1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2017 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a 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
, int needed
, int any_count
,
680 int table_size
, int *table
)
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 `table' 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 struct cleanup
*restore_personality
1122 = maybe_disable_address_space_randomization (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
);
1132 do_cleanups (restore_personality
);
1135 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1136 already attached. Returns true if a new LWP is found, false
1140 attach_proc_task_lwp_callback (ptid_t ptid
)
1142 struct lwp_info
*lp
;
1144 /* Ignore LWPs we're already attached to. */
1145 lp
= find_lwp_pid (ptid
);
1148 int lwpid
= ptid_get_lwp (ptid
);
1150 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1154 /* Be quiet if we simply raced with the thread exiting.
1155 EPERM is returned if the thread's task still exists, and
1156 is marked as exited or zombie, as well as other
1157 conditions, so in that case, confirm the status in
1158 /proc/PID/status. */
1160 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1162 if (debug_linux_nat
)
1164 fprintf_unfiltered (gdb_stdlog
,
1165 "Cannot attach to lwp %d: "
1166 "thread is gone (%d: %s)\n",
1167 lwpid
, err
, safe_strerror (err
));
1172 warning (_("Cannot attach to lwp %d: %s"),
1174 linux_ptrace_attach_fail_reason_string (ptid
,
1180 if (debug_linux_nat
)
1181 fprintf_unfiltered (gdb_stdlog
,
1182 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1183 target_pid_to_str (ptid
));
1185 lp
= add_lwp (ptid
);
1187 /* The next time we wait for this LWP we'll see a SIGSTOP as
1188 PTRACE_ATTACH brings it to a halt. */
1191 /* We need to wait for a stop before being able to make the
1192 next ptrace call on this LWP. */
1193 lp
->must_set_ptrace_flags
= 1;
1195 /* So that wait collects the SIGSTOP. */
1198 /* Also add the LWP to gdb's thread list, in case a
1199 matching libthread_db is not found (or the process uses
1201 add_thread (lp
->ptid
);
1202 set_running (lp
->ptid
, 1);
1203 set_executing (lp
->ptid
, 1);
1212 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1214 struct lwp_info
*lp
;
1218 /* Make sure we report all signals during attach. */
1219 linux_nat_pass_signals (ops
, 0, NULL
);
1223 linux_ops
->to_attach (ops
, args
, from_tty
);
1225 CATCH (ex
, RETURN_MASK_ERROR
)
1227 pid_t pid
= parse_pid_to_attach (args
);
1228 struct buffer buffer
;
1229 char *message
, *buffer_s
;
1231 message
= xstrdup (ex
.message
);
1232 make_cleanup (xfree
, message
);
1234 buffer_init (&buffer
);
1235 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1237 buffer_grow_str0 (&buffer
, "");
1238 buffer_s
= buffer_finish (&buffer
);
1239 make_cleanup (xfree
, buffer_s
);
1241 if (*buffer_s
!= '\0')
1242 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1244 throw_error (ex
.error
, "%s", message
);
1248 /* The ptrace base target adds the main thread with (pid,0,0)
1249 format. Decorate it with lwp info. */
1250 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1251 ptid_get_pid (inferior_ptid
),
1253 thread_change_ptid (inferior_ptid
, ptid
);
1255 /* Add the initial process as the first LWP to the list. */
1256 lp
= add_initial_lwp (ptid
);
1258 status
= linux_nat_post_attach_wait (lp
->ptid
, &lp
->signalled
);
1259 if (!WIFSTOPPED (status
))
1261 if (WIFEXITED (status
))
1263 int exit_code
= WEXITSTATUS (status
);
1265 target_terminal::ours ();
1266 target_mourn_inferior (inferior_ptid
);
1268 error (_("Unable to attach: program exited normally."));
1270 error (_("Unable to attach: program exited with code %d."),
1273 else if (WIFSIGNALED (status
))
1275 enum gdb_signal signo
;
1277 target_terminal::ours ();
1278 target_mourn_inferior (inferior_ptid
);
1280 signo
= gdb_signal_from_host (WTERMSIG (status
));
1281 error (_("Unable to attach: program terminated with signal "
1283 gdb_signal_to_name (signo
),
1284 gdb_signal_to_string (signo
));
1287 internal_error (__FILE__
, __LINE__
,
1288 _("unexpected status %d for PID %ld"),
1289 status
, (long) ptid_get_lwp (ptid
));
1294 /* Save the wait status to report later. */
1296 if (debug_linux_nat
)
1297 fprintf_unfiltered (gdb_stdlog
,
1298 "LNA: waitpid %ld, saving status %s\n",
1299 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1301 lp
->status
= status
;
1303 /* We must attach to every LWP. If /proc is mounted, use that to
1304 find them now. The inferior may be using raw clone instead of
1305 using pthreads. But even if it is using pthreads, thread_db
1306 walks structures in the inferior's address space to find the list
1307 of threads/LWPs, and those structures may well be corrupted.
1308 Note that once thread_db is loaded, we'll still use it to list
1309 threads and associate pthread info with each LWP. */
1310 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1311 attach_proc_task_lwp_callback
);
1313 if (target_can_async_p ())
1317 /* Get pending signal of THREAD as a host signal number, for detaching
1318 purposes. This is the signal the thread last stopped for, which we
1319 need to deliver to the thread when detaching, otherwise, it'd be
1323 get_detach_signal (struct lwp_info
*lp
)
1325 enum gdb_signal signo
= GDB_SIGNAL_0
;
1327 /* If we paused threads momentarily, we may have stored pending
1328 events in lp->status or lp->waitstatus (see stop_wait_callback),
1329 and GDB core hasn't seen any signal for those threads.
1330 Otherwise, the last signal reported to the core is found in the
1331 thread object's stop_signal.
1333 There's a corner case that isn't handled here at present. Only
1334 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1335 stop_signal make sense as a real signal to pass to the inferior.
1336 Some catchpoint related events, like
1337 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1338 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1339 those traps are debug API (ptrace in our case) related and
1340 induced; the inferior wouldn't see them if it wasn't being
1341 traced. Hence, we should never pass them to the inferior, even
1342 when set to pass state. Since this corner case isn't handled by
1343 infrun.c when proceeding with a signal, for consistency, neither
1344 do we handle it here (or elsewhere in the file we check for
1345 signal pass state). Normally SIGTRAP isn't set to pass state, so
1346 this is really a corner case. */
1348 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1349 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1350 else if (lp
->status
)
1351 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1352 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1354 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1356 if (tp
->suspend
.waitstatus_pending_p
)
1357 signo
= tp
->suspend
.waitstatus
.value
.sig
;
1359 signo
= tp
->suspend
.stop_signal
;
1361 else if (!target_is_non_stop_p ())
1363 struct target_waitstatus last
;
1366 get_last_target_status (&last_ptid
, &last
);
1368 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1370 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1372 signo
= tp
->suspend
.stop_signal
;
1376 if (signo
== GDB_SIGNAL_0
)
1378 if (debug_linux_nat
)
1379 fprintf_unfiltered (gdb_stdlog
,
1380 "GPT: lwp %s has no pending signal\n",
1381 target_pid_to_str (lp
->ptid
));
1383 else if (!signal_pass_state (signo
))
1385 if (debug_linux_nat
)
1386 fprintf_unfiltered (gdb_stdlog
,
1387 "GPT: lwp %s had signal %s, "
1388 "but it is in no pass state\n",
1389 target_pid_to_str (lp
->ptid
),
1390 gdb_signal_to_string (signo
));
1394 if (debug_linux_nat
)
1395 fprintf_unfiltered (gdb_stdlog
,
1396 "GPT: lwp %s has pending signal %s\n",
1397 target_pid_to_str (lp
->ptid
),
1398 gdb_signal_to_string (signo
));
1400 return gdb_signal_to_host (signo
);
1406 /* Detach from LP. If SIGNO_P is non-NULL, then it points to the
1407 signal number that should be passed to the LWP when detaching.
1408 Otherwise pass any pending signal the LWP may have, if any. */
1411 detach_one_lwp (struct lwp_info
*lp
, int *signo_p
)
1413 int lwpid
= ptid_get_lwp (lp
->ptid
);
1416 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1418 if (debug_linux_nat
&& lp
->status
)
1419 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1420 strsignal (WSTOPSIG (lp
->status
)),
1421 target_pid_to_str (lp
->ptid
));
1423 /* If there is a pending SIGSTOP, get rid of it. */
1426 if (debug_linux_nat
)
1427 fprintf_unfiltered (gdb_stdlog
,
1428 "DC: Sending SIGCONT to %s\n",
1429 target_pid_to_str (lp
->ptid
));
1431 kill_lwp (lwpid
, SIGCONT
);
1435 if (signo_p
== NULL
)
1437 /* Pass on any pending signal for this LWP. */
1438 signo
= get_detach_signal (lp
);
1443 /* Preparing to resume may try to write registers, and fail if the
1444 lwp is zombie. If that happens, ignore the error. We'll handle
1445 it below, when detach fails with ESRCH. */
1448 if (linux_nat_prepare_to_resume
!= NULL
)
1449 linux_nat_prepare_to_resume (lp
);
1451 CATCH (ex
, RETURN_MASK_ERROR
)
1453 if (!check_ptrace_stopped_lwp_gone (lp
))
1454 throw_exception (ex
);
1458 if (ptrace (PTRACE_DETACH
, lwpid
, 0, signo
) < 0)
1460 int save_errno
= errno
;
1462 /* We know the thread exists, so ESRCH must mean the lwp is
1463 zombie. This can happen if one of the already-detached
1464 threads exits the whole thread group. In that case we're
1465 still attached, and must reap the lwp. */
1466 if (save_errno
== ESRCH
)
1470 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1473 warning (_("Couldn't reap LWP %d while detaching: %s"),
1474 lwpid
, strerror (errno
));
1476 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1478 warning (_("Reaping LWP %d while detaching "
1479 "returned unexpected status 0x%x"),
1485 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1486 safe_strerror (save_errno
));
1489 else if (debug_linux_nat
)
1491 fprintf_unfiltered (gdb_stdlog
,
1492 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1493 target_pid_to_str (lp
->ptid
),
1497 delete_lwp (lp
->ptid
);
1501 detach_callback (struct lwp_info
*lp
, void *data
)
1503 /* We don't actually detach from the thread group leader just yet.
