1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops *linux_ops;
195 static struct target_ops linux_ops_saved;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread) (struct lwp_info *);
200 /* The method to call, if any, when a thread is destroyed. */
201 static void (*linux_nat_delete_thread) (struct arch_lwp_info *);
203 /* The method to call, if any, when a new fork is attached. */
204 static linux_nat_new_fork_ftype *linux_nat_new_fork;
206 /* The method to call, if any, when a process is no longer
208 static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
210 /* Hook to call prior to resuming a thread. */
211 static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
213 /* The method to call, if any, when the siginfo object needs to be
214 converted between the layout returned by ptrace, and the layout in
215 the architecture of the inferior. */
216 static int (*linux_nat_siginfo_fixup) (siginfo_t *,
220 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
221 Called by our to_xfer_partial. */
222 static target_xfer_partial_ftype *super_xfer_partial;
224 /* The saved to_close method, inherited from inf-ptrace.c.
225 Called by our to_close. */
226 static void (*super_close) (struct target_ops *);
228 static unsigned int debug_linux_nat;
230 show_debug_linux_nat (struct ui_file *file, int from_tty,
231 struct cmd_list_element *c, const char *value)
233 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
237 struct simple_pid_list
241 struct simple_pid_list *next;
243 struct simple_pid_list *stopped_pids;
245 /* Whether target_thread_events is in effect. */
246 static int report_thread_events;
248 /* Async mode support. */
250 /* The read/write ends of the pipe registered as waitable file in the
252 static int linux_nat_event_pipe[2] = { -1, -1 };
254 /* True if we're currently in async mode. */
255 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
257 /* Flush the event pipe. */
260 async_file_flush (void)
267 ret = read (linux_nat_event_pipe[0], &buf, 1);
269 while (ret >= 0 || (ret == -1 && errno == EINTR));
272 /* Put something (anything, doesn't matter what, or how much) in event
273 pipe, so that the select/poll in the event-loop realizes we have
274 something to process. */
277 async_file_mark (void)
281 /* It doesn't really matter what the pipe contains, as long we end
282 up with something in it. Might as well flush the previous
288 ret = write (linux_nat_event_pipe[1], "+", 1);
290 while (ret == -1 && errno == EINTR);
292 /* Ignore EAGAIN. If the pipe is full, the event loop will already
293 be awakened anyway. */
296 static int kill_lwp (int lwpid, int signo);
298 static int stop_callback (struct lwp_info *lp, void *data);
299 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
301 static void block_child_signals (sigset_t *prev_mask);
302 static void restore_child_signals_mask (sigset_t *prev_mask);
305 static struct lwp_info *add_lwp (ptid_t ptid);
306 static void purge_lwp_list (int pid);
307 static void delete_lwp (ptid_t ptid);
308 static struct lwp_info *find_lwp_pid (ptid_t ptid);
310 static int lwp_status_pending_p (struct lwp_info *lp);
312 static int sigtrap_is_event (int status);
313 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
315 static void save_stop_reason (struct lwp_info *lp);
320 /* See nat/linux-nat.h. */
323 ptid_of_lwp (struct lwp_info *lwp)
328 /* See nat/linux-nat.h. */
331 lwp_set_arch_private_info (struct lwp_info *lwp,
332 struct arch_lwp_info *info)
334 lwp->arch_private = info;
337 /* See nat/linux-nat.h. */
339 struct arch_lwp_info *
340 lwp_arch_private_info (struct lwp_info *lwp)
342 return lwp->arch_private;
345 /* See nat/linux-nat.h. */
348 lwp_is_stopped (struct lwp_info *lwp)
353 /* See nat/linux-nat.h. */
355 enum target_stop_reason
356 lwp_stop_reason (struct lwp_info *lwp)
358 return lwp->stop_reason;
361 /* See nat/linux-nat.h. */
364 lwp_is_stepping (struct lwp_info *lwp)
370 /* Trivial list manipulation functions to keep track of a list of
371 new stopped processes. */
373 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
375 struct simple_pid_list *new_pid = XNEW (struct simple_pid_list);
378 new_pid->status = status;
379 new_pid->next = *listp;
384 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
386 struct simple_pid_list **p;
388 for (p = listp; *p != NULL; p = &(*p)->next)
389 if ((*p)->pid == pid)
391 struct simple_pid_list *next = (*p)->next;
393 *statusp = (*p)->status;
401 /* Return the ptrace options that we want to try to enable. */
404 linux_nat_ptrace_options (int attached)
409 options |= PTRACE_O_EXITKILL;
411 options |= (PTRACE_O_TRACESYSGOOD
412 | PTRACE_O_TRACEVFORKDONE
413 | PTRACE_O_TRACEVFORK
415 | PTRACE_O_TRACEEXEC);
420 /* Initialize ptrace warnings and check for supported ptrace
423 ATTACHED should be nonzero iff we attached to the inferior. */
426 linux_init_ptrace (pid_t pid, int attached)
428 int options = linux_nat_ptrace_options (attached);
430 linux_enable_event_reporting (pid, options);
431 linux_ptrace_init_warnings ();
435 linux_child_post_attach (struct target_ops *self, int pid)
437 linux_init_ptrace (pid, 1);
441 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
443 linux_init_ptrace (ptid_get_pid (ptid), 0);
446 /* Return the number of known LWPs in the tgid given by PID. */
454 for (lp = lwp_list; lp; lp = lp->next)
455 if (ptid_get_pid (lp->ptid) == pid)
461 /* Call delete_lwp with prototype compatible for make_cleanup. */
464 delete_lwp_cleanup (void *lp_voidp)
466 struct lwp_info *lp = (struct lwp_info *) lp_voidp;
468 delete_lwp (lp->ptid);
471 /* Target hook for follow_fork. On entry inferior_ptid must be the
472 ptid of the followed inferior. At return, inferior_ptid will be
476 linux_child_follow_fork (struct target_ops *ops, int follow_child,
481 struct lwp_info *child_lp = NULL;
482 int status = W_STOPCODE (0);
484 ptid_t parent_ptid, child_ptid;
485 int parent_pid, child_pid;
487 has_vforked = (inferior_thread ()->pending_follow.kind
488 == TARGET_WAITKIND_VFORKED);
489 parent_ptid = inferior_ptid;
490 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
491 parent_pid = ptid_get_lwp (parent_ptid);
492 child_pid = ptid_get_lwp (child_ptid);
494 /* We're already attached to the parent, by default. */
495 child_lp = add_lwp (child_ptid);
496 child_lp->stopped = 1;
497 child_lp->last_resume_kind = resume_stop;
499 /* Detach new forked process? */
502 struct cleanup *old_chain = make_cleanup (delete_lwp_cleanup,
505 if (linux_nat_prepare_to_resume != NULL)
506 linux_nat_prepare_to_resume (child_lp);
508 /* When debugging an inferior in an architecture that supports
509 hardware single stepping on a kernel without commit
510 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
511 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
512 set if the parent process had them set.
513 To work around this, single step the child process
514 once before detaching to clear the flags. */
516 /* Note that we consult the parent's architecture instead of
517 the child's because there's no inferior for the child at
519 if (!gdbarch_software_single_step_p (target_thread_architecture
522 linux_disable_event_reporting (child_pid);
523 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
524 perror_with_name (_("Couldn't do single step"));
525 if (my_waitpid (child_pid, &status, 0) < 0)
526 perror_with_name (_("Couldn't wait vfork process"));
529 if (WIFSTOPPED (status))
533 signo = WSTOPSIG (status);
535 && !signal_pass_state (gdb_signal_from_host (signo)))
537 ptrace (PTRACE_DETACH, child_pid, 0, signo);
540 do_cleanups (old_chain);
544 scoped_restore save_inferior_ptid
545 = make_scoped_restore (&inferior_ptid);
546 inferior_ptid = child_ptid;
548 /* Let the thread_db layer learn about this new process. */
549 check_for_thread_db ();
554 struct lwp_info *parent_lp;
556 parent_lp = find_lwp_pid (parent_ptid);
557 gdb_assert (linux_supports_tracefork () >= 0);
559 if (linux_supports_tracevforkdone ())
562 fprintf_unfiltered (gdb_stdlog,
563 "LCFF: waiting for VFORK_DONE on %d\n",
565 parent_lp->stopped = 1;
567 /* We'll handle the VFORK_DONE event like any other
568 event, in target_wait. */
572 /* We can't insert breakpoints until the child has
573 finished with the shared memory region. We need to
574 wait until that happens. Ideal would be to just
576 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
577 - waitpid (parent_pid, &status, __WALL);
578 However, most architectures can't handle a syscall
579 being traced on the way out if it wasn't traced on
582 We might also think to loop, continuing the child
583 until it exits or gets a SIGTRAP. One problem is
584 that the child might call ptrace with PTRACE_TRACEME.
586 There's no simple and reliable way to figure out when
587 the vforked child will be done with its copy of the
588 shared memory. We could step it out of the syscall,
589 two instructions, let it go, and then single-step the
590 parent once. When we have hardware single-step, this
591 would work; with software single-step it could still
592 be made to work but we'd have to be able to insert
593 single-step breakpoints in the child, and we'd have
594 to insert -just- the single-step breakpoint in the
595 parent. Very awkward.
597 In the end, the best we can do is to make sure it
598 runs for a little while. Hopefully it will be out of
599 range of any breakpoints we reinsert. Usually this
600 is only the single-step breakpoint at vfork's return
604 fprintf_unfiltered (gdb_stdlog,
605 "LCFF: no VFORK_DONE "
606 "support, sleeping a bit\n");
610 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
611 and leave it pending. The next linux_nat_resume call
612 will notice a pending event, and bypasses actually
613 resuming the inferior. */
614 parent_lp->status = 0;
615 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
616 parent_lp->stopped = 1;
618 /* If we're in async mode, need to tell the event loop
619 there's something here to process. */
620 if (target_is_async_p ())
627 struct lwp_info *child_lp;
629 child_lp = add_lwp (inferior_ptid);
630 child_lp->stopped = 1;
631 child_lp->last_resume_kind = resume_stop;
633 /* Let the thread_db layer learn about this new process. */
634 check_for_thread_db ();
642 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
644 return !linux_supports_tracefork ();
648 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
654 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
656 return !linux_supports_tracefork ();
660 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
666 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
668 return !linux_supports_tracefork ();
672 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
678 linux_child_set_syscall_catchpoint (struct target_ops *self,
679 int pid, bool needed, int any_count,
680 gdb::array_view<const int> syscall_counts)
682 if (!linux_supports_tracesysgood ())
685 /* On GNU/Linux, we ignore the arguments. It means that we only
686 enable the syscall catchpoints, but do not disable them.
688 Also, we do not use the `syscall_counts' information because we do not
689 filter system calls here. We let GDB do the logic for us. */
693 /* List of known LWPs, keyed by LWP PID. This speeds up the common
694 case of mapping a PID returned from the kernel to our corresponding
695 lwp_info data structure. */
696 static htab_t lwp_lwpid_htab;
698 /* Calculate a hash from a lwp_info's LWP PID. */
701 lwp_info_hash (const void *ap)
703 const struct lwp_info *lp = (struct lwp_info *) ap;
704 pid_t pid = ptid_get_lwp (lp->ptid);
706 return iterative_hash_object (pid, 0);
709 /* Equality function for the lwp_info hash table. Compares the LWP's
713 lwp_lwpid_htab_eq (const void *a, const void *b)
715 const struct lwp_info *entry = (const struct lwp_info *) a;
716 const struct lwp_info *element = (const struct lwp_info *) b;
718 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
721 /* Create the lwp_lwpid_htab hash table. */
724 lwp_lwpid_htab_create (void)
726 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
729 /* Add LP to the hash table. */
732 lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
736 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
737 gdb_assert (slot != NULL && *slot == NULL);
741 /* Head of doubly-linked list of known LWPs. Sorted by reverse
742 creation order. This order is assumed in some cases. E.g.,
743 reaping status after killing alls lwps of a process: the leader LWP
744 must be reaped last. */
745 struct lwp_info *lwp_list;
747 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
750 lwp_list_add (struct lwp_info *lp)
753 if (lwp_list != NULL)
758 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
762 lwp_list_remove (struct lwp_info *lp)
764 /* Remove from sorted-by-creation-order list. */
765 if (lp->next != NULL)
766 lp->next->prev = lp->prev;
767 if (lp->prev != NULL)
768 lp->prev->next = lp->next;
775 /* Original signal mask. */
776 static sigset_t normal_mask;
778 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
779 _initialize_linux_nat. */
780 static sigset_t suspend_mask;
782 /* Signals to block to make that sigsuspend work. */
783 static sigset_t blocked_mask;
785 /* SIGCHLD action. */
786 struct sigaction sigchld_action;
788 /* Block child signals (SIGCHLD and linux threads signals), and store
789 the previous mask in PREV_MASK. */
792 block_child_signals (sigset_t *prev_mask)
794 /* Make sure SIGCHLD is blocked. */
795 if (!sigismember (&blocked_mask, SIGCHLD))
796 sigaddset (&blocked_mask, SIGCHLD);
798 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
801 /* Restore child signals mask, previously returned by
802 block_child_signals. */
805 restore_child_signals_mask (sigset_t *prev_mask)
807 sigprocmask (SIG_SETMASK, prev_mask, NULL);
810 /* Mask of signals to pass directly to the inferior. */
811 static sigset_t pass_mask;
813 /* Update signals to pass to the inferior. */
815 linux_nat_pass_signals (struct target_ops *self,
816 int numsigs, unsigned char *pass_signals)
820 sigemptyset (&pass_mask);
822 for (signo = 1; signo < NSIG; signo++)
824 int target_signo = gdb_signal_from_host (signo);
825 if (target_signo < numsigs && pass_signals[target_signo])
826 sigaddset (&pass_mask, signo);
832 /* Prototypes for local functions. */
833 static int stop_wait_callback (struct lwp_info *lp, void *data);
834 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
835 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
836 static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
840 /* Destroy and free LP. */
843 lwp_free (struct lwp_info *lp)
845 /* Let the arch specific bits release arch_lwp_info. */
846 if (linux_nat_delete_thread != NULL)
847 linux_nat_delete_thread (lp->arch_private);
849 gdb_assert (lp->arch_private == NULL);
854 /* Traversal function for purge_lwp_list. */
857 lwp_lwpid_htab_remove_pid (void **slot, void *info)
859 struct lwp_info *lp = (struct lwp_info *) *slot;
860 int pid = *(int *) info;
862 if (ptid_get_pid (lp->ptid) == pid)
864 htab_clear_slot (lwp_lwpid_htab, slot);
865 lwp_list_remove (lp);
872 /* Remove all LWPs belong to PID from the lwp list. */
875 purge_lwp_list (int pid)
877 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
880 /* Add the LWP specified by PTID to the list. PTID is the first LWP
881 in the process. Return a pointer to the structure describing the
884 This differs from add_lwp in that we don't let the arch specific
885 bits know about this new thread. Current clients of this callback
886 take the opportunity to install watchpoints in the new thread, and
887 we shouldn't do that for the first thread. If we're spawning a
888 child ("run"), the thread executes the shell wrapper first, and we
889 shouldn't touch it until it execs the program we want to debug.
