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 /* True if we're currently in async mode. */
223 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
225 /* Flush the event pipe. */
228 async_file_flush (void)
235 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
237 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
240 /* Put something (anything, doesn't matter what, or how much) in event
241 pipe, so that the select/poll in the event-loop realizes we have
242 something to process. */
245 async_file_mark (void)
249 /* It doesn't really matter what the pipe contains, as long we end
250 up with something in it. Might as well flush the previous
256 ret
= write (linux_nat_event_pipe
[1], "+", 1);
258 while (ret
== -1 && errno
== EINTR
);
260 /* Ignore EAGAIN. If the pipe is full, the event loop will already
261 be awakened anyway. */
264 static int kill_lwp (int lwpid
, int signo
);
266 static int stop_callback (struct lwp_info
*lp
, void *data
);
268 static void block_child_signals (sigset_t
*prev_mask
);
269 static void restore_child_signals_mask (sigset_t
*prev_mask
);
272 static struct lwp_info
*add_lwp (ptid_t ptid
);
273 static void purge_lwp_list (int pid
);
274 static void delete_lwp (ptid_t ptid
);
275 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
277 static int lwp_status_pending_p (struct lwp_info
*lp
);
279 static int check_stopped_by_breakpoint (struct lwp_info
*lp
);
280 static int sigtrap_is_event (int status
);
281 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
284 /* Trivial list manipulation functions to keep track of a list of
285 new stopped processes. */
287 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
289 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
292 new_pid
->status
= status
;
293 new_pid
->next
= *listp
;
298 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
300 struct simple_pid_list
*p
;
302 for (p
= list
; p
!= NULL
; p
= p
->next
)
309 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
311 struct simple_pid_list
**p
;
313 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
314 if ((*p
)->pid
== pid
)
316 struct simple_pid_list
*next
= (*p
)->next
;
318 *statusp
= (*p
)->status
;
326 /* Initialize ptrace warnings and check for supported ptrace
329 ATTACHED should be nonzero iff we attached to the inferior. */
332 linux_init_ptrace (pid_t pid
, int attached
)
334 linux_enable_event_reporting (pid
, attached
);
335 linux_ptrace_init_warnings ();
339 linux_child_post_attach (struct target_ops
*self
, int pid
)
341 linux_init_ptrace (pid
, 1);
345 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
347 linux_init_ptrace (ptid_get_pid (ptid
), 0);
350 /* Return the number of known LWPs in the tgid given by PID. */
358 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
359 if (ptid_get_pid (lp
->ptid
) == pid
)
365 /* Call delete_lwp with prototype compatible for make_cleanup. */
368 delete_lwp_cleanup (void *lp_voidp
)
370 struct lwp_info
*lp
= lp_voidp
;
372 delete_lwp (lp
->ptid
);
375 /* Target hook for follow_fork. On entry inferior_ptid must be the
376 ptid of the followed inferior. At return, inferior_ptid will be
380 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
385 struct lwp_info
*child_lp
= NULL
;
386 int status
= W_STOPCODE (0);
387 struct cleanup
*old_chain
;
389 int parent_pid
, child_pid
;
391 has_vforked
= (inferior_thread ()->pending_follow
.kind
392 == TARGET_WAITKIND_VFORKED
);
393 parent_pid
= ptid_get_lwp (inferior_ptid
);
395 parent_pid
= ptid_get_pid (inferior_ptid
);
397 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
400 /* We're already attached to the parent, by default. */
401 old_chain
= save_inferior_ptid ();
402 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
403 child_lp
= add_lwp (inferior_ptid
);
404 child_lp
->stopped
= 1;
405 child_lp
->last_resume_kind
= resume_stop
;
407 /* Detach new forked process? */
410 make_cleanup (delete_lwp_cleanup
, child_lp
);
412 if (linux_nat_prepare_to_resume
!= NULL
)
413 linux_nat_prepare_to_resume (child_lp
);
415 /* When debugging an inferior in an architecture that supports
416 hardware single stepping on a kernel without commit
417 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
418 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
419 set if the parent process had them set.
420 To work around this, single step the child process
421 once before detaching to clear the flags. */
423 if (!gdbarch_software_single_step_p (target_thread_architecture
426 linux_disable_event_reporting (child_pid
);
427 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
428 perror_with_name (_("Couldn't do single step"));
429 if (my_waitpid (child_pid
, &status
, 0) < 0)
430 perror_with_name (_("Couldn't wait vfork process"));
433 if (WIFSTOPPED (status
))
437 signo
= WSTOPSIG (status
);
439 && !signal_pass_state (gdb_signal_from_host (signo
)))
441 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
444 /* Resets value of inferior_ptid to parent ptid. */
445 do_cleanups (old_chain
);
449 /* Let the thread_db layer learn about this new process. */
450 check_for_thread_db ();
453 do_cleanups (old_chain
);
457 struct lwp_info
*parent_lp
;
459 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
460 gdb_assert (linux_supports_tracefork () >= 0);
462 if (linux_supports_tracevforkdone ())
465 fprintf_unfiltered (gdb_stdlog
,
466 "LCFF: waiting for VFORK_DONE on %d\n",
468 parent_lp
->stopped
= 1;
470 /* We'll handle the VFORK_DONE event like any other
471 event, in target_wait. */
475 /* We can't insert breakpoints until the child has
476 finished with the shared memory region. We need to
477 wait until that happens. Ideal would be to just
479 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
480 - waitpid (parent_pid, &status, __WALL);
481 However, most architectures can't handle a syscall
482 being traced on the way out if it wasn't traced on
485 We might also think to loop, continuing the child
486 until it exits or gets a SIGTRAP. One problem is
487 that the child might call ptrace with PTRACE_TRACEME.
489 There's no simple and reliable way to figure out when
490 the vforked child will be done with its copy of the
491 shared memory. We could step it out of the syscall,
492 two instructions, let it go, and then single-step the
493 parent once. When we have hardware single-step, this
494 would work; with software single-step it could still
495 be made to work but we'd have to be able to insert
496 single-step breakpoints in the child, and we'd have
497 to insert -just- the single-step breakpoint in the
498 parent. Very awkward.
500 In the end, the best we can do is to make sure it
501 runs for a little while. Hopefully it will be out of
502 range of any breakpoints we reinsert. Usually this
503 is only the single-step breakpoint at vfork's return
507 fprintf_unfiltered (gdb_stdlog
,
508 "LCFF: no VFORK_DONE "
509 "support, sleeping a bit\n");
513 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
514 and leave it pending. The next linux_nat_resume call
515 will notice a pending event, and bypasses actually
516 resuming the inferior. */
517 parent_lp
->status
= 0;
518 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
519 parent_lp
->stopped
= 1;
521 /* If we're in async mode, need to tell the event loop
522 there's something here to process. */
523 if (target_is_async_p ())
530 struct lwp_info
*child_lp
;
532 child_lp
= add_lwp (inferior_ptid
);
533 child_lp
->stopped
= 1;
534 child_lp
->last_resume_kind
= resume_stop
;
536 /* Let the thread_db layer learn about this new process. */
537 check_for_thread_db ();
545 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
547 return !linux_supports_tracefork ();
551 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
557 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
559 return !linux_supports_tracefork ();
563 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
569 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
571 return !linux_supports_tracefork ();
575 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
581 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
582 int pid
, int needed
, int any_count
,
583 int table_size
, int *table
)
585 if (!linux_supports_tracesysgood ())
588 /* On GNU/Linux, we ignore the arguments. It means that we only
589 enable the syscall catchpoints, but do not disable them.
591 Also, we do not use the `table' information because we do not
592 filter system calls here. We let GDB do the logic for us. */
596 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
597 are processes sharing the same VM space. A multi-threaded process
598 is basically a group of such processes. However, such a grouping
599 is almost entirely a user-space issue; the kernel doesn't enforce
600 such a grouping at all (this might change in the future). In
601 general, we'll rely on the threads library (i.e. the GNU/Linux
602 Threads library) to provide such a grouping.
604 It is perfectly well possible to write a multi-threaded application
605 without the assistance of a threads library, by using the clone
606 system call directly. This module should be able to give some
607 rudimentary support for debugging such applications if developers
608 specify the CLONE_PTRACE flag in the clone system call, and are
609 using the Linux kernel 2.4 or above.
611 Note that there are some peculiarities in GNU/Linux that affect
614 - In general one should specify the __WCLONE flag to waitpid in
615 order to make it report events for any of the cloned processes
616 (and leave it out for the initial process). However, if a cloned
617 process has exited the exit status is only reported if the
618 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
619 we cannot use it since GDB must work on older systems too.
621 - When a traced, cloned process exits and is waited for by the
622 debugger, the kernel reassigns it to the original parent and
623 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
624 library doesn't notice this, which leads to the "zombie problem":
625 When debugged a multi-threaded process that spawns a lot of
626 threads will run out of processes, even if the threads exit,
627 because the "zombies" stay around. */
629 /* List of known LWPs. */
630 struct lwp_info
*lwp_list
;
633 /* Original signal mask. */
634 static sigset_t normal_mask
;
636 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
637 _initialize_linux_nat. */
638 static sigset_t suspend_mask
;
640 /* Signals to block to make that sigsuspend work. */
641 static sigset_t blocked_mask
;
643 /* SIGCHLD action. */
644 struct sigaction sigchld_action
;
646 /* Block child signals (SIGCHLD and linux threads signals), and store
647 the previous mask in PREV_MASK. */
650 block_child_signals (sigset_t
*prev_mask
)
652 /* Make sure SIGCHLD is blocked. */
653 if (!sigismember (&blocked_mask
, SIGCHLD
))
654 sigaddset (&blocked_mask
, SIGCHLD
);
656 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
659 /* Restore child signals mask, previously returned by
660 block_child_signals. */
663 restore_child_signals_mask (sigset_t
*prev_mask
)
665 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
668 /* Mask of signals to pass directly to the inferior. */
669 static sigset_t pass_mask
;
671 /* Update signals to pass to the inferior. */
673 linux_nat_pass_signals (struct target_ops
*self
,
674 int numsigs
, unsigned char *pass_signals
)
678 sigemptyset (&pass_mask
);
680 for (signo
= 1; signo
< NSIG
; signo
++)
682 int target_signo
= gdb_signal_from_host (signo
);
683 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
684 sigaddset (&pass_mask
, signo
);
690 /* Prototypes for local functions. */
691 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
692 static int linux_thread_alive (ptid_t ptid
);
693 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
694 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
698 /* Destroy and free LP. */
701 lwp_free (struct lwp_info
*lp
)
703 xfree (lp
->arch_private
);
707 /* Remove all LWPs belong to PID from the lwp list. */
710 purge_lwp_list (int pid
)
712 struct lwp_info
*lp
, *lpprev
, *lpnext
;
716 for (lp
= lwp_list
; lp
; lp
= lpnext
)
720 if (ptid_get_pid (lp
->ptid
) == pid
)
725 lpprev
->next
= lp
->next
;
734 /* Add the LWP specified by PTID to the list. PTID is the first LWP
735 in the process. Return a pointer to the structure describing the
738 This differs from add_lwp in that we don't let the arch specific
739 bits know about this new thread. Current clients of this callback
740 take the opportunity to install watchpoints in the new thread, and
741 we shouldn't do that for the first thread. If we're spawning a
742 child ("run"), the thread executes the shell wrapper first, and we
743 shouldn't touch it until it execs the program we want to debug.
744 For "attach", it'd be okay to call the callback, but it's not
745 necessary, because watchpoints can't yet have been inserted into
748 static struct lwp_info
*
749 add_initial_lwp (ptid_t ptid
)
753 gdb_assert (ptid_lwp_p (ptid
));
755 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
757 memset (lp
, 0, sizeof (struct lwp_info
));
759 lp
->last_resume_kind
= resume_continue
;
760 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
771 /* Add the LWP specified by PID to the list. Return a pointer to the
772 structure describing the new LWP. The LWP should already be
775 static struct lwp_info
*
776 add_lwp (ptid_t ptid
)
780 lp
= add_initial_lwp (ptid
);
782 /* Let the arch specific bits know about this new thread. Current
783 clients of this callback take the opportunity to install
784 watchpoints in the new thread. We don't do this for the first
785 thread though. See add_initial_lwp. */
786 if (linux_nat_new_thread
!= NULL
)
787 linux_nat_new_thread (lp
);
792 /* Remove the LWP specified by PID from the list. */
795 delete_lwp (ptid_t ptid
)
797 struct lwp_info
*lp
, *lpprev
;
801 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
802 if (ptid_equal (lp
->ptid
, ptid
))
809 lpprev
->next
= lp
->next
;
816 /* Return a pointer to the structure describing the LWP corresponding
817 to PID. If no corresponding LWP could be found, return NULL. */
819 static struct lwp_info
*
820 find_lwp_pid (ptid_t ptid
)
825 if (ptid_lwp_p (ptid
))
826 lwp
= ptid_get_lwp (ptid
);
828 lwp
= ptid_get_pid (ptid
);
830 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
831 if (lwp
== ptid_get_lwp (lp
->ptid
))
837 /* Call CALLBACK with its second argument set to DATA for every LWP in
838 the list. If CALLBACK returns 1 for a particular LWP, return a
839 pointer to the structure describing that LWP immediately.
