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/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include "gdb_assert.h"
29 #ifdef HAVE_TKILL_SYSCALL
31 #include <sys/syscall.h>
33 #include <sys/ptrace.h>
34 #include "linux-nat.h"
35 #include "linux-ptrace.h"
36 #include "linux-procfs.h"
37 #include "linux-fork.h"
38 #include "gdbthread.h"
42 #include "inf-child.h"
43 #include "inf-ptrace.h"
45 #include <sys/procfs.h> /* for elf_gregset etc. */
46 #include "elf-bfd.h" /* for elfcore_write_* */
47 #include "gregset.h" /* for gregset */
48 #include "gdbcore.h" /* for get_exec_file */
49 #include <ctype.h> /* for isdigit */
50 #include <sys/stat.h> /* for struct stat */
51 #include <fcntl.h> /* for O_RDONLY */
53 #include "event-loop.h"
54 #include "event-top.h"
56 #include <sys/types.h>
58 #include "xml-support.h"
62 #include "linux-osdata.h"
63 #include "linux-tdep.h"
66 #include "tracepoint.h"
67 #include "exceptions.h"
69 #include "target-descriptions.h"
70 #include "filestuff.h"
74 #define SPUFS_MAGIC 0x23c9b64e
77 #ifdef HAVE_PERSONALITY
78 # include <sys/personality.h>
79 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
80 # define ADDR_NO_RANDOMIZE 0x0040000
82 #endif /* HAVE_PERSONALITY */
84 /* This comment documents high-level logic of this file.
86 Waiting for events in sync mode
87 ===============================
89 When waiting for an event in a specific thread, we just use waitpid, passing
90 the specific pid, and not passing WNOHANG.
92 When waiting for an event in all threads, waitpid is not quite good. Prior to
93 version 2.4, Linux can either wait for event in main thread, or in secondary
94 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
95 miss an event. The solution is to use non-blocking waitpid, together with
96 sigsuspend. First, we use non-blocking waitpid to get an event in the main
97 process, if any. Second, we use non-blocking waitpid with the __WCLONED
98 flag to check for events in cloned processes. If nothing is found, we use
99 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
100 happened to a child process -- and SIGCHLD will be delivered both for events
101 in main debugged process and in cloned processes. As soon as we know there's
102 an event, we get back to calling nonblocking waitpid with and without
105 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
106 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
107 blocked, the signal becomes pending and sigsuspend immediately
108 notices it and returns.
110 Waiting for events in async mode
111 ================================
113 In async mode, GDB should always be ready to handle both user input
114 and target events, so neither blocking waitpid nor sigsuspend are
115 viable options. Instead, we should asynchronously notify the GDB main
116 event loop whenever there's an unprocessed event from the target. We
117 detect asynchronous target events by handling SIGCHLD signals. To
118 notify the event loop about target events, the self-pipe trick is used
119 --- a pipe is registered as waitable event source in the event loop,
120 the event loop select/poll's on the read end of this pipe (as well on
121 other event sources, e.g., stdin), and the SIGCHLD handler writes a
122 byte to this pipe. This is more portable than relying on
123 pselect/ppoll, since on kernels that lack those syscalls, libc
124 emulates them with select/poll+sigprocmask, and that is racy
125 (a.k.a. plain broken).
127 Obviously, if we fail to notify the event loop if there's a target
128 event, it's bad. OTOH, if we notify the event loop when there's no
129 event from the target, linux_nat_wait will detect that there's no real
130 event to report, and return event of type TARGET_WAITKIND_IGNORE.
131 This is mostly harmless, but it will waste time and is better avoided.
133 The main design point is that every time GDB is outside linux-nat.c,
134 we have a SIGCHLD handler installed that is called when something
135 happens to the target and notifies the GDB event loop. Whenever GDB
136 core decides to handle the event, and calls into linux-nat.c, we
137 process things as in sync mode, except that the we never block in
140 While processing an event, we may end up momentarily blocked in
141 waitpid calls. Those waitpid calls, while blocking, are guarantied to
142 return quickly. E.g., in all-stop mode, before reporting to the core
143 that an LWP hit a breakpoint, all LWPs are stopped by sending them
144 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
145 Note that this is different from blocking indefinitely waiting for the
146 next event --- here, we're already handling an event.
151 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
152 signal is not entirely significant; we just need for a signal to be delivered,
153 so that we can intercept it. SIGSTOP's advantage is that it can not be
154 blocked. A disadvantage is that it is not a real-time signal, so it can only
155 be queued once; we do not keep track of other sources of SIGSTOP.
157 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
158 use them, because they have special behavior when the signal is generated -
159 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
160 kills the entire thread group.
162 A delivered SIGSTOP would stop the entire thread group, not just the thread we
163 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
164 cancel it (by PTRACE_CONT without passing SIGSTOP).
166 We could use a real-time signal instead. This would solve those problems; we
167 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
168 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
169 generates it, and there are races with trying to find a signal that is not
173 #define O_LARGEFILE 0
176 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
177 the use of the multi-threaded target. */
178 static struct target_ops *linux_ops;
179 static struct target_ops linux_ops_saved;
181 /* The method to call, if any, when a new thread is attached. */
182 static void (*linux_nat_new_thread) (struct lwp_info *);
184 /* The method to call, if any, when a new fork is attached. */
185 static linux_nat_new_fork_ftype *linux_nat_new_fork;
187 /* The method to call, if any, when a process is no longer
189 static linux_nat_forget_process_ftype *linux_nat_forget_process_hook;
191 /* Hook to call prior to resuming a thread. */
192 static void (*linux_nat_prepare_to_resume) (struct lwp_info *);
194 /* The method to call, if any, when the siginfo object needs to be
195 converted between the layout returned by ptrace, and the layout in
196 the architecture of the inferior. */
197 static int (*linux_nat_siginfo_fixup) (siginfo_t *,
201 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
202 Called by our to_xfer_partial. */
203 static target_xfer_partial_ftype *super_xfer_partial;
205 /* The saved to_close method, inherited from inf-ptrace.c.
206 Called by our to_close. */
207 static void (*super_close) (struct target_ops *);
209 static unsigned int debug_linux_nat;
211 show_debug_linux_nat (struct ui_file *file, int from_tty,
212 struct cmd_list_element *c, const char *value)
214 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
218 struct simple_pid_list
222 struct simple_pid_list *next;
224 struct simple_pid_list *stopped_pids;
226 /* Async mode support. */
228 /* The read/write ends of the pipe registered as waitable file in the
230 static int linux_nat_event_pipe[2] = { -1, -1 };
232 /* Flush the event pipe. */
235 async_file_flush (void)
242 ret = read (linux_nat_event_pipe[0], &buf, 1);
244 while (ret >= 0 || (ret == -1 && errno == EINTR));
247 /* Put something (anything, doesn't matter what, or how much) in event
248 pipe, so that the select/poll in the event-loop realizes we have
249 something to process. */
252 async_file_mark (void)
256 /* It doesn't really matter what the pipe contains, as long we end
257 up with something in it. Might as well flush the previous
263 ret = write (linux_nat_event_pipe[1], "+", 1);
265 while (ret == -1 && errno == EINTR);
267 /* Ignore EAGAIN. If the pipe is full, the event loop will already
268 be awakened anyway. */
271 static int kill_lwp (int lwpid, int signo);
273 static int stop_callback (struct lwp_info *lp, void *data);
275 static void block_child_signals (sigset_t *prev_mask);
276 static void restore_child_signals_mask (sigset_t *prev_mask);
279 static struct lwp_info *add_lwp (ptid_t ptid);
280 static void purge_lwp_list (int pid);
281 static void delete_lwp (ptid_t ptid);
282 static struct lwp_info *find_lwp_pid (ptid_t ptid);
285 /* Trivial list manipulation functions to keep track of a list of
286 new stopped processes. */
288 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
290 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
293 new_pid->status = status;
294 new_pid->next = *listp;
299 in_pid_list_p (struct simple_pid_list *list, int pid)
301 struct simple_pid_list *p;
303 for (p = list; p != NULL; p = p->next)
310 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
312 struct simple_pid_list **p;
314 for (p = listp; *p != NULL; p = &(*p)->next)
315 if ((*p)->pid == pid)
317 struct simple_pid_list *next = (*p)->next;
319 *statusp = (*p)->status;
327 /* Initialize ptrace warnings and check for supported ptrace
328 features given PID. */
331 linux_init_ptrace (pid_t pid)
333 linux_enable_event_reporting (pid);
334 linux_ptrace_init_warnings ();
338 linux_child_post_attach (struct target_ops *self, int pid)
340 linux_init_ptrace (pid);
344 linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
346 linux_init_ptrace (ptid_get_pid (ptid));
349 /* Return the number of known LWPs in the tgid given by PID. */
357 for (lp = lwp_list; lp; lp = lp->next)
358 if (ptid_get_pid (lp->ptid) == pid)
364 /* Call delete_lwp with prototype compatible for make_cleanup. */
367 delete_lwp_cleanup (void *lp_voidp)
369 struct lwp_info *lp = lp_voidp;
371 delete_lwp (lp->ptid);
375 linux_child_follow_fork (struct target_ops *ops, int follow_child,
379 int parent_pid, child_pid;
381 has_vforked = (inferior_thread ()->pending_follow.kind
382 == TARGET_WAITKIND_VFORKED);
383 parent_pid = ptid_get_lwp (inferior_ptid);
385 parent_pid = ptid_get_pid (inferior_ptid);
387 = ptid_get_pid (inferior_thread ()->pending_follow.value.related_pid);
390 && !non_stop /* Non-stop always resumes both branches. */
391 && (!target_is_async_p () || sync_execution)
392 && !(follow_child || detach_fork || sched_multi))
394 /* The parent stays blocked inside the vfork syscall until the
395 child execs or exits. If we don't let the child run, then
396 the parent stays blocked. If we're telling the parent to run
397 in the foreground, the user will not be able to ctrl-c to get
398 back the terminal, effectively hanging the debug session. */
399 fprintf_filtered (gdb_stderr, _("\
400 Can not resume the parent process over vfork in the foreground while\n\
401 holding the child stopped. Try \"set detach-on-fork\" or \
402 \"set schedule-multiple\".\n"));
403 /* FIXME output string > 80 columns. */
409 struct lwp_info *child_lp = NULL;
411 /* We're already attached to the parent, by default. */
413 /* Detach new forked process? */
416 struct cleanup *old_chain;
418 /* Before detaching from the child, remove all breakpoints
419 from it. If we forked, then this has already been taken
420 care of by infrun.c. If we vforked however, any
421 breakpoint inserted in the parent is visible in the
422 child, even those added while stopped in a vfork
423 catchpoint. This will remove the breakpoints from the
424 parent also, but they'll be reinserted below. */
427 /* keep breakpoints list in sync. */
428 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
431 if (info_verbose || debug_linux_nat)
433 target_terminal_ours ();
434 fprintf_filtered (gdb_stdlog,
435 "Detaching after fork from "
436 "child process %d.\n",
440 old_chain = save_inferior_ptid ();
441 inferior_ptid = ptid_build (child_pid, child_pid, 0);
443 child_lp = add_lwp (inferior_ptid);
444 child_lp->stopped = 1;
445 child_lp->last_resume_kind = resume_stop;
446 make_cleanup (delete_lwp_cleanup, child_lp);
448 if (linux_nat_prepare_to_resume != NULL)
449 linux_nat_prepare_to_resume (child_lp);
450 ptrace (PTRACE_DETACH, child_pid, 0, 0);
452 do_cleanups (old_chain);
456 struct inferior *parent_inf, *child_inf;
457 struct cleanup *old_chain;
459 /* Add process to GDB's tables. */
460 child_inf = add_inferior (child_pid);
462 parent_inf = current_inferior ();
463 child_inf->attach_flag = parent_inf->attach_flag;
464 copy_terminal_info (child_inf, parent_inf);
465 child_inf->gdbarch = parent_inf->gdbarch;
466 copy_inferior_target_desc_info (child_inf, parent_inf);
468 old_chain = save_inferior_ptid ();
469 save_current_program_space ();
471 inferior_ptid = ptid_build (child_pid, child_pid, 0);
472 add_thread (inferior_ptid);
473 child_lp = add_lwp (inferior_ptid);
474 child_lp->stopped = 1;
475 child_lp->last_resume_kind = resume_stop;
476 child_inf->symfile_flags = SYMFILE_NO_READ;
478 /* If this is a vfork child, then the address-space is
479 shared with the parent. */
482 child_inf->pspace = parent_inf->pspace;
483 child_inf->aspace = parent_inf->aspace;
485 /* The parent will be frozen until the child is done
486 with the shared region. Keep track of the
488 child_inf->vfork_parent = parent_inf;
489 child_inf->pending_detach = 0;
490 parent_inf->vfork_child = child_inf;
491 parent_inf->pending_detach = 0;
495 child_inf->aspace = new_address_space ();
496 child_inf->pspace = add_program_space (child_inf->aspace);
497 child_inf->removable = 1;
498 set_current_program_space (child_inf->pspace);
499 clone_program_space (child_inf->pspace, parent_inf->pspace);
501 /* Let the shared library layer (solib-svr4) learn about
502 this new process, relocate the cloned exec, pull in
503 shared libraries, and install the solib event
504 breakpoint. If a "cloned-VM" event was propagated
505 better throughout the core, this wouldn't be
507 solib_create_inferior_hook (0);
510 /* Let the thread_db layer learn about this new process. */
511 check_for_thread_db ();
513 do_cleanups (old_chain);
518 struct lwp_info *parent_lp;
519 struct inferior *parent_inf;
521 parent_inf = current_inferior ();
523 /* If we detached from the child, then we have to be careful
524 to not insert breakpoints in the parent until the child
525 is done with the shared memory region. However, if we're
526 staying attached to the child, then we can and should
527 insert breakpoints, so that we can debug it. A
528 subsequent child exec or exit is enough to know when does
529 the child stops using the parent's address space. */
530 parent_inf->waiting_for_vfork_done = detach_fork;
531 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
533 parent_lp = find_lwp_pid (pid_to_ptid (parent_pid));
534 gdb_assert (linux_supports_tracefork () >= 0);
536 if (linux_supports_tracevforkdone ())
539 fprintf_unfiltered (gdb_stdlog,
540 "LCFF: waiting for VFORK_DONE on %d\n",
542 parent_lp->stopped = 1;
544 /* We'll handle the VFORK_DONE event like any other
545 event, in target_wait. */
549 /* We can't insert breakpoints until the child has
550 finished with the shared memory region. We need to
551 wait until that happens. Ideal would be to just
553 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
554 - waitpid (parent_pid, &status, __WALL);
555 However, most architectures can't handle a syscall
556 being traced on the way out if it wasn't traced on
559 We might also think to loop, continuing the child
560 until it exits or gets a SIGTRAP. One problem is
561 that the child might call ptrace with PTRACE_TRACEME.
563 There's no simple and reliable way to figure out when
564 the vforked child will be done with its copy of the
565 shared memory. We could step it out of the syscall,
566 two instructions, let it go, and then single-step the
567 parent once. When we have hardware single-step, this
568 would work; with software single-step it could still
569 be made to work but we'd have to be able to insert
570 single-step breakpoints in the child, and we'd have
571 to insert -just- the single-step breakpoint in the
572 parent. Very awkward.
