1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a thread is destroyed. */
201 static void (*linux_nat_delete_thread
) (struct arch_lwp_info
*);
203 /* The method to call, if any, when a new fork is attached. */
204 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
206 /* The method to call, if any, when a process is no longer
208 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
210 /* Hook to call prior to resuming a thread. */
211 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
213 /* The method to call, if any, when the siginfo object needs to be
214 converted between the layout returned by ptrace, and the layout in
215 the architecture of the inferior. */
216 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
220 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
221 Called by our to_xfer_partial. */
222 static target_xfer_partial_ftype
*super_xfer_partial
;
224 /* The saved to_close method, inherited from inf-ptrace.c.
225 Called by our to_close. */
226 static void (*super_close
) (struct target_ops
*);
228 static unsigned int debug_linux_nat
;
230 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
231 struct cmd_list_element
*c
, const char *value
)
233 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
237 struct simple_pid_list
241 struct simple_pid_list
*next
;
243 struct simple_pid_list
*stopped_pids
;
245 /* Whether target_thread_events is in effect. */
246 static int report_thread_events
;
248 /* Async mode support. */
250 /* The read/write ends of the pipe registered as waitable file in the
252 static int linux_nat_event_pipe
[2] = { -1, -1 };
254 /* True if we're currently in async mode. */
255 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
257 /* Flush the event pipe. */
260 async_file_flush (void)
267 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
269 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
272 /* Put something (anything, doesn't matter what, or how much) in event
273 pipe, so that the select/poll in the event-loop realizes we have
274 something to process. */
277 async_file_mark (void)
281 /* It doesn't really matter what the pipe contains, as long we end
282 up with something in it. Might as well flush the previous
288 ret
= write (linux_nat_event_pipe
[1], "+", 1);
290 while (ret
== -1 && errno
== EINTR
);
292 /* Ignore EAGAIN. If the pipe is full, the event loop will already
293 be awakened anyway. */
296 static int kill_lwp (int lwpid
, int signo
);
298 static int stop_callback (struct lwp_info
*lp
, void *data
);
299 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
301 static void block_child_signals (sigset_t
*prev_mask
);
302 static void restore_child_signals_mask (sigset_t
*prev_mask
);
305 static struct lwp_info
*add_lwp (ptid_t ptid
);
306 static void purge_lwp_list (int pid
);
307 static void delete_lwp (ptid_t ptid
);
308 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
310 static int lwp_status_pending_p (struct lwp_info
*lp
);
312 static int sigtrap_is_event (int status
);
313 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
315 static void save_stop_reason (struct lwp_info
*lp
);
320 /* See nat/linux-nat.h. */
323 ptid_of_lwp (struct lwp_info
*lwp
)
328 /* See nat/linux-nat.h. */
331 lwp_set_arch_private_info (struct lwp_info
*lwp
,
332 struct arch_lwp_info
*info
)
334 lwp
->arch_private
= info
;
337 /* See nat/linux-nat.h. */
339 struct arch_lwp_info
*
340 lwp_arch_private_info (struct lwp_info
*lwp
)
342 return lwp
->arch_private
;
345 /* See nat/linux-nat.h. */
348 lwp_is_stopped (struct lwp_info
*lwp
)
353 /* See nat/linux-nat.h. */
355 enum target_stop_reason
356 lwp_stop_reason (struct lwp_info
*lwp
)
358 return lwp
->stop_reason
;
361 /* See nat/linux-nat.h. */
364 lwp_is_stepping (struct lwp_info
*lwp
)
370 /* Trivial list manipulation functions to keep track of a list of
371 new stopped processes. */
373 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
375 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
378 new_pid
->status
= status
;
379 new_pid
->next
= *listp
;
384 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
386 struct simple_pid_list
**p
;
388 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
389 if ((*p
)->pid
== pid
)
391 struct simple_pid_list
*next
= (*p
)->next
;
393 *statusp
= (*p
)->status
;
401 /* Return the ptrace options that we want to try to enable. */
404 linux_nat_ptrace_options (int attached
)
409 options
|= PTRACE_O_EXITKILL
;
411 options
|= (PTRACE_O_TRACESYSGOOD
412 | PTRACE_O_TRACEVFORKDONE
413 | PTRACE_O_TRACEVFORK
415 | PTRACE_O_TRACEEXEC
);
420 /* Initialize ptrace warnings and check for supported ptrace
423 ATTACHED should be nonzero iff we attached to the inferior. */
426 linux_init_ptrace (pid_t pid
, int attached
)
428 int options
= linux_nat_ptrace_options (attached
);
430 linux_enable_event_reporting (pid
, options
);
431 linux_ptrace_init_warnings ();
435 linux_child_post_attach (struct target_ops
*self
, int pid
)
437 linux_init_ptrace (pid
, 1);
441 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
443 linux_init_ptrace (ptid_get_pid (ptid
), 0);
446 /* Return the number of known LWPs in the tgid given by PID. */
454 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
455 if (ptid_get_pid (lp
->ptid
) == pid
)
461 /* Call delete_lwp with prototype compatible for make_cleanup. */
464 delete_lwp_cleanup (void *lp_voidp
)
466 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
468 delete_lwp (lp
->ptid
);
471 /* Target hook for follow_fork. On entry inferior_ptid must be the
472 ptid of the followed inferior. At return, inferior_ptid will be
476 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
481 struct lwp_info
*child_lp
= NULL
;
482 int status
= W_STOPCODE (0);
484 ptid_t parent_ptid
, child_ptid
;
485 int parent_pid
, child_pid
;
487 has_vforked
= (inferior_thread ()->pending_follow
.kind
488 == TARGET_WAITKIND_VFORKED
);
489 parent_ptid
= inferior_ptid
;
490 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
491 parent_pid
= ptid_get_lwp (parent_ptid
);
492 child_pid
= ptid_get_lwp (child_ptid
);
494 /* We're already attached to the parent, by default. */
495 child_lp
= add_lwp (child_ptid
);
496 child_lp
->stopped
= 1;
497 child_lp
->last_resume_kind
= resume_stop
;
499 /* Detach new forked process? */
502 struct cleanup
*old_chain
= make_cleanup (delete_lwp_cleanup
,
505 if (linux_nat_prepare_to_resume
!= NULL
)
506 linux_nat_prepare_to_resume (child_lp
);
508 /* When debugging an inferior in an architecture that supports
509 hardware single stepping on a kernel without commit
510 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
511 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
512 set if the parent process had them set.
513 To work around this, single step the child process
514 once before detaching to clear the flags. */
516 /* Note that we consult the parent's architecture instead of
517 the child's because there's no inferior for the child at
519 if (!gdbarch_software_single_step_p (target_thread_architecture
522 linux_disable_event_reporting (child_pid
);
523 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
524 perror_with_name (_("Couldn't do single step"));
525 if (my_waitpid (child_pid
, &status
, 0) < 0)
526 perror_with_name (_("Couldn't wait vfork process"));
529 if (WIFSTOPPED (status
))
533 signo
= WSTOPSIG (status
);
535 && !signal_pass_state (gdb_signal_from_host (signo
)))
537 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
540 do_cleanups (old_chain
);
544 scoped_restore save_inferior_ptid
545 = make_scoped_restore (&inferior_ptid
);
546 inferior_ptid
= child_ptid
;
548 /* Let the thread_db layer learn about this new process. */
549 check_for_thread_db ();
554 struct lwp_info
*parent_lp
;
556 parent_lp
= find_lwp_pid (parent_ptid
);
557 gdb_assert (linux_supports_tracefork () >= 0);
559 if (linux_supports_tracevforkdone ())
562 fprintf_unfiltered (gdb_stdlog
,
563 "LCFF: waiting for VFORK_DONE on %d\n",
565 parent_lp
->stopped
= 1;
567 /* We'll handle the VFORK_DONE event like any other
568 event, in target_wait. */
572 /* We can't insert breakpoints until the child has
573 finished with the shared memory region. We need to
574 wait until that happens. Ideal would be to just
576 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
577 - waitpid (parent_pid, &status, __WALL);
578 However, most architectures can't handle a syscall
579 being traced on the way out if it wasn't traced on
582 We might also think to loop, continuing the child
583 until it exits or gets a SIGTRAP. One problem is
584 that the child might call ptrace with PTRACE_TRACEME.
586 There's no simple and reliable way to figure out when
587 the vforked child will be done with its copy of the
588 shared memory. We could step it out of the syscall,
589 two instructions, let it go, and then single-step the
590 parent once. When we have hardware single-step, this
591 would work; with software single-step it could still
592 be made to work but we'd have to be able to insert
593 single-step breakpoints in the child, and we'd have
594 to insert -just- the single-step breakpoint in the
595 parent. Very awkward.
597 In the end, the best we can do is to make sure it
598 runs for a little while. Hopefully it will be out of
599 range of any breakpoints we reinsert. Usually this
600 is only the single-step breakpoint at vfork's return
604 fprintf_unfiltered (gdb_stdlog
,
605 "LCFF: no VFORK_DONE "
606 "support, sleeping a bit\n");
610 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
611 and leave it pending. The next linux_nat_resume call
612 will notice a pending event, and bypasses actually
613 resuming the inferior. */
614 parent_lp
->status
= 0;
615 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
616 parent_lp
->stopped
= 1;
618 /* If we're in async mode, need to tell the event loop
619 there's something here to process. */
620 if (target_is_async_p ())
627 struct lwp_info
*child_lp
;
629 child_lp
= add_lwp (inferior_ptid
);
630 child_lp
->stopped
= 1;
631 child_lp
->last_resume_kind
= resume_stop
;
633 /* Let the thread_db layer learn about this new process. */
634 check_for_thread_db ();
642 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
644 return !linux_supports_tracefork ();
648 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
654 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
656 return !linux_supports_tracefork ();
660 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
666 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
668 return !linux_supports_tracefork ();
672 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
678 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
679 int pid
, bool needed
, int any_count
,
680 gdb::array_view
<const int> syscall_counts
)
682 if (!linux_supports_tracesysgood ())
685 /* On GNU/Linux, we ignore the arguments. It means that we only
686 enable the syscall catchpoints, but do not disable them.
688 Also, we do not use the `syscall_counts' information because we do not
689 filter system calls here. We let GDB do the logic for us. */
693 /* List of known LWPs, keyed by LWP PID. This speeds up the common
694 case of mapping a PID returned from the kernel to our corresponding
695 lwp_info data structure. */
696 static htab_t lwp_lwpid_htab
;
698 /* Calculate a hash from a lwp_info's LWP PID. */
701 lwp_info_hash (const void *ap
)
703 const struct lwp_info
*lp
= (struct lwp_info
*) ap
;
704 pid_t pid
= ptid_get_lwp (lp
->ptid
);
706 return iterative_hash_object (pid
, 0);
709 /* Equality function for the lwp_info hash table. Compares the LWP's
713 lwp_lwpid_htab_eq (const void *a
, const void *b
)
715 const struct lwp_info
*entry
= (const struct lwp_info
*) a
;
716 const struct lwp_info
*element
= (const struct lwp_info
*) b
;
718 return ptid_get_lwp (entry
->ptid
) == ptid_get_lwp (element
->ptid
);
721 /* Create the lwp_lwpid_htab hash table. */
724 lwp_lwpid_htab_create (void)
726 lwp_lwpid_htab
= htab_create (100, lwp_info_hash
, lwp_lwpid_htab_eq
, NULL
);
729 /* Add LP to the hash table. */
732 lwp_lwpid_htab_add_lwp (struct lwp_info
*lp
)
736 slot
= htab_find_slot (lwp_lwpid_htab
, lp
, INSERT
);
737 gdb_assert (slot
!= NULL
&& *slot
== NULL
);
741 /* Head of doubly-linked list of known LWPs. Sorted by reverse
742 creation order. This order is assumed in some cases. E.g.,
743 reaping status after killing alls lwps of a process: the leader LWP
744 must be reaped last. */
745 struct lwp_info
*lwp_list
;
747 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
750 lwp_list_add (struct lwp_info
*lp
)
753 if (lwp_list
!= NULL
)
758 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
762 lwp_list_remove (struct lwp_info
*lp
)
764 /* Remove from sorted-by-creation-order list. */
765 if (lp
->next
!= NULL
)
766 lp
->next
->prev
= lp
->prev
;
767 if (lp
->prev
!= NULL
)
768 lp
->prev
->next
= lp
->next
;
775 /* Original signal mask. */
776 static sigset_t normal_mask
;
778 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
779 _initialize_linux_nat. */
780 static sigset_t suspend_mask
;
782 /* Signals to block to make that sigsuspend work. */
783 static sigset_t blocked_mask
;
785 /* SIGCHLD action. */
786 struct sigaction sigchld_action
;
788 /* Block child signals (SIGCHLD and linux threads signals), and store
789 the previous mask in PREV_MASK. */
792 block_child_signals (sigset_t
*prev_mask
)
794 /* Make sure SIGCHLD is blocked. */
795 if (!sigismember (&blocked_mask
, SIGCHLD
))
796 sigaddset (&blocked_mask
, SIGCHLD
);
798 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
801 /* Restore child signals mask, previously returned by
802 block_child_signals. */
805 restore_child_signals_mask (sigset_t
*prev_mask
)
807 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
810 /* Mask of signals to pass directly to the inferior. */
811 static sigset_t pass_mask
;
813 /* Update signals to pass to the inferior. */
815 linux_nat_pass_signals (struct target_ops
*self
,
816 int numsigs
, unsigned char *pass_signals
)
820 sigemptyset (&pass_mask
);
822 for (signo
= 1; signo
< NSIG
; signo
++)
824 int target_signo
= gdb_signal_from_host (signo
);
825 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
826 sigaddset (&pass_mask
, signo
);
832 /* Prototypes for local functions. */
833 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
834 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
835 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
836 static int check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
);
840 /* Destroy and free LP. */
843 lwp_free (struct lwp_info
*lp
)
845 /* Let the arch specific bits release arch_lwp_info. */
846 if (linux_nat_delete_thread
!= NULL
)
847 linux_nat_delete_thread (lp
->arch_private
);
849 gdb_assert (lp
->arch_private
== NULL
);
854 /* Traversal function for purge_lwp_list. */
857 lwp_lwpid_htab_remove_pid (void **slot
, void *info
)
859 struct lwp_info
*lp
= (struct lwp_info
*) *slot
;
860 int pid
= *(int *) info
;
862 if (ptid_get_pid (lp
->ptid
) == pid
)
864 htab_clear_slot (lwp_lwpid_htab
, slot
);
865 lwp_list_remove (lp
);
872 /* Remove all LWPs belong to PID from the lwp list. */
875 purge_lwp_list (int pid
)
877 htab_traverse_noresize (lwp_lwpid_htab
, lwp_lwpid_htab_remove_pid
, &pid
);
880 /* Add the LWP specified by PTID to the list. PTID is the first LWP
881 in the process. Return a pointer to the structure describing the
884 This differs from add_lwp in that we don't let the arch specific
885 bits know about this new thread. Current clients of this callback
886 take the opportunity to install watchpoints in the new thread, and
887 we shouldn't do that for the first thread. If we're spawning a
888 child ("run"), the thread executes the shell wrapper first, and we
889 shouldn't touch it until it execs the program we want to debug.