840 Otherwise return NULL. */
843 iterate_over_lwps (ptid_t filter
,
844 int (*callback
) (struct lwp_info
*, void *),
847 struct lwp_info
*lp
, *lpnext
;
849 for (lp
= lwp_list
; lp
; lp
= lpnext
)
853 if (ptid_match (lp
->ptid
, filter
))
855 if ((*callback
) (lp
, data
))
863 /* Update our internal state when changing from one checkpoint to
864 another indicated by NEW_PTID. We can only switch single-threaded
865 applications, so we only create one new LWP, and the previous list
869 linux_nat_switch_fork (ptid_t new_ptid
)
873 purge_lwp_list (ptid_get_pid (inferior_ptid
));
875 lp
= add_lwp (new_ptid
);
878 /* This changes the thread's ptid while preserving the gdb thread
879 num. Also changes the inferior pid, while preserving the
881 thread_change_ptid (inferior_ptid
, new_ptid
);
883 /* We've just told GDB core that the thread changed target id, but,
884 in fact, it really is a different thread, with different register
886 registers_changed ();
889 /* Handle the exit of a single thread LP. */
892 exit_lwp (struct lwp_info
*lp
)
894 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
898 if (print_thread_events
)
899 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
901 delete_thread (lp
->ptid
);
904 delete_lwp (lp
->ptid
);
907 /* Wait for the LWP specified by LP, which we have just attached to.
908 Returns a wait status for that LWP, to cache. */
911 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
914 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
917 if (linux_proc_pid_is_stopped (pid
))
920 fprintf_unfiltered (gdb_stdlog
,
921 "LNPAW: Attaching to a stopped process\n");
923 /* The process is definitely stopped. It is in a job control
924 stop, unless the kernel predates the TASK_STOPPED /
925 TASK_TRACED distinction, in which case it might be in a
926 ptrace stop. Make sure it is in a ptrace stop; from there we
927 can kill it, signal it, et cetera.
929 First make sure there is a pending SIGSTOP. Since we are
930 already attached, the process can not transition from stopped
931 to running without a PTRACE_CONT; so we know this signal will
932 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
933 probably already in the queue (unless this kernel is old
934 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
935 is not an RT signal, it can only be queued once. */
936 kill_lwp (pid
, SIGSTOP
);
938 /* Finally, resume the stopped process. This will deliver the SIGSTOP
939 (or a higher priority signal, just like normal PTRACE_ATTACH). */
940 ptrace (PTRACE_CONT
, pid
, 0, 0);
943 /* Make sure the initial process is stopped. The user-level threads
944 layer might want to poke around in the inferior, and that won't
945 work if things haven't stabilized yet. */
946 new_pid
= my_waitpid (pid
, &status
, 0);
947 if (new_pid
== -1 && errno
== ECHILD
)
950 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
952 /* Try again with __WCLONE to check cloned processes. */
953 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
957 gdb_assert (pid
== new_pid
);
959 if (!WIFSTOPPED (status
))
961 /* The pid we tried to attach has apparently just exited. */
963 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
964 pid
, status_to_str (status
));
968 if (WSTOPSIG (status
) != SIGSTOP
)
972 fprintf_unfiltered (gdb_stdlog
,
973 "LNPAW: Received %s after attaching\n",
974 status_to_str (status
));
980 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
981 the new LWP could not be attached, or 1 if we're already auto
982 attached to this thread, but haven't processed the
983 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
984 its existance, without considering it an error. */
987 lin_lwp_attach_lwp (ptid_t ptid
)
992 gdb_assert (ptid_lwp_p (ptid
));
994 lp
= find_lwp_pid (ptid
);
995 lwpid
= ptid_get_lwp (ptid
);
997 /* We assume that we're already attached to any LWP that is already
998 in our list of LWPs. If we're not seeing exit events from threads
999 and we've had PID wraparound since we last tried to stop all threads,
1000 this assumption might be wrong; fortunately, this is very unlikely
1004 int status
, cloned
= 0, signalled
= 0;
1006 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1008 if (linux_supports_tracefork ())
1010 /* If we haven't stopped all threads when we get here,
1011 we may have seen a thread listed in thread_db's list,
1012 but not processed the PTRACE_EVENT_CLONE yet. If
1013 that's the case, ignore this new thread, and let
1014 normal event handling discover it later. */
1015 if (in_pid_list_p (stopped_pids
, lwpid
))
1017 /* We've already seen this thread stop, but we
1018 haven't seen the PTRACE_EVENT_CLONE extended
1020 if (debug_linux_nat
)
1021 fprintf_unfiltered (gdb_stdlog
,
1022 "LLAL: attach failed, but already seen "
1023 "this thread %s stop\n",
1024 target_pid_to_str (ptid
));
1032 if (debug_linux_nat
)
1033 fprintf_unfiltered (gdb_stdlog
,
1034 "LLAL: attach failed, and haven't seen "
1035 "this thread %s stop yet\n",
1036 target_pid_to_str (ptid
));
1038 /* We may or may not be attached to the LWP already.
1039 Try waitpid on it. If that errors, we're not
1040 attached to the LWP yet. Otherwise, we're
1041 already attached. */
1042 gdb_assert (lwpid
> 0);
1043 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1044 if (new_pid
== -1 && errno
== ECHILD
)
1045 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1050 /* The child hasn't stopped for its initial
1051 SIGSTOP stop yet. */
1052 if (debug_linux_nat
)
1053 fprintf_unfiltered (gdb_stdlog
,
1054 "LLAL: child hasn't "
1057 else if (WIFSTOPPED (status
))
1059 if (debug_linux_nat
)
1060 fprintf_unfiltered (gdb_stdlog
,
1061 "LLAL: adding to stopped_pids\n");
1062 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1069 /* If we fail to attach to the thread, issue a warning,
1070 but continue. One way this can happen is if thread
1071 creation is interrupted; as of Linux kernel 2.6.19, a
1072 bug may place threads in the thread list and then fail
1074 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1075 safe_strerror (errno
));
1079 if (debug_linux_nat
)
1080 fprintf_unfiltered (gdb_stdlog
,
1081 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1082 target_pid_to_str (ptid
));
1084 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1085 if (!WIFSTOPPED (status
))
1088 lp
= add_lwp (ptid
);
1090 lp
->last_resume_kind
= resume_stop
;
1091 lp
->cloned
= cloned
;
1092 lp
->signalled
= signalled
;
1093 if (WSTOPSIG (status
) != SIGSTOP
)
1096 lp
->status
= status
;
1099 target_post_attach (ptid_get_lwp (lp
->ptid
));
1101 if (debug_linux_nat
)
1103 fprintf_unfiltered (gdb_stdlog
,
1104 "LLAL: waitpid %s received %s\n",
1105 target_pid_to_str (ptid
),
1106 status_to_str (status
));
1114 linux_nat_create_inferior (struct target_ops
*ops
,
1115 char *exec_file
, char *allargs
, char **env
,
1118 struct cleanup
*restore_personality
1119 = maybe_disable_address_space_randomization (disable_randomization
);
1121 /* The fork_child mechanism is synchronous and calls target_wait, so
1122 we have to mask the async mode. */
1124 /* Make sure we report all signals during startup. */
1125 linux_nat_pass_signals (ops
, 0, NULL
);
1127 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1129 do_cleanups (restore_personality
);
1132 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1133 already attached. Returns true if a new LWP is found, false
1137 attach_proc_task_lwp_callback (ptid_t ptid
)
1139 struct lwp_info
*lp
;
1141 /* Ignore LWPs we're already attached to. */
1142 lp
= find_lwp_pid (ptid
);
1145 int lwpid
= ptid_get_lwp (ptid
);
1147 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1151 /* Be quiet if we simply raced with the thread exiting.
1152 EPERM is returned if the thread's task still exists, and
1153 is marked as exited or zombie, as well as other
1154 conditions, so in that case, confirm the status in
1155 /proc/PID/status. */
1157 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1159 if (debug_linux_nat
)
1161 fprintf_unfiltered (gdb_stdlog
,
1162 "Cannot attach to lwp %d: "
1163 "thread is gone (%d: %s)\n",
1164 lwpid
, err
, safe_strerror (err
));
1169 warning (_("Cannot attach to lwp %d: %s"),
1171 linux_ptrace_attach_fail_reason_string (ptid
,
1177 if (debug_linux_nat
)
1178 fprintf_unfiltered (gdb_stdlog
,
1179 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1180 target_pid_to_str (ptid
));
1182 lp
= add_lwp (ptid
);
1185 /* The next time we wait for this LWP we'll see a SIGSTOP as
1186 PTRACE_ATTACH brings it to a halt. */
1189 /* We need to wait for a stop before being able to make the
1190 next ptrace call on this LWP. */
1191 lp
->must_set_ptrace_flags
= 1;
1200 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1202 struct lwp_info
*lp
;
1205 volatile struct gdb_exception ex
;
1207 /* Make sure we report all signals during attach. */
1208 linux_nat_pass_signals (ops
, 0, NULL
);
1210 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1212 linux_ops
->to_attach (ops
, args
, from_tty
);
1216 pid_t pid
= parse_pid_to_attach (args
);
1217 struct buffer buffer
;
1218 char *message
, *buffer_s
;
1220 message
= xstrdup (ex
.message
);
1221 make_cleanup (xfree
, message
);
1223 buffer_init (&buffer
);
1224 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1226 buffer_grow_str0 (&buffer
, "");
1227 buffer_s
= buffer_finish (&buffer
);
1228 make_cleanup (xfree
, buffer_s
);
1230 if (*buffer_s
!= '\0')
1231 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1233 throw_error (ex
.error
, "%s", message
);
1236 /* The ptrace base target adds the main thread with (pid,0,0)
1237 format. Decorate it with lwp info. */
1238 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1239 ptid_get_pid (inferior_ptid
),
1241 thread_change_ptid (inferior_ptid
, ptid
);
1243 /* Add the initial process as the first LWP to the list. */
1244 lp
= add_initial_lwp (ptid
);
1246 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1248 if (!WIFSTOPPED (status
))
1250 if (WIFEXITED (status
))
1252 int exit_code
= WEXITSTATUS (status
);
1254 target_terminal_ours ();
1255 target_mourn_inferior ();
1257 error (_("Unable to attach: program exited normally."));
1259 error (_("Unable to attach: program exited with code %d."),
1262 else if (WIFSIGNALED (status
))
1264 enum gdb_signal signo
;
1266 target_terminal_ours ();
1267 target_mourn_inferior ();
1269 signo
= gdb_signal_from_host (WTERMSIG (status
));
1270 error (_("Unable to attach: program terminated with signal "
1272 gdb_signal_to_name (signo
),
1273 gdb_signal_to_string (signo
));
1276 internal_error (__FILE__
, __LINE__
,
1277 _("unexpected status %d for PID %ld"),
1278 status
, (long) ptid_get_lwp (ptid
));
1283 /* Save the wait status to report later. */
1285 if (debug_linux_nat
)
1286 fprintf_unfiltered (gdb_stdlog
,
1287 "LNA: waitpid %ld, saving status %s\n",
1288 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1290 lp
->status
= status
;
1292 /* We must attach to every LWP. If /proc is mounted, use that to
1293 find them now. The inferior may be using raw clone instead of
1294 using pthreads. But even if it is using pthreads, thread_db
1295 walks structures in the inferior's address space to find the list
1296 of threads/LWPs, and those structures may well be corrupted.
1297 Note that once thread_db is loaded, we'll still use it to list
1298 threads and associate pthread info with each LWP. */
1299 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1300 attach_proc_task_lwp_callback
);
1302 if (target_can_async_p ())
1303 target_async (inferior_event_handler
, 0);
1306 /* Get pending status of LP. */
1308 get_pending_status (struct lwp_info
*lp
, int *status
)
1310 enum gdb_signal signo
= GDB_SIGNAL_0
;
1312 /* If we paused threads momentarily, we may have stored pending
1313 events in lp->status or lp->waitstatus (see stop_wait_callback),
1314 and GDB core hasn't seen any signal for those threads.
1315 Otherwise, the last signal reported to the core is found in the
1316 thread object's stop_signal.
1318 There's a corner case that isn't handled here at present. Only
1319 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1320 stop_signal make sense as a real signal to pass to the inferior.