574 In the end, the best we can do is to make sure it
575 runs for a little while. Hopefully it will be out of
576 range of any breakpoints we reinsert. Usually this
577 is only the single-step breakpoint at vfork's return
581 fprintf_unfiltered (gdb_stdlog,
582 "LCFF: no VFORK_DONE "
583 "support, sleeping a bit\n");
587 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
588 and leave it pending. The next linux_nat_resume call
589 will notice a pending event, and bypasses actually
590 resuming the inferior. */
591 parent_lp->status = 0;
592 parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
593 parent_lp->stopped = 1;
595 /* If we're in async mode, need to tell the event loop
596 there's something here to process. */
597 if (target_can_async_p ())
604 struct inferior *parent_inf, *child_inf;
605 struct lwp_info *child_lp;
606 struct program_space *parent_pspace;
608 if (info_verbose || debug_linux_nat)
610 target_terminal_ours ();
612 fprintf_filtered (gdb_stdlog,
613 _("Attaching after process %d "
614 "vfork to child process %d.\n"),
615 parent_pid, child_pid);
617 fprintf_filtered (gdb_stdlog,
618 _("Attaching after process %d "
619 "fork to child process %d.\n"),
620 parent_pid, child_pid);
623 /* Add the new inferior first, so that the target_detach below
624 doesn't unpush the target. */
626 child_inf = add_inferior (child_pid);
628 parent_inf = current_inferior ();
629 child_inf->attach_flag = parent_inf->attach_flag;
630 copy_terminal_info (child_inf, parent_inf);
631 child_inf->gdbarch = parent_inf->gdbarch;
632 copy_inferior_target_desc_info (child_inf, parent_inf);
634 parent_pspace = parent_inf->pspace;
636 /* If we're vforking, we want to hold on to the parent until the
637 child exits or execs. At child exec or exit time we can
638 remove the old breakpoints from the parent and detach or
639 resume debugging it. Otherwise, detach the parent now; we'll
640 want to reuse it's program/address spaces, but we can't set
641 them to the child before removing breakpoints from the
642 parent, otherwise, the breakpoints module could decide to
643 remove breakpoints from the wrong process (since they'd be
644 assigned to the same address space). */
648 gdb_assert (child_inf->vfork_parent == NULL);
649 gdb_assert (parent_inf->vfork_child == NULL);
650 child_inf->vfork_parent = parent_inf;
651 child_inf->pending_detach = 0;
652 parent_inf->vfork_child = child_inf;
653 parent_inf->pending_detach = detach_fork;
654 parent_inf->waiting_for_vfork_done = 0;
656 else if (detach_fork)
657 target_detach (NULL, 0);
659 /* Note that the detach above makes PARENT_INF dangling. */
661 /* Add the child thread to the appropriate lists, and switch to
662 this new thread, before cloning the program space, and
663 informing the solib layer about this new process. */
665 inferior_ptid = ptid_build (child_pid, child_pid, 0);
666 add_thread (inferior_ptid);
667 child_lp = add_lwp (inferior_ptid);
668 child_lp->stopped = 1;
669 child_lp->last_resume_kind = resume_stop;
671 /* If this is a vfork child, then the address-space is shared
672 with the parent. If we detached from the parent, then we can
673 reuse the parent's program/address spaces. */
674 if (has_vforked || detach_fork)
676 child_inf->pspace = parent_pspace;
677 child_inf->aspace = child_inf->pspace->aspace;
681 child_inf->aspace = new_address_space ();
682 child_inf->pspace = add_program_space (child_inf->aspace);
683 child_inf->removable = 1;
684 child_inf->symfile_flags = SYMFILE_NO_READ;
685 set_current_program_space (child_inf->pspace);
686 clone_program_space (child_inf->pspace, parent_pspace);
688 /* Let the shared library layer (solib-svr4) learn about
689 this new process, relocate the cloned exec, pull in
690 shared libraries, and install the solib event breakpoint.
691 If a "cloned-VM" event was propagated better throughout
692 the core, this wouldn't be required. */
693 solib_create_inferior_hook (0);
696 /* Let the thread_db layer learn about this new process. */
697 check_for_thread_db ();
705 linux_child_insert_fork_catchpoint (struct target_ops *self, int pid)
707 return !linux_supports_tracefork ();
711 linux_child_remove_fork_catchpoint (struct target_ops *self, int pid)
717 linux_child_insert_vfork_catchpoint (struct target_ops *self, int pid)
719 return !linux_supports_tracefork ();
723 linux_child_remove_vfork_catchpoint (struct target_ops *self, int pid)
729 linux_child_insert_exec_catchpoint (struct target_ops *self, int pid)
731 return !linux_supports_tracefork ();
735 linux_child_remove_exec_catchpoint (struct target_ops *self, int pid)
741 linux_child_set_syscall_catchpoint (struct target_ops *self,
742 int pid, int needed, int any_count,
743 int table_size, int *table)
745 if (!linux_supports_tracesysgood ())
748 /* On GNU/Linux, we ignore the arguments. It means that we only
749 enable the syscall catchpoints, but do not disable them.
751 Also, we do not use the `table' information because we do not
752 filter system calls here. We let GDB do the logic for us. */
756 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
757 are processes sharing the same VM space. A multi-threaded process
758 is basically a group of such processes. However, such a grouping
759 is almost entirely a user-space issue; the kernel doesn't enforce
760 such a grouping at all (this might change in the future). In
761 general, we'll rely on the threads library (i.e. the GNU/Linux
762 Threads library) to provide such a grouping.
764 It is perfectly well possible to write a multi-threaded application
765 without the assistance of a threads library, by using the clone
766 system call directly. This module should be able to give some
767 rudimentary support for debugging such applications if developers
768 specify the CLONE_PTRACE flag in the clone system call, and are
769 using the Linux kernel 2.4 or above.
771 Note that there are some peculiarities in GNU/Linux that affect
774 - In general one should specify the __WCLONE flag to waitpid in
775 order to make it report events for any of the cloned processes
776 (and leave it out for the initial process). However, if a cloned
777 process has exited the exit status is only reported if the
778 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
779 we cannot use it since GDB must work on older systems too.
781 - When a traced, cloned process exits and is waited for by the
782 debugger, the kernel reassigns it to the original parent and
783 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
784 library doesn't notice this, which leads to the "zombie problem":
785 When debugged a multi-threaded process that spawns a lot of
786 threads will run out of processes, even if the threads exit,
787 because the "zombies" stay around. */
789 /* List of known LWPs. */
790 struct lwp_info *lwp_list;
793 /* Original signal mask. */
794 static sigset_t normal_mask;
796 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
797 _initialize_linux_nat. */
798 static sigset_t suspend_mask;
800 /* Signals to block to make that sigsuspend work. */
801 static sigset_t blocked_mask;
803 /* SIGCHLD action. */
804 struct sigaction sigchld_action;
806 /* Block child signals (SIGCHLD and linux threads signals), and store
807 the previous mask in PREV_MASK. */
810 block_child_signals (sigset_t *prev_mask)
812 /* Make sure SIGCHLD is blocked. */
813 if (!sigismember (&blocked_mask, SIGCHLD))
814 sigaddset (&blocked_mask, SIGCHLD);
816 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
819 /* Restore child signals mask, previously returned by
820 block_child_signals. */
823 restore_child_signals_mask (sigset_t *prev_mask)
825 sigprocmask (SIG_SETMASK, prev_mask, NULL);
828 /* Mask of signals to pass directly to the inferior. */
829 static sigset_t pass_mask;
831 /* Update signals to pass to the inferior. */
833 linux_nat_pass_signals (struct target_ops *self,
834 int numsigs, unsigned char *pass_signals)
838 sigemptyset (&pass_mask);
840 for (signo = 1; signo < NSIG; signo++)
842 int target_signo = gdb_signal_from_host (signo);
843 if (target_signo < numsigs && pass_signals[target_signo])
844 sigaddset (&pass_mask, signo);
850 /* Prototypes for local functions. */
851 static int stop_wait_callback (struct lwp_info *lp, void *data);
852 static int linux_thread_alive (ptid_t ptid);
853 static char *linux_child_pid_to_exec_file (struct target_ops *self, int pid);
857 /* Destroy and free LP. */
860 lwp_free (struct lwp_info *lp)
862 xfree (lp->arch_private);
866 /* Remove all LWPs belong to PID from the lwp list. */
869 purge_lwp_list (int pid)
871 struct lwp_info *lp, *lpprev, *lpnext;
875 for (lp = lwp_list; lp; lp = lpnext)
879 if (ptid_get_pid (lp->ptid) == pid)
884 lpprev->next = lp->next;
893 /* Add the LWP specified by PTID to the list. PTID is the first LWP
894 in the process. Return a pointer to the structure describing the
897 This differs from add_lwp in that we don't let the arch specific
898 bits know about this new thread. Current clients of this callback
899 take the opportunity to install watchpoints in the new thread, and
900 we shouldn't do that for the first thread. If we're spawning a
901 child ("run"), the thread executes the shell wrapper first, and we
902 shouldn't touch it until it execs the program we want to debug.
903 For "attach", it'd be okay to call the callback, but it's not
904 necessary, because watchpoints can't yet have been inserted into
907 static struct lwp_info *
908 add_initial_lwp (ptid_t ptid)
912 gdb_assert (ptid_lwp_p (ptid));
914 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
916 memset (lp, 0, sizeof (struct lwp_info));
918 lp->last_resume_kind = resume_continue;
919 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
930 /* Add the LWP specified by PID to the list. Return a pointer to the
931 structure describing the new LWP. The LWP should already be
934 static struct lwp_info *
935 add_lwp (ptid_t ptid)
939 lp = add_initial_lwp (ptid);
941 /* Let the arch specific bits know about this new thread. Current
942 clients of this callback take the opportunity to install
943 watchpoints in the new thread. We don't do this for the first
944 thread though. See add_initial_lwp. */
945 if (linux_nat_new_thread != NULL)
946 linux_nat_new_thread (lp);
951 /* Remove the LWP specified by PID from the list. */
954 delete_lwp (ptid_t ptid)
956 struct lwp_info *lp, *lpprev;
960 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
961 if (ptid_equal (lp->ptid, ptid))
968 lpprev->next = lp->next;
975 /* Return a pointer to the structure describing the LWP corresponding
976 to PID. If no corresponding LWP could be found, return NULL. */
978 static struct lwp_info *
979 find_lwp_pid (ptid_t ptid)
984 if (ptid_lwp_p (ptid))
985 lwp = ptid_get_lwp (ptid);
987 lwp = ptid_get_pid (ptid);
989 for (lp = lwp_list; lp; lp = lp->next)
990 if (lwp == ptid_get_lwp (lp->ptid))
996 /* Call CALLBACK with its second argument set to DATA for every LWP in
997 the list. If CALLBACK returns 1 for a particular LWP, return a
998 pointer to the structure describing that LWP immediately.
999 Otherwise return NULL. */
1002 iterate_over_lwps (ptid_t filter,
1003 int (*callback) (struct lwp_info *, void *),
1006 struct lwp_info *lp, *lpnext;
1008 for (lp = lwp_list; lp; lp = lpnext)
1012 if (ptid_match (lp->ptid, filter))
1014 if ((*callback) (lp, data))
1022 /* Update our internal state when changing from one checkpoint to
1023 another indicated by NEW_PTID. We can only switch single-threaded
1024 applications, so we only create one new LWP, and the previous list
1028 linux_nat_switch_fork (ptid_t new_ptid)
1030 struct lwp_info *lp;
1032 purge_lwp_list (ptid_get_pid (inferior_ptid));
1034 lp = add_lwp (new_ptid);
1037 /* This changes the thread's ptid while preserving the gdb thread
1038 num. Also changes the inferior pid, while preserving the
1040 thread_change_ptid (inferior_ptid, new_ptid);
1042 /* We've just told GDB core that the thread changed target id, but,
1043 in fact, it really is a different thread, with different register
1045 registers_changed ();
1048 /* Handle the exit of a single thread LP. */
1051 exit_lwp (struct lwp_info *lp)
1053 struct thread_info *th = find_thread_ptid (lp->ptid);
1057 if (print_thread_events)
1058 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1060 delete_thread (lp->ptid);
1063 delete_lwp (lp->ptid);
1066 /* Wait for the LWP specified by LP, which we have just attached to.
1067 Returns a wait status for that LWP, to cache. */
1070 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1073 pid_t new_pid, pid = ptid_get_lwp (ptid);
1076 if (linux_proc_pid_is_stopped (pid))
1078 if (debug_linux_nat)
1079 fprintf_unfiltered (gdb_stdlog,
1080 "LNPAW: Attaching to a stopped process\n");
1082 /* The process is definitely stopped. It is in a job control
1083 stop, unless the kernel predates the TASK_STOPPED /
1084 TASK_TRACED distinction, in which case it might be in a
1085 ptrace stop. Make sure it is in a ptrace stop; from there we
1086 can kill it, signal it, et cetera.
1088 First make sure there is a pending SIGSTOP. Since we are
1089 already attached, the process can not transition from stopped
1090 to running without a PTRACE_CONT; so we know this signal will
1091 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1092 probably already in the queue (unless this kernel is old
1093 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1094 is not an RT signal, it can only be queued once. */
1095 kill_lwp (pid, SIGSTOP);
1097 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1098 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1099 ptrace (PTRACE_CONT, pid, 0, 0);
1102 /* Make sure the initial process is stopped. The user-level threads
1103 layer might want to poke around in the inferior, and that won't
1104 work if things haven't stabilized yet. */
1105 new_pid = my_waitpid (pid, &status, 0);
1106 if (new_pid == -1 && errno == ECHILD)
1109 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1111 /* Try again with __WCLONE to check cloned processes. */
1112 new_pid = my_waitpid (pid, &status, __WCLONE);
1116 gdb_assert (pid == new_pid);
1118 if (!WIFSTOPPED (status))
1120 /* The pid we tried to attach has apparently just exited. */
1121 if (debug_linux_nat)
1122 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1123 pid, status_to_str (status));
1127 if (WSTOPSIG (status) != SIGSTOP)
1130 if (debug_linux_nat)
1131 fprintf_unfiltered (gdb_stdlog,
1132 "LNPAW: Received %s after attaching\n",
1133 status_to_str (status));
1139 /* Attach to the LWP specified by PID. Return 0 if successful, -1 if
1140 the new LWP could not be attached, or 1 if we're already auto
1141 attached to this thread, but haven't processed the
1142 PTRACE_EVENT_CLONE event of its parent thread, so we just ignore
1143 its existance, without considering it an error. */
1146 lin_lwp_attach_lwp (ptid_t ptid)
1148 struct lwp_info *lp;
1151 gdb_assert (ptid_lwp_p (ptid));
1153 lp = find_lwp_pid (ptid);
1154 lwpid = ptid_get_lwp (ptid);
1156 /* We assume that we're already attached to any LWP that has an id
1157 equal to the overall process id, and to any LWP that is already
1158 in our list of LWPs. If we're not seeing exit events from threads
1159 and we've had PID wraparound since we last tried to stop all threads,
1160 this assumption might be wrong; fortunately, this is very unlikely
1162 if (lwpid != ptid_get_pid (ptid) && lp == NULL)
1164 int status, cloned = 0, signalled = 0;
1166 if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0)
1168 if (linux_supports_tracefork ())
1170 /* If we haven't stopped all threads when we get here,
1171 we may have seen a thread listed in thread_db's list,
1172 but not processed the PTRACE_EVENT_CLONE yet. If
1173 that's the case, ignore this new thread, and let
1174 normal event handling discover it later. */
1175 if (in_pid_list_p (stopped_pids, lwpid))
1177 /* We've already seen this thread stop, but we
1178 haven't seen the PTRACE_EVENT_CLONE extended
1187 /* See if we've got a stop for this new child
1188 pending. If so, we're already attached. */
1189 new_pid = my_waitpid (lwpid, &status, WNOHANG);
1190 if (new_pid == -1 && errno == ECHILD)
1191 new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG);
1194 if (WIFSTOPPED (status))
1195 add_to_pid_list (&stopped_pids, lwpid, status);
1201 /* If we fail to attach to the thread, issue a warning,
1202 but continue. One way this can happen is if thread
1203 creation is interrupted; as of Linux kernel 2.6.19, a
1204 bug may place threads in the thread list and then fail
1206 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1207 safe_strerror (errno));
1211 if (debug_linux_nat)
1212 fprintf_unfiltered (gdb_stdlog,
1213 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1214 target_pid_to_str (ptid));
1216 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1217 if (!WIFSTOPPED (status))
1220 lp = add_lwp (ptid);
1222 lp->cloned = cloned;
1223 lp->signalled = signalled;
1224 if (WSTOPSIG (status) != SIGSTOP)
1227 lp->status = status;
1230 target_post_attach (ptid_get_lwp (lp->ptid));
1232 if (debug_linux_nat)
1234 fprintf_unfiltered (gdb_stdlog,
1235 "LLAL: waitpid %s received %s\n",
1236 target_pid_to_str (ptid),
1237 status_to_str (status));
1242 /* We assume that the LWP representing the original process is
1243 already stopped. Mark it as stopped in the data structure
1244 that the GNU/linux ptrace layer uses to keep track of
1245 threads. Note that this won't have already been done since
1246 the main thread will have, we assume, been stopped by an
1247 attach from a different layer. */
1249 lp = add_lwp (ptid);
1253 lp->last_resume_kind = resume_stop;
1258 linux_nat_create_inferior (struct target_ops *ops,
1259 char *exec_file, char *allargs, char **env,
1262 #ifdef HAVE_PERSONALITY
1263 int personality_orig = 0, personality_set = 0;
1264 #endif /* HAVE_PERSONALITY */
1266 /* The fork_child mechanism is synchronous and calls target_wait, so
1267 we have to mask the async mode. */
1269 #ifdef HAVE_PERSONALITY
1270 if (disable_randomization)
1273 personality_orig = personality (0xffffffff);
1274 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1276 personality_set = 1;
1277 personality (personality_orig | ADDR_NO_RANDOMIZE);
1279 if (errno != 0 || (personality_set
1280 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1281 warning (_("Error disabling address space randomization: %s"),
1282 safe_strerror (errno));
1284 #endif /* HAVE_PERSONALITY */
1286 /* Make sure we report all signals during startup. */
1287 linux_nat_pass_signals (ops, 0, NULL);
1289 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1291 #ifdef HAVE_PERSONALITY
1292 if (personality_set)
1295 personality (personality_orig);
1297 warning (_("Error restoring address space randomization: %s"),
1298 safe_strerror (errno));
1300 #endif /* HAVE_PERSONALITY */
1304 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1306 struct lwp_info *lp;
1309 volatile struct gdb_exception ex;
1311 /* Make sure we report all signals during attach. */
1312 linux_nat_pass_signals (ops, 0, NULL);
1314 TRY_CATCH (ex, RETURN_MASK_ERROR)
1316 linux_ops->to_attach (ops, args, from_tty);
1320 pid_t pid = parse_pid_to_attach (args);
1321 struct buffer buffer;
1322 char *message, *buffer_s;
1324 message = xstrdup (ex.message);
1325 make_cleanup (xfree, message);
1327 buffer_init (&buffer);
1328 linux_ptrace_attach_fail_reason (pid, &buffer);
1330 buffer_grow_str0 (&buffer, "");
1331 buffer_s = buffer_finish (&buffer);
1332 make_cleanup (xfree, buffer_s);
1334 if (*buffer_s != '\0')
1335 throw_error (ex.error, "warning: %s\n%s", buffer_s, message);
1337 throw_error (ex.error, "%s", message);
1340 /* The ptrace base target adds the main thread with (pid,0,0)
1341 format. Decorate it with lwp info. */
1342 ptid = ptid_build (ptid_get_pid (inferior_ptid),
1343 ptid_get_pid (inferior_ptid),
1345 thread_change_ptid (inferior_ptid, ptid);
1347 /* Add the initial process as the first LWP to the list. */
1348 lp = add_initial_lwp (ptid);
1350 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1352 if (!WIFSTOPPED (status))
1354 if (WIFEXITED (status))
1356 int exit_code = WEXITSTATUS (status);
1358 target_terminal_ours ();
1359 target_mourn_inferior ();
1361 error (_("Unable to attach: program exited normally."));
1363 error (_("Unable to attach: program exited with code %d."),
1366 else if (WIFSIGNALED (status))
1368 enum gdb_signal signo;
1370 target_terminal_ours ();
1371 target_mourn_inferior ();
1373 signo = gdb_signal_from_host (WTERMSIG (status));
1374 error (_("Unable to attach: program terminated with signal "
1376 gdb_signal_to_name (signo),
1377 gdb_signal_to_string (signo));
1380 internal_error (__FILE__, __LINE__,
1381 _("unexpected status %d for PID %ld"),
1382 status, (long) ptid_get_lwp (ptid));
1387 /* Save the wait status to report later. */
1389 if (debug_linux_nat)
1390 fprintf_unfiltered (gdb_stdlog,
1391 "LNA: waitpid %ld, saving status %s\n",
1392 (long) ptid_get_pid (lp->ptid), status_to_str (status));
1394 lp->status = status;
1396 if (target_can_async_p ())
1397 target_async (inferior_event_handler, 0);
1400 /* Get pending status of LP. */
1402 get_pending_status (struct lwp_info *lp, int *status)
1404 enum gdb_signal signo = GDB_SIGNAL_0;
1406 /* If we paused threads momentarily, we may have stored pending
1407 events in lp->status or lp->waitstatus (see stop_wait_callback),
1408 and GDB core hasn't seen any signal for those threads.
