1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2014 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/>. */
23 #include "nat/linux-nat.h"
24 #include "nat/linux-waitpid.h"
27 #include "gdb_assert.h"
28 #ifdef HAVE_TKILL_SYSCALL
30 #include <sys/syscall.h>
32 #include <sys/ptrace.h>
33 #include "linux-nat.h"
34 #include "linux-ptrace.h"
35 #include "linux-procfs.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"
61 #include "linux-osdata.h"
62 #include "linux-tdep.h"
65 #include "tracepoint.h"
66 #include "exceptions.h"
68 #include "target-descriptions.h"
69 #include "filestuff.h"
72 #define SPUFS_MAGIC 0x23c9b64e
75 #ifdef HAVE_PERSONALITY
76 # include <sys/personality.h>
77 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
78 # define ADDR_NO_RANDOMIZE 0x0040000
80 #endif /* HAVE_PERSONALITY */
82 /* This comment documents high-level logic of this file.
84 Waiting for events in sync mode
85 ===============================
87 When waiting for an event in a specific thread, we just use waitpid, passing
88 the specific pid, and not passing WNOHANG.
90 When waiting for an event in all threads, waitpid is not quite good. Prior to
91 version 2.4, Linux can either wait for event in main thread, or in secondary
92 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
93 miss an event. The solution is to use non-blocking waitpid, together with
94 sigsuspend. First, we use non-blocking waitpid to get an event in the main
95 process, if any. Second, we use non-blocking waitpid with the __WCLONED
96 flag to check for events in cloned processes. If nothing is found, we use
97 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
98 happened to a child process -- and SIGCHLD will be delivered both for events
99 in main debugged process and in cloned processes. As soon as we know there's
100 an event, we get back to calling nonblocking waitpid with and without
103 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
104 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
105 blocked, the signal becomes pending and sigsuspend immediately
106 notices it and returns.
108 Waiting for events in async mode
109 ================================
111 In async mode, GDB should always be ready to handle both user input
112 and target events, so neither blocking waitpid nor sigsuspend are
113 viable options. Instead, we should asynchronously notify the GDB main
114 event loop whenever there's an unprocessed event from the target. We
115 detect asynchronous target events by handling SIGCHLD signals. To
116 notify the event loop about target events, the self-pipe trick is used
117 --- a pipe is registered as waitable event source in the event loop,
118 the event loop select/poll's on the read end of this pipe (as well on
119 other event sources, e.g., stdin), and the SIGCHLD handler writes a
120 byte to this pipe. This is more portable than relying on
121 pselect/ppoll, since on kernels that lack those syscalls, libc
122 emulates them with select/poll+sigprocmask, and that is racy
123 (a.k.a. plain broken).
125 Obviously, if we fail to notify the event loop if there's a target
126 event, it's bad. OTOH, if we notify the event loop when there's no
127 event from the target, linux_nat_wait will detect that there's no real
128 event to report, and return event of type TARGET_WAITKIND_IGNORE.
129 This is mostly harmless, but it will waste time and is better avoided.
131 The main design point is that every time GDB is outside linux-nat.c,
132 we have a SIGCHLD handler installed that is called when something
133 happens to the target and notifies the GDB event loop. Whenever GDB
134 core decides to handle the event, and calls into linux-nat.c, we
135 process things as in sync mode, except that the we never block in
138 While processing an event, we may end up momentarily blocked in
139 waitpid calls. Those waitpid calls, while blocking, are guarantied to
140 return quickly. E.g., in all-stop mode, before reporting to the core
141 that an LWP hit a breakpoint, all LWPs are stopped by sending them
142 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
143 Note that this is different from blocking indefinitely waiting for the
144 next event --- here, we're already handling an event.
149 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
150 signal is not entirely significant; we just need for a signal to be delivered,
151 so that we can intercept it. SIGSTOP's advantage is that it can not be
152 blocked. A disadvantage is that it is not a real-time signal, so it can only
153 be queued once; we do not keep track of other sources of SIGSTOP.
155 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
156 use them, because they have special behavior when the signal is generated -
157 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
158 kills the entire thread group.
160 A delivered SIGSTOP would stop the entire thread group, not just the thread we
161 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
162 cancel it (by PTRACE_CONT without passing SIGSTOP).
164 We could use a real-time signal instead. This would solve those problems; we
165 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
166 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
167 generates it, and there are races with trying to find a signal that is not
171 #define O_LARGEFILE 0
174 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
175 the use of the multi-threaded target. */
176 static struct target_ops
*linux_ops
;
177 static struct target_ops linux_ops_saved
;
179 /* The method to call, if any, when a new thread is attached. */
180 static void (*linux_nat_new_thread
) (struct lwp_info
*);
182 /* The method to call, if any, when a new fork is attached. */
183 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
185 /* The method to call, if any, when a process is no longer
187 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
189 /* Hook to call prior to resuming a thread. */
190 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
192 /* The method to call, if any, when the siginfo object needs to be
193 converted between the layout returned by ptrace, and the layout in
194 the architecture of the inferior. */
195 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
199 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
200 Called by our to_xfer_partial. */
201 static target_xfer_partial_ftype
*super_xfer_partial
;
203 static unsigned int debug_linux_nat
;
205 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
206 struct cmd_list_element
*c
, const char *value
)
208 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
212 struct simple_pid_list
216 struct simple_pid_list
*next
;
218 struct simple_pid_list
*stopped_pids
;
220 /* Async mode support. */
222 /* The read/write ends of the pipe registered as waitable file in the
224 static int linux_nat_event_pipe
[2] = { -1, -1 };
226 /* Flush the event pipe. */
229 async_file_flush (void)
236 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
238 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
241 /* Put something (anything, doesn't matter what, or how much) in event
242 pipe, so that the select/poll in the event-loop realizes we have
243 something to process. */
246 async_file_mark (void)
250 /* It doesn't really matter what the pipe contains, as long we end
251 up with something in it. Might as well flush the previous
257 ret
= write (linux_nat_event_pipe
[1], "+", 1);
259 while (ret
== -1 && errno
== EINTR
);
261 /* Ignore EAGAIN. If the pipe is full, the event loop will already
262 be awakened anyway. */
265 static int kill_lwp (int lwpid
, int signo
);
267 static int stop_callback (struct lwp_info
*lp
, void *data
);
269 static void block_child_signals (sigset_t
*prev_mask
);
270 static void restore_child_signals_mask (sigset_t
*prev_mask
);
273 static struct lwp_info
*add_lwp (ptid_t ptid
);
274 static void purge_lwp_list (int pid
);
275 static void delete_lwp (ptid_t ptid
);
276 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
279 /* Trivial list manipulation functions to keep track of a list of
280 new stopped processes. */
282 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
284 struct simple_pid_list
*new_pid
= xmalloc (sizeof (struct simple_pid_list
));
287 new_pid
->status
= status
;
288 new_pid
->next
= *listp
;
293 in_pid_list_p (struct simple_pid_list
*list
, int pid
)
295 struct simple_pid_list
*p
;
297 for (p
= list
; p
!= NULL
; p
= p
->next
)
304 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
306 struct simple_pid_list
**p
;
308 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
309 if ((*p
)->pid
== pid
)
311 struct simple_pid_list
*next
= (*p
)->next
;
313 *statusp
= (*p
)->status
;
321 /* Initialize ptrace warnings and check for supported ptrace
322 features given PID. */
325 linux_init_ptrace (pid_t pid
)
327 linux_enable_event_reporting (pid
);
328 linux_ptrace_init_warnings ();
332 linux_child_post_attach (struct target_ops
*self
, int pid
)
334 linux_init_ptrace (pid
);
338 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
340 linux_init_ptrace (ptid_get_pid (ptid
));
343 /* Return the number of known LWPs in the tgid given by PID. */
351 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
352 if (ptid_get_pid (lp
->ptid
) == pid
)
358 /* Call delete_lwp with prototype compatible for make_cleanup. */
361 delete_lwp_cleanup (void *lp_voidp
)
363 struct lwp_info
*lp
= lp_voidp
;
365 delete_lwp (lp
->ptid
);
369 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
373 int parent_pid
, child_pid
;
375 has_vforked
= (inferior_thread ()->pending_follow
.kind
376 == TARGET_WAITKIND_VFORKED
);
377 parent_pid
= ptid_get_lwp (inferior_ptid
);
379 parent_pid
= ptid_get_pid (inferior_ptid
);
381 = ptid_get_pid (inferior_thread ()->pending_follow
.value
.related_pid
);
384 && !non_stop
/* Non-stop always resumes both branches. */
385 && (!target_is_async_p () || sync_execution
)
386 && !(follow_child
|| detach_fork
|| sched_multi
))
388 /* The parent stays blocked inside the vfork syscall until the
389 child execs or exits. If we don't let the child run, then
390 the parent stays blocked. If we're telling the parent to run
391 in the foreground, the user will not be able to ctrl-c to get
392 back the terminal, effectively hanging the debug session. */
393 fprintf_filtered (gdb_stderr
, _("\
394 Can not resume the parent process over vfork in the foreground while\n\
395 holding the child stopped. Try \"set detach-on-fork\" or \
396 \"set schedule-multiple\".\n"));
397 /* FIXME output string > 80 columns. */
403 struct lwp_info
*child_lp
= NULL
;
405 /* We're already attached to the parent, by default. */
407 /* Detach new forked process? */
410 struct cleanup
*old_chain
;
412 /* Before detaching from the child, remove all breakpoints
413 from it. If we forked, then this has already been taken
414 care of by infrun.c. If we vforked however, any
415 breakpoint inserted in the parent is visible in the
416 child, even those added while stopped in a vfork
417 catchpoint. This will remove the breakpoints from the
418 parent also, but they'll be reinserted below. */
421 /* keep breakpoints list in sync. */
422 remove_breakpoints_pid (ptid_get_pid (inferior_ptid
));
425 if (info_verbose
|| debug_linux_nat
)
427 target_terminal_ours ();
428 fprintf_filtered (gdb_stdlog
,
429 "Detaching after fork from "
430 "child process %d.\n",
434 old_chain
= save_inferior_ptid ();
435 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
437 child_lp
= add_lwp (inferior_ptid
);
438 child_lp
->stopped
= 1;
439 child_lp
->last_resume_kind
= resume_stop
;
440 make_cleanup (delete_lwp_cleanup
, child_lp
);
442 if (linux_nat_prepare_to_resume
!= NULL
)
443 linux_nat_prepare_to_resume (child_lp
);
444 ptrace (PTRACE_DETACH
, child_pid
, 0, 0);
446 do_cleanups (old_chain
);
450 struct inferior
*parent_inf
, *child_inf
;
451 struct cleanup
*old_chain
;
453 /* Add process to GDB's tables. */
454 child_inf
= add_inferior (child_pid
);
456 parent_inf
= current_inferior ();
457 child_inf
->attach_flag
= parent_inf
->attach_flag
;
458 copy_terminal_info (child_inf
, parent_inf
);
459 child_inf
->gdbarch
= parent_inf
->gdbarch
;
460 copy_inferior_target_desc_info (child_inf
, parent_inf
);
462 old_chain
= save_inferior_ptid ();
463 save_current_program_space ();
465 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
466 add_thread (inferior_ptid
);
467 child_lp
= add_lwp (inferior_ptid
);
468 child_lp
->stopped
= 1;
469 child_lp
->last_resume_kind
= resume_stop
;
470 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
472 /* If this is a vfork child, then the address-space is
473 shared with the parent. */
476 child_inf
->pspace
= parent_inf
->pspace
;
477 child_inf
->aspace
= parent_inf
->aspace
;
479 /* The parent will be frozen until the child is done
480 with the shared region. Keep track of the
482 child_inf
->vfork_parent
= parent_inf
;
483 child_inf
->pending_detach
= 0;
484 parent_inf
->vfork_child
= child_inf
;
485 parent_inf
->pending_detach
= 0;
489 child_inf
->aspace
= new_address_space ();
490 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
491 child_inf
->removable
= 1;
492 set_current_program_space (child_inf
->pspace
);
493 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
495 /* Let the shared library layer (solib-svr4) learn about
496 this new process, relocate the cloned exec, pull in
497 shared libraries, and install the solib event
498 breakpoint. If a "cloned-VM" event was propagated
499 better throughout the core, this wouldn't be
501 solib_create_inferior_hook (0);
504 /* Let the thread_db layer learn about this new process. */
505 check_for_thread_db ();
507 do_cleanups (old_chain
);
512 struct lwp_info
*parent_lp
;
513 struct inferior
*parent_inf
;
515 parent_inf
= current_inferior ();
517 /* If we detached from the child, then we have to be careful
518 to not insert breakpoints in the parent until the child
519 is done with the shared memory region. However, if we're
520 staying attached to the child, then we can and should
521 insert breakpoints, so that we can debug it. A
522 subsequent child exec or exit is enough to know when does
523 the child stops using the parent's address space. */
524 parent_inf
->waiting_for_vfork_done
= detach_fork
;
525 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
527 parent_lp
= find_lwp_pid (pid_to_ptid (parent_pid
));
528 gdb_assert (linux_supports_tracefork () >= 0);
530 if (linux_supports_tracevforkdone ())
533 fprintf_unfiltered (gdb_stdlog
,
534 "LCFF: waiting for VFORK_DONE on %d\n",
536 parent_lp
->stopped
= 1;
538 /* We'll handle the VFORK_DONE event like any other
539 event, in target_wait. */
543 /* We can't insert breakpoints until the child has
544 finished with the shared memory region. We need to
545 wait until that happens. Ideal would be to just
547 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
548 - waitpid (parent_pid, &status, __WALL);
549 However, most architectures can't handle a syscall
550 being traced on the way out if it wasn't traced on
553 We might also think to loop, continuing the child
554 until it exits or gets a SIGTRAP. One problem is
555 that the child might call ptrace with PTRACE_TRACEME.
557 There's no simple and reliable way to figure out when
558 the vforked child will be done with its copy of the
559 shared memory. We could step it out of the syscall,
560 two instructions, let it go, and then single-step the
561 parent once. When we have hardware single-step, this
562 would work; with software single-step it could still
563 be made to work but we'd have to be able to insert
564 single-step breakpoints in the child, and we'd have
565 to insert -just- the single-step breakpoint in the
566 parent. Very awkward.
