1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a new fork is attached. */
201 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
203 /* The method to call, if any, when a process is no longer
205 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
207 /* Hook to call prior to resuming a thread. */
208 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
210 /* The method to call, if any, when the siginfo object needs to be
211 converted between the layout returned by ptrace, and the layout in
212 the architecture of the inferior. */
213 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
217 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
218 Called by our to_xfer_partial. */
219 static target_xfer_partial_ftype
*super_xfer_partial
;
221 /* The saved to_close method, inherited from inf-ptrace.c.
222 Called by our to_close. */
223 static void (*super_close
) (struct target_ops
*);
225 static unsigned int debug_linux_nat
;
227 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
228 struct cmd_list_element
*c
, const char *value
)
230 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 struct simple_pid_list
238 struct simple_pid_list
*next
;
240 struct simple_pid_list
*stopped_pids
;
242 /* Whether target_thread_events is in effect. */
243 static int report_thread_events
;
245 /* Async mode support. */
247 /* The read/write ends of the pipe registered as waitable file in the
249 static int linux_nat_event_pipe
[2] = { -1, -1 };
251 /* True if we're currently in async mode. */
252 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
254 /* Flush the event pipe. */
257 async_file_flush (void)
264 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
266 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
269 /* Put something (anything, doesn't matter what, or how much) in event
270 pipe, so that the select/poll in the event-loop realizes we have
271 something to process. */
274 async_file_mark (void)
278 /* It doesn't really matter what the pipe contains, as long we end
279 up with something in it. Might as well flush the previous
285 ret
= write (linux_nat_event_pipe
[1], "+", 1);
287 while (ret
== -1 && errno
== EINTR
);
289 /* Ignore EAGAIN. If the pipe is full, the event loop will already
290 be awakened anyway. */
293 static int kill_lwp (int lwpid
, int signo
);
295 static int stop_callback (struct lwp_info
*lp
, void *data
);
296 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
298 static void block_child_signals (sigset_t
*prev_mask
);
299 static void restore_child_signals_mask (sigset_t
*prev_mask
);
302 static struct lwp_info
*add_lwp (ptid_t ptid
);
303 static void purge_lwp_list (int pid
);
304 static void delete_lwp (ptid_t ptid
);
305 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
307 static int lwp_status_pending_p (struct lwp_info
*lp
);
309 static int sigtrap_is_event (int status
);
310 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
312 static void save_stop_reason (struct lwp_info
*lp
);
317 /* See nat/linux-nat.h. */
320 ptid_of_lwp (struct lwp_info
*lwp
)
325 /* See nat/linux-nat.h. */
328 lwp_set_arch_private_info (struct lwp_info
*lwp
,
329 struct arch_lwp_info
*info
)
331 lwp
->arch_private
= info
;
334 /* See nat/linux-nat.h. */
336 struct arch_lwp_info
*
337 lwp_arch_private_info (struct lwp_info
*lwp
)
339 return lwp
->arch_private
;
342 /* See nat/linux-nat.h. */
345 lwp_is_stopped (struct lwp_info
*lwp
)
350 /* See nat/linux-nat.h. */
352 enum target_stop_reason
353 lwp_stop_reason (struct lwp_info
*lwp
)
355 return lwp
->stop_reason
;
359 /* Trivial list manipulation functions to keep track of a list of
360 new stopped processes. */
362 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
364 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
367 new_pid
->status
= status
;
368 new_pid
->next
= *listp
;
373 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
375 struct simple_pid_list
**p
;
377 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
378 if ((*p
)->pid
== pid
)
380 struct simple_pid_list
*next
= (*p
)->next
;
382 *statusp
= (*p
)->status
;
390 /* Return the ptrace options that we want to try to enable. */
393 linux_nat_ptrace_options (int attached
)
398 options
|= PTRACE_O_EXITKILL
;
400 options
|= (PTRACE_O_TRACESYSGOOD
401 | PTRACE_O_TRACEVFORKDONE
402 | PTRACE_O_TRACEVFORK
404 | PTRACE_O_TRACEEXEC
);
409 /* Initialize ptrace warnings and check for supported ptrace
412 ATTACHED should be nonzero iff we attached to the inferior. */
415 linux_init_ptrace (pid_t pid
, int attached
)
417 int options
= linux_nat_ptrace_options (attached
);
419 linux_enable_event_reporting (pid
, options
);
420 linux_ptrace_init_warnings ();
424 linux_child_post_attach (struct target_ops
*self
, int pid
)
426 linux_init_ptrace (pid
, 1);
430 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
432 linux_init_ptrace (ptid_get_pid (ptid
), 0);
435 /* Return the number of known LWPs in the tgid given by PID. */
443 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
444 if (ptid_get_pid (lp
->ptid
) == pid
)
450 /* Call delete_lwp with prototype compatible for make_cleanup. */
453 delete_lwp_cleanup (void *lp_voidp
)
455 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
457 delete_lwp (lp
->ptid
);
460 /* Target hook for follow_fork. On entry inferior_ptid must be the
461 ptid of the followed inferior. At return, inferior_ptid will be
465 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
470 struct lwp_info
*child_lp
= NULL
;
471 int status
= W_STOPCODE (0);
472 struct cleanup
*old_chain
;
474 ptid_t parent_ptid
, child_ptid
;
475 int parent_pid
, child_pid
;
477 has_vforked
= (inferior_thread ()->pending_follow
.kind
478 == TARGET_WAITKIND_VFORKED
);
479 parent_ptid
= inferior_ptid
;
480 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
481 parent_pid
= ptid_get_lwp (parent_ptid
);
482 child_pid
= ptid_get_lwp (child_ptid
);
484 /* We're already attached to the parent, by default. */
485 old_chain
= save_inferior_ptid ();
486 inferior_ptid
= child_ptid
;
487 child_lp
= add_lwp (inferior_ptid
);
488 child_lp
->stopped
= 1;
489 child_lp
->last_resume_kind
= resume_stop
;
491 /* Detach new forked process? */
494 make_cleanup (delete_lwp_cleanup
, child_lp
);
496 if (linux_nat_prepare_to_resume
!= NULL
)
497 linux_nat_prepare_to_resume (child_lp
);
499 /* When debugging an inferior in an architecture that supports
500 hardware single stepping on a kernel without commit
501 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
502 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
503 set if the parent process had them set.
504 To work around this, single step the child process
505 once before detaching to clear the flags. */
507 if (!gdbarch_software_single_step_p (target_thread_architecture
510 linux_disable_event_reporting (child_pid
);
511 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
512 perror_with_name (_("Couldn't do single step"));
513 if (my_waitpid (child_pid
, &status
, 0) < 0)
514 perror_with_name (_("Couldn't wait vfork process"));
517 if (WIFSTOPPED (status
))
521 signo
= WSTOPSIG (status
);
523 && !signal_pass_state (gdb_signal_from_host (signo
)))
525 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
528 /* Resets value of inferior_ptid to parent ptid. */
529 do_cleanups (old_chain
);
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
537 do_cleanups (old_chain
);
541 struct lwp_info
*parent_lp
;
543 parent_lp
= find_lwp_pid (parent_ptid
);
544 gdb_assert (linux_supports_tracefork () >= 0);
546 if (linux_supports_tracevforkdone ())
549 fprintf_unfiltered (gdb_stdlog
,
550 "LCFF: waiting for VFORK_DONE on %d\n",
552 parent_lp
->stopped
= 1;
554 /* We'll handle the VFORK_DONE event like any other
555 event, in target_wait. */
559 /* We can't insert breakpoints until the child has
560 finished with the shared memory region. We need to
561 wait until that happens. Ideal would be to just
563 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
564 - waitpid (parent_pid, &status, __WALL);
565 However, most architectures can't handle a syscall
566 being traced on the way out if it wasn't traced on
569 We might also think to loop, continuing the child
570 until it exits or gets a SIGTRAP. One problem is
571 that the child might call ptrace with PTRACE_TRACEME.
573 There's no simple and reliable way to figure out when
574 the vforked child will be done with its copy of the
575 shared memory. We could step it out of the syscall,
576 two instructions, let it go, and then single-step the
577 parent once. When we have hardware single-step, this
578 would work; with software single-step it could still
579 be made to work but we'd have to be able to insert
580 single-step breakpoints in the child, and we'd have
581 to insert -just- the single-step breakpoint in the
582 parent. Very awkward.
584 In the end, the best we can do is to make sure it
585 runs for a little while. Hopefully it will be out of
586 range of any breakpoints we reinsert. Usually this
587 is only the single-step breakpoint at vfork's return
591 fprintf_unfiltered (gdb_stdlog
,
592 "LCFF: no VFORK_DONE "
593 "support, sleeping a bit\n");
597 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
598 and leave it pending. The next linux_nat_resume call
599 will notice a pending event, and bypasses actually
600 resuming the inferior. */
601 parent_lp
->status
= 0;
602 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
603 parent_lp
->stopped
= 1;
605 /* If we're in async mode, need to tell the event loop
606 there's something here to process. */
607 if (target_is_async_p ())
614 struct lwp_info
*child_lp
;
616 child_lp
= add_lwp (inferior_ptid
);
617 child_lp
->stopped
= 1;
618 child_lp
->last_resume_kind
= resume_stop
;
620 /* Let the thread_db layer learn about this new process. */
621 check_for_thread_db ();
629 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
631 return !linux_supports_tracefork ();
635 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
641 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
643 return !linux_supports_tracefork ();
647 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
653 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
655 return !linux_supports_tracefork ();
659 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
665 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
666 int pid
, int needed
, int any_count
,
667 int table_size
, int *table
)
669 if (!linux_supports_tracesysgood ())
672 /* On GNU/Linux, we ignore the arguments. It means that we only
673 enable the syscall catchpoints, but do not disable them.
675 Also, we do not use the `table' information because we do not
676 filter system calls here. We let GDB do the logic for us. */
680 /* List of known LWPs, keyed by LWP PID. This speeds up the common
681 case of mapping a PID returned from the kernel to our corresponding
682 lwp_info data structure. */
683 static htab_t lwp_lwpid_htab
;
685 /* Calculate a hash from a lwp_info's LWP PID. */
688 lwp_info_hash (const void *ap
)
690 const struct lwp_info
*lp
= (struct lwp_info
*) ap
;
691 pid_t pid
= ptid_get_lwp (lp
->ptid
);
693 return iterative_hash_object (pid
, 0);
696 /* Equality function for the lwp_info hash table. Compares the LWP's
700 lwp_lwpid_htab_eq (const void *a
, const void *b
)
702 const struct lwp_info
*entry
= (const struct lwp_info
*) a
;
703 const struct lwp_info
*element
= (const struct lwp_info
*) b
;
705 return ptid_get_lwp (entry
->ptid
) == ptid_get_lwp (element
->ptid
);
708 /* Create the lwp_lwpid_htab hash table. */
711 lwp_lwpid_htab_create (void)
713 lwp_lwpid_htab
= htab_create (100, lwp_info_hash
, lwp_lwpid_htab_eq
, NULL
);
716 /* Add LP to the hash table. */
719 lwp_lwpid_htab_add_lwp (struct lwp_info
*lp
)
723 slot
= htab_find_slot (lwp_lwpid_htab
, lp
, INSERT
);
724 gdb_assert (slot
!= NULL
&& *slot
== NULL
);
728 /* Head of doubly-linked list of known LWPs. Sorted by reverse
729 creation order. This order is assumed in some cases. E.g.,
730 reaping status after killing alls lwps of a process: the leader LWP
731 must be reaped last. */
732 struct lwp_info
*lwp_list
;
734 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
737 lwp_list_add (struct lwp_info
*lp
)
740 if (lwp_list
!= NULL
)
745 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
749 lwp_list_remove (struct lwp_info
*lp
)
751 /* Remove from sorted-by-creation-order list. */
752 if (lp
->next
!= NULL
)
753 lp
->next
->prev
= lp
->prev
;
754 if (lp
->prev
!= NULL
)
755 lp
->prev
->next
= lp
->next
;
762 /* Original signal mask. */
763 static sigset_t normal_mask
;
765 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
766 _initialize_linux_nat. */
767 static sigset_t suspend_mask
;
769 /* Signals to block to make that sigsuspend work. */
770 static sigset_t blocked_mask
;
772 /* SIGCHLD action. */
773 struct sigaction sigchld_action
;
775 /* Block child signals (SIGCHLD and linux threads signals), and store
776 the previous mask in PREV_MASK. */
779 block_child_signals (sigset_t
*prev_mask
)
781 /* Make sure SIGCHLD is blocked. */
782 if (!sigismember (&blocked_mask
, SIGCHLD
))
783 sigaddset (&blocked_mask
, SIGCHLD
);
785 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
788 /* Restore child signals mask, previously returned by
789 block_child_signals. */
792 restore_child_signals_mask (sigset_t
*prev_mask
)
794 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
797 /* Mask of signals to pass directly to the inferior. */
798 static sigset_t pass_mask
;
800 /* Update signals to pass to the inferior. */
802 linux_nat_pass_signals (struct target_ops
*self
,
803 int numsigs
, unsigned char *pass_signals
)
807 sigemptyset (&pass_mask
);
809 for (signo
= 1; signo
< NSIG
; signo
++)
811 int target_signo
= gdb_signal_from_host (signo
);
812 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
813 sigaddset (&pass_mask
, signo
);
819 /* Prototypes for local functions. */
820 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
821 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
822 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
826 /* Destroy and free LP. */
829 lwp_free (struct lwp_info
*lp
)
831 xfree (lp
->arch_private
);
835 /* Traversal function for purge_lwp_list. */
838 lwp_lwpid_htab_remove_pid (void **slot
, void *info
)
840 struct lwp_info
*lp
= (struct lwp_info
*) *slot
;
841 int pid
= *(int *) info
;
843 if (ptid_get_pid (lp
->ptid
) == pid
)
845 htab_clear_slot (lwp_lwpid_htab
, slot
);
846 lwp_list_remove (lp
);
853 /* Remove all LWPs belong to PID from the lwp list. */
856 purge_lwp_list (int pid
)
858 htab_traverse_noresize (lwp_lwpid_htab
, lwp_lwpid_htab_remove_pid
, &pid
);
861 /* Add the LWP specified by PTID to the list. PTID is the first LWP
862 in the process. Return a pointer to the structure describing the
865 This differs from add_lwp in that we don't let the arch specific
866 bits know about this new thread. Current clients of this callback
867 take the opportunity to install watchpoints in the new thread, and
868 we shouldn't do that for the first thread. If we're spawning a
869 child ("run"), the thread executes the shell wrapper first, and we
870 shouldn't touch it until it execs the program we want to debug.
