1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
26 #include "gdb_assert.h"
27 #ifdef HAVE_TKILL_SYSCALL
29 #include <sys/syscall.h>
31 #include <sys/ptrace.h>
32 #include "linux-nat.h"
33 #include "linux-fork.h"
34 #include "gdbthread.h"
38 #include "inf-ptrace.h"
40 #include <sys/param.h> /* for MAXPATHLEN */
41 #include <sys/procfs.h> /* for elf_gregset etc. */
42 #include "elf-bfd.h" /* for elfcore_write_* */
43 #include "gregset.h" /* for gregset */
44 #include "gdbcore.h" /* for get_exec_file */
45 #include <ctype.h> /* for isdigit */
46 #include "gdbthread.h" /* for struct thread_info etc. */
47 #include "gdb_stat.h" /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
54 #include "gdb_dirent.h"
55 #include "xml-support.h"
61 #define SPUFS_MAGIC 0x23c9b64e
64 #ifdef HAVE_PERSONALITY
65 # include <sys/personality.h>
66 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
67 # define ADDR_NO_RANDOMIZE 0x0040000
69 #endif /* HAVE_PERSONALITY */
71 /* This comment documents high-level logic of this file.
73 Waiting for events in sync mode
74 ===============================
76 When waiting for an event in a specific thread, we just use waitpid, passing
77 the specific pid, and not passing WNOHANG.
79 When waiting for an event in all threads, waitpid is not quite good. Prior to
80 version 2.4, Linux can either wait for event in main thread, or in secondary
81 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
82 miss an event. The solution is to use non-blocking waitpid, together with
83 sigsuspend. First, we use non-blocking waitpid to get an event in the main
84 process, if any. Second, we use non-blocking waitpid with the __WCLONED
85 flag to check for events in cloned processes. If nothing is found, we use
86 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
87 happened to a child process -- and SIGCHLD will be delivered both for events
88 in main debugged process and in cloned processes. As soon as we know there's
89 an event, we get back to calling nonblocking waitpid with and without __WCLONED.
91 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
92 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
93 blocked, the signal becomes pending and sigsuspend immediately
94 notices it and returns.
96 Waiting for events in async mode
97 ================================
99 In async mode, GDB should always be ready to handle both user input
100 and target events, so neither blocking waitpid nor sigsuspend are
101 viable options. Instead, we should asynchronously notify the GDB main
102 event loop whenever there's an unprocessed event from the target. We
103 detect asynchronous target events by handling SIGCHLD signals. To
104 notify the event loop about target events, the self-pipe trick is used
105 --- a pipe is registered as waitable event source in the event loop,
106 the event loop select/poll's on the read end of this pipe (as well on
107 other event sources, e.g., stdin), and the SIGCHLD handler writes a
108 byte to this pipe. This is more portable than relying on
109 pselect/ppoll, since on kernels that lack those syscalls, libc
110 emulates them with select/poll+sigprocmask, and that is racy
111 (a.k.a. plain broken).
113 Obviously, if we fail to notify the event loop if there's a target
114 event, it's bad. OTOH, if we notify the event loop when there's no
115 event from the target, linux_nat_wait will detect that there's no real
116 event to report, and return event of type TARGET_WAITKIND_IGNORE.
117 This is mostly harmless, but it will waste time and is better avoided.
119 The main design point is that every time GDB is outside linux-nat.c,
120 we have a SIGCHLD handler installed that is called when something
121 happens to the target and notifies the GDB event loop. Whenever GDB
122 core decides to handle the event, and calls into linux-nat.c, we
123 process things as in sync mode, except that the we never block in
126 While processing an event, we may end up momentarily blocked in
127 waitpid calls. Those waitpid calls, while blocking, are guarantied to
128 return quickly. E.g., in all-stop mode, before reporting to the core
129 that an LWP hit a breakpoint, all LWPs are stopped by sending them
130 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
131 Note that this is different from blocking indefinitely waiting for the
132 next event --- here, we're already handling an event.
137 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
138 signal is not entirely significant; we just need for a signal to be delivered,
139 so that we can intercept it. SIGSTOP's advantage is that it can not be
140 blocked. A disadvantage is that it is not a real-time signal, so it can only
141 be queued once; we do not keep track of other sources of SIGSTOP.
143 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
144 use them, because they have special behavior when the signal is generated -
145 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
146 kills the entire thread group.
148 A delivered SIGSTOP would stop the entire thread group, not just the thread we
149 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
150 cancel it (by PTRACE_CONT without passing SIGSTOP).
152 We could use a real-time signal instead. This would solve those problems; we
153 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
154 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
155 generates it, and there are races with trying to find a signal that is not
159 #define O_LARGEFILE 0
162 /* If the system headers did not provide the constants, hard-code the normal
164 #ifndef PTRACE_EVENT_FORK
166 #define PTRACE_SETOPTIONS 0x4200
167 #define PTRACE_GETEVENTMSG 0x4201
169 /* options set using PTRACE_SETOPTIONS */
170 #define PTRACE_O_TRACESYSGOOD 0x00000001
171 #define PTRACE_O_TRACEFORK 0x00000002
172 #define PTRACE_O_TRACEVFORK 0x00000004
173 #define PTRACE_O_TRACECLONE 0x00000008
174 #define PTRACE_O_TRACEEXEC 0x00000010
175 #define PTRACE_O_TRACEVFORKDONE 0x00000020
176 #define PTRACE_O_TRACEEXIT 0x00000040
178 /* Wait extended result codes for the above trace options. */
179 #define PTRACE_EVENT_FORK 1
180 #define PTRACE_EVENT_VFORK 2
181 #define PTRACE_EVENT_CLONE 3
182 #define PTRACE_EVENT_EXEC 4
183 #define PTRACE_EVENT_VFORK_DONE 5
184 #define PTRACE_EVENT_EXIT 6
186 #endif /* PTRACE_EVENT_FORK */
188 /* Unlike other extended result codes, WSTOPSIG (status) on
189 PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but
190 instead SIGTRAP with bit 7 set. */
191 #define SYSCALL_SIGTRAP (SIGTRAP | 0x80)
193 /* We can't always assume that this flag is available, but all systems
194 with the ptrace event handlers also have __WALL, so it's safe to use
197 #define __WALL 0x40000000 /* Wait for any child. */
200 #ifndef PTRACE_GETSIGINFO
201 # define PTRACE_GETSIGINFO 0x4202
202 # define PTRACE_SETSIGINFO 0x4203
205 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
206 the use of the multi-threaded target. */
207 static struct target_ops *linux_ops;
208 static struct target_ops linux_ops_saved;
210 /* The method to call, if any, when a new thread is attached. */
211 static void (*linux_nat_new_thread) (ptid_t);
213 /* The method to call, if any, when the siginfo object needs to be
214 converted between the layout returned by ptrace, and the layout in
215 the architecture of the inferior. */
216 static int (*linux_nat_siginfo_fixup) (struct siginfo *,
220 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
221 Called by our to_xfer_partial. */
222 static LONGEST (*super_xfer_partial) (struct target_ops *,
224 const char *, gdb_byte *,
228 static int debug_linux_nat;
230 show_debug_linux_nat (struct ui_file *file, int from_tty,
231 struct cmd_list_element *c, const char *value)
233 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
237 static int debug_linux_nat_async = 0;
239 show_debug_linux_nat_async (struct ui_file *file, int from_tty,
240 struct cmd_list_element *c, const char *value)
242 fprintf_filtered (file, _("Debugging of GNU/Linux async lwp module is %s.\n"),
246 static int disable_randomization = 1;
249 show_disable_randomization (struct ui_file *file, int from_tty,
250 struct cmd_list_element *c, const char *value)
252 #ifdef HAVE_PERSONALITY
253 fprintf_filtered (file, _("\
254 Disabling randomization of debuggee's virtual address space is %s.\n"),
256 #else /* !HAVE_PERSONALITY */
258 Disabling randomization of debuggee's virtual address space is unsupported on\n\
259 this platform.\n"), file);
260 #endif /* !HAVE_PERSONALITY */
264 set_disable_randomization (char *args, int from_tty, struct cmd_list_element *c)
266 #ifndef HAVE_PERSONALITY
268 Disabling randomization of debuggee's virtual address space is unsupported on\n\
270 #endif /* !HAVE_PERSONALITY */
273 struct simple_pid_list
277 struct simple_pid_list *next;
279 struct simple_pid_list *stopped_pids;
281 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
282 can not be used, 1 if it can. */
284 static int linux_supports_tracefork_flag = -1;
286 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACESYSGOOD
287 can not be used, 1 if it can. */
289 static int linux_supports_tracesysgood_flag = -1;
291 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
292 PTRACE_O_TRACEVFORKDONE. */
294 static int linux_supports_tracevforkdone_flag = -1;
296 /* Async mode support */
298 /* Zero if the async mode, although enabled, is masked, which means
299 linux_nat_wait should behave as if async mode was off. */
300 static int linux_nat_async_mask_value = 1;
302 /* Stores the current used ptrace() options. */
303 static int current_ptrace_options = 0;
305 /* The read/write ends of the pipe registered as waitable file in the
307 static int linux_nat_event_pipe[2] = { -1, -1 };
309 /* Flush the event pipe. */
312 async_file_flush (void)
319 ret = read (linux_nat_event_pipe[0], &buf, 1);
321 while (ret >= 0 || (ret == -1 && errno == EINTR));
324 /* Put something (anything, doesn't matter what, or how much) in event
325 pipe, so that the select/poll in the event-loop realizes we have
326 something to process. */
329 async_file_mark (void)
333 /* It doesn't really matter what the pipe contains, as long we end
334 up with something in it. Might as well flush the previous
340 ret = write (linux_nat_event_pipe[1], "+", 1);
342 while (ret == -1 && errno == EINTR);
344 /* Ignore EAGAIN. If the pipe is full, the event loop will already
345 be awakened anyway. */
348 static void linux_nat_async (void (*callback)
349 (enum inferior_event_type event_type, void *context),
351 static int linux_nat_async_mask (int mask);
352 static int kill_lwp (int lwpid, int signo);
354 static int stop_callback (struct lwp_info *lp, void *data);
356 static void block_child_signals (sigset_t *prev_mask);
357 static void restore_child_signals_mask (sigset_t *prev_mask);
360 static struct lwp_info *add_lwp (ptid_t ptid);
361 static void purge_lwp_list (int pid);
362 static struct lwp_info *find_lwp_pid (ptid_t ptid);
365 /* Trivial list manipulation functions to keep track of a list of
366 new stopped processes. */
368 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
370 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
373 new_pid->status = status;
374 new_pid->next = *listp;
379 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp)
381 struct simple_pid_list **p;
383 for (p = listp; *p != NULL; p = &(*p)->next)
384 if ((*p)->pid == pid)
386 struct simple_pid_list *next = (*p)->next;
388 *statusp = (*p)->status;
397 linux_record_stopped_pid (int pid, int status)
399 add_to_pid_list (&stopped_pids, pid, status);
403 /* A helper function for linux_test_for_tracefork, called after fork (). */
406 linux_tracefork_child (void)
408 ptrace (PTRACE_TRACEME, 0, 0, 0);
409 kill (getpid (), SIGSTOP);
414 /* Wrapper function for waitpid which handles EINTR. */
417 my_waitpid (int pid, int *statusp, int flags)
423 ret = waitpid (pid, statusp, flags);
425 while (ret == -1 && errno == EINTR);
430 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
432 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
433 we know that the feature is not available. This may change the tracing
434 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
436 However, if it succeeds, we don't know for sure that the feature is
437 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
438 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
439 fork tracing, and let it fork. If the process exits, we assume that we
440 can't use TRACEFORK; if we get the fork notification, and we can extract
441 the new child's PID, then we assume that we can. */
444 linux_test_for_tracefork (int original_pid)
446 int child_pid, ret, status;
450 /* We don't want those ptrace calls to be interrupted. */
451 block_child_signals (&prev_mask);
453 linux_supports_tracefork_flag = 0;
454 linux_supports_tracevforkdone_flag = 0;
456 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
459 restore_child_signals_mask (&prev_mask);
465 perror_with_name (("fork"));
468 linux_tracefork_child ();
470 ret = my_waitpid (child_pid, &status, 0);
472 perror_with_name (("waitpid"));
473 else if (ret != child_pid)
474 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
475 if (! WIFSTOPPED (status))
476 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status);
478 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
481 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
484 warning (_("linux_test_for_tracefork: failed to kill child"));
485 restore_child_signals_mask (&prev_mask);
489 ret = my_waitpid (child_pid, &status, 0);
490 if (ret != child_pid)
491 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
492 else if (!WIFSIGNALED (status))
493 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
494 "killed child"), status);
496 restore_child_signals_mask (&prev_mask);
500 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
501 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
502 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
503 linux_supports_tracevforkdone_flag = (ret == 0);
505 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
507 warning (_("linux_test_for_tracefork: failed to resume child"));
509 ret = my_waitpid (child_pid, &status, 0);
511 if (ret == child_pid && WIFSTOPPED (status)
512 && status >> 16 == PTRACE_EVENT_FORK)
515 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
516 if (ret == 0 && second_pid != 0)
520 linux_supports_tracefork_flag = 1;
521 my_waitpid (second_pid, &second_status, 0);
522 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
524 warning (_("linux_test_for_tracefork: failed to kill second child"));
525 my_waitpid (second_pid, &status, 0);
529 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
530 "(%d, status 0x%x)"), ret, status);
532 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
534 warning (_("linux_test_for_tracefork: failed to kill child"));
535 my_waitpid (child_pid, &status, 0);
537 restore_child_signals_mask (&prev_mask);
540 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
542 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
543 we know that the feature is not available. This may change the tracing
544 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
547 linux_test_for_tracesysgood (int original_pid)
552 /* We don't want those ptrace calls to be interrupted. */
553 block_child_signals (&prev_mask);
555 linux_supports_tracesysgood_flag = 0;
557 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD);
561 linux_supports_tracesysgood_flag = 1;
563 restore_child_signals_mask (&prev_mask);
566 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
567 This function also sets linux_supports_tracesysgood_flag. */
570 linux_supports_tracesysgood (int pid)
572 if (linux_supports_tracesysgood_flag == -1)
573 linux_test_for_tracesysgood (pid);
574 return linux_supports_tracesysgood_flag;
577 /* Return non-zero iff we have tracefork functionality available.