1321 Some catchpoint related events, like
1322 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1323 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1324 those traps are debug API (ptrace in our case) related and
1325 induced; the inferior wouldn't see them if it wasn't being
1326 traced. Hence, we should never pass them to the inferior, even
1327 when set to pass state. Since this corner case isn't handled by
1328 infrun.c when proceeding with a signal, for consistency, neither
1329 do we handle it here (or elsewhere in the file we check for
1330 signal pass state). Normally SIGTRAP isn't set to pass state, so
1331 this is really a corner case. */
1333 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1334 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1335 else if (lp
->status
)
1336 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1337 else if (non_stop
&& !is_executing (lp
->ptid
))
1339 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1341 signo
= tp
->suspend
.stop_signal
;
1345 struct target_waitstatus last
;
1348 get_last_target_status (&last_ptid
, &last
);
1350 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1352 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1354 signo
= tp
->suspend
.stop_signal
;
1360 if (signo
== GDB_SIGNAL_0
)
1362 if (debug_linux_nat
)
1363 fprintf_unfiltered (gdb_stdlog
,
1364 "GPT: lwp %s has no pending signal\n",
1365 target_pid_to_str (lp
->ptid
));
1367 else if (!signal_pass_state (signo
))
1369 if (debug_linux_nat
)
1370 fprintf_unfiltered (gdb_stdlog
,
1371 "GPT: lwp %s had signal %s, "
1372 "but it is in no pass state\n",
1373 target_pid_to_str (lp
->ptid
),
1374 gdb_signal_to_string (signo
));
1378 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1380 if (debug_linux_nat
)
1381 fprintf_unfiltered (gdb_stdlog
,
1382 "GPT: lwp %s has pending signal %s\n",
1383 target_pid_to_str (lp
->ptid
),
1384 gdb_signal_to_string (signo
));
1391 detach_callback (struct lwp_info
*lp
, void *data
)
1393 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1395 if (debug_linux_nat
&& lp
->status
)
1396 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1397 strsignal (WSTOPSIG (lp
->status
)),
1398 target_pid_to_str (lp
->ptid
));
1400 /* If there is a pending SIGSTOP, get rid of it. */
1403 if (debug_linux_nat
)
1404 fprintf_unfiltered (gdb_stdlog
,
1405 "DC: Sending SIGCONT to %s\n",
1406 target_pid_to_str (lp
->ptid
));
1408 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1412 /* We don't actually detach from the LWP that has an id equal to the
1413 overall process id just yet. */
1414 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1418 /* Pass on any pending signal for this LWP. */
1419 get_pending_status (lp
, &status
);
1421 if (linux_nat_prepare_to_resume
!= NULL
)
1422 linux_nat_prepare_to_resume (lp
);
1424 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1425 WSTOPSIG (status
)) < 0)
1426 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1427 safe_strerror (errno
));
1429 if (debug_linux_nat
)
1430 fprintf_unfiltered (gdb_stdlog
,
1431 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1432 target_pid_to_str (lp
->ptid
),
1433 strsignal (WSTOPSIG (status
)));
1435 delete_lwp (lp
->ptid
);
1442 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1446 struct lwp_info
*main_lwp
;
1448 pid
= ptid_get_pid (inferior_ptid
);
1450 /* Don't unregister from the event loop, as there may be other
1451 inferiors running. */
1453 /* Stop all threads before detaching. ptrace requires that the
1454 thread is stopped to sucessfully detach. */
1455 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1456 /* ... and wait until all of them have reported back that
1457 they're no longer running. */
1458 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1460 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1462 /* Only the initial process should be left right now. */
1463 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1465 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1467 /* Pass on any pending signal for the last LWP. */
1468 if ((args
== NULL
|| *args
== '\0')
1469 && get_pending_status (main_lwp
, &status
) != -1
1470 && WIFSTOPPED (status
))
1474 /* Put the signal number in ARGS so that inf_ptrace_detach will
1475 pass it along with PTRACE_DETACH. */
1477 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1479 if (debug_linux_nat
)
1480 fprintf_unfiltered (gdb_stdlog
,
1481 "LND: Sending signal %s to %s\n",
1483 target_pid_to_str (main_lwp
->ptid
));
1486 if (linux_nat_prepare_to_resume
!= NULL
)
1487 linux_nat_prepare_to_resume (main_lwp
);
1488 delete_lwp (main_lwp
->ptid
);
1490 if (forks_exist_p ())
1492 /* Multi-fork case. The current inferior_ptid is being detached
1493 from, but there are other viable forks to debug. Detach from
1494 the current fork, and context-switch to the first
1496 linux_fork_detach (args
, from_tty
);
1499 linux_ops
->to_detach (ops
, args
, from_tty
);
1502 /* Resume execution of the inferior process. If STEP is nonzero,
1503 single-step it. If SIGNAL is nonzero, give it that signal. */
1506 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1512 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1513 We only presently need that if the LWP is stepped though (to
1514 handle the case of stepping a breakpoint instruction). */
1517 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1519 lp
->stop_pc
= regcache_read_pc (regcache
);
1524 if (linux_nat_prepare_to_resume
!= NULL
)
1525 linux_nat_prepare_to_resume (lp
);
1526 /* Convert to something the lower layer understands. */
1527 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1528 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1529 lp
->stop_reason
= LWP_STOPPED_BY_NO_REASON
;
1531 registers_changed_ptid (lp
->ptid
);
1537 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1541 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1543 if (inf
->vfork_child
!= NULL
)
1545 if (debug_linux_nat
)
1546 fprintf_unfiltered (gdb_stdlog
,
1547 "RC: Not resuming %s (vfork parent)\n",
1548 target_pid_to_str (lp
->ptid
));
1550 else if (!lwp_status_pending_p (lp
))
1552 if (debug_linux_nat
)
1553 fprintf_unfiltered (gdb_stdlog
,
1554 "RC: Resuming sibling %s, %s, %s\n",
1555 target_pid_to_str (lp
->ptid
),
1556 (signo
!= GDB_SIGNAL_0
1557 ? strsignal (gdb_signal_to_host (signo
))
1559 step
? "step" : "resume");
1561 linux_resume_one_lwp (lp
, step
, signo
);
1565 if (debug_linux_nat
)
1566 fprintf_unfiltered (gdb_stdlog
,
1567 "RC: Not resuming sibling %s (has pending)\n",
1568 target_pid_to_str (lp
->ptid
));
1573 if (debug_linux_nat
)
1574 fprintf_unfiltered (gdb_stdlog
,
1575 "RC: Not resuming sibling %s (not stopped)\n",
1576 target_pid_to_str (lp
->ptid
));
1580 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1581 Resume LWP with the last stop signal, if it is in pass state. */
1584 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1586 enum gdb_signal signo
= GDB_SIGNAL_0
;
1593 struct thread_info
*thread
;
1595 thread
= find_thread_ptid (lp
->ptid
);
1598 signo
= thread
->suspend
.stop_signal
;
1599 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1603 resume_lwp (lp
, 0, signo
);
1608 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1611 lp
->last_resume_kind
= resume_stop
;
1616 resume_set_callback (struct lwp_info
*lp
, void *data
)
1619 lp
->last_resume_kind
= resume_continue
;
1624 linux_nat_resume (struct target_ops
*ops
,
1625 ptid_t ptid
, int step
, enum gdb_signal signo
)
1627 struct lwp_info
*lp
;
1630 if (debug_linux_nat
)
1631 fprintf_unfiltered (gdb_stdlog
,
1632 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1633 step
? "step" : "resume",
1634 target_pid_to_str (ptid
),
1635 (signo
!= GDB_SIGNAL_0
1636 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1637 target_pid_to_str (inferior_ptid
));
1639 /* A specific PTID means `step only this process id'. */
1640 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1641 || ptid_is_pid (ptid
));
1643 /* Mark the lwps we're resuming as resumed. */
1644 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1646 /* See if it's the current inferior that should be handled
1649 lp
= find_lwp_pid (inferior_ptid
);
1651 lp
= find_lwp_pid (ptid
);
1652 gdb_assert (lp
!= NULL
);
1654 /* Remember if we're stepping. */
1655 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1657 /* If we have a pending wait status for this thread, there is no
1658 point in resuming the process. But first make sure that
1659 linux_nat_wait won't preemptively handle the event - we
1660 should never take this short-circuit if we are going to
1661 leave LP running, since we have skipped resuming all the
1662 other threads. This bit of code needs to be synchronized
1663 with linux_nat_wait. */
1665 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1668 && WSTOPSIG (lp
->status
)
1669 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1671 if (debug_linux_nat
)
1672 fprintf_unfiltered (gdb_stdlog
,
1673 "LLR: Not short circuiting for ignored "
1674 "status 0x%x\n", lp
->status
);
1676 /* FIXME: What should we do if we are supposed to continue
1677 this thread with a signal? */
1678 gdb_assert (signo
== GDB_SIGNAL_0
);
1679 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1684 if (lwp_status_pending_p (lp
))
1686 /* FIXME: What should we do if we are supposed to continue
1687 this thread with a signal? */
1688 gdb_assert (signo
== GDB_SIGNAL_0
);
1690 if (debug_linux_nat
)
1691 fprintf_unfiltered (gdb_stdlog
,
1692 "LLR: Short circuiting for status 0x%x\n",
1695 if (target_can_async_p ())
1697 target_async (inferior_event_handler
, 0);
1698 /* Tell the event loop we have something to process. */
1705 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1707 linux_resume_one_lwp (lp
, step
, signo
);
1709 if (debug_linux_nat
)
1710 fprintf_unfiltered (gdb_stdlog
,
1711 "LLR: %s %s, %s (resume event thread)\n",
1712 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1713 target_pid_to_str (ptid
),
1714 (signo
!= GDB_SIGNAL_0
1715 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1717 if (target_can_async_p ())
1718 target_async (inferior_event_handler
, 0);
1721 /* Send a signal to an LWP. */
1724 kill_lwp (int lwpid
, int signo
)
1726 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1727 fails, then we are not using nptl threads and we should be using kill. */
1729 #ifdef HAVE_TKILL_SYSCALL
1731 static int tkill_failed
;
1738 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1739 if (errno
!= ENOSYS
)
1746 return kill (lwpid
, signo
);
1749 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1750 event, check if the core is interested in it: if not, ignore the
1751 event, and keep waiting; otherwise, we need to toggle the LWP's
1752 syscall entry/exit status, since the ptrace event itself doesn't
1753 indicate it, and report the trap to higher layers. */
1756 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1758 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1759 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1760 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1764 /* If we're stopping threads, there's a SIGSTOP pending, which
1765 makes it so that the LWP reports an immediate syscall return,
1766 followed by the SIGSTOP. Skip seeing that "return" using
1767 PTRACE_CONT directly, and let stop_wait_callback collect the
1768 SIGSTOP. Later when the thread is resumed, a new syscall
1769 entry event. If we didn't do this (and returned 0), we'd
1770 leave a syscall entry pending, and our caller, by using
1771 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1772 itself. Later, when the user re-resumes this LWP, we'd see
1773 another syscall entry event and we'd mistake it for a return.
1775 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1776 (leaving immediately with LWP->signalled set, without issuing
1777 a PTRACE_CONT), it would still be problematic to leave this
1778 syscall enter pending, as later when the thread is resumed,
1779 it would then see the same syscall exit mentioned above,
1780 followed by the delayed SIGSTOP, while the syscall didn't
1781 actually get to execute. It seems it would be even more
1782 confusing to the user. */
1784 if (debug_linux_nat
)
1785 fprintf_unfiltered (gdb_stdlog
,
1786 "LHST: ignoring syscall %d "
1787 "for LWP %ld (stopping threads), "
1788 "resuming with PTRACE_CONT for SIGSTOP\n",
1790 ptid_get_lwp (lp
->ptid
));
1792 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1793 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1798 if (catch_syscall_enabled ())
1800 /* Always update the entry/return state, even if this particular
1801 syscall isn't interesting to the core now. In async mode,
1802 the user could install a new catchpoint for this syscall
1803 between syscall enter/return, and we'll need to know to
1804 report a syscall return if that happens. */
1805 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1806 ? TARGET_WAITKIND_SYSCALL_RETURN
1807 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1809 if (catching_syscall_number (syscall_number
))
1811 /* Alright, an event to report. */
1812 ourstatus
->kind
= lp
->syscall_state
;
1813 ourstatus
->value
.syscall_number
= syscall_number
;
1815 if (debug_linux_nat
)
1816 fprintf_unfiltered (gdb_stdlog
,
1817 "LHST: stopping for %s of syscall %d"
1820 == TARGET_WAITKIND_SYSCALL_ENTRY
1821 ? "entry" : "return",
1823 ptid_get_lwp (lp
->ptid
));
1827 if (debug_linux_nat
)
1828 fprintf_unfiltered (gdb_stdlog
,
1829 "LHST: ignoring %s of syscall %d "
1831 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1832 ? "entry" : "return",
1834 ptid_get_lwp (lp
->ptid
));
1838 /* If we had been syscall tracing, and hence used PT_SYSCALL
1839 before on this LWP, it could happen that the user removes all
1840 syscall catchpoints before we get to process this event.
1841 There are two noteworthy issues here:
1843 - When stopped at a syscall entry event, resuming with
1844 PT_STEP still resumes executing the syscall and reports a
1847 - Only PT_SYSCALL catches syscall enters. If we last
1848 single-stepped this thread, then this event can't be a
1849 syscall enter. If we last single-stepped this thread, this
1850 has to be a syscall exit.
1852 The points above mean that the next resume, be it PT_STEP or
1853 PT_CONTINUE, can not trigger a syscall trace event. */
1854 if (debug_linux_nat
)
1855 fprintf_unfiltered (gdb_stdlog
,
1856 "LHST: caught syscall event "
1857 "with no syscall catchpoints."
1858 " %d for LWP %ld, ignoring\n",
1860 ptid_get_lwp (lp
->ptid
));
1861 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1864 /* The core isn't interested in this event. For efficiency, avoid
1865 stopping all threads only to have the core resume them all again.
