1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2017 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));
1170 warning (_("Cannot attach to lwp %d: %s"),
1172 linux_ptrace_attach_fail_reason_string (ptid,
1178 if (debug_linux_nat)
1179 fprintf_unfiltered (gdb_stdlog,
1180 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1181 target_pid_to_str (ptid));
1183 lp = add_lwp (ptid);
1185 /* The next time we wait for this LWP we'll see a SIGSTOP as
1186 PTRACE_ATTACH brings it to a halt. */
1189 /* We need to wait for a stop before being able to make the
1190 next ptrace call on this LWP. */
1191 lp->must_set_ptrace_flags = 1;
1193 /* So that wait collects the SIGSTOP. */
1196 /* Also add the LWP to gdb's thread list, in case a
1197 matching libthread_db is not found (or the process uses
1199 add_thread (lp->ptid);
1200 set_running (lp->ptid, 1);
1201 set_executing (lp->ptid, 1);
1210 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1212 struct lwp_info *lp;
1216 /* Make sure we report all signals during attach. */
1217 linux_nat_pass_signals (ops, 0, NULL);
1221 linux_ops->to_attach (ops, args, from_tty);
1223 CATCH (ex, RETURN_MASK_ERROR)
1225 pid_t pid = parse_pid_to_attach (args);
1226 struct buffer buffer;
1227 char *message, *buffer_s;
1229 message = xstrdup (ex.message);
1230 make_cleanup (xfree, message);
1232 buffer_init (&buffer);
1233 linux_ptrace_attach_fail_reason (pid, &buffer);
1235 buffer_grow_str0 (&buffer, "");
1236 buffer_s = buffer_finish (&buffer);
1237 make_cleanup (xfree, buffer_s);
1239 if (*buffer_s != '\0')
1240 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1242 throw_error (ex.error, "%s", message);
1246 /* The ptrace base target adds the main thread with (pid,0,0)
1247 format. Decorate it with lwp info. */
1248 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1249 ptid_get_pid (inferior_ptid),
1251 thread_change_ptid (inferior_ptid, ptid);
1253 /* Add the initial process as the first LWP to the list. */
1254 lp = add_initial_lwp (ptid);
1256 status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled);
1257 if (!WIFSTOPPED (status))
1259 if (WIFEXITED (status))
1261 int exit_code = WEXITSTATUS (status);
1263 target_terminal::ours ();
1264 target_mourn_inferior (inferior_ptid);
1266 error (_("Unable to attach: program exited normally."));
1268 error (_("Unable to attach: program exited with code %d."),
1271 else if (WIFSIGNALED (status))
1273 enum gdb_signal signo;
1275 target_terminal::ours ();
1276 target_mourn_inferior (inferior_ptid);
1278 signo = gdb_signal_from_host (WTERMSIG (status));
1279 error (_("Unable to attach: program terminated with signal "
1281 gdb_signal_to_name (signo),
1282 gdb_signal_to_string (signo));
1285 internal_error (__FILE__, __LINE__,
1286 _("unexpected status %d for PID %ld"),
1287 status, (long) ptid_get_lwp (ptid));
1292 /* Save the wait status to report later. */
1294 if (debug_linux_nat)
1295 fprintf_unfiltered (gdb_stdlog,
1296 "LNA: waitpid %ld, saving status %s\n",
1297 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1299 lp->status = status;
1301 /* We must attach to every LWP. If /proc is mounted, use that to
1302 find them now. The inferior may be using raw clone instead of
1303 using pthreads. But even if it is using pthreads, thread_db
1304 walks structures in the inferior's address space to find the list
1305 of threads/LWPs, and those structures may well be corrupted.
1306 Note that once thread_db is loaded, we'll still use it to list
1307 threads and associate pthread info with each LWP. */
1308 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1309 attach_proc_task_lwp_callback);
1311 if (target_can_async_p ())
1315 /* Get pending signal of THREAD as a host signal number, for detaching
1316 purposes. This is the signal the thread last stopped for, which we
1317 need to deliver to the thread when detaching, otherwise, it'd be
1321 get_detach_signal (struct lwp_info *lp)
1323 enum gdb_signal signo = GDB_SIGNAL_0;
1325 /* If we paused threads momentarily, we may have stored pending
1326 events in lp->status or lp->waitstatus (see stop_wait_callback),
1327 and GDB core hasn't seen any signal for those threads.
1328 Otherwise, the last signal reported to the core is found in the
1329 thread object's stop_signal.
1331 There's a corner case that isn't handled here at present. Only
1332 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1333 stop_signal make sense as a real signal to pass to the inferior.
1334 Some catchpoint related events, like
1335 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1336 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1337 those traps are debug API (ptrace in our case) related and
1338 induced; the inferior wouldn't see them if it wasn't being
1339 traced. Hence, we should never pass them to the inferior, even
1340 when set to pass state. Since this corner case isn't handled by
1341 infrun.c when proceeding with a signal, for consistency, neither
1342 do we handle it here (or elsewhere in the file we check for
1343 signal pass state). Normally SIGTRAP isn't set to pass state, so
1344 this is really a corner case. */
1346 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1347 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1348 else if (lp->status)
1349 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1350 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1352 struct thread_info *tp = find_thread_ptid (lp->ptid);
1354 if (tp->suspend.waitstatus_pending_p)
1355 signo = tp->suspend.waitstatus.value.sig;
1357 signo = tp->suspend.stop_signal;
1359 else if (!target_is_non_stop_p ())
1361 struct target_waitstatus last;
1364 get_last_target_status (&last_ptid, &last);
1366 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1368 struct thread_info *tp = find_thread_ptid (lp->ptid);
1370 signo = tp->suspend.stop_signal;
1374 if (signo == GDB_SIGNAL_0)
1376 if (debug_linux_nat)
1377 fprintf_unfiltered (gdb_stdlog,
1378 "GPT: lwp %s has no pending signal\n",
1379 target_pid_to_str (lp->ptid));
1381 else if (!signal_pass_state (signo))
1383 if (debug_linux_nat)
1384 fprintf_unfiltered (gdb_stdlog,
1385 "GPT: lwp %s had signal %s, "
1386 "but it is in no pass state\n",
1387 target_pid_to_str (lp->ptid),
1388 gdb_signal_to_string (signo));
1392 if (debug_linux_nat)
1393 fprintf_unfiltered (gdb_stdlog,
1394 "GPT: lwp %s has pending signal %s\n",
1395 target_pid_to_str (lp->ptid),
1396 gdb_signal_to_string (signo));
1398 return gdb_signal_to_host (signo);
1404 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1405 signal number that should be passed to the LWP when detaching.
1406 Otherwise pass any pending signal the LWP may have, if any. */
1409 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1411 int lwpid = ptid_get_lwp (lp->ptid);
1414 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1416 if (debug_linux_nat && lp->status)
1417 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1418 strsignal (WSTOPSIG (lp->status)),
1419 target_pid_to_str (lp->ptid));
1421 /* If there is a pending SIGSTOP, get rid of it. */
1424 if (debug_linux_nat)
1425 fprintf_unfiltered (gdb_stdlog,
1426 "DC: Sending SIGCONT to %s\n",
1427 target_pid_to_str (lp->ptid));
1429 kill_lwp (lwpid, SIGCONT);
1433 if (signo_p == NULL)
1435 /* Pass on any pending signal for this LWP. */
1436 signo = get_detach_signal (lp);
1441 /* Preparing to resume may try to write registers, and fail if the
1442 lwp is zombie. If that happens, ignore the error. We'll handle
1443 it below, when detach fails with ESRCH. */
1446 if (linux_nat_prepare_to_resume != NULL)
1447 linux_nat_prepare_to_resume (lp);
1449 CATCH (ex, RETURN_MASK_ERROR)
1451 if (!check_ptrace_stopped_lwp_gone (lp))
1452 throw_exception (ex);
1456 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1458 int save_errno = errno;
1460 /* We know the thread exists, so ESRCH must mean the lwp is
1461 zombie. This can happen if one of the already-detached
1462 threads exits the whole thread group. In that case we're
1463 still attached, and must reap the lwp. */
1464 if (save_errno == ESRCH)
1468 ret = my_waitpid (lwpid, &status, __WALL);
1471 warning (_("Couldn't reap LWP %d while detaching: %s"),
1472 lwpid, strerror (errno));
1474 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1476 warning (_("Reaping LWP %d while detaching "
1477 "returned unexpected status 0x%x"),
1483 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1484 safe_strerror (save_errno));
1487 else if (debug_linux_nat)
1489 fprintf_unfiltered (gdb_stdlog,
1490 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1491 target_pid_to_str (lp->ptid),
1495 delete_lwp (lp->ptid);
1499 detach_callback (struct lwp_info *lp, void *data)
1501 /* We don't actually detach from the thread group leader just yet.
