugging session. */
3685 res = my_waitpid (pid, NULL, __WALL);
3686 if (res != (pid_t) -1)
3688 if (debug_linux_nat)
3689 fprintf_unfiltered (gdb_stdlog,
3690 "KWC: wait %ld received unknown.\n",
3692 /* The Linux kernel sometimes fails to kill a thread
3693 completely after PTRACE_KILL; that goes from the stop
3694 point in do_fork out to the one in get_signal_to_deliver
3695 and waits again. So kill it again. */
3701 gdb_assert (res == -1 && errno == ECHILD);
3704 /* Callback for iterate_over_lwps. */
3707 kill_callback (struct lwp_info *lp, void *data)
3709 kill_one_lwp (ptid_get_lwp (lp->ptid));
3713 /* Callback for iterate_over_lwps. */
3716 kill_wait_callback (struct lwp_info *lp, void *data)
3718 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3722 /* Kill the fork children of any threads of inferior INF that are
3723 stopped at a fork event. */
3726 kill_unfollowed_fork_children (struct inferior *inf)
3728 struct thread_info *thread;
3730 ALL_NON_EXITED_THREADS (thread)
3731 if (thread->inf == inf)
3733 struct target_waitstatus *ws = &thread->pending_follow;
3735 if (ws->kind == TARGET_WAITKIND_FORKED
3736 || ws->kind == TARGET_WAITKIND_VFORKED)
3738 ptid_t child_ptid = ws->value.related_pid;
3739 int child_pid = ptid_get_pid (child_ptid);
3740 int child_lwp = ptid_get_lwp (child_ptid);
3742 kill_one_lwp (child_lwp);
3743 kill_wait_one_lwp (child_lwp);
3745 /* Let the arch-specific native code know this process is
3747 linux_nat_forget_process (child_pid);
3753 linux_nat_kill (struct target_ops *ops)
3755 /* If we're stopped while forking and we haven't followed yet,
3756 kill the other task. We need to do this first because the
3757 parent will be sleeping if this is a vfork. */
3758 kill_unfollowed_fork_children (current_inferior ());
3760 if (forks_exist_p ())
3761 linux_fork_killall ();
3764 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3766 /* Stop all threads before killing them, since ptrace requires
3767 that the thread is stopped to sucessfully PTRACE_KILL. */
3768 iterate_over_lwps (ptid, stop_callback, NULL);
3769 /* ... and wait until all of them have reported back that
3770 they're no longer running. */
3771 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3773 /* Kill all LWP's ... */
3774 iterate_over_lwps (ptid, kill_callback, NULL);
3776 /* ... and wait until we've flushed all events. */
3777 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3780 target_mourn_inferior (inferior_ptid);
3784 linux_nat_mourn_inferior (struct target_ops *ops)
3786 int pid = ptid_get_pid (inferior_ptid);
3788 purge_lwp_list (pid);
3790 if (! forks_exist_p ())
3791 /* Normal case, no other forks available. */
3792 linux_ops->to_mourn_inferior (ops);
3794 /* Multi-fork case. The current inferior_ptid has exited, but
3795 there are other viable forks to debug. Delete the exiting
3796 one and context-switch to the first available. */
3797 linux_fork_mourn_inferior ();
3799 /* Let the arch-specific native code know this process is gone. */
3800 linux_nat_forget_process (pid);
3803 /* Convert a native/host siginfo object, into/from the siginfo in the
3804 layout of the inferiors' architecture. */
3807 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3811 if (linux_nat_siginfo_fixup != NULL)
3812 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3814 /* If there was no callback, or the callback didn't do anything,
3815 then just do a straight memcpy. */
3819 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3821 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3825 static enum target_xfer_status
3826 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3827 const char *annex, gdb_byte *readbuf,
3828 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3829 ULONGEST *xfered_len)
3833 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3835 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3836 gdb_assert (readbuf || writebuf);
3838 pid = ptid_get_lwp (inferior_ptid);
3840 pid = ptid_get_pid (inferior_ptid);
3842 if (offset > sizeof (siginfo))
3843 return TARGET_XFER_E_IO;
3846 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3848 return TARGET_XFER_E_IO;
3850 /* When GDB is built as a 64-bit application, ptrace writes into
3851 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3852 inferior with a 64-bit GDB should look the same as debugging it
3853 with a 32-bit GDB, we need to convert it. GDB core always sees