1504 If the thread group exits, we must reap the zombie clone lwps
1505 before we're able to reap the leader. */
1506 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1507 detach_one_lwp (lp
, NULL
);
1512 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1515 struct lwp_info
*main_lwp
;
1517 pid
= ptid_get_pid (inferior_ptid
);
1519 /* Don't unregister from the event loop, as there may be other
1520 inferiors running. */
1522 /* Stop all threads before detaching. ptrace requires that the
1523 thread is stopped to sucessfully detach. */
1524 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1525 /* ... and wait until all of them have reported back that
1526 they're no longer running. */
1527 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1529 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1531 /* Only the initial process should be left right now. */
1532 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1534 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1536 if (forks_exist_p ())
1538 /* Multi-fork case. The current inferior_ptid is being detached
1539 from, but there are other viable forks to debug. Detach from
1540 the current fork, and context-switch to the first
1542 linux_fork_detach (args
, from_tty
);
1548 target_announce_detach (from_tty
);
1550 /* Pass on any pending signal for the last LWP, unless the user
1551 requested detaching with a different signal (most likely 0,
1552 meaning, discard the signal). */
1554 signo
= atoi (args
);
1556 signo
= get_detach_signal (main_lwp
);
1558 detach_one_lwp (main_lwp
, &signo
);
1560 inf_ptrace_detach_success (ops
);
1564 /* Resume execution of the inferior process. If STEP is nonzero,
1565 single-step it. If SIGNAL is nonzero, give it that signal. */
1568 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1569 enum gdb_signal signo
)
1573 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1574 We only presently need that if the LWP is stepped though (to
1575 handle the case of stepping a breakpoint instruction). */
1578 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1580 lp
->stop_pc
= regcache_read_pc (regcache
);
1585 if (linux_nat_prepare_to_resume
!= NULL
)
1586 linux_nat_prepare_to_resume (lp
);
1587 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1589 /* Successfully resumed. Clear state that no longer makes sense,
1590 and mark the LWP as running. Must not do this before resuming
1591 otherwise if that fails other code will be confused. E.g., we'd
1592 later try to stop the LWP and hang forever waiting for a stop
1593 status. Note that we must not throw after this is cleared,
1594 otherwise handle_zombie_lwp_error would get confused. */
1597 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1598 registers_changed_ptid (lp
->ptid
);
1601 /* Called when we try to resume a stopped LWP and that errors out. If
1602 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1603 or about to become), discard the error, clear any pending status
1604 the LWP may have, and return true (we'll collect the exit status
1605 soon enough). Otherwise, return false. */
1608 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1610 /* If we get an error after resuming the LWP successfully, we'd
1611 confuse !T state for the LWP being gone. */
1612 gdb_assert (lp
->stopped
);
1614 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1615 because even if ptrace failed with ESRCH, the tracee may be "not
1616 yet fully dead", but already refusing ptrace requests. In that
1617 case the tracee has 'R (Running)' state for a little bit
1618 (observed in Linux 3.18). See also the note on ESRCH in the
1619 ptrace(2) man page. Instead, check whether the LWP has any state
1620 other than ptrace-stopped. */
1622 /* Don't assume anything if /proc/PID/status can't be read. */
1623 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1625 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1627 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1633 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1634 disappears while we try to resume it. */
1637 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1641 linux_resume_one_lwp_throw (lp
, step
, signo
);
1643 CATCH (ex
, RETURN_MASK_ERROR
)
1645 if (!check_ptrace_stopped_lwp_gone (lp
))
1646 throw_exception (ex
);
1654 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1658 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1660 if (inf
->vfork_child
!= NULL
)
1662 if (debug_linux_nat
)
1663 fprintf_unfiltered (gdb_stdlog
,
1664 "RC: Not resuming %s (vfork parent)\n",
1665 target_pid_to_str (lp
->ptid
));
1667 else if (!lwp_status_pending_p (lp
))
1669 if (debug_linux_nat
)
1670 fprintf_unfiltered (gdb_stdlog
,
1671 "RC: Resuming sibling %s, %s, %s\n",
1672 target_pid_to_str (lp
->ptid
),
1673 (signo
!= GDB_SIGNAL_0
1674 ? strsignal (gdb_signal_to_host (signo
))
1676 step
? "step" : "resume");
1678 linux_resume_one_lwp (lp
, step
, signo
);
1682 if (debug_linux_nat
)
1683 fprintf_unfiltered (gdb_stdlog
,
1684 "RC: Not resuming sibling %s (has pending)\n",
1685 target_pid_to_str (lp
->ptid
));
1690 if (debug_linux_nat
)
1691 fprintf_unfiltered (gdb_stdlog
,
1692 "RC: Not resuming sibling %s (not stopped)\n",
1693 target_pid_to_str (lp
->ptid
));
1697 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1698 Resume LWP with the last stop signal, if it is in pass state. */
1701 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1703 enum gdb_signal signo
= GDB_SIGNAL_0
;
1710 struct thread_info
*thread
;
1712 thread
= find_thread_ptid (lp
->ptid
);
1715 signo
= thread
->suspend
.stop_signal
;
1716 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1720 resume_lwp (lp
, 0, signo
);
1725 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1728 lp
->last_resume_kind
= resume_stop
;
1733 resume_set_callback (struct lwp_info
*lp
, void *data
)
1736 lp
->last_resume_kind
= resume_continue
;
1741 linux_nat_resume (struct target_ops
*ops
,
1742 ptid_t ptid
, int step
, enum gdb_signal signo
)
1744 struct lwp_info
*lp
;
1747 if (debug_linux_nat
)
1748 fprintf_unfiltered (gdb_stdlog
,
1749 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1750 step
? "step" : "resume",
1751 target_pid_to_str (ptid
),
1752 (signo
!= GDB_SIGNAL_0
1753 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1754 target_pid_to_str (inferior_ptid
));
1756 /* A specific PTID means `step only this process id'. */
1757 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1758 || ptid_is_pid (ptid
));
1760 /* Mark the lwps we're resuming as resumed. */
1761 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1763 /* See if it's the current inferior that should be handled
1766 lp
= find_lwp_pid (inferior_ptid
);
1768 lp
= find_lwp_pid (ptid
);
1769 gdb_assert (lp
!= NULL
);
1771 /* Remember if we're stepping. */
1772 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1774 /* If we have a pending wait status for this thread, there is no
1775 point in resuming the process. But first make sure that
1776 linux_nat_wait won't preemptively handle the event - we
1777 should never take this short-circuit if we are going to
1778 leave LP running, since we have skipped resuming all the
1779 other threads. This bit of code needs to be synchronized
1780 with linux_nat_wait. */
1782 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1785 && WSTOPSIG (lp
->status
)
1786 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1788 if (debug_linux_nat
)
1789 fprintf_unfiltered (gdb_stdlog
,
1790 "LLR: Not short circuiting for ignored "
1791 "status 0x%x\n", lp
->status
);
1793 /* FIXME: What should we do if we are supposed to continue
1794 this thread with a signal? */
1795 gdb_assert (signo
== GDB_SIGNAL_0
);
1796 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1801 if (lwp_status_pending_p (lp
))
1803 /* FIXME: What should we do if we are supposed to continue
1804 this thread with a signal? */
1805 gdb_assert (signo
== GDB_SIGNAL_0
);
1807 if (debug_linux_nat
)
1808 fprintf_unfiltered (gdb_stdlog
,
1809 "LLR: Short circuiting for status 0x%x\n",
1812 if (target_can_async_p ())
1815 /* Tell the event loop we have something to process. */
1822 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1824 if (debug_linux_nat
)
1825 fprintf_unfiltered (gdb_stdlog
,
1826 "LLR: %s %s, %s (resume event thread)\n",
1827 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1828 target_pid_to_str (lp
->ptid
),
1829 (signo
!= GDB_SIGNAL_0
1830 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1832 linux_resume_one_lwp (lp
, step
, signo
);
1834 if (target_can_async_p ())
1838 /* Send a signal to an LWP. */
1841 kill_lwp (int lwpid
, int signo
)
1846 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1847 if (errno
== ENOSYS
)
1849 /* If tkill fails, then we are not using nptl threads, a
1850 configuration we no longer support. */
1851 perror_with_name (("tkill"));
1856 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1857 event, check if the core is interested in it: if not, ignore the
1858 event, and keep waiting; otherwise, we need to toggle the LWP's
1859 syscall entry/exit status, since the ptrace event itself doesn't
1860 indicate it, and report the trap to higher layers. */
1863 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1865 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1866 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1867 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1871 /* If we're stopping threads, there's a SIGSTOP pending, which
1872 makes it so that the LWP reports an immediate syscall return,
1873 followed by the SIGSTOP. Skip seeing that "return" using
1874 PTRACE_CONT directly, and let stop_wait_callback collect the
1875 SIGSTOP. Later when the thread is resumed, a new syscall
1876 entry event. If we didn't do this (and returned 0), we'd
1877 leave a syscall entry pending, and our caller, by using
1878 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1879 itself. Later, when the user re-resumes this LWP, we'd see
1880 another syscall entry event and we'd mistake it for a return.
1882 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1883 (leaving immediately with LWP->signalled set, without issuing
1884 a PTRACE_CONT), it would still be problematic to leave this
1885 syscall enter pending, as later when the thread is resumed,
1886 it would then see the same syscall exit mentioned above,
1887 followed by the delayed SIGSTOP, while the syscall didn't
1888 actually get to execute. It seems it would be even more
1889 confusing to the user. */
1891 if (debug_linux_nat
)
1892 fprintf_unfiltered (gdb_stdlog
,
1893 "LHST: ignoring syscall %d "
1894 "for LWP %ld (stopping threads), "
1895 "resuming with PTRACE_CONT for SIGSTOP\n",
1897 ptid_get_lwp (lp
->ptid
));
1899 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1900 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1905 /* Always update the entry/return state, even if this particular
1906 syscall isn't interesting to the core now. In async mode,
1907 the user could install a new catchpoint for this syscall
1908 between syscall enter/return, and we'll need to know to
1909 report a syscall return if that happens. */
1910 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1911 ? TARGET_WAITKIND_SYSCALL_RETURN
1912 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1914 if (catch_syscall_enabled ())
1916 if (catching_syscall_number (syscall_number
))
1918 /* Alright, an event to report. */
1919 ourstatus
->kind
= lp
->syscall_state
;
1920 ourstatus
->value
.syscall_number
= syscall_number
;
1922 if (debug_linux_nat
)
1923 fprintf_unfiltered (gdb_stdlog
,
1924 "LHST: stopping for %s of syscall %d"
1927 == TARGET_WAITKIND_SYSCALL_ENTRY
1928 ? "entry" : "return",
1930 ptid_get_lwp (lp
->ptid
));
1934 if (debug_linux_nat
)
1935 fprintf_unfiltered (gdb_stdlog
,
1936 "LHST: ignoring %s of syscall %d "
1938 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1939 ? "entry" : "return",
1941 ptid_get_lwp (lp
->ptid
));
1945 /* If we had been syscall tracing, and hence used PT_SYSCALL
1946 before on this LWP, it could happen that the user removes all
1947 syscall catchpoints before we get to process this event.
1948 There are two noteworthy issues here:
1950 - When stopped at a syscall entry event, resuming with
1951 PT_STEP still resumes executing the syscall and reports a
1954 - Only PT_SYSCALL catches syscall enters. If we last
1955 single-stepped this thread, then this event can't be a
1956 syscall enter. If we last single-stepped this thread, this
1957 has to be a syscall exit.
1959 The points above mean that the next resume, be it PT_STEP or
1960 PT_CONTINUE, can not trigger a syscall trace event. */
1961 if (debug_linux_nat
)
1962 fprintf_unfiltered (gdb_stdlog
,
1963 "LHST: caught syscall event "
1964 "with no syscall catchpoints."
1965 " %d for LWP %ld, ignoring\n",
1967 ptid_get_lwp (lp
->ptid
));
1968 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1971 /* The core isn't interested in this event. For efficiency, avoid
1972 stopping all threads only to have the core resume them all again.