890 For "attach", it'd be okay to call the callback, but it's not
891 necessary, because watchpoints can't yet have been inserted into
894 static struct lwp_info
*
895 add_initial_lwp (ptid_t ptid
)
899 gdb_assert (ptid_lwp_p (ptid
));
901 lp
= XNEW (struct lwp_info
);
903 memset (lp
, 0, sizeof (struct lwp_info
));
905 lp
->last_resume_kind
= resume_continue
;
906 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
911 /* Add to sorted-by-reverse-creation-order list. */
914 /* Add to keyed-by-pid htab. */
915 lwp_lwpid_htab_add_lwp (lp
);
920 /* Add the LWP specified by PID to the list. Return a pointer to the
921 structure describing the new LWP. The LWP should already be
924 static struct lwp_info
*
925 add_lwp (ptid_t ptid
)
929 lp
= add_initial_lwp (ptid
);
931 /* Let the arch specific bits know about this new thread. Current
932 clients of this callback take the opportunity to install
933 watchpoints in the new thread. We don't do this for the first
934 thread though. See add_initial_lwp. */
935 if (linux_nat_new_thread
!= NULL
)
936 linux_nat_new_thread (lp
);
941 /* Remove the LWP specified by PID from the list. */
944 delete_lwp (ptid_t ptid
)
948 struct lwp_info dummy
;
951 slot
= htab_find_slot (lwp_lwpid_htab
, &dummy
, NO_INSERT
);
955 lp
= *(struct lwp_info
**) slot
;
956 gdb_assert (lp
!= NULL
);
958 htab_clear_slot (lwp_lwpid_htab
, slot
);
960 /* Remove from sorted-by-creation-order list. */
961 lwp_list_remove (lp
);
967 /* Return a pointer to the structure describing the LWP corresponding
968 to PID. If no corresponding LWP could be found, return NULL. */
970 static struct lwp_info
*
971 find_lwp_pid (ptid_t ptid
)
975 struct lwp_info dummy
;
977 if (ptid_lwp_p (ptid
))
978 lwp
= ptid_get_lwp (ptid
);
980 lwp
= ptid_get_pid (ptid
);
982 dummy
.ptid
= ptid_build (0, lwp
, 0);
983 lp
= (struct lwp_info
*) htab_find (lwp_lwpid_htab
, &dummy
);
987 /* See nat/linux-nat.h. */
990 iterate_over_lwps (ptid_t filter
,
991 iterate_over_lwps_ftype callback
,
994 struct lwp_info
*lp
, *lpnext
;
996 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1000 if (ptid_match (lp
->ptid
, filter
))
1002 if ((*callback
) (lp
, data
) != 0)
1010 /* Update our internal state when changing from one checkpoint to
1011 another indicated by NEW_PTID. We can only switch single-threaded
1012 applications, so we only create one new LWP, and the previous list
1016 linux_nat_switch_fork (ptid_t new_ptid
)
1018 struct lwp_info
*lp
;
1020 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1022 lp
= add_lwp (new_ptid
);
1025 /* This changes the thread's ptid while preserving the gdb thread
1026 num. Also changes the inferior pid, while preserving the
1028 thread_change_ptid (inferior_ptid
, new_ptid
);
1030 /* We've just told GDB core that the thread changed target id, but,
1031 in fact, it really is a different thread, with different register
1033 registers_changed ();
1036 /* Handle the exit of a single thread LP. */
1039 exit_lwp (struct lwp_info
*lp
)
1041 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1045 if (print_thread_events
)
1046 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1048 delete_thread (lp
->ptid
);
1051 delete_lwp (lp
->ptid
);
1054 /* Wait for the LWP specified by LP, which we have just attached to.
1055 Returns a wait status for that LWP, to cache. */
1058 linux_nat_post_attach_wait (ptid_t ptid
, int *signalled
)
1060 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1063 if (linux_proc_pid_is_stopped (pid
))
1065 if (debug_linux_nat
)
1066 fprintf_unfiltered (gdb_stdlog
,
1067 "LNPAW: Attaching to a stopped process\n");
1069 /* The process is definitely stopped. It is in a job control
1070 stop, unless the kernel predates the TASK_STOPPED /
1071 TASK_TRACED distinction, in which case it might be in a
1072 ptrace stop. Make sure it is in a ptrace stop; from there we
1073 can kill it, signal it, et cetera.
1075 First make sure there is a pending SIGSTOP. Since we are
1076 already attached, the process can not transition from stopped
1077 to running without a PTRACE_CONT; so we know this signal will
1078 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1079 probably already in the queue (unless this kernel is old
1080 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1081 is not an RT signal, it can only be queued once. */
1082 kill_lwp (pid
, SIGSTOP
);
1084 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1085 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1086 ptrace (PTRACE_CONT
, pid
, 0, 0);
1089 /* Make sure the initial process is stopped. The user-level threads
1090 layer might want to poke around in the inferior, and that won't
1091 work if things haven't stabilized yet. */
1092 new_pid
= my_waitpid (pid
, &status
, __WALL
);
1093 gdb_assert (pid
== new_pid
);
1095 if (!WIFSTOPPED (status
))
1097 /* The pid we tried to attach has apparently just exited. */
1098 if (debug_linux_nat
)
1099 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1100 pid
, status_to_str (status
));
1104 if (WSTOPSIG (status
) != SIGSTOP
)
1107 if (debug_linux_nat
)
1108 fprintf_unfiltered (gdb_stdlog
,
1109 "LNPAW: Received %s after attaching\n",
1110 status_to_str (status
));
1117 linux_nat_create_inferior (struct target_ops
*ops
,
1118 const char *exec_file
, const std::string
&allargs
,
1119 char **env
, int from_tty
)
1121 maybe_disable_address_space_randomization restore_personality
1122 (disable_randomization
);
1124 /* The fork_child mechanism is synchronous and calls target_wait, so
1125 we have to mask the async mode. */
1127 /* Make sure we report all signals during startup. */
1128 linux_nat_pass_signals (ops
, 0, NULL
);
1130 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1133 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1134 already attached. Returns true if a new LWP is found, false
1138 attach_proc_task_lwp_callback (ptid_t ptid
)
1140 struct lwp_info
*lp
;
1142 /* Ignore LWPs we're already attached to. */
1143 lp
= find_lwp_pid (ptid
);
1146 int lwpid
= ptid_get_lwp (ptid
);
1148 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1152 /* Be quiet if we simply raced with the thread exiting.
1153 EPERM is returned if the thread's task still exists, and
1154 is marked as exited or zombie, as well as other
1155 conditions, so in that case, confirm the status in
1156 /proc/PID/status. */
1158 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1160 if (debug_linux_nat
)
1162 fprintf_unfiltered (gdb_stdlog
,
1163 "Cannot attach to lwp %d: "
1164 "thread is gone (%d: %s)\n",
1165 lwpid
, err
, safe_strerror (err
));
1171 = linux_ptrace_attach_fail_reason_string (ptid
, err
);
1173 warning (_("Cannot attach to lwp %d: %s"),
1174 lwpid
, reason
.c_str ());
1179 if (debug_linux_nat
)
1180 fprintf_unfiltered (gdb_stdlog
,
1181 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1182 target_pid_to_str (ptid
));
1184 lp
= add_lwp (ptid
);
1186 /* The next time we wait for this LWP we'll see a SIGSTOP as
1187 PTRACE_ATTACH brings it to a halt. */
1190 /* We need to wait for a stop before being able to make the
1191 next ptrace call on this LWP. */
1192 lp
->must_set_ptrace_flags
= 1;
1194 /* So that wait collects the SIGSTOP. */
1197 /* Also add the LWP to gdb's thread list, in case a
1198 matching libthread_db is not found (or the process uses
1200 add_thread (lp
->ptid
);
1201 set_running (lp
->ptid
, 1);
1202 set_executing (lp
->ptid
, 1);
1211 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1213 struct lwp_info
*lp
;
1217 /* Make sure we report all signals during attach. */
1218 linux_nat_pass_signals (ops
, 0, NULL
);
1222 linux_ops
->to_attach (ops
, args
, from_tty
);
1224 CATCH (ex
, RETURN_MASK_ERROR
)
1226 pid_t pid
= parse_pid_to_attach (args
);
1227 std::string reason
= linux_ptrace_attach_fail_reason (pid
);
1229 if (!reason
.empty ())
1230 throw_error (ex
.error
, "warning: %s\n%s", reason
.c_str (), ex
.message
);
1232 throw_error (ex
.error
, "%s", ex
.message
);
1236 /* The ptrace base target adds the main thread with (pid,0,0)
1237 format. Decorate it with lwp info. */
1238 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1239 ptid_get_pid (inferior_ptid
),
1241 thread_change_ptid (inferior_ptid
, ptid
);
1243 /* Add the initial process as the first LWP to the list. */
1244 lp
= add_initial_lwp (ptid
);
1246 status
= linux_nat_post_attach_wait (lp
->ptid
, &lp
->signalled
);
1247 if (!WIFSTOPPED (status
))
1249 if (WIFEXITED (status
))
1251 int exit_code
= WEXITSTATUS (status
);
1253 target_terminal::ours ();
1254 target_mourn_inferior (inferior_ptid
);
1256 error (_("Unable to attach: program exited normally."));
1258 error (_("Unable to attach: program exited with code %d."),
1261 else if (WIFSIGNALED (status
))
1263 enum gdb_signal signo
;
1265 target_terminal::ours ();
1266 target_mourn_inferior (inferior_ptid
);
1268 signo
= gdb_signal_from_host (WTERMSIG (status
));
1269 error (_("Unable to attach: program terminated with signal "
1271 gdb_signal_to_name (signo
),
1272 gdb_signal_to_string (signo
));
1275 internal_error (__FILE__
, __LINE__
,
1276 _("unexpected status %d for PID %ld"),
1277 status
, (long) ptid_get_lwp (ptid
));
1282 /* Save the wait status to report later. */
1284 if (debug_linux_nat
)
1285 fprintf_unfiltered (gdb_stdlog
,
1286 "LNA: waitpid %ld, saving status %s\n",
1287 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1289 lp
->status
= status
;
1291 /* We must attach to every LWP. If /proc is mounted, use that to
1292 find them now. The inferior may be using raw clone instead of
1293 using pthreads. But even if it is using pthreads, thread_db
1294 walks structures in the inferior's address space to find the list
1295 of threads/LWPs, and those structures may well be corrupted.
1296 Note that once thread_db is loaded, we'll still use it to list
1297 threads and associate pthread info with each LWP. */
1298 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1299 attach_proc_task_lwp_callback
);
1301 if (target_can_async_p ())
1305 /* Get pending signal of THREAD as a host signal number, for detaching
1306 purposes. This is the signal the thread last stopped for, which we
1307 need to deliver to the thread when detaching, otherwise, it'd be
1311 get_detach_signal (struct lwp_info
*lp
)
1313 enum gdb_signal signo
= GDB_SIGNAL_0
;
1315 /* If we paused threads momentarily, we may have stored pending
1316 events in lp->status or lp->waitstatus (see stop_wait_callback),
1317 and GDB core hasn't seen any signal for those threads.
1318 Otherwise, the last signal reported to the core is found in the
1319 thread object's stop_signal.
1321 There's a corner case that isn't handled here at present. Only
1322 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1323 stop_signal make sense as a real signal to pass to the inferior.
1324 Some catchpoint related events, like
1325 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1326 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1327 those traps are debug API (ptrace in our case) related and
1328 induced; the inferior wouldn't see them if it wasn't being
1329 traced. Hence, we should never pass them to the inferior, even
1330 when set to pass state. Since this corner case isn't handled by
1331 infrun.c when proceeding with a signal, for consistency, neither
1332 do we handle it here (or elsewhere in the file we check for
1333 signal pass state). Normally SIGTRAP isn't set to pass state, so
1334 this is really a corner case. */
1336 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1337 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1338 else if (lp
->status
)
1339 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1340 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1342 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1344 if (tp
->suspend
.waitstatus_pending_p
)
1345 signo
= tp
->suspend
.waitstatus
.value
.sig
;
1347 signo
= tp
->suspend
.stop_signal
;
1349 else if (!target_is_non_stop_p ())
1351 struct target_waitstatus last
;
1354 get_last_target_status (&last_ptid
, &last
);
1356 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1358 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1360 signo
= tp
->suspend
.stop_signal
;
1364 if (signo
== GDB_SIGNAL_0
)
1366 if (debug_linux_nat
)
1367 fprintf_unfiltered (gdb_stdlog
,
1368 "GPT: lwp %s has no pending signal\n",
1369 target_pid_to_str (lp
->ptid
));
1371 else if (!signal_pass_state (signo
))
1373 if (debug_linux_nat
)
1374 fprintf_unfiltered (gdb_stdlog
,
1375 "GPT: lwp %s had signal %s, "
1376 "but it is in no pass state\n",
1377 target_pid_to_str (lp
->ptid
),
1378 gdb_signal_to_string (signo
));
1382 if (debug_linux_nat
)
1383 fprintf_unfiltered (gdb_stdlog
,
1384 "GPT: lwp %s has pending signal %s\n",
1385 target_pid_to_str (lp
->ptid
),
1386 gdb_signal_to_string (signo
));
1388 return gdb_signal_to_host (signo
);
1394 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1395 signal number that should be passed to the LWP when detaching.