3854 the converted layout, so any read/write will have to be done
3856 siginfo_fixup (&siginfo, inf_siginfo, 0);
3858 if (offset + len > sizeof (siginfo))
3859 len = sizeof (siginfo) - offset;
3861 if (readbuf != NULL)
3862 memcpy (readbuf, inf_siginfo + offset, len);
3865 memcpy (inf_siginfo + offset, writebuf, len);
3867 /* Convert back to ptrace layout before flushing it out. */
3868 siginfo_fixup (&siginfo, inf_siginfo, 1);
3871 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3873 return TARGET_XFER_E_IO;
3877 return TARGET_XFER_OK;
3880 static enum target_xfer_status
3881 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3882 const char *annex, gdb_byte *readbuf,
3883 const gdb_byte *writebuf,
3884 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3886 enum target_xfer_status xfer;
3888 if (object == TARGET_OBJECT_SIGNAL_INFO)
3889 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3890 offset, len, xfered_len);
3892 /* The target is connected but no live inferior is selected. Pass
3893 this request down to a lower stratum (e.g., the executable
3895 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3896 return TARGET_XFER_EOF;
3898 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3899 offset, len, xfered_len);
3905 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3907 /* As long as a PTID is in lwp list, consider it alive. */
3908 return find_lwp_pid (ptid) != NULL;
3911 /* Implement the to_update_thread_list target method for this
3915 linux_nat_update_thread_list (struct target_ops *ops)
3917 struct lwp_info *lwp;
3919 /* We add/delete threads from the list as clone/exit events are
3920 processed, so just try deleting exited threads still in the
3922 delete_exited_threads ();
3924 /* Update the processor core that each lwp/thread was last seen
3928 /* Avoid accessing /proc if the thread hasn't run since we last
3929 time we fetched the thread's core. Accessing /proc becomes
3930 noticeably expensive when we have thousands of LWPs. */
3931 if (lwp->core == -1)
3932 lwp->core = linux_common_core_of_thread (lwp->ptid);
3937 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3939 static char buf[64];
3941 if (ptid_lwp_p (ptid)
3942 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3943 || num_lwps (ptid_get_pid (ptid)) > 1))
3945 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3949 return normal_pid_to_str (ptid);
3953 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3955 return linux_proc_tid_get_name (thr->ptid);
3958 /* Accepts an integer PID; Returns a string representing a file that
3959 can be opened to get the symbols for the child process. */
3962 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3964 return linux_proc_pid_to_exec_file (pid);
3967 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3968 Because we can use a single read/write call, this can be much more
3969 efficient than banging away at PTRACE_PEEKTEXT. */
3971 static enum target_xfer_status
3972 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3973 const char *annex, gdb_byte *readbuf,
3974 const gdb_byte *writebuf,
3975 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3981 if (object != TARGET_OBJECT_MEMORY)
3982 return TARGET_XFER_EOF;
3984 /* Don't bother for one word. */
3985 if (len < 3 * sizeof (long))
3986 return TARGET_XFER_EOF;
3988 /* We could keep this file open and cache it - possibly one per
3989 thread. That requires some juggling, but is even faster. */
3990 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3991 ptid_get_lwp (inferior_ptid));
3992 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
3995 return TARGET_XFER_EOF;
3997 /* Use pread64/pwrite64 if available, since they save a syscall and can
3998 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
3999 debugging a SPARC64 application). */
4001 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
4002 : pwrite64 (fd, writebuf, len, offset));
4004 ret = lseek (fd, offset, SEEK_SET);
4006 ret = (readbuf ? read (fd, readbuf, len)
4007 : write (fd, writebuf, len));
4012 if (ret == -1 || ret == 0)
4013 return TARGET_XFER_EOF;
4017 return TARGET_XFER_OK;
4022 /* Enumerate spufs IDs for process PID. */
4024 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4026 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4028 LONGEST written = 0;
4031 struct dirent *entry;