1973 Since we're not stopping threads, if we're still syscall tracing
1974 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1975 subsequent syscall. Simply resume using the inf-ptrace layer,
1976 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1978 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1982 /* Handle a GNU/Linux extended wait response. If we see a clone
1983 event, we need to add the new LWP to our list (and not report the
1984 trap to higher layers). This function returns non-zero if the
1985 event should be ignored and we should wait again. If STOPPING is
1986 true, the new LWP remains stopped, otherwise it is continued. */
1989 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1991 int pid
= ptid_get_lwp (lp
->ptid
);
1992 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1993 int event
= linux_ptrace_get_extended_event (status
);
1995 /* All extended events we currently use are mid-syscall. Only
1996 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1997 you have to be using PTRACE_SEIZE to get that. */
1998 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
2000 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
2001 || event
== PTRACE_EVENT_CLONE
)
2003 unsigned long new_pid
;
2006 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
2008 /* If we haven't already seen the new PID stop, wait for it now. */
2009 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
2011 /* The new child has a pending SIGSTOP. We can't affect it until it
2012 hits the SIGSTOP, but we're already attached. */
2013 ret
= my_waitpid (new_pid
, &status
, __WALL
);
2015 perror_with_name (_("waiting for new child"));
2016 else if (ret
!= new_pid
)
2017 internal_error (__FILE__
, __LINE__
,
2018 _("wait returned unexpected PID %d"), ret
);
2019 else if (!WIFSTOPPED (status
))
2020 internal_error (__FILE__
, __LINE__
,
2021 _("wait returned unexpected status 0x%x"), status
);
2024 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2026 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
2028 /* The arch-specific native code may need to know about new
2029 forks even if those end up never mapped to an
2031 if (linux_nat_new_fork
!= NULL
)
2032 linux_nat_new_fork (lp
, new_pid
);
2035 if (event
== PTRACE_EVENT_FORK
2036 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
2038 /* Handle checkpointing by linux-fork.c here as a special
2039 case. We don't want the follow-fork-mode or 'catch fork'
2040 to interfere with this. */
2042 /* This won't actually modify the breakpoint list, but will
2043 physically remove the breakpoints from the child. */
2044 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
2046 /* Retain child fork in ptrace (stopped) state. */
2047 if (!find_fork_pid (new_pid
))
2050 /* Report as spurious, so that infrun doesn't want to follow
2051 this fork. We're actually doing an infcall in
2053 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2055 /* Report the stop to the core. */
2059 if (event
== PTRACE_EVENT_FORK
)
2060 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2061 else if (event
== PTRACE_EVENT_VFORK
)
2062 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2063 else if (event
== PTRACE_EVENT_CLONE
)
2065 struct lwp_info
*new_lp
;
2067 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2069 if (debug_linux_nat
)
2070 fprintf_unfiltered (gdb_stdlog
,
2071 "LHEW: Got clone event "
2072 "from LWP %d, new child is LWP %ld\n",
2075 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2076 new_lp
->stopped
= 1;
2077 new_lp
->resumed
= 1;
2079 /* If the thread_db layer is active, let it record the user
2080 level thread id and status, and add the thread to GDB's
2082 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2084 /* The process is not using thread_db. Add the LWP to
2086 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2087 add_thread (new_lp
->ptid
);
2090 /* Even if we're stopping the thread for some reason
2091 internal to this module, from the perspective of infrun
2092 and the user/frontend, this new thread is running until
2093 it next reports a stop. */
2094 set_running (new_lp
->ptid
, 1);
2095 set_executing (new_lp
->ptid
, 1);
2097 if (WSTOPSIG (status
) != SIGSTOP
)
2099 /* This can happen if someone starts sending signals to
2100 the new thread before it gets a chance to run, which
2101 have a lower number than SIGSTOP (e.g. SIGUSR1).
2102 This is an unlikely case, and harder to handle for
2103 fork / vfork than for clone, so we do not try - but
2104 we handle it for clone events here. */
2106 new_lp
->signalled
= 1;
2108 /* We created NEW_LP so it cannot yet contain STATUS. */
2109 gdb_assert (new_lp
->status
== 0);
2111 /* Save the wait status to report later. */
2112 if (debug_linux_nat
)
2113 fprintf_unfiltered (gdb_stdlog
,
2114 "LHEW: waitpid of new LWP %ld, "
2115 "saving status %s\n",
2116 (long) ptid_get_lwp (new_lp
->ptid
),
2117 status_to_str (status
));
2118 new_lp
->status
= status
;
2120 else if (report_thread_events
)
2122 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2123 new_lp
->status
= status
;
2132 if (event
== PTRACE_EVENT_EXEC
)
2134 if (debug_linux_nat
)
2135 fprintf_unfiltered (gdb_stdlog
,
2136 "LHEW: Got exec event from LWP %ld\n",
2137 ptid_get_lwp (lp
->ptid
));
2139 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2140 ourstatus
->value
.execd_pathname
2141 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2143 /* The thread that execed must have been resumed, but, when a
2144 thread execs, it changes its tid to the tgid, and the old
2145 tgid thread might have not been resumed. */
2150 if (event
== PTRACE_EVENT_VFORK_DONE
)
2152 if (current_inferior ()->waiting_for_vfork_done
)
2154 if (debug_linux_nat
)
2155 fprintf_unfiltered (gdb_stdlog
,
2156 "LHEW: Got expected PTRACE_EVENT_"
2157 "VFORK_DONE from LWP %ld: stopping\n",
2158 ptid_get_lwp (lp
->ptid
));
2160 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2164 if (debug_linux_nat
)
2165 fprintf_unfiltered (gdb_stdlog
,
2166 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2167 "from LWP %ld: ignoring\n",
2168 ptid_get_lwp (lp
->ptid
));
2172 internal_error (__FILE__
, __LINE__
,
2173 _("unknown ptrace event %d"), event
);
2176 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2180 wait_lwp (struct lwp_info
*lp
)
2184 int thread_dead
= 0;
2187 gdb_assert (!lp
->stopped
);
2188 gdb_assert (lp
->status
== 0);
2190 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2191 block_child_signals (&prev_mask
);
2195 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2196 if (pid
== -1 && errno
== ECHILD
)
2198 /* The thread has previously exited. We need to delete it
2199 now because if this was a non-leader thread execing, we
2200 won't get an exit event. See comments on exec events at
2201 the top of the file. */
2203 if (debug_linux_nat
)
2204 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2205 target_pid_to_str (lp
->ptid
));
2210 /* Bugs 10970, 12702.
2211 Thread group leader may have exited in which case we'll lock up in
2212 waitpid if there are other threads, even if they are all zombies too.
2213 Basically, we're not supposed to use waitpid this way.
2214 tkill(pid,0) cannot be used here as it gets ESRCH for both
2215 for zombie and running processes.
2217 As a workaround, check if we're waiting for the thread group leader and
2218 if it's a zombie, and avoid calling waitpid if it is.
2220 This is racy, what if the tgl becomes a zombie right after we check?
2221 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2222 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2224 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2225 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2228 if (debug_linux_nat
)
2229 fprintf_unfiltered (gdb_stdlog
,
2230 "WL: Thread group leader %s vanished.\n",
2231 target_pid_to_str (lp
->ptid
));
2235 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2236 get invoked despite our caller had them intentionally blocked by
2237 block_child_signals. This is sensitive only to the loop of
2238 linux_nat_wait_1 and there if we get called my_waitpid gets called
2239 again before it gets to sigsuspend so we can safely let the handlers
2240 get executed here. */
2242 if (debug_linux_nat
)
2243 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2244 sigsuspend (&suspend_mask
);
2247 restore_child_signals_mask (&prev_mask
);
2251 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2253 if (debug_linux_nat
)
2255 fprintf_unfiltered (gdb_stdlog
,
2256 "WL: waitpid %s received %s\n",
2257 target_pid_to_str (lp
->ptid
),
2258 status_to_str (status
));
2261 /* Check if the thread has exited. */
2262 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2264 if (report_thread_events
2265 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2267 if (debug_linux_nat
)
2268 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2269 ptid_get_pid (lp
->ptid
));
2271 /* If this is the leader exiting, it means the whole
2272 process is gone. Store the status to report to the
2273 core. Store it in lp->waitstatus, because lp->status
2274 would be ambiguous (W_EXITCODE(0,0) == 0). */
2275 store_waitstatus (&lp
->waitstatus
, status
);
2280 if (debug_linux_nat
)
2281 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2282 target_pid_to_str (lp
->ptid
));
2292 gdb_assert (WIFSTOPPED (status
));
2295 if (lp
->must_set_ptrace_flags
)
2297 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2298 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2300 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2301 lp
->must_set_ptrace_flags
= 0;
2304 /* Handle GNU/Linux's syscall SIGTRAPs. */
2305 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2307 /* No longer need the sysgood bit. The ptrace event ends up
2308 recorded in lp->waitstatus if we care for it. We can carry
2309 on handling the event like a regular SIGTRAP from here
2311 status
= W_STOPCODE (SIGTRAP
);
2312 if (linux_handle_syscall_trap (lp
, 1))
2313 return wait_lwp (lp
);
2317 /* Almost all other ptrace-stops are known to be outside of system
2318 calls, with further exceptions in linux_handle_extended_wait. */
2319 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2322 /* Handle GNU/Linux's extended waitstatus for trace events. */
2323 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2324 && linux_is_extended_waitstatus (status
))
2326 if (debug_linux_nat
)
2327 fprintf_unfiltered (gdb_stdlog
,
2328 "WL: Handling extended status 0x%06x\n",
2330 linux_handle_extended_wait (lp
, status
);
2337 /* Send a SIGSTOP to LP. */
2340 stop_callback (struct lwp_info
*lp
, void *data
)
2342 if (!lp
->stopped
&& !lp
->signalled
)
2346 if (debug_linux_nat
)
2348 fprintf_unfiltered (gdb_stdlog
,
2349 "SC: kill %s **<SIGSTOP>**\n",
2350 target_pid_to_str (lp
->ptid
));
2353 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2354 if (debug_linux_nat
)
2356 fprintf_unfiltered (gdb_stdlog
,
2357 "SC: lwp kill %d %s\n",
2359 errno
? safe_strerror (errno
) : "ERRNO-OK");
2363 gdb_assert (lp
->status
== 0);
2369 /* Request a stop on LWP. */
2372 linux_stop_lwp (struct lwp_info
*lwp
)
2374 stop_callback (lwp
, NULL
);
2377 /* See linux-nat.h */
2380 linux_stop_and_wait_all_lwps (void)
2382 /* Stop all LWP's ... */
2383 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2385 /* ... and wait until all of them have reported back that
2386 they're no longer running. */
2387 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2390 /* See linux-nat.h */
2393 linux_unstop_all_lwps (void)
2395 iterate_over_lwps (minus_one_ptid
,
2396 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2399 /* Return non-zero if LWP PID has a pending SIGINT. */
2402 linux_nat_has_pending_sigint (int pid
)
2404 sigset_t pending
, blocked
, ignored
;
2406 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2408 if (sigismember (&pending
, SIGINT
)
2409 && !sigismember (&ignored
, SIGINT
))
2415 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2418 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2420 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2421 flag to consume the next one. */
2422 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2423 && WSTOPSIG (lp
->status
) == SIGINT
)
2426 lp
->ignore_sigint
= 1;
2431 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2432 This function is called after we know the LWP has stopped; if the LWP
2433 stopped before the expected SIGINT was delivered, then it will never have
2434 arrived. Also, if the signal was delivered to a shared queue and consumed
2435 by a different thread, it will never be delivered to this LWP. */
2438 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2440 if (!lp
->ignore_sigint
)
2443 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2445 if (debug_linux_nat
)
2446 fprintf_unfiltered (gdb_stdlog
,
2447 "MCIS: Clearing bogus flag for %s\n",
2448 target_pid_to_str (lp
->ptid
));
2449 lp
->ignore_sigint
= 0;
2453 /* Fetch the possible triggered data watchpoint info and store it in
2456 On some archs, like x86, that use debug registers to set
2457 watchpoints, it's possible that the way to know which watched
2458 address trapped, is to check the register that is used to select
2459 which address to watch. Problem is, between setting the watchpoint
