1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2016 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;
359 /* Trivial list manipulation functions to keep track of a list of
360 new stopped processes. */
362 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
364 struct simple_pid_list *new_pid = XNEW (struct simple_pid_list);
367 new_pid->status = status;
368 new_pid->next = *listp;
373 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
375 struct simple_pid_list **p;
377 for (p = listp; *p != NULL; p = &(*p)->next)
378 if ((*p)->pid == pid)
380 struct simple_pid_list *next = (*p)->next;
382 *statusp = (*p)->status;
390 /* Return the ptrace options that we want to try to enable. */
393 linux_nat_ptrace_options (int attached)
398 options |= PTRACE_O_EXITKILL;
400 options |= (PTRACE_O_TRACESYSGOOD
401 | PTRACE_O_TRACEVFORKDONE
402 | PTRACE_O_TRACEVFORK
404 | PTRACE_O_TRACEEXEC);
409 /* Initialize ptrace warnings and check for supported ptrace
412 ATTACHED should be nonzero iff we attached to the inferior. */
415 linux_init_ptrace (pid_t pid, int attached)
417 int options = linux_nat_ptrace_options (attached);
419 linux_enable_event_reporting (pid, options);
420 linux_ptrace_init_warnings ();
424 linux_child_post_attach (struct target_ops *self, int pid)
426 linux_init_ptrace (pid, 1);
430 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
432 linux_init_ptrace (ptid_get_pid (ptid), 0);
435 /* Return the number of known LWPs in the tgid given by PID. */
443 for (lp = lwp_list; lp; lp = lp->next)
444 if (ptid_get_pid (lp->ptid) == pid)
450 /* Call delete_lwp with prototype compatible for make_cleanup. */
453 delete_lwp_cleanup (void *lp_voidp)
455 struct lwp_info *lp = (struct lwp_info *) lp_voidp;
457 delete_lwp (lp->ptid);
460 /* Target hook for follow_fork. On entry inferior_ptid must be the
461 ptid of the followed inferior. At return, inferior_ptid will be
465 linux_child_follow_fork (struct target_ops *ops, int follow_child,
470 struct lwp_info *child_lp = NULL;
471 int status = W_STOPCODE (0);
472 struct cleanup *old_chain;
474 ptid_t parent_ptid, child_ptid;
475 int parent_pid, child_pid;
477 has_vforked = (inferior_thread ()->pending_follow.kind
478 == TARGET_WAITKIND_VFORKED);
479 parent_ptid = inferior_ptid;
480 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
481 parent_pid = ptid_get_lwp (parent_ptid);
482 child_pid = ptid_get_lwp (child_ptid);
484 /* We're already attached to the parent, by default. */
485 old_chain = save_inferior_ptid ();
486 inferior_ptid = child_ptid;
487 child_lp = add_lwp (inferior_ptid);
488 child_lp->stopped = 1;
489 child_lp->last_resume_kind = resume_stop;
491 /* Detach new forked process? */
494 make_cleanup (delete_lwp_cleanup, child_lp);
496 if (linux_nat_prepare_to_resume != NULL)
497 linux_nat_prepare_to_resume (child_lp);
499 /* When debugging an inferior in an architecture that supports
500 hardware single stepping on a kernel without commit
501 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
502 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
503 set if the parent process had them set.
504 To work around this, single step the child process
505 once before detaching to clear the flags. */
507 if (!gdbarch_software_single_step_p (target_thread_architecture
510 linux_disable_event_reporting (child_pid);
511 if (ptrace (PTRACE_SINGLESTEP, child_pid, 0, 0) < 0)
512 perror_with_name (_("Couldn't do single step"));
513 if (my_waitpid (child_pid, &status, 0) < 0)
514 perror_with_name (_("Couldn't wait vfork process"));
517 if (WIFSTOPPED (status))
521 signo = WSTOPSIG (status);
523 && !signal_pass_state (gdb_signal_from_host (signo)))
525 ptrace (PTRACE_DETACH, child_pid, 0, signo);
528 /* Resets value of inferior_ptid to parent ptid. */
529 do_cleanups (old_chain);
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
537 do_cleanups (old_chain);
541 struct lwp_info *parent_lp;
543 parent_lp = find_lwp_pid (parent_ptid);
544 gdb_assert (linux_supports_tracefork () >= 0);
546 if (linux_supports_tracevforkdone ())
549 fprintf_unfiltered (gdb_stdlog,
550 "LCFF: waiting for VFORK_DONE on %d\n",
552 parent_lp->stopped = 1;
554 /* We'll handle the VFORK_DONE event like any other
555 event, in target_wait. */
559 /* We can't insert breakpoints until the child has
560 finished with the shared memory region. We need to
561 wait until that happens. Ideal would be to just
563 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
564 - waitpid (parent_pid, &status, __WALL);
565 However, most architectures can't handle a syscall
566 being traced on the way out if it wasn't traced on
569 We might also think to loop, continuing the child
570 until it exits or gets a SIGTRAP. One problem is
571 that the child might call ptrace with PTRACE_TRACEME.
573 There's no simple and reliable way to figure out when
574 the vforked child will be done with its copy of the
575 shared memory. We could step it out of the syscall,
576 two instructions, let it go, and then single-step the
577 parent once. When we have hardware single-step, this
578 would work; with software single-step it could still
579 be made to work but we'd have to be able to insert
580 single-step breakpoints in the child, and we'd have
581 to insert -just- the single-step breakpoint in the
582 parent. Very awkward.
584 In the end, the best we can do is to make sure it
585 runs for a little while. Hopefully it will be out of
586 range of any breakpoints we reinsert. Usually this
587 is only the single-step breakpoint at vfork's return
591 fprintf_unfiltered (gdb_stdlog,
592 "LCFF: no VFORK_DONE "
593 "support, sleeping a bit\n");
597 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
598 and leave it pending. The next linux_nat_resume call
599 will notice a pending event, and bypasses actually
600 resuming the inferior. */
601 parent_lp->status = 0;
602 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
603 parent_lp->stopped = 1;
605 /* If we're in async mode, need to tell the event loop
606 there's something here to process. */
607 if (target_is_async_p ())
614 struct lwp_info *child_lp;
616 child_lp = add_lwp (inferior_ptid);
617 child_lp->stopped = 1;
618 child_lp->last_resume_kind = resume_stop;
620 /* Let the thread_db layer learn about this new process. */
621 check_for_thread_db ();
629 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
631 return !linux_supports_tracefork ();
635 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
641 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
643 return !linux_supports_tracefork ();
647 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
653 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
655 return !linux_supports_tracefork ();
659 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
665 linux_child_set_syscall_catchpoint (struct target_ops *self,
666 int pid, int needed, int any_count,
667 int table_size, int *table)
669 if (!linux_supports_tracesysgood ())
672 /* On GNU/Linux, we ignore the arguments. It means that we only
673 enable the syscall catchpoints, but do not disable them.
675 Also, we do not use the `table' information because we do not
676 filter system calls here. We let GDB do the logic for us. */
680 /* List of known LWPs, keyed by LWP PID. This speeds up the common
681 case of mapping a PID returned from the kernel to our corresponding
682 lwp_info data structure. */
683 static htab_t lwp_lwpid_htab;
685 /* Calculate a hash from a lwp_info's LWP PID. */
688 lwp_info_hash (const void *ap)
690 const struct lwp_info *lp = (struct lwp_info *) ap;
691 pid_t pid = ptid_get_lwp (lp->ptid);
693 return iterative_hash_object (pid, 0);
696 /* Equality function for the lwp_info hash table. Compares the LWP's
700 lwp_lwpid_htab_eq (const void *a, const void *b)
702 const struct lwp_info *entry = (const struct lwp_info *) a;
703 const struct lwp_info *element = (const struct lwp_info *) b;
705 return ptid_get_lwp (entry->ptid) == ptid_get_lwp (element->ptid);
708 /* Create the lwp_lwpid_htab hash table. */
711 lwp_lwpid_htab_create (void)
713 lwp_lwpid_htab = htab_create (100, lwp_info_hash, lwp_lwpid_htab_eq, NULL);
716 /* Add LP to the hash table. */
719 lwp_lwpid_htab_add_lwp (struct lwp_info *lp)
723 slot = htab_find_slot (lwp_lwpid_htab, lp, INSERT);
724 gdb_assert (slot != NULL && *slot == NULL);
728 /* Head of doubly-linked list of known LWPs. Sorted by reverse
729 creation order. This order is assumed in some cases. E.g.,
730 reaping status after killing alls lwps of a process: the leader LWP
731 must be reaped last. */
732 struct lwp_info *lwp_list;
734 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
737 lwp_list_add (struct lwp_info *lp)
740 if (lwp_list != NULL)
745 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
749 lwp_list_remove (struct lwp_info *lp)
751 /* Remove from sorted-by-creation-order list. */
752 if (lp->next != NULL)
753 lp->next->prev = lp->prev;
754 if (lp->prev != NULL)
755 lp->prev->next = lp->next;
762 /* Original signal mask. */
763 static sigset_t normal_mask;
765 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
766 _initialize_linux_nat. */
767 static sigset_t suspend_mask;
769 /* Signals to block to make that sigsuspend work. */
770 static sigset_t blocked_mask;
772 /* SIGCHLD action. */
773 struct sigaction sigchld_action;
775 /* Block child signals (SIGCHLD and linux threads signals), and store
776 the previous mask in PREV_MASK. */
779 block_child_signals (sigset_t *prev_mask)
781 /* Make sure SIGCHLD is blocked. */
782 if (!sigismember (&blocked_mask, SIGCHLD))
783 sigaddset (&blocked_mask, SIGCHLD);
785 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
788 /* Restore child signals mask, previously returned by
789 block_child_signals. */
792 restore_child_signals_mask (sigset_t *prev_mask)
794 sigprocmask (SIG_SETMASK, prev_mask, NULL);
797 /* Mask of signals to pass directly to the inferior. */
798 static sigset_t pass_mask;
800 /* Update signals to pass to the inferior. */
802 linux_nat_pass_signals (struct target_ops *self,
803 int numsigs, unsigned char *pass_signals)
807 sigemptyset (&pass_mask);
809 for (signo = 1; signo < NSIG; signo++)
811 int target_signo = gdb_signal_from_host (signo);
812 if (target_signo < numsigs && pass_signals[target_signo])
813 sigaddset (&pass_mask, signo);
819 /* Prototypes for local functions. */
820 static int stop_wait_callback (struct lwp_info *lp, void *data);
821 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
822 static int resume_stopped_resumed_lwps (struct lwp_info *lp, void *data);
823 static int check_ptrace_stopped_lwp_gone (struct lwp_info *lp);
827 /* Destroy and free LP. */
830 lwp_free (struct lwp_info *lp)
832 xfree (lp->arch_private);
836 /* Traversal function for purge_lwp_list. */
839 lwp_lwpid_htab_remove_pid (void **slot, void *info)
841 struct lwp_info *lp = (struct lwp_info *) *slot;
842 int pid = *(int *) info;
844 if (ptid_get_pid (lp->ptid) == pid)
846 htab_clear_slot (lwp_lwpid_htab, slot);
847 lwp_list_remove (lp);
854 /* Remove all LWPs belong to PID from the lwp list. */
857 purge_lwp_list (int pid)
859 htab_traverse_noresize (lwp_lwpid_htab, lwp_lwpid_htab_remove_pid, &pid);
862 /* Add the LWP specified by PTID to the list. PTID is the first LWP
863 in the process. Return a pointer to the structure describing the
866 This differs from add_lwp in that we don't let the arch specific
867 bits know about this new thread. Current clients of this callback
868 take the opportunity to install watchpoints in the new thread, and
869 we shouldn't do that for the first thread. If we're spawning a
870 child ("run"), the thread executes the shell wrapper first, and we
871 shouldn't touch it until it execs the program we want to debug.