1866 Since we're not stopping threads, if we're still syscall tracing
1867 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1868 subsequent syscall. Simply resume using the inf-ptrace layer,
1869 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1871 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1875 /* Handle a GNU/Linux extended wait response. If we see a clone
1876 event, we need to add the new LWP to our list (and not report the
1877 trap to higher layers). This function returns non-zero if the
1878 event should be ignored and we should wait again. If STOPPING is
1879 true, the new LWP remains stopped, otherwise it is continued. */
1882 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1885 int pid
= ptid_get_lwp (lp
->ptid
);
1886 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1887 int event
= linux_ptrace_get_extended_event (status
);
1889 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1890 || event
== PTRACE_EVENT_CLONE
)
1892 unsigned long new_pid
;
1895 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1897 /* If we haven't already seen the new PID stop, wait for it now. */
1898 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1900 /* The new child has a pending SIGSTOP. We can't affect it until it
1901 hits the SIGSTOP, but we're already attached. */
1902 ret
= my_waitpid (new_pid
, &status
,
1903 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
1905 perror_with_name (_("waiting for new child"));
1906 else if (ret
!= new_pid
)
1907 internal_error (__FILE__
, __LINE__
,
1908 _("wait returned unexpected PID %d"), ret
);
1909 else if (!WIFSTOPPED (status
))
1910 internal_error (__FILE__
, __LINE__
,
1911 _("wait returned unexpected status 0x%x"), status
);
1914 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1916 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1918 /* The arch-specific native code may need to know about new
1919 forks even if those end up never mapped to an
1921 if (linux_nat_new_fork
!= NULL
)
1922 linux_nat_new_fork (lp
, new_pid
);
1925 if (event
== PTRACE_EVENT_FORK
1926 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1928 /* Handle checkpointing by linux-fork.c here as a special
1929 case. We don't want the follow-fork-mode or 'catch fork'
1930 to interfere with this. */
1932 /* This won't actually modify the breakpoint list, but will
1933 physically remove the breakpoints from the child. */
1934 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1936 /* Retain child fork in ptrace (stopped) state. */
1937 if (!find_fork_pid (new_pid
))
1940 /* Report as spurious, so that infrun doesn't want to follow
1941 this fork. We're actually doing an infcall in
1943 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1945 /* Report the stop to the core. */
1949 if (event
== PTRACE_EVENT_FORK
)
1950 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1951 else if (event
== PTRACE_EVENT_VFORK
)
1952 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1955 struct lwp_info
*new_lp
;
1957 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1959 if (debug_linux_nat
)
1960 fprintf_unfiltered (gdb_stdlog
,
1961 "LHEW: Got clone event "
1962 "from LWP %d, new child is LWP %ld\n",
1965 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1967 new_lp
->stopped
= 1;
1969 if (WSTOPSIG (status
) != SIGSTOP
)
1971 /* This can happen if someone starts sending signals to
1972 the new thread before it gets a chance to run, which
1973 have a lower number than SIGSTOP (e.g. SIGUSR1).
1974 This is an unlikely case, and harder to handle for
1975 fork / vfork than for clone, so we do not try - but
1976 we handle it for clone events here. We'll send
1977 the other signal on to the thread below. */
1979 new_lp
->signalled
= 1;
1983 struct thread_info
*tp
;
1985 /* When we stop for an event in some other thread, and
1986 pull the thread list just as this thread has cloned,
1987 we'll have seen the new thread in the thread_db list
1988 before handling the CLONE event (glibc's
1989 pthread_create adds the new thread to the thread list
1990 before clone'ing, and has the kernel fill in the
1991 thread's tid on the clone call with
1992 CLONE_PARENT_SETTID). If that happened, and the core
1993 had requested the new thread to stop, we'll have
1994 killed it with SIGSTOP. But since SIGSTOP is not an
1995 RT signal, it can only be queued once. We need to be
1996 careful to not resume the LWP if we wanted it to
1997 stop. In that case, we'll leave the SIGSTOP pending.
1998 It will later be reported as GDB_SIGNAL_0. */
1999 tp
= find_thread_ptid (new_lp
->ptid
);
2000 if (tp
!= NULL
&& tp
->stop_requested
)
2001 new_lp
->last_resume_kind
= resume_stop
;
2008 /* Add the new thread to GDB's lists as soon as possible
2011 1) the frontend doesn't have to wait for a stop to
2014 2) we tag it with the correct running state. */
2016 /* If the thread_db layer is active, let it know about
2017 this new thread, and add it to GDB's list. */
2018 if (!thread_db_attach_lwp (new_lp
->ptid
))
2020 /* We're not using thread_db. Add it to GDB's
2022 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2023 add_thread (new_lp
->ptid
);
2028 set_running (new_lp
->ptid
, 1);
2029 set_executing (new_lp
->ptid
, 1);
2030 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2032 new_lp
->last_resume_kind
= resume_continue
;
2038 /* We created NEW_LP so it cannot yet contain STATUS. */
2039 gdb_assert (new_lp
->status
== 0);
2041 /* Save the wait status to report later. */
2042 if (debug_linux_nat
)
2043 fprintf_unfiltered (gdb_stdlog
,
2044 "LHEW: waitpid of new LWP %ld, "
2045 "saving status %s\n",
2046 (long) ptid_get_lwp (new_lp
->ptid
),
2047 status_to_str (status
));
2048 new_lp
->status
= status
;
2051 new_lp
->resumed
= !stopping
;
2058 if (event
== PTRACE_EVENT_EXEC
)
2060 if (debug_linux_nat
)
2061 fprintf_unfiltered (gdb_stdlog
,
2062 "LHEW: Got exec event from LWP %ld\n",
2063 ptid_get_lwp (lp
->ptid
));
2065 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2066 ourstatus
->value
.execd_pathname
2067 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2069 /* The thread that execed must have been resumed, but, when a
2070 thread execs, it changes its tid to the tgid, and the old
2071 tgid thread might have not been resumed. */
2076 if (event
== PTRACE_EVENT_VFORK_DONE
)
2078 if (current_inferior ()->waiting_for_vfork_done
)
2080 if (debug_linux_nat
)
2081 fprintf_unfiltered (gdb_stdlog
,
2082 "LHEW: Got expected PTRACE_EVENT_"
2083 "VFORK_DONE from LWP %ld: stopping\n",
2084 ptid_get_lwp (lp
->ptid
));
2086 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2090 if (debug_linux_nat
)
2091 fprintf_unfiltered (gdb_stdlog
,
2092 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2093 "from LWP %ld: ignoring\n",
2094 ptid_get_lwp (lp
->ptid
));
2098 internal_error (__FILE__
, __LINE__
,
2099 _("unknown ptrace event %d"), event
);
2102 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2106 wait_lwp (struct lwp_info
*lp
)
2110 int thread_dead
= 0;
2113 gdb_assert (!lp
->stopped
);
2114 gdb_assert (lp
->status
== 0);
2116 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2117 block_child_signals (&prev_mask
);
2121 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2122 was right and we should just call sigsuspend. */
2124 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2125 if (pid
== -1 && errno
== ECHILD
)
2126 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2127 if (pid
== -1 && errno
== ECHILD
)
2129 /* The thread has previously exited. We need to delete it
2130 now because, for some vendor 2.4 kernels with NPTL
2131 support backported, there won't be an exit event unless
2132 it is the main thread. 2.6 kernels will report an exit
2133 event for each thread that exits, as expected. */
2135 if (debug_linux_nat
)
2136 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2137 target_pid_to_str (lp
->ptid
));
2142 /* Bugs 10970, 12702.
2143 Thread group leader may have exited in which case we'll lock up in
2144 waitpid if there are other threads, even if they are all zombies too.
2145 Basically, we're not supposed to use waitpid this way.
2146 __WCLONE is not applicable for the leader so we can't use that.
2147 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2148 process; it gets ESRCH both for the zombie and for running processes.
2150 As a workaround, check if we're waiting for the thread group leader and
2151 if it's a zombie, and avoid calling waitpid if it is.
2153 This is racy, what if the tgl becomes a zombie right after we check?
2154 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2155 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2157 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2158 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2161 if (debug_linux_nat
)
2162 fprintf_unfiltered (gdb_stdlog
,
2163 "WL: Thread group leader %s vanished.\n",
2164 target_pid_to_str (lp
->ptid
));
2168 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2169 get invoked despite our caller had them intentionally blocked by
2170 block_child_signals. This is sensitive only to the loop of
2171 linux_nat_wait_1 and there if we get called my_waitpid gets called
2172 again before it gets to sigsuspend so we can safely let the handlers
2173 get executed here. */
2175 if (debug_linux_nat
)
2176 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2177 sigsuspend (&suspend_mask
);
2180 restore_child_signals_mask (&prev_mask
);
2184 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2186 if (debug_linux_nat
)
2188 fprintf_unfiltered (gdb_stdlog
,
2189 "WL: waitpid %s received %s\n",
2190 target_pid_to_str (lp
->ptid
),
2191 status_to_str (status
));
2194 /* Check if the thread has exited. */
2195 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2198 if (debug_linux_nat
)
2199 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2200 target_pid_to_str (lp
->ptid
));
2210 gdb_assert (WIFSTOPPED (status
));
2213 if (lp
->must_set_ptrace_flags
)
2215 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2217 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), inf
->attach_flag
);
2218 lp
->must_set_ptrace_flags
= 0;
2221 /* Handle GNU/Linux's syscall SIGTRAPs. */
2222 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2224 /* No longer need the sysgood bit. The ptrace event ends up
2225 recorded in lp->waitstatus if we care for it. We can carry
2226 on handling the event like a regular SIGTRAP from here
2228 status
= W_STOPCODE (SIGTRAP
);
2229 if (linux_handle_syscall_trap (lp
, 1))
2230 return wait_lwp (lp
);
2233 /* Handle GNU/Linux's extended waitstatus for trace events. */
2234 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2235 && linux_is_extended_waitstatus (status
))
2237 if (debug_linux_nat
)
2238 fprintf_unfiltered (gdb_stdlog
,
2239 "WL: Handling extended status 0x%06x\n",
2241 linux_handle_extended_wait (lp
, status
, 1);
2248 /* Send a SIGSTOP to LP. */
2251 stop_callback (struct lwp_info
*lp
, void *data
)
2253 if (!lp
->stopped
&& !lp
->signalled
)
2257 if (debug_linux_nat
)
2259 fprintf_unfiltered (gdb_stdlog
,
2260 "SC: kill %s **<SIGSTOP>**\n",
2261 target_pid_to_str (lp
->ptid
));
2264 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2265 if (debug_linux_nat
)
2267 fprintf_unfiltered (gdb_stdlog
,
2268 "SC: lwp kill %d %s\n",
2270 errno
? safe_strerror (errno
) : "ERRNO-OK");
2274 gdb_assert (lp
->status
== 0);
2280 /* Request a stop on LWP. */
2283 linux_stop_lwp (struct lwp_info
*lwp
)
2285 stop_callback (lwp
, NULL
);
2288 /* Return non-zero if LWP PID has a pending SIGINT. */
2291 linux_nat_has_pending_sigint (int pid
)
2293 sigset_t pending
, blocked
, ignored
;
2295 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2297 if (sigismember (&pending
, SIGINT
)
2298 && !sigismember (&ignored
, SIGINT
))
2304 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2307 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2309 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2310 flag to consume the next one. */
2311 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2312 && WSTOPSIG (lp
->status
) == SIGINT
)
2315 lp
->ignore_sigint
= 1;
2320 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2321 This function is called after we know the LWP has stopped; if the LWP
2322 stopped before the expected SIGINT was delivered, then it will never have
2323 arrived. Also, if the signal was delivered to a shared queue and consumed
2324 by a different thread, it will never be delivered to this LWP. */
2327 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2329 if (!lp
->ignore_sigint
)
2332 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2334 if (debug_linux_nat
)
2335 fprintf_unfiltered (gdb_stdlog
,
2336 "MCIS: Clearing bogus flag for %s\n",
2337 target_pid_to_str (lp
->ptid
));
2338 lp
->ignore_sigint
= 0;
2342 /* Fetch the possible triggered data watchpoint info and store it in
2345 On some archs, like x86, that use debug registers to set
2346 watchpoints, it's possible that the way to know which watched
2347 address trapped, is to check the register that is used to select
2348 which address to watch. Problem is, between setting the watchpoint
2349 and reading back which data address trapped, the user may change
2350 the set of watchpoints, and, as a consequence, GDB changes the
2351 debug registers in the inferior. To avoid reading back a stale
2352 stopped-data-address when that happens, we cache in LP the fact
2353 that a watchpoint trapped, and the corresponding data address, as
2354 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2355 registers meanwhile, we have the cached data we can rely on. */
2358 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2360 struct cleanup
*old_chain
;
2362 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2365 old_chain
= save_inferior_ptid ();
2366 inferior_ptid
= lp
->ptid
;