871 For "attach", it'd be okay to call the callback, but it's not
872 necessary, because watchpoints can't yet have been inserted into
875 static struct lwp_info
*
876 add_initial_lwp (ptid_t ptid
)
880 gdb_assert (ptid_lwp_p (ptid
));
882 lp
= XNEW (struct lwp_info
);
884 memset (lp
, 0, sizeof (struct lwp_info
));
886 lp
->last_resume_kind
= resume_continue
;
887 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
892 /* Add to sorted-by-reverse-creation-order list. */
895 /* Add to keyed-by-pid htab. */
896 lwp_lwpid_htab_add_lwp (lp
);
901 /* Add the LWP specified by PID to the list. Return a pointer to the
902 structure describing the new LWP. The LWP should already be
905 static struct lwp_info
*
906 add_lwp (ptid_t ptid
)
910 lp
= add_initial_lwp (ptid
);
912 /* Let the arch specific bits know about this new thread. Current
913 clients of this callback take the opportunity to install
914 watchpoints in the new thread. We don't do this for the first
915 thread though. See add_initial_lwp. */
916 if (linux_nat_new_thread
!= NULL
)
917 linux_nat_new_thread (lp
);
922 /* Remove the LWP specified by PID from the list. */
925 delete_lwp (ptid_t ptid
)
929 struct lwp_info dummy
;
932 slot
= htab_find_slot (lwp_lwpid_htab
, &dummy
, NO_INSERT
);
936 lp
= *(struct lwp_info
**) slot
;
937 gdb_assert (lp
!= NULL
);
939 htab_clear_slot (lwp_lwpid_htab
, slot
);
941 /* Remove from sorted-by-creation-order list. */
942 lwp_list_remove (lp
);
948 /* Return a pointer to the structure describing the LWP corresponding
949 to PID. If no corresponding LWP could be found, return NULL. */
951 static struct lwp_info
*
952 find_lwp_pid (ptid_t ptid
)
956 struct lwp_info dummy
;
958 if (ptid_lwp_p (ptid
))
959 lwp
= ptid_get_lwp (ptid
);
961 lwp
= ptid_get_pid (ptid
);
963 dummy
.ptid
= ptid_build (0, lwp
, 0);
964 lp
= (struct lwp_info
*) htab_find (lwp_lwpid_htab
, &dummy
);
968 /* See nat/linux-nat.h. */
971 iterate_over_lwps (ptid_t filter
,
972 iterate_over_lwps_ftype callback
,
975 struct lwp_info
*lp
, *lpnext
;
977 for (lp
= lwp_list
; lp
; lp
= lpnext
)
981 if (ptid_match (lp
->ptid
, filter
))
983 if ((*callback
) (lp
, data
) != 0)
991 /* Update our internal state when changing from one checkpoint to
992 another indicated by NEW_PTID. We can only switch single-threaded
993 applications, so we only create one new LWP, and the previous list
997 linux_nat_switch_fork (ptid_t new_ptid
)
1001 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1003 lp
= add_lwp (new_ptid
);
1006 /* This changes the thread's ptid while preserving the gdb thread
1007 num. Also changes the inferior pid, while preserving the
1009 thread_change_ptid (inferior_ptid
, new_ptid
);
1011 /* We've just told GDB core that the thread changed target id, but,
1012 in fact, it really is a different thread, with different register
1014 registers_changed ();
1017 /* Handle the exit of a single thread LP. */
1020 exit_lwp (struct lwp_info
*lp
)
1022 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1026 if (print_thread_events
)
1027 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1029 delete_thread (lp
->ptid
);
1032 delete_lwp (lp
->ptid
);
1035 /* Wait for the LWP specified by LP, which we have just attached to.
1036 Returns a wait status for that LWP, to cache. */
1039 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *signalled
)
1041 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1044 if (linux_proc_pid_is_stopped (pid
))
1046 if (debug_linux_nat
)
1047 fprintf_unfiltered (gdb_stdlog
,
1048 "LNPAW: Attaching to a stopped process\n");
1050 /* The process is definitely stopped. It is in a job control
1051 stop, unless the kernel predates the TASK_STOPPED /
1052 TASK_TRACED distinction, in which case it might be in a
1053 ptrace stop. Make sure it is in a ptrace stop; from there we
1054 can kill it, signal it, et cetera.
1056 First make sure there is a pending SIGSTOP. Since we are
1057 already attached, the process can not transition from stopped
1058 to running without a PTRACE_CONT; so we know this signal will
1059 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1060 probably already in the queue (unless this kernel is old
1061 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1062 is not an RT signal, it can only be queued once. */
1063 kill_lwp (pid
, SIGSTOP
);
1065 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1066 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1067 ptrace (PTRACE_CONT
, pid
, 0, 0);
1070 /* Make sure the initial process is stopped. The user-level threads
1071 layer might want to poke around in the inferior, and that won't
1072 work if things haven't stabilized yet. */
1073 new_pid
= my_waitpid (pid
, &status
, __WALL
);
1074 gdb_assert (pid
== new_pid
);
1076 if (!WIFSTOPPED (status
))
1078 /* The pid we tried to attach has apparently just exited. */
1079 if (debug_linux_nat
)
1080 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1081 pid
, status_to_str (status
));
1085 if (WSTOPSIG (status
) != SIGSTOP
)
1088 if (debug_linux_nat
)
1089 fprintf_unfiltered (gdb_stdlog
,
1090 "LNPAW: Received %s after attaching\n",
1091 status_to_str (status
));
1098 linux_nat_create_inferior (struct target_ops
*ops
,
1099 char *exec_file
, char *allargs
, char **env
,
1102 struct cleanup
*restore_personality
1103 = maybe_disable_address_space_randomization (disable_randomization
);
1105 /* The fork_child mechanism is synchronous and calls target_wait, so
1106 we have to mask the async mode. */
1108 /* Make sure we report all signals during startup. */
1109 linux_nat_pass_signals (ops
, 0, NULL
);
1111 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1113 do_cleanups (restore_personality
);
1116 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1117 already attached. Returns true if a new LWP is found, false
1121 attach_proc_task_lwp_callback (ptid_t ptid
)
1123 struct lwp_info
*lp
;
1125 /* Ignore LWPs we're already attached to. */
1126 lp
= find_lwp_pid (ptid
);
1129 int lwpid
= ptid_get_lwp (ptid
);
1131 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1135 /* Be quiet if we simply raced with the thread exiting.
1136 EPERM is returned if the thread's task still exists, and
1137 is marked as exited or zombie, as well as other
1138 conditions, so in that case, confirm the status in
1139 /proc/PID/status. */
1141 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1143 if (debug_linux_nat
)
1145 fprintf_unfiltered (gdb_stdlog
,
1146 "Cannot attach to lwp %d: "
1147 "thread is gone (%d: %s)\n",
1148 lwpid
, err
, safe_strerror (err
));
1153 warning (_("Cannot attach to lwp %d: %s"),
1155 linux_ptrace_attach_fail_reason_string (ptid
,
1161 if (debug_linux_nat
)
1162 fprintf_unfiltered (gdb_stdlog
,
1163 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1164 target_pid_to_str (ptid
));
1166 lp
= add_lwp (ptid
);
1168 /* The next time we wait for this LWP we'll see a SIGSTOP as
1169 PTRACE_ATTACH brings it to a halt. */
1172 /* We need to wait for a stop before being able to make the
1173 next ptrace call on this LWP. */
1174 lp
->must_set_ptrace_flags
= 1;
1183 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1185 struct lwp_info
*lp
;
1189 /* Make sure we report all signals during attach. */
1190 linux_nat_pass_signals (ops
, 0, NULL
);
1194 linux_ops
->to_attach (ops
, args
, from_tty
);
1196 CATCH (ex
, RETURN_MASK_ERROR
)
1198 pid_t pid
= parse_pid_to_attach (args
);
1199 struct buffer buffer
;
1200 char *message
, *buffer_s
;
1202 message
= xstrdup (ex
.message
);
1203 make_cleanup (xfree
, message
);
1205 buffer_init (&buffer
);
1206 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1208 buffer_grow_str0 (&buffer
, "");
1209 buffer_s
= buffer_finish (&buffer
);
1210 make_cleanup (xfree
, buffer_s
);
1212 if (*buffer_s
!= '\0')
1213 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1215 throw_error (ex
.error
, "%s", message
);
1219 /* The ptrace base target adds the main thread with (pid,0,0)
1220 format. Decorate it with lwp info. */
1221 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1222 ptid_get_pid (inferior_ptid
),
1224 thread_change_ptid (inferior_ptid
, ptid
);
1226 /* Add the initial process as the first LWP to the list. */
1227 lp
= add_initial_lwp (ptid
);
1229 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->signalled
);
1230 if (!WIFSTOPPED (status
))
1232 if (WIFEXITED (status
))
1234 int exit_code
= WEXITSTATUS (status
);
1236 target_terminal_ours ();
1237 target_mourn_inferior ();
1239 error (_("Unable to attach: program exited normally."));
1241 error (_("Unable to attach: program exited with code %d."),
1244 else if (WIFSIGNALED (status
))
1246 enum gdb_signal signo
;
1248 target_terminal_ours ();
1249 target_mourn_inferior ();
1251 signo
= gdb_signal_from_host (WTERMSIG (status
));
1252 error (_("Unable to attach: program terminated with signal "
1254 gdb_signal_to_name (signo
),
1255 gdb_signal_to_string (signo
));
1258 internal_error (__FILE__
, __LINE__
,
1259 _("unexpected status %d for PID %ld"),
1260 status
, (long) ptid_get_lwp (ptid
));
1265 /* Save the wait status to report later. */
1267 if (debug_linux_nat
)
1268 fprintf_unfiltered (gdb_stdlog
,
1269 "LNA: waitpid %ld, saving status %s\n",
1270 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1272 lp
->status
= status
;
1274 /* We must attach to every LWP. If /proc is mounted, use that to
1275 find them now. The inferior may be using raw clone instead of
1276 using pthreads. But even if it is using pthreads, thread_db
1277 walks structures in the inferior's address space to find the list
1278 of threads/LWPs, and those structures may well be corrupted.
1279 Note that once thread_db is loaded, we'll still use it to list
1280 threads and associate pthread info with each LWP. */
1281 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1282 attach_proc_task_lwp_callback
);
1284 if (target_can_async_p ())
1288 /* Get pending status of LP. */
1290 get_pending_status (struct lwp_info
*lp
, int *status
)
1292 enum gdb_signal signo
= GDB_SIGNAL_0
;
1294 /* If we paused threads momentarily, we may have stored pending
1295 events in lp->status or lp->waitstatus (see stop_wait_callback),
1296 and GDB core hasn't seen any signal for those threads.
1297 Otherwise, the last signal reported to the core is found in the
1298 thread object's stop_signal.
1300 There's a corner case that isn't handled here at present. Only
1301 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1302 stop_signal make sense as a real signal to pass to the inferior.