1396 Otherwise pass any pending signal the LWP may have, if any. */
1399 detach_one_lwp (struct lwp_info
*lp
, int *signo_p
)
1401 int lwpid
= ptid_get_lwp (lp
->ptid
);
1404 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1406 if (debug_linux_nat
&& lp
->status
)
1407 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1408 strsignal (WSTOPSIG (lp
->status
)),
1409 target_pid_to_str (lp
->ptid
));
1411 /* If there is a pending SIGSTOP, get rid of it. */
1414 if (debug_linux_nat
)
1415 fprintf_unfiltered (gdb_stdlog
,
1416 "DC: Sending SIGCONT to %s\n",
1417 target_pid_to_str (lp
->ptid
));
1419 kill_lwp (lwpid
, SIGCONT
);
1423 if (signo_p
== NULL
)
1425 /* Pass on any pending signal for this LWP. */
1426 signo
= get_detach_signal (lp
);
1431 /* Preparing to resume may try to write registers, and fail if the
1432 lwp is zombie. If that happens, ignore the error. We'll handle
1433 it below, when detach fails with ESRCH. */
1436 if (linux_nat_prepare_to_resume
!= NULL
)
1437 linux_nat_prepare_to_resume (lp
);
1439 CATCH (ex
, RETURN_MASK_ERROR
)
1441 if (!check_ptrace_stopped_lwp_gone (lp
))
1442 throw_exception (ex
);
1446 if (ptrace (PTRACE_DETACH
, lwpid
, 0, signo
) < 0)
1448 int save_errno
= errno
;
1450 /* We know the thread exists, so ESRCH must mean the lwp is
1451 zombie. This can happen if one of the already-detached
1452 threads exits the whole thread group. In that case we're
1453 still attached, and must reap the lwp. */
1454 if (save_errno
== ESRCH
)
1458 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1461 warning (_("Couldn't reap LWP %d while detaching: %s"),
1462 lwpid
, strerror (errno
));
1464 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1466 warning (_("Reaping LWP %d while detaching "
1467 "returned unexpected status 0x%x"),
1473 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1474 safe_strerror (save_errno
));
1477 else if (debug_linux_nat
)
1479 fprintf_unfiltered (gdb_stdlog
,
1480 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1481 target_pid_to_str (lp
->ptid
),
1485 delete_lwp (lp
->ptid
);
1489 detach_callback (struct lwp_info
*lp
, void *data
)
1491 /* We don't actually detach from the thread group leader just yet.
1492 If the thread group exits, we must reap the zombie clone lwps
1493 before we're able to reap the leader. */
1494 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1495 detach_one_lwp (lp
, NULL
);
1500 linux_nat_detach (struct target_ops
*ops
, inferior
*inf
, int from_tty
)
1503 struct lwp_info
*main_lwp
;
1505 pid
= ptid_get_pid (inferior_ptid
);
1507 /* Don't unregister from the event loop, as there may be other
1508 inferiors running. */
1510 /* Stop all threads before detaching. ptrace requires that the
1511 thread is stopped to sucessfully detach. */
1512 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1513 /* ... and wait until all of them have reported back that
1514 they're no longer running. */
1515 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1517 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1519 /* Only the initial process should be left right now. */
1520 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1522 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1524 if (forks_exist_p ())
1526 /* Multi-fork case. The current inferior_ptid is being detached
1527 from, but there are other viable forks to debug. Detach from
1528 the current fork, and context-switch to the first
1530 linux_fork_detach (from_tty
);
1534 target_announce_detach (from_tty
);
1536 /* Pass on any pending signal for the last LWP. */
1537 int signo
= get_detach_signal (main_lwp
);
1539 detach_one_lwp (main_lwp
, &signo
);
1541 inf_ptrace_detach_success (ops
);
1545 /* Resume execution of the inferior process. If STEP is nonzero,
1546 single-step it. If SIGNAL is nonzero, give it that signal. */
1549 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1550 enum gdb_signal signo
)
1554 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1555 We only presently need that if the LWP is stepped though (to
1556 handle the case of stepping a breakpoint instruction). */
1559 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1561 lp
->stop_pc
= regcache_read_pc (regcache
);
1566 if (linux_nat_prepare_to_resume
!= NULL
)
1567 linux_nat_prepare_to_resume (lp
);
1568 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1570 /* Successfully resumed. Clear state that no longer makes sense,
1571 and mark the LWP as running. Must not do this before resuming
1572 otherwise if that fails other code will be confused. E.g., we'd
1573 later try to stop the LWP and hang forever waiting for a stop
1574 status. Note that we must not throw after this is cleared,
1575 otherwise handle_zombie_lwp_error would get confused. */
1578 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1579 registers_changed_ptid (lp
->ptid
);
1582 /* Called when we try to resume a stopped LWP and that errors out. If
1583 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1584 or about to become), discard the error, clear any pending status
1585 the LWP may have, and return true (we'll collect the exit status
1586 soon enough). Otherwise, return false. */
1589 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1591 /* If we get an error after resuming the LWP successfully, we'd
1592 confuse !T state for the LWP being gone. */
1593 gdb_assert (lp
->stopped
);
1595 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1596 because even if ptrace failed with ESRCH, the tracee may be "not
1597 yet fully dead", but already refusing ptrace requests. In that
1598 case the tracee has 'R (Running)' state for a little bit
1599 (observed in Linux 3.18). See also the note on ESRCH in the
1600 ptrace(2) man page. Instead, check whether the LWP has any state
1601 other than ptrace-stopped. */
1603 /* Don't assume anything if /proc/PID/status can't be read. */
1604 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1606 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1608 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1614 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1615 disappears while we try to resume it. */
1618 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1622 linux_resume_one_lwp_throw (lp
, step
, signo
);
1624 CATCH (ex
, RETURN_MASK_ERROR
)
1626 if (!check_ptrace_stopped_lwp_gone (lp
))
1627 throw_exception (ex
);
1635 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1639 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1641 if (inf
->vfork_child
!= NULL
)
1643 if (debug_linux_nat
)
1644 fprintf_unfiltered (gdb_stdlog
,
1645 "RC: Not resuming %s (vfork parent)\n",
1646 target_pid_to_str (lp
->ptid
));
1648 else if (!lwp_status_pending_p (lp
))
1650 if (debug_linux_nat
)
1651 fprintf_unfiltered (gdb_stdlog
,
1652 "RC: Resuming sibling %s, %s, %s\n",
1653 target_pid_to_str (lp
->ptid
),
1654 (signo
!= GDB_SIGNAL_0
1655 ? strsignal (gdb_signal_to_host (signo
))
1657 step
? "step" : "resume");
1659 linux_resume_one_lwp (lp
, step
, signo
);
1663 if (debug_linux_nat
)
1664 fprintf_unfiltered (gdb_stdlog
,
1665 "RC: Not resuming sibling %s (has pending)\n",
1666 target_pid_to_str (lp
->ptid
));
1671 if (debug_linux_nat
)
1672 fprintf_unfiltered (gdb_stdlog
,
1673 "RC: Not resuming sibling %s (not stopped)\n",
1674 target_pid_to_str (lp
->ptid
));
1678 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1679 Resume LWP with the last stop signal, if it is in pass state. */
1682 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1684 enum gdb_signal signo
= GDB_SIGNAL_0
;
1691 struct thread_info
*thread
;
1693 thread
= find_thread_ptid (lp
->ptid
);
1696 signo
= thread
->suspend
.stop_signal
;
1697 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1701 resume_lwp (lp
, 0, signo
);
1706 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1709 lp
->last_resume_kind
= resume_stop
;
1714 resume_set_callback (struct lwp_info
*lp
, void *data
)
1717 lp
->last_resume_kind
= resume_continue
;
1722 linux_nat_resume (struct target_ops
*ops
,
1723 ptid_t ptid
, int step
, enum gdb_signal signo
)
1725 struct lwp_info
*lp
;
1728 if (debug_linux_nat
)
1729 fprintf_unfiltered (gdb_stdlog
,
1730 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1731 step
? "step" : "resume",
1732 target_pid_to_str (ptid
),
1733 (signo
!= GDB_SIGNAL_0
1734 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1735 target_pid_to_str (inferior_ptid
));
1737 /* A specific PTID means `step only this process id'. */
1738 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1739 || ptid_is_pid (ptid
));
1741 /* Mark the lwps we're resuming as resumed. */
1742 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1744 /* See if it's the current inferior that should be handled
1747 lp
= find_lwp_pid (inferior_ptid
);
1749 lp
= find_lwp_pid (ptid
);
1750 gdb_assert (lp
!= NULL
);
1752 /* Remember if we're stepping. */
1753 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1755 /* If we have a pending wait status for this thread, there is no
1756 point in resuming the process. But first make sure that
1757 linux_nat_wait won't preemptively handle the event - we
1758 should never take this short-circuit if we are going to
1759 leave LP running, since we have skipped resuming all the
1760 other threads. This bit of code needs to be synchronized
1761 with linux_nat_wait. */
1763 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1766 && WSTOPSIG (lp
->status
)
1767 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1769 if (debug_linux_nat
)
1770 fprintf_unfiltered (gdb_stdlog
,
1771 "LLR: Not short circuiting for ignored "
1772 "status 0x%x\n", lp
->status
);
1774 /* FIXME: What should we do if we are supposed to continue
1775 this thread with a signal? */
1776 gdb_assert (signo
== GDB_SIGNAL_0
);
1777 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1782 if (lwp_status_pending_p (lp
))
1784 /* FIXME: What should we do if we are supposed to continue
1785 this thread with a signal? */
1786 gdb_assert (signo
== GDB_SIGNAL_0
);
1788 if (debug_linux_nat
)
1789 fprintf_unfiltered (gdb_stdlog
,
1790 "LLR: Short circuiting for status 0x%x\n",
1793 if (target_can_async_p ())
1796 /* Tell the event loop we have something to process. */
1803 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1805 if (debug_linux_nat
)
1806 fprintf_unfiltered (gdb_stdlog
,
1807 "LLR: %s %s, %s (resume event thread)\n",
1808 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1809 target_pid_to_str (lp
->ptid
),
1810 (signo
!= GDB_SIGNAL_0
1811 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1813 linux_resume_one_lwp (lp
, step
, signo
);
1815 if (target_can_async_p ())
1819 /* Send a signal to an LWP. */
1822 kill_lwp (int lwpid
, int signo
)
1827 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1828 if (errno
== ENOSYS
)
1830 /* If tkill fails, then we are not using nptl threads, a
1831 configuration we no longer support. */
1832 perror_with_name (("tkill"));
1837 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1838 event, check if the core is interested in it: if not, ignore the
1839 event, and keep waiting; otherwise, we need to toggle the LWP's
1840 syscall entry/exit status, since the ptrace event itself doesn't
1841 indicate it, and report the trap to higher layers. */
1844 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1846 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1847 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1848 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1852 /* If we're stopping threads, there's a SIGSTOP pending, which
1853 makes it so that the LWP reports an immediate syscall return,
1854 followed by the SIGSTOP. Skip seeing that "return" using
1855 PTRACE_CONT directly, and let stop_wait_callback collect the
1856 SIGSTOP. Later when the thread is resumed, a new syscall
1857 entry event. If we didn't do this (and returned 0), we'd
1858 leave a syscall entry pending, and our caller, by using
1859 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1860 itself. Later, when the user re-resumes this LWP, we'd see
1861 another syscall entry event and we'd mistake it for a return.
1863 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1864 (leaving immediately with LWP->signalled set, without issuing
1865 a PTRACE_CONT), it would still be problematic to leave this
1866 syscall enter pending, as later when the thread is resumed,
1867 it would then see the same syscall exit mentioned above,
1868 followed by the delayed SIGSTOP, while the syscall didn't
1869 actually get to execute. It seems it would be even more
1870 confusing to the user. */
1872 if (debug_linux_nat
)
1873 fprintf_unfiltered (gdb_stdlog
,
1874 "LHST: ignoring syscall %d "
1875 "for LWP %ld (stopping threads), "
1876 "resuming with PTRACE_CONT for SIGSTOP\n",
1878 ptid_get_lwp (lp
->ptid
));
1880 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1881 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1886 /* Always update the entry/return state, even if this particular
1887 syscall isn't interesting to the core now. In async mode,
1888 the user could install a new catchpoint for this syscall
1889 between syscall enter/return, and we'll need to know to
1890 report a syscall return if that happens. */
1891 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1892 ? TARGET_WAITKIND_SYSCALL_RETURN
1893 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1895 if (catch_syscall_enabled ())
1897 if (catching_syscall_number (syscall_number
))
1899 /* Alright, an event to report. */
1900 ourstatus
->kind
= lp
->syscall_state
;
1901 ourstatus
->value
.syscall_number
= syscall_number
;
1903 if (debug_linux_nat
)
1904 fprintf_unfiltered (gdb_stdlog
,
1905 "LHST: stopping for %s of syscall %d"
1908 == TARGET_WAITKIND_SYSCALL_ENTRY
1909 ? "entry" : "return",
1911 ptid_get_lwp (lp
->ptid
));
1915 if (debug_linux_nat
)
1916 fprintf_unfiltered (gdb_stdlog
,
1917 "LHST: ignoring %s of syscall %d "
1919 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1920 ? "entry" : "return",
1922 ptid_get_lwp (lp
->ptid
));
1926 /* If we had been syscall tracing, and hence used PT_SYSCALL
1927 before on this LWP, it could happen that the user removes all
1928 syscall catchpoints before we get to process this event.
1929 There are two noteworthy issues here:
1931 - When stopped at a syscall entry event, resuming with
1932 PT_STEP still resumes executing the syscall and reports a
1935 - Only PT_SYSCALL catches syscall enters. If we last
1936 single-stepped this thread, then this event can't be a
1937 syscall enter. If we last single-stepped this thread, this
1938 has to be a syscall exit.
1940 The points above mean that the next resume, be it PT_STEP or
1941 PT_CONTINUE, can not trigger a syscall trace event. */
1942 if (debug_linux_nat
)
1943 fprintf_unfiltered (gdb_stdlog
,
1944 "LHST: caught syscall event "
1945 "with no syscall catchpoints."
1946 " %d for LWP %ld, ignoring\n",
1948 ptid_get_lwp (lp
->ptid
));
1949 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1952 /* The core isn't interested in this event. For efficiency, avoid
1953 stopping all threads only to have the core resume them all again.