1409 Otherwise, the last signal reported to the core is found in the
1410 thread object's stop_signal.
1412 There's a corner case that isn't handled here at present. Only
1413 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1414 stop_signal make sense as a real signal to pass to the inferior.
1415 Some catchpoint related events, like
1416 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1417 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1418 those traps are debug API (ptrace in our case) related and
1419 induced; the inferior wouldn't see them if it wasn't being
1420 traced. Hence, we should never pass them to the inferior, even
1421 when set to pass state. Since this corner case isn't handled by
1422 infrun.c when proceeding with a signal, for consistency, neither
1423 do we handle it here (or elsewhere in the file we check for
1424 signal pass state). Normally SIGTRAP isn't set to pass state, so
1425 this is really a corner case. */
1427 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1428 signo = GDB_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1429 else if (lp->status)
1430 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1431 else if (non_stop && !is_executing (lp->ptid))
1433 struct thread_info *tp = find_thread_ptid (lp->ptid);
1435 signo = tp->suspend.stop_signal;
1439 struct target_waitstatus last;
1442 get_last_target_status (&last_ptid, &last);
1444 if (ptid_get_lwp (lp->ptid) == ptid_get_lwp (last_ptid))
1446 struct thread_info *tp = find_thread_ptid (lp->ptid);
1448 signo = tp->suspend.stop_signal;
1454 if (signo == GDB_SIGNAL_0)
1456 if (debug_linux_nat)
1457 fprintf_unfiltered (gdb_stdlog,
1458 "GPT: lwp %s has no pending signal\n",
1459 target_pid_to_str (lp->ptid));
1461 else if (!signal_pass_state (signo))
1463 if (debug_linux_nat)
1464 fprintf_unfiltered (gdb_stdlog,
1465 "GPT: lwp %s had signal %s, "
1466 "but it is in no pass state\n",
1467 target_pid_to_str (lp->ptid),
1468 gdb_signal_to_string (signo));
1472 *status = W_STOPCODE (gdb_signal_to_host (signo));
1474 if (debug_linux_nat)
1475 fprintf_unfiltered (gdb_stdlog,
1476 "GPT: lwp %s has pending signal %s\n",
1477 target_pid_to_str (lp->ptid),
1478 gdb_signal_to_string (signo));
1485 detach_callback (struct lwp_info *lp, void *data)
1487 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1489 if (debug_linux_nat && lp->status)
1490 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1491 strsignal (WSTOPSIG (lp->status)),
1492 target_pid_to_str (lp->ptid));
1494 /* If there is a pending SIGSTOP, get rid of it. */
1497 if (debug_linux_nat)
1498 fprintf_unfiltered (gdb_stdlog,
1499 "DC: Sending SIGCONT to %s\n",
1500 target_pid_to_str (lp->ptid));
1502 kill_lwp (ptid_get_lwp (lp->ptid), SIGCONT);
1506 /* We don't actually detach from the LWP that has an id equal to the
1507 overall process id just yet. */
1508 if (ptid_get_lwp (lp->ptid) != ptid_get_pid (lp->ptid))
1512 /* Pass on any pending signal for this LWP. */
1513 get_pending_status (lp, &status);
1515 if (linux_nat_prepare_to_resume != NULL)
1516 linux_nat_prepare_to_resume (lp);
1518 if (ptrace (PTRACE_DETACH, ptid_get_lwp (lp->ptid), 0,
1519 WSTOPSIG (status)) < 0)
1520 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1521 safe_strerror (errno));
1523 if (debug_linux_nat)
1524 fprintf_unfiltered (gdb_stdlog,
1525 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1526 target_pid_to_str (lp->ptid),
1527 strsignal (WSTOPSIG (status)));
1529 delete_lwp (lp->ptid);
1536 linux_nat_detach (struct target_ops *ops, const char *args, int from_tty)
1540 struct lwp_info *main_lwp;
1542 pid = ptid_get_pid (inferior_ptid);
1544 /* Don't unregister from the event loop, as there may be other
1545 inferiors running. */
1547 /* Stop all threads before detaching. ptrace requires that the
1548 thread is stopped to sucessfully detach. */
1549 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1550 /* ... and wait until all of them have reported back that
1551 they're no longer running. */
1552 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1554 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1556 /* Only the initial process should be left right now. */
1557 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid)) == 1);
1559 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1561 /* Pass on any pending signal for the last LWP. */
1562 if ((args == NULL || *args == '\0')
1563 && get_pending_status (main_lwp, &status) != -1
1564 && WIFSTOPPED (status))
1568 /* Put the signal number in ARGS so that inf_ptrace_detach will
1569 pass it along with PTRACE_DETACH. */
1571 xsnprintf (tem, 8, "%d", (int) WSTOPSIG (status));
1573 if (debug_linux_nat)
1574 fprintf_unfiltered (gdb_stdlog,
1575 "LND: Sending signal %s to %s\n",
1577 target_pid_to_str (main_lwp->ptid));
1580 if (linux_nat_prepare_to_resume != NULL)
1581 linux_nat_prepare_to_resume (main_lwp);
1582 delete_lwp (main_lwp->ptid);
1584 if (forks_exist_p ())
1586 /* Multi-fork case. The current inferior_ptid is being detached
1587 from, but there are other viable forks to debug. Detach from
1588 the current fork, and context-switch to the first
1590 linux_fork_detach (args, from_tty);
1593 linux_ops->to_detach (ops, args, from_tty);
1599 resume_lwp (struct lwp_info *lp, int step, enum gdb_signal signo)
1603 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
1605 if (inf->vfork_child != NULL)
1607 if (debug_linux_nat)
1608 fprintf_unfiltered (gdb_stdlog,
1609 "RC: Not resuming %s (vfork parent)\n",
1610 target_pid_to_str (lp->ptid));
1612 else if (lp->status == 0
1613 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
1615 if (debug_linux_nat)
1616 fprintf_unfiltered (gdb_stdlog,
1617 "RC: Resuming sibling %s, %s, %s\n",
1618 target_pid_to_str (lp->ptid),
1619 (signo != GDB_SIGNAL_0
1620 ? strsignal (gdb_signal_to_host (signo))
1622 step ? "step" : "resume");
1624 if (linux_nat_prepare_to_resume != NULL)
1625 linux_nat_prepare_to_resume (lp);
1626 linux_ops->to_resume (linux_ops,
1627 pid_to_ptid (ptid_get_lwp (lp->ptid)),
1631 lp->stopped_by_watchpoint = 0;
1635 if (debug_linux_nat)
1636 fprintf_unfiltered (gdb_stdlog,
1637 "RC: Not resuming sibling %s (has pending)\n",
1638 target_pid_to_str (lp->ptid));
1643 if (debug_linux_nat)
1644 fprintf_unfiltered (gdb_stdlog,
1645 "RC: Not resuming sibling %s (not stopped)\n",
1646 target_pid_to_str (lp->ptid));
1650 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1651 Resume LWP with the last stop signal, if it is in pass state. */
1654 linux_nat_resume_callback (struct lwp_info *lp, void *except)
1656 enum gdb_signal signo = GDB_SIGNAL_0;
1663 struct thread_info *thread;
1665 thread = find_thread_ptid (lp->ptid);
1668 if (signal_pass_state (thread->suspend.stop_signal))
1669 signo = thread->suspend.stop_signal;
1670 thread->suspend.stop_signal = GDB_SIGNAL_0;
1674 resume_lwp (lp, 0, signo);
1679 resume_clear_callback (struct lwp_info *lp, void *data)
1682 lp->last_resume_kind = resume_stop;
1687 resume_set_callback (struct lwp_info *lp, void *data)
1690 lp->last_resume_kind = resume_continue;
1695 linux_nat_resume (struct target_ops *ops,
1696 ptid_t ptid, int step, enum gdb_signal signo)
1698 struct lwp_info *lp;
1701 if (debug_linux_nat)
1702 fprintf_unfiltered (gdb_stdlog,
1703 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1704 step ? "step" : "resume",
1705 target_pid_to_str (ptid),
1706 (signo != GDB_SIGNAL_0
1707 ? strsignal (gdb_signal_to_host (signo)) : "0"),
1708 target_pid_to_str (inferior_ptid));
1710 /* A specific PTID means `step only this process id'. */
1711 resume_many = (ptid_equal (minus_one_ptid, ptid)
1712 || ptid_is_pid (ptid));
1714 /* Mark the lwps we're resuming as resumed. */
1715 iterate_over_lwps (ptid, resume_set_callback, NULL);
1717 /* See if it's the current inferior that should be handled
1720 lp = find_lwp_pid (inferior_ptid);
1722 lp = find_lwp_pid (ptid);
1723 gdb_assert (lp != NULL);
1725 /* Remember if we're stepping. */
1727 lp->last_resume_kind = step ? resume_step : resume_continue;
1729 /* If we have a pending wait status for this thread, there is no
1730 point in resuming the process. But first make sure that
1731 linux_nat_wait won't preemptively handle the event - we
1732 should never take this short-circuit if we are going to
1733 leave LP running, since we have skipped resuming all the
1734 other threads. This bit of code needs to be synchronized
1735 with linux_nat_wait. */
1737 if (lp->status && WIFSTOPPED (lp->status))
1740 && WSTOPSIG (lp->status)
1741 && sigismember (&pass_mask, WSTOPSIG (lp->status)))
1743 if (debug_linux_nat)
1744 fprintf_unfiltered (gdb_stdlog,
1745 "LLR: Not short circuiting for ignored "
1746 "status 0x%x\n", lp->status);
1748 /* FIXME: What should we do if we are supposed to continue
1749 this thread with a signal? */
1750 gdb_assert (signo == GDB_SIGNAL_0);
1751 signo = gdb_signal_from_host (WSTOPSIG (lp->status));
1756 if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1758 /* FIXME: What should we do if we are supposed to continue
1759 this thread with a signal? */
1760 gdb_assert (signo == GDB_SIGNAL_0);
1762 if (debug_linux_nat)
1763 fprintf_unfiltered (gdb_stdlog,
1764 "LLR: Short circuiting for status 0x%x\n",
1767 if (target_can_async_p ())
1769 target_async (inferior_event_handler, 0);
1770 /* Tell the event loop we have something to process. */
1777 iterate_over_lwps (ptid, linux_nat_resume_callback, lp);
1779 /* Convert to something the lower layer understands. */
1780 ptid = pid_to_ptid (ptid_get_lwp (lp->ptid));
1782 if (linux_nat_prepare_to_resume != NULL)
1783 linux_nat_prepare_to_resume (lp);
1784 linux_ops->to_resume (linux_ops, ptid, step, signo);
1785 lp->stopped_by_watchpoint = 0;
1788 if (debug_linux_nat)
1789 fprintf_unfiltered (gdb_stdlog,
1790 "LLR: %s %s, %s (resume event thread)\n",
1791 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1792 target_pid_to_str (ptid),
1793 (signo != GDB_SIGNAL_0
1794 ? strsignal (gdb_signal_to_host (signo)) : "0"));
1796 if (target_can_async_p ())
1797 target_async (inferior_event_handler, 0);
1800 /* Send a signal to an LWP. */
1803 kill_lwp (int lwpid, int signo)
1805 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1806 fails, then we are not using nptl threads and we should be using kill. */
1808 #ifdef HAVE_TKILL_SYSCALL
1810 static int tkill_failed;
1817 ret = syscall (__NR_tkill, lwpid, signo);
1818 if (errno != ENOSYS)
1825 return kill (lwpid, signo);
1828 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1829 event, check if the core is interested in it: if not, ignore the
1830 event, and keep waiting; otherwise, we need to toggle the LWP's
1831 syscall entry/exit status, since the ptrace event itself doesn't
1832 indicate it, and report the trap to higher layers. */
1835 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
1837 struct target_waitstatus *ourstatus = &lp->waitstatus;
1838 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
1839 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
1843 /* If we're stopping threads, there's a SIGSTOP pending, which
1844 makes it so that the LWP reports an immediate syscall return,
1845 followed by the SIGSTOP. Skip seeing that "return" using
1846 PTRACE_CONT directly, and let stop_wait_callback collect the
1847 SIGSTOP. Later when the thread is resumed, a new syscall
1848 entry event. If we didn't do this (and returned 0), we'd
1849 leave a syscall entry pending, and our caller, by using
1850 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1851 itself. Later, when the user re-resumes this LWP, we'd see
1852 another syscall entry event and we'd mistake it for a return.