872 For "attach", it'd be okay to call the callback, but it's not
873 necessary, because watchpoints can't yet have been inserted into
876 static struct lwp_info *
877 add_initial_lwp (ptid_t ptid)
881 gdb_assert (ptid_lwp_p (ptid));
883 lp = XNEW (struct lwp_info);
885 memset (lp, 0, sizeof (struct lwp_info));
887 lp->last_resume_kind = resume_continue;
888 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
893 /* Add to sorted-by-reverse-creation-order list. */
896 /* Add to keyed-by-pid htab. */
897 lwp_lwpid_htab_add_lwp (lp);
902 /* Add the LWP specified by PID to the list. Return a pointer to the
903 structure describing the new LWP. The LWP should already be
906 static struct lwp_info *
907 add_lwp (ptid_t ptid)
911 lp = add_initial_lwp (ptid);
913 /* Let the arch specific bits know about this new thread. Current
914 clients of this callback take the opportunity to install
915 watchpoints in the new thread. We don't do this for the first
916 thread though. See add_initial_lwp. */
917 if (linux_nat_new_thread != NULL)
918 linux_nat_new_thread (lp);
923 /* Remove the LWP specified by PID from the list. */
926 delete_lwp (ptid_t ptid)
930 struct lwp_info dummy;
933 slot = htab_find_slot (lwp_lwpid_htab, &dummy, NO_INSERT);
937 lp = *(struct lwp_info **) slot;
938 gdb_assert (lp != NULL);
940 htab_clear_slot (lwp_lwpid_htab, slot);
942 /* Remove from sorted-by-creation-order list. */
943 lwp_list_remove (lp);
949 /* Return a pointer to the structure describing the LWP corresponding
950 to PID. If no corresponding LWP could be found, return NULL. */
952 static struct lwp_info *
953 find_lwp_pid (ptid_t ptid)
957 struct lwp_info dummy;
959 if (ptid_lwp_p (ptid))
960 lwp = ptid_get_lwp (ptid);
962 lwp = ptid_get_pid (ptid);
964 dummy.ptid = ptid_build (0, lwp, 0);
965 lp = (struct lwp_info *) htab_find (lwp_lwpid_htab, &dummy);
969 /* See nat/linux-nat.h. */
972 iterate_over_lwps (ptid_t filter,
973 iterate_over_lwps_ftype callback,
976 struct lwp_info *lp, *lpnext;
978 for (lp = lwp_list; lp; lp = lpnext)
982 if (ptid_match (lp->ptid, filter))
984 if ((*callback) (lp, data) != 0)
992 /* Update our internal state when changing from one checkpoint to
993 another indicated by NEW_PTID. We can only switch single-threaded
994 applications, so we only create one new LWP, and the previous list
998 linux_nat_switch_fork (ptid_t new_ptid)
1000 struct lwp_info *lp;
1002 purge_lwp_list (ptid_get_pid (inferior_ptid));
1004 lp = add_lwp (new_ptid);
1007 /* This changes the thread's ptid while preserving the gdb thread
1008 num. Also changes the inferior pid, while preserving the
1010 thread_change_ptid (inferior_ptid, new_ptid);
1012 /* We've just told GDB core that the thread changed target id, but,
1013 in fact, it really is a different thread, with different register
1015 registers_changed ();
1018 /* Handle the exit of a single thread LP. */
1021 exit_lwp (struct lwp_info *lp)
1023 struct thread_info *th = find_thread_ptid (lp->ptid);
1027 if (print_thread_events)
1028 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1030 delete_thread (lp->ptid);
1033 delete_lwp (lp->ptid);
1036 /* Wait for the LWP specified by LP, which we have just attached to.
1037 Returns a wait status for that LWP, to cache. */
1040 linux_nat_post_attach_wait (ptid_t ptid, int first, int *signalled)
1042 pid_t new_pid, pid = ptid_get_lwp (ptid);
1045 if (linux_proc_pid_is_stopped (pid))
1047 if (debug_linux_nat)
1048 fprintf_unfiltered (gdb_stdlog,
1049 "LNPAW: Attaching to a stopped process\n");
1051 /* The process is definitely stopped. It is in a job control
1052 stop, unless the kernel predates the TASK_STOPPED /
1053 TASK_TRACED distinction, in which case it might be in a
1054 ptrace stop. Make sure it is in a ptrace stop; from there we
1055 can kill it, signal it, et cetera.
1057 First make sure there is a pending SIGSTOP. Since we are
1058 already attached, the process can not transition from stopped
1059 to running without a PTRACE_CONT; so we know this signal will
1060 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1061 probably already in the queue (unless this kernel is old
1062 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1063 is not an RT signal, it can only be queued once. */
1064 kill_lwp (pid, SIGSTOP);
1066 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1067 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1068 ptrace (PTRACE_CONT, pid, 0, 0);
1071 /* Make sure the initial process is stopped. The user-level threads
1072 layer might want to poke around in the inferior, and that won't
1073 work if things haven't stabilized yet. */
1074 new_pid = my_waitpid (pid, &status, __WALL);
1075 gdb_assert (pid == new_pid);
1077 if (!WIFSTOPPED (status))
1079 /* The pid we tried to attach has apparently just exited. */
1080 if (debug_linux_nat)
1081 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1082 pid, status_to_str (status));
1086 if (WSTOPSIG (status) != SIGSTOP)
1089 if (debug_linux_nat)
1090 fprintf_unfiltered (gdb_stdlog,
1091 "LNPAW: Received %s after attaching\n",
1092 status_to_str (status));
1099 linux_nat_create_inferior (struct target_ops *ops,
1100 char *exec_file, char *allargs, char **env,
1103 struct cleanup *restore_personality
1104 = maybe_disable_address_space_randomization (disable_randomization);
1106 /* The fork_child mechanism is synchronous and calls target_wait, so
1107 we have to mask the async mode. */
1109 /* Make sure we report all signals during startup. */
1110 linux_nat_pass_signals (ops, 0, NULL);
1112 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1114 do_cleanups (restore_personality);
1117 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1118 already attached. Returns true if a new LWP is found, false
1122 attach_proc_task_lwp_callback (ptid_t ptid)
1124 struct lwp_info *lp;
1126 /* Ignore LWPs we're already attached to. */
1127 lp = find_lwp_pid (ptid);
1130 int lwpid = ptid_get_lwp (ptid);
1132 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1136 /* Be quiet if we simply raced with the thread exiting.
1137 EPERM is returned if the thread's task still exists, and
1138 is marked as exited or zombie, as well as other
1139 conditions, so in that case, confirm the status in
1140 /proc/PID/status. */
1142 || (err == EPERM && linux_proc_pid_is_gone (lwpid)))
1144 if (debug_linux_nat)
1146 fprintf_unfiltered (gdb_stdlog,
1147 "Cannot attach to lwp %d: "
1148 "thread is gone (%d: %s)\n",
1149 lwpid, err, safe_strerror (err));
1154 warning (_("Cannot attach to lwp %d: %s"),
1156 linux_ptrace_attach_fail_reason_string (ptid,
1162 if (debug_linux_nat)
1163 fprintf_unfiltered (gdb_stdlog,
1164 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1165 target_pid_to_str (ptid));
1167 lp = add_lwp (ptid);
1169 /* The next time we wait for this LWP we'll see a SIGSTOP as
1170 PTRACE_ATTACH brings it to a halt. */
1173 /* We need to wait for a stop before being able to make the
1174 next ptrace call on this LWP. */
1175 lp->must_set_ptrace_flags = 1;
1177 /* So that wait collects the SIGSTOP. */
1180 /* Also add the LWP to gdb's thread list, in case a
1181 matching libthread_db is not found (or the process uses
1183 add_thread (lp->ptid);
1184 set_running (lp->ptid, 1);
1185 set_executing (lp->ptid, 1);
1194 linux_nat_attach (struct target_ops *ops, const char *args, int from_tty)
1196 struct lwp_info *lp;
1200 /* Make sure we report all signals during attach. */
1201 linux_nat_pass_signals (ops, 0, NULL);
1205 linux_ops->to_attach (ops, args, from_tty);
1207 CATCH (ex, RETURN_MASK_ERROR)
1209 pid_t pid = parse_pid_to_attach (args);
1210 struct buffer buffer;
1211 char *message, *buffer_s;
1213 message = xstrdup (ex.message);
1214 make_cleanup (xfree, message);
1216 buffer_init (&buffer);
1217 linux_ptrace_attach_fail_reason (pid, &buffer);
1219 buffer_grow_str0 (&buffer, "");
1220 buffer_s = buffer_finish (&buffer);
1221 make_cleanup (xfree, buffer_s);
1223 if (*buffer_s != '\0')
1224 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1226 throw_error (ex.error, "%s", message);
1230 /* The ptrace base target adds the main thread with (pid,0,0)
1231 format. Decorate it with lwp info. */
1232 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1233 ptid_get_pid (inferior_ptid),
1235 thread_change_ptid (inferior_ptid, ptid);
1237 /* Add the initial process as the first LWP to the list. */
1238 lp = add_initial_lwp (ptid);
1240 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->signalled);
1241 if (!WIFSTOPPED (status))
1243 if (WIFEXITED (status))
1245 int exit_code = WEXITSTATUS (status);
1247 target_terminal_ours ();
1248 target_mourn_inferior ();
1250 error (_("Unable to attach: program exited normally."));
1252 error (_("Unable to attach: program exited with code %d."),
1255 else if (WIFSIGNALED (status))
1257 enum gdb_signal signo;
1259 target_terminal_ours ();
1260 target_mourn_inferior ();
1262 signo = gdb_signal_from_host (WTERMSIG (status));
1263 error (_("Unable to attach: program terminated with signal "
1265 gdb_signal_to_name (signo),
1266 gdb_signal_to_string (signo));
1269 internal_error (__FILE__, __LINE__,
1270 _("unexpected status %d for PID %ld"),
1271 status, (long) ptid_get_lwp (ptid));
1276 /* Save the wait status to report later. */
1278 if (debug_linux_nat)
1279 fprintf_unfiltered (gdb_stdlog,
1280 "LNA: waitpid %ld, saving status %s\n",
1281 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1283 lp->status = status;
1285 /* We must attach to every LWP. If /proc is mounted, use that to
1286 find them now. The inferior may be using raw clone instead of
1287 using pthreads. But even if it is using pthreads, thread_db
1288 walks structures in the inferior's address space to find the list
1289 of threads/LWPs, and those structures may well be corrupted.
1290 Note that once thread_db is loaded, we'll still use it to list
1291 threads and associate pthread info with each LWP. */
1292 linux_proc_attach_tgid_threads (ptid_get_pid (lp->ptid),
1293 attach_proc_task_lwp_callback);
1295 if (target_can_async_p ())
1299 /* Get pending signal of THREAD as a host signal number, for detaching
1300 purposes. This is the signal the thread last stopped for, which we
1301 need to deliver to the thread when detaching, otherwise, it'd be
1305 get_detach_signal (struct lwp_info *lp)
1307 enum gdb_signal signo = GDB_SIGNAL_0;
1309 /* If we paused threads momentarily, we may have stored pending
1310 events in lp->status or lp->waitstatus (see stop_wait_callback),
1311 and GDB core hasn't seen any signal for those threads.
1312 Otherwise, the last signal reported to the core is found in the
1313 thread object's stop_signal.
1315 There's a corner case that isn't handled here at present. Only
1316 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1317 stop_signal make sense as a real signal to pass to the inferior.
1318 Some catchpoint related events, like
1319 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1320 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1321 those traps are debug API (ptrace in our case) related and
1322 induced; the inferior wouldn't see them if it wasn't being
1323 traced. Hence, we should never pass them to the inferior, even
1324 when set to pass state. Since this corner case isn't handled by
1325 infrun.c when proceeding with a signal, for consistency, neither
1326 do we handle it here (or elsewhere in the file we check for
1327 signal pass state). Normally SIGTRAP isn't set to pass state, so
1328 this is really a corner case. */
1330 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1331 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1332 else if (lp->status)
1333 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1334 else if (target_is_non_stop_p () && !is_executing (lp->ptid))
1336 struct thread_info *tp = find_thread_ptid (lp->ptid);
1338 if (tp->suspend.waitstatus_pending_p)
1339 signo = tp->suspend.waitstatus.value.sig;
1341 signo = tp->suspend.stop_signal;
1343 else if (!target_is_non_stop_p ())
1345 struct target_waitstatus last;
1348 get_last_target_status (&last_ptid, &last);
1350 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1352 struct thread_info *tp = find_thread_ptid (lp->ptid);
1354 signo = tp->suspend.stop_signal;
1358 if (signo == GDB_SIGNAL_0)
1360 if (debug_linux_nat)
1361 fprintf_unfiltered (gdb_stdlog,
1362 "GPT: lwp %s has no pending signal\n",
1363 target_pid_to_str (lp->ptid));
1365 else if (!signal_pass_state (signo))
1367 if (debug_linux_nat)
1368 fprintf_unfiltered (gdb_stdlog,
1369 "GPT: lwp %s had signal %s, "
1370 "but it is in no pass state\n",
1371 target_pid_to_str (lp->ptid),
1372 gdb_signal_to_string (signo));
1376 if (debug_linux_nat)
1377 fprintf_unfiltered (gdb_stdlog,
1378 "GPT: lwp %s has pending signal %s\n",
1379 target_pid_to_str (lp->ptid),
1380 gdb_signal_to_string (signo));
1382 return gdb_signal_to_host (signo);
1388 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1389 signal number that should be passed to the LWP when detaching.
1390 Otherwise pass any pending signal the LWP may have, if any. */
1393 detach_one_lwp (struct lwp_info *lp, int *signo_p)
1395 int lwpid = ptid_get_lwp (lp->ptid);
1398 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1400 if (debug_linux_nat && lp->status)
1401 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1402 strsignal (WSTOPSIG (lp->status)),
1403 target_pid_to_str (lp->ptid));
1405 /* If there is a pending SIGSTOP, get rid of it. */
1408 if (debug_linux_nat)
1409 fprintf_unfiltered (gdb_stdlog,
1410 "DC: Sending SIGCONT to %s\n",
1411 target_pid_to_str (lp->ptid));
1413 kill_lwp (lwpid, SIGCONT);
1417 if (signo_p == NULL)
1419 /* Pass on any pending signal for this LWP. */
1420 signo = get_detach_signal (lp);
1425 /* Preparing to resume may try to write registers, and fail if the
1426 lwp is zombie. If that happens, ignore the error. We'll handle
1427 it below, when detach fails with ESRCH. */
1430 if (linux_nat_prepare_to_resume != NULL)
1431 linux_nat_prepare_to_resume (lp);
1433 CATCH (ex, RETURN_MASK_ERROR)
1435 if (!check_ptrace_stopped_lwp_gone (lp))
1436 throw_exception (ex);
1440 if (ptrace (PTRACE_DETACH, lwpid, 0, signo) < 0)
1442 int save_errno = errno;
1444 /* We know the thread exists, so ESRCH must mean the lwp is
1445 zombie. This can happen if one of the already-detached
1446 threads exits the whole thread group. In that case we're
1447 still attached, and must reap the lwp. */
1448 if (save_errno == ESRCH)
1452 ret = my_waitpid (lwpid, &status, __WALL);
1455 warning (_("Couldn't reap LWP %d while detaching: %s"),
1456 lwpid, strerror (errno));
1458 else if (!WIFEXITED (status) && !WIFSIGNALED (status))
1460 warning (_("Reaping LWP %d while detaching "
1461 "returned unexpected status 0x%x"),
1467 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1468 safe_strerror (save_errno));
1471 else if (debug_linux_nat)
1473 fprintf_unfiltered (gdb_stdlog,
1474 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1475 target_pid_to_str (lp->ptid),
1479 delete_lwp (lp->ptid);
1483 detach_callback (struct lwp_info *lp, void *data)
1485 /* We don't actually detach from the thread group leader just yet.