568 In the end, the best we can do is to make sure it
569 runs for a little while. Hopefully it will be out of
570 range of any breakpoints we reinsert. Usually this
571 is only the single-step breakpoint at vfork's return
575 fprintf_unfiltered (gdb_stdlog
,
576 "LCFF: no VFORK_DONE "
577 "support, sleeping a bit\n");
581 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
582 and leave it pending. The next linux_nat_resume call
583 will notice a pending event, and bypasses actually
584 resuming the inferior. */
585 parent_lp
->status
= 0;
586 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
587 parent_lp
->stopped
= 1;
589 /* If we're in async mode, need to tell the event loop
590 there's something here to process. */
591 if (target_can_async_p ())
598 struct inferior
*parent_inf
, *child_inf
;
599 struct lwp_info
*child_lp
;
600 struct program_space
*parent_pspace
;
602 if (info_verbose
|| debug_linux_nat
)
604 target_terminal_ours ();
606 fprintf_filtered (gdb_stdlog
,
607 _("Attaching after process %d "
608 "vfork to child process %d.\n"),
609 parent_pid
, child_pid
);
611 fprintf_filtered (gdb_stdlog
,
612 _("Attaching after process %d "
613 "fork to child process %d.\n"),
614 parent_pid
, child_pid
);
617 /* Add the new inferior first, so that the target_detach below
618 doesn't unpush the target. */
620 child_inf
= add_inferior (child_pid
);
622 parent_inf
= current_inferior ();
623 child_inf
->attach_flag
= parent_inf
->attach_flag
;
624 copy_terminal_info (child_inf
, parent_inf
);
625 child_inf
->gdbarch
= parent_inf
->gdbarch
;
626 copy_inferior_target_desc_info (child_inf
, parent_inf
);
628 parent_pspace
= parent_inf
->pspace
;
630 /* If we're vforking, we want to hold on to the parent until the
631 child exits or execs. At child exec or exit time we can
632 remove the old breakpoints from the parent and detach or
633 resume debugging it. Otherwise, detach the parent now; we'll
634 want to reuse it's program/address spaces, but we can't set
635 them to the child before removing breakpoints from the
636 parent, otherwise, the breakpoints module could decide to
637 remove breakpoints from the wrong process (since they'd be
638 assigned to the same address space). */
642 gdb_assert (child_inf
->vfork_parent
== NULL
);
643 gdb_assert (parent_inf
->vfork_child
== NULL
);
644 child_inf
->vfork_parent
= parent_inf
;
645 child_inf
->pending_detach
= 0;
646 parent_inf
->vfork_child
= child_inf
;
647 parent_inf
->pending_detach
= detach_fork
;
648 parent_inf
->waiting_for_vfork_done
= 0;
650 else if (detach_fork
)
651 target_detach (NULL
, 0);
653 /* Note that the detach above makes PARENT_INF dangling. */
655 /* Add the child thread to the appropriate lists, and switch to
656 this new thread, before cloning the program space, and
657 informing the solib layer about this new process. */
659 inferior_ptid
= ptid_build (child_pid
, child_pid
, 0);
660 add_thread (inferior_ptid
);
661 child_lp
= add_lwp (inferior_ptid
);
662 child_lp
->stopped
= 1;
663 child_lp
->last_resume_kind
= resume_stop
;
665 /* If this is a vfork child, then the address-space is shared
666 with the parent. If we detached from the parent, then we can
667 reuse the parent's program/address spaces. */
668 if (has_vforked
|| detach_fork
)
670 child_inf
->pspace
= parent_pspace
;
671 child_inf
->aspace
= child_inf
->pspace
->aspace
;
675 child_inf
->aspace
= new_address_space ();
676 child_inf
->pspace
= add_program_space (child_inf
->aspace
);
677 child_inf
->removable
= 1;
678 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
679 set_current_program_space (child_inf
->pspace
);
680 clone_program_space (child_inf
->pspace
, parent_pspace
);
682 /* Let the shared library layer (solib-svr4) learn about
683 this new process, relocate the cloned exec, pull in
684 shared libraries, and install the solib event breakpoint.
685 If a "cloned-VM" event was propagated better throughout
686 the core, this wouldn't be required. */
687 solib_create_inferior_hook (0);
690 /* Let the thread_db layer learn about this new process. */
691 check_for_thread_db ();
699 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
701 return !linux_supports_tracefork ();
705 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
711 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
713 return !linux_supports_tracefork ();
717 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
723 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
725 return !linux_supports_tracefork ();
729 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
735 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
736 int pid
, int needed
, int any_count
,
737 int table_size
, int *table
)
739 if (!linux_supports_tracesysgood ())
742 /* On GNU/Linux, we ignore the arguments. It means that we only
743 enable the syscall catchpoints, but do not disable them.
745 Also, we do not use the `table' information because we do not
746 filter system calls here. We let GDB do the logic for us. */
750 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
751 are processes sharing the same VM space. A multi-threaded process
752 is basically a group of such processes. However, such a grouping
753 is almost entirely a user-space issue; the kernel doesn't enforce
754 such a grouping at all (this might change in the future). In
755 general, we'll rely on the threads library (i.e. the GNU/Linux
756 Threads library) to provide such a grouping.
758 It is perfectly well possible to write a multi-threaded application
759 without the assistance of a threads library, by using the clone
760 system call directly. This module should be able to give some
761 rudimentary support for debugging such applications if developers
762 specify the CLONE_PTRACE flag in the clone system call, and are
763 using the Linux kernel 2.4 or above.
765 Note that there are some peculiarities in GNU/Linux that affect
768 - In general one should specify the __WCLONE flag to waitpid in
769 order to make it report events for any of the cloned processes
770 (and leave it out for the initial process). However, if a cloned
771 process has exited the exit status is only reported if the
772 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
773 we cannot use it since GDB must work on older systems too.
775 - When a traced, cloned process exits and is waited for by the
776 debugger, the kernel reassigns it to the original parent and
777 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
778 library doesn't notice this, which leads to the "zombie problem":
779 When debugged a multi-threaded process that spawns a lot of
780 threads will run out of processes, even if the threads exit,
781 because the "zombies" stay around. */
783 /* List of known LWPs. */
784 struct lwp_info
*lwp_list
;
787 /* Original signal mask. */
788 static sigset_t normal_mask
;
790 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
791 _initialize_linux_nat. */
792 static sigset_t suspend_mask
;
794 /* Signals to block to make that sigsuspend work. */
795 static sigset_t blocked_mask
;
797 /* SIGCHLD action. */
798 struct sigaction sigchld_action
;
800 /* Block child signals (SIGCHLD and linux threads signals), and store
801 the previous mask in PREV_MASK. */
804 block_child_signals (sigset_t
*prev_mask
)
806 /* Make sure SIGCHLD is blocked. */
807 if (!sigismember (&blocked_mask
, SIGCHLD
))
808 sigaddset (&blocked_mask
, SIGCHLD
);
810 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
813 /* Restore child signals mask, previously returned by
814 block_child_signals. */
817 restore_child_signals_mask (sigset_t
*prev_mask
)
819 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
822 /* Mask of signals to pass directly to the inferior. */
823 static sigset_t pass_mask
;
825 /* Update signals to pass to the inferior. */
827 linux_nat_pass_signals (int numsigs
, unsigned char *pass_signals
)
831 sigemptyset (&pass_mask
);
833 for (signo
= 1; signo
< NSIG
; signo
++)
835 int target_signo
= gdb_signal_from_host (signo
);
836 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
837 sigaddset (&pass_mask
, signo
);
843 /* Prototypes for local functions. */
844 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
845 static int linux_thread_alive (ptid_t ptid
);
846 static char *linux_child_pid_to_exec_file (int pid
);
849 /* Convert wait status STATUS to a string. Used for printing debug
853 status_to_str (int status
)
857 if (WIFSTOPPED (status
))
859 if (WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
860 snprintf (buf
, sizeof (buf
), "%s (stopped at syscall)",
861 strsignal (SIGTRAP
));
863 snprintf (buf
, sizeof (buf
), "%s (stopped)",
864 strsignal (WSTOPSIG (status
)));
866 else if (WIFSIGNALED (status
))
867 snprintf (buf
, sizeof (buf
), "%s (terminated)",
868 strsignal (WTERMSIG (status
)));
870 snprintf (buf
, sizeof (buf
), "%d (exited)", WEXITSTATUS (status
));
875 /* Destroy and free LP. */
878 lwp_free (struct lwp_info
*lp
)
880 xfree (lp
->arch_private
);
884 /* Remove all LWPs belong to PID from the lwp list. */
887 purge_lwp_list (int pid
)
889 struct lwp_info
*lp
, *lpprev
, *lpnext
;
893 for (lp
= lwp_list
; lp
; lp
= lpnext
)
897 if (ptid_get_pid (lp
->ptid
) == pid
)
902 lpprev
->next
= lp
->next
;
911 /* Add the LWP specified by PTID to the list. PTID is the first LWP
912 in the process. Return a pointer to the structure describing the
915 This differs from add_lwp in that we don't let the arch specific
916 bits know about this new thread. Current clients of this callback
917 take the opportunity to install watchpoints in the new thread, and
918 we shouldn't do that for the first thread. If we're spawning a
919 child ("run"), the thread executes the shell wrapper first, and we
920 shouldn't touch it until it execs the program we want to debug.
921 For "attach", it'd be okay to call the callback, but it's not
922 necessary, because watchpoints can't yet have been inserted into
925 static struct lwp_info
*
926 add_initial_lwp (ptid_t ptid
)
930 gdb_assert (ptid_lwp_p (ptid
));
932 lp
= (struct lwp_info
*) xmalloc (sizeof (struct lwp_info
));
934 memset (lp
, 0, sizeof (struct lwp_info
));
936 lp
->last_resume_kind
= resume_continue
;
937 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
948 /* Add the LWP specified by PID to the list. Return a pointer to the
949 structure describing the new LWP. The LWP should already be
952 static struct lwp_info
*
953 add_lwp (ptid_t ptid
)
957 lp
= add_initial_lwp (ptid
);
959 /* Let the arch specific bits know about this new thread. Current
960 clients of this callback take the opportunity to install
961 watchpoints in the new thread. We don't do this for the first
962 thread though. See add_initial_lwp. */
963 if (linux_nat_new_thread
!= NULL
)
964 linux_nat_new_thread (lp
);
969 /* Remove the LWP specified by PID from the list. */
972 delete_lwp (ptid_t ptid
)
974 struct lwp_info
*lp
, *lpprev
;
978 for (lp
= lwp_list
; lp
; lpprev
= lp
, lp
= lp
->next
)
979 if (ptid_equal (lp
->ptid
, ptid
))
986 lpprev
->next
= lp
->next
;
993 /* Return a pointer to the structure describing the LWP corresponding
994 to PID. If no corresponding LWP could be found, return NULL. */
996 static struct lwp_info
*
997 find_lwp_pid (ptid_t ptid
)
1002 if (ptid_lwp_p (ptid
))
1003 lwp
= ptid_get_lwp (ptid
);
1005 lwp
= ptid_get_pid (ptid
);
1007 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
1008 if (lwp
== ptid_get_lwp (lp
->ptid
))
1014 /* Call CALLBACK with its second argument set to DATA for every LWP in
1015 the list. If CALLBACK returns 1 for a particular LWP, return a
1016 pointer to the structure describing that LWP immediately.
1017 Otherwise return NULL. */
1020 iterate_over_lwps (ptid_t filter
,
1021 int (*callback
) (struct lwp_info
*, void *),
1024 struct lwp_info
*lp
, *lpnext
;
1026 for (lp
= lwp_list
; lp
; lp
= lpnext
)
1030 if (ptid_match (lp
->ptid
, filter
))
1032 if ((*callback
) (lp
, data
))
1040 /* Update our internal state when changing from one checkpoint to
1041 another indicated by NEW_PTID. We can only switch single-threaded
1042 applications, so we only create one new LWP, and the previous list
1046 linux_nat_switch_fork (ptid_t new_ptid
)
1048 struct lwp_info
*lp
;
1050 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1052 lp
= add_lwp (new_ptid
);
1055 /* This changes the thread's ptid while preserving the gdb thread
1056 num. Also changes the inferior pid, while preserving the
1058 thread_change_ptid (inferior_ptid
, new_ptid
);
1060 /* We've just told GDB core that the thread changed target id, but,
1061 in fact, it really is a different thread, with different register
1063 registers_changed ();
1066 /* Handle the exit of a single thread LP. */
1069 exit_lwp (struct lwp_info
*lp
)
1071 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1075 if (print_thread_events
)
1076 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1078 delete_thread (lp
->ptid
);
1081 delete_lwp (lp
->ptid
);
1084 /* Wait for the LWP specified by LP, which we have just attached to.
1085 Returns a wait status for that LWP, to cache. */
1088 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *cloned
,
1091 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1094 if (linux_proc_pid_is_stopped (pid
))
1096 if (debug_linux_nat
)
1097 fprintf_unfiltered (gdb_stdlog
,
1098 "LNPAW: Attaching to a stopped process\n");
1100 /* The process is definitely stopped. It is in a job control
1101 stop, unless the kernel predates the TASK_STOPPED /
1102 TASK_TRACED distinction, in which case it might be in a
1103 ptrace stop. Make sure it is in a ptrace stop; from there we
1104 can kill it, signal it, et cetera.
1106 First make sure there is a pending SIGSTOP. Since we are
1107 already attached, the process can not transition from stopped
1108 to running without a PTRACE_CONT; so we know this signal will
1109 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1110 probably already in the queue (unless this kernel is old
1111 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1112 is not an RT signal, it can only be queued once. */
1113 kill_lwp (pid
, SIGSTOP
);
1115 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1116 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1117 ptrace (PTRACE_CONT
, pid
, 0, 0);
1120 /* Make sure the initial process is stopped. The user-level threads
1121 layer might want to poke around in the inferior, and that won't
1122 work if things haven't stabilized yet. */
1123 new_pid
= my_waitpid (pid
, &status
, 0);
1124 if (new_pid
== -1 && errno
== ECHILD
)
1127 warning (_("%s is a cloned process"), target_pid_to_str (ptid
));
1129 /* Try again with __WCLONE to check cloned processes. */
1130 new_pid
= my_waitpid (pid
, &status
, __WCLONE
);
1134 gdb_assert (pid
== new_pid
);
1136 if (!WIFSTOPPED (status
))
1138 /* The pid we tried to attach has apparently just exited. */
1139 if (debug_linux_nat
)
1140 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1141 pid
, status_to_str (status
));
1145 if (WSTOPSIG (status
) != SIGSTOP
)
1148 if (debug_linux_nat
)
1149 fprintf_unfiltered (gdb_stdlog
,
1150 "LNPAW: Received %s after attaching\n",
1151 status_to_str (status
));
1157 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1158 the new LWP could not be attached, or 1 if we're already auto
1159 attached to this thread, but haven't processed the
1160 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1161 its existance, without considering it an error. */
1164 lin_lwp_attach_lwp (ptid_t ptid
)
1166 struct lwp_info
*lp
;
1169 gdb_assert (ptid_lwp_p (ptid
));
1171 lp
= find_lwp_pid (ptid
);
1172 lwpid
= ptid_get_lwp (ptid
);
1174 /* We assume that we're already attached to any LWP that has an id
1175 equal to the overall process id, and to any LWP that is already
1176 in our list of LWPs. If we're not seeing exit events from threads
1177 and we've had PID wraparound since we last tried to stop all threads,
1178 this assumption might be wrong; fortunately, this is very unlikely
1180 if (lwpid
!= ptid_get_pid (ptid
) && lp
== NULL
)
1182 int status
, cloned
= 0, signalled
= 0;
1184 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1186 if (linux_supports_tracefork ())
1188 /* If we haven't stopped all threads when we get here,
1189 we may have seen a thread listed in thread_db's list,
1190 but not processed the PTRACE_EVENT_CLONE yet. If
1191 that's the case, ignore this new thread, and let
1192 normal event handling discover it later. */
1193 if (in_pid_list_p (stopped_pids
, lwpid
))
1195 /* We've already seen this thread stop, but we
1196 haven't seen the PTRACE_EVENT_CLONE extended
1205 /* See if we've got a stop for this new child
1206 pending. If so, we're already attached. */
1207 new_pid
= my_waitpid (lwpid
, &status
, WNOHANG
);
1208 if (new_pid
== -1 && errno
== ECHILD
)
1209 new_pid
= my_waitpid (lwpid
, &status
, __WCLONE
| WNOHANG
);
1212 if (WIFSTOPPED (status
))
1213 add_to_pid_list (&stopped_pids
, lwpid
, status
);
1219 /* If we fail to attach to the thread, issue a warning,
1220 but continue. One way this can happen is if thread
1221 creation is interrupted; as of Linux kernel 2.6.19, a
1222 bug may place threads in the thread list and then fail
1224 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid
),
1225 safe_strerror (errno
));
1229 if (debug_linux_nat
)
1230 fprintf_unfiltered (gdb_stdlog
,
1231 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1232 target_pid_to_str (ptid
));
1234 status
= linux_nat_post_attach_wait (ptid
, 0, &cloned
, &signalled
);
1235 if (!WIFSTOPPED (status
))
1238 lp
= add_lwp (ptid
);
1240 lp
->cloned
= cloned
;
1241 lp
->signalled
= signalled
;
1242 if (WSTOPSIG (status
) != SIGSTOP
)
1245 lp
->status
= status
;
1248 target_post_attach (ptid_get_lwp (lp
->ptid
));
1250 if (debug_linux_nat
)
1252 fprintf_unfiltered (gdb_stdlog
,
1253 "LLAL: waitpid %s received %s\n",
1254 target_pid_to_str (ptid
),
1255 status_to_str (status
));
1260 /* We assume that the LWP representing the original process is
1261 already stopped. Mark it as stopped in the data structure
1262 that the GNU/linux ptrace layer uses to keep track of
1263 threads. Note that this won't have already been done since
1264 the main thread will have, we assume, been stopped by an
1265 attach from a different layer. */
1267 lp
= add_lwp (ptid
);
1271 lp
->last_resume_kind
= resume_stop
;
1276 linux_nat_create_inferior (struct target_ops
*ops
,
1277 char *exec_file
, char *allargs
, char **env
,
1280 #ifdef HAVE_PERSONALITY
1281 int personality_orig
= 0, personality_set
= 0;
1282 #endif /* HAVE_PERSONALITY */
1284 /* The fork_child mechanism is synchronous and calls target_wait, so
1285 we have to mask the async mode. */
1287 #ifdef HAVE_PERSONALITY
1288 if (disable_randomization
)
1291 personality_orig
= personality (0xffffffff);
1292 if (errno
== 0 && !(personality_orig
& ADDR_NO_RANDOMIZE
))
1294 personality_set
= 1;
1295 personality (personality_orig
| ADDR_NO_RANDOMIZE
);
1297 if (errno
!= 0 || (personality_set
1298 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE
)))
1299 warning (_("Error disabling address space randomization: %s"),
1300 safe_strerror (errno
));
1302 #endif /* HAVE_PERSONALITY */
1304 /* Make sure we report all signals during startup. */
1305 linux_nat_pass_signals (0, NULL
);
1307 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1309 #ifdef HAVE_PERSONALITY
1310 if (personality_set
)
1313 personality (personality_orig
);
1315 warning (_("Error restoring address space randomization: %s"),
1316 safe_strerror (errno
));
1318 #endif /* HAVE_PERSONALITY */
1322 linux_nat_attach (struct target_ops
*ops
, char *args
, int from_tty
)
1324 struct lwp_info
*lp
;
1327 volatile struct gdb_exception ex
;
1329 /* Make sure we report all signals during attach. */
1330 linux_nat_pass_signals (0, NULL
);
1332 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1334 linux_ops
->to_attach (ops
, args
, from_tty
);
1338 pid_t pid
= parse_pid_to_attach (args
);
1339 struct buffer buffer
;
1340 char *message
, *buffer_s
;
1342 message
= xstrdup (ex
.message
);
1343 make_cleanup (xfree
, message
);
1345 buffer_init (&buffer
);
1346 linux_ptrace_attach_warnings (pid
, &buffer
);
1348 buffer_grow_str0 (&buffer
, "");
1349 buffer_s
= buffer_finish (&buffer
);
1350 make_cleanup (xfree
, buffer_s
);
1352 throw_error (ex
.error
, "%s%s", buffer_s
, message
);
1355 /* The ptrace base target adds the main thread with (pid,0,0)
1356 format. Decorate it with lwp info. */
1357 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1358 ptid_get_pid (inferior_ptid
),
1360 thread_change_ptid (inferior_ptid
, ptid
);
1362 /* Add the initial process as the first LWP to the list. */
1363 lp
= add_initial_lwp (ptid
);
1365 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->cloned
,
1367 if (!WIFSTOPPED (status
))
1369 if (WIFEXITED (status
))
1371 int exit_code
= WEXITSTATUS (status
);
1373 target_terminal_ours ();
1374 target_mourn_inferior ();
1376 error (_("Unable to attach: program exited normally."));
1378 error (_("Unable to attach: program exited with code %d."),
1381 else if (WIFSIGNALED (status
))
1383 enum gdb_signal signo
;
1385 target_terminal_ours ();
1386 target_mourn_inferior ();
1388 signo
= gdb_signal_from_host (WTERMSIG (status
));
1389 error (_("Unable to attach: program terminated with signal "
1391 gdb_signal_to_name (signo
),
1392 gdb_signal_to_string (signo
));
1395 internal_error (__FILE__
, __LINE__
,
1396 _("unexpected status %d for PID %ld"),
1397 status
, (long) ptid_get_lwp (ptid
));
1402 /* Save the wait status to report later. */
1404 if (debug_linux_nat
)
1405 fprintf_unfiltered (gdb_stdlog
,
1406 "LNA: waitpid %ld, saving status %s\n",
1407 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1409 lp
->status
= status
;
1411 if (target_can_async_p ())
1412 target_async (inferior_event_handler
, 0);
1415 /* Get pending status of LP. */
1417 get_pending_status (struct lwp_info
*lp
, int *status
)
1419 enum gdb_signal signo
= GDB_SIGNAL_0
;
1421 /* If we paused threads momentarily, we may have stored pending
1422 events in lp->status or lp->waitstatus (see stop_wait_callback),
1423 and GDB core hasn't seen any signal for those threads.