1502 If the thread group exits, we must reap the zombie clone lwps
1503 before we're able to reap the leader. */
1504 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1505 detach_one_lwp (lp, NULL);
1510 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1513 struct lwp_info *main_lwp;
1515 pid = ptid_get_pid (inferior_ptid);
1517 /* Don't unregister from the event loop, as there may be other
1518 inferiors running. */
1520 /* Stop all threads before detaching. ptrace requires that the
1521 thread is stopped to sucessfully detach. */
1522 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1523 /* ... and wait until all of them have reported back that
1524 they're no longer running. */
1525 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1527 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1529 /* Only the initial process should be left right now. */
1530 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1532 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1534 if (forks_exist_p ())
1536 /* Multi-fork case. The current inferior_ptid is being detached
1537 from, but there are other viable forks to debug. Detach from
1538 the current fork, and context-switch to the first
1540 linux_fork_detach (args, from_tty);
1546 target_announce_detach (from_tty);
1548 /* Pass on any pending signal for the last LWP, unless the user
1549 requested detaching with a different signal (most likely 0,
1550 meaning, discard the signal). */
1552 signo = atoi (args);
1554 signo = get_detach_signal (main_lwp);
1556 detach_one_lwp (main_lwp, &signo);
1558 inf_ptrace_detach_success (ops);
1562 /* Resume execution of the inferior process. If STEP is nonzero,
1563 single-step it. If SIGNAL is nonzero, give it that signal. */
1566 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1567 enum gdb_signal signo)
1571 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1572 We only presently need that if the LWP is stepped though (to
1573 handle the case of stepping a breakpoint instruction). */
1576 struct regcache *regcache = get_thread_regcache (lp->ptid);
1578 lp->stop_pc = regcache_read_pc (regcache);
1583 if (linux_nat_prepare_to_resume != NULL)
1584 linux_nat_prepare_to_resume (lp);
1585 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1587 /* Successfully resumed. Clear state that no longer makes sense,
1588 and mark the LWP as running. Must not do this before resuming
1589 otherwise if that fails other code will be confused. E.g., we'd
1590 later try to stop the LWP and hang forever waiting for a stop
1591 status. Note that we must not throw after this is cleared,
1592 otherwise handle_zombie_lwp_error would get confused. */
1595 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1596 registers_changed_ptid (lp->ptid);
1599 /* Called when we try to resume a stopped LWP and that errors out. If
1600 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1601 or about to become), discard the error, clear any pending status
1602 the LWP may have, and return true (we'll collect the exit status
1603 soon enough). Otherwise, return false. */
1606 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1608 /* If we get an error after resuming the LWP successfully, we'd
1609 confuse !T state for the LWP being gone. */
1610 gdb_assert (lp->stopped);
1612 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1613 because even if ptrace failed with ESRCH, the tracee may be "not
1614 yet fully dead", but already refusing ptrace requests. In that
1615 case the tracee has 'R (Running)' state for a little bit
1616 (observed in Linux 3.18). See also the note on ESRCH in the
1617 ptrace(2) man page. Instead, check whether the LWP has any state
1618 other than ptrace-stopped. */
1620 /* Don't assume anything if /proc/PID/status can't be read. */
1621 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1623 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1625 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1631 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1632 disappears while we try to resume it. */
1635 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1639 linux_resume_one_lwp_throw (lp, step, signo);
1641 CATCH (ex, RETURN_MASK_ERROR)
1643 if (!check_ptrace_stopped_lwp_gone (lp))
1644 throw_exception (ex);
1652 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1656 struct inferior *inf = find_inferior_ptid (lp->ptid);
1658 if (inf->vfork_child != NULL)
1660 if (debug_linux_nat)
1661 fprintf_unfiltered (gdb_stdlog,
1662 "RC: Not resuming %s (vfork parent)\n",
1663 target_pid_to_str (lp->ptid));
1665 else if (!lwp_status_pending_p (lp))
1667 if (debug_linux_nat)
1668 fprintf_unfiltered (gdb_stdlog,
1669 "RC: Resuming sibling %s, %s, %s\n",
1670 target_pid_to_str (lp->ptid),
1671 (signo != GDB_SIGNAL_0
1672 ? strsignal (gdb_signal_to_host (signo))
1674 step ? "step" : "resume");
1676 linux_resume_one_lwp (lp, step, signo);
1680 if (debug_linux_nat)
1681 fprintf_unfiltered (gdb_stdlog,
1682 "RC: Not resuming sibling %s (has pending)\n",
1683 target_pid_to_str (lp->ptid));
1688 if (debug_linux_nat)
1689 fprintf_unfiltered (gdb_stdlog,
1690 "RC: Not resuming sibling %s (not stopped)\n",
1691 target_pid_to_str (lp->ptid));
1695 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1696 Resume LWP with the last stop signal, if it is in pass state. */
1699 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1701 enum gdb_signal signo = GDB_SIGNAL_0;
1708 struct thread_info *thread;
1710 thread = find_thread_ptid (lp->ptid);
1713 signo = thread->suspend.stop_signal;
1714 thread->suspend.stop_signal = GDB_SIGNAL_0;
1718 resume_lwp (lp, 0, signo);
1723 resume_clear_callback (struct lwp_info *lp, void *data)
1726 lp->last_resume_kind = resume_stop;
1731 resume_set_callback (struct lwp_info *lp, void *data)
1734 lp->last_resume_kind = resume_continue;
1739 linux_nat_resume (struct target_ops *ops,
1740 ptid_t ptid, int step, enum gdb_signal signo)
1742 struct lwp_info *lp;
1745 if (debug_linux_nat)
1746 fprintf_unfiltered (gdb_stdlog,
1747 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1748 step ? "step" : "resume",
1749 target_pid_to_str (ptid),
1750 (signo != GDB_SIGNAL_0
1751 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1752 target_pid_to_str (inferior_ptid));
1754 /* A specific PTID means `step only this process id'. */
1755 resume_many = (ptid_equal (minus_one_ptid, ptid)
1756 || ptid_is_pid (ptid));
1758 /* Mark the lwps we're resuming as resumed. */
1759 iterate_over_lwps (ptid, resume_set_callback, NULL);
1761 /* See if it's the current inferior that should be handled
1764 lp = find_lwp_pid (inferior_ptid);
1766 lp = find_lwp_pid (ptid);
1767 gdb_assert (lp != NULL);
1769 /* Remember if we're stepping. */
1770 lp->last_resume_kind = step ? resume_step : resume_continue;
1772 /* If we have a pending wait status for this thread, there is no
1773 point in resuming the process. But first make sure that
1774 linux_nat_wait won't preemptively handle the event - we
1775 should never take this short-circuit if we are going to
1776 leave LP running, since we have skipped resuming all the
1777 other threads. This bit of code needs to be synchronized
1778 with linux_nat_wait. */
1780 if (lp->status && WIFSTOPPED (lp->status))
1783 && WSTOPSIG (lp->status)
1784 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1786 if (debug_linux_nat)
1787 fprintf_unfiltered (gdb_stdlog,
1788 "LLR: Not short circuiting for ignored "
1789 "status 0x%x\n", lp->status);
1791 /* FIXME: What should we do if we are supposed to continue
1792 this thread with a signal? */
1793 gdb_assert (signo == GDB_SIGNAL_0);
1794 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1799 if (lwp_status_pending_p (lp))
1801 /* FIXME: What should we do if we are supposed to continue
1802 this thread with a signal? */
1803 gdb_assert (signo == GDB_SIGNAL_0);
1805 if (debug_linux_nat)
1806 fprintf_unfiltered (gdb_stdlog,
1807 "LLR: Short circuiting for status 0x%x\n",
1810 if (target_can_async_p ())
1813 /* Tell the event loop we have something to process. */
1820 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1822 if (debug_linux_nat)
1823 fprintf_unfiltered (gdb_stdlog,
1824 "LLR: %s %s, %s (resume event thread)\n",
1825 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1826 target_pid_to_str (lp->ptid),
1827 (signo != GDB_SIGNAL_0
1828 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1830 linux_resume_one_lwp (lp, step, signo);
1832 if (target_can_async_p ())
1836 /* Send a signal to an LWP. */
1839 kill_lwp (int lwpid, int signo)
1844 ret = syscall (__NR_tkill, lwpid, signo);
1845 if (errno == ENOSYS)
1847 /* If tkill fails, then we are not using nptl threads, a
1848 configuration we no longer support. */
1849 perror_with_name (("tkill"));
1854 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1855 event, check if the core is interested in it: if not, ignore the
1856 event, and keep waiting; otherwise, we need to toggle the LWP's
1857 syscall entry/exit status, since the ptrace event itself doesn't
1858 indicate it, and report the trap to higher layers. */
1861 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1863 struct target_waitstatus *ourstatus = &lp->waitstatus;
1864 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1865 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1869 /* If we're stopping threads, there's a SIGSTOP pending, which
1870 makes it so that the LWP reports an immediate syscall return,
1871 followed by the SIGSTOP. Skip seeing that "return" using
1872 PTRACE_CONT directly, and let stop_wait_callback collect the
1873 SIGSTOP. Later when the thread is resumed, a new syscall
1874 entry event. If we didn't do this (and returned 0), we'd
1875 leave a syscall entry pending, and our caller, by using
1876 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1877 itself. Later, when the user re-resumes this LWP, we'd see
1878 another syscall entry event and we'd mistake it for a return.
1880 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1881 (leaving immediately with LWP->signalled set, without issuing
1882 a PTRACE_CONT), it would still be problematic to leave this
1883 syscall enter pending, as later when the thread is resumed,
1884 it would then see the same syscall exit mentioned above,
1885 followed by the delayed SIGSTOP, while the syscall didn't
1886 actually get to execute. It seems it would be even more
1887 confusing to the user. */
1889 if (debug_linux_nat)
1890 fprintf_unfiltered (gdb_stdlog,
1891 "LHST: ignoring syscall %d "
1892 "for LWP %ld (stopping threads), "
1893 "resuming with PTRACE_CONT for SIGSTOP\n",
1895 ptid_get_lwp (lp->ptid));
1897 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1898 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1903 /* Always update the entry/return state, even if this particular
1904 syscall isn't interesting to the core now. In async mode,
1905 the user could install a new catchpoint for this syscall
1906 between syscall enter/return, and we'll need to know to
1907 report a syscall return if that happens. */
1908 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1909 ? TARGET_WAITKIND_SYSCALL_RETURN
1910 : TARGET_WAITKIND_SYSCALL_ENTRY);
1912 if (catch_syscall_enabled ())
1914 if (catching_syscall_number (syscall_number))
1916 /* Alright, an event to report. */
1917 ourstatus->kind = lp->syscall_state;
1918 ourstatus->value.syscall_number = syscall_number;
1920 if (debug_linux_nat)
1921 fprintf_unfiltered (gdb_stdlog,
1922 "LHST: stopping for %s of syscall %d"
1925 == TARGET_WAITKIND_SYSCALL_ENTRY
1926 ? "entry" : "return",
1928 ptid_get_lwp (lp->ptid));
1932 if (debug_linux_nat)
1933 fprintf_unfiltered (gdb_stdlog,
1934 "LHST: ignoring %s of syscall %d "
1936 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1937 ? "entry" : "return",
1939 ptid_get_lwp (lp->ptid));
1943 /* If we had been syscall tracing, and hence used PT_SYSCALL
1944 before on this LWP, it could happen that the user removes all
1945 syscall catchpoints before we get to process this event.
1946 There are two noteworthy issues here:
1948 - When stopped at a syscall entry event, resuming with
1949 PT_STEP still resumes executing the syscall and reports a
1952 - Only PT_SYSCALL catches syscall enters. If we last
1953 single-stepped this thread, then this event can't be a
1954 syscall enter. If we last single-stepped this thread, this
1955 has to be a syscall exit.
1957 The points above mean that the next resume, be it PT_STEP or
1958 PT_CONTINUE, can not trigger a syscall trace event. */
1959 if (debug_linux_nat)
1960 fprintf_unfiltered (gdb_stdlog,
1961 "LHST: caught syscall event "
1962 "with no syscall catchpoints."
1963 " %d for LWP %ld, ignoring\n",
1965 ptid_get_lwp (lp->ptid));
1966 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1969 /* The core isn't interested in this event. For efficiency, avoid
1970 stopping all threads only to have the core resume them all again.
1971 Since we're not stopping threads, if we're still syscall tracing
1972 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1973 subsequent syscall. Simply resume using the inf-ptrace layer,
1974 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1976 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1980 /* Handle a GNU/Linux extended wait response. If we see a clone
1981 event, we need to add the new LWP to our list (and not report the
1982 trap to higher layers). This function returns non-zero if the
1983 event should be ignored and we should wait again. If STOPPING is
1984 true, the new LWP remains stopped, otherwise it is continued. */
1987 linux_handle_extended_wait (struct lwp_info *lp, int status)
1989 int pid = ptid_get_lwp (lp->ptid);
1990 struct target_waitstatus *ourstatus = &lp->waitstatus;
1991 int event = linux_ptrace_get_extended_event (status);
1993 /* All extended events we currently use are mid-syscall. Only
1994 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1995 you have to be using PTRACE_SEIZE to get that. */
1996 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1998 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1999 || event == PTRACE_EVENT_CLONE)
2001 unsigned long new_pid;
2004 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2006 /* If we haven't already seen the new PID stop, wait for it now. */
2007 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2009 /* The new child has a pending SIGSTOP. We can't affect it until it
2010 hits the SIGSTOP, but we're already attached. */
2011 ret = my_waitpid (new_pid, &status, __WALL);
2013 perror_with_name (_("waiting for new child"));
2014 else if (ret != new_pid)
2015 internal_error (__FILE__, __LINE__,
2016 _("wait returned unexpected PID %d"), ret);
2017 else if (!WIFSTOPPED (status))
2018 internal_error (__FILE__, __LINE__,
2019 _("wait returned unexpected status 0x%x"), status);
2022 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2024 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2026 /* The arch-specific native code may need to know about new
2027 forks even if those end up never mapped to an
2029 if (linux_nat_new_fork != NULL)
2030 linux_nat_new_fork (lp, new_pid);
2033 if (event == PTRACE_EVENT_FORK
2034 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2036 /* Handle checkpointing by linux-fork.c here as a special
2037 case. We don't want the follow-fork-mode or 'catch fork'
2038 to interfere with this. */
2040 /* This won't actually modify the breakpoint list, but will
2041 physically remove the breakpoints from the child. */
2042 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2044 /* Retain child fork in ptrace (stopped) state. */
2045 if (!find_fork_pid (new_pid))
2048 /* Report as spurious, so that infrun doesn't want to follow
2049 this fork. We're actually doing an infcall in
2051 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2053 /* Report the stop to the core. */
2057 if (event == PTRACE_EVENT_FORK)
2058 ourstatus->kind = TARGET_WAITKIND_FORKED;
2059 else if (event == PTRACE_EVENT_VFORK)
2060 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2061 else if (event == PTRACE_EVENT_CLONE)
2063 struct lwp_info *new_lp;
2065 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2067 if (debug_linux_nat)
2068 fprintf_unfiltered (gdb_stdlog,
2069 "LHEW: Got clone event "
2070 "from LWP %d, new child is LWP %ld\n",
2073 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2074 new_lp->stopped = 1;
2075 new_lp->resumed = 1;
2077 /* If the thread_db layer is active, let it record the user
2078 level thread id and status, and add the thread to GDB's
2080 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2082 /* The process is not using thread_db. Add the LWP to
2084 target_post_attach (ptid_get_lwp (new_lp->ptid));
2085 add_thread (new_lp->ptid);
2088 /* Even if we're stopping the thread for some reason
2089 internal to this module, from the perspective of infrun
2090 and the user/frontend, this new thread is running until
2091 it next reports a stop. */
2092 set_running (new_lp->ptid, 1);
2093 set_executing (new_lp->ptid, 1);
2095 if (WSTOPSIG (status) != SIGSTOP)
2097 /* This can happen if someone starts sending signals to
2098 the new thread before it gets a chance to run, which
2099 have a lower number than SIGSTOP (e.g. SIGUSR1).