4033 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4034 dir = opendir (path);
4039 while ((entry = readdir (dir)) != NULL)
4045 fd = atoi (entry->d_name);
4049 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4050 if (stat (path, &st) != 0)
4052 if (!S_ISDIR (st.st_mode))
4055 if (statfs (path, &stfs) != 0)
4057 if (stfs.f_type != SPUFS_MAGIC)
4060 if (pos >= offset && pos + 4 <= offset + len)
4062 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4072 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4073 object type, using the /proc file system. */
4075 static enum target_xfer_status
4076 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4077 const char *annex, gdb_byte *readbuf,
4078 const gdb_byte *writebuf,
4079 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4084 int pid = ptid_get_lwp (inferior_ptid);
4089 return TARGET_XFER_E_IO;
4092 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4095 return TARGET_XFER_E_IO;
4097 return TARGET_XFER_EOF;
4100 *xfered_len = (ULONGEST) l;
4101 return TARGET_XFER_OK;
4106 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4107 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4109 return TARGET_XFER_E_IO;
4112 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4115 return TARGET_XFER_EOF;
4119 ret = write (fd, writebuf, (size_t) len);
4121 ret = read (fd, readbuf, (size_t) len);
4126 return TARGET_XFER_E_IO;
4128 return TARGET_XFER_EOF;
4131 *xfered_len = (ULONGEST) ret;
4132 return TARGET_XFER_OK;
4137 /* Parse LINE as a signal set and add its set bits to SIGS. */
4140 add_line_to_sigset (const char *line, sigset_t *sigs)
4142 int len = strlen (line) - 1;
4146 if (line[len] != '\n')
4147 error (_("Could not parse signal set: %s"), line);
4155 if (*p >= '0' && *p <= '9')
4157 else if (*p >= 'a' && *p <= 'f')
4158 digit = *p - 'a' + 10;
4160 error (_("Could not parse signal set: %s"), line);
4165 sigaddset (sigs, signum + 1);
4167 sigaddset (sigs, signum + 2);
4169 sigaddset (sigs, signum + 3);
4171 sigaddset (sigs, signum + 4);
4177 /* Find process PID's pending signals from /proc/pid/status and set
4181 linux_proc_pending_signals (int pid, sigset_t *pending,
4182 sigset_t *blocked, sigset_t *ignored)
4184 char buffer[PATH_MAX], fname[PATH_MAX];
4186 sigemptyset (pending);
4187 sigemptyset (blocked);
4188 sigemptyset (ignored);
4189 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4190 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
4191 if (procfile == NULL)
4192 error (_("Could not open %s"), fname);
4194 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
4196 /* Normal queued signals are on the SigPnd line in the status
4197 file. However, 2.6 kernels also have a "shared" pending
4198 queue for delivering signals to a thread group, so check for
4201 Unfortunately some Red Hat kernels include the shared pending
4202 queue but not the ShdPnd status field. */
4204 if (startswith (buffer, "SigPnd:\t"))
4205 add_line_to_sigset (buffer + 8, pending);
4206 else if (startswith (buffer, "ShdPnd:\t"))
4207 add_line_to_sigset (buffer + 8, pending);
4208 else if (startswith (buffer, "SigBlk:\t"))
4209 add_line_to_sigset (buffer + 8, blocked);
4210 else if (startswith (buffer, "SigIgn:\t"))
4211 add_line_to_sigset (buffer + 8, ignored);
4215 static enum target_xfer_status
4216 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4217 const char *annex, gdb_byte *readbuf,
4218 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4219 ULONGEST *xfered_len)
4221 gdb_assert (object == TARGET_OBJECT_OSDATA);
4223 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4224 if (*xfered_len == 0)
4225 return TARGET_XFER_EOF;
4227 return TARGET_XFER_OK;
4230 static enum target_xfer_status
4231 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4232 const char *annex, gdb_byte *readbuf,
4233 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4234 ULONGEST *xfered_len)
4236 enum target_xfer_status xfer;
4238 if (object == TARGET_OBJECT_AUXV)
4239 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4240 offset, len, xfered_len);
4242 if (object == TARGET_OBJECT_OSDATA)
4243 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4244 offset, len, xfered_len);
4246 if (object == TARGET_OBJECT_SPU)
4247 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4248 offset, len, xfered_len);
4250 /* GDB calculates all the addresses in possibly larget width of the address.