2368 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2370 lp
->stop_reason
= LWP_STOPPED_BY_WATCHPOINT
;
2372 if (linux_ops
->to_stopped_data_address
!= NULL
)
2373 lp
->stopped_data_address_p
=
2374 linux_ops
->to_stopped_data_address (¤t_target
,
2375 &lp
->stopped_data_address
);
2377 lp
->stopped_data_address_p
= 0;
2380 do_cleanups (old_chain
);
2382 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2385 /* Called when the LWP stopped for a trap that could be explained by a
2386 watchpoint or a breakpoint. */
2389 save_sigtrap (struct lwp_info
*lp
)
2391 gdb_assert (lp
->stop_reason
== LWP_STOPPED_BY_NO_REASON
);
2392 gdb_assert (lp
->status
!= 0);
2394 if (check_stopped_by_watchpoint (lp
))
2397 if (linux_nat_status_is_event (lp
->status
))
2398 check_stopped_by_breakpoint (lp
);
2401 /* Returns true if the LWP had stopped for a watchpoint. */
2404 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2406 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2408 gdb_assert (lp
!= NULL
);
2410 return lp
->stop_reason
== LWP_STOPPED_BY_WATCHPOINT
;
2414 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2416 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2418 gdb_assert (lp
!= NULL
);
2420 *addr_p
= lp
->stopped_data_address
;
2422 return lp
->stopped_data_address_p
;
2425 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2428 sigtrap_is_event (int status
)
2430 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2433 /* Set alternative SIGTRAP-like events recognizer. If
2434 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2438 linux_nat_set_status_is_event (struct target_ops
*t
,
2439 int (*status_is_event
) (int status
))
2441 linux_nat_status_is_event
= status_is_event
;
2444 /* Wait until LP is stopped. */
2447 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2449 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2451 /* If this is a vfork parent, bail out, it is not going to report
2452 any SIGSTOP until the vfork is done with. */
2453 if (inf
->vfork_child
!= NULL
)
2460 status
= wait_lwp (lp
);
2464 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2465 && WSTOPSIG (status
) == SIGINT
)
2467 lp
->ignore_sigint
= 0;
2470 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2472 if (debug_linux_nat
)
2473 fprintf_unfiltered (gdb_stdlog
,
2474 "PTRACE_CONT %s, 0, 0 (%s) "
2475 "(discarding SIGINT)\n",
2476 target_pid_to_str (lp
->ptid
),
2477 errno
? safe_strerror (errno
) : "OK");
2479 return stop_wait_callback (lp
, NULL
);
2482 maybe_clear_ignore_sigint (lp
);
2484 if (WSTOPSIG (status
) != SIGSTOP
)
2486 /* The thread was stopped with a signal other than SIGSTOP. */
2488 if (debug_linux_nat
)
2489 fprintf_unfiltered (gdb_stdlog
,
2490 "SWC: Pending event %s in %s\n",
2491 status_to_str ((int) status
),
2492 target_pid_to_str (lp
->ptid
));
2494 /* Save the sigtrap event. */
2495 lp
->status
= status
;
2496 gdb_assert (lp
->signalled
);
2501 /* We caught the SIGSTOP that we intended to catch, so
2502 there's no SIGSTOP pending. */
2504 if (debug_linux_nat
)
2505 fprintf_unfiltered (gdb_stdlog
,
2506 "SWC: Delayed SIGSTOP caught for %s.\n",
2507 target_pid_to_str (lp
->ptid
));
2509 /* Reset SIGNALLED only after the stop_wait_callback call
2510 above as it does gdb_assert on SIGNALLED. */
2518 /* Return non-zero if LP has a wait status pending. Discard the
2519 pending event and resume the LWP if the event that originally
2520 caused the stop became uninteresting. */
2523 status_callback (struct lwp_info
*lp
, void *data
)
2525 /* Only report a pending wait status if we pretend that this has
2526 indeed been resumed. */
2530 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
2531 || lp
->stop_reason
== LWP_STOPPED_BY_HW_BREAKPOINT
)
2533 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2534 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2538 gdb_assert (lp
->status
!= 0);
2540 pc
= regcache_read_pc (regcache
);
2542 if (pc
!= lp
->stop_pc
)
2544 if (debug_linux_nat
)
2545 fprintf_unfiltered (gdb_stdlog
,
2546 "SC: PC of %s changed. was=%s, now=%s\n",
2547 target_pid_to_str (lp
->ptid
),
2548 paddress (target_gdbarch (), lp
->stop_pc
),
2549 paddress (target_gdbarch (), pc
));
2552 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2554 if (debug_linux_nat
)
2555 fprintf_unfiltered (gdb_stdlog
,
2556 "SC: previous breakpoint of %s, at %s gone\n",
2557 target_pid_to_str (lp
->ptid
),
2558 paddress (target_gdbarch (), lp
->stop_pc
));
2565 if (debug_linux_nat
)
2566 fprintf_unfiltered (gdb_stdlog
,
2567 "SC: pending event of %s cancelled.\n",
2568 target_pid_to_str (lp
->ptid
));
2571 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2577 return lwp_status_pending_p (lp
);
2580 /* Return non-zero if LP isn't stopped. */
2583 running_callback (struct lwp_info
*lp
, void *data
)
2585 return (!lp
->stopped
2586 || (lwp_status_pending_p (lp
) && lp
->resumed
));
2589 /* Count the LWP's that have had events. */
2592 count_events_callback (struct lwp_info
*lp
, void *data
)
2596 gdb_assert (count
!= NULL
);
2598 /* Select only resumed LWPs that have an event pending. */
2599 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2605 /* Select the LWP (if any) that is currently being single-stepped. */
2608 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2610 if (lp
->last_resume_kind
== resume_step
2617 /* Returns true if LP has a status pending. */
2620 lwp_status_pending_p (struct lwp_info
*lp
)
2622 /* We check for lp->waitstatus in addition to lp->status, because we
2623 can have pending process exits recorded in lp->status and
2624 W_EXITCODE(0,0) happens to be 0. */
2625 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2628 /* Select the Nth LWP that has had a SIGTRAP event. */
2631 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2633 int *selector
= data
;
2635 gdb_assert (selector
!= NULL
);
2637 /* Select only resumed LWPs that have an event pending. */
2638 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2639 if ((*selector
)-- == 0)
2645 /* Called when the LWP got a signal/trap that could be explained by a
2646 software or hardware breakpoint. */
2649 check_stopped_by_breakpoint (struct lwp_info
*lp
)
2651 /* Arrange for a breakpoint to be hit again later. We don't keep
2652 the SIGTRAP status and don't forward the SIGTRAP signal to the
2653 LWP. We will handle the current event, eventually we will resume
2654 this LWP, and this breakpoint will trap again.
2656 If we do not do this, then we run the risk that the user will
2657 delete or disable the breakpoint, but the LWP will have already
2660 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2661 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2665 pc
= regcache_read_pc (regcache
);
2666 sw_bp_pc
= pc
- target_decr_pc_after_break (gdbarch
);
2668 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2669 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2672 /* The LWP was either continued, or stepped a software
2673 breakpoint instruction. */
2674 if (debug_linux_nat
)
2675 fprintf_unfiltered (gdb_stdlog
,
2676 "CB: Push back software breakpoint for %s\n",
2677 target_pid_to_str (lp
->ptid
));
2679 /* Back up the PC if necessary. */
2681 regcache_write_pc (regcache
, sw_bp_pc
);
2683 lp
->stop_pc
= sw_bp_pc
;
2684 lp
->stop_reason
= LWP_STOPPED_BY_SW_BREAKPOINT
;
2688 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2690 if (debug_linux_nat
)
2691 fprintf_unfiltered (gdb_stdlog
,
2692 "CB: Push back hardware breakpoint for %s\n",
2693 target_pid_to_str (lp
->ptid
));
2696 lp
->stop_reason
= LWP_STOPPED_BY_HW_BREAKPOINT
;
2703 /* Select one LWP out of those that have events pending. */
2706 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2709 int random_selector
;
2710 struct lwp_info
*event_lp
= NULL
;
2712 /* Record the wait status for the original LWP. */
2713 (*orig_lp
)->status
= *status
;
2715 /* In all-stop, give preference to the LWP that is being
2716 single-stepped. There will be at most one, and it will be the
2717 LWP that the core is most interested in. If we didn't do this,
2718 then we'd have to handle pending step SIGTRAPs somehow in case
2719 the core later continues the previously-stepped thread, as
2720 otherwise we'd report the pending SIGTRAP then, and the core, not
2721 having stepped the thread, wouldn't understand what the trap was
2722 for, and therefore would report it to the user as a random
2726 event_lp
= iterate_over_lwps (filter
,
2727 select_singlestep_lwp_callback
, NULL
);
2728 if (event_lp
!= NULL
)
2730 if (debug_linux_nat
)
2731 fprintf_unfiltered (gdb_stdlog
,
2732 "SEL: Select single-step %s\n",
2733 target_pid_to_str (event_lp
->ptid
));
2737 if (event_lp
== NULL
)
2739 /* Pick one at random, out of those which have had events. */
2741 /* First see how many events we have. */
2742 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2744 /* Now randomly pick a LWP out of those that have had
2746 random_selector
= (int)
2747 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2749 if (debug_linux_nat
&& num_events
> 1)
2750 fprintf_unfiltered (gdb_stdlog
,
2751 "SEL: Found %d events, selecting #%d\n",
2752 num_events
, random_selector
);
2754 event_lp
= iterate_over_lwps (filter
,
2755 select_event_lwp_callback
,
2759 if (event_lp
!= NULL
)
2761 /* Switch the event LWP. */
2762 *orig_lp
= event_lp
;
2763 *status
= event_lp
->status
;
2766 /* Flush the wait status for the event LWP. */
2767 (*orig_lp
)->status
= 0;
2770 /* Return non-zero if LP has been resumed. */
2773 resumed_callback (struct lwp_info
*lp
, void *data
)
2778 /* Stop an active thread, verify it still exists, then resume it. If
2779 the thread ends up with a pending status, then it is not resumed,
2780 and *DATA (really a pointer to int), is set. */
2783 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2787 ptid_t ptid
= lp
->ptid
;
2789 stop_callback (lp
, NULL
);
2790 stop_wait_callback (lp
, NULL
);
2792 /* Resume if the lwp still exists, and the core wanted it
2794 lp
= find_lwp_pid (ptid
);
2797 if (lp
->last_resume_kind
== resume_stop
2798 && !lwp_status_pending_p (lp
))
2800 /* The core wanted the LWP to stop. Even if it stopped
2801 cleanly (with SIGSTOP), leave the event pending. */
2802 if (debug_linux_nat
)
2803 fprintf_unfiltered (gdb_stdlog
,
2804 "SARC: core wanted LWP %ld stopped "
2805 "(leaving SIGSTOP pending)\n",
2806 ptid_get_lwp (lp
->ptid
));
2807 lp
->status
= W_STOPCODE (SIGSTOP
);
2810 if (!lwp_status_pending_p (lp
))
2812 if (debug_linux_nat
)
2813 fprintf_unfiltered (gdb_stdlog
,
2814 "SARC: re-resuming LWP %ld\n",
2815 ptid_get_lwp (lp
->ptid
));
2816 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2820 if (debug_linux_nat
)
2821 fprintf_unfiltered (gdb_stdlog
,
2822 "SARC: not re-resuming LWP %ld "
2824 ptid_get_lwp (lp
->ptid
));
2831 /* Check if we should go on and pass this event to common code.
2832 Return the affected lwp if we are, or NULL otherwise. */
2834 static struct lwp_info
*
2835 linux_nat_filter_event (int lwpid
, int status
)
2837 struct lwp_info
*lp
;
2838 int event
= linux_ptrace_get_extended_event (status
);
2840 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2842 /* Check for stop events reported by a process we didn't already
2843 know about - anything not already in our LWP list.
2845 If we're expecting to receive stopped processes after
2846 fork, vfork, and clone events, then we'll just add the
2847 new one to our list and go back to waiting for the event
2848 to be reported - the stopped process might be returned
2849 from waitpid before or after the event is.
2851 But note the case of a non-leader thread exec'ing after the
2852 leader having exited, and gone from our lists. The non-leader
2853 thread changes its tid to the tgid. */
2855 if (WIFSTOPPED (status
) && lp
== NULL
2856 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2858 /* A multi-thread exec after we had seen the leader exiting. */
2859 if (debug_linux_nat
)
2860 fprintf_unfiltered (gdb_stdlog
,
2861 "LLW: Re-adding thread group leader LWP %d.\n",
2864 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2867 add_thread (lp
->ptid
);
2870 if (WIFSTOPPED (status
) && !lp
)
2872 if (debug_linux_nat
)
2873 fprintf_unfiltered (gdb_stdlog
,
2874 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2875 (long) lwpid
, status_to_str (status
));
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
3092 except signals that might be caused by a breakpoint. */
3094 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3095 && !linux_wstatus_maybe_breakpoint (status
))
3097 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3098 if (debug_linux_nat
)
3099 fprintf_unfiltered (gdb_stdlog
,
3100 "LLW: %s %s, %s (preempt 'handle')\n",
3102 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3103 target_pid_to_str (lp
->ptid
),
3104 (signo
!= GDB_SIGNAL_0
3105 ? strsignal (gdb_signal_to_host (signo
))
3111 /* An interesting event. */
3113 lp
->status
= status
;
3118 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3119 their exits until all other threads in the group have exited. */
3122 check_zombie_leaders (void)
3124 struct inferior
*inf
;
3128 struct lwp_info
*leader_lp
;
3133 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3134 if (leader_lp
!= NULL
3135 /* Check if there are other threads in the group, as we may
3136 have raced with the inferior simply exiting. */
3137 && num_lwps (inf
->pid
) > 1
3138 && linux_proc_pid_is_zombie (inf
->pid
))
3140 if (debug_linux_nat
)
3141 fprintf_unfiltered (gdb_stdlog
,
3142 "CZL: Thread group leader %d zombie "
3143 "(it exited, or another thread execd).\n",
3146 /* A leader zombie can mean one of two things:
3148 - It exited, and there's an exit status pending
3149 available, or only the leader exited (not the whole
3150 program). In the latter case, we can't waitpid the
3151 leader's exit status until all other threads are gone.
