1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2017 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops *linux_ops;
195 static struct target_ops linux_ops_saved;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread) (struct lwp_info *);
200 /* The method to call, if any, when a new fork is attached. */
201 static linux_nat_new_fork_ftype *linux_nat_new_fork;
203 /* The method to call, if any, when a process is no longer
205 static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
207 /* Hook to call prior to resuming a thread. */
208 static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
210 /* The method to call, if any, when the siginfo object needs to be
211 converted between the layout returned by ptrace, and the layout in
212 the architecture of the inferior. */
213 static int (*linux_nat_siginfo_fixup) (siginfo_t *,
217 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
218 Called by our to_xfer_partial. */
219 static target_xfer_partial_ftype *super_xfer_partial;
221 /* The saved to_close method, inherited from inf-ptrace.c.
222 Called by our to_close. */
223 static void (*super_close) (struct target_ops *);
225 static unsigned int debug_linux_nat;
227 show_debug_linux_nat (struct ui_file *file, int from_tty,
228 struct cmd_list_element *c, const char *value)
230 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 struct simple_pid_list
238 struct simple_pid_list *next;
240 struct simple_pid_list *stopped_pids;
242 /* Whether target_thread_events is in effect. */
243 static int report_thread_events;
245 /* Async mode support. */
247 /* The read/write ends of the pipe registered as waitable file in the
249 static int linux_nat_event_pipe[2] = { -1, -1 };
251 /* True if we're currently in async mode. */
252 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
254 /* Flush the event pipe. */
257 async_file_flush (void)
264 ret = read (linux_nat_event_pipe[0], &buf, 1);
266 while (ret >= 0 || (ret == -1 && errno == EINTR));
269 /* Put something (anything, doesn't matter what, or how much) in event
270 pipe, so that the select/poll in the event-loop realizes we have
271 something to process. */
274 async_file_mark (void)
278 /* It doesn't really matter what the pipe contains, as long we end
279 up with something in it. Might as well flush the previous
285 ret = write (linux_nat_event_pipe[1], "+", 1);
287 while (ret == -1 && errno == EINTR);
289 /* Ignore EAGAIN. If the pipe is full, the event loop will already
290 be awakened anyway. */
293 static int kill_lwp (int lwpid, int signo);
295 static int stop_callback (struct lwp_info *lp, void *data);
296 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
298 static void block_child_signals (sigset_t *prev_mask);
299 static void restore_child_signals_mask (sigset_t *prev_mask);
302 static struct lwp_info *add_lwp (ptid_t ptid);
303 static void purge_lwp_list (int pid);
304 static void delete_lwp (ptid_t ptid);
305 static struct lwp_info *find_lwp_pid (ptid_t ptid);
307 static int lwp_status_pending_p (struct lwp_info *lp);
309 static int sigtrap_is_event (int status);
310 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
312 static void save_stop_reason (struct lwp_info *lp);
317 /* See nat/linux-nat.h. */
320 ptid_of_lwp (struct lwp_info *lwp)
325 /* See nat/linux-nat.h. */
328 lwp_set_arch_private_info (struct lwp_info *lwp,
329 struct arch_lwp_info *info)
331 lwp->arch_private = info;
334 /* See nat/linux-nat.h. */
336 struct arch_lwp_info *
337 lwp_arch_private_info (struct lwp_info *lwp)
339 return lwp->arch_private;
342 /* See nat/linux-nat.h. */
345 lwp_is_stopped (struct lwp_info *lwp)
350 /* See nat/linux-nat.h. */
352 enum target_stop_reason
353 lwp_stop_reason (struct lwp_info *lwp)
355 return lwp->stop_reason;
358 /* See nat/linux-nat.h. */
361 lwp_is_stepping (struct lwp_info *lwp)
367 /* Trivial list manipulation functions to keep track of a list of
368 new stopped processes. */
370 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
372 struct simple_pid_list *new_pid = XNEW (struct simple_pid_list);
375 new_pid->status = status;
376 new_pid->next = *listp;
381 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
383 struct simple_pid_list **p;
385 for (p = listp; *p != NULL; p = &(*p)->next)
386 if ((*p)->pid == pid)
388 struct simple_pid_list *next = (*p)->next;
390 *statusp = (*p)->status;
398 /* Return the ptrace options that we want to try to enable. */
401 linux_nat_ptrace_options (int attached)
406 options |= PTRACE_O_EXITKILL;
408 options |= (PTRACE_O_TRACESYSGOOD
409 | PTRACE_O_TRACEVFORKDONE
410 | PTRACE_O_TRACEVFORK
412 | PTRACE_O_TRACEEXEC);
417 /* Initialize ptrace warnings and check for supported ptrace
420 ATTACHED should be nonzero iff we attached to the inferior. */
423 linux_init_ptrace (pid_t pid, int attached)
425 int options = linux_nat_ptrace_options (attached);
427 linux_enable_event_reporting (pid, options);
428 linux_ptrace_init_warnings ();
432 linux_child_post_attach (struct target_ops *self, int pid)
434 linux_init_ptrace (pid, 1);
438 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
440 linux_init_ptrace (ptid_get_pid (ptid), 0);
443 /* Return the number of known LWPs in the tgid given by PID. */
451 for (lp = lwp_list; lp; lp = lp->next)
452 if (ptid_get_pid (lp->ptid) == pid)
458 /* Call delete_lwp with prototype compatible for make_cleanup. */
461 delete_lwp_cleanup (void *lp_voidp)
463 struct lwp_info *lp = (struct lwp_info *) lp_voidp;
465 delete_lwp (lp->ptid);
468 /* Target hook for follow_fork. On entry inferior_ptid must be the
469 ptid of the followed inferior. At return, inferior_ptid will be
473 linux_child_follow_fork (struct target_ops *ops, int follow_child,
478 struct lwp_info *child_lp = NULL;
479 int status = W_STOPCODE (0);
481 ptid_t parent_ptid, child_ptid;
482 int parent_pid, child_pid;
484 has_vforked = (inferior_thread ()->pending_follow.kind
485 == TARGET_WAITKIND_VFORKED);
486 parent_ptid = inferior_ptid;
487 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
488 parent_pid = ptid_get_lwp (parent_ptid);
489 child_pid = ptid_get_lwp (child_ptid);
491 /* We're already attached to the parent, by default. */
492 child_lp = add_lwp (child_ptid);
493 child_lp->stopped = 1;
494 child_lp->last_resume_kind = resume_stop;
496 /* Detach new forked process? */
499 struct cleanup *old_chain = make_cleanup (delete_lwp_cleanup,
502 if (linux_nat_prepare_to_resume != NULL)
503 linux_nat_prepare_to_resume (child_lp);
505 /* When debugging an inferior in an architecture that supports
506 hardware single stepping on a kernel without commit
507 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
508 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
509 set if the parent process had them set.
510 To work around this, single step the child process
511 once before detaching to clear the flags. */
513 /* Note that we consult the parent's architecture instead of
514 the child's because there's no inferior for the child at
516 if (!gdbarch_software_single_step_p (target_thread_architecture
519 linux_disable_event_reporting (child_pid);
520 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
521 perror_with_name (_("Couldn't do single step"));
522 if (my_waitpid (child_pid, &status, 0) < 0)
523 perror_with_name (_("Couldn't wait vfork process"));
526 if (WIFSTOPPED (status))
530 signo = WSTOPSIG (status);
532 && !signal_pass_state (gdb_signal_from_host (signo)))
534 ptrace (PTRACE_DETACH, child_pid, 0, signo);
537 do_cleanups (old_chain);
541 scoped_restore save_inferior_ptid
542 = make_scoped_restore (&inferior_ptid);
543 inferior_ptid = child_ptid;
545 /* Let the thread_db layer learn about this new process. */
546 check_for_thread_db ();
551 struct lwp_info *parent_lp;
553 parent_lp = find_lwp_pid (parent_ptid);
554 gdb_assert (linux_supports_tracefork () >= 0);
556 if (linux_supports_tracevforkdone ())
559 fprintf_unfiltered (gdb_stdlog,
560 "LCFF: waiting for VFORK_DONE on %d\n",
562 parent_lp->stopped = 1;
564 /* We'll handle the VFORK_DONE event like any other
565 event, in target_wait. */
569 /* We can't insert breakpoints until the child has
570 finished with the shared memory region. We need to
571 wait until that happens. Ideal would be to just
573 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
574 - waitpid (parent_pid, &status, __WALL);
575 However, most architectures can't handle a syscall
576 being traced on the way out if it wasn't traced on
579 We might also think to loop, continuing the child
580 until it exits or gets a SIGTRAP. One problem is
581 that the child might call ptrace with PTRACE_TRACEME.
583 There's no simple and reliable way to figure out when
584 the vforked child will be done with its copy of the
585 shared memory. We could step it out of the syscall,
586 two instructions, let it go, and then single-step the
587 parent once. When we have hardware single-step, this
588 would work; with software single-step it could still
589 be made to work but we'd have to be able to insert
590 single-step breakpoints in the child, and we'd have
591 to insert -just- the single-step breakpoint in the
592 parent. Very awkward.
594 In the end, the best we can do is to make sure it
595 runs for a little while. Hopefully it will be out of
596 range of any breakpoints we reinsert. Usually this
597 is only the single-step breakpoint at vfork's return
601 fprintf_unfiltered (gdb_stdlog,
602 "LCFF: no VFORK_DONE "
603 "support, sleeping a bit\n");
607 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
608 and leave it pending. The next linux_nat_resume call
609 will notice a pending event, and bypasses actually
610 resuming the inferior. */
611 parent_lp->status = 0;
612 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
613 parent_lp->stopped = 1;
615 /* If we're in async mode, need to tell the event loop
616 there's something here to process. */
617 if (target_is_async_p ())
624 struct lwp_info *child_lp;
626 child_lp = add_lwp (inferior_ptid);
627 child_lp->stopped = 1;
628 child_lp->last_resume_kind = resume_stop;
630 /* Let the thread_db layer learn about this new process. */
631 check_for_thread_db ();
639 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
641 return !linux_supports_tracefork ();
645 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
651 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
653 return !linux_supports_tracefork ();
657 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
663 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
665 return !linux_supports_tracefork ();
669 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
675 linux_child_set_syscall_catchpoint (struct target_ops *self,
676 int pid, int needed, int any_count,
677 int table_size, int *table)
679 if (!linux_supports_tracesysgood ())
682 /* On GNU/Linux, we ignore the arguments. It means that we only
683 enable the syscall catchpoints, but do not disable them.
685 Also, we do not use the `table' information because we do not
686 filter system calls here. We let GDB do the logic for us. */
690 /* List of known LWPs, keyed by LWP PID. This speeds up the common
691 case of mapping a PID returned from the kernel to our corresponding
692 lwp_info data structure. */
693 static htab_t lwp_lwpid_htab;
695 /* Calculate a hash from a lwp_info's LWP PID. */
698 lwp_info_hash (const void *ap)
700 const struct lwp_info *lp = (struct lwp_info *) ap;
701 pid_t pid = ptid_get_lwp (lp->ptid);
703 return iterative_hash_object (pid, 0);
706 /* Equality function for the lwp_info hash table. Compares the LWP's
710 lwp_lwpid_htab_eq (const void *a, const void *b)
712 const struct lwp_info *entry = (const struct lwp_info *) a;
713 const struct lwp_info *element = (const struct lwp_info *) b;
715 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
718 /* Create the lwp_lwpid_htab hash table. */
721 lwp_lwpid_htab_create (void)
723 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
726 /* Add LP to the hash table. */
729 lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
733 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
734 gdb_assert (slot != NULL && *slot == NULL);
738 /* Head of doubly-linked list of known LWPs. Sorted by reverse
739 creation order. This order is assumed in some cases. E.g.,
740 reaping status after killing alls lwps of a process: the leader LWP
741 must be reaped last. */
742 struct lwp_info *lwp_list;
744 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
747 lwp_list_add (struct lwp_info *lp)
750 if (lwp_list != NULL)
755 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
759 lwp_list_remove (struct lwp_info *lp)
761 /* Remove from sorted-by-creation-order list. */
762 if (lp->next != NULL)
763 lp->next->prev = lp->prev;
764 if (lp->prev != NULL)
765 lp->prev->next = lp->next;
772 /* Original signal mask. */
773 static sigset_t normal_mask;
775 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
776 _initialize_linux_nat. */
777 static sigset_t suspend_mask;
779 /* Signals to block to make that sigsuspend work. */
780 static sigset_t blocked_mask;
782 /* SIGCHLD action. */
783 struct sigaction sigchld_action;
785 /* Block child signals (SIGCHLD and linux threads signals), and store
786 the previous mask in PREV_MASK. */
789 block_child_signals (sigset_t *prev_mask)
791 /* Make sure SIGCHLD is blocked. */
792 if (!sigismember (&blocked_mask, SIGCHLD))
793 sigaddset (&blocked_mask, SIGCHLD);
795 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
798 /* Restore child signals mask, previously returned by
799 block_child_signals. */
802 restore_child_signals_mask (sigset_t *prev_mask)
804 sigprocmask (SIG_SETMASK, prev_mask, NULL);
807 /* Mask of signals to pass directly to the inferior. */
808 static sigset_t pass_mask;
810 /* Update signals to pass to the inferior. */
812 linux_nat_pass_signals (struct target_ops *self,
813 int numsigs, unsigned char *pass_signals)
817 sigemptyset (&pass_mask);
819 for (signo = 1; signo < NSIG; signo++)
821 int target_signo = gdb_signal_from_host (signo);
822 if (target_signo < numsigs && pass_signals[target_signo])
823 sigaddset (&pass_mask, signo);
829 /* Prototypes for local functions. */
830 static int stop_wait_callback (struct lwp_info *lp, void *data);
831 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
832 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
833 static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
837 /* Destroy and free LP. */
840 lwp_free (struct lwp_info *lp)
842 xfree (lp->arch_private);
846 /* Traversal function for purge_lwp_list. */
849 lwp_lwpid_htab_remove_pid (void **slot, void *info)
851 struct lwp_info *lp = (struct lwp_info *) *slot;
852 int pid = *(int *) info;
854 if (ptid_get_pid (lp->ptid) == pid)
856 htab_clear_slot (lwp_lwpid_htab, slot);
857 lwp_list_remove (lp);
864 /* Remove all LWPs belong to PID from the lwp list. */
867 purge_lwp_list (int pid)
869 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
872 /* Add the LWP specified by PTID to the list. PTID is the first LWP
873 in the process. Return a pointer to the structure describing the
876 This differs from add_lwp in that we don't let the arch specific
877 bits know about this new thread. Current clients of this callback
878 take the opportunity to install watchpoints in the new thread, and
879 we shouldn't do that for the first thread. If we're spawning a
880 child ("run"), the thread executes the shell wrapper first, and we
881 shouldn't touch it until it execs the program we want to debug.