4251 Address width needs to be masked before its final use - either by
4252 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4254 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4256 if (object == TARGET_OBJECT_MEMORY)
4258 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4260 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4261 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4264 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4265 offset, len, xfered_len);
4266 if (xfer != TARGET_XFER_EOF)
4269 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4270 offset, len, xfered_len);
4274 cleanup_target_stop (void *arg)
4276 ptid_t *ptid = (ptid_t *) arg;
4278 gdb_assert (arg != NULL);
4281 target_continue_no_signal (*ptid);
4284 static VEC(static_tracepoint_marker_p) *
4285 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4288 char s[IPA_CMD_BUF_SIZE];
4289 struct cleanup *old_chain;
4290 int pid = ptid_get_pid (inferior_ptid);
4291 VEC(static_tracepoint_marker_p) *markers = NULL;
4292 struct static_tracepoint_marker *marker = NULL;
4294 ptid_t ptid = ptid_build (pid, 0, 0);
4299 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4300 s[sizeof ("qTfSTM")] = 0;
4302 agent_run_command (pid, s, strlen (s) + 1);
4304 old_chain = make_cleanup (free_current_marker, &marker);
4305 make_cleanup (cleanup_target_stop, &ptid);
4310 marker = XCNEW (struct static_tracepoint_marker);
4314 parse_static_tracepoint_marker_definition (p, &p, marker);
4316 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4318 VEC_safe_push (static_tracepoint_marker_p,
4324 release_static_tracepoint_marker (marker);
4325 memset (marker, 0, sizeof (*marker));
4328 while (*p++ == ','); /* comma-separated list */
4330 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4331 s[sizeof ("qTsSTM")] = 0;
4332 agent_run_command (pid, s, strlen (s) + 1);
4336 do_cleanups (old_chain);
4341 /* Create a prototype generic GNU/Linux target. The client can override
4342 it with local methods. */
4345 linux_target_install_ops (struct target_ops *t)
4347 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4348 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4349 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4350 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4351 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4352 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4353 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4354 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4355 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4356 t->to_post_attach = linux_child_post_attach;
4357 t->to_follow_fork = linux_child_follow_fork;
4359 super_xfer_partial = t->to_xfer_partial;
4360 t->to_xfer_partial = linux_xfer_partial;
4362 t->to_static_tracepoint_markers_by_strid
4363 = linux_child_static_tracepoint_markers_by_strid;
4369 struct target_ops *t;
4371 t = inf_ptrace_target ();
4372 linux_target_install_ops (t);
4378 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4380 struct target_ops *t;
4382 t = inf_ptrace_trad_target (register_u_offset);
4383 linux_target_install_ops (t);
4388 /* target_is_async_p implementation. */
4391 linux_nat_is_async_p (struct target_ops *ops)
4393 return linux_is_async_p ();
4396 /* target_can_async_p implementation. */
4399 linux_nat_can_async_p (struct target_ops *ops)
4401 /* We're always async, unless the user explicitly prevented it with the
4402 "maint set target-async" command. */
4403 return target_async_permitted;
4407 linux_nat_supports_non_stop (struct target_ops *self)
4412 /* to_always_non_stop_p implementation. */
4415 linux_nat_always_non_stop_p (struct target_ops *self)
4420 /* True if we want to support multi-process. To be removed when GDB
4421 supports multi-exec. */
4423 int linux_multi_process = 1;
4426 linux_nat_supports_multi_process (struct target_ops *self)
4428 return linux_multi_process;
4432 linux_nat_supports_disable_randomization (struct target_ops *self)
4434 #ifdef HAVE_PERSONALITY
4441 static int async_terminal_is_ours = 1;
4443 /* target_terminal_inferior implementation.
4445 This is a wrapper around child_terminal_inferior to add async support. */
4448 linux_nat_terminal_inferior (struct target_ops *self)
4450 child_terminal_inferior (self);
4452 /* Calls to target_terminal_*() are meant to be idempotent. */
4453 if (!async_terminal_is_ours)
4456 async_terminal_is_ours = 0;
4460 /* target_terminal::ours implementation.
4462 This is a wrapper around child_terminal_ours to add async support (and
4463 implement the target_terminal::ours vs target_terminal::ours_for_output
4464 distinction). child_terminal_ours is currently no different than
4465 child_terminal_ours_for_output.