2100 This is an unlikely case, and harder to handle for
2101 fork / vfork than for clone, so we do not try - but
2102 we handle it for clone events here. */
2104 new_lp->signalled = 1;
2106 /* We created NEW_LP so it cannot yet contain STATUS. */
2107 gdb_assert (new_lp->status == 0);
2109 /* Save the wait status to report later. */
2110 if (debug_linux_nat)
2111 fprintf_unfiltered (gdb_stdlog,
2112 "LHEW: waitpid of new LWP %ld, "
2113 "saving status %s\n",
2114 (long) ptid_get_lwp (new_lp->ptid),
2115 status_to_str (status));
2116 new_lp->status = status;
2118 else if (report_thread_events)
2120 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2121 new_lp->status = status;
2130 if (event == PTRACE_EVENT_EXEC)
2132 if (debug_linux_nat)
2133 fprintf_unfiltered (gdb_stdlog,
2134 "LHEW: Got exec event from LWP %ld\n",
2135 ptid_get_lwp (lp->ptid));
2137 ourstatus->kind = TARGET_WAITKIND_EXECD;
2138 ourstatus->value.execd_pathname
2139 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2141 /* The thread that execed must have been resumed, but, when a
2142 thread execs, it changes its tid to the tgid, and the old
2143 tgid thread might have not been resumed. */
2148 if (event == PTRACE_EVENT_VFORK_DONE)
2150 if (current_inferior ()->waiting_for_vfork_done)
2152 if (debug_linux_nat)
2153 fprintf_unfiltered (gdb_stdlog,
2154 "LHEW: Got expected PTRACE_EVENT_"
2155 "VFORK_DONE from LWP %ld: stopping\n",
2156 ptid_get_lwp (lp->ptid));
2158 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2162 if (debug_linux_nat)
2163 fprintf_unfiltered (gdb_stdlog,
2164 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2165 "from LWP %ld: ignoring\n",
2166 ptid_get_lwp (lp->ptid));
2170 internal_error (__FILE__, __LINE__,
2171 _("unknown ptrace event %d"), event);
2174 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2178 wait_lwp (struct lwp_info *lp)
2182 int thread_dead = 0;
2185 gdb_assert (!lp->stopped);
2186 gdb_assert (lp->status == 0);
2188 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2189 block_child_signals (&prev_mask);
2193 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2194 if (pid == -1 && errno == ECHILD)
2196 /* The thread has previously exited. We need to delete it
2197 now because if this was a non-leader thread execing, we
2198 won't get an exit event. See comments on exec events at
2199 the top of the file. */
2201 if (debug_linux_nat)
2202 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2203 target_pid_to_str (lp->ptid));
2208 /* Bugs 10970, 12702.
2209 Thread group leader may have exited in which case we'll lock up in
2210 waitpid if there are other threads, even if they are all zombies too.
2211 Basically, we're not supposed to use waitpid this way.
2212 tkill(pid,0) cannot be used here as it gets ESRCH for both
2213 for zombie and running processes.
2215 As a workaround, check if we're waiting for the thread group leader and
2216 if it's a zombie, and avoid calling waitpid if it is.
2218 This is racy, what if the tgl becomes a zombie right after we check?
2219 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2220 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2222 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2223 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2226 if (debug_linux_nat)
2227 fprintf_unfiltered (gdb_stdlog,
2228 "WL: Thread group leader %s vanished.\n",
2229 target_pid_to_str (lp->ptid));
2233 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2234 get invoked despite our caller had them intentionally blocked by
2235 block_child_signals. This is sensitive only to the loop of
2236 linux_nat_wait_1 and there if we get called my_waitpid gets called
2237 again before it gets to sigsuspend so we can safely let the handlers
2238 get executed here. */
2240 if (debug_linux_nat)
2241 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2242 sigsuspend (&suspend_mask);
2245 restore_child_signals_mask (&prev_mask);
2249 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2251 if (debug_linux_nat)
2253 fprintf_unfiltered (gdb_stdlog,
2254 "WL: waitpid %s received %s\n",
2255 target_pid_to_str (lp->ptid),
2256 status_to_str (status));
2259 /* Check if the thread has exited. */
2260 if (WIFEXITED (status) || WIFSIGNALED (status))
2262 if (report_thread_events
2263 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2265 if (debug_linux_nat)
2266 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2267 ptid_get_pid (lp->ptid));
2269 /* If this is the leader exiting, it means the whole
2270 process is gone. Store the status to report to the
2271 core. Store it in lp->waitstatus, because lp->status
2272 would be ambiguous (W_EXITCODE(0,0) == 0). */
2273 store_waitstatus (&lp->waitstatus, status);
2278 if (debug_linux_nat)
2279 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2280 target_pid_to_str (lp->ptid));
2290 gdb_assert (WIFSTOPPED (status));
2293 if (lp->must_set_ptrace_flags)
2295 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2296 int options = linux_nat_ptrace_options (inf->attach_flag);
2298 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2299 lp->must_set_ptrace_flags = 0;
2302 /* Handle GNU/Linux's syscall SIGTRAPs. */
2303 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2305 /* No longer need the sysgood bit. The ptrace event ends up
2306 recorded in lp->waitstatus if we care for it. We can carry
2307 on handling the event like a regular SIGTRAP from here
2309 status = W_STOPCODE (SIGTRAP);
2310 if (linux_handle_syscall_trap (lp, 1))
2311 return wait_lwp (lp);
2315 /* Almost all other ptrace-stops are known to be outside of system
2316 calls, with further exceptions in linux_handle_extended_wait. */
2317 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2320 /* Handle GNU/Linux's extended waitstatus for trace events. */
2321 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2322 && linux_is_extended_waitstatus (status))
2324 if (debug_linux_nat)
2325 fprintf_unfiltered (gdb_stdlog,
2326 "WL: Handling extended status 0x%06x\n",
2328 linux_handle_extended_wait (lp, status);
2335 /* Send a SIGSTOP to LP. */
2338 stop_callback (struct lwp_info *lp, void *data)
2340 if (!lp->stopped && !lp->signalled)
2344 if (debug_linux_nat)
2346 fprintf_unfiltered (gdb_stdlog,
2347 "SC: kill %s **<SIGSTOP>**\n",
2348 target_pid_to_str (lp->ptid));
2351 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2352 if (debug_linux_nat)
2354 fprintf_unfiltered (gdb_stdlog,
2355 "SC: lwp kill %d %s\n",
2357 errno ? safe_strerror (errno) : "ERRNO-OK");
2361 gdb_assert (lp->status == 0);
2367 /* Request a stop on LWP. */
2370 linux_stop_lwp (struct lwp_info *lwp)
2372 stop_callback (lwp, NULL);
2375 /* See linux-nat.h */
2378 linux_stop_and_wait_all_lwps (void)
2380 /* Stop all LWP's ... */
2381 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2383 /* ... and wait until all of them have reported back that
2384 they're no longer running. */
2385 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2388 /* See linux-nat.h */
2391 linux_unstop_all_lwps (void)
2393 iterate_over_lwps (minus_one_ptid,
2394 resume_stopped_resumed_lwps, &minus_one_ptid);
2397 /* Return non-zero if LWP PID has a pending SIGINT. */
2400 linux_nat_has_pending_sigint (int pid)
2402 sigset_t pending, blocked, ignored;
2404 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2406 if (sigismember (&pending, SIGINT)
2407 && !sigismember (&ignored, SIGINT))
2413 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2416 set_ignore_sigint (struct lwp_info *lp, void *data)
2418 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2419 flag to consume the next one. */
2420 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2421 && WSTOPSIG (lp->status) == SIGINT)
2424 lp->ignore_sigint = 1;
2429 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2430 This function is called after we know the LWP has stopped; if the LWP
2431 stopped before the expected SIGINT was delivered, then it will never have
2432 arrived. Also, if the signal was delivered to a shared queue and consumed
2433 by a different thread, it will never be delivered to this LWP. */
2436 maybe_clear_ignore_sigint (struct lwp_info *lp)
2438 if (!lp->ignore_sigint)
2441 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2443 if (debug_linux_nat)
2444 fprintf_unfiltered (gdb_stdlog,
2445 "MCIS: Clearing bogus flag for %s\n",
2446 target_pid_to_str (lp->ptid));
2447 lp->ignore_sigint = 0;
2451 /* Fetch the possible triggered data watchpoint info and store it in
2454 On some archs, like x86, that use debug registers to set
2455 watchpoints, it's possible that the way to know which watched
2456 address trapped, is to check the register that is used to select
2457 which address to watch. Problem is, between setting the watchpoint
2458 and reading back which data address trapped, the user may change
2459 the set of watchpoints, and, as a consequence, GDB changes the
2460 debug registers in the inferior. To avoid reading back a stale
2461 stopped-data-address when that happens, we cache in LP the fact
2462 that a watchpoint trapped, and the corresponding data address, as
2463 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2464 registers meanwhile, we have the cached data we can rely on. */
2467 check_stopped_by_watchpoint (struct lwp_info *lp)
2469 if (linux_ops->to_stopped_by_watchpoint == NULL)
2472 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
2473 inferior_ptid = lp->ptid;
2475 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2477 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2479 if (linux_ops->to_stopped_data_address != NULL)
2480 lp->stopped_data_address_p =
2481 linux_ops->to_stopped_data_address (¤t_target,
2482 &lp->stopped_data_address);
2484 lp->stopped_data_address_p = 0;
2487 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2490 /* Returns true if the LWP had stopped for a watchpoint. */
2493 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2495 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2497 gdb_assert (lp != NULL);
2499 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2503 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2505 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2507 gdb_assert (lp != NULL);
2509 *addr_p = lp->stopped_data_address;
2511 return lp->stopped_data_address_p;
2514 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2517 sigtrap_is_event (int status)
2519 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2522 /* Set alternative SIGTRAP-like events recognizer. If
2523 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2527 linux_nat_set_status_is_event (struct target_ops *t,
2528 int (*status_is_event) (int status))
2530 linux_nat_status_is_event = status_is_event;
2533 /* Wait until LP is stopped. */
2536 stop_wait_callback (struct lwp_info *lp, void *data)
2538 struct inferior *inf = find_inferior_ptid (lp->ptid);
2540 /* If this is a vfork parent, bail out, it is not going to report