890 For "attach", it'd be okay to call the callback, but it's not
891 necessary, because watchpoints can't yet have been inserted into
894 static struct lwp_info *
895 add_initial_lwp (ptid_t ptid)
899 gdb_assert (ptid_lwp_p (ptid));
901 lp = XNEW (struct lwp_info);
903 memset (lp, 0, sizeof (struct lwp_info));
905 lp->last_resume_kind = resume_continue;
906 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
911 /* Add to sorted-by-reverse-creation-order list. */
914 /* Add to keyed-by-pid htab. */
915 lwp_lwpid_htab_add_lwp (lp);
920 /* Add the LWP specified by PID to the list. Return a pointer to the
921 structure describing the new LWP. The LWP should already be
924 static struct lwp_info *
925 add_lwp (ptid_t ptid)
929 lp = add_initial_lwp (ptid);
931 /* Let the arch specific bits know about this new thread. Current
932 clients of this callback take the opportunity to install
933 watchpoints in the new thread. We don't do this for the first
934 thread though. See add_initial_lwp. */
935 if (linux_nat_new_thread != NULL)
936 linux_nat_new_thread (lp);
941 /* Remove the LWP specified by PID from the list. */
944 delete_lwp (ptid_t ptid)
948 struct lwp_info dummy;
951 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
955 lp = *(struct lwp_info **) slot;
956 gdb_assert (lp != NULL);
958 htab_clear_slot (lwp_lwpid_htab, slot);
960 /* Remove from sorted-by-creation-order list. */
961 lwp_list_remove (lp);
967 /* Return a pointer to the structure describing the LWP corresponding
968 to PID. If no corresponding LWP could be found, return NULL. */
970 static struct lwp_info *
971 find_lwp_pid (ptid_t ptid)
975 struct lwp_info dummy;
977 if (ptid_lwp_p (ptid))
978 lwp = ptid_get_lwp (ptid);
980 lwp = ptid_get_pid (ptid);
982 dummy.ptid = ptid_build (0, lwp, 0);
983 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
987 /* See nat/linux-nat.h. */
990 iterate_over_lwps (ptid_t filter,
991 iterate_over_lwps_ftype callback,
994 struct lwp_info *lp, *lpnext;
996 for (lp = lwp_list; lp; lp = lpnext)
1000 if (ptid_match (lp->ptid, filter))
1002 if ((*callback) (lp, data) != 0)
1010 /* Update our internal state when changing from one checkpoint to
1011 another indicated by NEW_PTID. We can only switch single-threaded
1012 applications, so we only create one new LWP, and the previous list
1016 linux_nat_switch_fork (ptid_t new_ptid)
1018 struct lwp_info *lp;
1020 purge_lwp_list (ptid_get_pid (inferior_ptid));
1022 lp = add_lwp (new_ptid);
1025 /* This changes the thread's ptid while preserving the gdb thread
1026 num. Also changes the inferior pid, while preserving the
1028 thread_change_ptid (inferior_ptid, new_ptid);
1030 /* We've just told GDB core that the thread changed target id, but,
1031 in fact, it really is a different thread, with different register
1033 registers_changed ();
1036 /* Handle the exit of a single thread LP. */
1039 exit_lwp (struct lwp_info *lp)
1041 struct thread_info *th = find_thread_ptid (lp->ptid);
1045 if (print_thread_events)
1046 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1048 delete_thread (lp->ptid);
1051 delete_lwp (lp->ptid);
1054 /* Wait for the LWP specified by LP, which we have just attached to.
1055 Returns a wait status for that LWP, to cache. */
1058 linux_nat_post_attach_wait (ptid_t ptid, int *signalled)
1060 pid_t new_pid, pid = ptid_get_lwp (ptid);
1063 if (linux_proc_pid_is_stopped (pid))
1065 if (debug_linux_nat)
1066 fprintf_unfiltered (gdb_stdlog,
1067 "LNPAW: Attaching to a stopped process\n");
1069 /* The process is definitely stopped. It is in a job control
1070 stop, unless the kernel predates the TASK_STOPPED /
1071 TASK_TRACED distinction, in which case it might be in a
1072 ptrace stop. Make sure it is in a ptrace stop; from there we
1073 can kill it, signal it, et cetera.
1075 First make sure there is a pending SIGSTOP. Since we are
1076 already attached, the process can not transition from stopped
1077 to running without a PTRACE_CONT; so we know this signal will
1078 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1079 probably already in the queue (unless this kernel is old
1080 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1081 is not an RT signal, it can only be queued once. */
1082 kill_lwp (pid, SIGSTOP);
1084 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1085 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1086 ptrace (PTRACE_CONT, pid, 0, 0);
1089 /* Make sure the initial process is stopped. The user-level threads
1090 layer might want to poke around in the inferior, and that won't
1091 work if things haven't stabilized yet. */
1092 new_pid = my_waitpid (pid, &status, __WALL);
1093 gdb_assert (pid == new_pid);
1095 if (!WIFSTOPPED (status))
1097 /* The pid we tried to attach has apparently just exited. */
1098 if (debug_linux_nat)
1099 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1100 pid, status_to_str (status));
1104 if (WSTOPSIG (status) != SIGSTOP)
1107 if (debug_linux_nat)
1108 fprintf_unfiltered (gdb_stdlog,
1109 "LNPAW: Received %s after attaching\n",
1110 status_to_str (status));
1117 linux_nat_create_inferior (struct target_ops *ops,
1118 const char *exec_file, const std::string &allargs,
1119 char **env, int from_tty)
1121 maybe_disable_address_space_randomization restore_personality
1122 (disable_randomization);
1124 /* The fork_child mechanism is synchronous and calls target_wait, so
1125 we have to mask the async mode. */
1127 /* Make sure we report all signals during startup. */
1128 linux_nat_pass_signals (ops, 0, NULL);
1130 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1133 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1134 already attached. Returns true if a new LWP is found, false
1138 attach_proc_task_lwp_callback (ptid_t ptid)
1140 struct lwp_info *lp;
1142 /* Ignore LWPs we're already attached to. */
1143 lp = find_lwp_pid (ptid);
1146 int lwpid = ptid_get_lwp (ptid);
1148 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1152 /* Be quiet if we simply raced with the thread exiting.
1153 EPERM is returned if the thread's task still exists, and
1154 is marked as exited or zombie, as well as other
1155 conditions, so in that case, confirm the status in
1156 /proc/PID/status. */
1158 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1160 if (debug_linux_nat)
1162 fprintf_unfiltered (gdb_stdlog,
1163 "Cannot attach to lwp %d: "
1164 "thread is gone (%d: %s)\n",
1165 lwpid, err, safe_strerror (err));
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;
1229 buffer_init (&buffer);
1230 linux_ptrace_attach_fail_reason (pid, &buffer);
1232 buffer_grow_str0 (&buffer, "");
1233 buffer_s = buffer_finish (&buffer);
1234 make_cleanup (xfree, buffer_s);
1236 if (*buffer_s != '\0')
1237 throw_error (ex.error, "warning: %s\n%s", buffer_s, ex.message);
1239 throw_error (ex.error, "%s", ex.message);
1243 /* The ptrace base target adds the main thread with (pid,0,0)
1244 format. Decorate it with lwp info. */
1245 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1246 ptid_get_pid (inferior_ptid),
1248 thread_change_ptid (inferior_ptid, ptid);
1250 /* Add the initial process as the first LWP to the list. */
1251 lp = add_initial_lwp (ptid);
1253 status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled);
1254 if (!WIFSTOPPED (status))
1256 if (WIFEXITED (status))
1258 int exit_code = WEXITSTATUS (status);
1260 target_terminal::ours ();
1261 target_mourn_inferior (inferior_ptid);
1263 error (_("Unable to attach: program exited normally."));
1265 error (_("Unable to attach: program exited with code %d."),
1268 else if (WIFSIGNALED (status))
1270 enum gdb_signal signo;
1272 target_terminal::ours ();
1273 target_mourn_inferior (inferior_ptid);
1275 signo = gdb_signal_from_host (WTERMSIG (status));
1276 error (_("Unable to attach: program terminated with signal "
1278 gdb_signal_to_name (signo),
1279 gdb_signal_to_string (signo));
1282 internal_error (__FILE__, __LINE__,
1283 _("unexpected status %d for PID %ld"),
1284 status, (long) ptid_get_lwp (ptid));
1289 /* Save the wait status to report later. */
1291 if (debug_linux_nat)
1292 fprintf_unfiltered (gdb_stdlog,
1293 "LNA: waitpid %ld, saving status %s\n",
1294 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1296 lp->status = status;
1298 /* We must attach to every LWP. If /proc is mounted, use that to
1299 find them now. The inferior may be using raw clone instead of
1300 using pthreads. But even if it is using pthreads, thread_db
1301 walks structures in the inferior's address space to find the list
1302 of threads/LWPs, and those structures may well be corrupted.
1303 Note that once thread_db is loaded, we'll still use it to list
1304 threads and associate pthread info with each LWP. */
1305 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1306 attach_proc_task_lwp_callback);
1308 if (target_can_async_p ())
1312 /* Get pending signal of THREAD as a host signal number, for detaching
1313 purposes. This is the signal the thread last stopped for, which we
1314 need to deliver to the thread when detaching, otherwise, it'd be
1318 get_detach_signal (struct lwp_info *lp)
1320 enum gdb_signal signo = GDB_SIGNAL_0;
1322 /* If we paused threads momentarily, we may have stored pending
1323 events in lp->status or lp->waitstatus (see stop_wait_callback),
1324 and GDB core hasn't seen any signal for those threads.
1325 Otherwise, the last signal reported to the core is found in the
1326 thread object's stop_signal.
1328 There's a corner case that isn't handled here at present. Only
1329 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1330 stop_signal make sense as a real signal to pass to the inferior.
1331 Some catchpoint related events, like
1332 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1333 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1334 those traps are debug API (ptrace in our case) related and
1335 induced; the inferior wouldn't see them if it wasn't being
1336 traced. Hence, we should never pass them to the inferior, even
1337 when set to pass state. Since this corner case isn't handled by
1338 infrun.c when proceeding with a signal, for consistency, neither
1339 do we handle it here (or elsewhere in the file we check for
1340 signal pass state). Normally SIGTRAP isn't set to pass state, so
1341 this is really a corner case. */
1343 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1344 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1345 else if (lp->status)
1346 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1347 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1349 struct thread_info *tp = find_thread_ptid (lp->ptid);
1351 if (tp->suspend.waitstatus_pending_p)
1352 signo = tp->suspend.waitstatus.value.sig;
1354 signo = tp->suspend.stop_signal;
1356 else if (!target_is_non_stop_p ())
1358 struct target_waitstatus last;
1361 get_last_target_status (&last_ptid, &last);
1363 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1365 struct thread_info *tp = find_thread_ptid (lp->ptid);
1367 signo = tp->suspend.stop_signal;
1371 if (signo == GDB_SIGNAL_0)
1373 if (debug_linux_nat)
1374 fprintf_unfiltered (gdb_stdlog,
1375 "GPT: lwp %s has no pending signal\n",
1376 target_pid_to_str (lp->ptid));
1378 else if (!signal_pass_state (signo))
1380 if (debug_linux_nat)
1381 fprintf_unfiltered (gdb_stdlog,
1382 "GPT: lwp %s had signal %s, "
1383 "but it is in no pass state\n",
1384 target_pid_to_str (lp->ptid),
1385 gdb_signal_to_string (signo));
1389 if (debug_linux_nat)
1390 fprintf_unfiltered (gdb_stdlog,
1391 "GPT: lwp %s has pending signal %s\n",
1392 target_pid_to_str (lp->ptid),
1393 gdb_signal_to_string (signo));
1395 return gdb_signal_to_host (signo);
1401 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1402 signal number that should be passed to the LWP when detaching.
1403 Otherwise pass any pending signal the LWP may have, if any. */
1406 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1408 int lwpid = ptid_get_lwp (lp->ptid);
1411 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1413 if (debug_linux_nat && lp->status)
1414 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1415 strsignal (WSTOPSIG (lp->status)),
1416 target_pid_to_str (lp->ptid));
1418 /* If there is a pending SIGSTOP, get rid of it. */
1421 if (debug_linux_nat)
1422 fprintf_unfiltered (gdb_stdlog,
1423 "DC: Sending SIGCONT to %s\n",
1424 target_pid_to_str (lp->ptid));
1426 kill_lwp (lwpid, SIGCONT);
1430 if (signo_p == NULL)
1432 /* Pass on any pending signal for this LWP. */
1433 signo = get_detach_signal (lp);
1438 /* Preparing to resume may try to write registers, and fail if the
1439 lwp is zombie. If that happens, ignore the error. We'll handle
1440 it below, when detach fails with ESRCH. */
1443 if (linux_nat_prepare_to_resume != NULL)
1444 linux_nat_prepare_to_resume (lp);
1446 CATCH (ex, RETURN_MASK_ERROR)
1448 if (!check_ptrace_stopped_lwp_gone (lp))
1449 throw_exception (ex);
1453 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1455 int save_errno = errno;
1457 /* We know the thread exists, so ESRCH must mean the lwp is
1458 zombie. This can happen if one of the already-detached
1459 threads exits the whole thread group. In that case we're
1460 still attached, and must reap the lwp. */
1461 if (save_errno == ESRCH)
1465 ret = my_waitpid (lwpid, &status, __WALL);
1468 warning (_("Couldn't reap LWP %d while detaching: %s"),
1469 lwpid, strerror (errno));
1471 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1473 warning (_("Reaping LWP %d while detaching "
1474 "returned unexpected status 0x%x"),
1480 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1481 safe_strerror (save_errno));
1484 else if (debug_linux_nat)
1486 fprintf_unfiltered (gdb_stdlog,
1487 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1488 target_pid_to_str (lp->ptid),
1492 delete_lwp (lp->ptid);
1496 detach_callback (struct lwp_info *lp, void *data)
1498 /* We don't actually detach from the thread group leader just yet.