578 This function also sets linux_supports_tracefork_flag. */
581 linux_supports_tracefork (int pid)
583 if (linux_supports_tracefork_flag == -1)
584 linux_test_for_tracefork (pid);
585 return linux_supports_tracefork_flag;
589 linux_supports_tracevforkdone (int pid)
591 if (linux_supports_tracefork_flag == -1)
592 linux_test_for_tracefork (pid);
593 return linux_supports_tracevforkdone_flag;
597 linux_enable_tracesysgood (ptid_t ptid)
599 int pid = ptid_get_lwp (ptid);
602 pid = ptid_get_pid (ptid);
604 if (linux_supports_tracesysgood (pid) == 0)
607 current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
609 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
614 linux_enable_event_reporting (ptid_t ptid)
616 int pid = ptid_get_lwp (ptid);
619 pid = ptid_get_pid (ptid);
621 if (! linux_supports_tracefork (pid))
624 current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
625 | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE;
627 if (linux_supports_tracevforkdone (pid))
628 current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
630 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
631 read-only process state. */
633 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
637 linux_child_post_attach (int pid)
639 linux_enable_event_reporting (pid_to_ptid (pid));
640 check_for_thread_db ();
641 linux_enable_tracesysgood (pid_to_ptid (pid));
645 linux_child_post_startup_inferior (ptid_t ptid)
647 linux_enable_event_reporting (ptid);
648 check_for_thread_db ();
649 linux_enable_tracesysgood (ptid);
653 linux_child_follow_fork (struct target_ops *ops, int follow_child)
657 int parent_pid, child_pid;
659 block_child_signals (&prev_mask);
661 has_vforked = (inferior_thread ()->pending_follow.kind
662 == TARGET_WAITKIND_VFORKED);
663 parent_pid = ptid_get_lwp (inferior_ptid);
665 parent_pid = ptid_get_pid (inferior_ptid);
666 child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
669 linux_enable_event_reporting (pid_to_ptid (child_pid));
672 && !non_stop /* Non-stop always resumes both branches. */
673 && (!target_is_async_p () || sync_execution)
674 && !(follow_child || detach_fork || sched_multi))
676 /* The parent stays blocked inside the vfork syscall until the
677 child execs or exits. If we don't let the child run, then
678 the parent stays blocked. If we're telling the parent to run
679 in the foreground, the user will not be able to ctrl-c to get
680 back the terminal, effectively hanging the debug session. */
681 fprintf_filtered (gdb_stderr, _("\
682 Can not resume the parent process over vfork in the foreground while\n\
683 holding the child stopped. Try \"set detach-on-fork\" or \
684 \"set schedule-multiple\".\n"));
690 struct lwp_info *child_lp = NULL;
692 /* We're already attached to the parent, by default. */
694 /* Detach new forked process? */
697 /* Before detaching from the child, remove all breakpoints
698 from it. If we forked, then this has already been taken
699 care of by infrun.c. If we vforked however, any
700 breakpoint inserted in the parent is visible in the
701 child, even those added while stopped in a vfork
702 catchpoint. This will remove the breakpoints from the
703 parent also, but they'll be reinserted below. */
706 /* keep breakpoints list in sync. */
707 remove_breakpoints_pid (GET_PID (inferior_ptid));
710 if (info_verbose || debug_linux_nat)
712 target_terminal_ours ();
713 fprintf_filtered (gdb_stdlog,
714 "Detaching after fork from child process %d.\n",
718 ptrace (PTRACE_DETACH, child_pid, 0, 0);
722 struct inferior *parent_inf, *child_inf;
723 struct cleanup *old_chain;
725 /* Add process to GDB's tables. */
726 child_inf = add_inferior (child_pid);
728 parent_inf = current_inferior ();
729 child_inf->attach_flag = parent_inf->attach_flag;
730 copy_terminal_info (child_inf, parent_inf);
732 old_chain = save_inferior_ptid ();
733 save_current_program_space ();
735 inferior_ptid = ptid_build (child_pid, child_pid, 0);
736 add_thread (inferior_ptid);
737 child_lp = add_lwp (inferior_ptid);
738 child_lp->stopped = 1;
739 child_lp->resumed = 1;
741 /* If this is a vfork child, then the address-space is
742 shared with the parent. */
745 child_inf->pspace = parent_inf->pspace;
746 child_inf->aspace = parent_inf->aspace;
748 /* The parent will be frozen until the child is done
749 with the shared region. Keep track of the
751 child_inf->vfork_parent = parent_inf;
752 child_inf->pending_detach = 0;
753 parent_inf->vfork_child = child_inf;
754 parent_inf->pending_detach = 0;
758 child_inf->aspace = new_address_space ();
759 child_inf->pspace = add_program_space (child_inf->aspace);
760 child_inf->removable = 1;
761 set_current_program_space (child_inf->pspace);
762 clone_program_space (child_inf->pspace, parent_inf->pspace);
764 /* Let the shared library layer (solib-svr4) learn about
765 this new process, relocate the cloned exec, pull in
766 shared libraries, and install the solib event
767 breakpoint. If a "cloned-VM" event was propagated
768 better throughout the core, this wouldn't be
770 solib_create_inferior_hook (0);
773 /* Let the thread_db layer learn about this new process. */
774 check_for_thread_db ();
776 do_cleanups (old_chain);
782 struct inferior *parent_inf;
784 parent_inf = current_inferior ();
786 /* If we detached from the child, then we have to be careful
787 to not insert breakpoints in the parent until the child
788 is done with the shared memory region. However, if we're
789 staying attached to the child, then we can and should
790 insert breakpoints, so that we can debug it. A
791 subsequent child exec or exit is enough to know when does
792 the child stops using the parent's address space. */
793 parent_inf->waiting_for_vfork_done = detach_fork;
794 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
796 lp = find_lwp_pid (pid_to_ptid (parent_pid));
797 gdb_assert (linux_supports_tracefork_flag >= 0);
798 if (linux_supports_tracevforkdone (0))
801 fprintf_unfiltered (gdb_stdlog,
802 "LCFF: waiting for VFORK_DONE on %d\n",
808 /* We'll handle the VFORK_DONE event like any other
809 event, in target_wait. */
813 /* We can't insert breakpoints until the child has
814 finished with the shared memory region. We need to
815 wait until that happens. Ideal would be to just
817 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
818 - waitpid (parent_pid, &status, __WALL);
819 However, most architectures can't handle a syscall
820 being traced on the way out if it wasn't traced on
823 We might also think to loop, continuing the child
824 until it exits or gets a SIGTRAP. One problem is
825 that the child might call ptrace with PTRACE_TRACEME.
827 There's no simple and reliable way to figure out when
828 the vforked child will be done with its copy of the
829 shared memory. We could step it out of the syscall,
830 two instructions, let it go, and then single-step the
831 parent once. When we have hardware single-step, this
832 would work; with software single-step it could still
833 be made to work but we'd have to be able to insert
834 single-step breakpoints in the child, and we'd have
835 to insert -just- the single-step breakpoint in the
836 parent. Very awkward.
838 In the end, the best we can do is to make sure it
839 runs for a little while. Hopefully it will be out of
840 range of any breakpoints we reinsert. Usually this
841 is only the single-step breakpoint at vfork's return
845 fprintf_unfiltered (gdb_stdlog,
846 "LCFF: no VFORK_DONE support, sleeping a bit\n");
850 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
851 and leave it pending. The next linux_nat_resume call
852 will notice a pending event, and bypasses actually
853 resuming the inferior. */
855 lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
859 /* If we're in async mode, need to tell the event loop
860 there's something here to process. */
861 if (target_can_async_p ())
868 struct inferior *parent_inf, *child_inf;
870 struct program_space *parent_pspace;
872 if (info_verbose || debug_linux_nat)
874 target_terminal_ours ();
876 fprintf_filtered (gdb_stdlog, _("\
877 Attaching after process %d vfork to child process %d.\n"),
878 parent_pid, child_pid);
880 fprintf_filtered (gdb_stdlog, _("\
881 Attaching after process %d fork to child process %d.\n"),
882 parent_pid, child_pid);
885 /* Add the new inferior first, so that the target_detach below
886 doesn't unpush the target. */
888 child_inf = add_inferior (child_pid);
890 parent_inf = current_inferior ();
891 child_inf->attach_flag = parent_inf->attach_flag;
892 copy_terminal_info (child_inf, parent_inf);
894 parent_pspace = parent_inf->pspace;
896 /* If we're vforking, we want to hold on to the parent until the
897 child exits or execs. At child exec or exit time we can
898 remove the old breakpoints from the parent and detach or
899 resume debugging it. Otherwise, detach the parent now; we'll
900 want to reuse it's program/address spaces, but we can't set
901 them to the child before removing breakpoints from the
902 parent, otherwise, the breakpoints module could decide to
903 remove breakpoints from the wrong process (since they'd be
904 assigned to the same address space). */
908 gdb_assert (child_inf->vfork_parent == NULL);
909 gdb_assert (parent_inf->vfork_child == NULL);
910 child_inf->vfork_parent = parent_inf;
911 child_inf->pending_detach = 0;
912 parent_inf->vfork_child = child_inf;
913 parent_inf->pending_detach = detach_fork;
914 parent_inf->waiting_for_vfork_done = 0;
916 else if (detach_fork)
917 target_detach (NULL, 0);
919 /* Note that the detach above makes PARENT_INF dangling. */
921 /* Add the child thread to the appropriate lists, and switch to
922 this new thread, before cloning the program space, and
923 informing the solib layer about this new process. */
925 inferior_ptid = ptid_build (child_pid, child_pid, 0);
926 add_thread (inferior_ptid);
927 lp = add_lwp (inferior_ptid);
931 /* If this is a vfork child, then the address-space is shared
932 with the parent. If we detached from the parent, then we can
933 reuse the parent's program/address spaces. */
934 if (has_vforked || detach_fork)
936 child_inf->pspace = parent_pspace;
937 child_inf->aspace = child_inf->pspace->aspace;
941 child_inf->aspace = new_address_space ();
942 child_inf->pspace = add_program_space (child_inf->aspace);
943 child_inf->removable = 1;
944 set_current_program_space (child_inf->pspace);
945 clone_program_space (child_inf->pspace, parent_pspace);
947 /* Let the shared library layer (solib-svr4) learn about
948 this new process, relocate the cloned exec, pull in
949 shared libraries, and install the solib event breakpoint.
950 If a "cloned-VM" event was propagated better throughout
951 the core, this wouldn't be required. */
952 solib_create_inferior_hook (0);
955 /* Let the thread_db layer learn about this new process. */
956 check_for_thread_db ();
959 restore_child_signals_mask (&prev_mask);
965 linux_child_insert_fork_catchpoint (int pid)
967 if (! linux_supports_tracefork (pid))
968 error (_("Your system does not support fork catchpoints."));
972 linux_child_insert_vfork_catchpoint (int pid)
974 if (!linux_supports_tracefork (pid))
975 error (_("Your system does not support vfork catchpoints."));
979 linux_child_insert_exec_catchpoint (int pid)
981 if (!linux_supports_tracefork (pid))
982 error (_("Your system does not support exec catchpoints."));
986 linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
987 int table_size, int *table)
989 if (! linux_supports_tracesysgood (pid))
990 error (_("Your system does not support syscall catchpoints."));
991 /* On GNU/Linux, we ignore the arguments. It means that we only
992 enable the syscall catchpoints, but do not disable them.
994 Also, we do not use the `table' information because we do not
995 filter system calls here. We let GDB do the logic for us. */
999 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
1000 are processes sharing the same VM space. A multi-threaded process
1001 is basically a group of such processes. However, such a grouping
1002 is almost entirely a user-space issue; the kernel doesn't enforce
1003 such a grouping at all (this might change in the future). In
1004 general, we'll rely on the threads library (i.e. the GNU/Linux
1005 Threads library) to provide such a grouping.
1007 It is perfectly well possible to write a multi-threaded application
1008 without the assistance of a threads library, by using the clone
1009 system call directly. This module should be able to give some
1010 rudimentary support for debugging such applications if developers
1011 specify the CLONE_PTRACE flag in the clone system call, and are
1012 using the Linux kernel 2.4 or above.