3153 - There are 3 or more threads in the group, and a thread
3154 other than the leader exec'd. On an exec, the Linux
3155 kernel destroys all other threads (except the execing
3156 one) in the thread group, and resets the execing thread's
3157 tid to the tgid. No exit notification is sent for the
3158 execing thread -- from the ptracer's perspective, it
3159 appears as though the execing thread just vanishes.
3160 Until we reap all other threads except the leader and the
3161 execing thread, the leader will be zombie, and the
3162 execing thread will be in `D (disc sleep)'. As soon as
3163 all other threads are reaped, the execing thread changes
3164 it's tid to the tgid, and the previous (zombie) leader
3165 vanishes, giving place to the "new" leader. We could try
3166 distinguishing the exit and exec cases, by waiting once
3167 more, and seeing if something comes out, but it doesn't
3168 sound useful. The previous leader _does_ go away, and
3169 we'll re-add the new one once we see the exec event
3170 (which is just the same as what would happen if the
3171 previous leader did exit voluntarily before some other
3174 if (debug_linux_nat
)
3175 fprintf_unfiltered (gdb_stdlog
,
3176 "CZL: Thread group leader %d vanished.\n",
3178 exit_lwp (leader_lp
);
3184 linux_nat_wait_1 (struct target_ops
*ops
,
3185 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3189 enum resume_kind last_resume_kind
;
3190 struct lwp_info
*lp
;
3193 if (debug_linux_nat
)
3194 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3196 /* The first time we get here after starting a new inferior, we may
3197 not have added it to the LWP list yet - this is the earliest
3198 moment at which we know its PID. */
3199 if (ptid_is_pid (inferior_ptid
))
3201 /* Upgrade the main thread's ptid. */
3202 thread_change_ptid (inferior_ptid
,
3203 ptid_build (ptid_get_pid (inferior_ptid
),
3204 ptid_get_pid (inferior_ptid
), 0));
3206 lp
= add_initial_lwp (inferior_ptid
);
3210 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3211 block_child_signals (&prev_mask
);
3213 /* First check if there is a LWP with a wait status pending. */
3214 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3217 if (debug_linux_nat
)
3218 fprintf_unfiltered (gdb_stdlog
,
3219 "LLW: Using pending wait status %s for %s.\n",
3220 status_to_str (lp
->status
),
3221 target_pid_to_str (lp
->ptid
));
3224 if (!target_is_async_p ())
3226 /* Causes SIGINT to be passed on to the attached process. */
3230 /* But if we don't find a pending event, we'll have to wait. Always
3231 pull all events out of the kernel. We'll randomly select an
3232 event LWP out of all that have events, to prevent starvation. */
3238 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3241 - If the thread group leader exits while other threads in the
3242 thread group still exist, waitpid(TGID, ...) hangs. That
3243 waitpid won't return an exit status until the other threads
3244 in the group are reapped.
3246 - When a non-leader thread execs, that thread just vanishes
3247 without reporting an exit (so we'd hang if we waited for it
3248 explicitly in that case). The exec event is reported to
3252 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3253 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3254 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3256 if (debug_linux_nat
)
3257 fprintf_unfiltered (gdb_stdlog
,
3258 "LNW: waitpid(-1, ...) returned %d, %s\n",
3259 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3263 if (debug_linux_nat
)
3265 fprintf_unfiltered (gdb_stdlog
,
3266 "LLW: waitpid %ld received %s\n",
3267 (long) lwpid
, status_to_str (status
));
3270 linux_nat_filter_event (lwpid
, status
);
3271 /* Retry until nothing comes out of waitpid. A single
3272 SIGCHLD can indicate more than one child stopped. */
3276 /* Now that we've pulled all events out of the kernel, resume
3277 LWPs that don't have an interesting event to report. */
3278 iterate_over_lwps (minus_one_ptid
,
3279 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3281 /* ... and find an LWP with a status to report to the core, if
3283 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3287 /* Check for zombie thread group leaders. Those can't be reaped
3288 until all other threads in the thread group are. */
3289 check_zombie_leaders ();
3291 /* If there are no resumed children left, bail. We'd be stuck
3292 forever in the sigsuspend call below otherwise. */
3293 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3295 if (debug_linux_nat
)
3296 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3298 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3300 if (!target_is_async_p ())
3301 clear_sigint_trap ();
3303 restore_child_signals_mask (&prev_mask
);
3304 return minus_one_ptid
;
3307 /* No interesting event to report to the core. */
3309 if (target_options
& TARGET_WNOHANG
)
3311 if (debug_linux_nat
)
3312 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3314 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3315 restore_child_signals_mask (&prev_mask
);
3316 return minus_one_ptid
;
3319 /* We shouldn't end up here unless we want to try again. */
3320 gdb_assert (lp
== NULL
);
3322 /* Block until we get an event reported with SIGCHLD. */
3323 if (debug_linux_nat
)
3324 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3325 sigsuspend (&suspend_mask
);
3328 if (!target_is_async_p ())
3329 clear_sigint_trap ();
3333 status
= lp
->status
;
3338 /* Now stop all other LWP's ... */
3339 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3341 /* ... and wait until all of them have reported back that
3342 they're no longer running. */
3343 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3346 /* If we're not waiting for a specific LWP, choose an event LWP from
3347 among those that have had events. Giving equal priority to all
3348 LWPs that have had events helps prevent starvation. */
3349 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3350 select_event_lwp (ptid
, &lp
, &status
);
3352 gdb_assert (lp
!= NULL
);
3354 /* Now that we've selected our final event LWP, un-adjust its PC if
3355 it was a software breakpoint. */
3356 if (lp
->stop_reason
== LWP_STOPPED_BY_SW_BREAKPOINT
)
3358 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3359 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3360 int decr_pc
= target_decr_pc_after_break (gdbarch
);
3366 pc
= regcache_read_pc (regcache
);
3367 regcache_write_pc (regcache
, pc
+ decr_pc
);
3371 /* We'll need this to determine whether to report a SIGSTOP as
3372 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3374 last_resume_kind
= lp
->last_resume_kind
;
3378 /* In all-stop, from the core's perspective, all LWPs are now
3379 stopped until a new resume action is sent over. */
3380 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3384 resume_clear_callback (lp
, NULL
);
3387 if (linux_nat_status_is_event (status
))
3389 if (debug_linux_nat
)
3390 fprintf_unfiltered (gdb_stdlog
,
3391 "LLW: trap ptid is %s.\n",
3392 target_pid_to_str (lp
->ptid
));
3395 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3397 *ourstatus
= lp
->waitstatus
;
3398 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3401 store_waitstatus (ourstatus
, status
);
3403 if (debug_linux_nat
)
3404 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3406 restore_child_signals_mask (&prev_mask
);
3408 if (last_resume_kind
== resume_stop
3409 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3410 && WSTOPSIG (status
) == SIGSTOP
)
3412 /* A thread that has been requested to stop by GDB with
3413 target_stop, and it stopped cleanly, so report as SIG0. The
3414 use of SIGSTOP is an implementation detail. */
3415 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3418 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3419 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3422 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3427 /* Resume LWPs that are currently stopped without any pending status
3428 to report, but are resumed from the core's perspective. */
3431 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3433 ptid_t
*wait_ptid_p
= data
;
3437 && !lwp_status_pending_p (lp
))
3439 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3440 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3441 CORE_ADDR pc
= regcache_read_pc (regcache
);
3443 /* Don't bother if there's a breakpoint at PC that we'd hit
3444 immediately, and we're not waiting for this LWP. */
3445 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3447 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3451 if (debug_linux_nat
)
3452 fprintf_unfiltered (gdb_stdlog
,
3453 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3454 target_pid_to_str (lp
->ptid
),
3455 paddress (gdbarch
, pc
),
3458 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3465 linux_nat_wait (struct target_ops
*ops
,
3466 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3471 if (debug_linux_nat
)
3473 char *options_string
;
3475 options_string
= target_options_to_string (target_options
);
3476 fprintf_unfiltered (gdb_stdlog
,
3477 "linux_nat_wait: [%s], [%s]\n",
3478 target_pid_to_str (ptid
),
3480 xfree (options_string
);
3483 /* Flush the async file first. */
3484 if (target_is_async_p ())
3485 async_file_flush ();
3487 /* Resume LWPs that are currently stopped without any pending status
3488 to report, but are resumed from the core's perspective. LWPs get
3489 in this state if we find them stopping at a time we're not
3490 interested in reporting the event (target_wait on a
3491 specific_process, for example, see linux_nat_wait_1), and
3492 meanwhile the event became uninteresting. Don't bother resuming
3493 LWPs we're not going to wait for if they'd stop immediately. */
3495 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3497 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3499 /* If we requested any event, and something came out, assume there
3500 may be more. If we requested a specific lwp or process, also
3501 assume there may be more. */
3502 if (target_is_async_p ()
3503 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3504 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3505 || !ptid_equal (ptid
, minus_one_ptid
)))
3512 kill_callback (struct lwp_info
*lp
, void *data
)
3514 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3517 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3518 if (debug_linux_nat
)
3520 int save_errno
= errno
;
3522 fprintf_unfiltered (gdb_stdlog
,
3523 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3524 target_pid_to_str (lp
->ptid
),
3525 save_errno
? safe_strerror (save_errno
) : "OK");
3528 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3531 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3532 if (debug_linux_nat
)
3534 int save_errno
= errno
;
3536 fprintf_unfiltered (gdb_stdlog
,
3537 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3538 target_pid_to_str (lp
->ptid
),
3539 save_errno
? safe_strerror (save_errno
) : "OK");
3546 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3550 /* We must make sure that there are no pending events (delayed
3551 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3552 program doesn't interfere with any following debugging session. */
3554 /* For cloned processes we must check both with __WCLONE and
3555 without, since the exit status of a cloned process isn't reported
3561 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3562 if (pid
!= (pid_t
) -1)
3564 if (debug_linux_nat
)
3565 fprintf_unfiltered (gdb_stdlog
,
3566 "KWC: wait %s received unknown.\n",
3567 target_pid_to_str (lp
->ptid
));
3568 /* The Linux kernel sometimes fails to kill a thread
3569 completely after PTRACE_KILL; that goes from the stop
3570 point in do_fork out to the one in
3571 get_signal_to_deliever and waits again. So kill it
3573 kill_callback (lp
, NULL
);
3576 while (pid
== ptid_get_lwp (lp
->ptid
));
3578 gdb_assert (pid
== -1 && errno
== ECHILD
);
3583 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3584 if (pid
!= (pid_t
) -1)
3586 if (debug_linux_nat
)
3587 fprintf_unfiltered (gdb_stdlog
,
3588 "KWC: wait %s received unk.\n",
3589 target_pid_to_str (lp
->ptid
));
3590 /* See the call to kill_callback above. */
3591 kill_callback (lp
, NULL
);
3594 while (pid
== ptid_get_lwp (lp
->ptid
));
3596 gdb_assert (pid
== -1 && errno
== ECHILD
);
3601 linux_nat_kill (struct target_ops
*ops
)
3603 struct target_waitstatus last
;
3607 /* If we're stopped while forking and we haven't followed yet,
3608 kill the other task. We need to do this first because the
3609 parent will be sleeping if this is a vfork. */
3611 get_last_target_status (&last_ptid
, &last
);
3613 if (last
.kind
== TARGET_WAITKIND_FORKED
3614 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3616 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3619 /* Let the arch-specific native code know this process is
3621 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3624 if (forks_exist_p ())
3625 linux_fork_killall ();
3628 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3630 /* Stop all threads before killing them, since ptrace requires
3631 that the thread is stopped to sucessfully PTRACE_KILL. */
3632 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3633 /* ... and wait until all of them have reported back that
3634 they're no longer running. */
3635 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3637 /* Kill all LWP's ... */
3638 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3640 /* ... and wait until we've flushed all events. */
3641 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3644 target_mourn_inferior ();
3648 linux_nat_mourn_inferior (struct target_ops
*ops
)
3650 int pid
= ptid_get_pid (inferior_ptid
);
3652 purge_lwp_list (pid
);
3654 if (! forks_exist_p ())
3655 /* Normal case, no other forks available. */
3656 linux_ops
->to_mourn_inferior (ops
);
3658 /* Multi-fork case. The current inferior_ptid has exited, but
3659 there are other viable forks to debug. Delete the exiting
3660 one and context-switch to the first available. */
3661 linux_fork_mourn_inferior ();
3663 /* Let the arch-specific native code know this process is gone. */
3664 linux_nat_forget_process (pid
);
3667 /* Convert a native/host siginfo object, into/from the siginfo in the
3668 layout of the inferiors' architecture. */
3671 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3675 if (linux_nat_siginfo_fixup
!= NULL
)
3676 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3678 /* If there was no callback, or the callback didn't do anything,
3679 then just do a straight memcpy. */