1486 If the thread group exits, we must reap the zombie clone lwps
1487 before we're able to reap the leader. */
1488 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1489 detach_one_lwp (lp, NULL);
1494 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1497 struct lwp_info *main_lwp;
1499 pid = ptid_get_pid (inferior_ptid);
1501 /* Don't unregister from the event loop, as there may be other
1502 inferiors running. */
1504 /* Stop all threads before detaching. ptrace requires that the
1505 thread is stopped to sucessfully detach. */
1506 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1507 /* ... and wait until all of them have reported back that
1508 they're no longer running. */
1509 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1511 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1513 /* Only the initial process should be left right now. */
1514 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1516 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1518 if (forks_exist_p ())
1520 /* Multi-fork case. The current inferior_ptid is being detached
1521 from, but there are other viable forks to debug. Detach from
1522 the current fork, and context-switch to the first
1524 linux_fork_detach (args, from_tty);
1530 target_announce_detach (from_tty);
1532 /* Pass on any pending signal for the last LWP, unless the user
1533 requested detaching with a different signal (most likely 0,
1534 meaning, discard the signal). */
1536 signo = atoi (args);
1538 signo = get_detach_signal (main_lwp);
1540 detach_one_lwp (main_lwp, &signo);
1542 inf_ptrace_detach_success (ops);
1544 delete_lwp (main_lwp->ptid);
1547 /* Resume execution of the inferior process. If STEP is nonzero,
1548 single-step it. If SIGNAL is nonzero, give it that signal. */
1551 linux_resume_one_lwp_throw (struct lwp_info *lp, int step,
1552 enum gdb_signal signo)
1556 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1557 We only presently need that if the LWP is stepped though (to
1558 handle the case of stepping a breakpoint instruction). */
1561 struct regcache *regcache = get_thread_regcache (lp->ptid);
1563 lp->stop_pc = regcache_read_pc (regcache);
1568 if (linux_nat_prepare_to_resume != NULL)
1569 linux_nat_prepare_to_resume (lp);
1570 linux_ops->to_resume (linux_ops, lp->ptid, step, signo);
1572 /* Successfully resumed. Clear state that no longer makes sense,
1573 and mark the LWP as running. Must not do this before resuming
1574 otherwise if that fails other code will be confused. E.g., we'd
1575 later try to stop the LWP and hang forever waiting for a stop
1576 status. Note that we must not throw after this is cleared,
1577 otherwise handle_zombie_lwp_error would get confused. */
1580 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1581 registers_changed_ptid (lp->ptid);
1584 /* Called when we try to resume a stopped LWP and that errors out. If
1585 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1586 or about to become), discard the error, clear any pending status
1587 the LWP may have, and return true (we'll collect the exit status
1588 soon enough). Otherwise, return false. */
1591 check_ptrace_stopped_lwp_gone (struct lwp_info *lp)
1593 /* If we get an error after resuming the LWP successfully, we'd
1594 confuse !T state for the LWP being gone. */
1595 gdb_assert (lp->stopped);
1597 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1598 because even if ptrace failed with ESRCH, the tracee may be "not
1599 yet fully dead", but already refusing ptrace requests. In that
1600 case the tracee has 'R (Running)' state for a little bit
1601 (observed in Linux 3.18). See also the note on ESRCH in the
1602 ptrace(2) man page. Instead, check whether the LWP has any state
1603 other than ptrace-stopped. */
1605 /* Don't assume anything if /proc/PID/status can't be read. */
1606 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp->ptid)) == 0)
1608 lp->stop_reason = TARGET_STOPPED_BY_NO_REASON;
1610 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1616 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1617 disappears while we try to resume it. */
1620 linux_resume_one_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1624 linux_resume_one_lwp_throw (lp, step, signo);
1626 CATCH (ex, RETURN_MASK_ERROR)
1628 if (!check_ptrace_stopped_lwp_gone (lp))
1629 throw_exception (ex);
1637 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1641 struct inferior *inf = find_inferior_ptid (lp->ptid);
1643 if (inf->vfork_child != NULL)
1645 if (debug_linux_nat)
1646 fprintf_unfiltered (gdb_stdlog,
1647 "RC: Not resuming %s (vfork parent)\n",
1648 target_pid_to_str (lp->ptid));
1650 else if (!lwp_status_pending_p (lp))
1652 if (debug_linux_nat)
1653 fprintf_unfiltered (gdb_stdlog,
1654 "RC: Resuming sibling %s, %s, %s\n",
1655 target_pid_to_str (lp->ptid),
1656 (signo != GDB_SIGNAL_0
1657 ? strsignal (gdb_signal_to_host (signo))
1659 step ? "step" : "resume");
1661 linux_resume_one_lwp (lp, step, signo);
1665 if (debug_linux_nat)
1666 fprintf_unfiltered (gdb_stdlog,
1667 "RC: Not resuming sibling %s (has pending)\n",
1668 target_pid_to_str (lp->ptid));
1673 if (debug_linux_nat)
1674 fprintf_unfiltered (gdb_stdlog,
1675 "RC: Not resuming sibling %s (not stopped)\n",
1676 target_pid_to_str (lp->ptid));
1680 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1681 Resume LWP with the last stop signal, if it is in pass state. */
1684 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1686 enum gdb_signal signo = GDB_SIGNAL_0;
1693 struct thread_info *thread;
1695 thread = find_thread_ptid (lp->ptid);
1698 signo = thread->suspend.stop_signal;
1699 thread->suspend.stop_signal = GDB_SIGNAL_0;
1703 resume_lwp (lp, 0, signo);
1708 resume_clear_callback (struct lwp_info *lp, void *data)
1711 lp->last_resume_kind = resume_stop;
1716 resume_set_callback (struct lwp_info *lp, void *data)
1719 lp->last_resume_kind = resume_continue;
1724 linux_nat_resume (struct target_ops *ops,
1725 ptid_t ptid, int step, enum gdb_signal signo)
1727 struct lwp_info *lp;
1730 if (debug_linux_nat)
1731 fprintf_unfiltered (gdb_stdlog,
1732 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1733 step ? "step" : "resume",
1734 target_pid_to_str (ptid),
1735 (signo != GDB_SIGNAL_0
1736 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1737 target_pid_to_str (inferior_ptid));
1739 /* A specific PTID means `step only this process id'. */
1740 resume_many = (ptid_equal (minus_one_ptid, ptid)
1741 || ptid_is_pid (ptid));
1743 /* Mark the lwps we're resuming as resumed. */
1744 iterate_over_lwps (ptid, resume_set_callback, NULL);
1746 /* See if it's the current inferior that should be handled
1749 lp = find_lwp_pid (inferior_ptid);
1751 lp = find_lwp_pid (ptid);
1752 gdb_assert (lp != NULL);
1754 /* Remember if we're stepping. */
1755 lp->last_resume_kind = step ? resume_step : resume_continue;
1757 /* If we have a pending wait status for this thread, there is no
1758 point in resuming the process. But first make sure that
1759 linux_nat_wait won't preemptively handle the event - we
1760 should never take this short-circuit if we are going to
1761 leave LP running, since we have skipped resuming all the
1762 other threads. This bit of code needs to be synchronized
1763 with linux_nat_wait. */
1765 if (lp->status && WIFSTOPPED (lp->status))
1768 && WSTOPSIG (lp->status)
1769 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1771 if (debug_linux_nat)
1772 fprintf_unfiltered (gdb_stdlog,
1773 "LLR: Not short circuiting for ignored "
1774 "status 0x%x\n", lp->status);
1776 /* FIXME: What should we do if we are supposed to continue
1777 this thread with a signal? */
1778 gdb_assert (signo == GDB_SIGNAL_0);
1779 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1784 if (lwp_status_pending_p (lp))
1786 /* FIXME: What should we do if we are supposed to continue
1787 this thread with a signal? */
1788 gdb_assert (signo == GDB_SIGNAL_0);
1790 if (debug_linux_nat)
1791 fprintf_unfiltered (gdb_stdlog,
1792 "LLR: Short circuiting for status 0x%x\n",
1795 if (target_can_async_p ())
1798 /* Tell the event loop we have something to process. */
1805 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1807 if (debug_linux_nat)
1808 fprintf_unfiltered (gdb_stdlog,
1809 "LLR: %s %s, %s (resume event thread)\n",
1810 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1811 target_pid_to_str (lp->ptid),
1812 (signo != GDB_SIGNAL_0
1813 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1815 linux_resume_one_lwp (lp, step, signo);
1817 if (target_can_async_p ())
1821 /* Send a signal to an LWP. */
1824 kill_lwp (int lwpid, int signo)
1829 ret = syscall (__NR_tkill, lwpid, signo);
1830 if (errno == ENOSYS)
1832 /* If tkill fails, then we are not using nptl threads, a
1833 configuration we no longer support. */
1834 perror_with_name (("tkill"));
1839 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1840 event, check if the core is interested in it: if not, ignore the
1841 event, and keep waiting; otherwise, we need to toggle the LWP's
1842 syscall entry/exit status, since the ptrace event itself doesn't
1843 indicate it, and report the trap to higher layers. */
1846 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1848 struct target_waitstatus *ourstatus = &lp->waitstatus;
1849 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1850 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1854 /* If we're stopping threads, there's a SIGSTOP pending, which
1855 makes it so that the LWP reports an immediate syscall return,
1856 followed by the SIGSTOP. Skip seeing that "return" using
1857 PTRACE_CONT directly, and let stop_wait_callback collect the
1858 SIGSTOP. Later when the thread is resumed, a new syscall
1859 entry event. If we didn't do this (and returned 0), we'd
1860 leave a syscall entry pending, and our caller, by using
1861 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1862 itself. Later, when the user re-resumes this LWP, we'd see
1863 another syscall entry event and we'd mistake it for a return.
1865 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1866 (leaving immediately with LWP->signalled set, without issuing
1867 a PTRACE_CONT), it would still be problematic to leave this
1868 syscall enter pending, as later when the thread is resumed,
1869 it would then see the same syscall exit mentioned above,
1870 followed by the delayed SIGSTOP, while the syscall didn't
1871 actually get to execute. It seems it would be even more
1872 confusing to the user. */
1874 if (debug_linux_nat)
1875 fprintf_unfiltered (gdb_stdlog,
1876 "LHST: ignoring syscall %d "
1877 "for LWP %ld (stopping threads), "
1878 "resuming with PTRACE_CONT for SIGSTOP\n",
1880 ptid_get_lwp (lp->ptid));
1882 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1883 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1888 /* Always update the entry/return state, even if this particular
1889 syscall isn't interesting to the core now. In async mode,
1890 the user could install a new catchpoint for this syscall
1891 between syscall enter/return, and we'll need to know to
1892 report a syscall return if that happens. */
1893 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1894 ? TARGET_WAITKIND_SYSCALL_RETURN
1895 : TARGET_WAITKIND_SYSCALL_ENTRY);
1897 if (catch_syscall_enabled ())
1899 if (catching_syscall_number (syscall_number))
1901 /* Alright, an event to report. */
1902 ourstatus->kind = lp->syscall_state;
1903 ourstatus->value.syscall_number = syscall_number;
1905 if (debug_linux_nat)
1906 fprintf_unfiltered (gdb_stdlog,
1907 "LHST: stopping for %s of syscall %d"
1910 == TARGET_WAITKIND_SYSCALL_ENTRY
1911 ? "entry" : "return",
1913 ptid_get_lwp (lp->ptid));
1917 if (debug_linux_nat)
1918 fprintf_unfiltered (gdb_stdlog,
1919 "LHST: ignoring %s of syscall %d "
1921 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1922 ? "entry" : "return",
1924 ptid_get_lwp (lp->ptid));
1928 /* If we had been syscall tracing, and hence used PT_SYSCALL
1929 before on this LWP, it could happen that the user removes all
1930 syscall catchpoints before we get to process this event.
1931 There are two noteworthy issues here:
1933 - When stopped at a syscall entry event, resuming with
1934 PT_STEP still resumes executing the syscall and reports a
1937 - Only PT_SYSCALL catches syscall enters. If we last
1938 single-stepped this thread, then this event can't be a
1939 syscall enter. If we last single-stepped this thread, this
1940 has to be a syscall exit.
1942 The points above mean that the next resume, be it PT_STEP or
1943 PT_CONTINUE, can not trigger a syscall trace event. */
1944 if (debug_linux_nat)
1945 fprintf_unfiltered (gdb_stdlog,
1946 "LHST: caught syscall event "
1947 "with no syscall catchpoints."
1948 " %d for LWP %ld, ignoring\n",
1950 ptid_get_lwp (lp->ptid));
1951 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1954 /* The core isn't interested in this event. For efficiency, avoid
1955 stopping all threads only to have the core resume them all again.
