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, inferior *inf, int from_tty)
1502 struct lwp_info *main_lwp;
1505 /* Don't unregister from the event loop, as there may be other
1506 inferiors running. */
1508 /* Stop all threads before detaching. ptrace requires that the
1509 thread is stopped to sucessfully detach. */
1510 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1511 /* ... and wait until all of them have reported back that
1512 they're no longer running. */
1513 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1515 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1517 /* Only the initial process should be left right now. */
1518 gdb_assert (num_lwps (pid) == 1);
1520 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1522 if (forks_exist_p ())
1524 /* Multi-fork case. The current inferior_ptid is being detached
1525 from, but there are other viable forks to debug. Detach from
1526 the current fork, and context-switch to the first
1528 linux_fork_detach (from_tty);
1532 target_announce_detach (from_tty);
1534 /* Pass on any pending signal for the last LWP. */
1535 int signo = get_detach_signal (main_lwp);
1537 detach_one_lwp (main_lwp, &signo);
1539 inf_ptrace_detach_success (ops, inf);
1543 /* Resume execution of the inferior process. If STEP is nonzero,
1544 single-step it. If SIGNAL is nonzero, give it that signal. */
1547 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1548 enum gdb_signal signo)
1552 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1553 We only presently need that if the LWP is stepped though (to
1554 handle the case of stepping a breakpoint instruction). */
1557 struct regcache *regcache = get_thread_regcache (lp->ptid);
1559 lp->stop_pc = regcache_read_pc (regcache);
1564 if (linux_nat_prepare_to_resume != NULL)
1565 linux_nat_prepare_to_resume (lp);
1566 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1568 /* Successfully resumed. Clear state that no longer makes sense,
1569 and mark the LWP as running. Must not do this before resuming
1570 otherwise if that fails other code will be confused. E.g., we'd
1571 later try to stop the LWP and hang forever waiting for a stop
1572 status. Note that we must not throw after this is cleared,
1573 otherwise handle_zombie_lwp_error would get confused. */
1576 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1577 registers_changed_ptid (lp->ptid);
1580 /* Called when we try to resume a stopped LWP and that errors out. If
1581 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1582 or about to become), discard the error, clear any pending status
1583 the LWP may have, and return true (we'll collect the exit status
1584 soon enough). Otherwise, return false. */
1587 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1589 /* If we get an error after resuming the LWP successfully, we'd
1590 confuse !T state for the LWP being gone. */
1591 gdb_assert (lp->stopped);
1593 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1594 because even if ptrace failed with ESRCH, the tracee may be "not
1595 yet fully dead", but already refusing ptrace requests. In that
1596 case the tracee has 'R (Running)' state for a little bit
1597 (observed in Linux 3.18). See also the note on ESRCH in the
1598 ptrace(2) man page. Instead, check whether the LWP has any state
1599 other than ptrace-stopped. */
1601 /* Don't assume anything if /proc/PID/status can't be read. */
1602 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1604 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1606 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1612 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1613 disappears while we try to resume it. */
1616 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1620 linux_resume_one_lwp_throw (lp, step, signo);
1622 CATCH (ex, RETURN_MASK_ERROR)
1624 if (!check_ptrace_stopped_lwp_gone (lp))
1625 throw_exception (ex);
1633 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1637 struct inferior *inf = find_inferior_ptid (lp->ptid);
1639 if (inf->vfork_child != NULL)
1641 if (debug_linux_nat)
1642 fprintf_unfiltered (gdb_stdlog,
1643 "RC: Not resuming %s (vfork parent)\n",
1644 target_pid_to_str (lp->ptid));
1646 else if (!lwp_status_pending_p (lp))
1648 if (debug_linux_nat)
1649 fprintf_unfiltered (gdb_stdlog,
1650 "RC: Resuming sibling %s, %s, %s\n",
1651 target_pid_to_str (lp->ptid),
1652 (signo != GDB_SIGNAL_0
1653 ? strsignal (gdb_signal_to_host (signo))
1655 step ? "step" : "resume");
1657 linux_resume_one_lwp (lp, step, signo);
1661 if (debug_linux_nat)
1662 fprintf_unfiltered (gdb_stdlog,
1663 "RC: Not resuming sibling %s (has pending)\n",
1664 target_pid_to_str (lp->ptid));
1669 if (debug_linux_nat)
1670 fprintf_unfiltered (gdb_stdlog,
1671 "RC: Not resuming sibling %s (not stopped)\n",
1672 target_pid_to_str (lp->ptid));
1676 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1677 Resume LWP with the last stop signal, if it is in pass state. */
1680 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1682 enum gdb_signal signo = GDB_SIGNAL_0;
1689 struct thread_info *thread;
1691 thread = find_thread_ptid (lp->ptid);
1694 signo = thread->suspend.stop_signal;
1695 thread->suspend.stop_signal = GDB_SIGNAL_0;
1699 resume_lwp (lp, 0, signo);
1704 resume_clear_callback (struct lwp_info *lp, void *data)
1707 lp->last_resume_kind = resume_stop;
1712 resume_set_callback (struct lwp_info *lp, void *data)
1715 lp->last_resume_kind = resume_continue;
1720 linux_nat_resume (struct target_ops *ops,
1721 ptid_t ptid, int step, enum gdb_signal signo)
1723 struct lwp_info *lp;
1726 if (debug_linux_nat)
1727 fprintf_unfiltered (gdb_stdlog,
1728 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1729 step ? "step" : "resume",
1730 target_pid_to_str (ptid),
1731 (signo != GDB_SIGNAL_0
1732 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1733 target_pid_to_str (inferior_ptid));
1735 /* A specific PTID means `step only this process id'. */
1736 resume_many = (ptid_equal (minus_one_ptid, ptid)
1737 || ptid_is_pid (ptid));
1739 /* Mark the lwps we're resuming as resumed. */
1740 iterate_over_lwps (ptid, resume_set_callback, NULL);
1742 /* See if it's the current inferior that should be handled
1745 lp = find_lwp_pid (inferior_ptid);
1747 lp = find_lwp_pid (ptid);
1748 gdb_assert (lp != NULL);
1750 /* Remember if we're stepping. */
1751 lp->last_resume_kind = step ? resume_step : resume_continue;
1753 /* If we have a pending wait status for this thread, there is no
1754 point in resuming the process. But first make sure that
1755 linux_nat_wait won't preemptively handle the event - we
1756 should never take this short-circuit if we are going to
1757 leave LP running, since we have skipped resuming all the
1758 other threads. This bit of code needs to be synchronized
1759 with linux_nat_wait. */
1761 if (lp->status && WIFSTOPPED (lp->status))
1764 && WSTOPSIG (lp->status)
1765 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1767 if (debug_linux_nat)
1768 fprintf_unfiltered (gdb_stdlog,
1769 "LLR: Not short circuiting for ignored "
1770 "status 0x%x\n", lp->status);
1772 /* FIXME: What should we do if we are supposed to continue
1773 this thread with a signal? */
1774 gdb_assert (signo == GDB_SIGNAL_0);
1775 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1780 if (lwp_status_pending_p (lp))
1782 /* FIXME: What should we do if we are supposed to continue
1783 this thread with a signal? */
1784 gdb_assert (signo == GDB_SIGNAL_0);
1786 if (debug_linux_nat)
1787 fprintf_unfiltered (gdb_stdlog,
1788 "LLR: Short circuiting for status 0x%x\n",
1791 if (target_can_async_p ())
1794 /* Tell the event loop we have something to process. */
1801 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1803 if (debug_linux_nat)
1804 fprintf_unfiltered (gdb_stdlog,
1805 "LLR: %s %s, %s (resume event thread)\n",
1806 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1807 target_pid_to_str (lp->ptid),
1808 (signo != GDB_SIGNAL_0
1809 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1811 linux_resume_one_lwp (lp, step, signo);
1813 if (target_can_async_p ())
1817 /* Send a signal to an LWP. */
1820 kill_lwp (int lwpid, int signo)
1825 ret = syscall (__NR_tkill, lwpid, signo);
1826 if (errno == ENOSYS)
1828 /* If tkill fails, then we are not using nptl threads, a
1829 configuration we no longer support. */
1830 perror_with_name (("tkill"));
1835 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1836 event, check if the core is interested in it: if not, ignore the
1837 event, and keep waiting; otherwise, we need to toggle the LWP's
1838 syscall entry/exit status, since the ptrace event itself doesn't
1839 indicate it, and report the trap to higher layers. */
1842 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1844 struct target_waitstatus *ourstatus = &lp->waitstatus;
1845 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1846 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1850 /* If we're stopping threads, there's a SIGSTOP pending, which
1851 makes it so that the LWP reports an immediate syscall return,
1852 followed by the SIGSTOP. Skip seeing that "return" using
1853 PTRACE_CONT directly, and let stop_wait_callback collect the
1854 SIGSTOP. Later when the thread is resumed, a new syscall
1855 entry event. If we didn't do this (and returned 0), we'd
1856 leave a syscall entry pending, and our caller, by using
1857 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1858 itself. Later, when the user re-resumes this LWP, we'd see
1859 another syscall entry event and we'd mistake it for a return.
1861 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1862 (leaving immediately with LWP->signalled set, without issuing
1863 a PTRACE_CONT), it would still be problematic to leave this
1864 syscall enter pending, as later when the thread is resumed,
1865 it would then see the same syscall exit mentioned above,
1866 followed by the delayed SIGSTOP, while the syscall didn't
1867 actually get to execute. It seems it would be even more
1868 confusing to the user. */
1870 if (debug_linux_nat)
1871 fprintf_unfiltered (gdb_stdlog,
1872 "LHST: ignoring syscall %d "
1873 "for LWP %ld (stopping threads), "
1874 "resuming with PTRACE_CONT for SIGSTOP\n",
1876 ptid_get_lwp (lp->ptid));
1878 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1879 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1884 /* Always update the entry/return state, even if this particular
1885 syscall isn't interesting to the core now. In async mode,
1886 the user could install a new catchpoint for this syscall
1887 between syscall enter/return, and we'll need to know to
1888 report a syscall return if that happens. */
1889 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1890 ? TARGET_WAITKIND_SYSCALL_RETURN
1891 : TARGET_WAITKIND_SYSCALL_ENTRY);
1893 if (catch_syscall_enabled ())
1895 if (catching_syscall_number (syscall_number))
1897 /* Alright, an event to report. */
1898 ourstatus->kind = lp->syscall_state;
1899 ourstatus->value.syscall_number = syscall_number;
1901 if (debug_linux_nat)
1902 fprintf_unfiltered (gdb_stdlog,
1903 "LHST: stopping for %s of syscall %d"
1906 == TARGET_WAITKIND_SYSCALL_ENTRY
1907 ? "entry" : "return",
1909 ptid_get_lwp (lp->ptid));
1913 if (debug_linux_nat)
1914 fprintf_unfiltered (gdb_stdlog,
1915 "LHST: ignoring %s of syscall %d "
1917 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1918 ? "entry" : "return",
1920 ptid_get_lwp (lp->ptid));
1924 /* If we had been syscall tracing, and hence used PT_SYSCALL
1925 before on this LWP, it could happen that the user removes all
1926 syscall catchpoints before we get to process this event.
