1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2015 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"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "nat/linux-ptrace.h"
34 #include "nat/linux-procfs.h"
35 #include "nat/linux-personality.h"
36 #include "linux-fork.h"
37 #include "gdbthread.h"
41 #include "inf-child.h"
42 #include "inf-ptrace.h"
44 #include <sys/procfs.h> /* for elf_gregset etc. */
45 #include "elf-bfd.h" /* for elfcore_write_* */
46 #include "gregset.h" /* for gregset */
47 #include "gdbcore.h" /* for get_exec_file */
48 #include <ctype.h> /* for isdigit */
49 #include <sys/stat.h> /* for struct stat */
50 #include <fcntl.h> /* for O_RDONLY */
52 #include "event-loop.h"
53 #include "event-top.h"
55 #include <sys/types.h>
57 #include "xml-support.h"
60 #include "nat/linux-osdata.h"
61 #include "linux-tdep.h"
64 #include "tracepoint.h"
66 #include "target-descriptions.h"
67 #include "filestuff.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, passing
80 the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good. Prior to
83 version 2.4, Linux can either wait for event in main thread, or in secondary
84 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
85 miss an event. The solution is to use non-blocking waitpid, together with
86 sigsuspend. First, we use non-blocking waitpid to get an event in the main
87 process, if any. Second, we use non-blocking waitpid with the __WCLONED
88 flag to check for events in cloned processes. If nothing is found, we use
89 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
90 happened to a child process -- and SIGCHLD will be delivered both for events
91 in main debugged process and in cloned processes. As soon as we know there's
92 an event, we get back to calling nonblocking waitpid with and without
95 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
96 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
97 blocked, the signal becomes pending and sigsuspend immediately
98 notices it and returns.
100 Waiting for events in async mode
101 ================================
103 In async mode, GDB should always be ready to handle both user input
104 and target events, so neither blocking waitpid nor sigsuspend are
105 viable options. Instead, we should asynchronously notify the GDB main
106 event loop whenever there's an unprocessed event from the target. We
107 detect asynchronous target events by handling SIGCHLD signals. To
108 notify the event loop about target events, the self-pipe trick is used
109 --- a pipe is registered as waitable event source in the event loop,
110 the event loop select/poll's on the read end of this pipe (as well on
111 other event sources, e.g., stdin), and the SIGCHLD handler writes a
112 byte to this pipe. This is more portable than relying on
113 pselect/ppoll, since on kernels that lack those syscalls, libc
114 emulates them with select/poll+sigprocmask, and that is racy
115 (a.k.a. plain broken).
117 Obviously, if we fail to notify the event loop if there's a target
118 event, it's bad. OTOH, if we notify the event loop when there's no
119 event from the target, linux_nat_wait will detect that there's no real
120 event to report, and return event of type TARGET_WAITKIND_IGNORE.
121 This is mostly harmless, but it will waste time and is better avoided.
123 The main design point is that every time GDB is outside linux-nat.c,
124 we have a SIGCHLD handler installed that is called when something
125 happens to the target and notifies the GDB event loop. Whenever GDB
126 core decides to handle the event, and calls into linux-nat.c, we
127 process things as in sync mode, except that the we never block in
130 While processing an event, we may end up momentarily blocked in
131 waitpid calls. Those waitpid calls, while blocking, are guarantied to
132 return quickly. E.g., in all-stop mode, before reporting to the core
133 that an LWP hit a breakpoint, all LWPs are stopped by sending them
134 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
135 Note that this is different from blocking indefinitely waiting for the
136 next event --- here, we're already handling an event.
141 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
142 signal is not entirely significant; we just need for a signal to be delivered,
143 so that we can intercept it. SIGSTOP's advantage is that it can not be
144 blocked. A disadvantage is that it is not a real-time signal, so it can only
145 be queued once; we do not keep track of other sources of SIGSTOP.
147 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
148 use them, because they have special behavior when the signal is generated -
149 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
150 kills the entire thread group.
152 A delivered SIGSTOP would stop the entire thread group, not just the thread we
153 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
154 cancel it (by PTRACE_CONT without passing SIGSTOP).
156 We could use a real-time signal instead. This would solve those problems; we
157 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
158 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
159 generates it, and there are races with trying to find a signal that is not
163 #define O_LARGEFILE 0
166 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
167 the use of the multi-threaded target. */
168 static struct target_ops
*linux_ops
;
169 static struct target_ops linux_ops_saved
;
171 /* The method to call, if any, when a new thread is attached. */
172 static void (*linux_nat_new_thread
) (struct lwp_info
*);
174 /* The method to call, if any, when a new fork is attached. */
175 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
177 /* The method to call, if any, when a process is no longer
179 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
181 /* Hook to call prior to resuming a thread. */
182 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
184 /* The method to call, if any, when the siginfo object needs to be
185 converted between the layout returned by ptrace, and the layout in
186 the architecture of the inferior. */
187 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
191 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
192 Called by our to_xfer_partial. */
193 static target_xfer_partial_ftype
*super_xfer_partial
;
195 /* The saved to_close method, inherited from inf-ptrace.c.
196 Called by our to_close. */
197 static void (*super_close
) (struct target_ops
*);
199 static unsigned int debug_linux_nat
;
201 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
202 struct cmd_list_element
*c
, const char *value
)
204 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
208 struct simple_pid_list
212 struct simple_pid_list
*next
;
214 struct simple_pid_list
*stopped_pids
;
216 /* Async mode support. */
218 /* The read/write ends of the pipe registered as waitable file in the
220 static int linux_nat_event_pipe
[2] = { -1, -1 };
222 /* Flush the event pipe. */
225 async_file_flush (void)
232 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
234 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
237 /* Put something (anything, doesn't matter what, or how much) in event
238 pipe, so that the select/poll in the event-loop realizes we have
239 something to process. */
242 async_file_mark (void)
246 /* It doesn't really matter what the pipe contains, as long we end
247 up with something in it. Might as well flush the previous
253 ret
= write (linux_nat_event_pipe
[1], "+", 1);
255 while (ret
== -1 && errno
== EINTR
);
257 /* Ignore EAGAIN. If the pipe is full, the event loop will already
258 be awakened anyway. */
261 static int kill_lwp (int lwpid
, int signo
);
263 static int stop_callback (struct lwp_info
*lp
, void *data
);
265 static void block_child_signals (sigset_t
*prev_mask
);
266 static void restore_child_signals_mask (sigset_t
*prev_mask
);
269 static struct lwp_info
*add_lwp (ptid_t ptid
);
270 static void purge_lwp_list (int pid
);
271 static void delete_lwp (ptid_t ptid
);
272 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
274 static int lwp_status_pending_p (struct lwp_info
*lp
);
276 static int check_stopped_by_breakpoint (struct lwp_info
*lp
);
277 static int sigtrap_is_event (int status
);
278 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
281 /* Trivial list manipulation functions to keep track of a list of
282 new stopped processes. */
284 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
286 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
289 new_pid
->status
= status
;
290 new_pid
->next
= *listp
;
295 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
297 struct simple_pid_list
*p
;
299 for (p
= list
; p
!= NULL
; p
= p
->next
)
306 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
308 struct simple_pid_list
**p
;
310 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
311 if ((*p
)->pid
== pid
)
313 struct simple_pid_list
*next
= (*p
)->next
;
315 *statusp
= (*p
)->status
;
323 /* Initialize ptrace warnings and check for supported ptrace
326 ATTACHED should be nonzero iff we attached to the inferior. */
329 linux_init_ptrace (pid_t pid
, int attached
)
331 linux_enable_event_reporting (pid
, attached
);
332 linux_ptrace_init_warnings ();
336 linux_child_post_attach (struct target_ops
*self
, int pid
)
338 linux_init_ptrace (pid
, 1);
342 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
344 linux_init_ptrace (ptid_get_pid (ptid
), 0);
347 /* Return the number of known LWPs in the tgid given by PID. */
355 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
356 if (ptid_get_pid (lp
->ptid
) == pid
)
362 /* Call delete_lwp with prototype compatible for make_cleanup. */
365 delete_lwp_cleanup (void *lp_voidp
)
367 struct lwp_info
*lp
= lp_voidp
;
369 delete_lwp (lp
->ptid
);
372 /* Target hook for follow_fork. On entry inferior_ptid must be the
373 ptid of the followed inferior. At return, inferior_ptid will be
377 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
382 struct lwp_info
*child_lp
= NULL
;
383 int status
= W_STOPCODE (0);
384 struct cleanup
*old_chain
;
386 int parent_pid
, child_pid
;
388 has_vforked
= (inferior_thread ()->pending_follow
.kind
389 == TARGET_WAITKIND_VFORKED
);
390 parent_pid
= ptid_get_lwp (inferior_ptid
);
392 parent_pid
= ptid_get_pid (inferior_ptid
);
394 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
397 /* We're already attached to the parent, by default. */
398 old_chain
= save_inferior_ptid ();
399 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
400 child_lp
= add_lwp (inferior_ptid
);
401 child_lp
->stopped
= 1;
402 child_lp
->last_resume_kind
= resume_stop
;
404 /* Detach new forked process? */
407 make_cleanup (delete_lwp_cleanup
, child_lp
);
409 if (linux_nat_prepare_to_resume
!= NULL
)
410 linux_nat_prepare_to_resume (child_lp
);
412 /* When debugging an inferior in an architecture that supports
413 hardware single stepping on a kernel without commit
414 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
415 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
416 set if the parent process had them set.
417 To work around this, single step the child process
418 once before detaching to clear the flags. */
420 if (!gdbarch_software_single_step_p (target_thread_architecture
423 linux_disable_event_reporting (child_pid
);
424 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
425 perror_with_name (_("Couldn't do single step"));
426 if (my_waitpid (child_pid
, &status
, 0) < 0)
427 perror_with_name (_("Couldn't wait vfork process"));
430 if (WIFSTOPPED (status
))
434 signo
= WSTOPSIG (status
);
436 && !signal_pass_state (gdb_signal_from_host (signo
)))
438 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
441 /* Resets value of inferior_ptid to parent ptid. */
442 do_cleanups (old_chain
);
446 /* Let the thread_db layer learn about this new process. */
447 check_for_thread_db ();
450 do_cleanups (old_chain
);
454 struct lwp_info
*parent_lp
;
456 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
457 gdb_assert (linux_supports_tracefork () >= 0);
459 if (linux_supports_tracevforkdone ())
462 fprintf_unfiltered (gdb_stdlog
,
463 "LCFF: waiting for VFORK_DONE on %d\n",
465 parent_lp
->stopped
= 1;
467 /* We'll handle the VFORK_DONE event like any other
468 event, in target_wait. */
472 /* We can't insert breakpoints until the child has
473 finished with the shared memory region. We need to
474 wait until that happens. Ideal would be to just
476 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
477 - waitpid (parent_pid, &status, __WALL);
478 However, most architectures can't handle a syscall
479 being traced on the way out if it wasn't traced on
482 We might also think to loop, continuing the child
483 until it exits or gets a SIGTRAP. One problem is
484 that the child might call ptrace with PTRACE_TRACEME.
486 There's no simple and reliable way to figure out when
487 the vforked child will be done with its copy of the
488 shared memory. We could step it out of the syscall,
489 two instructions, let it go, and then single-step the
490 parent once. When we have hardware single-step, this
491 would work; with software single-step it could still
492 be made to work but we'd have to be able to insert
493 single-step breakpoints in the child, and we'd have
494 to insert -just- the single-step breakpoint in the
495 parent. Very awkward.
497 In the end, the best we can do is to make sure it
498 runs for a little while. Hopefully it will be out of
499 range of any breakpoints we reinsert. Usually this
500 is only the single-step breakpoint at vfork's return
504 fprintf_unfiltered (gdb_stdlog
,
505 "LCFF: no VFORK_DONE "
506 "support, sleeping a bit\n");
510 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
511 and leave it pending. The next linux_nat_resume call
512 will notice a pending event, and bypasses actually
513 resuming the inferior. */
514 parent_lp
->status
= 0;
515 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
516 parent_lp
->stopped
= 1;
518 /* If we're in async mode, need to tell the event loop
519 there's something here to process. */
520 if (target_can_async_p ())
527 struct lwp_info
*child_lp
;
529 child_lp
= add_lwp (inferior_ptid
);
530 child_lp
->stopped
= 1;
531 child_lp
->last_resume_kind
= resume_stop
;
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
542 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
544 return !linux_supports_tracefork ();
548 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
554 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
556 return !linux_supports_tracefork ();
560 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
566 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
568 return !linux_supports_tracefork ();
572 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
578 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
579 int pid
, int needed
, int any_count
,
580 int table_size
, int *table
)
582 if (!linux_supports_tracesysgood ())
585 /* On GNU/Linux, we ignore the arguments. It means that we only
586 enable the syscall catchpoints, but do not disable them.
588 Also, we do not use the `table' information because we do not
589 filter system calls here. We let GDB do the logic for us. */
593 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
594 are processes sharing the same VM space. A multi-threaded process
595 is basically a group of such processes. However, such a grouping
596 is almost entirely a user-space issue; the kernel doesn't enforce
597 such a grouping at all (this might change in the future). In
598 general, we'll rely on the threads library (i.e. the GNU/Linux
599 Threads library) to provide such a grouping.
601 It is perfectly well possible to write a multi-threaded application
602 without the assistance of a threads library, by using the clone
603 system call directly. This module should be able to give some
604 rudimentary support for debugging such applications if developers
605 specify the CLONE_PTRACE flag in the clone system call, and are
606 using the Linux kernel 2.4 or above.