882 For "attach", it'd be okay to call the callback, but it's not
883 necessary, because watchpoints can't yet have been inserted into
886 static struct lwp_info *
887 add_initial_lwp (ptid_t ptid)
891 gdb_assert (ptid_lwp_p (ptid));
893 lp = XNEW (struct lwp_info);
895 memset (lp, 0, sizeof (struct lwp_info));
897 lp->last_resume_kind = resume_continue;
898 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
903 /* Add to sorted-by-reverse-creation-order list. */
906 /* Add to keyed-by-pid htab. */
907 lwp_lwpid_htab_add_lwp (lp);
912 /* Add the LWP specified by PID to the list. Return a pointer to the
913 structure describing the new LWP. The LWP should already be
916 static struct lwp_info *
917 add_lwp (ptid_t ptid)
921 lp = add_initial_lwp (ptid);
923 /* Let the arch specific bits know about this new thread. Current
924 clients of this callback take the opportunity to install
925 watchpoints in the new thread. We don't do this for the first
926 thread though. See add_initial_lwp. */
927 if (linux_nat_new_thread != NULL)
928 linux_nat_new_thread (lp);
933 /* Remove the LWP specified by PID from the list. */
936 delete_lwp (ptid_t ptid)
940 struct lwp_info dummy;
943 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
947 lp = *(struct lwp_info **) slot;
948 gdb_assert (lp != NULL);
950 htab_clear_slot (lwp_lwpid_htab, slot);
952 /* Remove from sorted-by-creation-order list. */
953 lwp_list_remove (lp);
959 /* Return a pointer to the structure describing the LWP corresponding
960 to PID. If no corresponding LWP could be found, return NULL. */
962 static struct lwp_info *
963 find_lwp_pid (ptid_t ptid)
967 struct lwp_info dummy;
969 if (ptid_lwp_p (ptid))
970 lwp = ptid_get_lwp (ptid);
972 lwp = ptid_get_pid (ptid);
974 dummy.ptid = ptid_build (0, lwp, 0);
975 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
979 /* See nat/linux-nat.h. */
982 iterate_over_lwps (ptid_t filter,
983 iterate_over_lwps_ftype callback,
986 struct lwp_info *lp, *lpnext;
988 for (lp = lwp_list; lp; lp = lpnext)
992 if (ptid_match (lp->ptid, filter))
994 if ((*callback) (lp, data) != 0)
1002 /* Update our internal state when changing from one checkpoint to
1003 another indicated by NEW_PTID. We can only switch single-threaded
1004 applications, so we only create one new LWP, and the previous list
1008 linux_nat_switch_fork (ptid_t new_ptid)
1010 struct lwp_info *lp;
1012 purge_lwp_list (ptid_get_pid (inferior_ptid));
1014 lp = add_lwp (new_ptid);
1017 /* This changes the thread's ptid while preserving the gdb thread
1018 num. Also changes the inferior pid, while preserving the
1020 thread_change_ptid (inferior_ptid, new_ptid);
1022 /* We've just told GDB core that the thread changed target id, but,
1023 in fact, it really is a different thread, with different register
1025 registers_changed ();
1028 /* Handle the exit of a single thread LP. */
1031 exit_lwp (struct lwp_info *lp)
1033 struct thread_info *th = find_thread_ptid (lp->ptid);
1037 if (print_thread_events)
1038 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1040 delete_thread (lp->ptid);
1043 delete_lwp (lp->ptid);
1046 /* Wait for the LWP specified by LP, which we have just attached to.
1047 Returns a wait status for that LWP, to cache. */
1050 linux_nat_post_attach_wait (ptid_t ptid, int *signalled)
1052 pid_t new_pid, pid = ptid_get_lwp (ptid);
1055 if (linux_proc_pid_is_stopped (pid))
1057 if (debug_linux_nat)
1058 fprintf_unfiltered (gdb_stdlog,
1059 "LNPAW: Attaching to a stopped process\n");
1061 /* The process is definitely stopped. It is in a job control
1062 stop, unless the kernel predates the TASK_STOPPED /
1063 TASK_TRACED distinction, in which case it might be in a
1064 ptrace stop. Make sure it is in a ptrace stop; from there we
1065 can kill it, signal it, et cetera.
1067 First make sure there is a pending SIGSTOP. Since we are
1068 already attached, the process can not transition from stopped
1069 to running without a PTRACE_CONT; so we know this signal will
1070 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1071 probably already in the queue (unless this kernel is old
1072 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1073 is not an RT signal, it can only be queued once. */
1074 kill_lwp (pid, SIGSTOP);
1076 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1077 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1078 ptrace (PTRACE_CONT, pid, 0, 0);
1081 /* Make sure the initial process is stopped. The user-level threads
1082 layer might want to poke around in the inferior, and that won't
1083 work if things haven't stabilized yet. */
1084 new_pid = my_waitpid (pid, &status, __WALL);
1085 gdb_assert (pid == new_pid);
1087 if (!WIFSTOPPED (status))
1089 /* The pid we tried to attach has apparently just exited. */
1090 if (debug_linux_nat)
1091 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1092 pid, status_to_str (status));
1096 if (WSTOPSIG (status) != SIGSTOP)
1099 if (debug_linux_nat)
1100 fprintf_unfiltered (gdb_stdlog,
1101 "LNPAW: Received %s after attaching\n",
1102 status_to_str (status));
1109 linux_nat_create_inferior (struct target_ops *ops,
1110 const char *exec_file, const std::string &allargs,
1111 char **env, int from_tty)
1113 struct cleanup *restore_personality
1114 = maybe_disable_address_space_randomization (disable_randomization);
1116 /* The fork_child mechanism is synchronous and calls target_wait, so
1117 we have to mask the async mode. */
1119 /* Make sure we report all signals during startup. */
1120 linux_nat_pass_signals (ops, 0, NULL);
1122 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1124 do_cleanups (restore_personality);
1127 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1128 already attached. Returns true if a new LWP is found, false
1132 attach_proc_task_lwp_callback (ptid_t ptid)
1134 struct lwp_info *lp;
1136 /* Ignore LWPs we're already attached to. */
1137 lp = find_lwp_pid (ptid);
1140 int lwpid = ptid_get_lwp (ptid);
1142 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1146 /* Be quiet if we simply raced with the thread exiting.
1147 EPERM is returned if the thread's task still exists, and
1148 is marked as exited or zombie, as well as other
1149 conditions, so in that case, confirm the status in
1150 /proc/PID/status. */
1152 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1154 if (debug_linux_nat)
1156 fprintf_unfiltered (gdb_stdlog,
1157 "Cannot attach to lwp %d: "
1158 "thread is gone (%d: %s)\n",
1159 lwpid, err, safe_strerror (err));
1164 warning (_("Cannot attach to lwp %d: %s"),
1166 linux_ptrace_attach_fail_reason_string (ptid,
1172 if (debug_linux_nat)
1173 fprintf_unfiltered (gdb_stdlog,
1174 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1175 target_pid_to_str (ptid));
1177 lp = add_lwp (ptid);
1179 /* The next time we wait for this LWP we'll see a SIGSTOP as
1180 PTRACE_ATTACH brings it to a halt. */
1183 /* We need to wait for a stop before being able to make the
1184 next ptrace call on this LWP. */
1185 lp->must_set_ptrace_flags = 1;
1187 /* So that wait collects the SIGSTOP. */
1190 /* Also add the LWP to gdb's thread list, in case a
1191 matching libthread_db is not found (or the process uses
1193 add_thread (lp->ptid);
1194 set_running (lp->ptid, 1);
1195 set_executing (lp->ptid, 1);
1204 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1206 struct lwp_info *lp;
1210 /* Make sure we report all signals during attach. */
1211 linux_nat_pass_signals (ops, 0, NULL);
1215 linux_ops->to_attach (ops, args, from_tty);
1217 CATCH (ex, RETURN_MASK_ERROR)
1219 pid_t pid = parse_pid_to_attach (args);
1220 struct buffer buffer;
1221 char *message, *buffer_s;
1223 message = xstrdup (ex.message);
1224 make_cleanup (xfree, message);
1226 buffer_init (&buffer);
1227 linux_ptrace_attach_fail_reason (pid, &buffer);
1229 buffer_grow_str0 (&buffer, "");
1230 buffer_s = buffer_finish (&buffer);
1231 make_cleanup (xfree, buffer_s);
1233 if (*buffer_s != '\0')
1234 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1236 throw_error (ex.error, "%s", message);
1240 /* The ptrace base target adds the main thread with (pid,0,0)
1241 format. Decorate it with lwp info. */
1242 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1243 ptid_get_pid (inferior_ptid),
1245 thread_change_ptid (inferior_ptid, ptid);
1247 /* Add the initial process as the first LWP to the list. */
1248 lp = add_initial_lwp (ptid);
1250 status = linux_nat_post_attach_wait (lp->ptid, &lp->signalled);
1251 if (!WIFSTOPPED (status))
1253 if (WIFEXITED (status))
1255 int exit_code = WEXITSTATUS (status);
1257 target_terminal::ours ();
1258 target_mourn_inferior (inferior_ptid);
1260 error (_("Unable to attach: program exited normally."));
1262 error (_("Unable to attach: program exited with code %d."),
1265 else if (WIFSIGNALED (status))
1267 enum gdb_signal signo;
1269 target_terminal::ours ();
1270 target_mourn_inferior (inferior_ptid);
1272 signo = gdb_signal_from_host (WTERMSIG (status));
1273 error (_("Unable to attach: program terminated with signal "
1275 gdb_signal_to_name (signo),
1276 gdb_signal_to_string (signo));
1279 internal_error (__FILE__, __LINE__,
1280 _("unexpected status %d for PID %ld"),
1281 status, (long) ptid_get_lwp (ptid));
1286 /* Save the wait status to report later. */
1288 if (debug_linux_nat)
1289 fprintf_unfiltered (gdb_stdlog,
1290 "LNA: waitpid %ld, saving status %s\n",
1291 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1293 lp->status = status;
1295 /* We must attach to every LWP. If /proc is mounted, use that to
1296 find them now. The inferior may be using raw clone instead of
1297 using pthreads. But even if it is using pthreads, thread_db
1298 walks structures in the inferior's address space to find the list
1299 of threads/LWPs, and those structures may well be corrupted.
1300 Note that once thread_db is loaded, we'll still use it to list
1301 threads and associate pthread info with each LWP. */
1302 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1303 attach_proc_task_lwp_callback);
1305 if (target_can_async_p ())
1309 /* Get pending signal of THREAD as a host signal number, for detaching
1310 purposes. This is the signal the thread last stopped for, which we
1311 need to deliver to the thread when detaching, otherwise, it'd be
1315 get_detach_signal (struct lwp_info *lp)
1317 enum gdb_signal signo = GDB_SIGNAL_0;
1319 /* If we paused threads momentarily, we may have stored pending
1320 events in lp->status or lp->waitstatus (see stop_wait_callback),
1321 and GDB core hasn't seen any signal for those threads.
1322 Otherwise, the last signal reported to the core is found in the
1323 thread object's stop_signal.
1325 There's a corner case that isn't handled here at present. Only
1326 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1327 stop_signal make sense as a real signal to pass to the inferior.
1328 Some catchpoint related events, like
1329 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1330 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1331 those traps are debug API (ptrace in our case) related and
1332 induced; the inferior wouldn't see them if it wasn't being
1333 traced. Hence, we should never pass them to the inferior, even
1334 when set to pass state. Since this corner case isn't handled by
1335 infrun.c when proceeding with a signal, for consistency, neither
1336 do we handle it here (or elsewhere in the file we check for
1337 signal pass state). Normally SIGTRAP isn't set to pass state, so
1338 this is really a corner case. */
1340 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1341 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1342 else if (lp->status)
1343 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1344 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1346 struct thread_info *tp = find_thread_ptid (lp->ptid);
1348 if (tp->suspend.waitstatus_pending_p)
1349 signo = tp->suspend.waitstatus.value.sig;
1351 signo = tp->suspend.stop_signal;
1353 else if (!target_is_non_stop_p ())
1355 struct target_waitstatus last;
1358 get_last_target_status (&last_ptid, &last);
1360 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1362 struct thread_info *tp = find_thread_ptid (lp->ptid);
1364 signo = tp->suspend.stop_signal;
1368 if (signo == GDB_SIGNAL_0)
1370 if (debug_linux_nat)
1371 fprintf_unfiltered (gdb_stdlog,
1372 "GPT: lwp %s has no pending signal\n",
1373 target_pid_to_str (lp->ptid));
1375 else if (!signal_pass_state (signo))
1377 if (debug_linux_nat)
1378 fprintf_unfiltered (gdb_stdlog,
1379 "GPT: lwp %s had signal %s, "
1380 "but it is in no pass state\n",
1381 target_pid_to_str (lp->ptid),
1382 gdb_signal_to_string (signo));
1386 if (debug_linux_nat)
1387 fprintf_unfiltered (gdb_stdlog,
1388 "GPT: lwp %s has pending signal %s\n",
1389 target_pid_to_str (lp->ptid),
1390 gdb_signal_to_string (signo));
1392 return gdb_signal_to_host (signo);
1398 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1399 signal number that should be passed to the LWP when detaching.