1954 Since we're not stopping threads, if we're still syscall tracing
1955 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1956 subsequent syscall. Simply resume using the inf-ptrace layer,
1957 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1959 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1963 /* Handle a GNU/Linux extended wait response. If we see a clone
1964 event, we need to add the new LWP to our list (and not report the
1965 trap to higher layers). This function returns non-zero if the
1966 event should be ignored and we should wait again. If STOPPING is
1967 true, the new LWP remains stopped, otherwise it is continued. */
1970 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1972 int pid
= ptid_get_lwp (lp
->ptid
);
1973 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1974 int event
= linux_ptrace_get_extended_event (status
);
1976 /* All extended events we currently use are mid-syscall. Only
1977 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1978 you have to be using PTRACE_SEIZE to get that. */
1979 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1981 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1982 || event
== PTRACE_EVENT_CLONE
)
1984 unsigned long new_pid
;
1987 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1989 /* If we haven't already seen the new PID stop, wait for it now. */
1990 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1992 /* The new child has a pending SIGSTOP. We can't affect it until it
1993 hits the SIGSTOP, but we're already attached. */
1994 ret
= my_waitpid (new_pid
, &status
, __WALL
);
1996 perror_with_name (_("waiting for new child"));
1997 else if (ret
!= new_pid
)
1998 internal_error (__FILE__
, __LINE__
,
1999 _("wait returned unexpected PID %d"), ret
);
2000 else if (!WIFSTOPPED (status
))
2001 internal_error (__FILE__
, __LINE__
,
2002 _("wait returned unexpected status 0x%x"), status
);
2005 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2007 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
2009 /* The arch-specific native code may need to know about new
2010 forks even if those end up never mapped to an
2012 if (linux_nat_new_fork
!= NULL
)
2013 linux_nat_new_fork (lp
, new_pid
);
2016 if (event
== PTRACE_EVENT_FORK
2017 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
2019 /* Handle checkpointing by linux-fork.c here as a special
2020 case. We don't want the follow-fork-mode or 'catch fork'
2021 to interfere with this. */
2023 /* This won't actually modify the breakpoint list, but will
2024 physically remove the breakpoints from the child. */
2025 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
2027 /* Retain child fork in ptrace (stopped) state. */
2028 if (!find_fork_pid (new_pid
))
2031 /* Report as spurious, so that infrun doesn't want to follow
2032 this fork. We're actually doing an infcall in
2034 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2036 /* Report the stop to the core. */
2040 if (event
== PTRACE_EVENT_FORK
)
2041 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2042 else if (event
== PTRACE_EVENT_VFORK
)
2043 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2044 else if (event
== PTRACE_EVENT_CLONE
)
2046 struct lwp_info
*new_lp
;
2048 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2050 if (debug_linux_nat
)
2051 fprintf_unfiltered (gdb_stdlog
,
2052 "LHEW: Got clone event "
2053 "from LWP %d, new child is LWP %ld\n",
2056 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2057 new_lp
->stopped
= 1;
2058 new_lp
->resumed
= 1;
2060 /* If the thread_db layer is active, let it record the user
2061 level thread id and status, and add the thread to GDB's
2063 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2065 /* The process is not using thread_db. Add the LWP to
2067 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2068 add_thread (new_lp
->ptid
);
2071 /* Even if we're stopping the thread for some reason
2072 internal to this module, from the perspective of infrun
2073 and the user/frontend, this new thread is running until
2074 it next reports a stop. */
2075 set_running (new_lp
->ptid
, 1);
2076 set_executing (new_lp
->ptid
, 1);
2078 if (WSTOPSIG (status
) != SIGSTOP
)
2080 /* This can happen if someone starts sending signals to
2081 the new thread before it gets a chance to run, which
2082 have a lower number than SIGSTOP (e.g. SIGUSR1).
2083 This is an unlikely case, and harder to handle for
2084 fork / vfork than for clone, so we do not try - but
2085 we handle it for clone events here. */
2087 new_lp
->signalled
= 1;
2089 /* We created NEW_LP so it cannot yet contain STATUS. */
2090 gdb_assert (new_lp
->status
== 0);
2092 /* Save the wait status to report later. */
2093 if (debug_linux_nat
)
2094 fprintf_unfiltered (gdb_stdlog
,
2095 "LHEW: waitpid of new LWP %ld, "
2096 "saving status %s\n",
2097 (long) ptid_get_lwp (new_lp
->ptid
),
2098 status_to_str (status
));
2099 new_lp
->status
= status
;
2101 else if (report_thread_events
)
2103 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2104 new_lp
->status
= status
;
2113 if (event
== PTRACE_EVENT_EXEC
)
2115 if (debug_linux_nat
)
2116 fprintf_unfiltered (gdb_stdlog
,
2117 "LHEW: Got exec event from LWP %ld\n",
2118 ptid_get_lwp (lp
->ptid
));
2120 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2121 ourstatus
->value
.execd_pathname
2122 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2124 /* The thread that execed must have been resumed, but, when a
2125 thread execs, it changes its tid to the tgid, and the old
2126 tgid thread might have not been resumed. */
2131 if (event
== PTRACE_EVENT_VFORK_DONE
)
2133 if (current_inferior ()->waiting_for_vfork_done
)
2135 if (debug_linux_nat
)
2136 fprintf_unfiltered (gdb_stdlog
,
2137 "LHEW: Got expected PTRACE_EVENT_"
2138 "VFORK_DONE from LWP %ld: stopping\n",
2139 ptid_get_lwp (lp
->ptid
));
2141 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2145 if (debug_linux_nat
)
2146 fprintf_unfiltered (gdb_stdlog
,
2147 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2148 "from LWP %ld: ignoring\n",
2149 ptid_get_lwp (lp
->ptid
));
2153 internal_error (__FILE__
, __LINE__
,
2154 _("unknown ptrace event %d"), event
);
2157 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2161 wait_lwp (struct lwp_info
*lp
)
2165 int thread_dead
= 0;
2168 gdb_assert (!lp
->stopped
);
2169 gdb_assert (lp
->status
== 0);
2171 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2172 block_child_signals (&prev_mask
);
2176 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2177 if (pid
== -1 && errno
== ECHILD
)
2179 /* The thread has previously exited. We need to delete it
2180 now because if this was a non-leader thread execing, we
2181 won't get an exit event. See comments on exec events at
2182 the top of the file. */
2184 if (debug_linux_nat
)
2185 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2186 target_pid_to_str (lp
->ptid
));
2191 /* Bugs 10970, 12702.
2192 Thread group leader may have exited in which case we'll lock up in
2193 waitpid if there are other threads, even if they are all zombies too.
2194 Basically, we're not supposed to use waitpid this way.
2195 tkill(pid,0) cannot be used here as it gets ESRCH for both
2196 for zombie and running processes.
2198 As a workaround, check if we're waiting for the thread group leader and
2199 if it's a zombie, and avoid calling waitpid if it is.
2201 This is racy, what if the tgl becomes a zombie right after we check?
2202 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2203 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2205 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2206 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2209 if (debug_linux_nat
)
2210 fprintf_unfiltered (gdb_stdlog
,
2211 "WL: Thread group leader %s vanished.\n",
2212 target_pid_to_str (lp
->ptid
));
2216 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2217 get invoked despite our caller had them intentionally blocked by
2218 block_child_signals. This is sensitive only to the loop of
2219 linux_nat_wait_1 and there if we get called my_waitpid gets called
2220 again before it gets to sigsuspend so we can safely let the handlers
2221 get executed here. */
2223 if (debug_linux_nat
)
2224 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2225 sigsuspend (&suspend_mask
);
2228 restore_child_signals_mask (&prev_mask
);
2232 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2234 if (debug_linux_nat
)
2236 fprintf_unfiltered (gdb_stdlog
,
2237 "WL: waitpid %s received %s\n",
2238 target_pid_to_str (lp
->ptid
),
2239 status_to_str (status
));
2242 /* Check if the thread has exited. */
2243 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2245 if (report_thread_events
2246 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2248 if (debug_linux_nat
)
2249 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2250 ptid_get_pid (lp
->ptid
));
2252 /* If this is the leader exiting, it means the whole
2253 process is gone. Store the status to report to the
2254 core. Store it in lp->waitstatus, because lp->status
2255 would be ambiguous (W_EXITCODE(0,0) == 0). */
2256 store_waitstatus (&lp
->waitstatus
, status
);
2261 if (debug_linux_nat
)
2262 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2263 target_pid_to_str (lp
->ptid
));
2273 gdb_assert (WIFSTOPPED (status
));
2276 if (lp
->must_set_ptrace_flags
)
2278 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2279 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2281 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2282 lp
->must_set_ptrace_flags
= 0;
2285 /* Handle GNU/Linux's syscall SIGTRAPs. */
2286 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2288 /* No longer need the sysgood bit. The ptrace event ends up
2289 recorded in lp->waitstatus if we care for it. We can carry
2290 on handling the event like a regular SIGTRAP from here
2292 status
= W_STOPCODE (SIGTRAP
);
2293 if (linux_handle_syscall_trap (lp
, 1))
2294 return wait_lwp (lp
);
2298 /* Almost all other ptrace-stops are known to be outside of system
2299 calls, with further exceptions in linux_handle_extended_wait. */
2300 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2303 /* Handle GNU/Linux's extended waitstatus for trace events. */
2304 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2305 && linux_is_extended_waitstatus (status
))
2307 if (debug_linux_nat
)
2308 fprintf_unfiltered (gdb_stdlog
,
2309 "WL: Handling extended status 0x%06x\n",
2311 linux_handle_extended_wait (lp
, status
);
2318 /* Send a SIGSTOP to LP. */
2321 stop_callback (struct lwp_info
*lp
, void *data
)
2323 if (!lp
->stopped
&& !lp
->signalled
)
2327 if (debug_linux_nat
)
2329 fprintf_unfiltered (gdb_stdlog
,
2330 "SC: kill %s **<SIGSTOP>**\n",
2331 target_pid_to_str (lp
->ptid
));
2334 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2335 if (debug_linux_nat
)
2337 fprintf_unfiltered (gdb_stdlog
,
2338 "SC: lwp kill %d %s\n",
2340 errno
? safe_strerror (errno
) : "ERRNO-OK");
2344 gdb_assert (lp
->status
== 0);
2350 /* Request a stop on LWP. */
2353 linux_stop_lwp (struct lwp_info
*lwp
)
2355 stop_callback (lwp
, NULL
);
2358 /* See linux-nat.h */
2361 linux_stop_and_wait_all_lwps (void)
2363 /* Stop all LWP's ... */
2364 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2366 /* ... and wait until all of them have reported back that
2367 they're no longer running. */
2368 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2371 /* See linux-nat.h */
2374 linux_unstop_all_lwps (void)
2376 iterate_over_lwps (minus_one_ptid
,
2377 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2380 /* Return non-zero if LWP PID has a pending SIGINT. */
2383 linux_nat_has_pending_sigint (int pid
)
2385 sigset_t pending
, blocked
, ignored
;
2387 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2389 if (sigismember (&pending
, SIGINT
)
2390 && !sigismember (&ignored
, SIGINT
))
2396 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2399 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2401 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2402 flag to consume the next one. */
2403 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2404 && WSTOPSIG (lp
->status
) == SIGINT
)
2407 lp
->ignore_sigint
= 1;
2412 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2413 This function is called after we know the LWP has stopped; if the LWP
2414 stopped before the expected SIGINT was delivered, then it will never have
2415 arrived. Also, if the signal was delivered to a shared queue and consumed
2416 by a different thread, it will never be delivered to this LWP. */
2419 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2421 if (!lp
->ignore_sigint
)
2424 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2426 if (debug_linux_nat
)
2427 fprintf_unfiltered (gdb_stdlog
,
2428 "MCIS: Clearing bogus flag for %s\n",
2429 target_pid_to_str (lp
->ptid
));
2430 lp
->ignore_sigint
= 0;
2434 /* Fetch the possible triggered data watchpoint info and store it in
2437 On some archs, like x86, that use debug registers to set
2438 watchpoints, it's possible that the way to know which watched
2439 address trapped, is to check the register that is used to select
2440 which address to watch. Problem is, between setting the watchpoint
2441 and reading back which data address trapped, the user may change
2442 the set of watchpoints, and, as a consequence, GDB changes the
2443 debug registers in the inferior. To avoid reading back a stale
2444 stopped-data-address when that happens, we cache in LP the fact
2445 that a watchpoint trapped, and the corresponding data address, as
2446 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2447 registers meanwhile, we have the cached data we can rely on. */
2450 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2452 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2455 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
2456 inferior_ptid
= lp
->ptid
;
2458 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2460 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2462 if (linux_ops
->to_stopped_data_address
!= NULL
)
2463 lp
->stopped_data_address_p
=
2464 linux_ops
->to_stopped_data_address (¤t_target
,
2465 &lp
->stopped_data_address
);
2467 lp
->stopped_data_address_p
= 0;
2470 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2473 /* Returns true if the LWP had stopped for a watchpoint. */
2476 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2478 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2480 gdb_assert (lp
!= NULL
);
2482 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2486 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2488 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2490 gdb_assert (lp
!= NULL
);
2492 *addr_p
= lp
->stopped_data_address
;
2494 return lp
->stopped_data_address_p
;
2497 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2500 sigtrap_is_event (int status
)
2502 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2505 /* Set alternative SIGTRAP-like events recognizer. If
2506 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2510 linux_nat_set_status_is_event (struct target_ops
*t
,
2511 int (*status_is_event
) (int status
))
2513 linux_nat_status_is_event
= status_is_event
;
2516 /* Wait until LP is stopped. */
2519 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2521 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2523 /* If this is a vfork parent, bail out, it is not going to report
2524 any SIGSTOP until the vfork is done with. */
2525 if (inf
->vfork_child
!= NULL
)
2532 status
= wait_lwp (lp
);
2536 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2537 && WSTOPSIG (status
) == SIGINT
)
2539 lp
->ignore_sigint
= 0;
2542 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2544 if (debug_linux_nat
)
2545 fprintf_unfiltered (gdb_stdlog
,
2546 "PTRACE_CONT %s, 0, 0 (%s) "
2547 "(discarding SIGINT)\n",
2548 target_pid_to_str (lp
->ptid
),
2549 errno
? safe_strerror (errno
) : "OK");
2551 return stop_wait_callback (lp
, NULL
);
2554 maybe_clear_ignore_sigint (lp
);
2556 if (WSTOPSIG (status
) != SIGSTOP
)
2558 /* The thread was stopped with a signal other than SIGSTOP. */
2560 if (debug_linux_nat
)
2561 fprintf_unfiltered (gdb_stdlog
,