1854 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1855 (leaving immediately with LWP->signalled set, without issuing
1856 a PTRACE_CONT), it would still be problematic to leave this
1857 syscall enter pending, as later when the thread is resumed,
1858 it would then see the same syscall exit mentioned above,
1859 followed by the delayed SIGSTOP, while the syscall didn't
1860 actually get to execute. It seems it would be even more
1861 confusing to the user. */
1863 if (debug_linux_nat)
1864 fprintf_unfiltered (gdb_stdlog,
1865 "LHST: ignoring syscall %d "
1866 "for LWP %ld (stopping threads), "
1867 "resuming with PTRACE_CONT for SIGSTOP\n",
1869 ptid_get_lwp (lp->ptid));
1871 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1872 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
1877 if (catch_syscall_enabled ())
1879 /* Always update the entry/return state, even if this particular
1880 syscall isn't interesting to the core now. In async mode,
1881 the user could install a new catchpoint for this syscall
1882 between syscall enter/return, and we'll need to know to
1883 report a syscall return if that happens. */
1884 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1885 ? TARGET_WAITKIND_SYSCALL_RETURN
1886 : TARGET_WAITKIND_SYSCALL_ENTRY);
1888 if (catching_syscall_number (syscall_number))
1890 /* Alright, an event to report. */
1891 ourstatus->kind = lp->syscall_state;
1892 ourstatus->value.syscall_number = syscall_number;
1894 if (debug_linux_nat)
1895 fprintf_unfiltered (gdb_stdlog,
1896 "LHST: stopping for %s of syscall %d"
1899 == TARGET_WAITKIND_SYSCALL_ENTRY
1900 ? "entry" : "return",
1902 ptid_get_lwp (lp->ptid));
1906 if (debug_linux_nat)
1907 fprintf_unfiltered (gdb_stdlog,
1908 "LHST: ignoring %s of syscall %d "
1910 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
1911 ? "entry" : "return",
1913 ptid_get_lwp (lp->ptid));
1917 /* If we had been syscall tracing, and hence used PT_SYSCALL
1918 before on this LWP, it could happen that the user removes all
1919 syscall catchpoints before we get to process this event.
1920 There are two noteworthy issues here:
1922 - When stopped at a syscall entry event, resuming with
1923 PT_STEP still resumes executing the syscall and reports a
1926 - Only PT_SYSCALL catches syscall enters. If we last
1927 single-stepped this thread, then this event can't be a
1928 syscall enter. If we last single-stepped this thread, this
1929 has to be a syscall exit.
1931 The points above mean that the next resume, be it PT_STEP or
1932 PT_CONTINUE, can not trigger a syscall trace event. */
1933 if (debug_linux_nat)
1934 fprintf_unfiltered (gdb_stdlog,
1935 "LHST: caught syscall event "
1936 "with no syscall catchpoints."
1937 " %d for LWP %ld, ignoring\n",
1939 ptid_get_lwp (lp->ptid));
1940 lp->syscall_state = TARGET_WAITKIND_IGNORE;
1943 /* The core isn't interested in this event. For efficiency, avoid
1944 stopping all threads only to have the core resume them all again.
1945 Since we're not stopping threads, if we're still syscall tracing
1946 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1947 subsequent syscall. Simply resume using the inf-ptrace layer,
1948 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1950 /* Note that gdbarch_get_syscall_number may access registers, hence
1952 registers_changed ();
1953 if (linux_nat_prepare_to_resume != NULL)
1954 linux_nat_prepare_to_resume (lp);
1955 linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)),
1956 lp->step, GDB_SIGNAL_0);
1961 /* Handle a GNU/Linux extended wait response. If we see a clone
1962 event, we need to add the new LWP to our list (and not report the
1963 trap to higher layers). This function returns non-zero if the
1964 event should be ignored and we should wait again. If STOPPING is
1965 true, the new LWP remains stopped, otherwise it is continued. */
1968 linux_handle_extended_wait (struct lwp_info *lp, int status,
1971 int pid = ptid_get_lwp (lp->ptid);
1972 struct target_waitstatus *ourstatus = &lp->waitstatus;
1973 int event = status >> 16;
1975 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1976 || event == PTRACE_EVENT_CLONE)
1978 unsigned long new_pid;
1981 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1983 /* If we haven't already seen the new PID stop, wait for it now. */
1984 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1986 /* The new child has a pending SIGSTOP. We can't affect it until it
1987 hits the SIGSTOP, but we're already attached. */
1988 ret = my_waitpid (new_pid, &status,
1989 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
1991 perror_with_name (_("waiting for new child"));
1992 else if (ret != new_pid)
1993 internal_error (__FILE__, __LINE__,
1994 _("wait returned unexpected PID %d"), ret);
1995 else if (!WIFSTOPPED (status))
1996 internal_error (__FILE__, __LINE__,
1997 _("wait returned unexpected status 0x%x"), status);
2000 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2002 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK)
2004 /* The arch-specific native code may need to know about new
2005 forks even if those end up never mapped to an
2007 if (linux_nat_new_fork != NULL)
2008 linux_nat_new_fork (lp, new_pid);
2011 if (event == PTRACE_EVENT_FORK
2012 && linux_fork_checkpointing_p (ptid_get_pid (lp->ptid)))
2014 /* Handle checkpointing by linux-fork.c here as a special
2015 case. We don't want the follow-fork-mode or 'catch fork'
2016 to interfere with this. */
2018 /* This won't actually modify the breakpoint list, but will
2019 physically remove the breakpoints from the child. */
2020 detach_breakpoints (ptid_build (new_pid, new_pid, 0));
2022 /* Retain child fork in ptrace (stopped) state. */
2023 if (!find_fork_pid (new_pid))
2026 /* Report as spurious, so that infrun doesn't want to follow
2027 this fork. We're actually doing an infcall in
2029 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2031 /* Report the stop to the core. */
2035 if (event == PTRACE_EVENT_FORK)
2036 ourstatus->kind = TARGET_WAITKIND_FORKED;
2037 else if (event == PTRACE_EVENT_VFORK)
2038 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2041 struct lwp_info *new_lp;
2043 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2045 if (debug_linux_nat)
2046 fprintf_unfiltered (gdb_stdlog,
2047 "LHEW: Got clone event "
2048 "from LWP %d, new child is LWP %ld\n",
2051 new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0));
2053 new_lp->stopped = 1;
2055 if (WSTOPSIG (status) != SIGSTOP)
2057 /* This can happen if someone starts sending signals to
2058 the new thread before it gets a chance to run, which
2059 have a lower number than SIGSTOP (e.g. SIGUSR1).
2060 This is an unlikely case, and harder to handle for
2061 fork / vfork than for clone, so we do not try - but
2062 we handle it for clone events here. We'll send
2063 the other signal on to the thread below. */
2065 new_lp->signalled = 1;
2069 struct thread_info *tp;
2071 /* When we stop for an event in some other thread, and
2072 pull the thread list just as this thread has cloned,
2073 we'll have seen the new thread in the thread_db list
2074 before handling the CLONE event (glibc's
2075 pthread_create adds the new thread to the thread list
2076 before clone'ing, and has the kernel fill in the
2077 thread's tid on the clone call with
2078 CLONE_PARENT_SETTID). If that happened, and the core
2079 had requested the new thread to stop, we'll have
2080 killed it with SIGSTOP. But since SIGSTOP is not an
2081 RT signal, it can only be queued once. We need to be
2082 careful to not resume the LWP if we wanted it to
2083 stop. In that case, we'll leave the SIGSTOP pending.
2084 It will later be reported as GDB_SIGNAL_0. */
2085 tp = find_thread_ptid (new_lp->ptid);
2086 if (tp != NULL && tp->stop_requested)
2087 new_lp->last_resume_kind = resume_stop;
2094 /* Add the new thread to GDB's lists as soon as possible
2097 1) the frontend doesn't have to wait for a stop to
2100 2) we tag it with the correct running state. */
2102 /* If the thread_db layer is active, let it know about
2103 this new thread, and add it to GDB's list. */
2104 if (!thread_db_attach_lwp (new_lp->ptid))
2106 /* We're not using thread_db. Add it to GDB's
2108 target_post_attach (ptid_get_lwp (new_lp->ptid));
2109 add_thread (new_lp->ptid);
2114 set_running (new_lp->ptid, 1);
2115 set_executing (new_lp->ptid, 1);
2116 /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced
2118 new_lp->last_resume_kind = resume_continue;
2124 /* We created NEW_LP so it cannot yet contain STATUS. */
2125 gdb_assert (new_lp->status == 0);
2127 /* Save the wait status to report later. */
2128 if (debug_linux_nat)
2129 fprintf_unfiltered (gdb_stdlog,
2130 "LHEW: waitpid of new LWP %ld, "
2131 "saving status %s\n",
2132 (long) ptid_get_lwp (new_lp->ptid),
2133 status_to_str (status));
2134 new_lp->status = status;
2137 /* Note the need to use the low target ops to resume, to
2138 handle resuming with PT_SYSCALL if we have syscall
2142 new_lp->resumed = 1;
2146 gdb_assert (new_lp->last_resume_kind == resume_continue);
2147 if (debug_linux_nat)
2148 fprintf_unfiltered (gdb_stdlog,
2149 "LHEW: resuming new LWP %ld\n",
2150 ptid_get_lwp (new_lp->ptid));
2151 if (linux_nat_prepare_to_resume != NULL)
2152 linux_nat_prepare_to_resume (new_lp);
2153 linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
2155 new_lp->stopped = 0;
2159 if (debug_linux_nat)
2160 fprintf_unfiltered (gdb_stdlog,
2161 "LHEW: resuming parent LWP %d\n", pid);
2162 if (linux_nat_prepare_to_resume != NULL)
2163 linux_nat_prepare_to_resume (lp);
2164 linux_ops->to_resume (linux_ops,
2165 pid_to_ptid (ptid_get_lwp (lp->ptid)),
2174 if (event == PTRACE_EVENT_EXEC)
2176 if (debug_linux_nat)
2177 fprintf_unfiltered (gdb_stdlog,
2178 "LHEW: Got exec event from LWP %ld\n",
2179 ptid_get_lwp (lp->ptid));
2181 ourstatus->kind = TARGET_WAITKIND_EXECD;
2182 ourstatus->value.execd_pathname
2183 = xstrdup (linux_child_pid_to_exec_file (NULL, pid));
2188 if (event == PTRACE_EVENT_VFORK_DONE)
2190 if (current_inferior ()->waiting_for_vfork_done)
2192 if (debug_linux_nat)
2193 fprintf_unfiltered (gdb_stdlog,
2194 "LHEW: Got expected PTRACE_EVENT_"
2195 "VFORK_DONE from LWP %ld: stopping\n",
2196 ptid_get_lwp (lp->ptid));
2198 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2202 if (debug_linux_nat)
2203 fprintf_unfiltered (gdb_stdlog,
2204 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2205 "from LWP %ld: resuming\n",
2206 ptid_get_lwp (lp->ptid));
2207 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2211 internal_error (__FILE__, __LINE__,
2212 _("unknown ptrace event %d"), event);
2215 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2219 wait_lwp (struct lwp_info *lp)
2223 int thread_dead = 0;
2226 gdb_assert (!lp->stopped);
2227 gdb_assert (lp->status == 0);
2229 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2230 block_child_signals (&prev_mask);
2234 /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind
2235 was right and we should just call sigsuspend. */
2237 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, WNOHANG);
2238 if (pid == -1 && errno == ECHILD)
2239 pid = my_waitpid (ptid_get_lwp (lp->ptid), &status, __WCLONE | WNOHANG);
2240 if (pid == -1 && errno == ECHILD)
2242 /* The thread has previously exited. We need to delete it
2243 now because, for some vendor 2.4 kernels with NPTL
2244 support backported, there won't be an exit event unless
2245 it is the main thread. 2.6 kernels will report an exit
2246 event for each thread that exits, as expected. */
2248 if (debug_linux_nat)
2249 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2250 target_pid_to_str (lp->ptid));
2255 /* Bugs 10970, 12702.
2256 Thread group leader may have exited in which case we'll lock up in
2257 waitpid if there are other threads, even if they are all zombies too.
2258 Basically, we're not supposed to use waitpid this way.
2259 __WCLONE is not applicable for the leader so we can't use that.
2260 LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED
2261 process; it gets ESRCH both for the zombie and for running processes.
2263 As a workaround, check if we're waiting for the thread group leader and
2264 if it's a zombie, and avoid calling waitpid if it is.