1014 Note that there are some peculiarities in GNU/Linux that affect
1017 - In general one should specify the __WCLONE flag to waitpid in
1018 order to make it report events for any of the cloned processes
1019 (and leave it out for the initial process). However, if a cloned
1020 process has exited the exit status is only reported if the
1021 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1022 we cannot use it since GDB must work on older systems too.
1024 - When a traced, cloned process exits and is waited for by the
1025 debugger, the kernel reassigns it to the original parent and
1026 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1027 library doesn't notice this, which leads to the "zombie problem":
1028 When debugged a multi-threaded process that spawns a lot of
1029 threads will run out of processes, even if the threads exit,
1030 because the "zombies" stay around. */
1032 /* List of known LWPs. */
1033 struct lwp_info *lwp_list;
1036 /* Original signal mask. */
1037 static sigset_t normal_mask;
1039 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1040 _initialize_linux_nat. */
1041 static sigset_t suspend_mask;
1043 /* Signals to block to make that sigsuspend work. */
1044 static sigset_t blocked_mask;
1046 /* SIGCHLD action. */
1047 struct sigaction sigchld_action;
1049 /* Block child signals (SIGCHLD and linux threads signals), and store
1050 the previous mask in PREV_MASK. */
1053 block_child_signals (sigset_t *prev_mask)
1055 /* Make sure SIGCHLD is blocked. */
1056 if (!sigismember (&blocked_mask, SIGCHLD))
1057 sigaddset (&blocked_mask, SIGCHLD);
1059 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
1062 /* Restore child signals mask, previously returned by
1063 block_child_signals. */
1066 restore_child_signals_mask (sigset_t *prev_mask)
1068 sigprocmask (SIG_SETMASK, prev_mask, NULL);
1072 /* Prototypes for local functions. */
1073 static int stop_wait_callback (struct lwp_info *lp, void *data);
1074 static int linux_thread_alive (ptid_t ptid);
1075 static char *linux_child_pid_to_exec_file (int pid);
1078 /* Convert wait status STATUS to a string. Used for printing debug
1082 status_to_str (int status)
1084 static char buf[64];
1086 if (WIFSTOPPED (status))
1088 if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
1089 snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
1090 strsignal (SIGTRAP));
1092 snprintf (buf, sizeof (buf), "%s (stopped)",
1093 strsignal (WSTOPSIG (status)));
1095 else if (WIFSIGNALED (status))
1096 snprintf (buf, sizeof (buf), "%s (terminated)",
1097 strsignal (WSTOPSIG (status)));
1099 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
1104 /* Remove all LWPs belong to PID from the lwp list. */
1107 purge_lwp_list (int pid)
1109 struct lwp_info *lp, *lpprev, *lpnext;
1113 for (lp = lwp_list; lp; lp = lpnext)
1117 if (ptid_get_pid (lp->ptid) == pid)
1120 lwp_list = lp->next;
1122 lpprev->next = lp->next;
1131 /* Return the number of known LWPs in the tgid given by PID. */
1137 struct lwp_info *lp;
1139 for (lp = lwp_list; lp; lp = lp->next)
1140 if (ptid_get_pid (lp->ptid) == pid)
1146 /* Add the LWP specified by PID to the list. Return a pointer to the
1147 structure describing the new LWP. The LWP should already be stopped
1148 (with an exception for the very first LWP). */
1150 static struct lwp_info *
1151 add_lwp (ptid_t ptid)
1153 struct lwp_info *lp;
1155 gdb_assert (is_lwp (ptid));
1157 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
1159 memset (lp, 0, sizeof (struct lwp_info));
1161 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1166 lp->next = lwp_list;
1169 if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
1170 linux_nat_new_thread (ptid);
1175 /* Remove the LWP specified by PID from the list. */
1178 delete_lwp (ptid_t ptid)
1180 struct lwp_info *lp, *lpprev;
1184 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
1185 if (ptid_equal (lp->ptid, ptid))
1192 lpprev->next = lp->next;
1194 lwp_list = lp->next;
1199 /* Return a pointer to the structure describing the LWP corresponding
1200 to PID. If no corresponding LWP could be found, return NULL. */
1202 static struct lwp_info *
1203 find_lwp_pid (ptid_t ptid)
1205 struct lwp_info *lp;
1209 lwp = GET_LWP (ptid);
1211 lwp = GET_PID (ptid);
1213 for (lp = lwp_list; lp; lp = lp->next)
1214 if (lwp == GET_LWP (lp->ptid))
1220 /* Call CALLBACK with its second argument set to DATA for every LWP in
1221 the list. If CALLBACK returns 1 for a particular LWP, return a
1222 pointer to the structure describing that LWP immediately.
1223 Otherwise return NULL. */
1226 iterate_over_lwps (ptid_t filter,
1227 int (*callback) (struct lwp_info *, void *),
1230 struct lwp_info *lp, *lpnext;
1232 for (lp = lwp_list; lp; lp = lpnext)
1236 if (ptid_match (lp->ptid, filter))
1238 if ((*callback) (lp, data))
1246 /* Update our internal state when changing from one checkpoint to
1247 another indicated by NEW_PTID. We can only switch single-threaded
1248 applications, so we only create one new LWP, and the previous list
1252 linux_nat_switch_fork (ptid_t new_ptid)
1254 struct lwp_info *lp;
1256 purge_lwp_list (GET_PID (inferior_ptid));
1258 lp = add_lwp (new_ptid);
1261 /* This changes the thread's ptid while preserving the gdb thread
1262 num. Also changes the inferior pid, while preserving the
1264 thread_change_ptid (inferior_ptid, new_ptid);
1266 /* We've just told GDB core that the thread changed target id, but,
1267 in fact, it really is a different thread, with different register
1269 registers_changed ();
1272 /* Handle the exit of a single thread LP. */
1275 exit_lwp (struct lwp_info *lp)
1277 struct thread_info *th = find_thread_ptid (lp->ptid);
1281 if (print_thread_events)
1282 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1284 delete_thread (lp->ptid);
1287 delete_lwp (lp->ptid);
1290 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1293 linux_proc_get_tgid (int lwpid)
1299 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
1300 status_file = fopen (buf, "r");
1301 if (status_file != NULL)
1303 while (fgets (buf, sizeof (buf), status_file))
1305 if (strncmp (buf, "Tgid:", 5) == 0)
1307 tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
1312 fclose (status_file);
1318 /* Detect `T (stopped)' in `/proc/PID/status'.
1319 Other states including `T (tracing stop)' are reported as false. */
1322 pid_is_stopped (pid_t pid)
1328 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1329 status_file = fopen (buf, "r");
1330 if (status_file != NULL)
1334 while (fgets (buf, sizeof (buf), status_file))
1336 if (strncmp (buf, "State:", 6) == 0)
1342 if (have_state && strstr (buf, "T (stopped)") != NULL)
1344 fclose (status_file);
1349 /* Wait for the LWP specified by LP, which we have just attached to.
1350 Returns a wait status for that LWP, to cache. */
1353 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1356 pid_t new_pid, pid = GET_LWP (ptid);
1359 if (pid_is_stopped (pid))
1361 if (debug_linux_nat)
1362 fprintf_unfiltered (gdb_stdlog,
1363 "LNPAW: Attaching to a stopped process\n");
1365 /* The process is definitely stopped. It is in a job control
1366 stop, unless the kernel predates the TASK_STOPPED /
1367 TASK_TRACED distinction, in which case it might be in a
1368 ptrace stop. Make sure it is in a ptrace stop; from there we
1369 can kill it, signal it, et cetera.
1371 First make sure there is a pending SIGSTOP. Since we are
1372 already attached, the process can not transition from stopped
1373 to running without a PTRACE_CONT; so we know this signal will
1374 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1375 probably already in the queue (unless this kernel is old
1376 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1377 is not an RT signal, it can only be queued once. */
1378 kill_lwp (pid, SIGSTOP);
1380 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1381 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1382 ptrace (PTRACE_CONT, pid, 0, 0);
1385 /* Make sure the initial process is stopped. The user-level threads
1386 layer might want to poke around in the inferior, and that won't
1387 work if things haven't stabilized yet. */
1388 new_pid = my_waitpid (pid, &status, 0);
1389 if (new_pid == -1 && errno == ECHILD)
1392 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1394 /* Try again with __WCLONE to check cloned processes. */
1395 new_pid = my_waitpid (pid, &status, __WCLONE);
1399 gdb_assert (pid == new_pid);
1401 if (!WIFSTOPPED (status))
1403 /* The pid we tried to attach has apparently just exited. */
1404 if (debug_linux_nat)
1405 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1406 pid, status_to_str (status));
1410 if (WSTOPSIG (status) != SIGSTOP)
1413 if (debug_linux_nat)
1414 fprintf_unfiltered (gdb_stdlog,
1415 "LNPAW: Received %s after attaching\n",
1416 status_to_str (status));
1422 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1423 if the new LWP could not be attached. */
1426 lin_lwp_attach_lwp (ptid_t ptid)
1428 struct lwp_info *lp;
1431 gdb_assert (is_lwp (ptid));
1433 block_child_signals (&prev_mask);
1435 lp = find_lwp_pid (ptid);
1437 /* We assume that we're already attached to any LWP that has an id
1438 equal to the overall process id, and to any LWP that is already
1439 in our list of LWPs. If we're not seeing exit events from threads
1440 and we've had PID wraparound since we last tried to stop all threads,
1441 this assumption might be wrong; fortunately, this is very unlikely
1443 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1445 int status, cloned = 0, signalled = 0;
1447 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1449 /* If we fail to attach to the thread, issue a warning,
1450 but continue. One way this can happen is if thread
1451 creation is interrupted; as of Linux kernel 2.6.19, a
1452 bug may place threads in the thread list and then fail
1454 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1455 safe_strerror (errno));
1456 restore_child_signals_mask (&prev_mask);
1460 if (debug_linux_nat)
1461 fprintf_unfiltered (gdb_stdlog,
1462 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1463 target_pid_to_str (ptid));
1465 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1466 if (!WIFSTOPPED (status))
1469 lp = add_lwp (ptid);
1471 lp->cloned = cloned;
1472 lp->signalled = signalled;
1473 if (WSTOPSIG (status) != SIGSTOP)
1476 lp->status = status;
1479 target_post_attach (GET_LWP (lp->ptid));
1481 if (debug_linux_nat)
1483 fprintf_unfiltered (gdb_stdlog,
1484 "LLAL: waitpid %s received %s\n",
1485 target_pid_to_str (ptid),
1486 status_to_str (status));
1491 /* We assume that the LWP representing the original process is
1492 already stopped. Mark it as stopped in the data structure
1493 that the GNU/linux ptrace layer uses to keep track of
1494 threads. Note that this won't have already been done since
1495 the main thread will have, we assume, been stopped by an
1496 attach from a different layer. */
1498 lp = add_lwp (ptid);
1502 restore_child_signals_mask (&prev_mask);
1507 linux_nat_create_inferior (struct target_ops *ops,
1508 char *exec_file, char *allargs, char **env,
1511 #ifdef HAVE_PERSONALITY
1512 int personality_orig = 0, personality_set = 0;
1513 #endif /* HAVE_PERSONALITY */
1515 /* The fork_child mechanism is synchronous and calls target_wait, so
1516 we have to mask the async mode. */
1518 #ifdef HAVE_PERSONALITY
1519 if (disable_randomization)
1522 personality_orig = personality (0xffffffff);
1523 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1525 personality_set = 1;
1526 personality (personality_orig | ADDR_NO_RANDOMIZE);
1528 if (errno != 0 || (personality_set
1529 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1530 warning (_("Error disabling address space randomization: %s"),
1531 safe_strerror (errno));
1533 #endif /* HAVE_PERSONALITY */
1535 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1537 #ifdef HAVE_PERSONALITY
1538 if (personality_set)
1541 personality (personality_orig);
1543 warning (_("Error restoring address space randomization: %s"),
1544 safe_strerror (errno));
1546 #endif /* HAVE_PERSONALITY */
1550 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1552 struct lwp_info *lp;
1556 linux_ops->to_attach (ops, args, from_tty);
1558 /* The ptrace base target adds the main thread with (pid,0,0)
1559 format. Decorate it with lwp info. */
1560 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1561 thread_change_ptid (inferior_ptid, ptid);
1563 /* Add the initial process as the first LWP to the list. */
1564 lp = add_lwp (ptid);
1566 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1568 if (!WIFSTOPPED (status))
1570 if (WIFEXITED (status))
1572 int exit_code = WEXITSTATUS (status);
1574 target_terminal_ours ();
1575 target_mourn_inferior ();
1577 error (_("Unable to attach: program exited normally."));
1579 error (_("Unable to attach: program exited with code %d."),
1582 else if (WIFSIGNALED (status))
1584 enum target_signal signo;
1586 target_terminal_ours ();
1587 target_mourn_inferior ();
1589 signo = target_signal_from_host (WTERMSIG (status));
1590 error (_("Unable to attach: program terminated with signal "
1592 target_signal_to_name (signo),
1593 target_signal_to_string (signo));
1596 internal_error (__FILE__, __LINE__,
1597 _("unexpected status %d for PID %ld"),
1598 status, (long) GET_LWP (ptid));
1603 /* Save the wait status to report later. */
1605 if (debug_linux_nat)
1606 fprintf_unfiltered (gdb_stdlog,
1607 "LNA: waitpid %ld, saving status %s\n",
1608 (long) GET_PID (lp->ptid), status_to_str (status));
1610 lp->status = status;
1612 if (target_can_async_p ())
1613 target_async (inferior_event_handler, 0);
1616 /* Get pending status of LP. */
1618 get_pending_status (struct lwp_info *lp, int *status)
1620 enum target_signal signo = TARGET_SIGNAL_0;
1622 /* If we paused threads momentarily, we may have stored pending
1623 events in lp->status or lp->waitstatus (see stop_wait_callback),
1624 and GDB core hasn't seen any signal for those threads.