608 Note that there are some peculiarities in GNU/Linux that affect
611 - In general one should specify the __WCLONE flag to waitpid in
612 order to make it report events for any of the cloned processes
613 (and leave it out for the initial process). However, if a cloned
614 process has exited the exit status is only reported if the
615 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
616 we cannot use it since GDB must work on older systems too.
618 - When a traced, cloned process exits and is waited for by the
619 debugger, the kernel reassigns it to the original parent and
620 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
621 library doesn't notice this, which leads to the "zombie problem":
622 When debugged a multi-threaded process that spawns a lot of
623 threads will run out of processes, even if the threads exit,
624 because the "zombies" stay around. */
626 /* List of known LWPs. */
627 struct lwp_info
*lwp_list
;
630 /* Original signal mask. */
631 static sigset_t normal_mask
;
633 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
634 _initialize_linux_nat. */
635 static sigset_t suspend_mask
;
637 /* Signals to block to make that sigsuspend work. */
638 static sigset_t blocked_mask
;
640 /* SIGCHLD action. */
641 struct sigaction sigchld_action
;
643 /* Block child signals (SIGCHLD and linux threads signals), and store
644 the previous mask in PREV_MASK. */
647 block_child_signals (sigset_t
*prev_mask
)
649 /* Make sure SIGCHLD is blocked. */
650 if (!sigismember (&blocked_mask
, SIGCHLD
))
651 sigaddset (&blocked_mask
, SIGCHLD
);
653 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
656 /* Restore child signals mask, previously returned by
657 block_child_signals. */
660 restore_child_signals_mask (sigset_t
*prev_mask
)
662 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
665 /* Mask of signals to pass directly to the inferior. */
666 static sigset_t pass_mask
;
668 /* Update signals to pass to the inferior. */
670 linux_nat_pass_signals (struct target_ops
*self
,
671 int numsigs
, unsigned char *pass_signals
)
675 sigemptyset (&pass_mask
);
677 for (signo
= 1; signo
< NSIG
; signo
++)
679 int target_signo
= gdb_signal_from_host (signo
);
680 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
681 sigaddset (&pass_mask
, signo
);
687 /* Prototypes for local functions. */
688 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
689 static int linux_thread_alive (ptid_t ptid
);
690 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
694 /* Destroy and free LP. */
697 lwp_free (struct lwp_info
*lp
)
699 xfree (lp
->arch_private
);
703 /* Remove all LWPs belong to PID from the lwp list. */
706 purge_lwp_list (int pid
)
708 struct lwp_info
*lp
, *lpprev
, *lpnext
;
712 for (lp
= lwp_list
; lp
; lp
= lpnext
)
716 if (ptid_get_pid (lp
->ptid
) == pid
)
721 lpprev
->next
= lp
->next
;
730 /* Add the LWP specified by PTID to the list. PTID is the first LWP
731 in the process. Return a pointer to the structure describing the
734 This differs from add_lwp in that we don't let the arch specific
735 bits know about this new thread. Current clients of this callback
736 take the opportunity to install watchpoints in the new thread, and
737 we shouldn't do that for the first thread. If we're spawning a
738 child ("run"), the thread executes the shell wrapper first, and we
739 shouldn't touch it until it execs the program we want to debug.
740 For "attach", it'd be okay to call the callback, but it's not
741 necessary, because watchpoints can't yet have been inserted into
744 static struct lwp_info
*
745 add_initial_lwp (ptid_t ptid
)
749 gdb_assert (ptid_lwp_p (ptid
));
751 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
753 memset (lp
, 0, sizeof (struct lwp_info
));
755 lp
->last_resume_kind
= resume_continue
;
756 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
767 /* Add the LWP specified by PID to the list. Return a pointer to the
768 structure describing the new LWP. The LWP should already be
771 static struct lwp_info
*
772 add_lwp (ptid_t ptid
)
776 lp
= add_initial_lwp (ptid
);
778 /* Let the arch specific bits know about this new thread. Current
779 clients of this callback take the opportunity to install
780 watchpoints in the new thread. We don't do this for the first
781 thread though. See add_initial_lwp. */
782 if (linux_nat_new_thread
!= NULL
)
783 linux_nat_new_thread (lp
);
788 /* Remove the LWP specified by PID from the list. */
791 delete_lwp (ptid_t ptid
)
793 struct lwp_info
*lp
, *lpprev
;
797 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
798 if (ptid_equal (lp
->ptid
, ptid
))
805 lpprev
->next
= lp
->next
;
812 /* Return a pointer to the structure describing the LWP corresponding
813 to PID. If no corresponding LWP could be found, return NULL. */
815 static struct lwp_info
*
816 find_lwp_pid (ptid_t ptid
)
821 if (ptid_lwp_p (ptid
))
822 lwp
= ptid_get_lwp (ptid
);
824 lwp
= ptid_get_pid (ptid
);
826 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
827 if (lwp
== ptid_get_lwp (lp
->ptid
))
833 /* Call CALLBACK with its second argument set to DATA for every LWP in
834 the list. If CALLBACK returns 1 for a particular LWP, return a
835 pointer to the structure describing that LWP immediately.
836 Otherwise return NULL. */
839 iterate_over_lwps (ptid_t filter
,
840 int (*callback
) (struct lwp_info
*, void *),
843 struct lwp_info
*lp
, *lpnext
;
845 for (lp
= lwp_list
; lp
; lp
= lpnext
)
849 if (ptid_match (lp
->ptid
, filter
))
851 if ((*callback
) (lp
, data
))
859 /* Update our internal state when changing from one checkpoint to
860 another indicated by NEW_PTID. We can only switch single-threaded
861 applications, so we only create one new LWP, and the previous list
865 linux_nat_switch_fork (ptid_t new_ptid
)
869 purge_lwp_list (ptid_get_pid (inferior_ptid
));
871 lp
= add_lwp (new_ptid
);
874 /* This changes the thread's ptid while preserving the gdb thread
875 num. Also changes the inferior pid, while preserving the
877 thread_change_ptid (inferior_ptid
, new_ptid
);
879 /* We've just told GDB core that the thread changed target id, but,
880 in fact, it really is a different thread, with different register
882 registers_changed ();
885 /* Handle the exit of a single thread LP. */
888 exit_lwp (struct lwp_info
*lp
)
890 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
894 if (print_thread_events
)
895 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
897 delete_thread (lp
->ptid
);
900 delete_lwp (lp
->ptid
);
903 /* Wait for the LWP specified by LP, which we have just attached to.
904 Returns a wait status for that LWP, to cache. */
907 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
910 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
913 if (linux_proc_pid_is_stopped (pid
))
916 fprintf_unfiltered (gdb_stdlog
,
917 "LNPAW: Attaching to a stopped process\n");
919 /* The process is definitely stopped. It is in a job control
920 stop, unless the kernel predates the TASK_STOPPED /
921 TASK_TRACED distinction, in which case it might be in a
922 ptrace stop. Make sure it is in a ptrace stop; from there we
923 can kill it, signal it, et cetera.
925 First make sure there is a pending SIGSTOP. Since we are
926 already attached, the process can not transition from stopped
927 to running without a PTRACE_CONT; so we know this signal will
928 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
929 probably already in the queue (unless this kernel is old
930 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
931 is not an RT signal, it can only be queued once. */
932 kill_lwp (pid
, SIGSTOP
);
934 /* Finally, resume the stopped process. This will deliver the SIGSTOP
935 (or a higher priority signal, just like normal PTRACE_ATTACH). */
936 ptrace (PTRACE_CONT
, pid
, 0, 0);
939 /* Make sure the initial process is stopped. The user-level threads
940 layer might want to poke around in the inferior, and that won't
941 work if things haven't stabilized yet. */
942 new_pid
= my_waitpid (pid
, &status
, 0);
943 if (new_pid
== -1 && errno
== ECHILD
)
946 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
948 /* Try again with __WCLONE to check cloned processes. */
949 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
953 gdb_assert (pid
== new_pid
);
955 if (!WIFSTOPPED (status
))
957 /* The pid we tried to attach has apparently just exited. */
959 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
960 pid
, status_to_str (status
));
964 if (WSTOPSIG (status
) != SIGSTOP
)
968 fprintf_unfiltered (gdb_stdlog
,
969 "LNPAW: Received %s after attaching\n",
970 status_to_str (status
));
976 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
977 the new LWP could not be attached, or 1 if we're already auto
978 attached to this thread, but haven't processed the
979 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
980 its existance, without considering it an error. */
983 lin_lwp_attach_lwp (ptid_t ptid
)
988 gdb_assert (ptid_lwp_p (ptid
));
990 lp
= find_lwp_pid (ptid
);
991 lwpid
= ptid_get_lwp (ptid
);
993 /* We assume that we're already attached to any LWP that has an id
994 equal to the overall process id, and to any LWP that is already
995 in our list of LWPs. If we're not seeing exit events from threads
996 and we've had PID wraparound since we last tried to stop all threads,
997 this assumption might be wrong; fortunately, this is very unlikely
999 if (lwpid
!= ptid_get_pid (ptid
) && lp
== NULL
)
1001 int status
, cloned
= 0, signalled
= 0;
1003 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1005 if (linux_supports_tracefork ())
1007 /* If we haven't stopped all threads when we get here,
1008 we may have seen a thread listed in thread_db's list,
1009 but not processed the PTRACE_EVENT_CLONE yet. If
1010 that's the case, ignore this new thread, and let
1011 normal event handling discover it later. */
1012 if (in_pid_list_p (stopped_pids
, lwpid
))
1014 /* We've already seen this thread stop, but we
1015 haven't seen the PTRACE_EVENT_CLONE extended
1024 /* See if we've got a stop for this new child
1025 pending. If so, we're already attached. */
1026 gdb_assert (lwpid
> 0);
1027 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1028 if (new_pid
== -1 && errno
== ECHILD
)
1029 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1032 if (WIFSTOPPED (status
))
1033 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1039 /* If we fail to attach to the thread, issue a warning,
1040 but continue. One way this can happen is if thread
1041 creation is interrupted; as of Linux kernel 2.6.19, a
1042 bug may place threads in the thread list and then fail
1044 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1045 safe_strerror (errno
));
1049 if (debug_linux_nat
)
1050 fprintf_unfiltered (gdb_stdlog
,
1051 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1052 target_pid_to_str (ptid
));
1054 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1055 if (!WIFSTOPPED (status
))
1058 lp
= add_lwp (ptid
);
1060 lp
->cloned
= cloned
;
1061 lp
->signalled
= signalled
;
1062 if (WSTOPSIG (status
) != SIGSTOP
)
1065 lp
->status
= status
;
1068 target_post_attach (ptid_get_lwp (lp
->ptid
));
1070 if (debug_linux_nat
)
1072 fprintf_unfiltered (gdb_stdlog
,
1073 "LLAL: waitpid %s received %s\n",
1074 target_pid_to_str (ptid
),
1075 status_to_str (status
));
1080 /* We assume that the LWP representing the original process is
1081 already stopped. Mark it as stopped in the data structure
1082 that the GNU/linux ptrace layer uses to keep track of
1083 threads. Note that this won't have already been done since
1084 the main thread will have, we assume, been stopped by an
1085 attach from a different layer. */
1087 lp
= add_lwp (ptid
);
1091 lp
->last_resume_kind
= resume_stop
;
1096 linux_nat_create_inferior (struct target_ops
*ops
,
1097 char *exec_file
, char *allargs
, char **env
,
1100 struct cleanup
*restore_personality
1101 = maybe_disable_address_space_randomization (disable_randomization
);
1103 /* The fork_child mechanism is synchronous and calls target_wait, so
1104 we have to mask the async mode. */
1106 /* Make sure we report all signals during startup. */
1107 linux_nat_pass_signals (ops
, 0, NULL
);
1109 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1111 do_cleanups (restore_personality
);
1114 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1115 already attached. Returns true if a new LWP is found, false
1119 attach_proc_task_lwp_callback (ptid_t ptid
)
1121 struct lwp_info
*lp
;
1123 /* Ignore LWPs we're already attached to. */
1124 lp
= find_lwp_pid (ptid
);
1127 int lwpid
= ptid_get_lwp (ptid
);
1129 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1133 /* Be quiet if we simply raced with the thread exiting.