2266 This is racy, what if the tgl becomes a zombie right after we check?
2267 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2268 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2270 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid)
2271 && linux_proc_pid_is_zombie (ptid_get_lwp (lp->ptid)))
2274 if (debug_linux_nat)
2275 fprintf_unfiltered (gdb_stdlog,
2276 "WL: Thread group leader %s vanished.\n",
2277 target_pid_to_str (lp->ptid));
2281 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2282 get invoked despite our caller had them intentionally blocked by
2283 block_child_signals. This is sensitive only to the loop of
2284 linux_nat_wait_1 and there if we get called my_waitpid gets called
2285 again before it gets to sigsuspend so we can safely let the handlers
2286 get executed here. */
2288 sigsuspend (&suspend_mask);
2291 restore_child_signals_mask (&prev_mask);
2295 gdb_assert (pid == ptid_get_lwp (lp->ptid));
2297 if (debug_linux_nat)
2299 fprintf_unfiltered (gdb_stdlog,
2300 "WL: waitpid %s received %s\n",
2301 target_pid_to_str (lp->ptid),
2302 status_to_str (status));
2305 /* Check if the thread has exited. */
2306 if (WIFEXITED (status) || WIFSIGNALED (status))
2309 if (debug_linux_nat)
2310 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2311 target_pid_to_str (lp->ptid));
2321 gdb_assert (WIFSTOPPED (status));
2324 /* Handle GNU/Linux's syscall SIGTRAPs. */
2325 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2327 /* No longer need the sysgood bit. The ptrace event ends up
2328 recorded in lp->waitstatus if we care for it. We can carry
2329 on handling the event like a regular SIGTRAP from here
2331 status = W_STOPCODE (SIGTRAP);
2332 if (linux_handle_syscall_trap (lp, 1))
2333 return wait_lwp (lp);
2336 /* Handle GNU/Linux's extended waitstatus for trace events. */
2337 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2339 if (debug_linux_nat)
2340 fprintf_unfiltered (gdb_stdlog,
2341 "WL: Handling extended status 0x%06x\n",
2343 if (linux_handle_extended_wait (lp, status, 1))
2344 return wait_lwp (lp);
2350 /* Send a SIGSTOP to LP. */
2353 stop_callback (struct lwp_info *lp, void *data)
2355 if (!lp->stopped && !lp->signalled)
2359 if (debug_linux_nat)
2361 fprintf_unfiltered (gdb_stdlog,
2362 "SC: kill %s **<SIGSTOP>**\n",
2363 target_pid_to_str (lp->ptid));
2366 ret = kill_lwp (ptid_get_lwp (lp->ptid), SIGSTOP);
2367 if (debug_linux_nat)
2369 fprintf_unfiltered (gdb_stdlog,
2370 "SC: lwp kill %d %s\n",
2372 errno ? safe_strerror (errno) : "ERRNO-OK");
2376 gdb_assert (lp->status == 0);
2382 /* Request a stop on LWP. */
2385 linux_stop_lwp (struct lwp_info *lwp)
2387 stop_callback (lwp, NULL);
2390 /* Return non-zero if LWP PID has a pending SIGINT. */
2393 linux_nat_has_pending_sigint (int pid)
2395 sigset_t pending, blocked, ignored;
2397 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2399 if (sigismember (&pending, SIGINT)
2400 && !sigismember (&ignored, SIGINT))
2406 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2409 set_ignore_sigint (struct lwp_info *lp, void *data)
2411 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2412 flag to consume the next one. */
2413 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2414 && WSTOPSIG (lp->status) == SIGINT)
2417 lp->ignore_sigint = 1;
2422 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2423 This function is called after we know the LWP has stopped; if the LWP
2424 stopped before the expected SIGINT was delivered, then it will never have
2425 arrived. Also, if the signal was delivered to a shared queue and consumed
2426 by a different thread, it will never be delivered to this LWP. */
2429 maybe_clear_ignore_sigint (struct lwp_info *lp)
2431 if (!lp->ignore_sigint)
2434 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp->ptid)))
2436 if (debug_linux_nat)
2437 fprintf_unfiltered (gdb_stdlog,
2438 "MCIS: Clearing bogus flag for %s\n",
2439 target_pid_to_str (lp->ptid));
2440 lp->ignore_sigint = 0;
2444 /* Fetch the possible triggered data watchpoint info and store it in
2447 On some archs, like x86, that use debug registers to set
2448 watchpoints, it's possible that the way to know which watched
2449 address trapped, is to check the register that is used to select
2450 which address to watch. Problem is, between setting the watchpoint
2451 and reading back which data address trapped, the user may change
2452 the set of watchpoints, and, as a consequence, GDB changes the
2453 debug registers in the inferior. To avoid reading back a stale
2454 stopped-data-address when that happens, we cache in LP the fact
2455 that a watchpoint trapped, and the corresponding data address, as
2456 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2457 registers meanwhile, we have the cached data we can rely on. */
2460 save_sigtrap (struct lwp_info *lp)
2462 struct cleanup *old_chain;
2464 if (linux_ops->to_stopped_by_watchpoint == NULL)
2466 lp->stopped_by_watchpoint = 0;
2470 old_chain = save_inferior_ptid ();
2471 inferior_ptid = lp->ptid;
2473 lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (linux_ops);
2475 if (lp->stopped_by_watchpoint)
2477 if (linux_ops->to_stopped_data_address != NULL)
2478 lp->stopped_data_address_p =
2479 linux_ops->to_stopped_data_address (¤t_target,
2480 &lp->stopped_data_address);
2482 lp->stopped_data_address_p = 0;
2485 do_cleanups (old_chain);
2488 /* See save_sigtrap. */
2491 linux_nat_stopped_by_watchpoint (struct target_ops *ops)
2493 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2495 gdb_assert (lp != NULL);
2497 return lp->stopped_by_watchpoint;
2501 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2503 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2505 gdb_assert (lp != NULL);
2507 *addr_p = lp->stopped_data_address;
2509 return lp->stopped_data_address_p;
2512 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2515 sigtrap_is_event (int status)
2517 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2520 /* SIGTRAP-like events recognizer. */
2522 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
2524 /* Check for SIGTRAP-like events in LP. */
2527 linux_nat_lp_status_is_event (struct lwp_info *lp)
2529 /* We check for lp->waitstatus in addition to lp->status, because we can
2530 have pending process exits recorded in lp->status
2531 and W_EXITCODE(0,0) == 0. We should probably have an additional
2532 lp->status_p flag. */
2534 return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
2535 && linux_nat_status_is_event (lp->status));
2538 /* Set alternative SIGTRAP-like events recognizer. If
2539 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2543 linux_nat_set_status_is_event (struct target_ops *t,
2544 int (*status_is_event) (int status))
2546 linux_nat_status_is_event = status_is_event;
2549 /* Wait until LP is stopped. */
2552 stop_wait_callback (struct lwp_info *lp, void *data)
2554 struct inferior *inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2556 /* If this is a vfork parent, bail out, it is not going to report
2557 any SIGSTOP until the vfork is done with. */
2558 if (inf->vfork_child != NULL)
2565 status = wait_lwp (lp);
2569 if (lp->ignore_sigint && WIFSTOPPED (status)
2570 && WSTOPSIG (status) == SIGINT)
2572 lp->ignore_sigint = 0;
2575 ptrace (PTRACE_CONT, ptid_get_lwp (lp->ptid), 0, 0);
2577 if (debug_linux_nat)
2578 fprintf_unfiltered (gdb_stdlog,
2579 "PTRACE_CONT %s, 0, 0 (%s) "
2580 "(discarding SIGINT)\n",
2581 target_pid_to_str (lp->ptid),
2582 errno ? safe_strerror (errno) : "OK");
2584 return stop_wait_callback (lp, NULL);
2587 maybe_clear_ignore_sigint (lp);
2589 if (WSTOPSIG (status) != SIGSTOP)
2591 /* The thread was stopped with a signal other than SIGSTOP. */
2595 if (debug_linux_nat)
2596 fprintf_unfiltered (gdb_stdlog,
2597 "SWC: Pending event %s in %s\n",
2598 status_to_str ((int) status),
2599 target_pid_to_str (lp->ptid));
2601 /* Save the sigtrap event. */
2602 lp->status = status;
2603 gdb_assert (lp->signalled);
2607 /* We caught the SIGSTOP that we intended to catch, so
2608 there's no SIGSTOP pending. */
2610 if (debug_linux_nat)
2611 fprintf_unfiltered (gdb_stdlog,
2612 "SWC: Delayed SIGSTOP caught for %s.\n",
2613 target_pid_to_str (lp->ptid));
2615 /* Reset SIGNALLED only after the stop_wait_callback call
2616 above as it does gdb_assert on SIGNALLED. */
2624 /* Return non-zero if LP has a wait status pending. */
2627 status_callback (struct lwp_info *lp, void *data)
2629 /* Only report a pending wait status if we pretend that this has
2630 indeed been resumed. */
2634 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2636 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2637 or a pending process exit. Note that `W_EXITCODE(0,0) ==
2638 0', so a clean process exit can not be stored pending in
2639 lp->status, it is indistinguishable from
2640 no-pending-status. */
2644 if (lp->status != 0)
2650 /* Return non-zero if LP isn't stopped. */
2653 running_callback (struct lwp_info *lp, void *data)
2655 return (!lp->stopped
2656 || ((lp->status != 0
2657 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2661 /* Count the LWP's that have had events. */
2664 count_events_callback (struct lwp_info *lp, void *data)
2668 gdb_assert (count != NULL);
2670 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2671 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2677 /* Select the LWP (if any) that is currently being single-stepped. */
2680 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2682 if (lp->last_resume_kind == resume_step
2689 /* Select the Nth LWP that has had a SIGTRAP event. */
2692 select_event_lwp_callback (struct lwp_info *lp, void *data)
2694 int *selector = data;
2696 gdb_assert (selector != NULL);
2698 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2699 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2700 if ((*selector)-- == 0)
2707 cancel_breakpoint (struct lwp_info *lp)
2709 /* Arrange for a breakpoint to be hit again later. We don't keep
2710 the SIGTRAP status and don't forward the SIGTRAP signal to the
2711 LWP. We will handle the current event, eventually we will resume
2712 this LWP, and this breakpoint will trap again.
2714 If we do not do this, then we run the risk that the user will
2715 delete or disable the breakpoint, but the LWP will have already
2718 struct regcache *regcache = get_thread_regcache (lp->ptid);
2719 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2722 pc = regcache_read_pc (regcache) - target_decr_pc_after_break (gdbarch);
2723 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2725 if (debug_linux_nat)
2726 fprintf_unfiltered (gdb_stdlog,
2727 "CB: Push back breakpoint for %s\n",
2728 target_pid_to_str (lp->ptid));
2730 /* Back up the PC if necessary. */
2731 if (target_decr_pc_after_break (gdbarch))
2732 regcache_write_pc (regcache, pc);
2740 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2742 struct lwp_info *event_lp = data;
2744 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2748 /* If a LWP other than the LWP that we're reporting an event for has
2749 hit a GDB breakpoint (as opposed to some random trap signal),
2750 then just arrange for it to hit it again later. We don't keep
2751 the SIGTRAP status and don't forward the SIGTRAP signal to the
2752 LWP. We will handle the current event, eventually we will resume
2753 all LWPs, and this one will get its breakpoint trap again.
2755 If we do not do this, then we run the risk that the user will
2756 delete or disable the breakpoint, but the LWP will have already
2759 if (linux_nat_lp_status_is_event (lp)
2760 && cancel_breakpoint (lp))
2761 /* Throw away the SIGTRAP. */
2767 /* Select one LWP out of those that have events pending. */
2770 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2773 int random_selector;
2774 struct lwp_info *event_lp;
2776 /* Record the wait status for the original LWP. */
2777 (*orig_lp)->status = *status;
2779 /* Give preference to any LWP that is being single-stepped. */
2780 event_lp = iterate_over_lwps (filter,
2781 select_singlestep_lwp_callback, NULL);
2782 if (event_lp != NULL)
2784 if (debug_linux_nat)
2785 fprintf_unfiltered (gdb_stdlog,
2786 "SEL: Select single-step %s\n",
2787 target_pid_to_str (event_lp->ptid));
2791 /* No single-stepping LWP. Select one at random, out of those
2792 which have had SIGTRAP events. */
2794 /* First see how many SIGTRAP events we have. */
2795 iterate_over_lwps (filter, count_events_callback, &num_events);
2797 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2798 random_selector = (int)
2799 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2801 if (debug_linux_nat && num_events > 1)
2802 fprintf_unfiltered (gdb_stdlog,
2803 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2804 num_events, random_selector);
2806 event_lp = iterate_over_lwps (filter,
2807 select_event_lwp_callback,
2811 if (event_lp != NULL)
2813 /* Switch the event LWP. */
2814 *orig_lp = event_lp;
2815 *status = event_lp->status;
2818 /* Flush the wait status for the event LWP. */
2819 (*orig_lp)->status = 0;
2822 /* Return non-zero if LP has been resumed. */
2825 resumed_callback (struct lwp_info *lp, void *data)
2830 /* Stop an active thread, verify it still exists, then resume it. If
2831 the thread ends up with a pending status, then it is not resumed,
2832 and *DATA (really a pointer to int), is set. */
2835 stop_and_resume_callback (struct lwp_info *lp, void *data)
2837 int *new_pending_p = data;
2841 ptid_t ptid = lp->ptid;
2843 stop_callback (lp, NULL);
2844 stop_wait_callback (lp, NULL);
2846 /* Resume if the lwp still exists, and the core wanted it
2848 lp = find_lwp_pid (ptid);
2851 if (lp->last_resume_kind == resume_stop
2854 /* The core wanted the LWP to stop. Even if it stopped
2855 cleanly (with SIGSTOP), leave the event pending. */
2856 if (debug_linux_nat)
2857 fprintf_unfiltered (gdb_stdlog,
2858 "SARC: core wanted LWP %ld stopped "
2859 "(leaving SIGSTOP pending)\n",
2860 ptid_get_lwp (lp->ptid));
2861 lp->status = W_STOPCODE (SIGSTOP);
2864 if (lp->status == 0)
2866 if (debug_linux_nat)
2867 fprintf_unfiltered (gdb_stdlog,
2868 "SARC: re-resuming LWP %ld\n",
2869 ptid_get_lwp (lp->ptid));
2870 resume_lwp (lp, lp->step, GDB_SIGNAL_0);
2874 if (debug_linux_nat)
2875 fprintf_unfiltered (gdb_stdlog,
2876 "SARC: not re-resuming LWP %ld "
2878 ptid_get_lwp (lp->ptid));
2887 /* Check if we should go on and pass this event to common code.
2888 Return the affected lwp if we are, or NULL otherwise. If we stop
2889 all lwps temporarily, we may end up with new pending events in some
2890 other lwp. In that case set *NEW_PENDING_P to true. */
2892 static struct lwp_info *
2893 linux_nat_filter_event (int lwpid, int status, int *new_pending_p)
2895 struct lwp_info *lp;
2899 lp = find_lwp_pid (pid_to_ptid (lwpid));
2901 /* Check for stop events reported by a process we didn't already
2902 know about - anything not already in our LWP list.
2904 If we're expecting to receive stopped processes after
2905 fork, vfork, and clone events, then we'll just add the
2906 new one to our list and go back to waiting for the event
2907 to be reported - the stopped process might be returned
2908 from waitpid before or after the event is.
2910 But note the case of a non-leader thread exec'ing after the
2911 leader having exited, and gone from our lists. The non-leader
2912 thread changes its tid to the tgid. */
2914 if (WIFSTOPPED (status) && lp == NULL
2915 && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC))
2917 /* A multi-thread exec after we had seen the leader exiting. */
2918 if (debug_linux_nat)
2919 fprintf_unfiltered (gdb_stdlog,
2920 "LLW: Re-adding thread group leader LWP %d.\n",
2923 lp = add_lwp (ptid_build (lwpid, lwpid, 0));
2926 add_thread (lp->ptid);
2929 if (WIFSTOPPED (status) && !lp)
2931 add_to_pid_list (&stopped_pids, lwpid, status);
2935 /* Make sure we don't report an event for the exit of an LWP not in
2936 our list, i.e. not part of the current process. This can happen
2937 if we detach from a program we originally forked and then it
2939 if (!WIFSTOPPED (status) && !lp)
2942 /* This LWP is stopped now. (And if dead, this prevents it from
2943 ever being continued.) */
2946 /* Handle GNU/Linux's syscall SIGTRAPs. */
2947 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2949 /* No longer need the sysgood bit. The ptrace event ends up
2950 recorded in lp->waitstatus if we care for it. We can carry
2951 on handling the event like a regular SIGTRAP from here
2953 status = W_STOPCODE (SIGTRAP);
2954 if (linux_handle_syscall_trap (lp, 0))
2958 /* Handle GNU/Linux's extended waitstatus for trace events. */
2959 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2961 if (debug_linux_nat)
2962 fprintf_unfiltered (gdb_stdlog,
2963 "LLW: Handling extended status 0x%06x\n",
2965 if (linux_handle_extended_wait (lp, status, 0))
2969 if (linux_nat_status_is_event (status))
2972 /* Check if the thread has exited. */
2973 if ((WIFEXITED (status) || WIFSIGNALED (status))
2974 && num_lwps (ptid_get_pid (lp->ptid)) > 1)
2976 /* If this is the main thread, we must stop all threads and verify
2977 if they are still alive. This is because in the nptl thread model
2978 on Linux 2.4, there is no signal issued for exiting LWPs
2979 other than the main thread. We only get the main thread exit
2980 signal once all child threads have already exited. If we
2981 stop all the threads and use the stop_wait_callback to check
2982 if they have exited we can determine whether this signal
2983 should be ignored or whether it means the end of the debugged
2984 application, regardless of which threading model is being
2986 if (ptid_get_pid (lp->ptid) == ptid_get_lwp (lp->ptid))
2988 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp->ptid)),
2989 stop_and_resume_callback, new_pending_p);
2992 if (debug_linux_nat)
2993 fprintf_unfiltered (gdb_stdlog,
2994 "LLW: %s exited.\n",
2995 target_pid_to_str (lp->ptid));
2997 if (num_lwps (ptid_get_pid (lp->ptid)) > 1)
2999 /* If there is at least one more LWP, then the exit signal
3000 was not the end of the debugged application and should be
3007 /* Check if the current LWP has previously exited. In the nptl
3008 thread model, LWPs other than the main thread do not issue
3009 signals when they exit so we must check whenever the thread has
3010 stopped. A similar check is made in stop_wait_callback(). */
3011 if (num_lwps (ptid_get_pid (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3013 ptid_t ptid = pid_to_ptid (ptid_get_pid (lp->ptid));
3015 if (debug_linux_nat)
3016 fprintf_unfiltered (gdb_stdlog,
3017 "LLW: %s exited.\n",
3018 target_pid_to_str (lp->ptid));
3022 /* Make sure there is at least one thread running. */
3023 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3025 /* Discard the event. */
3029 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3030 an attempt to stop an LWP. */
3032 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3034 if (debug_linux_nat)
3035 fprintf_unfiltered (gdb_stdlog,
3036 "LLW: Delayed SIGSTOP caught for %s.\n",
3037 target_pid_to_str (lp->ptid));
3041 if (lp->last_resume_kind != resume_stop)
3043 /* This is a delayed SIGSTOP. */
3045 registers_changed ();
3047 if (linux_nat_prepare_to_resume != NULL)
3048 linux_nat_prepare_to_resume (lp);
3049 linux_ops->to_resume (linux_ops,
3050 pid_to_ptid (ptid_get_lwp (lp->ptid)),
3051 lp->step, GDB_SIGNAL_0);
3052 if (debug_linux_nat)
3053 fprintf_unfiltered (gdb_stdlog,
3054 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3056 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3057 target_pid_to_str (lp->ptid));
3060 gdb_assert (lp->resumed);
3062 /* Discard the event. */
3067 /* Make sure we don't report a SIGINT that we have already displayed
3068 for another thread. */
3069 if (lp->ignore_sigint
3070 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3072 if (debug_linux_nat)
3073 fprintf_unfiltered (gdb_stdlog,
3074 "LLW: Delayed SIGINT caught for %s.\n",
3075 target_pid_to_str (lp->ptid));
3077 /* This is a delayed SIGINT. */
3078 lp->ignore_sigint = 0;
3080 registers_changed ();
3081 if (linux_nat_prepare_to_resume != NULL)
3082 linux_nat_prepare_to_resume (lp);
3083 linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)),
3084 lp->step, GDB_SIGNAL_0);
3085 if (debug_linux_nat)
3086 fprintf_unfiltered (gdb_stdlog,
3087 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3089 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3090 target_pid_to_str (lp->ptid));
3093 gdb_assert (lp->resumed);
3095 /* Discard the event. */
3099 /* An interesting event. */
3101 lp->status = status;
3105 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3106 their exits until all other threads in the group have exited. */
3109 check_zombie_leaders (void)
3111 struct inferior *inf;
3115 struct lwp_info *leader_lp;
3120 leader_lp = find_lwp_pid (pid_to_ptid (inf->pid));
3121 if (leader_lp != NULL
3122 /* Check if there are other threads in the group, as we may
3123 have raced with the inferior simply exiting. */
3124 && num_lwps (inf->pid) > 1
3125 && linux_proc_pid_is_zombie (inf->pid))
3127 if (debug_linux_nat)
3128 fprintf_unfiltered (gdb_stdlog,
3129 "CZL: Thread group leader %d zombie "
3130 "(it exited, or another thread execd).\n",
3133 /* A leader zombie can mean one of two things:
3135 - It exited, and there's an exit status pending
3136 available, or only the leader exited (not the whole
3137 program). In the latter case, we can't waitpid the
3138 leader's exit status until all other threads are gone.