1424 Otherwise, the last signal reported to the core is found in the
1425 thread object's stop_signal.
1427 There's a corner case that isn't handled here at present. Only
1428 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1429 stop_signal make sense as a real signal to pass to the inferior.
1430 Some catchpoint related events, like
1431 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1432 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1433 those traps are debug API (ptrace in our case) related and
1434 induced; the inferior wouldn't see them if it wasn't being
1435 traced. Hence, we should never pass them to the inferior, even
1436 when set to pass state. Since this corner case isn't handled by
1437 infrun.c when proceeding with a signal, for consistency, neither
1438 do we handle it here (or elsewhere in the file we check for
1439 signal pass state). Normally SIGTRAP isn't set to pass state, so
1440 this is really a corner case. */
1442 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1443 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1444 else if (lp
->status
)
1445 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1446 else if (non_stop
&& !is_executing (lp
->ptid
))
1448 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1450 signo
= tp
->suspend
.stop_signal
;
1454 struct target_waitstatus last
;
1457 get_last_target_status (&last_ptid
, &last
);
1459 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1461 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1463 signo
= tp
->suspend
.stop_signal
;
1469 if (signo
== GDB_SIGNAL_0
)
1471 if (debug_linux_nat
)
1472 fprintf_unfiltered (gdb_stdlog
,
1473 "GPT: lwp %s has no pending signal\n",
1474 target_pid_to_str (lp
->ptid
));
1476 else if (!signal_pass_state (signo
))
1478 if (debug_linux_nat
)
1479 fprintf_unfiltered (gdb_stdlog
,
1480 "GPT: lwp %s had signal %s, "
1481 "but it is in no pass state\n",
1482 target_pid_to_str (lp
->ptid
),
1483 gdb_signal_to_string (signo
));
1487 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1489 if (debug_linux_nat
)
1490 fprintf_unfiltered (gdb_stdlog
,
1491 "GPT: lwp %s has pending signal %s\n",
1492 target_pid_to_str (lp
->ptid
),
1493 gdb_signal_to_string (signo
));
1500 detach_callback (struct lwp_info
*lp
, void *data
)
1502 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1504 if (debug_linux_nat
&& lp
->status
)
1505 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1506 strsignal (WSTOPSIG (lp
->status
)),
1507 target_pid_to_str (lp
->ptid
));
1509 /* If there is a pending SIGSTOP, get rid of it. */
1512 if (debug_linux_nat
)
1513 fprintf_unfiltered (gdb_stdlog
,
1514 "DC: Sending SIGCONT to %s\n",
1515 target_pid_to_str (lp
->ptid
));
1517 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1521 /* We don't actually detach from the LWP that has an id equal to the
1522 overall process id just yet. */
1523 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1527 /* Pass on any pending signal for this LWP. */
1528 get_pending_status (lp
, &status
);
1530 if (linux_nat_prepare_to_resume
!= NULL
)
1531 linux_nat_prepare_to_resume (lp
);
1533 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1534 WSTOPSIG (status
)) < 0)
1535 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1536 safe_strerror (errno
));
1538 if (debug_linux_nat
)
1539 fprintf_unfiltered (gdb_stdlog
,
1540 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1541 target_pid_to_str (lp
->ptid
),
1542 strsignal (WSTOPSIG (status
)));
1544 delete_lwp (lp
->ptid
);
1551 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1555 struct lwp_info
*main_lwp
;
1557 pid
= ptid_get_pid (inferior_ptid
);
1559 /* Don't unregister from the event loop, as there may be other
1560 inferiors running. */
1562 /* Stop all threads before detaching. ptrace requires that the
1563 thread is stopped to sucessfully detach. */
1564 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1565 /* ... and wait until all of them have reported back that
1566 they're no longer running. */
1567 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1569 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1571 /* Only the initial process should be left right now. */
1572 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1574 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1576 /* Pass on any pending signal for the last LWP. */
1577 if ((args
== NULL
|| *args
== '\0')
1578 && get_pending_status (main_lwp
, &status
) != -1
1579 && WIFSTOPPED (status
))
1583 /* Put the signal number in ARGS so that inf_ptrace_detach will
1584 pass it along with PTRACE_DETACH. */
1586 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1588 if (debug_linux_nat
)
1589 fprintf_unfiltered (gdb_stdlog
,
1590 "LND: Sending signal %s to %s\n",
1592 target_pid_to_str (main_lwp
->ptid
));
1595 if (linux_nat_prepare_to_resume
!= NULL
)
1596 linux_nat_prepare_to_resume (main_lwp
);
1597 delete_lwp (main_lwp
->ptid
);
1599 if (forks_exist_p ())
1601 /* Multi-fork case. The current inferior_ptid is being detached
1602 from, but there are other viable forks to debug. Detach from
1603 the current fork, and context-switch to the first
1605 linux_fork_detach (args
, from_tty
);
1608 linux_ops
->to_detach (ops
, args
, from_tty
);
1614 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1618 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
1620 if (inf
->vfork_child
!= NULL
)
1622 if (debug_linux_nat
)
1623 fprintf_unfiltered (gdb_stdlog
,
1624 "RC: Not resuming %s (vfork parent)\n",
1625 target_pid_to_str (lp
->ptid
));
1627 else if (lp
->status
== 0
1628 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
1630 if (debug_linux_nat
)
1631 fprintf_unfiltered (gdb_stdlog
,
1632 "RC: Resuming sibling %s, %s, %s\n",
1633 target_pid_to_str (lp
->ptid
),
1634 (signo
!= GDB_SIGNAL_0
1635 ? strsignal (gdb_signal_to_host (signo
))
1637 step
? "step" : "resume");
1639 if (linux_nat_prepare_to_resume
!= NULL
)
1640 linux_nat_prepare_to_resume (lp
);
1641 linux_ops
->to_resume (linux_ops
,
1642 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1646 lp
->stopped_by_watchpoint
= 0;
1650 if (debug_linux_nat
)
1651 fprintf_unfiltered (gdb_stdlog
,
1652 "RC: Not resuming sibling %s (has pending)\n",
1653 target_pid_to_str (lp
->ptid
));
1658 if (debug_linux_nat
)
1659 fprintf_unfiltered (gdb_stdlog
,
1660 "RC: Not resuming sibling %s (not stopped)\n",
1661 target_pid_to_str (lp
->ptid
));
1665 /* Resume LWP, with the last stop signal, if it is in pass state. */
1668 linux_nat_resume_callback (struct lwp_info
*lp
, void *data
)
1670 enum gdb_signal signo
= GDB_SIGNAL_0
;
1674 struct thread_info
*thread
;
1676 thread
= find_thread_ptid (lp
->ptid
);
1679 if (signal_pass_state (thread
->suspend
.stop_signal
))
1680 signo
= thread
->suspend
.stop_signal
;
1681 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1685 resume_lwp (lp
, 0, signo
);
1690 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1693 lp
->last_resume_kind
= resume_stop
;
1698 resume_set_callback (struct lwp_info
*lp
, void *data
)
1701 lp
->last_resume_kind
= resume_continue
;
1706 linux_nat_resume (struct target_ops
*ops
,
1707 ptid_t ptid
, int step
, enum gdb_signal signo
)
1709 struct lwp_info
*lp
;
1712 if (debug_linux_nat
)
1713 fprintf_unfiltered (gdb_stdlog
,
1714 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1715 step
? "step" : "resume",
1716 target_pid_to_str (ptid
),
1717 (signo
!= GDB_SIGNAL_0
1718 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1719 target_pid_to_str (inferior_ptid
));
1721 /* A specific PTID means `step only this process id'. */
1722 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1723 || ptid_is_pid (ptid
));
1725 /* Mark the lwps we're resuming as resumed. */
1726 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1728 /* See if it's the current inferior that should be handled
1731 lp
= find_lwp_pid (inferior_ptid
);
1733 lp
= find_lwp_pid (ptid
);
1734 gdb_assert (lp
!= NULL
);
1736 /* Remember if we're stepping. */
1738 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1740 /* If we have a pending wait status for this thread, there is no
1741 point in resuming the process. But first make sure that
1742 linux_nat_wait won't preemptively handle the event - we
1743 should never take this short-circuit if we are going to
1744 leave LP running, since we have skipped resuming all the
1745 other threads. This bit of code needs to be synchronized
1746 with linux_nat_wait. */
1748 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1751 && WSTOPSIG (lp
->status
)
1752 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1754 if (debug_linux_nat
)
1755 fprintf_unfiltered (gdb_stdlog
,
1756 "LLR: Not short circuiting for ignored "
1757 "status 0x%x\n", lp
->status
);
1759 /* FIXME: What should we do if we are supposed to continue
1760 this thread with a signal? */
1761 gdb_assert (signo
== GDB_SIGNAL_0
);
1762 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1767 if (lp
->status
|| lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1769 /* FIXME: What should we do if we are supposed to continue
1770 this thread with a signal? */
1771 gdb_assert (signo
== GDB_SIGNAL_0
);
1773 if (debug_linux_nat
)
1774 fprintf_unfiltered (gdb_stdlog
,
1775 "LLR: Short circuiting for status 0x%x\n",
1778 if (target_can_async_p ())
1780 target_async (inferior_event_handler
, 0);
1781 /* Tell the event loop we have something to process. */
1787 /* Mark LWP as not stopped to prevent it from being continued by
1788 linux_nat_resume_callback. */
1792 iterate_over_lwps (ptid
, linux_nat_resume_callback
, NULL
);
1794 /* Convert to something the lower layer understands. */
1795 ptid
= pid_to_ptid (ptid_get_lwp (lp
->ptid
));
1797 if (linux_nat_prepare_to_resume
!= NULL
)
1798 linux_nat_prepare_to_resume (lp
);
1799 linux_ops
->to_resume (linux_ops
, ptid
, step
, signo
);
1800 lp
->stopped_by_watchpoint
= 0;
1802 if (debug_linux_nat
)
1803 fprintf_unfiltered (gdb_stdlog
,
1804 "LLR: %s %s, %s (resume event thread)\n",
1805 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1806 target_pid_to_str (ptid
),
1807 (signo
!= GDB_SIGNAL_0
1808 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1810 if (target_can_async_p ())
1811 target_async (inferior_event_handler
, 0);
1814 /* Send a signal to an LWP. */
1817 kill_lwp (int lwpid
, int signo
)
1819 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1820 fails, then we are not using nptl threads and we should be using kill. */
1822 #ifdef HAVE_TKILL_SYSCALL
1824 static int tkill_failed
;
1831 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1832 if (errno
!= ENOSYS
)
1839 return kill (lwpid
, signo
);
1842 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1843 event, check if the core is interested in it: if not, ignore the
1844 event, and keep waiting; otherwise, we need to toggle the LWP's
1845 syscall entry/exit status, since the ptrace event itself doesn't
1846 indicate it, and report the trap to higher layers. */
1849 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1851 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1852 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1853 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1857 /* If we're stopping threads, there's a SIGSTOP pending, which
1858 makes it so that the LWP reports an immediate syscall return,
1859 followed by the SIGSTOP. Skip seeing that "return" using
1860 PTRACE_CONT directly, and let stop_wait_callback collect the
1861 SIGSTOP. Later when the thread is resumed, a new syscall
1862 entry event. If we didn't do this (and returned 0), we'd
1863 leave a syscall entry pending, and our caller, by using
1864 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1865 itself. Later, when the user re-resumes this LWP, we'd see
1866 another syscall entry event and we'd mistake it for a return.