1499 If the thread group exits, we must reap the zombie clone lwps
1500 before we're able to reap the leader. */
1501 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1502 detach_one_lwp (lp, NULL);
1507 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1510 struct lwp_info *main_lwp;
1512 pid = ptid_get_pid (inferior_ptid);
1514 /* Don't unregister from the event loop, as there may be other
1515 inferiors running. */
1517 /* Stop all threads before detaching. ptrace requires that the
1518 thread is stopped to sucessfully detach. */
1519 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1520 /* ... and wait until all of them have reported back that
1521 they're no longer running. */
1522 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1524 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1526 /* Only the initial process should be left right now. */
1527 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1529 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1531 if (forks_exist_p ())
1533 /* Multi-fork case. The current inferior_ptid is being detached
1534 from, but there are other viable forks to debug. Detach from
1535 the current fork, and context-switch to the first
1537 linux_fork_detach (args, from_tty);
1543 target_announce_detach (from_tty);
1545 /* Pass on any pending signal for the last LWP, unless the user
1546 requested detaching with a different signal (most likely 0,
1547 meaning, discard the signal). */
1549 signo = atoi (args);
1551 signo = get_detach_signal (main_lwp);
1553 detach_one_lwp (main_lwp, &signo);
1555 inf_ptrace_detach_success (ops);
1559 /* Resume execution of the inferior process. If STEP is nonzero,
1560 single-step it. If SIGNAL is nonzero, give it that signal. */
1563 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1564 enum gdb_signal signo)
1568 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1569 We only presently need that if the LWP is stepped though (to
1570 handle the case of stepping a breakpoint instruction). */
1573 struct regcache *regcache = get_thread_regcache (lp->ptid);
1575 lp->stop_pc = regcache_read_pc (regcache);
1580 if (linux_nat_prepare_to_resume != NULL)
1581 linux_nat_prepare_to_resume (lp);
1582 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1584 /* Successfully resumed. Clear state that no longer makes sense,
1585 and mark the LWP as running. Must not do this before resuming
1586 otherwise if that fails other code will be confused. E.g., we'd
1587 later try to stop the LWP and hang forever waiting for a stop
1588 status. Note that we must not throw after this is cleared,
1589 otherwise handle_zombie_lwp_error would get confused. */
1592 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1593 registers_changed_ptid (lp->ptid);
1596 /* Called when we try to resume a stopped LWP and that errors out. If
1597 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1598 or about to become), discard the error, clear any pending status
1599 the LWP may have, and return true (we'll collect the exit status
1600 soon enough). Otherwise, return false. */
1603 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1605 /* If we get an error after resuming the LWP successfully, we'd
1606 confuse !T state for the LWP being gone. */
1607 gdb_assert (lp->stopped);
1609 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1610 because even if ptrace failed with ESRCH, the tracee may be "not
1611 yet fully dead", but already refusing ptrace requests. In that
1612 case the tracee has 'R (Running)' state for a little bit
1613 (observed in Linux 3.18). See also the note on ESRCH in the
1614 ptrace(2) man page. Instead, check whether the LWP has any state
1615 other than ptrace-stopped. */
1617 /* Don't assume anything if /proc/PID/status can't be read. */
1618 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1620 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1622 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1628 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1629 disappears while we try to resume it. */
1632 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1636 linux_resume_one_lwp_throw (lp, step, signo);
1638 CATCH (ex, RETURN_MASK_ERROR)
1640 if (!check_ptrace_stopped_lwp_gone (lp))
1641 throw_exception (ex);
1649 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1653 struct inferior *inf = find_inferior_ptid (lp->ptid);
1655 if (inf->vfork_child != NULL)
1657 if (debug_linux_nat)
1658 fprintf_unfiltered (gdb_stdlog,
1659 "RC: Not resuming %s (vfork parent)\n",
1660 target_pid_to_str (lp->ptid));
1662 else if (!lwp_status_pending_p (lp))
1664 if (debug_linux_nat)
1665 fprintf_unfiltered (gdb_stdlog,
1666 "RC: Resuming sibling %s, %s, %s\n",
1667 target_pid_to_str (lp->ptid),
1668 (signo != GDB_SIGNAL_0
1669 ? strsignal (gdb_signal_to_host (signo))
1671 step ? "step" : "resume");
1673 linux_resume_one_lwp (lp, step, signo);
1677 if (debug_linux_nat)
1678 fprintf_unfiltered (gdb_stdlog,
1679 "RC: Not resuming sibling %s (has pending)\n",
1680 target_pid_to_str (lp->ptid));
1685 if (debug_linux_nat)
1686 fprintf_unfiltered (gdb_stdlog,
1687 "RC: Not resuming sibling %s (not stopped)\n",
1688 target_pid_to_str (lp->ptid));
1692 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1693 Resume LWP with the last stop signal, if it is in pass state. */
1696 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1698 enum gdb_signal signo = GDB_SIGNAL_0;
1705 struct thread_info *thread;
1707 thread = find_thread_ptid (lp->ptid);
1710 signo = thread->suspend.stop_signal;
1711 thread->suspend.stop_signal = GDB_SIGNAL_0;
1715 resume_lwp (lp, 0, signo);
1720 resume_clear_callback (struct lwp_info *lp, void *data)
1723 lp->last_resume_kind = resume_stop;
1728 resume_set_callback (struct lwp_info *lp, void *data)
1731 lp->last_resume_kind = resume_continue;
1736 linux_nat_resume (struct target_ops *ops,
1737 ptid_t ptid, int step, enum gdb_signal signo)
1739 struct lwp_info *lp;
1742 if (debug_linux_nat)
1743 fprintf_unfiltered (gdb_stdlog,
1744 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1745 step ? "step" : "resume",
1746 target_pid_to_str (ptid),
1747 (signo != GDB_SIGNAL_0
1748 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1749 target_pid_to_str (inferior_ptid));
1751 /* A specific PTID means `step only this process id'. */
1752 resume_many = (ptid_equal (minus_one_ptid, ptid)
1753 || ptid_is_pid (ptid));
1755 /* Mark the lwps we're resuming as resumed. */
1756 iterate_over_lwps (ptid, resume_set_callback, NULL);
1758 /* See if it's the current inferior that should be handled
1761 lp = find_lwp_pid (inferior_ptid);
1763 lp = find_lwp_pid (ptid);
1764 gdb_assert (lp != NULL);
1766 /* Remember if we're stepping. */
1767 lp->last_resume_kind = step ? resume_step : resume_continue;
1769 /* If we have a pending wait status for this thread, there is no
1770 point in resuming the process. But first make sure that
1771 linux_nat_wait won't preemptively handle the event - we
1772 should never take this short-circuit if we are going to
1773 leave LP running, since we have skipped resuming all the
1774 other threads. This bit of code needs to be synchronized
1775 with linux_nat_wait. */
1777 if (lp->status && WIFSTOPPED (lp->status))
1780 && WSTOPSIG (lp->status)
1781 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1783 if (debug_linux_nat)
1784 fprintf_unfiltered (gdb_stdlog,
1785 "LLR: Not short circuiting for ignored "
1786 "status 0x%x\n", lp->status);
1788 /* FIXME: What should we do if we are supposed to continue
1789 this thread with a signal? */
1790 gdb_assert (signo == GDB_SIGNAL_0);
1791 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1796 if (lwp_status_pending_p (lp))
1798 /* FIXME: What should we do if we are supposed to continue
1799 this thread with a signal? */
1800 gdb_assert (signo == GDB_SIGNAL_0);
1802 if (debug_linux_nat)
1803 fprintf_unfiltered (gdb_stdlog,
1804 "LLR: Short circuiting for status 0x%x\n",
1807 if (target_can_async_p ())
1810 /* Tell the event loop we have something to process. */
1817 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1819 if (debug_linux_nat)
1820 fprintf_unfiltered (gdb_stdlog,
1821 "LLR: %s %s, %s (resume event thread)\n",
1822 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1823 target_pid_to_str (lp->ptid),
1824 (signo != GDB_SIGNAL_0
1825 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1827 linux_resume_one_lwp (lp, step, signo);
1829 if (target_can_async_p ())
1833 /* Send a signal to an LWP. */
1836 kill_lwp (int lwpid, int signo)
1841 ret = syscall (__NR_tkill, lwpid, signo);
1842 if (errno == ENOSYS)
1844 /* If tkill fails, then we are not using nptl threads, a
1845 configuration we no longer support. */
1846 perror_with_name (("tkill"));
1851 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1852 event, check if the core is interested in it: if not, ignore the
1853 event, and keep waiting; otherwise, we need to toggle the LWP's
1854 syscall entry/exit status, since the ptrace event itself doesn't
1855 indicate it, and report the trap to higher layers. */
1858 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1860 struct target_waitstatus *ourstatus = &lp->waitstatus;
1861 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1862 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1866 /* If we're stopping threads, there's a SIGSTOP pending, which
1867 makes it so that the LWP reports an immediate syscall return,
1868 followed by the SIGSTOP. Skip seeing that "return" using
1869 PTRACE_CONT directly, and let stop_wait_callback collect the
1870 SIGSTOP. Later when the thread is resumed, a new syscall
1871 entry event. If we didn't do this (and returned 0), we'd
1872 leave a syscall entry pending, and our caller, by using
1873 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1874 itself. Later, when the user re-resumes this LWP, we'd see
1875 another syscall entry event and we'd mistake it for a return.
1877 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1878 (leaving immediately with LWP->signalled set, without issuing
1879 a PTRACE_CONT), it would still be problematic to leave this
1880 syscall enter pending, as later when the thread is resumed,
1881 it would then see the same syscall exit mentioned above,
1882 followed by the delayed SIGSTOP, while the syscall didn't
1883 actually get to execute. It seems it would be even more
1884 confusing to the user. */
1886 if (debug_linux_nat)
1887 fprintf_unfiltered (gdb_stdlog,
1888 "LHST: ignoring syscall %d "
1889 "for LWP %ld (stopping threads), "
1890 "resuming with PTRACE_CONT for SIGSTOP\n",
1892 ptid_get_lwp (lp->ptid));
1894 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1895 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1900 /* Always update the entry/return state, even if this particular
1901 syscall isn't interesting to the core now. In async mode,
1902 the user could install a new catchpoint for this syscall
1903 between syscall enter/return, and we'll need to know to
1904 report a syscall return if that happens. */
1905 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1906 ? TARGET_WAITKIND_SYSCALL_RETURN
1907 : TARGET_WAITKIND_SYSCALL_ENTRY);
1909 if (catch_syscall_enabled ())
1911 if (catching_syscall_number (syscall_number))
1913 /* Alright, an event to report. */
1914 ourstatus->kind = lp->syscall_state;
1915 ourstatus->value.syscall_number = syscall_number;
1917 if (debug_linux_nat)
1918 fprintf_unfiltered (gdb_stdlog,
1919 "LHST: stopping for %s of syscall %d"
1922 == TARGET_WAITKIND_SYSCALL_ENTRY
1923 ? "entry" : "return",
1925 ptid_get_lwp (lp->ptid));
1929 if (debug_linux_nat)
1930 fprintf_unfiltered (gdb_stdlog,
1931 "LHST: ignoring %s of syscall %d "
1933 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1934 ? "entry" : "return",
1936 ptid_get_lwp (lp->ptid));
1940 /* If we had been syscall tracing, and hence used PT_SYSCALL
1941 before on this LWP, it could happen that the user removes all
1942 syscall catchpoints before we get to process this event.
1943 There are two noteworthy issues here:
1945 - When stopped at a syscall entry event, resuming with
1946 PT_STEP still resumes executing the syscall and reports a
1949 - Only PT_SYSCALL catches syscall enters. If we last
1950 single-stepped this thread, then this event can't be a
1951 syscall enter. If we last single-stepped this thread, this
1952 has to be a syscall exit.
1954 The points above mean that the next resume, be it PT_STEP or
1955 PT_CONTINUE, can not trigger a syscall trace event. */
1956 if (debug_linux_nat)
1957 fprintf_unfiltered (gdb_stdlog,
1958 "LHST: caught syscall event "
1959 "with no syscall catchpoints."
1960 " %d for LWP %ld, ignoring\n",
1962 ptid_get_lwp (lp->ptid));
1963 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1966 /* The core isn't interested in this event. For efficiency, avoid
1967 stopping all threads only to have the core resume them all again.