1927 There are two noteworthy issues here:
1929 - When stopped at a syscall entry event, resuming with
1930 PT_STEP still resumes executing the syscall and reports a
1933 - Only PT_SYSCALL catches syscall enters. If we last
1934 single-stepped this thread, then this event can't be a
1935 syscall enter. If we last single-stepped this thread, this
1936 has to be a syscall exit.
1938 The points above mean that the next resume, be it PT_STEP or
1939 PT_CONTINUE, can not trigger a syscall trace event. */
1940 if (debug_linux_nat)
1941 fprintf_unfiltered (gdb_stdlog,
1942 "LHST: caught syscall event "
1943 "with no syscall catchpoints."
1944 " %d for LWP %ld, ignoring\n",
1946 ptid_get_lwp (lp->ptid));
1947 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1950 /* The core isn't interested in this event. For efficiency, avoid
1951 stopping all threads only to have the core resume them all again.
1952 Since we're not stopping threads, if we're still syscall tracing
1953 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1954 subsequent syscall. Simply resume using the inf-ptrace layer,
1955 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1957 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1961 /* Handle a GNU/Linux extended wait response. If we see a clone
1962 event, we need to add the new LWP to our list (and not report the
1963 trap to higher layers). This function returns non-zero if the
1964 event should be ignored and we should wait again. If STOPPING is
1965 true, the new LWP remains stopped, otherwise it is continued. */
1968 linux_handle_extended_wait (struct lwp_info *lp, int status)
1970 int pid = ptid_get_lwp (lp->ptid);
1971 struct target_waitstatus *ourstatus = &lp->waitstatus;
1972 int event = linux_ptrace_get_extended_event (status);
1974 /* All extended events we currently use are mid-syscall. Only
1975 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1976 you have to be using PTRACE_SEIZE to get that. */
1977 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1979 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1980 || event == PTRACE_EVENT_CLONE)
1982 unsigned long new_pid;
1985 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1987 /* If we haven't already seen the new PID stop, wait for it now. */
1988 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1990 /* The new child has a pending SIGSTOP. We can't affect it until it
1991 hits the SIGSTOP, but we're already attached. */
1992 ret = my_waitpid (new_pid, &status, __WALL);
1994 perror_with_name (_("waiting for new child"));
1995 else if (ret != new_pid)
1996 internal_error (__FILE__, __LINE__,
1997 _("wait returned unexpected PID %d"), ret);
1998 else if (!WIFSTOPPED (status))
1999 internal_error (__FILE__, __LINE__,
2000 _("wait returned unexpected status 0x%x"), status);
2003 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2005 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2007 /* The arch-specific native code may need to know about new
2008 forks even if those end up never mapped to an
2010 if (linux_nat_new_fork != NULL)
2011 linux_nat_new_fork (lp, new_pid);
2014 if (event == PTRACE_EVENT_FORK
2015 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2017 /* Handle checkpointing by linux-fork.c here as a special
2018 case. We don't want the follow-fork-mode or 'catch fork'
2019 to interfere with this. */
2021 /* This won't actually modify the breakpoint list, but will
2022 physically remove the breakpoints from the child. */
2023 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2025 /* Retain child fork in ptrace (stopped) state. */
2026 if (!find_fork_pid (new_pid))
2029 /* Report as spurious, so that infrun doesn't want to follow
2030 this fork. We're actually doing an infcall in
2032 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2034 /* Report the stop to the core. */
2038 if (event == PTRACE_EVENT_FORK)
2039 ourstatus->kind = TARGET_WAITKIND_FORKED;
2040 else if (event == PTRACE_EVENT_VFORK)
2041 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2042 else if (event == PTRACE_EVENT_CLONE)
2044 struct lwp_info *new_lp;
2046 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2048 if (debug_linux_nat)
2049 fprintf_unfiltered (gdb_stdlog,
2050 "LHEW: Got clone event "
2051 "from LWP %d, new child is LWP %ld\n",
2054 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2055 new_lp->stopped = 1;
2056 new_lp->resumed = 1;
2058 /* If the thread_db layer is active, let it record the user
2059 level thread id and status, and add the thread to GDB's
2061 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2063 /* The process is not using thread_db. Add the LWP to
2065 target_post_attach (ptid_get_lwp (new_lp->ptid));
2066 add_thread (new_lp->ptid);
2069 /* Even if we're stopping the thread for some reason
2070 internal to this module, from the perspective of infrun
2071 and the user/frontend, this new thread is running until
2072 it next reports a stop. */
2073 set_running (new_lp->ptid, 1);
2074 set_executing (new_lp->ptid, 1);
2076 if (WSTOPSIG (status) != SIGSTOP)
2078 /* This can happen if someone starts sending signals to
2079 the new thread before it gets a chance to run, which
2080 have a lower number than SIGSTOP (e.g. SIGUSR1).
2081 This is an unlikely case, and harder to handle for
2082 fork / vfork than for clone, so we do not try - but
2083 we handle it for clone events here. */
2085 new_lp->signalled = 1;
2087 /* We created NEW_LP so it cannot yet contain STATUS. */
2088 gdb_assert (new_lp->status == 0);
2090 /* Save the wait status to report later. */
2091 if (debug_linux_nat)
2092 fprintf_unfiltered (gdb_stdlog,
2093 "LHEW: waitpid of new LWP %ld, "
2094 "saving status %s\n",
2095 (long) ptid_get_lwp (new_lp->ptid),
2096 status_to_str (status));
2097 new_lp->status = status;
2099 else if (report_thread_events)
2101 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2102 new_lp->status = status;
2111 if (event == PTRACE_EVENT_EXEC)
2113 if (debug_linux_nat)
2114 fprintf_unfiltered (gdb_stdlog,
2115 "LHEW: Got exec event from LWP %ld\n",
2116 ptid_get_lwp (lp->ptid));
2118 ourstatus->kind = TARGET_WAITKIND_EXECD;
2119 ourstatus->value.execd_pathname
2120 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2122 /* The thread that execed must have been resumed, but, when a
2123 thread execs, it changes its tid to the tgid, and the old
2124 tgid thread might have not been resumed. */
2129 if (event == PTRACE_EVENT_VFORK_DONE)
2131 if (current_inferior ()->waiting_for_vfork_done)
2133 if (debug_linux_nat)
2134 fprintf_unfiltered (gdb_stdlog,
2135 "LHEW: Got expected PTRACE_EVENT_"
2136 "VFORK_DONE from LWP %ld: stopping\n",
2137 ptid_get_lwp (lp->ptid));
2139 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2143 if (debug_linux_nat)
2144 fprintf_unfiltered (gdb_stdlog,
2145 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2146 "from LWP %ld: ignoring\n",
2147 ptid_get_lwp (lp->ptid));
2151 internal_error (__FILE__, __LINE__,
2152 _("unknown ptrace event %d"), event);
2155 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2159 wait_lwp (struct lwp_info *lp)
2163 int thread_dead = 0;
2166 gdb_assert (!lp->stopped);
2167 gdb_assert (lp->status == 0);
2169 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2170 block_child_signals (&prev_mask);
2174 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2175 if (pid == -1 && errno == ECHILD)
2177 /* The thread has previously exited. We need to delete it
2178 now because if this was a non-leader thread execing, we
2179 won't get an exit event. See comments on exec events at
2180 the top of the file. */
2182 if (debug_linux_nat)
2183 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2184 target_pid_to_str (lp->ptid));
2189 /* Bugs 10970, 12702.
2190 Thread group leader may have exited in which case we'll lock up in
2191 waitpid if there are other threads, even if they are all zombies too.
2192 Basically, we're not supposed to use waitpid this way.
2193 tkill(pid,0) cannot be used here as it gets ESRCH for both
2194 for zombie and running processes.
2196 As a workaround, check if we're waiting for the thread group leader and
2197 if it's a zombie, and avoid calling waitpid if it is.