1134 EPERM is returned if the thread's task still exists, and
1135 is marked as exited or zombie, as well as other
1136 conditions, so in that case, confirm the status in
1137 /proc/PID/status. */
1139 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1141 if (debug_linux_nat
)
1143 fprintf_unfiltered (gdb_stdlog
,
1144 "Cannot attach to lwp %d: "
1145 "thread is gone (%d: %s)\n",
1146 lwpid
, err
, safe_strerror (err
));
1151 warning (_("Cannot attach to lwp %d: %s"),
1153 linux_ptrace_attach_fail_reason_string (ptid
,
1159 if (debug_linux_nat
)
1160 fprintf_unfiltered (gdb_stdlog
,
1161 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1162 target_pid_to_str (ptid
));
1164 lp
= add_lwp (ptid
);
1167 /* The next time we wait for this LWP we'll see a SIGSTOP as
1168 PTRACE_ATTACH brings it to a halt. */
1171 /* We need to wait for a stop before being able to make the
1172 next ptrace call on this LWP. */
1173 lp
->must_set_ptrace_flags
= 1;
1182 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1184 struct lwp_info
*lp
;
1187 volatile struct gdb_exception ex
;
1189 /* Make sure we report all signals during attach. */
1190 linux_nat_pass_signals (ops
, 0, NULL
);
1192 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1194 linux_ops
->to_attach (ops
, args
, from_tty
);
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
);
1218 /* The ptrace base target adds the main thread with (pid,0,0)
1219 format. Decorate it with lwp info. */
1220 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1221 ptid_get_pid (inferior_ptid
),
1223 thread_change_ptid (inferior_ptid
, ptid
);
1225 /* Add the initial process as the first LWP to the list. */
1226 lp
= add_initial_lwp (ptid
);
1228 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
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 ())
1285 target_async (inferior_event_handler
, 0);
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 (non_stop
&& !is_executing (lp
->ptid
))
1321 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1323 signo
= tp
->suspend
.stop_signal
;
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. */
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 (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1494 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1495 We only presently need that if the LWP is stepped though (to
1496 handle the case of stepping a breakpoint instruction). */
1499 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1501 lp
->stop_pc
= regcache_read_pc (regcache
);
1506 if (linux_nat_prepare_to_resume
!= NULL
)
1507 linux_nat_prepare_to_resume (lp
);
1508 /* Convert to something the lower layer understands. */
1509 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1510 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1511 lp
->stop_reason
= LWP_STOPPED_BY_NO_REASON
;
1513 registers_changed_ptid (lp
->ptid
);
1519 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1523 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1525 if (inf
->vfork_child
!= NULL
)
1527 if (debug_linux_nat
)
1528 fprintf_unfiltered (gdb_stdlog
,
1529 "RC: Not resuming %s (vfork parent)\n",
1530 target_pid_to_str (lp
->ptid
));
1532 else if (!lwp_status_pending_p (lp
))
1534 if (debug_linux_nat
)
1535 fprintf_unfiltered (gdb_stdlog
,
1536 "RC: Resuming sibling %s, %s, %s\n",
1537 target_pid_to_str (lp
->ptid
),
1538 (signo
!= GDB_SIGNAL_0
1539 ? strsignal (gdb_signal_to_host (signo
))
1541 step
? "step" : "resume");
1543 linux_resume_one_lwp (lp
, step
, signo
);
1547 if (debug_linux_nat
)
1548 fprintf_unfiltered (gdb_stdlog
,
1549 "RC: Not resuming sibling %s (has pending)\n",
1550 target_pid_to_str (lp
->ptid
));
1555 if (debug_linux_nat
)
1556 fprintf_unfiltered (gdb_stdlog
,
1557 "RC: Not resuming sibling %s (not stopped)\n",
1558 target_pid_to_str (lp
->ptid
));
1562 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1563 Resume LWP with the last stop signal, if it is in pass state. */
1566 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1568 enum gdb_signal signo
= GDB_SIGNAL_0
;
1575 struct thread_info
*thread
;
1577 thread
= find_thread_ptid (lp
->ptid
);
1580 signo
= thread
->suspend
.stop_signal
;
1581 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1585 resume_lwp (lp
, 0, signo
);
1590 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1593 lp
->last_resume_kind
= resume_stop
;
1598 resume_set_callback (struct lwp_info
*lp
, void *data
)
1601 lp
->last_resume_kind
= resume_continue
;
1606 linux_nat_resume (struct target_ops
*ops
,
1607 ptid_t ptid
, int step
, enum gdb_signal signo
)
1609 struct lwp_info
*lp
;
1612 if (debug_linux_nat
)
1613 fprintf_unfiltered (gdb_stdlog
,
1614 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1615 step
? "step" : "resume",
1616 target_pid_to_str (ptid
),
1617 (signo
!= GDB_SIGNAL_0
1618 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1619 target_pid_to_str (inferior_ptid
));
1621 /* A specific PTID means `step only this process id'. */
1622 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1623 || ptid_is_pid (ptid
));
1625 /* Mark the lwps we're resuming as resumed. */
1626 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1628 /* See if it's the current inferior that should be handled
1631 lp
= find_lwp_pid (inferior_ptid
);
1633 lp
= find_lwp_pid (ptid
);
1634 gdb_assert (lp
!= NULL
);
1636 /* Remember if we're stepping. */
1637 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1639 /* If we have a pending wait status for this thread, there is no
1640 point in resuming the process. But first make sure that
1641 linux_nat_wait won't preemptively handle the event - we
1642 should never take this short-circuit if we are going to
1643 leave LP running, since we have skipped resuming all the
1644 other threads. This bit of code needs to be synchronized
1645 with linux_nat_wait. */
1647 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1650 && WSTOPSIG (lp
->status
)
1651 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1653 if (debug_linux_nat
)
1654 fprintf_unfiltered (gdb_stdlog
,
1655 "LLR: Not short circuiting for ignored "
1656 "status 0x%x\n", lp
->status
);
1658 /* FIXME: What should we do if we are supposed to continue
1659 this thread with a signal? */
1660 gdb_assert (signo
== GDB_SIGNAL_0
);
1661 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1666 if (lwp_status_pending_p (lp
))
1668 /* FIXME: What should we do if we are supposed to continue
1669 this thread with a signal? */
1670 gdb_assert (signo
== GDB_SIGNAL_0
);
1672 if (debug_linux_nat
)
1673 fprintf_unfiltered (gdb_stdlog
,
1674 "LLR: Short circuiting for status 0x%x\n",
1677 if (target_can_async_p ())
1679 target_async (inferior_event_handler
, 0);
1680 /* Tell the event loop we have something to process. */
1687 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1689 linux_resume_one_lwp (lp
, step
, signo
);
1691 if (debug_linux_nat
)
1692 fprintf_unfiltered (gdb_stdlog
,
1693 "LLR: %s %s, %s (resume event thread)\n",
1694 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1695 target_pid_to_str (ptid
),
1696 (signo
!= GDB_SIGNAL_0
1697 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1699 if (target_can_async_p ())
1700 target_async (inferior_event_handler
, 0);
1703 /* Send a signal to an LWP. */
1706 kill_lwp (int lwpid
, int signo
)
1708 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1709 fails, then we are not using nptl threads and we should be using kill. */
1711 #ifdef HAVE_TKILL_SYSCALL
1713 static int tkill_failed
;
1720 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1721 if (errno
!= ENOSYS
)
1728 return kill (lwpid
, signo
);
1731 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1732 event, check if the core is interested in it: if not, ignore the
1733 event, and keep waiting; otherwise, we need to toggle the LWP's
1734 syscall entry/exit status, since the ptrace event itself doesn't
1735 indicate it, and report the trap to higher layers. */
1738 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1740 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1741 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1742 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1746 /* If we're stopping threads, there's a SIGSTOP pending, which
1747 makes it so that the LWP reports an immediate syscall return,
1748 followed by the SIGSTOP. Skip seeing that "return" using
1749 PTRACE_CONT directly, and let stop_wait_callback collect the
1750 SIGSTOP. Later when the thread is resumed, a new syscall
1751 entry event. If we didn't do this (and returned 0), we'd
1752 leave a syscall entry pending, and our caller, by using
1753 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1754 itself. Later, when the user re-resumes this LWP, we'd see
1755 another syscall entry event and we'd mistake it for a return.
1757 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1758 (leaving immediately with LWP->signalled set, without issuing
1759 a PTRACE_CONT), it would still be problematic to leave this
1760 syscall enter pending, as later when the thread is resumed,
1761 it would then see the same syscall exit mentioned above,
1762 followed by the delayed SIGSTOP, while the syscall didn't
1763 actually get to execute. It seems it would be even more
1764 confusing to the user. */
1766 if (debug_linux_nat
)
1767 fprintf_unfiltered (gdb_stdlog
,
1768 "LHST: ignoring syscall %d "
1769 "for LWP %ld (stopping threads), "
1770 "resuming with PTRACE_CONT for SIGSTOP\n",
1772 ptid_get_lwp (lp
->ptid
));
1774 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1775 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1780 if (catch_syscall_enabled ())
1782 /* Always update the entry/return state, even if this particular
1783 syscall isn't interesting to the core now. In async mode,
1784 the user could install a new catchpoint for this syscall
1785 between syscall enter/return, and we'll need to know to
1786 report a syscall return if that happens. */
1787 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1788 ? TARGET_WAITKIND_SYSCALL_RETURN
1789 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1791 if (catching_syscall_number (syscall_number
))
1793 /* Alright, an event to report. */
1794 ourstatus
->kind
= lp
->syscall_state
;
1795 ourstatus
->value
.syscall_number
= syscall_number
;
1797 if (debug_linux_nat
)
1798 fprintf_unfiltered (gdb_stdlog
,
1799 "LHST: stopping for %s of syscall %d"
1802 == TARGET_WAITKIND_SYSCALL_ENTRY
1803 ? "entry" : "return",
1805 ptid_get_lwp (lp
->ptid
));
1809 if (debug_linux_nat
)
1810 fprintf_unfiltered (gdb_stdlog
,
1811 "LHST: ignoring %s of syscall %d "
1813 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1814 ? "entry" : "return",
1816 ptid_get_lwp (lp
->ptid
));
1820 /* If we had been syscall tracing, and hence used PT_SYSCALL
1821 before on this LWP, it could happen that the user removes all
1822 syscall catchpoints before we get to process this event.
1823 There are two noteworthy issues here:
1825 - When stopped at a syscall entry event, resuming with
1826 PT_STEP still resumes executing the syscall and reports a
1829 - Only PT_SYSCALL catches syscall enters. If we last
1830 single-stepped this thread, then this event can't be a
1831 syscall enter. If we last single-stepped this thread, this
1832 has to be a syscall exit.
1834 The points above mean that the next resume, be it PT_STEP or
1835 PT_CONTINUE, can not trigger a syscall trace event. */
1836 if (debug_linux_nat
)
1837 fprintf_unfiltered (gdb_stdlog
,
1838 "LHST: caught syscall event "
1839 "with no syscall catchpoints."
1840 " %d for LWP %ld, ignoring\n",
1842 ptid_get_lwp (lp
->ptid
));
1843 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1846 /* The core isn't interested in this event. For efficiency, avoid
1847 stopping all threads only to have the core resume them all again.
1848 Since we're not stopping threads, if we're still syscall tracing
1849 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1850 subsequent syscall. Simply resume using the inf-ptrace layer,
1851 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1853 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1857 /* Handle a GNU/Linux extended wait response. If we see a clone
1858 event, we need to add the new LWP to our list (and not report the
1859 trap to higher layers). This function returns non-zero if the
1860 event should be ignored and we should wait again. If STOPPING is
1861 true, the new LWP remains stopped, otherwise it is continued. */
1864 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1867 int pid
= ptid_get_lwp (lp
->ptid
);
1868 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1869 int event
= linux_ptrace_get_extended_event (status
);
1871 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1872 || event
== PTRACE_EVENT_CLONE
)
1874 unsigned long new_pid
;
1877 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1879 /* If we haven't already seen the new PID stop, wait for it now. */
1880 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1882 /* The new child has a pending SIGSTOP. We can't affect it until it
1883 hits the SIGSTOP, but we're already attached. */
1884 ret
= my_waitpid (new_pid
, &status
,
1885 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1887 perror_with_name (_("waiting for new child"));
1888 else if (ret
!= new_pid
)
1889 internal_error (__FILE__
, __LINE__
,
1890 _("wait returned unexpected PID %d"), ret
);
1891 else if (!WIFSTOPPED (status
))
1892 internal_error (__FILE__
, __LINE__
,
1893 _("wait returned unexpected status 0x%x"), status
);
1896 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1898 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1900 /* The arch-specific native code may need to know about new
1901 forks even if those end up never mapped to an
1903 if (linux_nat_new_fork
!= NULL
)
1904 linux_nat_new_fork (lp
, new_pid
);
1907 if (event
== PTRACE_EVENT_FORK
1908 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1910 /* Handle checkpointing by linux-fork.c here as a special
1911 case. We don't want the follow-fork-mode or 'catch fork'
1912 to interfere with this. */
1914 /* This won't actually modify the breakpoint list, but will
1915 physically remove the breakpoints from the child. */
1916 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1918 /* Retain child fork in ptrace (stopped) state. */
1919 if (!find_fork_pid (new_pid
))
1922 /* Report as spurious, so that infrun doesn't want to follow
1923 this fork. We're actually doing an infcall in
1925 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1927 /* Report the stop to the core. */
1931 if (event
== PTRACE_EVENT_FORK
)
1932 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1933 else if (event
== PTRACE_EVENT_VFORK
)
1934 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1937 struct lwp_info
*new_lp
;
1939 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1941 if (debug_linux_nat
)
1942 fprintf_unfiltered (gdb_stdlog
,
1943 "LHEW: Got clone event "
1944 "from LWP %d, new child is LWP %ld\n",
1947 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1949 new_lp
->stopped
= 1;
1951 if (WSTOPSIG (status
) != SIGSTOP
)
1953 /* This can happen if someone starts sending signals to
1954 the new thread before it gets a chance to run, which
1955 have a lower number than SIGSTOP (e.g. SIGUSR1).
1956 This is an unlikely case, and harder to handle for
1957 fork / vfork than for clone, so we do not try - but
1958 we handle it for clone events here. We'll send
1959 the other signal on to the thread below. */
1961 new_lp
->signalled
= 1;
1965 struct thread_info
*tp
;
1967 /* When we stop for an event in some other thread, and
1968 pull the thread list just as this thread has cloned,
1969 we'll have seen the new thread in the thread_db list
1970 before handling the CLONE event (glibc's
1971 pthread_create adds the new thread to the thread list
1972 before clone'ing, and has the kernel fill in the
1973 thread's tid on the clone call with
1974 CLONE_PARENT_SETTID). If that happened, and the core
1975 had requested the new thread to stop, we'll have
1976 killed it with SIGSTOP. But since SIGSTOP is not an
1977 RT signal, it can only be queued once. We need to be
1978 careful to not resume the LWP if we wanted it to
1979 stop. In that case, we'll leave the SIGSTOP pending.