1625 Otherwise, the last signal reported to the core is found in the
1626 thread object's stop_signal.
1628 There's a corner case that isn't handled here at present. Only
1629 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1630 stop_signal make sense as a real signal to pass to the inferior.
1631 Some catchpoint related events, like
1632 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1633 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1634 those traps are debug API (ptrace in our case) related and
1635 induced; the inferior wouldn't see them if it wasn't being
1636 traced. Hence, we should never pass them to the inferior, even
1637 when set to pass state. Since this corner case isn't handled by
1638 infrun.c when proceeding with a signal, for consistency, neither
1639 do we handle it here (or elsewhere in the file we check for
1640 signal pass state). Normally SIGTRAP isn't set to pass state, so
1641 this is really a corner case. */
1643 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1644 signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1645 else if (lp->status)
1646 signo = target_signal_from_host (WSTOPSIG (lp->status));
1647 else if (non_stop && !is_executing (lp->ptid))
1649 struct thread_info *tp = find_thread_ptid (lp->ptid);
1651 signo = tp->stop_signal;
1655 struct target_waitstatus last;
1658 get_last_target_status (&last_ptid, &last);
1660 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1662 struct thread_info *tp = find_thread_ptid (lp->ptid);
1664 signo = tp->stop_signal;
1670 if (signo == TARGET_SIGNAL_0)
1672 if (debug_linux_nat)
1673 fprintf_unfiltered (gdb_stdlog,
1674 "GPT: lwp %s has no pending signal\n",
1675 target_pid_to_str (lp->ptid));
1677 else if (!signal_pass_state (signo))
1679 if (debug_linux_nat)
1680 fprintf_unfiltered (gdb_stdlog, "\
1681 GPT: lwp %s had signal %s, but it is in no pass state\n",
1682 target_pid_to_str (lp->ptid),
1683 target_signal_to_string (signo));
1687 *status = W_STOPCODE (target_signal_to_host (signo));
1689 if (debug_linux_nat)
1690 fprintf_unfiltered (gdb_stdlog,
1691 "GPT: lwp %s has pending signal %s\n",
1692 target_pid_to_str (lp->ptid),
1693 target_signal_to_string (signo));
1700 detach_callback (struct lwp_info *lp, void *data)
1702 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1704 if (debug_linux_nat && lp->status)
1705 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1706 strsignal (WSTOPSIG (lp->status)),
1707 target_pid_to_str (lp->ptid));
1709 /* If there is a pending SIGSTOP, get rid of it. */
1712 if (debug_linux_nat)
1713 fprintf_unfiltered (gdb_stdlog,
1714 "DC: Sending SIGCONT to %s\n",
1715 target_pid_to_str (lp->ptid));
1717 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1721 /* We don't actually detach from the LWP that has an id equal to the
1722 overall process id just yet. */
1723 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1727 /* Pass on any pending signal for this LWP. */
1728 get_pending_status (lp, &status);
1731 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1732 WSTOPSIG (status)) < 0)
1733 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1734 safe_strerror (errno));
1736 if (debug_linux_nat)
1737 fprintf_unfiltered (gdb_stdlog,
1738 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1739 target_pid_to_str (lp->ptid),
1740 strsignal (WSTOPSIG (status)));
1742 delete_lwp (lp->ptid);
1749 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1753 struct lwp_info *main_lwp;
1755 pid = GET_PID (inferior_ptid);
1757 if (target_can_async_p ())
1758 linux_nat_async (NULL, 0);
1760 /* Stop all threads before detaching. ptrace requires that the
1761 thread is stopped to sucessfully detach. */
1762 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1763 /* ... and wait until all of them have reported back that
1764 they're no longer running. */
1765 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1767 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1769 /* Only the initial process should be left right now. */
1770 gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1);
1772 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1774 /* Pass on any pending signal for the last LWP. */
1775 if ((args == NULL || *args == '\0')
1776 && get_pending_status (main_lwp, &status) != -1
1777 && WIFSTOPPED (status))
1779 /* Put the signal number in ARGS so that inf_ptrace_detach will
1780 pass it along with PTRACE_DETACH. */
1782 sprintf (args, "%d", (int) WSTOPSIG (status));
1783 if (debug_linux_nat)
1784 fprintf_unfiltered (gdb_stdlog,
1785 "LND: Sending signal %s to %s\n",
1787 target_pid_to_str (main_lwp->ptid));
1790 delete_lwp (main_lwp->ptid);
1792 if (forks_exist_p ())
1794 /* Multi-fork case. The current inferior_ptid is being detached
1795 from, but there are other viable forks to debug. Detach from
1796 the current fork, and context-switch to the first
1798 linux_fork_detach (args, from_tty);
1800 if (non_stop && target_can_async_p ())
1801 target_async (inferior_event_handler, 0);
1804 linux_ops->to_detach (ops, args, from_tty);
1810 resume_callback (struct lwp_info *lp, void *data)
1812 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
1814 if (lp->stopped && inf->vfork_child != NULL)
1816 if (debug_linux_nat)
1817 fprintf_unfiltered (gdb_stdlog,
1818 "RC: Not resuming %s (vfork parent)\n",
1819 target_pid_to_str (lp->ptid));
1821 else if (lp->stopped && lp->status == 0)
1823 if (debug_linux_nat)
1824 fprintf_unfiltered (gdb_stdlog,
1825 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1826 target_pid_to_str (lp->ptid));
1828 linux_ops->to_resume (linux_ops,
1829 pid_to_ptid (GET_LWP (lp->ptid)),
1830 0, TARGET_SIGNAL_0);
1831 if (debug_linux_nat)
1832 fprintf_unfiltered (gdb_stdlog,
1833 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1834 target_pid_to_str (lp->ptid));
1837 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1838 lp->stopped_by_watchpoint = 0;
1840 else if (lp->stopped && debug_linux_nat)
1841 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
1842 target_pid_to_str (lp->ptid));
1843 else if (debug_linux_nat)
1844 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
1845 target_pid_to_str (lp->ptid));
1851 resume_clear_callback (struct lwp_info *lp, void *data)
1858 resume_set_callback (struct lwp_info *lp, void *data)
1865 linux_nat_resume (struct target_ops *ops,
1866 ptid_t ptid, int step, enum target_signal signo)
1869 struct lwp_info *lp;
1872 if (debug_linux_nat)
1873 fprintf_unfiltered (gdb_stdlog,
1874 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1875 step ? "step" : "resume",
1876 target_pid_to_str (ptid),
1877 signo ? strsignal (signo) : "0",
1878 target_pid_to_str (inferior_ptid));
1880 block_child_signals (&prev_mask);
1882 /* A specific PTID means `step only this process id'. */
1883 resume_many = (ptid_equal (minus_one_ptid, ptid)
1884 || ptid_is_pid (ptid));
1886 /* Mark the lwps we're resuming as resumed. */
1887 iterate_over_lwps (ptid, resume_set_callback, NULL);
1889 /* See if it's the current inferior that should be handled
1892 lp = find_lwp_pid (inferior_ptid);
1894 lp = find_lwp_pid (ptid);
1895 gdb_assert (lp != NULL);
1897 /* Remember if we're stepping. */
1900 /* If we have a pending wait status for this thread, there is no
1901 point in resuming the process. But first make sure that
1902 linux_nat_wait won't preemptively handle the event - we
1903 should never take this short-circuit if we are going to
1904 leave LP running, since we have skipped resuming all the
1905 other threads. This bit of code needs to be synchronized
1906 with linux_nat_wait. */
1908 if (lp->status && WIFSTOPPED (lp->status))
1911 struct inferior *inf;
1913 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
1915 saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
1917 /* Defer to common code if we're gaining control of the
1919 if (inf->stop_soon == NO_STOP_QUIETLY
1920 && signal_stop_state (saved_signo) == 0
1921 && signal_print_state (saved_signo) == 0
1922 && signal_pass_state (saved_signo) == 1)
1924 if (debug_linux_nat)
1925 fprintf_unfiltered (gdb_stdlog,
1926 "LLR: Not short circuiting for ignored "
1927 "status 0x%x\n", lp->status);
1929 /* FIXME: What should we do if we are supposed to continue
1930 this thread with a signal? */
1931 gdb_assert (signo == TARGET_SIGNAL_0);
1932 signo = saved_signo;
1937 if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1939 /* FIXME: What should we do if we are supposed to continue
1940 this thread with a signal? */
1941 gdb_assert (signo == TARGET_SIGNAL_0);
1943 if (debug_linux_nat)
1944 fprintf_unfiltered (gdb_stdlog,
1945 "LLR: Short circuiting for status 0x%x\n",
1948 restore_child_signals_mask (&prev_mask);
1949 if (target_can_async_p ())
1951 target_async (inferior_event_handler, 0);
1952 /* Tell the event loop we have something to process. */
1958 /* Mark LWP as not stopped to prevent it from being continued by
1963 iterate_over_lwps (ptid, resume_callback, NULL);
1965 /* Convert to something the lower layer understands. */
1966 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1968 linux_ops->to_resume (linux_ops, ptid, step, signo);
1969 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1970 lp->stopped_by_watchpoint = 0;
1972 if (debug_linux_nat)
1973 fprintf_unfiltered (gdb_stdlog,
1974 "LLR: %s %s, %s (resume event thread)\n",
1975 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1976 target_pid_to_str (ptid),
1977 signo ? strsignal (signo) : "0");
1979 restore_child_signals_mask (&prev_mask);
1980 if (target_can_async_p ())
1981 target_async (inferior_event_handler, 0);
1984 /* Send a signal to an LWP. */
1987 kill_lwp (int lwpid, int signo)
1989 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1990 fails, then we are not using nptl threads and we should be using kill. */
1992 #ifdef HAVE_TKILL_SYSCALL
1994 static int tkill_failed;
2001 ret = syscall (__NR_tkill, lwpid, signo);
2002 if (errno != ENOSYS)
2009 return kill (lwpid, signo);
2012 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2013 event, check if the core is interested in it: if not, ignore the
2014 event, and keep waiting; otherwise, we need to toggle the LWP's
2015 syscall entry/exit status, since the ptrace event itself doesn't
2016 indicate it, and report the trap to higher layers. */
2019 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
2021 struct target_waitstatus *ourstatus = &lp->waitstatus;
2022 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
2023 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
2027 /* If we're stopping threads, there's a SIGSTOP pending, which
2028 makes it so that the LWP reports an immediate syscall return,
2029 followed by the SIGSTOP. Skip seeing that "return" using
2030 PTRACE_CONT directly, and let stop_wait_callback collect the
2031 SIGSTOP. Later when the thread is resumed, a new syscall
2032 entry event. If we didn't do this (and returned 0), we'd
2033 leave a syscall entry pending, and our caller, by using
2034 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2035 itself. Later, when the user re-resumes this LWP, we'd see
2036 another syscall entry event and we'd mistake it for a return.
2038 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2039 (leaving immediately with LWP->signalled set, without issuing
2040 a PTRACE_CONT), it would still be problematic to leave this
2041 syscall enter pending, as later when the thread is resumed,
2042 it would then see the same syscall exit mentioned above,
2043 followed by the delayed SIGSTOP, while the syscall didn't
2044 actually get to execute. It seems it would be even more
2045 confusing to the user. */
2047 if (debug_linux_nat)
2048 fprintf_unfiltered (gdb_stdlog,
2049 "LHST: ignoring syscall %d "
2050 "for LWP %ld (stopping threads), "
2051 "resuming with PTRACE_CONT for SIGSTOP\n",
2053 GET_LWP (lp->ptid));
2055 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2056 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2060 if (catch_syscall_enabled ())
2062 /* Always update the entry/return state, even if this particular
2063 syscall isn't interesting to the core now. In async mode,
2064 the user could install a new catchpoint for this syscall
2065 between syscall enter/return, and we'll need to know to
2066 report a syscall return if that happens. */
2067 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2068 ? TARGET_WAITKIND_SYSCALL_RETURN
2069 : TARGET_WAITKIND_SYSCALL_ENTRY);
2071 if (catching_syscall_number (syscall_number))
2073 /* Alright, an event to report. */
2074 ourstatus->kind = lp->syscall_state;
2075 ourstatus->value.syscall_number = syscall_number;
2077 if (debug_linux_nat)
2078 fprintf_unfiltered (gdb_stdlog,
2079 "LHST: stopping for %s of syscall %d"
2081 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2082 ? "entry" : "return",
2084 GET_LWP (lp->ptid));
2088 if (debug_linux_nat)
2089 fprintf_unfiltered (gdb_stdlog,
2090 "LHST: ignoring %s of syscall %d "
2092 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2093 ? "entry" : "return",
2095 GET_LWP (lp->ptid));
2099 /* If we had been syscall tracing, and hence used PT_SYSCALL
2100 before on this LWP, it could happen that the user removes all
2101 syscall catchpoints before we get to process this event.