4466 We leave target_terminal::ours_for_output alone, leaving it to
4467 child_terminal_ours_for_output. */
4470 linux_nat_terminal_ours (struct target_ops *self)
4472 /* GDB should never give the terminal to the inferior if the
4473 inferior is running in the background (run&, continue&, etc.),
4474 but claiming it sure should. */
4475 child_terminal_ours (self);
4477 if (async_terminal_is_ours)
4480 clear_sigint_trap ();
4481 async_terminal_is_ours = 1;
4484 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4485 so we notice when any child changes state, and notify the
4486 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4487 above to wait for the arrival of a SIGCHLD. */
4490 sigchld_handler (int signo)
4492 int old_errno = errno;
4494 if (debug_linux_nat)
4495 ui_file_write_async_safe (gdb_stdlog,
4496 "sigchld\n", sizeof ("sigchld\n") - 1);
4498 if (signo == SIGCHLD
4499 && linux_nat_event_pipe[0] != -1)
4500 async_file_mark (); /* Let the event loop know that there are
4501 events to handle. */
4506 /* Callback registered with the target events file descriptor. */
4509 handle_target_event (int error, gdb_client_data client_data)
4511 inferior_event_handler (INF_REG_EVENT, NULL);
4514 /* Create/destroy the target events pipe. Returns previous state. */
4517 linux_async_pipe (int enable)
4519 int previous = linux_is_async_p ();
4521 if (previous != enable)
4525 /* Block child signals while we create/destroy the pipe, as
4526 their handler writes to it. */
4527 block_child_signals (&prev_mask);
4531 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4532 internal_error (__FILE__, __LINE__,
4533 "creating event pipe failed.");
4535 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4536 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4540 close (linux_nat_event_pipe[0]);
4541 close (linux_nat_event_pipe[1]);
4542 linux_nat_event_pipe[0] = -1;
4543 linux_nat_event_pipe[1] = -1;
4546 restore_child_signals_mask (&prev_mask);
4552 /* target_async implementation. */
4555 linux_nat_async (struct target_ops *ops, int enable)
4559 if (!linux_async_pipe (1))
4561 add_file_handler (linux_nat_event_pipe[0],
4562 handle_target_event, NULL);
4563 /* There may be pending events to handle. Tell the event loop
4570 delete_file_handler (linux_nat_event_pipe[0]);
4571 linux_async_pipe (0);
4576 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4580 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4584 if (debug_linux_nat)
4585 fprintf_unfiltered (gdb_stdlog,
4586 "LNSL: running -> suspending %s\n",
4587 target_pid_to_str (lwp->ptid));
4590 if (lwp->last_resume_kind == resume_stop)
4592 if (debug_linux_nat)
4593 fprintf_unfiltered (gdb_stdlog,
4594 "linux-nat: already stopping LWP %ld at "
4596 ptid_get_lwp (lwp->ptid));
4600 stop_callback (lwp, NULL);
4601 lwp->last_resume_kind = resume_stop;
4605 /* Already known to be stopped; do nothing. */
4607 if (debug_linux_nat)
4609 if (find_thread_ptid (lwp->ptid)->stop_requested)
4610 fprintf_unfiltered (gdb_stdlog,
4611 "LNSL: already stopped/stop_requested %s\n",
4612 target_pid_to_str (lwp->ptid));
4614 fprintf_unfiltered (gdb_stdlog,
4615 "LNSL: already stopped/no "
4616 "stop_requested yet %s\n",
4617 target_pid_to_str (lwp->ptid));
4624 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4626 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4630 linux_nat_close (struct target_ops *self)
4632 /* Unregister from the event loop. */
4633 if (linux_nat_is_async_p (self))
4634 linux_nat_async (self, 0);
4636 if (linux_ops->to_close)
4637 linux_ops->to_close (linux_ops);
4642 /* When requests are passed down from the linux-nat layer to the
4643 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4644 used. The address space pointer is stored in the inferior object,
4645 but the common code that is passed such ptid can't tell whether
4646 lwpid is a "main" process id or not (it assumes so). We reverse
4647 look up the "main" process id from the lwp here. */
4649 static struct address_space *
4650 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4652 struct lwp_info *lwp;
4653 struct inferior *inf;
4656 if (ptid_get_lwp (ptid) == 0)
4658 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4660 lwp = find_lwp_pid (ptid);
4661 pid = ptid_get_pid (lwp->ptid);
4665 /* A (pid,lwpid,0) ptid. */
4666 pid = ptid_get_pid (ptid);
4669 inf = find_inferior_pid (pid);
4670 gdb_assert (inf != NULL);