1956 Since we're not stopping threads, if we're still syscall tracing
1957 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1958 subsequent syscall. Simply resume using the inf-ptrace layer,
1959 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1961 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
1965 /* Handle a GNU/Linux extended wait response. If we see a clone
1966 event, we need to add the new LWP to our list (and not report the
1967 trap to higher layers). This function returns non-zero if the
1968 event should be ignored and we should wait again. If STOPPING is
1969 true, the new LWP remains stopped, otherwise it is continued. */
1972 linux_handle_extended_wait (struct lwp_info *lp, int status)
1974 int pid = ptid_get_lwp (lp->ptid);
1975 struct target_waitstatus *ourstatus = &lp->waitstatus;
1976 int event = linux_ptrace_get_extended_event (status);
1978 /* All extended events we currently use are mid-syscall. Only
1979 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1980 you have to be using PTRACE_SEIZE to get that. */
1981 lp->syscall_state = TARGET_WAITKIND_SYSCALL_ENTRY;
1983 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1984 || event == PTRACE_EVENT_CLONE)
1986 unsigned long new_pid;
1989 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1991 /* If we haven't already seen the new PID stop, wait for it now. */
1992 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1994 /* The new child has a pending SIGSTOP. We can't affect it until it
1995 hits the SIGSTOP, but we're already attached. */
1996 ret = my_waitpid (new_pid, &status, __WALL);
1998 perror_with_name (_("waiting for new child"));
1999 else if (ret != new_pid)
2000 internal_error (__FILE__, __LINE__,
2001 _("wait returned unexpected PID %d"), ret);
2002 else if (!WIFSTOPPED (status))
2003 internal_error (__FILE__, __LINE__,
2004 _("wait returned unexpected status 0x%x"), status);
2007 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2009 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2011 /* The arch-specific native code may need to know about new
2012 forks even if those end up never mapped to an
2014 if (linux_nat_new_fork != NULL)
2015 linux_nat_new_fork (lp, new_pid);
2018 if (event == PTRACE_EVENT_FORK
2019 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2021 /* Handle checkpointing by linux-fork.c here as a special
2022 case. We don't want the follow-fork-mode or 'catch fork'
2023 to interfere with this. */
2025 /* This won't actually modify the breakpoint list, but will
2026 physically remove the breakpoints from the child. */
2027 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2029 /* Retain child fork in ptrace (stopped) state. */
2030 if (!find_fork_pid (new_pid))
2033 /* Report as spurious, so that infrun doesn't want to follow
2034 this fork. We're actually doing an infcall in
2036 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2038 /* Report the stop to the core. */
2042 if (event == PTRACE_EVENT_FORK)
2043 ourstatus->kind = TARGET_WAITKIND_FORKED;
2044 else if (event == PTRACE_EVENT_VFORK)
2045 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2046 else if (event == PTRACE_EVENT_CLONE)
2048 struct lwp_info *new_lp;
2050 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2052 if (debug_linux_nat)
2053 fprintf_unfiltered (gdb_stdlog,
2054 "LHEW: Got clone event "
2055 "from LWP %d, new child is LWP %ld\n",
2058 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2059 new_lp->stopped = 1;
2060 new_lp->resumed = 1;
2062 /* If the thread_db layer is active, let it record the user
2063 level thread id and status, and add the thread to GDB's
2065 if (!thread_db_notice_clone (lp->ptid, new_lp->ptid))
2067 /* The process is not using thread_db. Add the LWP to
2069 target_post_attach (ptid_get_lwp (new_lp->ptid));
2070 add_thread (new_lp->ptid);
2073 /* Even if we're stopping the thread for some reason
2074 internal to this module, from the perspective of infrun
2075 and the user/frontend, this new thread is running until
2076 it next reports a stop. */
2077 set_running (new_lp->ptid, 1);
2078 set_executing (new_lp->ptid, 1);
2080 if (WSTOPSIG (status) != SIGSTOP)
2082 /* This can happen if someone starts sending signals to
2083 the new thread before it gets a chance to run, which
2084 have a lower number than SIGSTOP (e.g. SIGUSR1).
2085 This is an unlikely case, and harder to handle for
2086 fork / vfork than for clone, so we do not try - but
2087 we handle it for clone events here. */
2089 new_lp->signalled = 1;
2091 /* We created NEW_LP so it cannot yet contain STATUS. */
2092 gdb_assert (new_lp->status == 0);
2094 /* Save the wait status to report later. */
2095 if (debug_linux_nat)
2096 fprintf_unfiltered (gdb_stdlog,
2097 "LHEW: waitpid of new LWP %ld, "
2098 "saving status %s\n",
2099 (long) ptid_get_lwp (new_lp->ptid),
2100 status_to_str (status));
2101 new_lp->status = status;
2103 else if (report_thread_events)
2105 new_lp->waitstatus.kind = TARGET_WAITKIND_THREAD_CREATED;
2106 new_lp->status = status;
2115 if (event == PTRACE_EVENT_EXEC)
2117 if (debug_linux_nat)
2118 fprintf_unfiltered (gdb_stdlog,
2119 "LHEW: Got exec event from LWP %ld\n",
2120 ptid_get_lwp (lp->ptid));
2122 ourstatus->kind = TARGET_WAITKIND_EXECD;
2123 ourstatus->value.execd_pathname
2124 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2126 /* The thread that execed must have been resumed, but, when a
2127 thread execs, it changes its tid to the tgid, and the old
2128 tgid thread might have not been resumed. */
2133 if (event == PTRACE_EVENT_VFORK_DONE)
2135 if (current_inferior ()->waiting_for_vfork_done)
2137 if (debug_linux_nat)
2138 fprintf_unfiltered (gdb_stdlog,
2139 "LHEW: Got expected PTRACE_EVENT_"
2140 "VFORK_DONE from LWP %ld: stopping\n",
2141 ptid_get_lwp (lp->ptid));
2143 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2147 if (debug_linux_nat)
2148 fprintf_unfiltered (gdb_stdlog,
2149 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2150 "from LWP %ld: ignoring\n",
2151 ptid_get_lwp (lp->ptid));
2155 internal_error (__FILE__, __LINE__,
2156 _("unknown ptrace event %d"), event);
2159 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2163 wait_lwp (struct lwp_info *lp)
2167 int thread_dead = 0;
2170 gdb_assert (!lp->stopped);
2171 gdb_assert (lp->status == 0);
2173 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2174 block_child_signals (&prev_mask);
2178 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WALL | WNOHANG);
2179 if (pid == -1 && errno == ECHILD)
2181 /* The thread has previously exited. We need to delete it
2182 now because if this was a non-leader thread execing, we
2183 won't get an exit event. See comments on exec events at
2184 the top of the file. */
2186 if (debug_linux_nat)
2187 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2188 target_pid_to_str (lp->ptid));
2193 /* Bugs 10970, 12702.
2194 Thread group leader may have exited in which case we'll lock up in
2195 waitpid if there are other threads, even if they are all zombies too.
2196 Basically, we're not supposed to use waitpid this way.
2197 tkill(pid,0) cannot be used here as it gets ESRCH for both
2198 for zombie and running processes.
2200 As a workaround, check if we're waiting for the thread group leader and
2201 if it's a zombie, and avoid calling waitpid if it is.
2203 This is racy, what if the tgl becomes a zombie right after we check?
2204 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2205 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2207 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2208 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2211 if (debug_linux_nat)
2212 fprintf_unfiltered (gdb_stdlog,
2213 "WL: Thread group leader %s vanished.\n",
2214 target_pid_to_str (lp->ptid));
2218 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2219 get invoked despite our caller had them intentionally blocked by
2220 block_child_signals. This is sensitive only to the loop of
2221 linux_nat_wait_1 and there if we get called my_waitpid gets called
2222 again before it gets to sigsuspend so we can safely let the handlers
2223 get executed here. */
2225 if (debug_linux_nat)
2226 fprintf_unfiltered (gdb_stdlog, "WL: about to sigsuspend\n");
2227 sigsuspend (&suspend_mask);
2230 restore_child_signals_mask (&prev_mask);
2234 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2236 if (debug_linux_nat)
2238 fprintf_unfiltered (gdb_stdlog,
2239 "WL: waitpid %s received %s\n",
2240 target_pid_to_str (lp->ptid),
2241 status_to_str (status));
2244 /* Check if the thread has exited. */
2245 if (WIFEXITED (status) || WIFSIGNALED (status))
2247 if (report_thread_events
2248 || ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2250 if (debug_linux_nat)
2251 fprintf_unfiltered (gdb_stdlog, "WL: LWP %d exited.\n",
2252 ptid_get_pid (lp->ptid));
2254 /* If this is the leader exiting, it means the whole
2255 process is gone. Store the status to report to the
2256 core. Store it in lp->waitstatus, because lp->status
2257 would be ambiguous (W_EXITCODE(0,0) == 0). */
2258 store_waitstatus (&lp->waitstatus, status);
2263 if (debug_linux_nat)
2264 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2265 target_pid_to_str (lp->ptid));
2275 gdb_assert (WIFSTOPPED (status));
2278 if (lp->must_set_ptrace_flags)
2280 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2281 int options = linux_nat_ptrace_options (inf->attach_flag);
2283 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
2284 lp->must_set_ptrace_flags = 0;
2287 /* Handle GNU/Linux's syscall SIGTRAPs. */
2288 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2290 /* No longer need the sysgood bit. The ptrace event ends up
2291 recorded in lp->waitstatus if we care for it. We can carry
2292 on handling the event like a regular SIGTRAP from here
2294 status = W_STOPCODE (SIGTRAP);
2295 if (linux_handle_syscall_trap (lp, 1))
2296 return wait_lwp (lp);
2300 /* Almost all other ptrace-stops are known to be outside of system
2301 calls, with further exceptions in linux_handle_extended_wait. */
2302 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2305 /* Handle GNU/Linux's extended waitstatus for trace events. */
2306 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
2307 && linux_is_extended_waitstatus (status))
2309 if (debug_linux_nat)
2310 fprintf_unfiltered (gdb_stdlog,
2311 "WL: Handling extended status 0x%06x\n",
2313 linux_handle_extended_wait (lp, status);
2320 /* Send a SIGSTOP to LP. */
2323 stop_callback (struct lwp_info *lp, void *data)
2325 if (!lp->stopped && !lp->signalled)
2329 if (debug_linux_nat)
2331 fprintf_unfiltered (gdb_stdlog,
2332 "SC: kill %s **<SIGSTOP>**\n",
2333 target_pid_to_str (lp->ptid));
2336 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2337 if (debug_linux_nat)
2339 fprintf_unfiltered (gdb_stdlog,
2340 "SC: lwp kill %d %s\n",
2342 errno ? safe_strerror (errno) : "ERRNO-OK");
2346 gdb_assert (lp->status == 0);
2352 /* Request a stop on LWP. */
2355 linux_stop_lwp (struct lwp_info *lwp)
2357 stop_callback (lwp, NULL);
2360 /* See linux-nat.h */
2363 linux_stop_and_wait_all_lwps (void)
2365 /* Stop all LWP's ... */
2366 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
2368 /* ... and wait until all of them have reported back that
2369 they're no longer running. */
2370 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
2373 /* See linux-nat.h */
2376 linux_unstop_all_lwps (void)
2378 iterate_over_lwps (minus_one_ptid,
2379 resume_stopped_resumed_lwps, &minus_one_ptid);
2382 /* Return non-zero if LWP PID has a pending SIGINT. */
2385 linux_nat_has_pending_sigint (int pid)
2387 sigset_t pending, blocked, ignored;
2389 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2391 if (sigismember (&pending, SIGINT)
2392 && !sigismember (&ignored, SIGINT))
2398 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2401 set_ignore_sigint (struct lwp_info *lp, void *data)
2403 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2404 flag to consume the next one. */
2405 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2406 && WSTOPSIG (lp->status) == SIGINT)
2409 lp->ignore_sigint = 1;
2414 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2415 This function is called after we know the LWP has stopped; if the LWP
2416 stopped before the expected SIGINT was delivered, then it will never have
2417 arrived. Also, if the signal was delivered to a shared queue and consumed
2418 by a different thread, it will never be delivered to this LWP. */
2421 maybe_clear_ignore_sigint (struct lwp_info *lp)
2423 if (!lp->ignore_sigint)
2426 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2428 if (debug_linux_nat)
2429 fprintf_unfiltered (gdb_stdlog,
2430 "MCIS: Clearing bogus flag for %s\n",
2431 target_pid_to_str (lp->ptid));
2432 lp->ignore_sigint = 0;
2436 /* Fetch the possible triggered data watchpoint info and store it in
2439 On some archs, like x86, that use debug registers to set
2440 watchpoints, it's possible that the way to know which watched
2441 address trapped, is to check the register that is used to select
2442 which address to watch. Problem is, between setting the watchpoint
2443 and reading back which data address trapped, the user may change