2102 There are two noteworthy issues here:
2104 - When stopped at a syscall entry event, resuming with
2105 PT_STEP still resumes executing the syscall and reports a
2108 - Only PT_SYSCALL catches syscall enters. If we last
2109 single-stepped this thread, then this event can't be a
2110 syscall enter. If we last single-stepped this thread, this
2111 has to be a syscall exit.
2113 The points above mean that the next resume, be it PT_STEP or
2114 PT_CONTINUE, can not trigger a syscall trace event. */
2115 if (debug_linux_nat)
2116 fprintf_unfiltered (gdb_stdlog,
2117 "LHST: caught syscall event with no syscall catchpoints."
2118 " %d for LWP %ld, ignoring\n",
2120 GET_LWP (lp->ptid));
2121 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2124 /* The core isn't interested in this event. For efficiency, avoid
2125 stopping all threads only to have the core resume them all again.
2126 Since we're not stopping threads, if we're still syscall tracing
2127 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2128 subsequent syscall. Simply resume using the inf-ptrace layer,
2129 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2131 /* Note that gdbarch_get_syscall_number may access registers, hence
2133 registers_changed ();
2134 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2135 lp->step, TARGET_SIGNAL_0);
2139 /* Handle a GNU/Linux extended wait response. If we see a clone
2140 event, we need to add the new LWP to our list (and not report the
2141 trap to higher layers). This function returns non-zero if the
2142 event should be ignored and we should wait again. If STOPPING is
2143 true, the new LWP remains stopped, otherwise it is continued. */
2146 linux_handle_extended_wait (struct lwp_info *lp, int status,
2149 int pid = GET_LWP (lp->ptid);
2150 struct target_waitstatus *ourstatus = &lp->waitstatus;
2151 int event = status >> 16;
2153 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
2154 || event == PTRACE_EVENT_CLONE)
2156 unsigned long new_pid;
2159 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2161 /* If we haven't already seen the new PID stop, wait for it now. */
2162 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2164 /* The new child has a pending SIGSTOP. We can't affect it until it
2165 hits the SIGSTOP, but we're already attached. */
2166 ret = my_waitpid (new_pid, &status,
2167 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
2169 perror_with_name (_("waiting for new child"));
2170 else if (ret != new_pid)
2171 internal_error (__FILE__, __LINE__,
2172 _("wait returned unexpected PID %d"), ret);
2173 else if (!WIFSTOPPED (status))
2174 internal_error (__FILE__, __LINE__,
2175 _("wait returned unexpected status 0x%x"), status);
2178 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2180 if (event == PTRACE_EVENT_FORK
2181 && linux_fork_checkpointing_p (GET_PID (lp->ptid)))
2183 struct fork_info *fp;
2185 /* Handle checkpointing by linux-fork.c here as a special
2186 case. We don't want the follow-fork-mode or 'catch fork'
2187 to interfere with this. */
2189 /* This won't actually modify the breakpoint list, but will
2190 physically remove the breakpoints from the child. */
2191 detach_breakpoints (new_pid);
2193 /* Retain child fork in ptrace (stopped) state. */
2194 fp = find_fork_pid (new_pid);
2196 fp = add_fork (new_pid);
2198 /* Report as spurious, so that infrun doesn't want to follow
2199 this fork. We're actually doing an infcall in
2201 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2202 linux_enable_event_reporting (pid_to_ptid (new_pid));
2204 /* Report the stop to the core. */
2208 if (event == PTRACE_EVENT_FORK)
2209 ourstatus->kind = TARGET_WAITKIND_FORKED;
2210 else if (event == PTRACE_EVENT_VFORK)
2211 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2214 struct lwp_info *new_lp;
2216 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2218 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
2220 new_lp->stopped = 1;
2222 if (WSTOPSIG (status) != SIGSTOP)
2224 /* This can happen if someone starts sending signals to
2225 the new thread before it gets a chance to run, which
2226 have a lower number than SIGSTOP (e.g. SIGUSR1).
2227 This is an unlikely case, and harder to handle for
2228 fork / vfork than for clone, so we do not try - but
2229 we handle it for clone events here. We'll send
2230 the other signal on to the thread below. */
2232 new_lp->signalled = 1;
2239 /* Add the new thread to GDB's lists as soon as possible
2242 1) the frontend doesn't have to wait for a stop to
2245 2) we tag it with the correct running state. */
2247 /* If the thread_db layer is active, let it know about
2248 this new thread, and add it to GDB's list. */
2249 if (!thread_db_attach_lwp (new_lp->ptid))
2251 /* We're not using thread_db. Add it to GDB's
2253 target_post_attach (GET_LWP (new_lp->ptid));
2254 add_thread (new_lp->ptid);
2259 set_running (new_lp->ptid, 1);
2260 set_executing (new_lp->ptid, 1);
2264 /* Note the need to use the low target ops to resume, to
2265 handle resuming with PT_SYSCALL if we have syscall
2271 new_lp->stopped = 0;
2272 new_lp->resumed = 1;
2275 ? target_signal_from_host (WSTOPSIG (status))
2278 linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
2285 /* We created NEW_LP so it cannot yet contain STATUS. */
2286 gdb_assert (new_lp->status == 0);
2288 /* Save the wait status to report later. */
2289 if (debug_linux_nat)
2290 fprintf_unfiltered (gdb_stdlog,
2291 "LHEW: waitpid of new LWP %ld, "
2292 "saving status %s\n",
2293 (long) GET_LWP (new_lp->ptid),
2294 status_to_str (status));
2295 new_lp->status = status;
2299 if (debug_linux_nat)
2300 fprintf_unfiltered (gdb_stdlog,
2301 "LHEW: Got clone event from LWP %ld, resuming\n",
2302 GET_LWP (lp->ptid));
2303 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2304 0, TARGET_SIGNAL_0);
2312 if (event == PTRACE_EVENT_EXEC)
2314 if (debug_linux_nat)
2315 fprintf_unfiltered (gdb_stdlog,
2316 "LHEW: Got exec event from LWP %ld\n",
2317 GET_LWP (lp->ptid));
2319 ourstatus->kind = TARGET_WAITKIND_EXECD;
2320 ourstatus->value.execd_pathname
2321 = xstrdup (linux_child_pid_to_exec_file (pid));
2326 if (event == PTRACE_EVENT_VFORK_DONE)
2328 if (current_inferior ()->waiting_for_vfork_done)
2330 if (debug_linux_nat)
2331 fprintf_unfiltered (gdb_stdlog, "\
2332 LHEW: Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping\n",
2333 GET_LWP (lp->ptid));
2335 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2339 if (debug_linux_nat)
2340 fprintf_unfiltered (gdb_stdlog, "\
2341 LHEW: Got PTRACE_EVENT_VFORK_DONE from LWP %ld: resuming\n",
2342 GET_LWP (lp->ptid));
2343 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2347 internal_error (__FILE__, __LINE__,
2348 _("unknown ptrace event %d"), event);
2351 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2355 wait_lwp (struct lwp_info *lp)
2359 int thread_dead = 0;
2361 gdb_assert (!lp->stopped);
2362 gdb_assert (lp->status == 0);
2364 pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
2365 if (pid == -1 && errno == ECHILD)
2367 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
2368 if (pid == -1 && errno == ECHILD)
2370 /* The thread has previously exited. We need to delete it
2371 now because, for some vendor 2.4 kernels with NPTL
2372 support backported, there won't be an exit event unless
2373 it is the main thread. 2.6 kernels will report an exit
2374 event for each thread that exits, as expected. */
2376 if (debug_linux_nat)
2377 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2378 target_pid_to_str (lp->ptid));
2384 gdb_assert (pid == GET_LWP (lp->ptid));
2386 if (debug_linux_nat)
2388 fprintf_unfiltered (gdb_stdlog,
2389 "WL: waitpid %s received %s\n",
2390 target_pid_to_str (lp->ptid),
2391 status_to_str (status));
2395 /* Check if the thread has exited. */
2396 if (WIFEXITED (status) || WIFSIGNALED (status))
2399 if (debug_linux_nat)
2400 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2401 target_pid_to_str (lp->ptid));
2410 gdb_assert (WIFSTOPPED (status));
2412 /* Handle GNU/Linux's syscall SIGTRAPs. */
2413 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2415 /* No longer need the sysgood bit. The ptrace event ends up
2416 recorded in lp->waitstatus if we care for it. We can carry
2417 on handling the event like a regular SIGTRAP from here
2419 status = W_STOPCODE (SIGTRAP);
2420 if (linux_handle_syscall_trap (lp, 1))
2421 return wait_lwp (lp);
2424 /* Handle GNU/Linux's extended waitstatus for trace events. */
2425 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2427 if (debug_linux_nat)
2428 fprintf_unfiltered (gdb_stdlog,
2429 "WL: Handling extended status 0x%06x\n",
2431 if (linux_handle_extended_wait (lp, status, 1))
2432 return wait_lwp (lp);
2438 /* Save the most recent siginfo for LP. This is currently only called
2439 for SIGTRAP; some ports use the si_addr field for
2440 target_stopped_data_address. In the future, it may also be used to
2441 restore the siginfo of requeued signals. */
2444 save_siginfo (struct lwp_info *lp)
2447 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2448 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2451 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2454 /* Send a SIGSTOP to LP. */
2457 stop_callback (struct lwp_info *lp, void *data)
2459 if (!lp->stopped && !lp->signalled)
2463 if (debug_linux_nat)
2465 fprintf_unfiltered (gdb_stdlog,
2466 "SC: kill %s **<SIGSTOP>**\n",
2467 target_pid_to_str (lp->ptid));
2470 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2471 if (debug_linux_nat)
2473 fprintf_unfiltered (gdb_stdlog,
2474 "SC: lwp kill %d %s\n",
2476 errno ? safe_strerror (errno) : "ERRNO-OK");
2480 gdb_assert (lp->status == 0);
2486 /* Return non-zero if LWP PID has a pending SIGINT. */
2489 linux_nat_has_pending_sigint (int pid)
2491 sigset_t pending, blocked, ignored;
2493 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2495 if (sigismember (&pending, SIGINT)
2496 && !sigismember (&ignored, SIGINT))
2502 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2505 set_ignore_sigint (struct lwp_info *lp, void *data)
2507 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2508 flag to consume the next one. */
2509 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2510 && WSTOPSIG (lp->status) == SIGINT)
2513 lp->ignore_sigint = 1;
2518 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2519 This function is called after we know the LWP has stopped; if the LWP
2520 stopped before the expected SIGINT was delivered, then it will never have
2521 arrived. Also, if the signal was delivered to a shared queue and consumed
2522 by a different thread, it will never be delivered to this LWP. */
2525 maybe_clear_ignore_sigint (struct lwp_info *lp)
2527 if (!lp->ignore_sigint)
2530 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2532 if (debug_linux_nat)
2533 fprintf_unfiltered (gdb_stdlog,
2534 "MCIS: Clearing bogus flag for %s\n",
2535 target_pid_to_str (lp->ptid));
2536 lp->ignore_sigint = 0;
2540 /* Fetch the possible triggered data watchpoint info and store it in
2543 On some archs, like x86, that use debug registers to set
2544 watchpoints, it's possible that the way to know which watched
2545 address trapped, is to check the register that is used to select
2546 which address to watch. Problem is, between setting the watchpoint
2547 and reading back which data address trapped, the user may change
2548 the set of watchpoints, and, as a consequence, GDB changes the
2549 debug registers in the inferior. To avoid reading back a stale