3140 - There are 3 or more threads in the group, and a thread
3141 other than the leader exec'd. On an exec, the Linux
3142 kernel destroys all other threads (except the execing
3143 one) in the thread group, and resets the execing thread's
3144 tid to the tgid. No exit notification is sent for the
3145 execing thread -- from the ptracer's perspective, it
3146 appears as though the execing thread just vanishes.
3147 Until we reap all other threads except the leader and the
3148 execing thread, the leader will be zombie, and the
3149 execing thread will be in `D (disc sleep)'. As soon as
3150 all other threads are reaped, the execing thread changes
3151 it's tid to the tgid, and the previous (zombie) leader
3152 vanishes, giving place to the "new" leader. We could try
3153 distinguishing the exit and exec cases, by waiting once
3154 more, and seeing if something comes out, but it doesn't
3155 sound useful. The previous leader _does_ go away, and
3156 we'll re-add the new one once we see the exec event
3157 (which is just the same as what would happen if the
3158 previous leader did exit voluntarily before some other
3161 if (debug_linux_nat)
3162 fprintf_unfiltered (gdb_stdlog,
3163 "CZL: Thread group leader %d vanished.\n",
3165 exit_lwp (leader_lp);
3171 linux_nat_wait_1 (struct target_ops *ops,
3172 ptid_t ptid, struct target_waitstatus *ourstatus,
3175 static sigset_t prev_mask;
3176 enum resume_kind last_resume_kind;
3177 struct lwp_info *lp;
3180 if (debug_linux_nat)
3181 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3183 /* The first time we get here after starting a new inferior, we may
3184 not have added it to the LWP list yet - this is the earliest
3185 moment at which we know its PID. */
3186 if (ptid_is_pid (inferior_ptid))
3188 /* Upgrade the main thread's ptid. */
3189 thread_change_ptid (inferior_ptid,
3190 ptid_build (ptid_get_pid (inferior_ptid),
3191 ptid_get_pid (inferior_ptid), 0));
3193 lp = add_initial_lwp (inferior_ptid);
3197 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3198 block_child_signals (&prev_mask);
3204 /* First check if there is a LWP with a wait status pending. */
3205 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3207 /* Any LWP in the PTID group that's been resumed will do. */
3208 lp = iterate_over_lwps (ptid, status_callback, NULL);
3211 if (debug_linux_nat && lp->status)
3212 fprintf_unfiltered (gdb_stdlog,
3213 "LLW: Using pending wait status %s for %s.\n",
3214 status_to_str (lp->status),
3215 target_pid_to_str (lp->ptid));
3218 else if (ptid_lwp_p (ptid))
3220 if (debug_linux_nat)
3221 fprintf_unfiltered (gdb_stdlog,
3222 "LLW: Waiting for specific LWP %s.\n",
3223 target_pid_to_str (ptid));
3225 /* We have a specific LWP to check. */
3226 lp = find_lwp_pid (ptid);
3229 if (debug_linux_nat && lp->status)
3230 fprintf_unfiltered (gdb_stdlog,
3231 "LLW: Using pending wait status %s for %s.\n",
3232 status_to_str (lp->status),
3233 target_pid_to_str (lp->ptid));
3235 /* We check for lp->waitstatus in addition to lp->status,
3236 because we can have pending process exits recorded in
3237 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3238 an additional lp->status_p flag. */
3239 if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3243 if (!target_can_async_p ())
3245 /* Causes SIGINT to be passed on to the attached process. */
3249 /* But if we don't find a pending event, we'll have to wait. */
3255 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3258 - If the thread group leader exits while other threads in the
3259 thread group still exist, waitpid(TGID, ...) hangs. That
3260 waitpid won't return an exit status until the other threads
3261 in the group are reapped.
3263 - When a non-leader thread execs, that thread just vanishes
3264 without reporting an exit (so we'd hang if we waited for it
3265 explicitly in that case). The exec event is reported to
3269 lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG);
3270 if (lwpid == 0 || (lwpid == -1 && errno == ECHILD))
3271 lwpid = my_waitpid (-1, &status, WNOHANG);
3273 if (debug_linux_nat)
3274 fprintf_unfiltered (gdb_stdlog,
3275 "LNW: waitpid(-1, ...) returned %d, %s\n",
3276 lwpid, errno ? safe_strerror (errno) : "ERRNO-OK");
3280 /* If this is true, then we paused LWPs momentarily, and may
3281 now have pending events to handle. */
3284 if (debug_linux_nat)
3286 fprintf_unfiltered (gdb_stdlog,
3287 "LLW: waitpid %ld received %s\n",
3288 (long) lwpid, status_to_str (status));
3291 lp = linux_nat_filter_event (lwpid, status, &new_pending);
3293 /* STATUS is now no longer valid, use LP->STATUS instead. */
3296 if (lp && !ptid_match (lp->ptid, ptid))
3298 gdb_assert (lp->resumed);
3300 if (debug_linux_nat)
3302 "LWP %ld got an event %06x, leaving pending.\n",
3303 ptid_get_lwp (lp->ptid), lp->status);
3305 if (WIFSTOPPED (lp->status))
3307 if (WSTOPSIG (lp->status) != SIGSTOP)
3309 /* Cancel breakpoint hits. The breakpoint may
3310 be removed before we fetch events from this
3311 process to report to the core. It is best
3312 not to assume the moribund breakpoints
3313 heuristic always handles these cases --- it
3314 could be too many events go through to the
3315 core before this one is handled. All-stop
3316 always cancels breakpoint hits in all
3319 && linux_nat_lp_status_is_event (lp)
3320 && cancel_breakpoint (lp))
3322 /* Throw away the SIGTRAP. */
3325 if (debug_linux_nat)
3327 "LLW: LWP %ld hit a breakpoint while"
3328 " waiting for another process;"
3330 ptid_get_lwp (lp->ptid));
3336 else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status))
3338 if (debug_linux_nat)
3340 "Process %ld exited while stopping LWPs\n",
3341 ptid_get_lwp (lp->ptid));
3343 /* This was the last lwp in the process. Since
3344 events are serialized to GDB core, and we can't
3345 report this one right now, but GDB core and the
3346 other target layers will want to be notified
3347 about the exit code/signal, leave the status
3348 pending for the next time we're able to report
3351 /* Dead LWP's aren't expected to reported a pending
3355 /* Store the pending event in the waitstatus as
3356 well, because W_EXITCODE(0,0) == 0. */
3357 store_waitstatus (&lp->waitstatus, lp->status);
3366 /* Some LWP now has a pending event. Go all the way
3367 back to check it. */
3373 /* We got an event to report to the core. */
3377 /* Retry until nothing comes out of waitpid. A single
3378 SIGCHLD can indicate more than one child stopped. */
3382 /* Check for zombie thread group leaders. Those can't be reaped
3383 until all other threads in the thread group are. */
3384 check_zombie_leaders ();
3386 /* If there are no resumed children left, bail. We'd be stuck
3387 forever in the sigsuspend call below otherwise. */
3388 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3390 if (debug_linux_nat)
3391 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3393 ourstatus->kind = TARGET_WAITKIND_NO_RESUMED;
3395 if (!target_can_async_p ())
3396 clear_sigint_trap ();
3398 restore_child_signals_mask (&prev_mask);
3399 return minus_one_ptid;
3402 /* No interesting event to report to the core. */
3404 if (target_options & TARGET_WNOHANG)
3406 if (debug_linux_nat)
3407 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3409 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3410 restore_child_signals_mask (&prev_mask);
3411 return minus_one_ptid;
3414 /* We shouldn't end up here unless we want to try again. */
3415 gdb_assert (lp == NULL);
3417 /* Block until we get an event reported with SIGCHLD. */
3418 sigsuspend (&suspend_mask);
3421 if (!target_can_async_p ())
3422 clear_sigint_trap ();
3426 status = lp->status;
3429 /* Don't report signals that GDB isn't interested in, such as
3430 signals that are neither printed nor stopped upon. Stopping all
3431 threads can be a bit time-consuming so if we want decent
3432 performance with heavily multi-threaded programs, especially when
3433 they're using a high frequency timer, we'd better avoid it if we
3436 if (WIFSTOPPED (status))
3438 enum gdb_signal signo = gdb_signal_from_host (WSTOPSIG (status));
3440 /* When using hardware single-step, we need to report every signal.
3441 Otherwise, signals in pass_mask may be short-circuited. */
3443 && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status)))
3445 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3446 here? It is not clear we should. GDB may not expect
3447 other threads to run. On the other hand, not resuming
3448 newly attached threads may cause an unwanted delay in
3449 getting them running. */
3450 registers_changed ();
3451 if (linux_nat_prepare_to_resume != NULL)
3452 linux_nat_prepare_to_resume (lp);
3453 linux_ops->to_resume (linux_ops,
3454 pid_to_ptid (ptid_get_lwp (lp->ptid)),
3456 if (debug_linux_nat)
3457 fprintf_unfiltered (gdb_stdlog,
3458 "LLW: %s %s, %s (preempt 'handle')\n",
3460 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3461 target_pid_to_str (lp->ptid),
3462 (signo != GDB_SIGNAL_0
3463 ? strsignal (gdb_signal_to_host (signo))
3471 /* Only do the below in all-stop, as we currently use SIGINT
3472 to implement target_stop (see linux_nat_stop) in
3474 if (signo == GDB_SIGNAL_INT && signal_pass_state (signo) == 0)
3476 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3477 forwarded to the entire process group, that is, all LWPs
3478 will receive it - unless they're using CLONE_THREAD to
3479 share signals. Since we only want to report it once, we
3480 mark it as ignored for all LWPs except this one. */
3481 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
3482 set_ignore_sigint, NULL);
3483 lp->ignore_sigint = 0;
3486 maybe_clear_ignore_sigint (lp);
3490 /* This LWP is stopped now. */
3493 if (debug_linux_nat)
3494 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3495 status_to_str (status), target_pid_to_str (lp->ptid));
3499 /* Now stop all other LWP's ... */
3500 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3502 /* ... and wait until all of them have reported back that
3503 they're no longer running. */
3504 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3506 /* If we're not waiting for a specific LWP, choose an event LWP
3507 from among those that have had events. Giving equal priority
3508 to all LWPs that have had events helps prevent
3510 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3511 select_event_lwp (ptid, &lp, &status);
3513 /* Now that we've selected our final event LWP, cancel any
3514 breakpoints in other LWPs that have hit a GDB breakpoint.
3515 See the comment in cancel_breakpoints_callback to find out
3517 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3519 /* We'll need this to determine whether to report a SIGSTOP as
3520 TARGET_WAITKIND_0. Need to take a copy because
3521 resume_clear_callback clears it. */
3522 last_resume_kind = lp->last_resume_kind;
3524 /* In all-stop, from the core's perspective, all LWPs are now
3525 stopped until a new resume action is sent over. */
3526 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3531 last_resume_kind = lp->last_resume_kind;
3532 resume_clear_callback (lp, NULL);
3535 if (linux_nat_status_is_event (status))
3537 if (debug_linux_nat)
3538 fprintf_unfiltered (gdb_stdlog,
3539 "LLW: trap ptid is %s.\n",
3540 target_pid_to_str (lp->ptid));
3543 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3545 *ourstatus = lp->waitstatus;
3546 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3549 store_waitstatus (ourstatus, status);
3551 if (debug_linux_nat)
3552 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3554 restore_child_signals_mask (&prev_mask);
3556 if (last_resume_kind == resume_stop
3557 && ourstatus->kind == TARGET_WAITKIND_STOPPED
3558 && WSTOPSIG (status) == SIGSTOP)
3560 /* A thread that has been requested to stop by GDB with
3561 target_stop, and it stopped cleanly, so report as SIG0. The
3562 use of SIGSTOP is an implementation detail. */
3563 ourstatus->value.sig = GDB_SIGNAL_0;
3566 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3567 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3570 lp->core = linux_common_core_of_thread (lp->ptid);
3575 /* Resume LWPs that are currently stopped without any pending status
3576 to report, but are resumed from the core's perspective. */
3579 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3581 ptid_t *wait_ptid_p = data;
3586 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3588 struct regcache *regcache = get_thread_regcache (lp->ptid);
3589 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3590 CORE_ADDR pc = regcache_read_pc (regcache);
3592 gdb_assert (is_executing (lp->ptid));
3594 /* Don't bother if there's a breakpoint at PC that we'd hit
3595 immediately, and we're not waiting for this LWP. */
3596 if (!ptid_match (lp->ptid, *wait_ptid_p))
3598 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3602 if (debug_linux_nat)
3603 fprintf_unfiltered (gdb_stdlog,
3604 "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
3605 target_pid_to_str (lp->ptid),
3606 paddress (gdbarch, pc),
3609 registers_changed ();
3610 if (linux_nat_prepare_to_resume != NULL)
3611 linux_nat_prepare_to_resume (lp);
3612 linux_ops->to_resume (linux_ops, pid_to_ptid (ptid_get_lwp (lp->ptid)),
3613 lp->step, GDB_SIGNAL_0);
3615 lp->stopped_by_watchpoint = 0;
3622 linux_nat_wait (struct target_ops *ops,
3623 ptid_t ptid, struct target_waitstatus *ourstatus,
3628 if (debug_linux_nat)
3630 char *options_string;
3632 options_string = target_options_to_string (target_options);
3633 fprintf_unfiltered (gdb_stdlog,
3634 "linux_nat_wait: [%s], [%s]\n",
3635 target_pid_to_str (ptid),
3637 xfree (options_string);
3640 /* Flush the async file first. */
3641 if (target_can_async_p ())
3642 async_file_flush ();
3644 /* Resume LWPs that are currently stopped without any pending status
3645 to report, but are resumed from the core's perspective. LWPs get
3646 in this state if we find them stopping at a time we're not
3647 interested in reporting the event (target_wait on a
3648 specific_process, for example, see linux_nat_wait_1), and
3649 meanwhile the event became uninteresting. Don't bother resuming
3650 LWPs we're not going to wait for if they'd stop immediately. */
3652 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3654 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3656 /* If we requested any event, and something came out, assume there
3657 may be more. If we requested a specific lwp or process, also
3658 assume there may be more. */
3659 if (target_can_async_p ()
3660 && ((ourstatus->kind != TARGET_WAITKIND_IGNORE
3661 && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED)
3662 || !ptid_equal (ptid, minus_one_ptid)))
3665 /* Get ready for the next event. */
3666 if (target_can_async_p ())
3667 target_async (inferior_event_handler, 0);
3673 kill_callback (struct lwp_info *lp, void *data)
3675 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3678 kill (ptid_get_lwp (lp->ptid), SIGKILL);
3679 if (debug_linux_nat)
3680 fprintf_unfiltered (gdb_stdlog,
3681 "KC: kill (SIGKILL) %s, 0, 0 (%s)\n",
3682 target_pid_to_str (lp->ptid),
3683 errno ? safe_strerror (errno) : "OK");
3685 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3688 ptrace (PTRACE_KILL, ptid_get_lwp (lp->ptid), 0, 0);
3689 if (debug_linux_nat)
3690 fprintf_unfiltered (gdb_stdlog,
3691 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3692 target_pid_to_str (lp->ptid),
3693 errno ? safe_strerror (errno) : "OK");
3699 kill_wait_callback (struct lwp_info *lp, void *data)
3703 /* We must make sure that there are no pending events (delayed