1980 It will later be reported as GDB_SIGNAL_0. */
1981 tp
= find_thread_ptid (new_lp
->ptid
);
1982 if (tp
!= NULL
&& tp
->stop_requested
)
1983 new_lp
->last_resume_kind
= resume_stop
;
1990 /* Add the new thread to GDB's lists as soon as possible
1993 1) the frontend doesn't have to wait for a stop to
1996 2) we tag it with the correct running state. */
1998 /* If the thread_db layer is active, let it know about
1999 this new thread, and add it to GDB's list. */
2000 if (!thread_db_attach_lwp (new_lp
->ptid
))
2002 /* We're not using thread_db. Add it to GDB's
2004 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2005 add_thread (new_lp
->ptid
);
2010 set_running (new_lp
->ptid
, 1);
2011 set_executing (new_lp
->ptid
, 1);
2012 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2014 new_lp
->last_resume_kind
= resume_continue
;
2020 /* We created NEW_LP so it cannot yet contain STATUS. */
2021 gdb_assert (new_lp
->status
== 0);
2023 /* Save the wait status to report later. */
2024 if (debug_linux_nat
)
2025 fprintf_unfiltered (gdb_stdlog
,
2026 "LHEW: waitpid of new LWP %ld, "
2027 "saving status %s\n",
2028 (long) ptid_get_lwp (new_lp
->ptid
),
2029 status_to_str (status
));
2030 new_lp
->status
= status
;
2033 /* Note the need to use the low target ops to resume, to
2034 handle resuming with PT_SYSCALL if we have syscall
2038 new_lp
->resumed
= 1;
2042 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2043 if (debug_linux_nat
)
2044 fprintf_unfiltered (gdb_stdlog
,
2045 "LHEW: resuming new LWP %ld\n",
2046 ptid_get_lwp (new_lp
->ptid
));
2047 linux_resume_one_lwp (new_lp
, 0, GDB_SIGNAL_0
);
2051 if (debug_linux_nat
)
2052 fprintf_unfiltered (gdb_stdlog
,
2053 "LHEW: resuming parent LWP %d\n", pid
);
2054 linux_resume_one_lwp (lp
, 0, GDB_SIGNAL_0
);
2061 if (event
== PTRACE_EVENT_EXEC
)
2063 if (debug_linux_nat
)
2064 fprintf_unfiltered (gdb_stdlog
,
2065 "LHEW: Got exec event from LWP %ld\n",
2066 ptid_get_lwp (lp
->ptid
));
2068 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2069 ourstatus
->value
.execd_pathname
2070 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2072 /* The thread that execed must have been resumed, but, when a
2073 thread execs, it changes its tid to the tgid, and the old
2074 tgid thread might have not been resumed. */
2079 if (event
== PTRACE_EVENT_VFORK_DONE
)
2081 if (current_inferior ()->waiting_for_vfork_done
)
2083 if (debug_linux_nat
)
2084 fprintf_unfiltered (gdb_stdlog
,
2085 "LHEW: Got expected PTRACE_EVENT_"
2086 "VFORK_DONE from LWP %ld: stopping\n",
2087 ptid_get_lwp (lp
->ptid
));
2089 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2093 if (debug_linux_nat
)
2094 fprintf_unfiltered (gdb_stdlog
,
2095 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2096 "from LWP %ld: resuming\n",
2097 ptid_get_lwp (lp
->ptid
));
2098 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2102 internal_error (__FILE__
, __LINE__
,
2103 _("unknown ptrace event %d"), event
);
2106 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2110 wait_lwp (struct lwp_info
*lp
)
2114 int thread_dead
= 0;
2117 gdb_assert (!lp
->stopped
);
2118 gdb_assert (lp
->status
== 0);
2120 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2121 block_child_signals (&prev_mask
);
2125 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2126 was right and we should just call sigsuspend. */
2128 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2129 if (pid
== -1 && errno
== ECHILD
)
2130 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2131 if (pid
== -1 && errno
== ECHILD
)
2133 /* The thread has previously exited. We need to delete it
2134 now because, for some vendor 2.4 kernels with NPTL
2135 support backported, there won't be an exit event unless
2136 it is the main thread. 2.6 kernels will report an exit
2137 event for each thread that exits, as expected. */
2139 if (debug_linux_nat
)
2140 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2141 target_pid_to_str (lp
->ptid
));
2146 /* Bugs 10970, 12702.
2147 Thread group leader may have exited in which case we'll lock up in
2148 waitpid if there are other threads, even if they are all zombies too.
2149 Basically, we're not supposed to use waitpid this way.
2150 __WCLONE is not applicable for the leader so we can't use that.
2151 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2152 process; it gets ESRCH both for the zombie and for running processes.
2154 As a workaround, check if we're waiting for the thread group leader and
2155 if it's a zombie, and avoid calling waitpid if it is.
2157 This is racy, what if the tgl becomes a zombie right after we check?
2158 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2159 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2161 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2162 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2165 if (debug_linux_nat
)
2166 fprintf_unfiltered (gdb_stdlog
,
2167 "WL: Thread group leader %s vanished.\n",
2168 target_pid_to_str (lp
->ptid
));
2172 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2173 get invoked despite our caller had them intentionally blocked by
2174 block_child_signals. This is sensitive only to the loop of
2175 linux_nat_wait_1 and there if we get called my_waitpid gets called
2176 again before it gets to sigsuspend so we can safely let the handlers
2177 get executed here. */
2179 if (debug_linux_nat
)
2180 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2181 sigsuspend (&suspend_mask
);
2184 restore_child_signals_mask (&prev_mask
);
2188 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2190 if (debug_linux_nat
)
2192 fprintf_unfiltered (gdb_stdlog
,
2193 "WL: waitpid %s received %s\n",
2194 target_pid_to_str (lp
->ptid
),
2195 status_to_str (status
));
2198 /* Check if the thread has exited. */
2199 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2202 if (debug_linux_nat
)
2203 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2204 target_pid_to_str (lp
->ptid
));
2214 gdb_assert (WIFSTOPPED (status
));
2217 if (lp
->must_set_ptrace_flags
)
2219 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2221 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), inf
->attach_flag
);
2222 lp
->must_set_ptrace_flags
= 0;
2225 /* Handle GNU/Linux's syscall SIGTRAPs. */
2226 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2228 /* No longer need the sysgood bit. The ptrace event ends up
2229 recorded in lp->waitstatus if we care for it. We can carry
2230 on handling the event like a regular SIGTRAP from here
2232 status
= W_STOPCODE (SIGTRAP
);
2233 if (linux_handle_syscall_trap (lp
, 1))
2234 return wait_lwp (lp
);
2237 /* Handle GNU/Linux's extended waitstatus for trace events. */
2238 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2239 && linux_is_extended_waitstatus (status
))
2241 if (debug_linux_nat
)
2242 fprintf_unfiltered (gdb_stdlog
,
2243 "WL: Handling extended status 0x%06x\n",
2245 if (linux_handle_extended_wait (lp
, status
, 1))
2246 return wait_lwp (lp
);
2252 /* Send a SIGSTOP to LP. */
2255 stop_callback (struct lwp_info
*lp
, void *data
)
2257 if (!lp
->stopped
&& !lp
->signalled
)
2261 if (debug_linux_nat
)
2263 fprintf_unfiltered (gdb_stdlog
,
2264 "SC: kill %s **<SIGSTOP>**\n",
2265 target_pid_to_str (lp
->ptid
));
2268 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2269 if (debug_linux_nat
)
2271 fprintf_unfiltered (gdb_stdlog
,
2272 "SC: lwp kill %d %s\n",
2274 errno
? safe_strerror (errno
) : "ERRNO-OK");
2278 gdb_assert (lp
->status
== 0);
2284 /* Request a stop on LWP. */
2287 linux_stop_lwp (struct lwp_info
*lwp
)
2289 stop_callback (lwp
, NULL
);
2292 /* Return non-zero if LWP PID has a pending SIGINT. */
2295 linux_nat_has_pending_sigint (int pid
)
2297 sigset_t pending
, blocked
, ignored
;
2299 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2301 if (sigismember (&pending
, SIGINT
)
2302 && !sigismember (&ignored
, SIGINT
))
2308 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2311 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2313 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2314 flag to consume the next one. */
2315 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2316 && WSTOPSIG (lp
->status
) == SIGINT
)
2319 lp
->ignore_sigint
= 1;
2324 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2325 This function is called after we know the LWP has stopped; if the LWP
2326 stopped before the expected SIGINT was delivered, then it will never have
2327 arrived. Also, if the signal was delivered to a shared queue and consumed
2328 by a different thread, it will never be delivered to this LWP. */
2331 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2333 if (!lp
->ignore_sigint
)
2336 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2338 if (debug_linux_nat
)
2339 fprintf_unfiltered (gdb_stdlog
,
2340 "MCIS: Clearing bogus flag for %s\n",
2341 target_pid_to_str (lp
->ptid
));
2342 lp
->ignore_sigint
= 0;
2346 /* Fetch the possible triggered data watchpoint info and store it in
2349 On some archs, like x86, that use debug registers to set
2350 watchpoints, it's possible that the way to know which watched
2351 address trapped, is to check the register that is used to select
2352 which address to watch. Problem is, between setting the watchpoint
2353 and reading back which data address trapped, the user may change
2354 the set of watchpoints, and, as a consequence, GDB changes the
2355 debug registers in the inferior. To avoid reading back a stale
2356 stopped-data-address when that happens, we cache in LP the fact
2357 that a watchpoint trapped, and the corresponding data address, as
2358 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2359 registers meanwhile, we have the cached data we can rely on. */
2362 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2364 struct cleanup
*old_chain
;
2366 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2369 old_chain
= save_inferior_ptid ();
2370 inferior_ptid
= lp
->ptid
;
2372 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2374 lp
->stop_reason
= LWP_STOPPED_BY_WATCHPOINT
;
2376 if (linux_ops
->to_stopped_data_address
!= NULL
)
2377 lp
->stopped_data_address_p
=
2378 linux_ops
->to_stopped_data_address (¤t_target
,
2379 &lp
->stopped_data_address
);
2381 lp
->stopped_data_address_p
= 0;
2384 do_cleanups (old_chain
);
2386 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2389 /* Called when the LWP stopped for a trap that could be explained by a
2390 watchpoint or a breakpoint. */
2393 save_sigtrap (struct lwp_info
*lp
)
2395 gdb_assert (lp
->stop_reason
== LWP_STOPPED_BY_NO_REASON
);
2396 gdb_assert (lp
->status
!= 0);
2398 if (check_stopped_by_watchpoint (lp
))
2401 if (linux_nat_status_is_event (lp
->status
))
2402 check_stopped_by_breakpoint (lp
);
2405 /* Returns true if the LWP had stopped for a watchpoint. */
2408 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2410 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2412 gdb_assert (lp
!= NULL
);
2414 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2418 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2420 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2422 gdb_assert (lp
!= NULL
);
2424 *addr_p
= lp
->stopped_data_address
;
2426 return lp
->stopped_data_address_p
;
2429 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2432 sigtrap_is_event (int status
)
2434 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2437 /* Set alternative SIGTRAP-like events recognizer. If
2438 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2442 linux_nat_set_status_is_event (struct target_ops
*t
,
2443 int (*status_is_event
) (int status
))
2445 linux_nat_status_is_event
= status_is_event
;
2448 /* Wait until LP is stopped. */
2451 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2453 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2455 /* If this is a vfork parent, bail out, it is not going to report
2456 any SIGSTOP until the vfork is done with. */
2457 if (inf
->vfork_child
!= NULL
)
2464 status
= wait_lwp (lp
);
2468 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2469 && WSTOPSIG (status
) == SIGINT
)
2471 lp
->ignore_sigint
= 0;
2474 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2476 if (debug_linux_nat
)
2477 fprintf_unfiltered (gdb_stdlog
,
2478 "PTRACE_CONT %s, 0, 0 (%s) "
2479 "(discarding SIGINT)\n",
2480 target_pid_to_str (lp
->ptid
),
2481 errno
? safe_strerror (errno
) : "OK");
2483 return stop_wait_callback (lp
, NULL
);
2486 maybe_clear_ignore_sigint (lp
);
2488 if (WSTOPSIG (status
) != SIGSTOP
)
2490 /* The thread was stopped with a signal other than SIGSTOP. */
2492 if (debug_linux_nat
)
2493 fprintf_unfiltered (gdb_stdlog
,
2494 "SWC: Pending event %s in %s\n",
2495 status_to_str ((int) status
),
2496 target_pid_to_str (lp
->ptid
));
2498 /* Save the sigtrap event. */
2499 lp
->status
= status
;
2500 gdb_assert (lp
->signalled
);
2505 /* We caught the SIGSTOP that we intended to catch, so
2506 there's no SIGSTOP pending. */
2508 if (debug_linux_nat
)
2509 fprintf_unfiltered (gdb_stdlog
,
2510 "SWC: Delayed SIGSTOP caught for %s.\n",
2511 target_pid_to_str (lp
->ptid
));
2513 /* Reset SIGNALLED only after the stop_wait_callback call
2514 above as it does gdb_assert on SIGNALLED. */
2522 /* Return non-zero if LP has a wait status pending. Discard the
2523 pending event and resume the LWP if the event that originally
2524 caused the stop became uninteresting. */
2527 status_callback (struct lwp_info
*lp
, void *data
)
2529 /* Only report a pending wait status if we pretend that this has
2530 indeed been resumed. */
2534 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
2535 || lp
->stop_reason
== LWP_STOPPED_BY_HW_BREAKPOINT
)
2537 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2538 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2542 gdb_assert (lp
->status
!= 0);
2544 pc
= regcache_read_pc (regcache
);
2546 if (pc
!= lp
->stop_pc
)
2548 if (debug_linux_nat
)
2549 fprintf_unfiltered (gdb_stdlog
,
2550 "SC: PC of %s changed. was=%s, now=%s\n",
2551 target_pid_to_str (lp
->ptid
),
2552 paddress (target_gdbarch (), lp
->stop_pc
),
2553 paddress (target_gdbarch (), pc
));
2556 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2558 if (debug_linux_nat
)
2559 fprintf_unfiltered (gdb_stdlog
,
2560 "SC: previous breakpoint of %s, at %s gone\n",
2561 target_pid_to_str (lp
->ptid
),
2562 paddress (target_gdbarch (), lp
->stop_pc
));
2569 if (debug_linux_nat
)
2570 fprintf_unfiltered (gdb_stdlog
,
2571 "SC: pending event of %s cancelled.\n",
2572 target_pid_to_str (lp
->ptid
));
2575 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2581 return lwp_status_pending_p (lp
);
2584 /* Return non-zero if LP isn't stopped. */
2587 running_callback (struct lwp_info
*lp
, void *data
)
2589 return (!lp
->stopped
2590 || (lwp_status_pending_p (lp
) && lp
->resumed
));
2593 /* Count the LWP's that have had events. */
2596 count_events_callback (struct lwp_info
*lp
, void *data
)
2600 gdb_assert (count
!= NULL
);
2602 /* Select only resumed LWPs that have an event pending. */
2603 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2609 /* Select the LWP (if any) that is currently being single-stepped. */
2612 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2614 if (lp
->last_resume_kind
== resume_step
2621 /* Returns true if LP has a status pending. */
2624 lwp_status_pending_p (struct lwp_info
*lp
)
2626 /* We check for lp->waitstatus in addition to lp->status, because we
2627 can have pending process exits recorded in lp->status and
2628 W_EXITCODE(0,0) happens to be 0. */
2629 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2632 /* Select the Nth LWP that has had a SIGTRAP event. */
2635 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2637 int *selector
= data
;
2639 gdb_assert (selector
!= NULL
);
2641 /* Select only resumed LWPs that have an event pending. */
2642 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2643 if ((*selector
)-- == 0)
2649 /* Called when the LWP got a signal/trap that could be explained by a
2650 software or hardware breakpoint. */
2653 check_stopped_by_breakpoint (struct lwp_info
*lp
)
2655 /* Arrange for a breakpoint to be hit again later. We don't keep
2656 the SIGTRAP status and don't forward the SIGTRAP signal to the
2657 LWP. We will handle the current event, eventually we will resume
2658 this LWP, and this breakpoint will trap again.