2550 stopped-data-address when that happens, we cache in LP the fact
2551 that a watchpoint trapped, and the corresponding data address, as
2552 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2553 registers meanwhile, we have the cached data we can rely on. */
2556 save_sigtrap (struct lwp_info *lp)
2558 struct cleanup *old_chain;
2560 if (linux_ops->to_stopped_by_watchpoint == NULL)
2562 lp->stopped_by_watchpoint = 0;
2566 old_chain = save_inferior_ptid ();
2567 inferior_ptid = lp->ptid;
2569 lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint ();
2571 if (lp->stopped_by_watchpoint)
2573 if (linux_ops->to_stopped_data_address != NULL)
2574 lp->stopped_data_address_p =
2575 linux_ops->to_stopped_data_address (¤t_target,
2576 &lp->stopped_data_address);
2578 lp->stopped_data_address_p = 0;
2581 do_cleanups (old_chain);
2584 /* See save_sigtrap. */
2587 linux_nat_stopped_by_watchpoint (void)
2589 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2591 gdb_assert (lp != NULL);
2593 return lp->stopped_by_watchpoint;
2597 linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
2599 struct lwp_info *lp = find_lwp_pid (inferior_ptid);
2601 gdb_assert (lp != NULL);
2603 *addr_p = lp->stopped_data_address;
2605 return lp->stopped_data_address_p;
2608 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2611 sigtrap_is_event (int status)
2613 return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP;
2616 /* SIGTRAP-like events recognizer. */
2618 static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event;
2620 /* Check for SIGTRAP-like events in LP. */
2623 linux_nat_lp_status_is_event (struct lwp_info *lp)
2625 /* We check for lp->waitstatus in addition to lp->status, because we can
2626 have pending process exits recorded in lp->status
2627 and W_EXITCODE(0,0) == 0. We should probably have an additional
2628 lp->status_p flag. */
2630 return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
2631 && linux_nat_status_is_event (lp->status));
2634 /* Set alternative SIGTRAP-like events recognizer. If
2635 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2639 linux_nat_set_status_is_event (struct target_ops *t,
2640 int (*status_is_event) (int status))
2642 linux_nat_status_is_event = status_is_event;
2645 /* Wait until LP is stopped. */
2648 stop_wait_callback (struct lwp_info *lp, void *data)
2650 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
2652 /* If this is a vfork parent, bail out, it is not going to report
2653 any SIGSTOP until the vfork is done with. */
2654 if (inf->vfork_child != NULL)
2661 status = wait_lwp (lp);
2665 if (lp->ignore_sigint && WIFSTOPPED (status)
2666 && WSTOPSIG (status) == SIGINT)
2668 lp->ignore_sigint = 0;
2671 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2672 if (debug_linux_nat)
2673 fprintf_unfiltered (gdb_stdlog,
2674 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2675 target_pid_to_str (lp->ptid),
2676 errno ? safe_strerror (errno) : "OK");
2678 return stop_wait_callback (lp, NULL);
2681 maybe_clear_ignore_sigint (lp);
2683 if (WSTOPSIG (status) != SIGSTOP)
2685 if (linux_nat_status_is_event (status))
2687 /* If a LWP other than the LWP that we're reporting an
2688 event for has hit a GDB breakpoint (as opposed to
2689 some random trap signal), then just arrange for it to
2690 hit it again later. We don't keep the SIGTRAP status
2691 and don't forward the SIGTRAP signal to the LWP. We
2692 will handle the current event, eventually we will
2693 resume all LWPs, and this one will get its breakpoint
2696 If we do not do this, then we run the risk that the
2697 user will delete or disable the breakpoint, but the
2698 thread will have already tripped on it. */
2700 /* Save the trap's siginfo in case we need it later. */
2705 /* Now resume this LWP and get the SIGSTOP event. */
2707 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2708 if (debug_linux_nat)
2710 fprintf_unfiltered (gdb_stdlog,
2711 "PTRACE_CONT %s, 0, 0 (%s)\n",
2712 target_pid_to_str (lp->ptid),
2713 errno ? safe_strerror (errno) : "OK");
2715 fprintf_unfiltered (gdb_stdlog,
2716 "SWC: Candidate SIGTRAP event in %s\n",
2717 target_pid_to_str (lp->ptid));
2719 /* Hold this event/waitstatus while we check to see if
2720 there are any more (we still want to get that SIGSTOP). */
2721 stop_wait_callback (lp, NULL);
2723 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2724 there's another event, throw it back into the
2728 if (debug_linux_nat)
2729 fprintf_unfiltered (gdb_stdlog,
2730 "SWC: kill %s, %s\n",
2731 target_pid_to_str (lp->ptid),
2732 status_to_str ((int) status));
2733 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2736 /* Save the sigtrap event. */
2737 lp->status = status;
2742 /* The thread was stopped with a signal other than
2743 SIGSTOP, and didn't accidentally trip a breakpoint. */
2745 if (debug_linux_nat)
2747 fprintf_unfiltered (gdb_stdlog,
2748 "SWC: Pending event %s in %s\n",
2749 status_to_str ((int) status),
2750 target_pid_to_str (lp->ptid));
2752 /* Now resume this LWP and get the SIGSTOP event. */
2754 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2755 if (debug_linux_nat)
2756 fprintf_unfiltered (gdb_stdlog,
2757 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2758 target_pid_to_str (lp->ptid),
2759 errno ? safe_strerror (errno) : "OK");
2761 /* Hold this event/waitstatus while we check to see if
2762 there are any more (we still want to get that SIGSTOP). */
2763 stop_wait_callback (lp, NULL);
2765 /* If the lp->status field is still empty, use it to
2766 hold this event. If not, then this event must be
2767 returned to the event queue of the LWP. */
2770 if (debug_linux_nat)
2772 fprintf_unfiltered (gdb_stdlog,
2773 "SWC: kill %s, %s\n",
2774 target_pid_to_str (lp->ptid),
2775 status_to_str ((int) status));
2777 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2780 lp->status = status;
2786 /* We caught the SIGSTOP that we intended to catch, so
2787 there's no SIGSTOP pending. */
2796 /* Return non-zero if LP has a wait status pending. */
2799 status_callback (struct lwp_info *lp, void *data)
2801 /* Only report a pending wait status if we pretend that this has
2802 indeed been resumed. */
2806 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2808 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2809 or a a pending process exit. Note that `W_EXITCODE(0,0) ==
2810 0', so a clean process exit can not be stored pending in
2811 lp->status, it is indistinguishable from
2812 no-pending-status. */
2816 if (lp->status != 0)
2822 /* Return non-zero if LP isn't stopped. */
2825 running_callback (struct lwp_info *lp, void *data)
2827 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2830 /* Count the LWP's that have had events. */
2833 count_events_callback (struct lwp_info *lp, void *data)
2837 gdb_assert (count != NULL);
2839 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2840 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2846 /* Select the LWP (if any) that is currently being single-stepped. */
2849 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2851 if (lp->step && lp->status != 0)
2857 /* Select the Nth LWP that has had a SIGTRAP event. */
2860 select_event_lwp_callback (struct lwp_info *lp, void *data)
2862 int *selector = data;
2864 gdb_assert (selector != NULL);
2866 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2867 if (lp->resumed && linux_nat_lp_status_is_event (lp))
2868 if ((*selector)-- == 0)
2875 cancel_breakpoint (struct lwp_info *lp)
2877 /* Arrange for a breakpoint to be hit again later. We don't keep
2878 the SIGTRAP status and don't forward the SIGTRAP signal to the
2879 LWP. We will handle the current event, eventually we will resume
2880 this LWP, and this breakpoint will trap again.
2882 If we do not do this, then we run the risk that the user will
2883 delete or disable the breakpoint, but the LWP will have already
2886 struct regcache *regcache = get_thread_regcache (lp->ptid);
2887 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2890 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2891 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2893 if (debug_linux_nat)
2894 fprintf_unfiltered (gdb_stdlog,
2895 "CB: Push back breakpoint for %s\n",
2896 target_pid_to_str (lp->ptid));
2898 /* Back up the PC if necessary. */
2899 if (gdbarch_decr_pc_after_break (gdbarch))
2900 regcache_write_pc (regcache, pc);
2908 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2910 struct lwp_info *event_lp = data;
2912 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2916 /* If a LWP other than the LWP that we're reporting an event for has
2917 hit a GDB breakpoint (as opposed to some random trap signal),
2918 then just arrange for it to hit it again later. We don't keep
2919 the SIGTRAP status and don't forward the SIGTRAP signal to the
2920 LWP. We will handle the current event, eventually we will resume
2921 all LWPs, and this one will get its breakpoint trap again.
2923 If we do not do this, then we run the risk that the user will
2924 delete or disable the breakpoint, but the LWP will have already
2927 if (linux_nat_lp_status_is_event (lp)
2928 && cancel_breakpoint (lp))
2929 /* Throw away the SIGTRAP. */
2935 /* Select one LWP out of those that have events pending. */
2938 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2941 int random_selector;
2942 struct lwp_info *event_lp;
2944 /* Record the wait status for the original LWP. */
2945 (*orig_lp)->status = *status;
2947 /* Give preference to any LWP that is being single-stepped. */
2948 event_lp = iterate_over_lwps (filter,
2949 select_singlestep_lwp_callback, NULL);
2950 if (event_lp != NULL)
2952 if (debug_linux_nat)
2953 fprintf_unfiltered (gdb_stdlog,
2954 "SEL: Select single-step %s\n",
2955 target_pid_to_str (event_lp->ptid));
2959 /* No single-stepping LWP. Select one at random, out of those
2960 which have had SIGTRAP events. */
2962 /* First see how many SIGTRAP events we have. */
2963 iterate_over_lwps (filter, count_events_callback, &num_events);
2965 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2966 random_selector = (int)
2967 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2969 if (debug_linux_nat && num_events > 1)
2970 fprintf_unfiltered (gdb_stdlog,
2971 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2972 num_events, random_selector);
2974 event_lp = iterate_over_lwps (filter,
2975 select_event_lwp_callback,
2979 if (event_lp != NULL)
2981 /* Switch the event LWP. */
2982 *orig_lp = event_lp;
2983 *status = event_lp->status;
2986 /* Flush the wait status for the event LWP. */
2987 (*orig_lp)->status = 0;
2990 /* Return non-zero if LP has been resumed. */
2993 resumed_callback (struct lwp_info *lp, void *data)
2998 /* Stop an active thread, verify it still exists, then resume it. */
3001 stop_and_resume_callback (struct lwp_info *lp, void *data)
3003 struct lwp_info *ptr;
3005 if (!lp->stopped && !lp->signalled)
3007 stop_callback (lp, NULL);
3008 stop_wait_callback (lp, NULL);
3009 /* Resume if the lwp still exists. */
3010 for (ptr = lwp_list; ptr; ptr = ptr->next)
3013 resume_callback (lp, NULL);
3014 resume_set_callback (lp, NULL);
3020 /* Check if we should go on and pass this event to common code.
3021 Return the affected lwp if we are, or NULL otherwise. */
3022 static struct lwp_info *
3023 linux_nat_filter_event (int lwpid, int status, int options)
3025 struct lwp_info *lp;
3027 lp = find_lwp_pid (pid_to_ptid (lwpid));
3029 /* Check for stop events reported by a process we didn't already
3030 know about - anything not already in our LWP list.