3704 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3705 program doesn't interfere with any following debugging session. */
3707 /* For cloned processes we must check both with __WCLONE and
3708 without, since the exit status of a cloned process isn't reported
3714 pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, __WCLONE);
3715 if (pid != (pid_t) -1)
3717 if (debug_linux_nat)
3718 fprintf_unfiltered (gdb_stdlog,
3719 "KWC: wait %s received unknown.\n",
3720 target_pid_to_str (lp->ptid));
3721 /* The Linux kernel sometimes fails to kill a thread
3722 completely after PTRACE_KILL; that goes from the stop
3723 point in do_fork out to the one in
3724 get_signal_to_deliever and waits again. So kill it
3726 kill_callback (lp, NULL);
3729 while (pid == ptid_get_lwp (lp->ptid));
3731 gdb_assert (pid == -1 && errno == ECHILD);
3736 pid = my_waitpid (ptid_get_lwp (lp->ptid), NULL, 0);
3737 if (pid != (pid_t) -1)
3739 if (debug_linux_nat)
3740 fprintf_unfiltered (gdb_stdlog,
3741 "KWC: wait %s received unk.\n",
3742 target_pid_to_str (lp->ptid));
3743 /* See the call to kill_callback above. */
3744 kill_callback (lp, NULL);
3747 while (pid == ptid_get_lwp (lp->ptid));
3749 gdb_assert (pid == -1 && errno == ECHILD);
3754 linux_nat_kill (struct target_ops *ops)
3756 struct target_waitstatus last;
3760 /* If we're stopped while forking and we haven't followed yet,
3761 kill the other task. We need to do this first because the
3762 parent will be sleeping if this is a vfork. */
3764 get_last_target_status (&last_ptid, &last);
3766 if (last.kind == TARGET_WAITKIND_FORKED
3767 || last.kind == TARGET_WAITKIND_VFORKED)
3769 ptrace (PT_KILL, ptid_get_pid (last.value.related_pid), 0, 0);
3772 /* Let the arch-specific native code know this process is
3774 linux_nat_forget_process (ptid_get_pid (last.value.related_pid));
3777 if (forks_exist_p ())
3778 linux_fork_killall ();
3781 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3783 /* Stop all threads before killing them, since ptrace requires
3784 that the thread is stopped to sucessfully PTRACE_KILL. */
3785 iterate_over_lwps (ptid, stop_callback, NULL);
3786 /* ... and wait until all of them have reported back that
3787 they're no longer running. */
3788 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3790 /* Kill all LWP's ... */
3791 iterate_over_lwps (ptid, kill_callback, NULL);
3793 /* ... and wait until we've flushed all events. */
3794 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3797 target_mourn_inferior ();
3801 linux_nat_mourn_inferior (struct target_ops *ops)
3803 int pid = ptid_get_pid (inferior_ptid);
3805 purge_lwp_list (pid);
3807 if (! forks_exist_p ())
3808 /* Normal case, no other forks available. */
3809 linux_ops->to_mourn_inferior (ops);
3811 /* Multi-fork case. The current inferior_ptid has exited, but
3812 there are other viable forks to debug. Delete the exiting
3813 one and context-switch to the first available. */
3814 linux_fork_mourn_inferior ();
3816 /* Let the arch-specific native code know this process is gone. */
3817 linux_nat_forget_process (pid);
3820 /* Convert a native/host siginfo object, into/from the siginfo in the
3821 layout of the inferiors' architecture. */
3824 siginfo_fixup (siginfo_t *siginfo, gdb_byte *inf_siginfo, int direction)
3828 if (linux_nat_siginfo_fixup != NULL)
3829 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3831 /* If there was no callback, or the callback didn't do anything,
3832 then just do a straight memcpy. */
3836 memcpy (siginfo, inf_siginfo, sizeof (siginfo_t));
3838 memcpy (inf_siginfo, siginfo, sizeof (siginfo_t));
3842 static enum target_xfer_status
3843 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3844 const char *annex, gdb_byte *readbuf,
3845 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
3846 ULONGEST *xfered_len)
3850 gdb_byte inf_siginfo[sizeof (siginfo_t)];
3852 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3853 gdb_assert (readbuf || writebuf);
3855 pid = ptid_get_lwp (inferior_ptid);
3857 pid = ptid_get_pid (inferior_ptid);
3859 if (offset > sizeof (siginfo))
3860 return TARGET_XFER_E_IO;
3863 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3865 return TARGET_XFER_E_IO;
3867 /* When GDB is built as a 64-bit application, ptrace writes into
3868 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3869 inferior with a 64-bit GDB should look the same as debugging it
3870 with a 32-bit GDB, we need to convert it. GDB core always sees
3871 the converted layout, so any read/write will have to be done
3873 siginfo_fixup (&siginfo, inf_siginfo, 0);
3875 if (offset + len > sizeof (siginfo))
3876 len = sizeof (siginfo) - offset;
3878 if (readbuf != NULL)
3879 memcpy (readbuf, inf_siginfo + offset, len);
3882 memcpy (inf_siginfo + offset, writebuf, len);
3884 /* Convert back to ptrace layout before flushing it out. */
3885 siginfo_fixup (&siginfo, inf_siginfo, 1);
3888 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3890 return TARGET_XFER_E_IO;
3894 return TARGET_XFER_OK;
3897 static enum target_xfer_status
3898 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3899 const char *annex, gdb_byte *readbuf,
3900 const gdb_byte *writebuf,
3901 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
3903 struct cleanup *old_chain;
3904 enum target_xfer_status xfer;
3906 if (object == TARGET_OBJECT_SIGNAL_INFO)
3907 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3908 offset, len, xfered_len);
3910 /* The target is connected but no live inferior is selected. Pass
3911 this request down to a lower stratum (e.g., the executable
3913 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3914 return TARGET_XFER_EOF;
3916 old_chain = save_inferior_ptid ();
3918 if (ptid_lwp_p (inferior_ptid))
3919 inferior_ptid = pid_to_ptid (ptid_get_lwp (inferior_ptid));
3921 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3922 offset, len, xfered_len);
3924 do_cleanups (old_chain);
3929 linux_thread_alive (ptid_t ptid)
3933 gdb_assert (ptid_lwp_p (ptid));
3935 /* Send signal 0 instead of anything ptrace, because ptracing a
3936 running thread errors out claiming that the thread doesn't
3938 err = kill_lwp (ptid_get_lwp (ptid), 0);
3940 if (debug_linux_nat)
3941 fprintf_unfiltered (gdb_stdlog,
3942 "LLTA: KILL(SIG0) %s (%s)\n",
3943 target_pid_to_str (ptid),
3944 err ? safe_strerror (tmp_errno) : "OK");
3953 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3955 return linux_thread_alive (ptid);
3959 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3961 static char buf[64];
3963 if (ptid_lwp_p (ptid)
3964 && (ptid_get_pid (ptid) != ptid_get_lwp (ptid)
3965 || num_lwps (ptid_get_pid (ptid)) > 1))
3967 snprintf (buf, sizeof (buf), "LWP %ld", ptid_get_lwp (ptid));
3971 return normal_pid_to_str (ptid);
3975 linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
3977 int pid = ptid_get_pid (thr->ptid);
3978 long lwp = ptid_get_lwp (thr->ptid);
3979 #define FORMAT "/proc/%d/task/%ld/comm"
3980 char buf[sizeof (FORMAT) + 30];
3982 char *result = NULL;
3984 snprintf (buf, sizeof (buf), FORMAT, pid, lwp);
3985 comm_file = gdb_fopen_cloexec (buf, "r");
3988 /* Not exported by the kernel, so we define it here. */
3990 static char line[COMM_LEN + 1];
3992 if (fgets (line, sizeof (line), comm_file))
3994 char *nl = strchr (line, '\n');
4011 /* Accepts an integer PID; Returns a string representing a file that
4012 can be opened to get the symbols for the child process. */
4015 linux_child_pid_to_exec_file (struct target_ops *self, int pid)
4017 static char buf[PATH_MAX];
4018 char name[PATH_MAX];
4020 xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
4021 memset (buf, 0, PATH_MAX);
4022 if (readlink (name, buf, PATH_MAX - 1) <= 0)
4028 /* Records the thread's register state for the corefile note
4032 linux_nat_collect_thread_registers (const struct regcache *regcache,
4033 ptid_t ptid, bfd *obfd,
4034 char *note_data, int *note_size,
4035 enum gdb_signal stop_signal)
4037 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4038 const struct regset *regset;
4040 gdb_gregset_t gregs;
4041 gdb_fpregset_t fpregs;
4043 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
4046 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
4048 != NULL && regset->collect_regset != NULL)
4049 regset->collect_regset (regset, regcache, -1, &gregs, sizeof (gregs));
4051 fill_gregset (regcache, &gregs, -1);
4053 note_data = (char *) elfcore_write_prstatus
4054 (obfd, note_data, note_size, ptid_get_lwp (ptid),
4055 gdb_signal_to_host (stop_signal), &gregs);
4058 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
4060 != NULL && regset->collect_regset != NULL)
4061 regset->collect_regset (regset, regcache, -1, &fpregs, sizeof (fpregs));
4063 fill_fpregset (regcache, &fpregs, -1);
4065 note_data = (char *) elfcore_write_prfpreg (obfd, note_data, note_size,
4066 &fpregs, sizeof (fpregs));
4071 /* Fills the "to_make_corefile_note" target vector. Builds the note
4072 section for a corefile, and returns it in a malloc buffer. */
4075 linux_nat_make_corefile_notes (struct target_ops *self,
4076 bfd *obfd, int *note_size)
4078 /* FIXME: uweigand/2011-10-06: Once all GNU/Linux architectures have been
4079 converted to gdbarch_core_regset_sections, this function can go away. */
4080 return linux_make_corefile_notes (target_gdbarch (), obfd, note_size,
4081 linux_nat_collect_thread_registers);
4084 /* Implement the to_xfer_partial interface for memory reads using the /proc
4085 filesystem. Because we can use a single read() call for /proc, this
4086 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4087 but it doesn't support writes. */
4089 static enum target_xfer_status
4090 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4091 const char *annex, gdb_byte *readbuf,
4092 const gdb_byte *writebuf,
4093 ULONGEST offset, LONGEST len, ULONGEST *xfered_len)
4099 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4102 /* Don't bother for one word. */
4103 if (len < 3 * sizeof (long))
4104 return TARGET_XFER_EOF;
4106 /* We could keep this file open and cache it - possibly one per
4107 thread. That requires some juggling, but is even faster. */
4108 xsnprintf (filename, sizeof filename, "/proc/%d/mem",
4109 ptid_get_pid (inferior_ptid));
4110 fd = gdb_open_cloexec (filename, O_RDONLY | O_LARGEFILE, 0);
4112 return TARGET_XFER_EOF;
4114 /* If pread64 is available, use it. It's faster if the kernel
4115 supports it (only one syscall), and it's 64-bit safe even on
4116 32-bit platforms (for instance, SPARC debugging a SPARC64
4119 if (pread64 (fd, readbuf, len, offset) != len)
4121 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4130 return TARGET_XFER_EOF;
4134 return TARGET_XFER_OK;
4139 /* Enumerate spufs IDs for process PID. */
4141 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, ULONGEST len)
4143 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
4145 LONGEST written = 0;
4148 struct dirent *entry;
4150 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4151 dir = opendir (path);
4156 while ((entry = readdir (dir)) != NULL)
4162 fd = atoi (entry->d_name);
4166 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4167 if (stat (path, &st) != 0)
4169 if (!S_ISDIR (st.st_mode))
4172 if (statfs (path, &stfs) != 0)
4174 if (stfs.f_type != SPUFS_MAGIC)
4177 if (pos >= offset && pos + 4 <= offset + len)
4179 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4189 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4190 object type, using the /proc file system. */
4192 static enum target_xfer_status
4193 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4194 const char *annex, gdb_byte *readbuf,
4195 const gdb_byte *writebuf,
4196 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
4201 int pid = ptid_get_pid (inferior_ptid);
4206 return TARGET_XFER_E_IO;
4209 LONGEST l = spu_enumerate_spu_ids (pid, readbuf, offset, len);
4212 return TARGET_XFER_E_IO;
4214 return TARGET_XFER_EOF;
4217 *xfered_len = (ULONGEST) l;
4218 return TARGET_XFER_OK;
4223 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4224 fd = gdb_open_cloexec (buf, writebuf? O_WRONLY : O_RDONLY, 0);
4226 return TARGET_XFER_E_IO;
4229 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4232 return TARGET_XFER_EOF;
4236 ret = write (fd, writebuf, (size_t) len);
4238 ret = read (fd, readbuf, (size_t) len);
4243 return TARGET_XFER_E_IO;
4245 return TARGET_XFER_EOF;
4248 *xfered_len = (ULONGEST) ret;
4249 return TARGET_XFER_OK;
4254 /* Parse LINE as a signal set and add its set bits to SIGS. */
4257 add_line_to_sigset (const char *line, sigset_t *sigs)
4259 int len = strlen (line) - 1;
4263 if (line[len] != '\n')
4264 error (_("Could not parse signal set: %s"), line);
4272 if (*p >= '0' && *p <= '9')
4274 else if (*p >= 'a' && *p <= 'f')
4275 digit = *p - 'a' + 10;
4277 error (_("Could not parse signal set: %s"), line);
4282 sigaddset (sigs, signum + 1);
4284 sigaddset (sigs, signum + 2);
4286 sigaddset (sigs, signum + 3);
4288 sigaddset (sigs, signum + 4);
4294 /* Find process PID's pending signals from /proc/pid/status and set
4298 linux_proc_pending_signals (int pid, sigset_t *pending,
4299 sigset_t *blocked, sigset_t *ignored)
4302 char buffer[PATH_MAX], fname[PATH_MAX];
4303 struct cleanup *cleanup;
4305 sigemptyset (pending);
4306 sigemptyset (blocked);
4307 sigemptyset (ignored);
4308 xsnprintf (fname, sizeof fname, "/proc/%d/status", pid);
4309 procfile = gdb_fopen_cloexec (fname, "r");
4310 if (procfile == NULL)
4311 error (_("Could not open %s"), fname);
4312 cleanup = make_cleanup_fclose (procfile);
4314 while (fgets (buffer, PATH_MAX, procfile) != NULL)
4316 /* Normal queued signals are on the SigPnd line in the status
4317 file. However, 2.6 kernels also have a "shared" pending
4318 queue for delivering signals to a thread group, so check for
4321 Unfortunately some Red Hat kernels include the shared pending
4322 queue but not the ShdPnd status field. */
4324 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
4325 add_line_to_sigset (buffer + 8, pending);
4326 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
4327 add_line_to_sigset (buffer + 8, pending);
4328 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
4329 add_line_to_sigset (buffer + 8, blocked);
4330 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
4331 add_line_to_sigset (buffer + 8, ignored);
4334 do_cleanups (cleanup);
4337 static enum target_xfer_status
4338 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4339 const char *annex, gdb_byte *readbuf,
4340 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4341 ULONGEST *xfered_len)
4343 gdb_assert (object == TARGET_OBJECT_OSDATA);
4345 *xfered_len = linux_common_xfer_osdata (annex, readbuf, offset, len);
4346 if (*xfered_len == 0)
4347 return TARGET_XFER_EOF;
4349 return TARGET_XFER_OK;
4352 static enum target_xfer_status
4353 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4354 const char *annex, gdb_byte *readbuf,
4355 const gdb_byte *writebuf, ULONGEST offset, ULONGEST len,
4356 ULONGEST *xfered_len)
4358 enum target_xfer_status xfer;
4360 if (object == TARGET_OBJECT_AUXV)
4361 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
4362 offset, len, xfered_len);
4364 if (object == TARGET_OBJECT_OSDATA)
4365 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4366 offset, len, xfered_len);
4368 if (object == TARGET_OBJECT_SPU)
4369 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4370 offset, len, xfered_len);
4372 /* GDB calculates all the addresses in possibly larget width of the address.