2660 If we do not do this, then we run the risk that the user will
2661 delete or disable the breakpoint, but the LWP will have already
2664 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2665 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2669 pc
= regcache_read_pc (regcache
);
2670 sw_bp_pc
= pc
- target_decr_pc_after_break (gdbarch
);
2672 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2673 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2676 /* The LWP was either continued, or stepped a software
2677 breakpoint instruction. */
2678 if (debug_linux_nat
)
2679 fprintf_unfiltered (gdb_stdlog
,
2680 "CB: Push back software breakpoint for %s\n",
2681 target_pid_to_str (lp
->ptid
));
2683 /* Back up the PC if necessary. */
2685 regcache_write_pc (regcache
, sw_bp_pc
);
2687 lp
->stop_pc
= sw_bp_pc
;
2688 lp
->stop_reason
= LWP_STOPPED_BY_SW_BREAKPOINT
;
2692 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2694 if (debug_linux_nat
)
2695 fprintf_unfiltered (gdb_stdlog
,
2696 "CB: Push back hardware breakpoint for %s\n",
2697 target_pid_to_str (lp
->ptid
));
2700 lp
->stop_reason
= LWP_STOPPED_BY_HW_BREAKPOINT
;
2707 /* Select one LWP out of those that have events pending. */
2710 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2713 int random_selector
;
2714 struct lwp_info
*event_lp
= NULL
;
2716 /* Record the wait status for the original LWP. */
2717 (*orig_lp
)->status
= *status
;
2719 /* In all-stop, give preference to the LWP that is being
2720 single-stepped. There will be at most one, and it will be the
2721 LWP that the core is most interested in. If we didn't do this,
2722 then we'd have to handle pending step SIGTRAPs somehow in case
2723 the core later continues the previously-stepped thread, as
2724 otherwise we'd report the pending SIGTRAP then, and the core, not
2725 having stepped the thread, wouldn't understand what the trap was
2726 for, and therefore would report it to the user as a random
2730 event_lp
= iterate_over_lwps (filter
,
2731 select_singlestep_lwp_callback
, NULL
);
2732 if (event_lp
!= NULL
)
2734 if (debug_linux_nat
)
2735 fprintf_unfiltered (gdb_stdlog
,
2736 "SEL: Select single-step %s\n",
2737 target_pid_to_str (event_lp
->ptid
));
2741 if (event_lp
== NULL
)
2743 /* Pick one at random, out of those which have had events. */
2745 /* First see how many events we have. */
2746 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2748 /* Now randomly pick a LWP out of those that have had
2750 random_selector
= (int)
2751 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2753 if (debug_linux_nat
&& num_events
> 1)
2754 fprintf_unfiltered (gdb_stdlog
,
2755 "SEL: Found %d events, selecting #%d\n",
2756 num_events
, random_selector
);
2758 event_lp
= iterate_over_lwps (filter
,
2759 select_event_lwp_callback
,
2763 if (event_lp
!= NULL
)
2765 /* Switch the event LWP. */
2766 *orig_lp
= event_lp
;
2767 *status
= event_lp
->status
;
2770 /* Flush the wait status for the event LWP. */
2771 (*orig_lp
)->status
= 0;
2774 /* Return non-zero if LP has been resumed. */
2777 resumed_callback (struct lwp_info
*lp
, void *data
)
2782 /* Stop an active thread, verify it still exists, then resume it. If
2783 the thread ends up with a pending status, then it is not resumed,
2784 and *DATA (really a pointer to int), is set. */
2787 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2791 ptid_t ptid
= lp
->ptid
;
2793 stop_callback (lp
, NULL
);
2794 stop_wait_callback (lp
, NULL
);
2796 /* Resume if the lwp still exists, and the core wanted it
2798 lp
= find_lwp_pid (ptid
);
2801 if (lp
->last_resume_kind
== resume_stop
2802 && !lwp_status_pending_p (lp
))
2804 /* The core wanted the LWP to stop. Even if it stopped
2805 cleanly (with SIGSTOP), leave the event pending. */
2806 if (debug_linux_nat
)
2807 fprintf_unfiltered (gdb_stdlog
,
2808 "SARC: core wanted LWP %ld stopped "
2809 "(leaving SIGSTOP pending)\n",
2810 ptid_get_lwp (lp
->ptid
));
2811 lp
->status
= W_STOPCODE (SIGSTOP
);
2814 if (!lwp_status_pending_p (lp
))
2816 if (debug_linux_nat
)
2817 fprintf_unfiltered (gdb_stdlog
,
2818 "SARC: re-resuming LWP %ld\n",
2819 ptid_get_lwp (lp
->ptid
));
2820 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2824 if (debug_linux_nat
)
2825 fprintf_unfiltered (gdb_stdlog
,
2826 "SARC: not re-resuming LWP %ld "
2828 ptid_get_lwp (lp
->ptid
));
2835 /* Check if we should go on and pass this event to common code.
2836 Return the affected lwp if we are, or NULL otherwise. */
2838 static struct lwp_info
*
2839 linux_nat_filter_event (int lwpid
, int status
)
2841 struct lwp_info
*lp
;
2842 int event
= linux_ptrace_get_extended_event (status
);
2844 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2846 /* Check for stop events reported by a process we didn't already
2847 know about - anything not already in our LWP list.
2849 If we're expecting to receive stopped processes after
2850 fork, vfork, and clone events, then we'll just add the
2851 new one to our list and go back to waiting for the event
2852 to be reported - the stopped process might be returned
2853 from waitpid before or after the event is.
2855 But note the case of a non-leader thread exec'ing after the
2856 leader having exited, and gone from our lists. The non-leader
2857 thread changes its tid to the tgid. */
2859 if (WIFSTOPPED (status
) && lp
== NULL
2860 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2862 /* A multi-thread exec after we had seen the leader exiting. */
2863 if (debug_linux_nat
)
2864 fprintf_unfiltered (gdb_stdlog
,
2865 "LLW: Re-adding thread group leader LWP %d.\n",
2868 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2871 add_thread (lp
->ptid
);
2874 if (WIFSTOPPED (status
) && !lp
)
2876 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2880 /* Make sure we don't report an event for the exit of an LWP not in
2881 our list, i.e. not part of the current process. This can happen
2882 if we detach from a program we originally forked and then it
2884 if (!WIFSTOPPED (status
) && !lp
)
2887 /* This LWP is stopped now. (And if dead, this prevents it from
2888 ever being continued.) */
2891 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2893 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2895 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), inf
->attach_flag
);
2896 lp
->must_set_ptrace_flags
= 0;
2899 /* Handle GNU/Linux's syscall SIGTRAPs. */
2900 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2902 /* No longer need the sysgood bit. The ptrace event ends up
2903 recorded in lp->waitstatus if we care for it. We can carry
2904 on handling the event like a regular SIGTRAP from here
2906 status
= W_STOPCODE (SIGTRAP
);
2907 if (linux_handle_syscall_trap (lp
, 0))
2911 /* Handle GNU/Linux's extended waitstatus for trace events. */
2912 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2913 && linux_is_extended_waitstatus (status
))
2915 if (debug_linux_nat
)
2916 fprintf_unfiltered (gdb_stdlog
,
2917 "LLW: Handling extended status 0x%06x\n",
2919 if (linux_handle_extended_wait (lp
, status
, 0))
2923 /* Check if the thread has exited. */
2924 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2926 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2928 /* If this is the main thread, we must stop all threads and
2929 verify if they are still alive. This is because in the
2930 nptl thread model on Linux 2.4, there is no signal issued
2931 for exiting LWPs other than the main thread. We only get
2932 the main thread exit signal once all child threads have
2933 already exited. If we stop all the threads and use the
2934 stop_wait_callback to check if they have exited we can
2935 determine whether this signal should be ignored or
2936 whether it means the end of the debugged application,
2937 regardless of which threading model is being used. */
2938 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2940 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
2941 stop_and_resume_callback
, NULL
);
2944 if (debug_linux_nat
)
2945 fprintf_unfiltered (gdb_stdlog
,
2946 "LLW: %s exited.\n",
2947 target_pid_to_str (lp
->ptid
));
2949 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2951 /* If there is at least one more LWP, then the exit signal
2952 was not the end of the debugged application and should be
2959 gdb_assert (lp
->resumed
);
2961 if (debug_linux_nat
)
2962 fprintf_unfiltered (gdb_stdlog
,
2963 "Process %ld exited\n",
2964 ptid_get_lwp (lp
->ptid
));
2966 /* This was the last lwp in the process. Since events are
2967 serialized to GDB core, we may not be able report this one
2968 right now, but GDB core and the other target layers will want
2969 to be notified about the exit code/signal, leave the status
2970 pending for the next time we're able to report it. */
2972 /* Dead LWP's aren't expected to reported a pending sigstop. */
2975 /* Store the pending event in the waitstatus, because
2976 W_EXITCODE(0,0) == 0. */
2977 store_waitstatus (&lp
->waitstatus
, status
);
2981 /* Check if the current LWP has previously exited. In the nptl
2982 thread model, LWPs other than the main thread do not issue
2983 signals when they exit so we must check whenever the thread has
2984 stopped. A similar check is made in stop_wait_callback(). */
2985 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
2987 ptid_t ptid
= pid_to_ptid (ptid_get_pid (lp
->ptid
));
2989 if (debug_linux_nat
)
2990 fprintf_unfiltered (gdb_stdlog
,
2991 "LLW: %s exited.\n",
2992 target_pid_to_str (lp
->ptid
));
2996 /* Make sure there is at least one thread running. */
2997 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
2999 /* Discard the event. */
3003 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3004 an attempt to stop an LWP. */
3006 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3008 if (debug_linux_nat
)
3009 fprintf_unfiltered (gdb_stdlog
,
3010 "LLW: Delayed SIGSTOP caught for %s.\n",
3011 target_pid_to_str (lp
->ptid
));
3015 if (lp
->last_resume_kind
!= resume_stop
)
3017 /* This is a delayed SIGSTOP. */
3019 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3020 if (debug_linux_nat
)
3021 fprintf_unfiltered (gdb_stdlog
,
3022 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3024 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3025 target_pid_to_str (lp
->ptid
));
3027 gdb_assert (lp
->resumed
);
3029 /* Discard the event. */
3034 /* Make sure we don't report a SIGINT that we have already displayed
3035 for another thread. */
3036 if (lp
->ignore_sigint
3037 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3039 if (debug_linux_nat
)
3040 fprintf_unfiltered (gdb_stdlog
,
3041 "LLW: Delayed SIGINT caught for %s.\n",
3042 target_pid_to_str (lp
->ptid
));
3044 /* This is a delayed SIGINT. */
3045 lp
->ignore_sigint
= 0;
3047 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3048 if (debug_linux_nat
)
3049 fprintf_unfiltered (gdb_stdlog
,
3050 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3052 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3053 target_pid_to_str (lp
->ptid
));
3054 gdb_assert (lp
->resumed
);
3056 /* Discard the event. */
3060 /* Don't report signals that GDB isn't interested in, such as
3061 signals that are neither printed nor stopped upon. Stopping all
3062 threads can be a bit time-consuming so if we want decent
3063 performance with heavily multi-threaded programs, especially when
3064 they're using a high frequency timer, we'd better avoid it if we
3066 if (WIFSTOPPED (status
))
3068 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3072 /* Only do the below in all-stop, as we currently use SIGSTOP
3073 to implement target_stop (see linux_nat_stop) in
3075 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3077 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3078 forwarded to the entire process group, that is, all LWPs
3079 will receive it - unless they're using CLONE_THREAD to
3080 share signals. Since we only want to report it once, we
3081 mark it as ignored for all LWPs except this one. */
3082 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3083 set_ignore_sigint
, NULL
);
3084 lp
->ignore_sigint
= 0;
3087 maybe_clear_ignore_sigint (lp
);
3090 /* When using hardware single-step, we need to report every signal.