1968 Since we're not stopping threads, if we're still syscall tracing
1969 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1970 subsequent syscall. Simply resume using the inf-ptrace layer,
1971 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1973 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1977 /* Handle a GNU/Linux extended wait response. If we see a clone
1978 event, we need to add the new LWP to our list (and not report the
1979 trap to higher layers). This function returns non-zero if the
1980 event should be ignored and we should wait again. If STOPPING is
1981 true, the new LWP remains stopped, otherwise it is continued. */
1984 linux_handle_extended_wait (struct lwp_info *lp, int status)
1986 int pid = ptid_get_lwp (lp->ptid);
1987 struct target_waitstatus *ourstatus = &lp->waitstatus;
1988 int event = linux_ptrace_get_extended_event (status);
1990 /* All extended events we currently use are mid-syscall. Only
1991 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1992 you have to be using PTRACE_SEIZE to get that. */
1993 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1995 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1996 || event == PTRACE_EVENT_CLONE)
1998 unsigned long new_pid;
2001 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2003 /* If we haven't already seen the new PID stop, wait for it now. */
2004 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2006 /* The new child has a pending SIGSTOP. We can't affect it until it
2007 hits the SIGSTOP, but we're already attached. */
2008 ret = my_waitpid (new_pid, &status, __WALL);
2010 perror_with_name (_("waiting for new child"));
2011 else if (ret != new_pid)
2012 internal_error (__FILE__, __LINE__,
2013 _("wait returned unexpected PID %d"), ret);
2014 else if (!WIFSTOPPED (status))
2015 internal_error (__FILE__, __LINE__,
2016 _("wait returned unexpected status 0x%x"), status);
2019 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2021 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2023 /* The arch-specific native code may need to know about new
2024 forks even if those end up never mapped to an
2026 if (linux_nat_new_fork != NULL)
2027 linux_nat_new_fork (lp, new_pid);
2030 if (event == PTRACE_EVENT_FORK
2031 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2033 /* Handle checkpointing by linux-fork.c here as a special
2034 case. We don't want the follow-fork-mode or 'catch fork'
2035 to interfere with this. */
2037 /* This won't actually modify the breakpoint list, but will
2038 physically remove the breakpoints from the child. */
2039 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2041 /* Retain child fork in ptrace (stopped) state. */
2042 if (!find_fork_pid (new_pid))
2045 /* Report as spurious, so that infrun doesn't want to follow
2046 this fork. We're actually doing an infcall in
2048 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2050 /* Report the stop to the core. */
2054 if (event == PTRACE_EVENT_FORK)
2055 ourstatus->kind = TARGET_WAITKIND_FORKED;
2056 else if (event == PTRACE_EVENT_VFORK)
2057 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2058 else if (event == PTRACE_EVENT_CLONE)
2060 struct lwp_info *new_lp;
2062 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2064 if (debug_linux_nat)
2065 fprintf_unfiltered (gdb_stdlog,
2066 "LHEW: Got clone event "
2067 "from LWP %d, new child is LWP %ld\n",
2070 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2071 new_lp->stopped = 1;
2072 new_lp->resumed = 1;
2074 /* If the thread_db layer is active, let it record the user
2075 level thread id and status, and add the thread to GDB's
2077 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2079 /* The process is not using thread_db. Add the LWP to
2081 target_post_attach (ptid_get_lwp (new_lp->ptid));
2082 add_thread (new_lp->ptid);
2085 /* Even if we're stopping the thread for some reason
2086 internal to this module, from the perspective of infrun
2087 and the user/frontend, this new thread is running until
2088 it next reports a stop. */
2089 set_running (new_lp->ptid, 1);
2090 set_executing (new_lp->ptid, 1);
2092 if (WSTOPSIG (status) != SIGSTOP)
2094 /* This can happen if someone starts sending signals to
2095 the new thread before it gets a chance to run, which
2096 have a lower number than SIGSTOP (e.g. SIGUSR1).
2097 This is an unlikely case, and harder to handle for
2098 fork / vfork than for clone, so we do not try - but
2099 we handle it for clone events here. */
2101 new_lp->signalled = 1;
2103 /* We created NEW_LP so it cannot yet contain STATUS. */
2104 gdb_assert (new_lp->status == 0);
2106 /* Save the wait status to report later. */
2107 if (debug_linux_nat)
2108 fprintf_unfiltered (gdb_stdlog,
2109 "LHEW: waitpid of new LWP %ld, "
2110 "saving status %s\n",
2111 (long) ptid_get_lwp (new_lp->ptid),
2112 status_to_str (status));
2113 new_lp->status = status;
2115 else if (report_thread_events)
2117 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2118 new_lp->status = status;
2127 if (event == PTRACE_EVENT_EXEC)
2129 if (debug_linux_nat)
2130 fprintf_unfiltered (gdb_stdlog,
2131 "LHEW: Got exec event from LWP %ld\n",
2132 ptid_get_lwp (lp->ptid));
2134 ourstatus->kind = TARGET_WAITKIND_EXECD;
2135 ourstatus->value.execd_pathname
2136 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2138 /* The thread that execed must have been resumed, but, when a
2139 thread execs, it changes its tid to the tgid, and the old
2140 tgid thread might have not been resumed. */
2145 if (event == PTRACE_EVENT_VFORK_DONE)
2147 if (current_inferior ()->waiting_for_vfork_done)
2149 if (debug_linux_nat)
2150 fprintf_unfiltered (gdb_stdlog,
2151 "LHEW: Got expected PTRACE_EVENT_"
2152 "VFORK_DONE from LWP %ld: stopping\n",
2153 ptid_get_lwp (lp->ptid));
2155 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2159 if (debug_linux_nat)
2160 fprintf_unfiltered (gdb_stdlog,
2161 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2162 "from LWP %ld: ignoring\n",
2163 ptid_get_lwp (lp->ptid));
2167 internal_error (__FILE__, __LINE__,
2168 _("unknown ptrace event %d"), event);
2171 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2175 wait_lwp (struct lwp_info *lp)
2179 int thread_dead = 0;
2182 gdb_assert (!lp->stopped);
2183 gdb_assert (lp->status == 0);
2185 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2186 block_child_signals (&prev_mask);
2190 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2191 if (pid == -1 && errno == ECHILD)
2193 /* The thread has previously exited. We need to delete it
2194 now because if this was a non-leader thread execing, we
2195 won't get an exit event. See comments on exec events at
2196 the top of the file. */
2198 if (debug_linux_nat)
2199 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2200 target_pid_to_str (lp->ptid));
2205 /* Bugs 10970, 12702.
2206 Thread group leader may have exited in which case we'll lock up in
2207 waitpid if there are other threads, even if they are all zombies too.
2208 Basically, we're not supposed to use waitpid this way.
2209 tkill(pid,0) cannot be used here as it gets ESRCH for both
2210 for zombie and running processes.
2212 As a workaround, check if we're waiting for the thread group leader and
2213 if it's a zombie, and avoid calling waitpid if it is.
2215 This is racy, what if the tgl becomes a zombie right after we check?
2216 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2217 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2219 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2220 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2223 if (debug_linux_nat)
2224 fprintf_unfiltered (gdb_stdlog,
2225 "WL: Thread group leader %s vanished.\n",
2226 target_pid_to_str (lp->ptid));
2230 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2231 get invoked despite our caller had them intentionally blocked by
2232 block_child_signals. This is sensitive only to the loop of
2233 linux_nat_wait_1 and there if we get called my_waitpid gets called
2234 again before it gets to sigsuspend so we can safely let the handlers
2235 get executed here. */
2237 if (debug_linux_nat)
2238 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2239 sigsuspend (&suspend_mask);
2242 restore_child_signals_mask (&prev_mask);
2246 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2248 if (debug_linux_nat)
2250 fprintf_unfiltered (gdb_stdlog,
2251 "WL: waitpid %s received %s\n",
2252 target_pid_to_str (lp->ptid),
2253 status_to_str (status));
2256 /* Check if the thread has exited. */
2257 if (WIFEXITED (status) || WIFSIGNALED (status))
2259 if (report_thread_events
2260 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2262 if (debug_linux_nat)
2263 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2264 ptid_get_pid (lp->ptid));
2266 /* If this is the leader exiting, it means the whole
2267 process is gone. Store the status to report to the
2268 core. Store it in lp->waitstatus, because lp->status
2269 would be ambiguous (W_EXITCODE(0,0) == 0). */
2270 store_waitstatus (&lp->waitstatus, status);
2275 if (debug_linux_nat)
2276 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2277 target_pid_to_str (lp->ptid));
2287 gdb_assert (WIFSTOPPED (status));
2290 if (lp->must_set_ptrace_flags)
2292 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2293 int options = linux_nat_ptrace_options (inf->attach_flag);
2295 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2296 lp->must_set_ptrace_flags = 0;
2299 /* Handle GNU/Linux's syscall SIGTRAPs. */
2300 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2302 /* No longer need the sysgood bit. The ptrace event ends up
2303 recorded in lp->waitstatus if we care for it. We can carry
2304 on handling the event like a regular SIGTRAP from here
2306 status = W_STOPCODE (SIGTRAP);
2307 if (linux_handle_syscall_trap (lp, 1))
2308 return wait_lwp (lp);
2312 /* Almost all other ptrace-stops are known to be outside of system
2313 calls, with further exceptions in linux_handle_extended_wait. */
2314 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2317 /* Handle GNU/Linux's extended waitstatus for trace events. */
2318 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2319 && linux_is_extended_waitstatus (status))
2321 if (debug_linux_nat)
2322 fprintf_unfiltered (gdb_stdlog,
2323 "WL: Handling extended status 0x%06x\n",
2325 linux_handle_extended_wait (lp, status);
2332 /* Send a SIGSTOP to LP. */
2335 stop_callback (struct lwp_info *lp, void *data)
2337 if (!lp->stopped && !lp->signalled)
2341 if (debug_linux_nat)
2343 fprintf_unfiltered (gdb_stdlog,
2344 "SC: kill %s **<SIGSTOP>**\n",
2345 target_pid_to_str (lp->ptid));
2348 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2349 if (debug_linux_nat)
2351 fprintf_unfiltered (gdb_stdlog,
2352 "SC: lwp kill %d %s\n",
2354 errno ? safe_strerror (errno) : "ERRNO-OK");
2358 gdb_assert (lp->status == 0);
2364 /* Request a stop on LWP. */
2367 linux_stop_lwp (struct lwp_info *lwp)
2369 stop_callback (lwp, NULL);
2372 /* See linux-nat.h */
2375 linux_stop_and_wait_all_lwps (void)
2377 /* Stop all LWP's ... */
2378 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2380 /* ... and wait until all of them have reported back that
2381 they're no longer running. */
2382 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2385 /* See linux-nat.h */
2388 linux_unstop_all_lwps (void)
2390 iterate_over_lwps (minus_one_ptid,
2391 resume_stopped_resumed_lwps, &minus_one_ptid);
2394 /* Return non-zero if LWP PID has a pending SIGINT. */
2397 linux_nat_has_pending_sigint (int pid)
2399 sigset_t pending, blocked, ignored;
2401 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2403 if (sigismember (&pending, SIGINT)
2404 && !sigismember (&ignored, SIGINT))
2410 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2413 set_ignore_sigint (struct lwp_info *lp, void *data)
2415 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2416 flag to consume the next one. */
2417 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2418 && WSTOPSIG (lp->status) == SIGINT)
2421 lp->ignore_sigint = 1;
2426 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2427 This function is called after we know the LWP has stopped; if the LWP
2428 stopped before the expected SIGINT was delivered, then it will never have
2429 arrived. Also, if the signal was delivered to a shared queue and consumed
2430 by a different thread, it will never be delivered to this LWP. */
2433 maybe_clear_ignore_sigint (struct lwp_info *lp)
2435 if (!lp->ignore_sigint)
2438 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2440 if (debug_linux_nat)
2441 fprintf_unfiltered (gdb_stdlog,
2442 "MCIS: Clearing bogus flag for %s\n",
2443 target_pid_to_str (lp->ptid));
2444 lp->ignore_sigint = 0;
2448 /* Fetch the possible triggered data watchpoint info and store it in
2451 On some archs, like x86, that use debug registers to set
2452 watchpoints, it's possible that the way to know which watched
2453 address trapped, is to check the register that is used to select
2454 which address to watch. Problem is, between setting the watchpoint
2455 and reading back which data address trapped, the user may change
2456 the set of watchpoints, and, as a consequence, GDB changes the
2457 debug registers in the inferior. To avoid reading back a stale
2458 stopped-data-address when that happens, we cache in LP the fact
2459 that a watchpoint trapped, and the corresponding data address, as
2460 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2461 registers meanwhile, we have the cached data we can rely on. */
2464 check_stopped_by_watchpoint (struct lwp_info *lp)
2466 if (linux_ops->to_stopped_by_watchpoint == NULL)
2469 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
2470 inferior_ptid = lp->ptid;
2472 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2474 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2476 if (linux_ops->to_stopped_data_address != NULL)
2477 lp->stopped_data_address_p =
2478 linux_ops->to_stopped_data_address (¤t_target,
2479 &lp->stopped_data_address);
2481 lp->stopped_data_address_p = 0;
2484 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2487 /* Returns true if the LWP had stopped for a watchpoint. */
2490 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2492 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2494 gdb_assert (lp != NULL);
2496 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2500 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2502 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2504 gdb_assert (lp != NULL);
2506 *addr_p = lp->stopped_data_address;
2508 return lp->stopped_data_address_p;
2511 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2514 sigtrap_is_event (int status)
2516 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2519 /* Set alternative SIGTRAP-like events recognizer. If
2520 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2524 linux_nat_set_status_is_event (struct target_ops *t,
2525 int (*status_is_event) (int status))
2527 linux_nat_status_is_event = status_is_event;
2530 /* Wait until LP is stopped. */
2533 stop_wait_callback (struct lwp_info *lp, void *data)
2535 struct inferior *inf = find_inferior_ptid (lp->ptid);
2537 /* If this is a vfork parent, bail out, it is not going to report
2538 any SIGSTOP until the vfork is done with. */
2539 if (inf->vfork_child != NULL)
2546 status = wait_lwp (lp);
2550 if (lp->ignore_sigint && WIFSTOPPED (status)
2551 && WSTOPSIG (status) == SIGINT)
2553 lp->ignore_sigint = 0;
2556 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2558 if (debug_linux_nat)
2559 fprintf_unfiltered (gdb_stdlog,
2560 "PTRACE_CONT %s, 0, 0 (%s) "
2561 "(discarding SIGINT)\n",
2562 target_pid_to_str (lp->ptid),
2563 errno ? safe_strerror (errno) : "OK");
2565 return stop_wait_callback (lp, NULL);
2568 maybe_clear_ignore_sigint (lp);
2570 if (WSTOPSIG (status) != SIGSTOP)
2572 /* The thread was stopped with a signal other than SIGSTOP. */
2574 if (debug_linux_nat)
2575 fprintf_unfiltered (gdb_stdlog,
2576 "SWC: Pending event %s in %s\n",