1868 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1869 (leaving immediately with LWP->signalled set, without issuing
1870 a PTRACE_CONT), it would still be problematic to leave this
1871 syscall enter pending, as later when the thread is resumed,
1872 it would then see the same syscall exit mentioned above,
1873 followed by the delayed SIGSTOP, while the syscall didn't
1874 actually get to execute. It seems it would be even more
1875 confusing to the user. */
1877 if (debug_linux_nat
)
1878 fprintf_unfiltered (gdb_stdlog
,
1879 "LHST: ignoring syscall %d "
1880 "for LWP %ld (stopping threads), "
1881 "resuming with PTRACE_CONT for SIGSTOP\n",
1883 ptid_get_lwp (lp
->ptid
));
1885 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1886 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1890 if (catch_syscall_enabled ())
1892 /* Always update the entry/return state, even if this particular
1893 syscall isn't interesting to the core now. In async mode,
1894 the user could install a new catchpoint for this syscall
1895 between syscall enter/return, and we'll need to know to
1896 report a syscall return if that happens. */
1897 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1898 ? TARGET_WAITKIND_SYSCALL_RETURN
1899 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1901 if (catching_syscall_number (syscall_number
))
1903 /* Alright, an event to report. */
1904 ourstatus
->kind
= lp
->syscall_state
;
1905 ourstatus
->value
.syscall_number
= syscall_number
;
1907 if (debug_linux_nat
)
1908 fprintf_unfiltered (gdb_stdlog
,
1909 "LHST: stopping for %s of syscall %d"
1912 == TARGET_WAITKIND_SYSCALL_ENTRY
1913 ? "entry" : "return",
1915 ptid_get_lwp (lp
->ptid
));
1919 if (debug_linux_nat
)
1920 fprintf_unfiltered (gdb_stdlog
,
1921 "LHST: ignoring %s of syscall %d "
1923 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1924 ? "entry" : "return",
1926 ptid_get_lwp (lp
->ptid
));
1930 /* If we had been syscall tracing, and hence used PT_SYSCALL
1931 before on this LWP, it could happen that the user removes all
1932 syscall catchpoints before we get to process this event.
1933 There are two noteworthy issues here:
1935 - When stopped at a syscall entry event, resuming with
1936 PT_STEP still resumes executing the syscall and reports a
1939 - Only PT_SYSCALL catches syscall enters. If we last
1940 single-stepped this thread, then this event can't be a
1941 syscall enter. If we last single-stepped this thread, this
1942 has to be a syscall exit.
1944 The points above mean that the next resume, be it PT_STEP or
1945 PT_CONTINUE, can not trigger a syscall trace event. */
1946 if (debug_linux_nat
)
1947 fprintf_unfiltered (gdb_stdlog
,
1948 "LHST: caught syscall event "
1949 "with no syscall catchpoints."
1950 " %d for LWP %ld, ignoring\n",
1952 ptid_get_lwp (lp
->ptid
));
1953 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1956 /* The core isn't interested in this event. For efficiency, avoid
1957 stopping all threads only to have the core resume them all again.
1958 Since we're not stopping threads, if we're still syscall tracing
1959 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1960 subsequent syscall. Simply resume using the inf-ptrace layer,
1961 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1963 /* Note that gdbarch_get_syscall_number may access registers, hence
1965 registers_changed ();
1966 if (linux_nat_prepare_to_resume
!= NULL
)
1967 linux_nat_prepare_to_resume (lp
);
1968 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
1969 lp
->step
, GDB_SIGNAL_0
);
1973 /* Handle a GNU/Linux extended wait response. If we see a clone
1974 event, we need to add the new LWP to our list (and not report the
1975 trap to higher layers). This function returns non-zero if the
1976 event should be ignored and we should wait again. If STOPPING is
1977 true, the new LWP remains stopped, otherwise it is continued. */
1980 linux_handle_extended_wait (struct lwp_info
*lp
, int status
,
1983 int pid
= ptid_get_lwp (lp
->ptid
);
1984 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1985 int event
= status
>> 16;
1987 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1988 || event
== PTRACE_EVENT_CLONE
)
1990 unsigned long new_pid
;
1993 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1995 /* If we haven't already seen the new PID stop, wait for it now. */
1996 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1998 /* The new child has a pending SIGSTOP. We can't affect it until it
1999 hits the SIGSTOP, but we're already attached. */
2000 ret
= my_waitpid (new_pid
, &status
,
2001 (event
== PTRACE_EVENT_CLONE
) ? __WCLONE
: 0);
2003 perror_with_name (_("waiting for new child"));
2004 else if (ret
!= new_pid
)
2005 internal_error (__FILE__
, __LINE__
,
2006 _("wait returned unexpected PID %d"), ret
);
2007 else if (!WIFSTOPPED (status
))
2008 internal_error (__FILE__
, __LINE__
,
2009 _("wait returned unexpected status 0x%x"), status
);
2012 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
2014 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
2016 /* The arch-specific native code may need to know about new
2017 forks even if those end up never mapped to an
2019 if (linux_nat_new_fork
!= NULL
)
2020 linux_nat_new_fork (lp
, new_pid
);
2023 if (event
== PTRACE_EVENT_FORK
2024 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
2026 /* Handle checkpointing by linux-fork.c here as a special
2027 case. We don't want the follow-fork-mode or 'catch fork'
2028 to interfere with this. */
2030 /* This won't actually modify the breakpoint list, but will
2031 physically remove the breakpoints from the child. */
2032 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
2034 /* Retain child fork in ptrace (stopped) state. */
2035 if (!find_fork_pid (new_pid
))
2038 /* Report as spurious, so that infrun doesn't want to follow
2039 this fork. We're actually doing an infcall in
2041 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
2043 /* Report the stop to the core. */
2047 if (event
== PTRACE_EVENT_FORK
)
2048 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
2049 else if (event
== PTRACE_EVENT_VFORK
)
2050 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
2053 struct lwp_info
*new_lp
;
2055 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2057 if (debug_linux_nat
)
2058 fprintf_unfiltered (gdb_stdlog
,
2059 "LHEW: Got clone event "
2060 "from LWP %d, new child is LWP %ld\n",
2063 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
2065 new_lp
->stopped
= 1;
2067 if (WSTOPSIG (status
) != SIGSTOP
)
2069 /* This can happen if someone starts sending signals to
2070 the new thread before it gets a chance to run, which
2071 have a lower number than SIGSTOP (e.g. SIGUSR1).
2072 This is an unlikely case, and harder to handle for
2073 fork / vfork than for clone, so we do not try - but
2074 we handle it for clone events here. We'll send
2075 the other signal on to the thread below. */
2077 new_lp
->signalled
= 1;
2081 struct thread_info
*tp
;
2083 /* When we stop for an event in some other thread, and
2084 pull the thread list just as this thread has cloned,
2085 we'll have seen the new thread in the thread_db list
2086 before handling the CLONE event (glibc's
2087 pthread_create adds the new thread to the thread list
2088 before clone'ing, and has the kernel fill in the
2089 thread's tid on the clone call with
2090 CLONE_PARENT_SETTID). If that happened, and the core
2091 had requested the new thread to stop, we'll have
2092 killed it with SIGSTOP. But since SIGSTOP is not an
2093 RT signal, it can only be queued once. We need to be
2094 careful to not resume the LWP if we wanted it to
2095 stop. In that case, we'll leave the SIGSTOP pending.
2096 It will later be reported as GDB_SIGNAL_0. */
2097 tp
= find_thread_ptid (new_lp
->ptid
);
2098 if (tp
!= NULL
&& tp
->stop_requested
)
2099 new_lp
->last_resume_kind
= resume_stop
;
2106 /* Add the new thread to GDB's lists as soon as possible
2109 1) the frontend doesn't have to wait for a stop to
2112 2) we tag it with the correct running state. */
2114 /* If the thread_db layer is active, let it know about
2115 this new thread, and add it to GDB's list. */
2116 if (!thread_db_attach_lwp (new_lp
->ptid
))
2118 /* We're not using thread_db. Add it to GDB's
2120 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2121 add_thread (new_lp
->ptid
);
2126 set_running (new_lp
->ptid
, 1);
2127 set_executing (new_lp
->ptid
, 1);
2128 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2130 new_lp
->last_resume_kind
= resume_continue
;
2136 /* We created NEW_LP so it cannot yet contain STATUS. */
2137 gdb_assert (new_lp
->status
== 0);
2139 /* Save the wait status to report later. */
2140 if (debug_linux_nat
)
2141 fprintf_unfiltered (gdb_stdlog
,
2142 "LHEW: waitpid of new LWP %ld, "
2143 "saving status %s\n",
2144 (long) ptid_get_lwp (new_lp
->ptid
),
2145 status_to_str (status
));
2146 new_lp
->status
= status
;
2149 /* Note the need to use the low target ops to resume, to
2150 handle resuming with PT_SYSCALL if we have syscall
2154 new_lp
->resumed
= 1;
2158 gdb_assert (new_lp
->last_resume_kind
== resume_continue
);
2159 if (debug_linux_nat
)
2160 fprintf_unfiltered (gdb_stdlog
,
2161 "LHEW: resuming new LWP %ld\n",
2162 ptid_get_lwp (new_lp
->ptid
));
2163 if (linux_nat_prepare_to_resume
!= NULL
)
2164 linux_nat_prepare_to_resume (new_lp
);
2165 linux_ops
->to_resume (linux_ops
, pid_to_ptid (new_pid
),
2167 new_lp
->stopped
= 0;
2171 if (debug_linux_nat
)
2172 fprintf_unfiltered (gdb_stdlog
,
2173 "LHEW: resuming parent LWP %d\n", pid
);
2174 if (linux_nat_prepare_to_resume
!= NULL
)
2175 linux_nat_prepare_to_resume (lp
);
2176 linux_ops
->to_resume (linux_ops
,
2177 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
2186 if (event
== PTRACE_EVENT_EXEC
)
2188 if (debug_linux_nat
)
2189 fprintf_unfiltered (gdb_stdlog
,
2190 "LHEW: Got exec event from LWP %ld\n",
2191 ptid_get_lwp (lp
->ptid
));
2193 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2194 ourstatus
->value
.execd_pathname
2195 = xstrdup (linux_child_pid_to_exec_file (pid
));
2200 if (event
== PTRACE_EVENT_VFORK_DONE
)
2202 if (current_inferior ()->waiting_for_vfork_done
)
2204 if (debug_linux_nat
)
2205 fprintf_unfiltered (gdb_stdlog
,
2206 "LHEW: Got expected PTRACE_EVENT_"
2207 "VFORK_DONE from LWP %ld: stopping\n",
2208 ptid_get_lwp (lp
->ptid
));
2210 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2214 if (debug_linux_nat
)
2215 fprintf_unfiltered (gdb_stdlog
,
2216 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2217 "from LWP %ld: resuming\n",
2218 ptid_get_lwp (lp
->ptid
));
2219 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2223 internal_error (__FILE__
, __LINE__
,
2224 _("unknown ptrace event %d"), event
);
2227 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2231 wait_lwp (struct lwp_info
*lp
)
2235 int thread_dead
= 0;
2238 gdb_assert (!lp
->stopped
);
2239 gdb_assert (lp
->status
== 0);
2241 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2242 block_child_signals (&prev_mask
);
2246 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2247 was right and we should just call sigsuspend. */
2249 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, WNOHANG
);
2250 if (pid
== -1 && errno
== ECHILD
)
2251 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WCLONE
| WNOHANG
);
2252 if (pid
== -1 && errno
== ECHILD
)
2254 /* The thread has previously exited. We need to delete it
2255 now because, for some vendor 2.4 kernels with NPTL
2256 support backported, there won't be an exit event unless
2257 it is the main thread. 2.6 kernels will report an exit
2258 event for each thread that exits, as expected. */
2260 if (debug_linux_nat
)
2261 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2262 target_pid_to_str (lp
->ptid
));
2267 /* Bugs 10970, 12702.
2268 Thread group leader may have exited in which case we'll lock up in
2269 waitpid if there are other threads, even if they are all zombies too.
2270 Basically, we're not supposed to use waitpid this way.
2271 __WCLONE is not applicable for the leader so we can't use that.
2272 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2273 process; it gets ESRCH both for the zombie and for running processes.
2275 As a workaround, check if we're waiting for the thread group leader and
2276 if it's a zombie, and avoid calling waitpid if it is.
