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);
480 struct cleanup *old_chain;
482 ptid_t parent_ptid, child_ptid;
483 int parent_pid, child_pid;
485 has_vforked = (inferior_thread ()->pending_follow.kind
486 == TARGET_WAITKIND_VFORKED);
487 parent_ptid = inferior_ptid;
488 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
489 parent_pid = ptid_get_lwp (parent_ptid);
490 child_pid = ptid_get_lwp (child_ptid);
492 /* We're already attached to the parent, by default. */
493 old_chain = save_inferior_ptid ();
494 inferior_ptid = child_ptid;
495 child_lp = add_lwp (inferior_ptid);
496 child_lp->stopped = 1;
497 child_lp->last_resume_kind = resume_stop;
499 /* Detach new forked process? */
502 make_cleanup (delete_lwp_cleanup, child_lp);
504 if (linux_nat_prepare_to_resume != NULL)
505 linux_nat_prepare_to_resume (child_lp);
507 /* When debugging an inferior in an architecture that supports
508 hardware single stepping on a kernel without commit
509 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
510 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
511 set if the parent process had them set.
512 To work around this, single step the child process
513 once before detaching to clear the flags. */
515 if (!gdbarch_software_single_step_p (target_thread_architecture
518 linux_disable_event_reporting (child_pid);
519 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
520 perror_with_name (_("Couldn't do single step"));
521 if (my_waitpid (child_pid, &status, 0) < 0)
522 perror_with_name (_("Couldn't wait vfork process"));
525 if (WIFSTOPPED (status))
529 signo = WSTOPSIG (status);
531 && !signal_pass_state (gdb_signal_from_host (signo)))
533 ptrace (PTRACE_DETACH, child_pid, 0, signo);
536 /* Resets value of inferior_ptid to parent ptid. */
537 do_cleanups (old_chain);
541 /* Let the thread_db layer learn about this new process. */
542 check_for_thread_db ();
545 do_cleanups (old_chain);
549 struct lwp_info *parent_lp;
551 parent_lp = find_lwp_pid (parent_ptid);
552 gdb_assert (linux_supports_tracefork () >= 0);
554 if (linux_supports_tracevforkdone ())
557 fprintf_unfiltered (gdb_stdlog,
558 "LCFF: waiting for VFORK_DONE on %d\n",
560 parent_lp->stopped = 1;
562 /* We'll handle the VFORK_DONE event like any other
563 event, in target_wait. */
567 /* We can't insert breakpoints until the child has
568 finished with the shared memory region. We need to
569 wait until that happens. Ideal would be to just
571 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
572 - waitpid (parent_pid, &status, __WALL);
573 However, most architectures can't handle a syscall
574 being traced on the way out if it wasn't traced on
577 We might also think to loop, continuing the child
578 until it exits or gets a SIGTRAP. One problem is
579 that the child might call ptrace with PTRACE_TRACEME.
581 There's no simple and reliable way to figure out when
582 the vforked child will be done with its copy of the
583 shared memory. We could step it out of the syscall,
584 two instructions, let it go, and then single-step the
585 parent once. When we have hardware single-step, this
586 would work; with software single-step it could still
587 be made to work but we'd have to be able to insert
588 single-step breakpoints in the child, and we'd have
589 to insert -just- the single-step breakpoint in the
590 parent. Very awkward.
592 In the end, the best we can do is to make sure it
593 runs for a little while. Hopefully it will be out of
594 range of any breakpoints we reinsert. Usually this
595 is only the single-step breakpoint at vfork's return
599 fprintf_unfiltered (gdb_stdlog,
600 "LCFF: no VFORK_DONE "
601 "support, sleeping a bit\n");
605 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
606 and leave it pending. The next linux_nat_resume call
607 will notice a pending event, and bypasses actually
608 resuming the inferior. */
609 parent_lp->status = 0;
610 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
611 parent_lp->stopped = 1;
613 /* If we're in async mode, need to tell the event loop
614 there's something here to process. */
615 if (target_is_async_p ())
622 struct lwp_info *child_lp;
624 child_lp = add_lwp (inferior_ptid);
625 child_lp->stopped = 1;
626 child_lp->last_resume_kind = resume_stop;
628 /* Let the thread_db layer learn about this new process. */
629 check_for_thread_db ();
637 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
639 return !linux_supports_tracefork ();
643 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
649 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
651 return !linux_supports_tracefork ();
655 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
661 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
663 return !linux_supports_tracefork ();
667 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
673 linux_child_set_syscall_catchpoint (struct target_ops *self,
674 int pid, int needed, int any_count,
675 int table_size, int *table)
677 if (!linux_supports_tracesysgood ())
680 /* On GNU/Linux, we ignore the arguments. It means that we only
681 enable the syscall catchpoints, but do not disable them.
683 Also, we do not use the `table' information because we do not
684 filter system calls here. We let GDB do the logic for us. */
688 /* List of known LWPs, keyed by LWP PID. This speeds up the common
689 case of mapping a PID returned from the kernel to our corresponding
690 lwp_info data structure. */
691 static htab_t lwp_lwpid_htab;
693 /* Calculate a hash from a lwp_info's LWP PID. */
696 lwp_info_hash (const void *ap)
698 const struct lwp_info *lp = (struct lwp_info *) ap;
699 pid_t pid = ptid_get_lwp (lp->ptid);
701 return iterative_hash_object (pid, 0);
704 /* Equality function for the lwp_info hash table. Compares the LWP's
708 lwp_lwpid_htab_eq (const void *a, const void *b)
710 const struct lwp_info *entry = (const struct lwp_info *) a;
711 const struct lwp_info *element = (const struct lwp_info *) b;
713 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
716 /* Create the lwp_lwpid_htab hash table. */
719 lwp_lwpid_htab_create (void)
721 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
724 /* Add LP to the hash table. */
727 lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
731 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
732 gdb_assert (slot != NULL && *slot == NULL);
736 /* Head of doubly-linked list of known LWPs. Sorted by reverse
737 creation order. This order is assumed in some cases. E.g.,
738 reaping status after killing alls lwps of a process: the leader LWP
739 must be reaped last. */
740 struct lwp_info *lwp_list;
742 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
745 lwp_list_add (struct lwp_info *lp)
748 if (lwp_list != NULL)
753 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
757 lwp_list_remove (struct lwp_info *lp)
759 /* Remove from sorted-by-creation-order list. */
760 if (lp->next != NULL)
761 lp->next->prev = lp->prev;
762 if (lp->prev != NULL)
763 lp->prev->next = lp->next;
770 /* Original signal mask. */
771 static sigset_t normal_mask;
773 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
774 _initialize_linux_nat. */
775 static sigset_t suspend_mask;
777 /* Signals to block to make that sigsuspend work. */
778 static sigset_t blocked_mask;
780 /* SIGCHLD action. */
781 struct sigaction sigchld_action;
783 /* Block child signals (SIGCHLD and linux threads signals), and store
784 the previous mask in PREV_MASK. */
787 block_child_signals (sigset_t *prev_mask)
789 /* Make sure SIGCHLD is blocked. */
790 if (!sigismember (&blocked_mask, SIGCHLD))
791 sigaddset (&blocked_mask, SIGCHLD);
793 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
796 /* Restore child signals mask, previously returned by
797 block_child_signals. */
800 restore_child_signals_mask (sigset_t *prev_mask)
802 sigprocmask (SIG_SETMASK, prev_mask, NULL);
805 /* Mask of signals to pass directly to the inferior. */
806 static sigset_t pass_mask;
808 /* Update signals to pass to the inferior. */
810 linux_nat_pass_signals (struct target_ops *self,
811 int numsigs, unsigned char *pass_signals)
815 sigemptyset (&pass_mask);
817 for (signo = 1; signo < NSIG; signo++)
819 int target_signo = gdb_signal_from_host (signo);
820 if (target_signo < numsigs && pass_signals[target_signo])
821 sigaddset (&pass_mask, signo);
827 /* Prototypes for local functions. */
828 static int stop_wait_callback (struct lwp_info *lp, void *data);
829 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
830 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
831 static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
835 /* Destroy and free LP. */
838 lwp_free (struct lwp_info *lp)
840 xfree (lp->arch_private);
844 /* Traversal function for purge_lwp_list. */
847 lwp_lwpid_htab_remove_pid (void **slot, void *info)
849 struct lwp_info *lp = (struct lwp_info *) *slot;
850 int pid = *(int *) info;
852 if (ptid_get_pid (lp->ptid) == pid)
854 htab_clear_slot (lwp_lwpid_htab, slot);
855 lwp_list_remove (lp);
862 /* Remove all LWPs belong to PID from the lwp list. */
865 purge_lwp_list (int pid)
867 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
870 /* Add the LWP specified by PTID to the list. PTID is the first LWP
871 in the process. Return a pointer to the structure describing the
874 This differs from add_lwp in that we don't let the arch specific
875 bits know about this new thread. Current clients of this callback
876 take the opportunity to install watchpoints in the new thread, and
877 we shouldn't do that for the first thread. If we're spawning a
878 child ("run"), the thread executes the shell wrapper first, and we
879 shouldn't touch it until it execs the program we want to debug.
880 For "attach", it'd be okay to call the callback, but it's not
881 necessary, because watchpoints can't yet have been inserted into
884 static struct lwp_info *
885 add_initial_lwp (ptid_t ptid)
889 gdb_assert (ptid_lwp_p (ptid));
891 lp = XNEW (struct lwp_info);
893 memset (lp, 0, sizeof (struct lwp_info));
895 lp->last_resume_kind = resume_continue;
896 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
901 /* Add to sorted-by-reverse-creation-order list. */
904 /* Add to keyed-by-pid htab. */
905 lwp_lwpid_htab_add_lwp (lp);
910 /* Add the LWP specified by PID to the list. Return a pointer to the
911 structure describing the new LWP. The LWP should already be
914 static struct lwp_info *
915 add_lwp (ptid_t ptid)
919 lp = add_initial_lwp (ptid);
921 /* Let the arch specific bits know about this new thread. Current
922 clients of this callback take the opportunity to install
923 watchpoints in the new thread. We don't do this for the first
924 thread though. See add_initial_lwp. */
925 if (linux_nat_new_thread != NULL)
926 linux_nat_new_thread (lp);
931 /* Remove the LWP specified by PID from the list. */
934 delete_lwp (ptid_t ptid)
938 struct lwp_info dummy;
941 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
945 lp = *(struct lwp_info **) slot;
946 gdb_assert (lp != NULL);
948 htab_clear_slot (lwp_lwpid_htab, slot);
950 /* Remove from sorted-by-creation-order list. */
951 lwp_list_remove (lp);
957 /* Return a pointer to the structure describing the LWP corresponding
958 to PID. If no corresponding LWP could be found, return NULL. */
960 static struct lwp_info *
961 find_lwp_pid (ptid_t ptid)
965 struct lwp_info dummy;
967 if (ptid_lwp_p (ptid))
968 lwp = ptid_get_lwp (ptid);
970 lwp = ptid_get_pid (ptid);
972 dummy.ptid = ptid_build (0, lwp, 0);
973 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
977 /* See nat/linux-nat.h. */
980 iterate_over_lwps (ptid_t filter,
981 iterate_over_lwps_ftype callback,
984 struct lwp_info *lp, *lpnext;
986 for (lp = lwp_list; lp; lp = lpnext)
990 if (ptid_match (lp->ptid, filter))
992 if ((*callback) (lp, data) != 0)
1000 /* Update our internal state when changing from one checkpoint to
1001 another indicated by NEW_PTID. We can only switch single-threaded
1002 applications, so we only create one new LWP, and the previous list
1006 linux_nat_switch_fork (ptid_t new_ptid)
1008 struct lwp_info *lp;
1010 purge_lwp_list (ptid_get_pid (inferior_ptid));
1012 lp = add_lwp (new_ptid);
1015 /* This changes the thread's ptid while preserving the gdb thread
1016 num. Also changes the inferior pid, while preserving the
1018 thread_change_ptid (inferior_ptid, new_ptid);
1020 /* We've just told GDB core that the thread changed target id, but,
1021 in fact, it really is a different thread, with different register
1023 registers_changed ();
1026 /* Handle the exit of a single thread LP. */
1029 exit_lwp (struct lwp_info *lp)
1031 struct thread_info *th = find_thread_ptid (lp->ptid);
1035 if (print_thread_events)
1036 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1038 delete_thread (lp->ptid);
1041 delete_lwp (lp->ptid);
1044 /* Wait for the LWP specified by LP, which we have just attached to.
1045 Returns a wait status for that LWP, to cache. */
1048 linux_nat_post_attach_wait (ptid_t ptid, int first, int *signalled)
1050 pid_t new_pid, pid = ptid_get_lwp (ptid);
1053 if (linux_proc_pid_is_stopped (pid))
1055 if (debug_linux_nat)
1056 fprintf_unfiltered (gdb_stdlog,
1057 "LNPAW: Attaching to a stopped process\n");
1059 /* The process is definitely stopped. It is in a job control
1060 stop, unless the kernel predates the TASK_STOPPED /
1061 TASK_TRACED distinction, in which case it might be in a
1062 ptrace stop. Make sure it is in a ptrace stop; from there we
1063 can kill it, signal it, et cetera.