2444 the set of watchpoints, and, as a consequence, GDB changes the
2445 debug registers in the inferior. To avoid reading back a stale
2446 stopped-data-address when that happens, we cache in LP the fact
2447 that a watchpoint trapped, and the corresponding data address, as
2448 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2449 registers meanwhile, we have the cached data we can rely on. */
2452 check_stopped_by_watchpoint (struct lwp_info *lp)
2454 struct cleanup *old_chain;
2456 if (linux_ops->to_stopped_by_watchpoint == NULL)
2459 old_chain = save_inferior_ptid ();
2460 inferior_ptid = lp->ptid;
2462 if (linux_ops->to_stopped_by_watchpoint (linux_ops))
2464 lp->stop_reason = TARGET_STOPPED_BY_WATCHPOINT;
2466 if (linux_ops->to_stopped_data_address != NULL)
2467 lp->stopped_data_address_p =
2468 linux_ops->to_stopped_data_address (¤t_target,
2469 &lp->stopped_data_address);
2471 lp->stopped_data_address_p = 0;
2474 do_cleanups (old_chain);
2476 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2479 /* Returns true if the LWP had stopped for a watchpoint. */
2482 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2484 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2486 gdb_assert (lp != NULL);
2488 return lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT;
2492 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2494 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2496 gdb_assert (lp != NULL);
2498 *addr_p = lp->stopped_data_address;
2500 return lp->stopped_data_address_p;
2503 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2506 sigtrap_is_event (int status)
2508 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2511 /* Set alternative SIGTRAP-like events recognizer. If
2512 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2516 linux_nat_set_status_is_event (struct target_ops *t,
2517 int (*status_is_event) (int status))
2519 linux_nat_status_is_event = status_is_event;
2522 /* Wait until LP is stopped. */
2525 stop_wait_callback (struct lwp_info *lp, void *data)
2527 struct inferior *inf = find_inferior_ptid (lp->ptid);
2529 /* If this is a vfork parent, bail out, it is not going to report
2530 any SIGSTOP until the vfork is done with. */
2531 if (inf->vfork_child != NULL)
2538 status = wait_lwp (lp);
2542 if (lp->ignore_sigint && WIFSTOPPED (status)
2543 && WSTOPSIG (status) == SIGINT)
2545 lp->ignore_sigint = 0;
2548 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2550 if (debug_linux_nat)
2551 fprintf_unfiltered (gdb_stdlog,
2552 "PTRACE_CONT %s, 0, 0 (%s) "
2553 "(discarding SIGINT)\n",
2554 target_pid_to_str (lp->ptid),
2555 errno ? safe_strerror (errno) : "OK");
2557 return stop_wait_callback (lp, NULL);
2560 maybe_clear_ignore_sigint (lp);
2562 if (WSTOPSIG (status) != SIGSTOP)
2564 /* The thread was stopped with a signal other than SIGSTOP. */
2566 if (debug_linux_nat)
2567 fprintf_unfiltered (gdb_stdlog,
2568 "SWC: Pending event %s in %s\n",
2569 status_to_str ((int) status),
2570 target_pid_to_str (lp->ptid));
2572 /* Save the sigtrap event. */
2573 lp->status = status;
2574 gdb_assert (lp->signalled);
2575 save_stop_reason (lp);
2579 /* We caught the SIGSTOP that we intended to catch, so
2580 there's no SIGSTOP pending. */
2582 if (debug_linux_nat)
2583 fprintf_unfiltered (gdb_stdlog,
2584 "SWC: Expected SIGSTOP caught for %s.\n",
2585 target_pid_to_str (lp->ptid));
2587 /* Reset SIGNALLED only after the stop_wait_callback call
2588 above as it does gdb_assert on SIGNALLED. */
2596 /* Return non-zero if LP has a wait status pending. Discard the
2597 pending event and resume the LWP if the event that originally
2598 caused the stop became uninteresting. */
2601 status_callback (struct lwp_info *lp, void *data)
2603 /* Only report a pending wait status if we pretend that this has
2604 indeed been resumed. */
2608 if (!lwp_status_pending_p (lp))
2611 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
2612 || lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2614 struct regcache *regcache = get_thread_regcache (lp->ptid);
2618 pc = regcache_read_pc (regcache);
2620 if (pc != lp->stop_pc)
2622 if (debug_linux_nat)
2623 fprintf_unfiltered (gdb_stdlog,
2624 "SC: PC of %s changed. was=%s, now=%s\n",
2625 target_pid_to_str (lp->ptid),
2626 paddress (target_gdbarch (), lp->stop_pc),
2627 paddress (target_gdbarch (), pc));
2631 #if !USE_SIGTRAP_SIGINFO
2632 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2634 if (debug_linux_nat)
2635 fprintf_unfiltered (gdb_stdlog,
2636 "SC: previous breakpoint of %s, at %s gone\n",
2637 target_pid_to_str (lp->ptid),
2638 paddress (target_gdbarch (), lp->stop_pc));
2646 if (debug_linux_nat)
2647 fprintf_unfiltered (gdb_stdlog,
2648 "SC: pending event of %s cancelled.\n",
2649 target_pid_to_str (lp->ptid));
2652 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
2660 /* Count the LWP's that have had events. */
2663 count_events_callback (struct lwp_info *lp, void *data)
2665 int *count = (int *) data;
2667 gdb_assert (count != NULL);
2669 /* Select only resumed LWPs that have an event pending. */
2670 if (lp->resumed && lwp_status_pending_p (lp))
2676 /* Select the LWP (if any) that is currently being single-stepped. */
2679 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2681 if (lp->last_resume_kind == resume_step
2688 /* Returns true if LP has a status pending. */
2691 lwp_status_pending_p (struct lwp_info *lp)
2693 /* We check for lp->waitstatus in addition to lp->status, because we
2694 can have pending process exits recorded in lp->status and
2695 W_EXITCODE(0,0) happens to be 0. */
2696 return lp->status != 0 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE;
2699 /* Select the Nth LWP that has had an event. */
2702 select_event_lwp_callback (struct lwp_info *lp, void *data)
2704 int *selector = (int *) data;
2706 gdb_assert (selector != NULL);
2708 /* Select only resumed LWPs that have an event pending. */
2709 if (lp->resumed && lwp_status_pending_p (lp))
2710 if ((*selector)-- == 0)
2716 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2717 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2718 and save the result in the LWP's stop_reason field. If it stopped
2719 for a breakpoint, decrement the PC if necessary on the lwp's
2723 save_stop_reason (struct lwp_info *lp)
2725 struct regcache *regcache;
2726 struct gdbarch *gdbarch;
2729 #if USE_SIGTRAP_SIGINFO
2733 gdb_assert (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON);
2734 gdb_assert (lp->status != 0);
2736 if (!linux_nat_status_is_event (lp->status))
2739 regcache = get_thread_regcache (lp->ptid);
2740 gdbarch = get_regcache_arch (regcache);
2742 pc = regcache_read_pc (regcache);
2743 sw_bp_pc = pc - gdbarch_decr_pc_after_break (gdbarch);
2745 #if USE_SIGTRAP_SIGINFO
2746 if (linux_nat_get_siginfo (lp->ptid, &siginfo))
2748 if (siginfo.si_signo == SIGTRAP)
2750 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code)
2751 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2753 /* The si_code is ambiguous on this arch -- check debug
2755 if (!check_stopped_by_watchpoint (lp))
2756 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2758 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo.si_code))
2760 /* If we determine the LWP stopped for a SW breakpoint,
2761 trust it. Particularly don't check watchpoint
2762 registers, because at least on s390, we'd find
2763 stopped-by-watchpoint as long as there's a watchpoint
2765 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2767 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo.si_code))
2769 /* This can indicate either a hardware breakpoint or
2770 hardware watchpoint. Check debug registers. */
2771 if (!check_stopped_by_watchpoint (lp))
2772 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2774 else if (siginfo.si_code == TRAP_TRACE)
2776 if (debug_linux_nat)
2777 fprintf_unfiltered (gdb_stdlog,
2778 "CSBB: %s stopped by trace\n",
2779 target_pid_to_str (lp->ptid));
2781 /* We may have single stepped an instruction that
2782 triggered a watchpoint. In that case, on some
2783 architectures (such as x86), instead of TRAP_HWBKPT,
2784 si_code indicates TRAP_TRACE, and we need to check
2785 the debug registers separately. */
2786 check_stopped_by_watchpoint (lp);
2791 if ((!lp->step || lp->stop_pc == sw_bp_pc)
2792 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2795 /* The LWP was either continued, or stepped a software
2796 breakpoint instruction. */
2797 lp->stop_reason = TARGET_STOPPED_BY_SW_BREAKPOINT;
2800 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2801 lp->stop_reason = TARGET_STOPPED_BY_HW_BREAKPOINT;
2803 if (lp->stop_reason == TARGET_STOPPED_BY_NO_REASON)
2804 check_stopped_by_watchpoint (lp);
2807 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT)
2809 if (debug_linux_nat)
2810 fprintf_unfiltered (gdb_stdlog,
2811 "CSBB: %s stopped by software breakpoint\n",
2812 target_pid_to_str (lp->ptid));
2814 /* Back up the PC if necessary. */
2816 regcache_write_pc (regcache, sw_bp_pc);
2818 /* Update this so we record the correct stop PC below. */
2821 else if (lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT)
2823 if (debug_linux_nat)
2824 fprintf_unfiltered (gdb_stdlog,
2825 "CSBB: %s stopped by hardware breakpoint\n",
2826 target_pid_to_str (lp->ptid));
2828 else if (lp->stop_reason == TARGET_STOPPED_BY_WATCHPOINT)
2830 if (debug_linux_nat)
2831 fprintf_unfiltered (gdb_stdlog,
2832 "CSBB: %s stopped by hardware watchpoint\n",
2833 target_pid_to_str (lp->ptid));
2840 /* Returns true if the LWP had stopped for a software breakpoint. */
2843 linux_nat_stopped_by_sw_breakpoint (struct target_ops *ops)
2845 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2847 gdb_assert (lp != NULL);
2849 return lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT;
2852 /* Implement the supports_stopped_by_sw_breakpoint method. */
2855 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops *ops)
2857 return USE_SIGTRAP_SIGINFO;
2860 /* Returns true if the LWP had stopped for a hardware
2861 breakpoint/watchpoint. */
2864 linux_nat_stopped_by_hw_breakpoint (struct target_ops *ops)
2866 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2868 gdb_assert (lp != NULL);
2870 return lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT;
2873 /* Implement the supports_stopped_by_hw_breakpoint method. */
2876 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops *ops)
2878 return USE_SIGTRAP_SIGINFO;
2881 /* Select one LWP out of those that have events pending. */
2884 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2887 int random_selector;
2888 struct lwp_info *event_lp = NULL;
2890 /* Record the wait status for the original LWP. */
2891 (*orig_lp)->status = *status;
2893 /* In all-stop, give preference to the LWP that is being
2894 single-stepped. There will be at most one, and it will be the
2895 LWP that the core is most interested in. If we didn't do this,
2896 then we'd have to handle pending step SIGTRAPs somehow in case
2897 the core later continues the previously-stepped thread, as
2898 otherwise we'd report the pending SIGTRAP then, and the core, not
2899 having stepped the thread, wouldn't understand what the trap was
2900 for, and therefore would report it to the user as a random
2902 if (!target_is_non_stop_p ())
2904 event_lp = iterate_over_lwps (filter,
2905 select_singlestep_lwp_callback, NULL);
2906 if (event_lp != NULL)
2908 if (debug_linux_nat)
2909 fprintf_unfiltered (gdb_stdlog,
2910 "SEL: Select single-step %s\n",
2911 target_pid_to_str (event_lp->ptid));
2915 if (event_lp == NULL)
2917 /* Pick one at random, out of those which have had events. */
2919 /* First see how many events we have. */
2920 iterate_over_lwps (filter, count_events_callback, &num_events);
2921 gdb_assert (num_events > 0);
2923 /* Now randomly pick a LWP out of those that have had
2925 random_selector = (int)
2926 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2928 if (debug_linux_nat && num_events > 1)
2929 fprintf_unfiltered (gdb_stdlog,
2930 "SEL: Found %d events, selecting #%d\n",
2931 num_events, random_selector);
2933 event_lp = iterate_over_lwps (filter,
2934 select_event_lwp_callback,
2938 if (event_lp != NULL)
2940 /* Switch the event LWP. */
2941 *orig_lp = event_lp;
2942 *status = event_lp->status;
2945 /* Flush the wait status for the event LWP. */
2946 (*orig_lp)->status = 0;
2949 /* Return non-zero if LP has been resumed. */
2952 resumed_callback (struct lwp_info *lp, void *data)
2957 /* Check if we should go on and pass this event to common code.
2958 Return the affected lwp if we are, or NULL otherwise. */
2960 static struct lwp_info *
2961 linux_nat_filter_event (int lwpid, int status)
2963 struct lwp_info *lp;
2964 int event = linux_ptrace_get_extended_event (status);
2966 lp = find_lwp_pid (pid_to_ptid (lwpid));
2968 /* Check for stop events reported by a process we didn't already
2969 know about - anything not already in our LWP list.
2971 If we're expecting to receive stopped processes after
2972 fork, vfork, and clone events, then we'll just add the
2973 new one to our list and go back to waiting for the event
2974 to be reported - the stopped process might be returned
2975 from waitpid before or after the event is.