2199 This is racy, what if the tgl becomes a zombie right after we check?
2200 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2201 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2203 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2204 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2207 if (debug_linux_nat)
2208 fprintf_unfiltered (gdb_stdlog,
2209 "WL: Thread group leader %s vanished.\n",
2210 target_pid_to_str (lp->ptid));
2214 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2215 get invoked despite our caller had them intentionally blocked by
2216 block_child_signals. This is sensitive only to the loop of
2217 linux_nat_wait_1 and there if we get called my_waitpid gets called
2218 again before it gets to sigsuspend so we can safely let the handlers
2219 get executed here. */
2221 if (debug_linux_nat)
2222 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2223 sigsuspend (&suspend_mask);
2226 restore_child_signals_mask (&prev_mask);
2230 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2232 if (debug_linux_nat)
2234 fprintf_unfiltered (gdb_stdlog,
2235 "WL: waitpid %s received %s\n",
2236 target_pid_to_str (lp->ptid),
2237 status_to_str (status));
2240 /* Check if the thread has exited. */
2241 if (WIFEXITED (status) || WIFSIGNALED (status))
2243 if (report_thread_events
2244 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2246 if (debug_linux_nat)
2247 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2248 ptid_get_pid (lp->ptid));
2250 /* If this is the leader exiting, it means the whole
2251 process is gone. Store the status to report to the
2252 core. Store it in lp->waitstatus, because lp->status
2253 would be ambiguous (W_EXITCODE(0,0) == 0). */
2254 store_waitstatus (&lp->waitstatus, status);
2259 if (debug_linux_nat)
2260 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2261 target_pid_to_str (lp->ptid));
2271 gdb_assert (WIFSTOPPED (status));
2274 if (lp->must_set_ptrace_flags)
2276 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2277 int options = linux_nat_ptrace_options (inf->attach_flag);
2279 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2280 lp->must_set_ptrace_flags = 0;
2283 /* Handle GNU/Linux's syscall SIGTRAPs. */
2284 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2286 /* No longer need the sysgood bit. The ptrace event ends up
2287 recorded in lp->waitstatus if we care for it. We can carry
2288 on handling the event like a regular SIGTRAP from here
2290 status = W_STOPCODE (SIGTRAP);
2291 if (linux_handle_syscall_trap (lp, 1))
2292 return wait_lwp (lp);
2296 /* Almost all other ptrace-stops are known to be outside of system
2297 calls, with further exceptions in linux_handle_extended_wait. */
2298 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2301 /* Handle GNU/Linux's extended waitstatus for trace events. */
2302 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2303 && linux_is_extended_waitstatus (status))
2305 if (debug_linux_nat)
2306 fprintf_unfiltered (gdb_stdlog,
2307 "WL: Handling extended status 0x%06x\n",
2309 linux_handle_extended_wait (lp, status);
2316 /* Send a SIGSTOP to LP. */
2319 stop_callback (struct lwp_info *lp, void *data)
2321 if (!lp->stopped && !lp->signalled)
2325 if (debug_linux_nat)
2327 fprintf_unfiltered (gdb_stdlog,
2328 "SC: kill %s **<SIGSTOP>**\n",
2329 target_pid_to_str (lp->ptid));
2332 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2333 if (debug_linux_nat)
2335 fprintf_unfiltered (gdb_stdlog,
2336 "SC: lwp kill %d %s\n",
2338 errno ? safe_strerror (errno) : "ERRNO-OK");
2342 gdb_assert (lp->status == 0);
2348 /* Request a stop on LWP. */
2351 linux_stop_lwp (struct lwp_info *lwp)
2353 stop_callback (lwp, NULL);
2356 /* See linux-nat.h */
2359 linux_stop_and_wait_all_lwps (void)
2361 /* Stop all LWP's ... */
2362 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2364 /* ... and wait until all of them have reported back that
2365 they're no longer running. */
2366 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2369 /* See linux-nat.h */
2372 linux_unstop_all_lwps (void)
2374 iterate_over_lwps (minus_one_ptid,
2375 resume_stopped_resumed_lwps, &minus_one_ptid);
2378 /* Return non-zero if LWP PID has a pending SIGINT. */
2381 linux_nat_has_pending_sigint (int pid)
2383 sigset_t pending, blocked, ignored;
2385 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2387 if (sigismember (&pending, SIGINT)
2388 && !sigismember (&ignored, SIGINT))
2394 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2397 set_ignore_sigint (struct lwp_info *lp, void *data)
2399 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2400 flag to consume the next one. */
2401 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2402 && WSTOPSIG (lp->status) == SIGINT)
2405 lp->ignore_sigint = 1;
2410 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2411 This function is called after we know the LWP has stopped; if the LWP
2412 stopped before the expected SIGINT was delivered, then it will never have
2413 arrived. Also, if the signal was delivered to a shared queue and consumed
2414 by a different thread, it will never be delivered to this LWP. */
2417 maybe_clear_ignore_sigint (struct lwp_info *lp)
2419 if (!lp->ignore_sigint)
2422 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2424 if (debug_linux_nat)
2425 fprintf_unfiltered (gdb_stdlog,
2426 "MCIS: Clearing bogus flag for %s\n",
2427 target_pid_to_str (lp->ptid));
2428 lp->ignore_sigint = 0;
2432 /* Fetch the possible triggered data watchpoint info and store it in
2435 On some archs, like x86, that use debug registers to set
2436 watchpoints, it's possible that the way to know which watched
2437 address trapped, is to check the register that is used to select
2438 which address to watch. Problem is, between setting the watchpoint
2439 and reading back which data address trapped, the user may change
2440 the set of watchpoints, and, as a consequence, GDB changes the
2441 debug registers in the inferior. To avoid reading back a stale
2442 stopped-data-address when that happens, we cache in LP the fact
2443 that a watchpoint trapped, and the corresponding data address, as
2444 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2445 registers meanwhile, we have the cached data we can rely on. */
2448 check_stopped_by_watchpoint (struct lwp_info *lp)
2450 if (linux_ops->to_stopped_by_watchpoint == NULL)
2453 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
2454 inferior_ptid = lp->ptid;
2456 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2458 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2460 if (linux_ops->to_stopped_data_address != NULL)
2461 lp->stopped_data_address_p =
2462 linux_ops->to_stopped_data_address (¤t_target,
2463 &lp->stopped_data_address);
2465 lp->stopped_data_address_p = 0;
2468 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2471 /* Returns true if the LWP had stopped for a watchpoint. */
2474 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2476 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2478 gdb_assert (lp != NULL);
2480 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2484 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2486 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2488 gdb_assert (lp != NULL);
2490 *addr_p = lp->stopped_data_address;
2492 return lp->stopped_data_address_p;
2495 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2498 sigtrap_is_event (int status)
2500 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2503 /* Set alternative SIGTRAP-like events recognizer. If
2504 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2508 linux_nat_set_status_is_event (struct target_ops *t,
2509 int (*status_is_event) (int status))
2511 linux_nat_status_is_event = status_is_event;
2514 /* Wait until LP is stopped. */
2517 stop_wait_callback (struct lwp_info *lp, void *data)
2519 struct inferior *inf = find_inferior_ptid (lp->ptid);
2521 /* If this is a vfork parent, bail out, it is not going to report
2522 any SIGSTOP until the vfork is done with. */
2523 if (inf->vfork_child != NULL)
2530 status = wait_lwp (lp);
2534 if (lp->ignore_sigint && WIFSTOPPED (status)
2535 && WSTOPSIG (status) == SIGINT)
2537 lp->ignore_sigint = 0;
2540 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2542 if (debug_linux_nat)
2543 fprintf_unfiltered (gdb_stdlog,
2544 "PTRACE_CONT %s, 0, 0 (%s) "
2545 "(discarding SIGINT)\n",
2546 target_pid_to_str (lp->ptid),
2547 errno ? safe_strerror (errno) : "OK");
2549 return stop_wait_callback (lp, NULL);
2552 maybe_clear_ignore_sigint (lp);
2554 if (WSTOPSIG (status) != SIGSTOP)
2556 /* The thread was stopped with a signal other than SIGSTOP. */
2558 if (debug_linux_nat)
2559 fprintf_unfiltered (gdb_stdlog,
2560 "SWC: Pending event %s in %s\n",
2561 status_to_str ((int) status),
2562 target_pid_to_str (lp->ptid));
2564 /* Save the sigtrap event. */
2565 lp->status = status;
2566 gdb_assert (lp->signalled);
2567 save_stop_reason (lp);
2571 /* We caught the SIGSTOP that we intended to catch, so
2572 there's no SIGSTOP pending. */
2574 if (debug_linux_nat)
2575 fprintf_unfiltered (gdb_stdlog,
2576 "SWC: Expected SIGSTOP caught for %s.\n",
2577 target_pid_to_str (lp->ptid));
2579 /* Reset SIGNALLED only after the stop_wait_callback call
2580 above as it does gdb_assert on SIGNALLED. */
2588 /* Return non-zero if LP has a wait status pending. Discard the
2589 pending event and resume the LWP if the event that originally
2590 caused the stop became uninteresting. */
2593 status_callback (struct lwp_info *lp, void *data)
2595 /* Only report a pending wait status if we pretend that this has
2596 indeed been resumed. */
2600 if (!lwp_status_pending_p (lp))
2603 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2604 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2606 struct regcache *regcache = get_thread_regcache (lp->ptid);
2610 pc = regcache_read_pc (regcache);
2612 if (pc != lp->stop_pc)
2614 if (debug_linux_nat)
2615 fprintf_unfiltered (gdb_stdlog,
2616 "SC: PC of %s changed. was=%s, now=%s\n",
2617 target_pid_to_str (lp->ptid),
2618 paddress (target_gdbarch (), lp->stop_pc),
2619 paddress (target_gdbarch (), pc));
2623 #if !USE_SIGTRAP_SIGINFO
2624 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
2626 if (debug_linux_nat)
2627 fprintf_unfiltered (gdb_stdlog,
2628 "SC: previous breakpoint of %s, at %s gone\n",
2629 target_pid_to_str (lp->ptid),
2630 paddress (target_gdbarch (), lp->stop_pc));
2638 if (debug_linux_nat)
2639 fprintf_unfiltered (gdb_stdlog,
2640 "SC: pending event of %s cancelled.\n",
2641 target_pid_to_str (lp->ptid));
2644 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2652 /* Count the LWP's that have had events. */
2655 count_events_callback (struct lwp_info *lp, void *data)
2657 int *count = (int *) data;
2659 gdb_assert (count != NULL);
2661 /* Select only resumed LWPs that have an event pending. */
2662 if (lp->resumed && lwp_status_pending_p (lp))
2668 /* Select the LWP (if any) that is currently being single-stepped. */
2671 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2673 if (lp->last_resume_kind == resume_step
2680 /* Returns true if LP has a status pending. */
2683 lwp_status_pending_p (struct lwp_info *lp)
2685 /* We check for lp->waitstatus in addition to lp->status, because we
2686 can have pending process exits recorded in lp->status and
2687 W_EXITCODE(0,0) happens to be 0. */
2688 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2691 /* Select the Nth LWP that has had an event. */
2694 select_event_lwp_callback (struct lwp_info *lp, void *data)
2696 int *selector = (int *) data;
2698 gdb_assert (selector != NULL);
2700 /* Select only resumed LWPs that have an event pending. */
2701 if (lp->resumed && lwp_status_pending_p (lp))
2702 if ((*selector)-- == 0)
2708 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2709 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2710 and save the result in the LWP's stop_reason field. If it stopped
2711 for a breakpoint, decrement the PC if necessary on the lwp's
2715 save_stop_reason (struct lwp_info *lp)
2717 struct regcache *regcache;
2718 struct gdbarch *gdbarch;
2721 #if USE_SIGTRAP_SIGINFO
2725 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2726 gdb_assert (lp->status != 0);
2728 if (!linux_nat_status_is_event (lp->status))
2731 regcache = get_thread_regcache (lp->ptid);
2732 gdbarch = regcache->arch ();