1400 Otherwise pass any pending signal the LWP may have, if any. */
1403 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1405 int lwpid = ptid_get_lwp (lp->ptid);
1408 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1410 if (debug_linux_nat && lp->status)
1411 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1412 strsignal (WSTOPSIG (lp->status)),
1413 target_pid_to_str (lp->ptid));
1415 /* If there is a pending SIGSTOP, get rid of it. */
1418 if (debug_linux_nat)
1419 fprintf_unfiltered (gdb_stdlog,
1420 "DC: Sending SIGCONT to %s\n",
1421 target_pid_to_str (lp->ptid));
1423 kill_lwp (lwpid, SIGCONT);
1427 if (signo_p == NULL)
1429 /* Pass on any pending signal for this LWP. */
1430 signo = get_detach_signal (lp);
1435 /* Preparing to resume may try to write registers, and fail if the
1436 lwp is zombie. If that happens, ignore the error. We'll handle
1437 it below, when detach fails with ESRCH. */
1440 if (linux_nat_prepare_to_resume != NULL)
1441 linux_nat_prepare_to_resume (lp);
1443 CATCH (ex, RETURN_MASK_ERROR)
1445 if (!check_ptrace_stopped_lwp_gone (lp))
1446 throw_exception (ex);
1450 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1452 int save_errno = errno;
1454 /* We know the thread exists, so ESRCH must mean the lwp is
1455 zombie. This can happen if one of the already-detached
1456 threads exits the whole thread group. In that case we're
1457 still attached, and must reap the lwp. */
1458 if (save_errno == ESRCH)
1462 ret = my_waitpid (lwpid, &status, __WALL);
1465 warning (_("Couldn't reap LWP %d while detaching: %s"),
1466 lwpid, strerror (errno));
1468 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1470 warning (_("Reaping LWP %d while detaching "
1471 "returned unexpected status 0x%x"),
1477 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1478 safe_strerror (save_errno));
1481 else if (debug_linux_nat)
1483 fprintf_unfiltered (gdb_stdlog,
1484 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1485 target_pid_to_str (lp->ptid),
1489 delete_lwp (lp->ptid);
1493 detach_callback (struct lwp_info *lp, void *data)
1495 /* We don't actually detach from the thread group leader just yet.
1496 If the thread group exits, we must reap the zombie clone lwps
1497 before we're able to reap the leader. */
1498 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1499 detach_one_lwp (lp, NULL);
1504 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1507 struct lwp_info *main_lwp;
1509 pid = ptid_get_pid (inferior_ptid);
1511 /* Don't unregister from the event loop, as there may be other
1512 inferiors running. */
1514 /* Stop all threads before detaching. ptrace requires that the
1515 thread is stopped to sucessfully detach. */
1516 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1517 /* ... and wait until all of them have reported back that
1518 they're no longer running. */
1519 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1521 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1523 /* Only the initial process should be left right now. */
1524 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1526 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1528 if (forks_exist_p ())
1530 /* Multi-fork case. The current inferior_ptid is being detached
1531 from, but there are other viable forks to debug. Detach from
1532 the current fork, and context-switch to the first
1534 linux_fork_detach (args, from_tty);
1540 target_announce_detach (from_tty);
1542 /* Pass on any pending signal for the last LWP, unless the user
1543 requested detaching with a different signal (most likely 0,
1544 meaning, discard the signal). */
1546 signo = atoi (args);
1548 signo = get_detach_signal (main_lwp);
1550 detach_one_lwp (main_lwp, &signo);
1552 inf_ptrace_detach_success (ops);
1556 /* Resume execution of the inferior process. If STEP is nonzero,
1557 single-step it. If SIGNAL is nonzero, give it that signal. */
1560 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1561 enum gdb_signal signo)
1565 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1566 We only presently need that if the LWP is stepped though (to
1567 handle the case of stepping a breakpoint instruction). */
1570 struct regcache *regcache = get_thread_regcache (lp->ptid);
1572 lp->stop_pc = regcache_read_pc (regcache);
1577 if (linux_nat_prepare_to_resume != NULL)
1578 linux_nat_prepare_to_resume (lp);
1579 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1581 /* Successfully resumed. Clear state that no longer makes sense,
1582 and mark the LWP as running. Must not do this before resuming
1583 otherwise if that fails other code will be confused. E.g., we'd
1584 later try to stop the LWP and hang forever waiting for a stop
1585 status. Note that we must not throw after this is cleared,
1586 otherwise handle_zombie_lwp_error would get confused. */
1589 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1590 registers_changed_ptid (lp->ptid);
1593 /* Called when we try to resume a stopped LWP and that errors out. If
1594 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1595 or about to become), discard the error, clear any pending status
1596 the LWP may have, and return true (we'll collect the exit status
1597 soon enough). Otherwise, return false. */
1600 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1602 /* If we get an error after resuming the LWP successfully, we'd
1603 confuse !T state for the LWP being gone. */
1604 gdb_assert (lp->stopped);
1606 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1607 because even if ptrace failed with ESRCH, the tracee may be "not
1608 yet fully dead", but already refusing ptrace requests. In that
1609 case the tracee has 'R (Running)' state for a little bit
1610 (observed in Linux 3.18). See also the note on ESRCH in the
1611 ptrace(2) man page. Instead, check whether the LWP has any state
1612 other than ptrace-stopped. */
1614 /* Don't assume anything if /proc/PID/status can't be read. */
1615 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1617 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1619 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1625 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1626 disappears while we try to resume it. */
1629 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1633 linux_resume_one_lwp_throw (lp, step, signo);
1635 CATCH (ex, RETURN_MASK_ERROR)
1637 if (!check_ptrace_stopped_lwp_gone (lp))
1638 throw_exception (ex);
1646 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1650 struct inferior *inf = find_inferior_ptid (lp->ptid);
1652 if (inf->vfork_child != NULL)
1654 if (debug_linux_nat)
1655 fprintf_unfiltered (gdb_stdlog,
1656 "RC: Not resuming %s (vfork parent)\n",
1657 target_pid_to_str (lp->ptid));
1659 else if (!lwp_status_pending_p (lp))
1661 if (debug_linux_nat)
1662 fprintf_unfiltered (gdb_stdlog,
1663 "RC: Resuming sibling %s, %s, %s\n",
1664 target_pid_to_str (lp->ptid),
1665 (signo != GDB_SIGNAL_0
1666 ? strsignal (gdb_signal_to_host (signo))
1668 step ? "step" : "resume");
1670 linux_resume_one_lwp (lp, step, signo);
1674 if (debug_linux_nat)
1675 fprintf_unfiltered (gdb_stdlog,
1676 "RC: Not resuming sibling %s (has pending)\n",
1677 target_pid_to_str (lp->ptid));
1682 if (debug_linux_nat)
1683 fprintf_unfiltered (gdb_stdlog,
1684 "RC: Not resuming sibling %s (not stopped)\n",
1685 target_pid_to_str (lp->ptid));
1689 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1690 Resume LWP with the last stop signal, if it is in pass state. */
1693 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1695 enum gdb_signal signo = GDB_SIGNAL_0;
1702 struct thread_info *thread;
1704 thread = find_thread_ptid (lp->ptid);
1707 signo = thread->suspend.stop_signal;
1708 thread->suspend.stop_signal = GDB_SIGNAL_0;
1712 resume_lwp (lp, 0, signo);
1717 resume_clear_callback (struct lwp_info *lp, void *data)
1720 lp->last_resume_kind = resume_stop;
1725 resume_set_callback (struct lwp_info *lp, void *data)
1728 lp->last_resume_kind = resume_continue;
1733 linux_nat_resume (struct target_ops *ops,
1734 ptid_t ptid, int step, enum gdb_signal signo)
1736 struct lwp_info *lp;
1739 if (debug_linux_nat)
1740 fprintf_unfiltered (gdb_stdlog,
1741 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1742 step ? "step" : "resume",
1743 target_pid_to_str (ptid),
1744 (signo != GDB_SIGNAL_0
1745 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1746 target_pid_to_str (inferior_ptid));
1748 /* A specific PTID means `step only this process id'. */
1749 resume_many = (ptid_equal (minus_one_ptid, ptid)
1750 || ptid_is_pid (ptid));
1752 /* Mark the lwps we're resuming as resumed. */
1753 iterate_over_lwps (ptid, resume_set_callback, NULL);
1755 /* See if it's the current inferior that should be handled
1758 lp = find_lwp_pid (inferior_ptid);
1760 lp = find_lwp_pid (ptid);
1761 gdb_assert (lp != NULL);
1763 /* Remember if we're stepping. */
1764 lp->last_resume_kind = step ? resume_step : resume_continue;
1766 /* If we have a pending wait status for this thread, there is no
1767 point in resuming the process. But first make sure that
1768 linux_nat_wait won't preemptively handle the event - we
1769 should never take this short-circuit if we are going to
1770 leave LP running, since we have skipped resuming all the
1771 other threads. This bit of code needs to be synchronized
1772 with linux_nat_wait. */
1774 if (lp->status && WIFSTOPPED (lp->status))
1777 && WSTOPSIG (lp->status)
1778 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1780 if (debug_linux_nat)
1781 fprintf_unfiltered (gdb_stdlog,
1782 "LLR: Not short circuiting for ignored "
1783 "status 0x%x\n", lp->status);
1785 /* FIXME: What should we do if we are supposed to continue
1786 this thread with a signal? */
1787 gdb_assert (signo == GDB_SIGNAL_0);
1788 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1793 if (lwp_status_pending_p (lp))
1795 /* FIXME: What should we do if we are supposed to continue
1796 this thread with a signal? */
1797 gdb_assert (signo == GDB_SIGNAL_0);
1799 if (debug_linux_nat)
1800 fprintf_unfiltered (gdb_stdlog,
1801 "LLR: Short circuiting for status 0x%x\n",
1804 if (target_can_async_p ())
1807 /* Tell the event loop we have something to process. */
1814 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1816 if (debug_linux_nat)
1817 fprintf_unfiltered (gdb_stdlog,
1818 "LLR: %s %s, %s (resume event thread)\n",
1819 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1820 target_pid_to_str (lp->ptid),
1821 (signo != GDB_SIGNAL_0
1822 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1824 linux_resume_one_lwp (lp, step, signo);
1826 if (target_can_async_p ())
1830 /* Send a signal to an LWP. */
1833 kill_lwp (int lwpid, int signo)
1838 ret = syscall (__NR_tkill, lwpid, signo);
1839 if (errno == ENOSYS)
1841 /* If tkill fails, then we are not using nptl threads, a
1842 configuration we no longer support. */
1843 perror_with_name (("tkill"));
1848 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1849 event, check if the core is interested in it: if not, ignore the
1850 event, and keep waiting; otherwise, we need to toggle the LWP's
1851 syscall entry/exit status, since the ptrace event itself doesn't
1852 indicate it, and report the trap to higher layers. */
1855 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1857 struct target_waitstatus *ourstatus = &lp->waitstatus;
1858 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1859 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1863 /* If we're stopping threads, there's a SIGSTOP pending, which
1864 makes it so that the LWP reports an immediate syscall return,
1865 followed by the SIGSTOP. Skip seeing that "return" using
1866 PTRACE_CONT directly, and let stop_wait_callback collect the
1867 SIGSTOP. Later when the thread is resumed, a new syscall
1868 entry event. If we didn't do this (and returned 0), we'd
1869 leave a syscall entry pending, and our caller, by using
1870 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1871 itself. Later, when the user re-resumes this LWP, we'd see
1872 another syscall entry event and we'd mistake it for a return.
1874 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1875 (leaving immediately with LWP->signalled set, without issuing
1876 a PTRACE_CONT), it would still be problematic to leave this
1877 syscall enter pending, as later when the thread is resumed,
1878 it would then see the same syscall exit mentioned above,
1879 followed by the delayed SIGSTOP, while the syscall didn't
1880 actually get to execute. It seems it would be even more
1881 confusing to the user. */
1883 if (debug_linux_nat)
1884 fprintf_unfiltered (gdb_stdlog,
1885 "LHST: ignoring syscall %d "
1886 "for LWP %ld (stopping threads), "
1887 "resuming with PTRACE_CONT for SIGSTOP\n",
1889 ptid_get_lwp (lp->ptid));
1891 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1892 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1897 /* Always update the entry/return state, even if this particular
1898 syscall isn't interesting to the core now. In async mode,
1899 the user could install a new catchpoint for this syscall
1900 between syscall enter/return, and we'll need to know to
1901 report a syscall return if that happens. */
1902 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1903 ? TARGET_WAITKIND_SYSCALL_RETURN
1904 : TARGET_WAITKIND_SYSCALL_ENTRY);
1906 if (catch_syscall_enabled ())
1908 if (catching_syscall_number (syscall_number))
1910 /* Alright, an event to report. */
1911 ourstatus->kind = lp->syscall_state;
1912 ourstatus->value.syscall_number = syscall_number;
1914 if (debug_linux_nat)
1915 fprintf_unfiltered (gdb_stdlog,
1916 "LHST: stopping for %s of syscall %d"
1919 == TARGET_WAITKIND_SYSCALL_ENTRY
1920 ? "entry" : "return",
1922 ptid_get_lwp (lp->ptid));
1926 if (debug_linux_nat)
1927 fprintf_unfiltered (gdb_stdlog,
1928 "LHST: ignoring %s of syscall %d "
1930 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1931 ? "entry" : "return",
1933 ptid_get_lwp (lp->ptid));
1937 /* If we had been syscall tracing, and hence used PT_SYSCALL
1938 before on this LWP, it could happen that the user removes all
1939 syscall catchpoints before we get to process this event.
1940 There are two noteworthy issues here:
1942 - When stopped at a syscall entry event, resuming with
1943 PT_STEP still resumes executing the syscall and reports a
1946 - Only PT_SYSCALL catches syscall enters. If we last
1947 single-stepped this thread, then this event can't be a
1948 syscall enter. If we last single-stepped this thread, this
1949 has to be a syscall exit.
1951 The points above mean that the next resume, be it PT_STEP or
1952 PT_CONTINUE, can not trigger a syscall trace event. */
1953 if (debug_linux_nat)
1954 fprintf_unfiltered (gdb_stdlog,
1955 "LHST: caught syscall event "
1956 "with no syscall catchpoints."
1957 " %d for LWP %ld, ignoring\n",
1959 ptid_get_lwp (lp->ptid));
1960 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1963 /* The core isn't interested in this event. For efficiency, avoid
1964 stopping all threads only to have the core resume them all again.