1303 Some catchpoint related events, like
1304 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1305 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1306 those traps are debug API (ptrace in our case) related and
1307 induced; the inferior wouldn't see them if it wasn't being
1308 traced. Hence, we should never pass them to the inferior, even
1309 when set to pass state. Since this corner case isn't handled by
1310 infrun.c when proceeding with a signal, for consistency, neither
1311 do we handle it here (or elsewhere in the file we check for
1312 signal pass state). Normally SIGTRAP isn't set to pass state, so
1313 this is really a corner case. */
1315 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1316 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1317 else if (lp
->status
)
1318 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1319 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1321 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1323 signo
= tp
->suspend
.stop_signal
;
1325 else if (!target_is_non_stop_p ())
1327 struct target_waitstatus last
;
1330 get_last_target_status (&last_ptid
, &last
);
1332 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1334 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1336 signo
= tp
->suspend
.stop_signal
;
1342 if (signo
== GDB_SIGNAL_0
)
1344 if (debug_linux_nat
)
1345 fprintf_unfiltered (gdb_stdlog
,
1346 "GPT: lwp %s has no pending signal\n",
1347 target_pid_to_str (lp
->ptid
));
1349 else if (!signal_pass_state (signo
))
1351 if (debug_linux_nat
)
1352 fprintf_unfiltered (gdb_stdlog
,
1353 "GPT: lwp %s had signal %s, "
1354 "but it is in no pass state\n",
1355 target_pid_to_str (lp
->ptid
),
1356 gdb_signal_to_string (signo
));
1360 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1362 if (debug_linux_nat
)
1363 fprintf_unfiltered (gdb_stdlog
,
1364 "GPT: lwp %s has pending signal %s\n",
1365 target_pid_to_str (lp
->ptid
),
1366 gdb_signal_to_string (signo
));
1373 detach_callback (struct lwp_info
*lp
, void *data
)
1375 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1377 if (debug_linux_nat
&& lp
->status
)
1378 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1379 strsignal (WSTOPSIG (lp
->status
)),
1380 target_pid_to_str (lp
->ptid
));
1382 /* If there is a pending SIGSTOP, get rid of it. */
1385 if (debug_linux_nat
)
1386 fprintf_unfiltered (gdb_stdlog
,
1387 "DC: Sending SIGCONT to %s\n",
1388 target_pid_to_str (lp
->ptid
));
1390 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1394 /* We don't actually detach from the LWP that has an id equal to the
1395 overall process id just yet. */
1396 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1400 /* Pass on any pending signal for this LWP. */
1401 get_pending_status (lp
, &status
);
1403 if (linux_nat_prepare_to_resume
!= NULL
)
1404 linux_nat_prepare_to_resume (lp
);
1406 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1407 WSTOPSIG (status
)) < 0)
1408 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1409 safe_strerror (errno
));
1411 if (debug_linux_nat
)
1412 fprintf_unfiltered (gdb_stdlog
,
1413 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1414 target_pid_to_str (lp
->ptid
),
1415 strsignal (WSTOPSIG (status
)));
1417 delete_lwp (lp
->ptid
);
1424 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1428 struct lwp_info
*main_lwp
;
1430 pid
= ptid_get_pid (inferior_ptid
);
1432 /* Don't unregister from the event loop, as there may be other
1433 inferiors running. */
1435 /* Stop all threads before detaching. ptrace requires that the
1436 thread is stopped to sucessfully detach. */
1437 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1438 /* ... and wait until all of them have reported back that
1439 they're no longer running. */
1440 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1442 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1444 /* Only the initial process should be left right now. */
1445 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1447 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1449 /* Pass on any pending signal for the last LWP. */
1450 if ((args
== NULL
|| *args
== '\0')
1451 && get_pending_status (main_lwp
, &status
) != -1
1452 && WIFSTOPPED (status
))
1456 /* Put the signal number in ARGS so that inf_ptrace_detach will
1457 pass it along with PTRACE_DETACH. */
1458 tem
= (char *) alloca (8);
1459 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1461 if (debug_linux_nat
)
1462 fprintf_unfiltered (gdb_stdlog
,
1463 "LND: Sending signal %s to %s\n",
1465 target_pid_to_str (main_lwp
->ptid
));
1468 if (linux_nat_prepare_to_resume
!= NULL
)
1469 linux_nat_prepare_to_resume (main_lwp
);
1470 delete_lwp (main_lwp
->ptid
);
1472 if (forks_exist_p ())
1474 /* Multi-fork case. The current inferior_ptid is being detached
1475 from, but there are other viable forks to debug. Detach from
1476 the current fork, and context-switch to the first
1478 linux_fork_detach (args
, from_tty
);
1481 linux_ops
->to_detach (ops
, args
, from_tty
);
1484 /* Resume execution of the inferior process. If STEP is nonzero,
1485 single-step it. If SIGNAL is nonzero, give it that signal. */
1488 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1489 enum gdb_signal signo
)
1493 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1494 We only presently need that if the LWP is stepped though (to
1495 handle the case of stepping a breakpoint instruction). */
1498 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1500 lp
->stop_pc
= regcache_read_pc (regcache
);
1505 if (linux_nat_prepare_to_resume
!= NULL
)
1506 linux_nat_prepare_to_resume (lp
);
1507 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1509 /* Successfully resumed. Clear state that no longer makes sense,
1510 and mark the LWP as running. Must not do this before resuming
1511 otherwise if that fails other code will be confused. E.g., we'd
1512 later try to stop the LWP and hang forever waiting for a stop
1513 status. Note that we must not throw after this is cleared,
1514 otherwise handle_zombie_lwp_error would get confused. */
1517 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1518 registers_changed_ptid (lp
->ptid
);
1521 /* Called when we try to resume a stopped LWP and that errors out. If
1522 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1523 or about to become), discard the error, clear any pending status
1524 the LWP may have, and return true (we'll collect the exit status
1525 soon enough). Otherwise, return false. */
1528 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1530 /* If we get an error after resuming the LWP successfully, we'd
1531 confuse !T state for the LWP being gone. */
1532 gdb_assert (lp
->stopped
);
1534 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1535 because even if ptrace failed with ESRCH, the tracee may be "not
1536 yet fully dead", but already refusing ptrace requests. In that
1537 case the tracee has 'R (Running)' state for a little bit
1538 (observed in Linux 3.18). See also the note on ESRCH in the
1539 ptrace(2) man page. Instead, check whether the LWP has any state
1540 other than ptrace-stopped. */
1542 /* Don't assume anything if /proc/PID/status can't be read. */
1543 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1545 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1547 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1553 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1554 disappears while we try to resume it. */
1557 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1561 linux_resume_one_lwp_throw (lp
, step
, signo
);
1563 CATCH (ex
, RETURN_MASK_ERROR
)
1565 if (!check_ptrace_stopped_lwp_gone (lp
))
1566 throw_exception (ex
);
1574 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1578 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1580 if (inf
->vfork_child
!= NULL
)
1582 if (debug_linux_nat
)
1583 fprintf_unfiltered (gdb_stdlog
,
1584 "RC: Not resuming %s (vfork parent)\n",
1585 target_pid_to_str (lp
->ptid
));
1587 else if (!lwp_status_pending_p (lp
))
1589 if (debug_linux_nat
)
1590 fprintf_unfiltered (gdb_stdlog
,
1591 "RC: Resuming sibling %s, %s, %s\n",
1592 target_pid_to_str (lp
->ptid
),
1593 (signo
!= GDB_SIGNAL_0
1594 ? strsignal (gdb_signal_to_host (signo
))
1596 step
? "step" : "resume");
1598 linux_resume_one_lwp (lp
, step
, signo
);
1602 if (debug_linux_nat
)
1603 fprintf_unfiltered (gdb_stdlog
,
1604 "RC: Not resuming sibling %s (has pending)\n",
1605 target_pid_to_str (lp
->ptid
));
1610 if (debug_linux_nat
)
1611 fprintf_unfiltered (gdb_stdlog
,
1612 "RC: Not resuming sibling %s (not stopped)\n",
1613 target_pid_to_str (lp
->ptid
));
1617 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1618 Resume LWP with the last stop signal, if it is in pass state. */
1621 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1623 enum gdb_signal signo
= GDB_SIGNAL_0
;
1630 struct thread_info
*thread
;
1632 thread
= find_thread_ptid (lp
->ptid
);
1635 signo
= thread
->suspend
.stop_signal
;
1636 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1640 resume_lwp (lp
, 0, signo
);
1645 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1648 lp
->last_resume_kind
= resume_stop
;
1653 resume_set_callback (struct lwp_info
*lp
, void *data
)
1656 lp
->last_resume_kind
= resume_continue
;
1661 linux_nat_resume (struct target_ops
*ops
,
1662 ptid_t ptid
, int step
, enum gdb_signal signo
)
1664 struct lwp_info
*lp
;
1667 if (debug_linux_nat
)
1668 fprintf_unfiltered (gdb_stdlog
,
1669 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1670 step
? "step" : "resume",
1671 target_pid_to_str (ptid
),
1672 (signo
!= GDB_SIGNAL_0
1673 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1674 target_pid_to_str (inferior_ptid
));
1676 /* A specific PTID means `step only this process id'. */
1677 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1678 || ptid_is_pid (ptid
));
1680 /* Mark the lwps we're resuming as resumed. */
1681 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1683 /* See if it's the current inferior that should be handled
1686 lp
= find_lwp_pid (inferior_ptid
);
1688 lp
= find_lwp_pid (ptid
);
1689 gdb_assert (lp
!= NULL
);
1691 /* Remember if we're stepping. */
1692 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1694 /* If we have a pending wait status for this thread, there is no
1695 point in resuming the process. But first make sure that
1696 linux_nat_wait won't preemptively handle the event - we
1697 should never take this short-circuit if we are going to
1698 leave LP running, since we have skipped resuming all the
1699 other threads. This bit of code needs to be synchronized
1700 with linux_nat_wait. */
1702 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1705 && WSTOPSIG (lp
->status
)
1706 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1708 if (debug_linux_nat
)
1709 fprintf_unfiltered (gdb_stdlog
,
1710 "LLR: Not short circuiting for ignored "
1711 "status 0x%x\n", lp
->status
);
1713 /* FIXME: What should we do if we are supposed to continue
1714 this thread with a signal? */
1715 gdb_assert (signo
== GDB_SIGNAL_0
);
1716 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1721 if (lwp_status_pending_p (lp
))
1723 /* FIXME: What should we do if we are supposed to continue
1724 this thread with a signal? */
1725 gdb_assert (signo
== GDB_SIGNAL_0
);
1727 if (debug_linux_nat
)
1728 fprintf_unfiltered (gdb_stdlog
,
1729 "LLR: Short circuiting for status 0x%x\n",
1732 if (target_can_async_p ())
1735 /* Tell the event loop we have something to process. */
1742 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1744 if (debug_linux_nat
)
1745 fprintf_unfiltered (gdb_stdlog
,
1746 "LLR: %s %s, %s (resume event thread)\n",
1747 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1748 target_pid_to_str (lp
->ptid
),
1749 (signo
!= GDB_SIGNAL_0
1750 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1752 linux_resume_one_lwp (lp
, step
, signo
);
1754 if (target_can_async_p ())
1758 /* Send a signal to an LWP. */
1761 kill_lwp (int lwpid
, int signo
)
1766 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1767 if (errno
== ENOSYS
)
1769 /* If tkill fails, then we are not using nptl threads, a
1770 configuration we no longer support. */
1771 perror_with_name (("tkill"));
1776 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1777 event, check if the core is interested in it: if not, ignore the
1778 event, and keep waiting; otherwise, we need to toggle the LWP's
1779 syscall entry/exit status, since the ptrace event itself doesn't
1780 indicate it, and report the trap to higher layers. */
1783 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1785 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1786 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1787 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1791 /* If we're stopping threads, there's a SIGSTOP pending, which
1792 makes it so that the LWP reports an immediate syscall return,
1793 followed by the SIGSTOP. Skip seeing that "return" using
1794 PTRACE_CONT directly, and let stop_wait_callback collect the
1795 SIGSTOP. Later when the thread is resumed, a new syscall
1796 entry event. If we didn't do this (and returned 0), we'd
1797 leave a syscall entry pending, and our caller, by using
1798 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1799 itself. Later, when the user re-resumes this LWP, we'd see
1800 another syscall entry event and we'd mistake it for a return.
1802 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1803 (leaving immediately with LWP->signalled set, without issuing
1804 a PTRACE_CONT), it would still be problematic to leave this
1805 syscall enter pending, as later when the thread is resumed,
1806 it would then see the same syscall exit mentioned above,
1807 followed by the delayed SIGSTOP, while the syscall didn't
1808 actually get to execute. It seems it would be even more
1809 confusing to the user. */
1811 if (debug_linux_nat
)
1812 fprintf_unfiltered (gdb_stdlog
,
1813 "LHST: ignoring syscall %d "
1814 "for LWP %ld (stopping threads), "
1815 "resuming with PTRACE_CONT for SIGSTOP\n",
1817 ptid_get_lwp (lp
->ptid
));
1819 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1820 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1825 /* Always update the entry/return state, even if this particular
1826 syscall isn't interesting to the core now. In async mode,
1827 the user could install a new catchpoint for this syscall
1828 between syscall enter/return, and we'll need to know to
1829 report a syscall return if that happens. */
1830 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1831 ? TARGET_WAITKIND_SYSCALL_RETURN
1832 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1834 if (catch_syscall_enabled ())
1836 if (catching_syscall_number (syscall_number
))
1838 /* Alright, an event to report. */
1839 ourstatus
->kind
= lp
->syscall_state
;
1840 ourstatus
->value
.syscall_number
= syscall_number
;
1842 if (debug_linux_nat
)
1843 fprintf_unfiltered (gdb_stdlog
,
1844 "LHST: stopping for %s of syscall %d"
1847 == TARGET_WAITKIND_SYSCALL_ENTRY
1848 ? "entry" : "return",
1850 ptid_get_lwp (lp
->ptid
));
1854 if (debug_linux_nat
)
1855 fprintf_unfiltered (gdb_stdlog
,
1856 "LHST: ignoring %s of syscall %d "
1858 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1859 ? "entry" : "return",
1861 ptid_get_lwp (lp
->ptid
));
1865 /* If we had been syscall tracing, and hence used PT_SYSCALL
1866 before on this LWP, it could happen that the user removes all
1867 syscall catchpoints before we get to process this event.
1868 There are two noteworthy issues here:
1870 - When stopped at a syscall entry event, resuming with
1871 PT_STEP still resumes executing the syscall and reports a
1874 - Only PT_SYSCALL catches syscall enters. If we last
1875 single-stepped this thread, then this event can't be a
1876 syscall enter. If we last single-stepped this thread, this
1877 has to be a syscall exit.
1879 The points above mean that the next resume, be it PT_STEP or
1880 PT_CONTINUE, can not trigger a syscall trace event. */
1881 if (debug_linux_nat
)
1882 fprintf_unfiltered (gdb_stdlog
,
1883 "LHST: caught syscall event "
1884 "with no syscall catchpoints."
1885 " %d for LWP %ld, ignoring\n",
1887 ptid_get_lwp (lp
->ptid
));
1888 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1891 /* The core isn't interested in this event. For efficiency, avoid
1892 stopping all threads only to have the core resume them all again.