2460 and reading back which data address trapped, the user may change
2461 the set of watchpoints, and, as a consequence, GDB changes the
2462 debug registers in the inferior. To avoid reading back a stale
2463 stopped-data-address when that happens, we cache in LP the fact
2464 that a watchpoint trapped, and the corresponding data address, as
2465 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2466 registers meanwhile, we have the cached data we can rely on. */
2469 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2471 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2474 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
2475 inferior_ptid
= lp
->ptid
;
2477 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2479 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2481 if (linux_ops
->to_stopped_data_address
!= NULL
)
2482 lp
->stopped_data_address_p
=
2483 linux_ops
->to_stopped_data_address (¤t_target
,
2484 &lp
->stopped_data_address
);
2486 lp
->stopped_data_address_p
= 0;
2489 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2492 /* Returns true if the LWP had stopped for a watchpoint. */
2495 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2497 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2499 gdb_assert (lp
!= NULL
);
2501 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2505 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2507 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2509 gdb_assert (lp
!= NULL
);
2511 *addr_p
= lp
->stopped_data_address
;
2513 return lp
->stopped_data_address_p
;
2516 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2519 sigtrap_is_event (int status
)
2521 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2524 /* Set alternative SIGTRAP-like events recognizer. If
2525 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2529 linux_nat_set_status_is_event (struct target_ops
*t
,
2530 int (*status_is_event
) (int status
))
2532 linux_nat_status_is_event
= status_is_event
;
2535 /* Wait until LP is stopped. */
2538 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2540 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2542 /* If this is a vfork parent, bail out, it is not going to report
2543 any SIGSTOP until the vfork is done with. */
2544 if (inf
->vfork_child
!= NULL
)
2551 status
= wait_lwp (lp
);
2555 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2556 && WSTOPSIG (status
) == SIGINT
)
2558 lp
->ignore_sigint
= 0;
2561 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2563 if (debug_linux_nat
)
2564 fprintf_unfiltered (gdb_stdlog
,
2565 "PTRACE_CONT %s, 0, 0 (%s) "
2566 "(discarding SIGINT)\n",
2567 target_pid_to_str (lp
->ptid
),
2568 errno
? safe_strerror (errno
) : "OK");
2570 return stop_wait_callback (lp
, NULL
);
2573 maybe_clear_ignore_sigint (lp
);
2575 if (WSTOPSIG (status
) != SIGSTOP
)
2577 /* The thread was stopped with a signal other than SIGSTOP. */
2579 if (debug_linux_nat
)
2580 fprintf_unfiltered (gdb_stdlog
,
2581 "SWC: Pending event %s in %s\n",
2582 status_to_str ((int) status
),
2583 target_pid_to_str (lp
->ptid
));
2585 /* Save the sigtrap event. */
2586 lp
->status
= status
;
2587 gdb_assert (lp
->signalled
);
2588 save_stop_reason (lp
);
2592 /* We caught the SIGSTOP that we intended to catch, so
2593 there's no SIGSTOP pending. */
2595 if (debug_linux_nat
)
2596 fprintf_unfiltered (gdb_stdlog
,
2597 "SWC: Expected SIGSTOP caught for %s.\n",
2598 target_pid_to_str (lp
->ptid
));
2600 /* Reset SIGNALLED only after the stop_wait_callback call
2601 above as it does gdb_assert on SIGNALLED. */
2609 /* Return non-zero if LP has a wait status pending. Discard the
2610 pending event and resume the LWP if the event that originally
2611 caused the stop became uninteresting. */
2614 status_callback (struct lwp_info
*lp
, void *data
)
2616 /* Only report a pending wait status if we pretend that this has
2617 indeed been resumed. */
2621 if (!lwp_status_pending_p (lp
))
2624 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2625 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2627 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2631 pc
= regcache_read_pc (regcache
);
2633 if (pc
!= lp
->stop_pc
)
2635 if (debug_linux_nat
)
2636 fprintf_unfiltered (gdb_stdlog
,
2637 "SC: PC of %s changed. was=%s, now=%s\n",
2638 target_pid_to_str (lp
->ptid
),
2639 paddress (target_gdbarch (), lp
->stop_pc
),
2640 paddress (target_gdbarch (), pc
));
2644 #if !USE_SIGTRAP_SIGINFO
2645 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2647 if (debug_linux_nat
)
2648 fprintf_unfiltered (gdb_stdlog
,
2649 "SC: previous breakpoint of %s, at %s gone\n",
2650 target_pid_to_str (lp
->ptid
),
2651 paddress (target_gdbarch (), lp
->stop_pc
));
2659 if (debug_linux_nat
)
2660 fprintf_unfiltered (gdb_stdlog
,
2661 "SC: pending event of %s cancelled.\n",
2662 target_pid_to_str (lp
->ptid
));
2665 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2673 /* Count the LWP's that have had events. */
2676 count_events_callback (struct lwp_info
*lp
, void *data
)
2678 int *count
= (int *) data
;
2680 gdb_assert (count
!= NULL
);
2682 /* Select only resumed LWPs that have an event pending. */
2683 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2689 /* Select the LWP (if any) that is currently being single-stepped. */
2692 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2694 if (lp
->last_resume_kind
== resume_step
2701 /* Returns true if LP has a status pending. */
2704 lwp_status_pending_p (struct lwp_info
*lp
)
2706 /* We check for lp->waitstatus in addition to lp->status, because we
2707 can have pending process exits recorded in lp->status and
2708 W_EXITCODE(0,0) happens to be 0. */
2709 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2712 /* Select the Nth LWP that has had an event. */
2715 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2717 int *selector
= (int *) data
;
2719 gdb_assert (selector
!= NULL
);
2721 /* Select only resumed LWPs that have an event pending. */
2722 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2723 if ((*selector
)-- == 0)
2729 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2730 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2731 and save the result in the LWP's stop_reason field. If it stopped
2732 for a breakpoint, decrement the PC if necessary on the lwp's
2736 save_stop_reason (struct lwp_info
*lp
)
2738 struct regcache
*regcache
;
2739 struct gdbarch
*gdbarch
;
2742 #if USE_SIGTRAP_SIGINFO
2746 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2747 gdb_assert (lp
->status
!= 0);
2749 if (!linux_nat_status_is_event (lp
->status
))
2752 regcache
= get_thread_regcache (lp
->ptid
);
2753 gdbarch
= regcache
->arch ();
2755 pc
= regcache_read_pc (regcache
);
2756 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2758 #if USE_SIGTRAP_SIGINFO
2759 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2761 if (siginfo
.si_signo
== SIGTRAP
)
2763 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2764 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2766 /* The si_code is ambiguous on this arch -- check debug
2768 if (!check_stopped_by_watchpoint (lp
))
2769 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2771 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2773 /* If we determine the LWP stopped for a SW breakpoint,
2774 trust it. Particularly don't check watchpoint
2775 registers, because at least on s390, we'd find
2776 stopped-by-watchpoint as long as there's a watchpoint
2778 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2780 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2782 /* This can indicate either a hardware breakpoint or
2783 hardware watchpoint. Check debug registers. */
2784 if (!check_stopped_by_watchpoint (lp
))
2785 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2787 else if (siginfo
.si_code
== TRAP_TRACE
)
2789 if (debug_linux_nat
)
2790 fprintf_unfiltered (gdb_stdlog
,
2791 "CSBB: %s stopped by trace\n",
2792 target_pid_to_str (lp
->ptid
));
2794 /* We may have single stepped an instruction that
2795 triggered a watchpoint. In that case, on some
2796 architectures (such as x86), instead of TRAP_HWBKPT,
2797 si_code indicates TRAP_TRACE, and we need to check
2798 the debug registers separately. */
2799 check_stopped_by_watchpoint (lp
);
2804 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2805 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2808 /* The LWP was either continued, or stepped a software
2809 breakpoint instruction. */
2810 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2813 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2814 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2816 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2817 check_stopped_by_watchpoint (lp
);
2820 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2822 if (debug_linux_nat
)
2823 fprintf_unfiltered (gdb_stdlog
,
2824 "CSBB: %s stopped by software breakpoint\n",
2825 target_pid_to_str (lp
->ptid
));
2827 /* Back up the PC if necessary. */
2829 regcache_write_pc (regcache
, sw_bp_pc
);
2831 /* Update this so we record the correct stop PC below. */
2834 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2836 if (debug_linux_nat
)
2837 fprintf_unfiltered (gdb_stdlog
,
2838 "CSBB: %s stopped by hardware breakpoint\n",
2839 target_pid_to_str (lp
->ptid
));
2841 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2843 if (debug_linux_nat
)
2844 fprintf_unfiltered (gdb_stdlog
,
2845 "CSBB: %s stopped by hardware watchpoint\n",
2846 target_pid_to_str (lp
->ptid
));
2853 /* Returns true if the LWP had stopped for a software breakpoint. */
2856 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2858 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2860 gdb_assert (lp
!= NULL
);
2862 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2865 /* Implement the supports_stopped_by_sw_breakpoint method. */
2868 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2870 return USE_SIGTRAP_SIGINFO
;
2873 /* Returns true if the LWP had stopped for a hardware
2874 breakpoint/watchpoint. */
2877 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2879 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2881 gdb_assert (lp
!= NULL
);
2883 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2886 /* Implement the supports_stopped_by_hw_breakpoint method. */
2889 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2891 return USE_SIGTRAP_SIGINFO
;
2894 /* Select one LWP out of those that have events pending. */
2897 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2900 int random_selector
;
2901 struct lwp_info
*event_lp
= NULL
;
2903 /* Record the wait status for the original LWP. */
2904 (*orig_lp
)->status
= *status
;
2906 /* In all-stop, give preference to the LWP that is being
2907 single-stepped. There will be at most one, and it will be the
2908 LWP that the core is most interested in. If we didn't do this,
2909 then we'd have to handle pending step SIGTRAPs somehow in case
2910 the core later continues the previously-stepped thread, as
2911 otherwise we'd report the pending SIGTRAP then, and the core, not
2912 having stepped the thread, wouldn't understand what the trap was
2913 for, and therefore would report it to the user as a random
2915 if (!target_is_non_stop_p ())
2917 event_lp
= iterate_over_lwps (filter
,
2918 select_singlestep_lwp_callback
, NULL
);
2919 if (event_lp
!= NULL
)
2921 if (debug_linux_nat
)
2922 fprintf_unfiltered (gdb_stdlog
,
2923 "SEL: Select single-step %s\n",
2924 target_pid_to_str (event_lp
->ptid
));
2928 if (event_lp
== NULL
)
2930 /* Pick one at random, out of those which have had events. */
2932 /* First see how many events we have. */
2933 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2934 gdb_assert (num_events
> 0);
2936 /* Now randomly pick a LWP out of those that have had
2938 random_selector
= (int)
2939 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2941 if (debug_linux_nat
&& num_events
> 1)
2942 fprintf_unfiltered (gdb_stdlog
,
2943 "SEL: Found %d events, selecting #%d\n",
2944 num_events
, random_selector
);
2946 event_lp
= iterate_over_lwps (filter
,
2947 select_event_lwp_callback
,
2951 if (event_lp
!= NULL
)
2953 /* Switch the event LWP. */
2954 *orig_lp
= event_lp
;
2955 *status
= event_lp
->status
;
2958 /* Flush the wait status for the event LWP. */
2959 (*orig_lp
)->status
= 0;
2962 /* Return non-zero if LP has been resumed. */
2965 resumed_callback (struct lwp_info
*lp
, void *data
)
2970 /* Check if we should go on and pass this event to common code.
2971 Return the affected lwp if we are, or NULL otherwise. */
2973 static struct lwp_info
*
2974 linux_nat_filter_event (int lwpid
, int status
)
2976 struct lwp_info
*lp
;
2977 int event
= linux_ptrace_get_extended_event (status
);
2979 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2981 /* Check for stop events reported by a process we didn't already
2982 know about - anything not already in our LWP list.
2984 If we're expecting to receive stopped processes after
2985 fork, vfork, and clone events, then we'll just add the
2986 new one to our list and go back to waiting for the event
2987 to be reported - the stopped process might be returned
2988 from waitpid before or after the event is.