2562 "SWC: Pending event %s in %s\n",
2563 status_to_str ((int) status
),
2564 target_pid_to_str (lp
->ptid
));
2566 /* Save the sigtrap event. */
2567 lp
->status
= status
;
2568 gdb_assert (lp
->signalled
);
2569 save_stop_reason (lp
);
2573 /* We caught the SIGSTOP that we intended to catch, so
2574 there's no SIGSTOP pending. */
2576 if (debug_linux_nat
)
2577 fprintf_unfiltered (gdb_stdlog
,
2578 "SWC: Expected SIGSTOP caught for %s.\n",
2579 target_pid_to_str (lp
->ptid
));
2581 /* Reset SIGNALLED only after the stop_wait_callback call
2582 above as it does gdb_assert on SIGNALLED. */
2590 /* Return non-zero if LP has a wait status pending. Discard the
2591 pending event and resume the LWP if the event that originally
2592 caused the stop became uninteresting. */
2595 status_callback (struct lwp_info
*lp
, void *data
)
2597 /* Only report a pending wait status if we pretend that this has
2598 indeed been resumed. */
2602 if (!lwp_status_pending_p (lp
))
2605 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2606 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2608 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2612 pc
= regcache_read_pc (regcache
);
2614 if (pc
!= lp
->stop_pc
)
2616 if (debug_linux_nat
)
2617 fprintf_unfiltered (gdb_stdlog
,
2618 "SC: PC of %s changed. was=%s, now=%s\n",
2619 target_pid_to_str (lp
->ptid
),
2620 paddress (target_gdbarch (), lp
->stop_pc
),
2621 paddress (target_gdbarch (), pc
));
2625 #if !USE_SIGTRAP_SIGINFO
2626 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
2628 if (debug_linux_nat
)
2629 fprintf_unfiltered (gdb_stdlog
,
2630 "SC: previous breakpoint of %s, at %s gone\n",
2631 target_pid_to_str (lp
->ptid
),
2632 paddress (target_gdbarch (), lp
->stop_pc
));
2640 if (debug_linux_nat
)
2641 fprintf_unfiltered (gdb_stdlog
,
2642 "SC: pending event of %s cancelled.\n",
2643 target_pid_to_str (lp
->ptid
));
2646 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2654 /* Count the LWP's that have had events. */
2657 count_events_callback (struct lwp_info
*lp
, void *data
)
2659 int *count
= (int *) data
;
2661 gdb_assert (count
!= NULL
);
2663 /* Select only resumed LWPs that have an event pending. */
2664 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2670 /* Select the LWP (if any) that is currently being single-stepped. */
2673 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2675 if (lp
->last_resume_kind
== resume_step
2682 /* Returns true if LP has a status pending. */
2685 lwp_status_pending_p (struct lwp_info
*lp
)
2687 /* We check for lp->waitstatus in addition to lp->status, because we
2688 can have pending process exits recorded in lp->status and
2689 W_EXITCODE(0,0) happens to be 0. */
2690 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2693 /* Select the Nth LWP that has had an event. */
2696 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2698 int *selector
= (int *) data
;
2700 gdb_assert (selector
!= NULL
);
2702 /* Select only resumed LWPs that have an event pending. */
2703 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2704 if ((*selector
)-- == 0)
2710 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2711 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2712 and save the result in the LWP's stop_reason field. If it stopped
2713 for a breakpoint, decrement the PC if necessary on the lwp's
2717 save_stop_reason (struct lwp_info
*lp
)
2719 struct regcache
*regcache
;
2720 struct gdbarch
*gdbarch
;
2723 #if USE_SIGTRAP_SIGINFO
2727 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2728 gdb_assert (lp
->status
!= 0);
2730 if (!linux_nat_status_is_event (lp
->status
))
2733 regcache
= get_thread_regcache (lp
->ptid
);
2734 gdbarch
= regcache
->arch ();
2736 pc
= regcache_read_pc (regcache
);
2737 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2739 #if USE_SIGTRAP_SIGINFO
2740 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2742 if (siginfo
.si_signo
== SIGTRAP
)
2744 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2745 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2747 /* The si_code is ambiguous on this arch -- check debug
2749 if (!check_stopped_by_watchpoint (lp
))
2750 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2752 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2754 /* If we determine the LWP stopped for a SW breakpoint,
2755 trust it. Particularly don't check watchpoint
2756 registers, because at least on s390, we'd find
2757 stopped-by-watchpoint as long as there's a watchpoint
2759 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2761 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2763 /* This can indicate either a hardware breakpoint or
2764 hardware watchpoint. Check debug registers. */
2765 if (!check_stopped_by_watchpoint (lp
))
2766 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2768 else if (siginfo
.si_code
== TRAP_TRACE
)
2770 if (debug_linux_nat
)
2771 fprintf_unfiltered (gdb_stdlog
,
2772 "CSBB: %s stopped by trace\n",
2773 target_pid_to_str (lp
->ptid
));
2775 /* We may have single stepped an instruction that
2776 triggered a watchpoint. In that case, on some
2777 architectures (such as x86), instead of TRAP_HWBKPT,
2778 si_code indicates TRAP_TRACE, and we need to check
2779 the debug registers separately. */
2780 check_stopped_by_watchpoint (lp
);
2785 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2786 && software_breakpoint_inserted_here_p (regcache
->aspace (),
2789 /* The LWP was either continued, or stepped a software
2790 breakpoint instruction. */
2791 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2794 if (hardware_breakpoint_inserted_here_p (regcache
->aspace (), pc
))
2795 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2797 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2798 check_stopped_by_watchpoint (lp
);
2801 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2803 if (debug_linux_nat
)
2804 fprintf_unfiltered (gdb_stdlog
,
2805 "CSBB: %s stopped by software breakpoint\n",
2806 target_pid_to_str (lp
->ptid
));
2808 /* Back up the PC if necessary. */
2810 regcache_write_pc (regcache
, sw_bp_pc
);
2812 /* Update this so we record the correct stop PC below. */
2815 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2817 if (debug_linux_nat
)
2818 fprintf_unfiltered (gdb_stdlog
,
2819 "CSBB: %s stopped by hardware breakpoint\n",
2820 target_pid_to_str (lp
->ptid
));
2822 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2824 if (debug_linux_nat
)
2825 fprintf_unfiltered (gdb_stdlog
,
2826 "CSBB: %s stopped by hardware watchpoint\n",
2827 target_pid_to_str (lp
->ptid
));
2834 /* Returns true if the LWP had stopped for a software breakpoint. */
2837 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2839 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2841 gdb_assert (lp
!= NULL
);
2843 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2846 /* Implement the supports_stopped_by_sw_breakpoint method. */
2849 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2851 return USE_SIGTRAP_SIGINFO
;
2854 /* Returns true if the LWP had stopped for a hardware
2855 breakpoint/watchpoint. */
2858 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2860 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2862 gdb_assert (lp
!= NULL
);
2864 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2867 /* Implement the supports_stopped_by_hw_breakpoint method. */
2870 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2872 return USE_SIGTRAP_SIGINFO
;
2875 /* Select one LWP out of those that have events pending. */
2878 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2881 int random_selector
;
2882 struct lwp_info
*event_lp
= NULL
;
2884 /* Record the wait status for the original LWP. */
2885 (*orig_lp
)->status
= *status
;
2887 /* In all-stop, give preference to the LWP that is being
2888 single-stepped. There will be at most one, and it will be the
2889 LWP that the core is most interested in. If we didn't do this,
2890 then we'd have to handle pending step SIGTRAPs somehow in case
2891 the core later continues the previously-stepped thread, as
2892 otherwise we'd report the pending SIGTRAP then, and the core, not
2893 having stepped the thread, wouldn't understand what the trap was
2894 for, and therefore would report it to the user as a random
2896 if (!target_is_non_stop_p ())
2898 event_lp
= iterate_over_lwps (filter
,
2899 select_singlestep_lwp_callback
, NULL
);
2900 if (event_lp
!= NULL
)
2902 if (debug_linux_nat
)
2903 fprintf_unfiltered (gdb_stdlog
,
2904 "SEL: Select single-step %s\n",
2905 target_pid_to_str (event_lp
->ptid
));
2909 if (event_lp
== NULL
)
2911 /* Pick one at random, out of those which have had events. */
2913 /* First see how many events we have. */
2914 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2915 gdb_assert (num_events
> 0);
2917 /* Now randomly pick a LWP out of those that have had
2919 random_selector
= (int)
2920 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2922 if (debug_linux_nat
&& num_events
> 1)
2923 fprintf_unfiltered (gdb_stdlog
,
2924 "SEL: Found %d events, selecting #%d\n",
2925 num_events
, random_selector
);
2927 event_lp
= iterate_over_lwps (filter
,
2928 select_event_lwp_callback
,
2932 if (event_lp
!= NULL
)
2934 /* Switch the event LWP. */
2935 *orig_lp
= event_lp
;
2936 *status
= event_lp
->status
;
2939 /* Flush the wait status for the event LWP. */
2940 (*orig_lp
)->status
= 0;
2943 /* Return non-zero if LP has been resumed. */
2946 resumed_callback (struct lwp_info
*lp
, void *data
)
2951 /* Check if we should go on and pass this event to common code.
2952 Return the affected lwp if we are, or NULL otherwise. */
2954 static struct lwp_info
*
2955 linux_nat_filter_event (int lwpid
, int status
)
2957 struct lwp_info
*lp
;
2958 int event
= linux_ptrace_get_extended_event (status
);
2960 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2962 /* Check for stop events reported by a process we didn't already
2963 know about - anything not already in our LWP list.
2965 If we're expecting to receive stopped processes after
2966 fork, vfork, and clone events, then we'll just add the
2967 new one to our list and go back to waiting for the event
2968 to be reported - the stopped process might be returned
2969 from waitpid before or after the event is.
2971 But note the case of a non-leader thread exec'ing after the
2972 leader having exited, and gone from our lists. The non-leader
2973 thread changes its tid to the tgid. */
2975 if (WIFSTOPPED (status
) && lp
== NULL
2976 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2978 /* A multi-thread exec after we had seen the leader exiting. */
2979 if (debug_linux_nat
)
2980 fprintf_unfiltered (gdb_stdlog
,
2981 "LLW: Re-adding thread group leader LWP %d.\n",
2984 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2987 add_thread (lp
->ptid
);
2990 if (WIFSTOPPED (status
) && !lp
)
2992 if (debug_linux_nat
)
2993 fprintf_unfiltered (gdb_stdlog
,
2994 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2995 (long) lwpid
, status_to_str (status
));
2996 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3000 /* Make sure we don't report an event for the exit of an LWP not in
3001 our list, i.e. not part of the current process. This can happen
3002 if we detach from a program we originally forked and then it
3004 if (!WIFSTOPPED (status
) && !lp
)
3007 /* This LWP is stopped now. (And if dead, this prevents it from
3008 ever being continued.) */
3011 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
3013 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
3014 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
3016 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
3017 lp
->must_set_ptrace_flags
= 0;
3020 /* Handle GNU/Linux's syscall SIGTRAPs. */
3021 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3023 /* No longer need the sysgood bit. The ptrace event ends up
3024 recorded in lp->waitstatus if we care for it. We can carry
3025 on handling the event like a regular SIGTRAP from here
3027 status
= W_STOPCODE (SIGTRAP
);
3028 if (linux_handle_syscall_trap (lp
, 0))
3033 /* Almost all other ptrace-stops are known to be outside of system
3034 calls, with further exceptions in linux_handle_extended_wait. */
3035 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
3038 /* Handle GNU/Linux's extended waitstatus for trace events. */
3039 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
3040 && linux_is_extended_waitstatus (status
))
3042 if (debug_linux_nat
)
3043 fprintf_unfiltered (gdb_stdlog
,
3044 "LLW: Handling extended status 0x%06x\n",
3046 if (linux_handle_extended_wait (lp
, status
))
3050 /* Check if the thread has exited. */
3051 if (WIFEXITED (status
) || WIFSIGNALED (status
))
3053 if (!report_thread_events
3054 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3056 if (debug_linux_nat
)
3057 fprintf_unfiltered (gdb_stdlog
,
3058 "LLW: %s exited.\n",
3059 target_pid_to_str (lp
->ptid
));
3061 /* If there is at least one more LWP, then the exit signal
3062 was not the end of the debugged application and should be
3068 /* Note that even if the leader was ptrace-stopped, it can still
3069 exit, if e.g., some other thread brings down the whole
3070 process (calls `exit'). So don't assert that the lwp is
3072 if (debug_linux_nat
)
3073 fprintf_unfiltered (gdb_stdlog
,
3074 "LWP %ld exited (resumed=%d)\n",
3075 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3077 /* Dead LWP's aren't expected to reported a pending sigstop. */
3080 /* Store the pending event in the waitstatus, because
3081 W_EXITCODE(0,0) == 0. */
3082 store_waitstatus (&lp
->waitstatus
, status
);
3086 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3087 an attempt to stop an LWP. */
3089 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3093 if (lp
->last_resume_kind
== resume_stop
)
3095 if (debug_linux_nat
)
3096 fprintf_unfiltered (gdb_stdlog
,
3097 "LLW: resume_stop SIGSTOP caught for %s.\n",
3098 target_pid_to_str (lp
->ptid
));
3102 /* This is a delayed SIGSTOP. Filter out the event. */
3104 if (debug_linux_nat
)
3105 fprintf_unfiltered (gdb_stdlog
,
3106 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3108 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3109 target_pid_to_str (lp
->ptid
));
3111 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3112 gdb_assert (lp
->resumed
);
3117 /* Make sure we don't report a SIGINT that we have already displayed
3118 for another thread. */
3119 if (lp
->ignore_sigint
3120 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3122 if (debug_linux_nat
)
3123 fprintf_unfiltered (gdb_stdlog
,
3124 "LLW: Delayed SIGINT caught for %s.\n",
3125 target_pid_to_str (lp
->ptid
));
3127 /* This is a delayed SIGINT. */
3128 lp
->ignore_sigint
= 0;
3130 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3131 if (debug_linux_nat
)
3132 fprintf_unfiltered (gdb_stdlog
,
3133 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3135 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3136 target_pid_to_str (lp
->ptid
));
3137 gdb_assert (lp
->resumed
);
3139 /* Discard the event. */
3143 /* Don't report signals that GDB isn't interested in, such as
3144 signals that are neither printed nor stopped upon. Stopping all
3145 threads can be a bit time-consuming so if we want decent
3146 performance with heavily multi-threaded programs, especially when
3147 they're using a high frequency timer, we'd better avoid it if we
3149 if (WIFSTOPPED (status
))
3151 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3153 if (!target_is_non_stop_p ())
3155 /* Only do the below in all-stop, as we currently use SIGSTOP
3156 to implement target_stop (see linux_nat_stop) in
3158 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3160 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3161 forwarded to the entire process group, that is, all LWPs
3162 will receive it - unless they're using CLONE_THREAD to
3163 share signals. Since we only want to report it once, we
3164 mark it as ignored for all LWPs except this one. */
3165 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3166 set_ignore_sigint
, NULL
);
3167 lp
->ignore_sigint
= 0;
3170 maybe_clear_ignore_sigint (lp
);
3173 /* When using hardware single-step, we need to report every signal.