2541 any SIGSTOP until the vfork is done with. */
2542 if (inf->vfork_child != NULL)
2549 status = wait_lwp (lp);
2553 if (lp->ignore_sigint && WIFSTOPPED (status)
2554 && WSTOPSIG (status) == SIGINT)
2556 lp->ignore_sigint = 0;
2559 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2561 if (debug_linux_nat)
2562 fprintf_unfiltered (gdb_stdlog,
2563 "PTRACE_CONT %s, 0, 0 (%s) "
2564 "(discarding SIGINT)\n",
2565 target_pid_to_str (lp->ptid),
2566 errno ? safe_strerror (errno) : "OK");
2568 return stop_wait_callback (lp, NULL);
2571 maybe_clear_ignore_sigint (lp);
2573 if (WSTOPSIG (status) != SIGSTOP)
2575 /* The thread was stopped with a signal other than SIGSTOP. */
2577 if (debug_linux_nat)
2578 fprintf_unfiltered (gdb_stdlog,
2579 "SWC: Pending event %s in %s\n",
2580 status_to_str ((int) status),
2581 target_pid_to_str (lp->ptid));
2583 /* Save the sigtrap event. */
2584 lp->status = status;
2585 gdb_assert (lp->signalled);
2586 save_stop_reason (lp);
2590 /* We caught the SIGSTOP that we intended to catch, so
2591 there's no SIGSTOP pending. */
2593 if (debug_linux_nat)
2594 fprintf_unfiltered (gdb_stdlog,
2595 "SWC: Expected SIGSTOP caught for %s.\n",
2596 target_pid_to_str (lp->ptid));
2598 /* Reset SIGNALLED only after the stop_wait_callback call
2599 above as it does gdb_assert on SIGNALLED. */
2607 /* Return non-zero if LP has a wait status pending. Discard the
2608 pending event and resume the LWP if the event that originally
2609 caused the stop became uninteresting. */
2612 status_callback (struct lwp_info *lp, void *data)
2614 /* Only report a pending wait status if we pretend that this has
2615 indeed been resumed. */
2619 if (!lwp_status_pending_p (lp))
2622 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2623 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2625 struct regcache *regcache = get_thread_regcache (lp->ptid);
2629 pc = regcache_read_pc (regcache);
2631 if (pc != lp->stop_pc)
2633 if (debug_linux_nat)
2634 fprintf_unfiltered (gdb_stdlog,
2635 "SC: PC of %s changed. was=%s, now=%s\n",
2636 target_pid_to_str (lp->ptid),
2637 paddress (target_gdbarch (), lp->stop_pc),
2638 paddress (target_gdbarch (), pc));
2642 #if !USE_SIGTRAP_SIGINFO
2643 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
2645 if (debug_linux_nat)
2646 fprintf_unfiltered (gdb_stdlog,
2647 "SC: previous breakpoint of %s, at %s gone\n",
2648 target_pid_to_str (lp->ptid),
2649 paddress (target_gdbarch (), lp->stop_pc));
2657 if (debug_linux_nat)
2658 fprintf_unfiltered (gdb_stdlog,
2659 "SC: pending event of %s cancelled.\n",
2660 target_pid_to_str (lp->ptid));
2663 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2671 /* Count the LWP's that have had events. */
2674 count_events_callback (struct lwp_info *lp, void *data)
2676 int *count = (int *) data;
2678 gdb_assert (count != NULL);
2680 /* Select only resumed LWPs that have an event pending. */
2681 if (lp->resumed && lwp_status_pending_p (lp))
2687 /* Select the LWP (if any) that is currently being single-stepped. */
2690 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2692 if (lp->last_resume_kind == resume_step
2699 /* Returns true if LP has a status pending. */
2702 lwp_status_pending_p (struct lwp_info *lp)
2704 /* We check for lp->waitstatus in addition to lp->status, because we
2705 can have pending process exits recorded in lp->status and
2706 W_EXITCODE(0,0) happens to be 0. */
2707 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2710 /* Select the Nth LWP that has had an event. */
2713 select_event_lwp_callback (struct lwp_info *lp, void *data)
2715 int *selector = (int *) data;
2717 gdb_assert (selector != NULL);
2719 /* Select only resumed LWPs that have an event pending. */
2720 if (lp->resumed && lwp_status_pending_p (lp))
2721 if ((*selector)-- == 0)
2727 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2728 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2729 and save the result in the LWP's stop_reason field. If it stopped
2730 for a breakpoint, decrement the PC if necessary on the lwp's
2734 save_stop_reason (struct lwp_info *lp)
2736 struct regcache *regcache;
2737 struct gdbarch *gdbarch;
2740 #if USE_SIGTRAP_SIGINFO
2744 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2745 gdb_assert (lp->status != 0);
2747 if (!linux_nat_status_is_event (lp->status))
2750 regcache = get_thread_regcache (lp->ptid);
2751 gdbarch = regcache->arch ();
2753 pc = regcache_read_pc (regcache);
2754 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2756 #if USE_SIGTRAP_SIGINFO
2757 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2759 if (siginfo.si_signo == SIGTRAP)
2761 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2762 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2764 /* The si_code is ambiguous on this arch -- check debug
2766 if (!check_stopped_by_watchpoint (lp))
2767 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2769 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2771 /* If we determine the LWP stopped for a SW breakpoint,
2772 trust it. Particularly don't check watchpoint
2773 registers, because at least on s390, we'd find
2774 stopped-by-watchpoint as long as there's a watchpoint
2776 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2778 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2780 /* This can indicate either a hardware breakpoint or
2781 hardware watchpoint. Check debug registers. */
2782 if (!check_stopped_by_watchpoint (lp))
2783 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2785 else if (siginfo.si_code == TRAP_TRACE)
2787 if (debug_linux_nat)
2788 fprintf_unfiltered (gdb_stdlog,
2789 "CSBB: %s stopped by trace\n",
2790 target_pid_to_str (lp->ptid));
2792 /* We may have single stepped an instruction that
2793 triggered a watchpoint. In that case, on some
2794 architectures (such as x86), instead of TRAP_HWBKPT,
2795 si_code indicates TRAP_TRACE, and we need to check
2796 the debug registers separately. */
2797 check_stopped_by_watchpoint (lp);
2802 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2803 && software_breakpoint_inserted_here_p (regcache->aspace (),
2806 /* The LWP was either continued, or stepped a software
2807 breakpoint instruction. */
2808 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2811 if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc))
2812 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2814 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2815 check_stopped_by_watchpoint (lp);
2818 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2820 if (debug_linux_nat)
2821 fprintf_unfiltered (gdb_stdlog,
2822 "CSBB: %s stopped by software breakpoint\n",
2823 target_pid_to_str (lp->ptid));
2825 /* Back up the PC if necessary. */
2827 regcache_write_pc (regcache, sw_bp_pc);
2829 /* Update this so we record the correct stop PC below. */
2832 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2834 if (debug_linux_nat)
2835 fprintf_unfiltered (gdb_stdlog,
2836 "CSBB: %s stopped by hardware breakpoint\n",
2837 target_pid_to_str (lp->ptid));
2839 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2841 if (debug_linux_nat)
2842 fprintf_unfiltered (gdb_stdlog,
2843 "CSBB: %s stopped by hardware watchpoint\n",
2844 target_pid_to_str (lp->ptid));
2851 /* Returns true if the LWP had stopped for a software breakpoint. */
2854 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2856 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2858 gdb_assert (lp != NULL);
2860 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2863 /* Implement the supports_stopped_by_sw_breakpoint method. */
2866 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2868 return USE_SIGTRAP_SIGINFO;
2871 /* Returns true if the LWP had stopped for a hardware
2872 breakpoint/watchpoint. */
2875 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2877 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2879 gdb_assert (lp != NULL);
2881 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2884 /* Implement the supports_stopped_by_hw_breakpoint method. */
2887 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2889 return USE_SIGTRAP_SIGINFO;
2892 /* Select one LWP out of those that have events pending. */
2895 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2898 int random_selector;
2899 struct lwp_info *event_lp = NULL;
2901 /* Record the wait status for the original LWP. */
2902 (*orig_lp)->status = *status;
2904 /* In all-stop, give preference to the LWP that is being
2905 single-stepped. There will be at most one, and it will be the
2906 LWP that the core is most interested in. If we didn't do this,
2907 then we'd have to handle pending step SIGTRAPs somehow in case
2908 the core later continues the previously-stepped thread, as
2909 otherwise we'd report the pending SIGTRAP then, and the core, not
2910 having stepped the thread, wouldn't understand what the trap was
2911 for, and therefore would report it to the user as a random
2913 if (!target_is_non_stop_p ())
2915 event_lp = iterate_over_lwps (filter,
2916 select_singlestep_lwp_callback, NULL);
2917 if (event_lp != NULL)
2919 if (debug_linux_nat)
2920 fprintf_unfiltered (gdb_stdlog,
2921 "SEL: Select single-step %s\n",
2922 target_pid_to_str (event_lp->ptid));
2926 if (event_lp == NULL)
2928 /* Pick one at random, out of those which have had events. */
2930 /* First see how many events we have. */
2931 iterate_over_lwps (filter, count_events_callback, &num_events);
2932 gdb_assert (num_events > 0);
2934 /* Now randomly pick a LWP out of those that have had
2936 random_selector = (int)
2937 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2939 if (debug_linux_nat && num_events > 1)
2940 fprintf_unfiltered (gdb_stdlog,
2941 "SEL: Found %d events, selecting #%d\n",
2942 num_events, random_selector);
2944 event_lp = iterate_over_lwps (filter,
2945 select_event_lwp_callback,
2949 if (event_lp != NULL)
2951 /* Switch the event LWP. */
2952 *orig_lp = event_lp;
2953 *status = event_lp->status;
2956 /* Flush the wait status for the event LWP. */
2957 (*orig_lp)->status = 0;
2960 /* Return non-zero if LP has been resumed. */
2963 resumed_callback (struct lwp_info *lp, void *data)
2968 /* Check if we should go on and pass this event to common code.
2969 Return the affected lwp if we are, or NULL otherwise. */
2971 static struct lwp_info *
2972 linux_nat_filter_event (int lwpid, int status)
2974 struct lwp_info *lp;
2975 int event = linux_ptrace_get_extended_event (status);
2977 lp = find_lwp_pid (pid_to_ptid (lwpid));
2979 /* Check for stop events reported by a process we didn't already
2980 know about - anything not already in our LWP list.
2982 If we're expecting to receive stopped processes after
2983 fork, vfork, and clone events, then we'll just add the
2984 new one to our list and go back to waiting for the event
2985 to be reported - the stopped process might be returned
2986 from waitpid before or after the event is.