2278 This is racy, what if the tgl becomes a zombie right after we check?
2279 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2280 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2282 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2283 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2286 if (debug_linux_nat
)
2287 fprintf_unfiltered (gdb_stdlog
,
2288 "WL: Thread group leader %s vanished.\n",
2289 target_pid_to_str (lp
->ptid
));
2293 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2294 get invoked despite our caller had them intentionally blocked by
2295 block_child_signals. This is sensitive only to the loop of
2296 linux_nat_wait_1 and there if we get called my_waitpid gets called
2297 again before it gets to sigsuspend so we can safely let the handlers
2298 get executed here. */
2300 sigsuspend (&suspend_mask
);
2303 restore_child_signals_mask (&prev_mask
);
2307 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2309 if (debug_linux_nat
)
2311 fprintf_unfiltered (gdb_stdlog
,
2312 "WL: waitpid %s received %s\n",
2313 target_pid_to_str (lp
->ptid
),
2314 status_to_str (status
));
2317 /* Check if the thread has exited. */
2318 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2321 if (debug_linux_nat
)
2322 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2323 target_pid_to_str (lp
->ptid
));
2333 gdb_assert (WIFSTOPPED (status
));
2335 /* Handle GNU/Linux's syscall SIGTRAPs. */
2336 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2338 /* No longer need the sysgood bit. The ptrace event ends up
2339 recorded in lp->waitstatus if we care for it. We can carry
2340 on handling the event like a regular SIGTRAP from here
2342 status
= W_STOPCODE (SIGTRAP
);
2343 if (linux_handle_syscall_trap (lp
, 1))
2344 return wait_lwp (lp
);
2347 /* Handle GNU/Linux's extended waitstatus for trace events. */
2348 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2350 if (debug_linux_nat
)
2351 fprintf_unfiltered (gdb_stdlog
,
2352 "WL: Handling extended status 0x%06x\n",
2354 if (linux_handle_extended_wait (lp
, status
, 1))
2355 return wait_lwp (lp
);
2361 /* Send a SIGSTOP to LP. */
2364 stop_callback (struct lwp_info
*lp
, void *data
)
2366 if (!lp
->stopped
&& !lp
->signalled
)
2370 if (debug_linux_nat
)
2372 fprintf_unfiltered (gdb_stdlog
,
2373 "SC: kill %s **<SIGSTOP>**\n",
2374 target_pid_to_str (lp
->ptid
));
2377 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2378 if (debug_linux_nat
)
2380 fprintf_unfiltered (gdb_stdlog
,
2381 "SC: lwp kill %d %s\n",
2383 errno
? safe_strerror (errno
) : "ERRNO-OK");
2387 gdb_assert (lp
->status
== 0);
2393 /* Request a stop on LWP. */
2396 linux_stop_lwp (struct lwp_info
*lwp
)
2398 stop_callback (lwp
, NULL
);
2401 /* Return non-zero if LWP PID has a pending SIGINT. */
2404 linux_nat_has_pending_sigint (int pid
)
2406 sigset_t pending
, blocked
, ignored
;
2408 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2410 if (sigismember (&pending
, SIGINT
)
2411 && !sigismember (&ignored
, SIGINT
))
2417 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2420 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2422 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2423 flag to consume the next one. */
2424 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2425 && WSTOPSIG (lp
->status
) == SIGINT
)
2428 lp
->ignore_sigint
= 1;
2433 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2434 This function is called after we know the LWP has stopped; if the LWP
2435 stopped before the expected SIGINT was delivered, then it will never have
2436 arrived. Also, if the signal was delivered to a shared queue and consumed
2437 by a different thread, it will never be delivered to this LWP. */
2440 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2442 if (!lp
->ignore_sigint
)
2445 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2447 if (debug_linux_nat
)
2448 fprintf_unfiltered (gdb_stdlog
,
2449 "MCIS: Clearing bogus flag for %s\n",
2450 target_pid_to_str (lp
->ptid
));
2451 lp
->ignore_sigint
= 0;
2455 /* Fetch the possible triggered data watchpoint info and store it in
2458 On some archs, like x86, that use debug registers to set
2459 watchpoints, it's possible that the way to know which watched
2460 address trapped, is to check the register that is used to select
2461 which address to watch. Problem is, between setting the watchpoint
2462 and reading back which data address trapped, the user may change
2463 the set of watchpoints, and, as a consequence, GDB changes the
2464 debug registers in the inferior. To avoid reading back a stale
2465 stopped-data-address when that happens, we cache in LP the fact
2466 that a watchpoint trapped, and the corresponding data address, as
2467 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2468 registers meanwhile, we have the cached data we can rely on. */
2471 save_sigtrap (struct lwp_info
*lp
)
2473 struct cleanup
*old_chain
;
2475 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2477 lp
->stopped_by_watchpoint
= 0;
2481 old_chain
= save_inferior_ptid ();
2482 inferior_ptid
= lp
->ptid
;
2484 lp
->stopped_by_watchpoint
= linux_ops
->to_stopped_by_watchpoint (linux_ops
);
2486 if (lp
->stopped_by_watchpoint
)
2488 if (linux_ops
->to_stopped_data_address
!= NULL
)
2489 lp
->stopped_data_address_p
=
2490 linux_ops
->to_stopped_data_address (¤t_target
,
2491 &lp
->stopped_data_address
);
2493 lp
->stopped_data_address_p
= 0;
2496 do_cleanups (old_chain
);
2499 /* See save_sigtrap. */
2502 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2504 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2506 gdb_assert (lp
!= NULL
);
2508 return lp
->stopped_by_watchpoint
;
2512 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2514 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2516 gdb_assert (lp
!= NULL
);
2518 *addr_p
= lp
->stopped_data_address
;
2520 return lp
->stopped_data_address_p
;
2523 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2526 sigtrap_is_event (int status
)
2528 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2531 /* SIGTRAP-like events recognizer. */
2533 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
2535 /* Check for SIGTRAP-like events in LP. */
2538 linux_nat_lp_status_is_event (struct lwp_info
*lp
)
2540 /* We check for lp->waitstatus in addition to lp->status, because we can
2541 have pending process exits recorded in lp->status
2542 and W_EXITCODE(0,0) == 0. We should probably have an additional
2543 lp->status_p flag. */
2545 return (lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
2546 && linux_nat_status_is_event (lp
->status
));
2549 /* Set alternative SIGTRAP-like events recognizer. If
2550 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2554 linux_nat_set_status_is_event (struct target_ops
*t
,
2555 int (*status_is_event
) (int status
))
2557 linux_nat_status_is_event
= status_is_event
;
2560 /* Wait until LP is stopped. */
2563 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2565 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2567 /* If this is a vfork parent, bail out, it is not going to report
2568 any SIGSTOP until the vfork is done with. */
2569 if (inf
->vfork_child
!= NULL
)
2576 status
= wait_lwp (lp
);
2580 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2581 && WSTOPSIG (status
) == SIGINT
)
2583 lp
->ignore_sigint
= 0;
2586 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2587 if (debug_linux_nat
)
2588 fprintf_unfiltered (gdb_stdlog
,
2589 "PTRACE_CONT %s, 0, 0 (%s) "
2590 "(discarding SIGINT)\n",
2591 target_pid_to_str (lp
->ptid
),
2592 errno
? safe_strerror (errno
) : "OK");
2594 return stop_wait_callback (lp
, NULL
);
2597 maybe_clear_ignore_sigint (lp
);
2599 if (WSTOPSIG (status
) != SIGSTOP
)
2601 /* The thread was stopped with a signal other than SIGSTOP. */
2605 if (debug_linux_nat
)
2606 fprintf_unfiltered (gdb_stdlog
,
2607 "SWC: Pending event %s in %s\n",
2608 status_to_str ((int) status
),
2609 target_pid_to_str (lp
->ptid
));
2611 /* Save the sigtrap event. */
2612 lp
->status
= status
;
2613 gdb_assert (!lp
->stopped
);
2614 gdb_assert (lp
->signalled
);
2619 /* We caught the SIGSTOP that we intended to catch, so
2620 there's no SIGSTOP pending. */
2622 if (debug_linux_nat
)
2623 fprintf_unfiltered (gdb_stdlog
,
2624 "SWC: Delayed SIGSTOP caught for %s.\n",
2625 target_pid_to_str (lp
->ptid
));
2629 /* Reset SIGNALLED only after the stop_wait_callback call
2630 above as it does gdb_assert on SIGNALLED. */
2638 /* Return non-zero if LP has a wait status pending. */
2641 status_callback (struct lwp_info
*lp
, void *data
)
2643 /* Only report a pending wait status if we pretend that this has
2644 indeed been resumed. */
2648 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2650 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2651 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2652 0', so a clean process exit can not be stored pending in
2653 lp->status, it is indistinguishable from
2654 no-pending-status. */
2658 if (lp
->status
!= 0)
2664 /* Return non-zero if LP isn't stopped. */
2667 running_callback (struct lwp_info
*lp
, void *data
)
2669 return (!lp
->stopped
2670 || ((lp
->status
!= 0
2671 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
2675 /* Count the LWP's that have had events. */
2678 count_events_callback (struct lwp_info
*lp
, void *data
)
2682 gdb_assert (count
!= NULL
);
2684 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2685 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2691 /* Select the LWP (if any) that is currently being single-stepped. */
2694 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2696 if (lp
->last_resume_kind
== resume_step
2703 /* Select the Nth LWP that has had a SIGTRAP event. */
2706 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2708 int *selector
= data
;
2710 gdb_assert (selector
!= NULL
);
2712 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2713 if (lp
->resumed
&& linux_nat_lp_status_is_event (lp
))
2714 if ((*selector
)-- == 0)
2721 cancel_breakpoint (struct lwp_info
*lp
)
2723 /* Arrange for a breakpoint to be hit again later. We don't keep
2724 the SIGTRAP status and don't forward the SIGTRAP signal to the
2725 LWP. We will handle the current event, eventually we will resume
2726 this LWP, and this breakpoint will trap again.
2728 If we do not do this, then we run the risk that the user will
2729 delete or disable the breakpoint, but the LWP will have already
2732 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2733 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
2736 pc
= regcache_read_pc (regcache
) - target_decr_pc_after_break (gdbarch
);
2737 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2739 if (debug_linux_nat
)
2740 fprintf_unfiltered (gdb_stdlog
,
2741 "CB: Push back breakpoint for %s\n",
2742 target_pid_to_str (lp
->ptid
));
2744 /* Back up the PC if necessary. */
2745 if (target_decr_pc_after_break (gdbarch
))
2746 regcache_write_pc (regcache
, pc
);
2754 cancel_breakpoints_callback (struct lwp_info
*lp
, void *data
)
2756 struct lwp_info
*event_lp
= data
;
2758 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2762 /* If a LWP other than the LWP that we're reporting an event for has
2763 hit a GDB breakpoint (as opposed to some random trap signal),
2764 then just arrange for it to hit it again later. We don't keep
2765 the SIGTRAP status and don't forward the SIGTRAP signal to the
2766 LWP. We will handle the current event, eventually we will resume
2767 all LWPs, and this one will get its breakpoint trap again.
2769 If we do not do this, then we run the risk that the user will
2770 delete or disable the breakpoint, but the LWP will have already
2773 if (linux_nat_lp_status_is_event (lp
)
2774 && cancel_breakpoint (lp
))
2775 /* Throw away the SIGTRAP. */
2781 /* Select one LWP out of those that have events pending. */
2784 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2787 int random_selector
;
2788 struct lwp_info
*event_lp
;
2790 /* Record the wait status for the original LWP. */
2791 (*orig_lp
)->status
= *status
;
2793 /* Give preference to any LWP that is being single-stepped. */
2794 event_lp
= iterate_over_lwps (filter
,
2795 select_singlestep_lwp_callback
, NULL
);
2796 if (event_lp
!= NULL
)
2798 if (debug_linux_nat
)
2799 fprintf_unfiltered (gdb_stdlog
,
2800 "SEL: Select single-step %s\n",
2801 target_pid_to_str (event_lp
->ptid
));
2805 /* No single-stepping LWP. Select one at random, out of those
2806 which have had SIGTRAP events. */
2808 /* First see how many SIGTRAP events we have. */
2809 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2811 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2812 random_selector
= (int)
2813 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2815 if (debug_linux_nat
&& num_events
> 1)
2816 fprintf_unfiltered (gdb_stdlog
,
2817 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2818 num_events
, random_selector
);
2820 event_lp
= iterate_over_lwps (filter
,
2821 select_event_lwp_callback
,
2825 if (event_lp
!= NULL
)
2827 /* Switch the event LWP. */
2828 *orig_lp
= event_lp
;
2829 *status
= event_lp
->status
;
2832 /* Flush the wait status for the event LWP. */
2833 (*orig_lp
)->status
= 0;
2836 /* Return non-zero if LP has been resumed. */
2839 resumed_callback (struct lwp_info
*lp
, void *data
)
2844 /* Stop an active thread, verify it still exists, then resume it. If
2845 the thread ends up with a pending status, then it is not resumed,
2846 and *DATA (really a pointer to int), is set. */
2849 stop_and_resume_callback (struct lwp_info
*lp
, void *data
)
2851 int *new_pending_p
= data
;
2855 ptid_t ptid
= lp
->ptid
;
2857 stop_callback (lp
, NULL
);
2858 stop_wait_callback (lp
, NULL
);
2860 /* Resume if the lwp still exists, and the core wanted it
2862 lp
= find_lwp_pid (ptid
);
2865 if (lp
->last_resume_kind
== resume_stop
2868 /* The core wanted the LWP to stop. Even if it stopped
2869 cleanly (with SIGSTOP), leave the event pending. */
2870 if (debug_linux_nat
)
2871 fprintf_unfiltered (gdb_stdlog
,
2872 "SARC: core wanted LWP %ld stopped "
2873 "(leaving SIGSTOP pending)\n",
2874 ptid_get_lwp (lp
->ptid
));
2875 lp
->status
= W_STOPCODE (SIGSTOP
);
2878 if (lp
->status
== 0)
2880 if (debug_linux_nat
)
2881 fprintf_unfiltered (gdb_stdlog
,
2882 "SARC: re-resuming LWP %ld\n",
2883 ptid_get_lwp (lp
->ptid
));
2884 resume_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2888 if (debug_linux_nat
)
2889 fprintf_unfiltered (gdb_stdlog
,
2890 "SARC: not re-resuming LWP %ld "
2892 ptid_get_lwp (lp
->ptid
));
2901 /* Check if we should go on and pass this event to common code.
2902 Return the affected lwp if we are, or NULL otherwise. If we stop
2903 all lwps temporarily, we may end up with new pending events in some
2904 other lwp. In that case set *NEW_PENDING_P to true. */
2906 static struct lwp_info
*
2907 linux_nat_filter_event (int lwpid
, int status
, int *new_pending_p
)
2909 struct lwp_info
*lp
;
2913 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2915 /* Check for stop events reported by a process we didn't already
2916 know about - anything not already in our LWP list.
2918 If we're expecting to receive stopped processes after
2919 fork, vfork, and clone events, then we'll just add the
2920 new one to our list and go back to waiting for the event
2921 to be reported - the stopped process might be returned
2922 from waitpid before or after the event is.
2924 But note the case of a non-leader thread exec'ing after the
2925 leader having exited, and gone from our lists. The non-leader
2926 thread changes its tid to the tgid. */
2928 if (WIFSTOPPED (status
) && lp
== NULL
2929 && (WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 == PTRACE_EVENT_EXEC
))
2931 /* A multi-thread exec after we had seen the leader exiting. */
2932 if (debug_linux_nat
)
2933 fprintf_unfiltered (gdb_stdlog
,
2934 "LLW: Re-adding thread group leader LWP %d.\n",
2937 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2940 add_thread (lp
->ptid
);
2943 if (WIFSTOPPED (status
) && !lp
)
2945 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2949 /* Make sure we don't report an event for the exit of an LWP not in
2950 our list, i.e. not part of the current process. This can happen
2951 if we detach from a program we originally forked and then it
2953 if (!WIFSTOPPED (status
) && !lp
)
2956 /* Handle GNU/Linux's syscall SIGTRAPs. */
2957 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2959 /* No longer need the sysgood bit. The ptrace event ends up
2960 recorded in lp->waitstatus if we care for it. We can carry
2961 on handling the event like a regular SIGTRAP from here
2963 status
= W_STOPCODE (SIGTRAP
);
2964 if (linux_handle_syscall_trap (lp
, 0))
2968 /* Handle GNU/Linux's extended waitstatus for trace events. */
2969 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
&& status
>> 16 != 0)
2971 if (debug_linux_nat
)
2972 fprintf_unfiltered (gdb_stdlog
,
2973 "LLW: Handling extended status 0x%06x\n",
2975 if (linux_handle_extended_wait (lp
, status
, 0))
2979 if (linux_nat_status_is_event (status
))
2982 /* Check if the thread has exited. */
2983 if ((WIFEXITED (status
) || WIFSIGNALED (status
))
2984 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
2986 /* If this is the main thread, we must stop all threads and verify
2987 if they are still alive. This is because in the nptl thread model
2988 on Linux 2.4, there is no signal issued for exiting LWPs
2989 other than the main thread. We only get the main thread exit
2990 signal once all child threads have already exited. If we
2991 stop all the threads and use the stop_wait_callback to check
2992 if they have exited we can determine whether this signal
2993 should be ignored or whether it means the end of the debugged
2994 application, regardless of which threading model is being
2996 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2999 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3000 stop_and_resume_callback
, new_pending_p
);
3003 if (debug_linux_nat
)
3004 fprintf_unfiltered (gdb_stdlog
,
3005 "LLW: %s exited.\n",
3006 target_pid_to_str (lp
->ptid
));
3008 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3010 /* If there is at least one more LWP, then the exit signal
3011 was not the end of the debugged application and should be
3018 /* Check if the current LWP has previously exited. In the nptl
3019 thread model, LWPs other than the main thread do not issue
3020 signals when they exit so we must check whenever the thread has
3021 stopped. A similar check is made in stop_wait_callback(). */
3022 if (num_lwps (ptid_get_pid (lp
->ptid
)) > 1 && !linux_thread_alive (lp
->ptid
))
3024 ptid_t ptid
= pid_to_ptid (ptid_get_pid (lp
->ptid
));
3026 if (debug_linux_nat
)
3027 fprintf_unfiltered (gdb_stdlog
,
3028 "LLW: %s exited.\n",
3029 target_pid_to_str (lp
->ptid
));
3033 /* Make sure there is at least one thread running. */
3034 gdb_assert (iterate_over_lwps (ptid
, running_callback
, NULL
));
3036 /* Discard the event. */
3040 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3041 an attempt to stop an LWP. */
3043 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3045 if (debug_linux_nat
)
3046 fprintf_unfiltered (gdb_stdlog
,
3047 "LLW: Delayed SIGSTOP caught for %s.\n",
3048 target_pid_to_str (lp
->ptid
));
3052 if (lp
->last_resume_kind
!= resume_stop
)
3054 /* This is a delayed SIGSTOP. */
3056 registers_changed ();
3058 if (linux_nat_prepare_to_resume
!= NULL
)
3059 linux_nat_prepare_to_resume (lp
);
3060 linux_ops
->to_resume (linux_ops
,
3061 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3062 lp
->step
, GDB_SIGNAL_0
);
3063 if (debug_linux_nat
)
3064 fprintf_unfiltered (gdb_stdlog
,
3065 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3067 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3068 target_pid_to_str (lp
->ptid
));
3071 gdb_assert (lp
->resumed
);
3073 /* Discard the event. */
3078 /* Make sure we don't report a SIGINT that we have already displayed
3079 for another thread. */
3080 if (lp
->ignore_sigint
3081 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3083 if (debug_linux_nat
)
3084 fprintf_unfiltered (gdb_stdlog
,
3085 "LLW: Delayed SIGINT caught for %s.\n",
3086 target_pid_to_str (lp
->ptid
));
3088 /* This is a delayed SIGINT. */
3089 lp
->ignore_sigint
= 0;
3091 registers_changed ();
3092 if (linux_nat_prepare_to_resume
!= NULL
)
3093 linux_nat_prepare_to_resume (lp
);
3094 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3095 lp
->step
, GDB_SIGNAL_0
);
3096 if (debug_linux_nat
)
3097 fprintf_unfiltered (gdb_stdlog
,
3098 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3100 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3101 target_pid_to_str (lp
->ptid
));
3104 gdb_assert (lp
->resumed
);
3106 /* Discard the event. */
3110 /* An interesting event. */
3112 lp
->status
= status
;
3116 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3117 their exits until all other threads in the group have exited. */
3120 check_zombie_leaders (void)
3122 struct inferior
*inf
;
3126 struct lwp_info
*leader_lp
;
3131 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3132 if (leader_lp
!= NULL
3133 /* Check if there are other threads in the group, as we may
3134 have raced with the inferior simply exiting. */
3135 && num_lwps (inf
->pid
) > 1
3136 && linux_proc_pid_is_zombie (inf
->pid
))
3138 if (debug_linux_nat
)
3139 fprintf_unfiltered (gdb_stdlog
,
3140 "CZL: Thread group leader %d zombie "
3141 "(it exited, or another thread execd).\n",
3144 /* A leader zombie can mean one of two things:
3146 - It exited, and there's an exit status pending
3147 available, or only the leader exited (not the whole
3148 program). In the latter case, we can't waitpid the
3149 leader's exit status until all other threads are gone.