2577 status_to_str ((int) status),
2578 target_pid_to_str (lp->ptid));
2580 /* Save the sigtrap event. */
2581 lp->status = status;
2582 gdb_assert (lp->signalled);
2583 save_stop_reason (lp);
2587 /* We caught the SIGSTOP that we intended to catch, so
2588 there's no SIGSTOP pending. */
2590 if (debug_linux_nat)
2591 fprintf_unfiltered (gdb_stdlog,
2592 "SWC: Expected SIGSTOP caught for %s.\n",
2593 target_pid_to_str (lp->ptid));
2595 /* Reset SIGNALLED only after the stop_wait_callback call
2596 above as it does gdb_assert on SIGNALLED. */
2604 /* Return non-zero if LP has a wait status pending. Discard the
2605 pending event and resume the LWP if the event that originally
2606 caused the stop became uninteresting. */
2609 status_callback (struct lwp_info *lp, void *data)
2611 /* Only report a pending wait status if we pretend that this has
2612 indeed been resumed. */
2616 if (!lwp_status_pending_p (lp))
2619 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2620 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2622 struct regcache *regcache = get_thread_regcache (lp->ptid);
2626 pc = regcache_read_pc (regcache);
2628 if (pc != lp->stop_pc)
2630 if (debug_linux_nat)
2631 fprintf_unfiltered (gdb_stdlog,
2632 "SC: PC of %s changed. was=%s, now=%s\n",
2633 target_pid_to_str (lp->ptid),
2634 paddress (target_gdbarch (), lp->stop_pc),
2635 paddress (target_gdbarch (), pc));
2639 #if !USE_SIGTRAP_SIGINFO
2640 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
2642 if (debug_linux_nat)
2643 fprintf_unfiltered (gdb_stdlog,
2644 "SC: previous breakpoint of %s, at %s gone\n",
2645 target_pid_to_str (lp->ptid),
2646 paddress (target_gdbarch (), lp->stop_pc));
2654 if (debug_linux_nat)
2655 fprintf_unfiltered (gdb_stdlog,
2656 "SC: pending event of %s cancelled.\n",
2657 target_pid_to_str (lp->ptid));
2660 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2668 /* Count the LWP's that have had events. */
2671 count_events_callback (struct lwp_info *lp, void *data)
2673 int *count = (int *) data;
2675 gdb_assert (count != NULL);
2677 /* Select only resumed LWPs that have an event pending. */
2678 if (lp->resumed && lwp_status_pending_p (lp))
2684 /* Select the LWP (if any) that is currently being single-stepped. */
2687 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2689 if (lp->last_resume_kind == resume_step
2696 /* Returns true if LP has a status pending. */
2699 lwp_status_pending_p (struct lwp_info *lp)
2701 /* We check for lp->waitstatus in addition to lp->status, because we
2702 can have pending process exits recorded in lp->status and
2703 W_EXITCODE(0,0) happens to be 0. */
2704 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2707 /* Select the Nth LWP that has had an event. */
2710 select_event_lwp_callback (struct lwp_info *lp, void *data)
2712 int *selector = (int *) data;
2714 gdb_assert (selector != NULL);
2716 /* Select only resumed LWPs that have an event pending. */
2717 if (lp->resumed && lwp_status_pending_p (lp))
2718 if ((*selector)-- == 0)
2724 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2725 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2726 and save the result in the LWP's stop_reason field. If it stopped
2727 for a breakpoint, decrement the PC if necessary on the lwp's
2731 save_stop_reason (struct lwp_info *lp)
2733 struct regcache *regcache;
2734 struct gdbarch *gdbarch;
2737 #if USE_SIGTRAP_SIGINFO
2741 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2742 gdb_assert (lp->status != 0);
2744 if (!linux_nat_status_is_event (lp->status))
2747 regcache = get_thread_regcache (lp->ptid);
2748 gdbarch = regcache->arch ();
2750 pc = regcache_read_pc (regcache);
2751 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2753 #if USE_SIGTRAP_SIGINFO
2754 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2756 if (siginfo.si_signo == SIGTRAP)
2758 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2759 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2761 /* The si_code is ambiguous on this arch -- check debug
2763 if (!check_stopped_by_watchpoint (lp))
2764 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2766 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2768 /* If we determine the LWP stopped for a SW breakpoint,
2769 trust it. Particularly don't check watchpoint
2770 registers, because at least on s390, we'd find
2771 stopped-by-watchpoint as long as there's a watchpoint
2773 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2775 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2777 /* This can indicate either a hardware breakpoint or
2778 hardware watchpoint. Check debug registers. */
2779 if (!check_stopped_by_watchpoint (lp))
2780 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2782 else if (siginfo.si_code == TRAP_TRACE)
2784 if (debug_linux_nat)
2785 fprintf_unfiltered (gdb_stdlog,
2786 "CSBB: %s stopped by trace\n",
2787 target_pid_to_str (lp->ptid));
2789 /* We may have single stepped an instruction that
2790 triggered a watchpoint. In that case, on some
2791 architectures (such as x86), instead of TRAP_HWBKPT,
2792 si_code indicates TRAP_TRACE, and we need to check
2793 the debug registers separately. */
2794 check_stopped_by_watchpoint (lp);
2799 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2800 && software_breakpoint_inserted_here_p (regcache->aspace (),
2803 /* The LWP was either continued, or stepped a software
2804 breakpoint instruction. */
2805 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2808 if (hardware_breakpoint_inserted_here_p (regcache->aspace (), pc))
2809 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2811 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2812 check_stopped_by_watchpoint (lp);
2815 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2817 if (debug_linux_nat)
2818 fprintf_unfiltered (gdb_stdlog,
2819 "CSBB: %s stopped by software breakpoint\n",
2820 target_pid_to_str (lp->ptid));
2822 /* Back up the PC if necessary. */
2824 regcache_write_pc (regcache, sw_bp_pc);
2826 /* Update this so we record the correct stop PC below. */
2829 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2831 if (debug_linux_nat)
2832 fprintf_unfiltered (gdb_stdlog,
2833 "CSBB: %s stopped by hardware breakpoint\n",
2834 target_pid_to_str (lp->ptid));
2836 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2838 if (debug_linux_nat)
2839 fprintf_unfiltered (gdb_stdlog,
2840 "CSBB: %s stopped by hardware watchpoint\n",
2841 target_pid_to_str (lp->ptid));
2848 /* Returns true if the LWP had stopped for a software breakpoint. */
2851 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2853 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2855 gdb_assert (lp != NULL);
2857 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2860 /* Implement the supports_stopped_by_sw_breakpoint method. */
2863 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2865 return USE_SIGTRAP_SIGINFO;
2868 /* Returns true if the LWP had stopped for a hardware
2869 breakpoint/watchpoint. */
2872 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2874 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2876 gdb_assert (lp != NULL);
2878 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2881 /* Implement the supports_stopped_by_hw_breakpoint method. */
2884 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2886 return USE_SIGTRAP_SIGINFO;
2889 /* Select one LWP out of those that have events pending. */
2892 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2895 int random_selector;
2896 struct lwp_info *event_lp = NULL;
2898 /* Record the wait status for the original LWP. */
2899 (*orig_lp)->status = *status;
2901 /* In all-stop, give preference to the LWP that is being
2902 single-stepped. There will be at most one, and it will be the
2903 LWP that the core is most interested in. If we didn't do this,
2904 then we'd have to handle pending step SIGTRAPs somehow in case
2905 the core later continues the previously-stepped thread, as
2906 otherwise we'd report the pending SIGTRAP then, and the core, not
2907 having stepped the thread, wouldn't understand what the trap was
2908 for, and therefore would report it to the user as a random
2910 if (!target_is_non_stop_p ())
2912 event_lp = iterate_over_lwps (filter,
2913 select_singlestep_lwp_callback, NULL);
2914 if (event_lp != NULL)
2916 if (debug_linux_nat)
2917 fprintf_unfiltered (gdb_stdlog,
2918 "SEL: Select single-step %s\n",
2919 target_pid_to_str (event_lp->ptid));
2923 if (event_lp == NULL)
2925 /* Pick one at random, out of those which have had events. */
2927 /* First see how many events we have. */
2928 iterate_over_lwps (filter, count_events_callback, &num_events);
2929 gdb_assert (num_events > 0);
2931 /* Now randomly pick a LWP out of those that have had
2933 random_selector = (int)
2934 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2936 if (debug_linux_nat && num_events > 1)
2937 fprintf_unfiltered (gdb_stdlog,
2938 "SEL: Found %d events, selecting #%d\n",
2939 num_events, random_selector);
2941 event_lp = iterate_over_lwps (filter,
2942 select_event_lwp_callback,
2946 if (event_lp != NULL)
2948 /* Switch the event LWP. */
2949 *orig_lp = event_lp;
2950 *status = event_lp->status;
2953 /* Flush the wait status for the event LWP. */
2954 (*orig_lp)->status = 0;
2957 /* Return non-zero if LP has been resumed. */
2960 resumed_callback (struct lwp_info *lp, void *data)
2965 /* Check if we should go on and pass this event to common code.
2966 Return the affected lwp if we are, or NULL otherwise. */
2968 static struct lwp_info *
2969 linux_nat_filter_event (int lwpid, int status)
2971 struct lwp_info *lp;
2972 int event = linux_ptrace_get_extended_event (status);
2974 lp = find_lwp_pid (pid_to_ptid (lwpid));
2976 /* Check for stop events reported by a process we didn't already
2977 know about - anything not already in our LWP list.
2979 If we're expecting to receive stopped processes after
2980 fork, vfork, and clone events, then we'll just add the
2981 new one to our list and go back to waiting for the event
2982 to be reported - the stopped process might be returned
2983 from waitpid before or after the event is.
2985 But note the case of a non-leader thread exec'ing after the
2986 leader having exited, and gone from our lists. The non-leader
2987 thread changes its tid to the tgid. */
2989 if (WIFSTOPPED (status) && lp == NULL
2990 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2992 /* A multi-thread exec after we had seen the leader exiting. */
2993 if (debug_linux_nat)
2994 fprintf_unfiltered (gdb_stdlog,
2995 "LLW: Re-adding thread group leader LWP %d.\n",
2998 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
3001 add_thread (lp->ptid);
3004 if (WIFSTOPPED (status) && !lp)
3006 if (debug_linux_nat)
3007 fprintf_unfiltered (gdb_stdlog,
3008 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3009 (long) lwpid, status_to_str (status));
3010 add_to_pid_list (&stopped_pids, lwpid, status);
3014 /* Make sure we don't report an event for the exit of an LWP not in
3015 our list, i.e. not part of the current process. This can happen
3016 if we detach from a program we originally forked and then it
3018 if (!WIFSTOPPED (status) && !lp)
3021 /* This LWP is stopped now. (And if dead, this prevents it from
3022 ever being continued.) */
3025 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3027 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3028 int options = linux_nat_ptrace_options (inf->attach_flag);
3030 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3031 lp->must_set_ptrace_flags = 0;
3034 /* Handle GNU/Linux's syscall SIGTRAPs. */
3035 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3037 /* No longer need the sysgood bit. The ptrace event ends up
3038 recorded in lp->waitstatus if we care for it. We can carry
3039 on handling the event like a regular SIGTRAP from here
3041 status = W_STOPCODE (SIGTRAP);
3042 if (linux_handle_syscall_trap (lp, 0))
3047 /* Almost all other ptrace-stops are known to be outside of system
3048 calls, with further exceptions in linux_handle_extended_wait. */
3049 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3052 /* Handle GNU/Linux's extended waitstatus for trace events. */
3053 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3054 && linux_is_extended_waitstatus (status))
3056 if (debug_linux_nat)
3057 fprintf_unfiltered (gdb_stdlog,
3058 "LLW: Handling extended status 0x%06x\n",
3060 if (linux_handle_extended_wait (lp, status))
3064 /* Check if the thread has exited. */
3065 if (WIFEXITED (status) || WIFSIGNALED (status))
3067 if (!report_thread_events
3068 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3070 if (debug_linux_nat)
3071 fprintf_unfiltered (gdb_stdlog,
3072 "LLW: %s exited.\n",
3073 target_pid_to_str (lp->ptid));
3075 /* If there is at least one more LWP, then the exit signal
3076 was not the end of the debugged application and should be
3082 /* Note that even if the leader was ptrace-stopped, it can still
3083 exit, if e.g., some other thread brings down the whole
3084 process (calls `exit'). So don't assert that the lwp is
3086 if (debug_linux_nat)
3087 fprintf_unfiltered (gdb_stdlog,
3088 "LWP %ld exited (resumed=%d)\n",
3089 ptid_get_lwp (lp->ptid), lp->resumed);
3091 /* Dead LWP's aren't expected to reported a pending sigstop. */
3094 /* Store the pending event in the waitstatus, because
3095 W_EXITCODE(0,0) == 0. */
3096 store_waitstatus (&lp->waitstatus, status);
3100 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3101 an attempt to stop an LWP. */
3103 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3107 if (lp->last_resume_kind == resume_stop)
3109 if (debug_linux_nat)
3110 fprintf_unfiltered (gdb_stdlog,
3111 "LLW: resume_stop SIGSTOP caught for %s.\n",
3112 target_pid_to_str (lp->ptid));
3116 /* This is a delayed SIGSTOP. Filter out the event. */
3118 if (debug_linux_nat)
3119 fprintf_unfiltered (gdb_stdlog,
3120 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3122 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3123 target_pid_to_str (lp->ptid));
3125 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3126 gdb_assert (lp->resumed);
3131 /* Make sure we don't report a SIGINT that we have already displayed
3132 for another thread. */
3133 if (lp->ignore_sigint
3134 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3136 if (debug_linux_nat)
3137 fprintf_unfiltered (gdb_stdlog,
3138 "LLW: Delayed SIGINT caught for %s.\n",
3139 target_pid_to_str (lp->ptid));
3141 /* This is a delayed SIGINT. */
3142 lp->ignore_sigint = 0;
3144 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3145 if (debug_linux_nat)
3146 fprintf_unfiltered (gdb_stdlog,
3147 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3149 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3150 target_pid_to_str (lp->ptid));
3151 gdb_assert (lp->resumed);
3153 /* Discard the event. */
3157 /* Don't report signals that GDB isn't interested in, such as
3158 signals that are neither printed nor stopped upon. Stopping all
3159 threads can be a bit time-consuming so if we want decent
3160 performance with heavily multi-threaded programs, especially when
3161 they're using a high frequency timer, we'd better avoid it if we
3163 if (WIFSTOPPED (status))
3165 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3167 if (!target_is_non_stop_p ())
3169 /* Only do the below in all-stop, as we currently use SIGSTOP
3170 to implement target_stop (see linux_nat_stop) in
3172 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3174 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3175 forwarded to the entire process group, that is, all LWPs
3176 will receive it - unless they're using CLONE_THREAD to
3177 share signals. Since we only want to report it once, we
3178 mark it as ignored for all LWPs except this one. */
3179 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3180 set_ignore_sigint, NULL);
3181 lp->ignore_sigint = 0;
3184 maybe_clear_ignore_sigint (lp);
3187 /* When using hardware single-step, we need to report every signal.