2990 But note the case of a non-leader thread exec'ing after the
2991 leader having exited, and gone from our lists. The non-leader
2992 thread changes its tid to the tgid. */
2994 if (WIFSTOPPED (status
) && lp
== NULL
2995 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2997 /* A multi-thread exec after we had seen the leader exiting. */
2998 if (debug_linux_nat
)
2999 fprintf_unfiltered (gdb_stdlog
,
3000 "LLW: Re-adding thread group leader LWP %d.\n",
3003 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
3006 add_thread (lp
->ptid
);
3009 if (WIFSTOPPED (status
) && !lp
)
3011 if (debug_linux_nat
)
3012 fprintf_unfiltered (gdb_stdlog
,
3013 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
3014 (long) lwpid
, status_to_str (status
));
3015 add_to_pid_list (&stopped_pids
, lwpid
, status
);
3019 /* Make sure we don't report an event for the exit of an LWP not in
3020 our list, i.e. not part of the current process. This can happen
3021 if we detach from a program we originally forked and then it
3023 if (!WIFSTOPPED (status
) && !lp
)
3026 /* This LWP is stopped now. (And if dead, this prevents it from
3027 ever being continued.) */
3030 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
3032 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
3033 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
3035 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
3036 lp
->must_set_ptrace_flags
= 0;
3039 /* Handle GNU/Linux's syscall SIGTRAPs. */
3040 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
3042 /* No longer need the sysgood bit. The ptrace event ends up
3043 recorded in lp->waitstatus if we care for it. We can carry
3044 on handling the event like a regular SIGTRAP from here
3046 status
= W_STOPCODE (SIGTRAP
);
3047 if (linux_handle_syscall_trap (lp
, 0))
3052 /* Almost all other ptrace-stops are known to be outside of system
3053 calls, with further exceptions in linux_handle_extended_wait. */
3054 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
3057 /* Handle GNU/Linux's extended waitstatus for trace events. */
3058 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
3059 && linux_is_extended_waitstatus (status
))
3061 if (debug_linux_nat
)
3062 fprintf_unfiltered (gdb_stdlog
,
3063 "LLW: Handling extended status 0x%06x\n",
3065 if (linux_handle_extended_wait (lp
, status
))
3069 /* Check if the thread has exited. */
3070 if (WIFEXITED (status
) || WIFSIGNALED (status
))
3072 if (!report_thread_events
3073 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3075 if (debug_linux_nat
)
3076 fprintf_unfiltered (gdb_stdlog
,
3077 "LLW: %s exited.\n",
3078 target_pid_to_str (lp
->ptid
));
3080 /* If there is at least one more LWP, then the exit signal
3081 was not the end of the debugged application and should be
3087 /* Note that even if the leader was ptrace-stopped, it can still
3088 exit, if e.g., some other thread brings down the whole
3089 process (calls `exit'). So don't assert that the lwp is
3091 if (debug_linux_nat
)
3092 fprintf_unfiltered (gdb_stdlog
,
3093 "LWP %ld exited (resumed=%d)\n",
3094 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3096 /* Dead LWP's aren't expected to reported a pending sigstop. */
3099 /* Store the pending event in the waitstatus, because
3100 W_EXITCODE(0,0) == 0. */
3101 store_waitstatus (&lp
->waitstatus
, status
);
3105 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3106 an attempt to stop an LWP. */
3108 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3112 if (lp
->last_resume_kind
== resume_stop
)
3114 if (debug_linux_nat
)
3115 fprintf_unfiltered (gdb_stdlog
,
3116 "LLW: resume_stop SIGSTOP caught for %s.\n",
3117 target_pid_to_str (lp
->ptid
));
3121 /* This is a delayed SIGSTOP. Filter out the event. */
3123 if (debug_linux_nat
)
3124 fprintf_unfiltered (gdb_stdlog
,
3125 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3127 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3128 target_pid_to_str (lp
->ptid
));
3130 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3131 gdb_assert (lp
->resumed
);
3136 /* Make sure we don't report a SIGINT that we have already displayed
3137 for another thread. */
3138 if (lp
->ignore_sigint
3139 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3141 if (debug_linux_nat
)
3142 fprintf_unfiltered (gdb_stdlog
,
3143 "LLW: Delayed SIGINT caught for %s.\n",
3144 target_pid_to_str (lp
->ptid
));
3146 /* This is a delayed SIGINT. */
3147 lp
->ignore_sigint
= 0;
3149 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3150 if (debug_linux_nat
)
3151 fprintf_unfiltered (gdb_stdlog
,
3152 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3154 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3155 target_pid_to_str (lp
->ptid
));
3156 gdb_assert (lp
->resumed
);
3158 /* Discard the event. */
3162 /* Don't report signals that GDB isn't interested in, such as
3163 signals that are neither printed nor stopped upon. Stopping all
3164 threads can be a bit time-consuming so if we want decent
3165 performance with heavily multi-threaded programs, especially when
3166 they're using a high frequency timer, we'd better avoid it if we
3168 if (WIFSTOPPED (status
))
3170 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3172 if (!target_is_non_stop_p ())
3174 /* Only do the below in all-stop, as we currently use SIGSTOP
3175 to implement target_stop (see linux_nat_stop) in
3177 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3179 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3180 forwarded to the entire process group, that is, all LWPs
3181 will receive it - unless they're using CLONE_THREAD to
3182 share signals. Since we only want to report it once, we
3183 mark it as ignored for all LWPs except this one. */
3184 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3185 set_ignore_sigint
, NULL
);
3186 lp
->ignore_sigint
= 0;
3189 maybe_clear_ignore_sigint (lp
);
3192 /* When using hardware single-step, we need to report every signal.
3193 Otherwise, signals in pass_mask may be short-circuited
3194 except signals that might be caused by a breakpoint. */
3196 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3197 && !linux_wstatus_maybe_breakpoint (status
))
3199 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3200 if (debug_linux_nat
)
3201 fprintf_unfiltered (gdb_stdlog
,
3202 "LLW: %s %s, %s (preempt 'handle')\n",
3204 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3205 target_pid_to_str (lp
->ptid
),
3206 (signo
!= GDB_SIGNAL_0
3207 ? strsignal (gdb_signal_to_host (signo
))
3213 /* An interesting event. */
3215 lp
->status
= status
;
3216 save_stop_reason (lp
);
3220 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3221 their exits until all other threads in the group have exited. */
3224 check_zombie_leaders (void)
3226 struct inferior
*inf
;
3230 struct lwp_info
*leader_lp
;
3235 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3236 if (leader_lp
!= NULL
3237 /* Check if there are other threads in the group, as we may
3238 have raced with the inferior simply exiting. */
3239 && num_lwps (inf
->pid
) > 1
3240 && linux_proc_pid_is_zombie (inf
->pid
))
3242 if (debug_linux_nat
)
3243 fprintf_unfiltered (gdb_stdlog
,
3244 "CZL: Thread group leader %d zombie "
3245 "(it exited, or another thread execd).\n",
3248 /* A leader zombie can mean one of two things:
3250 - It exited, and there's an exit status pending
3251 available, or only the leader exited (not the whole
3252 program). In the latter case, we can't waitpid the
3253 leader's exit status until all other threads are gone.
3255 - There are 3 or more threads in the group, and a thread
3256 other than the leader exec'd. See comments on exec
3257 events at the top of the file. We could try
3258 distinguishing the exit and exec cases, by waiting once
3259 more, and seeing if something comes out, but it doesn't
3260 sound useful. The previous leader _does_ go away, and
3261 we'll re-add the new one once we see the exec event
3262 (which is just the same as what would happen if the
3263 previous leader did exit voluntarily before some other
3266 if (debug_linux_nat
)
3267 fprintf_unfiltered (gdb_stdlog
,
3268 "CZL: Thread group leader %d vanished.\n",
3270 exit_lwp (leader_lp
);
3275 /* Convenience function that is called when the kernel reports an exit
3276 event. This decides whether to report the event to GDB as a
3277 process exit event, a thread exit event, or to suppress the
3281 filter_exit_event (struct lwp_info
*event_child
,
3282 struct target_waitstatus
*ourstatus
)
3284 ptid_t ptid
= event_child
->ptid
;
3286 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3288 if (report_thread_events
)
3289 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3291 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3293 exit_lwp (event_child
);
3300 linux_nat_wait_1 (struct target_ops
*ops
,
3301 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3305 enum resume_kind last_resume_kind
;
3306 struct lwp_info
*lp
;
3309 if (debug_linux_nat
)
3310 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3312 /* The first time we get here after starting a new inferior, we may
3313 not have added it to the LWP list yet - this is the earliest
3314 moment at which we know its PID. */
3315 if (ptid_is_pid (inferior_ptid
))
3317 /* Upgrade the main thread's ptid. */
3318 thread_change_ptid (inferior_ptid
,
3319 ptid_build (ptid_get_pid (inferior_ptid
),
3320 ptid_get_pid (inferior_ptid
), 0));
3322 lp
= add_initial_lwp (inferior_ptid
);
3326 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3327 block_child_signals (&prev_mask
);
3329 /* First check if there is a LWP with a wait status pending. */
3330 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3333 if (debug_linux_nat
)
3334 fprintf_unfiltered (gdb_stdlog
,
3335 "LLW: Using pending wait status %s for %s.\n",
3336 status_to_str (lp
->status
),
3337 target_pid_to_str (lp
->ptid
));
3340 /* But if we don't find a pending event, we'll have to wait. Always
3341 pull all events out of the kernel. We'll randomly select an
3342 event LWP out of all that have events, to prevent starvation. */
3348 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3351 - If the thread group leader exits while other threads in the
3352 thread group still exist, waitpid(TGID, ...) hangs. That
3353 waitpid won't return an exit status until the other threads
3354 in the group are reapped.