2988 But note the case of a non-leader thread exec'ing after the
2989 leader having exited, and gone from our lists. The non-leader
2990 thread changes its tid to the tgid. */
2992 if (WIFSTOPPED (status) && lp == NULL
2993 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2995 /* A multi-thread exec after we had seen the leader exiting. */
2996 if (debug_linux_nat)
2997 fprintf_unfiltered (gdb_stdlog,
2998 "LLW: Re-adding thread group leader LWP %d.\n",
3001 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
3004 add_thread (lp->ptid);
3007 if (WIFSTOPPED (status) && !lp)
3009 if (debug_linux_nat)
3010 fprintf_unfiltered (gdb_stdlog,
3011 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3012 (long) lwpid, status_to_str (status));
3013 add_to_pid_list (&stopped_pids, lwpid, status);
3017 /* Make sure we don't report an event for the exit of an LWP not in
3018 our list, i.e. not part of the current process. This can happen
3019 if we detach from a program we originally forked and then it
3021 if (!WIFSTOPPED (status) && !lp)
3024 /* This LWP is stopped now. (And if dead, this prevents it from
3025 ever being continued.) */
3028 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3030 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3031 int options = linux_nat_ptrace_options (inf->attach_flag);
3033 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3034 lp->must_set_ptrace_flags = 0;
3037 /* Handle GNU/Linux's syscall SIGTRAPs. */
3038 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3040 /* No longer need the sysgood bit. The ptrace event ends up
3041 recorded in lp->waitstatus if we care for it. We can carry
3042 on handling the event like a regular SIGTRAP from here
3044 status = W_STOPCODE (SIGTRAP);
3045 if (linux_handle_syscall_trap (lp, 0))
3050 /* Almost all other ptrace-stops are known to be outside of system
3051 calls, with further exceptions in linux_handle_extended_wait. */
3052 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3055 /* Handle GNU/Linux's extended waitstatus for trace events. */
3056 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3057 && linux_is_extended_waitstatus (status))
3059 if (debug_linux_nat)
3060 fprintf_unfiltered (gdb_stdlog,
3061 "LLW: Handling extended status 0x%06x\n",
3063 if (linux_handle_extended_wait (lp, status))
3067 /* Check if the thread has exited. */
3068 if (WIFEXITED (status) || WIFSIGNALED (status))
3070 if (!report_thread_events
3071 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3073 if (debug_linux_nat)
3074 fprintf_unfiltered (gdb_stdlog,
3075 "LLW: %s exited.\n",
3076 target_pid_to_str (lp->ptid));
3078 /* If there is at least one more LWP, then the exit signal
3079 was not the end of the debugged application and should be
3085 /* Note that even if the leader was ptrace-stopped, it can still
3086 exit, if e.g., some other thread brings down the whole
3087 process (calls `exit'). So don't assert that the lwp is
3089 if (debug_linux_nat)
3090 fprintf_unfiltered (gdb_stdlog,
3091 "LWP %ld exited (resumed=%d)\n",
3092 ptid_get_lwp (lp->ptid), lp->resumed);
3094 /* Dead LWP's aren't expected to reported a pending sigstop. */
3097 /* Store the pending event in the waitstatus, because
3098 W_EXITCODE(0,0) == 0. */
3099 store_waitstatus (&lp->waitstatus, status);
3103 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3104 an attempt to stop an LWP. */
3106 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3110 if (lp->last_resume_kind == resume_stop)
3112 if (debug_linux_nat)
3113 fprintf_unfiltered (gdb_stdlog,
3114 "LLW: resume_stop SIGSTOP caught for %s.\n",
3115 target_pid_to_str (lp->ptid));
3119 /* This is a delayed SIGSTOP. Filter out the event. */
3121 if (debug_linux_nat)
3122 fprintf_unfiltered (gdb_stdlog,
3123 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3125 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3126 target_pid_to_str (lp->ptid));
3128 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3129 gdb_assert (lp->resumed);
3134 /* Make sure we don't report a SIGINT that we have already displayed
3135 for another thread. */
3136 if (lp->ignore_sigint
3137 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3139 if (debug_linux_nat)
3140 fprintf_unfiltered (gdb_stdlog,
3141 "LLW: Delayed SIGINT caught for %s.\n",
3142 target_pid_to_str (lp->ptid));
3144 /* This is a delayed SIGINT. */
3145 lp->ignore_sigint = 0;
3147 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3148 if (debug_linux_nat)
3149 fprintf_unfiltered (gdb_stdlog,
3150 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3152 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3153 target_pid_to_str (lp->ptid));
3154 gdb_assert (lp->resumed);
3156 /* Discard the event. */
3160 /* Don't report signals that GDB isn't interested in, such as
3161 signals that are neither printed nor stopped upon. Stopping all
3162 threads can be a bit time-consuming so if we want decent
3163 performance with heavily multi-threaded programs, especially when
3164 they're using a high frequency timer, we'd better avoid it if we
3166 if (WIFSTOPPED (status))
3168 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3170 if (!target_is_non_stop_p ())
3172 /* Only do the below in all-stop, as we currently use SIGSTOP
3173 to implement target_stop (see linux_nat_stop) in
3175 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3177 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3178 forwarded to the entire process group, that is, all LWPs
3179 will receive it - unless they're using CLONE_THREAD to
3180 share signals. Since we only want to report it once, we
3181 mark it as ignored for all LWPs except this one. */
3182 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3183 set_ignore_sigint, NULL);
3184 lp->ignore_sigint = 0;
3187 maybe_clear_ignore_sigint (lp);
3190 /* When using hardware single-step, we need to report every signal.
3191 Otherwise, signals in pass_mask may be short-circuited
3192 except signals that might be caused by a breakpoint. */
3194 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3195 && !linux_wstatus_maybe_breakpoint (status))
3197 linux_resume_one_lwp (lp, lp->step, signo);
3198 if (debug_linux_nat)
3199 fprintf_unfiltered (gdb_stdlog,
3200 "LLW: %s %s, %s (preempt 'handle')\n",
3202 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3203 target_pid_to_str (lp->ptid),
3204 (signo != GDB_SIGNAL_0
3205 ? strsignal (gdb_signal_to_host (signo))
3211 /* An interesting event. */
3213 lp->status = status;
3214 save_stop_reason (lp);
3218 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3219 their exits until all other threads in the group have exited. */
3222 check_zombie_leaders (void)
3224 struct inferior *inf;
3228 struct lwp_info *leader_lp;
3233 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3234 if (leader_lp != NULL
3235 /* Check if there are other threads in the group, as we may
3236 have raced with the inferior simply exiting. */
3237 && num_lwps (inf->pid) > 1
3238 && linux_proc_pid_is_zombie (inf->pid))
3240 if (debug_linux_nat)
3241 fprintf_unfiltered (gdb_stdlog,
3242 "CZL: Thread group leader %d zombie "
3243 "(it exited, or another thread execd).\n",
3246 /* A leader zombie can mean one of two things:
3248 - It exited, and there's an exit status pending
3249 available, or only the leader exited (not the whole
3250 program). In the latter case, we can't waitpid the
3251 leader's exit status until all other threads are gone.
3253 - There are 3 or more threads in the group, and a thread
3254 other than the leader exec'd. See comments on exec
3255 events at the top of the file. We could try
3256 distinguishing the exit and exec cases, by waiting once
3257 more, and seeing if something comes out, but it doesn't
3258 sound useful. The previous leader _does_ go away, and
3259 we'll re-add the new one once we see the exec event
3260 (which is just the same as what would happen if the
3261 previous leader did exit voluntarily before some other
3264 if (debug_linux_nat)
3265 fprintf_unfiltered (gdb_stdlog,
3266 "CZL: Thread group leader %d vanished.\n",
3268 exit_lwp (leader_lp);
3273 /* Convenience function that is called when the kernel reports an exit
3274 event. This decides whether to report the event to GDB as a
3275 process exit event, a thread exit event, or to suppress the
3279 filter_exit_event (struct lwp_info *event_child,
3280 struct target_waitstatus *ourstatus)
3282 ptid_t ptid = event_child->ptid;
3284 if (num_lwps (ptid_get_pid (ptid)) > 1)
3286 if (report_thread_events)
3287 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3289 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3291 exit_lwp (event_child);
3298 linux_nat_wait_1 (struct target_ops *ops,
3299 ptid_t ptid, struct target_waitstatus *ourstatus,
3303 enum resume_kind last_resume_kind;
3304 struct lwp_info *lp;
3307 if (debug_linux_nat)
3308 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3310 /* The first time we get here after starting a new inferior, we may
3311 not have added it to the LWP list yet - this is the earliest
3312 moment at which we know its PID. */
3313 if (ptid_is_pid (inferior_ptid))
3315 /* Upgrade the main thread's ptid. */
3316 thread_change_ptid (inferior_ptid,
3317 ptid_build (ptid_get_pid (inferior_ptid),
3318 ptid_get_pid (inferior_ptid), 0));
3320 lp = add_initial_lwp (inferior_ptid);
3324 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3325 block_child_signals (&prev_mask);
3327 /* First check if there is a LWP with a wait status pending. */
3328 lp = iterate_over_lwps (ptid, status_callback, NULL);
3331 if (debug_linux_nat)
3332 fprintf_unfiltered (gdb_stdlog,
3333 "LLW: Using pending wait status %s for %s.\n",
3334 status_to_str (lp->status),
3335 target_pid_to_str (lp->ptid));
3338 /* But if we don't find a pending event, we'll have to wait. Always
3339 pull all events out of the kernel. We'll randomly select an
3340 event LWP out of all that have events, to prevent starvation. */
3346 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3349 - If the thread group leader exits while other threads in the
3350 thread group still exist, waitpid(TGID, ...) hangs. That
3351 waitpid won't return an exit status until the other threads
3352 in the group are reapped.