3188 Otherwise, signals in pass_mask may be short-circuited
3189 except signals that might be caused by a breakpoint. */
3191 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3192 && !linux_wstatus_maybe_breakpoint (status))
3194 linux_resume_one_lwp (lp, lp->step, signo);
3195 if (debug_linux_nat)
3196 fprintf_unfiltered (gdb_stdlog,
3197 "LLW: %s %s, %s (preempt 'handle')\n",
3199 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3200 target_pid_to_str (lp->ptid),
3201 (signo != GDB_SIGNAL_0
3202 ? strsignal (gdb_signal_to_host (signo))
3208 /* An interesting event. */
3210 lp->status = status;
3211 save_stop_reason (lp);
3215 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3216 their exits until all other threads in the group have exited. */
3219 check_zombie_leaders (void)
3221 struct inferior *inf;
3225 struct lwp_info *leader_lp;
3230 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3231 if (leader_lp != NULL
3232 /* Check if there are other threads in the group, as we may
3233 have raced with the inferior simply exiting. */
3234 && num_lwps (inf->pid) > 1
3235 && linux_proc_pid_is_zombie (inf->pid))
3237 if (debug_linux_nat)
3238 fprintf_unfiltered (gdb_stdlog,
3239 "CZL: Thread group leader %d zombie "
3240 "(it exited, or another thread execd).\n",
3243 /* A leader zombie can mean one of two things:
3245 - It exited, and there's an exit status pending
3246 available, or only the leader exited (not the whole
3247 program). In the latter case, we can't waitpid the
3248 leader's exit status until all other threads are gone.
3250 - There are 3 or more threads in the group, and a thread
3251 other than the leader exec'd. See comments on exec
3252 events at the top of the file. We could try
3253 distinguishing the exit and exec cases, by waiting once
3254 more, and seeing if something comes out, but it doesn't
3255 sound useful. The previous leader _does_ go away, and
3256 we'll re-add the new one once we see the exec event
3257 (which is just the same as what would happen if the
3258 previous leader did exit voluntarily before some other
3261 if (debug_linux_nat)
3262 fprintf_unfiltered (gdb_stdlog,
3263 "CZL: Thread group leader %d vanished.\n",
3265 exit_lwp (leader_lp);
3270 /* Convenience function that is called when the kernel reports an exit
3271 event. This decides whether to report the event to GDB as a
3272 process exit event, a thread exit event, or to suppress the
3276 filter_exit_event (struct lwp_info *event_child,
3277 struct target_waitstatus *ourstatus)
3279 ptid_t ptid = event_child->ptid;
3281 if (num_lwps (ptid_get_pid (ptid)) > 1)
3283 if (report_thread_events)
3284 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3286 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3288 exit_lwp (event_child);
3295 linux_nat_wait_1 (struct target_ops *ops,
3296 ptid_t ptid, struct target_waitstatus *ourstatus,
3300 enum resume_kind last_resume_kind;
3301 struct lwp_info *lp;
3304 if (debug_linux_nat)
3305 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3307 /* The first time we get here after starting a new inferior, we may
3308 not have added it to the LWP list yet - this is the earliest
3309 moment at which we know its PID. */
3310 if (ptid_is_pid (inferior_ptid))
3312 /* Upgrade the main thread's ptid. */
3313 thread_change_ptid (inferior_ptid,
3314 ptid_build (ptid_get_pid (inferior_ptid),
3315 ptid_get_pid (inferior_ptid), 0));
3317 lp = add_initial_lwp (inferior_ptid);
3321 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3322 block_child_signals (&prev_mask);
3324 /* First check if there is a LWP with a wait status pending. */
3325 lp = iterate_over_lwps (ptid, status_callback, NULL);
3328 if (debug_linux_nat)
3329 fprintf_unfiltered (gdb_stdlog,
3330 "LLW: Using pending wait status %s for %s.\n",
3331 status_to_str (lp->status),
3332 target_pid_to_str (lp->ptid));
3335 /* But if we don't find a pending event, we'll have to wait. Always
3336 pull all events out of the kernel. We'll randomly select an
3337 event LWP out of all that have events, to prevent starvation. */
3343 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3346 - If the thread group leader exits while other threads in the
3347 thread group still exist, waitpid(TGID, ...) hangs. That
3348 waitpid won't return an exit status until the other threads
3349 in the group are reapped.
3351 - When a non-leader thread execs, that thread just vanishes
3352 without reporting an exit (so we'd hang if we waited for it
3353 explicitly in that case). The exec event is reported to
3357 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3359 if (debug_linux_nat)
3360 fprintf_unfiltered (gdb_stdlog,
3361 "LNW: waitpid(-1, ...) returned %d, %s\n",
3362 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3366 if (debug_linux_nat)
3368 fprintf_unfiltered (gdb_stdlog,
3369 "LLW: waitpid %ld received %s\n",
3370 (long) lwpid, status_to_str (status));
3373 linux_nat_filter_event (lwpid, status);
3374 /* Retry until nothing comes out of waitpid. A single
3375 SIGCHLD can indicate more than one child stopped. */
3379 /* Now that we've pulled all events out of the kernel, resume
3380 LWPs that don't have an interesting event to report. */
3381 iterate_over_lwps (minus_one_ptid,
3382 resume_stopped_resumed_lwps, &minus_one_ptid);
3384 /* ... and find an LWP with a status to report to the core, if
3386 lp = iterate_over_lwps (ptid, status_callback, NULL);
3390 /* Check for zombie thread group leaders. Those can't be reaped
3391 until all other threads in the thread group are. */
3392 check_zombie_leaders ();
3394 /* If there are no resumed children left, bail. We'd be stuck
3395 forever in the sigsuspend call below otherwise. */
3396 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3398 if (debug_linux_nat)
3399 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3401 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3403 restore_child_signals_mask (&prev_mask);
3404 return minus_one_ptid;
3407 /* No interesting event to report to the core. */
3409 if (target_options & TARGET_WNOHANG)
3411 if (debug_linux_nat)
3412 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3414 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3415 restore_child_signals_mask (&prev_mask);
3416 return minus_one_ptid;
3419 /* We shouldn't end up here unless we want to try again. */
3420 gdb_assert (lp == NULL);
3422 /* Block until we get an event reported with SIGCHLD. */
3423 if (debug_linux_nat)
3424 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3425 sigsuspend (&suspend_mask);
3430 status = lp->status;
3433 if (!target_is_non_stop_p ())
3435 /* Now stop all other LWP's ... */
3436 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3438 /* ... and wait until all of them have reported back that
3439 they're no longer running. */
3440 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3443 /* If we're not waiting for a specific LWP, choose an event LWP from
3444 among those that have had events. Giving equal priority to all
3445 LWPs that have had events helps prevent starvation. */
3446 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3447 select_event_lwp (ptid, &lp, &status);
3449 gdb_assert (lp != NULL);
3451 /* Now that we've selected our final event LWP, un-adjust its PC if
3452 it was a software breakpoint, and we can't reliably support the
3453 "stopped by software breakpoint" stop reason. */
3454 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3455 && !USE_SIGTRAP_SIGINFO)
3457 struct regcache *regcache = get_thread_regcache (lp->ptid);
3458 struct gdbarch *gdbarch = regcache->arch ();
3459 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3465 pc = regcache_read_pc (regcache);
3466 regcache_write_pc (regcache, pc + decr_pc);
3470 /* We'll need this to determine whether to report a SIGSTOP as
3471 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3473 last_resume_kind = lp->last_resume_kind;
3475 if (!target_is_non_stop_p ())
3477 /* In all-stop, from the core's perspective, all LWPs are now
3478 stopped until a new resume action is sent over. */
3479 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3483 resume_clear_callback (lp, NULL);
3486 if (linux_nat_status_is_event (status))
3488 if (debug_linux_nat)
3489 fprintf_unfiltered (gdb_stdlog,
3490 "LLW: trap ptid is %s.\n",
3491 target_pid_to_str (lp->ptid));
3494 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3496 *ourstatus = lp->waitstatus;
3497 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3500 store_waitstatus (ourstatus, status);
3502 if (debug_linux_nat)
3503 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3505 restore_child_signals_mask (&prev_mask);
3507 if (last_resume_kind == resume_stop
3508 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3509 && WSTOPSIG (status) == SIGSTOP)
3511 /* A thread that has been requested to stop by GDB with
3512 target_stop, and it stopped cleanly, so report as SIG0. The
3513 use of SIGSTOP is an implementation detail. */
3514 ourstatus->value.sig = GDB_SIGNAL_0;
3517 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3518 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3521 lp->core = linux_common_core_of_thread (lp->ptid);
3523 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3524 return filter_exit_event (lp, ourstatus);
3529 /* Resume LWPs that are currently stopped without any pending status
3530 to report, but are resumed from the core's perspective. */
3533 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3535 ptid_t *wait_ptid_p = (ptid_t *) data;
3539 if (debug_linux_nat)
3540 fprintf_unfiltered (gdb_stdlog,
3541 "RSRL: NOT resuming LWP %s, not stopped\n",
3542 target_pid_to_str (lp->ptid));
3544 else if (!lp->resumed)
3546 if (debug_linux_nat)
3547 fprintf_unfiltered (gdb_stdlog,
3548 "RSRL: NOT resuming LWP %s, not resumed\n",
3549 target_pid_to_str (lp->ptid));
3551 else if (lwp_status_pending_p (lp))
3553 if (debug_linux_nat)
3554 fprintf_unfiltered (gdb_stdlog,
3555 "RSRL: NOT resuming LWP %s, has pending status\n",
3556 target_pid_to_str (lp->ptid));
3560 struct regcache *regcache = get_thread_regcache (lp->ptid);
3561 struct gdbarch *gdbarch = regcache->arch ();
3565 CORE_ADDR pc = regcache_read_pc (regcache);
3566 int leave_stopped = 0;
3568 /* Don't bother if there's a breakpoint at PC that we'd hit
3569 immediately, and we're not waiting for this LWP. */
3570 if (!ptid_match (lp->ptid, *wait_ptid_p))
3572 if (breakpoint_inserted_here_p (regcache->aspace (), pc))
3578 if (debug_linux_nat)
3579 fprintf_unfiltered (gdb_stdlog,
3580 "RSRL: resuming stopped-resumed LWP %s at "
3582 target_pid_to_str (lp->ptid),
3583 paddress (gdbarch, pc),
3586 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3589 CATCH (ex, RETURN_MASK_ERROR)
3591 if (!check_ptrace_stopped_lwp_gone (lp))
3592 throw_exception (ex);
3601 linux_nat_wait (struct target_ops *ops,
3602 ptid_t ptid, struct target_waitstatus *ourstatus,
3607 if (debug_linux_nat)
3609 char *options_string;
3611 options_string = target_options_to_string (target_options);
3612 fprintf_unfiltered (gdb_stdlog,
3613 "linux_nat_wait: [%s], [%s]\n",
3614 target_pid_to_str (ptid),
3616 xfree (options_string);
3619 /* Flush the async file first. */
3620 if (target_is_async_p ())
3621 async_file_flush ();
3623 /* Resume LWPs that are currently stopped without any pending status
3624 to report, but are resumed from the core's perspective. LWPs get
3625 in this state if we find them stopping at a time we're not
3626 interested in reporting the event (target_wait on a
3627 specific_process, for example, see linux_nat_wait_1), and
3628 meanwhile the event became uninteresting. Don't bother resuming
3629 LWPs we're not going to wait for if they'd stop immediately. */
3630 if (target_is_non_stop_p ())
3631 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3633 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3635 /* If we requested any event, and something came out, assume there
3636 may be more. If we requested a specific lwp or process, also
3637 assume there may be more. */
3638 if (target_is_async_p ()
3639 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3640 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3641 || !ptid_equal (ptid, minus_one_ptid)))
3650 kill_one_lwp (pid_t pid)
3652 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3655 kill_lwp (pid, SIGKILL);
3656 if (debug_linux_nat)
3658 int save_errno = errno;
3660 fprintf_unfiltered (gdb_stdlog,
3661 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3662 save_errno ? safe_strerror (save_errno) : "OK");
3665 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3668 ptrace (PTRACE_KILL, pid, 0, 0);
3669 if (debug_linux_nat)
3671 int save_errno = errno;
3673 fprintf_unfiltered (gdb_stdlog,
3674 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3675 save_errno ? safe_strerror (save_errno) : "OK");
3679 /* Wait for an LWP to die. */
3682 kill_wait_one_lwp (pid_t pid)
3686 /* We must make sure that there are no pending events (delayed
3687 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3688 program doesn't interfere with any following debugging session. */
3692 res = my_waitpid (pid, NULL, __WALL);
3693 if (res != (pid_t) -1)
3695 if (debug_linux_nat)
3696 fprintf_unfiltered (gdb_stdlog,
3697 "KWC: wait %ld received unknown.\n",
3699 /* The Linux kernel sometimes fails to kill a thread
3700 completely after PTRACE_KILL; that goes from the stop
3701 point in do_fork out to the one in get_signal_to_deliver
3702 and waits again. So kill it again. */
3708 gdb_assert (res == -1 && errno == ECHILD);
3711 /* Callback for iterate_over_lwps. */
3714 kill_callback (struct lwp_info *lp, void *data)
3716 kill_one_lwp (ptid_get_lwp (lp->ptid));
3720 /* Callback for iterate_over_lwps. */
3723 kill_wait_callback (struct lwp_info *lp, void *data)
3725 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3729 /* Kill the fork children of any threads of inferior INF that are
3730 stopped at a fork event. */
3733 kill_unfollowed_fork_children (struct inferior *inf)
3735 struct thread_info *thread;
3737 ALL_NON_EXITED_THREADS (thread)
3738 if (thread->inf == inf)
3740 struct target_waitstatus *ws = &thread->pending_follow;
3742 if (ws->kind == TARGET_WAITKIND_FORKED
3743 || ws->kind == TARGET_WAITKIND_VFORKED)
3745 ptid_t child_ptid = ws->value.related_pid;
3746 int child_pid = ptid_get_pid (child_ptid);
3747 int child_lwp = ptid_get_lwp (child_ptid);
3749 kill_one_lwp (child_lwp);
3750 kill_wait_one_lwp (child_lwp);
3752 /* Let the arch-specific native code know this process is
3754 linux_nat_forget_process (child_pid);
3760 linux_nat_kill (struct target_ops *ops)
3762 /* If we're stopped while forking and we haven't followed yet,
3763 kill the other task. We need to do this first because the
3764 parent will be sleeping if this is a vfork. */
3765 kill_unfollowed_fork_children (current_inferior ());
3767 if (forks_exist_p ())
3768 linux_fork_killall ();
3771 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3773 /* Stop all threads before killing them, since ptrace requires
3774 that the thread is stopped to sucessfully PTRACE_KILL. */
3775 iterate_over_lwps (ptid, stop_callback, NULL);