2734 pc = regcache_read_pc (regcache);
2735 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2737 #if USE_SIGTRAP_SIGINFO
2738 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2740 if (siginfo.si_signo == SIGTRAP)
2742 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2743 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2745 /* The si_code is ambiguous on this arch -- check debug
2747 if (!check_stopped_by_watchpoint (lp))
2748 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2750 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2752 /* If we determine the LWP stopped for a SW breakpoint,
2753 trust it. Particularly don't check watchpoint
2754 registers, because at least on s390, we'd find
2755 stopped-by-watchpoint as long as there's a watchpoint
2757 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2759 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2761 /* This can indicate either a hardware breakpoint or
2762 hardware watchpoint. Check debug registers. */
2763 if (!check_stopped_by_watchpoint (lp))
2764 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2766 else if (siginfo.si_code == TRAP_TRACE)
2768 if (debug_linux_nat)
2769 fprintf_unfiltered (gdb_stdlog,
2770 "CSBB: %s stopped by trace\n",
2771 target_pid_to_str (lp->ptid));
2773 /* We may have single stepped an instruction that
2774 triggered a watchpoint. In that case, on some
2775 architectures (such as x86), instead of TRAP_HWBKPT,
2776 si_code indicates TRAP_TRACE, and we need to check
2777 the debug registers separately. */
2778 check_stopped_by_watchpoint (lp);
2783 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2784 && software_breakpoint_inserted_here_p (regcache->aspace (),
2787 /* The LWP was either continued, or stepped a software
2788 breakpoint instruction. */
2789 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2792 if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc))
2793 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2795 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2796 check_stopped_by_watchpoint (lp);
2799 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2801 if (debug_linux_nat)
2802 fprintf_unfiltered (gdb_stdlog,
2803 "CSBB: %s stopped by software breakpoint\n",
2804 target_pid_to_str (lp->ptid));
2806 /* Back up the PC if necessary. */
2808 regcache_write_pc (regcache, sw_bp_pc);
2810 /* Update this so we record the correct stop PC below. */
2813 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2815 if (debug_linux_nat)
2816 fprintf_unfiltered (gdb_stdlog,
2817 "CSBB: %s stopped by hardware breakpoint\n",
2818 target_pid_to_str (lp->ptid));
2820 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2822 if (debug_linux_nat)
2823 fprintf_unfiltered (gdb_stdlog,
2824 "CSBB: %s stopped by hardware watchpoint\n",
2825 target_pid_to_str (lp->ptid));
2832 /* Returns true if the LWP had stopped for a software breakpoint. */
2835 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2837 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2839 gdb_assert (lp != NULL);
2841 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2844 /* Implement the supports_stopped_by_sw_breakpoint method. */
2847 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2849 return USE_SIGTRAP_SIGINFO;
2852 /* Returns true if the LWP had stopped for a hardware
2853 breakpoint/watchpoint. */
2856 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2858 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2860 gdb_assert (lp != NULL);
2862 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2865 /* Implement the supports_stopped_by_hw_breakpoint method. */
2868 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2870 return USE_SIGTRAP_SIGINFO;
2873 /* Select one LWP out of those that have events pending. */
2876 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2879 int random_selector;
2880 struct lwp_info *event_lp = NULL;
2882 /* Record the wait status for the original LWP. */
2883 (*orig_lp)->status = *status;
2885 /* In all-stop, give preference to the LWP that is being
2886 single-stepped. There will be at most one, and it will be the
2887 LWP that the core is most interested in. If we didn't do this,
2888 then we'd have to handle pending step SIGTRAPs somehow in case
2889 the core later continues the previously-stepped thread, as
2890 otherwise we'd report the pending SIGTRAP then, and the core, not
2891 having stepped the thread, wouldn't understand what the trap was
2892 for, and therefore would report it to the user as a random
2894 if (!target_is_non_stop_p ())
2896 event_lp = iterate_over_lwps (filter,
2897 select_singlestep_lwp_callback, NULL);
2898 if (event_lp != NULL)
2900 if (debug_linux_nat)
2901 fprintf_unfiltered (gdb_stdlog,
2902 "SEL: Select single-step %s\n",
2903 target_pid_to_str (event_lp->ptid));
2907 if (event_lp == NULL)
2909 /* Pick one at random, out of those which have had events. */
2911 /* First see how many events we have. */
2912 iterate_over_lwps (filter, count_events_callback, &num_events);
2913 gdb_assert (num_events > 0);
2915 /* Now randomly pick a LWP out of those that have had
2917 random_selector = (int)
2918 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2920 if (debug_linux_nat && num_events > 1)
2921 fprintf_unfiltered (gdb_stdlog,
2922 "SEL: Found %d events, selecting #%d\n",
2923 num_events, random_selector);
2925 event_lp = iterate_over_lwps (filter,
2926 select_event_lwp_callback,
2930 if (event_lp != NULL)
2932 /* Switch the event LWP. */
2933 *orig_lp = event_lp;
2934 *status = event_lp->status;
2937 /* Flush the wait status for the event LWP. */
2938 (*orig_lp)->status = 0;
2941 /* Return non-zero if LP has been resumed. */
2944 resumed_callback (struct lwp_info *lp, void *data)
2949 /* Check if we should go on and pass this event to common code.
2950 Return the affected lwp if we are, or NULL otherwise. */
2952 static struct lwp_info *
2953 linux_nat_filter_event (int lwpid, int status)
2955 struct lwp_info *lp;
2956 int event = linux_ptrace_get_extended_event (status);
2958 lp = find_lwp_pid (pid_to_ptid (lwpid));
2960 /* Check for stop events reported by a process we didn't already
2961 know about - anything not already in our LWP list.
2963 If we're expecting to receive stopped processes after
2964 fork, vfork, and clone events, then we'll just add the
2965 new one to our list and go back to waiting for the event
2966 to be reported - the stopped process might be returned
2967 from waitpid before or after the event is.
2969 But note the case of a non-leader thread exec'ing after the
2970 leader having exited, and gone from our lists. The non-leader
2971 thread changes its tid to the tgid. */
2973 if (WIFSTOPPED (status) && lp == NULL
2974 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2976 /* A multi-thread exec after we had seen the leader exiting. */
2977 if (debug_linux_nat)
2978 fprintf_unfiltered (gdb_stdlog,
2979 "LLW: Re-adding thread group leader LWP %d.\n",
2982 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
2985 add_thread (lp->ptid);
2988 if (WIFSTOPPED (status) && !lp)
2990 if (debug_linux_nat)
2991 fprintf_unfiltered (gdb_stdlog,
2992 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2993 (long) lwpid, status_to_str (status));
2994 add_to_pid_list (&stopped_pids, lwpid, status);
2998 /* Make sure we don't report an event for the exit of an LWP not in
2999 our list, i.e. not part of the current process. This can happen
3000 if we detach from a program we originally forked and then it
3002 if (!WIFSTOPPED (status) && !lp)
3005 /* This LWP is stopped now. (And if dead, this prevents it from
3006 ever being continued.) */
3009 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3011 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3012 int options = linux_nat_ptrace_options (inf->attach_flag);
3014 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3015 lp->must_set_ptrace_flags = 0;
3018 /* Handle GNU/Linux's syscall SIGTRAPs. */
3019 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3021 /* No longer need the sysgood bit. The ptrace event ends up
3022 recorded in lp->waitstatus if we care for it. We can carry
3023 on handling the event like a regular SIGTRAP from here
3025 status = W_STOPCODE (SIGTRAP);
3026 if (linux_handle_syscall_trap (lp, 0))
3031 /* Almost all other ptrace-stops are known to be outside of system
3032 calls, with further exceptions in linux_handle_extended_wait. */
3033 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3036 /* Handle GNU/Linux's extended waitstatus for trace events. */
3037 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3038 && linux_is_extended_waitstatus (status))
3040 if (debug_linux_nat)
3041 fprintf_unfiltered (gdb_stdlog,
3042 "LLW: Handling extended status 0x%06x\n",
3044 if (linux_handle_extended_wait (lp, status))
3048 /* Check if the thread has exited. */
3049 if (WIFEXITED (status) || WIFSIGNALED (status))
3051 if (!report_thread_events
3052 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3054 if (debug_linux_nat)
3055 fprintf_unfiltered (gdb_stdlog,
3056 "LLW: %s exited.\n",
3057 target_pid_to_str (lp->ptid));
3059 /* If there is at least one more LWP, then the exit signal
3060 was not the end of the debugged application and should be
3066 /* Note that even if the leader was ptrace-stopped, it can still
3067 exit, if e.g., some other thread brings down the whole
3068 process (calls `exit'). So don't assert that the lwp is
3070 if (debug_linux_nat)
3071 fprintf_unfiltered (gdb_stdlog,
3072 "LWP %ld exited (resumed=%d)\n",
3073 ptid_get_lwp (lp->ptid), lp->resumed);
3075 /* Dead LWP's aren't expected to reported a pending sigstop. */
3078 /* Store the pending event in the waitstatus, because
3079 W_EXITCODE(0,0) == 0. */
3080 store_waitstatus (&lp->waitstatus, status);
3084 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3085 an attempt to stop an LWP. */
3087 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3091 if (lp->last_resume_kind == resume_stop)
3093 if (debug_linux_nat)
3094 fprintf_unfiltered (gdb_stdlog,
3095 "LLW: resume_stop SIGSTOP caught for %s.\n",
3096 target_pid_to_str (lp->ptid));
3100 /* This is a delayed SIGSTOP. Filter out the event. */
3102 if (debug_linux_nat)
3103 fprintf_unfiltered (gdb_stdlog,
3104 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3106 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3107 target_pid_to_str (lp->ptid));
3109 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3110 gdb_assert (lp->resumed);
3115 /* Make sure we don't report a SIGINT that we have already displayed
3116 for another thread. */
3117 if (lp->ignore_sigint
3118 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3120 if (debug_linux_nat)
3121 fprintf_unfiltered (gdb_stdlog,
3122 "LLW: Delayed SIGINT caught for %s.\n",
3123 target_pid_to_str (lp->ptid));
3125 /* This is a delayed SIGINT. */
3126 lp->ignore_sigint = 0;
3128 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3129 if (debug_linux_nat)
3130 fprintf_unfiltered (gdb_stdlog,
3131 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3133 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3134 target_pid_to_str (lp->ptid));
3135 gdb_assert (lp->resumed);
3137 /* Discard the event. */
3141 /* Don't report signals that GDB isn't interested in, such as
3142 signals that are neither printed nor stopped upon. Stopping all
3143 threads can be a bit time-consuming so if we want decent
3144 performance with heavily multi-threaded programs, especially when
3145 they're using a high frequency timer, we'd better avoid it if we
3147 if (WIFSTOPPED (status))
3149 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3151 if (!target_is_non_stop_p ())
3153 /* Only do the below in all-stop, as we currently use SIGSTOP
3154 to implement target_stop (see linux_nat_stop) in
3156 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3158 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3159 forwarded to the entire process group, that is, all LWPs
3160 will receive it - unless they're using CLONE_THREAD to
3161 share signals. Since we only want to report it once, we
3162 mark it as ignored for all LWPs except this one. */
3163 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3164 set_ignore_sigint, NULL);
3165 lp->ignore_sigint = 0;
3168 maybe_clear_ignore_sigint (lp);
3171 /* When using hardware single-step, we need to report every signal.