3032 If we're expecting to receive stopped processes after
3033 fork, vfork, and clone events, then we'll just add the
3034 new one to our list and go back to waiting for the event
3035 to be reported - the stopped process might be returned
3036 from waitpid before or after the event is. */
3037 if (WIFSTOPPED (status) && !lp)
3039 linux_record_stopped_pid (lwpid, status);
3043 /* Make sure we don't report an event for the exit of an LWP not in
3044 our list, i.e. not part of the current process. This can happen
3045 if we detach from a program we original forked and then it
3047 if (!WIFSTOPPED (status) && !lp)
3050 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
3051 CLONE_PTRACE processes which do not use the thread library -
3052 otherwise we wouldn't find the new LWP this way. That doesn't
3053 currently work, and the following code is currently unreachable
3054 due to the two blocks above. If it's fixed some day, this code
3055 should be broken out into a function so that we can also pick up
3056 LWPs from the new interface. */
3059 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
3060 if (options & __WCLONE)
3063 gdb_assert (WIFSTOPPED (status)
3064 && WSTOPSIG (status) == SIGSTOP);
3067 if (!in_thread_list (inferior_ptid))
3069 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
3070 GET_PID (inferior_ptid));
3071 add_thread (inferior_ptid);
3074 add_thread (lp->ptid);
3077 /* Handle GNU/Linux's syscall SIGTRAPs. */
3078 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3080 /* No longer need the sysgood bit. The ptrace event ends up
3081 recorded in lp->waitstatus if we care for it. We can carry
3082 on handling the event like a regular SIGTRAP from here
3084 status = W_STOPCODE (SIGTRAP);
3085 if (linux_handle_syscall_trap (lp, 0))
3089 /* Handle GNU/Linux's extended waitstatus for trace events. */
3090 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
3092 if (debug_linux_nat)
3093 fprintf_unfiltered (gdb_stdlog,
3094 "LLW: Handling extended status 0x%06x\n",
3096 if (linux_handle_extended_wait (lp, status, 0))
3100 if (linux_nat_status_is_event (status))
3102 /* Save the trap's siginfo in case we need it later. */
3108 /* Check if the thread has exited. */
3109 if ((WIFEXITED (status) || WIFSIGNALED (status))
3110 && num_lwps (GET_PID (lp->ptid)) > 1)
3112 /* If this is the main thread, we must stop all threads and verify
3113 if they are still alive. This is because in the nptl thread model
3114 on Linux 2.4, there is no signal issued for exiting LWPs
3115 other than the main thread. We only get the main thread exit
3116 signal once all child threads have already exited. If we
3117 stop all the threads and use the stop_wait_callback to check
3118 if they have exited we can determine whether this signal
3119 should be ignored or whether it means the end of the debugged
3120 application, regardless of which threading model is being
3122 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
3125 iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
3126 stop_and_resume_callback, NULL);
3129 if (debug_linux_nat)
3130 fprintf_unfiltered (gdb_stdlog,
3131 "LLW: %s exited.\n",
3132 target_pid_to_str (lp->ptid));
3134 if (num_lwps (GET_PID (lp->ptid)) > 1)
3136 /* If there is at least one more LWP, then the exit signal
3137 was not the end of the debugged application and should be
3144 /* Check if the current LWP has previously exited. In the nptl
3145 thread model, LWPs other than the main thread do not issue
3146 signals when they exit so we must check whenever the thread has
3147 stopped. A similar check is made in stop_wait_callback(). */
3148 if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3150 ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid));
3152 if (debug_linux_nat)
3153 fprintf_unfiltered (gdb_stdlog,
3154 "LLW: %s exited.\n",
3155 target_pid_to_str (lp->ptid));
3159 /* Make sure there is at least one thread running. */
3160 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3162 /* Discard the event. */
3166 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3167 an attempt to stop an LWP. */
3169 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3171 if (debug_linux_nat)
3172 fprintf_unfiltered (gdb_stdlog,
3173 "LLW: Delayed SIGSTOP caught for %s.\n",
3174 target_pid_to_str (lp->ptid));
3176 /* This is a delayed SIGSTOP. */
3179 registers_changed ();
3181 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3182 lp->step, TARGET_SIGNAL_0);
3183 if (debug_linux_nat)
3184 fprintf_unfiltered (gdb_stdlog,
3185 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3187 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3188 target_pid_to_str (lp->ptid));
3191 gdb_assert (lp->resumed);
3193 /* Discard the event. */
3197 /* Make sure we don't report a SIGINT that we have already displayed
3198 for another thread. */
3199 if (lp->ignore_sigint
3200 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3202 if (debug_linux_nat)
3203 fprintf_unfiltered (gdb_stdlog,
3204 "LLW: Delayed SIGINT caught for %s.\n",
3205 target_pid_to_str (lp->ptid));
3207 /* This is a delayed SIGINT. */
3208 lp->ignore_sigint = 0;
3210 registers_changed ();
3211 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3212 lp->step, TARGET_SIGNAL_0);
3213 if (debug_linux_nat)
3214 fprintf_unfiltered (gdb_stdlog,
3215 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3217 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3218 target_pid_to_str (lp->ptid));
3221 gdb_assert (lp->resumed);
3223 /* Discard the event. */
3227 /* An interesting event. */
3229 lp->status = status;
3234 linux_nat_wait_1 (struct target_ops *ops,
3235 ptid_t ptid, struct target_waitstatus *ourstatus,
3238 static sigset_t prev_mask;
3239 struct lwp_info *lp = NULL;
3244 if (debug_linux_nat_async)
3245 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3247 /* The first time we get here after starting a new inferior, we may
3248 not have added it to the LWP list yet - this is the earliest
3249 moment at which we know its PID. */
3250 if (ptid_is_pid (inferior_ptid))
3252 /* Upgrade the main thread's ptid. */
3253 thread_change_ptid (inferior_ptid,
3254 BUILD_LWP (GET_PID (inferior_ptid),
3255 GET_PID (inferior_ptid)));
3257 lp = add_lwp (inferior_ptid);
3261 /* Make sure SIGCHLD is blocked. */
3262 block_child_signals (&prev_mask);
3264 if (ptid_equal (ptid, minus_one_ptid))
3266 else if (ptid_is_pid (ptid))
3267 /* A request to wait for a specific tgid. This is not possible
3268 with waitpid, so instead, we wait for any child, and leave
3269 children we're not interested in right now with a pending
3270 status to report later. */
3273 pid = GET_LWP (ptid);
3279 /* Make sure that of those LWPs we want to get an event from, there
3280 is at least one LWP that has been resumed. If there's none, just
3281 bail out. The core may just be flushing asynchronously all
3283 if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL)
3285 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3287 if (debug_linux_nat_async)
3288 fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n");
3290 restore_child_signals_mask (&prev_mask);
3291 return minus_one_ptid;
3294 /* First check if there is a LWP with a wait status pending. */
3297 /* Any LWP that's been resumed will do. */
3298 lp = iterate_over_lwps (ptid, status_callback, NULL);
3301 if (debug_linux_nat && lp->status)
3302 fprintf_unfiltered (gdb_stdlog,
3303 "LLW: Using pending wait status %s for %s.\n",
3304 status_to_str (lp->status),
3305 target_pid_to_str (lp->ptid));
3308 /* But if we don't find one, we'll have to wait, and check both
3309 cloned and uncloned processes. We start with the cloned
3311 options = __WCLONE | WNOHANG;
3313 else if (is_lwp (ptid))
3315 if (debug_linux_nat)
3316 fprintf_unfiltered (gdb_stdlog,
3317 "LLW: Waiting for specific LWP %s.\n",
3318 target_pid_to_str (ptid));
3320 /* We have a specific LWP to check. */
3321 lp = find_lwp_pid (ptid);
3324 if (debug_linux_nat && lp->status)
3325 fprintf_unfiltered (gdb_stdlog,
3326 "LLW: Using pending wait status %s for %s.\n",
3327 status_to_str (lp->status),
3328 target_pid_to_str (lp->ptid));
3330 /* If we have to wait, take into account whether PID is a cloned
3331 process or not. And we have to convert it to something that
3332 the layer beneath us can understand. */
3333 options = lp->cloned ? __WCLONE : 0;
3334 pid = GET_LWP (ptid);
3336 /* We check for lp->waitstatus in addition to lp->status,
3337 because we can have pending process exits recorded in
3338 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3339 an additional lp->status_p flag. */
3340 if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3344 if (lp && lp->signalled)
3346 /* A pending SIGSTOP may interfere with the normal stream of
3347 events. In a typical case where interference is a problem,
3348 we have a SIGSTOP signal pending for LWP A while
3349 single-stepping it, encounter an event in LWP B, and take the
3350 pending SIGSTOP while trying to stop LWP A. After processing
3351 the event in LWP B, LWP A is continued, and we'll never see
3352 the SIGTRAP associated with the last time we were
3353 single-stepping LWP A. */
3355 /* Resume the thread. It should halt immediately returning the
3357 registers_changed ();
3358 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3359 lp->step, TARGET_SIGNAL_0);
3360 if (debug_linux_nat)
3361 fprintf_unfiltered (gdb_stdlog,
3362 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3363 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3364 target_pid_to_str (lp->ptid));
3366 gdb_assert (lp->resumed);
3368 /* Catch the pending SIGSTOP. */
3369 status = lp->status;
3372 stop_wait_callback (lp, NULL);
3374 /* If the lp->status field isn't empty, we caught another signal
3375 while flushing the SIGSTOP. Return it back to the event
3376 queue of the LWP, as we already have an event to handle. */
3379 if (debug_linux_nat)
3380 fprintf_unfiltered (gdb_stdlog,
3381 "LLW: kill %s, %s\n",
3382 target_pid_to_str (lp->ptid),
3383 status_to_str (lp->status));
3384 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
3387 lp->status = status;
3390 if (!target_can_async_p ())
3392 /* Causes SIGINT to be passed on to the attached process. */
3396 /* Translate generic target_wait options into waitpid options. */
3397 if (target_options & TARGET_WNOHANG)
3404 lwpid = my_waitpid (pid, &status, options);
3408 gdb_assert (pid == -1 || lwpid == pid);
3410 if (debug_linux_nat)
3412 fprintf_unfiltered (gdb_stdlog,
3413 "LLW: waitpid %ld received %s\n",
3414 (long) lwpid, status_to_str (status));
3417 lp = linux_nat_filter_event (lwpid, status, options);
3419 /* STATUS is now no longer valid, use LP->STATUS instead. */
3423 && ptid_is_pid (ptid)
3424 && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
3426 gdb_assert (lp->resumed);
3428 if (debug_linux_nat)
3429 fprintf (stderr, "LWP %ld got an event %06x, leaving pending.\n",
3430 ptid_get_lwp (lp->ptid), lp->status);
3432 if (WIFSTOPPED (lp->status))
3434 if (WSTOPSIG (lp->status) != SIGSTOP)
3436 /* Cancel breakpoint hits. The breakpoint may
3437 be removed before we fetch events from this
3438 process to report to the core. It is best
3439 not to assume the moribund breakpoints
3440 heuristic always handles these cases --- it
3441 could be too many events go through to the
3442 core before this one is handled. All-stop
3443 always cancels breakpoint hits in all
3446 && linux_nat_lp_status_is_event (lp)
3447 && cancel_breakpoint (lp))
3449 /* Throw away the SIGTRAP. */
3452 if (debug_linux_nat)
3454 "LLW: LWP %ld hit a breakpoint while waiting "
3455 "for another process; cancelled it\n",
3456 ptid_get_lwp (lp->ptid));
3466 else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status))
3468 if (debug_linux_nat)
3469 fprintf (stderr, "Process %ld exited while stopping LWPs\n",
3470 ptid_get_lwp (lp->ptid));
3472 /* This was the last lwp in the process. Since
3473 events are serialized to GDB core, and we can't
3474 report this one right now, but GDB core and the
3475 other target layers will want to be notified
3476 about the exit code/signal, leave the status
3477 pending for the next time we're able to report
3480 /* Prevent trying to stop this thread again. We'll
3481 never try to resume it because it has a pending
3485 /* Dead LWP's aren't expected to reported a pending
3489 /* Store the pending event in the waitstatus as
3490 well, because W_EXITCODE(0,0) == 0. */
3491 store_waitstatus (&lp->waitstatus, lp->status);
3505 /* waitpid did return something. Restart over. */
3506 options |= __WCLONE;
3514 /* Alternate between checking cloned and uncloned processes. */
3515 options ^= __WCLONE;
3517 /* And every time we have checked both:
3518 In async mode, return to event loop;
3519 In sync mode, suspend waiting for a SIGCHLD signal. */
3520 if (options & __WCLONE)
3522 if (target_options & TARGET_WNOHANG)
3524 /* No interesting event. */
3525 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3527 if (debug_linux_nat_async)
3528 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3530 restore_child_signals_mask (&prev_mask);
3531 return minus_one_ptid;
3534 sigsuspend (&suspend_mask);
3537 else if (target_options & TARGET_WNOHANG)
3539 /* No interesting event for PID yet. */
3540 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3542 if (debug_linux_nat_async)
3543 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3545 restore_child_signals_mask (&prev_mask);
3546 return minus_one_ptid;
3549 /* We shouldn't end up here unless we want to try again. */
3550 gdb_assert (lp == NULL);
3553 if (!target_can_async_p ())
3554 clear_sigint_trap ();
3558 status = lp->status;
3561 /* Don't report signals that GDB isn't interested in, such as
3562 signals that are neither printed nor stopped upon. Stopping all
3563 threads can be a bit time-consuming so if we want decent
3564 performance with heavily multi-threaded programs, especially when
3565 they're using a high frequency timer, we'd better avoid it if we
3568 if (WIFSTOPPED (status))
3570 int signo = target_signal_from_host (WSTOPSIG (status));
3571 struct inferior *inf;
3573 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3576 /* Defer to common code if we get a signal while
3577 single-stepping, since that may need special care, e.g. to
3578 skip the signal handler, or, if we're gaining control of the
3581 && inf->stop_soon == NO_STOP_QUIETLY
3582 && signal_stop_state (signo) == 0
3583 && signal_print_state (signo) == 0
3584 && signal_pass_state (signo) == 1)
3586 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3587 here? It is not clear we should. GDB may not expect
3588 other threads to run. On the other hand, not resuming
3589 newly attached threads may cause an unwanted delay in
3590 getting them running. */
3591 registers_changed ();
3592 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3594 if (debug_linux_nat)
3595 fprintf_unfiltered (gdb_stdlog,
3596 "LLW: %s %s, %s (preempt 'handle')\n",
3598 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3599 target_pid_to_str (lp->ptid),
3600 signo ? strsignal (signo) : "0");
3607 /* Only do the below in all-stop, as we currently use SIGINT
3608 to implement target_stop (see linux_nat_stop) in
3610 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
3612 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3613 forwarded to the entire process group, that is, all LWPs
3614 will receive it - unless they're using CLONE_THREAD to
3615 share signals. Since we only want to report it once, we
3616 mark it as ignored for all LWPs except this one. */
3617 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
3618 set_ignore_sigint, NULL);
3619 lp->ignore_sigint = 0;
3622 maybe_clear_ignore_sigint (lp);
3626 /* This LWP is stopped now. */
3629 if (debug_linux_nat)
3630 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3631 status_to_str (status), target_pid_to_str (lp->ptid));
3635 /* Now stop all other LWP's ... */
3636 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3638 /* ... and wait until all of them have reported back that
3639 they're no longer running. */
3640 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3642 /* If we're not waiting for a specific LWP, choose an event LWP
3643 from among those that have had events. Giving equal priority
3644 to all LWPs that have had events helps prevent
3647 select_event_lwp (ptid, &lp, &status);
3649 /* Now that we've selected our final event LWP, cancel any
3650 breakpoints in other LWPs that have hit a GDB breakpoint.