1965 Since we're not stopping threads, if we're still syscall tracing
1966 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1967 subsequent syscall. Simply resume using the inf-ptrace layer,
1968 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1970 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1974 /* Handle a GNU/Linux extended wait response. If we see a clone
1975 event, we need to add the new LWP to our list (and not report the
1976 trap to higher layers). This function returns non-zero if the
1977 event should be ignored and we should wait again. If STOPPING is
1978 true, the new LWP remains stopped, otherwise it is continued. */
1981 linux_handle_extended_wait (struct lwp_info *lp, int status)
1983 int pid = ptid_get_lwp (lp->ptid);
1984 struct target_waitstatus *ourstatus = &lp->waitstatus;
1985 int event = linux_ptrace_get_extended_event (status);
1987 /* All extended events we currently use are mid-syscall. Only
1988 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1989 you have to be using PTRACE_SEIZE to get that. */
1990 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1992 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1993 || event == PTRACE_EVENT_CLONE)
1995 unsigned long new_pid;
1998 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2000 /* If we haven't already seen the new PID stop, wait for it now. */
2001 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2003 /* The new child has a pending SIGSTOP. We can't affect it until it
2004 hits the SIGSTOP, but we're already attached. */
2005 ret = my_waitpid (new_pid, &status, __WALL);
2007 perror_with_name (_("waiting for new child"));
2008 else if (ret != new_pid)
2009 internal_error (__FILE__, __LINE__,
2010 _("wait returned unexpected PID %d"), ret);
2011 else if (!WIFSTOPPED (status))
2012 internal_error (__FILE__, __LINE__,
2013 _("wait returned unexpected status 0x%x"), status);
2016 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2018 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2020 /* The arch-specific native code may need to know about new
2021 forks even if those end up never mapped to an
2023 if (linux_nat_new_fork != NULL)
2024 linux_nat_new_fork (lp, new_pid);
2027 if (event == PTRACE_EVENT_FORK
2028 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2030 /* Handle checkpointing by linux-fork.c here as a special
2031 case. We don't want the follow-fork-mode or 'catch fork'
2032 to interfere with this. */
2034 /* This won't actually modify the breakpoint list, but will
2035 physically remove the breakpoints from the child. */
2036 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2038 /* Retain child fork in ptrace (stopped) state. */
2039 if (!find_fork_pid (new_pid))
2042 /* Report as spurious, so that infrun doesn't want to follow
2043 this fork. We're actually doing an infcall in
2045 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2047 /* Report the stop to the core. */
2051 if (event == PTRACE_EVENT_FORK)
2052 ourstatus->kind = TARGET_WAITKIND_FORKED;
2053 else if (event == PTRACE_EVENT_VFORK)
2054 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2055 else if (event == PTRACE_EVENT_CLONE)
2057 struct lwp_info *new_lp;
2059 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2061 if (debug_linux_nat)
2062 fprintf_unfiltered (gdb_stdlog,
2063 "LHEW: Got clone event "
2064 "from LWP %d, new child is LWP %ld\n",
2067 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2068 new_lp->stopped = 1;
2069 new_lp->resumed = 1;
2071 /* If the thread_db layer is active, let it record the user
2072 level thread id and status, and add the thread to GDB's
2074 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2076 /* The process is not using thread_db. Add the LWP to
2078 target_post_attach (ptid_get_lwp (new_lp->ptid));
2079 add_thread (new_lp->ptid);
2082 /* Even if we're stopping the thread for some reason
2083 internal to this module, from the perspective of infrun
2084 and the user/frontend, this new thread is running until
2085 it next reports a stop. */
2086 set_running (new_lp->ptid, 1);
2087 set_executing (new_lp->ptid, 1);
2089 if (WSTOPSIG (status) != SIGSTOP)
2091 /* This can happen if someone starts sending signals to
2092 the new thread before it gets a chance to run, which
2093 have a lower number than SIGSTOP (e.g. SIGUSR1).
2094 This is an unlikely case, and harder to handle for
2095 fork / vfork than for clone, so we do not try - but
2096 we handle it for clone events here. */
2098 new_lp->signalled = 1;
2100 /* We created NEW_LP so it cannot yet contain STATUS. */
2101 gdb_assert (new_lp->status == 0);
2103 /* Save the wait status to report later. */
2104 if (debug_linux_nat)
2105 fprintf_unfiltered (gdb_stdlog,
2106 "LHEW: waitpid of new LWP %ld, "
2107 "saving status %s\n",
2108 (long) ptid_get_lwp (new_lp->ptid),
2109 status_to_str (status));
2110 new_lp->status = status;
2112 else if (report_thread_events)
2114 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2115 new_lp->status = status;
2124 if (event == PTRACE_EVENT_EXEC)
2126 if (debug_linux_nat)
2127 fprintf_unfiltered (gdb_stdlog,
2128 "LHEW: Got exec event from LWP %ld\n",
2129 ptid_get_lwp (lp->ptid));
2131 ourstatus->kind = TARGET_WAITKIND_EXECD;
2132 ourstatus->value.execd_pathname
2133 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2135 /* The thread that execed must have been resumed, but, when a
2136 thread execs, it changes its tid to the tgid, and the old
2137 tgid thread might have not been resumed. */
2142 if (event == PTRACE_EVENT_VFORK_DONE)
2144 if (current_inferior ()->waiting_for_vfork_done)
2146 if (debug_linux_nat)
2147 fprintf_unfiltered (gdb_stdlog,
2148 "LHEW: Got expected PTRACE_EVENT_"
2149 "VFORK_DONE from LWP %ld: stopping\n",
2150 ptid_get_lwp (lp->ptid));
2152 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2156 if (debug_linux_nat)
2157 fprintf_unfiltered (gdb_stdlog,
2158 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2159 "from LWP %ld: ignoring\n",
2160 ptid_get_lwp (lp->ptid));
2164 internal_error (__FILE__, __LINE__,
2165 _("unknown ptrace event %d"), event);
2168 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2172 wait_lwp (struct lwp_info *lp)
2176 int thread_dead = 0;
2179 gdb_assert (!lp->stopped);
2180 gdb_assert (lp->status == 0);
2182 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2183 block_child_signals (&prev_mask);
2187 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2188 if (pid == -1 && errno == ECHILD)
2190 /* The thread has previously exited. We need to delete it
2191 now because if this was a non-leader thread execing, we
2192 won't get an exit event. See comments on exec events at
2193 the top of the file. */
2195 if (debug_linux_nat)
2196 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2197 target_pid_to_str (lp->ptid));
2202 /* Bugs 10970, 12702.
2203 Thread group leader may have exited in which case we'll lock up in
2204 waitpid if there are other threads, even if they are all zombies too.
2205 Basically, we're not supposed to use waitpid this way.
2206 tkill(pid,0) cannot be used here as it gets ESRCH for both
2207 for zombie and running processes.
2209 As a workaround, check if we're waiting for the thread group leader and
2210 if it's a zombie, and avoid calling waitpid if it is.
2212 This is racy, what if the tgl becomes a zombie right after we check?
2213 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2214 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2216 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2217 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2220 if (debug_linux_nat)
2221 fprintf_unfiltered (gdb_stdlog,
2222 "WL: Thread group leader %s vanished.\n",
2223 target_pid_to_str (lp->ptid));
2227 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2228 get invoked despite our caller had them intentionally blocked by
2229 block_child_signals. This is sensitive only to the loop of
2230 linux_nat_wait_1 and there if we get called my_waitpid gets called
2231 again before it gets to sigsuspend so we can safely let the handlers
2232 get executed here. */
2234 if (debug_linux_nat)
2235 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2236 sigsuspend (&suspend_mask);
2239 restore_child_signals_mask (&prev_mask);
2243 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2245 if (debug_linux_nat)
2247 fprintf_unfiltered (gdb_stdlog,
2248 "WL: waitpid %s received %s\n",
2249 target_pid_to_str (lp->ptid),
2250 status_to_str (status));
2253 /* Check if the thread has exited. */
2254 if (WIFEXITED (status) || WIFSIGNALED (status))
2256 if (report_thread_events
2257 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2259 if (debug_linux_nat)
2260 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2261 ptid_get_pid (lp->ptid));
2263 /* If this is the leader exiting, it means the whole
2264 process is gone. Store the status to report to the
2265 core. Store it in lp->waitstatus, because lp->status
2266 would be ambiguous (W_EXITCODE(0,0) == 0). */
2267 store_waitstatus (&lp->waitstatus, status);
2272 if (debug_linux_nat)
2273 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2274 target_pid_to_str (lp->ptid));
2284 gdb_assert (WIFSTOPPED (status));
2287 if (lp->must_set_ptrace_flags)
2289 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2290 int options = linux_nat_ptrace_options (inf->attach_flag);
2292 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2293 lp->must_set_ptrace_flags = 0;
2296 /* Handle GNU/Linux's syscall SIGTRAPs. */
2297 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2299 /* No longer need the sysgood bit. The ptrace event ends up
2300 recorded in lp->waitstatus if we care for it. We can carry
2301 on handling the event like a regular SIGTRAP from here
2303 status = W_STOPCODE (SIGTRAP);
2304 if (linux_handle_syscall_trap (lp, 1))
2305 return wait_lwp (lp);
2309 /* Almost all other ptrace-stops are known to be outside of system
2310 calls, with further exceptions in linux_handle_extended_wait. */
2311 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2314 /* Handle GNU/Linux's extended waitstatus for trace events. */
2315 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2316 && linux_is_extended_waitstatus (status))
2318 if (debug_linux_nat)
2319 fprintf_unfiltered (gdb_stdlog,
2320 "WL: Handling extended status 0x%06x\n",
2322 linux_handle_extended_wait (lp, status);
2329 /* Send a SIGSTOP to LP. */
2332 stop_callback (struct lwp_info *lp, void *data)
2334 if (!lp->stopped && !lp->signalled)
2338 if (debug_linux_nat)
2340 fprintf_unfiltered (gdb_stdlog,
2341 "SC: kill %s **<SIGSTOP>**\n",
2342 target_pid_to_str (lp->ptid));
2345 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2346 if (debug_linux_nat)
2348 fprintf_unfiltered (gdb_stdlog,
2349 "SC: lwp kill %d %s\n",
2351 errno ? safe_strerror (errno) : "ERRNO-OK");
2355 gdb_assert (lp->status == 0);
2361 /* Request a stop on LWP. */
2364 linux_stop_lwp (struct lwp_info *lwp)
2366 stop_callback (lwp, NULL);
2369 /* See linux-nat.h */
2372 linux_stop_and_wait_all_lwps (void)
2374 /* Stop all LWP's ... */
2375 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2377 /* ... and wait until all of them have reported back that
2378 they're no longer running. */
2379 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2382 /* See linux-nat.h */
2385 linux_unstop_all_lwps (void)
2387 iterate_over_lwps (minus_one_ptid,
2388 resume_stopped_resumed_lwps, &minus_one_ptid);
2391 /* Return non-zero if LWP PID has a pending SIGINT. */
2394 linux_nat_has_pending_sigint (int pid)
2396 sigset_t pending, blocked, ignored;
2398 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2400 if (sigismember (&pending, SIGINT)
2401 && !sigismember (&ignored, SIGINT))
2407 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2410 set_ignore_sigint (struct lwp_info *lp, void *data)
2412 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2413 flag to consume the next one. */
2414 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2415 && WSTOPSIG (lp->status) == SIGINT)
2418 lp->ignore_sigint = 1;
2423 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2424 This function is called after we know the LWP has stopped; if the LWP
2425 stopped before the expected SIGINT was delivered, then it will never have
2426 arrived. Also, if the signal was delivered to a shared queue and consumed
2427 by a different thread, it will never be delivered to this LWP. */
2430 maybe_clear_ignore_sigint (struct lwp_info *lp)
2432 if (!lp->ignore_sigint)
2435 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2437 if (debug_linux_nat)
2438 fprintf_unfiltered (gdb_stdlog,
2439 "MCIS: Clearing bogus flag for %s\n",
2440 target_pid_to_str (lp->ptid));
2441 lp->ignore_sigint = 0;
2445 /* Fetch the possible triggered data watchpoint info and store it in
2448 On some archs, like x86, that use debug registers to set
2449 watchpoints, it's possible that the way to know which watched
2450 address trapped, is to check the register that is used to select
2451 which address to watch. Problem is, between setting the watchpoint
2452 and reading back which data address trapped, the user may change
2453 the set of watchpoints, and, as a consequence, GDB changes the
2454 debug registers in the inferior. To avoid reading back a stale
2455 stopped-data-address when that happens, we cache in LP the fact
2456 that a watchpoint trapped, and the corresponding data address, as
2457 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2458 registers meanwhile, we have the cached data we can rely on. */
2461 check_stopped_by_watchpoint (struct lwp_info *lp)
2463 if (linux_ops->to_stopped_by_watchpoint == NULL)
2466 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
2467 inferior_ptid = lp->ptid;
2469 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2471 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2473 if (linux_ops->to_stopped_data_address != NULL)
2474 lp->stopped_data_address_p =
2475 linux_ops->to_stopped_data_address (¤t_target,
2476 &lp->stopped_data_address);
2478 lp->stopped_data_address_p = 0;
2481 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2484 /* Returns true if the LWP had stopped for a watchpoint. */
2487 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2489 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2491 gdb_assert (lp != NULL);
2493 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2497 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2499 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2501 gdb_assert (lp != NULL);
2503 *addr_p = lp->stopped_data_address;
2505 return lp->stopped_data_address_p;
2508 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2511 sigtrap_is_event (int status)
2513 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2516 /* Set alternative SIGTRAP-like events recognizer. If
2517 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2521 linux_nat_set_status_is_event (struct target_ops *t,
2522 int (*status_is_event) (int status))
2524 linux_nat_status_is_event = status_is_event;
2527 /* Wait until LP is stopped. */
2530 stop_wait_callback (struct lwp_info *lp, void *data)
2532 struct inferior *inf = find_inferior_ptid (lp->ptid);
2534 /* If this is a vfork parent, bail out, it is not going to report
2535 any SIGSTOP until the vfork is done with. */
2536 if (inf->vfork_child != NULL)
2543 status = wait_lwp (lp);
2547 if (lp->ignore_sigint && WIFSTOPPED (status)
2548 && WSTOPSIG (status) == SIGINT)
2550 lp->ignore_sigint = 0;
2553 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2555 if (debug_linux_nat)
2556 fprintf_unfiltered (gdb_stdlog,
2557 "PTRACE_CONT %s, 0, 0 (%s) "
2558 "(discarding SIGINT)\n",
2559 target_pid_to_str (lp->ptid),
2560 errno ? safe_strerror (errno) : "OK");
2562 return stop_wait_callback (lp, NULL);
2565 maybe_clear_ignore_sigint (lp);
2567 if (WSTOPSIG (status) != SIGSTOP)
2569 /* The thread was stopped with a signal other than SIGSTOP. */
2571 if (debug_linux_nat)
2572 fprintf_unfiltered (gdb_stdlog,
2573 "SWC: Pending event %s in %s\n",