3151 - There are 3 or more threads in the group, and a thread
3152 other than the leader exec'd. On an exec, the Linux
3153 kernel destroys all other threads (except the execing
3154 one) in the thread group, and resets the execing thread's
3155 tid to the tgid. No exit notification is sent for the
3156 execing thread -- from the ptracer's perspective, it
3157 appears as though the execing thread just vanishes.
3158 Until we reap all other threads except the leader and the
3159 execing thread, the leader will be zombie, and the
3160 execing thread will be in `D (disc sleep)'. As soon as
3161 all other threads are reaped, the execing thread changes
3162 it's tid to the tgid, and the previous (zombie) leader
3163 vanishes, giving place to the "new" leader. We could try
3164 distinguishing the exit and exec cases, by waiting once
3165 more, and seeing if something comes out, but it doesn't
3166 sound useful. The previous leader _does_ go away, and
3167 we'll re-add the new one once we see the exec event
3168 (which is just the same as what would happen if the
3169 previous leader did exit voluntarily before some other
3172 if (debug_linux_nat
)
3173 fprintf_unfiltered (gdb_stdlog
,
3174 "CZL: Thread group leader %d vanished.\n",
3176 exit_lwp (leader_lp
);
3182 linux_nat_wait_1 (struct target_ops
*ops
,
3183 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3186 static sigset_t prev_mask
;
3187 enum resume_kind last_resume_kind
;
3188 struct lwp_info
*lp
;
3191 if (debug_linux_nat
)
3192 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3194 /* The first time we get here after starting a new inferior, we may
3195 not have added it to the LWP list yet - this is the earliest
3196 moment at which we know its PID. */
3197 if (ptid_is_pid (inferior_ptid
))
3199 /* Upgrade the main thread's ptid. */
3200 thread_change_ptid (inferior_ptid
,
3201 ptid_build (ptid_get_pid (inferior_ptid
),
3202 ptid_get_pid (inferior_ptid
), 0));
3204 lp
= add_initial_lwp (inferior_ptid
);
3208 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3209 block_child_signals (&prev_mask
);
3215 /* First check if there is a LWP with a wait status pending. */
3216 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3218 /* Any LWP in the PTID group that's been resumed will do. */
3219 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3222 if (debug_linux_nat
&& lp
->status
)
3223 fprintf_unfiltered (gdb_stdlog
,
3224 "LLW: Using pending wait status %s for %s.\n",
3225 status_to_str (lp
->status
),
3226 target_pid_to_str (lp
->ptid
));
3229 else if (ptid_lwp_p (ptid
))
3231 if (debug_linux_nat
)
3232 fprintf_unfiltered (gdb_stdlog
,
3233 "LLW: Waiting for specific LWP %s.\n",
3234 target_pid_to_str (ptid
));
3236 /* We have a specific LWP to check. */
3237 lp
= find_lwp_pid (ptid
);
3240 if (debug_linux_nat
&& lp
->status
)
3241 fprintf_unfiltered (gdb_stdlog
,
3242 "LLW: Using pending wait status %s for %s.\n",
3243 status_to_str (lp
->status
),
3244 target_pid_to_str (lp
->ptid
));
3246 /* We check for lp->waitstatus in addition to lp->status,
3247 because we can have pending process exits recorded in
3248 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3249 an additional lp->status_p flag. */
3250 if (lp
->status
== 0 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3254 if (!target_can_async_p ())
3256 /* Causes SIGINT to be passed on to the attached process. */
3260 /* But if we don't find a pending event, we'll have to wait. */
3266 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3269 - If the thread group leader exits while other threads in the
3270 thread group still exist, waitpid(TGID, ...) hangs. That
3271 waitpid won't return an exit status until the other threads
3272 in the group are reapped.
3274 - When a non-leader thread execs, that thread just vanishes
3275 without reporting an exit (so we'd hang if we waited for it
3276 explicitly in that case). The exec event is reported to
3280 lwpid
= my_waitpid (-1, &status
, __WCLONE
| WNOHANG
);
3281 if (lwpid
== 0 || (lwpid
== -1 && errno
== ECHILD
))
3282 lwpid
= my_waitpid (-1, &status
, WNOHANG
);
3284 if (debug_linux_nat
)
3285 fprintf_unfiltered (gdb_stdlog
,
3286 "LNW: waitpid(-1, ...) returned %d, %s\n",
3287 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3291 /* If this is true, then we paused LWPs momentarily, and may
3292 now have pending events to handle. */
3295 if (debug_linux_nat
)
3297 fprintf_unfiltered (gdb_stdlog
,
3298 "LLW: waitpid %ld received %s\n",
3299 (long) lwpid
, status_to_str (status
));
3302 lp
= linux_nat_filter_event (lwpid
, status
, &new_pending
);
3304 /* STATUS is now no longer valid, use LP->STATUS instead. */
3307 if (lp
&& !ptid_match (lp
->ptid
, ptid
))
3309 gdb_assert (lp
->resumed
);
3311 if (debug_linux_nat
)
3313 "LWP %ld got an event %06x, leaving pending.\n",
3314 ptid_get_lwp (lp
->ptid
), lp
->status
);
3316 if (WIFSTOPPED (lp
->status
))
3318 if (WSTOPSIG (lp
->status
) != SIGSTOP
)
3320 /* Cancel breakpoint hits. The breakpoint may
3321 be removed before we fetch events from this
3322 process to report to the core. It is best
3323 not to assume the moribund breakpoints
3324 heuristic always handles these cases --- it
3325 could be too many events go through to the
3326 core before this one is handled. All-stop
3327 always cancels breakpoint hits in all
3330 && linux_nat_lp_status_is_event (lp
)
3331 && cancel_breakpoint (lp
))
3333 /* Throw away the SIGTRAP. */
3336 if (debug_linux_nat
)
3338 "LLW: LWP %ld hit a breakpoint while"
3339 " waiting for another process;"
3341 ptid_get_lwp (lp
->ptid
));
3351 else if (WIFEXITED (lp
->status
) || WIFSIGNALED (lp
->status
))
3353 if (debug_linux_nat
)
3355 "Process %ld exited while stopping LWPs\n",
3356 ptid_get_lwp (lp
->ptid
));
3358 /* This was the last lwp in the process. Since
3359 events are serialized to GDB core, and we can't
3360 report this one right now, but GDB core and the
3361 other target layers will want to be notified
3362 about the exit code/signal, leave the status
3363 pending for the next time we're able to report
3366 /* Prevent trying to stop this thread again. We'll
3367 never try to resume it because it has a pending
3371 /* Dead LWP's aren't expected to reported a pending
3375 /* Store the pending event in the waitstatus as
3376 well, because W_EXITCODE(0,0) == 0. */
3377 store_waitstatus (&lp
->waitstatus
, lp
->status
);
3386 /* Some LWP now has a pending event. Go all the way
3387 back to check it. */
3393 /* We got an event to report to the core. */
3397 /* Retry until nothing comes out of waitpid. A single
3398 SIGCHLD can indicate more than one child stopped. */
3402 /* Check for zombie thread group leaders. Those can't be reaped
3403 until all other threads in the thread group are. */
3404 check_zombie_leaders ();
3406 /* If there are no resumed children left, bail. We'd be stuck
3407 forever in the sigsuspend call below otherwise. */
3408 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3410 if (debug_linux_nat
)
3411 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3413 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3415 if (!target_can_async_p ())
3416 clear_sigint_trap ();
3418 restore_child_signals_mask (&prev_mask
);
3419 return minus_one_ptid
;
3422 /* No interesting event to report to the core. */
3424 if (target_options
& TARGET_WNOHANG
)
3426 if (debug_linux_nat
)
3427 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3429 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3430 restore_child_signals_mask (&prev_mask
);
3431 return minus_one_ptid
;
3434 /* We shouldn't end up here unless we want to try again. */
3435 gdb_assert (lp
== NULL
);
3437 /* Block until we get an event reported with SIGCHLD. */
3438 sigsuspend (&suspend_mask
);
3441 if (!target_can_async_p ())
3442 clear_sigint_trap ();
3446 status
= lp
->status
;
3449 /* Don't report signals that GDB isn't interested in, such as
3450 signals that are neither printed nor stopped upon. Stopping all
3451 threads can be a bit time-consuming so if we want decent
3452 performance with heavily multi-threaded programs, especially when
3453 they're using a high frequency timer, we'd better avoid it if we
3456 if (WIFSTOPPED (status
))
3458 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3460 /* When using hardware single-step, we need to report every signal.
3461 Otherwise, signals in pass_mask may be short-circuited. */
3463 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
)))
3465 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3466 here? It is not clear we should. GDB may not expect
3467 other threads to run. On the other hand, not resuming
3468 newly attached threads may cause an unwanted delay in
3469 getting them running. */
3470 registers_changed ();
3471 if (linux_nat_prepare_to_resume
!= NULL
)
3472 linux_nat_prepare_to_resume (lp
);
3473 linux_ops
->to_resume (linux_ops
,
3474 pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3476 if (debug_linux_nat
)
3477 fprintf_unfiltered (gdb_stdlog
,
3478 "LLW: %s %s, %s (preempt 'handle')\n",
3480 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3481 target_pid_to_str (lp
->ptid
),
3482 (signo
!= GDB_SIGNAL_0
3483 ? strsignal (gdb_signal_to_host (signo
))
3491 /* Only do the below in all-stop, as we currently use SIGINT
3492 to implement target_stop (see linux_nat_stop) in
3494 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3496 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3497 forwarded to the entire process group, that is, all LWPs
3498 will receive it - unless they're using CLONE_THREAD to
3499 share signals. Since we only want to report it once, we
3500 mark it as ignored for all LWPs except this one. */
3501 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid
)),
3502 set_ignore_sigint
, NULL
);
3503 lp
->ignore_sigint
= 0;
3506 maybe_clear_ignore_sigint (lp
);
3510 /* This LWP is stopped now. */
3513 if (debug_linux_nat
)
3514 fprintf_unfiltered (gdb_stdlog
, "LLW: Candidate event %s in %s.\n",
3515 status_to_str (status
), target_pid_to_str (lp
->ptid
));
3519 /* Now stop all other LWP's ... */
3520 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3522 /* ... and wait until all of them have reported back that
3523 they're no longer running. */
3524 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3526 /* If we're not waiting for a specific LWP, choose an event LWP
3527 from among those that have had events. Giving equal priority
3528 to all LWPs that have had events helps prevent
3530 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3531 select_event_lwp (ptid
, &lp
, &status
);
3533 /* Now that we've selected our final event LWP, cancel any
3534 breakpoints in other LWPs that have hit a GDB breakpoint.