1893 Since we're not stopping threads, if we're still syscall tracing
1894 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1895 subsequent syscall. Simply resume using the inf-ptrace layer,
1896 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1898 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1902 /* Handle a GNU/Linux extended wait response. If we see a clone
1903 event, we need to add the new LWP to our list (and not report the
1904 trap to higher layers). This function returns non-zero if the
1905 event should be ignored and we should wait again. If STOPPING is
1906 true, the new LWP remains stopped, otherwise it is continued. */
1909 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1911 int pid
= ptid_get_lwp (lp
->ptid
);
1912 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1913 int event
= linux_ptrace_get_extended_event (status
);
1915 /* All extended events we currently use are mid-syscall. Only
1916 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1917 you have to be using PTRACE_SEIZE to get that. */
1918 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1920 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1921 || event
== PTRACE_EVENT_CLONE
)
1923 unsigned long new_pid
;
1926 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1928 /* If we haven't already seen the new PID stop, wait for it now. */
1929 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1931 /* The new child has a pending SIGSTOP. We can't affect it until it
1932 hits the SIGSTOP, but we're already attached. */
1933 ret
= my_waitpid (new_pid
, &status
, __WALL
);
1935 perror_with_name (_("waiting for new child"));
1936 else if (ret
!= new_pid
)
1937 internal_error (__FILE__
, __LINE__
,
1938 _("wait returned unexpected PID %d"), ret
);
1939 else if (!WIFSTOPPED (status
))
1940 internal_error (__FILE__
, __LINE__
,
1941 _("wait returned unexpected status 0x%x"), status
);
1944 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1946 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1948 /* The arch-specific native code may need to know about new
1949 forks even if those end up never mapped to an
1951 if (linux_nat_new_fork
!= NULL
)
1952 linux_nat_new_fork (lp
, new_pid
);
1955 if (event
== PTRACE_EVENT_FORK
1956 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1958 /* Handle checkpointing by linux-fork.c here as a special
1959 case. We don't want the follow-fork-mode or 'catch fork'
1960 to interfere with this. */
1962 /* This won't actually modify the breakpoint list, but will
1963 physically remove the breakpoints from the child. */
1964 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1966 /* Retain child fork in ptrace (stopped) state. */
1967 if (!find_fork_pid (new_pid
))
1970 /* Report as spurious, so that infrun doesn't want to follow
1971 this fork. We're actually doing an infcall in
1973 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1975 /* Report the stop to the core. */
1979 if (event
== PTRACE_EVENT_FORK
)
1980 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1981 else if (event
== PTRACE_EVENT_VFORK
)
1982 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1983 else if (event
== PTRACE_EVENT_CLONE
)
1985 struct lwp_info
*new_lp
;
1987 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1989 if (debug_linux_nat
)
1990 fprintf_unfiltered (gdb_stdlog
,
1991 "LHEW: Got clone event "
1992 "from LWP %d, new child is LWP %ld\n",
1995 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1996 new_lp
->stopped
= 1;
1997 new_lp
->resumed
= 1;
1999 /* If the thread_db layer is active, let it record the user
2000 level thread id and status, and add the thread to GDB's
2002 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2004 /* The process is not using thread_db. Add the LWP to
2006 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2007 add_thread (new_lp
->ptid
);
2010 /* Even if we're stopping the thread for some reason
2011 internal to this module, from the perspective of infrun
2012 and the user/frontend, this new thread is running until
2013 it next reports a stop. */
2014 set_running (new_lp
->ptid
, 1);
2015 set_executing (new_lp
->ptid
, 1);
2017 if (WSTOPSIG (status
) != SIGSTOP
)
2019 /* This can happen if someone starts sending signals to
2020 the new thread before it gets a chance to run, which
2021 have a lower number than SIGSTOP (e.g. SIGUSR1).
2022 This is an unlikely case, and harder to handle for
2023 fork / vfork than for clone, so we do not try - but
2024 we handle it for clone events here. */
2026 new_lp
->signalled
= 1;
2028 /* We created NEW_LP so it cannot yet contain STATUS. */
2029 gdb_assert (new_lp
->status
== 0);
2031 /* Save the wait status to report later. */
2032 if (debug_linux_nat
)
2033 fprintf_unfiltered (gdb_stdlog
,
2034 "LHEW: waitpid of new LWP %ld, "
2035 "saving status %s\n",
2036 (long) ptid_get_lwp (new_lp
->ptid
),
2037 status_to_str (status
));
2038 new_lp
->status
= status
;
2040 else if (report_thread_events
)
2042 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2043 new_lp
->status
= status
;
2052 if (event
== PTRACE_EVENT_EXEC
)
2054 if (debug_linux_nat
)
2055 fprintf_unfiltered (gdb_stdlog
,
2056 "LHEW: Got exec event from LWP %ld\n",
2057 ptid_get_lwp (lp
->ptid
));
2059 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2060 ourstatus
->value
.execd_pathname
2061 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2063 /* The thread that execed must have been resumed, but, when a
2064 thread execs, it changes its tid to the tgid, and the old
2065 tgid thread might have not been resumed. */
2070 if (event
== PTRACE_EVENT_VFORK_DONE
)
2072 if (current_inferior ()->waiting_for_vfork_done
)
2074 if (debug_linux_nat
)
2075 fprintf_unfiltered (gdb_stdlog
,
2076 "LHEW: Got expected PTRACE_EVENT_"
2077 "VFORK_DONE from LWP %ld: stopping\n",
2078 ptid_get_lwp (lp
->ptid
));
2080 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2084 if (debug_linux_nat
)
2085 fprintf_unfiltered (gdb_stdlog
,
2086 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2087 "from LWP %ld: ignoring\n",
2088 ptid_get_lwp (lp
->ptid
));
2092 internal_error (__FILE__
, __LINE__
,
2093 _("unknown ptrace event %d"), event
);
2096 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2100 wait_lwp (struct lwp_info
*lp
)
2104 int thread_dead
= 0;
2107 gdb_assert (!lp
->stopped
);
2108 gdb_assert (lp
->status
== 0);
2110 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2111 block_child_signals (&prev_mask
);
2115 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2116 if (pid
== -1 && errno
== ECHILD
)
2118 /* The thread has previously exited. We need to delete it
2119 now because if this was a non-leader thread execing, we
2120 won't get an exit event. See comments on exec events at
2121 the top of the file. */
2123 if (debug_linux_nat
)
2124 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2125 target_pid_to_str (lp
->ptid
));
2130 /* Bugs 10970, 12702.
2131 Thread group leader may have exited in which case we'll lock up in
2132 waitpid if there are other threads, even if they are all zombies too.
2133 Basically, we're not supposed to use waitpid this way.
2134 tkill(pid,0) cannot be used here as it gets ESRCH for both
2135 for zombie and running processes.
2137 As a workaround, check if we're waiting for the thread group leader and
2138 if it's a zombie, and avoid calling waitpid if it is.
2140 This is racy, what if the tgl becomes a zombie right after we check?
2141 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2142 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2144 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2145 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2148 if (debug_linux_nat
)
2149 fprintf_unfiltered (gdb_stdlog
,
2150 "WL: Thread group leader %s vanished.\n",
2151 target_pid_to_str (lp
->ptid
));
2155 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2156 get invoked despite our caller had them intentionally blocked by
2157 block_child_signals. This is sensitive only to the loop of
2158 linux_nat_wait_1 and there if we get called my_waitpid gets called
2159 again before it gets to sigsuspend so we can safely let the handlers
2160 get executed here. */
2162 if (debug_linux_nat
)
2163 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2164 sigsuspend (&suspend_mask
);
2167 restore_child_signals_mask (&prev_mask
);
2171 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2173 if (debug_linux_nat
)
2175 fprintf_unfiltered (gdb_stdlog
,
2176 "WL: waitpid %s received %s\n",
2177 target_pid_to_str (lp
->ptid
),
2178 status_to_str (status
));
2181 /* Check if the thread has exited. */
2182 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2184 if (report_thread_events
2185 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2187 if (debug_linux_nat
)
2188 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2189 ptid_get_pid (lp
->ptid
));
2191 /* If this is the leader exiting, it means the whole
2192 process is gone. Store the status to report to the
2193 core. Store it in lp->waitstatus, because lp->status
2194 would be ambiguous (W_EXITCODE(0,0) == 0). */
2195 store_waitstatus (&lp
->waitstatus
, status
);
2200 if (debug_linux_nat
)
2201 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2202 target_pid_to_str (lp
->ptid
));
2212 gdb_assert (WIFSTOPPED (status
));
2215 if (lp
->must_set_ptrace_flags
)
2217 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2218 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2220 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2221 lp
->must_set_ptrace_flags
= 0;
2224 /* Handle GNU/Linux's syscall SIGTRAPs. */
2225 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2227 /* No longer need the sysgood bit. The ptrace event ends up
2228 recorded in lp->waitstatus if we care for it. We can carry
2229 on handling the event like a regular SIGTRAP from here
2231 status
= W_STOPCODE (SIGTRAP
);
2232 if (linux_handle_syscall_trap (lp
, 1))
2233 return wait_lwp (lp
);
2237 /* Almost all other ptrace-stops are known to be outside of system
2238 calls, with further exceptions in linux_handle_extended_wait. */
2239 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2242 /* Handle GNU/Linux's extended waitstatus for trace events. */
2243 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2244 && linux_is_extended_waitstatus (status
))
2246 if (debug_linux_nat
)
2247 fprintf_unfiltered (gdb_stdlog
,
2248 "WL: Handling extended status 0x%06x\n",
2250 linux_handle_extended_wait (lp
, status
);
2257 /* Send a SIGSTOP to LP. */
2260 stop_callback (struct lwp_info
*lp
, void *data
)
2262 if (!lp
->stopped
&& !lp
->signalled
)
2266 if (debug_linux_nat
)
2268 fprintf_unfiltered (gdb_stdlog
,
2269 "SC: kill %s **<SIGSTOP>**\n",
2270 target_pid_to_str (lp
->ptid
));
2273 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2274 if (debug_linux_nat
)
2276 fprintf_unfiltered (gdb_stdlog
,
2277 "SC: lwp kill %d %s\n",
2279 errno
? safe_strerror (errno
) : "ERRNO-OK");
2283 gdb_assert (lp
->status
== 0);
2289 /* Request a stop on LWP. */
2292 linux_stop_lwp (struct lwp_info
*lwp
)
2294 stop_callback (lwp
, NULL
);
2297 /* See linux-nat.h */
2300 linux_stop_and_wait_all_lwps (void)
2302 /* Stop all LWP's ... */
2303 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2305 /* ... and wait until all of them have reported back that
2306 they're no longer running. */
2307 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2310 /* See linux-nat.h */
2313 linux_unstop_all_lwps (void)
2315 iterate_over_lwps (minus_one_ptid
,
2316 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2319 /* Return non-zero if LWP PID has a pending SIGINT. */
2322 linux_nat_has_pending_sigint (int pid
)
2324 sigset_t pending
, blocked
, ignored
;
2326 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2328 if (sigismember (&pending
, SIGINT
)
2329 && !sigismember (&ignored
, SIGINT
))
2335 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2338 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2340 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2341 flag to consume the next one. */
2342 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2343 && WSTOPSIG (lp
->status
) == SIGINT
)
2346 lp
->ignore_sigint
= 1;
2351 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2352 This function is called after we know the LWP has stopped; if the LWP
2353 stopped before the expected SIGINT was delivered, then it will never have
2354 arrived. Also, if the signal was delivered to a shared queue and consumed
2355 by a different thread, it will never be delivered to this LWP. */
2358 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2360 if (!lp
->ignore_sigint
)
2363 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2365 if (debug_linux_nat
)
2366 fprintf_unfiltered (gdb_stdlog
,
2367 "MCIS: Clearing bogus flag for %s\n",
2368 target_pid_to_str (lp
->ptid
));
2369 lp
->ignore_sigint
= 0;
2373 /* Fetch the possible triggered data watchpoint info and store it in
2376 On some archs, like x86, that use debug registers to set
2377 watchpoints, it's possible that the way to know which watched
2378 address trapped, is to check the register that is used to select
2379 which address to watch. Problem is, between setting the watchpoint
2380 and reading back which data address trapped, the user may change
2381 the set of watchpoints, and, as a consequence, GDB changes the
2382 debug registers in the inferior. To avoid reading back a stale
2383 stopped-data-address when that happens, we cache in LP the fact
2384 that a watchpoint trapped, and the corresponding data address, as
2385 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2386 registers meanwhile, we have the cached data we can rely on. */
2389 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2391 struct cleanup
*old_chain
;
2393 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2396 old_chain
= save_inferior_ptid ();
2397 inferior_ptid
= lp
->ptid
;
2399 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2401 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2403 if (linux_ops
->to_stopped_data_address
!= NULL
)
2404 lp
->stopped_data_address_p
=
2405 linux_ops
->to_stopped_data_address (¤t_target
,
2406 &lp
->stopped_data_address
);
2408 lp
->stopped_data_address_p
= 0;
2411 do_cleanups (old_chain
);
2413 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2416 /* Returns true if the LWP had stopped for a watchpoint. */
2419 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2421 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2423 gdb_assert (lp
!= NULL
);
2425 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2429 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2431 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2433 gdb_assert (lp
!= NULL
);
2435 *addr_p
= lp
->stopped_data_address
;
2437 return lp
->stopped_data_address_p
;
2440 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2443 sigtrap_is_event (int status
)
2445 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2448 /* Set alternative SIGTRAP-like events recognizer. If
2449 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2453 linux_nat_set_status_is_event (struct target_ops
*t
,
2454 int (*status_is_event
) (int status
))
2456 linux_nat_status_is_event
= status_is_event
;
2459 /* Wait until LP is stopped. */
2462 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2464 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2466 /* If this is a vfork parent, bail out, it is not going to report
2467 any SIGSTOP until the vfork is done with. */
2468 if (inf
->vfork_child
!= NULL
)
2475 status
= wait_lwp (lp
);
2479 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2480 && WSTOPSIG (status
) == SIGINT
)
2482 lp
->ignore_sigint
= 0;
2485 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2487 if (debug_linux_nat
)
2488 fprintf_unfiltered (gdb_stdlog
,
2489 "PTRACE_CONT %s, 0, 0 (%s) "
2490 "(discarding SIGINT)\n",
2491 target_pid_to_str (lp
->ptid
),
2492 errno
? safe_strerror (errno
) : "OK");
2494 return stop_wait_callback (lp
, NULL
);
2497 maybe_clear_ignore_sigint (lp
);
2499 if (WSTOPSIG (status
) != SIGSTOP
)
2501 /* The thread was stopped with a signal other than SIGSTOP. */
2503 if (debug_linux_nat
)