2977 But note the case of a non-leader thread exec'ing after the
2978 leader having exited, and gone from our lists. The non-leader
2979 thread changes its tid to the tgid. */
2981 if (WIFSTOPPED (status) && lp == NULL
2982 && (WSTOPSIG (status) == SIGTRAP && event == PTRACE_EVENT_EXEC))
2984 /* A multi-thread exec after we had seen the leader exiting. */
2985 if (debug_linux_nat)
2986 fprintf_unfiltered (gdb_stdlog,
2987 "LLW: Re-adding thread group leader LWP %d.\n",
2990 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
2993 add_thread (lp->ptid);
2996 if (WIFSTOPPED (status) && !lp)
2998 if (debug_linux_nat)
2999 fprintf_unfiltered (gdb_stdlog,
3000 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3001 (long) lwpid, status_to_str (status));
3002 add_to_pid_list (&stopped_pids, lwpid, status);
3006 /* Make sure we don't report an event for the exit of an LWP not in
3007 our list, i.e. not part of the current process. This can happen
3008 if we detach from a program we originally forked and then it
3010 if (!WIFSTOPPED (status) && !lp)
3013 /* This LWP is stopped now. (And if dead, this prevents it from
3014 ever being continued.) */
3017 if (WIFSTOPPED (status) && lp->must_set_ptrace_flags)
3019 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3020 int options = linux_nat_ptrace_options (inf->attach_flag);
3022 linux_enable_event_reporting (ptid_get_lwp (lp->ptid), options);
3023 lp->must_set_ptrace_flags = 0;
3026 /* Handle GNU/Linux's syscall SIGTRAPs. */
3027 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3029 /* No longer need the sysgood bit. The ptrace event ends up
3030 recorded in lp->waitstatus if we care for it. We can carry
3031 on handling the event like a regular SIGTRAP from here
3033 status = W_STOPCODE (SIGTRAP);
3034 if (linux_handle_syscall_trap (lp, 0))
3039 /* Almost all other ptrace-stops are known to be outside of system
3040 calls, with further exceptions in linux_handle_extended_wait. */
3041 lp->syscall_state = TARGET_WAITKIND_IGNORE;
3044 /* Handle GNU/Linux's extended waitstatus for trace events. */
3045 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP
3046 && linux_is_extended_waitstatus (status))
3048 if (debug_linux_nat)
3049 fprintf_unfiltered (gdb_stdlog,
3050 "LLW: Handling extended status 0x%06x\n",
3052 if (linux_handle_extended_wait (lp, status))
3056 /* Check if the thread has exited. */
3057 if (WIFEXITED (status) || WIFSIGNALED (status))
3059 if (!report_thread_events
3060 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
3062 if (debug_linux_nat)
3063 fprintf_unfiltered (gdb_stdlog,
3064 "LLW: %s exited.\n",
3065 target_pid_to_str (lp->ptid));
3067 /* If there is at least one more LWP, then the exit signal
3068 was not the end of the debugged application and should be
3074 /* Note that even if the leader was ptrace-stopped, it can still
3075 exit, if e.g., some other thread brings down the whole
3076 process (calls `exit'). So don't assert that the lwp is
3078 if (debug_linux_nat)
3079 fprintf_unfiltered (gdb_stdlog,
3080 "LWP %ld exited (resumed=%d)\n",
3081 ptid_get_lwp (lp->ptid), lp->resumed);
3083 /* Dead LWP's aren't expected to reported a pending sigstop. */
3086 /* Store the pending event in the waitstatus, because
3087 W_EXITCODE(0,0) == 0. */
3088 store_waitstatus (&lp->waitstatus, status);
3092 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3093 an attempt to stop an LWP. */
3095 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3099 if (lp->last_resume_kind == resume_stop)
3101 if (debug_linux_nat)
3102 fprintf_unfiltered (gdb_stdlog,
3103 "LLW: resume_stop SIGSTOP caught for %s.\n",
3104 target_pid_to_str (lp->ptid));
3108 /* This is a delayed SIGSTOP. Filter out the event. */
3110 if (debug_linux_nat)
3111 fprintf_unfiltered (gdb_stdlog,
3112 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3114 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3115 target_pid_to_str (lp->ptid));
3117 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3118 gdb_assert (lp->resumed);
3123 /* Make sure we don't report a SIGINT that we have already displayed
3124 for another thread. */
3125 if (lp->ignore_sigint
3126 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3128 if (debug_linux_nat)
3129 fprintf_unfiltered (gdb_stdlog,
3130 "LLW: Delayed SIGINT caught for %s.\n",
3131 target_pid_to_str (lp->ptid));
3133 /* This is a delayed SIGINT. */
3134 lp->ignore_sigint = 0;
3136 linux_resume_one_lwp (lp, lp->step, GDB_SIGNAL_0);
3137 if (debug_linux_nat)
3138 fprintf_unfiltered (gdb_stdlog,
3139 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3141 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3142 target_pid_to_str (lp->ptid));
3143 gdb_assert (lp->resumed);
3145 /* Discard the event. */
3149 /* Don't report signals that GDB isn't interested in, such as
3150 signals that are neither printed nor stopped upon. Stopping all
3151 threads can be a bit time-consuming so if we want decent
3152 performance with heavily multi-threaded programs, especially when
3153 they're using a high frequency timer, we'd better avoid it if we
3155 if (WIFSTOPPED (status))
3157 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3159 if (!target_is_non_stop_p ())
3161 /* Only do the below in all-stop, as we currently use SIGSTOP
3162 to implement target_stop (see linux_nat_stop) in
3164 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3166 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3167 forwarded to the entire process group, that is, all LWPs
3168 will receive it - unless they're using CLONE_THREAD to
3169 share signals. Since we only want to report it once, we
3170 mark it as ignored for all LWPs except this one. */
3171 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
3172 set_ignore_sigint, NULL);
3173 lp->ignore_sigint = 0;
3176 maybe_clear_ignore_sigint (lp);
3179 /* When using hardware single-step, we need to report every signal.
3180 Otherwise, signals in pass_mask may be short-circuited
3181 except signals that might be caused by a breakpoint. */
3183 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))
3184 && !linux_wstatus_maybe_breakpoint (status))
3186 linux_resume_one_lwp (lp, lp->step, signo);
3187 if (debug_linux_nat)
3188 fprintf_unfiltered (gdb_stdlog,
3189 "LLW: %s %s, %s (preempt 'handle')\n",
3191 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3192 target_pid_to_str (lp->ptid),
3193 (signo != GDB_SIGNAL_0
3194 ? strsignal (gdb_signal_to_host (signo))
3200 /* An interesting event. */
3202 lp->status = status;
3203 save_stop_reason (lp);
3207 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3208 their exits until all other threads in the group have exited. */
3211 check_zombie_leaders (void)
3213 struct inferior *inf;
3217 struct lwp_info *leader_lp;
3222 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3223 if (leader_lp != NULL
3224 /* Check if there are other threads in the group, as we may
3225 have raced with the inferior simply exiting. */
3226 && num_lwps (inf->pid) > 1
3227 && linux_proc_pid_is_zombie (inf->pid))
3229 if (debug_linux_nat)
3230 fprintf_unfiltered (gdb_stdlog,
3231 "CZL: Thread group leader %d zombie "
3232 "(it exited, or another thread execd).\n",
3235 /* A leader zombie can mean one of two things:
3237 - It exited, and there's an exit status pending
3238 available, or only the leader exited (not the whole
3239 program). In the latter case, we can't waitpid the
3240 leader's exit status until all other threads are gone.
3242 - There are 3 or more threads in the group, and a thread
3243 other than the leader exec'd. See comments on exec
3244 events at the top of the file. We could try
3245 distinguishing the exit and exec cases, by waiting once
3246 more, and seeing if something comes out, but it doesn't
3247 sound useful. The previous leader _does_ go away, and
3248 we'll re-add the new one once we see the exec event
3249 (which is just the same as what would happen if the
3250 previous leader did exit voluntarily before some other
3253 if (debug_linux_nat)
3254 fprintf_unfiltered (gdb_stdlog,
3255 "CZL: Thread group leader %d vanished.\n",
3257 exit_lwp (leader_lp);
3262 /* Convenience function that is called when the kernel reports an exit
3263 event. This decides whether to report the event to GDB as a
3264 process exit event, a thread exit event, or to suppress the
3268 filter_exit_event (struct lwp_info *event_child,
3269 struct target_waitstatus *ourstatus)
3271 ptid_t ptid = event_child->ptid;
3273 if (num_lwps (ptid_get_pid (ptid)) > 1)
3275 if (report_thread_events)
3276 ourstatus->kind = TARGET_WAITKIND_THREAD_EXITED;
3278 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3280 exit_lwp (event_child);
3287 linux_nat_wait_1 (struct target_ops *ops,
3288 ptid_t ptid, struct target_waitstatus *ourstatus,
3292 enum resume_kind last_resume_kind;
3293 struct lwp_info *lp;
3296 if (debug_linux_nat)
3297 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3299 /* The first time we get here after starting a new inferior, we may
3300 not have added it to the LWP list yet - this is the earliest
3301 moment at which we know its PID. */
3302 if (ptid_is_pid (inferior_ptid))
3304 /* Upgrade the main thread's ptid. */
3305 thread_change_ptid (inferior_ptid,
3306 ptid_build (ptid_get_pid (inferior_ptid),
3307 ptid_get_pid (inferior_ptid), 0));
3309 lp = add_initial_lwp (inferior_ptid);
3313 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3314 block_child_signals (&prev_mask);
3316 /* First check if there is a LWP with a wait status pending. */
3317 lp = iterate_over_lwps (ptid, status_callback, NULL);
3320 if (debug_linux_nat)
3321 fprintf_unfiltered (gdb_stdlog,
3322 "LLW: Using pending wait status %s for %s.\n",
3323 status_to_str (lp->status),
3324 target_pid_to_str (lp->ptid));
3327 /* But if we don't find a pending event, we'll have to wait. Always
3328 pull all events out of the kernel. We'll randomly select an
3329 event LWP out of all that have events, to prevent starvation. */
3335 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3338 - If the thread group leader exits while other threads in the
3339 thread group still exist, waitpid(TGID, ...) hangs. That
3340 waitpid won't return an exit status until the other threads
3341 in the group are reapped.