3172 Otherwise, signals in pass_mask may be short-circuited
3173 except signals that might be caused by a breakpoint. */
3175 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3176 && !linux_wstatus_maybe_breakpoint (status))
3178 linux_resume_one_lwp (lp, lp->step, signo);
3179 if (debug_linux_nat)
3180 fprintf_unfiltered (gdb_stdlog,
3181 "LLW: %s %s, %s (preempt 'handle')\n",
3183 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3184 target_pid_to_str (lp->ptid),
3185 (signo != GDB_SIGNAL_0
3186 ? strsignal (gdb_signal_to_host (signo))
3192 /* An interesting event. */
3194 lp->status = status;
3195 save_stop_reason (lp);
3199 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3200 their exits until all other threads in the group have exited. */
3203 check_zombie_leaders (void)
3205 struct inferior *inf;
3209 struct lwp_info *leader_lp;
3214 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3215 if (leader_lp != NULL
3216 /* Check if there are other threads in the group, as we may
3217 have raced with the inferior simply exiting. */
3218 && num_lwps (inf->pid) > 1
3219 && linux_proc_pid_is_zombie (inf->pid))
3221 if (debug_linux_nat)
3222 fprintf_unfiltered (gdb_stdlog,
3223 "CZL: Thread group leader %d zombie "
3224 "(it exited, or another thread execd).\n",
3227 /* A leader zombie can mean one of two things:
3229 - It exited, and there's an exit status pending
3230 available, or only the leader exited (not the whole
3231 program). In the latter case, we can't waitpid the
3232 leader's exit status until all other threads are gone.
3234 - There are 3 or more threads in the group, and a thread
3235 other than the leader exec'd. See comments on exec
3236 events at the top of the file. We could try
3237 distinguishing the exit and exec cases, by waiting once
3238 more, and seeing if something comes out, but it doesn't
3239 sound useful. The previous leader _does_ go away, and
3240 we'll re-add the new one once we see the exec event
3241 (which is just the same as what would happen if the
3242 previous leader did exit voluntarily before some other
3245 if (debug_linux_nat)
3246 fprintf_unfiltered (gdb_stdlog,
3247 "CZL: Thread group leader %d vanished.\n",
3249 exit_lwp (leader_lp);
3254 /* Convenience function that is called when the kernel reports an exit
3255 event. This decides whether to report the event to GDB as a
3256 process exit event, a thread exit event, or to suppress the
3260 filter_exit_event (struct lwp_info *event_child,
3261 struct target_waitstatus *ourstatus)
3263 ptid_t ptid = event_child->ptid;
3265 if (num_lwps (ptid_get_pid (ptid)) > 1)
3267 if (report_thread_events)
3268 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3270 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3272 exit_lwp (event_child);
3279 linux_nat_wait_1 (struct target_ops *ops,
3280 ptid_t ptid, struct target_waitstatus *ourstatus,
3284 enum resume_kind last_resume_kind;
3285 struct lwp_info *lp;
3288 if (debug_linux_nat)
3289 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3291 /* The first time we get here after starting a new inferior, we may
3292 not have added it to the LWP list yet - this is the earliest
3293 moment at which we know its PID. */
3294 if (ptid_is_pid (inferior_ptid))
3296 /* Upgrade the main thread's ptid. */
3297 thread_change_ptid (inferior_ptid,
3298 ptid_build (ptid_get_pid (inferior_ptid),
3299 ptid_get_pid (inferior_ptid), 0));
3301 lp = add_initial_lwp (inferior_ptid);
3305 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3306 block_child_signals (&prev_mask);
3308 /* First check if there is a LWP with a wait status pending. */
3309 lp = iterate_over_lwps (ptid, status_callback, NULL);
3312 if (debug_linux_nat)
3313 fprintf_unfiltered (gdb_stdlog,
3314 "LLW: Using pending wait status %s for %s.\n",
3315 status_to_str (lp->status),
3316 target_pid_to_str (lp->ptid));
3319 /* But if we don't find a pending event, we'll have to wait. Always
3320 pull all events out of the kernel. We'll randomly select an
3321 event LWP out of all that have events, to prevent starvation. */
3327 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3330 - If the thread group leader exits while other threads in the
3331 thread group still exist, waitpid(TGID, ...) hangs. That
3332 waitpid won't return an exit status until the other threads
3333 in the group are reapped.
3335 - When a non-leader thread execs, that thread just vanishes
3336 without reporting an exit (so we'd hang if we waited for it
3337 explicitly in that case). The exec event is reported to
3341 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3343 if (debug_linux_nat)
3344 fprintf_unfiltered (gdb_stdlog,
3345 "LNW: waitpid(-1, ...) returned %d, %s\n",
3346 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3350 if (debug_linux_nat)
3352 fprintf_unfiltered (gdb_stdlog,
3353 "LLW: waitpid %ld received %s\n",
3354 (long) lwpid, status_to_str (status));
3357 linux_nat_filter_event (lwpid, status);
3358 /* Retry until nothing comes out of waitpid. A single
3359 SIGCHLD can indicate more than one child stopped. */
3363 /* Now that we've pulled all events out of the kernel, resume
3364 LWPs that don't have an interesting event to report. */
3365 iterate_over_lwps (minus_one_ptid,
3366 resume_stopped_resumed_lwps, &minus_one_ptid);
3368 /* ... and find an LWP with a status to report to the core, if
3370 lp = iterate_over_lwps (ptid, status_callback, NULL);
3374 /* Check for zombie thread group leaders. Those can't be reaped
3375 until all other threads in the thread group are. */
3376 check_zombie_leaders ();
3378 /* If there are no resumed children left, bail. We'd be stuck
3379 forever in the sigsuspend call below otherwise. */
3380 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3382 if (debug_linux_nat)
3383 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3385 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3387 restore_child_signals_mask (&prev_mask);
3388 return minus_one_ptid;
3391 /* No interesting event to report to the core. */
3393 if (target_options & TARGET_WNOHANG)
3395 if (debug_linux_nat)
3396 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3398 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3399 restore_child_signals_mask (&prev_mask);
3400 return minus_one_ptid;
3403 /* We shouldn't end up here unless we want to try again. */
3404 gdb_assert (lp == NULL);
3406 /* Block until we get an event reported with SIGCHLD. */
3407 if (debug_linux_nat)
3408 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3409 sigsuspend (&suspend_mask);
3414 status = lp->status;
3417 if (!target_is_non_stop_p ())
3419 /* Now stop all other LWP's ... */
3420 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3422 /* ... and wait until all of them have reported back that
3423 they're no longer running. */
3424 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3427 /* If we're not waiting for a specific LWP, choose an event LWP from
3428 among those that have had events. Giving equal priority to all
3429 LWPs that have had events helps prevent starvation. */
3430 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3431 select_event_lwp (ptid, &lp, &status);
3433 gdb_assert (lp != NULL);
3435 /* Now that we've selected our final event LWP, un-adjust its PC if
3436 it was a software breakpoint, and we can't reliably support the
3437 "stopped by software breakpoint" stop reason. */
3438 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3439 && !USE_SIGTRAP_SIGINFO)
3441 struct regcache *regcache = get_thread_regcache (lp->ptid);
3442 struct gdbarch *gdbarch = regcache->arch ();
3443 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3449 pc = regcache_read_pc (regcache);
3450 regcache_write_pc (regcache, pc + decr_pc);
3454 /* We'll need this to determine whether to report a SIGSTOP as
3455 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3457 last_resume_kind = lp->last_resume_kind;
3459 if (!target_is_non_stop_p ())
3461 /* In all-stop, from the core's perspective, all LWPs are now
3462 stopped until a new resume action is sent over. */
3463 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3467 resume_clear_callback (lp, NULL);
3470 if (linux_nat_status_is_event (status))
3472 if (debug_linux_nat)
3473 fprintf_unfiltered (gdb_stdlog,
3474 "LLW: trap ptid is %s.\n",
3475 target_pid_to_str (lp->ptid));
3478 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3480 *ourstatus = lp->waitstatus;
3481 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3484 store_waitstatus (ourstatus, status);
3486 if (debug_linux_nat)
3487 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3489 restore_child_signals_mask (&prev_mask);
3491 if (last_resume_kind == resume_stop
3492 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3493 && WSTOPSIG (status) == SIGSTOP)
3495 /* A thread that has been requested to stop by GDB with
3496 target_stop, and it stopped cleanly, so report as SIG0. The
3497 use of SIGSTOP is an implementation detail. */
3498 ourstatus->value.sig = GDB_SIGNAL_0;
3501 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3502 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3505 lp->core = linux_common_core_of_thread (lp->ptid);
3507 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3508 return filter_exit_event (lp, ourstatus);
3513 /* Resume LWPs that are currently stopped without any pending status
3514 to report, but are resumed from the core's perspective. */
3517 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3519 ptid_t *wait_ptid_p = (ptid_t *) data;
3523 if (debug_linux_nat)
3524 fprintf_unfiltered (gdb_stdlog,
3525 "RSRL: NOT resuming LWP %s, not stopped\n",
3526 target_pid_to_str (lp->ptid));
3528 else if (!lp->resumed)
3530 if (debug_linux_nat)
3531 fprintf_unfiltered (gdb_stdlog,
3532 "RSRL: NOT resuming LWP %s, not resumed\n",
3533 target_pid_to_str (lp->ptid));
3535 else if (lwp_status_pending_p (lp))
3537 if (debug_linux_nat)
3538 fprintf_unfiltered (gdb_stdlog,
3539 "RSRL: NOT resuming LWP %s, has pending status\n",
3540 target_pid_to_str (lp->ptid));
3544 struct regcache *regcache = get_thread_regcache (lp->ptid);
3545 struct gdbarch *gdbarch = regcache->arch ();
3549 CORE_ADDR pc = regcache_read_pc (regcache);
3550 int leave_stopped = 0;
3552 /* Don't bother if there's a breakpoint at PC that we'd hit