3174 Otherwise, signals in pass_mask may be short-circuited
3175 except signals that might be caused by a breakpoint. */
3177 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3178 && !linux_wstatus_maybe_breakpoint (status
))
3180 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3181 if (debug_linux_nat
)
3182 fprintf_unfiltered (gdb_stdlog
,
3183 "LLW: %s %s, %s (preempt 'handle')\n",
3185 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3186 target_pid_to_str (lp
->ptid
),
3187 (signo
!= GDB_SIGNAL_0
3188 ? strsignal (gdb_signal_to_host (signo
))
3194 /* An interesting event. */
3196 lp
->status
= status
;
3197 save_stop_reason (lp
);
3201 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3202 their exits until all other threads in the group have exited. */
3205 check_zombie_leaders (void)
3207 struct inferior
*inf
;
3211 struct lwp_info
*leader_lp
;
3216 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3217 if (leader_lp
!= NULL
3218 /* Check if there are other threads in the group, as we may
3219 have raced with the inferior simply exiting. */
3220 && num_lwps (inf
->pid
) > 1
3221 && linux_proc_pid_is_zombie (inf
->pid
))
3223 if (debug_linux_nat
)
3224 fprintf_unfiltered (gdb_stdlog
,
3225 "CZL: Thread group leader %d zombie "
3226 "(it exited, or another thread execd).\n",
3229 /* A leader zombie can mean one of two things:
3231 - It exited, and there's an exit status pending
3232 available, or only the leader exited (not the whole
3233 program). In the latter case, we can't waitpid the
3234 leader's exit status until all other threads are gone.
3236 - There are 3 or more threads in the group, and a thread
3237 other than the leader exec'd. See comments on exec
3238 events at the top of the file. We could try
3239 distinguishing the exit and exec cases, by waiting once
3240 more, and seeing if something comes out, but it doesn't
3241 sound useful. The previous leader _does_ go away, and
3242 we'll re-add the new one once we see the exec event
3243 (which is just the same as what would happen if the
3244 previous leader did exit voluntarily before some other
3247 if (debug_linux_nat
)
3248 fprintf_unfiltered (gdb_stdlog
,
3249 "CZL: Thread group leader %d vanished.\n",
3251 exit_lwp (leader_lp
);
3256 /* Convenience function that is called when the kernel reports an exit
3257 event. This decides whether to report the event to GDB as a
3258 process exit event, a thread exit event, or to suppress the
3262 filter_exit_event (struct lwp_info
*event_child
,
3263 struct target_waitstatus
*ourstatus
)
3265 ptid_t ptid
= event_child
->ptid
;
3267 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3269 if (report_thread_events
)
3270 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3272 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3274 exit_lwp (event_child
);
3281 linux_nat_wait_1 (struct target_ops
*ops
,
3282 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3286 enum resume_kind last_resume_kind
;
3287 struct lwp_info
*lp
;
3290 if (debug_linux_nat
)
3291 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3293 /* The first time we get here after starting a new inferior, we may
3294 not have added it to the LWP list yet - this is the earliest
3295 moment at which we know its PID. */
3296 if (ptid_is_pid (inferior_ptid
))
3298 /* Upgrade the main thread's ptid. */
3299 thread_change_ptid (inferior_ptid
,
3300 ptid_build (ptid_get_pid (inferior_ptid
),
3301 ptid_get_pid (inferior_ptid
), 0));
3303 lp
= add_initial_lwp (inferior_ptid
);
3307 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3308 block_child_signals (&prev_mask
);
3310 /* First check if there is a LWP with a wait status pending. */
3311 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3314 if (debug_linux_nat
)
3315 fprintf_unfiltered (gdb_stdlog
,
3316 "LLW: Using pending wait status %s for %s.\n",
3317 status_to_str (lp
->status
),
3318 target_pid_to_str (lp
->ptid
));
3321 /* But if we don't find a pending event, we'll have to wait. Always
3322 pull all events out of the kernel. We'll randomly select an
3323 event LWP out of all that have events, to prevent starvation. */
3329 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3332 - If the thread group leader exits while other threads in the
3333 thread group still exist, waitpid(TGID, ...) hangs. That
3334 waitpid won't return an exit status until the other threads
3335 in the group are reapped.
3337 - When a non-leader thread execs, that thread just vanishes
3338 without reporting an exit (so we'd hang if we waited for it
3339 explicitly in that case). The exec event is reported to
3343 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3345 if (debug_linux_nat
)
3346 fprintf_unfiltered (gdb_stdlog
,
3347 "LNW: waitpid(-1, ...) returned %d, %s\n",
3348 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3352 if (debug_linux_nat
)
3354 fprintf_unfiltered (gdb_stdlog
,
3355 "LLW: waitpid %ld received %s\n",
3356 (long) lwpid
, status_to_str (status
));
3359 linux_nat_filter_event (lwpid
, status
);
3360 /* Retry until nothing comes out of waitpid. A single
3361 SIGCHLD can indicate more than one child stopped. */
3365 /* Now that we've pulled all events out of the kernel, resume
3366 LWPs that don't have an interesting event to report. */
3367 iterate_over_lwps (minus_one_ptid
,
3368 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3370 /* ... and find an LWP with a status to report to the core, if
3372 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3376 /* Check for zombie thread group leaders. Those can't be reaped
3377 until all other threads in the thread group are. */
3378 check_zombie_leaders ();
3380 /* If there are no resumed children left, bail. We'd be stuck
3381 forever in the sigsuspend call below otherwise. */
3382 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3384 if (debug_linux_nat
)
3385 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3387 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3389 restore_child_signals_mask (&prev_mask
);
3390 return minus_one_ptid
;
3393 /* No interesting event to report to the core. */
3395 if (target_options
& TARGET_WNOHANG
)
3397 if (debug_linux_nat
)
3398 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3400 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3401 restore_child_signals_mask (&prev_mask
);
3402 return minus_one_ptid
;
3405 /* We shouldn't end up here unless we want to try again. */
3406 gdb_assert (lp
== NULL
);
3408 /* Block until we get an event reported with SIGCHLD. */
3409 if (debug_linux_nat
)
3410 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3411 sigsuspend (&suspend_mask
);
3416 status
= lp
->status
;
3419 if (!target_is_non_stop_p ())
3421 /* Now stop all other LWP's ... */
3422 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3424 /* ... and wait until all of them have reported back that
3425 they're no longer running. */
3426 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3429 /* If we're not waiting for a specific LWP, choose an event LWP from
3430 among those that have had events. Giving equal priority to all
3431 LWPs that have had events helps prevent starvation. */
3432 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3433 select_event_lwp (ptid
, &lp
, &status
);
3435 gdb_assert (lp
!= NULL
);
3437 /* Now that we've selected our final event LWP, un-adjust its PC if
3438 it was a software breakpoint, and we can't reliably support the
3439 "stopped by software breakpoint" stop reason. */
3440 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3441 && !USE_SIGTRAP_SIGINFO
)
3443 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3444 struct gdbarch
*gdbarch
= regcache
->arch ();
3445 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3451 pc
= regcache_read_pc (regcache
);
3452 regcache_write_pc (regcache
, pc
+ decr_pc
);
3456 /* We'll need this to determine whether to report a SIGSTOP as
3457 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3459 last_resume_kind
= lp
->last_resume_kind
;
3461 if (!target_is_non_stop_p ())
3463 /* In all-stop, from the core's perspective, all LWPs are now
3464 stopped until a new resume action is sent over. */
3465 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3469 resume_clear_callback (lp
, NULL
);
3472 if (linux_nat_status_is_event (status
))
3474 if (debug_linux_nat
)
3475 fprintf_unfiltered (gdb_stdlog
,
3476 "LLW: trap ptid is %s.\n",
3477 target_pid_to_str (lp
->ptid
));
3480 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3482 *ourstatus
= lp
->waitstatus
;
3483 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3486 store_waitstatus (ourstatus
, status
);
3488 if (debug_linux_nat
)
3489 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3491 restore_child_signals_mask (&prev_mask
);
3493 if (last_resume_kind
== resume_stop
3494 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3495 && WSTOPSIG (status
) == SIGSTOP
)
3497 /* A thread that has been requested to stop by GDB with
3498 target_stop, and it stopped cleanly, so report as SIG0. The
3499 use of SIGSTOP is an implementation detail. */
3500 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3503 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3504 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3507 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3509 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3510 return filter_exit_event (lp
, ourstatus
);
3515 /* Resume LWPs that are currently stopped without any pending status
3516 to report, but are resumed from the core's perspective. */
3519 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3521 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3525 if (debug_linux_nat
)
3526 fprintf_unfiltered (gdb_stdlog
,
3527 "RSRL: NOT resuming LWP %s, not stopped\n",
3528 target_pid_to_str (lp
->ptid
));
3530 else if (!lp
->resumed
)
3532 if (debug_linux_nat
)
3533 fprintf_unfiltered (gdb_stdlog
,
3534 "RSRL: NOT resuming LWP %s, not resumed\n",
3535 target_pid_to_str (lp
->ptid
));
3537 else if (lwp_status_pending_p (lp
))
3539 if (debug_linux_nat
)
3540 fprintf_unfiltered (gdb_stdlog
,
3541 "RSRL: NOT resuming LWP %s, has pending status\n",
3542 target_pid_to_str (lp
->ptid
));
3546 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3547 struct gdbarch
*gdbarch
= regcache
->arch ();
3551 CORE_ADDR pc
= regcache_read_pc (regcache
);
3552 int leave_stopped
= 0;
3554 /* Don't bother if there's a breakpoint at PC that we'd hit
3555 immediately, and we're not waiting for this LWP. */
3556 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3558 if (breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3564 if (debug_linux_nat
)
3565 fprintf_unfiltered (gdb_stdlog
,
3566 "RSRL: resuming stopped-resumed LWP %s at "
3568 target_pid_to_str (lp
->ptid
),
3569 paddress (gdbarch
, pc
),
3572 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3575 CATCH (ex
, RETURN_MASK_ERROR
)
3577 if (!check_ptrace_stopped_lwp_gone (lp
))
3578 throw_exception (ex
);
3587 linux_nat_wait (struct target_ops
*ops
,
3588 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3593 if (debug_linux_nat
)
3595 char *options_string
;
3597 options_string
= target_options_to_string (target_options
);
3598 fprintf_unfiltered (gdb_stdlog
,
3599 "linux_nat_wait: [%s], [%s]\n",
3600 target_pid_to_str (ptid
),
3602 xfree (options_string
);
3605 /* Flush the async file first. */
3606 if (target_is_async_p ())
3607 async_file_flush ();
3609 /* Resume LWPs that are currently stopped without any pending status
3610 to report, but are resumed from the core's perspective. LWPs get
3611 in this state if we find them stopping at a time we're not
3612 interested in reporting the event (target_wait on a
3613 specific_process, for example, see linux_nat_wait_1), and
3614 meanwhile the event became uninteresting. Don't bother resuming
3615 LWPs we're not going to wait for if they'd stop immediately. */
3616 if (target_is_non_stop_p ())
3617 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3619 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3621 /* If we requested any event, and something came out, assume there
3622 may be more. If we requested a specific lwp or process, also
3623 assume there may be more. */
3624 if (target_is_async_p ()
3625 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3626 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3627 || !ptid_equal (ptid
, minus_one_ptid
)))
3636 kill_one_lwp (pid_t pid
)
3638 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3641 kill_lwp (pid
, SIGKILL
);
3642 if (debug_linux_nat
)
3644 int save_errno
= errno
;
3646 fprintf_unfiltered (gdb_stdlog
,
3647 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3648 save_errno
? safe_strerror (save_errno
) : "OK");
3651 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3654 ptrace (PTRACE_KILL
, pid
, 0, 0);
3655 if (debug_linux_nat
)
3657 int save_errno
= errno
;
3659 fprintf_unfiltered (gdb_stdlog
,
3660 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3661 save_errno
? safe_strerror (save_errno
) : "OK");
3665 /* Wait for an LWP to die. */
3668 kill_wait_one_lwp (pid_t pid
)
3672 /* We must make sure that there are no pending events (delayed
3673 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3674 program doesn't interfere with any following debugging session. */
3678 res
= my_waitpid (pid
, NULL
, __WALL
);
3679 if (res
!= (pid_t
) -1)
3681 if (debug_linux_nat
)
3682 fprintf_unfiltered (gdb_stdlog
,
3683 "KWC: wait %ld received unknown.\n",
3685 /* The Linux kernel sometimes fails to kill a thread
3686 completely after PTRACE_KILL; that goes from the stop
3687 point in do_fork out to the one in get_signal_to_deliver
3688 and waits again. So kill it again. */
3694 gdb_assert (res
== -1 && errno
== ECHILD
);
3697 /* Callback for iterate_over_lwps. */
3700 kill_callback (struct lwp_info
*lp
, void *data
)
3702 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3706 /* Callback for iterate_over_lwps. */
3709 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3711 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3715 /* Kill the fork children of any threads of inferior INF that are
3716 stopped at a fork event. */
3719 kill_unfollowed_fork_children (struct inferior
*inf
)
3721 struct thread_info
*thread
;
3723 ALL_NON_EXITED_THREADS (thread
)
3724 if (thread
->inf
== inf
)
3726 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3728 if (ws
->kind
== TARGET_WAITKIND_FORKED
3729 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3731 ptid_t child_ptid
= ws
->value
.related_pid
;
3732 int child_pid
= ptid_get_pid (child_ptid
);
3733 int child_lwp
= ptid_get_lwp (child_ptid
);
3735 kill_one_lwp (child_lwp
);
3736 kill_wait_one_lwp (child_lwp
);
3738 /* Let the arch-specific native code know this process is
3740 linux_nat_forget_process (child_pid
);
3746 linux_nat_kill (struct target_ops
*ops
)
3748 /* If we're stopped while forking and we haven't followed yet,
3749 kill the other task. We need to do this first because the
3750 parent will be sleeping if this is a vfork. */
3751 kill_unfollowed_fork_children (current_inferior ());
3753 if (forks_exist_p ())
3754 linux_fork_killall ();
3757 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3759 /* Stop all threads before killing them, since ptrace requires
3760 that the thread is stopped to sucessfully PTRACE_KILL. */
3761 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3762 /* ... and wait until all of them have reported back that