4674 /* Return the cached value of the processor core for thread PTID. */
4677 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4679 struct lwp_info *info = find_lwp_pid (ptid);
4686 /* Implementation of to_filesystem_is_local. */
4689 linux_nat_filesystem_is_local (struct target_ops *ops)
4691 struct inferior *inf = current_inferior ();
4693 if (inf->fake_pid_p || inf->pid == 0)
4696 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4699 /* Convert the INF argument passed to a to_fileio_* method
4700 to a process ID suitable for passing to its corresponding
4701 linux_mntns_* function. If INF is non-NULL then the
4702 caller is requesting the filesystem seen by INF. If INF
4703 is NULL then the caller is requesting the filesystem seen
4704 by the GDB. We fall back to GDB's filesystem in the case
4705 that INF is non-NULL but its PID is unknown. */
4708 linux_nat_fileio_pid_of (struct inferior *inf)
4710 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4716 /* Implementation of to_fileio_open. */
4719 linux_nat_fileio_open (struct target_ops *self,
4720 struct inferior *inf, const char *filename,
4721 int flags, int mode, int warn_if_slow,
4728 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4729 || fileio_to_host_mode (mode, &nat_mode) == -1)
4731 *target_errno = FILEIO_EINVAL;
4735 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4736 filename, nat_flags, nat_mode);
4738 *target_errno = host_to_fileio_error (errno);
4743 /* Implementation of to_fileio_readlink. */
4746 linux_nat_fileio_readlink (struct target_ops *self,
4747 struct inferior *inf, const char *filename,
4754 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4755 filename, buf, sizeof (buf));
4758 *target_errno = host_to_fileio_error (errno);
4762 ret = (char *) xmalloc (len + 1);
4763 memcpy (ret, buf, len);
4768 /* Implementation of to_fileio_unlink. */
4771 linux_nat_fileio_unlink (struct target_ops *self,
4772 struct inferior *inf, const char *filename,
4777 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4780 *target_errno = host_to_fileio_error (errno);
4785 /* Implementation of the to_thread_events method. */
4788 linux_nat_thread_events (struct target_ops *ops, int enable)
4790 report_thread_events = enable;
4794 linux_nat_add_target (struct target_ops *t)
4796 /* Save the provided single-threaded target. We save this in a separate
4797 variable because another target we've inherited from (e.g. inf-ptrace)
4798 may have saved a pointer to T; we want to use it for the final
4799 process stratum target. */
4800 linux_ops_saved = *t;
4801 linux_ops = &linux_ops_saved;
4803 /* Override some methods for multithreading. */
4804 t->to_create_inferior = linux_nat_create_inferior;
4805 t->to_attach = linux_nat_attach;
4806 t->to_detach = linux_nat_detach;
4807 t->to_resume = linux_nat_resume;
4808 t->to_wait = linux_nat_wait;
4809 t->to_pass_signals = linux_nat_pass_signals;
4810 t->to_xfer_partial = linux_nat_xfer_partial;
4811 t->to_kill = linux_nat_kill;
4812 t->to_mourn_inferior = linux_nat_mourn_inferior;
4813 t->to_thread_alive = linux_nat_thread_alive;
4814 t->to_update_thread_list = linux_nat_update_thread_list;
4815 t->to_pid_to_str = linux_nat_pid_to_str;
4816 t->to_thread_name = linux_nat_thread_name;
4817 t->to_has_thread_control = tc_schedlock;
4818 t->to_thread_address_space = linux_nat_thread_address_space;
4819 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4820 t->to_stopped_data_address = linux_nat_stopped_data_address;
4821 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4822 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4823 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4824 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4825 t->to_thread_events = linux_nat_thread_events;
4827 t->to_can_async_p = linux_nat_can_async_p;
4828 t->to_is_async_p = linux_nat_is_async_p;
4829 t->to_supports_non_stop = linux_nat_supports_non_stop;
4830 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4831 t->to_async = linux_nat_async;
4832 t->to_terminal_inferior = linux_nat_terminal_inferior;
4833 t->to_terminal_ours = linux_nat_terminal_ours;
4835 super_close = t->to_close;
4836 t->to_close = linux_nat_close;
4838 t->to_stop = linux_nat_stop;
4840 t->to_supports_multi_process = linux_nat_supports_multi_process;
4842 t->to_supports_disable_randomization
4843 = linux_nat_supports_disable_randomization;
4845 t->to_core_of_thread = linux_nat_core_of_thread;