2574 status_to_str ((int) status),
2575 target_pid_to_str (lp->ptid));
2577 /* Save the sigtrap event. */
2578 lp->status = status;
2579 gdb_assert (lp->signalled);
2580 save_stop_reason (lp);
2584 /* We caught the SIGSTOP that we intended to catch, so
2585 there's no SIGSTOP pending. */
2587 if (debug_linux_nat)
2588 fprintf_unfiltered (gdb_stdlog,
2589 "SWC: Expected SIGSTOP caught for %s.\n",
2590 target_pid_to_str (lp->ptid));
2592 /* Reset SIGNALLED only after the stop_wait_callback call
2593 above as it does gdb_assert on SIGNALLED. */
2601 /* Return non-zero if LP has a wait status pending. Discard the
2602 pending event and resume the LWP if the event that originally
2603 caused the stop became uninteresting. */
2606 status_callback (struct lwp_info *lp, void *data)
2608 /* Only report a pending wait status if we pretend that this has
2609 indeed been resumed. */
2613 if (!lwp_status_pending_p (lp))
2616 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2617 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2619 struct regcache *regcache = get_thread_regcache (lp->ptid);
2623 pc = regcache_read_pc (regcache);
2625 if (pc != lp->stop_pc)
2627 if (debug_linux_nat)
2628 fprintf_unfiltered (gdb_stdlog,
2629 "SC: PC of %s changed. was=%s, now=%s\n",
2630 target_pid_to_str (lp->ptid),
2631 paddress (target_gdbarch (), lp->stop_pc),
2632 paddress (target_gdbarch (), pc));
2636 #if !USE_SIGTRAP_SIGINFO
2637 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2639 if (debug_linux_nat)
2640 fprintf_unfiltered (gdb_stdlog,
2641 "SC: previous breakpoint of %s, at %s gone\n",
2642 target_pid_to_str (lp->ptid),
2643 paddress (target_gdbarch (), lp->stop_pc));
2651 if (debug_linux_nat)
2652 fprintf_unfiltered (gdb_stdlog,
2653 "SC: pending event of %s cancelled.\n",
2654 target_pid_to_str (lp->ptid));
2657 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2665 /* Count the LWP's that have had events. */
2668 count_events_callback (struct lwp_info *lp, void *data)
2670 int *count = (int *) data;
2672 gdb_assert (count != NULL);
2674 /* Select only resumed LWPs that have an event pending. */
2675 if (lp->resumed && lwp_status_pending_p (lp))
2681 /* Select the LWP (if any) that is currently being single-stepped. */
2684 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2686 if (lp->last_resume_kind == resume_step
2693 /* Returns true if LP has a status pending. */
2696 lwp_status_pending_p (struct lwp_info *lp)
2698 /* We check for lp->waitstatus in addition to lp->status, because we
2699 can have pending process exits recorded in lp->status and
2700 W_EXITCODE(0,0) happens to be 0. */
2701 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2704 /* Select the Nth LWP that has had an event. */
2707 select_event_lwp_callback (struct lwp_info *lp, void *data)
2709 int *selector = (int *) data;
2711 gdb_assert (selector != NULL);
2713 /* Select only resumed LWPs that have an event pending. */
2714 if (lp->resumed && lwp_status_pending_p (lp))
2715 if ((*selector)-- == 0)
2721 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2722 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2723 and save the result in the LWP's stop_reason field. If it stopped
2724 for a breakpoint, decrement the PC if necessary on the lwp's
2728 save_stop_reason (struct lwp_info *lp)
2730 struct regcache *regcache;
2731 struct gdbarch *gdbarch;
2734 #if USE_SIGTRAP_SIGINFO
2738 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2739 gdb_assert (lp->status != 0);
2741 if (!linux_nat_status_is_event (lp->status))
2744 regcache = get_thread_regcache (lp->ptid);
2745 gdbarch = get_regcache_arch (regcache);
2747 pc = regcache_read_pc (regcache);
2748 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2750 #if USE_SIGTRAP_SIGINFO
2751 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2753 if (siginfo.si_signo == SIGTRAP)
2755 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2756 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2758 /* The si_code is ambiguous on this arch -- check debug
2760 if (!check_stopped_by_watchpoint (lp))
2761 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2763 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2765 /* If we determine the LWP stopped for a SW breakpoint,
2766 trust it. Particularly don't check watchpoint
2767 registers, because at least on s390, we'd find
2768 stopped-by-watchpoint as long as there's a watchpoint
2770 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2772 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2774 /* This can indicate either a hardware breakpoint or
2775 hardware watchpoint. Check debug registers. */
2776 if (!check_stopped_by_watchpoint (lp))
2777 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2779 else if (siginfo.si_code == TRAP_TRACE)
2781 if (debug_linux_nat)
2782 fprintf_unfiltered (gdb_stdlog,
2783 "CSBB: %s stopped by trace\n",
2784 target_pid_to_str (lp->ptid));
2786 /* We may have single stepped an instruction that
2787 triggered a watchpoint. In that case, on some
2788 architectures (such as x86), instead of TRAP_HWBKPT,
2789 si_code indicates TRAP_TRACE, and we need to check
2790 the debug registers separately. */
2791 check_stopped_by_watchpoint (lp);
2796 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2797 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2800 /* The LWP was either continued, or stepped a software
2801 breakpoint instruction. */
2802 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2805 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2806 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2808 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2809 check_stopped_by_watchpoint (lp);
2812 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2814 if (debug_linux_nat)
2815 fprintf_unfiltered (gdb_stdlog,
2816 "CSBB: %s stopped by software breakpoint\n",
2817 target_pid_to_str (lp->ptid));
2819 /* Back up the PC if necessary. */
2821 regcache_write_pc (regcache, sw_bp_pc);
2823 /* Update this so we record the correct stop PC below. */
2826 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2828 if (debug_linux_nat)
2829 fprintf_unfiltered (gdb_stdlog,
2830 "CSBB: %s stopped by hardware breakpoint\n",
2831 target_pid_to_str (lp->ptid));
2833 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2835 if (debug_linux_nat)
2836 fprintf_unfiltered (gdb_stdlog,
2837 "CSBB: %s stopped by hardware watchpoint\n",
2838 target_pid_to_str (lp->ptid));
2845 /* Returns true if the LWP had stopped for a software breakpoint. */
2848 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2850 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2852 gdb_assert (lp != NULL);
2854 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2857 /* Implement the supports_stopped_by_sw_breakpoint method. */
2860 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2862 return USE_SIGTRAP_SIGINFO;
2865 /* Returns true if the LWP had stopped for a hardware
2866 breakpoint/watchpoint. */
2869 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2871 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2873 gdb_assert (lp != NULL);
2875 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2878 /* Implement the supports_stopped_by_hw_breakpoint method. */
2881 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2883 return USE_SIGTRAP_SIGINFO;
2886 /* Select one LWP out of those that have events pending. */
2889 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2892 int random_selector;
2893 struct lwp_info *event_lp = NULL;
2895 /* Record the wait status for the original LWP. */
2896 (*orig_lp)->status = *status;
2898 /* In all-stop, give preference to the LWP that is being
2899 single-stepped. There will be at most one, and it will be the
2900 LWP that the core is most interested in. If we didn't do this,
2901 then we'd have to handle pending step SIGTRAPs somehow in case
2902 the core later continues the previously-stepped thread, as
2903 otherwise we'd report the pending SIGTRAP then, and the core, not
2904 having stepped the thread, wouldn't understand what the trap was
2905 for, and therefore would report it to the user as a random
2907 if (!target_is_non_stop_p ())
2909 event_lp = iterate_over_lwps (filter,
2910 select_singlestep_lwp_callback, NULL);
2911 if (event_lp != NULL)
2913 if (debug_linux_nat)
2914 fprintf_unfiltered (gdb_stdlog,
2915 "SEL: Select single-step %s\n",
2916 target_pid_to_str (event_lp->ptid));
2920 if (event_lp == NULL)
2922 /* Pick one at random, out of those which have had events. */
2924 /* First see how many events we have. */
2925 iterate_over_lwps (filter, count_events_callback, &num_events);
2926 gdb_assert (num_events > 0);
2928 /* Now randomly pick a LWP out of those that have had
2930 random_selector = (int)
2931 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2933 if (debug_linux_nat && num_events > 1)
2934 fprintf_unfiltered (gdb_stdlog,
2935 "SEL: Found %d events, selecting #%d\n",
2936 num_events, random_selector);
2938 event_lp = iterate_over_lwps (filter,
2939 select_event_lwp_callback,
2943 if (event_lp != NULL)
2945 /* Switch the event LWP. */
2946 *orig_lp = event_lp;
2947 *status = event_lp->status;
2950 /* Flush the wait status for the event LWP. */
2951 (*orig_lp)->status = 0;
2954 /* Return non-zero if LP has been resumed. */
2957 resumed_callback (struct lwp_info *lp, void *data)
2962 /* Check if we should go on and pass this event to common code.
2963 Return the affected lwp if we are, or NULL otherwise. */
2965 static struct lwp_info *
2966 linux_nat_filter_event (int lwpid, int status)
2968 struct lwp_info *lp;
2969 int event = linux_ptrace_get_extended_event (status);
2971 lp = find_lwp_pid (pid_to_ptid (lwpid));
2973 /* Check for stop events reported by a process we didn't already
2974 know about - anything not already in our LWP list.
2976 If we're expecting to receive stopped processes after
2977 fork, vfork, and clone events, then we'll just add the
2978 new one to our list and go back to waiting for the event
2979 to be reported - the stopped process might be returned
2980 from waitpid before or after the event is.
2982 But note the case of a non-leader thread exec'ing after the
2983 leader having exited, and gone from our lists. The non-leader
2984 thread changes its tid to the tgid. */
2986 if (WIFSTOPPED (status) && lp == NULL
2987 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2989 /* A multi-thread exec after we had seen the leader exiting. */
2990 if (debug_linux_nat)
2991 fprintf_unfiltered (gdb_stdlog,
2992 "LLW: Re-adding thread group leader LWP %d.\n",
2995 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
2998 add_thread (lp->ptid);
3001 if (WIFSTOPPED (status) && !lp)
3003 if (debug_linux_nat)
3004 fprintf_unfiltered (gdb_stdlog,
3005 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3006 (long) lwpid, status_to_str (status));
3007 add_to_pid_list (&stopped_pids, lwpid, status);
3011 /* Make sure we don't report an event for the exit of an LWP not in
3012 our list, i.e. not part of the current process. This can happen
3013 if we detach from a program we originally forked and then it
3015 if (!WIFSTOPPED (status) && !lp)
3018 /* This LWP is stopped now. (And if dead, this prevents it from
3019 ever being continued.) */
3022 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3024 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3025 int options = linux_nat_ptrace_options (inf->attach_flag);
3027 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3028 lp->must_set_ptrace_flags = 0;
3031 /* Handle GNU/Linux's syscall SIGTRAPs. */
3032 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3034 /* No longer need the sysgood bit. The ptrace event ends up
3035 recorded in lp->waitstatus if we care for it. We can carry
3036 on handling the event like a regular SIGTRAP from here
3038 status = W_STOPCODE (SIGTRAP);
3039 if (linux_handle_syscall_trap (lp, 0))
3044 /* Almost all other ptrace-stops are known to be outside of system
3045 calls, with further exceptions in linux_handle_extended_wait. */
3046 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3049 /* Handle GNU/Linux's extended waitstatus for trace events. */
3050 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3051 && linux_is_extended_waitstatus (status))
3053 if (debug_linux_nat)
3054 fprintf_unfiltered (gdb_stdlog,
3055 "LLW: Handling extended status 0x%06x\n",
3057 if (linux_handle_extended_wait (lp, status))
3061 /* Check if the thread has exited. */
3062 if (WIFEXITED (status) || WIFSIGNALED (status))
3064 if (!report_thread_events
3065 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3067 if (debug_linux_nat)
3068 fprintf_unfiltered (gdb_stdlog,
3069 "LLW: %s exited.\n",
3070 target_pid_to_str (lp->ptid));
3072 /* If there is at least one more LWP, then the exit signal
3073 was not the end of the debugged application and should be
3079 /* Note that even if the leader was ptrace-stopped, it can still
3080 exit, if e.g., some other thread brings down the whole
3081 process (calls `exit'). So don't assert that the lwp is
3083 if (debug_linux_nat)
3084 fprintf_unfiltered (gdb_stdlog,
3085 "LWP %ld exited (resumed=%d)\n",
3086 ptid_get_lwp (lp->ptid), lp->resumed);
3088 /* Dead LWP's aren't expected to reported a pending sigstop. */
3091 /* Store the pending event in the waitstatus, because
3092 W_EXITCODE(0,0) == 0. */
3093 store_waitstatus (&lp->waitstatus, status);
3097 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3098 an attempt to stop an LWP. */
3100 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3104 if (lp->last_resume_kind == resume_stop)
3106 if (debug_linux_nat)
3107 fprintf_unfiltered (gdb_stdlog,
3108 "LLW: resume_stop SIGSTOP caught for %s.\n",
3109 target_pid_to_str (lp->ptid));
3113 /* This is a delayed SIGSTOP. Filter out the event. */
3115 if (debug_linux_nat)
3116 fprintf_unfiltered (gdb_stdlog,
3117 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3119 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3120 target_pid_to_str (lp->ptid));
3122 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3123 gdb_assert (lp->resumed);
3128 /* Make sure we don't report a SIGINT that we have already displayed
3129 for another thread. */
3130 if (lp->ignore_sigint
3131 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3133 if (debug_linux_nat)
3134 fprintf_unfiltered (gdb_stdlog,
3135 "LLW: Delayed SIGINT caught for %s.\n",
3136 target_pid_to_str (lp->ptid));
3138 /* This is a delayed SIGINT. */
3139 lp->ignore_sigint = 0;
3141 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3142 if (debug_linux_nat)
3143 fprintf_unfiltered (gdb_stdlog,
3144 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3146 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3147 target_pid_to_str (lp->ptid));
3148 gdb_assert (lp->resumed);
3150 /* Discard the event. */
3154 /* Don't report signals that GDB isn't interested in, such as
3155 signals that are neither printed nor stopped upon. Stopping all
3156 threads can be a bit time-consuming so if we want decent
3157 performance with heavily multi-threaded programs, especially when
3158 they're using a high frequency timer, we'd better avoid it if we
3160 if (WIFSTOPPED (status))
3162 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3164 if (!target_is_non_stop_p ())
3166 /* Only do the below in all-stop, as we currently use SIGSTOP
3167 to implement target_stop (see linux_nat_stop) in
3169 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3171 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3172 forwarded to the entire process group, that is, all LWPs
3173 will receive it - unless they're using CLONE_THREAD to
3174 share signals. Since we only want to report it once, we
3175 mark it as ignored for all LWPs except this one. */
3176 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3177 set_ignore_sigint, NULL);
3178 lp->ignore_sigint = 0;
3181 maybe_clear_ignore_sigint (lp);
3184 /* When using hardware single-step, we need to report every signal.