1065 First make sure there is a pending SIGSTOP. Since we are
1066 already attached, the process can not transition from stopped
1067 to running without a PTRACE_CONT; so we know this signal will
1068 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1069 probably already in the queue (unless this kernel is old
1070 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1071 is not an RT signal, it can only be queued once. */
1072 kill_lwp (pid, SIGSTOP);
1074 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1075 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1076 ptrace (PTRACE_CONT, pid, 0, 0);
1079 /* Make sure the initial process is stopped. The user-level threads
1080 layer might want to poke around in the inferior, and that won't
1081 work if things haven't stabilized yet. */
1082 new_pid = my_waitpid (pid, &status, __WALL);
1083 gdb_assert (pid == new_pid);
1085 if (!WIFSTOPPED (status))
1087 /* The pid we tried to attach has apparently just exited. */
1088 if (debug_linux_nat)
1089 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1090 pid, status_to_str (status));
1094 if (WSTOPSIG (status) != SIGSTOP)
1097 if (debug_linux_nat)
1098 fprintf_unfiltered (gdb_stdlog,
1099 "LNPAW: Received %s after attaching\n",
1100 status_to_str (status));
1107 linux_nat_create_inferior (struct target_ops *ops,
1108 const char *exec_file, const std::string &allargs,
1109 char **env, int from_tty)
1111 struct cleanup *restore_personality
1112 = maybe_disable_address_space_randomization (disable_randomization);
1114 /* The fork_child mechanism is synchronous and calls target_wait, so
1115 we have to mask the async mode. */
1117 /* Make sure we report all signals during startup. */
1118 linux_nat_pass_signals (ops, 0, NULL);
1120 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1122 do_cleanups (restore_personality);
1125 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1126 already attached. Returns true if a new LWP is found, false
1130 attach_proc_task_lwp_callback (ptid_t ptid)
1132 struct lwp_info *lp;
1134 /* Ignore LWPs we're already attached to. */
1135 lp = find_lwp_pid (ptid);
1138 int lwpid = ptid_get_lwp (ptid);
1140 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1144 /* Be quiet if we simply raced with the thread exiting.
1145 EPERM is returned if the thread's task still exists, and
1146 is marked as exited or zombie, as well as other
1147 conditions, so in that case, confirm the status in
1148 /proc/PID/status. */
1150 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1152 if (debug_linux_nat)
1154 fprintf_unfiltered (gdb_stdlog,
1155 "Cannot attach to lwp %d: "
1156 "thread is gone (%d: %s)\n",
1157 lwpid, err, safe_strerror (err));
1162 warning (_("Cannot attach to lwp %d: %s"),
1164 linux_ptrace_attach_fail_reason_string (ptid,
1170 if (debug_linux_nat)
1171 fprintf_unfiltered (gdb_stdlog,
1172 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1173 target_pid_to_str (ptid));
1175 lp = add_lwp (ptid);
1177 /* The next time we wait for this LWP we'll see a SIGSTOP as
1178 PTRACE_ATTACH brings it to a halt. */
1181 /* We need to wait for a stop before being able to make the
1182 next ptrace call on this LWP. */
1183 lp->must_set_ptrace_flags = 1;
1185 /* So that wait collects the SIGSTOP. */
1188 /* Also add the LWP to gdb's thread list, in case a
1189 matching libthread_db is not found (or the process uses
1191 add_thread (lp->ptid);
1192 set_running (lp->ptid, 1);
1193 set_executing (lp->ptid, 1);
1202 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1204 struct lwp_info *lp;
1208 /* Make sure we report all signals during attach. */
1209 linux_nat_pass_signals (ops, 0, NULL);
1213 linux_ops->to_attach (ops, args, from_tty);
1215 CATCH (ex, RETURN_MASK_ERROR)
1217 pid_t pid = parse_pid_to_attach (args);
1218 struct buffer buffer;
1219 char *message, *buffer_s;
1221 message = xstrdup (ex.message);
1222 make_cleanup (xfree, message);
1224 buffer_init (&buffer);
1225 linux_ptrace_attach_fail_reason (pid, &buffer);
1227 buffer_grow_str0 (&buffer, "");
1228 buffer_s = buffer_finish (&buffer);
1229 make_cleanup (xfree, buffer_s);
1231 if (*buffer_s != '\0')
1232 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1234 throw_error (ex.error, "%s", message);
1238 /* The ptrace base target adds the main thread with (pid,0,0)
1239 format. Decorate it with lwp info. */
1240 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1241 ptid_get_pid (inferior_ptid),
1243 thread_change_ptid (inferior_ptid, ptid);
1245 /* Add the initial process as the first LWP to the list. */
1246 lp = add_initial_lwp (ptid);
1248 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->signalled);
1249 if (!WIFSTOPPED (status))
1251 if (WIFEXITED (status))
1253 int exit_code = WEXITSTATUS (status);
1255 target_terminal_ours ();
1256 target_mourn_inferior (inferior_ptid);
1258 error (_("Unable to attach: program exited normally."));
1260 error (_("Unable to attach: program exited with code %d."),
1263 else if (WIFSIGNALED (status))
1265 enum gdb_signal signo;
1267 target_terminal_ours ();
1268 target_mourn_inferior (inferior_ptid);
1270 signo = gdb_signal_from_host (WTERMSIG (status));
1271 error (_("Unable to attach: program terminated with signal "
1273 gdb_signal_to_name (signo),
1274 gdb_signal_to_string (signo));
1277 internal_error (__FILE__, __LINE__,
1278 _("unexpected status %d for PID %ld"),
1279 status, (long) ptid_get_lwp (ptid));
1284 /* Save the wait status to report later. */
1286 if (debug_linux_nat)
1287 fprintf_unfiltered (gdb_stdlog,
1288 "LNA: waitpid %ld, saving status %s\n",
1289 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1291 lp->status = status;
1293 /* We must attach to every LWP. If /proc is mounted, use that to
1294 find them now. The inferior may be using raw clone instead of
1295 using pthreads. But even if it is using pthreads, thread_db
1296 walks structures in the inferior's address space to find the list
1297 of threads/LWPs, and those structures may well be corrupted.
1298 Note that once thread_db is loaded, we'll still use it to list
1299 threads and associate pthread info with each LWP. */
1300 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1301 attach_proc_task_lwp_callback);
1303 if (target_can_async_p ())
1307 /* Get pending signal of THREAD as a host signal number, for detaching
1308 purposes. This is the signal the thread last stopped for, which we
1309 need to deliver to the thread when detaching, otherwise, it'd be
1313 get_detach_signal (struct lwp_info *lp)
1315 enum gdb_signal signo = GDB_SIGNAL_0;
1317 /* If we paused threads momentarily, we may have stored pending
1318 events in lp->status or lp->waitstatus (see stop_wait_callback),
1319 and GDB core hasn't seen any signal for those threads.
1320 Otherwise, the last signal reported to the core is found in the
1321 thread object's stop_signal.
1323 There's a corner case that isn't handled here at present. Only
1324 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1325 stop_signal make sense as a real signal to pass to the inferior.
1326 Some catchpoint related events, like
1327 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1328 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1329 those traps are debug API (ptrace in our case) related and
1330 induced; the inferior wouldn't see them if it wasn't being
1331 traced. Hence, we should never pass them to the inferior, even
1332 when set to pass state. Since this corner case isn't handled by
1333 infrun.c when proceeding with a signal, for consistency, neither
1334 do we handle it here (or elsewhere in the file we check for
1335 signal pass state). Normally SIGTRAP isn't set to pass state, so
1336 this is really a corner case. */
1338 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1339 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1340 else if (lp->status)
1341 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1342 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1344 struct thread_info *tp = find_thread_ptid (lp->ptid);
1346 if (tp->suspend.waitstatus_pending_p)
1347 signo = tp->suspend.waitstatus.value.sig;
1349 signo = tp->suspend.stop_signal;
1351 else if (!target_is_non_stop_p ())
1353 struct target_waitstatus last;
1356 get_last_target_status (&last_ptid, &last);
1358 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1360 struct thread_info *tp = find_thread_ptid (lp->ptid);
1362 signo = tp->suspend.stop_signal;
1366 if (signo == GDB_SIGNAL_0)
1368 if (debug_linux_nat)
1369 fprintf_unfiltered (gdb_stdlog,
1370 "GPT: lwp %s has no pending signal\n",
1371 target_pid_to_str (lp->ptid));
1373 else if (!signal_pass_state (signo))
1375 if (debug_linux_nat)
1376 fprintf_unfiltered (gdb_stdlog,
1377 "GPT: lwp %s had signal %s, "
1378 "but it is in no pass state\n",
1379 target_pid_to_str (lp->ptid),
1380 gdb_signal_to_string (signo));
1384 if (debug_linux_nat)
1385 fprintf_unfiltered (gdb_stdlog,
1386 "GPT: lwp %s has pending signal %s\n",
1387 target_pid_to_str (lp->ptid),
1388 gdb_signal_to_string (signo));
1390 return gdb_signal_to_host (signo);
1396 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1397 signal number that should be passed to the LWP when detaching.
1398 Otherwise pass any pending signal the LWP may have, if any. */
1401 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1403 int lwpid = ptid_get_lwp (lp->ptid);
1406 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1408 if (debug_linux_nat && lp->status)
1409 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1410 strsignal (WSTOPSIG (lp->status)),
1411 target_pid_to_str (lp->ptid));
1413 /* If there is a pending SIGSTOP, get rid of it. */
1416 if (debug_linux_nat)
1417 fprintf_unfiltered (gdb_stdlog,
1418 "DC: Sending SIGCONT to %s\n",
1419 target_pid_to_str (lp->ptid));
1421 kill_lwp (lwpid, SIGCONT);
1425 if (signo_p == NULL)
1427 /* Pass on any pending signal for this LWP. */
1428 signo = get_detach_signal (lp);
1433 /* Preparing to resume may try to write registers, and fail if the
1434 lwp is zombie. If that happens, ignore the error. We'll handle
1435 it below, when detach fails with ESRCH. */
1438 if (linux_nat_prepare_to_resume != NULL)
1439 linux_nat_prepare_to_resume (lp);
1441 CATCH (ex, RETURN_MASK_ERROR)
1443 if (!check_ptrace_stopped_lwp_gone (lp))
1444 throw_exception (ex);
1448 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1450 int save_errno = errno;
1452 /* We know the thread exists, so ESRCH must mean the lwp is
1453 zombie. This can happen if one of the already-detached
1454 threads exits the whole thread group. In that case we're
1455 still attached, and must reap the lwp. */
1456 if (save_errno == ESRCH)
1460 ret = my_waitpid (lwpid, &status, __WALL);
1463 warning (_("Couldn't reap LWP %d while detaching: %s"),
1464 lwpid, strerror (errno));
1466 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1468 warning (_("Reaping LWP %d while detaching "
1469 "returned unexpected status 0x%x"),
1475 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1476 safe_strerror (save_errno));
1479 else if (debug_linux_nat)
1481 fprintf_unfiltered (gdb_stdlog,
1482 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1483 target_pid_to_str (lp->ptid),
1487 delete_lwp (lp->ptid);
1491 detach_callback (struct lwp_info *lp, void *data)
1493 /* We don't actually detach from the thread group leader just yet.