2504 fprintf_unfiltered (gdb_stdlog
,
2505 "SWC: Pending event %s in %s\n",
2506 status_to_str ((int) status
),
2507 target_pid_to_str (lp
->ptid
));
2509 /* Save the sigtrap event. */
2510 lp
->status
= status
;
2511 gdb_assert (lp
->signalled
);
2512 save_stop_reason (lp
);
2516 /* We caught the SIGSTOP that we intended to catch, so
2517 there's no SIGSTOP pending. */
2519 if (debug_linux_nat
)
2520 fprintf_unfiltered (gdb_stdlog
,
2521 "SWC: Expected SIGSTOP caught for %s.\n",
2522 target_pid_to_str (lp
->ptid
));
2524 /* Reset SIGNALLED only after the stop_wait_callback call
2525 above as it does gdb_assert on SIGNALLED. */
2533 /* Return non-zero if LP has a wait status pending. Discard the
2534 pending event and resume the LWP if the event that originally
2535 caused the stop became uninteresting. */
2538 status_callback (struct lwp_info
*lp
, void *data
)
2540 /* Only report a pending wait status if we pretend that this has
2541 indeed been resumed. */
2545 if (!lwp_status_pending_p (lp
))
2548 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2549 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2551 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2555 pc
= regcache_read_pc (regcache
);
2557 if (pc
!= lp
->stop_pc
)
2559 if (debug_linux_nat
)
2560 fprintf_unfiltered (gdb_stdlog
,
2561 "SC: PC of %s changed. was=%s, now=%s\n",
2562 target_pid_to_str (lp
->ptid
),
2563 paddress (target_gdbarch (), lp
->stop_pc
),
2564 paddress (target_gdbarch (), pc
));
2568 #if !USE_SIGTRAP_SIGINFO
2569 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2571 if (debug_linux_nat
)
2572 fprintf_unfiltered (gdb_stdlog
,
2573 "SC: previous breakpoint of %s, at %s gone\n",
2574 target_pid_to_str (lp
->ptid
),
2575 paddress (target_gdbarch (), lp
->stop_pc
));
2583 if (debug_linux_nat
)
2584 fprintf_unfiltered (gdb_stdlog
,
2585 "SC: pending event of %s cancelled.\n",
2586 target_pid_to_str (lp
->ptid
));
2589 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2597 /* Count the LWP's that have had events. */
2600 count_events_callback (struct lwp_info
*lp
, void *data
)
2602 int *count
= (int *) data
;
2604 gdb_assert (count
!= NULL
);
2606 /* Select only resumed LWPs that have an event pending. */
2607 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2613 /* Select the LWP (if any) that is currently being single-stepped. */
2616 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2618 if (lp
->last_resume_kind
== resume_step
2625 /* Returns true if LP has a status pending. */
2628 lwp_status_pending_p (struct lwp_info
*lp
)
2630 /* We check for lp->waitstatus in addition to lp->status, because we
2631 can have pending process exits recorded in lp->status and
2632 W_EXITCODE(0,0) happens to be 0. */
2633 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2636 /* Select the Nth LWP that has had an event. */
2639 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2641 int *selector
= (int *) data
;
2643 gdb_assert (selector
!= NULL
);
2645 /* Select only resumed LWPs that have an event pending. */
2646 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2647 if ((*selector
)-- == 0)
2653 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2654 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2655 and save the result in the LWP's stop_reason field. If it stopped
2656 for a breakpoint, decrement the PC if necessary on the lwp's
2660 save_stop_reason (struct lwp_info
*lp
)
2662 struct regcache
*regcache
;
2663 struct gdbarch
*gdbarch
;
2666 #if USE_SIGTRAP_SIGINFO
2670 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2671 gdb_assert (lp
->status
!= 0);
2673 if (!linux_nat_status_is_event (lp
->status
))
2676 regcache
= get_thread_regcache (lp
->ptid
);
2677 gdbarch
= get_regcache_arch (regcache
);
2679 pc
= regcache_read_pc (regcache
);
2680 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2682 #if USE_SIGTRAP_SIGINFO
2683 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2685 if (siginfo
.si_signo
== SIGTRAP
)
2687 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2688 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2690 /* The si_code is ambiguous on this arch -- check debug
2692 if (!check_stopped_by_watchpoint (lp
))
2693 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2695 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2697 /* If we determine the LWP stopped for a SW breakpoint,
2698 trust it. Particularly don't check watchpoint
2699 registers, because at least on s390, we'd find
2700 stopped-by-watchpoint as long as there's a watchpoint
2702 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2704 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2706 /* This can indicate either a hardware breakpoint or
2707 hardware watchpoint. Check debug registers. */
2708 if (!check_stopped_by_watchpoint (lp
))
2709 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2711 else if (siginfo
.si_code
== TRAP_TRACE
)
2713 if (debug_linux_nat
)
2714 fprintf_unfiltered (gdb_stdlog
,
2715 "CSBB: %s stopped by trace\n",
2716 target_pid_to_str (lp
->ptid
));
2718 /* We may have single stepped an instruction that
2719 triggered a watchpoint. In that case, on some
2720 architectures (such as x86), instead of TRAP_HWBKPT,
2721 si_code indicates TRAP_TRACE, and we need to check
2722 the debug registers separately. */
2723 check_stopped_by_watchpoint (lp
);
2728 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2729 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2732 /* The LWP was either continued, or stepped a software
2733 breakpoint instruction. */
2734 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2737 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2738 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2740 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2741 check_stopped_by_watchpoint (lp
);
2744 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2746 if (debug_linux_nat
)
2747 fprintf_unfiltered (gdb_stdlog
,
2748 "CSBB: %s stopped by software breakpoint\n",
2749 target_pid_to_str (lp
->ptid
));
2751 /* Back up the PC if necessary. */
2753 regcache_write_pc (regcache
, sw_bp_pc
);
2755 /* Update this so we record the correct stop PC below. */
2758 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2760 if (debug_linux_nat
)
2761 fprintf_unfiltered (gdb_stdlog
,
2762 "CSBB: %s stopped by hardware breakpoint\n",
2763 target_pid_to_str (lp
->ptid
));
2765 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2767 if (debug_linux_nat
)
2768 fprintf_unfiltered (gdb_stdlog
,
2769 "CSBB: %s stopped by hardware watchpoint\n",
2770 target_pid_to_str (lp
->ptid
));
2777 /* Returns true if the LWP had stopped for a software breakpoint. */
2780 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2782 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2784 gdb_assert (lp
!= NULL
);
2786 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2789 /* Implement the supports_stopped_by_sw_breakpoint method. */
2792 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2794 return USE_SIGTRAP_SIGINFO
;
2797 /* Returns true if the LWP had stopped for a hardware
2798 breakpoint/watchpoint. */
2801 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2803 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2805 gdb_assert (lp
!= NULL
);
2807 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2810 /* Implement the supports_stopped_by_hw_breakpoint method. */
2813 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2815 return USE_SIGTRAP_SIGINFO
;
2818 /* Select one LWP out of those that have events pending. */
2821 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2824 int random_selector
;
2825 struct lwp_info
*event_lp
= NULL
;
2827 /* Record the wait status for the original LWP. */
2828 (*orig_lp
)->status
= *status
;
2830 /* In all-stop, give preference to the LWP that is being
2831 single-stepped. There will be at most one, and it will be the
2832 LWP that the core is most interested in. If we didn't do this,
2833 then we'd have to handle pending step SIGTRAPs somehow in case
2834 the core later continues the previously-stepped thread, as
2835 otherwise we'd report the pending SIGTRAP then, and the core, not
2836 having stepped the thread, wouldn't understand what the trap was
2837 for, and therefore would report it to the user as a random
2839 if (!target_is_non_stop_p ())
2841 event_lp
= iterate_over_lwps (filter
,
2842 select_singlestep_lwp_callback
, NULL
);
2843 if (event_lp
!= NULL
)
2845 if (debug_linux_nat
)
2846 fprintf_unfiltered (gdb_stdlog
,
2847 "SEL: Select single-step %s\n",
2848 target_pid_to_str (event_lp
->ptid
));
2852 if (event_lp
== NULL
)
2854 /* Pick one at random, out of those which have had events. */
2856 /* First see how many events we have. */
2857 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2858 gdb_assert (num_events
> 0);
2860 /* Now randomly pick a LWP out of those that have had
2862 random_selector
= (int)
2863 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2865 if (debug_linux_nat
&& num_events
> 1)
2866 fprintf_unfiltered (gdb_stdlog
,
2867 "SEL: Found %d events, selecting #%d\n",
2868 num_events
, random_selector
);
2870 event_lp
= iterate_over_lwps (filter
,
2871 select_event_lwp_callback
,
2875 if (event_lp
!= NULL
)
2877 /* Switch the event LWP. */
2878 *orig_lp
= event_lp
;
2879 *status
= event_lp
->status
;
2882 /* Flush the wait status for the event LWP. */
2883 (*orig_lp
)->status
= 0;
2886 /* Return non-zero if LP has been resumed. */
2889 resumed_callback (struct lwp_info
*lp
, void *data
)
2894 /* Check if we should go on and pass this event to common code.
2895 Return the affected lwp if we are, or NULL otherwise. */
2897 static struct lwp_info
*
2898 linux_nat_filter_event (int lwpid
, int status
)
2900 struct lwp_info
*lp
;
2901 int event
= linux_ptrace_get_extended_event (status
);
2903 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2905 /* Check for stop events reported by a process we didn't already
2906 know about - anything not already in our LWP list.
2908 If we're expecting to receive stopped processes after
2909 fork, vfork, and clone events, then we'll just add the
2910 new one to our list and go back to waiting for the event
2911 to be reported - the stopped process might be returned
2912 from waitpid before or after the event is.
2914 But note the case of a non-leader thread exec'ing after the
2915 leader having exited, and gone from our lists. The non-leader
2916 thread changes its tid to the tgid. */
2918 if (WIFSTOPPED (status
) && lp
== NULL
2919 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2921 /* A multi-thread exec after we had seen the leader exiting. */
2922 if (debug_linux_nat
)
2923 fprintf_unfiltered (gdb_stdlog
,
2924 "LLW: Re-adding thread group leader LWP %d.\n",
2927 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2930 add_thread (lp
->ptid
);
2933 if (WIFSTOPPED (status
) && !lp
)
2935 if (debug_linux_nat
)
2936 fprintf_unfiltered (gdb_stdlog
,
2937 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2938 (long) lwpid
, status_to_str (status
));
2939 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2943 /* Make sure we don't report an event for the exit of an LWP not in
2944 our list, i.e. not part of the current process. This can happen
2945 if we detach from a program we originally forked and then it
2947 if (!WIFSTOPPED (status
) && !lp
)
2950 /* This LWP is stopped now. (And if dead, this prevents it from
2951 ever being continued.) */
2954 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2956 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2957 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2959 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2960 lp
->must_set_ptrace_flags
= 0;
2963 /* Handle GNU/Linux's syscall SIGTRAPs. */
2964 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2966 /* No longer need the sysgood bit. The ptrace event ends up
2967 recorded in lp->waitstatus if we care for it. We can carry
2968 on handling the event like a regular SIGTRAP from here
2970 status
= W_STOPCODE (SIGTRAP
);
2971 if (linux_handle_syscall_trap (lp
, 0))
2976 /* Almost all other ptrace-stops are known to be outside of system
2977 calls, with further exceptions in linux_handle_extended_wait. */
2978 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2981 /* Handle GNU/Linux's extended waitstatus for trace events. */
2982 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2983 && linux_is_extended_waitstatus (status
))
2985 if (debug_linux_nat
)
2986 fprintf_unfiltered (gdb_stdlog
,
2987 "LLW: Handling extended status 0x%06x\n",
2989 if (linux_handle_extended_wait (lp
, status
))
2993 /* Check if the thread has exited. */
2994 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2996 if (!report_thread_events
2997 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2999 if (debug_linux_nat
)
3000 fprintf_unfiltered (gdb_stdlog
,
3001 "LLW: %s exited.\n",
3002 target_pid_to_str (lp
->ptid
));
3004 /* If there is at least one more LWP, then the exit signal
3005 was not the end of the debugged application and should be
3011 /* Note that even if the leader was ptrace-stopped, it can still
3012 exit, if e.g., some other thread brings down the whole
3013 process (calls `exit'). So don't assert that the lwp is
3015 if (debug_linux_nat
)
3016 fprintf_unfiltered (gdb_stdlog
,
3017 "LWP %ld exited (resumed=%d)\n",
3018 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3020 /* Dead LWP's aren't expected to reported a pending sigstop. */
3023 /* Store the pending event in the waitstatus, because
3024 W_EXITCODE(0,0) == 0. */
3025 store_waitstatus (&lp
->waitstatus
, status
);
3029 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3030 an attempt to stop an LWP. */
3032 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3036 if (lp
->last_resume_kind
== resume_stop
)
3038 if (debug_linux_nat
)
3039 fprintf_unfiltered (gdb_stdlog
,
3040 "LLW: resume_stop SIGSTOP caught for %s.\n",
3041 target_pid_to_str (lp
->ptid
));
3045 /* This is a delayed SIGSTOP. Filter out the event. */
3047 if (debug_linux_nat
)
3048 fprintf_unfiltered (gdb_stdlog
,
3049 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3051 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3052 target_pid_to_str (lp
->ptid
));
3054 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3055 gdb_assert (lp
->resumed
);
3060 /* Make sure we don't report a SIGINT that we have already displayed
3061 for another thread. */
3062 if (lp
->ignore_sigint
3063 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3065 if (debug_linux_nat
)
3066 fprintf_unfiltered (gdb_stdlog
,
3067 "LLW: Delayed SIGINT caught for %s.\n",
3068 target_pid_to_str (lp
->ptid
));
3070 /* This is a delayed SIGINT. */
3071 lp
->ignore_sigint
= 0;
3073 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3074 if (debug_linux_nat
)
3075 fprintf_unfiltered (gdb_stdlog
,
3076 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3078 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3079 target_pid_to_str (lp
->ptid
));
3080 gdb_assert (lp
->resumed
);
3082 /* Discard the event. */
3086 /* Don't report signals that GDB isn't interested in, such as
3087 signals that are neither printed nor stopped upon. Stopping all
3088 threads can be a bit time-consuming so if we want decent
3089 performance with heavily multi-threaded programs, especially when
3090 they're using a high frequency timer, we'd better avoid it if we
3092 if (WIFSTOPPED (status
))
3094 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3096 if (!target_is_non_stop_p ())
3098 /* Only do the below in all-stop, as we currently use SIGSTOP
3099 to implement target_stop (see linux_nat_stop) in
3101 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3103 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3104 forwarded to the entire process group, that is, all LWPs
3105 will receive it - unless they're using CLONE_THREAD to
3106 share signals. Since we only want to report it once, we
3107 mark it as ignored for all LWPs except this one. */
3108 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3109 set_ignore_sigint
, NULL
);
3110 lp
->ignore_sigint
= 0;
3113 maybe_clear_ignore_sigint (lp
);
3116 /* When using hardware single-step, we need to report every signal.