3776 /* ... and wait until all of them have reported back that
3777 they're no longer running. */
3778 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3780 /* Kill all LWP's ... */
3781 iterate_over_lwps (ptid, kill_callback, NULL);
3783 /* ... and wait until we've flushed all events. */
3784 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3787 target_mourn_inferior (inferior_ptid);
3791 linux_nat_mourn_inferior (struct target_ops *ops)
3793 int pid = ptid_get_pid (inferior_ptid);
3795 purge_lwp_list (pid);
3797 if (! forks_exist_p ())
3798 /* Normal case, no other forks available. */
3799 linux_ops->to_mourn_inferior (ops);
3801 /* Multi-fork case. The current inferior_ptid has exited, but
3802 there are other viable forks to debug. Delete the exiting
3803 one and context-switch to the first available. */
3804 linux_fork_mourn_inferior ();
3806 /* Let the arch-specific native code know this process is gone. */
3807 linux_nat_forget_process (pid);
3810 /* Convert a native/host siginfo object, into/from the siginfo in the
3811 layout of the inferiors' architecture. */
3814 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3818 if (linux_nat_siginfo_fixup != NULL)
3819 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3821 /* If there was no callback, or the callback didn't do anything,
3822 then just do a straight memcpy. */
3826 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3828 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3832 static enum target_xfer_status
3833 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3834 const char *annex, gdb_byte *readbuf,
3835 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3836 ULONGEST *xfered_len)
3840 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3842 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3843 gdb_assert (readbuf || writebuf);
3845 pid = ptid_get_lwp (inferior_ptid);
3847 pid = ptid_get_pid (inferior_ptid);
3849 if (offset > sizeof (siginfo))
3850 return TARGET_XFER_E_IO;
3853 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3855 return TARGET_XFER_E_IO;
3857 /* When GDB is built as a 64-bit application, ptrace writes into
3858 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3859 inferior with a 64-bit GDB should look the same as debugging it
3860 with a 32-bit GDB, we need to convert it. GDB core always sees
3861 the converted layout, so any read/write will have to be done
3863 siginfo_fixup (&siginfo, inf_siginfo, 0);
3865 if (offset + len > sizeof (siginfo))
3866 len = sizeof (siginfo) - offset;
3868 if (readbuf != NULL)
3869 memcpy (readbuf, inf_siginfo + offset, len);
3872 memcpy (inf_siginfo + offset, writebuf, len);
3874 /* Convert back to ptrace layout before flushing it out. */
3875 siginfo_fixup (&siginfo, inf_siginfo, 1);
3878 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3880 return TARGET_XFER_E_IO;
3884 return TARGET_XFER_OK;
3887 static enum target_xfer_status
3888 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3889 const char *annex, gdb_byte *readbuf,
3890 const gdb_byte *writebuf,
3891 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3893 enum target_xfer_status xfer;
3895 if (object == TARGET_OBJECT_SIGNAL_INFO)
3896 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3897 offset, len, xfered_len);
3899 /* The target is connected but no live inferior is selected. Pass
3900 this request down to a lower stratum (e.g., the executable
3902 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3903 return TARGET_XFER_EOF;
3905 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3906 offset, len, xfered_len);
3912 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3914 /* As long as a PTID is in lwp list, consider it alive. */
3915 return find_lwp_pid (ptid) != NULL;
3918 /* Implement the to_update_thread_list target method for this
3922 linux_nat_update_thread_list (struct target_ops *ops)
3924 struct lwp_info *lwp;
3926 /* We add/delete threads from the list as clone/exit events are
3927 processed, so just try deleting exited threads still in the
3929 delete_exited_threads ();
3931 /* Update the processor core that each lwp/thread was last seen
3935 /* Avoid accessing /proc if the thread hasn't run since we last
3936 time we fetched the thread's core. Accessing /proc becomes
3937 noticeably expensive when we have thousands of LWPs. */
3938 if (lwp->core == -1)
3939 lwp->core = linux_common_core_of_thread (lwp->ptid);
3944 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3946 static char buf[64];
3948 if (ptid_lwp_p (ptid)
3949 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3950 || num_lwps (ptid_get_pid (ptid)) > 1))
3952 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3956 return normal_pid_to_str (ptid);
3960 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3962 return linux_proc_tid_get_name (thr->ptid);
3965 /* Accepts an integer PID; Returns a string representing a file that
3966 can be opened to get the symbols for the child process. */
3969 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3971 return linux_proc_pid_to_exec_file (pid);
3974 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3975 Because we can use a single read/write call, this can be much more
3976 efficient than banging away at PTRACE_PEEKTEXT. */
3978 static enum target_xfer_status
3979 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3980 const char *annex, gdb_byte *readbuf,
3981 const gdb_byte *writebuf,
3982 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3988 if (object != TARGET_OBJECT_MEMORY)
3989 return TARGET_XFER_EOF;
3991 /* Don't bother for one word. */
3992 if (len < 3 * sizeof (long))
3993 return TARGET_XFER_EOF;
3995 /* We could keep this file open and cache it - possibly one per
3996 thread. That requires some juggling, but is even faster. */
3997 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3998 ptid_get_lwp (inferior_ptid));
3999 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
4002 return TARGET_XFER_EOF;
4004 /* Use pread64/pwrite64 if available, since they save a syscall and can
4005 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
4006 debugging a SPARC64 application). */
4008 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
4009 : pwrite64 (fd, writebuf, len, offset));
4011 ret = lseek (fd, offset, SEEK_SET);
4013 ret = (readbuf ? read (fd, readbuf, len)
4014 : write (fd, writebuf, len));
4019 if (ret == -1 || ret == 0)
4020 return TARGET_XFER_EOF;
4024 return TARGET_XFER_OK;
4029 /* Enumerate spufs IDs for process PID. */
4031 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4033 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4035 LONGEST written = 0;
4038 struct dirent *entry;
4040 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4041 dir = opendir (path);
4046 while ((entry = readdir (dir)) != NULL)
4052 fd = atoi (entry->d_name);
4056 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4057 if (stat (path, &st) != 0)
4059 if (!S_ISDIR (st.st_mode))
4062 if (statfs (path, &stfs) != 0)
4064 if (stfs.f_type != SPUFS_MAGIC)
4067 if (pos >= offset && pos + 4 <= offset + len)
4069 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4079 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4080 object type, using the /proc file system. */
4082 static enum target_xfer_status
4083 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4084 const char *annex, gdb_byte *readbuf,
4085 const gdb_byte *writebuf,
4086 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4091 int pid = ptid_get_lwp (inferior_ptid);
4096 return TARGET_XFER_E_IO;
4099 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4102 return TARGET_XFER_E_IO;
4104 return TARGET_XFER_EOF;
4107 *xfered_len = (ULONGEST) l;
4108 return TARGET_XFER_OK;
4113 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4114 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4116 return TARGET_XFER_E_IO;
4119 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4122 return TARGET_XFER_EOF;
4126 ret = write (fd, writebuf, (size_t) len);
4128 ret = read (fd, readbuf, (size_t) len);
4133 return TARGET_XFER_E_IO;
4135 return TARGET_XFER_EOF;
4138 *xfered_len = (ULONGEST) ret;
4139 return TARGET_XFER_OK;
4144 /* Parse LINE as a signal set and add its set bits to SIGS. */
4147 add_line_to_sigset (const char *line, sigset_t *sigs)
4149 int len = strlen (line) - 1;
4153 if (line[len] != '\n')
4154 error (_("Could not parse signal set: %s"), line);
4162 if (*p >= '0' && *p <= '9')
4164 else if (*p >= 'a' && *p <= 'f')
4165 digit = *p - 'a' + 10;
4167 error (_("Could not parse signal set: %s"), line);
4172 sigaddset (sigs, signum + 1);
4174 sigaddset (sigs, signum + 2);
4176 sigaddset (sigs, signum + 3);
4178 sigaddset (sigs, signum + 4);
4184 /* Find process PID's pending signals from /proc/pid/status and set
4188 linux_proc_pending_signals (int pid, sigset_t *pending,
4189 sigset_t *blocked, sigset_t *ignored)
4191 char buffer[PATH_MAX], fname[PATH_MAX];
4193 sigemptyset (pending);
4194 sigemptyset (blocked);
4195 sigemptyset (ignored);
4196 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4197 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
4198 if (procfile == NULL)
4199 error (_("Could not open %s"), fname);
4201 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
4203 /* Normal queued signals are on the SigPnd line in the status
4204 file. However, 2.6 kernels also have a "shared" pending
4205 queue for delivering signals to a thread group, so check for
4208 Unfortunately some Red Hat kernels include the shared pending
4209 queue but not the ShdPnd status field. */
4211 if (startswith (buffer, "SigPnd:\t"))
4212 add_line_to_sigset (buffer + 8, pending);
4213 else if (startswith (buffer, "ShdPnd:\t"))
4214 add_line_to_sigset (buffer + 8, pending);
4215 else if (startswith (buffer, "SigBlk:\t"))
4216 add_line_to_sigset (buffer + 8, blocked);
4217 else if (startswith (buffer, "SigIgn:\t"))
4218 add_line_to_sigset (buffer + 8, ignored);
4222 static enum target_xfer_status
4223 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4224 const char *annex, gdb_byte *readbuf,
4225 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4226 ULONGEST *xfered_len)
4228 gdb_assert (object == TARGET_OBJECT_OSDATA);
4230 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4231 if (*xfered_len == 0)
4232 return TARGET_XFER_EOF;
4234 return TARGET_XFER_OK;
4237 static enum target_xfer_status
4238 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4239 const char *annex, gdb_byte *readbuf,
4240 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4241 ULONGEST *xfered_len)
4243 enum target_xfer_status xfer;
4245 if (object == TARGET_OBJECT_AUXV)
4246 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4247 offset, len, xfered_len);
4249 if (object == TARGET_OBJECT_OSDATA)
4250 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4251 offset, len, xfered_len);
4253 if (object == TARGET_OBJECT_SPU)
4254 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4255 offset, len, xfered_len);
4257 /* GDB calculates all the addresses in possibly larget width of the address.
4258 Address width needs to be masked before its final use - either by
4259 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4261 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4263 if (object == TARGET_OBJECT_MEMORY)
4265 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4267 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4268 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4271 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4272 offset, len, xfered_len);
4273 if (xfer != TARGET_XFER_EOF)
4276 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4277 offset, len, xfered_len);
4281 cleanup_target_stop (void *arg)
4283 ptid_t *ptid = (ptid_t *) arg;
4285 gdb_assert (arg != NULL);
4288 target_continue_no_signal (*ptid);
4291 static VEC(static_tracepoint_marker_p) *
4292 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4295 char s[IPA_CMD_BUF_SIZE];
4296 struct cleanup *old_chain;
4297 int pid = ptid_get_pid (inferior_ptid);
4298 VEC(static_tracepoint_marker_p) *markers = NULL;
4299 struct static_tracepoint_marker *marker = NULL;
4301 ptid_t ptid = ptid_build (pid, 0, 0);
4306 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4307 s[sizeof ("qTfSTM")] = 0;
4309 agent_run_command (pid, s, strlen (s) + 1);
4311 old_chain = make_cleanup (free_current_marker, &marker);
4312 make_cleanup (cleanup_target_stop, &ptid);
4317 marker = XCNEW (struct static_tracepoint_marker);
4321 parse_static_tracepoint_marker_definition (p, &p, marker);
4323 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4325 VEC_safe_push (static_tracepoint_marker_p,
4331 release_static_tracepoint_marker (marker);
4332 memset (marker, 0, sizeof (*marker));
4335 while (*p++ == ','); /* comma-separated list */
4337 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4338 s[sizeof ("qTsSTM")] = 0;
4339 agent_run_command (pid, s, strlen (s) + 1);
4343 do_cleanups (old_chain);
4348 /* Create a prototype generic GNU/Linux target. The client can override
4349 it with local methods. */
4352 linux_target_install_ops (struct target_ops *t)
4354 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4355 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4356 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4357 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4358 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4359 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4360 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4361 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4362 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4363 t->to_post_attach = linux_child_post_attach;
4364 t->to_follow_fork = linux_child_follow_fork;
4366 super_xfer_partial = t->to_xfer_partial;
4367 t->to_xfer_partial = linux_xfer_partial;
4369 t->to_static_tracepoint_markers_by_strid
4370 = linux_child_static_tracepoint_markers_by_strid;
4376 struct target_ops *t;
4378 t = inf_ptrace_target ();
4379 linux_target_install_ops (t);
4385 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4387 struct target_ops *t;
4389 t = inf_ptrace_trad_target (register_u_offset);
4390 linux_target_install_ops (t);
4395 /* target_is_async_p implementation. */
4398 linux_nat_is_async_p (struct target_ops *ops)
4400 return linux_is_async_p ();
4403 /* target_can_async_p implementation. */
4406 linux_nat_can_async_p (struct target_ops *ops)
4408 /* We're always async, unless the user explicitly prevented it with the
4409 "maint set target-async" command. */
4410 return target_async_permitted;
4414 linux_nat_supports_non_stop (struct target_ops *self)
4419 /* to_always_non_stop_p implementation. */
4422 linux_nat_always_non_stop_p (struct target_ops *self)
4427 /* True if we want to support multi-process. To be removed when GDB
4428 supports multi-exec. */
4430 int linux_multi_process = 1;
4433 linux_nat_supports_multi_process (struct target_ops *self)
4435 return linux_multi_process;
4439 linux_nat_supports_disable_randomization (struct target_ops *self)
4441 #ifdef HAVE_PERSONALITY
4448 static int async_terminal_is_ours = 1;
4450 /* target_terminal_inferior implementation.