3354 - When a non-leader thread execs, that thread just vanishes
3355 without reporting an exit (so we'd hang if we waited for it
3356 explicitly in that case). The exec event is reported to
3360 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3362 if (debug_linux_nat)
3363 fprintf_unfiltered (gdb_stdlog,
3364 "LNW: waitpid(-1, ...) returned %d, %s\n",
3365 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3369 if (debug_linux_nat)
3371 fprintf_unfiltered (gdb_stdlog,
3372 "LLW: waitpid %ld received %s\n",
3373 (long) lwpid, status_to_str (status));
3376 linux_nat_filter_event (lwpid, status);
3377 /* Retry until nothing comes out of waitpid. A single
3378 SIGCHLD can indicate more than one child stopped. */
3382 /* Now that we've pulled all events out of the kernel, resume
3383 LWPs that don't have an interesting event to report. */
3384 iterate_over_lwps (minus_one_ptid,
3385 resume_stopped_resumed_lwps, &minus_one_ptid);
3387 /* ... and find an LWP with a status to report to the core, if
3389 lp = iterate_over_lwps (ptid, status_callback, NULL);
3393 /* Check for zombie thread group leaders. Those can't be reaped
3394 until all other threads in the thread group are. */
3395 check_zombie_leaders ();
3397 /* If there are no resumed children left, bail. We'd be stuck
3398 forever in the sigsuspend call below otherwise. */
3399 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3401 if (debug_linux_nat)
3402 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3404 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3406 restore_child_signals_mask (&prev_mask);
3407 return minus_one_ptid;
3410 /* No interesting event to report to the core. */
3412 if (target_options & TARGET_WNOHANG)
3414 if (debug_linux_nat)
3415 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3417 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3418 restore_child_signals_mask (&prev_mask);
3419 return minus_one_ptid;
3422 /* We shouldn't end up here unless we want to try again. */
3423 gdb_assert (lp == NULL);
3425 /* Block until we get an event reported with SIGCHLD. */
3426 if (debug_linux_nat)
3427 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3428 sigsuspend (&suspend_mask);
3433 status = lp->status;
3436 if (!target_is_non_stop_p ())
3438 /* Now stop all other LWP's ... */
3439 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3441 /* ... and wait until all of them have reported back that
3442 they're no longer running. */
3443 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3446 /* If we're not waiting for a specific LWP, choose an event LWP from
3447 among those that have had events. Giving equal priority to all
3448 LWPs that have had events helps prevent starvation. */
3449 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3450 select_event_lwp (ptid, &lp, &status);
3452 gdb_assert (lp != NULL);
3454 /* Now that we've selected our final event LWP, un-adjust its PC if
3455 it was a software breakpoint, and we can't reliably support the
3456 "stopped by software breakpoint" stop reason. */
3457 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3458 && !USE_SIGTRAP_SIGINFO)
3460 struct regcache *regcache = get_thread_regcache (lp->ptid);
3461 struct gdbarch *gdbarch = regcache->arch ();
3462 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3468 pc = regcache_read_pc (regcache);
3469 regcache_write_pc (regcache, pc + decr_pc);
3473 /* We'll need this to determine whether to report a SIGSTOP as
3474 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3476 last_resume_kind = lp->last_resume_kind;
3478 if (!target_is_non_stop_p ())
3480 /* In all-stop, from the core's perspective, all LWPs are now
3481 stopped until a new resume action is sent over. */
3482 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3486 resume_clear_callback (lp, NULL);
3489 if (linux_nat_status_is_event (status))
3491 if (debug_linux_nat)
3492 fprintf_unfiltered (gdb_stdlog,
3493 "LLW: trap ptid is %s.\n",
3494 target_pid_to_str (lp->ptid));
3497 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3499 *ourstatus = lp->waitstatus;
3500 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3503 store_waitstatus (ourstatus, status);
3505 if (debug_linux_nat)
3506 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3508 restore_child_signals_mask (&prev_mask);
3510 if (last_resume_kind == resume_stop
3511 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3512 && WSTOPSIG (status) == SIGSTOP)
3514 /* A thread that has been requested to stop by GDB with
3515 target_stop, and it stopped cleanly, so report as SIG0. The
3516 use of SIGSTOP is an implementation detail. */
3517 ourstatus->value.sig = GDB_SIGNAL_0;
3520 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3521 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3524 lp->core = linux_common_core_of_thread (lp->ptid);
3526 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3527 return filter_exit_event (lp, ourstatus);
3532 /* Resume LWPs that are currently stopped without any pending status
3533 to report, but are resumed from the core's perspective. */
3536 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3538 ptid_t *wait_ptid_p = (ptid_t *) data;
3542 if (debug_linux_nat)
3543 fprintf_unfiltered (gdb_stdlog,
3544 "RSRL: NOT resuming LWP %s, not stopped\n",
3545 target_pid_to_str (lp->ptid));
3547 else if (!lp->resumed)
3549 if (debug_linux_nat)
3550 fprintf_unfiltered (gdb_stdlog,
3551 "RSRL: NOT resuming LWP %s, not resumed\n",
3552 target_pid_to_str (lp->ptid));
3554 else if (lwp_status_pending_p (lp))
3556 if (debug_linux_nat)
3557 fprintf_unfiltered (gdb_stdlog,
3558 "RSRL: NOT resuming LWP %s, has pending status\n",
3559 target_pid_to_str (lp->ptid));
3563 struct regcache *regcache = get_thread_regcache (lp->ptid);
3564 struct gdbarch *gdbarch = regcache->arch ();
3568 CORE_ADDR pc = regcache_read_pc (regcache);
3569 int leave_stopped = 0;
3571 /* Don't bother if there's a breakpoint at PC that we'd hit
3572 immediately, and we're not waiting for this LWP. */
3573 if (!ptid_match (lp->ptid, *wait_ptid_p))
3575 if (breakpoint_inserted_here_p (regcache->aspace (), pc))
3581 if (debug_linux_nat)
3582 fprintf_unfiltered (gdb_stdlog,
3583 "RSRL: resuming stopped-resumed LWP %s at "
3585 target_pid_to_str (lp->ptid),
3586 paddress (gdbarch, pc),
3589 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3592 CATCH (ex, RETURN_MASK_ERROR)
3594 if (!check_ptrace_stopped_lwp_gone (lp))
3595 throw_exception (ex);
3604 linux_nat_wait (struct target_ops *ops,
3605 ptid_t ptid, struct target_waitstatus *ourstatus,
3610 if (debug_linux_nat)
3612 char *options_string;
3614 options_string = target_options_to_string (target_options);
3615 fprintf_unfiltered (gdb_stdlog,
3616 "linux_nat_wait: [%s], [%s]\n",
3617 target_pid_to_str (ptid),
3619 xfree (options_string);
3622 /* Flush the async file first. */
3623 if (target_is_async_p ())
3624 async_file_flush ();
3626 /* Resume LWPs that are currently stopped without any pending status
3627 to report, but are resumed from the core's perspective. LWPs get
3628 in this state if we find them stopping at a time we're not
3629 interested in reporting the event (target_wait on a
3630 specific_process, for example, see linux_nat_wait_1), and
3631 meanwhile the event became uninteresting. Don't bother resuming
3632 LWPs we're not going to wait for if they'd stop immediately. */
3633 if (target_is_non_stop_p ())
3634 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3636 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3638 /* If we requested any event, and something came out, assume there
3639 may be more. If we requested a specific lwp or process, also
3640 assume there may be more. */
3641 if (target_is_async_p ()
3642 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3643 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3644 || !ptid_equal (ptid, minus_one_ptid)))
3653 kill_one_lwp (pid_t pid)
3655 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3658 kill_lwp (pid, SIGKILL);
3659 if (debug_linux_nat)
3661 int save_errno = errno;
3663 fprintf_unfiltered (gdb_stdlog,
3664 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3665 save_errno ? safe_strerror (save_errno) : "OK");
3668 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3671 ptrace (PTRACE_KILL, pid, 0, 0);
3672 if (debug_linux_nat)
3674 int save_errno = errno;
3676 fprintf_unfiltered (gdb_stdlog,
3677 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3678 save_errno ? safe_strerror (save_errno) : "OK");
3682 /* Wait for an LWP to die. */
3685 kill_wait_one_lwp (pid_t pid)
3689 /* We must make sure that there are no pending events (delayed
3690 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3691 program doesn't interfere with any following debugging session. */
3695 res = my_waitpid (pid, NULL, __WALL);
3696 if (res != (pid_t) -1)
3698 if (debug_linux_nat)
3699 fprintf_unfiltered (gdb_stdlog,
3700 "KWC: wait %ld received unknown.\n",
3702 /* The Linux kernel sometimes fails to kill a thread
3703 completely after PTRACE_KILL; that goes from the stop
3704 point in do_fork out to the one in get_signal_to_deliver
3705 and waits again. So kill it again. */
3711 gdb_assert (res == -1 && errno == ECHILD);
3714 /* Callback for iterate_over_lwps. */
3717 kill_callback (struct lwp_info *lp, void *data)
3719 kill_one_lwp (ptid_get_lwp (lp->ptid));
3723 /* Callback for iterate_over_lwps. */
3726 kill_wait_callback (struct lwp_info *lp, void *data)
3728 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3732 /* Kill the fork children of any threads of inferior INF that are
3733 stopped at a fork event. */
3736 kill_unfollowed_fork_children (struct inferior *inf)
3738 struct thread_info *thread;
3740 ALL_NON_EXITED_THREADS (thread)
3741 if (thread->inf == inf)
3743 struct target_waitstatus *ws = &thread->pending_follow;
3745 if (ws->kind == TARGET_WAITKIND_FORKED
3746 || ws->kind == TARGET_WAITKIND_VFORKED)
3748 ptid_t child_ptid = ws->value.related_pid;
3749 int child_pid = ptid_get_pid (child_ptid);
3750 int child_lwp = ptid_get_lwp (child_ptid);
3752 kill_one_lwp (child_lwp);
3753 kill_wait_one_lwp (child_lwp);
3755 /* Let the arch-specific native code know this process is
3757 linux_nat_forget_process (child_pid);
3763 linux_nat_kill (struct target_ops *ops)
3765 /* If we're stopped while forking and we haven't followed yet,
3766 kill the other task. We need to do this first because the
3767 parent will be sleeping if this is a vfork. */
3768 kill_unfollowed_fork_children (current_inferior ());
3770 if (forks_exist_p ())
3771 linux_fork_killall ();
3774 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3776 /* Stop all threads before killing them, since ptrace requires
3777 that the thread is stopped to sucessfully PTRACE_KILL. */
3778 iterate_over_lwps (ptid, stop_callback, NULL);
3779 /* ... and wait until all of them have reported back that
3780 they're no longer running. */
3781 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3783 /* Kill all LWP's ... */
3784 iterate_over_lwps (ptid, kill_callback, NULL);
3786 /* ... and wait until we've flushed all events. */
3787 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3790 target_mourn_inferior (inferior_ptid);
3794 linux_nat_mourn_inferior (struct target_ops *ops)
3796 int pid = ptid_get_pid (inferior_ptid);
3798 purge_lwp_list (pid);
3800 if (! forks_exist_p ())
3801 /* Normal case, no other forks available. */
3802 linux_ops->to_mourn_inferior (ops);
3804 /* Multi-fork case. The current inferior_ptid has exited, but
3805 there are other viable forks to debug. Delete the exiting
3806 one and context-switch to the first available. */
3807 linux_fork_mourn_inferior ();
3809 /* Let the arch-specific native code know this process is gone. */
3810 linux_nat_forget_process (pid);
3813 /* Convert a native/host siginfo object, into/from the siginfo in the
3814 layout of the inferiors' architecture. */
3817 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3821 if (linux_nat_siginfo_fixup != NULL)
3822 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3824 /* If there was no callback, or the callback didn't do anything,
3825 then just do a straight memcpy. */
3829 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3831 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3835 static enum target_xfer_status
3836 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3837 const char *annex, gdb_byte *readbuf,
3838 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3839 ULONGEST *xfered_len)
3843 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3845 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3846 gdb_assert (readbuf || writebuf);
3848 pid = ptid_get_lwp (inferior_ptid);
3850 pid = ptid_get_pid (inferior_ptid);
3852 if (offset > sizeof (siginfo))
3853 return TARGET_XFER_E_IO;
3856 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3858 return TARGET_XFER_E_IO;
3860 /* When GDB is built as a 64-bit application, ptrace writes into
3861 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3862 inferior with a 64-bit GDB should look the same as debugging it
3863 with a 32-bit GDB, we need to convert it. GDB core always sees
3864 the converted layout, so any read/write will have to be done
3866 siginfo_fixup (&siginfo, inf_siginfo, 0);
3868 if (offset + len > sizeof (siginfo))