3343 - When a non-leader thread execs, that thread just vanishes
3344 without reporting an exit (so we'd hang if we waited for it
3345 explicitly in that case). The exec event is reported to
3349 lwpid = my_waitpid (-1, &status, __WALL | WNOHANG);
3351 if (debug_linux_nat)
3352 fprintf_unfiltered (gdb_stdlog,
3353 "LNW: waitpid(-1, ...) returned %d, %s\n",
3354 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3358 if (debug_linux_nat)
3360 fprintf_unfiltered (gdb_stdlog,
3361 "LLW: waitpid %ld received %s\n",
3362 (long) lwpid, status_to_str (status));
3365 linux_nat_filter_event (lwpid, status);
3366 /* Retry until nothing comes out of waitpid. A single
3367 SIGCHLD can indicate more than one child stopped. */
3371 /* Now that we've pulled all events out of the kernel, resume
3372 LWPs that don't have an interesting event to report. */
3373 iterate_over_lwps (minus_one_ptid,
3374 resume_stopped_resumed_lwps, &minus_one_ptid);
3376 /* ... and find an LWP with a status to report to the core, if
3378 lp = iterate_over_lwps (ptid, status_callback, NULL);
3382 /* Check for zombie thread group leaders. Those can't be reaped
3383 until all other threads in the thread group are. */
3384 check_zombie_leaders ();
3386 /* If there are no resumed children left, bail. We'd be stuck
3387 forever in the sigsuspend call below otherwise. */
3388 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3390 if (debug_linux_nat)
3391 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3393 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3395 restore_child_signals_mask (&prev_mask);
3396 return minus_one_ptid;
3399 /* No interesting event to report to the core. */
3401 if (target_options & TARGET_WNOHANG)
3403 if (debug_linux_nat)
3404 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3406 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3407 restore_child_signals_mask (&prev_mask);
3408 return minus_one_ptid;
3411 /* We shouldn't end up here unless we want to try again. */
3412 gdb_assert (lp == NULL);
3414 /* Block until we get an event reported with SIGCHLD. */
3415 if (debug_linux_nat)
3416 fprintf_unfiltered (gdb_stdlog, "LNW: about to sigsuspend\n");
3417 sigsuspend (&suspend_mask);
3422 status = lp->status;
3425 if (!target_is_non_stop_p ())
3427 /* Now stop all other LWP's ... */
3428 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3430 /* ... and wait until all of them have reported back that
3431 they're no longer running. */
3432 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3435 /* If we're not waiting for a specific LWP, choose an event LWP from
3436 among those that have had events. Giving equal priority to all
3437 LWPs that have had events helps prevent starvation. */
3438 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3439 select_event_lwp (ptid, &lp, &status);
3441 gdb_assert (lp != NULL);
3443 /* Now that we've selected our final event LWP, un-adjust its PC if
3444 it was a software breakpoint, and we can't reliably support the
3445 "stopped by software breakpoint" stop reason. */
3446 if (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3447 && !USE_SIGTRAP_SIGINFO)
3449 struct regcache *regcache = get_thread_regcache (lp->ptid);
3450 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3451 int decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3457 pc = regcache_read_pc (regcache);
3458 regcache_write_pc (regcache, pc + decr_pc);
3462 /* We'll need this to determine whether to report a SIGSTOP as
3463 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3465 last_resume_kind = lp->last_resume_kind;
3467 if (!target_is_non_stop_p ())
3469 /* In all-stop, from the core's perspective, all LWPs are now
3470 stopped until a new resume action is sent over. */
3471 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3475 resume_clear_callback (lp, NULL);
3478 if (linux_nat_status_is_event (status))
3480 if (debug_linux_nat)
3481 fprintf_unfiltered (gdb_stdlog,
3482 "LLW: trap ptid is %s.\n",
3483 target_pid_to_str (lp->ptid));
3486 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3488 *ourstatus = lp->waitstatus;
3489 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3492 store_waitstatus (ourstatus, status);
3494 if (debug_linux_nat)
3495 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3497 restore_child_signals_mask (&prev_mask);
3499 if (last_resume_kind == resume_stop
3500 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3501 && WSTOPSIG (status) == SIGSTOP)
3503 /* A thread that has been requested to stop by GDB with
3504 target_stop, and it stopped cleanly, so report as SIG0. The
3505 use of SIGSTOP is an implementation detail. */
3506 ourstatus->value.sig = GDB_SIGNAL_0;
3509 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3510 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3513 lp->core = linux_common_core_of_thread (lp->ptid);
3515 if (ourstatus->kind == TARGET_WAITKIND_EXITED)
3516 return filter_exit_event (lp, ourstatus);
3521 /* Resume LWPs that are currently stopped without any pending status
3522 to report, but are resumed from the core's perspective. */
3525 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3527 ptid_t *wait_ptid_p = (ptid_t *) data;
3531 if (debug_linux_nat)
3532 fprintf_unfiltered (gdb_stdlog,
3533 "RSRL: NOT resuming LWP %s, not stopped\n",
3534 target_pid_to_str (lp->ptid));
3536 else if (!lp->resumed)
3538 if (debug_linux_nat)
3539 fprintf_unfiltered (gdb_stdlog,
3540 "RSRL: NOT resuming LWP %s, not resumed\n",
3541 target_pid_to_str (lp->ptid));
3543 else if (lwp_status_pending_p (lp))
3545 if (debug_linux_nat)
3546 fprintf_unfiltered (gdb_stdlog,
3547 "RSRL: NOT resuming LWP %s, has pending status\n",
3548 target_pid_to_str (lp->ptid));
3552 struct regcache *regcache = get_thread_regcache (lp->ptid);
3553 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3557 CORE_ADDR pc = regcache_read_pc (regcache);
3558 int leave_stopped = 0;
3560 /* Don't bother if there's a breakpoint at PC that we'd hit
3561 immediately, and we're not waiting for this LWP. */
3562 if (!ptid_match (lp->ptid, *wait_ptid_p))
3564 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3570 if (debug_linux_nat)
3571 fprintf_unfiltered (gdb_stdlog,
3572 "RSRL: resuming stopped-resumed LWP %s at "
3574 target_pid_to_str (lp->ptid),
3575 paddress (gdbarch, pc),
3578 linux_resume_one_lwp_throw (lp, lp->step, GDB_SIGNAL_0);
3581 CATCH (ex, RETURN_MASK_ERROR)
3583 if (!check_ptrace_stopped_lwp_gone (lp))
3584 throw_exception (ex);
3593 linux_nat_wait (struct target_ops *ops,
3594 ptid_t ptid, struct target_waitstatus *ourstatus,
3599 if (debug_linux_nat)
3601 char *options_string;
3603 options_string = target_options_to_string (target_options);
3604 fprintf_unfiltered (gdb_stdlog,
3605 "linux_nat_wait: [%s], [%s]\n",
3606 target_pid_to_str (ptid),
3608 xfree (options_string);
3611 /* Flush the async file first. */
3612 if (target_is_async_p ())
3613 async_file_flush ();
3615 /* Resume LWPs that are currently stopped without any pending status
3616 to report, but are resumed from the core's perspective. LWPs get
3617 in this state if we find them stopping at a time we're not
3618 interested in reporting the event (target_wait on a
3619 specific_process, for example, see linux_nat_wait_1), and
3620 meanwhile the event became uninteresting. Don't bother resuming
3621 LWPs we're not going to wait for if they'd stop immediately. */
3622 if (target_is_non_stop_p ())
3623 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3625 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3627 /* If we requested any event, and something came out, assume there
3628 may be more. If we requested a specific lwp or process, also
3629 assume there may be more. */
3630 if (target_is_async_p ()
3631 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3632 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3633 || !ptid_equal (ptid, minus_one_ptid)))
3642 kill_one_lwp (pid_t pid)
3644 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3647 kill_lwp (pid, SIGKILL);
3648 if (debug_linux_nat)
3650 int save_errno = errno;
3652 fprintf_unfiltered (gdb_stdlog,
3653 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid,
3654 save_errno ? safe_strerror (save_errno) : "OK");
3657 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3660 ptrace (PTRACE_KILL, pid, 0, 0);
3661 if (debug_linux_nat)
3663 int save_errno = errno;
3665 fprintf_unfiltered (gdb_stdlog,
3666 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid,
3667 save_errno ? safe_strerror (save_errno) : "OK");
3671 /* Wait for an LWP to die. */
3674 kill_wait_one_lwp (pid_t pid)
3678 /* We must make sure that there are no pending events (delayed
3679 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3680 program doesn't interfere with any following debugging session. */
3684 res = my_waitpid (pid, NULL, __WALL);
3685 if (res != (pid_t) -1)
3687 if (debug_linux_nat)
3688 fprintf_unfiltered (gdb_stdlog,
3689 "KWC: wait %ld received unknown.\n",
3691 /* The Linux kernel sometimes fails to kill a thread
3692 completely after PTRACE_KILL; that goes from the stop
3693 point in do_fork out to the one in get_signal_to_deliver
3694 and waits again. So kill it again. */
3700 gdb_assert (res == -1 && errno == ECHILD);
3703 /* Callback for iterate_over_lwps. */
3706 kill_callback (struct lwp_info *lp, void *data)
3708 kill_one_lwp (ptid_get_lwp (lp->ptid));
3712 /* Callback for iterate_over_lwps. */
3715 kill_wait_callback (struct lwp_info *lp, void *data)
3717 kill_wait_one_lwp (ptid_get_lwp (lp->ptid));
3721 /* Kill the fork children of any threads of inferior INF that are
3722 stopped at a fork event. */
3725 kill_unfollowed_fork_children (struct inferior *inf)
3727 struct thread_info *thread;
3729 ALL_NON_EXITED_THREADS (thread)
3730 if (thread->inf == inf)
3732 struct target_waitstatus *ws = &thread->pending_follow;
3734 if (ws->kind == TARGET_WAITKIND_FORKED
3735 || ws->kind == TARGET_WAITKIND_VFORKED)
3737 ptid_t child_ptid = ws->value.related_pid;
3738 int child_pid = ptid_get_pid (child_ptid);
3739 int child_lwp = ptid_get_lwp (child_ptid);
3741 kill_one_lwp (child_lwp);
3742 kill_wait_one_lwp (child_lwp);
3744 /* Let the arch-specific native code know this process is
3746 linux_nat_forget_process (child_pid);
3752 linux_nat_kill (struct target_ops *ops)
3754 /* If we're stopped while forking and we haven't followed yet,
3755 kill the other task. We need to do this first because the
3756 parent will be sleeping if this is a vfork. */
3757 kill_unfollowed_fork_children (current_inferior ());
3759 if (forks_exist_p ())
3760 linux_fork_killall ();
3763 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3765 /* Stop all threads before killing them, since ptrace requires
3766 that the thread is stopped to sucessfully PTRACE_KILL. */
3767 iterate_over_lwps (ptid, stop_callback, NULL);
3768 /* ... and wait until all of them have reported back that
3769 they're no longer running. */
3770 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3772 /* Kill all LWP's ... */
3773 iterate_over_lwps (ptid, kill_callback, NULL);
3775 /* ... and wait until we've flushed all events. */
3776 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3779 target_mourn_inferior ();
3783 linux_nat_mourn_inferior (struct target_ops *ops)
3785 int pid = ptid_get_pid (inferior_ptid);
3787 purge_lwp_list (pid);
3789 if (! forks_exist_p ())
3790 /* Normal case, no other forks available. */
3791 linux_ops->to_mourn_inferior (ops);
3793 /* Multi-fork case. The current inferior_ptid has exited, but
3794 there are other viable forks to debug. Delete the exiting
3795 one and context-switch to the first available. */
3796 linux_fork_mourn_inferior ();
3798 /* Let the arch-specific native code know this process is gone. */
3799 linux_nat_forget_process (pid);
3802 /* Convert a native/host siginfo object, into/from the siginfo in the
3803 layout of the inferiors' architecture. */
3806 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3810 if (linux_nat_siginfo_fixup != NULL)
3811 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3813 /* If there was no callback, or the callback didn't do anything,
3814 then just do a straight memcpy. */
3818 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3820 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3824 static enum target_xfer_status
3825 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3826 const char *annex, gdb_byte *readbuf,
3827 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3828 ULONGEST *xfered_len)
3832 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3834 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3835 gdb_assert (readbuf || writebuf);
3837 pid = ptid_get_lwp (inferior_ptid);
3839 pid = ptid_get_pid (inferior_ptid);
3841 if (offset > sizeof (siginfo))
3842 return TARGET_XFER_E_IO;
3845 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3847 return TARGET_XFER_E_IO;
3849 /* When GDB is built as a 64-bit application, ptrace writes into
3850 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3851 inferior with a 64-bit GDB should look the same as debugging it
3852 with a 32-bit GDB, we need to convert it. GDB core always sees
3853 the converted layout, so any read/write will have to be done
3855 siginfo_fixup (&siginfo, inf_siginfo, 0);
3857 if (offset + len > sizeof (siginfo))
3858 len = sizeof (siginfo) - offset;
3860 if (readbuf != NULL)
3861 memcpy (readbuf, inf_siginfo + offset, len);
3864 memcpy (inf_siginfo + offset, writebuf, len);
3866 /* Convert back to ptrace layout before flushing it out. */
3867 siginfo_fixup (&siginfo, inf_siginfo, 1);
3870 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3872 return TARGET_XFER_E_IO;
3876 return TARGET_XFER_OK;
3879 static enum target_xfer_status
3880 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3881 const char *annex, gdb_byte *readbuf,
3882 const gdb_byte *writebuf,
3883 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3885 struct cleanup *old_chain;
3886 enum target_xfer_status xfer;
3888 if (object == TARGET_OBJECT_SIGNAL_INFO)
3889 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3890 offset, len, xfered_len);
3892 /* The target is connected but no live inferior is selected. Pass
3893 this request down to a lower stratum (e.g., the executable
3895 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3896 return TARGET_XFER_EOF;
3898 old_chain = save_inferior_ptid ();
3900 if (ptid_lwp_p (inferior_ptid))
3901 inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid));
3903 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3904 offset, len, xfered_len);
3906 do_cleanups (old_chain);
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 interface for memory reads using the /proc
3974 filesystem. Because we can use a single read() call for /proc, this
3975 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3976 but it doesn't support writes. */
3978 static enum target_xfer_status
3979 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3980 const char *annex, gdb_byte *readbuf,
3981 const gdb_byte *writebuf,
3982 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
3988 if (object != TARGET_OBJECT_MEMORY || !readbuf)
3989 return TARGET_XFER_EOF;
3991 /* Don't bother for one word. */
3992 if (len < 3 * sizeof (long))
3993 return TARGET_XFER_EOF;
3995 /* We could keep this file open and cache it - possibly one per
3996 thread. That requires some juggling, but is even faster. */
3997 xsnprintf (filename, sizeof filename, "/proc/%d/mem",
3998 ptid_get_pid (inferior_ptid));
3999 fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0);
4001 return TARGET_XFER_EOF;
4003 /* If pread64 is available, use it. It's faster if the kernel
4004 supports it (only one syscall), and it's 64-bit safe even on
4005 32-bit platforms (for instance, SPARC debugging a SPARC64
4008 if (pread64 (fd, readbuf, len, offset) != len)
4010 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
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_pid (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 /* NOTE: palves 2008-03-21: We're only async when the user requests
4413 it explicitly with the "set target-async" command.
4414 Someday, linux will always be async. */
4415 return target_async_permitted;
4419 linux_nat_supports_non_stop (struct target_ops *self)
4424 /* to_always_non_stop_p implementation. */
4427 linux_nat_always_non_stop_p (struct target_ops *self)
4432 /* True if we want to support multi-process. To be removed when GDB
4433 supports multi-exec. */
4435 int linux_multi_process = 1;
4438 linux_nat_supports_multi_process (struct target_ops *self)
4440 return linux_multi_process;
4444 linux_nat_supports_disable_randomization (struct target_ops *self)
4446 #ifdef HAVE_PERSONALITY
4453 static int async_terminal_is_ours = 1;
4455 /* target_terminal_inferior implementation.
4457 This is a wrapper around child_terminal_inferior to add async support. */
4460 linux_nat_terminal_inferior (struct target_ops *self)
4462 child_terminal_inferior (self);
4464 /* Calls to target_terminal_*() are meant to be idempotent. */
4465 if (!async_terminal_is_ours)
4468 async_terminal_is_ours = 0;
4472 /* target_terminal_ours implementation.
4474 This is a wrapper around child_terminal_ours to add async support (and
4475 implement the target_terminal_ours vs target_terminal_ours_for_output
4476 distinction). child_terminal_ours is currently no different than
4477 child_terminal_ours_for_output.