4452 This is a wrapper around child_terminal_inferior to add async support. */
4455 linux_nat_terminal_inferior (struct target_ops *self)
4457 child_terminal_inferior (self);
4459 /* Calls to target_terminal_*() are meant to be idempotent. */
4460 if (!async_terminal_is_ours)
4463 async_terminal_is_ours = 0;
4467 /* target_terminal::ours implementation.
4469 This is a wrapper around child_terminal_ours to add async support (and
4470 implement the target_terminal::ours vs target_terminal::ours_for_output
4471 distinction). child_terminal_ours is currently no different than
4472 child_terminal_ours_for_output.
4473 We leave target_terminal::ours_for_output alone, leaving it to
4474 child_terminal_ours_for_output. */
4477 linux_nat_terminal_ours (struct target_ops *self)
4479 /* GDB should never give the terminal to the inferior if the
4480 inferior is running in the background (run&, continue&, etc.),
4481 but claiming it sure should. */
4482 child_terminal_ours (self);
4484 if (async_terminal_is_ours)
4487 clear_sigint_trap ();
4488 async_terminal_is_ours = 1;
4491 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4492 so we notice when any child changes state, and notify the
4493 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4494 above to wait for the arrival of a SIGCHLD. */
4497 sigchld_handler (int signo)
4499 int old_errno = errno;
4501 if (debug_linux_nat)
4502 ui_file_write_async_safe (gdb_stdlog,
4503 "sigchld\n", sizeof ("sigchld\n") - 1);
4505 if (signo == SIGCHLD
4506 && linux_nat_event_pipe[0] != -1)
4507 async_file_mark (); /* Let the event loop know that there are
4508 events to handle. */
4513 /* Callback registered with the target events file descriptor. */
4516 handle_target_event (int error, gdb_client_data client_data)
4518 inferior_event_handler (INF_REG_EVENT, NULL);
4521 /* Create/destroy the target events pipe. Returns previous state. */
4524 linux_async_pipe (int enable)
4526 int previous = linux_is_async_p ();
4528 if (previous != enable)
4532 /* Block child signals while we create/destroy the pipe, as
4533 their handler writes to it. */
4534 block_child_signals (&prev_mask);
4538 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4539 internal_error (__FILE__, __LINE__,
4540 "creating event pipe failed.");
4542 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4543 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4547 close (linux_nat_event_pipe[0]);
4548 close (linux_nat_event_pipe[1]);
4549 linux_nat_event_pipe[0] = -1;
4550 linux_nat_event_pipe[1] = -1;
4553 restore_child_signals_mask (&prev_mask);
4559 /* target_async implementation. */
4562 linux_nat_async (struct target_ops *ops, int enable)
4566 if (!linux_async_pipe (1))
4568 add_file_handler (linux_nat_event_pipe[0],
4569 handle_target_event, NULL);
4570 /* There may be pending events to handle. Tell the event loop
4577 delete_file_handler (linux_nat_event_pipe[0]);
4578 linux_async_pipe (0);
4583 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4587 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4591 if (debug_linux_nat)
4592 fprintf_unfiltered (gdb_stdlog,
4593 "LNSL: running -> suspending %s\n",
4594 target_pid_to_str (lwp->ptid));
4597 if (lwp->last_resume_kind == resume_stop)
4599 if (debug_linux_nat)
4600 fprintf_unfiltered (gdb_stdlog,
4601 "linux-nat: already stopping LWP %ld at "
4603 ptid_get_lwp (lwp->ptid));
4607 stop_callback (lwp, NULL);
4608 lwp->last_resume_kind = resume_stop;
4612 /* Already known to be stopped; do nothing. */
4614 if (debug_linux_nat)
4616 if (find_thread_ptid (lwp->ptid)->stop_requested)
4617 fprintf_unfiltered (gdb_stdlog,
4618 "LNSL: already stopped/stop_requested %s\n",
4619 target_pid_to_str (lwp->ptid));
4621 fprintf_unfiltered (gdb_stdlog,
4622 "LNSL: already stopped/no "
4623 "stop_requested yet %s\n",
4624 target_pid_to_str (lwp->ptid));
4631 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4633 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4637 linux_nat_close (struct target_ops *self)
4639 /* Unregister from the event loop. */
4640 if (linux_nat_is_async_p (self))
4641 linux_nat_async (self, 0);
4643 if (linux_ops->to_close)
4644 linux_ops->to_close (linux_ops);
4649 /* When requests are passed down from the linux-nat layer to the
4650 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4651 used. The address space pointer is stored in the inferior object,
4652 but the common code that is passed such ptid can't tell whether
4653 lwpid is a "main" process id or not (it assumes so). We reverse
4654 look up the "main" process id from the lwp here. */
4656 static struct address_space *
4657 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4659 struct lwp_info *lwp;
4660 struct inferior *inf;
4663 if (ptid_get_lwp (ptid) == 0)
4665 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4667 lwp = find_lwp_pid (ptid);
4668 pid = ptid_get_pid (lwp->ptid);
4672 /* A (pid,lwpid,0) ptid. */
4673 pid = ptid_get_pid (ptid);
4676 inf = find_inferior_pid (pid);
4677 gdb_assert (inf != NULL);
4681 /* Return the cached value of the processor core for thread PTID. */
4684 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4686 struct lwp_info *info = find_lwp_pid (ptid);
4693 /* Implementation of to_filesystem_is_local. */
4696 linux_nat_filesystem_is_local (struct target_ops *ops)
4698 struct inferior *inf = current_inferior ();
4700 if (inf->fake_pid_p || inf->pid == 0)
4703 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4706 /* Convert the INF argument passed to a to_fileio_* method
4707 to a process ID suitable for passing to its corresponding
4708 linux_mntns_* function. If INF is non-NULL then the
4709 caller is requesting the filesystem seen by INF. If INF
4710 is NULL then the caller is requesting the filesystem seen
4711 by the GDB. We fall back to GDB's filesystem in the case
4712 that INF is non-NULL but its PID is unknown. */
4715 linux_nat_fileio_pid_of (struct inferior *inf)
4717 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4723 /* Implementation of to_fileio_open. */
4726 linux_nat_fileio_open (struct target_ops *self,
4727 struct inferior *inf, const char *filename,
4728 int flags, int mode, int warn_if_slow,
4735 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4736 || fileio_to_host_mode (mode, &nat_mode) == -1)
4738 *target_errno = FILEIO_EINVAL;
4742 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4743 filename, nat_flags, nat_mode);
4745 *target_errno = host_to_fileio_error (errno);
4750 /* Implementation of to_fileio_readlink. */
4753 linux_nat_fileio_readlink (struct target_ops *self,
4754 struct inferior *inf, const char *filename,
4761 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4762 filename, buf, sizeof (buf));
4765 *target_errno = host_to_fileio_error (errno);
4769 ret = (char *) xmalloc (len + 1);
4770 memcpy (ret, buf, len);
4775 /* Implementation of to_fileio_unlink. */
4778 linux_nat_fileio_unlink (struct target_ops *self,
4779 struct inferior *inf, const char *filename,
4784 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4787 *target_errno = host_to_fileio_error (errno);
4792 /* Implementation of the to_thread_events method. */
4795 linux_nat_thread_events (struct target_ops *ops, int enable)
4797 report_thread_events = enable;
4801 linux_nat_add_target (struct target_ops *t)
4803 /* Save the provided single-threaded target. We save this in a separate
4804 variable because another target we've inherited from (e.g. inf-ptrace)
4805 may have saved a pointer to T; we want to use it for the final
4806 process stratum target. */
4807 linux_ops_saved = *t;
4808 linux_ops = &linux_ops_saved;
4810 /* Override some methods for multithreading. */
4811 t->to_create_inferior = linux_nat_create_inferior;
4812 t->to_attach = linux_nat_attach;
4813 t->to_detach = linux_nat_detach;
4814 t->to_resume = linux_nat_resume;
4815 t->to_wait = linux_nat_wait;
4816 t->to_pass_signals = linux_nat_pass_signals;
4817 t->to_xfer_partial = linux_nat_xfer_partial;
4818 t->to_kill = linux_nat_kill;
4819 t->to_mourn_inferior = linux_nat_mourn_inferior;
4820 t->to_thread_alive = linux_nat_thread_alive;
4821 t->to_update_thread_list = linux_nat_update_thread_list;
4822 t->to_pid_to_str = linux_nat_pid_to_str;
4823 t->to_thread_name = linux_nat_thread_name;
4824 t->to_has_thread_control = tc_schedlock;
4825 t->to_thread_address_space = linux_nat_thread_address_space;
4826 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4827 t->to_stopped_data_address = linux_nat_stopped_data_address;
4828 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4829 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4830 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4831 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4832 t->to_thread_events = linux_nat_thread_events;
4834 t->to_can_async_p = linux_nat_can_async_p;
4835 t->to_is_async_p = linux_nat_is_async_p;
4836 t->to_supports_non_stop = linux_nat_supports_non_stop;
4837 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4838 t->to_async = linux_nat_async;
4839 t->to_terminal_inferior = linux_nat_terminal_inferior;
4840 t->to_terminal_ours = linux_nat_terminal_ours;
4842 super_close = t->to_close;
4843 t->to_close = linux_nat_close;
4845 t->to_stop = linux_nat_stop;
4847 t->to_supports_multi_process = linux_nat_supports_multi_process;
4849 t->to_supports_disable_randomization
4850 = linux_nat_supports_disable_randomization;
4852 t->to_core_of_thread = linux_nat_core_of_thread;
4854 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4855 t->to_fileio_open = linux_nat_fileio_open;
4856 t->to_fileio_readlink = linux_nat_fileio_readlink;
4857 t->to_fileio_unlink = linux_nat_fileio_unlink;
4859 /* We don't change the stratum; this target will sit at
4860 process_stratum and thread_db will set at thread_stratum. This
4861 is a little strange, since this is a multi-threaded-capable
4862 target, but we want to be on the stack below thread_db, and we
4863 also want to be used for single-threaded processes. */
4868 /* Register a method to call whenever a new thread is attached. */
4870 linux_nat_set_new_thread (struct target_ops *t,
4871 void (*new_thread) (struct lwp_info *))
4873 /* Save the pointer. We only support a single registered instance
4874 of the GNU/Linux native target, so we do not need to map this to
4876 linux_nat_new_thread = new_thread;
4879 /* Register a method to call whenever a new thread is attached. */
4881 linux_nat_set_delete_thread (struct target_ops *t,
4882 void (*delete_thread) (struct arch_lwp_info *))
4884 /* Save the pointer. We only support a single registered instance
4885 of the GNU/Linux native target, so we do not need to map this to
4887 linux_nat_delete_thread = delete_thread;
4890 /* See declaration in linux-nat.h. */
4893 linux_nat_set_new_fork (struct target_ops *t,
4894 linux_nat_new_fork_ftype *new_fork)
4896 /* Save the pointer. */
4897 linux_nat_new_fork = new_fork;
4900 /* See declaration in linux-nat.h. */
4903 linux_nat_set_forget_process (struct target_ops *t,
4904 linux_nat_forget_process_ftype *fn)
4906 /* Save the pointer. */
4907 linux_nat_forget_process_hook = fn;
4910 /* See declaration in linux-nat.h. */
4913 linux_nat_forget_process (pid_t pid)
4915 if (linux_nat_forget_process_hook != NULL)
4916 linux_nat_forget_process_hook (pid);
4919 /* Register a method that converts a siginfo object between the layout
4920 that ptrace returns, and the layout in the architecture of the
4923 linux_nat_set_siginfo_fixup (struct target_ops *t,
4924 int (*siginfo_fixup) (siginfo_t *,
4928 /* Save the pointer. */
4929 linux_nat_siginfo_fixup = siginfo_fixup;
4932 /* Register a method to call prior to resuming a thread. */
4935 linux_nat_set_prepare_to_resume (struct target_ops *t,
4936 void (*prepare_to_resume) (struct lwp_info *))
4938 /* Save the pointer. */
4939 linux_nat_prepare_to_resume = prepare_to_resume;
4942 /* See linux-nat.h. */
4945 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4949 pid = ptid_get_lwp (ptid);
4951 pid = ptid_get_pid (ptid);
4954 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4957 memset (siginfo, 0, sizeof (*siginfo));
4963 /* See nat/linux-nat.h. */
4966 current_lwp_ptid (void)
4968 gdb_assert (ptid_lwp_p (inferior_ptid));
4969 return inferior_ptid;
4973 _initialize_linux_nat (void)
4975 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4976 &debug_linux_nat, _("\
4977 Set debugging of GNU/Linux lwp module."), _("\
4978 Show debugging of GNU/Linux lwp module."), _("\
4979 Enables printf debugging output."),
4981 show_debug_linux_nat,
4982 &setdebuglist, &showdebuglist);
4984 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4985 &debug_linux_namespaces, _("\
4986 Set debugging of GNU/Linux namespaces module."), _("\
4987 Show debugging of GNU/Linux namespaces module."), _("\
4988 Enables printf debugging output."),
4991 &setdebuglist, &showdebuglist);
4993 /* Save this mask as the default. */
4994 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4996 /* Install a SIGCHLD handler. */
4997 sigchld_action.sa_handler = sigchld_handler;
4998 sigemptyset (&sigchld_action.sa_mask);
4999 sigchld_action.sa_flags = SA_RESTART;
5001 /* Make it the default. */
5002 sigaction (SIGCHLD, &sigchld_action, NULL);
5004 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5005 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5006 sigdelset (&suspend_mask, SIGCHLD);
5008 sigemptyset (&blocked_mask);
5010 lwp_lwpid_htab_create ();
5014 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5015 the GNU/Linux Threads library and therefore doesn't really belong
5018 /* Return the set of signals used by the threads library in *SET. */
5021 lin_thread_get_thread_signals (sigset_t *set)
5025 /* NPTL reserves the first two RT signals, but does not provide any
5026 way for the debugger to query the signal numbers - fortunately
5027 they don't change. */
5028 sigaddset (set, __SIGRTMIN);
5029 sigaddset (set, __SIGRTMIN + 1);