3869 len = sizeof (siginfo) - offset;
3871 if (readbuf != NULL)
3872 memcpy (readbuf, inf_siginfo + offset, len);
3875 memcpy (inf_siginfo + offset, writebuf, len);
3877 /* Convert back to ptrace layout before flushing it out. */
3878 siginfo_fixup (&siginfo, inf_siginfo, 1);
3881 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3883 return TARGET_XFER_E_IO;
3887 return TARGET_XFER_OK;
3890 static enum target_xfer_status
3891 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3892 const char *annex, gdb_byte *readbuf,
3893 const gdb_byte *writebuf,
3894 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3896 enum target_xfer_status xfer;
3898 if (object == TARGET_OBJECT_SIGNAL_INFO)
3899 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3900 offset, len, xfered_len);
3902 /* The target is connected but no live inferior is selected. Pass
3903 this request down to a lower stratum (e.g., the executable
3905 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3906 return TARGET_XFER_EOF;
3908 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3909 offset, len, xfered_len);
3915 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3917 /* As long as a PTID is in lwp list, consider it alive. */
3918 return find_lwp_pid (ptid) != NULL;
3921 /* Implement the to_update_thread_list target method for this
3925 linux_nat_update_thread_list (struct target_ops *ops)
3927 struct lwp_info *lwp;
3929 /* We add/delete threads from the list as clone/exit events are
3930 processed, so just try deleting exited threads still in the
3932 delete_exited_threads ();
3934 /* Update the processor core that each lwp/thread was last seen
3938 /* Avoid accessing /proc if the thread hasn't run since we last
3939 time we fetched the thread's core. Accessing /proc becomes
3940 noticeably expensive when we have thousands of LWPs. */
3941 if (lwp->core == -1)
3942 lwp->core = linux_common_core_of_thread (lwp->ptid);
3947 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3949 static char buf[64];
3951 if (ptid_lwp_p (ptid)
3952 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3953 || num_lwps (ptid_get_pid (ptid)) > 1))
3955 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3959 return normal_pid_to_str (ptid);
3963 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3965 return linux_proc_tid_get_name (thr->ptid);
3968 /* Accepts an integer PID; Returns a string representing a file that
3969 can be opened to get the symbols for the child process. */
3972 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3974 return linux_proc_pid_to_exec_file (pid);
3977 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3978 Because we can use a single read/write call, this can be much more
3979 efficient than banging away at PTRACE_PEEKTEXT. */
3981 static enum target_xfer_status
3982 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3983 const char *annex, gdb_byte *readbuf,
3984 const gdb_byte *writebuf,
3985 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3991 if (object != TARGET_OBJECT_MEMORY)
3992 return TARGET_XFER_EOF;
3994 /* Don't bother for one word. */
3995 if (len < 3 * sizeof (long))
3996 return TARGET_XFER_EOF;
3998 /* We could keep this file open and cache it - possibly one per
3999 thread. That requires some juggling, but is even faster. */
4000 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
4001 ptid_get_lwp (inferior_ptid));
4002 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
4005 return TARGET_XFER_EOF;
4007 /* Use pread64/pwrite64 if available, since they save a syscall and can
4008 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
4009 debugging a SPARC64 application). */
4011 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
4012 : pwrite64 (fd, writebuf, len, offset));
4014 ret = lseek (fd, offset, SEEK_SET);
4016 ret = (readbuf ? read (fd, readbuf, len)
4017 : write (fd, writebuf, len));
4022 if (ret == -1 || ret == 0)
4023 return TARGET_XFER_EOF;
4027 return TARGET_XFER_OK;
4032 /* Enumerate spufs IDs for process PID. */
4034 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4036 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4038 LONGEST written = 0;
4041 struct dirent *entry;
4043 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4044 dir = opendir (path);
4049 while ((entry = readdir (dir)) != NULL)
4055 fd = atoi (entry->d_name);
4059 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4060 if (stat (path, &st) != 0)
4062 if (!S_ISDIR (st.st_mode))
4065 if (statfs (path, &stfs) != 0)
4067 if (stfs.f_type != SPUFS_MAGIC)
4070 if (pos >= offset && pos + 4 <= offset + len)
4072 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4082 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4083 object type, using the /proc file system. */
4085 static enum target_xfer_status
4086 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4087 const char *annex, gdb_byte *readbuf,
4088 const gdb_byte *writebuf,
4089 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4094 int pid = ptid_get_lwp (inferior_ptid);
4099 return TARGET_XFER_E_IO;
4102 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4105 return TARGET_XFER_E_IO;
4107 return TARGET_XFER_EOF;
4110 *xfered_len = (ULONGEST) l;
4111 return TARGET_XFER_OK;
4116 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4117 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4119 return TARGET_XFER_E_IO;
4122 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4125 return TARGET_XFER_EOF;
4129 ret = write (fd, writebuf, (size_t) len);
4131 ret = read (fd, readbuf, (size_t) len);
4136 return TARGET_XFER_E_IO;
4138 return TARGET_XFER_EOF;
4141 *xfered_len = (ULONGEST) ret;
4142 return TARGET_XFER_OK;
4147 /* Parse LINE as a signal set and add its set bits to SIGS. */
4150 add_line_to_sigset (const char *line, sigset_t *sigs)
4152 int len = strlen (line) - 1;
4156 if (line[len] != '\n')
4157 error (_("Could not parse signal set: %s"), line);
4165 if (*p >= '0' && *p <= '9')
4167 else if (*p >= 'a' && *p <= 'f')
4168 digit = *p - 'a' + 10;
4170 error (_("Could not parse signal set: %s"), line);
4175 sigaddset (sigs, signum + 1);
4177 sigaddset (sigs, signum + 2);
4179 sigaddset (sigs, signum + 3);
4181 sigaddset (sigs, signum + 4);
4187 /* Find process PID's pending signals from /proc/pid/status and set
4191 linux_proc_pending_signals (int pid, sigset_t *pending,
4192 sigset_t *blocked, sigset_t *ignored)
4194 char buffer[PATH_MAX], fname[PATH_MAX];
4196 sigemptyset (pending);
4197 sigemptyset (blocked);
4198 sigemptyset (ignored);
4199 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4200 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
4201 if (procfile == NULL)
4202 error (_("Could not open %s"), fname);
4204 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
4206 /* Normal queued signals are on the SigPnd line in the status
4207 file. However, 2.6 kernels also have a "shared" pending
4208 queue for delivering signals to a thread group, so check for
4211 Unfortunately some Red Hat kernels include the shared pending
4212 queue but not the ShdPnd status field. */
4214 if (startswith (buffer, "SigPnd:\t"))
4215 add_line_to_sigset (buffer + 8, pending);
4216 else if (startswith (buffer, "ShdPnd:\t"))
4217 add_line_to_sigset (buffer + 8, pending);
4218 else if (startswith (buffer, "SigBlk:\t"))
4219 add_line_to_sigset (buffer + 8, blocked);
4220 else if (startswith (buffer, "SigIgn:\t"))
4221 add_line_to_sigset (buffer + 8, ignored);
4225 static enum target_xfer_status
4226 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4227 const char *annex, gdb_byte *readbuf,
4228 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4229 ULONGEST *xfered_len)
4231 gdb_assert (object == TARGET_OBJECT_OSDATA);
4233 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4234 if (*xfered_len == 0)
4235 return TARGET_XFER_EOF;
4237 return TARGET_XFER_OK;
4240 static enum target_xfer_status
4241 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4242 const char *annex, gdb_byte *readbuf,
4243 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4244 ULONGEST *xfered_len)
4246 enum target_xfer_status xfer;
4248 if (object == TARGET_OBJECT_AUXV)
4249 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4250 offset, len, xfered_len);
4252 if (object == TARGET_OBJECT_OSDATA)
4253 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4254 offset, len, xfered_len);
4256 if (object == TARGET_OBJECT_SPU)
4257 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4258 offset, len, xfered_len);
4260 /* GDB calculates all the addresses in possibly larget width of the address.
4261 Address width needs to be masked before its final use - either by
4262 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4264 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4266 if (object == TARGET_OBJECT_MEMORY)
4268 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4270 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4271 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4274 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4275 offset, len, xfered_len);
4276 if (xfer != TARGET_XFER_EOF)
4279 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4280 offset, len, xfered_len);
4284 cleanup_target_stop (void *arg)
4286 ptid_t *ptid = (ptid_t *) arg;
4288 gdb_assert (arg != NULL);
4291 target_continue_no_signal (*ptid);
4294 static VEC(static_tracepoint_marker_p) *
4295 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4298 char s[IPA_CMD_BUF_SIZE];
4299 struct cleanup *old_chain;
4300 int pid = ptid_get_pid (inferior_ptid);
4301 VEC(static_tracepoint_marker_p) *markers = NULL;
4302 struct static_tracepoint_marker *marker = NULL;
4304 ptid_t ptid = ptid_build (pid, 0, 0);
4309 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4310 s[sizeof ("qTfSTM")] = 0;
4312 agent_run_command (pid, s, strlen (s) + 1);
4314 old_chain = make_cleanup (free_current_marker, &marker);
4315 make_cleanup (cleanup_target_stop, &ptid);
4320 marker = XCNEW (struct static_tracepoint_marker);
4324 parse_static_tracepoint_marker_definition (p, &p, marker);
4326 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4328 VEC_safe_push (static_tracepoint_marker_p,
4334 release_static_tracepoint_marker (marker);
4335 memset (marker, 0, sizeof (*marker));
4338 while (*p++ == ','); /* comma-separated list */
4340 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4341 s[sizeof ("qTsSTM")] = 0;
4342 agent_run_command (pid, s, strlen (s) + 1);
4346 do_cleanups (old_chain);
4351 /* Create a prototype generic GNU/Linux target. The client can override
4352 it with local methods. */
4355 linux_target_install_ops (struct target_ops *t)
4357 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4358 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4359 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4360 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4361 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4362 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4363 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4364 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4365 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4366 t->to_post_attach = linux_child_post_attach;
4367 t->to_follow_fork = linux_child_follow_fork;
4369 super_xfer_partial = t->to_xfer_partial;
4370 t->to_xfer_partial = linux_xfer_partial;
4372 t->to_static_tracepoint_markers_by_strid
4373 = linux_child_static_tracepoint_markers_by_strid;
4379 struct target_ops *t;
4381 t = inf_ptrace_target ();
4382 linux_target_install_ops (t);
4388 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4390 struct target_ops *t;
4392 t = inf_ptrace_trad_target (register_u_offset);
4393 linux_target_install_ops (t);
4398 /* target_is_async_p implementation. */
4401 linux_nat_is_async_p (struct target_ops *ops)
4403 return linux_is_async_p ();
4406 /* target_can_async_p implementation. */
4409 linux_nat_can_async_p (struct target_ops *ops)
4411 /* We're always async, unless the user explicitly prevented it with the
4412 "maint set target-async" command. */
4413 return target_async_permitted;
4417 linux_nat_supports_non_stop (struct target_ops *self)
4422 /* to_always_non_stop_p implementation. */
4425 linux_nat_always_non_stop_p (struct target_ops *self)
4430 /* True if we want to support multi-process. To be removed when GDB
4431 supports multi-exec. */
4433 int linux_multi_process = 1;
4436 linux_nat_supports_multi_process (struct target_ops *self)
4438 return linux_multi_process;
4442 linux_nat_supports_disable_randomization (struct target_ops *self)
4444 #ifdef HAVE_PERSONALITY
4451 static int async_terminal_is_ours = 1;
4453 /* target_terminal_inferior implementation.
4455 This is a wrapper around child_terminal_inferior to add async support. */
4458 linux_nat_terminal_inferior (struct target_ops *self)
4460 child_terminal_inferior (self);
4462 /* Calls to target_terminal_*() are meant to be idempotent. */
4463 if (!async_terminal_is_ours)
4466 async_terminal_is_ours = 0;
4470 /* target_terminal::ours implementation.
4472 This is a wrapper around child_terminal_ours to add async support (and
4473 implement the target_terminal::ours vs target_terminal::ours_for_output
4474 distinction). child_terminal_ours is currently no different than
4475 child_terminal_ours_for_output.