3091 Otherwise, signals in pass_mask may be short-circuited. */
3093 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3095 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3096 if (debug_linux_nat
)
3097 fprintf_unfiltered (gdb_stdlog
,
3098 "LLW: %s %s, %s (preempt 'handle')\n",
3100 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3101 target_pid_to_str (lp
->ptid
),
3102 (signo
!= GDB_SIGNAL_0
3103 ? strsignal (gdb_signal_to_host (signo
))
3109 /* An interesting event. */
3111 lp
->status
= status
;
3116 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3117 their exits until all other threads in the group have exited. */
3120 check_zombie_leaders (void)
3122 struct inferior
*inf
;
3126 struct lwp_info
*leader_lp
;
3131 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3132 if (leader_lp
!= NULL
3133 /* Check if there are other threads in the group, as we may
3134 have raced with the inferior simply exiting. */
3135 && num_lwps (inf
->pid
) > 1
3136 && linux_proc_pid_is_zombie (inf
->pid
))
3138 if (debug_linux_nat
)
3139 fprintf_unfiltered (gdb_stdlog
,
3140 "CZL: Thread group leader %d zombie "
3141 "(it exited, or another thread execd).\n",
3144 /* A leader zombie can mean one of two things:
3146 - It exited, and there's an exit status pending
3147 available, or only the leader exited (not the whole
3148 program). In the latter case, we can't waitpid the
3149 leader's exit status until all other threads are gone.
3151 - There are 3 or more threads in the group, and a thread
3152 other than the leader exec'd. On an exec, the Linux
3153 kernel destroys all other threads (except the execing
3154 one) in the thread group, and resets the execing thread's
3155 tid to the tgid. No exit notification is sent for the
3156 execing thread -- from the ptracer's perspective, it
3157 appears as though the execing thread just vanishes.
3158 Until we reap all other threads except the leader and the
3159 execing thread, the leader will be zombie, and the
3160 execing thread will be in `D (disc sleep)'. As soon as
3161 all other threads are reaped, the execing thread changes
3162 it's tid to the tgid, and the previous (zombie) leader
3163 vanishes, giving place to the "new" leader. We could try
3164 distinguishing the exit and exec cases, by waiting once
3165 more, and seeing if something comes out, but it doesn't
3166 sound useful. The previous leader _does_ go away, and
3167 we'll re-add the new one once we see the exec event
3168 (which is just the same as what would happen if the
3169 previous leader did exit voluntarily before some other
3172 if (debug_linux_nat
)
3173 fprintf_unfiltered (gdb_stdlog
,
3174 "CZL: Thread group leader %d vanished.\n",
3176 exit_lwp (leader_lp
);
3182 linux_nat_wait_1 (struct target_ops
*ops
,
3183 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3187 enum resume_kind last_resume_kind
;
3188 struct lwp_info
*lp
;
3191 if (debug_linux_nat
)
3192 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3194 /* The first time we get here after starting a new inferior, we may
3195 not have added it to the LWP list yet - this is the earliest
3196 moment at which we know its PID. */
3197 if (ptid_is_pid (inferior_ptid
))
3199 /* Upgrade the main thread's ptid. */
3200 thread_change_ptid (inferior_ptid
,
3201 ptid_build (ptid_get_pid (inferior_ptid
),
3202 ptid_get_pid (inferior_ptid
), 0));
3204 lp
= add_initial_lwp (inferior_ptid
);
3208 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3209 block_child_signals (&prev_mask
);
3211 /* First check if there is a LWP with a wait status pending. */
3212 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3215 if (debug_linux_nat
)
3216 fprintf_unfiltered (gdb_stdlog
,
3217 "LLW: Using pending wait status %s for %s.\n",
3218 status_to_str (lp
->status
),
3219 target_pid_to_str (lp
->ptid
));
3222 if (!target_can_async_p ())
3224 /* Causes SIGINT to be passed on to the attached process. */
3228 /* But if we don't find a pending event, we'll have to wait. Always
3229 pull all events out of the kernel. We'll randomly select an
3230 event LWP out of all that have events, to prevent starvation. */
3236 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3239 - If the thread group leader exits while other threads in the
3240 thread group still exist, waitpid(TGID, ...) hangs. That
3241 waitpid won't return an exit status until the other threads
3242 in the group are reapped.
3244 - When a non-leader thread execs, that thread just vanishes
3245 without reporting an exit (so we'd hang if we waited for it
3246 explicitly in that case). The exec event is reported to
3250 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3251 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3252 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3254 if (debug_linux_nat
)
3255 fprintf_unfiltered (gdb_stdlog
,
3256 "LNW: waitpid(-1, ...) returned %d, %s\n",
3257 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3261 if (debug_linux_nat
)
3263 fprintf_unfiltered (gdb_stdlog
,
3264 "LLW: waitpid %ld received %s\n",
3265 (long) lwpid
, status_to_str (status
));
3268 linux_nat_filter_event (lwpid
, status
);
3269 /* Retry until nothing comes out of waitpid. A single
3270 SIGCHLD can indicate more than one child stopped. */
3274 /* Now that we've pulled all events out of the kernel, check if
3275 there's any LWP with a status to report to the core. */
3276 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3280 /* Check for zombie thread group leaders. Those can't be reaped
3281 until all other threads in the thread group are. */
3282 check_zombie_leaders ();
3284 /* If there are no resumed children left, bail. We'd be stuck
3285 forever in the sigsuspend call below otherwise. */
3286 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3288 if (debug_linux_nat
)
3289 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3291 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3293 if (!target_can_async_p ())
3294 clear_sigint_trap ();
3296 restore_child_signals_mask (&prev_mask
);
3297 return minus_one_ptid
;
3300 /* No interesting event to report to the core. */
3302 if (target_options
& TARGET_WNOHANG
)
3304 if (debug_linux_nat
)
3305 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3307 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3308 restore_child_signals_mask (&prev_mask
);
3309 return minus_one_ptid
;
3312 /* We shouldn't end up here unless we want to try again. */
3313 gdb_assert (lp
== NULL
);
3315 /* Block until we get an event reported with SIGCHLD. */
3316 if (debug_linux_nat
)
3317 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3318 sigsuspend (&suspend_mask
);
3321 if (!target_can_async_p ())
3322 clear_sigint_trap ();
3326 status
= lp
->status
;
3331 /* Now stop all other LWP's ... */
3332 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3334 /* ... and wait until all of them have reported back that
3335 they're no longer running. */
3336 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3339 /* If we're not waiting for a specific LWP, choose an event LWP from
3340 among those that have had events. Giving equal priority to all
3341 LWPs that have had events helps prevent starvation. */
3342 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3343 select_event_lwp (ptid
, &lp
, &status
);
3345 gdb_assert (lp
!= NULL
);
3347 /* Now that we've selected our final event LWP, un-adjust its PC if
3348 it was a software breakpoint. */
3349 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
)
3351 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3352 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3353 int decr_pc
= target_decr_pc_after_break (gdbarch
);
3359 pc
= regcache_read_pc (regcache
);
3360 regcache_write_pc (regcache
, pc
+ decr_pc
);
3364 /* We'll need this to determine whether to report a SIGSTOP as
3365 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3367 last_resume_kind
= lp
->last_resume_kind
;
3371 /* In all-stop, from the core's perspective, all LWPs are now
3372 stopped until a new resume action is sent over. */
3373 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3377 resume_clear_callback (lp
, NULL
);
3380 if (linux_nat_status_is_event (status
))
3382 if (debug_linux_nat
)
3383 fprintf_unfiltered (gdb_stdlog
,
3384 "LLW: trap ptid is %s.\n",
3385 target_pid_to_str (lp
->ptid
));
3388 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3390 *ourstatus
= lp
->waitstatus
;
3391 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3394 store_waitstatus (ourstatus
, status
);
3396 if (debug_linux_nat
)
3397 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3399 restore_child_signals_mask (&prev_mask
);
3401 if (last_resume_kind
== resume_stop
3402 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3403 && WSTOPSIG (status
) == SIGSTOP
)
3405 /* A thread that has been requested to stop by GDB with
3406 target_stop, and it stopped cleanly, so report as SIG0. The
3407 use of SIGSTOP is an implementation detail. */
3408 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3411 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3412 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3415 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3420 /* Resume LWPs that are currently stopped without any pending status
3421 to report, but are resumed from the core's perspective. */
3424 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3426 ptid_t
*wait_ptid_p
= data
;
3430 && !lwp_status_pending_p (lp
))
3432 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3433 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3434 CORE_ADDR pc
= regcache_read_pc (regcache
);
3436 gdb_assert (is_executing (lp
->ptid
));
3438 /* Don't bother if there's a breakpoint at PC that we'd hit
3439 immediately, and we're not waiting for this LWP. */
3440 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3442 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3446 if (debug_linux_nat
)
3447 fprintf_unfiltered (gdb_stdlog
,
3448 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3449 target_pid_to_str (lp
->ptid
),
3450 paddress (gdbarch
, pc
),
3453 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3460 linux_nat_wait (struct target_ops
*ops
,
3461 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3466 if (debug_linux_nat
)
3468 char *options_string
;
3470 options_string
= target_options_to_string (target_options
);
3471 fprintf_unfiltered (gdb_stdlog
,
3472 "linux_nat_wait: [%s], [%s]\n",
3473 target_pid_to_str (ptid
),
3475 xfree (options_string
);
3478 /* Flush the async file first. */
3479 if (target_can_async_p ())
3480 async_file_flush ();
3482 /* Resume LWPs that are currently stopped without any pending status
3483 to report, but are resumed from the core's perspective. LWPs get
3484 in this state if we find them stopping at a time we're not
3485 interested in reporting the event (target_wait on a
3486 specific_process, for example, see linux_nat_wait_1), and
3487 meanwhile the event became uninteresting. Don't bother resuming
3488 LWPs we're not going to wait for if they'd stop immediately. */
3490 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3492 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3494 /* If we requested any event, and something came out, assume there
3495 may be more. If we requested a specific lwp or process, also
3496 assume there may be more. */
3497 if (target_can_async_p ()
3498 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3499 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3500 || !ptid_equal (ptid
, minus_one_ptid
)))
3503 /* Get ready for the next event. */
3504 if (target_can_async_p ())
3505 target_async (inferior_event_handler
, 0);
3511 kill_callback (struct lwp_info
*lp
, void *data
)
3513 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3516 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3517 if (debug_linux_nat
)
3519 int save_errno
= errno
;
3521 fprintf_unfiltered (gdb_stdlog
,
3522 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3523 target_pid_to_str (lp
->ptid
),
3524 save_errno
? safe_strerror (save_errno
) : "OK");
3527 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3530 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3531 if (debug_linux_nat
)
3533 int save_errno
= errno
;
3535 fprintf_unfiltered (gdb_stdlog
,
3536 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3537 target_pid_to_str (lp
->ptid
),
3538 save_errno
? safe_strerror (save_errno
) : "OK");
3545 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3549 /* We must make sure that there are no pending events (delayed
3550 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3551 program doesn't interfere with any following debugging session. */
3553 /* For cloned processes we must check both with __WCLONE and
3554 without, since the exit status of a cloned process isn't reported
3560 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3561 if (pid
!= (pid_t
) -1)
3563 if (debug_linux_nat
)
3564 fprintf_unfiltered (gdb_stdlog
,
3565 "KWC: wait %s received unknown.\n",
3566 target_pid_to_str (lp
->ptid
));
3567 /* The Linux kernel sometimes fails to kill a thread
3568 completely after PTRACE_KILL; that goes from the stop
3569 point in do_fork out to the one in
3570 get_signal_to_deliever and waits again. So kill it
3572 kill_callback (lp
, NULL
);
3575 while (pid
== ptid_get_lwp (lp
->ptid
));
3577 gdb_assert (pid
== -1 && errno
== ECHILD
);
3582 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3583 if (pid
!= (pid_t
) -1)
3585 if (debug_linux_nat
)
3586 fprintf_unfiltered (gdb_stdlog
,
3587 "KWC: wait %s received unk.\n",
3588 target_pid_to_str (lp
->ptid
));
3589 /* See the call to kill_callback above. */
3590 kill_callback (lp
, NULL
);
3593 while (pid
== ptid_get_lwp (lp
->ptid
));
3595 gdb_assert (pid
== -1 && errno
== ECHILD
);
3600 linux_nat_kill (struct target_ops
*ops
)
3602 struct target_waitstatus last
;
3606 /* If we're stopped while forking and we haven't followed yet,
3607 kill the other task. We need to do this first because the
3608 parent will be sleeping if this is a vfork. */
3610 get_last_target_status (&last_ptid
, &last
);
3612 if (last
.kind
== TARGET_WAITKIND_FORKED
3613 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3615 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3618 /* Let the arch-specific native code know this process is
3620 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3623 if (forks_exist_p ())
3624 linux_fork_killall ();
3627 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3629 /* Stop all threads before killing them, since ptrace requires
3630 that the thread is stopped to sucessfully PTRACE_KILL. */
3631 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3632 /* ... and wait until all of them have reported back that
3633 they're no longer running. */
3634 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3636 /* Kill all LWP's ... */
3637 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3639 /* ... and wait until we've flushed all events. */