3185 Otherwise, signals in pass_mask may be short-circuited
3186 except signals that might be caused by a breakpoint. */
3188 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3189 && !linux_wstatus_maybe_breakpoint (status))
3191 linux_resume_one_lwp (lp, lp->step, signo);
3192 if (debug_linux_nat)
3193 fprintf_unfiltered (gdb_stdlog,
3194 "LLW: %s %s, %s (preempt 'handle')\n",
3196 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3197 target_pid_to_str (lp->ptid),
3198 (signo != GDB_SIGNAL_0
3199 ? strsignal (gdb_signal_to_host (signo))
3205 /* An interesting event. */
3207 lp->status = status;
3208 save_stop_reason (lp);
3212 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3213 their exits until all other threads in the group have exited. */
3216 check_zombie_leaders (void)
3218 struct inferior *inf;
3222 struct lwp_info *leader_lp;
3227 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3228 if (leader_lp != NULL
3229 /* Check if there are other threads in the group, as we may
3230 have raced with the inferior simply exiting. */
3231 && num_lwps (inf->pid) > 1
3232 && linux_proc_pid_is_zombie (inf->pid))
3234 if (debug_linux_nat)
3235 fprintf_unfiltered (gdb_stdlog,
3236 "CZL: Thread group leader %d zombie "
3237 "(it exited, or another thread execd).\n",
3240 /* A leader zombie can mean one of two things:
3242 - It exited, and there's an exit status pending
3243 available, or only the leader exited (not the whole
3244 program). In the latter case, we can't waitpid the
3245 leader's exit status until all other threads are gone.
3247 - There are 3 or more threads in the group, and a thread
3248 other than the leader exec'd. See comments on exec
3249 events at the top of the file. We could try
3250 distinguishing the exit and exec cases, by waiting once
3251 more, and seeing if something comes out, but it doesn't
3252 sound useful. The previous leader _does_ go away, and
3253 we'll re-add the new one once we see the exec event
3254 (which is just the same as what would happen if the
3255 previous leader did exit voluntarily before some other
3258 if (debug_linux_nat)
3259 fprintf_unfiltered (gdb_stdlog,
3260 "CZL: Thread group leader %d vanished.\n",
3262 exit_lwp (leader_lp);
3267 /* Convenience function that is called when the kernel reports an exit
3268 event. This decides whether to report the event to GDB as a
3269 process exit event, a thread exit event, or to suppress the
3273 filter_exit_event (struct lwp_info *event_child,
3274 struct target_waitstatus *ourstatus)
3276 ptid_t ptid = event_child->ptid;
3278 if (num_lwps (ptid_get_pid (ptid)) > 1)
3280 if (report_thread_events)
3281 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3283 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3285 exit_lwp (event_child);
3292 linux_nat_wait_1 (struct target_ops *ops,
3293 ptid_t ptid, struct target_waitstatus *ourstatus,
3297 enum resume_kind last_resume_kind;
3298 struct lwp_info *lp;
3301 if (debug_linux_nat)
3302 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3304 /* The first time we get here after starting a new inferior, we may
3305 not have added it to the LWP list yet - this is the earliest
3306 moment at which we know its PID. */
3307 if (ptid_is_pid (inferior_ptid))
3309 /* Upgrade the main thread's ptid. */
3310 thread_change_ptid (inferior_ptid,
3311 ptid_build (ptid_get_pid (inferior_ptid),
3312 ptid_get_pid (inferior_ptid), 0));
3314 lp = add_initial_lwp (inferior_ptid);
3318 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3319 block_child_signals (&prev_mask);
3321 /* First check if there is a LWP with a wait status pending. */
3322 lp = iterate_over_lwps (ptid, status_callback, NULL);
3325 if (debug_linux_nat)
3326 fprintf_unfiltered (gdb_stdlog,
3327 "LLW: Using pending wait status %s for %s.\n",
3328 status_to_str (lp->status),
3329 target_pid_to_str (lp->ptid));
3332 /* But if we don't find a pending event, we'll have to wait. Always
3333 pull all events out of the kernel. We'll randomly select an
3334 event LWP out of all that have events, to prevent starvation. */
3340 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3343 - If the thread group leader exits while other threads in the
3344 thread group still exist, waitpid(TGID, ...) hangs. That
3345 waitpid won't return an exit status until the other threads
3346 in the group are reapped.
3348 - When a non-leader thread execs, that thread just vanishes
3349 without reporting an exit (so we'd hang if we waited for it
3350 explicitly in that case). The exec event is reported to
3354 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3356 if (debug_linux_nat)
3357 fprintf_unfiltered (gdb_stdlog,
3358 "LNW: waitpid(-1, ...) returned %d, %s\n",
3359 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3363 if (debug_linux_nat)
3365 fprintf_unfiltered (gdb_stdlog,
3366 "LLW: waitpid %ld received %s\n",
3367 (long) lwpid, status_to_str (status));
3370 linux_nat_filter_event (lwpid, status);
3371 /* Retry until nothing comes out of waitpid. A single
3372 SIGCHLD can indicate more than one child stopped. */
3376 /* Now that we've pulled all events out of the kernel, resume
3377 LWPs that don't have an interesting event to report. */
3378 iterate_over_lwps (minus_one_ptid,
3379 resume_stopped_resumed_lwps, &minus_one_ptid);
3381 /* ... and find an LWP with a status to report to the core, if
3383 lp = iterate_over_lwps (ptid, status_callback, NULL);
3387 /* Check for zombie thread group leaders. Those can't be reaped
3388 until all other threads in the thread group are. */
3389 check_zombie_leaders ();
3391 /* If there are no resumed children left, bail. We'd be stuck
3392 forever in the sigsuspend call below otherwise. */
3393 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3395 if (debug_linux_nat)
3396 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3398 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3400 restore_child_signals_mask (&prev_mask);
3401 return minus_one_ptid;
3404 /* No interesting event to report to the core. */
3406 if (target_options & TARGET_WNOHANG)
3408 if (debug_linux_nat)
3409 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3411 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3412 restore_child_signals_mask (&prev_mask);
3413 return minus_one_ptid;
3416 /* We shouldn't end up here unless we want to try again. */
3417 gdb_assert (lp == NULL);
3419 /* Block until we get an event reported with SIGCHLD. */
3420 if (debug_linux_nat)
3421 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3422 sigsuspend (&suspend_mask);
3427 status = lp->status;
3430 if (!target_is_non_stop_p ())
3432 /* Now stop all other LWP's ... */
3433 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3435 /* ... and wait until all of them have reported back that
3436 they're no longer running. */
3437 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3440 /* If we're not waiting for a specific LWP, choose an event LWP from
3441 among those that have had events. Giving equal priority to all
3442 LWPs that have had events helps prevent starvation. */
3443 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3444 select_event_lwp (ptid, &lp, &status);
3446 gdb_assert (lp != NULL);
3448 /* Now that we've selected our final event LWP, un-adjust its PC if
3449 it was a software breakpoint, and we can't reliably support the
3450 "stopped by software breakpoint" stop reason. */
3451 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3452 && !USE_SIGTRAP_SIGINFO)
3454 struct regcache *regcache = get_thread_regcache (lp->ptid);
3455 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3456 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3462 pc = regcache_read_pc (regcache);
3463 regcache_write_pc (regcache, pc + decr_pc);
3467 /* We'll need this to determine whether to report a SIGSTOP as
3468 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3470 last_resume_kind = lp->last_resume_kind;
3472 if (!target_is_non_stop_p ())
3474 /* In all-stop, from the core's perspective, all LWPs are now
3475 stopped until a new resume action is sent over. */
3476 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3480 resume_clear_callback (lp, NULL);
3483 if (linux_nat_status_is_event (status))
3485 if (debug_linux_nat)
3486 fprintf_unfiltered (gdb_stdlog,
3487 "LLW: trap ptid is %s.\n",
3488 target_pid_to_str (lp->ptid));
3491 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3493 *ourstatus = lp->waitstatus;
3494 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3497 store_waitstatus (ourstatus, status);
3499 if (debug_linux_nat)
3500 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3502 restore_child_signals_mask (&prev_mask);
3504 if (last_resume_kind == resume_stop
3505 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3506 && WSTOPSIG (status) == SIGSTOP)
3508 /* A thread that has been requested to stop by GDB with
3509 target_stop, and it stopped cleanly, so report as SIG0. The
3510 use of SIGSTOP is an implementation detail. */
3511 ourstatus->value.sig = GDB_SIGNAL_0;
3514 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3515 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3518 lp->core = linux_common_core_of_thread (lp->ptid);
3520 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3521 return filter_exit_event (lp, ourstatus);
3526 /* Resume LWPs that are currently stopped without any pending status
3527 to report, but are resumed from the core's perspective. */
3530 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3532 ptid_t *wait_ptid_p = (ptid_t *) data;
3536 if (debug_linux_nat)
3537 fprintf_unfiltered (gdb_stdlog,
3538 "RSRL: NOT resuming LWP %s, not stopped\n",
3539 target_pid_to_str (lp->ptid));
3541 else if (!lp->resumed)
3543 if (debug_linux_nat)
3544 fprintf_unfiltered (gdb_stdlog,
3545 "RSRL: NOT resuming LWP %s, not resumed\n",
3546 target_pid_to_str (lp->ptid));
3548 else if (lwp_status_pending_p (lp))
3550 if (debug_linux_nat)
3551 fprintf_unfiltered (gdb_stdlog,
3552 "RSRL: NOT resuming LWP %s, has pending status\n",
3553 target_pid_to_str (lp->ptid));
3557 struct regcache *regcache = get_thread_regcache (lp->ptid);
3558 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3562 CORE_ADDR pc = regcache_read_pc (regcache);
3563 int leave_stopped = 0;
3565 /* Don't bother if there's a breakpoint at PC that we'd hit
3566 immediately, and we're not waiting for this LWP. */
3567 if (!ptid_match (lp->ptid, *wait_ptid_p))
3569 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3575 if (debug_linux_nat)
3576 fprintf_unfiltered (gdb_stdlog,
3577 "RSRL: resuming stopped-resumed LWP %s at "
3579 target_pid_to_str (lp->ptid),
3580 paddress (gdbarch, pc),
3583 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3586 CATCH (ex, RETURN_MASK_ERROR)
3588 if (!check_ptrace_stopped_lwp_gone (lp))
3589 throw_exception (ex);
3598 linux_nat_wait (struct target_ops *ops,
3599 ptid_t ptid, struct target_waitstatus *ourstatus,
3604 if (debug_linux_nat)
3606 char *options_string;
3608 options_string = target_options_to_string (target_options);
3609 fprintf_unfiltered (gdb_stdlog,
3610 "linux_nat_wait: [%s], [%s]\n",
3611 target_pid_to_str (ptid),
3613 xfree (options_string);
3616 /* Flush the async file first. */
3617 if (target_is_async_p ())
3618 async_file_flush ();
3620 /* Resume LWPs that are currently stopped without any pending status
3621 to report, but are resumed from the core's perspective. LWPs get
3622 in this state if we find them stopping at a time we're not
3623 interested in reporting the event (target_wait on a
3624 specific_process, for example, see linux_nat_wait_1), and
3625 meanwhile the event became uninteresting. Don't bother resuming
3626 LWPs we're not going to wait for if they'd stop immediately. */
3627 if (target_is_non_stop_p ())
3628 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3630 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3632 /* If we requested any event, and something came out, assume there
3633 may be more. If we requested a specific lwp or process, also
3634 assume there may be more. */
3635 if (target_is_async_p ()
3636 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3637 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3638 || !ptid_equal (ptid, minus_one_ptid)))
3647 kill_one_lwp (pid_t pid)
3649 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3652 kill_lwp (pid, SIGKILL);
3653 if (debug_linux_nat)
3655 int save_errno = errno;
3657 fprintf_unfiltered (gdb_stdlog,
3658 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3659 save_errno ? safe_strerror (save_errno) : "OK");
3662 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3665 ptrace (PTRACE_KILL, pid, 0, 0);
3666 if (debug_linux_nat)
3668 int save_errno = errno;
3670 fprintf_unfiltered (gdb_stdlog,
3671 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3672 save_errno ? safe_strerror (save_errno) : "OK");
3676 /* Wait for an LWP to die. */
3679 kill_wait_one_lwp (pid_t pid)
3683 /* We must make sure that there are no pending events (delayed
3684 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3685 program doesn't interfere with any following debugging session. */
3689 res = my_waitpid (pid, NULL, __WALL);
3690 if (res != (pid_t) -1)
3692 if (debug_linux_nat)
3693 fprintf_unfiltered (gdb_stdlog,
3694 "KWC: wait %ld received unknown.\n",
3696 /* The Linux kernel sometimes fails to kill a thread
3697 completely after PTRACE_KILL; that goes from the stop
3698 point in do_fork out to the one in get_signal_to_deliver
3699 and waits again. So kill it again. */
3705 gdb_assert (res == -1 && errno == ECHILD);
3708 /* Callback for iterate_over_lwps. */
3711 kill_callback (struct lwp_info *lp, void *data)
3713 kill_one_lwp (ptid_get_lwp (lp->ptid));
3717 /* Callback for iterate_over_lwps. */
3720 kill_wait_callback (struct lwp_info *lp, void *data)
3722 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3726 /* Kill the fork children of any threads of inferior INF that are
3727 stopped at a fork event. */
3730 kill_unfollowed_fork_children (struct inferior *inf)
3732 struct thread_info *thread;
3734 ALL_NON_EXITED_THREADS (thread)
3735 if (thread->inf == inf)
3737 struct target_waitstatus *ws = &thread->pending_follow;
3739 if (ws->kind == TARGET_WAITKIND_FORKED
3740 || ws->kind == TARGET_WAITKIND_VFORKED)
3742 ptid_t child_ptid = ws->value.related_pid;
3743 int child_pid = ptid_get_pid (child_ptid);
3744 int child_lwp = ptid_get_lwp (child_ptid);
3746 kill_one_lwp (child_lwp);
3747 kill_wait_one_lwp (child_lwp);
3749 /* Let the arch-specific native code know this process is
3751 linux_nat_forget_process (child_pid);
3757 linux_nat_kill (struct target_ops *ops)
3759 /* If we're stopped while forking and we haven't followed yet,
3760 kill the other task. We need to do this first because the
3761 parent will be sleeping if this is a vfork. */
3762 kill_unfollowed_fork_children (current_inferior ());
3764 if (forks_exist_p ())
3765 linux_fork_killall ();
3768 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3770 /* Stop all threads before killing them, since ptrace requires
3771 that the thread is stopped to sucessfully PTRACE_KILL. */
3772 iterate_over_lwps (ptid, stop_callback, NULL);