3117 Otherwise, signals in pass_mask may be short-circuited
3118 except signals that might be caused by a breakpoint. */
3120 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3121 && !linux_wstatus_maybe_breakpoint (status
))
3123 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3124 if (debug_linux_nat
)
3125 fprintf_unfiltered (gdb_stdlog
,
3126 "LLW: %s %s, %s (preempt 'handle')\n",
3128 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3129 target_pid_to_str (lp
->ptid
),
3130 (signo
!= GDB_SIGNAL_0
3131 ? strsignal (gdb_signal_to_host (signo
))
3137 /* An interesting event. */
3139 lp
->status
= status
;
3140 save_stop_reason (lp
);
3144 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3145 their exits until all other threads in the group have exited. */
3148 check_zombie_leaders (void)
3150 struct inferior
*inf
;
3154 struct lwp_info
*leader_lp
;
3159 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3160 if (leader_lp
!= NULL
3161 /* Check if there are other threads in the group, as we may
3162 have raced with the inferior simply exiting. */
3163 && num_lwps (inf
->pid
) > 1
3164 && linux_proc_pid_is_zombie (inf
->pid
))
3166 if (debug_linux_nat
)
3167 fprintf_unfiltered (gdb_stdlog
,
3168 "CZL: Thread group leader %d zombie "
3169 "(it exited, or another thread execd).\n",
3172 /* A leader zombie can mean one of two things:
3174 - It exited, and there's an exit status pending
3175 available, or only the leader exited (not the whole
3176 program). In the latter case, we can't waitpid the
3177 leader's exit status until all other threads are gone.
3179 - There are 3 or more threads in the group, and a thread
3180 other than the leader exec'd. See comments on exec
3181 events at the top of the file. We could try
3182 distinguishing the exit and exec cases, by waiting once
3183 more, and seeing if something comes out, but it doesn't
3184 sound useful. The previous leader _does_ go away, and
3185 we'll re-add the new one once we see the exec event
3186 (which is just the same as what would happen if the
3187 previous leader did exit voluntarily before some other
3190 if (debug_linux_nat
)
3191 fprintf_unfiltered (gdb_stdlog
,
3192 "CZL: Thread group leader %d vanished.\n",
3194 exit_lwp (leader_lp
);
3199 /* Convenience function that is called when the kernel reports an exit
3200 event. This decides whether to report the event to GDB as a
3201 process exit event, a thread exit event, or to suppress the
3205 filter_exit_event (struct lwp_info
*event_child
,
3206 struct target_waitstatus
*ourstatus
)
3208 ptid_t ptid
= event_child
->ptid
;
3210 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3212 if (report_thread_events
)
3213 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3215 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3217 exit_lwp (event_child
);
3224 linux_nat_wait_1 (struct target_ops
*ops
,
3225 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3229 enum resume_kind last_resume_kind
;
3230 struct lwp_info
*lp
;
3233 if (debug_linux_nat
)
3234 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3236 /* The first time we get here after starting a new inferior, we may
3237 not have added it to the LWP list yet - this is the earliest
3238 moment at which we know its PID. */
3239 if (ptid_is_pid (inferior_ptid
))
3241 /* Upgrade the main thread's ptid. */
3242 thread_change_ptid (inferior_ptid
,
3243 ptid_build (ptid_get_pid (inferior_ptid
),
3244 ptid_get_pid (inferior_ptid
), 0));
3246 lp
= add_initial_lwp (inferior_ptid
);
3250 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3251 block_child_signals (&prev_mask
);
3253 /* First check if there is a LWP with a wait status pending. */
3254 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3257 if (debug_linux_nat
)
3258 fprintf_unfiltered (gdb_stdlog
,
3259 "LLW: Using pending wait status %s for %s.\n",
3260 status_to_str (lp
->status
),
3261 target_pid_to_str (lp
->ptid
));
3264 /* But if we don't find a pending event, we'll have to wait. Always
3265 pull all events out of the kernel. We'll randomly select an
3266 event LWP out of all that have events, to prevent starvation. */
3272 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3275 - If the thread group leader exits while other threads in the
3276 thread group still exist, waitpid(TGID, ...) hangs. That
3277 waitpid won't return an exit status until the other threads
3278 in the group are reapped.
3280 - When a non-leader thread execs, that thread just vanishes
3281 without reporting an exit (so we'd hang if we waited for it
3282 explicitly in that case). The exec event is reported to
3286 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3288 if (debug_linux_nat
)
3289 fprintf_unfiltered (gdb_stdlog
,
3290 "LNW: waitpid(-1, ...) returned %d, %s\n",
3291 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3295 if (debug_linux_nat
)
3297 fprintf_unfiltered (gdb_stdlog
,
3298 "LLW: waitpid %ld received %s\n",
3299 (long) lwpid
, status_to_str (status
));
3302 linux_nat_filter_event (lwpid
, status
);
3303 /* Retry until nothing comes out of waitpid. A single
3304 SIGCHLD can indicate more than one child stopped. */
3308 /* Now that we've pulled all events out of the kernel, resume
3309 LWPs that don't have an interesting event to report. */
3310 iterate_over_lwps (minus_one_ptid
,
3311 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3313 /* ... and find an LWP with a status to report to the core, if
3315 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3319 /* Check for zombie thread group leaders. Those can't be reaped
3320 until all other threads in the thread group are. */
3321 check_zombie_leaders ();
3323 /* If there are no resumed children left, bail. We'd be stuck
3324 forever in the sigsuspend call below otherwise. */
3325 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3327 if (debug_linux_nat
)
3328 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3330 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3332 restore_child_signals_mask (&prev_mask
);
3333 return minus_one_ptid
;
3336 /* No interesting event to report to the core. */
3338 if (target_options
& TARGET_WNOHANG
)
3340 if (debug_linux_nat
)
3341 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3343 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3344 restore_child_signals_mask (&prev_mask
);
3345 return minus_one_ptid
;
3348 /* We shouldn't end up here unless we want to try again. */
3349 gdb_assert (lp
== NULL
);
3351 /* Block until we get an event reported with SIGCHLD. */
3352 if (debug_linux_nat
)
3353 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3354 sigsuspend (&suspend_mask
);
3359 status
= lp
->status
;
3362 if (!target_is_non_stop_p ())
3364 /* Now stop all other LWP's ... */
3365 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3367 /* ... and wait until all of them have reported back that
3368 they're no longer running. */
3369 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3372 /* If we're not waiting for a specific LWP, choose an event LWP from
3373 among those that have had events. Giving equal priority to all
3374 LWPs that have had events helps prevent starvation. */
3375 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3376 select_event_lwp (ptid
, &lp
, &status
);
3378 gdb_assert (lp
!= NULL
);
3380 /* Now that we've selected our final event LWP, un-adjust its PC if
3381 it was a software breakpoint, and we can't reliably support the
3382 "stopped by software breakpoint" stop reason. */
3383 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3384 && !USE_SIGTRAP_SIGINFO
)
3386 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3387 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3388 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3394 pc
= regcache_read_pc (regcache
);
3395 regcache_write_pc (regcache
, pc
+ decr_pc
);
3399 /* We'll need this to determine whether to report a SIGSTOP as
3400 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3402 last_resume_kind
= lp
->last_resume_kind
;
3404 if (!target_is_non_stop_p ())
3406 /* In all-stop, from the core's perspective, all LWPs are now
3407 stopped until a new resume action is sent over. */
3408 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3412 resume_clear_callback (lp
, NULL
);
3415 if (linux_nat_status_is_event (status
))
3417 if (debug_linux_nat
)
3418 fprintf_unfiltered (gdb_stdlog
,
3419 "LLW: trap ptid is %s.\n",
3420 target_pid_to_str (lp
->ptid
));
3423 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3425 *ourstatus
= lp
->waitstatus
;
3426 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3429 store_waitstatus (ourstatus
, status
);
3431 if (debug_linux_nat
)
3432 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3434 restore_child_signals_mask (&prev_mask
);
3436 if (last_resume_kind
== resume_stop
3437 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3438 && WSTOPSIG (status
) == SIGSTOP
)
3440 /* A thread that has been requested to stop by GDB with
3441 target_stop, and it stopped cleanly, so report as SIG0. The
3442 use of SIGSTOP is an implementation detail. */
3443 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3446 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3447 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3450 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3452 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3453 return filter_exit_event (lp
, ourstatus
);
3458 /* Resume LWPs that are currently stopped without any pending status
3459 to report, but are resumed from the core's perspective. */
3462 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3464 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3468 if (debug_linux_nat
)
3469 fprintf_unfiltered (gdb_stdlog
,
3470 "RSRL: NOT resuming LWP %s, not stopped\n",
3471 target_pid_to_str (lp
->ptid
));
3473 else if (!lp
->resumed
)
3475 if (debug_linux_nat
)
3476 fprintf_unfiltered (gdb_stdlog
,
3477 "RSRL: NOT resuming LWP %s, not resumed\n",
3478 target_pid_to_str (lp
->ptid
));
3480 else if (lwp_status_pending_p (lp
))
3482 if (debug_linux_nat
)
3483 fprintf_unfiltered (gdb_stdlog
,
3484 "RSRL: NOT resuming LWP %s, has pending status\n",
3485 target_pid_to_str (lp
->ptid
));
3489 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3490 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3494 CORE_ADDR pc
= regcache_read_pc (regcache
);
3495 int leave_stopped
= 0;
3497 /* Don't bother if there's a breakpoint at PC that we'd hit
3498 immediately, and we're not waiting for this LWP. */
3499 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3501 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3507 if (debug_linux_nat
)
3508 fprintf_unfiltered (gdb_stdlog
,
3509 "RSRL: resuming stopped-resumed LWP %s at "
3511 target_pid_to_str (lp
->ptid
),
3512 paddress (gdbarch
, pc
),
3515 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3518 CATCH (ex
, RETURN_MASK_ERROR
)
3520 if (!check_ptrace_stopped_lwp_gone (lp
))
3521 throw_exception (ex
);
3530 linux_nat_wait (struct target_ops
*ops
,
3531 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3536 if (debug_linux_nat
)
3538 char *options_string
;
3540 options_string
= target_options_to_string (target_options
);
3541 fprintf_unfiltered (gdb_stdlog
,
3542 "linux_nat_wait: [%s], [%s]\n",
3543 target_pid_to_str (ptid
),
3545 xfree (options_string
);
3548 /* Flush the async file first. */
3549 if (target_is_async_p ())
3550 async_file_flush ();
3552 /* Resume LWPs that are currently stopped without any pending status
3553 to report, but are resumed from the core's perspective. LWPs get
3554 in this state if we find them stopping at a time we're not
3555 interested in reporting the event (target_wait on a
3556 specific_process, for example, see linux_nat_wait_1), and
3557 meanwhile the event became uninteresting. Don't bother resuming
3558 LWPs we're not going to wait for if they'd stop immediately. */
3559 if (target_is_non_stop_p ())
3560 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3562 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3564 /* If we requested any event, and something came out, assume there
3565 may be more. If we requested a specific lwp or process, also
3566 assume there may be more. */
3567 if (target_is_async_p ()
3568 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3569 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3570 || !ptid_equal (ptid
, minus_one_ptid
)))
3579 kill_one_lwp (pid_t pid
)
3581 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3584 kill_lwp (pid
, SIGKILL
);
3585 if (debug_linux_nat
)
3587 int save_errno
= errno
;
3589 fprintf_unfiltered (gdb_stdlog
,
3590 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3591 save_errno
? safe_strerror (save_errno
) : "OK");
3594 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3597 ptrace (PTRACE_KILL
, pid
, 0, 0);
3598 if (debug_linux_nat
)
3600 int save_errno
= errno
;
3602 fprintf_unfiltered (gdb_stdlog
,
3603 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3604 save_errno
? safe_strerror (save_errno
) : "OK");
3608 /* Wait for an LWP to die. */
3611 kill_wait_one_lwp (pid_t pid
)
3615 /* We must make sure that there are no pending events (delayed
3616 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3617 program doesn't interfere with any following debugging session. */
3621 res
= my_waitpid (pid
, NULL
, __WALL
);
3622 if (res
!= (pid_t
) -1)
3624 if (debug_linux_nat
)
3625 fprintf_unfiltered (gdb_stdlog
,
3626 "KWC: wait %ld received unknown.\n",
3628 /* The Linux kernel sometimes fails to kill a thread
3629 completely after PTRACE_KILL; that goes from the stop
3630 point in do_fork out to the one in get_signal_to_deliver
3631 and waits again. So kill it again. */
3637 gdb_assert (res
== -1 && errno
== ECHILD
);
3640 /* Callback for iterate_over_lwps. */
3643 kill_callback (struct lwp_info
*lp
, void *data
)
3645 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3649 /* Callback for iterate_over_lwps. */
3652 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3654 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3658 /* Kill the fork children of any threads of inferior INF that are
3659 stopped at a fork event. */
3662 kill_unfollowed_fork_children (struct inferior
*inf
)
3664 struct thread_info
*thread
;
3666 ALL_NON_EXITED_THREADS (thread
)
3667 if (thread
->inf
== inf
)
3669 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3671 if (ws
->kind
== TARGET_WAITKIND_FORKED
3672 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3674 ptid_t child_ptid
= ws
->value
.related_pid
;
3675 int child_pid
= ptid_get_pid (child_ptid
);
3676 int child_lwp
= ptid_get_lwp (child_ptid
);
3678 kill_one_lwp (child_lwp
);
3679 kill_wait_one_lwp (child_lwp
);
3681 /* Let the arch-specific native code know this process is
3683 linux_nat_forget_process (child_pid
);
3689 linux_nat_kill (struct target_ops
*ops
)
3691 /* If we're stopped while forking and we haven't followed yet,
3692 kill the other task. We need to do this first because the
3693 parent will be sleeping if this is a vfork. */
3694 kill_unfollowed_fork_children (current_inferior ());
3696 if (forks_exist_p ())
3697 linux_fork_killall ();
3700 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3702 /* Stop all threads before killing them, since ptrace requires