4847 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4848 t->to_fileio_open = linux_nat_fileio_open;
4849 t->to_fileio_readlink = linux_nat_fileio_readlink;
4850 t->to_fileio_unlink = linux_nat_fileio_unlink;
4852 /* We don't change the stratum; this target will sit at
4853 process_stratum and thread_db will set at thread_stratum. This
4854 is a little strange, since this is a multi-threaded-capable
4855 target, but we want to be on the stack below thread_db, and we
4856 also want to be used for single-threaded processes. */
4861 /* Register a method to call whenever a new thread is attached. */
4863 linux_nat_set_new_thread (struct target_ops *t,
4864 void (*new_thread) (struct lwp_info *))
4866 /* Save the pointer. We only support a single registered instance
4867 of the GNU/Linux native target, so we do not need to map this to
4869 linux_nat_new_thread = new_thread;
4872 /* Register a method to call whenever a new thread is attached. */
4874 linux_nat_set_delete_thread (struct target_ops *t,
4875 void (*delete_thread) (struct arch_lwp_info *))
4877 /* Save the pointer. We only support a single registered instance
4878 of the GNU/Linux native target, so we do not need to map this to
4880 linux_nat_delete_thread = delete_thread;
4883 /* See declaration in linux-nat.h. */
4886 linux_nat_set_new_fork (struct target_ops *t,
4887 linux_nat_new_fork_ftype *new_fork)
4889 /* Save the pointer. */
4890 linux_nat_new_fork = new_fork;
4893 /* See declaration in linux-nat.h. */
4896 linux_nat_set_forget_process (struct target_ops *t,
4897 linux_nat_forget_process_ftype *fn)
4899 /* Save the pointer. */
4900 linux_nat_forget_process_hook = fn;
4903 /* See declaration in linux-nat.h. */
4906 linux_nat_forget_process (pid_t pid)
4908 if (linux_nat_forget_process_hook != NULL)
4909 linux_nat_forget_process_hook (pid);
4912 /* Register a method that converts a siginfo object between the layout
4913 that ptrace returns, and the layout in the architecture of the
4916 linux_nat_set_siginfo_fixup (struct target_ops *t,
4917 int (*siginfo_fixup) (siginfo_t *,
4921 /* Save the pointer. */
4922 linux_nat_siginfo_fixup = siginfo_fixup;
4925 /* Register a method to call prior to resuming a thread. */
4928 linux_nat_set_prepare_to_resume (struct target_ops *t,
4929 void (*prepare_to_resume) (struct lwp_info *))
4931 /* Save the pointer. */
4932 linux_nat_prepare_to_resume = prepare_to_resume;
4935 /* See linux-nat.h. */
4938 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4942 pid = ptid_get_lwp (ptid);
4944 pid = ptid_get_pid (ptid);
4947 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4950 memset (siginfo, 0, sizeof (*siginfo));
4956 /* See nat/linux-nat.h. */
4959 current_lwp_ptid (void)
4961 gdb_assert (ptid_lwp_p (inferior_ptid));
4962 return inferior_ptid;
4966 _initialize_linux_nat (void)
4968 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4969 &debug_linux_nat, _("\
4970 Set debugging of GNU/Linux lwp module."), _("\
4971 Show debugging of GNU/Linux lwp module."), _("\
4972 Enables printf debugging output."),
4974 show_debug_linux_nat,
4975 &setdebuglist, &showdebuglist);
4977 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4978 &debug_linux_namespaces, _("\
4979 Set debugging of GNU/Linux namespaces module."), _("\
4980 Show debugging of GNU/Linux namespaces module."), _("\
4981 Enables printf debugging output."),
4984 &setdebuglist, &showdebuglist);
4986 /* Save this mask as the default. */
4987 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4989 /* Install a SIGCHLD handler. */
4990 sigchld_action.sa_handler = sigchld_handler;
4991 sigemptyset (&sigchld_action.sa_mask);
4992 sigchld_action.sa_flags = SA_RESTART;
4994 /* Make it the default. */
4995 sigaction (SIGCHLD, &sigchld_action, NULL);
4997 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4998 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4999 sigdelset (&suspend_mask, SIGCHLD);
5001 sigemptyset (&blocked_mask);
5003 lwp_lwpid_htab_create ();
5007 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5008 the GNU/Linux Threads library and therefore doesn't really belong
5011 /* Return the set of signals used by the threads library in *SET. */
5014 lin_thread_get_thread_signals (sigset_t *set)
5018 /* NPTL reserves the first two RT signals, but does not provide any
5019 way for the debugger to query the signal numbers - fortunately
5020 they don't change. */
5021 sigaddset (set, __SIGRTMIN);
5022 sigaddset (set, __SIGRTMIN + 1);