3773 /* ... and wait until all of them have reported back that
3774 they're no longer running. */
3775 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3777 /* Kill all LWP's ... */
3778 iterate_over_lwps (ptid, kill_callback, NULL);
3780 /* ... and wait until we've flushed all events. */
3781 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3784 target_mourn_inferior (inferior_ptid);
3788 linux_nat_mourn_inferior (struct target_ops *ops)
3790 int pid = ptid_get_pid (inferior_ptid);
3792 purge_lwp_list (pid);
3794 if (! forks_exist_p ())
3795 /* Normal case, no other forks available. */
3796 linux_ops->to_mourn_inferior (ops);
3798 /* Multi-fork case. The current inferior_ptid has exited, but
3799 there are other viable forks to debug. Delete the exiting
3800 one and context-switch to the first available. */
3801 linux_fork_mourn_inferior ();
3803 /* Let the arch-specific native code know this process is gone. */
3804 linux_nat_forget_process (pid);
3807 /* Convert a native/host siginfo object, into/from the siginfo in the
3808 layout of the inferiors' architecture. */
3811 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3815 if (linux_nat_siginfo_fixup != NULL)
3816 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3818 /* If there was no callback, or the callback didn't do anything,
3819 then just do a straight memcpy. */
3823 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3825 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3829 static enum target_xfer_status
3830 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3831 const char *annex, gdb_byte *readbuf,
3832 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3833 ULONGEST *xfered_len)
3837 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3839 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3840 gdb_assert (readbuf || writebuf);
3842 pid = ptid_get_lwp (inferior_ptid);
3844 pid = ptid_get_pid (inferior_ptid);
3846 if (offset > sizeof (siginfo))
3847 return TARGET_XFER_E_IO;
3850 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3852 return TARGET_XFER_E_IO;
3854 /* When GDB is built as a 64-bit application, ptrace writes into
3855 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3856 inferior with a 64-bit GDB should look the same as debugging it
3857 with a 32-bit GDB, we need to convert it. GDB core always sees
3858 the converted layout, so any read/write will have to be done
3860 siginfo_fixup (&siginfo, inf_siginfo, 0);
3862 if (offset + len > sizeof (siginfo))
3863 len = sizeof (siginfo) - offset;
3865 if (readbuf != NULL)
3866 memcpy (readbuf, inf_siginfo + offset, len);
3869 memcpy (inf_siginfo + offset, writebuf, len);
3871 /* Convert back to ptrace layout before flushing it out. */
3872 siginfo_fixup (&siginfo, inf_siginfo, 1);
3875 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3877 return TARGET_XFER_E_IO;
3881 return TARGET_XFER_OK;
3884 static enum target_xfer_status
3885 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3886 const char *annex, gdb_byte *readbuf,
3887 const gdb_byte *writebuf,
3888 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3890 enum target_xfer_status xfer;
3892 if (object == TARGET_OBJECT_SIGNAL_INFO)
3893 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3894 offset, len, xfered_len);
3896 /* The target is connected but no live inferior is selected. Pass
3897 this request down to a lower stratum (e.g., the executable
3899 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3900 return TARGET_XFER_EOF;
3902 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3903 offset, len, xfered_len);
3909 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3911 /* As long as a PTID is in lwp list, consider it alive. */
3912 return find_lwp_pid (ptid) != NULL;
3915 /* Implement the to_update_thread_list target method for this
3919 linux_nat_update_thread_list (struct target_ops *ops)
3921 struct lwp_info *lwp;
3923 /* We add/delete threads from the list as clone/exit events are
3924 processed, so just try deleting exited threads still in the
3926 delete_exited_threads ();
3928 /* Update the processor core that each lwp/thread was last seen
3932 /* Avoid accessing /proc if the thread hasn't run since we last
3933 time we fetched the thread's core. Accessing /proc becomes
3934 noticeably expensive when we have thousands of LWPs. */
3935 if (lwp->core == -1)
3936 lwp->core = linux_common_core_of_thread (lwp->ptid);
3941 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3943 static char buf[64];
3945 if (ptid_lwp_p (ptid)
3946 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3947 || num_lwps (ptid_get_pid (ptid)) > 1))
3949 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3953 return normal_pid_to_str (ptid);
3957 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3959 return linux_proc_tid_get_name (thr->ptid);
3962 /* Accepts an integer PID; Returns a string representing a file that
3963 can be opened to get the symbols for the child process. */
3966 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3968 return linux_proc_pid_to_exec_file (pid);
3971 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3972 Because we can use a single read/write call, this can be much more
3973 efficient than banging away at PTRACE_PEEKTEXT. */
3975 static enum target_xfer_status
3976 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3977 const char *annex, gdb_byte *readbuf,
3978 const gdb_byte *writebuf,
3979 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3985 if (object != TARGET_OBJECT_MEMORY)
3986 return TARGET_XFER_EOF;
3988 /* Don't bother for one word. */
3989 if (len < 3 * sizeof (long))
3990 return TARGET_XFER_EOF;
3992 /* We could keep this file open and cache it - possibly one per
3993 thread. That requires some juggling, but is even faster. */
3994 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3995 ptid_get_lwp (inferior_ptid));
3996 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
3999 return TARGET_XFER_EOF;
4001 /* Use pread64/pwrite64 if available, since they save a syscall and can
4002 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
4003 debugging a SPARC64 application). */
4005 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
4006 : pwrite64 (fd, writebuf, len, offset));
4008 ret = lseek (fd, offset, SEEK_SET);
4010 ret = (readbuf ? read (fd, readbuf, len)
4011 : write (fd, writebuf, len));
4016 if (ret == -1 || ret == 0)
4017 return TARGET_XFER_EOF;
4021 return TARGET_XFER_OK;
4026 /* Enumerate spufs IDs for process PID. */
4028 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4030 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4032 LONGEST written = 0;
4035 struct dirent *entry;
4037 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4038 dir = opendir (path);
4043 while ((entry = readdir (dir)) != NULL)
4049 fd = atoi (entry->d_name);
4053 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4054 if (stat (path, &st) != 0)
4056 if (!S_ISDIR (st.st_mode))
4059 if (statfs (path, &stfs) != 0)
4061 if (stfs.f_type != SPUFS_MAGIC)
4064 if (pos >= offset && pos + 4 <= offset + len)
4066 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4076 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4077 object type, using the /proc file system. */
4079 static enum target_xfer_status
4080 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4081 const char *annex, gdb_byte *readbuf,
4082 const gdb_byte *writebuf,
4083 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4088 int pid = ptid_get_lwp (inferior_ptid);
4093 return TARGET_XFER_E_IO;
4096 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4099 return TARGET_XFER_E_IO;
4101 return TARGET_XFER_EOF;
4104 *xfered_len = (ULONGEST) l;
4105 return TARGET_XFER_OK;
4110 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4111 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4113 return TARGET_XFER_E_IO;
4116 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4119 return TARGET_XFER_EOF;
4123 ret = write (fd, writebuf, (size_t) len);
4125 ret = read (fd, readbuf, (size_t) len);
4130 return TARGET_XFER_E_IO;
4132 return TARGET_XFER_EOF;
4135 *xfered_len = (ULONGEST) ret;
4136 return TARGET_XFER_OK;
4141 /* Parse LINE as a signal set and add its set bits to SIGS. */
4144 add_line_to_sigset (const char *line, sigset_t *sigs)
4146 int len = strlen (line) - 1;
4150 if (line[len] != '\n')
4151 error (_("Could not parse signal set: %s"), line);
4159 if (*p >= '0' && *p <= '9')
4161 else if (*p >= 'a' && *p <= 'f')
4162 digit = *p - 'a' + 10;
4164 error (_("Could not parse signal set: %s"), line);
4169 sigaddset (sigs, signum + 1);
4171 sigaddset (sigs, signum + 2);
4173 sigaddset (sigs, signum + 3);
4175 sigaddset (sigs, signum + 4);
4181 /* Find process PID's pending signals from /proc/pid/status and set
4185 linux_proc_pending_signals (int pid, sigset_t *pending,
4186 sigset_t *blocked, sigset_t *ignored)
4188 char buffer[PATH_MAX], fname[PATH_MAX];
4190 sigemptyset (pending);
4191 sigemptyset (blocked);
4192 sigemptyset (ignored);
4193 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4194 gdb_file_up procfile = gdb_fopen_cloexec (fname, "r");
4195 if (procfile == NULL)
4196 error (_("Could not open %s"), fname);
4198 while (fgets (buffer, PATH_MAX, procfile.get ()) != NULL)
4200 /* Normal queued signals are on the SigPnd line in the status
4201 file. However, 2.6 kernels also have a "shared" pending
4202 queue for delivering signals to a thread group, so check for
4205 Unfortunately some Red Hat kernels include the shared pending
4206 queue but not the ShdPnd status field. */
4208 if (startswith (buffer, "SigPnd:\t"))
4209 add_line_to_sigset (buffer + 8, pending);
4210 else if (startswith (buffer, "ShdPnd:\t"))
4211 add_line_to_sigset (buffer + 8, pending);
4212 else if (startswith (buffer, "SigBlk:\t"))
4213 add_line_to_sigset (buffer + 8, blocked);
4214 else if (startswith (buffer, "SigIgn:\t"))
4215 add_line_to_sigset (buffer + 8, ignored);
4219 static enum target_xfer_status
4220 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4221 const char *annex, gdb_byte *readbuf,
4222 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4223 ULONGEST *xfered_len)
4225 gdb_assert (object == TARGET_OBJECT_OSDATA);
4227 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4228 if (*xfered_len == 0)
4229 return TARGET_XFER_EOF;
4231 return TARGET_XFER_OK;
4234 static enum target_xfer_status
4235 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4236 const char *annex, gdb_byte *readbuf,
4237 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4238 ULONGEST *xfered_len)
4240 enum target_xfer_status xfer;
4242 if (object == TARGET_OBJECT_AUXV)
4243 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4244 offset, len, xfered_len);
4246 if (object == TARGET_OBJECT_OSDATA)
4247 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4248 offset, len, xfered_len);
4250 if (object == TARGET_OBJECT_SPU)
4251 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4252 offset, len, xfered_len);
4254 /* GDB calculates all the addresses in possibly larget width of the address.
4255 Address width needs to be masked before its final use - either by
4256 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4258 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4260 if (object == TARGET_OBJECT_MEMORY)
4262 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4264 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4265 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4268 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4269 offset, len, xfered_len);
4270 if (xfer != TARGET_XFER_EOF)
4273 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4274 offset, len, xfered_len);
4278 cleanup_target_stop (void *arg)
4280 ptid_t *ptid = (ptid_t *) arg;
4282 gdb_assert (arg != NULL);
4285 target_continue_no_signal (*ptid);
4288 static VEC(static_tracepoint_marker_p) *
4289 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4292 char s[IPA_CMD_BUF_SIZE];
4293 struct cleanup *old_chain;
4294 int pid = ptid_get_pid (inferior_ptid);
4295 VEC(static_tracepoint_marker_p) *markers = NULL;
4296 struct static_tracepoint_marker *marker = NULL;
4298 ptid_t ptid = ptid_build (pid, 0, 0);
4303 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4304 s[sizeof ("qTfSTM")] = 0;
4306 agent_run_command (pid, s, strlen (s) + 1);
4308 old_chain = make_cleanup (free_current_marker, &marker);
4309 make_cleanup (cleanup_target_stop, &ptid);
4314 marker = XCNEW (struct static_tracepoint_marker);
4318 parse_static_tracepoint_marker_definition (p, &p, marker);
4320 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4322 VEC_safe_push (static_tracepoint_marker_p,
4328 release_static_tracepoint_marker (marker);
4329 memset (marker, 0, sizeof (*marker));
4332 while (*p++ == ','); /* comma-separated list */
4334 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4335 s[sizeof ("qTsSTM")] = 0;
4336 agent_run_command (pid, s, strlen (s) + 1);
4340 do_cleanups (old_chain);
4345 /* Create a prototype generic GNU/Linux target. The client can override
4346 it with local methods. */
4349 linux_target_install_ops (struct target_ops *t)
4351 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4352 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4353 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4354 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4355 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4356 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4357 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4358 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4359 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4360 t->to_post_attach = linux_child_post_attach;
4361 t->to_follow_fork = linux_child_follow_fork;
4363 super_xfer_partial = t->to_xfer_partial;
4364 t->to_xfer_partial = linux_xfer_partial;
4366 t->to_static_tracepoint_markers_by_strid
4367 = linux_child_static_tracepoint_markers_by_strid;
4373 struct target_ops *t;
4375 t = inf_ptrace_target ();
4376 linux_target_install_ops (t);
4382 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4384 struct target_ops *t;
4386 t = inf_ptrace_trad_target (register_u_offset);
4387 linux_target_install_ops (t);
4392 /* target_is_async_p implementation. */
4395 linux_nat_is_async_p (struct target_ops *ops)
4397 return linux_is_async_p ();
4400 /* target_can_async_p implementation. */
4403 linux_nat_can_async_p (struct target_ops *ops)
4405 /* We're always async, unless the user explicitly prevented it with the
4406 "maint set target-async" command. */
4407 return target_async_permitted;
4411 linux_nat_supports_non_stop (struct target_ops *self)
4416 /* to_always_non_stop_p implementation. */
4419 linux_nat_always_non_stop_p (struct target_ops *self)
4424 /* True if we want to support multi-process. To be removed when GDB
4425 supports multi-exec. */
4427 int linux_multi_process = 1;
4430 linux_nat_supports_multi_process (struct target_ops *self)
4432 return linux_multi_process;
4436 linux_nat_supports_disable_randomization (struct target_ops *self)
4438 #ifdef HAVE_PERSONALITY
4445 static int async_terminal_is_ours = 1;
4447 /* target_terminal_inferior implementation.