4476 We leave target_terminal::ours_for_output alone, leaving it to
4477 child_terminal_ours_for_output. */
4480 linux_nat_terminal_ours (struct target_ops *self)
4482 /* GDB should never give the terminal to the inferior if the
4483 inferior is running in the background (run&, continue&, etc.),
4484 but claiming it sure should. */
4485 child_terminal_ours (self);
4487 if (async_terminal_is_ours)
4490 clear_sigint_trap ();
4491 async_terminal_is_ours = 1;
4494 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4495 so we notice when any child changes state, and notify the
4496 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4497 above to wait for the arrival of a SIGCHLD. */
4500 sigchld_handler (int signo)
4502 int old_errno = errno;
4504 if (debug_linux_nat)
4505 ui_file_write_async_safe (gdb_stdlog,
4506 "sigchld\n", sizeof ("sigchld\n") - 1);
4508 if (signo == SIGCHLD
4509 && linux_nat_event_pipe[0] != -1)
4510 async_file_mark (); /* Let the event loop know that there are
4511 events to handle. */
4516 /* Callback registered with the target events file descriptor. */
4519 handle_target_event (int error, gdb_client_data client_data)
4521 inferior_event_handler (INF_REG_EVENT, NULL);
4524 /* Create/destroy the target events pipe. Returns previous state. */
4527 linux_async_pipe (int enable)
4529 int previous = linux_is_async_p ();
4531 if (previous != enable)
4535 /* Block child signals while we create/destroy the pipe, as
4536 their handler writes to it. */
4537 block_child_signals (&prev_mask);
4541 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4542 internal_error (__FILE__, __LINE__,
4543 "creating event pipe failed.");
4545 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4546 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4550 close (linux_nat_event_pipe[0]);
4551 close (linux_nat_event_pipe[1]);
4552 linux_nat_event_pipe[0] = -1;
4553 linux_nat_event_pipe[1] = -1;
4556 restore_child_signals_mask (&prev_mask);
4562 /* target_async implementation. */
4565 linux_nat_async (struct target_ops *ops, int enable)
4569 if (!linux_async_pipe (1))
4571 add_file_handler (linux_nat_event_pipe[0],
4572 handle_target_event, NULL);
4573 /* There may be pending events to handle. Tell the event loop
4580 delete_file_handler (linux_nat_event_pipe[0]);
4581 linux_async_pipe (0);
4586 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4590 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4594 if (debug_linux_nat)
4595 fprintf_unfiltered (gdb_stdlog,
4596 "LNSL: running -> suspending %s\n",
4597 target_pid_to_str (lwp->ptid));
4600 if (lwp->last_resume_kind == resume_stop)
4602 if (debug_linux_nat)
4603 fprintf_unfiltered (gdb_stdlog,
4604 "linux-nat: already stopping LWP %ld at "
4606 ptid_get_lwp (lwp->ptid));
4610 stop_callback (lwp, NULL);
4611 lwp->last_resume_kind = resume_stop;
4615 /* Already known to be stopped; do nothing. */
4617 if (debug_linux_nat)
4619 if (find_thread_ptid (lwp->ptid)->stop_requested)
4620 fprintf_unfiltered (gdb_stdlog,
4621 "LNSL: already stopped/stop_requested %s\n",
4622 target_pid_to_str (lwp->ptid));
4624 fprintf_unfiltered (gdb_stdlog,
4625 "LNSL: already stopped/no "
4626 "stop_requested yet %s\n",
4627 target_pid_to_str (lwp->ptid));
4634 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4636 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4640 linux_nat_close (struct target_ops *self)
4642 /* Unregister from the event loop. */
4643 if (linux_nat_is_async_p (self))
4644 linux_nat_async (self, 0);
4646 if (linux_ops->to_close)
4647 linux_ops->to_close (linux_ops);
4652 /* When requests are passed down from the linux-nat layer to the
4653 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4654 used. The address space pointer is stored in the inferior object,
4655 but the common code that is passed such ptid can't tell whether
4656 lwpid is a "main" process id or not (it assumes so). We reverse
4657 look up the "main" process id from the lwp here. */
4659 static struct address_space *
4660 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4662 struct lwp_info *lwp;
4663 struct inferior *inf;
4666 if (ptid_get_lwp (ptid) == 0)
4668 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4670 lwp = find_lwp_pid (ptid);
4671 pid = ptid_get_pid (lwp->ptid);
4675 /* A (pid,lwpid,0) ptid. */
4676 pid = ptid_get_pid (ptid);
4679 inf = find_inferior_pid (pid);
4680 gdb_assert (inf != NULL);
4684 /* Return the cached value of the processor core for thread PTID. */
4687 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4689 struct lwp_info *info = find_lwp_pid (ptid);
4696 /* Implementation of to_filesystem_is_local. */
4699 linux_nat_filesystem_is_local (struct target_ops *ops)
4701 struct inferior *inf = current_inferior ();
4703 if (inf->fake_pid_p || inf->pid == 0)
4706 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4709 /* Convert the INF argument passed to a to_fileio_* method
4710 to a process ID suitable for passing to its corresponding
4711 linux_mntns_* function. If INF is non-NULL then the
4712 caller is requesting the filesystem seen by INF. If INF
4713 is NULL then the caller is requesting the filesystem seen
4714 by the GDB. We fall back to GDB's filesystem in the case
4715 that INF is non-NULL but its PID is unknown. */
4718 linux_nat_fileio_pid_of (struct inferior *inf)
4720 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4726 /* Implementation of to_fileio_open. */
4729 linux_nat_fileio_open (struct target_ops *self,
4730 struct inferior *inf, const char *filename,
4731 int flags, int mode, int warn_if_slow,
4738 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4739 || fileio_to_host_mode (mode, &nat_mode) == -1)
4741 *target_errno = FILEIO_EINVAL;
4745 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4746 filename, nat_flags, nat_mode);
4748 *target_errno = host_to_fileio_error (errno);
4753 /* Implementation of to_fileio_readlink. */
4756 linux_nat_fileio_readlink (struct target_ops *self,
4757 struct inferior *inf, const char *filename,
4764 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4765 filename, buf, sizeof (buf));
4768 *target_errno = host_to_fileio_error (errno);
4772 ret = (char *) xmalloc (len + 1);
4773 memcpy (ret, buf, len);
4778 /* Implementation of to_fileio_unlink. */
4781 linux_nat_fileio_unlink (struct target_ops *self,
4782 struct inferior *inf, const char *filename,
4787 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4790 *target_errno = host_to_fileio_error (errno);
4795 /* Implementation of the to_thread_events method. */
4798 linux_nat_thread_events (struct target_ops *ops, int enable)
4800 report_thread_events = enable;
4804 linux_nat_add_target (struct target_ops *t)
4806 /* Save the provided single-threaded target. We save this in a separate
4807 variable because another target we've inherited from (e.g. inf-ptrace)
4808 may have saved a pointer to T; we want to use it for the final
4809 process stratum target. */
4810 linux_ops_saved = *t;
4811 linux_ops = &linux_ops_saved;
4813 /* Override some methods for multithreading. */
4814 t->to_create_inferior = linux_nat_create_inferior;
4815 t->to_attach = linux_nat_attach;
4816 t->to_detach = linux_nat_detach;
4817 t->to_resume = linux_nat_resume;
4818 t->to_wait = linux_nat_wait;
4819 t->to_pass_signals = linux_nat_pass_signals;
4820 t->to_xfer_partial = linux_nat_xfer_partial;
4821 t->to_kill = linux_nat_kill;
4822 t->to_mourn_inferior = linux_nat_mourn_inferior;
4823 t->to_thread_alive = linux_nat_thread_alive;
4824 t->to_update_thread_list = linux_nat_update_thread_list;
4825 t->to_pid_to_str = linux_nat_pid_to_str;
4826 t->to_thread_name = linux_nat_thread_name;
4827 t->to_has_thread_control = tc_schedlock;
4828 t->to_thread_address_space = linux_nat_thread_address_space;
4829 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4830 t->to_stopped_data_address = linux_nat_stopped_data_address;
4831 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4832 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4833 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4834 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4835 t->to_thread_events = linux_nat_thread_events;
4837 t->to_can_async_p = linux_nat_can_async_p;
4838 t->to_is_async_p = linux_nat_is_async_p;
4839 t->to_supports_non_stop = linux_nat_supports_non_stop;
4840 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4841 t->to_async = linux_nat_async;
4842 t->to_terminal_inferior = linux_nat_terminal_inferior;
4843 t->to_terminal_ours = linux_nat_terminal_ours;
4845 super_close = t->to_close;
4846 t->to_close = linux_nat_close;
4848 t->to_stop = linux_nat_stop;
4850 t->to_supports_multi_process = linux_nat_supports_multi_process;
4852 t->to_supports_disable_randomization
4853 = linux_nat_supports_disable_randomization;
4855 t->to_core_of_thread = linux_nat_core_of_thread;
4857 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4858 t->to_fileio_open = linux_nat_fileio_open;
4859 t->to_fileio_readlink = linux_nat_fileio_readlink;
4860 t->to_fileio_unlink = linux_nat_fileio_unlink;
4862 /* We don't change the stratum; this target will sit at
4863 process_stratum and thread_db will set at thread_stratum. This
4864 is a little strange, since this is a multi-threaded-capable
4865 target, but we want to be on the stack below thread_db, and we
4866 also want to be used for single-threaded processes. */
4871 /* Register a method to call whenever a new thread is attached. */
4873 linux_nat_set_new_thread (struct target_ops *t,
4874 void (*new_thread) (struct lwp_info *))
4876 /* Save the pointer. We only support a single registered instance
4877 of the GNU/Linux native target, so we do not need to map this to
4879 linux_nat_new_thread = new_thread;
4882 /* Register a method to call whenever a new thread is attached. */
4884 linux_nat_set_delete_thread (struct target_ops *t,
4885 void (*delete_thread) (struct arch_lwp_info *))
4887 /* Save the pointer. We only support a single registered instance
4888 of the GNU/Linux native target, so we do not need to map this to
4890 linux_nat_delete_thread = delete_thread;
4893 /* See declaration in linux-nat.h. */
4896 linux_nat_set_new_fork (struct target_ops *t,
4897 linux_nat_new_fork_ftype *new_fork)
4899 /* Save the pointer. */
4900 linux_nat_new_fork = new_fork;
4903 /* See declaration in linux-nat.h. */
4906 linux_nat_set_forget_process (struct target_ops *t,
4907 linux_nat_forget_process_ftype *fn)
4909 /* Save the pointer. */
4910 linux_nat_forget_process_hook = fn;
4913 /* See declaration in linux-nat.h. */
4916 linux_nat_forget_process (pid_t pid)
4918 if (linux_nat_forget_process_hook != NULL)
4919 linux_nat_forget_process_hook (pid);
4922 /* Register a method that converts a siginfo object between the layout
4923 that ptrace returns, and the layout in the architecture of the
4926 linux_nat_set_siginfo_fixup (struct target_ops *t,
4927 int (*siginfo_fixup) (siginfo_t *,
4931 /* Save the pointer. */
4932 linux_nat_siginfo_fixup = siginfo_fixup;
4935 /* Register a method to call prior to resuming a thread. */
4938 linux_nat_set_prepare_to_resume (struct target_ops *t,
4939 void (*prepare_to_resume) (struct lwp_info *))
4941 /* Save the pointer. */
4942 linux_nat_prepare_to_resume = prepare_to_resume;
4945 /* See linux-nat.h. */
4948 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4952 pid = ptid_get_lwp (ptid);
4954 pid = ptid_get_pid (ptid);
4957 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4960 memset (siginfo, 0, sizeof (*siginfo));
4966 /* See nat/linux-nat.h. */
4969 current_lwp_ptid (void)
4971 gdb_assert (ptid_lwp_p (inferior_ptid));
4972 return inferior_ptid;
4976 _initialize_linux_nat (void)
4978 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4979 &debug_linux_nat, _("\
4980 Set debugging of GNU/Linux lwp module."), _("\
4981 Show debugging of GNU/Linux lwp module."), _("\
4982 Enables printf debugging output."),
4984 show_debug_linux_nat,
4985 &setdebuglist, &showdebuglist);
4987 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4988 &debug_linux_namespaces, _("\
4989 Set debugging of GNU/Linux namespaces module."), _("\
4990 Show debugging of GNU/Linux namespaces module."), _("\
4991 Enables printf debugging output."),
4994 &setdebuglist, &showdebuglist);
4996 /* Save this mask as the default. */
4997 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4999 /* Install a SIGCHLD handler. */
5000 sigchld_action.sa_handler = sigchld_handler;
5001 sigemptyset (&sigchld_action.sa_mask);
5002 sigchld_action.sa_flags = SA_RESTART;
5004 /* Make it the default. */
5005 sigaction (SIGCHLD, &sigchld_action, NULL);
5007 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5008 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5009 sigdelset (&suspend_mask, SIGCHLD);
5011 sigemptyset (&blocked_mask);
5013 lwp_lwpid_htab_create ();
5017 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5018 the GNU/Linux Threads library and therefore doesn't really belong
5021 /* Return the set of signals used by the threads library in *SET. */
5024 lin_thread_get_thread_signals (sigset_t *set)
5028 /* NPTL reserves the first two RT signals, but does not provide any
5029 way for the debugger to query the signal numbers - fortunately
5030 they don't change. */
5031 sigaddset (set, __SIGRTMIN);
5032 sigaddset (set, __SIGRTMIN + 1);