1494 If the thread group exits, we must reap the zombie clone lwps
1495 before we're able to reap the leader. */
1496 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1497 detach_one_lwp (lp, NULL);
1502 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1505 struct lwp_info *main_lwp;
1507 pid = ptid_get_pid (inferior_ptid);
1509 /* Don't unregister from the event loop, as there may be other
1510 inferiors running. */
1512 /* Stop all threads before detaching. ptrace requires that the
1513 thread is stopped to sucessfully detach. */
1514 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1515 /* ... and wait until all of them have reported back that
1516 they're no longer running. */
1517 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1519 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1521 /* Only the initial process should be left right now. */
1522 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1524 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1526 if (forks_exist_p ())
1528 /* Multi-fork case. The current inferior_ptid is being detached
1529 from, but there are other viable forks to debug. Detach from
1530 the current fork, and context-switch to the first
1532 linux_fork_detach (args, from_tty);
1538 target_announce_detach (from_tty);
1540 /* Pass on any pending signal for the last LWP, unless the user
1541 requested detaching with a different signal (most likely 0,
1542 meaning, discard the signal). */
1544 signo = atoi (args);
1546 signo = get_detach_signal (main_lwp);
1548 detach_one_lwp (main_lwp, &signo);
1550 inf_ptrace_detach_success (ops);
1554 /* Resume execution of the inferior process. If STEP is nonzero,
1555 single-step it. If SIGNAL is nonzero, give it that signal. */
1558 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1559 enum gdb_signal signo)
1563 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1564 We only presently need that if the LWP is stepped though (to
1565 handle the case of stepping a breakpoint instruction). */
1568 struct regcache *regcache = get_thread_regcache (lp->ptid);
1570 lp->stop_pc = regcache_read_pc (regcache);
1575 if (linux_nat_prepare_to_resume != NULL)
1576 linux_nat_prepare_to_resume (lp);
1577 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1579 /* Successfully resumed. Clear state that no longer makes sense,
1580 and mark the LWP as running. Must not do this before resuming
1581 otherwise if that fails other code will be confused. E.g., we'd
1582 later try to stop the LWP and hang forever waiting for a stop
1583 status. Note that we must not throw after this is cleared,
1584 otherwise handle_zombie_lwp_error would get confused. */
1587 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1588 registers_changed_ptid (lp->ptid);
1591 /* Called when we try to resume a stopped LWP and that errors out. If
1592 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1593 or about to become), discard the error, clear any pending status
1594 the LWP may have, and return true (we'll collect the exit status
1595 soon enough). Otherwise, return false. */
1598 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1600 /* If we get an error after resuming the LWP successfully, we'd
1601 confuse !T state for the LWP being gone. */
1602 gdb_assert (lp->stopped);
1604 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1605 because even if ptrace failed with ESRCH, the tracee may be "not
1606 yet fully dead", but already refusing ptrace requests. In that
1607 case the tracee has 'R (Running)' state for a little bit
1608 (observed in Linux 3.18). See also the note on ESRCH in the
1609 ptrace(2) man page. Instead, check whether the LWP has any state
1610 other than ptrace-stopped. */
1612 /* Don't assume anything if /proc/PID/status can't be read. */
1613 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1615 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1617 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1623 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1624 disappears while we try to resume it. */
1627 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1631 linux_resume_one_lwp_throw (lp, step, signo);
1633 CATCH (ex, RETURN_MASK_ERROR)
1635 if (!check_ptrace_stopped_lwp_gone (lp))
1636 throw_exception (ex);
1644 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1648 struct inferior *inf = find_inferior_ptid (lp->ptid);
1650 if (inf->vfork_child != NULL)
1652 if (debug_linux_nat)
1653 fprintf_unfiltered (gdb_stdlog,
1654 "RC: Not resuming %s (vfork parent)\n",
1655 target_pid_to_str (lp->ptid));
1657 else if (!lwp_status_pending_p (lp))
1659 if (debug_linux_nat)
1660 fprintf_unfiltered (gdb_stdlog,
1661 "RC: Resuming sibling %s, %s, %s\n",
1662 target_pid_to_str (lp->ptid),
1663 (signo != GDB_SIGNAL_0
1664 ? strsignal (gdb_signal_to_host (signo))
1666 step ? "step" : "resume");
1668 linux_resume_one_lwp (lp, step, signo);
1672 if (debug_linux_nat)
1673 fprintf_unfiltered (gdb_stdlog,
1674 "RC: Not resuming sibling %s (has pending)\n",
1675 target_pid_to_str (lp->ptid));
1680 if (debug_linux_nat)
1681 fprintf_unfiltered (gdb_stdlog,
1682 "RC: Not resuming sibling %s (not stopped)\n",
1683 target_pid_to_str (lp->ptid));
1687 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1688 Resume LWP with the last stop signal, if it is in pass state. */
1691 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1693 enum gdb_signal signo = GDB_SIGNAL_0;
1700 struct thread_info *thread;
1702 thread = find_thread_ptid (lp->ptid);
1705 signo = thread->suspend.stop_signal;
1706 thread->suspend.stop_signal = GDB_SIGNAL_0;
1710 resume_lwp (lp, 0, signo);
1715 resume_clear_callback (struct lwp_info *lp, void *data)
1718 lp->last_resume_kind = resume_stop;
1723 resume_set_callback (struct lwp_info *lp, void *data)
1726 lp->last_resume_kind = resume_continue;
1731 linux_nat_resume (struct target_ops *ops,
1732 ptid_t ptid, int step, enum gdb_signal signo)
1734 struct lwp_info *lp;
1737 if (debug_linux_nat)
1738 fprintf_unfiltered (gdb_stdlog,
1739 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1740 step ? "step" : "resume",
1741 target_pid_to_str (ptid),
1742 (signo != GDB_SIGNAL_0
1743 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1744 target_pid_to_str (inferior_ptid));
1746 /* A specific PTID means `step only this process id'. */
1747 resume_many = (ptid_equal (minus_one_ptid, ptid)
1748 || ptid_is_pid (ptid));
1750 /* Mark the lwps we're resuming as resumed. */
1751 iterate_over_lwps (ptid, resume_set_callback, NULL);
1753 /* See if it's the current inferior that should be handled
1756 lp = find_lwp_pid (inferior_ptid);
1758 lp = find_lwp_pid (ptid);
1759 gdb_assert (lp != NULL);
1761 /* Remember if we're stepping. */
1762 lp->last_resume_kind = step ? resume_step : resume_continue;
1764 /* If we have a pending wait status for this thread, there is no
1765 point in resuming the process. But first make sure that
1766 linux_nat_wait won't preemptively handle the event - we
1767 should never take this short-circuit if we are going to
1768 leave LP running, since we have skipped resuming all the
1769 other threads. This bit of code needs to be synchronized
1770 with linux_nat_wait. */
1772 if (lp->status && WIFSTOPPED (lp->status))
1775 && WSTOPSIG (lp->status)
1776 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1778 if (debug_linux_nat)
1779 fprintf_unfiltered (gdb_stdlog,
1780 "LLR: Not short circuiting for ignored "
1781 "status 0x%x\n", lp->status);
1783 /* FIXME: What should we do if we are supposed to continue
1784 this thread with a signal? */
1785 gdb_assert (signo == GDB_SIGNAL_0);
1786 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1791 if (lwp_status_pending_p (lp))
1793 /* FIXME: What should we do if we are supposed to continue
1794 this thread with a signal? */
1795 gdb_assert (signo == GDB_SIGNAL_0);
1797 if (debug_linux_nat)
1798 fprintf_unfiltered (gdb_stdlog,
1799 "LLR: Short circuiting for status 0x%x\n",
1802 if (target_can_async_p ())
1805 /* Tell the event loop we have something to process. */
1812 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1814 if (debug_linux_nat)
1815 fprintf_unfiltered (gdb_stdlog,
1816 "LLR: %s %s, %s (resume event thread)\n",
1817 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1818 target_pid_to_str (lp->ptid),
1819 (signo != GDB_SIGNAL_0
1820 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1822 linux_resume_one_lwp (lp, step, signo);
1824 if (target_can_async_p ())
1828 /* Send a signal to an LWP. */
1831 kill_lwp (int lwpid, int signo)
1836 ret = syscall (__NR_tkill, lwpid, signo);
1837 if (errno == ENOSYS)
1839 /* If tkill fails, then we are not using nptl threads, a
1840 configuration we no longer support. */
1841 perror_with_name (("tkill"));
1846 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1847 event, check if the core is interested in it: if not, ignore the
1848 event, and keep waiting; otherwise, we need to toggle the LWP's
1849 syscall entry/exit status, since the ptrace event itself doesn't
1850 indicate it, and report the trap to higher layers. */
1853 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1855 struct target_waitstatus *ourstatus = &lp->waitstatus;
1856 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1857 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1861 /* If we're stopping threads, there's a SIGSTOP pending, which
1862 makes it so that the LWP reports an immediate syscall return,
1863 followed by the SIGSTOP. Skip seeing that "return" using
1864 PTRACE_CONT directly, and let stop_wait_callback collect the
1865 SIGSTOP. Later when the thread is resumed, a new syscall
1866 entry event. If we didn't do this (and returned 0), we'd
1867 leave a syscall entry pending, and our caller, by using
1868 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1869 itself. Later, when the user re-resumes this LWP, we'd see
1870 another syscall entry event and we'd mistake it for a return.
1872 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1873 (leaving immediately with LWP->signalled set, without issuing
1874 a PTRACE_CONT), it would still be problematic to leave this
1875 syscall enter pending, as later when the thread is resumed,
1876 it would then see the same syscall exit mentioned above,
1877 followed by the delayed SIGSTOP, while the syscall didn't
1878 actually get to execute. It seems it would be even more
1879 confusing to the user. */
1881 if (debug_linux_nat)
1882 fprintf_unfiltered (gdb_stdlog,
1883 "LHST: ignoring syscall %d "
1884 "for LWP %ld (stopping threads), "
1885 "resuming with PTRACE_CONT for SIGSTOP\n",
1887 ptid_get_lwp (lp->ptid));
1889 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1890 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1895 /* Always update the entry/return state, even if this particular
1896 syscall isn't interesting to the core now. In async mode,
1897 the user could install a new catchpoint for this syscall
1898 between syscall enter/return, and we'll need to know to
1899 report a syscall return if that happens. */
1900 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1901 ? TARGET_WAITKIND_SYSCALL_RETURN
1902 : TARGET_WAITKIND_SYSCALL_ENTRY);
1904 if (catch_syscall_enabled ())
1906 if (catching_syscall_number (syscall_number))
1908 /* Alright, an event to report. */
1909 ourstatus->kind = lp->syscall_state;
1910 ourstatus->value.syscall_number = syscall_number;
1912 if (debug_linux_nat)
1913 fprintf_unfiltered (gdb_stdlog,
1914 "LHST: stopping for %s of syscall %d"
1917 == TARGET_WAITKIND_SYSCALL_ENTRY
1918 ? "entry" : "return",
1920 ptid_get_lwp (lp->ptid));
1924 if (debug_linux_nat)
1925 fprintf_unfiltered (gdb_stdlog,
1926 "LHST: ignoring %s of syscall %d "
1928 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1929 ? "entry" : "return",
1931 ptid_get_lwp (lp->ptid));
1935 /* If we had been syscall tracing, and hence used PT_SYSCALL
1936 before on this LWP, it could happen that the user removes all
1937 syscall catchpoints before we get to process this event.
1938 There are two noteworthy issues here:
1940 - When stopped at a syscall entry event, resuming with
1941 PT_STEP still resumes executing the syscall and reports a
1944 - Only PT_SYSCALL catches syscall enters. If we last
1945 single-stepped this thread, then this event can't be a
1946 syscall enter. If we last single-stepped this thread, this
1947 has to be a syscall exit.
1949 The points above mean that the next resume, be it PT_STEP or
1950 PT_CONTINUE, can not trigger a syscall trace event. */
1951 if (debug_linux_nat)
1952 fprintf_unfiltered (gdb_stdlog,
1953 "LHST: caught syscall event "
1954 "with no syscall catchpoints."
1955 " %d for LWP %ld, ignoring\n",
1957 ptid_get_lwp (lp->ptid));
1958 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1961 /* The core isn't interested in this event. For efficiency, avoid
1962 stopping all threads only to have the core resume them all again.
1963 Since we're not stopping threads, if we're still syscall tracing
1964 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1965 subsequent syscall. Simply resume using the inf-ptrace layer,
1966 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1968 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1972 /* Handle a GNU/Linux extended wait response. If we see a clone
1973 event, we need to add the new LWP to our list (and not report the
1974 trap to higher layers). This function returns non-zero if the
1975 event should be ignored and we should wait again. If STOPPING is
1976 true, the new LWP remains stopped, otherwise it is continued. */
1979 linux_handle_extended_wait (struct lwp_info *lp, int status)
1981 int pid = ptid_get_lwp (lp->ptid);
1982 struct target_waitstatus *ourstatus = &lp->waitstatus;
1983 int event = linux_ptrace_get_extended_event (status);
1985 /* All extended events we currently use are mid-syscall. Only
1986 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1987 you have to be using PTRACE_SEIZE to get that. */
1988 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1990 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1991 || event == PTRACE_EVENT_CLONE)
1993 unsigned long new_pid;
1996 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1998 /* If we haven't already seen the new PID stop, wait for it now. */
1999 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2001 /* The new child has a pending SIGSTOP. We can't affect it until it
2002 hits the SIGSTOP, but we're already attached. */
2003 ret = my_waitpid (new_pid, &status, __WALL);
2005 perror_with_name (_("waiting for new child"));
2006 else if (ret != new_pid)
2007 internal_error (__FILE__, __LINE__,
2008 _("wait returned unexpected PID %d"), ret);
2009 else if (!WIFSTOPPED (status))
2010 internal_error (__FILE__, __LINE__,
2011 _("wait returned unexpected status 0x%x"), status);
2014 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2016 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2018 /* The arch-specific native code may need to know about new
2019 forks even if those end up never mapped to an
2021 if (linux_nat_new_fork != NULL)
2022 linux_nat_new_fork (lp, new_pid);
2025 if (event == PTRACE_EVENT_FORK
2026 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2028 /* Handle checkpointing by linux-fork.c here as a special
2029 case. We don't want the follow-fork-mode or 'catch fork'
2030 to interfere with this. */
2032 /* This won't actually modify the breakpoint list, but will
2033 physically remove the breakpoints from the child. */
2034 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2036 /* Retain child fork in ptrace (stopped) state. */
2037 if (!find_fork_pid (new_pid))
2040 /* Report as spurious, so that infrun doesn't want to follow
2041 this fork. We're actually doing an infcall in
2043 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2045 /* Report the stop to the core. */
2049 if (event == PTRACE_EVENT_FORK)
2050 ourstatus->kind = TARGET_WAITKIND_FORKED;
2051 else if (event == PTRACE_EVENT_VFORK)
2052 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2053 else if (event == PTRACE_EVENT_CLONE)
2055 struct lwp_info *new_lp;
2057 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2059 if (debug_linux_nat)
2060 fprintf_unfiltered (gdb_stdlog,
2061 "LHEW: Got clone event "
2062 "from LWP %d, new child is LWP %ld\n",
2065 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2066 new_lp->stopped = 1;
2067 new_lp->resumed = 1;
2069 /* If the thread_db layer is active, let it record the user
2070 level thread id and status, and add the thread to GDB's
2072 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2074 /* The process is not using thread_db. Add the LWP to
2076 target_post_attach (ptid_get_lwp (new_lp->ptid));
2077 add_thread (new_lp->ptid);
2080 /* Even if we're stopping the thread for some reason
2081 internal to this module, from the perspective of infrun
2082 and the user/frontend, this new thread is running until
2083 it next reports a stop. */
2084 set_running (new_lp->ptid, 1);
2085 set_executing (new_lp->ptid, 1);
2087 if (WSTOPSIG (status) != SIGSTOP)
2089 /* This can happen if someone starts sending signals to
2090 the new thread before it gets a chance to run, which
2091 have a lower number than SIGSTOP (e.g. SIGUSR1).