4478 We leave target_terminal_ours_for_output alone, leaving it to
4479 child_terminal_ours_for_output. */
4482 linux_nat_terminal_ours (struct target_ops *self)
4484 /* GDB should never give the terminal to the inferior if the
4485 inferior is running in the background (run&, continue&, etc.),
4486 but claiming it sure should. */
4487 child_terminal_ours (self);
4489 if (async_terminal_is_ours)
4492 clear_sigint_trap ();
4493 async_terminal_is_ours = 1;
4496 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4497 so we notice when any child changes state, and notify the
4498 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4499 above to wait for the arrival of a SIGCHLD. */
4502 sigchld_handler (int signo)
4504 int old_errno = errno;
4506 if (debug_linux_nat)
4507 ui_file_write_async_safe (gdb_stdlog,
4508 "sigchld\n", sizeof ("sigchld\n") - 1);
4510 if (signo == SIGCHLD
4511 && linux_nat_event_pipe[0] != -1)
4512 async_file_mark (); /* Let the event loop know that there are
4513 events to handle. */
4518 /* Callback registered with the target events file descriptor. */
4521 handle_target_event (int error, gdb_client_data client_data)
4523 inferior_event_handler (INF_REG_EVENT, NULL);
4526 /* Create/destroy the target events pipe. Returns previous state. */
4529 linux_async_pipe (int enable)
4531 int previous = linux_is_async_p ();
4533 if (previous != enable)
4537 /* Block child signals while we create/destroy the pipe, as
4538 their handler writes to it. */
4539 block_child_signals (&prev_mask);
4543 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4544 internal_error (__FILE__, __LINE__,
4545 "creating event pipe failed.");
4547 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4548 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4552 close (linux_nat_event_pipe[0]);
4553 close (linux_nat_event_pipe[1]);
4554 linux_nat_event_pipe[0] = -1;
4555 linux_nat_event_pipe[1] = -1;
4558 restore_child_signals_mask (&prev_mask);
4564 /* target_async implementation. */
4567 linux_nat_async (struct target_ops *ops, int enable)
4571 if (!linux_async_pipe (1))
4573 add_file_handler (linux_nat_event_pipe[0],
4574 handle_target_event, NULL);
4575 /* There may be pending events to handle. Tell the event loop
4582 delete_file_handler (linux_nat_event_pipe[0]);
4583 linux_async_pipe (0);
4588 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4592 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4596 if (debug_linux_nat)
4597 fprintf_unfiltered (gdb_stdlog,
4598 "LNSL: running -> suspending %s\n",
4599 target_pid_to_str (lwp->ptid));
4602 if (lwp->last_resume_kind == resume_stop)
4604 if (debug_linux_nat)
4605 fprintf_unfiltered (gdb_stdlog,
4606 "linux-nat: already stopping LWP %ld at "
4608 ptid_get_lwp (lwp->ptid));
4612 stop_callback (lwp, NULL);
4613 lwp->last_resume_kind = resume_stop;
4617 /* Already known to be stopped; do nothing. */
4619 if (debug_linux_nat)
4621 if (find_thread_ptid (lwp->ptid)->stop_requested)
4622 fprintf_unfiltered (gdb_stdlog,
4623 "LNSL: already stopped/stop_requested %s\n",
4624 target_pid_to_str (lwp->ptid));
4626 fprintf_unfiltered (gdb_stdlog,
4627 "LNSL: already stopped/no "
4628 "stop_requested yet %s\n",
4629 target_pid_to_str (lwp->ptid));
4636 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4638 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4642 linux_nat_close (struct target_ops *self)
4644 /* Unregister from the event loop. */
4645 if (linux_nat_is_async_p (self))
4646 linux_nat_async (self, 0);
4648 if (linux_ops->to_close)
4649 linux_ops->to_close (linux_ops);
4654 /* When requests are passed down from the linux-nat layer to the
4655 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4656 used. The address space pointer is stored in the inferior object,
4657 but the common code that is passed such ptid can't tell whether
4658 lwpid is a "main" process id or not (it assumes so). We reverse
4659 look up the "main" process id from the lwp here. */
4661 static struct address_space *
4662 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4664 struct lwp_info *lwp;
4665 struct inferior *inf;
4668 if (ptid_get_lwp (ptid) == 0)
4670 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4672 lwp = find_lwp_pid (ptid);
4673 pid = ptid_get_pid (lwp->ptid);
4677 /* A (pid,lwpid,0) ptid. */
4678 pid = ptid_get_pid (ptid);
4681 inf = find_inferior_pid (pid);
4682 gdb_assert (inf != NULL);
4686 /* Return the cached value of the processor core for thread PTID. */
4689 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4691 struct lwp_info *info = find_lwp_pid (ptid);
4698 /* Implementation of to_filesystem_is_local. */
4701 linux_nat_filesystem_is_local (struct target_ops *ops)
4703 struct inferior *inf = current_inferior ();
4705 if (inf->fake_pid_p || inf->pid == 0)
4708 return linux_ns_same (inf->pid, LINUX_NS_MNT);
4711 /* Convert the INF argument passed to a to_fileio_* method
4712 to a process ID suitable for passing to its corresponding
4713 linux_mntns_* function. If INF is non-NULL then the
4714 caller is requesting the filesystem seen by INF. If INF
4715 is NULL then the caller is requesting the filesystem seen
4716 by the GDB. We fall back to GDB's filesystem in the case
4717 that INF is non-NULL but its PID is unknown. */
4720 linux_nat_fileio_pid_of (struct inferior *inf)
4722 if (inf == NULL || inf->fake_pid_p || inf->pid == 0)
4728 /* Implementation of to_fileio_open. */
4731 linux_nat_fileio_open (struct target_ops *self,
4732 struct inferior *inf, const char *filename,
4733 int flags, int mode, int warn_if_slow,
4740 if (fileio_to_host_openflags (flags, &nat_flags) == -1
4741 || fileio_to_host_mode (mode, &nat_mode) == -1)
4743 *target_errno = FILEIO_EINVAL;
4747 fd = linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf),
4748 filename, nat_flags, nat_mode);
4750 *target_errno = host_to_fileio_error (errno);
4755 /* Implementation of to_fileio_readlink. */
4758 linux_nat_fileio_readlink (struct target_ops *self,
4759 struct inferior *inf, const char *filename,
4766 len = linux_mntns_readlink (linux_nat_fileio_pid_of (inf),
4767 filename, buf, sizeof (buf));
4770 *target_errno = host_to_fileio_error (errno);
4774 ret = (char *) xmalloc (len + 1);
4775 memcpy (ret, buf, len);
4780 /* Implementation of to_fileio_unlink. */
4783 linux_nat_fileio_unlink (struct target_ops *self,
4784 struct inferior *inf, const char *filename,
4789 ret = linux_mntns_unlink (linux_nat_fileio_pid_of (inf),
4792 *target_errno = host_to_fileio_error (errno);
4797 /* Implementation of the to_thread_events method. */
4800 linux_nat_thread_events (struct target_ops *ops, int enable)
4802 report_thread_events = enable;
4806 linux_nat_add_target (struct target_ops *t)
4808 /* Save the provided single-threaded target. We save this in a separate
4809 variable because another target we've inherited from (e.g. inf-ptrace)
4810 may have saved a pointer to T; we want to use it for the final
4811 process stratum target. */
4812 linux_ops_saved = *t;
4813 linux_ops = &linux_ops_saved;
4815 /* Override some methods for multithreading. */
4816 t->to_create_inferior = linux_nat_create_inferior;
4817 t->to_attach = linux_nat_attach;
4818 t->to_detach = linux_nat_detach;
4819 t->to_resume = linux_nat_resume;
4820 t->to_wait = linux_nat_wait;
4821 t->to_pass_signals = linux_nat_pass_signals;
4822 t->to_xfer_partial = linux_nat_xfer_partial;
4823 t->to_kill = linux_nat_kill;
4824 t->to_mourn_inferior = linux_nat_mourn_inferior;
4825 t->to_thread_alive = linux_nat_thread_alive;
4826 t->to_update_thread_list = linux_nat_update_thread_list;
4827 t->to_pid_to_str = linux_nat_pid_to_str;
4828 t->to_thread_name = linux_nat_thread_name;
4829 t->to_has_thread_control = tc_schedlock;
4830 t->to_thread_address_space = linux_nat_thread_address_space;
4831 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4832 t->to_stopped_data_address = linux_nat_stopped_data_address;
4833 t->to_stopped_by_sw_breakpoint = linux_nat_stopped_by_sw_breakpoint;
4834 t->to_supports_stopped_by_sw_breakpoint = linux_nat_supports_stopped_by_sw_breakpoint;
4835 t->to_stopped_by_hw_breakpoint = linux_nat_stopped_by_hw_breakpoint;
4836 t->to_supports_stopped_by_hw_breakpoint = linux_nat_supports_stopped_by_hw_breakpoint;
4837 t->to_thread_events = linux_nat_thread_events;
4839 t->to_can_async_p = linux_nat_can_async_p;
4840 t->to_is_async_p = linux_nat_is_async_p;
4841 t->to_supports_non_stop = linux_nat_supports_non_stop;
4842 t->to_always_non_stop_p = linux_nat_always_non_stop_p;
4843 t->to_async = linux_nat_async;
4844 t->to_terminal_inferior = linux_nat_terminal_inferior;
4845 t->to_terminal_ours = linux_nat_terminal_ours;
4847 super_close = t->to_close;
4848 t->to_close = linux_nat_close;
4850 t->to_stop = linux_nat_stop;
4852 t->to_supports_multi_process = linux_nat_supports_multi_process;
4854 t->to_supports_disable_randomization
4855 = linux_nat_supports_disable_randomization;
4857 t->to_core_of_thread = linux_nat_core_of_thread;
4859 t->to_filesystem_is_local = linux_nat_filesystem_is_local;
4860 t->to_fileio_open = linux_nat_fileio_open;
4861 t->to_fileio_readlink = linux_nat_fileio_readlink;
4862 t->to_fileio_unlink = linux_nat_fileio_unlink;
4864 /* We don't change the stratum; this target will sit at
4865 process_stratum and thread_db will set at thread_stratum. This
4866 is a little strange, since this is a multi-threaded-capable
4867 target, but we want to be on the stack below thread_db, and we
4868 also want to be used for single-threaded processes. */
4873 /* Register a method to call whenever a new thread is attached. */
4875 linux_nat_set_new_thread (struct target_ops *t,
4876 void (*new_thread) (struct lwp_info *))
4878 /* Save the pointer. We only support a single registered instance
4879 of the GNU/Linux native target, so we do not need to map this to
4881 linux_nat_new_thread = new_thread;
4884 /* See declaration in linux-nat.h. */
4887 linux_nat_set_new_fork (struct target_ops *t,
4888 linux_nat_new_fork_ftype *new_fork)
4890 /* Save the pointer. */
4891 linux_nat_new_fork = new_fork;
4894 /* See declaration in linux-nat.h. */
4897 linux_nat_set_forget_process (struct target_ops *t,
4898 linux_nat_forget_process_ftype *fn)
4900 /* Save the pointer. */
4901 linux_nat_forget_process_hook = fn;
4904 /* See declaration in linux-nat.h. */
4907 linux_nat_forget_process (pid_t pid)
4909 if (linux_nat_forget_process_hook != NULL)
4910 linux_nat_forget_process_hook (pid);
4913 /* Register a method that converts a siginfo object between the layout
4914 that ptrace returns, and the layout in the architecture of the
4917 linux_nat_set_siginfo_fixup (struct target_ops *t,
4918 int (*siginfo_fixup) (siginfo_t *,
4922 /* Save the pointer. */
4923 linux_nat_siginfo_fixup = siginfo_fixup;
4926 /* Register a method to call prior to resuming a thread. */
4929 linux_nat_set_prepare_to_resume (struct target_ops *t,
4930 void (*prepare_to_resume) (struct lwp_info *))
4932 /* Save the pointer. */
4933 linux_nat_prepare_to_resume = prepare_to_resume;
4936 /* See linux-nat.h. */
4939 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4943 pid = ptid_get_lwp (ptid);
4945 pid = ptid_get_pid (ptid);
4948 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4951 memset (siginfo, 0, sizeof (*siginfo));
4957 /* See nat/linux-nat.h. */
4960 current_lwp_ptid (void)
4962 gdb_assert (ptid_lwp_p (inferior_ptid));
4963 return inferior_ptid;
4966 /* Provide a prototype to silence -Wmissing-prototypes. */
4967 extern initialize_file_ftype _initialize_linux_nat;
4970 _initialize_linux_nat (void)
4972 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4973 &debug_linux_nat, _("\
4974 Set debugging of GNU/Linux lwp module."), _("\
4975 Show debugging of GNU/Linux lwp module."), _("\
4976 Enables printf debugging output."),
4978 show_debug_linux_nat,
4979 &setdebuglist, &showdebuglist);
4981 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance,
4982 &debug_linux_namespaces, _("\
4983 Set debugging of GNU/Linux namespaces module."), _("\
4984 Show debugging of GNU/Linux namespaces module."), _("\
4985 Enables printf debugging output."),
4988 &setdebuglist, &showdebuglist);
4990 /* Save this mask as the default. */
4991 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4993 /* Install a SIGCHLD handler. */
4994 sigchld_action.sa_handler = sigchld_handler;
4995 sigemptyset (&sigchld_action.sa_mask);
4996 sigchld_action.sa_flags = SA_RESTART;
4998 /* Make it the default. */
4999 sigaction (SIGCHLD, &sigchld_action, NULL);
5001 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5002 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5003 sigdelset (&suspend_mask, SIGCHLD);
5005 sigemptyset (&blocked_mask);
5007 lwp_lwpid_htab_create ();
5011 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5012 the GNU/Linux Threads library and therefore doesn't really belong
5015 /* Return the set of signals used by the threads library in *SET. */
5018 lin_thread_get_thread_signals (sigset_t *set)
5022 /* NPTL reserves the first two RT signals, but does not provide any
5023 way for the debugger to query the signal numbers - fortunately
5024 they don't change. */
5025 sigaddset (set, __SIGRTMIN);
5026 sigaddset (set, __SIGRTMIN + 1);