4373 Address width needs to be masked before its final use - either by
4374 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4376 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4378 if (object == TARGET_OBJECT_MEMORY)
4380 int addr_bit = gdbarch_addr_bit (target_gdbarch ());
4382 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4383 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4386 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4387 offset, len, xfered_len);
4388 if (xfer != TARGET_XFER_EOF)
4391 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4392 offset, len, xfered_len);
4396 cleanup_target_stop (void *arg)
4398 ptid_t *ptid = (ptid_t *) arg;
4400 gdb_assert (arg != NULL);
4403 target_resume (*ptid, 0, GDB_SIGNAL_0);
4406 static VEC(static_tracepoint_marker_p) *
4407 linux_child_static_tracepoint_markers_by_strid (struct target_ops *self,
4410 char s[IPA_CMD_BUF_SIZE];
4411 struct cleanup *old_chain;
4412 int pid = ptid_get_pid (inferior_ptid);
4413 VEC(static_tracepoint_marker_p) *markers = NULL;
4414 struct static_tracepoint_marker *marker = NULL;
4416 ptid_t ptid = ptid_build (pid, 0, 0);
4421 memcpy (s, "qTfSTM", sizeof ("qTfSTM"));
4422 s[sizeof ("qTfSTM")] = 0;
4424 agent_run_command (pid, s, strlen (s) + 1);
4426 old_chain = make_cleanup (free_current_marker, &marker);
4427 make_cleanup (cleanup_target_stop, &ptid);
4432 marker = XCNEW (struct static_tracepoint_marker);
4436 parse_static_tracepoint_marker_definition (p, &p, marker);
4438 if (strid == NULL || strcmp (strid, marker->str_id) == 0)
4440 VEC_safe_push (static_tracepoint_marker_p,
4446 release_static_tracepoint_marker (marker);
4447 memset (marker, 0, sizeof (*marker));
4450 while (*p++ == ','); /* comma-separated list */
4452 memcpy (s, "qTsSTM", sizeof ("qTsSTM"));
4453 s[sizeof ("qTsSTM")] = 0;
4454 agent_run_command (pid, s, strlen (s) + 1);
4458 do_cleanups (old_chain);
4463 /* Create a prototype generic GNU/Linux target. The client can override
4464 it with local methods. */
4467 linux_target_install_ops (struct target_ops *t)
4469 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4470 t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint;
4471 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4472 t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint;
4473 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4474 t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint;
4475 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4476 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4477 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4478 t->to_post_attach = linux_child_post_attach;
4479 t->to_follow_fork = linux_child_follow_fork;
4480 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
4482 super_xfer_partial = t->to_xfer_partial;
4483 t->to_xfer_partial = linux_xfer_partial;
4485 t->to_static_tracepoint_markers_by_strid
4486 = linux_child_static_tracepoint_markers_by_strid;
4492 struct target_ops *t;
4494 t = inf_ptrace_target ();
4495 linux_target_install_ops (t);
4501 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4503 struct target_ops *t;
4505 t = inf_ptrace_trad_target (register_u_offset);
4506 linux_target_install_ops (t);
4511 /* target_is_async_p implementation. */
4514 linux_nat_is_async_p (struct target_ops *ops)
4516 /* NOTE: palves 2008-03-21: We're only async when the user requests
4517 it explicitly with the "set target-async" command.
4518 Someday, linux will always be async. */
4519 return target_async_permitted;
4522 /* target_can_async_p implementation. */
4525 linux_nat_can_async_p (struct target_ops *ops)
4527 /* NOTE: palves 2008-03-21: We're only async when the user requests
4528 it explicitly with the "set target-async" command.
4529 Someday, linux will always be async. */
4530 return target_async_permitted;
4534 linux_nat_supports_non_stop (struct target_ops *self)
4539 /* True if we want to support multi-process. To be removed when GDB
4540 supports multi-exec. */
4542 int linux_multi_process = 1;
4545 linux_nat_supports_multi_process (struct target_ops *self)
4547 return linux_multi_process;
4551 linux_nat_supports_disable_randomization (struct target_ops *self)
4553 #ifdef HAVE_PERSONALITY
4560 static int async_terminal_is_ours = 1;
4562 /* target_terminal_inferior implementation. */
4565 linux_nat_terminal_inferior (struct target_ops *self)
4567 if (!target_is_async_p ())
4569 /* Async mode is disabled. */
4570 child_terminal_inferior (self);
4574 child_terminal_inferior (self);
4576 /* Calls to target_terminal_*() are meant to be idempotent. */
4577 if (!async_terminal_is_ours)
4580 delete_file_handler (input_fd);
4581 async_terminal_is_ours = 0;
4585 /* target_terminal_ours implementation. */
4588 linux_nat_terminal_ours (struct target_ops *self)
4590 if (!target_is_async_p ())
4592 /* Async mode is disabled. */
4593 child_terminal_ours (self);
4597 /* GDB should never give the terminal to the inferior if the
4598 inferior is running in the background (run&, continue&, etc.),
4599 but claiming it sure should. */
4600 child_terminal_ours (self);
4602 if (async_terminal_is_ours)
4605 clear_sigint_trap ();
4606 add_file_handler (input_fd, stdin_event_handler, 0);
4607 async_terminal_is_ours = 1;
4610 static void (*async_client_callback) (enum inferior_event_type event_type,
4612 static void *async_client_context;
4614 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4615 so we notice when any child changes state, and notify the
4616 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4617 above to wait for the arrival of a SIGCHLD. */
4620 sigchld_handler (int signo)
4622 int old_errno = errno;
4624 if (debug_linux_nat)
4625 ui_file_write_async_safe (gdb_stdlog,
4626 "sigchld\n", sizeof ("sigchld\n") - 1);
4628 if (signo == SIGCHLD
4629 && linux_nat_event_pipe[0] != -1)
4630 async_file_mark (); /* Let the event loop know that there are
4631 events to handle. */
4636 /* Callback registered with the target events file descriptor. */
4639 handle_target_event (int error, gdb_client_data client_data)
4641 (*async_client_callback) (INF_REG_EVENT, async_client_context);
4644 /* Create/destroy the target events pipe. Returns previous state. */
4647 linux_async_pipe (int enable)
4649 int previous = (linux_nat_event_pipe[0] != -1);
4651 if (previous != enable)
4655 /* Block child signals while we create/destroy the pipe, as
4656 their handler writes to it. */
4657 block_child_signals (&prev_mask);
4661 if (gdb_pipe_cloexec (linux_nat_event_pipe) == -1)
4662 internal_error (__FILE__, __LINE__,
4663 "creating event pipe failed.");
4665 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4666 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4670 close (linux_nat_event_pipe[0]);
4671 close (linux_nat_event_pipe[1]);
4672 linux_nat_event_pipe[0] = -1;
4673 linux_nat_event_pipe[1] = -1;
4676 restore_child_signals_mask (&prev_mask);
4682 /* target_async implementation. */
4685 linux_nat_async (struct target_ops *ops,
4686 void (*callback) (enum inferior_event_type event_type,
4690 if (callback != NULL)
4692 async_client_callback = callback;
4693 async_client_context = context;
4694 if (!linux_async_pipe (1))
4696 add_file_handler (linux_nat_event_pipe[0],
4697 handle_target_event, NULL);
4698 /* There may be pending events to handle. Tell the event loop
4705 async_client_callback = callback;
4706 async_client_context = context;
4707 delete_file_handler (linux_nat_event_pipe[0]);
4708 linux_async_pipe (0);
4713 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4717 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4721 if (debug_linux_nat)
4722 fprintf_unfiltered (gdb_stdlog,
4723 "LNSL: running -> suspending %s\n",
4724 target_pid_to_str (lwp->ptid));
4727 if (lwp->last_resume_kind == resume_stop)
4729 if (debug_linux_nat)
4730 fprintf_unfiltered (gdb_stdlog,
4731 "linux-nat: already stopping LWP %ld at "
4733 ptid_get_lwp (lwp->ptid));
4737 stop_callback (lwp, NULL);
4738 lwp->last_resume_kind = resume_stop;
4742 /* Already known to be stopped; do nothing. */
4744 if (debug_linux_nat)
4746 if (find_thread_ptid (lwp->ptid)->stop_requested)
4747 fprintf_unfiltered (gdb_stdlog,
4748 "LNSL: already stopped/stop_requested %s\n",
4749 target_pid_to_str (lwp->ptid));
4751 fprintf_unfiltered (gdb_stdlog,
4752 "LNSL: already stopped/no "
4753 "stop_requested yet %s\n",
4754 target_pid_to_str (lwp->ptid));
4761 linux_nat_stop (struct target_ops *self, ptid_t ptid)
4764 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4766 linux_ops->to_stop (linux_ops, ptid);
4770 linux_nat_close (struct target_ops *self)
4772 /* Unregister from the event loop. */
4773 if (linux_nat_is_async_p (NULL))
4774 linux_nat_async (NULL, NULL, 0);
4776 if (linux_ops->to_close)
4777 linux_ops->to_close (linux_ops);
4782 /* When requests are passed down from the linux-nat layer to the
4783 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4784 used. The address space pointer is stored in the inferior object,
4785 but the common code that is passed such ptid can't tell whether
4786 lwpid is a "main" process id or not (it assumes so). We reverse
4787 look up the "main" process id from the lwp here. */
4789 static struct address_space *
4790 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
4792 struct lwp_info *lwp;
4793 struct inferior *inf;
4796 pid = ptid_get_lwp (ptid);
4797 if (ptid_get_lwp (ptid) == 0)
4799 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4801 lwp = find_lwp_pid (ptid);
4802 pid = ptid_get_pid (lwp->ptid);
4806 /* A (pid,lwpid,0) ptid. */
4807 pid = ptid_get_pid (ptid);
4810 inf = find_inferior_pid (pid);
4811 gdb_assert (inf != NULL);
4815 /* Return the cached value of the processor core for thread PTID. */
4818 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
4820 struct lwp_info *info = find_lwp_pid (ptid);
4828 linux_nat_add_target (struct target_ops *t)
4830 /* Save the provided single-threaded target. We save this in a separate
4831 variable because another target we've inherited from (e.g. inf-ptrace)
4832 may have saved a pointer to T; we want to use it for the final
4833 process stratum target. */
4834 linux_ops_saved = *t;
4835 linux_ops = &linux_ops_saved;
4837 /* Override some methods for multithreading. */
4838 t->to_create_inferior = linux_nat_create_inferior;
4839 t->to_attach = linux_nat_attach;
4840 t->to_detach = linux_nat_detach;
4841 t->to_resume = linux_nat_resume;
4842 t->to_wait = linux_nat_wait;
4843 t->to_pass_signals = linux_nat_pass_signals;
4844 t->to_xfer_partial = linux_nat_xfer_partial;
4845 t->to_kill = linux_nat_kill;
4846 t->to_mourn_inferior = linux_nat_mourn_inferior;
4847 t->to_thread_alive = linux_nat_thread_alive;
4848 t->to_pid_to_str = linux_nat_pid_to_str;
4849 t->to_thread_name = linux_nat_thread_name;
4850 t->to_has_thread_control = tc_schedlock;
4851 t->to_thread_address_space = linux_nat_thread_address_space;
4852 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
4853 t->to_stopped_data_address = linux_nat_stopped_data_address;
4855 t->to_can_async_p = linux_nat_can_async_p;
4856 t->to_is_async_p = linux_nat_is_async_p;
4857 t->to_supports_non_stop = linux_nat_supports_non_stop;
4858 t->to_async = linux_nat_async;
4859 t->to_terminal_inferior = linux_nat_terminal_inferior;
4860 t->to_terminal_ours = linux_nat_terminal_ours;
4862 super_close = t->to_close;
4863 t->to_close = linux_nat_close;
4865 /* Methods for non-stop support. */
4866 t->to_stop = linux_nat_stop;
4868 t->to_supports_multi_process = linux_nat_supports_multi_process;
4870 t->to_supports_disable_randomization
4871 = linux_nat_supports_disable_randomization;
4873 t->to_core_of_thread = linux_nat_core_of_thread;
4875 /* We don't change the stratum; this target will sit at
4876 process_stratum and thread_db will set at thread_stratum. This
4877 is a little strange, since this is a multi-threaded-capable
4878 target, but we want to be on the stack below thread_db, and we
4879 also want to be used for single-threaded processes. */
4884 /* Register a method to call whenever a new thread is attached. */
4886 linux_nat_set_new_thread (struct target_ops *t,
4887 void (*new_thread) (struct lwp_info *))
4889 /* Save the pointer. We only support a single registered instance
4890 of the GNU/Linux native target, so we do not need to map this to
4892 linux_nat_new_thread = new_thread;
4895 /* See declaration in linux-nat.h. */
4898 linux_nat_set_new_fork (struct target_ops *t,
4899 linux_nat_new_fork_ftype *new_fork)
4901 /* Save the pointer. */
4902 linux_nat_new_fork = new_fork;
4905 /* See declaration in linux-nat.h. */
4908 linux_nat_set_forget_process (struct target_ops *t,
4909 linux_nat_forget_process_ftype *fn)
4911 /* Save the pointer. */
4912 linux_nat_forget_process_hook = fn;
4915 /* See declaration in linux-nat.h. */
4918 linux_nat_forget_process (pid_t pid)
4920 if (linux_nat_forget_process_hook != NULL)
4921 linux_nat_forget_process_hook (pid);
4924 /* Register a method that converts a siginfo object between the layout
4925 that ptrace returns, and the layout in the architecture of the
4928 linux_nat_set_siginfo_fixup (struct target_ops *t,
4929 int (*siginfo_fixup) (siginfo_t *,
4933 /* Save the pointer. */
4934 linux_nat_siginfo_fixup = siginfo_fixup;
4937 /* Register a method to call prior to resuming a thread. */
4940 linux_nat_set_prepare_to_resume (struct target_ops *t,
4941 void (*prepare_to_resume) (struct lwp_info *))
4943 /* Save the pointer. */
4944 linux_nat_prepare_to_resume = prepare_to_resume;
4947 /* See linux-nat.h. */
4950 linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo)
4954 pid = ptid_get_lwp (ptid);
4956 pid = ptid_get_pid (ptid);
4959 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, siginfo);
4962 memset (siginfo, 0, sizeof (*siginfo));
4968 /* Provide a prototype to silence -Wmissing-prototypes. */
4969 extern initialize_file_ftype _initialize_linux_nat;
4972 _initialize_linux_nat (void)
4974 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance,
4975 &debug_linux_nat, _("\
4976 Set debugging of GNU/Linux lwp module."), _("\
4977 Show debugging of GNU/Linux lwp module."), _("\
4978 Enables printf debugging output."),
4980 show_debug_linux_nat,
4981 &setdebuglist, &showdebuglist);
4983 /* Save this mask as the default. */
4984 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4986 /* Install a SIGCHLD handler. */
4987 sigchld_action.sa_handler = sigchld_handler;
4988 sigemptyset (&sigchld_action.sa_mask);
4989 sigchld_action.sa_flags = SA_RESTART;
4991 /* Make it the default. */
4992 sigaction (SIGCHLD, &sigchld_action, NULL);
4994 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4995 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4996 sigdelset (&suspend_mask, SIGCHLD);
4998 sigemptyset (&blocked_mask);
5002 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5003 the GNU/Linux Threads library and therefore doesn't really belong
5006 /* Read variable NAME in the target and return its value if found.
5007 Otherwise return zero. It is assumed that the type of the variable
5011 get_signo (const char *name)
5013 struct bound_minimal_symbol ms;
5016 ms = lookup_minimal_symbol (name, NULL, NULL);
5017 if (ms.minsym == NULL)
5020 if (target_read_memory (BMSYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5021 sizeof (signo)) != 0)
5027 /* Return the set of signals used by the threads library in *SET. */
5030 lin_thread_get_thread_signals (sigset_t *set)
5032 struct sigaction action;
5033 int restart, cancel;
5035 sigemptyset (&blocked_mask);
5038 restart = get_signo ("__pthread_sig_restart");
5039 cancel = get_signo ("__pthread_sig_cancel");
5041 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5042 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5043 not provide any way for the debugger to query the signal numbers -
5044 fortunately they don't change! */
5047 restart = __SIGRTMIN;
5050 cancel = __SIGRTMIN + 1;
5052 sigaddset (set, restart);
5053 sigaddset (set, cancel);
5055 /* The GNU/Linux Threads library makes terminating threads send a
5056 special "cancel" signal instead of SIGCHLD. Make sure we catch
5057 those (to prevent them from terminating GDB itself, which is
5058 likely to be their default action) and treat them the same way as
5061 action.sa_handler = sigchld_handler;
5062 sigemptyset (&action.sa_mask);
5063 action.sa_flags = SA_RESTART;
5064 sigaction (cancel, &action, NULL);
5066 /* We block the "cancel" signal throughout this code ... */
5067 sigaddset (&blocked_mask, cancel);
5068 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5070 /* ... except during a sigsuspend. */
5071 sigdelset (&suspend_mask, cancel);