2092 This is an unlikely case, and harder to handle for
2093 fork / vfork than for clone, so we do not try - but
2094 we handle it for clone events here. */
2096 new_lp->signalled = 1;
2098 /* We created NEW_LP so it cannot yet contain STATUS. */
2099 gdb_assert (new_lp->status == 0);
2101 /* Save the wait status to report later. */
2102 if (debug_linux_nat)
2103 fprintf_unfiltered (gdb_stdlog,
2104 "LHEW: waitpid of new LWP %ld, "
2105 "saving status %s\n",
2106 (long) ptid_get_lwp (new_lp->ptid),
2107 status_to_str (status));
2108 new_lp->status = status;
2110 else if (report_thread_events)
2112 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2113 new_lp->status = status;
2122 if (event == PTRACE_EVENT_EXEC)
2124 if (debug_linux_nat)
2125 fprintf_unfiltered (gdb_stdlog,
2126 "LHEW: Got exec event from LWP %ld\n",
2127 ptid_get_lwp (lp->ptid));
2129 ourstatus->kind = TARGET_WAITKIND_EXECD;
2130 ourstatus->value.execd_pathname
2131 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2133 /* The thread that execed must have been resumed, but, when a
2134 thread execs, it changes its tid to the tgid, and the old
2135 tgid thread might have not been resumed. */
2140 if (event == PTRACE_EVENT_VFORK_DONE)
2142 if (current_inferior ()->waiting_for_vfork_done)
2144 if (debug_linux_nat)
2145 fprintf_unfiltered (gdb_stdlog,
2146 "LHEW: Got expected PTRACE_EVENT_"
2147 "VFORK_DONE from LWP %ld: stopping\n",
2148 ptid_get_lwp (lp->ptid));
2150 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2154 if (debug_linux_nat)
2155 fprintf_unfiltered (gdb_stdlog,
2156 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2157 "from LWP %ld: ignoring\n",
2158 ptid_get_lwp (lp->ptid));
2162 internal_error (__FILE__, __LINE__,
2163 _("unknown ptrace event %d"), event);
2166 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2170 wait_lwp (struct lwp_info *lp)
2174 int thread_dead = 0;
2177 gdb_assert (!lp->stopped);
2178 gdb_assert (lp->status == 0);
2180 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2181 block_child_signals (&prev_mask);
2185 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2186 if (pid == -1 && errno == ECHILD)
2188 /* The thread has previously exited. We need to delete it
2189 now because if this was a non-leader thread execing, we
2190 won't get an exit event. See comments on exec events at
2191 the top of the file. */
2193 if (debug_linux_nat)
2194 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2195 target_pid_to_str (lp->ptid));
2200 /* Bugs 10970, 12702.
2201 Thread group leader may have exited in which case we'll lock up in
2202 waitpid if there are other threads, even if they are all zombies too.
2203 Basically, we're not supposed to use waitpid this way.
2204 tkill(pid,0) cannot be used here as it gets ESRCH for both
2205 for zombie and running processes.
2207 As a workaround, check if we're waiting for the thread group leader and
2208 if it's a zombie, and avoid calling waitpid if it is.
2210 This is racy, what if the tgl becomes a zombie right after we check?
2211 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2212 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2214 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2215 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2218 if (debug_linux_nat)
2219 fprintf_unfiltered (gdb_stdlog,
2220 "WL: Thread group leader %s vanished.\n",
2221 target_pid_to_str (lp->ptid));
2225 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2226 get invoked despite our caller had them intentionally blocked by
2227 block_child_signals. This is sensitive only to the loop of
2228 linux_nat_wait_1 and there if we get called my_waitpid gets called
2229 again before it gets to sigsuspend so we can safely let the handlers
2230 get executed here. */
2232 if (debug_linux_nat)
2233 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2234 sigsuspend (&suspend_mask);
2237 restore_child_signals_mask (&prev_mask);
2241 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2243 if (debug_linux_nat)
2245 fprintf_unfiltered (gdb_stdlog,
2246 "WL: waitpid %s received %s\n",
2247 target_pid_to_str (lp->ptid),
2248 status_to_str (status));
2251 /* Check if the thread has exited. */
2252 if (WIFEXITED (status) || WIFSIGNALED (status))
2254 if (report_thread_events
2255 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2257 if (debug_linux_nat)
2258 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2259 ptid_get_pid (lp->ptid));
2261 /* If this is the leader exiting, it means the whole
2262 process is gone. Store the status to report to the
2263 core. Store it in lp->waitstatus, because lp->status
2264 would be ambiguous (W_EXITCODE(0,0) == 0). */
2265 store_waitstatus (&lp->waitstatus, status);
2270 if (debug_linux_nat)
2271 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2272 target_pid_to_str (lp->ptid));
2282 gdb_assert (WIFSTOPPED (status));
2285 if (lp->must_set_ptrace_flags)
2287 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2288 int options = linux_nat_ptrace_options (inf->attach_flag);
2290 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2291 lp->must_set_ptrace_flags = 0;
2294 /* Handle GNU/Linux's syscall SIGTRAPs. */
2295 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2297 /* No longer need the sysgood bit. The ptrace event ends up
2298 recorded in lp->waitstatus if we care for it. We can carry
2299 on handling the event like a regular SIGTRAP from here
2301 status = W_STOPCODE (SIGTRAP);
2302 if (linux_handle_syscall_trap (lp, 1))
2303 return wait_lwp (lp);
2307 /* Almost all other ptrace-stops are known to be outside of system
2308 calls, with further exceptions in linux_handle_extended_wait. */
2309 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2312 /* Handle GNU/Linux's extended waitstatus for trace events. */
2313 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2314 && linux_is_extended_waitstatus (status))
2316 if (debug_linux_nat)
2317 fprintf_unfiltered (gdb_stdlog,
2318 "WL: Handling extended status 0x%06x\n",
2320 linux_handle_extended_wait (lp, status);
2327 /* Send a SIGSTOP to LP. */
2330 stop_callback (struct lwp_info *lp, void *data)
2332 if (!lp->stopped && !lp->signalled)
2336 if (debug_linux_nat)
2338 fprintf_unfiltered (gdb_stdlog,
2339 "SC: kill %s **<SIGSTOP>**\n",
2340 target_pid_to_str (lp->ptid));
2343 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2344 if (debug_linux_nat)
2346 fprintf_unfiltered (gdb_stdlog,
2347 "SC: lwp kill %d %s\n",
2349 errno ? safe_strerror (errno) : "ERRNO-OK");
2353 gdb_assert (lp->status == 0);
2359 /* Request a stop on LWP. */
2362 linux_stop_lwp (struct lwp_info *lwp)
2364 stop_callback (lwp, NULL);
2367 /* See linux-nat.h */
2370 linux_stop_and_wait_all_lwps (void)
2372 /* Stop all LWP's ... */
2373 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2375 /* ... and wait until all of them have reported back that
2376 they're no longer running. */
2377 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2380 /* See linux-nat.h */
2383 linux_unstop_all_lwps (void)
2385 iterate_over_lwps (minus_one_ptid,
2386 resume_stopped_resumed_lwps, &minus_one_ptid);
2389 /* Return non-zero if LWP PID has a pending SIGINT. */
2392 linux_nat_has_pending_sigint (int pid)
2394 sigset_t pending, blocked, ignored;
2396 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2398 if (sigismember (&pending, SIGINT)
2399 && !sigismember (&ignored, SIGINT))
2405 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2408 set_ignore_sigint (struct lwp_info *lp, void *data)
2410 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2411 flag to consume the next one. */
2412 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2413 && WSTOPSIG (lp->status) == SIGINT)
2416 lp->ignore_sigint = 1;
2421 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2422 This function is called after we know the LWP has stopped; if the LWP
2423 stopped before the expected SIGINT was delivered, then it will never have
2424 arrived. Also, if the signal was delivered to a shared queue and consumed
2425 by a different thread, it will never be delivered to this LWP. */
2428 maybe_clear_ignore_sigint (struct lwp_info *lp)
2430 if (!lp->ignore_sigint)
2433 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2435 if (debug_linux_nat)
2436 fprintf_unfiltered (gdb_stdlog,
2437 "MCIS: Clearing bogus flag for %s\n",
2438 target_pid_to_str (lp->ptid));
2439 lp->ignore_sigint = 0;
2443 /* Fetch the possible triggered data watchpoint info and store it in
2446 On some archs, like x86, that use debug registers to set
2447 watchpoints, it's possible that the way to know which watched
2448 address trapped, is to check the register that is used to select
2449 which address to watch. Problem is, between setting the watchpoint
2450 and reading back which data address trapped, the user may change
2451 the set of watchpoints, and, as a consequence, GDB changes the
2452 debug registers in the inferior. To avoid reading back a stale
2453 stopped-data-address when that happens, we cache in LP the fact
2454 that a watchpoint trapped, and the corresponding data address, as
2455 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2456 registers meanwhile, we have the cached data we can rely on. */
2459 check_stopped_by_watchpoint (struct lwp_info *lp)
2461 struct cleanup *old_chain;
2463 if (linux_ops->to_stopped_by_watchpoint == NULL)
2466 old_chain = save_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 do_cleanups (old_chain);
2483 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2486 /* Returns true if the LWP had stopped for a watchpoint. */
2489 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2491 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2493 gdb_assert (lp != NULL);
2495 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2499 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2501 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2503 gdb_assert (lp != NULL);
2505 *addr_p = lp->stopped_data_address;
2507 return lp->stopped_data_address_p;
2510 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2513 sigtrap_is_event (int status)
2515 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2518 /* Set alternative SIGTRAP-like events recognizer. If
2519 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2523 linux_nat_set_status_is_event (struct target_ops *t,
2524 int (*status_is_event) (int status))
2526 linux_nat_status_is_event = status_is_event;
2529 /* Wait until LP is stopped. */
2532 stop_wait_callback (struct lwp_info *lp, void *data)
2534 struct inferior *inf = find_inferior_ptid (lp->ptid);
2536 /* If this is a vfork parent, bail out, it is not going to report
2537 any SIGSTOP until the vfork is done with. */
2538 if (inf->vfork_child != NULL)
2545 status = wait_lwp (lp);
2549 if (lp->ignore_sigint && WIFSTOPPED (status)
2550 && WSTOPSIG (status) == SIGINT)
2552 lp->ignore_sigint = 0;
2555 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2557 if (debug_linux_nat)
2558 fprintf_unfiltered (gdb_stdlog,
2559 "PTRACE_CONT %s, 0, 0 (%s) "
2560 "(discarding SIGINT)\n",
2561 target_pid_to_str (lp->ptid),
2562 errno ? safe_strerror (errno) : "OK");
2564 return stop_wait_callback (lp, NULL);
2567 maybe_clear_ignore_sigint (lp);
2569 if (WSTOPSIG (status) != SIGSTOP)
2571 /* The thread was stopped with a signal other than SIGSTOP. */
2573 if (debug_linux_nat)
2574 fprintf_unfiltered (gdb_stdlog,
2575 "SWC: Pending event %s in %s\n",
2576 status_to_str ((int) status),
2577 target_pid_to_str (lp->ptid));
2579 /* Save the sigtrap event. */
2580 lp->status = status;
2581 gdb_assert (lp->signalled);
2582 save_stop_reason (lp);
2586 /* We caught the SIGSTOP that we intended to catch, so
2587 there's no SIGSTOP pending. */
2589 if (debug_linux_nat)
2590 fprintf_unfiltered (gdb_stdlog,
2591 "SWC: Expected SIGSTOP caught for %s.\n",
2592 target_pid_to_str (lp->ptid));
2594 /* Reset SIGNALLED only after the stop_wait_callback call
2595 above as it does gdb_assert on SIGNALLED. */
2603 /* Return non-zero if LP has a wait status pending. Discard the
2604 pending event and resume the LWP if the event that originally
2605 caused the stop became uninteresting. */
2608 status_callback (struct lwp_info *lp, void *data)
2610 /* Only report a pending wait status if we pretend that this has
2611 indeed been resumed. */
2615 if (!lwp_status_pending_p (lp))
2618 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2619 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2621 struct regcache *regcache = get_thread_regcache (lp->ptid);
2625 pc = regcache_read_pc (regcache);
2627 if (pc != lp->stop_pc)
2629 if (debug_linux_nat)
2630 fprintf_unfiltered (gdb_stdlog,
2631 "SC: PC of %s changed. was=%s, now=%s\n",
2632 target_pid_to_str (lp->ptid),
2633 paddress (target_gdbarch (), lp->stop_pc),
2634 paddress (target_gdbarch (), pc));
2638 #if !USE_SIGTRAP_SIGINFO
2639 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2641 if (debug_linux_nat)
2642 fprintf_unfiltered (gdb_stdlog,
2643 "SC: previous breakpoint of %s, at %s gone\n",
2644 target_pid_to_str (lp->ptid),
2645 paddress (target_gdbarch (), lp->stop_pc));
2653 if (debug_linux_nat)
2654 fprintf_unfiltered (gdb_stdlog,
2655 "SC: pending event of %s cancelled.\n",
2656 target_pid_to_str (lp->ptid));
2659 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2667 /* Count the LWP's that have had events. */
2670 count_events_callback (struct lwp_info *lp, void *data)
2672 int *count = (int *) data;
2674 gdb_assert (count != NULL);
2676 /* Select only resumed LWPs that have an event pending. */
2677 if (lp->resumed && lwp_status_pending_p (lp))
2683 /* Select the LWP (if any) that is currently being single-stepped. */
2686 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2688 if (lp->last_resume_kind == resume_step
2695 /* Returns true if LP has a status pending. */
2698 lwp_status_pending_p (struct lwp_info *lp)
2700 /* We check for lp->waitstatus in addition to lp->status, because we
2701 can have pending process exits recorded in lp->status and
2702 W_EXITCODE(0,0) happens to be 0. */
2703 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2706 /* Select the Nth LWP that has had an event. */
2709 select_event_lwp_callback (struct lwp_info *lp, void *data)
2711 int *selector = (int *) data;
2713 gdb_assert (selector != NULL);
2715 /* Select only resumed LWPs that have an event pending. */
2716 if (lp->resumed && lwp_status_pending_p (lp))
2717 if ((*selector)-- == 0)