3553 immediately, and we're not waiting for this LWP. */
3554 if (!ptid_match (lp->ptid, *wait_ptid_p))
3556 if (breakpoint_inserted_here_p (regcache->aspace (), pc))
3562 if (debug_linux_nat)
3563 fprintf_unfiltered (gdb_stdlog,
3564 "RSRL: resuming stopped-resumed LWP %s at "
3566 target_pid_to_str (lp->ptid),
3567 paddress (gdbarch, pc),
3570 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3573 CATCH (ex, RETURN_MASK_ERROR)
3575 if (!check_ptrace_stopped_lwp_gone (lp))
3576 throw_exception (ex);
3585 linux_nat_wait (struct target_ops *ops,
3586 ptid_t ptid, struct target_waitstatus *ourstatus,
3591 if (debug_linux_nat)
3593 char *options_string;
3595 options_string = target_options_to_string (target_options);
3596 fprintf_unfiltered (gdb_stdlog,
3597 "linux_nat_wait: [%s], [%s]\n",
3598 target_pid_to_str (ptid),
3600 xfree (options_string);
3603 /* Flush the async file first. */
3604 if (target_is_async_p ())
3605 async_file_flush ();
3607 /* Resume LWPs that are currently stopped without any pending status
3608 to report, but are resumed from the core's perspective. LWPs get
3609 in this state if we find them stopping at a time we're not
3610 interested in reporting the event (target_wait on a
3611 specific_process, for example, see linux_nat_wait_1), and
3612 meanwhile the event became uninteresting. Don't bother resuming
3613 LWPs we're not going to wait for if they'd stop immediately. */
3614 if (target_is_non_stop_p ())
3615 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3617 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3619 /* If we requested any event, and something came out, assume there
3620 may be more. If we requested a specific lwp or process, also
3621 assume there may be more. */
3622 if (target_is_async_p ()
3623 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3624 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3625 || !ptid_equal (ptid, minus_one_ptid)))
3634 kill_one_lwp (pid_t pid)
3636 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3639 kill_lwp (pid, SIGKILL);
3640 if (debug_linux_nat)
3642 int save_errno = errno;
3644 fprintf_unfiltered (gdb_stdlog,
3645 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3646 save_errno ? safe_strerror (save_errno) : "OK");
3649 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3652 ptrace (PTRACE_KILL, pid, 0, 0);
3653 if (debug_linux_nat)
3655 int save_errno = errno;
3657 fprintf_unfiltered (gdb_stdlog,
3658 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3659 save_errno ? safe_strerror (save_errno) : "OK");
3663 /* Wait for an LWP to die. */
3666 kill_wait_one_lwp (pid_t pid)
3670 /* We must make sure that there are no pending events (delayed
3671 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3672 program doesn't interfere with any following debugging session. */
3676 res = my_waitpid (pid, NULL, __WALL);
3677 if (res != (pid_t) -1)
3679 if (debug_linux_nat)
3680 fprintf_unfiltered (gdb_stdlog,
3681 "KWC: wait %ld received unknown.\n",
3683 /* The Linux kernel sometimes fails to kill a thread
3684 completely after PTRACE_KILL; that goes from the stop
3685 point in do_fork out to the one in get_signal_to_deliver
3686 and waits again. So kill it again. */
3692 gdb_assert (res == -1 && errno == ECHILD);
3695 /* Callback for iterate_over_lwps. */
3698 kill_callback (struct lwp_info *lp, void *data)
3700 kill_one_lwp (ptid_get_lwp (lp->ptid));
3704 /* Callback for iterate_over_lwps. */
3707 kill_wait_callback (struct lwp_info *lp, void *data)
3709 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3713 /* Kill the fork children of any threads of inferior INF that are
3714 stopped at a fork event. */
3717 kill_unfollowed_fork_children (struct inferior *inf)
3719 struct thread_info *thread;
3721 ALL_NON_EXITED_THREADS (thread)
3722 if (thread->inf == inf)
3724 struct target_waitstatus *ws = &thread->pending_follow;
3726 if (ws->kind == TARGET_WAITKIND_FORKED
3727 || ws->kind == TARGET_WAITKIND_VFORKED)
3729 ptid_t child_ptid = ws->value.related_pid;
3730 int child_pid = ptid_get_pid (child_ptid);
3731 int child_lwp = ptid_get_lwp (child_ptid);
3733 kill_one_lwp (child_lwp);
3734 kill_wait_one_lwp (child_lwp);
3736 /* Let the arch-specific native code know this process is
3738 linux_nat_forget_process (child_pid);
3744 linux_nat_kill (struct target_ops *ops)
3746 /* If we're stopped while forking and we haven't followed yet,
3747 kill the other task. We need to do this first because the
3748 parent will be sleeping if this is a vfork. */
3749 kill_unfollowed_fork_children (current_inferior ());
3751 if (forks_exist_p ())
3752 linux_fork_killall ();
3755 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3757 /* Stop all threads before killing them, since ptrace requires
3758 that the thread is stopped to sucessfully PTRACE_KILL. */
3759 iterate_over_lwps (ptid, stop_callback, NULL);
3760 /* ... and wait until all of them have reported back that
3761 they're no longer running. */
3762 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3764 /* Kill all LWP's ... */
3765 iterate_over_lwps (ptid, kill_callback, NULL);
3767 /* ... and wait until we've flushed all events. */
3768 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3771 target_mourn_inferior (inferior_ptid);
3775 linux_nat_mourn_inferior (struct target_ops *ops)
3777 int pid = ptid_get_pid (inferior_ptid);
3779 purge_lwp_list (pid);
3781 if (! forks_exist_p ())
3782 /* Normal case, no other forks available. */
3783 linux_ops->to_mourn_inferior (ops);
3785 /* Multi-fork case. The current inferior_ptid has exited, but
3786 there are other viable forks to debug. Delete the exiting
3787 one and context-switch to the first available. */
3788 linux_fork_mourn_inferior ();
3790 /* Let the arch-specific native code know this process is gone. */
3791 linux_nat_forget_process (pid);
3794 /* Convert a native/host siginfo object, into/from the siginfo in the
3795 layout of the inferiors' architecture. */
3798 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3802 if (linux_nat_siginfo_fixup != NULL)
3803 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3805 /* If there was no callback, or the callback didn't do anything,
3806 then just do a straight memcpy. */
3810 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3812 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3816 static enum target_xfer_status
3817 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3818 const char *annex, gdb_byte *readbuf,
3819 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3820 ULONGEST *xfered_len)
3824 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3826 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3827 gdb_assert (readbuf || writebuf);
3829 pid = ptid_get_lwp (inferior_ptid);
3831 pid = ptid_get_pid (inferior_ptid);
3833 if (offset > sizeof (siginfo))
3834 return TARGET_XFER_E_IO;
3837 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3839 return TARGET_XFER_E_IO;
3841 /* When GDB is built as a 64-bit application, ptrace writes into
3842 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3843 inferior with a 64-bit GDB should look the same as debugging it
3844 with a 32-bit GDB, we need to convert it. GDB core always sees
3845 the converted layout, so any read/write will have to be done
3847 siginfo_fixup (&siginfo, inf_siginfo, 0);
3849 if (offset + len > sizeof (siginfo))
3850 len = sizeof (siginfo) - offset;
3852 if (readbuf != NULL)
3853 memcpy (readbuf, inf_siginfo + offset, len);
3856 memcpy (inf_siginfo + offset, writebuf, len);
3858 /* Convert back to ptrace layout before flushing it out. */
3859 siginfo_fixup (&siginfo, inf_siginfo, 1);
3862 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3864 return TARGET_XFER_E_IO;
3868 return TARGET_XFER_OK;
3871 static enum target_xfer_status
3872 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3873 const char *annex, gdb_byte *readbuf,
3874 const gdb_byte *writebuf,
3875 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3877 enum target_xfer_status xfer;
3879 if (object == TARGET_OBJECT_SIGNAL_INFO)
3880 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3881 offset, len, xfered_len);
3883 /* The target is connected but no live inferior is selected. Pass
3884 this request down to a lower stratum (e.g., the executable
3886 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3887 return TARGET_XFER_EOF;
3889 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3890 offset, len, xfered_len);
3896 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3898 /* As long as a PTID is in lwp list, consider it alive. */
3899 return find_lwp_pid (ptid) != NULL;
3902 /* Implement the to_update_thread_list target method for this
3906 linux_nat_update_thread_list (struct target_ops *ops)
3908 struct lwp_info *lwp;
3910 /* We add/delete threads from the list as clone/exit events are
3911 processed, so just try deleting exited threads still in the
3913 delete_exited_threads ();
3915 /* Update the processor core that each lwp/thread was last seen
3919 /* Avoid accessing /proc if the thread hasn't run since we last
3920 time we fetched the thread's core. Accessing /proc becomes
3921 noticeably expensive when we have thousands of LWPs. */
3922 if (lwp->core == -1)
3923 lwp->core = linux_common_core_of_thread (lwp->ptid);
3928 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3930 static char buf[64];
3932 if (ptid_lwp_p (ptid)
3933 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3934 || num_lwps (ptid_get_pid (ptid)) > 1))
3936 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3940 return normal_pid_to_str (ptid);
3944 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3946 return linux_proc_tid_get_name (thr->ptid);
3949 /* Accepts an integer PID; Returns a string representing a file that
3950 can be opened to get the symbols for the child process. */
3953 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3955 return linux_proc_pid_to_exec_file (pid);
3958 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3959 Because we can use a single read/write call, this can be much more
3960 efficient than banging away at PTRACE_PEEKTEXT. */
3962 static enum target_xfer_status
3963 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3964 const char *annex, gdb_byte *readbuf,
3965 const gdb_byte *writebuf,