3640 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3643 target_mourn_inferior ();
3647 linux_nat_mourn_inferior (struct target_ops
*ops
)
3649 int pid
= ptid_get_pid (inferior_ptid
);
3651 purge_lwp_list (pid
);
3653 if (! forks_exist_p ())
3654 /* Normal case, no other forks available. */
3655 linux_ops
->to_mourn_inferior (ops
);
3657 /* Multi-fork case. The current inferior_ptid has exited, but
3658 there are other viable forks to debug. Delete the exiting
3659 one and context-switch to the first available. */
3660 linux_fork_mourn_inferior ();
3662 /* Let the arch-specific native code know this process is gone. */
3663 linux_nat_forget_process (pid
);
3666 /* Convert a native/host siginfo object, into/from the siginfo in the
3667 layout of the inferiors' architecture. */
3670 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3674 if (linux_nat_siginfo_fixup
!= NULL
)
3675 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3677 /* If there was no callback, or the callback didn't do anything,
3678 then just do a straight memcpy. */
3682 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3684 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3688 static enum target_xfer_status
3689 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3690 const char *annex
, gdb_byte
*readbuf
,
3691 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3692 ULONGEST
*xfered_len
)
3696 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3698 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3699 gdb_assert (readbuf
|| writebuf
);
3701 pid
= ptid_get_lwp (inferior_ptid
);
3703 pid
= ptid_get_pid (inferior_ptid
);
3705 if (offset
> sizeof (siginfo
))
3706 return TARGET_XFER_E_IO
;
3709 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3711 return TARGET_XFER_E_IO
;
3713 /* When GDB is built as a 64-bit application, ptrace writes into
3714 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3715 inferior with a 64-bit GDB should look the same as debugging it
3716 with a 32-bit GDB, we need to convert it. GDB core always sees
3717 the converted layout, so any read/write will have to be done
3719 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3721 if (offset
+ len
> sizeof (siginfo
))
3722 len
= sizeof (siginfo
) - offset
;
3724 if (readbuf
!= NULL
)
3725 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3728 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3730 /* Convert back to ptrace layout before flushing it out. */
3731 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3734 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3736 return TARGET_XFER_E_IO
;
3740 return TARGET_XFER_OK
;
3743 static enum target_xfer_status
3744 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3745 const char *annex
, gdb_byte
*readbuf
,
3746 const gdb_byte
*writebuf
,
3747 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3749 struct cleanup
*old_chain
;
3750 enum target_xfer_status xfer
;
3752 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3753 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3754 offset
, len
, xfered_len
);
3756 /* The target is connected but no live inferior is selected. Pass
3757 this request down to a lower stratum (e.g., the executable
3759 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3760 return TARGET_XFER_EOF
;
3762 old_chain
= save_inferior_ptid ();
3764 if (ptid_lwp_p (inferior_ptid
))
3765 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3767 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3768 offset
, len
, xfered_len
);
3770 do_cleanups (old_chain
);
3775 linux_thread_alive (ptid_t ptid
)
3779 gdb_assert (ptid_lwp_p (ptid
));
3781 /* Send signal 0 instead of anything ptrace, because ptracing a
3782 running thread errors out claiming that the thread doesn't
3784 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3786 if (debug_linux_nat
)
3787 fprintf_unfiltered (gdb_stdlog
,
3788 "LLTA: KILL(SIG0) %s (%s)\n",
3789 target_pid_to_str (ptid
),
3790 err
? safe_strerror (tmp_errno
) : "OK");
3799 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3801 return linux_thread_alive (ptid
);
3805 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3807 static char buf
[64];
3809 if (ptid_lwp_p (ptid
)
3810 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3811 || num_lwps (ptid_get_pid (ptid
)) > 1))
3813 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3817 return normal_pid_to_str (ptid
);
3821 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3823 int pid
= ptid_get_pid (thr
->ptid
);
3824 long lwp
= ptid_get_lwp (thr
->ptid
);
3825 #define FORMAT "/proc/%d/task/%ld/comm"
3826 char buf
[sizeof (FORMAT
) + 30];
3828 char *result
= NULL
;
3830 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
3831 comm_file
= gdb_fopen_cloexec (buf
, "r");
3834 /* Not exported by the kernel, so we define it here. */
3836 static char line
[COMM_LEN
+ 1];
3838 if (fgets (line
, sizeof (line
), comm_file
))
3840 char *nl
= strchr (line
, '\n');
3857 /* Accepts an integer PID; Returns a string representing a file that
3858 can be opened to get the symbols for the child process. */
3861 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3863 static char buf
[PATH_MAX
];
3864 char name
[PATH_MAX
];
3866 xsnprintf (name
, PATH_MAX
, "/proc/%d/exe", pid
);
3867 memset (buf
, 0, PATH_MAX
);
3868 if (readlink (name
, buf
, PATH_MAX
- 1) <= 0)
3874 /* Implement the to_xfer_partial interface for memory reads using the /proc
3875 filesystem. Because we can use a single read() call for /proc, this
3876 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3877 but it doesn't support writes. */
3879 static enum target_xfer_status
3880 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3881 const char *annex
, gdb_byte
*readbuf
,
3882 const gdb_byte
*writebuf
,
3883 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3889 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3892 /* Don't bother for one word. */
3893 if (len
< 3 * sizeof (long))
3894 return TARGET_XFER_EOF
;
3896 /* We could keep this file open and cache it - possibly one per
3897 thread. That requires some juggling, but is even faster. */
3898 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3899 ptid_get_pid (inferior_ptid
));
3900 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3902 return TARGET_XFER_EOF
;
3904 /* If pread64 is available, use it. It's faster if the kernel
3905 supports it (only one syscall), and it's 64-bit safe even on
3906 32-bit platforms (for instance, SPARC debugging a SPARC64
3909 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3911 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3920 return TARGET_XFER_EOF
;
3924 return TARGET_XFER_OK
;
3929 /* Enumerate spufs IDs for process PID. */
3931 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3933 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3935 LONGEST written
= 0;
3938 struct dirent
*entry
;
3940 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3941 dir
= opendir (path
);
3946 while ((entry
= readdir (dir
)) != NULL
)
3952 fd
= atoi (entry
->d_name
);
3956 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3957 if (stat (path
, &st
) != 0)
3959 if (!S_ISDIR (st
.st_mode
))
3962 if (statfs (path
, &stfs
) != 0)
3964 if (stfs
.f_type
!= SPUFS_MAGIC
)
3967 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
3969 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
3979 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
3980 object type, using the /proc file system. */
3982 static enum target_xfer_status
3983 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
3984 const char *annex
, gdb_byte
*readbuf
,
3985 const gdb_byte
*writebuf
,
3986 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3991 int pid
= ptid_get_pid (inferior_ptid
);
3996 return TARGET_XFER_E_IO
;
3999 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4002 return TARGET_XFER_E_IO
;
4004 return TARGET_XFER_EOF
;
4007 *xfered_len
= (ULONGEST
) l
;
4008 return TARGET_XFER_OK
;
4013 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4014 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4016 return TARGET_XFER_E_IO
;
4019 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4022 return TARGET_XFER_EOF
;
4026 ret
= write (fd
, writebuf
, (size_t) len
);
4028 ret
= read (fd
, readbuf
, (size_t) len
);
4033 return TARGET_XFER_E_IO
;
4035 return TARGET_XFER_EOF
;
4038 *xfered_len
= (ULONGEST
) ret
;
4039 return TARGET_XFER_OK
;
4044 /* Parse LINE as a signal set and add its set bits to SIGS. */
4047 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4049 int len
= strlen (line
) - 1;
4053 if (line
[len
] != '\n')
4054 error (_("Could not parse signal set: %s"), line
);
4062 if (*p
>= '0' && *p
<= '9')
4064 else if (*p
>= 'a' && *p
<= 'f')
4065 digit
= *p
- 'a' + 10;
4067 error (_("Could not parse signal set: %s"), line
);
4072 sigaddset (sigs
, signum
+ 1);
4074 sigaddset (sigs
, signum
+ 2);
4076 sigaddset (sigs
, signum
+ 3);
4078 sigaddset (sigs
, signum
+ 4);
4084 /* Find process PID's pending signals from /proc/pid/status and set
4088 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4089 sigset_t
*blocked
, sigset_t
*ignored
)
4092 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4093 struct cleanup
*cleanup
;
4095 sigemptyset (pending
);
4096 sigemptyset (blocked
);
4097 sigemptyset (ignored
);
4098 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4099 procfile
= gdb_fopen_cloexec (fname
, "r");
4100 if (procfile
== NULL
)
4101 error (_("Could not open %s"), fname
);
4102 cleanup
= make_cleanup_fclose (procfile
);
4104 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4106 /* Normal queued signals are on the SigPnd line in the status
4107 file. However, 2.6 kernels also have a "shared" pending
4108 queue for delivering signals to a thread group, so check for
4111 Unfortunately some Red Hat kernels include the shared pending
4112 queue but not the ShdPnd status field. */
4114 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4115 add_line_to_sigset (buffer
+ 8, pending
);
4116 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4117 add_line_to_sigset (buffer
+ 8, pending
);
4118 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4119 add_line_to_sigset (buffer
+ 8, blocked
);
4120 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4121 add_line_to_sigset (buffer
+ 8, ignored
);
4124 do_cleanups (cleanup
);
4127 static enum target_xfer_status
4128 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4129 const char *annex
, gdb_byte
*readbuf
,
4130 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4131 ULONGEST
*xfered_len
)
4133 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4135 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4136 if (*xfered_len
== 0)
4137 return TARGET_XFER_EOF
;
4139 return TARGET_XFER_OK
;
4142 static enum target_xfer_status
4143 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4144 const char *annex
, gdb_byte
*readbuf
,
4145 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4146 ULONGEST
*xfered_len
)
4148 enum target_xfer_status xfer
;
4150 if (object
== TARGET_OBJECT_AUXV
)
4151 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4152 offset
, len
, xfered_len
);
4154 if (object
== TARGET_OBJECT_OSDATA
)
4155 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4156 offset
, len
, xfered_len
);
4158 if (object
== TARGET_OBJECT_SPU
)
4159 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4160 offset
, len
, xfered_len
);
4162 /* GDB calculates all the addresses in possibly larget width of the address.
4163 Address width needs to be masked before its final use - either by
4164 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4166 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4168 if (object
== TARGET_OBJECT_MEMORY
)
4170 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4172 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4173 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4176 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4177 offset
, len
, xfered_len
);
4178 if (xfer
!= TARGET_XFER_EOF
)
4181 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4182 offset
, len
, xfered_len
);
4186 cleanup_target_stop (void *arg
)
4188 ptid_t
*ptid
= (ptid_t
*) arg
;
4190 gdb_assert (arg
!= NULL
);
4193 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4196 static VEC(static_tracepoint_marker_p
) *
4197 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4200 char s
[IPA_CMD_BUF_SIZE
];
4201 struct cleanup
*old_chain
;
4202 int pid
= ptid_get_pid (inferior_ptid
);
4203 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4204 struct static_tracepoint_marker
*marker
= NULL
;
4206 ptid_t ptid
= ptid_build (pid
, 0, 0);
4211 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4212 s
[sizeof ("qTfSTM")] = 0;
4214 agent_run_command (pid
, s
, strlen (s
) + 1);
4216 old_chain
= make_cleanup (free_current_marker
, &marker
);
4217 make_cleanup (cleanup_target_stop
, &ptid
);
4222 marker
= XCNEW (struct static_tracepoint_marker
);
4226 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4228 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4230 VEC_safe_push (static_tracepoint_marker_p
,
4236 release_static_tracepoint_marker (marker
);
4237 memset (marker
, 0, sizeof (*marker
));
4240 while (*p
++ == ','); /* comma-separated list */
4242 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4243 s
[sizeof ("qTsSTM")] = 0;
4244 agent_run_command (pid
, s
, strlen (s
) + 1);
4248 do_cleanups (old_chain
);
4253 /* Create a prototype generic GNU/Linux target. The client can override
4254 it with local methods. */
4257 linux_target_install_ops (struct target_ops
*t
)
4259 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4260 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4261 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4262 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4263 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4264 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4265 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4266 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4267 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4268 t
->to_post_attach
= linux_child_post_attach
;
4269 t
->to_follow_fork
= linux_child_follow_fork
;
4271 super_xfer_partial
= t
->to_xfer_partial
;
4272 t
->to_xfer_partial
= linux_xfer_partial
;
4274 t
->to_static_tracepoint_markers_by_strid
4275 = linux_child_static_tracepoint_markers_by_strid
;
4281 struct target_ops
*t
;
4283 t
= inf_ptrace_target ();
4284 linux_target_install_ops (t
);
4290 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4292 struct target_ops
*t
;
4294 t
= inf_ptrace_trad_target (register_u_offset
);
4295 linux_target_install_ops (t
);
4300 /* target_is_async_p implementation. */
4303 linux_nat_is_async_p (struct target_ops
*ops
)
4305 /* NOTE: palves 2008-03-21: We're only async when the user requests
4306 it explicitly with the "set target-async" command.