3683 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3685 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3689 static enum target_xfer_status
3690 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3691 const char *annex
, gdb_byte
*readbuf
,
3692 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3693 ULONGEST
*xfered_len
)
3697 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3699 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3700 gdb_assert (readbuf
|| writebuf
);
3702 pid
= ptid_get_lwp (inferior_ptid
);
3704 pid
= ptid_get_pid (inferior_ptid
);
3706 if (offset
> sizeof (siginfo
))
3707 return TARGET_XFER_E_IO
;
3710 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3712 return TARGET_XFER_E_IO
;
3714 /* When GDB is built as a 64-bit application, ptrace writes into
3715 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3716 inferior with a 64-bit GDB should look the same as debugging it
3717 with a 32-bit GDB, we need to convert it. GDB core always sees
3718 the converted layout, so any read/write will have to be done
3720 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3722 if (offset
+ len
> sizeof (siginfo
))
3723 len
= sizeof (siginfo
) - offset
;
3725 if (readbuf
!= NULL
)
3726 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3729 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3731 /* Convert back to ptrace layout before flushing it out. */
3732 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3735 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3737 return TARGET_XFER_E_IO
;
3741 return TARGET_XFER_OK
;
3744 static enum target_xfer_status
3745 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3746 const char *annex
, gdb_byte
*readbuf
,
3747 const gdb_byte
*writebuf
,
3748 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3750 struct cleanup
*old_chain
;
3751 enum target_xfer_status xfer
;
3753 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3754 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3755 offset
, len
, xfered_len
);
3757 /* The target is connected but no live inferior is selected. Pass
3758 this request down to a lower stratum (e.g., the executable
3760 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3761 return TARGET_XFER_EOF
;
3763 old_chain
= save_inferior_ptid ();
3765 if (ptid_lwp_p (inferior_ptid
))
3766 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3768 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3769 offset
, len
, xfered_len
);
3771 do_cleanups (old_chain
);
3776 linux_thread_alive (ptid_t ptid
)
3780 gdb_assert (ptid_lwp_p (ptid
));
3782 /* Send signal 0 instead of anything ptrace, because ptracing a
3783 running thread errors out claiming that the thread doesn't
3785 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3787 if (debug_linux_nat
)
3788 fprintf_unfiltered (gdb_stdlog
,
3789 "LLTA: KILL(SIG0) %s (%s)\n",
3790 target_pid_to_str (ptid
),
3791 err
? safe_strerror (tmp_errno
) : "OK");
3800 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3802 return linux_thread_alive (ptid
);
3806 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3808 static char buf
[64];
3810 if (ptid_lwp_p (ptid
)
3811 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3812 || num_lwps (ptid_get_pid (ptid
)) > 1))
3814 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3818 return normal_pid_to_str (ptid
);
3822 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3824 int pid
= ptid_get_pid (thr
->ptid
);
3825 long lwp
= ptid_get_lwp (thr
->ptid
);
3826 #define FORMAT "/proc/%d/task/%ld/comm"
3827 char buf
[sizeof (FORMAT
) + 30];
3829 char *result
= NULL
;
3831 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
3832 comm_file
= gdb_fopen_cloexec (buf
, "r");
3835 /* Not exported by the kernel, so we define it here. */
3837 static char line
[COMM_LEN
+ 1];
3839 if (fgets (line
, sizeof (line
), comm_file
))
3841 char *nl
= strchr (line
, '\n');
3858 /* Accepts an integer PID; Returns a string representing a file that
3859 can be opened to get the symbols for the child process. */
3862 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3864 static char buf
[PATH_MAX
];
3865 char name
[PATH_MAX
];
3867 xsnprintf (name
, PATH_MAX
, "/proc/%d/exe", pid
);
3868 memset (buf
, 0, PATH_MAX
);
3869 if (readlink (name
, buf
, PATH_MAX
- 1) <= 0)
3875 /* Implement the to_xfer_partial interface for memory reads using the /proc
3876 filesystem. Because we can use a single read() call for /proc, this
3877 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3878 but it doesn't support writes. */
3880 static enum target_xfer_status
3881 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3882 const char *annex
, gdb_byte
*readbuf
,
3883 const gdb_byte
*writebuf
,
3884 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3890 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3893 /* Don't bother for one word. */
3894 if (len
< 3 * sizeof (long))
3895 return TARGET_XFER_EOF
;
3897 /* We could keep this file open and cache it - possibly one per
3898 thread. That requires some juggling, but is even faster. */
3899 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3900 ptid_get_pid (inferior_ptid
));
3901 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3903 return TARGET_XFER_EOF
;
3905 /* If pread64 is available, use it. It's faster if the kernel
3906 supports it (only one syscall), and it's 64-bit safe even on
3907 32-bit platforms (for instance, SPARC debugging a SPARC64
3910 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3912 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3921 return TARGET_XFER_EOF
;
3925 return TARGET_XFER_OK
;
3930 /* Enumerate spufs IDs for process PID. */
3932 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3934 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3936 LONGEST written
= 0;
3939 struct dirent
*entry
;
3941 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3942 dir
= opendir (path
);
3947 while ((entry
= readdir (dir
)) != NULL
)
3953 fd
= atoi (entry
->d_name
);
3957 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3958 if (stat (path
, &st
) != 0)
3960 if (!S_ISDIR (st
.st_mode
))
3963 if (statfs (path
, &stfs
) != 0)
3965 if (stfs
.f_type
!= SPUFS_MAGIC
)
3968 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
3970 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
3980 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
3981 object type, using the /proc file system. */
3983 static enum target_xfer_status
3984 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
3985 const char *annex
, gdb_byte
*readbuf
,
3986 const gdb_byte
*writebuf
,
3987 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3992 int pid
= ptid_get_pid (inferior_ptid
);
3997 return TARGET_XFER_E_IO
;
4000 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4003 return TARGET_XFER_E_IO
;
4005 return TARGET_XFER_EOF
;
4008 *xfered_len
= (ULONGEST
) l
;
4009 return TARGET_XFER_OK
;
4014 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4015 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4017 return TARGET_XFER_E_IO
;
4020 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4023 return TARGET_XFER_EOF
;
4027 ret
= write (fd
, writebuf
, (size_t) len
);
4029 ret
= read (fd
, readbuf
, (size_t) len
);
4034 return TARGET_XFER_E_IO
;
4036 return TARGET_XFER_EOF
;
4039 *xfered_len
= (ULONGEST
) ret
;
4040 return TARGET_XFER_OK
;
4045 /* Parse LINE as a signal set and add its set bits to SIGS. */
4048 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4050 int len
= strlen (line
) - 1;
4054 if (line
[len
] != '\n')
4055 error (_("Could not parse signal set: %s"), line
);
4063 if (*p
>= '0' && *p
<= '9')
4065 else if (*p
>= 'a' && *p
<= 'f')
4066 digit
= *p
- 'a' + 10;
4068 error (_("Could not parse signal set: %s"), line
);
4073 sigaddset (sigs
, signum
+ 1);
4075 sigaddset (sigs
, signum
+ 2);
4077 sigaddset (sigs
, signum
+ 3);
4079 sigaddset (sigs
, signum
+ 4);
4085 /* Find process PID's pending signals from /proc/pid/status and set
4089 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4090 sigset_t
*blocked
, sigset_t
*ignored
)
4093 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4094 struct cleanup
*cleanup
;
4096 sigemptyset (pending
);
4097 sigemptyset (blocked
);
4098 sigemptyset (ignored
);
4099 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4100 procfile
= gdb_fopen_cloexec (fname
, "r");
4101 if (procfile
== NULL
)
4102 error (_("Could not open %s"), fname
);
4103 cleanup
= make_cleanup_fclose (procfile
);
4105 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4107 /* Normal queued signals are on the SigPnd line in the status
4108 file. However, 2.6 kernels also have a "shared" pending
4109 queue for delivering signals to a thread group, so check for
4112 Unfortunately some Red Hat kernels include the shared pending
4113 queue but not the ShdPnd status field. */
4115 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4116 add_line_to_sigset (buffer
+ 8, pending
);
4117 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4118 add_line_to_sigset (buffer
+ 8, pending
);
4119 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4120 add_line_to_sigset (buffer
+ 8, blocked
);
4121 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4122 add_line_to_sigset (buffer
+ 8, ignored
);
4125 do_cleanups (cleanup
);
4128 static enum target_xfer_status
4129 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4130 const char *annex
, gdb_byte
*readbuf
,
4131 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4132 ULONGEST
*xfered_len
)
4134 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4136 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4137 if (*xfered_len
== 0)
4138 return TARGET_XFER_EOF
;
4140 return TARGET_XFER_OK
;
4143 static enum target_xfer_status
4144 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4145 const char *annex
, gdb_byte
*readbuf
,
4146 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4147 ULONGEST
*xfered_len
)
4149 enum target_xfer_status xfer
;
4151 if (object
== TARGET_OBJECT_AUXV
)
4152 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4153 offset
, len
, xfered_len
);
4155 if (object
== TARGET_OBJECT_OSDATA
)
4156 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4157 offset
, len
, xfered_len
);
4159 if (object
== TARGET_OBJECT_SPU
)
4160 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4161 offset
, len
, xfered_len
);
4163 /* GDB calculates all the addresses in possibly larget width of the address.
4164 Address width needs to be masked before its final use - either by
4165 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4167 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4169 if (object
== TARGET_OBJECT_MEMORY
)
4171 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4173 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4174 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4177 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4178 offset
, len
, xfered_len
);
4179 if (xfer
!= TARGET_XFER_EOF
)
4182 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4183 offset
, len
, xfered_len
);
4187 cleanup_target_stop (void *arg
)
4189 ptid_t
*ptid
= (ptid_t
*) arg
;
4191 gdb_assert (arg
!= NULL
);
4194 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4197 static VEC(static_tracepoint_marker_p
) *
4198 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4201 char s
[IPA_CMD_BUF_SIZE
];
4202 struct cleanup
*old_chain
;
4203 int pid
= ptid_get_pid (inferior_ptid
);
4204 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4205 struct static_tracepoint_marker
*marker
= NULL
;
4207 ptid_t ptid
= ptid_build (pid
, 0, 0);
4212 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4213 s
[sizeof ("qTfSTM")] = 0;
4215 agent_run_command (pid
, s
, strlen (s
) + 1);
4217 old_chain
= make_cleanup (free_current_marker
, &marker
);
4218 make_cleanup (cleanup_target_stop
, &ptid
);
4223 marker
= XCNEW (struct static_tracepoint_marker
);
4227 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4229 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4231 VEC_safe_push (static_tracepoint_marker_p
,
4237 release_static_tracepoint_marker (marker
);
4238 memset (marker
, 0, sizeof (*marker
));
4241 while (*p
++ == ','); /* comma-separated list */
4243 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4244 s
[sizeof ("qTsSTM")] = 0;
4245 agent_run_command (pid
, s
, strlen (s
) + 1);
4249 do_cleanups (old_chain
);
4254 /* Create a prototype generic GNU/Linux target. The client can override
4255 it with local methods. */
4258 linux_target_install_ops (struct target_ops
*t
)
4260 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4261 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4262 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4263 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4264 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4265 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4266 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4267 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4268 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4269 t
->to_post_attach
= linux_child_post_attach
;
4270 t
->to_follow_fork
= linux_child_follow_fork
;
4272 super_xfer_partial
= t
->to_xfer_partial
;
4273 t
->to_xfer_partial
= linux_xfer_partial
;
4275 t
->to_static_tracepoint_markers_by_strid
4276 = linux_child_static_tracepoint_markers_by_strid
;
4282 struct target_ops
*t
;
4284 t
= inf_ptrace_target ();
4285 linux_target_install_ops (t
);
4291 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4293 struct target_ops
*t
;
4295 t
= inf_ptrace_trad_target (register_u_offset
);
4296 linux_target_install_ops (t
);
4301 /* target_is_async_p implementation. */
4304 linux_nat_is_async_p (struct target_ops
*ops
)
4306 return linux_is_async_p ();
4309 /* target_can_async_p implementation. */
4312 linux_nat_can_async_p (struct target_ops
*ops
)
4314 /* NOTE: palves 2008-03-21: We're only async when the user requests
4315 it explicitly with the "set target-async" command.
4316 Someday, linux will always be async. */
4317 return target_async_permitted
;
4321 linux_nat_supports_non_stop (struct target_ops
*self
)
4326 /* True if we want to support multi-process. To be removed when GDB
4327 supports multi-exec. */
4329 int linux_multi_process
= 1;
4332 linux_nat_supports_multi_process (struct target_ops
*self
)
4334 return linux_multi_process
;
4338 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4340 #ifdef HAVE_PERSONALITY
4347 static int async_terminal_is_ours
= 1;
4349 /* target_terminal_inferior implementation.