3966 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3972 if (object != TARGET_OBJECT_MEMORY)
3973 return TARGET_XFER_EOF;
3975 /* Don't bother for one word. */
3976 if (len < 3 * sizeof (long))
3977 return TARGET_XFER_EOF;
3979 /* We could keep this file open and cache it - possibly one per
3980 thread. That requires some juggling, but is even faster. */
3981 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3982 ptid_get_lwp (inferior_ptid));
3983 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
3986 return TARGET_XFER_EOF;
3988 /* Use pread64/pwrite64 if available, since they save a syscall and can
3989 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
3990 debugging a SPARC64 application). */
3992 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
3993 : pwrite64 (fd, writebuf, len, offset));
3995 ret = lseek (fd, offset, SEEK_SET);
3997 ret = (readbuf ? read (fd, readbuf, len)
3998 : write (fd, writebuf, len));
4003 if (ret == -1 || ret == 0)
4004 return TARGET_XFER_EOF;
4008 return TARGET_XFER_OK;
4013 /* Enumerate spufs IDs for process PID. */
4015 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4017 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4019 LONGEST written = 0;
4022 struct dirent *entry;
4024 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4025 dir = opendir (path);
4030 while ((entry = readdir (dir)) != NULL)
4036 fd = atoi (entry->d_name);
4040 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4041 if (stat (path, &st) != 0)
4043 if (!S_ISDIR (st.st_mode))
4046 if (statfs (path, &stfs) != 0)
4048 if (stfs.f_type != SPUFS_MAGIC)
4051 if (pos >= offset && pos + 4 <= offset + len)
4053 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4063 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4064 object type, using the /proc file system. */
4066 static enum target_xfer_status
4067 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4068 const char *annex, gdb_byte *readbuf,
4069 const gdb_byte *writebuf,
4070 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4075 int pid = ptid_get_lwp (inferior_ptid);
4080 return TARGET_XFER_E_IO;
4083 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4086 return TARGET_XFER_E_IO;
4088 return TARGET_XFER_EOF;
4091 *xfered_len = (ULONGEST) l;
4092 return TARGET_XFER_OK;
4097 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4098 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4100 return TARGET_XFER_E_IO;
4103 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4106 return TARGET_XFER_EOF;
4110 ret = write (fd, writebuf, (size_t) len);
4112 ret = read (fd, readbuf, (size_t) len);
4117 return TARGET_XFER_E_IO;
4119 return TARGET_XFER_EOF;
4122 *xfered_len = (ULONGEST) ret;
4123 return TARGET_XFER_OK;
4128 /* Parse LINE as a signal set and add its set bits to SIGS. */
4131 add_line_to_sigset (const char *line, sigset_t *sigs)
4133 int len = strlen (line) - 1;
4137 if (line[len] != '\n')
4138 error (_("Could not parse signal set: %s"), line);
4146 if (*p >= '0' && *p <= '9')
4148 else if (*p >= 'a' && *p <= 'f')
4149 digit = *p - 'a' + 10;
4151 error (_("Could not parse signal set: %s"), line);
4156 sigaddset (sigs, signum + 1);
4158 sigaddset (sigs, signum + 2);
4160 sigaddset (sigs, signum + 3);
4162 sigaddset (sigs, signum + 4);
4168 /* Find process PID's pending signals from /proc/pid/status and set
4172 linux_proc_pending_signals (int pid, sigset_t *pending,
4173 sigset_t *blocked, sigset_t *ignored)
4175 char buffer[PATH_MAX], fname[PATH_MAX];
4177 sigemptyset (pending);
4178 sigemptyset (blocked);
4179 sigemptyset (ignored);
4180 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4181 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
4182 if (procfile == NULL)
4183 error (_("Could not open %s"), fname);
4185 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
4187 /* Normal queued signals are on the SigPnd line in the status
4188 file. However, 2.6 kernels also have a "shared" pending
4189 queue for delivering signals to a thread group, so check for
4192 Unfortunately some Red Hat kernels include the shared pending
4193 queue but not the ShdPnd status field. */
4195 if (startswith (buffer, "SigPnd:\t"))
4196 add_line_to_sigset (buffer + 8, pending);
4197 else if (startswith (buffer, "ShdPnd:\t"))
4198 add_line_to_sigset (buffer + 8, pending);
4199 else if (startswith (buffer, "SigBlk:\t"))
4200 add_line_to_sigset (buffer + 8, blocked);
4201 else if (startswith (buffer, "SigIgn:\t"))
4202 add_line_to_sigset (buffer + 8, ignored);
4206 static enum target_xfer_status
4207 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4208 const char *annex, gdb_byte *readbuf,
4209 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4210 ULONGEST *xfered_len)
4212 gdb_assert (object == TARGET_OBJECT_OSDATA);
4214 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4215 if (*xfered_len == 0)
4216 return TARGET_XFER_EOF;
4218 return TARGET_XFER_OK;
4221 static enum target_xfer_status
4222 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4223 const char *annex, gdb_byte *readbuf,
4224 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4225 ULONGEST *xfered_len)
4227 enum target_xfer_status xfer;
4229 if (object == TARGET_OBJECT_AUXV)
4230 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4231 offset, len, xfered_len);
4233 if (object == TARGET_OBJECT_OSDATA)
4234 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4235 offset, len, xfered_len);
4237 if (object == TARGET_OBJECT_SPU)
4238 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4239 offset, len, xfered_len);
4241 /* GDB calculates all the addresses in possibly larget width of the address.
4242 Address width needs to be masked before its final use - either by
4243 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4245 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4247 if (object == TARGET_OBJECT_MEMORY)
4249 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4251 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4252 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4255 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4256 offset, len, xfered_len);
4257 if (xfer != TARGET_XFER_EOF)
4260 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4261 offset, len, xfered_len);
4265 cleanup_target_stop (void *arg)
4267 ptid_t *ptid = (ptid_t *) arg;
4269 gdb_assert (arg != NULL);
4272 target_continue_no_signal (*ptid);
4275 static VEC(static_tracepoint_marker_p) *
4276 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4279 char s[IPA_CMD_BUF_SIZE];
4280 struct cleanup *old_chain;
4281 int pid = ptid_get_pid (inferior_ptid);
4282 VEC(static_tracepoint_marker_p) *markers = NULL;
4283 struct static_tracepoint_marker *marker = NULL;
4285 ptid_t ptid = ptid_build (pid, 0, 0);
4290 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4291 s[sizeof ("qTfSTM")] = 0;
4293 agent_run_command (pid, s, strlen (s) + 1);
4295 old_chain = make_cleanup (free_current_marker, &marker);
4296 make_cleanup (cleanup_target_stop, &ptid);
4301 marker = XCNEW (struct static_tracepoint_marker);
4305 parse_static_tracepoint_marker_definition (p, &p, marker);
4307 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4309 VEC_safe_push (static_tracepoint_marker_p,
4315 release_static_tracepoint_marker (marker);
4316 memset (marker, 0, sizeof (*marker));
4319 while (*p++ == ','); /* comma-separated list */
4321 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4322 s[sizeof ("qTsSTM")] = 0;
4323 agent_run_command (pid, s, strlen (s) + 1);
4327 do_cleanups (old_chain);
4332 /* Create a prototype generic GNU/Linux target. The client can override
4333 it with local methods. */
4336 linux_target_install_ops (struct target_ops *t)
4338 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4339 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4340 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4341 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4342 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4343 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4344 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4345 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4346 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4347 t->to_post_attach = linux_child_post_attach;
4348 t->to_follow_fork = linux_child_follow_fork;
4350 super_xfer_partial = t->to_xfer_partial;
4351 t->to_xfer_partial = linux_xfer_partial;
4353 t->to_static_tracepoint_markers_by_strid
4354 = linux_child_static_tracepoint_markers_by_strid;
4360 struct target_ops *t;
4362 t = inf_ptrace_target ();
4363 linux_target_install_ops (t);
4369 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4371 struct target_ops *t;
4373 t = inf_ptrace_trad_target (register_u_offset);
4374 linux_target_install_ops (t);
4379 /* target_is_async_p implementation. */
4382 linux_nat_is_async_p (struct target_ops *ops)
4384 return linux_is_async_p ();
4387 /* target_can_async_p implementation. */
4390 linux_nat_can_async_p (struct target_ops *ops)
4392 /* We're always async, unless the user explicitly prevented it with the
4393 "maint set target-async" command. */
4394 return target_async_permitted;
4398 linux_nat_supports_non_stop (struct target_ops *self)
4403 /* to_always_non_stop_p implementation. */
4406 linux_nat_always_non_stop_p (struct target_ops *self)
4411 /* True if we want to support multi-process. To be removed when GDB
4412 supports multi-exec. */
4414 int linux_multi_process = 1;
4417 linux_nat_supports_multi_process (struct target_ops *self)
4419 return linux_multi_process;
4423 linux_nat_supports_disable_randomization (struct target_ops *self)
4425 #ifdef HAVE_PERSONALITY
4432 static int async_terminal_is_ours = 1;
4434 /* target_terminal_inferior implementation.
4436 This is a wrapper around child_terminal_inferior to add async support. */
4439 linux_nat_terminal_inferior (struct target_ops *self)
4441 child_terminal_inferior (self);
4443 /* Calls to target_terminal_*() are meant to be idempotent. */
4444 if (!async_terminal_is_ours)
4447 async_terminal_is_ours = 0;
4451 /* target_terminal::ours implementation.
4453 This is a wrapper around child_terminal_ours to add async support (and
4454 implement the target_terminal::ours vs target_terminal::ours_for_output
4455 distinction). child_terminal_ours is currently no different than
4456 child_terminal_ours_for_output.