4449 This is a wrapper around child_terminal_inferior to add async support. */
4452 linux_nat_terminal_inferior (struct target_ops *self)
4454 child_terminal_inferior (self);
4456 /* Calls to target_terminal_*() are meant to be idempotent. */
4457 if (!async_terminal_is_ours)
4460 async_terminal_is_ours = 0;
4464 /* target_terminal::ours implementation.
4466 This is a wrapper around child_terminal_ours to add async support (and
4467 implement the target_terminal::ours vs target_terminal::ours_for_output
4468 distinction). child_terminal_ours is currently no different than
4469 child_terminal_ours_for_output.
4470 We leave target_terminal::ours_for_output alone, leaving it to
4471 child_terminal_ours_for_output. */
4474 linux_nat_terminal_ours (struct target_ops *self)
4476 /* GDB should never give the terminal to the inferior if the
4477 inferior is running in the background (run&, continue&, etc.),
4478 but claiming it sure should. */
4479 child_terminal_ours (self);
4481 if (async_terminal_is_ours)
4484 clear_sigint_trap ();
4485 async_terminal_is_ours = 1;
4488 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4489 so we notice when any child changes state, and notify the
4490 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4491 above to wait for the arrival of a SIGCHLD. */
4494 sigchld_handler (int signo)
4496 int old_errno = errno;
4498 if (debug_linux_nat)
4499 ui_file_write_async_safe (gdb_stdlog,
4500 "sigchld\n", sizeof ("sigchld\n") - 1);
4502 if (signo == SIGCHLD
4503 && linux_nat_event_pipe[0] != -1)
4504 async_file_mark (); /* Let the event loop know that there are
4505 events to handle. */
4510 /* Callback registered with the target events file descriptor. */
4513 handle_target_event (int error, gdb_client_data client_data)
4515 inferior_event_handler (INF_REG_EVENT, NULL);
4518 /* Create/destroy the target events pipe. Returns previous state. */
4521 linux_async_pipe (int enable)
4523 int previous = linux_is_async_p ();
4525 if (previous != enable)
4529 /* Block child signals while we create/destroy the pipe, as
4530 their handler writes to it. */
4531 block_child_signals (&prev_mask);
4535 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4536 internal_error (__FILE__, __LINE__,
4537 "creating event pipe failed.");
4539 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4540 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4544 close (linux_nat_event_pipe[0]);
4545 close (linux_nat_event_pipe[1]);
4546 linux_nat_event_pipe[0] = -1;
4547 linux_nat_event_pipe[1] = -1;
4550 restore_child_signals_mask (&prev_mask);
4556 /* target_async implementation. */
4559 linux_nat_async (struct target_ops *ops, int enable)
4563 if (!linux_async_pipe (1))
4565 add_file_handler (linux_nat_event_pipe[0],
4566 handle_target_event, NULL);
4567 /* There may be pending events to handle. Tell the event loop
4574 delete_file_handler (linux_nat_event_pipe[0]);
4575 linux_async_pipe (0);
4580 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4584 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4588 if (debug_linux_nat)
4589 fprintf_unfiltered (gdb_stdlog,
4590 "LNSL: running -> suspending %s\n",
4591 target_pid_to_str (lwp->ptid));
4594 if (lwp->last_resume_kind == resume_stop)
4596 if (debug_linux_nat)
4597 fprintf_unfiltered (gdb_stdlog,
4598 "linux-nat: already stopping LWP %ld at "
4600 ptid_get_lwp (lwp->ptid));
4604 stop_callback (lwp, NULL);
4605 lwp->last_resume_kind = resume_stop;
4609 /* Already known to be stopped; do nothing. */
4611 if (debug_linux_nat)
4613 if (find_thread_ptid (lwp->ptid)->stop_requested)
4614 fprintf_unfiltered (gdb_stdlog,
4615 "LNSL: already stopped/stop_requested %s\n",
4616 target_pid_to_str (lwp->ptid));
4618 fprintf_unfiltered (gdb_stdlog,
4619 "LNSL: already stopped/no "
4620 "stop_requested yet %s\n",
4621 target_pid_to_str (lwp->ptid));
4628 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4630 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4634 linux_nat_close (struct target_ops *self)
4636 /* Unregister from the event loop. */
4637 if (linux_nat_is_async_p (self))
4638 linux_nat_async (self, 0);
4640 if (linux_ops->to_close)
4641 linux_ops->to_close (linux_ops);
4646 /* When requests are passed down from the linux-nat layer to the
4647 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4648 used. The address space pointer is stored in the inferior object,
4649 but the common code that is passed such ptid can't tell whether
4650 lwpid is a "main" process id or not (it assumes so). We reverse
4651 look up the "main" process id from the lwp here. */
4653 static struct address_space *
4654 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4656 struct lwp_info *lwp;
4657 struct inferior *inf;
4660 if (ptid_get_lwp (ptid) == 0)
4662 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4664 lwp = find_lwp_pid (ptid);
4665 pid = ptid_get_pid (lwp->ptid);
4669 /* A (pid,lwpid,0) ptid. */
4670 pid = ptid_get_pid (ptid);
4673 inf = find_inferior_pid (pid);
4674 gdb_assert (inf != NULL);
4678 /* Return the cached value of the processor core for thread PTID. */
4681 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4683 struct lwp_info *info = find_lwp_pid (ptid);
4690 /* Implementation of to_filesystem_is_local. */
4693 linux_nat_filesystem_is_local (struct target_ops *ops)
4695 struct inferior *inf = current_inferior ();
4697 if (inf->fake_pid_p || inf->pid == 0)
4700 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4703 /* Convert the INF argument passed to a to_fileio_* method
4704 to a process ID suitable for passing to its corresponding
4705 linux_mntns_* function. If INF is non-NULL then the
4706 caller is requesting the filesystem seen by INF. If INF
4707 is NULL then the caller is requesting the filesystem seen
4708 by the GDB. We fall back to GDB's filesystem in the case
4709 that INF is non-NULL but its PID is unknown. */
4712 linux_nat_fileio_pid_of (struct inferior *inf)
4714 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4720 /* Implementation of to_fileio_open. */
4723 linux_nat_fileio_open (struct target_ops *self,
4724 struct inferior *inf, const char *filename,
4725 int flags, int mode, int warn_if_slow,
4732 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4733 || fileio_to_host_mode (mode, &nat_mode) == -1)
4735 *target_errno = FILEIO_EINVAL;
4739 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4740 filename, nat_flags, nat_mode);
4742 *target_errno = host_to_fileio_error (errno);
4747 /* Implementation of to_fileio_readlink. */
4750 linux_nat_fileio_readlink (struct target_ops *self,
4751 struct inferior *inf, const char *filename,
4758 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4759 filename, buf, sizeof (buf));
4762 *target_errno = host_to_fileio_error (errno);
4766 ret = (char *) xmalloc (len + 1);
4767 memcpy (ret, buf, len);
4772 /* Implementation of to_fileio_unlink. */
4775 linux_nat_fileio_unlink (struct target_ops *self,
4776 struct inferior *inf, const char *filename,
4781 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4784 *target_errno = host_to_fileio_error (errno);
4789 /* Implementation of the to_thread_events method. */
4792 linux_nat_thread_events (struct target_ops *ops, int enable)
4794 report_thread_events = enable;
4798 linux_nat_add_target (struct target_ops *t)
4800 /* Save the provided single-threaded target. We save this in a separate
4801 variable because another target we've inherited from (e.g. inf-ptrace)
4802 may have saved a pointer to T; we want to use it for the final
4803 process stratum target. */
4804 linux_ops_saved = *t;
4805 linux_ops = &linux_ops_saved;
4807 /* Override some methods for multithreading. */
4808 t->to_create_inferior = linux_nat_create_inferior;
4809 t->to_attach = linux_nat_attach;
4810 t->to_detach = linux_nat_detach;
4811 t->to_resume = linux_nat_resume;
4812 t->to_wait = linux_nat_wait;
4813 t->to_pass_signals = linux_nat_pass_signals;
4814 t->to_xfer_partial = linux_nat_xfer_partial;
4815 t->to_kill = linux_nat_kill;
4816 t->to_mourn_inferior = linux_nat_mourn_inferior;
4817 t->to_thread_alive = linux_nat_thread_alive;
4818 t->to_update_thread_list = linux_nat_update_thread_list;
4819 t->to_pid_to_str = linux_nat_pid_to_str;
4820 t->to_thread_name = linux_nat_thread_name;
4821 t->to_has_thread_control = tc_schedlock;
4822 t->to_thread_address_space = linux_nat_thread_address_space;
4823 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4824 t->to_stopped_data_address = linux_nat_stopped_data_address;
4825 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4826 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4827 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4828 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4829 t->to_thread_events = linux_nat_thread_events;
4831 t->to_can_async_p = linux_nat_can_async_p;
4832 t->to_is_async_p = linux_nat_is_async_p;
4833 t->to_supports_non_stop = linux_nat_supports_non_stop;
4834 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4835 t->to_async = linux_nat_async;
4836 t->to_terminal_inferior = linux_nat_terminal_inferior;
4837 t->to_terminal_ours = linux_nat_terminal_ours;
4839 super_close = t->to_close;
4840 t->to_close = linux_nat_close;
4842 t->to_stop = linux_nat_stop;
4844 t->to_supports_multi_process = linux_nat_supports_multi_process;
4846 t->to_supports_disable_randomization
4847 = linux_nat_supports_disable_randomization;
4849 t->to_core_of_thread = linux_nat_core_of_thread;
4851 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4852 t->to_fileio_open = linux_nat_fileio_open;
4853 t->to_fileio_readlink = linux_nat_fileio_readlink;
4854 t->to_fileio_unlink = linux_nat_fileio_unlink;
4856 /* We don't change the stratum; this target will sit at
4857 process_stratum and thread_db will set at thread_stratum. This
4858 is a little strange, since this is a multi-threaded-capable
4859 target, but we want to be on the stack below thread_db, and we
4860 also want to be used for single-threaded processes. */
4865 /* Register a method to call whenever a new thread is attached. */
4867 linux_nat_set_new_thread (struct target_ops *t,
4868 void (*new_thread) (struct lwp_info *))
4870 /* Save the pointer. We only support a single registered instance
4871 of the GNU/Linux native target, so we do not need to map this to
4873 linux_nat_new_thread = new_thread;
4876 /* See declaration in linux-nat.h. */
4879 linux_nat_set_new_fork (struct target_ops *t,
4880 linux_nat_new_fork_ftype *new_fork)
4882 /* Save the pointer. */
4883 linux_nat_new_fork = new_fork;
4886 /* See declaration in linux-nat.h. */
4889 linux_nat_set_forget_process (struct target_ops *t,
4890 linux_nat_forget_process_ftype *fn)
4892 /* Save the pointer. */
4893 linux_nat_forget_process_hook = fn;
4896 /* See declaration in linux-nat.h. */
4899 linux_nat_forget_process (pid_t pid)
4901 if (linux_nat_forget_process_hook != NULL)
4902 linux_nat_forget_process_hook (pid);
4905 /* Register a method that converts a siginfo object between the layout
4906 that ptrace returns, and the layout in the architecture of the
4909 linux_nat_set_siginfo_fixup (struct target_ops *t,
4910 int (*siginfo_fixup) (siginfo_t *,
4914 /* Save the pointer. */
4915 linux_nat_siginfo_fixup = siginfo_fixup;
4918 /* Register a method to call prior to resuming a thread. */
4921 linux_nat_set_prepare_to_resume (struct target_ops *t,
4922 void (*prepare_to_resume) (struct lwp_info *))
4924 /* Save the pointer. */
4925 linux_nat_prepare_to_resume = prepare_to_resume;
4928 /* See linux-nat.h. */
4931 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4935 pid = ptid_get_lwp (ptid);
4937 pid = ptid_get_pid (ptid);
4940 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4943 memset (siginfo, 0, sizeof (*siginfo));
4949 /* See nat/linux-nat.h. */
4952 current_lwp_ptid (void)
4954 gdb_assert (ptid_lwp_p (inferior_ptid));
4955 return inferior_ptid;
4959 _initialize_linux_nat (void)
4961 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4962 &debug_linux_nat, _("\
4963 Set debugging of GNU/Linux lwp module."), _("\
4964 Show debugging of GNU/Linux lwp module."), _("\
4965 Enables printf debugging output."),
4967 show_debug_linux_nat,
4968 &setdebuglist, &showdebuglist);
4970 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4971 &debug_linux_namespaces, _("\
4972 Set debugging of GNU/Linux namespaces module."), _("\
4973 Show debugging of GNU/Linux namespaces module."), _("\
4974 Enables printf debugging output."),
4977 &setdebuglist, &showdebuglist);
4979 /* Save this mask as the default. */
4980 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4982 /* Install a SIGCHLD handler. */
4983 sigchld_action.sa_handler = sigchld_handler;
4984 sigemptyset (&sigchld_action.sa_mask);
4985 sigchld_action.sa_flags = SA_RESTART;
4987 /* Make it the default. */
4988 sigaction (SIGCHLD, &sigchld_action, NULL);
4990 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4991 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4992 sigdelset (&suspend_mask, SIGCHLD);
4994 sigemptyset (&blocked_mask);
4996 lwp_lwpid_htab_create ();
5000 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5001 the GNU/Linux Threads library and therefore doesn't really belong
5004 /* Return the set of signals used by the threads library in *SET. */
5007 lin_thread_get_thread_signals (sigset_t *set)
5011 /* NPTL reserves the first two RT signals, but does not provide any
5012 way for the debugger to query the signal numbers - fortunately
5013 they don't change. */
5014 sigaddset (set, __SIGRTMIN);
5015 sigaddset (set, __SIGRTMIN + 1);