3763 they're no longer running. */
3764 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3766 /* Kill all LWP's ... */
3767 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3769 /* ... and wait until we've flushed all events. */
3770 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3773 target_mourn_inferior (inferior_ptid
);
3777 linux_nat_mourn_inferior (struct target_ops
*ops
)
3779 int pid
= ptid_get_pid (inferior_ptid
);
3781 purge_lwp_list (pid
);
3783 if (! forks_exist_p ())
3784 /* Normal case, no other forks available. */
3785 linux_ops
->to_mourn_inferior (ops
);
3787 /* Multi-fork case. The current inferior_ptid has exited, but
3788 there are other viable forks to debug. Delete the exiting
3789 one and context-switch to the first available. */
3790 linux_fork_mourn_inferior ();
3792 /* Let the arch-specific native code know this process is gone. */
3793 linux_nat_forget_process (pid
);
3796 /* Convert a native/host siginfo object, into/from the siginfo in the
3797 layout of the inferiors' architecture. */
3800 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3804 if (linux_nat_siginfo_fixup
!= NULL
)
3805 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3807 /* If there was no callback, or the callback didn't do anything,
3808 then just do a straight memcpy. */
3812 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3814 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3818 static enum target_xfer_status
3819 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3820 const char *annex
, gdb_byte
*readbuf
,
3821 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3822 ULONGEST
*xfered_len
)
3826 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3828 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3829 gdb_assert (readbuf
|| writebuf
);
3831 pid
= ptid_get_lwp (inferior_ptid
);
3833 pid
= ptid_get_pid (inferior_ptid
);
3835 if (offset
> sizeof (siginfo
))
3836 return TARGET_XFER_E_IO
;
3839 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3841 return TARGET_XFER_E_IO
;
3843 /* When GDB is built as a 64-bit application, ptrace writes into
3844 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3845 inferior with a 64-bit GDB should look the same as debugging it
3846 with a 32-bit GDB, we need to convert it. GDB core always sees
3847 the converted layout, so any read/write will have to be done
3849 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3851 if (offset
+ len
> sizeof (siginfo
))
3852 len
= sizeof (siginfo
) - offset
;
3854 if (readbuf
!= NULL
)
3855 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3858 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3860 /* Convert back to ptrace layout before flushing it out. */
3861 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3864 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3866 return TARGET_XFER_E_IO
;
3870 return TARGET_XFER_OK
;
3873 static enum target_xfer_status
3874 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3875 const char *annex
, gdb_byte
*readbuf
,
3876 const gdb_byte
*writebuf
,
3877 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3879 enum target_xfer_status xfer
;
3881 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3882 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3883 offset
, len
, xfered_len
);
3885 /* The target is connected but no live inferior is selected. Pass
3886 this request down to a lower stratum (e.g., the executable
3888 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3889 return TARGET_XFER_EOF
;
3891 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3892 offset
, len
, xfered_len
);
3898 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3900 /* As long as a PTID is in lwp list, consider it alive. */
3901 return find_lwp_pid (ptid
) != NULL
;
3904 /* Implement the to_update_thread_list target method for this
3908 linux_nat_update_thread_list (struct target_ops
*ops
)
3910 struct lwp_info
*lwp
;
3912 /* We add/delete threads from the list as clone/exit events are
3913 processed, so just try deleting exited threads still in the
3915 delete_exited_threads ();
3917 /* Update the processor core that each lwp/thread was last seen
3921 /* Avoid accessing /proc if the thread hasn't run since we last
3922 time we fetched the thread's core. Accessing /proc becomes
3923 noticeably expensive when we have thousands of LWPs. */
3924 if (lwp
->core
== -1)
3925 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3930 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3932 static char buf
[64];
3934 if (ptid_lwp_p (ptid
)
3935 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3936 || num_lwps (ptid_get_pid (ptid
)) > 1))
3938 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3942 return normal_pid_to_str (ptid
);
3946 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3948 return linux_proc_tid_get_name (thr
->ptid
);
3951 /* Accepts an integer PID; Returns a string representing a file that
3952 can be opened to get the symbols for the child process. */
3955 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3957 return linux_proc_pid_to_exec_file (pid
);
3960 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3961 Because we can use a single read/write call, this can be much more
3962 efficient than banging away at PTRACE_PEEKTEXT. */
3964 static enum target_xfer_status
3965 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3966 const char *annex
, gdb_byte
*readbuf
,
3967 const gdb_byte
*writebuf
,
3968 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3974 if (object
!= TARGET_OBJECT_MEMORY
)
3975 return TARGET_XFER_EOF
;
3977 /* Don't bother for one word. */
3978 if (len
< 3 * sizeof (long))
3979 return TARGET_XFER_EOF
;
3981 /* We could keep this file open and cache it - possibly one per
3982 thread. That requires some juggling, but is even faster. */
3983 xsnprintf (filename
, sizeof filename
, "/proc/%ld/mem",
3984 ptid_get_lwp (inferior_ptid
));
3985 fd
= gdb_open_cloexec (filename
, ((readbuf
? O_RDONLY
: O_WRONLY
)
3988 return TARGET_XFER_EOF
;
3990 /* Use pread64/pwrite64 if available, since they save a syscall and can
3991 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
3992 debugging a SPARC64 application). */
3994 ret
= (readbuf
? pread64 (fd
, readbuf
, len
, offset
)
3995 : pwrite64 (fd
, writebuf
, len
, offset
));
3997 ret
= lseek (fd
, offset
, SEEK_SET
);
3999 ret
= (readbuf
? read (fd
, readbuf
, len
)
4000 : write (fd
, writebuf
, len
));
4005 if (ret
== -1 || ret
== 0)
4006 return TARGET_XFER_EOF
;
4010 return TARGET_XFER_OK
;
4015 /* Enumerate spufs IDs for process PID. */
4017 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
4019 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
4021 LONGEST written
= 0;
4024 struct dirent
*entry
;
4026 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4027 dir
= opendir (path
);
4032 while ((entry
= readdir (dir
)) != NULL
)
4038 fd
= atoi (entry
->d_name
);
4042 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4043 if (stat (path
, &st
) != 0)
4045 if (!S_ISDIR (st
.st_mode
))
4048 if (statfs (path
, &stfs
) != 0)
4050 if (stfs
.f_type
!= SPUFS_MAGIC
)
4053 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4055 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4065 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4066 object type, using the /proc file system. */
4068 static enum target_xfer_status
4069 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4070 const char *annex
, gdb_byte
*readbuf
,
4071 const gdb_byte
*writebuf
,
4072 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4077 int pid
= ptid_get_lwp (inferior_ptid
);
4082 return TARGET_XFER_E_IO
;
4085 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4088 return TARGET_XFER_E_IO
;
4090 return TARGET_XFER_EOF
;
4093 *xfered_len
= (ULONGEST
) l
;
4094 return TARGET_XFER_OK
;
4099 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4100 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4102 return TARGET_XFER_E_IO
;
4105 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4108 return TARGET_XFER_EOF
;
4112 ret
= write (fd
, writebuf
, (size_t) len
);
4114 ret
= read (fd
, readbuf
, (size_t) len
);
4119 return TARGET_XFER_E_IO
;
4121 return TARGET_XFER_EOF
;
4124 *xfered_len
= (ULONGEST
) ret
;
4125 return TARGET_XFER_OK
;
4130 /* Parse LINE as a signal set and add its set bits to SIGS. */
4133 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4135 int len
= strlen (line
) - 1;
4139 if (line
[len
] != '\n')
4140 error (_("Could not parse signal set: %s"), line
);
4148 if (*p
>= '0' && *p
<= '9')
4150 else if (*p
>= 'a' && *p
<= 'f')
4151 digit
= *p
- 'a' + 10;
4153 error (_("Could not parse signal set: %s"), line
);
4158 sigaddset (sigs
, signum
+ 1);
4160 sigaddset (sigs
, signum
+ 2);
4162 sigaddset (sigs
, signum
+ 3);
4164 sigaddset (sigs
, signum
+ 4);
4170 /* Find process PID's pending signals from /proc/pid/status and set
4174 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4175 sigset_t
*blocked
, sigset_t
*ignored
)
4177 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4179 sigemptyset (pending
);
4180 sigemptyset (blocked
);
4181 sigemptyset (ignored
);
4182 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4183 gdb_file_up procfile
= gdb_fopen_cloexec (fname
, "r");
4184 if (procfile
== NULL
)
4185 error (_("Could not open %s"), fname
);
4187 while (fgets (buffer
, PATH_MAX
, procfile
.get ()) != NULL
)
4189 /* Normal queued signals are on the SigPnd line in the status
4190 file. However, 2.6 kernels also have a "shared" pending
4191 queue for delivering signals to a thread group, so check for
4194 Unfortunately some Red Hat kernels include the shared pending
4195 queue but not the ShdPnd status field. */
4197 if (startswith (buffer
, "SigPnd:\t"))
4198 add_line_to_sigset (buffer
+ 8, pending
);
4199 else if (startswith (buffer
, "ShdPnd:\t"))
4200 add_line_to_sigset (buffer
+ 8, pending
);
4201 else if (startswith (buffer
, "SigBlk:\t"))
4202 add_line_to_sigset (buffer
+ 8, blocked
);
4203 else if (startswith (buffer
, "SigIgn:\t"))
4204 add_line_to_sigset (buffer
+ 8, ignored
);
4208 static enum target_xfer_status
4209 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4210 const char *annex
, gdb_byte
*readbuf
,
4211 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4212 ULONGEST
*xfered_len
)
4214 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4216 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4217 if (*xfered_len
== 0)
4218 return TARGET_XFER_EOF
;
4220 return TARGET_XFER_OK
;
4223 static enum target_xfer_status
4224 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4225 const char *annex
, gdb_byte
*readbuf
,
4226 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4227 ULONGEST
*xfered_len
)
4229 enum target_xfer_status xfer
;
4231 if (object
== TARGET_OBJECT_AUXV
)
4232 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4233 offset
, len
, xfered_len
);
4235 if (object
== TARGET_OBJECT_OSDATA
)
4236 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4237 offset
, len
, xfered_len
);
4239 if (object
== TARGET_OBJECT_SPU
)
4240 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4241 offset
, len
, xfered_len
);
4243 /* GDB calculates all the addresses in possibly larget width of the address.
4244 Address width needs to be masked before its final use - either by
4245 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4247 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4249 if (object
== TARGET_OBJECT_MEMORY
)
4251 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4253 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4254 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4257 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4258 offset
, len
, xfered_len
);
4259 if (xfer
!= TARGET_XFER_EOF
)
4262 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4263 offset
, len
, xfered_len
);
4267 cleanup_target_stop (void *arg
)
4269 ptid_t
*ptid
= (ptid_t
*) arg
;
4271 gdb_assert (arg
!= NULL
);
4274 target_continue_no_signal (*ptid
);
4277 static VEC(static_tracepoint_marker_p
) *
4278 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4281 char s
[IPA_CMD_BUF_SIZE
];
4282 struct cleanup
*old_chain
;
4283 int pid
= ptid_get_pid (inferior_ptid
);
4284 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4285 struct static_tracepoint_marker
*marker
= NULL
;
4287 ptid_t ptid
= ptid_build (pid
, 0, 0);
4292 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4293 s
[sizeof ("qTfSTM")] = 0;
4295 agent_run_command (pid
, s
, strlen (s
) + 1);
4297 old_chain
= make_cleanup (free_current_marker
, &marker
);
4298 make_cleanup (cleanup_target_stop
, &ptid
);
4303 marker
= XCNEW (struct static_tracepoint_marker
);
4307 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4309 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4311 VEC_safe_push (static_tracepoint_marker_p
,
4317 release_static_tracepoint_marker (marker
);
4318 memset (marker
, 0, sizeof (*marker
));
4321 while (*p
++ == ','); /* comma-separated list */
4323 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4324 s
[sizeof ("qTsSTM")] = 0;
4325 agent_run_command (pid
, s
, strlen (s
) + 1);
4329 do_cleanups (old_chain
);
4334 /* Create a prototype generic GNU/Linux target. The client can override
4335 it with local methods. */
4338 linux_target_install_ops (struct target_ops
*t
)
4340 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4341 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4342 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4343 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4344 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4345 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4346 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4347 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4348 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4349 t
->to_post_attach
= linux_child_post_attach
;
4350 t
->to_follow_fork
= linux_child_follow_fork
;
4352 super_xfer_partial
= t
->to_xfer_partial
;
4353 t
->to_xfer_partial
= linux_xfer_partial
;
4355 t
->to_static_tracepoint_markers_by_strid
4356 = linux_child_static_tracepoint_markers_by_strid
;
4362 struct target_ops
*t
;
4364 t
= inf_ptrace_target ();
4365 linux_target_install_ops (t
);
4371 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4373 struct target_ops
*t
;
4375 t
= inf_ptrace_trad_target (register_u_offset
);
4376 linux_target_install_ops (t
);
4381 /* target_is_async_p implementation. */
4384 linux_nat_is_async_p (struct target_ops
*ops
)
4386 return linux_is_async_p ();
4389 /* target_can_async_p implementation. */
4392 linux_nat_can_async_p (struct target_ops
*ops
)
4394 /* We're always async, unless the user explicitly prevented it with the
4395 "maint set target-async" command. */
4396 return target_async_permitted
;
4400 linux_nat_supports_non_stop (struct target_ops
*self
)
4405 /* to_always_non_stop_p implementation. */
4408 linux_nat_always_non_stop_p (struct target_ops
*self
)
4413 /* True if we want to support multi-process. To be removed when GDB
4414 supports multi-exec. */
4416 int linux_multi_process
= 1;
4419 linux_nat_supports_multi_process (struct target_ops
*self
)
4421 return linux_multi_process
;
4425 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4427 #ifdef HAVE_PERSONALITY
4434 static int async_terminal_is_ours
= 1;
4436 /* target_terminal_inferior implementation.