3535 See the comment in cancel_breakpoints_callback to find out
3537 iterate_over_lwps (minus_one_ptid
, cancel_breakpoints_callback
, lp
);
3539 /* We'll need this to determine whether to report a SIGSTOP as
3540 TARGET_WAITKIND_0. Need to take a copy because
3541 resume_clear_callback clears it. */
3542 last_resume_kind
= lp
->last_resume_kind
;
3544 /* In all-stop, from the core's perspective, all LWPs are now
3545 stopped until a new resume action is sent over. */
3546 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3551 last_resume_kind
= lp
->last_resume_kind
;
3552 resume_clear_callback (lp
, NULL
);
3555 if (linux_nat_status_is_event (status
))
3557 if (debug_linux_nat
)
3558 fprintf_unfiltered (gdb_stdlog
,
3559 "LLW: trap ptid is %s.\n",
3560 target_pid_to_str (lp
->ptid
));
3563 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3565 *ourstatus
= lp
->waitstatus
;
3566 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3569 store_waitstatus (ourstatus
, status
);
3571 if (debug_linux_nat
)
3572 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3574 restore_child_signals_mask (&prev_mask
);
3576 if (last_resume_kind
== resume_stop
3577 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3578 && WSTOPSIG (status
) == SIGSTOP
)
3580 /* A thread that has been requested to stop by GDB with
3581 target_stop, and it stopped cleanly, so report as SIG0. The
3582 use of SIGSTOP is an implementation detail. */
3583 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3586 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3587 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3590 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3595 /* Resume LWPs that are currently stopped without any pending status
3596 to report, but are resumed from the core's perspective. */
3599 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3601 ptid_t
*wait_ptid_p
= data
;
3606 && lp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
)
3608 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3609 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3610 CORE_ADDR pc
= regcache_read_pc (regcache
);
3612 gdb_assert (is_executing (lp
->ptid
));
3614 /* Don't bother if there's a breakpoint at PC that we'd hit
3615 immediately, and we're not waiting for this LWP. */
3616 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3618 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3622 if (debug_linux_nat
)
3623 fprintf_unfiltered (gdb_stdlog
,
3624 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3625 target_pid_to_str (lp
->ptid
),
3626 paddress (gdbarch
, pc
),
3629 registers_changed ();
3630 if (linux_nat_prepare_to_resume
!= NULL
)
3631 linux_nat_prepare_to_resume (lp
);
3632 linux_ops
->to_resume (linux_ops
, pid_to_ptid (ptid_get_lwp (lp
->ptid
)),
3633 lp
->step
, GDB_SIGNAL_0
);
3635 lp
->stopped_by_watchpoint
= 0;
3642 linux_nat_wait (struct target_ops
*ops
,
3643 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3648 if (debug_linux_nat
)
3650 char *options_string
;
3652 options_string
= target_options_to_string (target_options
);
3653 fprintf_unfiltered (gdb_stdlog
,
3654 "linux_nat_wait: [%s], [%s]\n",
3655 target_pid_to_str (ptid
),
3657 xfree (options_string
);
3660 /* Flush the async file first. */
3661 if (target_can_async_p ())
3662 async_file_flush ();
3664 /* Resume LWPs that are currently stopped without any pending status
3665 to report, but are resumed from the core's perspective. LWPs get
3666 in this state if we find them stopping at a time we're not
3667 interested in reporting the event (target_wait on a
3668 specific_process, for example, see linux_nat_wait_1), and
3669 meanwhile the event became uninteresting. Don't bother resuming
3670 LWPs we're not going to wait for if they'd stop immediately. */
3672 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3674 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3676 /* If we requested any event, and something came out, assume there
3677 may be more. If we requested a specific lwp or process, also
3678 assume there may be more. */
3679 if (target_can_async_p ()
3680 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3681 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3682 || !ptid_equal (ptid
, minus_one_ptid
)))
3685 /* Get ready for the next event. */
3686 if (target_can_async_p ())
3687 target_async (inferior_event_handler
, 0);
3693 kill_callback (struct lwp_info
*lp
, void *data
)
3695 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3698 kill (ptid_get_lwp (lp
->ptid
), SIGKILL
);
3699 if (debug_linux_nat
)
3700 fprintf_unfiltered (gdb_stdlog
,
3701 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3702 target_pid_to_str (lp
->ptid
),
3703 errno
? safe_strerror (errno
) : "OK");
3705 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3708 ptrace (PTRACE_KILL
, ptid_get_lwp (lp
->ptid
), 0, 0);
3709 if (debug_linux_nat
)
3710 fprintf_unfiltered (gdb_stdlog
,
3711 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3712 target_pid_to_str (lp
->ptid
),
3713 errno
? safe_strerror (errno
) : "OK");
3719 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3723 /* We must make sure that there are no pending events (delayed
3724 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3725 program doesn't interfere with any following debugging session. */
3727 /* For cloned processes we must check both with __WCLONE and
3728 without, since the exit status of a cloned process isn't reported
3734 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, __WCLONE
);
3735 if (pid
!= (pid_t
) -1)
3737 if (debug_linux_nat
)
3738 fprintf_unfiltered (gdb_stdlog
,
3739 "KWC: wait %s received unknown.\n",
3740 target_pid_to_str (lp
->ptid
));
3741 /* The Linux kernel sometimes fails to kill a thread
3742 completely after PTRACE_KILL; that goes from the stop
3743 point in do_fork out to the one in
3744 get_signal_to_deliever and waits again. So kill it
3746 kill_callback (lp
, NULL
);
3749 while (pid
== ptid_get_lwp (lp
->ptid
));
3751 gdb_assert (pid
== -1 && errno
== ECHILD
);
3756 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), NULL
, 0);
3757 if (pid
!= (pid_t
) -1)
3759 if (debug_linux_nat
)
3760 fprintf_unfiltered (gdb_stdlog
,
3761 "KWC: wait %s received unk.\n",
3762 target_pid_to_str (lp
->ptid
));
3763 /* See the call to kill_callback above. */
3764 kill_callback (lp
, NULL
);
3767 while (pid
== ptid_get_lwp (lp
->ptid
));
3769 gdb_assert (pid
== -1 && errno
== ECHILD
);
3774 linux_nat_kill (struct target_ops
*ops
)
3776 struct target_waitstatus last
;
3780 /* If we're stopped while forking and we haven't followed yet,
3781 kill the other task. We need to do this first because the
3782 parent will be sleeping if this is a vfork. */
3784 get_last_target_status (&last_ptid
, &last
);
3786 if (last
.kind
== TARGET_WAITKIND_FORKED
3787 || last
.kind
== TARGET_WAITKIND_VFORKED
)
3789 ptrace (PT_KILL
, ptid_get_pid (last
.value
.related_pid
), 0, 0);
3792 /* Let the arch-specific native code know this process is
3794 linux_nat_forget_process (ptid_get_pid (last
.value
.related_pid
));
3797 if (forks_exist_p ())
3798 linux_fork_killall ();
3801 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3803 /* Stop all threads before killing them, since ptrace requires
3804 that the thread is stopped to sucessfully PTRACE_KILL. */
3805 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3806 /* ... and wait until all of them have reported back that
3807 they're no longer running. */
3808 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3810 /* Kill all LWP's ... */
3811 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3813 /* ... and wait until we've flushed all events. */
3814 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3817 target_mourn_inferior ();
3821 linux_nat_mourn_inferior (struct target_ops
*ops
)
3823 int pid
= ptid_get_pid (inferior_ptid
);
3825 purge_lwp_list (pid
);
3827 if (! forks_exist_p ())
3828 /* Normal case, no other forks available. */
3829 linux_ops
->to_mourn_inferior (ops
);
3831 /* Multi-fork case. The current inferior_ptid has exited, but
3832 there are other viable forks to debug. Delete the exiting
3833 one and context-switch to the first available. */
3834 linux_fork_mourn_inferior ();
3836 /* Let the arch-specific native code know this process is gone. */
3837 linux_nat_forget_process (pid
);
3840 /* Convert a native/host siginfo object, into/from the siginfo in the
3841 layout of the inferiors' architecture. */
3844 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3848 if (linux_nat_siginfo_fixup
!= NULL
)
3849 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3851 /* If there was no callback, or the callback didn't do anything,
3852 then just do a straight memcpy. */
3856 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3858 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3862 static enum target_xfer_status
3863 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3864 const char *annex
, gdb_byte
*readbuf
,
3865 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3866 ULONGEST
*xfered_len
)
3870 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3872 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3873 gdb_assert (readbuf
|| writebuf
);
3875 pid
= ptid_get_lwp (inferior_ptid
);
3877 pid
= ptid_get_pid (inferior_ptid
);
3879 if (offset
> sizeof (siginfo
))
3880 return TARGET_XFER_E_IO
;
3883 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3885 return TARGET_XFER_E_IO
;
3887 /* When GDB is built as a 64-bit application, ptrace writes into
3888 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3889 inferior with a 64-bit GDB should look the same as debugging it
3890 with a 32-bit GDB, we need to convert it. GDB core always sees
3891 the converted layout, so any read/write will have to be done
3893 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3895 if (offset
+ len
> sizeof (siginfo
))
3896 len
= sizeof (siginfo
) - offset
;
3898 if (readbuf
!= NULL
)
3899 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3902 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3904 /* Convert back to ptrace layout before flushing it out. */
3905 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3908 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3910 return TARGET_XFER_E_IO
;
3914 return TARGET_XFER_OK
;
3917 static enum target_xfer_status
3918 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3919 const char *annex
, gdb_byte
*readbuf
,
3920 const gdb_byte
*writebuf
,
3921 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3923 struct cleanup
*old_chain
;
3924 enum target_xfer_status xfer
;
3926 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3927 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3928 offset
, len
, xfered_len
);
3930 /* The target is connected but no live inferior is selected. Pass
3931 this request down to a lower stratum (e.g., the executable
3933 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3934 return TARGET_XFER_EOF
;
3936 old_chain
= save_inferior_ptid ();
3938 if (ptid_lwp_p (inferior_ptid
))
3939 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3941 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3942 offset
, len
, xfered_len
);
3944 do_cleanups (old_chain
);
3949 linux_thread_alive (ptid_t ptid
)
3953 gdb_assert (ptid_lwp_p (ptid
));
3955 /* Send signal 0 instead of anything ptrace, because ptracing a
3956 running thread errors out claiming that the thread doesn't
3958 err
= kill_lwp (ptid_get_lwp (ptid
), 0);
3960 if (debug_linux_nat
)
3961 fprintf_unfiltered (gdb_stdlog
,
3962 "LLTA: KILL(SIG0) %s (%s)\n",
3963 target_pid_to_str (ptid
),
3964 err
? safe_strerror (tmp_errno
) : "OK");
3973 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3975 return linux_thread_alive (ptid
);
3979 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3981 static char buf
[64];
3983 if (ptid_lwp_p (ptid
)
3984 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3985 || num_lwps (ptid_get_pid (ptid
)) > 1))
3987 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3991 return normal_pid_to_str (ptid
);
3995 linux_nat_thread_name (struct thread_info
*thr
)
3997 int pid
= ptid_get_pid (thr
->ptid
);
3998 long lwp
= ptid_get_lwp (thr
->ptid
);
3999 #define FORMAT "/proc/%d/task/%ld/comm"
4000 char buf
[sizeof (FORMAT
) + 30];
4002 char *result
= NULL
;
4004 snprintf (buf
, sizeof (buf
), FORMAT
, pid
, lwp
);
4005 comm_file
= gdb_fopen_cloexec (buf
, "r");
4008 /* Not exported by the kernel, so we define it here. */
4010 static char line
[COMM_LEN
+ 1];
4012 if (fgets (line
, sizeof (line
), comm_file
))
4014 char *nl
= strchr (line
, '\n');
4031 /* Accepts an integer PID; Returns a string representing a file that
4032 can be opened to get the symbols for the child process. */
4035 linux_child_pid_to_exec_file (int pid
)
4037 char *name1
, *name2
;
4039 name1
= xmalloc (PATH_MAX
);
4040 name2
= xmalloc (PATH_MAX
);
4041 make_cleanup (xfree
, name1
);
4042 make_cleanup (xfree
, name2
);
4043 memset (name2
, 0, PATH_MAX
);
4045 xsnprintf (name1
, PATH_MAX
, "/proc/%d/exe", pid
);
4046 if (readlink (name1
, name2
, PATH_MAX
- 1) > 0)
4052 /* Records the thread's register state for the corefile note
4056 linux_nat_collect_thread_registers (const struct regcache
*regcache
,
4057 ptid_t ptid
, bfd
*obfd
,
4058 char *note_data
, int *note_size
,
4059 enum gdb_signal stop_signal
)
4061 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
4062 const struct regset
*regset
;
4064 gdb_gregset_t gregs
;
4065 gdb_fpregset_t fpregs
;
4067 core_regset_p
= gdbarch_regset_from_core_section_p (gdbarch
);
4070 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg",
4072 != NULL
&& regset
->collect_regset
!= NULL
)
4073 regset
->collect_regset (regset
, regcache
, -1, &gregs
, sizeof (gregs
));
4075 fill_gregset (regcache
, &gregs
, -1);
4077 note_data
= (char *) elfcore_write_prstatus
4078 (obfd
, note_data
, note_size
, ptid_get_lwp (ptid
),
4079 gdb_signal_to_host (stop_signal
), &gregs
);
4082 && (regset
= gdbarch_regset_from_core_section (gdbarch
, ".reg2",
4084 != NULL
&& regset
->collect_regset
!= NULL
)
4085 regset
->collect_regset (regset
, regcache
, -1, &fpregs
, sizeof (fpregs
));
4087 fill_fpregset (regcache
, &fpregs
, -1);
4089 note_data
= (char *) elfcore_write_prfpreg (obfd
, note_data
, note_size
,
4090 &fpregs
, sizeof (fpregs
));
4095 /* Fills the "to_make_corefile_note" target vector. Builds the note
4096 section for a corefile, and returns it in a malloc buffer. */
4099 linux_nat_make_corefile_notes (bfd
*obfd
, int *note_size
)
4101 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4102 converted to gdbarch_core_regset_sections, this function can go away. */
4103 return linux_make_corefile_notes (target_gdbarch (), obfd
, note_size
,
4104 linux_nat_collect_thread_registers
);
4107 /* Implement the to_xfer_partial interface for memory reads using the /proc
4108 filesystem. Because we can use a single read() call for /proc, this
4109 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4110 but it doesn't support writes. */
4112 static enum target_xfer_status
4113 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4114 const char *annex
, gdb_byte
*readbuf
,
4115 const gdb_byte
*writebuf
,
4116 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
4122 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
4125 /* Don't bother for one word. */
4126 if (len
< 3 * sizeof (long))
4127 return TARGET_XFER_EOF
;
4129 /* We could keep this file open and cache it - possibly one per
4130 thread. That requires some juggling, but is even faster. */
4131 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
4132 ptid_get_pid (inferior_ptid
));
4133 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
4135 return TARGET_XFER_EOF
;
4137 /* If pread64 is available, use it. It's faster if the kernel
4138 supports it (only one syscall), and it's 64-bit safe even on
4139 32-bit platforms (for instance, SPARC debugging a SPARC64
4142 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
4144 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
4153 return TARGET_XFER_EOF
;
4157 return TARGET_XFER_OK
;
4162 /* Enumerate spufs IDs for process PID. */
4164 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
4166 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
4168 LONGEST written
= 0;
4171 struct dirent
*entry
;
4173 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
4174 dir
= opendir (path
);
4179 while ((entry
= readdir (dir
)) != NULL
)
4185 fd
= atoi (entry
->d_name
);
4189 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
4190 if (stat (path
, &st
) != 0)
4192 if (!S_ISDIR (st
.st_mode
))
4195 if (statfs (path
, &stfs
) != 0)
4197 if (stfs
.f_type
!= SPUFS_MAGIC
)
4200 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4202 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4212 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4213 object type, using the /proc file system. */
4215 static enum target_xfer_status
4216 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4217 const char *annex
, gdb_byte
*readbuf
,
4218 const gdb_byte
*writebuf
,
4219 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4224 int pid
= ptid_get_pid (inferior_ptid
);
4229 return TARGET_XFER_E_IO
;
4232 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4235 return TARGET_XFER_E_IO
;
4237 return TARGET_XFER_EOF
;
4240 *xfered_len
= (ULONGEST
) l
;
4241 return TARGET_XFER_OK
;
4246 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4247 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4249 return TARGET_XFER_E_IO
;
4252 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4255 return TARGET_XFER_EOF
;
4259 ret
= write (fd
, writebuf
, (size_t) len
);
4261 ret
= read (fd
, readbuf
, (size_t) len
);
4266 return TARGET_XFER_E_IO
;
4268 return TARGET_XFER_EOF
;
4271 *xfered_len
= (ULONGEST
) ret
;
4272 return TARGET_XFER_OK
;
4277 /* Parse LINE as a signal set and add its set bits to SIGS. */
4280 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4282 int len
= strlen (line
) - 1;
4286 if (line
[len
] != '\n')
4287 error (_("Could not parse signal set: %s"), line
);
4295 if (*p
>= '0' && *p
<= '9')
4297 else if (*p
>= 'a' && *p
<= 'f')
4298 digit
= *p
- 'a' + 10;
4300 error (_("Could not parse signal set: %s"), line
);
4305 sigaddset (sigs
, signum
+ 1);
4307 sigaddset (sigs
, signum
+ 2);
4309 sigaddset (sigs
, signum
+ 3);
4311 sigaddset (sigs
, signum
+ 4);
4317 /* Find process PID's pending signals from /proc/pid/status and set
4321 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4322 sigset_t
*blocked
, sigset_t
*ignored
)
4325 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4326 struct cleanup
*cleanup
;
4328 sigemptyset (pending
);
4329 sigemptyset (blocked
);
4330 sigemptyset (ignored
);
4331 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4332 procfile
= gdb_fopen_cloexec (fname
, "r");
4333 if (procfile
== NULL
)
4334 error (_("Could not open %s"), fname
);
4335 cleanup
= make_cleanup_fclose (procfile
);
4337 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4339 /* Normal queued signals are on the SigPnd line in the status
4340 file. However, 2.6 kernels also have a "shared" pending
4341 queue for delivering signals to a thread group, so check for
4344 Unfortunately some Red Hat kernels include the shared pending
4345 queue but not the ShdPnd status field. */
4347 if (strncmp (buffer
, "SigPnd:\t", 8) == 0)
4348 add_line_to_sigset (buffer
+ 8, pending
);
4349 else if (strncmp (buffer
, "ShdPnd:\t", 8) == 0)
4350 add_line_to_sigset (buffer
+ 8, pending
);
4351 else if (strncmp (buffer
, "SigBlk:\t", 8) == 0)
4352 add_line_to_sigset (buffer
+ 8, blocked
);
4353 else if (strncmp (buffer
, "SigIgn:\t", 8) == 0)
4354 add_line_to_sigset (buffer
+ 8, ignored
);
4357 do_cleanups (cleanup
);
4360 static enum target_xfer_status
4361 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4362 const char *annex
, gdb_byte
*readbuf
,
4363 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4364 ULONGEST
*xfered_len
)
4366 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4368 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4369 if (*xfered_len
== 0)
4370 return TARGET_XFER_EOF
;
4372 return TARGET_XFER_OK
;
4375 static enum target_xfer_status
4376 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4377 const char *annex
, gdb_byte
*readbuf
,
4378 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4379 ULONGEST
*xfered_len
)
4381 enum target_xfer_status xfer
;
4383 if (object
== TARGET_OBJECT_AUXV
)
4384 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4385 offset
, len
, xfered_len
);
4387 if (object
== TARGET_OBJECT_OSDATA
)
4388 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4389 offset
, len
, xfered_len
);
4391 if (object
== TARGET_OBJECT_SPU
)
4392 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4393 offset
, len
, xfered_len
);
4395 /* GDB calculates all the addresses in possibly larget width of the address.