4351 This is a wrapper around child_terminal_inferior to add async support. */
4354 linux_nat_terminal_inferior (struct target_ops
*self
)
4356 /* Like target_terminal_inferior, use target_can_async_p, not
4357 target_is_async_p, since at this point the target is not async
4358 yet. If it can async, then we know it will become async prior to
4360 if (!target_can_async_p ())
4362 /* Async mode is disabled. */
4363 child_terminal_inferior (self
);
4367 child_terminal_inferior (self
);
4369 /* Calls to target_terminal_*() are meant to be idempotent. */
4370 if (!async_terminal_is_ours
)
4373 delete_file_handler (input_fd
);
4374 async_terminal_is_ours
= 0;
4378 /* target_terminal_ours implementation.
4380 This is a wrapper around child_terminal_ours to add async support (and
4381 implement the target_terminal_ours vs target_terminal_ours_for_output
4382 distinction). child_terminal_ours is currently no different than
4383 child_terminal_ours_for_output.
4384 We leave target_terminal_ours_for_output alone, leaving it to
4385 child_terminal_ours_for_output. */
4388 linux_nat_terminal_ours (struct target_ops
*self
)
4390 /* GDB should never give the terminal to the inferior if the
4391 inferior is running in the background (run&, continue&, etc.),
4392 but claiming it sure should. */
4393 child_terminal_ours (self
);
4395 if (async_terminal_is_ours
)
4398 clear_sigint_trap ();
4399 add_file_handler (input_fd
, stdin_event_handler
, 0);
4400 async_terminal_is_ours
= 1;
4403 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4405 static void *async_client_context
;
4407 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4408 so we notice when any child changes state, and notify the
4409 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4410 above to wait for the arrival of a SIGCHLD. */
4413 sigchld_handler (int signo
)
4415 int old_errno
= errno
;
4417 if (debug_linux_nat
)
4418 ui_file_write_async_safe (gdb_stdlog
,
4419 "sigchld\n", sizeof ("sigchld\n") - 1);
4421 if (signo
== SIGCHLD
4422 && linux_nat_event_pipe
[0] != -1)
4423 async_file_mark (); /* Let the event loop know that there are
4424 events to handle. */
4429 /* Callback registered with the target events file descriptor. */
4432 handle_target_event (int error
, gdb_client_data client_data
)
4434 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4437 /* Create/destroy the target events pipe. Returns previous state. */
4440 linux_async_pipe (int enable
)
4442 int previous
= linux_is_async_p ();
4444 if (previous
!= enable
)
4448 /* Block child signals while we create/destroy the pipe, as
4449 their handler writes to it. */
4450 block_child_signals (&prev_mask
);
4454 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4455 internal_error (__FILE__
, __LINE__
,
4456 "creating event pipe failed.");
4458 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4459 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4463 close (linux_nat_event_pipe
[0]);
4464 close (linux_nat_event_pipe
[1]);
4465 linux_nat_event_pipe
[0] = -1;
4466 linux_nat_event_pipe
[1] = -1;
4469 restore_child_signals_mask (&prev_mask
);
4475 /* target_async implementation. */
4478 linux_nat_async (struct target_ops
*ops
,
4479 void (*callback
) (enum inferior_event_type event_type
,
4483 if (callback
!= NULL
)
4485 async_client_callback
= callback
;
4486 async_client_context
= context
;
4487 if (!linux_async_pipe (1))
4489 add_file_handler (linux_nat_event_pipe
[0],
4490 handle_target_event
, NULL
);
4491 /* There may be pending events to handle. Tell the event loop
4498 async_client_callback
= callback
;
4499 async_client_context
= context
;
4500 delete_file_handler (linux_nat_event_pipe
[0]);
4501 linux_async_pipe (0);
4506 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4510 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4514 if (debug_linux_nat
)
4515 fprintf_unfiltered (gdb_stdlog
,
4516 "LNSL: running -> suspending %s\n",
4517 target_pid_to_str (lwp
->ptid
));
4520 if (lwp
->last_resume_kind
== resume_stop
)
4522 if (debug_linux_nat
)
4523 fprintf_unfiltered (gdb_stdlog
,
4524 "linux-nat: already stopping LWP %ld at "
4526 ptid_get_lwp (lwp
->ptid
));
4530 stop_callback (lwp
, NULL
);
4531 lwp
->last_resume_kind
= resume_stop
;
4535 /* Already known to be stopped; do nothing. */
4537 if (debug_linux_nat
)
4539 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4540 fprintf_unfiltered (gdb_stdlog
,
4541 "LNSL: already stopped/stop_requested %s\n",
4542 target_pid_to_str (lwp
->ptid
));
4544 fprintf_unfiltered (gdb_stdlog
,
4545 "LNSL: already stopped/no "
4546 "stop_requested yet %s\n",
4547 target_pid_to_str (lwp
->ptid
));
4554 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4557 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4559 linux_ops
->to_stop (linux_ops
, ptid
);
4563 linux_nat_close (struct target_ops
*self
)
4565 /* Unregister from the event loop. */
4566 if (linux_nat_is_async_p (self
))
4567 linux_nat_async (self
, NULL
, NULL
);
4569 if (linux_ops
->to_close
)
4570 linux_ops
->to_close (linux_ops
);
4575 /* When requests are passed down from the linux-nat layer to the
4576 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4577 used. The address space pointer is stored in the inferior object,
4578 but the common code that is passed such ptid can't tell whether
4579 lwpid is a "main" process id or not (it assumes so). We reverse
4580 look up the "main" process id from the lwp here. */
4582 static struct address_space
*
4583 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4585 struct lwp_info
*lwp
;
4586 struct inferior
*inf
;
4589 if (ptid_get_lwp (ptid
) == 0)
4591 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4593 lwp
= find_lwp_pid (ptid
);
4594 pid
= ptid_get_pid (lwp
->ptid
);
4598 /* A (pid,lwpid,0) ptid. */
4599 pid
= ptid_get_pid (ptid
);
4602 inf
= find_inferior_pid (pid
);
4603 gdb_assert (inf
!= NULL
);
4607 /* Return the cached value of the processor core for thread PTID. */
4610 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4612 struct lwp_info
*info
= find_lwp_pid (ptid
);
4620 linux_nat_add_target (struct target_ops
*t
)
4622 /* Save the provided single-threaded target. We save this in a separate
4623 variable because another target we've inherited from (e.g. inf-ptrace)
4624 may have saved a pointer to T; we want to use it for the final
4625 process stratum target. */
4626 linux_ops_saved
= *t
;
4627 linux_ops
= &linux_ops_saved
;
4629 /* Override some methods for multithreading. */
4630 t
->to_create_inferior
= linux_nat_create_inferior
;
4631 t
->to_attach
= linux_nat_attach
;
4632 t
->to_detach
= linux_nat_detach
;
4633 t
->to_resume
= linux_nat_resume
;
4634 t
->to_wait
= linux_nat_wait
;
4635 t
->to_pass_signals
= linux_nat_pass_signals
;
4636 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4637 t
->to_kill
= linux_nat_kill
;
4638 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4639 t
->to_thread_alive
= linux_nat_thread_alive
;
4640 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4641 t
->to_thread_name
= linux_nat_thread_name
;
4642 t
->to_has_thread_control
= tc_schedlock
;
4643 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4644 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4645 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4647 t
->to_can_async_p
= linux_nat_can_async_p
;
4648 t
->to_is_async_p
= linux_nat_is_async_p
;
4649 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4650 t
->to_async
= linux_nat_async
;
4651 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4652 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4654 super_close
= t
->to_close
;
4655 t
->to_close
= linux_nat_close
;
4657 /* Methods for non-stop support. */
4658 t
->to_stop
= linux_nat_stop
;
4660 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4662 t
->to_supports_disable_randomization
4663 = linux_nat_supports_disable_randomization
;
4665 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4667 /* We don't change the stratum; this target will sit at
4668 process_stratum and thread_db will set at thread_stratum. This
4669 is a little strange, since this is a multi-threaded-capable
4670 target, but we want to be on the stack below thread_db, and we
4671 also want to be used for single-threaded processes. */
4676 /* Register a method to call whenever a new thread is attached. */
4678 linux_nat_set_new_thread (struct target_ops
*t
,
4679 void (*new_thread
) (struct lwp_info
*))
4681 /* Save the pointer. We only support a single registered instance
4682 of the GNU/Linux native target, so we do not need to map this to
4684 linux_nat_new_thread
= new_thread
;
4687 /* See declaration in linux-nat.h. */
4690 linux_nat_set_new_fork (struct target_ops
*t
,
4691 linux_nat_new_fork_ftype
*new_fork
)
4693 /* Save the pointer. */
4694 linux_nat_new_fork
= new_fork
;
4697 /* See declaration in linux-nat.h. */
4700 linux_nat_set_forget_process (struct target_ops
*t
,
4701 linux_nat_forget_process_ftype
*fn
)
4703 /* Save the pointer. */
4704 linux_nat_forget_process_hook
= fn
;
4707 /* See declaration in linux-nat.h. */
4710 linux_nat_forget_process (pid_t pid
)
4712 if (linux_nat_forget_process_hook
!= NULL
)
4713 linux_nat_forget_process_hook (pid
);
4716 /* Register a method that converts a siginfo object between the layout
4717 that ptrace returns, and the layout in the architecture of the
4720 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4721 int (*siginfo_fixup
) (siginfo_t
*,
4725 /* Save the pointer. */
4726 linux_nat_siginfo_fixup
= siginfo_fixup
;
4729 /* Register a method to call prior to resuming a thread. */
4732 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4733 void (*prepare_to_resume
) (struct lwp_info
*))
4735 /* Save the pointer. */
4736 linux_nat_prepare_to_resume
= prepare_to_resume
;
4739 /* See linux-nat.h. */
4742 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4746 pid
= ptid_get_lwp (ptid
);
4748 pid
= ptid_get_pid (ptid
);
4751 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4754 memset (siginfo
, 0, sizeof (*siginfo
));
4760 /* Provide a prototype to silence -Wmissing-prototypes. */
4761 extern initialize_file_ftype _initialize_linux_nat
;
4764 _initialize_linux_nat (void)
4766 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4767 &debug_linux_nat
, _("\
4768 Set debugging of GNU/Linux lwp module."), _("\
4769 Show debugging of GNU/Linux lwp module."), _("\
4770 Enables printf debugging output."),
4772 show_debug_linux_nat
,
4773 &setdebuglist
, &showdebuglist
);
4775 /* Save this mask as the default. */
4776 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4778 /* Install a SIGCHLD handler. */
4779 sigchld_action
.sa_handler
= sigchld_handler
;
4780 sigemptyset (&sigchld_action
.sa_mask
);
4781 sigchld_action
.sa_flags
= SA_RESTART
;
4783 /* Make it the default. */
4784 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4786 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4787 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4788 sigdelset (&suspend_mask
, SIGCHLD
);
4790 sigemptyset (&blocked_mask
);
4792 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to
4793 support read-only process state. */
4794 linux_ptrace_set_additional_flags (PTRACE_O_TRACESYSGOOD
4795 | PTRACE_O_TRACEVFORKDONE
4796 | PTRACE_O_TRACEVFORK
4797 | PTRACE_O_TRACEFORK
4798 | PTRACE_O_TRACEEXEC
);
4802 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4803 the GNU/Linux Threads library and therefore doesn't really belong
4806 /* Read variable NAME in the target and return its value if found.
4807 Otherwise return zero. It is assumed that the type of the variable
4811 get_signo (const char *name
)
4813 struct bound_minimal_symbol ms
;
4816 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
4817 if (ms
.minsym
== NULL
)
4820 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
4821 sizeof (signo
)) != 0)
4827 /* Return the set of signals used by the threads library in *SET. */
4830 lin_thread_get_thread_signals (sigset_t
*set
)
4832 struct sigaction action
;
4833 int restart
, cancel
;
4835 sigemptyset (&blocked_mask
);
4838 restart
= get_signo ("__pthread_sig_restart");
4839 cancel
= get_signo ("__pthread_sig_cancel");
4841 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4842 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4843 not provide any way for the debugger to query the signal numbers -
4844 fortunately they don't change! */
4847 restart
= __SIGRTMIN
;
4850 cancel
= __SIGRTMIN
+ 1;
4852 sigaddset (set
, restart
);
4853 sigaddset (set
, cancel
);
4855 /* The GNU/Linux Threads library makes terminating threads send a
4856 special "cancel" signal instead of SIGCHLD. Make sure we catch
4857 those (to prevent them from terminating GDB itself, which is
4858 likely to be their default action) and treat them the same way as
4861 action
.sa_handler
= sigchld_handler
;
4862 sigemptyset (&action
.sa_mask
);
4863 action
.sa_flags
= SA_RESTART
;
4864 sigaction (cancel
, &action
, NULL
);
4866 /* We block the "cancel" signal throughout this code ... */
4867 sigaddset (&blocked_mask
, cancel
);
4868 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
4870 /* ... except during a sigsuspend. */
4871 sigdelset (&suspend_mask
, cancel
);