4438 This is a wrapper around child_terminal_inferior to add async support. */
4441 linux_nat_terminal_inferior (struct target_ops
*self
)
4443 child_terminal_inferior (self
);
4445 /* Calls to target_terminal_*() are meant to be idempotent. */
4446 if (!async_terminal_is_ours
)
4449 async_terminal_is_ours
= 0;
4453 /* target_terminal::ours implementation.
4455 This is a wrapper around child_terminal_ours to add async support (and
4456 implement the target_terminal::ours vs target_terminal::ours_for_output
4457 distinction). child_terminal_ours is currently no different than
4458 child_terminal_ours_for_output.
4459 We leave target_terminal::ours_for_output alone, leaving it to
4460 child_terminal_ours_for_output. */
4463 linux_nat_terminal_ours (struct target_ops
*self
)
4465 /* GDB should never give the terminal to the inferior if the
4466 inferior is running in the background (run&, continue&, etc.),
4467 but claiming it sure should. */
4468 child_terminal_ours (self
);
4470 if (async_terminal_is_ours
)
4473 clear_sigint_trap ();
4474 async_terminal_is_ours
= 1;
4477 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4478 so we notice when any child changes state, and notify the
4479 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4480 above to wait for the arrival of a SIGCHLD. */
4483 sigchld_handler (int signo
)
4485 int old_errno
= errno
;
4487 if (debug_linux_nat
)
4488 ui_file_write_async_safe (gdb_stdlog
,
4489 "sigchld\n", sizeof ("sigchld\n") - 1);
4491 if (signo
== SIGCHLD
4492 && linux_nat_event_pipe
[0] != -1)
4493 async_file_mark (); /* Let the event loop know that there are
4494 events to handle. */
4499 /* Callback registered with the target events file descriptor. */
4502 handle_target_event (int error
, gdb_client_data client_data
)
4504 inferior_event_handler (INF_REG_EVENT
, NULL
);
4507 /* Create/destroy the target events pipe. Returns previous state. */
4510 linux_async_pipe (int enable
)
4512 int previous
= linux_is_async_p ();
4514 if (previous
!= enable
)
4518 /* Block child signals while we create/destroy the pipe, as
4519 their handler writes to it. */
4520 block_child_signals (&prev_mask
);
4524 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4525 internal_error (__FILE__
, __LINE__
,
4526 "creating event pipe failed.");
4528 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4529 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4533 close (linux_nat_event_pipe
[0]);
4534 close (linux_nat_event_pipe
[1]);
4535 linux_nat_event_pipe
[0] = -1;
4536 linux_nat_event_pipe
[1] = -1;
4539 restore_child_signals_mask (&prev_mask
);
4545 /* target_async implementation. */
4548 linux_nat_async (struct target_ops
*ops
, int enable
)
4552 if (!linux_async_pipe (1))
4554 add_file_handler (linux_nat_event_pipe
[0],
4555 handle_target_event
, NULL
);
4556 /* There may be pending events to handle. Tell the event loop
4563 delete_file_handler (linux_nat_event_pipe
[0]);
4564 linux_async_pipe (0);
4569 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4573 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4577 if (debug_linux_nat
)
4578 fprintf_unfiltered (gdb_stdlog
,
4579 "LNSL: running -> suspending %s\n",
4580 target_pid_to_str (lwp
->ptid
));
4583 if (lwp
->last_resume_kind
== resume_stop
)
4585 if (debug_linux_nat
)
4586 fprintf_unfiltered (gdb_stdlog
,
4587 "linux-nat: already stopping LWP %ld at "
4589 ptid_get_lwp (lwp
->ptid
));
4593 stop_callback (lwp
, NULL
);
4594 lwp
->last_resume_kind
= resume_stop
;
4598 /* Already known to be stopped; do nothing. */
4600 if (debug_linux_nat
)
4602 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4603 fprintf_unfiltered (gdb_stdlog
,
4604 "LNSL: already stopped/stop_requested %s\n",
4605 target_pid_to_str (lwp
->ptid
));
4607 fprintf_unfiltered (gdb_stdlog
,
4608 "LNSL: already stopped/no "
4609 "stop_requested yet %s\n",
4610 target_pid_to_str (lwp
->ptid
));
4617 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4619 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4623 linux_nat_close (struct target_ops
*self
)
4625 /* Unregister from the event loop. */
4626 if (linux_nat_is_async_p (self
))
4627 linux_nat_async (self
, 0);
4629 if (linux_ops
->to_close
)
4630 linux_ops
->to_close (linux_ops
);
4635 /* When requests are passed down from the linux-nat layer to the
4636 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4637 used. The address space pointer is stored in the inferior object,
4638 but the common code that is passed such ptid can't tell whether
4639 lwpid is a "main" process id or not (it assumes so). We reverse
4640 look up the "main" process id from the lwp here. */
4642 static struct address_space
*
4643 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4645 struct lwp_info
*lwp
;
4646 struct inferior
*inf
;
4649 if (ptid_get_lwp (ptid
) == 0)
4651 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4653 lwp
= find_lwp_pid (ptid
);
4654 pid
= ptid_get_pid (lwp
->ptid
);
4658 /* A (pid,lwpid,0) ptid. */
4659 pid
= ptid_get_pid (ptid
);
4662 inf
= find_inferior_pid (pid
);
4663 gdb_assert (inf
!= NULL
);
4667 /* Return the cached value of the processor core for thread PTID. */
4670 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4672 struct lwp_info
*info
= find_lwp_pid (ptid
);
4679 /* Implementation of to_filesystem_is_local. */
4682 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4684 struct inferior
*inf
= current_inferior ();
4686 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4689 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4692 /* Convert the INF argument passed to a to_fileio_* method
4693 to a process ID suitable for passing to its corresponding
4694 linux_mntns_* function. If INF is non-NULL then the
4695 caller is requesting the filesystem seen by INF. If INF
4696 is NULL then the caller is requesting the filesystem seen
4697 by the GDB. We fall back to GDB's filesystem in the case
4698 that INF is non-NULL but its PID is unknown. */
4701 linux_nat_fileio_pid_of (struct inferior
*inf
)
4703 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4709 /* Implementation of to_fileio_open. */
4712 linux_nat_fileio_open (struct target_ops
*self
,
4713 struct inferior
*inf
, const char *filename
,
4714 int flags
, int mode
, int warn_if_slow
,
4721 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4722 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4724 *target_errno
= FILEIO_EINVAL
;
4728 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4729 filename
, nat_flags
, nat_mode
);
4731 *target_errno
= host_to_fileio_error (errno
);
4736 /* Implementation of to_fileio_readlink. */
4739 linux_nat_fileio_readlink (struct target_ops
*self
,
4740 struct inferior
*inf
, const char *filename
,
4747 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4748 filename
, buf
, sizeof (buf
));
4751 *target_errno
= host_to_fileio_error (errno
);
4755 ret
= (char *) xmalloc (len
+ 1);
4756 memcpy (ret
, buf
, len
);
4761 /* Implementation of to_fileio_unlink. */
4764 linux_nat_fileio_unlink (struct target_ops
*self
,
4765 struct inferior
*inf
, const char *filename
,
4770 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4773 *target_errno
= host_to_fileio_error (errno
);
4778 /* Implementation of the to_thread_events method. */
4781 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4783 report_thread_events
= enable
;
4787 linux_nat_add_target (struct target_ops
*t
)
4789 /* Save the provided single-threaded target. We save this in a separate
4790 variable because another target we've inherited from (e.g. inf-ptrace)
4791 may have saved a pointer to T; we want to use it for the final
4792 process stratum target. */
4793 linux_ops_saved
= *t
;
4794 linux_ops
= &linux_ops_saved
;
4796 /* Override some methods for multithreading. */
4797 t
->to_create_inferior
= linux_nat_create_inferior
;
4798 t
->to_attach
= linux_nat_attach
;
4799 t
->to_detach
= linux_nat_detach
;
4800 t
->to_resume
= linux_nat_resume
;
4801 t
->to_wait
= linux_nat_wait
;
4802 t
->to_pass_signals
= linux_nat_pass_signals
;
4803 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4804 t
->to_kill
= linux_nat_kill
;
4805 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4806 t
->to_thread_alive
= linux_nat_thread_alive
;
4807 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4808 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4809 t
->to_thread_name
= linux_nat_thread_name
;
4810 t
->to_has_thread_control
= tc_schedlock
;
4811 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4812 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4813 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4814 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4815 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4816 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4817 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4818 t
->to_thread_events
= linux_nat_thread_events
;
4820 t
->to_can_async_p
= linux_nat_can_async_p
;
4821 t
->to_is_async_p
= linux_nat_is_async_p
;
4822 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4823 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4824 t
->to_async
= linux_nat_async
;
4825 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4826 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4828 super_close
= t
->to_close
;
4829 t
->to_close
= linux_nat_close
;
4831 t
->to_stop
= linux_nat_stop
;
4833 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4835 t
->to_supports_disable_randomization
4836 = linux_nat_supports_disable_randomization
;
4838 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4840 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4841 t
->to_fileio_open
= linux_nat_fileio_open
;
4842 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4843 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4845 /* We don't change the stratum; this target will sit at
4846 process_stratum and thread_db will set at thread_stratum. This
4847 is a little strange, since this is a multi-threaded-capable
4848 target, but we want to be on the stack below thread_db, and we
4849 also want to be used for single-threaded processes. */
4854 /* Register a method to call whenever a new thread is attached. */
4856 linux_nat_set_new_thread (struct target_ops
*t
,
4857 void (*new_thread
) (struct lwp_info
*))
4859 /* Save the pointer. We only support a single registered instance
4860 of the GNU/Linux native target, so we do not need to map this to
4862 linux_nat_new_thread
= new_thread
;
4865 /* Register a method to call whenever a new thread is attached. */
4867 linux_nat_set_delete_thread (struct target_ops
*t
,
4868 void (*delete_thread
) (struct arch_lwp_info
*))
4870 /* Save the pointer. We only support a single registered instance
4871 of the GNU/Linux native target, so we do not need to map this to
4873 linux_nat_delete_thread
= delete_thread
;
4876 /* See declaration in linux-nat.h. */
4879 linux_nat_set_new_fork (struct target_ops
*t
,
4880 linux_nat_new_fork_ftype
*new_fork
)
4882 /* Save the pointer. */
4883 linux_nat_new_fork
= new_fork
;
4886 /* See declaration in linux-nat.h. */
4889 linux_nat_set_forget_process (struct target_ops
*t
,
4890 linux_nat_forget_process_ftype
*fn
)
4892 /* Save the pointer. */
4893 linux_nat_forget_process_hook
= fn
;
4896 /* See declaration in linux-nat.h. */
4899 linux_nat_forget_process (pid_t pid
)
4901 if (linux_nat_forget_process_hook
!= NULL
)
4902 linux_nat_forget_process_hook (pid
);
4905 /* Register a method that converts a siginfo object between the layout
4906 that ptrace returns, and the layout in the architecture of the
4909 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4910 int (*siginfo_fixup
) (siginfo_t
*,
4914 /* Save the pointer. */
4915 linux_nat_siginfo_fixup
= siginfo_fixup
;
4918 /* Register a method to call prior to resuming a thread. */
4921 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4922 void (*prepare_to_resume
) (struct lwp_info
*))
4924 /* Save the pointer. */
4925 linux_nat_prepare_to_resume
= prepare_to_resume
;
4928 /* See linux-nat.h. */
4931 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4935 pid
= ptid_get_lwp (ptid
);
4937 pid
= ptid_get_pid (ptid
);
4940 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4943 memset (siginfo
, 0, sizeof (*siginfo
));
4949 /* See nat/linux-nat.h. */
4952 current_lwp_ptid (void)
4954 gdb_assert (ptid_lwp_p (inferior_ptid
));
4955 return inferior_ptid
;
4959 _initialize_linux_nat (void)
4961 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4962 &debug_linux_nat
, _("\
4963 Set debugging of GNU/Linux lwp module."), _("\
4964 Show debugging of GNU/Linux lwp module."), _("\
4965 Enables printf debugging output."),
4967 show_debug_linux_nat
,
4968 &setdebuglist
, &showdebuglist
);
4970 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4971 &debug_linux_namespaces
, _("\
4972 Set debugging of GNU/Linux namespaces module."), _("\
4973 Show debugging of GNU/Linux namespaces module."), _("\
4974 Enables printf debugging output."),
4977 &setdebuglist
, &showdebuglist
);
4979 /* Save this mask as the default. */
4980 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4982 /* Install a SIGCHLD handler. */
4983 sigchld_action
.sa_handler
= sigchld_handler
;
4984 sigemptyset (&sigchld_action
.sa_mask
);
4985 sigchld_action
.sa_flags
= SA_RESTART
;
4987 /* Make it the default. */
4988 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4990 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4991 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4992 sigdelset (&suspend_mask
, SIGCHLD
);
4994 sigemptyset (&blocked_mask
);
4996 lwp_lwpid_htab_create ();
5000 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5001 the GNU/Linux Threads library and therefore doesn't really belong
5004 /* Return the set of signals used by the threads library in *SET. */
5007 lin_thread_get_thread_signals (sigset_t
*set
)
5011 /* NPTL reserves the first two RT signals, but does not provide any
5012 way for the debugger to query the signal numbers - fortunately
5013 they don't change. */
5014 sigaddset (set
, __SIGRTMIN
);
5015 sigaddset (set
, __SIGRTMIN
+ 1);