2723 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2724 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2725 and save the result in the LWP's stop_reason field. If it stopped
2726 for a breakpoint, decrement the PC if necessary on the lwp's
2730 save_stop_reason (struct lwp_info *lp)
2732 struct regcache *regcache;
2733 struct gdbarch *gdbarch;
2736 #if USE_SIGTRAP_SIGINFO
2740 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2741 gdb_assert (lp->status != 0);
2743 if (!linux_nat_status_is_event (lp->status))
2746 regcache = get_thread_regcache (lp->ptid);
2747 gdbarch = get_regcache_arch (regcache);
2749 pc = regcache_read_pc (regcache);
2750 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2752 #if USE_SIGTRAP_SIGINFO
2753 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2755 if (siginfo.si_signo == SIGTRAP)
2757 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2758 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2760 /* The si_code is ambiguous on this arch -- check debug
2762 if (!check_stopped_by_watchpoint (lp))
2763 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2765 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2767 /* If we determine the LWP stopped for a SW breakpoint,
2768 trust it. Particularly don't check watchpoint
2769 registers, because at least on s390, we'd find
2770 stopped-by-watchpoint as long as there's a watchpoint
2772 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2774 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2776 /* This can indicate either a hardware breakpoint or
2777 hardware watchpoint. Check debug registers. */
2778 if (!check_stopped_by_watchpoint (lp))
2779 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2781 else if (siginfo.si_code == TRAP_TRACE)
2783 if (debug_linux_nat)
2784 fprintf_unfiltered (gdb_stdlog,
2785 "CSBB: %s stopped by trace\n",
2786 target_pid_to_str (lp->ptid));
2788 /* We may have single stepped an instruction that
2789 triggered a watchpoint. In that case, on some
2790 architectures (such as x86), instead of TRAP_HWBKPT,
2791 si_code indicates TRAP_TRACE, and we need to check
2792 the debug registers separately. */
2793 check_stopped_by_watchpoint (lp);
2798 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2799 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2802 /* The LWP was either continued, or stepped a software
2803 breakpoint instruction. */
2804 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2807 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2808 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2810 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2811 check_stopped_by_watchpoint (lp);
2814 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2816 if (debug_linux_nat)
2817 fprintf_unfiltered (gdb_stdlog,
2818 "CSBB: %s stopped by software breakpoint\n",
2819 target_pid_to_str (lp->ptid));
2821 /* Back up the PC if necessary. */
2823 regcache_write_pc (regcache, sw_bp_pc);
2825 /* Update this so we record the correct stop PC below. */
2828 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2830 if (debug_linux_nat)
2831 fprintf_unfiltered (gdb_stdlog,
2832 "CSBB: %s stopped by hardware breakpoint\n",
2833 target_pid_to_str (lp->ptid));
2835 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2837 if (debug_linux_nat)
2838 fprintf_unfiltered (gdb_stdlog,
2839 "CSBB: %s stopped by hardware watchpoint\n",
2840 target_pid_to_str (lp->ptid));
2847 /* Returns true if the LWP had stopped for a software breakpoint. */
2850 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2852 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2854 gdb_assert (lp != NULL);
2856 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2859 /* Implement the supports_stopped_by_sw_breakpoint method. */
2862 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2864 return USE_SIGTRAP_SIGINFO;
2867 /* Returns true if the LWP had stopped for a hardware
2868 breakpoint/watchpoint. */
2871 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2873 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2875 gdb_assert (lp != NULL);
2877 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2880 /* Implement the supports_stopped_by_hw_breakpoint method. */
2883 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2885 return USE_SIGTRAP_SIGINFO;
2888 /* Select one LWP out of those that have events pending. */
2891 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2894 int random_selector;
2895 struct lwp_info *event_lp = NULL;
2897 /* Record the wait status for the original LWP. */
2898 (*orig_lp)->status = *status;
2900 /* In all-stop, give preference to the LWP that is being
2901 single-stepped. There will be at most one, and it will be the
2902 LWP that the core is most interested in. If we didn't do this,
2903 then we'd have to handle pending step SIGTRAPs somehow in case
2904 the core later continues the previously-stepped thread, as
2905 otherwise we'd report the pending SIGTRAP then, and the core, not
2906 having stepped the thread, wouldn't understand what the trap was
2907 for, and therefore would report it to the user as a random
2909 if (!target_is_non_stop_p ())
2911 event_lp = iterate_over_lwps (filter,
2912 select_singlestep_lwp_callback, NULL);
2913 if (event_lp != NULL)
2915 if (debug_linux_nat)
2916 fprintf_unfiltered (gdb_stdlog,
2917 "SEL: Select single-step %s\n",
2918 target_pid_to_str (event_lp->ptid));
2922 if (event_lp == NULL)
2924 /* Pick one at random, out of those which have had events. */
2926 /* First see how many events we have. */
2927 iterate_over_lwps (filter, count_events_callback, &num_events);
2928 gdb_assert (num_events > 0);
2930 /* Now randomly pick a LWP out of those that have had
2932 random_selector = (int)
2933 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2935 if (debug_linux_nat && num_events > 1)
2936 fprintf_unfiltered (gdb_stdlog,
2937 "SEL: Found %d events, selecting #%d\n",
2938 num_events, random_selector);
2940 event_lp = iterate_over_lwps (filter,
2941 select_event_lwp_callback,
2945 if (event_lp != NULL)
2947 /* Switch the event LWP. */
2948 *orig_lp = event_lp;
2949 *status = event_lp->status;
2952 /* Flush the wait status for the event LWP. */
2953 (*orig_lp)->status = 0;
2956 /* Return non-zero if LP has been resumed. */
2959 resumed_callback (struct lwp_info *lp, void *data)
2964 /* Check if we should go on and pass this event to common code.
2965 Return the affected lwp if we are, or NULL otherwise. */
2967 static struct lwp_info *
2968 linux_nat_filter_event (int lwpid, int status)
2970 struct lwp_info *lp;
2971 int event = linux_ptrace_get_extended_event (status);
2973 lp = find_lwp_pid (pid_to_ptid (lwpid));
2975 /* Check for stop events reported by a process we didn't already
2976 know about - anything not already in our LWP list.
2978 If we're expecting to receive stopped processes after
2979 fork, vfork, and clone events, then we'll just add the
2980 new one to our list and go back to waiting for the event
2981 to be reported - the stopped process might be returned
2982 from waitpid before or after the event is.
2984 But note the case of a non-leader thread exec'ing after the
2985 leader having exited, and gone from our lists. The non-leader
2986 thread changes its tid to the tgid. */
2988 if (WIFSTOPPED (status) && lp == NULL
2989 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2991 /* A multi-thread exec after we had seen the leader exiting. */
2992 if (debug_linux_nat)
2993 fprintf_unfiltered (gdb_stdlog,
2994 "LLW: Re-adding thread group leader LWP %d.\n",
2997 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
3000 add_thread (lp->ptid);
3003 if (WIFSTOPPED (status) && !lp)
3005 if (debug_linux_nat)
3006 fprintf_unfiltered (gdb_stdlog,
3007 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3008 (long) lwpid, status_to_str (status));
3009 add_to_pid_list (&stopped_pids, lwpid, status);
3013 /* Make sure we don't report an event for the exit of an LWP not in
3014 our list, i.e. not part of the current process. This can happen
3015 if we detach from a program we originally forked and then it
3017 if (!WIFSTOPPED (status) && !lp)
3020 /* This LWP is stopped now. (And if dead, this prevents it from
3021 ever being continued.) */
3024 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3026 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3027 int options = linux_nat_ptrace_options (inf->attach_flag);
3029 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3030 lp->must_set_ptrace_flags = 0;
3033 /* Handle GNU/Linux's syscall SIGTRAPs. */
3034 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3036 /* No longer need the sysgood bit. The ptrace event ends up
3037 recorded in lp->waitstatus if we care for it. We can carry
3038 on handling the event like a regular SIGTRAP from here
3040 status = W_STOPCODE (SIGTRAP);
3041 if (linux_handle_syscall_trap (lp, 0))
3046 /* Almost all other ptrace-stops are known to be outside of system
3047 calls, with further exceptions in linux_handle_extended_wait. */
3048 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3051 /* Handle GNU/Linux's extended waitstatus for trace events. */
3052 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3053 && linux_is_extended_waitstatus (status))
3055 if (debug_linux_nat)
3056 fprintf_unfiltered (gdb_stdlog,
3057 "LLW: Handling extended status 0x%06x\n",
3059 if (linux_handle_extended_wait (lp, status))
3063 /* Check if the thread has exited. */
3064 if (WIFEXITED (status) || WIFSIGNALED (status))
3066 if (!report_thread_events
3067 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3069 if (debug_linux_nat)
3070 fprintf_unfiltered (gdb_stdlog,
3071 "LLW: %s exited.\n",
3072 target_pid_to_str (lp->ptid));
3074 /* If there is at least one more LWP, then the exit signal
3075 was not the end of the debugged application and should be
3081 /* Note that even if the leader was ptrace-stopped, it can still
3082 exit, if e.g., some other thread brings down the whole
3083 process (calls `exit'). So don't assert that the lwp is
3085 if (debug_linux_nat)
3086 fprintf_unfiltered (gdb_stdlog,
3087 "LWP %ld exited (resumed=%d)\n",
3088 ptid_get_lwp (lp->ptid), lp->resumed);
3090 /* Dead LWP's aren't expected to reported a pending sigstop. */
3093 /* Store the pending event in the waitstatus, because
3094 W_EXITCODE(0,0) == 0. */
3095 store_waitstatus (&lp->waitstatus, status);
3099 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3100 an attempt to stop an LWP. */
3102 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3106 if (lp->last_resume_kind == resume_stop)
3108 if (debug_linux_nat)
3109 fprintf_unfiltered (gdb_stdlog,
3110 "LLW: resume_stop SIGSTOP caught for %s.\n",
3111 target_pid_to_str (lp->ptid));
3115 /* This is a delayed SIGSTOP. Filter out the event. */
3117 if (debug_linux_nat)
3118 fprintf_unfiltered (gdb_stdlog,
3119 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3121 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3122 target_pid_to_str (lp->ptid));
3124 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3125 gdb_assert (lp->resumed);
3130 /* Make sure we don't report a SIGINT that we have already displayed
3131 for another thread. */
3132 if (lp->ignore_sigint
3133 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3135 if (debug_linux_nat)
3136 fprintf_unfiltered (gdb_stdlog,
3137 "LLW: Delayed SIGINT caught for %s.\n",
3138 target_pid_to_str (lp->ptid));
3140 /* This is a delayed SIGINT. */
3141 lp->ignore_sigint = 0;
3143 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3144 if (debug_linux_nat)
3145 fprintf_unfiltered (gdb_stdlog,
3146 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3148 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3149 target_pid_to_str (lp->ptid));
3150 gdb_assert (lp->resumed);
3152 /* Discard the event. */
3156 /* Don't report signals that GDB isn't interested in, such as
3157 signals that are neither printed nor stopped upon. Stopping all
3158 threads can be a bit time-consuming so if we want decent
3159 performance with heavily multi-threaded programs, especially when
3160 they're using a high frequency timer, we'd better avoid it if we
3162 if (WIFSTOPPED (status))
3164 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3166 if (!target_is_non_stop_p ())
3168 /* Only do the below in all-stop, as we currently use SIGSTOP
3169 to implement target_stop (see linux_nat_stop) in
3171 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3173 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3174 forwarded to the entire process group, that is, all LWPs
3175 will receive it - unless they're using CLONE_THREAD to
3176 share signals. Since we only want to report it once, we
3177 mark it as ignored for all LWPs except this one. */
3178 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3179 set_ignore_sigint, NULL);
3180 lp->ignore_sigint = 0;
3183 maybe_clear_ignore_sigint (lp);
3186 /* When using hardware single-step, we need to report every signal.
3187 Otherwise, signals in pass_mask may be short-circuited
3188 except signals that might be caused by a breakpoint. */
3190 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3191 && !linux_wstatus_maybe_breakpoint (status))
3193 linux_resume_one_lwp (lp, lp->step, signo);
3194 if (debug_linux_nat)
3195 fprintf_unfiltered (gdb_stdlog,
3196 "LLW: %s %s, %s (preempt 'handle')\n",
3198 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3199 target_pid_to_str (lp->ptid),
3200 (signo != GDB_SIGNAL_0
3201 ? strsignal (gdb_signal_to_host (signo))
3207 /* An interesting event. */
3209 lp->status = status;
3210 save_stop_reason (lp);
3214 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3215 their exits until all other threads in the group have exited. */
3218 check_zombie_leaders (void)
3220 struct inferior *inf;
3224 struct lwp_info *leader_lp;
3229 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3230 if (leader_lp != NULL
3231 /* Check if there are other threads in the group, as we may
3232 have raced with the inferior simply exiting. */
3233 && num_lwps (inf->pid) > 1
3234 && linux_proc_pid_is_zombie (inf->pid))
3236 if (debug_linux_nat)
3237 fprintf_unfiltered (gdb_stdlog,
3238 "CZL: Thread group leader %d zombie "
3239 "(it exited, or another thread execd).\n",
3242 /* A leader zombie can mean one of two things:
3244 - It exited, and there's an exit status pending
3245 available, or only the leader exited (not the whole
3246 program). In the latter case, we can't waitpid the
3247 leader's exit status until all other threads are gone.