3356 - When a non-leader thread execs, that thread just vanishes
3357 without reporting an exit (so we'd hang if we waited for it
3358 explicitly in that case). The exec event is reported to
3362 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3364 if (debug_linux_nat
)
3365 fprintf_unfiltered (gdb_stdlog
,
3366 "LNW: waitpid(-1, ...) returned %d, %s\n",
3367 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3371 if (debug_linux_nat
)
3373 fprintf_unfiltered (gdb_stdlog
,
3374 "LLW: waitpid %ld received %s\n",
3375 (long) lwpid
, status_to_str (status
));
3378 linux_nat_filter_event (lwpid
, status
);
3379 /* Retry until nothing comes out of waitpid. A single
3380 SIGCHLD can indicate more than one child stopped. */
3384 /* Now that we've pulled all events out of the kernel, resume
3385 LWPs that don't have an interesting event to report. */
3386 iterate_over_lwps (minus_one_ptid
,
3387 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3389 /* ... and find an LWP with a status to report to the core, if
3391 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3395 /* Check for zombie thread group leaders. Those can't be reaped
3396 until all other threads in the thread group are. */
3397 check_zombie_leaders ();
3399 /* If there are no resumed children left, bail. We'd be stuck
3400 forever in the sigsuspend call below otherwise. */
3401 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3403 if (debug_linux_nat
)
3404 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3406 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3408 restore_child_signals_mask (&prev_mask
);
3409 return minus_one_ptid
;
3412 /* No interesting event to report to the core. */
3414 if (target_options
& TARGET_WNOHANG
)
3416 if (debug_linux_nat
)
3417 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3419 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3420 restore_child_signals_mask (&prev_mask
);
3421 return minus_one_ptid
;
3424 /* We shouldn't end up here unless we want to try again. */
3425 gdb_assert (lp
== NULL
);
3427 /* Block until we get an event reported with SIGCHLD. */
3428 if (debug_linux_nat
)
3429 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3430 sigsuspend (&suspend_mask
);
3435 status
= lp
->status
;
3438 if (!target_is_non_stop_p ())
3440 /* Now stop all other LWP's ... */
3441 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3443 /* ... and wait until all of them have reported back that
3444 they're no longer running. */
3445 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3448 /* If we're not waiting for a specific LWP, choose an event LWP from
3449 among those that have had events. Giving equal priority to all
3450 LWPs that have had events helps prevent starvation. */
3451 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3452 select_event_lwp (ptid
, &lp
, &status
);
3454 gdb_assert (lp
!= NULL
);
3456 /* Now that we've selected our final event LWP, un-adjust its PC if
3457 it was a software breakpoint, and we can't reliably support the
3458 "stopped by software breakpoint" stop reason. */
3459 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3460 && !USE_SIGTRAP_SIGINFO
)
3462 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3463 struct gdbarch
*gdbarch
= regcache
->arch ();
3464 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3470 pc
= regcache_read_pc (regcache
);
3471 regcache_write_pc (regcache
, pc
+ decr_pc
);
3475 /* We'll need this to determine whether to report a SIGSTOP as
3476 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3478 last_resume_kind
= lp
->last_resume_kind
;
3480 if (!target_is_non_stop_p ())
3482 /* In all-stop, from the core's perspective, all LWPs are now
3483 stopped until a new resume action is sent over. */
3484 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3488 resume_clear_callback (lp
, NULL
);
3491 if (linux_nat_status_is_event (status
))
3493 if (debug_linux_nat
)
3494 fprintf_unfiltered (gdb_stdlog
,
3495 "LLW: trap ptid is %s.\n",
3496 target_pid_to_str (lp
->ptid
));
3499 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3501 *ourstatus
= lp
->waitstatus
;
3502 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3505 store_waitstatus (ourstatus
, status
);
3507 if (debug_linux_nat
)
3508 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3510 restore_child_signals_mask (&prev_mask
);
3512 if (last_resume_kind
== resume_stop
3513 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3514 && WSTOPSIG (status
) == SIGSTOP
)
3516 /* A thread that has been requested to stop by GDB with
3517 target_stop, and it stopped cleanly, so report as SIG0. The
3518 use of SIGSTOP is an implementation detail. */
3519 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3522 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3523 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3526 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3528 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3529 return filter_exit_event (lp
, ourstatus
);
3534 /* Resume LWPs that are currently stopped without any pending status
3535 to report, but are resumed from the core's perspective. */
3538 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3540 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3544 if (debug_linux_nat
)
3545 fprintf_unfiltered (gdb_stdlog
,
3546 "RSRL: NOT resuming LWP %s, not stopped\n",
3547 target_pid_to_str (lp
->ptid
));
3549 else if (!lp
->resumed
)
3551 if (debug_linux_nat
)
3552 fprintf_unfiltered (gdb_stdlog
,
3553 "RSRL: NOT resuming LWP %s, not resumed\n",
3554 target_pid_to_str (lp
->ptid
));
3556 else if (lwp_status_pending_p (lp
))
3558 if (debug_linux_nat
)
3559 fprintf_unfiltered (gdb_stdlog
,
3560 "RSRL: NOT resuming LWP %s, has pending status\n",
3561 target_pid_to_str (lp
->ptid
));
3565 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3566 struct gdbarch
*gdbarch
= regcache
->arch ();
3570 CORE_ADDR pc
= regcache_read_pc (regcache
);
3571 int leave_stopped
= 0;
3573 /* Don't bother if there's a breakpoint at PC that we'd hit
3574 immediately, and we're not waiting for this LWP. */
3575 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3577 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3583 if (debug_linux_nat
)
3584 fprintf_unfiltered (gdb_stdlog
,
3585 "RSRL: resuming stopped-resumed LWP %s at "
3587 target_pid_to_str (lp
->ptid
),
3588 paddress (gdbarch
, pc
),
3591 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3594 CATCH (ex
, RETURN_MASK_ERROR
)
3596 if (!check_ptrace_stopped_lwp_gone (lp
))
3597 throw_exception (ex
);
3606 linux_nat_wait (struct target_ops
*ops
,
3607 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3612 if (debug_linux_nat
)
3614 char *options_string
;
3616 options_string
= target_options_to_string (target_options
);
3617 fprintf_unfiltered (gdb_stdlog
,
3618 "linux_nat_wait: [%s], [%s]\n",
3619 target_pid_to_str (ptid
),
3621 xfree (options_string
);
3624 /* Flush the async file first. */
3625 if (target_is_async_p ())
3626 async_file_flush ();
3628 /* Resume LWPs that are currently stopped without any pending status
3629 to report, but are resumed from the core's perspective. LWPs get
3630 in this state if we find them stopping at a time we're not
3631 interested in reporting the event (target_wait on a
3632 specific_process, for example, see linux_nat_wait_1), and
3633 meanwhile the event became uninteresting. Don't bother resuming
3634 LWPs we're not going to wait for if they'd stop immediately. */
3635 if (target_is_non_stop_p ())
3636 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3638 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3640 /* If we requested any event, and something came out, assume there
3641 may be more. If we requested a specific lwp or process, also
3642 assume there may be more. */
3643 if (target_is_async_p ()
3644 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3645 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3646 || !ptid_equal (ptid
, minus_one_ptid
)))
3655 kill_one_lwp (pid_t pid
)
3657 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3660 kill_lwp (pid
, SIGKILL
);
3661 if (debug_linux_nat
)
3663 int save_errno
= errno
;
3665 fprintf_unfiltered (gdb_stdlog
,
3666 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3667 save_errno
? safe_strerror (save_errno
) : "OK");
3670 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3673 ptrace (PTRACE_KILL
, pid
, 0, 0);
3674 if (debug_linux_nat
)
3676 int save_errno
= errno
;
3678 fprintf_unfiltered (gdb_stdlog
,
3679 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3680 save_errno
? safe_strerror (save_errno
) : "OK");
3684 /* Wait for an LWP to die. */
3687 kill_wait_one_lwp (pid_t pid
)
3691 /* We must make sure that there are no pending events (delayed
3692 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3693 program doesn't interfere with any following debugging session. */
3697 res
= my_waitpid (pid
, NULL
, __WALL
);
3698 if (res
!= (pid_t
) -1)
3700 if (debug_linux_nat
)
3701 fprintf_unfiltered (gdb_stdlog
,
3702 "KWC: wait %ld received unknown.\n",
3704 /* The Linux kernel sometimes fails to kill a thread
3705 completely after PTRACE_KILL; that goes from the stop
3706 point in do_fork out to the one in get_signal_to_deliver
3707 and waits again. So kill it again. */
3713 gdb_assert (res
== -1 && errno
== ECHILD
);
3716 /* Callback for iterate_over_lwps. */
3719 kill_callback (struct lwp_info
*lp
, void *data
)
3721 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3725 /* Callback for iterate_over_lwps. */
3728 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3730 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3734 /* Kill the fork children of any threads of inferior INF that are
3735 stopped at a fork event. */
3738 kill_unfollowed_fork_children (struct inferior
*inf
)
3740 struct thread_info
*thread
;
3742 ALL_NON_EXITED_THREADS (thread
)
3743 if (thread
->inf
== inf
)
3745 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3747 if (ws
->kind
== TARGET_WAITKIND_FORKED
3748 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3750 ptid_t child_ptid
= ws
->value
.related_pid
;
3751 int child_pid
= ptid_get_pid (child_ptid
);
3752 int child_lwp
= ptid_get_lwp (child_ptid
);
3754 kill_one_lwp (child_lwp
);
3755 kill_wait_one_lwp (child_lwp
);
3757 /* Let the arch-specific native code know this process is
3759 linux_nat_forget_process (child_pid
);
3765 linux_nat_kill (struct target_ops
*ops
)
3767 /* If we're stopped while forking and we haven't followed yet,
3768 kill the other task. We need to do this first because the
3769 parent will be sleeping if this is a vfork. */
3770 kill_unfollowed_fork_children (current_inferior ());
3772 if (forks_exist_p ())
3773 linux_fork_killall ();
3776 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3778 /* Stop all threads before killing them, since ptrace requires
3779 that the thread is stopped to sucessfully PTRACE_KILL. */
3780 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3781 /* ... and wait until all of them have reported back that
3782 they're no longer running. */
3783 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3785 /* Kill all LWP's ... */
3786 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3788 /* ... and wait until we've flushed all events. */
3789 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3792 target_mourn_inferior (inferior_ptid
);
3796 linux_nat_mourn_inferior (struct target_ops
*ops
)
3798 int pid
= ptid_get_pid (inferior_ptid
);
3800 purge_lwp_list (pid
);
3802 if (! forks_exist_p ())
3803 /* Normal case, no other forks available. */
3804 linux_ops
->to_mourn_inferior (ops
);
3806 /* Multi-fork case. The current inferior_ptid has exited, but
3807 there are other viable forks to debug. Delete the exiting
3808 one and context-switch to the first available. */
3809 linux_fork_mourn_inferior ();
3811 /* Let the arch-specific native code know this process is gone. */
3812 linux_nat_forget_process (pid
);
3815 /* Convert a native/host siginfo object, into/from the siginfo in the
3816 layout of the inferiors' architecture. */
3819 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3823 if (linux_nat_siginfo_fixup
!= NULL
)
3824 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3826 /* If there was no callback, or the callback didn't do anything,
3827 then just do a straight memcpy. */
3831 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3833 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3837 static enum target_xfer_status
3838 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3839 const char *annex
, gdb_byte
*readbuf
,
3840 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3841 ULONGEST
*xfered_len
)
3845 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3847 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3848 gdb_assert (readbuf
|| writebuf
);
3850 pid
= ptid_get_lwp (inferior_ptid
);
3852 pid
= ptid_get_pid (inferior_ptid
);
3854 if (offset
> sizeof (siginfo
))
3855 return TARGET_XFER_E_IO
;
3858 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3860 return TARGET_XFER_E_IO
;
3862 /* When GDB is built as a 64-bit application, ptrace writes into
3863 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3864 inferior with a 64-bit GDB should look the same as debugging it
3865 with a 32-bit GDB, we need to convert it. GDB core always sees
3866 the converted layout, so any read/write will have to be done
3868 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3870 if (offset
+ len
> sizeof (siginfo
))
3871 len
= sizeof (siginfo
) - offset
;
3873 if (readbuf
!= NULL
)
3874 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3877 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3879 /* Convert back to ptrace layout before flushing it out. */
3880 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3883 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3885 return TARGET_XFER_E_IO
;
3889 return TARGET_XFER_OK
;
3892 static enum target_xfer_status
3893 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3894 const char *annex
, gdb_byte
*readbuf
,
3895 const gdb_byte
*writebuf
,
3896 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3898 enum target_xfer_status xfer
;
3900 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3901 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3902 offset
, len
, xfered_len
);
3904 /* The target is connected but no live inferior is selected. Pass
3905 this request down to a lower stratum (e.g., the executable
3907 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3908 return TARGET_XFER_EOF
;
3910 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3911 offset
, len
, xfered_len
);
3917 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3919 /* As long as a PTID is in lwp list, consider it alive. */
3920 return find_lwp_pid (ptid
) != NULL
;
3923 /* Implement the to_update_thread_list target method for this
3927 linux_nat_update_thread_list (struct target_ops
*ops
)
3929 struct lwp_info
*lwp
;
3931 /* We add/delete threads from the list as clone/exit events are
3932 processed, so just try deleting exited threads still in the
3934 delete_exited_threads ();
3936 /* Update the processor core that each lwp/thread was last seen
3940 /* Avoid accessing /proc if the thread hasn't run since we last
3941 time we fetched the thread's core. Accessing /proc becomes
3942 noticeably expensive when we have thousands of LWPs. */
3943 if (lwp
->core
== -1)
3944 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3949 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3951 static char buf
[64];
3953 if (ptid_lwp_p (ptid
)
3954 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3955 || num_lwps (ptid_get_pid (ptid
)) > 1))
3957 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3961 return normal_pid_to_str (ptid
);
3965 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3967 return linux_proc_tid_get_name (thr
->ptid
);
3970 /* Accepts an integer PID; Returns a string representing a file that
3971 can be opened to get the symbols for the child process. */
3974 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3976 return linux_proc_pid_to_exec_file (pid
);
3979 /* Implement the to_xfer_partial target method using /proc/<pid>/mem.