3703 that the thread is stopped to sucessfully PTRACE_KILL. */
3704 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3705 /* ... and wait until all of them have reported back that
3706 they're no longer running. */
3707 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3709 /* Kill all LWP's ... */
3710 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3712 /* ... and wait until we've flushed all events. */
3713 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3716 target_mourn_inferior ();
3720 linux_nat_mourn_inferior (struct target_ops
*ops
)
3722 int pid
= ptid_get_pid (inferior_ptid
);
3724 purge_lwp_list (pid
);
3726 if (! forks_exist_p ())
3727 /* Normal case, no other forks available. */
3728 linux_ops
->to_mourn_inferior (ops
);
3730 /* Multi-fork case. The current inferior_ptid has exited, but
3731 there are other viable forks to debug. Delete the exiting
3732 one and context-switch to the first available. */
3733 linux_fork_mourn_inferior ();
3735 /* Let the arch-specific native code know this process is gone. */
3736 linux_nat_forget_process (pid
);
3739 /* Convert a native/host siginfo object, into/from the siginfo in the
3740 layout of the inferiors' architecture. */
3743 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3747 if (linux_nat_siginfo_fixup
!= NULL
)
3748 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3750 /* If there was no callback, or the callback didn't do anything,
3751 then just do a straight memcpy. */
3755 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3757 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3761 static enum target_xfer_status
3762 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3763 const char *annex
, gdb_byte
*readbuf
,
3764 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3765 ULONGEST
*xfered_len
)
3769 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3771 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3772 gdb_assert (readbuf
|| writebuf
);
3774 pid
= ptid_get_lwp (inferior_ptid
);
3776 pid
= ptid_get_pid (inferior_ptid
);
3778 if (offset
> sizeof (siginfo
))
3779 return TARGET_XFER_E_IO
;
3782 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3784 return TARGET_XFER_E_IO
;
3786 /* When GDB is built as a 64-bit application, ptrace writes into
3787 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3788 inferior with a 64-bit GDB should look the same as debugging it
3789 with a 32-bit GDB, we need to convert it. GDB core always sees
3790 the converted layout, so any read/write will have to be done
3792 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3794 if (offset
+ len
> sizeof (siginfo
))
3795 len
= sizeof (siginfo
) - offset
;
3797 if (readbuf
!= NULL
)
3798 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3801 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3803 /* Convert back to ptrace layout before flushing it out. */
3804 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3807 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3809 return TARGET_XFER_E_IO
;
3813 return TARGET_XFER_OK
;
3816 static enum target_xfer_status
3817 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3818 const char *annex
, gdb_byte
*readbuf
,
3819 const gdb_byte
*writebuf
,
3820 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3822 struct cleanup
*old_chain
;
3823 enum target_xfer_status xfer
;
3825 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3826 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3827 offset
, len
, xfered_len
);
3829 /* The target is connected but no live inferior is selected. Pass
3830 this request down to a lower stratum (e.g., the executable
3832 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3833 return TARGET_XFER_EOF
;
3835 old_chain
= save_inferior_ptid ();
3837 if (ptid_lwp_p (inferior_ptid
))
3838 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3840 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3841 offset
, len
, xfered_len
);
3843 do_cleanups (old_chain
);
3848 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3850 /* As long as a PTID is in lwp list, consider it alive. */
3851 return find_lwp_pid (ptid
) != NULL
;
3854 /* Implement the to_update_thread_list target method for this
3858 linux_nat_update_thread_list (struct target_ops
*ops
)
3860 struct lwp_info
*lwp
;
3862 /* We add/delete threads from the list as clone/exit events are
3863 processed, so just try deleting exited threads still in the
3865 delete_exited_threads ();
3867 /* Update the processor core that each lwp/thread was last seen
3871 /* Avoid accessing /proc if the thread hasn't run since we last
3872 time we fetched the thread's core. Accessing /proc becomes
3873 noticeably expensive when we have thousands of LWPs. */
3874 if (lwp
->core
== -1)
3875 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3880 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3882 static char buf
[64];
3884 if (ptid_lwp_p (ptid
)
3885 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3886 || num_lwps (ptid_get_pid (ptid
)) > 1))
3888 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3892 return normal_pid_to_str (ptid
);
3896 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3898 return linux_proc_tid_get_name (thr
->ptid
);
3901 /* Accepts an integer PID; Returns a string representing a file that
3902 can be opened to get the symbols for the child process. */
3905 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3907 return linux_proc_pid_to_exec_file (pid
);
3910 /* Implement the to_xfer_partial interface for memory reads using the /proc
3911 filesystem. Because we can use a single read() call for /proc, this
3912 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3913 but it doesn't support writes. */
3915 static enum target_xfer_status
3916 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3917 const char *annex
, gdb_byte
*readbuf
,
3918 const gdb_byte
*writebuf
,
3919 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3925 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3926 return TARGET_XFER_EOF
;
3928 /* Don't bother for one word. */
3929 if (len
< 3 * sizeof (long))
3930 return TARGET_XFER_EOF
;
3932 /* We could keep this file open and cache it - possibly one per
3933 thread. That requires some juggling, but is even faster. */
3934 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3935 ptid_get_pid (inferior_ptid
));
3936 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3938 return TARGET_XFER_EOF
;
3940 /* If pread64 is available, use it. It's faster if the kernel
3941 supports it (only one syscall), and it's 64-bit safe even on
3942 32-bit platforms (for instance, SPARC debugging a SPARC64
3945 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3947 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3956 return TARGET_XFER_EOF
;
3960 return TARGET_XFER_OK
;
3965 /* Enumerate spufs IDs for process PID. */
3967 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3969 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3971 LONGEST written
= 0;
3974 struct dirent
*entry
;
3976 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3977 dir
= opendir (path
);
3982 while ((entry
= readdir (dir
)) != NULL
)
3988 fd
= atoi (entry
->d_name
);
3992 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3993 if (stat (path
, &st
) != 0)
3995 if (!S_ISDIR (st
.st_mode
))
3998 if (statfs (path
, &stfs
) != 0)
4000 if (stfs
.f_type
!= SPUFS_MAGIC
)
4003 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4005 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4015 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4016 object type, using the /proc file system. */
4018 static enum target_xfer_status
4019 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4020 const char *annex
, gdb_byte
*readbuf
,
4021 const gdb_byte
*writebuf
,
4022 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4027 int pid
= ptid_get_pid (inferior_ptid
);
4032 return TARGET_XFER_E_IO
;
4035 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4038 return TARGET_XFER_E_IO
;
4040 return TARGET_XFER_EOF
;
4043 *xfered_len
= (ULONGEST
) l
;
4044 return TARGET_XFER_OK
;
4049 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4050 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4052 return TARGET_XFER_E_IO
;
4055 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4058 return TARGET_XFER_EOF
;
4062 ret
= write (fd
, writebuf
, (size_t) len
);
4064 ret
= read (fd
, readbuf
, (size_t) len
);
4069 return TARGET_XFER_E_IO
;
4071 return TARGET_XFER_EOF
;
4074 *xfered_len
= (ULONGEST
) ret
;
4075 return TARGET_XFER_OK
;
4080 /* Parse LINE as a signal set and add its set bits to SIGS. */
4083 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4085 int len
= strlen (line
) - 1;
4089 if (line
[len
] != '\n')
4090 error (_("Could not parse signal set: %s"), line
);
4098 if (*p
>= '0' && *p
<= '9')
4100 else if (*p
>= 'a' && *p
<= 'f')
4101 digit
= *p
- 'a' + 10;
4103 error (_("Could not parse signal set: %s"), line
);
4108 sigaddset (sigs
, signum
+ 1);
4110 sigaddset (sigs
, signum
+ 2);
4112 sigaddset (sigs
, signum
+ 3);
4114 sigaddset (sigs
, signum
+ 4);
4120 /* Find process PID's pending signals from /proc/pid/status and set
4124 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4125 sigset_t
*blocked
, sigset_t
*ignored
)
4128 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4129 struct cleanup
*cleanup
;
4131 sigemptyset (pending
);
4132 sigemptyset (blocked
);
4133 sigemptyset (ignored
);
4134 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4135 procfile
= gdb_fopen_cloexec (fname
, "r");
4136 if (procfile
== NULL
)
4137 error (_("Could not open %s"), fname
);
4138 cleanup
= make_cleanup_fclose (procfile
);
4140 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4142 /* Normal queued signals are on the SigPnd line in the status
4143 file. However, 2.6 kernels also have a "shared" pending
4144 queue for delivering signals to a thread group, so check for
4147 Unfortunately some Red Hat kernels include the shared pending
4148 queue but not the ShdPnd status field. */
4150 if (startswith (buffer
, "SigPnd:\t"))
4151 add_line_to_sigset (buffer
+ 8, pending
);
4152 else if (startswith (buffer
, "ShdPnd:\t"))
4153 add_line_to_sigset (buffer
+ 8, pending
);
4154 else if (startswith (buffer
, "SigBlk:\t"))
4155 add_line_to_sigset (buffer
+ 8, blocked
);
4156 else if (startswith (buffer
, "SigIgn:\t"))
4157 add_line_to_sigset (buffer
+ 8, ignored
);
4160 do_cleanups (cleanup
);
4163 static enum target_xfer_status
4164 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4165 const char *annex
, gdb_byte
*readbuf
,
4166 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4167 ULONGEST
*xfered_len
)
4169 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4171 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4172 if (*xfered_len
== 0)
4173 return TARGET_XFER_EOF
;
4175 return TARGET_XFER_OK
;
4178 static enum target_xfer_status
4179 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4180 const char *annex
, gdb_byte
*readbuf
,
4181 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4182 ULONGEST
*xfered_len
)
4184 enum target_xfer_status xfer
;
4186 if (object
== TARGET_OBJECT_AUXV
)
4187 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4188 offset
, len
, xfered_len
);
4190 if (object
== TARGET_OBJECT_OSDATA
)
4191 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4192 offset
, len
, xfered_len
);
4194 if (object
== TARGET_OBJECT_SPU
)
4195 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4196 offset
, len
, xfered_len
);
4198 /* GDB calculates all the addresses in possibly larget width of the address.
4199 Address width needs to be masked before its final use - either by
4200 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4202 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4204 if (object
== TARGET_OBJECT_MEMORY
)
4206 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4208 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4209 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4212 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4213 offset
, len
, xfered_len
);
4214 if (xfer
!= TARGET_XFER_EOF
)
4217 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4218 offset
, len
, xfered_len
);
4222 cleanup_target_stop (void *arg
)
4224 ptid_t
*ptid
= (ptid_t
*) arg
;
4226 gdb_assert (arg
!= NULL
);
4229 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4232 static VEC(static_tracepoint_marker_p
) *
4233 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4236 char s
[IPA_CMD_BUF_SIZE
];
4237 struct cleanup
*old_chain
;
4238 int pid
= ptid_get_pid (inferior_ptid
);
4239 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4240 struct static_tracepoint_marker
*marker
= NULL
;
4242 ptid_t ptid
= ptid_build (pid
, 0, 0);
4247 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4248 s
[sizeof ("qTfSTM")] = 0;
4250 agent_run_command (pid
, s
, strlen (s
) + 1);
4252 old_chain
= make_cleanup (free_current_marker
, &marker
);
4253 make_cleanup (cleanup_target_stop
, &ptid
);
4258 marker
= XCNEW (struct static_tracepoint_marker
);
4262 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4264 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4266 VEC_safe_push (static_tracepoint_marker_p
,
4272 release_static_tracepoint_marker (marker
);
4273 memset (marker
, 0, sizeof (*marker
));
4276 while (*p
++ == ','); /* comma-separated list */
4278 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4279 s
[sizeof ("qTsSTM")] = 0;
4280 agent_run_command (pid
, s
, strlen (s
) + 1);
4284 do_cleanups (old_chain
);
4289 /* Create a prototype generic GNU/Linux target. The client can override
4290 it with local methods. */
4293 linux_target_install_ops (struct target_ops
*t
)
4295 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4296 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4297 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4298 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4299 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4300 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4301 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4302 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4303 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4304 t
->to_post_attach
= linux_child_post_attach
;
4305 t
->to_follow_fork
= linux_child_follow_fork
;
4307 super_xfer_partial
= t
->to_xfer_partial
;
4308 t
->to_xfer_partial
= linux_xfer_partial
;
4310 t
->to_static_tracepoint_markers_by_strid
4311 = linux_child_static_tracepoint_markers_by_strid
;
4317 struct target_ops
*t
;
4319 t
= inf_ptrace_target ();
4320 linux_target_install_ops (t
);
4326 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4328 struct target_ops
*t
;
4330 t
= inf_ptrace_trad_target (register_u_offset
);
4331 linux_target_install_ops (t
);
4336 /* target_is_async_p implementation. */
4339 linux_nat_is_async_p (struct target_ops
*ops
)
4341 return linux_is_async_p ();
4344 /* target_can_async_p implementation. */
4347 linux_nat_can_async_p (struct target_ops
*ops
)
4349 /* NOTE: palves 2008-03-21: We're only async when the user requests
4350 it explicitly with the "set target-async" command.