4396 Address width needs to be masked before its final use - either by
4397 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4399 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4401 if (object
== TARGET_OBJECT_MEMORY
)
4403 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4405 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4406 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4409 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4410 offset
, len
, xfered_len
);
4411 if (xfer
!= TARGET_XFER_EOF
)
4414 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4415 offset
, len
, xfered_len
);
4419 cleanup_target_stop (void *arg
)
4421 ptid_t
*ptid
= (ptid_t
*) arg
;
4423 gdb_assert (arg
!= NULL
);
4426 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4429 static VEC(static_tracepoint_marker_p
) *
4430 linux_child_static_tracepoint_markers_by_strid (const char *strid
)
4432 char s
[IPA_CMD_BUF_SIZE
];
4433 struct cleanup
*old_chain
;
4434 int pid
= ptid_get_pid (inferior_ptid
);
4435 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4436 struct static_tracepoint_marker
*marker
= NULL
;
4438 ptid_t ptid
= ptid_build (pid
, 0, 0);
4443 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4444 s
[sizeof ("qTfSTM")] = 0;
4446 agent_run_command (pid
, s
, strlen (s
) + 1);
4448 old_chain
= make_cleanup (free_current_marker
, &marker
);
4449 make_cleanup (cleanup_target_stop
, &ptid
);
4454 marker
= XCNEW (struct static_tracepoint_marker
);
4458 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4460 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4462 VEC_safe_push (static_tracepoint_marker_p
,
4468 release_static_tracepoint_marker (marker
);
4469 memset (marker
, 0, sizeof (*marker
));
4472 while (*p
++ == ','); /* comma-separated list */
4474 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4475 s
[sizeof ("qTsSTM")] = 0;
4476 agent_run_command (pid
, s
, strlen (s
) + 1);
4480 do_cleanups (old_chain
);
4485 /* Create a prototype generic GNU/Linux target. The client can override
4486 it with local methods. */
4489 linux_target_install_ops (struct target_ops
*t
)
4491 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4492 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4493 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4494 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4495 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4496 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4497 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4498 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4499 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4500 t
->to_post_attach
= linux_child_post_attach
;
4501 t
->to_follow_fork
= linux_child_follow_fork
;
4502 t
->to_make_corefile_notes
= linux_nat_make_corefile_notes
;
4504 super_xfer_partial
= t
->to_xfer_partial
;
4505 t
->to_xfer_partial
= linux_xfer_partial
;
4507 t
->to_static_tracepoint_markers_by_strid
4508 = linux_child_static_tracepoint_markers_by_strid
;
4514 struct target_ops
*t
;
4516 t
= inf_ptrace_target ();
4517 linux_target_install_ops (t
);
4523 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4525 struct target_ops
*t
;
4527 t
= inf_ptrace_trad_target (register_u_offset
);
4528 linux_target_install_ops (t
);
4533 /* target_is_async_p implementation. */
4536 linux_nat_is_async_p (struct target_ops
*ops
)
4538 /* NOTE: palves 2008-03-21: We're only async when the user requests
4539 it explicitly with the "set target-async" command.
4540 Someday, linux will always be async. */
4541 return target_async_permitted
;
4544 /* target_can_async_p implementation. */
4547 linux_nat_can_async_p (struct target_ops
*ops
)
4549 /* NOTE: palves 2008-03-21: We're only async when the user requests
4550 it explicitly with the "set target-async" command.
4551 Someday, linux will always be async. */
4552 return target_async_permitted
;
4556 linux_nat_supports_non_stop (void)
4561 /* True if we want to support multi-process. To be removed when GDB
4562 supports multi-exec. */
4564 int linux_multi_process
= 1;
4567 linux_nat_supports_multi_process (void)
4569 return linux_multi_process
;
4573 linux_nat_supports_disable_randomization (void)
4575 #ifdef HAVE_PERSONALITY
4582 static int async_terminal_is_ours
= 1;
4584 /* target_terminal_inferior implementation. */
4587 linux_nat_terminal_inferior (struct target_ops
*self
)
4589 if (!target_is_async_p ())
4591 /* Async mode is disabled. */
4592 terminal_inferior (self
);
4596 terminal_inferior (self
);
4598 /* Calls to target_terminal_*() are meant to be idempotent. */
4599 if (!async_terminal_is_ours
)
4602 delete_file_handler (input_fd
);
4603 async_terminal_is_ours
= 0;
4607 /* target_terminal_ours implementation. */
4610 linux_nat_terminal_ours (struct target_ops
*self
)
4612 if (!target_is_async_p ())
4614 /* Async mode is disabled. */
4615 terminal_ours (self
);
4619 /* GDB should never give the terminal to the inferior if the
4620 inferior is running in the background (run&, continue&, etc.),
4621 but claiming it sure should. */
4622 terminal_ours (self
);
4624 if (async_terminal_is_ours
)
4627 clear_sigint_trap ();
4628 add_file_handler (input_fd
, stdin_event_handler
, 0);
4629 async_terminal_is_ours
= 1;
4632 static void (*async_client_callback
) (enum inferior_event_type event_type
,
4634 static void *async_client_context
;
4636 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4637 so we notice when any child changes state, and notify the
4638 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4639 above to wait for the arrival of a SIGCHLD. */
4642 sigchld_handler (int signo
)
4644 int old_errno
= errno
;
4646 if (debug_linux_nat
)
4647 ui_file_write_async_safe (gdb_stdlog
,
4648 "sigchld\n", sizeof ("sigchld\n") - 1);
4650 if (signo
== SIGCHLD
4651 && linux_nat_event_pipe
[0] != -1)
4652 async_file_mark (); /* Let the event loop know that there are
4653 events to handle. */
4658 /* Callback registered with the target events file descriptor. */
4661 handle_target_event (int error
, gdb_client_data client_data
)
4663 (*async_client_callback
) (INF_REG_EVENT
, async_client_context
);
4666 /* Create/destroy the target events pipe. Returns previous state. */
4669 linux_async_pipe (int enable
)
4671 int previous
= (linux_nat_event_pipe
[0] != -1);
4673 if (previous
!= enable
)
4677 /* Block child signals while we create/destroy the pipe, as
4678 their handler writes to it. */
4679 block_child_signals (&prev_mask
);
4683 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4684 internal_error (__FILE__
, __LINE__
,
4685 "creating event pipe failed.");
4687 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4688 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4692 close (linux_nat_event_pipe
[0]);
4693 close (linux_nat_event_pipe
[1]);
4694 linux_nat_event_pipe
[0] = -1;
4695 linux_nat_event_pipe
[1] = -1;
4698 restore_child_signals_mask (&prev_mask
);
4704 /* target_async implementation. */
4707 linux_nat_async (struct target_ops
*ops
,
4708 void (*callback
) (enum inferior_event_type event_type
,
4712 if (callback
!= NULL
)
4714 async_client_callback
= callback
;
4715 async_client_context
= context
;
4716 if (!linux_async_pipe (1))
4718 add_file_handler (linux_nat_event_pipe
[0],
4719 handle_target_event
, NULL
);
4720 /* There may be pending events to handle. Tell the event loop
4727 async_client_callback
= callback
;
4728 async_client_context
= context
;
4729 delete_file_handler (linux_nat_event_pipe
[0]);
4730 linux_async_pipe (0);
4735 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4739 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4743 if (debug_linux_nat
)
4744 fprintf_unfiltered (gdb_stdlog
,
4745 "LNSL: running -> suspending %s\n",
4746 target_pid_to_str (lwp
->ptid
));
4749 if (lwp
->last_resume_kind
== resume_stop
)
4751 if (debug_linux_nat
)
4752 fprintf_unfiltered (gdb_stdlog
,
4753 "linux-nat: already stopping LWP %ld at "
4755 ptid_get_lwp (lwp
->ptid
));
4759 stop_callback (lwp
, NULL
);
4760 lwp
->last_resume_kind
= resume_stop
;
4764 /* Already known to be stopped; do nothing. */
4766 if (debug_linux_nat
)
4768 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4769 fprintf_unfiltered (gdb_stdlog
,
4770 "LNSL: already stopped/stop_requested %s\n",
4771 target_pid_to_str (lwp
->ptid
));
4773 fprintf_unfiltered (gdb_stdlog
,
4774 "LNSL: already stopped/no "
4775 "stop_requested yet %s\n",
4776 target_pid_to_str (lwp
->ptid
));
4783 linux_nat_stop (ptid_t ptid
)
4786 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4788 linux_ops
->to_stop (ptid
);
4792 linux_nat_close (struct target_ops
*self
)
4794 /* Unregister from the event loop. */
4795 if (linux_nat_is_async_p (NULL
))
4796 linux_nat_async (NULL
, NULL
, 0);
4798 if (linux_ops
->to_close
)
4799 linux_ops
->to_close (linux_ops
);
4802 /* When requests are passed down from the linux-nat layer to the
4803 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4804 used. The address space pointer is stored in the inferior object,
4805 but the common code that is passed such ptid can't tell whether
4806 lwpid is a "main" process id or not (it assumes so). We reverse
4807 look up the "main" process id from the lwp here. */
4809 static struct address_space
*
4810 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4812 struct lwp_info
*lwp
;
4813 struct inferior
*inf
;
4816 pid
= ptid_get_lwp (ptid
);
4817 if (ptid_get_lwp (ptid
) == 0)
4819 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4821 lwp
= find_lwp_pid (ptid
);
4822 pid
= ptid_get_pid (lwp
->ptid
);
4826 /* A (pid,lwpid,0) ptid. */
4827 pid
= ptid_get_pid (ptid
);
4830 inf
= find_inferior_pid (pid
);
4831 gdb_assert (inf
!= NULL
);
4835 /* Return the cached value of the processor core for thread PTID. */
4838 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4840 struct lwp_info
*info
= find_lwp_pid (ptid
);
4848 linux_nat_add_target (struct target_ops
*t
)
4850 /* Save the provided single-threaded target. We save this in a separate
4851 variable because another target we've inherited from (e.g. inf-ptrace)
4852 may have saved a pointer to T; we want to use it for the final
4853 process stratum target. */
4854 linux_ops_saved
= *t
;
4855 linux_ops
= &linux_ops_saved
;
4857 /* Override some methods for multithreading. */
4858 t
->to_create_inferior
= linux_nat_create_inferior
;
4859 t
->to_attach
= linux_nat_attach
;
4860 t
->to_detach
= linux_nat_detach
;
4861 t
->to_resume
= linux_nat_resume
;
4862 t
->to_wait
= linux_nat_wait
;
4863 t
->to_pass_signals
= linux_nat_pass_signals
;
4864 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4865 t
->to_kill
= linux_nat_kill
;
4866 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4867 t
->to_thread_alive
= linux_nat_thread_alive
;
4868 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4869 t
->to_thread_name
= linux_nat_thread_name
;
4870 t
->to_has_thread_control
= tc_schedlock
;
4871 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4872 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4873 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4875 t
->to_can_async_p
= linux_nat_can_async_p
;
4876 t
->to_is_async_p
= linux_nat_is_async_p
;
4877 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4878 t
->to_async
= linux_nat_async
;
4879 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4880 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4881 t
->to_close
= linux_nat_close
;
4883 /* Methods for non-stop support. */
4884 t
->to_stop
= linux_nat_stop
;
4886 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4888 t
->to_supports_disable_randomization
4889 = linux_nat_supports_disable_randomization
;
4891 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4893 /* We don't change the stratum; this target will sit at
4894 process_stratum and thread_db will set at thread_stratum. This
4895 is a little strange, since this is a multi-threaded-capable
4896 target, but we want to be on the stack below thread_db, and we
4897 also want to be used for single-threaded processes. */
4902 /* Register a method to call whenever a new thread is attached. */
4904 linux_nat_set_new_thread (struct target_ops
*t
,
4905 void (*new_thread
) (struct lwp_info
*))
4907 /* Save the pointer. We only support a single registered instance
4908 of the GNU/Linux native target, so we do not need to map this to
4910 linux_nat_new_thread
= new_thread
;
4913 /* See declaration in linux-nat.h. */
4916 linux_nat_set_new_fork (struct target_ops
*t
,
4917 linux_nat_new_fork_ftype
*new_fork
)
4919 /* Save the pointer. */
4920 linux_nat_new_fork
= new_fork
;
4923 /* See declaration in linux-nat.h. */
4926 linux_nat_set_forget_process (struct target_ops
*t
,
4927 linux_nat_forget_process_ftype
*fn
)
4929 /* Save the pointer. */
4930 linux_nat_forget_process_hook
= fn
;
4933 /* See declaration in linux-nat.h. */
4936 linux_nat_forget_process (pid_t pid
)
4938 if (linux_nat_forget_process_hook
!= NULL
)
4939 linux_nat_forget_process_hook (pid
);
4942 /* Register a method that converts a siginfo object between the layout
4943 that ptrace returns, and the layout in the architecture of the
4946 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4947 int (*siginfo_fixup
) (siginfo_t
*,
4951 /* Save the pointer. */
4952 linux_nat_siginfo_fixup
= siginfo_fixup
;
4955 /* Register a method to call prior to resuming a thread. */
4958 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4959 void (*prepare_to_resume
) (struct lwp_info
*))
4961 /* Save the pointer. */
4962 linux_nat_prepare_to_resume
= prepare_to_resume
;
4965 /* See linux-nat.h. */
4968 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4972 pid
= ptid_get_lwp (ptid
);
4974 pid
= ptid_get_pid (ptid
);
4977 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4980 memset (siginfo
, 0, sizeof (*siginfo
));
4986 /* Provide a prototype to silence -Wmissing-prototypes. */
4987 extern initialize_file_ftype _initialize_linux_nat
;
4990 _initialize_linux_nat (void)
4992 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4993 &debug_linux_nat
, _("\
4994 Set debugging of GNU/Linux lwp module."), _("\
4995 Show debugging of GNU/Linux lwp module."), _("\
4996 Enables printf debugging output."),
4998 show_debug_linux_nat
,
4999 &setdebuglist
, &showdebuglist
);
5001 /* Save this mask as the default. */
5002 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
5004 /* Install a SIGCHLD handler. */
5005 sigchld_action
.sa_handler
= sigchld_handler
;
5006 sigemptyset (&sigchld_action
.sa_mask
);
5007 sigchld_action
.sa_flags
= SA_RESTART
;
5009 /* Make it the default. */
5010 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
5012 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5013 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
5014 sigdelset (&suspend_mask
, SIGCHLD
);
5016 sigemptyset (&blocked_mask
);
5020 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5021 the GNU/Linux Threads library and therefore doesn't really belong
5024 /* Read variable NAME in the target and return its value if found.
5025 Otherwise return zero. It is assumed that the type of the variable
5029 get_signo (const char *name
)
5031 struct minimal_symbol
*ms
;
5034 ms
= lookup_minimal_symbol (name
, NULL
, NULL
);
5038 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms
), (gdb_byte
*) &signo
,
5039 sizeof (signo
)) != 0)
5045 /* Return the set of signals used by the threads library in *SET. */
5048 lin_thread_get_thread_signals (sigset_t
*set
)
5050 struct sigaction action
;
5051 int restart
, cancel
;
5053 sigemptyset (&blocked_mask
);
5056 restart
= get_signo ("__pthread_sig_restart");
5057 cancel
= get_signo ("__pthread_sig_cancel");
5059 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5060 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5061 not provide any way for the debugger to query the signal numbers -
5062 fortunately they don't change! */
5065 restart
= __SIGRTMIN
;
5068 cancel
= __SIGRTMIN
+ 1;
5070 sigaddset (set
, restart
);
5071 sigaddset (set
, cancel
);
5073 /* The GNU/Linux Threads library makes terminating threads send a
5074 special "cancel" signal instead of SIGCHLD. Make sure we catch
5075 those (to prevent them from terminating GDB itself, which is
5076 likely to be their default action) and treat them the same way as
5079 action
.sa_handler
= sigchld_handler
;
5080 sigemptyset (&action
.sa_mask
);
5081 action
.sa_flags
= SA_RESTART
;
5082 sigaction (cancel
, &action
, NULL
);
5084 /* We block the "cancel" signal throughout this code ... */
5085 sigaddset (&blocked_mask
, cancel
);
5086 sigprocmask (SIG_BLOCK
, &blocked_mask
, NULL
);
5088 /* ... except during a sigsuspend. */
5089 sigdelset (&suspend_mask
, cancel
);