3980 Because we can use a single read/write call, this can be much more
3981 efficient than banging away at PTRACE_PEEKTEXT. */
3983 static enum target_xfer_status
3984 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3985 const char *annex
, gdb_byte
*readbuf
,
3986 const gdb_byte
*writebuf
,
3987 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3993 if (object
!= TARGET_OBJECT_MEMORY
)
3994 return TARGET_XFER_EOF
;
3996 /* Don't bother for one word. */
3997 if (len
< 3 * sizeof (long))
3998 return TARGET_XFER_EOF
;
4000 /* We could keep this file open and cache it - possibly one per
4001 thread. That requires some juggling, but is even faster. */
4002 xsnprintf (filename
, sizeof filename
, "/proc/%ld/mem",
4003 ptid_get_lwp (inferior_ptid
));
4004 fd
= gdb_open_cloexec (filename
, ((readbuf
? O_RDONLY
: O_WRONLY
)
4007 return TARGET_XFER_EOF
;
4009 /* Use pread64/pwrite64 if available, since they save a syscall and can
4010 handle 64-bit offsets even on 32-bit platforms (for instance, SPARC
4011 debugging a SPARC64 application). */
4013 ret
= (readbuf
? pread64 (fd
, readbuf
, len
, offset
)
4014 : pwrite64 (fd
, writebuf
, len
, offset
));
4016 ret
= lseek (fd
, offset
, SEEK_SET
);
4018 ret
= (readbuf
? read (fd
, readbuf
, len
)
4019 : write (fd
, writebuf
, len
));
4024 if (ret
== -1 || ret
== 0)
4025 return TARGET_XFER_EOF
;
4029 return TARGET_XFER_OK
;
4034 /* Enumerate spufs IDs for process PID. */
4036 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
4038 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
4040 LONGEST written
= 0;
4043 struct dirent
*entry
;
4045 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4046 dir
= opendir (path
);
4051 while ((entry
= readdir (dir
)) != NULL
)
4057 fd
= atoi (entry
->d_name
);
4061 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4062 if (stat (path
, &st
) != 0)
4064 if (!S_ISDIR (st
.st_mode
))
4067 if (statfs (path
, &stfs
) != 0)
4069 if (stfs
.f_type
!= SPUFS_MAGIC
)
4072 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4074 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4084 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4085 object type, using the /proc file system. */
4087 static enum target_xfer_status
4088 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4089 const char *annex
, gdb_byte
*readbuf
,
4090 const gdb_byte
*writebuf
,
4091 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4096 int pid
= ptid_get_lwp (inferior_ptid
);
4101 return TARGET_XFER_E_IO
;
4104 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4107 return TARGET_XFER_E_IO
;
4109 return TARGET_XFER_EOF
;
4112 *xfered_len
= (ULONGEST
) l
;
4113 return TARGET_XFER_OK
;
4118 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4119 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4121 return TARGET_XFER_E_IO
;
4124 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4127 return TARGET_XFER_EOF
;
4131 ret
= write (fd
, writebuf
, (size_t) len
);
4133 ret
= read (fd
, readbuf
, (size_t) len
);
4138 return TARGET_XFER_E_IO
;
4140 return TARGET_XFER_EOF
;
4143 *xfered_len
= (ULONGEST
) ret
;
4144 return TARGET_XFER_OK
;
4149 /* Parse LINE as a signal set and add its set bits to SIGS. */
4152 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4154 int len
= strlen (line
) - 1;
4158 if (line
[len
] != '\n')
4159 error (_("Could not parse signal set: %s"), line
);
4167 if (*p
>= '0' && *p
<= '9')
4169 else if (*p
>= 'a' && *p
<= 'f')
4170 digit
= *p
- 'a' + 10;
4172 error (_("Could not parse signal set: %s"), line
);
4177 sigaddset (sigs
, signum
+ 1);
4179 sigaddset (sigs
, signum
+ 2);
4181 sigaddset (sigs
, signum
+ 3);
4183 sigaddset (sigs
, signum
+ 4);
4189 /* Find process PID's pending signals from /proc/pid/status and set
4193 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4194 sigset_t
*blocked
, sigset_t
*ignored
)
4196 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4198 sigemptyset (pending
);
4199 sigemptyset (blocked
);
4200 sigemptyset (ignored
);
4201 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4202 gdb_file_up procfile
= gdb_fopen_cloexec (fname
, "r");
4203 if (procfile
== NULL
)
4204 error (_("Could not open %s"), fname
);
4206 while (fgets (buffer
, PATH_MAX
, procfile
.get ()) != NULL
)
4208 /* Normal queued signals are on the SigPnd line in the status
4209 file. However, 2.6 kernels also have a "shared" pending
4210 queue for delivering signals to a thread group, so check for
4213 Unfortunately some Red Hat kernels include the shared pending
4214 queue but not the ShdPnd status field. */
4216 if (startswith (buffer
, "SigPnd:\t"))
4217 add_line_to_sigset (buffer
+ 8, pending
);
4218 else if (startswith (buffer
, "ShdPnd:\t"))
4219 add_line_to_sigset (buffer
+ 8, pending
);
4220 else if (startswith (buffer
, "SigBlk:\t"))
4221 add_line_to_sigset (buffer
+ 8, blocked
);
4222 else if (startswith (buffer
, "SigIgn:\t"))
4223 add_line_to_sigset (buffer
+ 8, ignored
);
4227 static enum target_xfer_status
4228 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4229 const char *annex
, gdb_byte
*readbuf
,
4230 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4231 ULONGEST
*xfered_len
)
4233 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4235 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4236 if (*xfered_len
== 0)
4237 return TARGET_XFER_EOF
;
4239 return TARGET_XFER_OK
;
4242 static enum target_xfer_status
4243 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4244 const char *annex
, gdb_byte
*readbuf
,
4245 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4246 ULONGEST
*xfered_len
)
4248 enum target_xfer_status xfer
;
4250 if (object
== TARGET_OBJECT_AUXV
)
4251 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4252 offset
, len
, xfered_len
);
4254 if (object
== TARGET_OBJECT_OSDATA
)
4255 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4256 offset
, len
, xfered_len
);
4258 if (object
== TARGET_OBJECT_SPU
)
4259 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4260 offset
, len
, xfered_len
);
4262 /* GDB calculates all the addresses in possibly larget width of the address.
4263 Address width needs to be masked before its final use - either by
4264 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4266 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4268 if (object
== TARGET_OBJECT_MEMORY
)
4270 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4272 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4273 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4276 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4277 offset
, len
, xfered_len
);
4278 if (xfer
!= TARGET_XFER_EOF
)
4281 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4282 offset
, len
, xfered_len
);
4286 cleanup_target_stop (void *arg
)
4288 ptid_t
*ptid
= (ptid_t
*) arg
;
4290 gdb_assert (arg
!= NULL
);
4293 target_continue_no_signal (*ptid
);
4296 static VEC(static_tracepoint_marker_p
) *
4297 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4300 char s
[IPA_CMD_BUF_SIZE
];
4301 struct cleanup
*old_chain
;
4302 int pid
= ptid_get_pid (inferior_ptid
);
4303 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4304 struct static_tracepoint_marker
*marker
= NULL
;
4306 ptid_t ptid
= ptid_build (pid
, 0, 0);
4311 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4312 s
[sizeof ("qTfSTM")] = 0;
4314 agent_run_command (pid
, s
, strlen (s
) + 1);
4316 old_chain
= make_cleanup (free_current_marker
, &marker
);
4317 make_cleanup (cleanup_target_stop
, &ptid
);
4322 marker
= XCNEW (struct static_tracepoint_marker
);
4326 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4328 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4330 VEC_safe_push (static_tracepoint_marker_p
,
4336 release_static_tracepoint_marker (marker
);
4337 memset (marker
, 0, sizeof (*marker
));
4340 while (*p
++ == ','); /* comma-separated list */
4342 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4343 s
[sizeof ("qTsSTM")] = 0;
4344 agent_run_command (pid
, s
, strlen (s
) + 1);
4348 do_cleanups (old_chain
);
4353 /* Create a prototype generic GNU/Linux target. The client can override
4354 it with local methods. */
4357 linux_target_install_ops (struct target_ops
*t
)
4359 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4360 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4361 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4362 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4363 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4364 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4365 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4366 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4367 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4368 t
->to_post_attach
= linux_child_post_attach
;
4369 t
->to_follow_fork
= linux_child_follow_fork
;
4371 super_xfer_partial
= t
->to_xfer_partial
;
4372 t
->to_xfer_partial
= linux_xfer_partial
;
4374 t
->to_static_tracepoint_markers_by_strid
4375 = linux_child_static_tracepoint_markers_by_strid
;
4381 struct target_ops
*t
;
4383 t
= inf_ptrace_target ();
4384 linux_target_install_ops (t
);
4390 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4392 struct target_ops
*t
;
4394 t
= inf_ptrace_trad_target (register_u_offset
);
4395 linux_target_install_ops (t
);
4400 /* target_is_async_p implementation. */
4403 linux_nat_is_async_p (struct target_ops
*ops
)
4405 return linux_is_async_p ();
4408 /* target_can_async_p implementation. */
4411 linux_nat_can_async_p (struct target_ops
*ops
)
4413 /* We're always async, unless the user explicitly prevented it with the
4414 "maint set target-async" command. */
4415 return target_async_permitted
;
4419 linux_nat_supports_non_stop (struct target_ops
*self
)
4424 /* to_always_non_stop_p implementation. */
4427 linux_nat_always_non_stop_p (struct target_ops
*self
)
4432 /* True if we want to support multi-process. To be removed when GDB
4433 supports multi-exec. */
4435 int linux_multi_process
= 1;
4438 linux_nat_supports_multi_process (struct target_ops
*self
)
4440 return linux_multi_process
;
4444 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4446 #ifdef HAVE_PERSONALITY
4453 static int async_terminal_is_ours
= 1;
4455 /* target_terminal_inferior implementation.
4457 This is a wrapper around child_terminal_inferior to add async support. */
4460 linux_nat_terminal_inferior (struct target_ops
*self
)
4462 child_terminal_inferior (self
);
4464 /* Calls to target_terminal_*() are meant to be idempotent. */
4465 if (!async_terminal_is_ours
)
4468 async_terminal_is_ours
= 0;
4472 /* target_terminal::ours implementation.
4474 This is a wrapper around child_terminal_ours to add async support (and
4475 implement the target_terminal::ours vs target_terminal::ours_for_output
4476 distinction). child_terminal_ours is currently no different than
4477 child_terminal_ours_for_output.