4457 We leave target_terminal::ours_for_output alone, leaving it to
4458 child_terminal_ours_for_output. */
4461 linux_nat_terminal_ours (struct target_ops *self)
4463 /* GDB should never give the terminal to the inferior if the
4464 inferior is running in the background (run&, continue&, etc.),
4465 but claiming it sure should. */
4466 child_terminal_ours (self);
4468 if (async_terminal_is_ours)
4471 clear_sigint_trap ();
4472 async_terminal_is_ours = 1;
4475 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4476 so we notice when any child changes state, and notify the
4477 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4478 above to wait for the arrival of a SIGCHLD. */
4481 sigchld_handler (int signo)
4483 int old_errno = errno;
4485 if (debug_linux_nat)
4486 ui_file_write_async_safe (gdb_stdlog,
4487 "sigchld\n", sizeof ("sigchld\n") - 1);
4489 if (signo == SIGCHLD
4490 && linux_nat_event_pipe[0] != -1)
4491 async_file_mark (); /* Let the event loop know that there are
4492 events to handle. */
4497 /* Callback registered with the target events file descriptor. */
4500 handle_target_event (int error, gdb_client_data client_data)
4502 inferior_event_handler (INF_REG_EVENT, NULL);
4505 /* Create/destroy the target events pipe. Returns previous state. */
4508 linux_async_pipe (int enable)
4510 int previous = linux_is_async_p ();
4512 if (previous != enable)
4516 /* Block child signals while we create/destroy the pipe, as
4517 their handler writes to it. */
4518 block_child_signals (&prev_mask);
4522 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4523 internal_error (__FILE__, __LINE__,
4524 "creating event pipe failed.");
4526 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4527 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4531 close (linux_nat_event_pipe[0]);
4532 close (linux_nat_event_pipe[1]);
4533 linux_nat_event_pipe[0] = -1;
4534 linux_nat_event_pipe[1] = -1;
4537 restore_child_signals_mask (&prev_mask);
4543 /* target_async implementation. */
4546 linux_nat_async (struct target_ops *ops, int enable)
4550 if (!linux_async_pipe (1))
4552 add_file_handler (linux_nat_event_pipe[0],
4553 handle_target_event, NULL);
4554 /* There may be pending events to handle. Tell the event loop
4561 delete_file_handler (linux_nat_event_pipe[0]);
4562 linux_async_pipe (0);
4567 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4571 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4575 if (debug_linux_nat)
4576 fprintf_unfiltered (gdb_stdlog,
4577 "LNSL: running -> suspending %s\n",
4578 target_pid_to_str (lwp->ptid));
4581 if (lwp->last_resume_kind == resume_stop)
4583 if (debug_linux_nat)
4584 fprintf_unfiltered (gdb_stdlog,
4585 "linux-nat: already stopping LWP %ld at "
4587 ptid_get_lwp (lwp->ptid));
4591 stop_callback (lwp, NULL);
4592 lwp->last_resume_kind = resume_stop;
4596 /* Already known to be stopped; do nothing. */
4598 if (debug_linux_nat)
4600 if (find_thread_ptid (lwp->ptid)->stop_requested)
4601 fprintf_unfiltered (gdb_stdlog,
4602 "LNSL: already stopped/stop_requested %s\n",
4603 target_pid_to_str (lwp->ptid));
4605 fprintf_unfiltered (gdb_stdlog,
4606 "LNSL: already stopped/no "
4607 "stop_requested yet %s\n",
4608 target_pid_to_str (lwp->ptid));
4615 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4617 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4621 linux_nat_close (struct target_ops *self)
4623 /* Unregister from the event loop. */
4624 if (linux_nat_is_async_p (self))
4625 linux_nat_async (self, 0);
4627 if (linux_ops->to_close)
4628 linux_ops->to_close (linux_ops);
4633 /* When requests are passed down from the linux-nat layer to the
4634 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4635 used. The address space pointer is stored in the inferior object,
4636 but the common code that is passed such ptid can't tell whether
4637 lwpid is a "main" process id or not (it assumes so). We reverse
4638 look up the "main" process id from the lwp here. */
4640 static struct address_space *
4641 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4643 struct lwp_info *lwp;
4644 struct inferior *inf;
4647 if (ptid_get_lwp (ptid) == 0)
4649 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4651 lwp = find_lwp_pid (ptid);
4652 pid = ptid_get_pid (lwp->ptid);
4656 /* A (pid,lwpid,0) ptid. */
4657 pid = ptid_get_pid (ptid);
4660 inf = find_inferior_pid (pid);
4661 gdb_assert (inf != NULL);
4665 /* Return the cached value of the processor core for thread PTID. */
4668 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4670 struct lwp_info *info = find_lwp_pid (ptid);
4677 /* Implementation of to_filesystem_is_local. */
4680 linux_nat_filesystem_is_local (struct target_ops *ops)
4682 struct inferior *inf = current_inferior ();
4684 if (inf->fake_pid_p || inf->pid == 0)
4687 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4690 /* Convert the INF argument passed to a to_fileio_* method
4691 to a process ID suitable for passing to its corresponding
4692 linux_mntns_* function. If INF is non-NULL then the
4693 caller is requesting the filesystem seen by INF. If INF
4694 is NULL then the caller is requesting the filesystem seen
4695 by the GDB. We fall back to GDB's filesystem in the case
4696 that INF is non-NULL but its PID is unknown. */
4699 linux_nat_fileio_pid_of (struct inferior *inf)
4701 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4707 /* Implementation of to_fileio_open. */
4710 linux_nat_fileio_open (struct target_ops *self,
4711 struct inferior *inf, const char *filename,
4712 int flags, int mode, int warn_if_slow,
4719 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4720 || fileio_to_host_mode (mode, &nat_mode) == -1)
4722 *target_errno = FILEIO_EINVAL;
4726 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4727 filename, nat_flags, nat_mode);
4729 *target_errno = host_to_fileio_error (errno);
4734 /* Implementation of to_fileio_readlink. */
4737 linux_nat_fileio_readlink (struct target_ops *self,
4738 struct inferior *inf, const char *filename,
4745 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4746 filename, buf, sizeof (buf));
4749 *target_errno = host_to_fileio_error (errno);
4753 ret = (char *) xmalloc (len + 1);
4754 memcpy (ret, buf, len);
4759 /* Implementation of to_fileio_unlink. */
4762 linux_nat_fileio_unlink (struct target_ops *self,
4763 struct inferior *inf, const char *filename,
4768 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4771 *target_errno = host_to_fileio_error (errno);
4776 /* Implementation of the to_thread_events method. */
4779 linux_nat_thread_events (struct target_ops *ops, int enable)
4781 report_thread_events = enable;
4785 linux_nat_add_target (struct target_ops *t)
4787 /* Save the provided single-threaded target. We save this in a separate
4788 variable because another target we've inherited from (e.g. inf-ptrace)
4789 may have saved a pointer to T; we want to use it for the final
4790 process stratum target. */
4791 linux_ops_saved = *t;
4792 linux_ops = &linux_ops_saved;
4794 /* Override some methods for multithreading. */
4795 t->to_create_inferior = linux_nat_create_inferior;
4796 t->to_attach = linux_nat_attach;
4797 t->to_detach = linux_nat_detach;
4798 t->to_resume = linux_nat_resume;
4799 t->to_wait = linux_nat_wait;
4800 t->to_pass_signals = linux_nat_pass_signals;
4801 t->to_xfer_partial = linux_nat_xfer_partial;
4802 t->to_kill = linux_nat_kill;
4803 t->to_mourn_inferior = linux_nat_mourn_inferior;
4804 t->to_thread_alive = linux_nat_thread_alive;
4805 t->to_update_thread_list = linux_nat_update_thread_list;
4806 t->to_pid_to_str = linux_nat_pid_to_str;
4807 t->to_thread_name = linux_nat_thread_name;
4808 t->to_has_thread_control = tc_schedlock;
4809 t->to_thread_address_space = linux_nat_thread_address_space;
4810 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4811 t->to_stopped_data_address = linux_nat_stopped_data_address;
4812 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4813 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4814 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4815 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4816 t->to_thread_events = linux_nat_thread_events;
4818 t->to_can_async_p = linux_nat_can_async_p;
4819 t->to_is_async_p = linux_nat_is_async_p;
4820 t->to_supports_non_stop = linux_nat_supports_non_stop;
4821 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4822 t->to_async = linux_nat_async;
4823 t->to_terminal_inferior = linux_nat_terminal_inferior;
4824 t->to_terminal_ours = linux_nat_terminal_ours;
4826 super_close = t->to_close;
4827 t->to_close = linux_nat_close;
4829 t->to_stop = linux_nat_stop;
4831 t->to_supports_multi_process = linux_nat_supports_multi_process;
4833 t->to_supports_disable_randomization
4834 = linux_nat_supports_disable_randomization;
4836 t->to_core_of_thread = linux_nat_core_of_thread;
4838 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4839 t->to_fileio_open = linux_nat_fileio_open;
4840 t->to_fileio_readlink = linux_nat_fileio_readlink;
4841 t->to_fileio_unlink = linux_nat_fileio_unlink;
4843 /* We don't change the stratum; this target will sit at
4844 process_stratum and thread_db will set at thread_stratum. This
4845 is a little strange, since this is a multi-threaded-capable
4846 target, but we want to be on the stack below thread_db, and we
4847 also want to be used for single-threaded processes. */
4852 /* Register a method to call whenever a new thread is attached. */
4854 linux_nat_set_new_thread (struct target_ops *t,
4855 void (*new_thread) (struct lwp_info *))
4857 /* Save the pointer. We only support a single registered instance
4858 of the GNU/Linux native target, so we do not need to map this to
4860 linux_nat_new_thread = new_thread;
4863 /* Register a method to call whenever a new thread is attached. */
4865 linux_nat_set_delete_thread (struct target_ops *t,
4866 void (*delete_thread) (struct arch_lwp_info *))
4868 /* Save the pointer. We only support a single registered instance
4869 of the GNU/Linux native target, so we do not need to map this to
4871 linux_nat_delete_thread = delete_thread;
4874 /* See declaration in linux-nat.h. */
4877 linux_nat_set_new_fork (struct target_ops *t,
4878 linux_nat_new_fork_ftype *new_fork)
4880 /* Save the pointer. */
4881 linux_nat_new_fork = new_fork;
4884 /* See declaration in linux-nat.h. */
4887 linux_nat_set_forget_process (struct target_ops *t,
4888 linux_nat_forget_process_ftype *fn)
4890 /* Save the pointer. */
4891 linux_nat_forget_process_hook = fn;
4894 /* See declaration in linux-nat.h. */
4897 linux_nat_forget_process (pid_t pid)
4899 if (linux_nat_forget_process_hook != NULL)
4900 linux_nat_forget_process_hook (pid);
4903 /* Register a method that converts a siginfo object between the layout
4904 that ptrace returns, and the layout in the architecture of the
4907 linux_nat_set_siginfo_fixup (struct target_ops *t,
4908 int (*siginfo_fixup) (siginfo_t *,
4912 /* Save the pointer. */
4913 linux_nat_siginfo_fixup = siginfo_fixup;
4916 /* Register a method to call prior to resuming a thread. */
4919 linux_nat_set_prepare_to_resume (struct target_ops *t,
4920 void (*prepare_to_resume) (struct lwp_info *))
4922 /* Save the pointer. */
4923 linux_nat_prepare_to_resume = prepare_to_resume;
4926 /* See linux-nat.h. */
4929 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4933 pid = ptid_get_lwp (ptid);
4935 pid = ptid_get_pid (ptid);
4938 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4941 memset (siginfo, 0, sizeof (*siginfo));
4947 /* See nat/linux-nat.h. */
4950 current_lwp_ptid (void)
4952 gdb_assert (ptid_lwp_p (inferior_ptid));
4953 return inferior_ptid;
4957 _initialize_linux_nat (void)
4959 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4960 &debug_linux_nat, _("\
4961 Set debugging of GNU/Linux lwp module."), _("\
4962 Show debugging of GNU/Linux lwp module."), _("\
4963 Enables printf debugging output."),
4965 show_debug_linux_nat,
4966 &setdebuglist, &showdebuglist);
4968 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4969 &debug_linux_namespaces, _("\
4970 Set debugging of GNU/Linux namespaces module."), _("\
4971 Show debugging of GNU/Linux namespaces module."), _("\
4972 Enables printf debugging output."),
4975 &setdebuglist, &showdebuglist);
4977 /* Save this mask as the default. */
4978 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4980 /* Install a SIGCHLD handler. */
4981 sigchld_action.sa_handler = sigchld_handler;
4982 sigemptyset (&sigchld_action.sa_mask);
4983 sigchld_action.sa_flags = SA_RESTART;
4985 /* Make it the default. */
4986 sigaction (SIGCHLD, &sigchld_action, NULL);
4988 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4989 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4990 sigdelset (&suspend_mask, SIGCHLD);
4992 sigemptyset (&blocked_mask);
4994 lwp_lwpid_htab_create ();
4998 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4999 the GNU/Linux Threads library and therefore doesn't really belong
5002 /* Return the set of signals used by the threads library in *SET. */
5005 lin_thread_get_thread_signals (sigset_t *set)
5009 /* NPTL reserves the first two RT signals, but does not provide any
5010 way for the debugger to query the signal numbers - fortunately
5011 they don't change. */
5012 sigaddset (set, __SIGRTMIN);
5013 sigaddset (set, __SIGRTMIN + 1);