3249 - There are 3 or more threads in the group, and a thread
3250 other than the leader exec'd. See comments on exec
3251 events at the top of the file. We could try
3252 distinguishing the exit and exec cases, by waiting once
3253 more, and seeing if something comes out, but it doesn't
3254 sound useful. The previous leader _does_ go away, and
3255 we'll re-add the new one once we see the exec event
3256 (which is just the same as what would happen if the
3257 previous leader did exit voluntarily before some other
3260 if (debug_linux_nat)
3261 fprintf_unfiltered (gdb_stdlog,
3262 "CZL: Thread group leader %d vanished.\n",
3264 exit_lwp (leader_lp);
3269 /* Convenience function that is called when the kernel reports an exit
3270 event. This decides whether to report the event to GDB as a
3271 process exit event, a thread exit event, or to suppress the
3275 filter_exit_event (struct lwp_info *event_child,
3276 struct target_waitstatus *ourstatus)
3278 ptid_t ptid = event_child->ptid;
3280 if (num_lwps (ptid_get_pid (ptid)) > 1)
3282 if (report_thread_events)
3283 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3285 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3287 exit_lwp (event_child);
3294 linux_nat_wait_1 (struct target_ops *ops,
3295 ptid_t ptid, struct target_waitstatus *ourstatus,
3299 enum resume_kind last_resume_kind;
3300 struct lwp_info *lp;
3303 if (debug_linux_nat)
3304 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3306 /* The first time we get here after starting a new inferior, we may
3307 not have added it to the LWP list yet - this is the earliest
3308 moment at which we know its PID. */
3309 if (ptid_is_pid (inferior_ptid))
3311 /* Upgrade the main thread's ptid. */
3312 thread_change_ptid (inferior_ptid,
3313 ptid_build (ptid_get_pid (inferior_ptid),
3314 ptid_get_pid (inferior_ptid), 0));
3316 lp = add_initial_lwp (inferior_ptid);
3320 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3321 block_child_signals (&prev_mask);
3323 /* First check if there is a LWP with a wait status pending. */
3324 lp = iterate_over_lwps (ptid, status_callback, NULL);
3327 if (debug_linux_nat)
3328 fprintf_unfiltered (gdb_stdlog,
3329 "LLW: Using pending wait status %s for %s.\n",
3330 status_to_str (lp->status),
3331 target_pid_to_str (lp->ptid));
3334 /* But if we don't find a pending event, we'll have to wait. Always
3335 pull all events out of the kernel. We'll randomly select an
3336 event LWP out of all that have events, to prevent starvation. */
3342 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3345 - If the thread group leader exits while other threads in the
3346 thread group still exist, waitpid(TGID, ...) hangs. That
3347 waitpid won't return an exit status until the other threads
3348 in the group are reapped.
3350 - When a non-leader thread execs, that thread just vanishes
3351 without reporting an exit (so we'd hang if we waited for it
3352 explicitly in that case). The exec event is reported to
3356 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3358 if (debug_linux_nat)
3359 fprintf_unfiltered (gdb_stdlog,
3360 "LNW: waitpid(-1, ...) returned %d, %s\n",
3361 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3365 if (debug_linux_nat)
3367 fprintf_unfiltered (gdb_stdlog,
3368 "LLW: waitpid %ld received %s\n",
3369 (long) lwpid, status_to_str (status));
3372 linux_nat_filter_event (lwpid, status);
3373 /* Retry until nothing comes out of waitpid. A single
3374 SIGCHLD can indicate more than one child stopped. */
3378 /* Now that we've pulled all events out of the kernel, resume
3379 LWPs that don't have an interesting event to report. */
3380 iterate_over_lwps (minus_one_ptid,
3381 resume_stopped_resumed_lwps, &minus_one_ptid);
3383 /* ... and find an LWP with a status to report to the core, if
3385 lp = iterate_over_lwps (ptid, status_callback, NULL);
3389 /* Check for zombie thread group leaders. Those can't be reaped
3390 until all other threads in the thread group are. */
3391 check_zombie_leaders ();
3393 /* If there are no resumed children left, bail. We'd be stuck
3394 forever in the sigsuspend call below otherwise. */
3395 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3397 if (debug_linux_nat)
3398 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3400 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3402 restore_child_signals_mask (&prev_mask);
3403 return minus_one_ptid;
3406 /* No interesting event to report to the core. */
3408 if (target_options & TARGET_WNOHANG)
3410 if (debug_linux_nat)
3411 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3413 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3414 restore_child_signals_mask (&prev_mask);
3415 return minus_one_ptid;
3418 /* We shouldn't end up here unless we want to try again. */
3419 gdb_assert (lp == NULL);
3421 /* Block until we get an event reported with SIGCHLD. */
3422 if (debug_linux_nat)
3423 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3424 sigsuspend (&suspend_mask);
3429 status = lp->status;
3432 if (!target_is_non_stop_p ())
3434 /* Now stop all other LWP's ... */
3435 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3437 /* ... and wait until all of them have reported back that
3438 they're no longer running. */
3439 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3442 /* If we're not waiting for a specific LWP, choose an event LWP from
3443 among those that have had events. Giving equal priority to all
3444 LWPs that have had events helps prevent starvation. */
3445 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3446 select_event_lwp (ptid, &lp, &status);
3448 gdb_assert (lp != NULL);
3450 /* Now that we've selected our final event LWP, un-adjust its PC if
3451 it was a software breakpoint, and we can't reliably support the
3452 "stopped by software breakpoint" stop reason. */
3453 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3454 && !USE_SIGTRAP_SIGINFO)
3456 struct regcache *regcache = get_thread_regcache (lp->ptid);
3457 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3458 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3464 pc = regcache_read_pc (regcache);
3465 regcache_write_pc (regcache, pc + decr_pc);
3469 /* We'll need this to determine whether to report a SIGSTOP as
3470 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3472 last_resume_kind = lp->last_resume_kind;
3474 if (!target_is_non_stop_p ())
3476 /* In all-stop, from the core's perspective, all LWPs are now
3477 stopped until a new resume action is sent over. */
3478 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3482 resume_clear_callback (lp, NULL);
3485 if (linux_nat_status_is_event (status))
3487 if (debug_linux_nat)
3488 fprintf_unfiltered (gdb_stdlog,
3489 "LLW: trap ptid is %s.\n",
3490 target_pid_to_str (lp->ptid));
3493 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3495 *ourstatus = lp->waitstatus;
3496 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3499 store_waitstatus (ourstatus, status);
3501 if (debug_linux_nat)
3502 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3504 restore_child_signals_mask (&prev_mask);
3506 if (last_resume_kind == resume_stop
3507 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3508 && WSTOPSIG (status) == SIGSTOP)
3510 /* A thread that has been requested to stop by GDB with
3511 target_stop, and it stopped cleanly, so report as SIG0. The
3512 use of SIGSTOP is an implementation detail. */
3513 ourstatus->value.sig = GDB_SIGNAL_0;
3516 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3517 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3520 lp->core = linux_common_core_of_thread (lp->ptid);
3522 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3523 return filter_exit_event (lp, ourstatus);
3528 /* Resume LWPs that are currently stopped without any pending status
3529 to report, but are resumed from the core's perspective. */
3532 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3534 ptid_t *wait_ptid_p = (ptid_t *) data;
3538 if (debug_linux_nat)
3539 fprintf_unfiltered (gdb_stdlog,
3540 "RSRL: NOT resuming LWP %s, not stopped\n",
3541 target_pid_to_str (lp->ptid));
3543 else if (!lp->resumed)
3545 if (debug_linux_nat)
3546 fprintf_unfiltered (gdb_stdlog,
3547 "RSRL: NOT resuming LWP %s, not resumed\n",
3548 target_pid_to_str (lp->ptid));
3550 else if (lwp_status_pending_p (lp))
3552 if (debug_linux_nat)
3553 fprintf_unfiltered (gdb_stdlog,
3554 "RSRL: NOT resuming LWP %s, has pending status\n",
3555 target_pid_to_str (lp->ptid));
3559 struct regcache *regcache = get_thread_regcache (lp->ptid);
3560 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3564 CORE_ADDR pc = regcache_read_pc (regcache);
3565 int leave_stopped = 0;
3567 /* Don't bother if there's a breakpoint at PC that we'd hit
3568 immediately, and we're not waiting for this LWP. */
3569 if (!ptid_match (lp->ptid, *wait_ptid_p))
3571 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3577 if (debug_linux_nat)
3578 fprintf_unfiltered (gdb_stdlog,
3579 "RSRL: resuming stopped-resumed LWP %s at "
3581 target_pid_to_str (lp->ptid),
3582 paddress (gdbarch, pc),
3585 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3588 CATCH (ex, RETURN_MASK_ERROR)
3590 if (!check_ptrace_stopped_lwp_gone (lp))
3591 throw_exception (ex);
3600 linux_nat_wait (struct target_ops *ops,
3601 ptid_t ptid, struct target_waitstatus *ourstatus,
3606 if (debug_linux_nat)
3608 char *options_string;
3610 options_string = target_options_to_string (target_options);
3611 fprintf_unfiltered (gdb_stdlog,
3612 "linux_nat_wait: [%s], [%s]\n",
3613 target_pid_to_str (ptid),
3615 xfree (options_string);
3618 /* Flush the async file first. */
3619 if (target_is_async_p ())
3620 async_file_flush ();
3622 /* Resume LWPs that are currently stopped without any pending status
3623 to report, but are resumed from the core's perspective. LWPs get
3624 in this state if we find them stopping at a time we're not
3625 interested in reporting the event (target_wait on a
3626 specific_process, for example, see linux_nat_wait_1), and
3627 meanwhile the event became uninteresting. Don't bother resuming
3628 LWPs we're not going to wait for if they'd stop immediately. */
3629 if (target_is_non_stop_p ())
3630 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3632 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3634 /* If we requested any event, and something came out, assume there
3635 may be more. If we requested a specific lwp or process, also
3636 assume there may be more. */
3637 if (target_is_async_p ()
3638 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3639 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3640 || !ptid_equal (ptid, minus_one_ptid)))
3649 kill_one_lwp (pid_t pid)
3651 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3654 kill_lwp (pid, SIGKILL);
3655 if (debug_linux_nat)
3657 int save_errno = errno;
3659 fprintf_unfiltered (gdb_stdlog,
3660 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3661 save_errno ? safe_strerror (save_errno) : "OK");
3664 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3667 ptrace (PTRACE_KILL, pid, 0, 0);
3668 if (debug_linux_nat)
3670 int save_errno = errno;
3672 fprintf_unfiltered (gdb_stdlog,
3673 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3674 save_errno ? safe_strerror (save_errno) : "OK");
3678 /* Wait for an LWP to die. */
3681 kill_wait_one_lwp (pid_t pid)
3685 /* We must make sure that there are no pending events (delayed
3686 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3687 program doesn't interfere with any following debugging session. */
3691 res = my_waitpid (pid, NULL, __WALL);
3692 if (res != (pid_t) -1)
3694 if (debug_linux_nat)
3695 fprintf_unfiltered (gdb_stdlog,
3696 "KWC: wait %ld received unknown.\n",
3698 /* The Linux kernel sometimes fails to kill a thread
3699 completely after PTRACE_KILL; that goes from the stop
3700 point in do_fork out to the one in get_signal_to_deliver
3701 and waits again. So kill it again. */
3707 gdb_assert (res == -1 && errno == ECHILD);
3710 /* Callback for iterate_over_lwps. */
3713 kill_callback (struct lwp_info *lp, void *data)
3715 kill_one_lwp (ptid_get_lwp (lp->ptid));
3719 /* Callback for iterate_over_lwps. */
3722 kill_wait_callback (struct lwp_info *lp, void *data)
3724 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3728 /* Kill the fork children of any threads of inferior INF that are
3729 stopped at a fork event. */
3732 kill_unfollowed_fork_children (struct inferior *inf)
3734 struct thread_info *thread;
3736 ALL_NON_EXITED_THREADS (thread)
3737 if (thread->inf == inf)
3739 struct target_waitstatus *ws = &thread->pending_follow;
3741 if (ws->kind == TARGET_WAITKIND_FORKED
3742 || ws->kind == TARGET_WAITKIND_VFORKED)
3744 ptid_t child_ptid = ws->value.related_pid;
3745 int child_pid = ptid_get_pid (child_ptid);
3746 int child_lwp = ptid_get_lwp (child_ptid);
3748 kill_one_lwp (child_lwp);
3749 kill_wait_one_lwp (child_lwp);
3751 /* Let the arch-specific native code know this process is
3753 linux_nat_forget_process (child_pid);
3759 linux_nat_kill (struct target_ops *ops)
3761 /* If we're stopped while forking and we haven't followed yet,
3762 kill the other task. We need to do this first because the
3763 parent will be sleeping if this is a vfork. */
3764 kill_unfollowed_fork_children (current_inferior ());
3766 if (forks_exist_p ())
3767 linux_fork_killall ();
3770 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3772 /* Stop all threads before killing them, since ptrace requires
3773 that the thread is stopped to sucessfully PTRACE_KILL. */
3774 iterate_over_lwps (ptid, stop_callback, NULL);
3775 /* ... and wait until all of them have reported back that
3776 they're no longer running. */
3777 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3779 /* Kill all LWP's ... */
3780 iterate_over_lwps (ptid, kill_callback, NULL);
3782 /* ... and wait until we've flushed all events. */
3783 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3786 target_mourn_inferior (inferior_ptid);
3790 linux_nat_mourn_inferior (struct target_ops *ops)
3792 int pid = ptid_get_pid (inferior_ptid);
3794 purge_lwp_list (pid);
3796 if (! forks_exist_p ())
3797 /* Normal case, no other forks available. */
3798 linux_ops->to_mourn_inferior (ops);
3800 /* Multi-fork case. The current inferior_ptid has exited, but
3801 there are other viable forks to debug. Delete the exiting
3802 one and context-switch to the first available. */