4478 We leave target_terminal::ours_for_output alone, leaving it to
4479 child_terminal_ours_for_output. */
4482 linux_nat_terminal_ours (struct target_ops
*self
)
4484 /* GDB should never give the terminal to the inferior if the
4485 inferior is running in the background (run&, continue&, etc.),
4486 but claiming it sure should. */
4487 child_terminal_ours (self
);
4489 if (async_terminal_is_ours
)
4492 clear_sigint_trap ();
4493 async_terminal_is_ours
= 1;
4496 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4497 so we notice when any child changes state, and notify the
4498 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4499 above to wait for the arrival of a SIGCHLD. */
4502 sigchld_handler (int signo
)
4504 int old_errno
= errno
;
4506 if (debug_linux_nat
)
4507 ui_file_write_async_safe (gdb_stdlog
,
4508 "sigchld\n", sizeof ("sigchld\n") - 1);
4510 if (signo
== SIGCHLD
4511 && linux_nat_event_pipe
[0] != -1)
4512 async_file_mark (); /* Let the event loop know that there are
4513 events to handle. */
4518 /* Callback registered with the target events file descriptor. */
4521 handle_target_event (int error
, gdb_client_data client_data
)
4523 inferior_event_handler (INF_REG_EVENT
, NULL
);
4526 /* Create/destroy the target events pipe. Returns previous state. */
4529 linux_async_pipe (int enable
)
4531 int previous
= linux_is_async_p ();
4533 if (previous
!= enable
)
4537 /* Block child signals while we create/destroy the pipe, as
4538 their handler writes to it. */
4539 block_child_signals (&prev_mask
);
4543 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4544 internal_error (__FILE__
, __LINE__
,
4545 "creating event pipe failed.");
4547 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4548 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4552 close (linux_nat_event_pipe
[0]);
4553 close (linux_nat_event_pipe
[1]);
4554 linux_nat_event_pipe
[0] = -1;
4555 linux_nat_event_pipe
[1] = -1;
4558 restore_child_signals_mask (&prev_mask
);
4564 /* target_async implementation. */
4567 linux_nat_async (struct target_ops
*ops
, int enable
)
4571 if (!linux_async_pipe (1))
4573 add_file_handler (linux_nat_event_pipe
[0],
4574 handle_target_event
, NULL
);
4575 /* There may be pending events to handle. Tell the event loop
4582 delete_file_handler (linux_nat_event_pipe
[0]);
4583 linux_async_pipe (0);
4588 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4592 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4596 if (debug_linux_nat
)
4597 fprintf_unfiltered (gdb_stdlog
,
4598 "LNSL: running -> suspending %s\n",
4599 target_pid_to_str (lwp
->ptid
));
4602 if (lwp
->last_resume_kind
== resume_stop
)
4604 if (debug_linux_nat
)
4605 fprintf_unfiltered (gdb_stdlog
,
4606 "linux-nat: already stopping LWP %ld at "
4608 ptid_get_lwp (lwp
->ptid
));
4612 stop_callback (lwp
, NULL
);
4613 lwp
->last_resume_kind
= resume_stop
;
4617 /* Already known to be stopped; do nothing. */
4619 if (debug_linux_nat
)
4621 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4622 fprintf_unfiltered (gdb_stdlog
,
4623 "LNSL: already stopped/stop_requested %s\n",
4624 target_pid_to_str (lwp
->ptid
));
4626 fprintf_unfiltered (gdb_stdlog
,
4627 "LNSL: already stopped/no "
4628 "stop_requested yet %s\n",
4629 target_pid_to_str (lwp
->ptid
));
4636 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4638 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4642 linux_nat_close (struct target_ops
*self
)
4644 /* Unregister from the event loop. */
4645 if (linux_nat_is_async_p (self
))
4646 linux_nat_async (self
, 0);
4648 if (linux_ops
->to_close
)
4649 linux_ops
->to_close (linux_ops
);
4654 /* When requests are passed down from the linux-nat layer to the
4655 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4656 used. The address space pointer is stored in the inferior object,
4657 but the common code that is passed such ptid can't tell whether
4658 lwpid is a "main" process id or not (it assumes so). We reverse
4659 look up the "main" process id from the lwp here. */
4661 static struct address_space
*
4662 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4664 struct lwp_info
*lwp
;
4665 struct inferior
*inf
;
4668 if (ptid_get_lwp (ptid
) == 0)
4670 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4672 lwp
= find_lwp_pid (ptid
);
4673 pid
= ptid_get_pid (lwp
->ptid
);
4677 /* A (pid,lwpid,0) ptid. */
4678 pid
= ptid_get_pid (ptid
);
4681 inf
= find_inferior_pid (pid
);
4682 gdb_assert (inf
!= NULL
);
4686 /* Return the cached value of the processor core for thread PTID. */
4689 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4691 struct lwp_info
*info
= find_lwp_pid (ptid
);
4698 /* Implementation of to_filesystem_is_local. */
4701 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4703 struct inferior
*inf
= current_inferior ();
4705 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4708 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4711 /* Convert the INF argument passed to a to_fileio_* method
4712 to a process ID suitable for passing to its corresponding
4713 linux_mntns_* function. If INF is non-NULL then the
4714 caller is requesting the filesystem seen by INF. If INF
4715 is NULL then the caller is requesting the filesystem seen
4716 by the GDB. We fall back to GDB's filesystem in the case
4717 that INF is non-NULL but its PID is unknown. */
4720 linux_nat_fileio_pid_of (struct inferior
*inf
)
4722 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4728 /* Implementation of to_fileio_open. */
4731 linux_nat_fileio_open (struct target_ops
*self
,
4732 struct inferior
*inf
, const char *filename
,
4733 int flags
, int mode
, int warn_if_slow
,
4740 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4741 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4743 *target_errno
= FILEIO_EINVAL
;
4747 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4748 filename
, nat_flags
, nat_mode
);
4750 *target_errno
= host_to_fileio_error (errno
);
4755 /* Implementation of to_fileio_readlink. */
4758 linux_nat_fileio_readlink (struct target_ops
*self
,
4759 struct inferior
*inf
, const char *filename
,
4766 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4767 filename
, buf
, sizeof (buf
));
4770 *target_errno
= host_to_fileio_error (errno
);
4774 ret
= (char *) xmalloc (len
+ 1);
4775 memcpy (ret
, buf
, len
);
4780 /* Implementation of to_fileio_unlink. */
4783 linux_nat_fileio_unlink (struct target_ops
*self
,
4784 struct inferior
*inf
, const char *filename
,
4789 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4792 *target_errno
= host_to_fileio_error (errno
);
4797 /* Implementation of the to_thread_events method. */
4800 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4802 report_thread_events
= enable
;
4806 linux_nat_add_target (struct target_ops
*t
)
4808 /* Save the provided single-threaded target. We save this in a separate
4809 variable because another target we've inherited from (e.g. inf-ptrace)
4810 may have saved a pointer to T; we want to use it for the final
4811 process stratum target. */
4812 linux_ops_saved
= *t
;
4813 linux_ops
= &linux_ops_saved
;
4815 /* Override some methods for multithreading. */
4816 t
->to_create_inferior
= linux_nat_create_inferior
;
4817 t
->to_attach
= linux_nat_attach
;
4818 t
->to_detach
= linux_nat_detach
;
4819 t
->to_resume
= linux_nat_resume
;
4820 t
->to_wait
= linux_nat_wait
;
4821 t
->to_pass_signals
= linux_nat_pass_signals
;
4822 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4823 t
->to_kill
= linux_nat_kill
;
4824 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4825 t
->to_thread_alive
= linux_nat_thread_alive
;
4826 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4827 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4828 t
->to_thread_name
= linux_nat_thread_name
;
4829 t
->to_has_thread_control
= tc_schedlock
;
4830 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4831 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4832 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4833 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4834 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4835 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4836 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4837 t
->to_thread_events
= linux_nat_thread_events
;
4839 t
->to_can_async_p
= linux_nat_can_async_p
;
4840 t
->to_is_async_p
= linux_nat_is_async_p
;
4841 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4842 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4843 t
->to_async
= linux_nat_async
;
4844 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4845 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4847 super_close
= t
->to_close
;
4848 t
->to_close
= linux_nat_close
;
4850 t
->to_stop
= linux_nat_stop
;
4852 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4854 t
->to_supports_disable_randomization
4855 = linux_nat_supports_disable_randomization
;
4857 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4859 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4860 t
->to_fileio_open
= linux_nat_fileio_open
;
4861 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4862 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4864 /* We don't change the stratum; this target will sit at
4865 process_stratum and thread_db will set at thread_stratum. This
4866 is a little strange, since this is a multi-threaded-capable
4867 target, but we want to be on the stack below thread_db, and we
4868 also want to be used for single-threaded processes. */
4873 /* Register a method to call whenever a new thread is attached. */
4875 linux_nat_set_new_thread (struct target_ops
*t
,
4876 void (*new_thread
) (struct lwp_info
*))
4878 /* Save the pointer. We only support a single registered instance
4879 of the GNU/Linux native target, so we do not need to map this to
4881 linux_nat_new_thread
= new_thread
;
4884 /* Register a method to call whenever a new thread is attached. */
4886 linux_nat_set_delete_thread (struct target_ops
*t
,
4887 void (*delete_thread
) (struct arch_lwp_info
*))
4889 /* Save the pointer. We only support a single registered instance
4890 of the GNU/Linux native target, so we do not need to map this to
4892 linux_nat_delete_thread
= delete_thread
;
4895 /* See declaration in linux-nat.h. */
4898 linux_nat_set_new_fork (struct target_ops
*t
,
4899 linux_nat_new_fork_ftype
*new_fork
)
4901 /* Save the pointer. */
4902 linux_nat_new_fork
= new_fork
;
4905 /* See declaration in linux-nat.h. */
4908 linux_nat_set_forget_process (struct target_ops
*t
,
4909 linux_nat_forget_process_ftype
*fn
)
4911 /* Save the pointer. */
4912 linux_nat_forget_process_hook
= fn
;
4915 /* See declaration in linux-nat.h. */
4918 linux_nat_forget_process (pid_t pid
)
4920 if (linux_nat_forget_process_hook
!= NULL
)
4921 linux_nat_forget_process_hook (pid
);
4924 /* Register a method that converts a siginfo object between the layout
4925 that ptrace returns, and the layout in the architecture of the
4928 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4929 int (*siginfo_fixup
) (siginfo_t
*,
4933 /* Save the pointer. */
4934 linux_nat_siginfo_fixup
= siginfo_fixup
;
4937 /* Register a method to call prior to resuming a thread. */
4940 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4941 void (*prepare_to_resume
) (struct lwp_info
*))
4943 /* Save the pointer. */
4944 linux_nat_prepare_to_resume
= prepare_to_resume
;
4947 /* See linux-nat.h. */
4950 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4954 pid
= ptid_get_lwp (ptid
);
4956 pid
= ptid_get_pid (ptid
);
4959 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4962 memset (siginfo
, 0, sizeof (*siginfo
));
4968 /* See nat/linux-nat.h. */
4971 current_lwp_ptid (void)
4973 gdb_assert (ptid_lwp_p (inferior_ptid
));
4974 return inferior_ptid
;
4978 _initialize_linux_nat (void)
4980 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4981 &debug_linux_nat
, _("\
4982 Set debugging of GNU/Linux lwp module."), _("\
4983 Show debugging of GNU/Linux lwp module."), _("\
4984 Enables printf debugging output."),
4986 show_debug_linux_nat
,
4987 &setdebuglist
, &showdebuglist
);
4989 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4990 &debug_linux_namespaces
, _("\
4991 Set debugging of GNU/Linux namespaces module."), _("\
4992 Show debugging of GNU/Linux namespaces module."), _("\
4993 Enables printf debugging output."),
4996 &setdebuglist
, &showdebuglist
);
4998 /* Save this mask as the default. */
4999 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5001 /* Install a SIGCHLD handler. */
5002 sigchld_action
.sa_handler
= sigchld_handler
;
5003 sigemptyset (&sigchld_action
.sa_mask
);
5004 sigchld_action
.sa_flags
= SA_RESTART
;
5006 /* Make it the default. */
5007 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5009 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5010 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5011 sigdelset (&suspend_mask
, SIGCHLD
);
5013 sigemptyset (&blocked_mask
);
5015 lwp_lwpid_htab_create ();
5019 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5020 the GNU/Linux Threads library and therefore doesn't really belong
5023 /* Return the set of signals used by the threads library in *SET. */
5026 lin_thread_get_thread_signals (sigset_t
*set
)
5030 /* NPTL reserves the first two RT signals, but does not provide any
5031 way for the debugger to query the signal numbers - fortunately
5032 they don't change. */
5033 sigaddset (set
, __SIGRTMIN
);
5034 sigaddset (set
, __SIGRTMIN
+ 1);