4351 Someday, linux will always be async. */
4352 return target_async_permitted
;
4356 linux_nat_supports_non_stop (struct target_ops
*self
)
4361 /* to_always_non_stop_p implementation. */
4364 linux_nat_always_non_stop_p (struct target_ops
*self
)
4369 /* True if we want to support multi-process. To be removed when GDB
4370 supports multi-exec. */
4372 int linux_multi_process
= 1;
4375 linux_nat_supports_multi_process (struct target_ops
*self
)
4377 return linux_multi_process
;
4381 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4383 #ifdef HAVE_PERSONALITY
4390 static int async_terminal_is_ours
= 1;
4392 /* target_terminal_inferior implementation.
4394 This is a wrapper around child_terminal_inferior to add async support. */
4397 linux_nat_terminal_inferior (struct target_ops
*self
)
4399 child_terminal_inferior (self
);
4401 /* Calls to target_terminal_*() are meant to be idempotent. */
4402 if (!async_terminal_is_ours
)
4405 delete_file_handler (input_fd
);
4406 async_terminal_is_ours
= 0;
4410 /* target_terminal_ours implementation.
4412 This is a wrapper around child_terminal_ours to add async support (and
4413 implement the target_terminal_ours vs target_terminal_ours_for_output
4414 distinction). child_terminal_ours is currently no different than
4415 child_terminal_ours_for_output.
4416 We leave target_terminal_ours_for_output alone, leaving it to
4417 child_terminal_ours_for_output. */
4420 linux_nat_terminal_ours (struct target_ops
*self
)
4422 /* GDB should never give the terminal to the inferior if the
4423 inferior is running in the background (run&, continue&, etc.),
4424 but claiming it sure should. */
4425 child_terminal_ours (self
);
4427 if (async_terminal_is_ours
)
4430 clear_sigint_trap ();
4431 add_file_handler (input_fd
, stdin_event_handler
, 0);
4432 async_terminal_is_ours
= 1;
4435 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4436 so we notice when any child changes state, and notify the
4437 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4438 above to wait for the arrival of a SIGCHLD. */
4441 sigchld_handler (int signo
)
4443 int old_errno
= errno
;
4445 if (debug_linux_nat
)
4446 ui_file_write_async_safe (gdb_stdlog
,
4447 "sigchld\n", sizeof ("sigchld\n") - 1);
4449 if (signo
== SIGCHLD
4450 && linux_nat_event_pipe
[0] != -1)
4451 async_file_mark (); /* Let the event loop know that there are
4452 events to handle. */
4457 /* Callback registered with the target events file descriptor. */
4460 handle_target_event (int error
, gdb_client_data client_data
)
4462 inferior_event_handler (INF_REG_EVENT
, NULL
);
4465 /* Create/destroy the target events pipe. Returns previous state. */
4468 linux_async_pipe (int enable
)
4470 int previous
= linux_is_async_p ();
4472 if (previous
!= enable
)
4476 /* Block child signals while we create/destroy the pipe, as
4477 their handler writes to it. */
4478 block_child_signals (&prev_mask
);
4482 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4483 internal_error (__FILE__
, __LINE__
,
4484 "creating event pipe failed.");
4486 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4487 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4491 close (linux_nat_event_pipe
[0]);
4492 close (linux_nat_event_pipe
[1]);
4493 linux_nat_event_pipe
[0] = -1;
4494 linux_nat_event_pipe
[1] = -1;
4497 restore_child_signals_mask (&prev_mask
);
4503 /* target_async implementation. */
4506 linux_nat_async (struct target_ops
*ops
, int enable
)
4510 if (!linux_async_pipe (1))
4512 add_file_handler (linux_nat_event_pipe
[0],
4513 handle_target_event
, NULL
);
4514 /* There may be pending events to handle. Tell the event loop
4521 delete_file_handler (linux_nat_event_pipe
[0]);
4522 linux_async_pipe (0);
4527 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4531 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4535 if (debug_linux_nat
)
4536 fprintf_unfiltered (gdb_stdlog
,
4537 "LNSL: running -> suspending %s\n",
4538 target_pid_to_str (lwp
->ptid
));
4541 if (lwp
->last_resume_kind
== resume_stop
)
4543 if (debug_linux_nat
)
4544 fprintf_unfiltered (gdb_stdlog
,
4545 "linux-nat: already stopping LWP %ld at "
4547 ptid_get_lwp (lwp
->ptid
));
4551 stop_callback (lwp
, NULL
);
4552 lwp
->last_resume_kind
= resume_stop
;
4556 /* Already known to be stopped; do nothing. */
4558 if (debug_linux_nat
)
4560 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4561 fprintf_unfiltered (gdb_stdlog
,
4562 "LNSL: already stopped/stop_requested %s\n",
4563 target_pid_to_str (lwp
->ptid
));
4565 fprintf_unfiltered (gdb_stdlog
,
4566 "LNSL: already stopped/no "
4567 "stop_requested yet %s\n",
4568 target_pid_to_str (lwp
->ptid
));
4575 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4577 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4581 linux_nat_close (struct target_ops
*self
)
4583 /* Unregister from the event loop. */
4584 if (linux_nat_is_async_p (self
))
4585 linux_nat_async (self
, 0);
4587 if (linux_ops
->to_close
)
4588 linux_ops
->to_close (linux_ops
);
4593 /* When requests are passed down from the linux-nat layer to the
4594 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4595 used. The address space pointer is stored in the inferior object,
4596 but the common code that is passed such ptid can't tell whether
4597 lwpid is a "main" process id or not (it assumes so). We reverse
4598 look up the "main" process id from the lwp here. */
4600 static struct address_space
*
4601 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4603 struct lwp_info
*lwp
;
4604 struct inferior
*inf
;
4607 if (ptid_get_lwp (ptid
) == 0)
4609 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4611 lwp
= find_lwp_pid (ptid
);
4612 pid
= ptid_get_pid (lwp
->ptid
);
4616 /* A (pid,lwpid,0) ptid. */
4617 pid
= ptid_get_pid (ptid
);
4620 inf
= find_inferior_pid (pid
);
4621 gdb_assert (inf
!= NULL
);
4625 /* Return the cached value of the processor core for thread PTID. */
4628 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4630 struct lwp_info
*info
= find_lwp_pid (ptid
);
4637 /* Implementation of to_filesystem_is_local. */
4640 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4642 struct inferior
*inf
= current_inferior ();
4644 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4647 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4650 /* Convert the INF argument passed to a to_fileio_* method
4651 to a process ID suitable for passing to its corresponding
4652 linux_mntns_* function. If INF is non-NULL then the
4653 caller is requesting the filesystem seen by INF. If INF
4654 is NULL then the caller is requesting the filesystem seen
4655 by the GDB. We fall back to GDB's filesystem in the case
4656 that INF is non-NULL but its PID is unknown. */
4659 linux_nat_fileio_pid_of (struct inferior
*inf
)
4661 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4667 /* Implementation of to_fileio_open. */
4670 linux_nat_fileio_open (struct target_ops
*self
,
4671 struct inferior
*inf
, const char *filename
,
4672 int flags
, int mode
, int warn_if_slow
,
4679 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4680 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4682 *target_errno
= FILEIO_EINVAL
;
4686 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4687 filename
, nat_flags
, nat_mode
);
4689 *target_errno
= host_to_fileio_error (errno
);
4694 /* Implementation of to_fileio_readlink. */
4697 linux_nat_fileio_readlink (struct target_ops
*self
,
4698 struct inferior
*inf
, const char *filename
,
4705 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4706 filename
, buf
, sizeof (buf
));
4709 *target_errno
= host_to_fileio_error (errno
);
4713 ret
= (char *) xmalloc (len
+ 1);
4714 memcpy (ret
, buf
, len
);
4719 /* Implementation of to_fileio_unlink. */
4722 linux_nat_fileio_unlink (struct target_ops
*self
,
4723 struct inferior
*inf
, const char *filename
,
4728 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4731 *target_errno
= host_to_fileio_error (errno
);
4736 /* Implementation of the to_thread_events method. */
4739 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4741 report_thread_events
= enable
;
4745 linux_nat_add_target (struct target_ops
*t
)
4747 /* Save the provided single-threaded target. We save this in a separate
4748 variable because another target we've inherited from (e.g. inf-ptrace)
4749 may have saved a pointer to T; we want to use it for the final
4750 process stratum target. */
4751 linux_ops_saved
= *t
;
4752 linux_ops
= &linux_ops_saved
;
4754 /* Override some methods for multithreading. */
4755 t
->to_create_inferior
= linux_nat_create_inferior
;
4756 t
->to_attach
= linux_nat_attach
;
4757 t
->to_detach
= linux_nat_detach
;
4758 t
->to_resume
= linux_nat_resume
;
4759 t
->to_wait
= linux_nat_wait
;
4760 t
->to_pass_signals
= linux_nat_pass_signals
;
4761 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4762 t
->to_kill
= linux_nat_kill
;
4763 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4764 t
->to_thread_alive
= linux_nat_thread_alive
;
4765 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4766 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4767 t
->to_thread_name
= linux_nat_thread_name
;
4768 t
->to_has_thread_control
= tc_schedlock
;
4769 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4770 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4771 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4772 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4773 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4774 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4775 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4776 t
->to_thread_events
= linux_nat_thread_events
;
4778 t
->to_can_async_p
= linux_nat_can_async_p
;
4779 t
->to_is_async_p
= linux_nat_is_async_p
;
4780 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4781 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4782 t
->to_async
= linux_nat_async
;
4783 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4784 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4786 super_close
= t
->to_close
;
4787 t
->to_close
= linux_nat_close
;
4789 t
->to_stop
= linux_nat_stop
;
4791 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4793 t
->to_supports_disable_randomization
4794 = linux_nat_supports_disable_randomization
;
4796 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4798 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4799 t
->to_fileio_open
= linux_nat_fileio_open
;
4800 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4801 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4803 /* We don't change the stratum; this target will sit at
4804 process_stratum and thread_db will set at thread_stratum. This
4805 is a little strange, since this is a multi-threaded-capable
4806 target, but we want to be on the stack below thread_db, and we
4807 also want to be used for single-threaded processes. */
4812 /* Register a method to call whenever a new thread is attached. */
4814 linux_nat_set_new_thread (struct target_ops
*t
,
4815 void (*new_thread
) (struct lwp_info
*))
4817 /* Save the pointer. We only support a single registered instance
4818 of the GNU/Linux native target, so we do not need to map this to
4820 linux_nat_new_thread
= new_thread
;
4823 /* See declaration in linux-nat.h. */
4826 linux_nat_set_new_fork (struct target_ops
*t
,
4827 linux_nat_new_fork_ftype
*new_fork
)
4829 /* Save the pointer. */
4830 linux_nat_new_fork
= new_fork
;
4833 /* See declaration in linux-nat.h. */
4836 linux_nat_set_forget_process (struct target_ops
*t
,
4837 linux_nat_forget_process_ftype
*fn
)
4839 /* Save the pointer. */
4840 linux_nat_forget_process_hook
= fn
;
4843 /* See declaration in linux-nat.h. */
4846 linux_nat_forget_process (pid_t pid
)
4848 if (linux_nat_forget_process_hook
!= NULL
)
4849 linux_nat_forget_process_hook (pid
);
4852 /* Register a method that converts a siginfo object between the layout
4853 that ptrace returns, and the layout in the architecture of the
4856 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4857 int (*siginfo_fixup
) (siginfo_t
*,
4861 /* Save the pointer. */
4862 linux_nat_siginfo_fixup
= siginfo_fixup
;
4865 /* Register a method to call prior to resuming a thread. */
4868 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4869 void (*prepare_to_resume
) (struct lwp_info
*))
4871 /* Save the pointer. */
4872 linux_nat_prepare_to_resume
= prepare_to_resume
;
4875 /* See linux-nat.h. */
4878 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4882 pid
= ptid_get_lwp (ptid
);
4884 pid
= ptid_get_pid (ptid
);
4887 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4890 memset (siginfo
, 0, sizeof (*siginfo
));
4896 /* See nat/linux-nat.h. */
4899 current_lwp_ptid (void)
4901 gdb_assert (ptid_lwp_p (inferior_ptid
));
4902 return inferior_ptid
;
4905 /* Provide a prototype to silence -Wmissing-prototypes. */
4906 extern initialize_file_ftype _initialize_linux_nat
;
4909 _initialize_linux_nat (void)
4911 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4912 &debug_linux_nat
, _("\
4913 Set debugging of GNU/Linux lwp module."), _("\
4914 Show debugging of GNU/Linux lwp module."), _("\
4915 Enables printf debugging output."),
4917 show_debug_linux_nat
,
4918 &setdebuglist
, &showdebuglist
);
4920 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4921 &debug_linux_namespaces
, _("\
4922 Set debugging of GNU/Linux namespaces module."), _("\
4923 Show debugging of GNU/Linux namespaces module."), _("\
4924 Enables printf debugging output."),
4927 &setdebuglist
, &showdebuglist
);
4929 /* Save this mask as the default. */
4930 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4932 /* Install a SIGCHLD handler. */
4933 sigchld_action
.sa_handler
= sigchld_handler
;
4934 sigemptyset (&sigchld_action
.sa_mask
);
4935 sigchld_action
.sa_flags
= SA_RESTART
;
4937 /* Make it the default. */
4938 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4940 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4941 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4942 sigdelset (&suspend_mask
, SIGCHLD
);
4944 sigemptyset (&blocked_mask
);
4946 lwp_lwpid_htab_create ();
4950 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4951 the GNU/Linux Threads library and therefore doesn't really belong
4954 /* Return the set of signals used by the threads library in *SET. */
4957 lin_thread_get_thread_signals (sigset_t
*set
)
4961 /* NPTL reserves the first two RT signals, but does not provide any
4962 way for the debugger to query the signal numbers - fortunately
4963 they don't change. */
4964 sigaddset (set
, __SIGRTMIN
);
4965 sigaddset (set
, __SIGRTMIN
+ 1);