3803 linux_fork_mourn_inferior ();
3805 /* Let the arch-specific native code know this process is gone. */
3806 linux_nat_forget_process (pid);
3809 /* Convert a native/host siginfo object, into/from the siginfo in the
3810 layout of the inferiors' architecture. */
3813 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3817 if (linux_nat_siginfo_fixup != NULL)
3818 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3820 /* If there was no callback, or the callback didn't do anything,
3821 then just do a straight memcpy. */
3825 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3827 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3831 static enum target_xfer_status
3832 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3833 const char *annex, gdb_byte *readbuf,
3834 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3835 ULONGEST *xfered_len)
3839 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3841 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3842 gdb_assert (readbuf || writebuf);
3844 pid = ptid_get_lwp (inferior_ptid);
3846 pid = ptid_get_pid (inferior_ptid);
3848 if (offset > sizeof (siginfo))
3849 return TARGET_XFER_E_IO;
3852 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3854 return TARGET_XFER_E_IO;
3856 /* When GDB is built as a 64-bit application, ptrace writes into
3857 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3858 inferior with a 64-bit GDB should look the same as debugging it
3859 with a 32-bit GDB, we need to convert it. GDB core always sees
3860 the converted layout, so any read/write will have to be done
3862 siginfo_fixup (&siginfo, inf_siginfo, 0);
3864 if (offset + len > sizeof (siginfo))
3865 len = sizeof (siginfo) - offset;
3867 if (readbuf != NULL)
3868 memcpy (readbuf, inf_siginfo + offset, len);
3871 memcpy (inf_siginfo + offset, writebuf, len);
3873 /* Convert back to ptrace layout before flushing it out. */
3874 siginfo_fixup (&siginfo, inf_siginfo, 1);
3877 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3879 return TARGET_XFER_E_IO;
3883 return TARGET_XFER_OK;
3886 static enum target_xfer_status
3887 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3888 const char *annex, gdb_byte *readbuf,
3889 const gdb_byte *writebuf,
3890 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3892 enum target_xfer_status xfer;
3894 if (object == TARGET_OBJECT_SIGNAL_INFO)
3895 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3896 offset, len, xfered_len);
3898 /* The target is connected but no live inferior is selected. Pass
3899 this request down to a lower stratum (e.g., the executable
3901 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3902 return TARGET_XFER_EOF;
3904 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3905 offset, len, xfered_len);
3911 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3913 /* As long as a PTID is in lwp list, consider it alive. */
3914 return find_lwp_pid (ptid) != NULL;
3917 /* Implement the to_update_thread_list target method for this
3921 linux_nat_update_thread_list (struct target_ops *ops)
3923 struct lwp_info *lwp;
3925 /* We add/delete threads from the list as clone/exit events are
3926 processed, so just try deleting exited threads still in the
3928 delete_exited_threads ();
3930 /* Update the processor core that each lwp/thread was last seen
3934 /* Avoid accessing /proc if the thread hasn't run since we last
3935 time we fetched the thread's core. Accessing /proc becomes
3936 noticeably expensive when we have thousands of LWPs. */
3937 if (lwp->core == -1)
3938 lwp->core = linux_common_core_of_thread (lwp->ptid);
3943 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3945 static char buf[64];
3947 if (ptid_lwp_p (ptid)
3948 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3949 || num_lwps (ptid_get_pid (ptid)) > 1))
3951 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3955 return normal_pid_to_str (ptid);
3959 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3961 return linux_proc_tid_get_name (thr->ptid);
3964 /* Accepts an integer PID; Returns a string representing a file that
3965 can be opened to get the symbols for the child process. */
3968 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
3970 return linux_proc_pid_to_exec_file (pid);
3973 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3974 Because we can use a single read/write call, this can be much more
3975 efficient than banging away at PTRACE_PEEKTEXT. */
3977 static enum target_xfer_status
3978 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3979 const char *annex, gdb_byte *readbuf,
3980 const gdb_byte *writebuf,
3981 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3987 if (object != TARGET_OBJECT_MEMORY)
3988 return TARGET_XFER_EOF;
3990 /* Don't bother for one word. */
3991 if (len < 3 * sizeof (long))
3992 return TARGET_XFER_EOF;
3994 /* We could keep this file open and cache it - possibly one per
3995 thread. That requires some juggling, but is even faster. */
3996 xsnprintf (filename, sizeof filename, "/proc/%ld/mem",
3997 ptid_get_lwp (inferior_ptid));
3998 fd = gdb_open_cloexec (filename, ((readbuf ? O_RDONLY : O_WRONLY)
4001 return TARGET_XFER_EOF;
4003 /* Use pread64/pwrite64 if available, since they save a syscall and can
4004 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
4005 debugging a SPARC64 application). */
4007 ret = (readbuf ? pread64 (fd, readbuf, len, offset)
4008 : pwrite64 (fd, writebuf, len, offset));
4010 ret = lseek (fd, offset, SEEK_SET);
4012 ret = (readbuf ? read (fd, readbuf, len)
4013 : write (fd, writebuf, len));
4018 if (ret == -1 || ret == 0)
4019 return TARGET_XFER_EOF;
4023 return TARGET_XFER_OK;
4028 /* Enumerate spufs IDs for process PID. */
4030 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4032 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4034 LONGEST written = 0;
4037 struct dirent *entry;
4039 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4040 dir = opendir (path);
4045 while ((entry = readdir (dir)) != NULL)
4051 fd = atoi (entry->d_name);
4055 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4056 if (stat (path, &st) != 0)
4058 if (!S_ISDIR (st.st_mode))
4061 if (statfs (path, &stfs) != 0)
4063 if (stfs.f_type != SPUFS_MAGIC)
4066 if (pos >= offset && pos + 4 <= offset + len)
4068 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4078 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4079 object type, using the /proc file system. */
4081 static enum target_xfer_status
4082 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4083 const char *annex, gdb_byte *readbuf,
4084 const gdb_byte *writebuf,
4085 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4090 int pid = ptid_get_lwp (inferior_ptid);
4095 return TARGET_XFER_E_IO;
4098 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4101 return TARGET_XFER_E_IO;
4103 return TARGET_XFER_EOF;
4106 *xfered_len = (ULONGEST) l;
4107 return TARGET_XFER_OK;
4112 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4113 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4115 return TARGET_XFER_E_IO;
4118 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4121 return TARGET_XFER_EOF;
4125 ret = write (fd, writebuf, (size_t) len);
4127 ret = read (fd, readbuf, (size_t) len);
4132 return TARGET_XFER_E_IO;
4134 return TARGET_XFER_EOF;
4137 *xfered_len = (ULONGEST) ret;
4138 return TARGET_XFER_OK;
4143 /* Parse LINE as a signal set and add its set bits to SIGS. */
4146 add_line_to_sigset (const char *line, sigset_t *sigs)
4148 int len = strlen (line) - 1;
4152 if (line[len] != '\n')
4153 error (_("Could not parse signal set: %s"), line);
4161 if (*p >= '0' && *p <= '9')
4163 else if (*p >= 'a' && *p <= 'f')
4164 digit = *p - 'a' + 10;
4166 error (_("Could not parse signal set: %s"), line);
4171 sigaddset (sigs, signum + 1);
4173 sigaddset (sigs, signum + 2);
4175 sigaddset (sigs, signum + 3);
4177 sigaddset (sigs, signum + 4);
4183 /* Find process PID's pending signals from /proc/pid/status and set
4187 linux_proc_pending_signals (int pid, sigset_t *pending,
4188 sigset_t *blocked, sigset_t *ignored)
4191 char buffer[PATH_MAX], fname[PATH_MAX];
4192 struct cleanup *cleanup;
4194 sigemptyset (pending);
4195 sigemptyset (blocked);
4196 sigemptyset (ignored);
4197 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4198 procfile = gdb_fopen_cloexec (fname, "r");
4199 if (procfile == NULL)
4200 error (_("Could not open %s"), fname);
4201 cleanup = make_cleanup_fclose (procfile);
4203 while (fgets (buffer, PATH_MAX, procfile) != NULL)
4205 /* Normal queued signals are on the SigPnd line in the status
4206 file. However, 2.6 kernels also have a "shared" pending
4207 queue for delivering signals to a thread group, so check for
4210 Unfortunately some Red Hat kernels include the shared pending
4211 queue but not the ShdPnd status field. */
4213 if (startswith (buffer, "SigPnd:\t"))
4214 add_line_to_sigset (buffer + 8, pending);
4215 else if (startswith (buffer, "ShdPnd:\t"))
4216 add_line_to_sigset (buffer + 8, pending);
4217 else if (startswith (buffer, "SigBlk:\t"))
4218 add_line_to_sigset (buffer + 8, blocked);
4219 else if (startswith (buffer, "SigIgn:\t"))
4220 add_line_to_sigset (buffer + 8, ignored);
4223 do_cleanups (cleanup);
4226 static enum target_xfer_status
4227 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4228 const char *annex, gdb_byte *readbuf,
4229 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4230 ULONGEST *xfered_len)
4232 gdb_assert (object == TARGET_OBJECT_OSDATA);
4234 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4235 if (*xfered_len == 0)
4236 return TARGET_XFER_EOF;
4238 return TARGET_XFER_OK;
4241 static enum target_xfer_status
4242 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4243 const char *annex, gdb_byte *readbuf,
4244 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4245 ULONGEST *xfered_len)
4247 enum target_xfer_status xfer;
4249 if (object == TARGET_OBJECT_AUXV)
4250 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4251 offset, len, xfered_len);
4253 if (object == TARGET_OBJECT_OSDATA)
4254 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4255 offset, len, xfered_len);
4257 if (object == TARGET_OBJECT_SPU)
4258 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4259 offset, len, xfered_len);
4261 /* GDB calculates all the addresses in possibly larget width of the address.
4262 Address width needs to be masked before its final use - either by
4263 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4265 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4267 if (object == TARGET_OBJECT_MEMORY)
4269 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4271 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4272 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4275 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4276 offset, len, xfered_len);
4277 if (xfer != TARGET_XFER_EOF)
4280 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4281 offset, len, xfered_len);
4285 cleanup_target_stop (void *arg)
4287 ptid_t *ptid = (ptid_t *) arg;
4289 gdb_assert (arg != NULL);
4292 target_continue_no_signal (*ptid);
4295 static VEC(static_tracepoint_marker_p) *
4296 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4299 char s[IPA_CMD_BUF_SIZE];
4300 struct cleanup *old_chain;
4301 int pid = ptid_get_pid (inferior_ptid);
4302 VEC(static_tracepoint_marker_p) *markers = NULL;
4303 struct static_tracepoint_marker *marker = NULL;
4305 ptid_t ptid = ptid_build (pid, 0, 0);
4310 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4311 s[sizeof ("qTfSTM")] = 0;
4313 agent_run_command (pid, s, strlen (s) + 1);
4315 old_chain = make_cleanup (free_current_marker, &marker);
4316 make_cleanup (cleanup_target_stop, &ptid);
4321 marker = XCNEW (struct static_tracepoint_marker);
4325 parse_static_tracepoint_marker_definition (p, &p, marker);
4327 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4329 VEC_safe_push (static_tracepoint_marker_p,
4335 release_static_tracepoint_marker (marker);
4336 memset (marker, 0, sizeof (*marker));
4339 while (*p++ == ','); /* comma-separated list */
4341 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4342 s[sizeof ("qTsSTM")] = 0;
4343 agent_run_command (pid, s, strlen (s) + 1);
4347 do_cleanups (old_chain);
4352 /* Create a prototype generic GNU/Linux target. The client can override
4353 it with local methods. */
4356 linux_target_install_ops (struct target_ops *t)
4358 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4359 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4360 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4361 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4362 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4363 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4364 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4365 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4366 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4367 t->to_post_attach = linux_child_post_attach;
4368 t->to_follow_fork = linux_child_follow_fork;
4370 super_xfer_partial = t->to_xfer_partial;
4371 t->to_xfer_partial = linux_xfer_partial;
4373 t->to_static_tracepoint_markers_by_strid
4374 = linux_child_static_tracepoint_markers_by_strid;
4380 struct target_ops *t;
4382 t = inf_ptrace_target ();
4383 linux_target_install_ops (t);
4389 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4391 struct target_ops *t;
4393 t = inf_ptrace_trad_target (register_u_offset);
4394 linux_target_install_ops (t);
4399 /* target_is_async_p implementation. */
4402 linux_nat_is_async_p (struct target_ops *ops)
4404 return linux_is_async_p ();
4407 /* target_can_async_p implementation. */
4410 linux_nat_can_async_p (struct target_ops *ops)
4412 /* We're always async, unless the user explicitly prevented it with the
4413 "maint set target-async" command. */
4414 return target_async_permitted;
4418 linux_nat_supports_non_stop (struct target_ops *self)
4423 /* to_always_non_stop_p implementation. */
4426 linux_nat_always_non_stop_p (struct target_ops *self)
4431 /* True if we want to support multi-process. To be removed when GDB
4432 supports multi-exec. */
4434 int linux_multi_process = 1;
4437 linux_nat_supports_multi_process (struct target_ops *self)
4439 return linux_multi_process;
4443 linux_nat_supports_disable_randomization (struct target_ops *self)
4445 #ifdef HAVE_PERSONALITY
4452 static int async_terminal_is_ours = 1;
4454 /* target_terminal_inferior implementation.