4307 Someday, linux will always be async. */
4308 return target_async_permitted
;
4311 /* target_can_async_p implementation. */
4314 linux_nat_can_async_p (struct target_ops
*ops
)
4316 /* NOTE: palves 2008-03-21: We're only async when the user requests
4317 it explicitly with the "set target-async" command.
4318 Someday, linux will always be async. */
4319 return target_async_permitted
;
4323 linux_nat_supports_non_stop (struct target_ops
*self
)
4328 /* True if we want to support multi-process. To be removed when GDB
4329 supports multi-exec. */
4331 int linux_multi_process
= 1;
4334 linux_nat_supports_multi_process (struct target_ops
*self
)
4336 return linux_multi_process
;
4340 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4342 #ifdef HAVE_PERSONALITY
4349 static int async_terminal_is_ours
= 1;
4351 /* target_terminal_inferior implementation.
4353 This is a wrapper around child_terminal_inferior to add async support. */
4356 linux_nat_terminal_inferior (struct target_ops
*self
)
4358 if (!target_is_async_p ())
4360 /* Async mode is disabled. */
4361 child_terminal_inferior (self
);
4365 child_terminal_inferior (self
);
4367 /* Calls to target_terminal_*() are meant to be idempotent. */
4368 if (!async_terminal_is_ours
)
4371 delete_file_handler (input_fd
);
4372 async_terminal_is_ours
= 0;
4376 /* target_terminal_ours implementation.
4378 This is a wrapper around child_terminal_ours to add async support (and
4379 implement the target_terminal_ours vs target_terminal_ours_for_output
4380 distinction). child_terminal_ours is currently no different than
4381 child_terminal_ours_for_output.
4382 We leave target_terminal_ours_for_output alone, leaving it to
4383 child_terminal_ours_for_output. */
4386 linux_nat_terminal_ours (struct target_ops
*self
)
4388 if (!target_is_async_p ())
4390 /* Async mode is disabled. */
4391 child_terminal_ours (self
);
4395 /* GDB should never give the terminal to the inferior if the
4396 inferior is running in the background (run&, continue&, etc.),
4397 but claiming it sure should. */
4398 child_terminal_ours (self
);
4400 if (async_terminal_is_ours
)
4403 clear_sigint_trap ();
4404 add_file_handler (input_fd
, stdin_event_handler
, 0);
4405 async_terminal_is_ours
= 1;
4408 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4410 static void *async_client_context
;
4412 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4413 so we notice when any child changes state, and notify the
4414 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4415 above to wait for the arrival of a SIGCHLD. */
4418 sigchld_handler (int signo
)
4420 int old_errno
= errno
;
4422 if (debug_linux_nat
)
4423 ui_file_write_async_safe (gdb_stdlog
,
4424 "sigchld\n", sizeof ("sigchld\n") - 1);
4426 if (signo
== SIGCHLD
4427 && linux_nat_event_pipe
[0] != -1)
4428 async_file_mark (); /* Let the event loop know that there are
4429 events to handle. */
4434 /* Callback registered with the target events file descriptor. */
4437 handle_target_event (int error
, gdb_client_data client_data
)
4439 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4442 /* Create/destroy the target events pipe. Returns previous state. */
4445 linux_async_pipe (int enable
)
4447 int previous
= (linux_nat_event_pipe
[0] != -1);
4449 if (previous
!= enable
)
4453 /* Block child signals while we create/destroy the pipe, as
4454 their handler writes to it. */
4455 block_child_signals (&prev_mask
);
4459 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4460 internal_error (__FILE__
, __LINE__
,
4461 "creating event pipe failed.");
4463 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4464 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4468 close (linux_nat_event_pipe
[0]);
4469 close (linux_nat_event_pipe
[1]);
4470 linux_nat_event_pipe
[0] = -1;
4471 linux_nat_event_pipe
[1] = -1;
4474 restore_child_signals_mask (&prev_mask
);
4480 /* target_async implementation. */
4483 linux_nat_async (struct target_ops
*ops
,
4484 void (*callback
) (enum inferior_event_type event_type
,
4488 if (callback
!= NULL
)
4490 async_client_callback
= callback
;
4491 async_client_context
= context
;
4492 if (!linux_async_pipe (1))
4494 add_file_handler (linux_nat_event_pipe
[0],
4495 handle_target_event
, NULL
);
4496 /* There may be pending events to handle. Tell the event loop
4503 async_client_callback
= callback
;
4504 async_client_context
= context
;
4505 delete_file_handler (linux_nat_event_pipe
[0]);
4506 linux_async_pipe (0);
4511 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4515 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4519 if (debug_linux_nat
)
4520 fprintf_unfiltered (gdb_stdlog
,
4521 "LNSL: running -> suspending %s\n",
4522 target_pid_to_str (lwp
->ptid
));
4525 if (lwp
->last_resume_kind
== resume_stop
)
4527 if (debug_linux_nat
)
4528 fprintf_unfiltered (gdb_stdlog
,
4529 "linux-nat: already stopping LWP %ld at "
4531 ptid_get_lwp (lwp
->ptid
));
4535 stop_callback (lwp
, NULL
);
4536 lwp
->last_resume_kind
= resume_stop
;
4540 /* Already known to be stopped; do nothing. */
4542 if (debug_linux_nat
)
4544 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4545 fprintf_unfiltered (gdb_stdlog
,
4546 "LNSL: already stopped/stop_requested %s\n",
4547 target_pid_to_str (lwp
->ptid
));
4549 fprintf_unfiltered (gdb_stdlog
,
4550 "LNSL: already stopped/no "
4551 "stop_requested yet %s\n",
4552 target_pid_to_str (lwp
->ptid
));
4559 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4562 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4564 linux_ops
->to_stop (linux_ops
, ptid
);
4568 linux_nat_close (struct target_ops
*self
)
4570 /* Unregister from the event loop. */
4571 if (linux_nat_is_async_p (self
))
4572 linux_nat_async (self
, NULL
, NULL
);
4574 if (linux_ops
->to_close
)
4575 linux_ops
->to_close (linux_ops
);
4580 /* When requests are passed down from the linux-nat layer to the
4581 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4582 used. The address space pointer is stored in the inferior object,
4583 but the common code that is passed such ptid can't tell whether
4584 lwpid is a "main" process id or not (it assumes so). We reverse
4585 look up the "main" process id from the lwp here. */
4587 static struct address_space
*
4588 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4590 struct lwp_info
*lwp
;
4591 struct inferior
*inf
;
4594 if (ptid_get_lwp (ptid
) == 0)
4596 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4598 lwp
= find_lwp_pid (ptid
);
4599 pid
= ptid_get_pid (lwp
->ptid
);
4603 /* A (pid,lwpid,0) ptid. */
4604 pid
= ptid_get_pid (ptid
);
4607 inf
= find_inferior_pid (pid
);
4608 gdb_assert (inf
!= NULL
);
4612 /* Return the cached value of the processor core for thread PTID. */
4615 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4617 struct lwp_info
*info
= find_lwp_pid (ptid
);
4625 linux_nat_add_target (struct target_ops
*t
)
4627 /* Save the provided single-threaded target. We save this in a separate
4628 variable because another target we've inherited from (e.g. inf-ptrace)
4629 may have saved a pointer to T; we want to use it for the final
4630 process stratum target. */
4631 linux_ops_saved
= *t
;
4632 linux_ops
= &linux_ops_saved
;
4634 /* Override some methods for multithreading. */
4635 t
->to_create_inferior
= linux_nat_create_inferior
;
4636 t
->to_attach
= linux_nat_attach
;
4637 t
->to_detach
= linux_nat_detach
;
4638 t
->to_resume
= linux_nat_resume
;
4639 t
->to_wait
= linux_nat_wait
;
4640 t
->to_pass_signals
= linux_nat_pass_signals
;
4641 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4642 t
->to_kill
= linux_nat_kill
;
4643 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4644 t
->to_thread_alive
= linux_nat_thread_alive
;
4645 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4646 t
->to_thread_name
= linux_nat_thread_name
;
4647 t
->to_has_thread_control
= tc_schedlock
;
4648 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4649 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4650 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4652 t
->to_can_async_p
= linux_nat_can_async_p
;
4653 t
->to_is_async_p
= linux_nat_is_async_p
;
4654 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4655 t
->to_async
= linux_nat_async
;
4656 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4657 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4659 super_close
= t
->to_close
;
4660 t
->to_close
= linux_nat_close
;
4662 /* Methods for non-stop support. */
4663 t
->to_stop
= linux_nat_stop
;
4665 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4667 t
->to_supports_disable_randomization
4668 = linux_nat_supports_disable_randomization
;
4670 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4672 /* We don't change the stratum; this target will sit at
4673 process_stratum and thread_db will set at thread_stratum. This
4674 is a little strange, since this is a multi-threaded-capable
4675 target, but we want to be on the stack below thread_db, and we
4676 also want to be used for single-threaded processes. */
4681 /* Register a method to call whenever a new thread is attached. */
4683 linux_nat_set_new_thread (struct target_ops
*t
,
4684 void (*new_thread
) (struct lwp_info
*))
4686 /* Save the pointer. We only support a single registered instance
4687 of the GNU/Linux native target, so we do not need to map this to
4689 linux_nat_new_thread
= new_thread
;
4692 /* See declaration in linux-nat.h. */
4695 linux_nat_set_new_fork (struct target_ops
*t
,
4696 linux_nat_new_fork_ftype
*new_fork
)
4698 /* Save the pointer. */
4699 linux_nat_new_fork
= new_fork
;
4702 /* See declaration in linux-nat.h. */
4705 linux_nat_set_forget_process (struct target_ops
*t
,
4706 linux_nat_forget_process_ftype
*fn
)
4708 /* Save the pointer. */
4709 linux_nat_forget_process_hook
= fn
;
4712 /* See declaration in linux-nat.h. */
4715 linux_nat_forget_process (pid_t pid
)
4717 if (linux_nat_forget_process_hook
!= NULL
)
4718 linux_nat_forget_process_hook (pid
);
4721 /* Register a method that converts a siginfo object between the layout
4722 that ptrace returns, and the layout in the architecture of the
4725 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4726 int (*siginfo_fixup
) (siginfo_t
*,
4730 /* Save the pointer. */
4731 linux_nat_siginfo_fixup
= siginfo_fixup
;
4734 /* Register a method to call prior to resuming a thread. */
4737 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4738 void (*prepare_to_resume
) (struct lwp_info
*))
4740 /* Save the pointer. */
4741 linux_nat_prepare_to_resume
= prepare_to_resume
;
4744 /* See linux-nat.h. */
4747 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4751 pid
= ptid_get_lwp (ptid
);
4753 pid
= ptid_get_pid (ptid
);
4756 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4759 memset (siginfo
, 0, sizeof (*siginfo
));
4765 /* Provide a prototype to silence -Wmissing-prototypes. */
4766 extern initialize_file_ftype _initialize_linux_nat
;
4769 _initialize_linux_nat (void)
4771 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4772 &debug_linux_nat
, _("\
4773 Set debugging of GNU/Linux lwp module."), _("\
4774 Show debugging of GNU/Linux lwp module."), _("\
4775 Enables printf debugging output."),
4777 show_debug_linux_nat
,
4778 &setdebuglist
, &showdebuglist
);
4780 /* Save this mask as the default. */
4781 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4783 /* Install a SIGCHLD handler. */
4784 sigchld_action
.sa_handler
= sigchld_handler
;
4785 sigemptyset (&sigchld_action
.sa_mask
);
4786 sigchld_action
.sa_flags
= SA_RESTART
;
4788 /* Make it the default. */
4789 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4791 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4792 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4793 sigdelset (&suspend_mask
, SIGCHLD
);
4795 sigemptyset (&blocked_mask
);
4797 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
4798 support read-only process state. */
4799 linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD
4800 | PTRACE_O_TRACEVFORKDONE
4801 | PTRACE_O_TRACEVFORK
4802 | PTRACE_O_TRACEFORK
4803 | PTRACE_O_TRACEEXEC
);
4807 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4808 the GNU/Linux Threads library and therefore doesn't really belong
4811 /* Read variable NAME in the target and return its value if found.
4812 Otherwise return zero. It is assumed that the type of the variable
4816 get_signo (const char *name
)
4818 struct bound_minimal_symbol ms
;
4821 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4822 if (ms
.minsym
== NULL
)
4825 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4826 sizeof (signo
)) != 0)
4832 /* Return the set of signals used by the threads library in *SET. */
4835 lin_thread_get_thread_signals (sigset_t
*set
)
4837 struct sigaction action
;
4838 int restart
, cancel
;
4840 sigemptyset (&blocked_mask
);
4843 restart
= get_signo ("__pthread_sig_restart");
4844 cancel
= get_signo ("__pthread_sig_cancel");
4846 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4847 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4848 not provide any way for the debugger to query the signal numbers -
4849 fortunately they don't change! */
4852 restart
= __SIGRTMIN
;
4855 cancel
= __SIGRTMIN
+ 1;
4857 sigaddset (set
, restart
);
4858 sigaddset (set
, cancel
);
4860 /* The GNU/Linux Threads library makes terminating threads send a
4861 special "cancel" signal instead of SIGCHLD. Make sure we catch
4862 those (to prevent them from terminating GDB itself, which is
4863 likely to be their default action) and treat them the same way as
4866 action
.sa_handler
= sigchld_handler
;
4867 sigemptyset (&action
.sa_mask
);
4868 action
.sa_flags
= SA_RESTART
;
4869 sigaction (cancel
, &action
, NULL
);
4871 /* We block the "cancel" signal throughout this code ... */
4872 sigaddset (&blocked_mask
, cancel
);
4873 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4875 /* ... except during a sigsuspend. */
4876 sigdelset (&suspend_mask
, cancel
);