4456 This is a wrapper around child_terminal_inferior to add async support. */
4459 linux_nat_terminal_inferior (struct target_ops *self)
4461 child_terminal_inferior (self);
4463 /* Calls to target_terminal_*() are meant to be idempotent. */
4464 if (!async_terminal_is_ours)
4467 async_terminal_is_ours = 0;
4471 /* target_terminal_ours implementation.
4473 This is a wrapper around child_terminal_ours to add async support (and
4474 implement the target_terminal_ours vs target_terminal_ours_for_output
4475 distinction). child_terminal_ours is currently no different than
4476 child_terminal_ours_for_output.
4477 We leave target_terminal_ours_for_output alone, leaving it to
4478 child_terminal_ours_for_output. */
4481 linux_nat_terminal_ours (struct target_ops *self)
4483 /* GDB should never give the terminal to the inferior if the
4484 inferior is running in the background (run&, continue&, etc.),
4485 but claiming it sure should. */
4486 child_terminal_ours (self);
4488 if (async_terminal_is_ours)
4491 clear_sigint_trap ();
4492 async_terminal_is_ours = 1;
4495 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4496 so we notice when any child changes state, and notify the
4497 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4498 above to wait for the arrival of a SIGCHLD. */
4501 sigchld_handler (int signo)
4503 int old_errno = errno;
4505 if (debug_linux_nat)
4506 ui_file_write_async_safe (gdb_stdlog,
4507 "sigchld\n", sizeof ("sigchld\n") - 1);
4509 if (signo == SIGCHLD
4510 && linux_nat_event_pipe[0] != -1)
4511 async_file_mark (); /* Let the event loop know that there are
4512 events to handle. */
4517 /* Callback registered with the target events file descriptor. */
4520 handle_target_event (int error, gdb_client_data client_data)
4522 inferior_event_handler (INF_REG_EVENT, NULL);
4525 /* Create/destroy the target events pipe. Returns previous state. */
4528 linux_async_pipe (int enable)
4530 int previous = linux_is_async_p ();
4532 if (previous != enable)
4536 /* Block child signals while we create/destroy the pipe, as
4537 their handler writes to it. */
4538 block_child_signals (&prev_mask);
4542 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4543 internal_error (__FILE__, __LINE__,
4544 "creating event pipe failed.");
4546 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4547 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4551 close (linux_nat_event_pipe[0]);
4552 close (linux_nat_event_pipe[1]);
4553 linux_nat_event_pipe[0] = -1;
4554 linux_nat_event_pipe[1] = -1;
4557 restore_child_signals_mask (&prev_mask);
4563 /* target_async implementation. */
4566 linux_nat_async (struct target_ops *ops, int enable)
4570 if (!linux_async_pipe (1))
4572 add_file_handler (linux_nat_event_pipe[0],
4573 handle_target_event, NULL);
4574 /* There may be pending events to handle. Tell the event loop
4581 delete_file_handler (linux_nat_event_pipe[0]);
4582 linux_async_pipe (0);
4587 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4591 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4595 if (debug_linux_nat)
4596 fprintf_unfiltered (gdb_stdlog,
4597 "LNSL: running -> suspending %s\n",
4598 target_pid_to_str (lwp->ptid));
4601 if (lwp->last_resume_kind == resume_stop)
4603 if (debug_linux_nat)
4604 fprintf_unfiltered (gdb_stdlog,
4605 "linux-nat: already stopping LWP %ld at "
4607 ptid_get_lwp (lwp->ptid));
4611 stop_callback (lwp, NULL);
4612 lwp->last_resume_kind = resume_stop;
4616 /* Already known to be stopped; do nothing. */
4618 if (debug_linux_nat)
4620 if (find_thread_ptid (lwp->ptid)->stop_requested)
4621 fprintf_unfiltered (gdb_stdlog,
4622 "LNSL: already stopped/stop_requested %s\n",
4623 target_pid_to_str (lwp->ptid));
4625 fprintf_unfiltered (gdb_stdlog,
4626 "LNSL: already stopped/no "
4627 "stop_requested yet %s\n",
4628 target_pid_to_str (lwp->ptid));
4635 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4637 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4641 linux_nat_close (struct target_ops *self)
4643 /* Unregister from the event loop. */
4644 if (linux_nat_is_async_p (self))
4645 linux_nat_async (self, 0);
4647 if (linux_ops->to_close)
4648 linux_ops->to_close (linux_ops);
4653 /* When requests are passed down from the linux-nat layer to the
4654 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4655 used. The address space pointer is stored in the inferior object,
4656 but the common code that is passed such ptid can't tell whether
4657 lwpid is a "main" process id or not (it assumes so). We reverse
4658 look up the "main" process id from the lwp here. */
4660 static struct address_space *
4661 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4663 struct lwp_info *lwp;
4664 struct inferior *inf;
4667 if (ptid_get_lwp (ptid) == 0)
4669 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4671 lwp = find_lwp_pid (ptid);
4672 pid = ptid_get_pid (lwp->ptid);
4676 /* A (pid,lwpid,0) ptid. */
4677 pid = ptid_get_pid (ptid);
4680 inf = find_inferior_pid (pid);
4681 gdb_assert (inf != NULL);
4685 /* Return the cached value of the processor core for thread PTID. */
4688 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4690 struct lwp_info *info = find_lwp_pid (ptid);
4697 /* Implementation of to_filesystem_is_local. */
4700 linux_nat_filesystem_is_local (struct target_ops *ops)
4702 struct inferior *inf = current_inferior ();
4704 if (inf->fake_pid_p || inf->pid == 0)
4707 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4710 /* Convert the INF argument passed to a to_fileio_* method
4711 to a process ID suitable for passing to its corresponding
4712 linux_mntns_* function. If INF is non-NULL then the
4713 caller is requesting the filesystem seen by INF. If INF
4714 is NULL then the caller is requesting the filesystem seen
4715 by the GDB. We fall back to GDB's filesystem in the case
4716 that INF is non-NULL but its PID is unknown. */
4719 linux_nat_fileio_pid_of (struct inferior *inf)
4721 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4727 /* Implementation of to_fileio_open. */
4730 linux_nat_fileio_open (struct target_ops *self,
4731 struct inferior *inf, const char *filename,
4732 int flags, int mode, int warn_if_slow,
4739 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4740 || fileio_to_host_mode (mode, &nat_mode) == -1)
4742 *target_errno = FILEIO_EINVAL;
4746 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4747 filename, nat_flags, nat_mode);
4749 *target_errno = host_to_fileio_error (errno);
4754 /* Implementation of to_fileio_readlink. */
4757 linux_nat_fileio_readlink (struct target_ops *self,
4758 struct inferior *inf, const char *filename,
4765 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4766 filename, buf, sizeof (buf));
4769 *target_errno = host_to_fileio_error (errno);
4773 ret = (char *) xmalloc (len + 1);
4774 memcpy (ret, buf, len);
4779 /* Implementation of to_fileio_unlink. */
4782 linux_nat_fileio_unlink (struct target_ops *self,
4783 struct inferior *inf, const char *filename,
4788 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4791 *target_errno = host_to_fileio_error (errno);
4796 /* Implementation of the to_thread_events method. */
4799 linux_nat_thread_events (struct target_ops *ops, int enable)
4801 report_thread_events = enable;
4805 linux_nat_add_target (struct target_ops *t)
4807 /* Save the provided single-threaded target. We save this in a separate
4808 variable because another target we've inherited from (e.g. inf-ptrace)
4809 may have saved a pointer to T; we want to use it for the final
4810 process stratum target. */
4811 linux_ops_saved = *t;
4812 linux_ops = &linux_ops_saved;
4814 /* Override some methods for multithreading. */
4815 t->to_create_inferior = linux_nat_create_inferior;
4816 t->to_attach = linux_nat_attach;
4817 t->to_detach = linux_nat_detach;
4818 t->to_resume = linux_nat_resume;
4819 t->to_wait = linux_nat_wait;
4820 t->to_pass_signals = linux_nat_pass_signals;
4821 t->to_xfer_partial = linux_nat_xfer_partial;
4822 t->to_kill = linux_nat_kill;
4823 t->to_mourn_inferior = linux_nat_mourn_inferior;
4824 t->to_thread_alive = linux_nat_thread_alive;
4825 t->to_update_thread_list = linux_nat_update_thread_list;
4826 t->to_pid_to_str = linux_nat_pid_to_str;
4827 t->to_thread_name = linux_nat_thread_name;
4828 t->to_has_thread_control = tc_schedlock;
4829 t->to_thread_address_space = linux_nat_thread_address_space;
4830 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4831 t->to_stopped_data_address = linux_nat_stopped_data_address;
4832 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4833 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4834 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4835 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4836 t->to_thread_events = linux_nat_thread_events;
4838 t->to_can_async_p = linux_nat_can_async_p;
4839 t->to_is_async_p = linux_nat_is_async_p;
4840 t->to_supports_non_stop = linux_nat_supports_non_stop;
4841 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4842 t->to_async = linux_nat_async;
4843 t->to_terminal_inferior = linux_nat_terminal_inferior;
4844 t->to_terminal_ours = linux_nat_terminal_ours;
4846 super_close = t->to_close;
4847 t->to_close = linux_nat_close;
4849 t->to_stop = linux_nat_stop;
4851 t->to_supports_multi_process = linux_nat_supports_multi_process;
4853 t->to_supports_disable_randomization
4854 = linux_nat_supports_disable_randomization;
4856 t->to_core_of_thread = linux_nat_core_of_thread;
4858 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4859 t->to_fileio_open = linux_nat_fileio_open;
4860 t->to_fileio_readlink = linux_nat_fileio_readlink;
4861 t->to_fileio_unlink = linux_nat_fileio_unlink;
4863 /* We don't change the stratum; this target will sit at
4864 process_stratum and thread_db will set at thread_stratum. This
4865 is a little strange, since this is a multi-threaded-capable
4866 target, but we want to be on the stack below thread_db, and we
4867 also want to be used for single-threaded processes. */
4872 /* Register a method to call whenever a new thread is attached. */
4874 linux_nat_set_new_thread (struct target_ops *t,
4875 void (*new_thread) (struct lwp_info *))
4877 /* Save the pointer. We only support a single registered instance
4878 of the GNU/Linux native target, so we do not need to map this to
4880 linux_nat_new_thread = new_thread;
4883 /* See declaration in linux-nat.h. */
4886 linux_nat_set_new_fork (struct target_ops *t,
4887 linux_nat_new_fork_ftype *new_fork)
4889 /* Save the pointer. */
4890 linux_nat_new_fork = new_fork;
4893 /* See declaration in linux-nat.h. */
4896 linux_nat_set_forget_process (struct target_ops *t,
4897 linux_nat_forget_process_ftype *fn)
4899 /* Save the pointer. */
4900 linux_nat_forget_process_hook = fn;
4903 /* See declaration in linux-nat.h. */
4906 linux_nat_forget_process (pid_t pid)
4908 if (linux_nat_forget_process_hook != NULL)
4909 linux_nat_forget_process_hook (pid);
4912 /* Register a method that converts a siginfo object between the layout
4913 that ptrace returns, and the layout in the architecture of the
4916 linux_nat_set_siginfo_fixup (struct target_ops *t,
4917 int (*siginfo_fixup) (siginfo_t *,
4921 /* Save the pointer. */
4922 linux_nat_siginfo_fixup = siginfo_fixup;
4925 /* Register a method to call prior to resuming a thread. */
4928 linux_nat_set_prepare_to_resume (struct target_ops *t,
4929 void (*prepare_to_resume) (struct lwp_info *))
4931 /* Save the pointer. */
4932 linux_nat_prepare_to_resume = prepare_to_resume;
4935 /* See linux-nat.h. */
4938 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4942 pid = ptid_get_lwp (ptid);
4944 pid = ptid_get_pid (ptid);
4947 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4950 memset (siginfo, 0, sizeof (*siginfo));
4956 /* See nat/linux-nat.h. */
4959 current_lwp_ptid (void)
4961 gdb_assert (ptid_lwp_p (inferior_ptid));
4962 return inferior_ptid;
4965 /* Provide a prototype to silence -Wmissing-prototypes. */
4966 extern initialize_file_ftype _initialize_linux_nat;
4969 _initialize_linux_nat (void)
4971 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4972 &debug_linux_nat, _("\
4973 Set debugging of GNU/Linux lwp module."), _("\
4974 Show debugging of GNU/Linux lwp module."), _("\
4975 Enables printf debugging output."),
4977 show_debug_linux_nat,
4978 &setdebuglist, &showdebuglist);
4980 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4981 &debug_linux_namespaces, _("\
4982 Set debugging of GNU/Linux namespaces module."), _("\
4983 Show debugging of GNU/Linux namespaces module."), _("\
4984 Enables printf debugging output."),
4987 &setdebuglist, &showdebuglist);
4989 /* Save this mask as the default. */
4990 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4992 /* Install a SIGCHLD handler. */
4993 sigchld_action.sa_handler = sigchld_handler;
4994 sigemptyset (&sigchld_action.sa_mask);
4995 sigchld_action.sa_flags = SA_RESTART;
4997 /* Make it the default. */
4998 sigaction (SIGCHLD, &sigchld_action, NULL);
5000 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5001 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5002 sigdelset (&suspend_mask, SIGCHLD);
5004 sigemptyset (&blocked_mask);
5006 lwp_lwpid_htab_create ();
5010 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5011 the GNU/Linux Threads library and therefore doesn't really belong
5014 /* Return the set of signals used by the threads library in *SET. */
5017 lin_thread_get_thread_signals (sigset_t *set)
5021 /* NPTL reserves the first two RT signals, but does not provide any
5022 way for the debugger to query the signal numbers - fortunately
5023 they don't change. */
5024 sigaddset (set, __SIGRTMIN);
5025 sigaddset (set, __SIGRTMIN + 1);