3651 See the comment in cancel_breakpoints_callback to find out
3653 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3655 /* In all-stop, from the core's perspective, all LWPs are now
3656 stopped until a new resume action is sent over. */
3657 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
3662 if (linux_nat_status_is_event (status))
3664 if (debug_linux_nat)
3665 fprintf_unfiltered (gdb_stdlog,
3666 "LLW: trap ptid is %s.\n",
3667 target_pid_to_str (lp->ptid));
3670 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3672 *ourstatus = lp->waitstatus;
3673 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3676 store_waitstatus (ourstatus, status);
3678 if (debug_linux_nat_async)
3679 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3681 restore_child_signals_mask (&prev_mask);
3683 if (ourstatus->kind == TARGET_WAITKIND_EXITED
3684 || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
3687 lp->core = linux_nat_core_of_thread_1 (lp->ptid);
3692 /* Resume LWPs that are currently stopped without any pending status
3693 to report, but are resumed from the core's perspective. */
3696 resume_stopped_resumed_lwps (struct lwp_info *lp, void *data)
3698 ptid_t *wait_ptid_p = data;
3703 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3705 gdb_assert (is_executing (lp->ptid));
3707 /* Don't bother if there's a breakpoint at PC that we'd hit
3708 immediately, and we're not waiting for this LWP. */
3709 if (!ptid_match (lp->ptid, *wait_ptid_p))
3711 struct regcache *regcache = get_thread_regcache (lp->ptid);
3712 CORE_ADDR pc = regcache_read_pc (regcache);
3714 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3718 if (debug_linux_nat)
3719 fprintf_unfiltered (gdb_stdlog,
3720 "RSRL: resuming stopped-resumed LWP %s\n",
3721 target_pid_to_str (lp->ptid));
3723 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3724 lp->step, TARGET_SIGNAL_0);
3726 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
3727 lp->stopped_by_watchpoint = 0;
3734 linux_nat_wait (struct target_ops *ops,
3735 ptid_t ptid, struct target_waitstatus *ourstatus,
3740 if (debug_linux_nat)
3741 fprintf_unfiltered (gdb_stdlog, "linux_nat_wait: [%s]\n", target_pid_to_str (ptid));
3743 /* Flush the async file first. */
3744 if (target_can_async_p ())
3745 async_file_flush ();
3747 /* Resume LWPs that are currently stopped without any pending status
3748 to report, but are resumed from the core's perspective. LWPs get
3749 in this state if we find them stopping at a time we're not
3750 interested in reporting the event (target_wait on a
3751 specific_process, for example, see linux_nat_wait_1), and
3752 meanwhile the event became uninteresting. Don't bother resuming
3753 LWPs we're not going to wait for if they'd stop immediately. */
3755 iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid);
3757 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3759 /* If we requested any event, and something came out, assume there
3760 may be more. If we requested a specific lwp or process, also
3761 assume there may be more. */
3762 if (target_can_async_p ()
3763 && (ourstatus->kind != TARGET_WAITKIND_IGNORE
3764 || !ptid_equal (ptid, minus_one_ptid)))
3767 /* Get ready for the next event. */
3768 if (target_can_async_p ())
3769 target_async (inferior_event_handler, 0);
3775 kill_callback (struct lwp_info *lp, void *data)
3778 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3779 if (debug_linux_nat)
3780 fprintf_unfiltered (gdb_stdlog,
3781 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3782 target_pid_to_str (lp->ptid),
3783 errno ? safe_strerror (errno) : "OK");
3789 kill_wait_callback (struct lwp_info *lp, void *data)
3793 /* We must make sure that there are no pending events (delayed
3794 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3795 program doesn't interfere with any following debugging session. */
3797 /* For cloned processes we must check both with __WCLONE and
3798 without, since the exit status of a cloned process isn't reported
3804 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3805 if (pid != (pid_t) -1)
3807 if (debug_linux_nat)
3808 fprintf_unfiltered (gdb_stdlog,
3809 "KWC: wait %s received unknown.\n",
3810 target_pid_to_str (lp->ptid));
3811 /* The Linux kernel sometimes fails to kill a thread
3812 completely after PTRACE_KILL; that goes from the stop
3813 point in do_fork out to the one in
3814 get_signal_to_deliever and waits again. So kill it
3816 kill_callback (lp, NULL);
3819 while (pid == GET_LWP (lp->ptid));
3821 gdb_assert (pid == -1 && errno == ECHILD);
3826 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3827 if (pid != (pid_t) -1)
3829 if (debug_linux_nat)
3830 fprintf_unfiltered (gdb_stdlog,
3831 "KWC: wait %s received unk.\n",
3832 target_pid_to_str (lp->ptid));
3833 /* See the call to kill_callback above. */
3834 kill_callback (lp, NULL);
3837 while (pid == GET_LWP (lp->ptid));
3839 gdb_assert (pid == -1 && errno == ECHILD);
3844 linux_nat_kill (struct target_ops *ops)
3846 struct target_waitstatus last;
3850 /* If we're stopped while forking and we haven't followed yet,
3851 kill the other task. We need to do this first because the
3852 parent will be sleeping if this is a vfork. */
3854 get_last_target_status (&last_ptid, &last);
3856 if (last.kind == TARGET_WAITKIND_FORKED
3857 || last.kind == TARGET_WAITKIND_VFORKED)
3859 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3863 if (forks_exist_p ())
3864 linux_fork_killall ();
3867 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3869 /* Stop all threads before killing them, since ptrace requires
3870 that the thread is stopped to sucessfully PTRACE_KILL. */
3871 iterate_over_lwps (ptid, stop_callback, NULL);
3872 /* ... and wait until all of them have reported back that
3873 they're no longer running. */
3874 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3876 /* Kill all LWP's ... */
3877 iterate_over_lwps (ptid, kill_callback, NULL);
3879 /* ... and wait until we've flushed all events. */
3880 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3883 target_mourn_inferior ();
3887 linux_nat_mourn_inferior (struct target_ops *ops)
3889 purge_lwp_list (ptid_get_pid (inferior_ptid));
3891 if (! forks_exist_p ())
3892 /* Normal case, no other forks available. */
3893 linux_ops->to_mourn_inferior (ops);
3895 /* Multi-fork case. The current inferior_ptid has exited, but
3896 there are other viable forks to debug. Delete the exiting
3897 one and context-switch to the first available. */
3898 linux_fork_mourn_inferior ();
3901 /* Convert a native/host siginfo object, into/from the siginfo in the
3902 layout of the inferiors' architecture. */
3905 siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction)
3909 if (linux_nat_siginfo_fixup != NULL)
3910 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3912 /* If there was no callback, or the callback didn't do anything,
3913 then just do a straight memcpy. */
3917 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
3919 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
3924 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3925 const char *annex, gdb_byte *readbuf,
3926 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
3929 struct siginfo siginfo;
3930 gdb_byte inf_siginfo[sizeof (struct siginfo)];
3932 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3933 gdb_assert (readbuf || writebuf);
3935 pid = GET_LWP (inferior_ptid);
3937 pid = GET_PID (inferior_ptid);
3939 if (offset > sizeof (siginfo))
3943 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3947 /* When GDB is built as a 64-bit application, ptrace writes into
3948 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3949 inferior with a 64-bit GDB should look the same as debugging it
3950 with a 32-bit GDB, we need to convert it. GDB core always sees
3951 the converted layout, so any read/write will have to be done
3953 siginfo_fixup (&siginfo, inf_siginfo, 0);
3955 if (offset + len > sizeof (siginfo))
3956 len = sizeof (siginfo) - offset;
3958 if (readbuf != NULL)
3959 memcpy (readbuf, inf_siginfo + offset, len);
3962 memcpy (inf_siginfo + offset, writebuf, len);
3964 /* Convert back to ptrace layout before flushing it out. */
3965 siginfo_fixup (&siginfo, inf_siginfo, 1);
3968 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3977 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3978 const char *annex, gdb_byte *readbuf,
3979 const gdb_byte *writebuf,
3980 ULONGEST offset, LONGEST len)
3982 struct cleanup *old_chain;
3985 if (object == TARGET_OBJECT_SIGNAL_INFO)
3986 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3989 /* The target is connected but no live inferior is selected. Pass
3990 this request down to a lower stratum (e.g., the executable
3992 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3995 old_chain = save_inferior_ptid ();
3997 if (is_lwp (inferior_ptid))
3998 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
4000 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
4003 do_cleanups (old_chain);
4008 linux_thread_alive (ptid_t ptid)
4012 gdb_assert (is_lwp (ptid));
4014 /* Send signal 0 instead of anything ptrace, because ptracing a
4015 running thread errors out claiming that the thread doesn't
4017 err = kill_lwp (GET_LWP (ptid), 0);
4019 if (debug_linux_nat)
4020 fprintf_unfiltered (gdb_stdlog,
4021 "LLTA: KILL(SIG0) %s (%s)\n",
4022 target_pid_to_str (ptid),
4023 err ? safe_strerror (err) : "OK");
4032 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
4034 return linux_thread_alive (ptid);
4038 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
4040 static char buf[64];
4043 && (GET_PID (ptid) != GET_LWP (ptid)
4044 || num_lwps (GET_PID (ptid)) > 1))
4046 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
4050 return normal_pid_to_str (ptid);
4053 /* Accepts an integer PID; Returns a string representing a file that
4054 can be opened to get the symbols for the child process. */
4057 linux_child_pid_to_exec_file (int pid)
4059 char *name1, *name2;
4061 name1 = xmalloc (MAXPATHLEN);
4062 name2 = xmalloc (MAXPATHLEN);
4063 make_cleanup (xfree, name1);
4064 make_cleanup (xfree, name2);
4065 memset (name2, 0, MAXPATHLEN);
4067 sprintf (name1, "/proc/%d/exe", pid);
4068 if (readlink (name1, name2, MAXPATHLEN) > 0)
4074 /* Service function for corefiles and info proc. */
4077 read_mapping (FILE *mapfile,
4082 char *device, long long *inode, char *filename)
4084 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
4085 addr, endaddr, permissions, offset, device, inode);
4088 if (ret > 0 && ret != EOF)
4090 /* Eat everything up to EOL for the filename. This will prevent
4091 weird filenames (such as one with embedded whitespace) from
4092 confusing this code. It also makes this code more robust in
4093 respect to annotations the kernel may add after the filename.
4095 Note the filename is used for informational purposes
4097 ret += fscanf (mapfile, "%[^\n]\n", filename);
4100 return (ret != 0 && ret != EOF);
4103 /* Fills the "to_find_memory_regions" target vector. Lists the memory
4104 regions in the inferior for a corefile. */
4107 linux_nat_find_memory_regions (find_memory_region_ftype func, void *obfd)
4109 int pid = PIDGET (inferior_ptid);
4110 char mapsfilename[MAXPATHLEN];
4112 long long addr, endaddr, size, offset, inode;
4113 char permissions[8], device[8], filename[MAXPATHLEN];
4114 int read, write, exec;
4115 struct cleanup *cleanup;
4117 /* Compose the filename for the /proc memory map, and open it. */
4118 sprintf (mapsfilename, "/proc/%d/maps", pid);
4119 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
4120 error (_("Could not open %s."), mapsfilename);
4121 cleanup = make_cleanup_fclose (mapsfile);
4124 fprintf_filtered (gdb_stdout,
4125 "Reading memory regions from %s\n", mapsfilename);
4127 /* Now iterate until end-of-file. */
4128 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
4129 &offset, &device[0], &inode, &filename[0]))
4131 size = endaddr - addr;
4133 /* Get the segment's permissions. */
4134 read = (strchr (permissions, 'r') != 0);
4135 write = (strchr (permissions, 'w') != 0);
4136 exec = (strchr (permissions, 'x') != 0);
4140 fprintf_filtered (gdb_stdout,
4141 "Save segment, %s bytes at %s (%c%c%c)",
4142 plongest (size), paddress (target_gdbarch, addr),
4144 write ? 'w' : ' ', exec ? 'x' : ' ');
4146 fprintf_filtered (gdb_stdout, " for %s", filename);
4147 fprintf_filtered (gdb_stdout, "\n");
4150 /* Invoke the callback function to create the corefile
4152 func (addr, size, read, write, exec, obfd);
4154 do_cleanups (cleanup);
4159 find_signalled_thread (struct thread_info *info, void *data)
4161 if (info->stop_signal != TARGET_SIGNAL_0
4162 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
4168 static enum target_signal
4169 find_stop_signal (void)
4171 struct thread_info *info =
4172 iterate_over_threads (find_signalled_thread, NULL);
4175 return info->stop_signal;
4177 return TARGET_SIGNAL_0;
4180 /* Records the thread's register state for the corefile note
4184 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
4185 char *note_data, int *note_size,
4186 enum target_signal stop_signal)
4188 unsigned long lwp = ptid_get_lwp (ptid);
4189 struct gdbarch *gdbarch = target_gdbarch;
4190 struct regcache *regcache = get_thread_arch_regcache (ptid, gdbarch);
4191 const struct regset *regset;
4193 struct cleanup *old_chain;
4194 struct core_regset_section *sect_list;
4197 old_chain = save_inferior_ptid ();
4198 inferior_ptid = ptid;
4199 target_fetch_registers (regcache, -1);
4200 do_cleanups (old_chain);
4202 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
4203 sect_list = gdbarch_core_regset_sections (gdbarch);
4205 /* The loop below uses the new struct core_regset_section, which stores
4206 the supported section names and sizes for the core file. Note that
4207 note PRSTATUS needs to be treated specially. But the other notes are
4208 structurally the same, so they can benefit from the new struct. */
4209 if (core_regset_p && sect_list != NULL)
4210 while (sect_list->sect_name != NULL)
4212 regset = gdbarch_regset_from_core_section (gdbarch,
4213 sect_list->sect_name,
4215 gdb_assert (regset && regset->collect_regset);
4216 gdb_regset = xmalloc (sect_list->size);
4217 regset->collect_regset (regset, regcache, -1,
4218 gdb_regset, sect_list->size);
4220 if (strcmp (sect_list->sect_name, ".reg") == 0)
4221 note_data = (char *) elfcore_write_prstatus
4222 (obfd, note_data, note_size,
4223 lwp, target_signal_to_host (stop_signal),
4226 note_data = (char *) elfcore_write_register_note
4227 (obfd, note_data, note_size,
4228 sect_list->sect_name, gdb_regset,
4234 /* For architectures that does not have the struct core_regset_section
4235 implemented, we use the old method. When all the architectures have
4236 the new support, the code below should be deleted. */
4239 gdb_gregset_t gregs;
4240 gdb_fpregset_t fpregs;
4243 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
4244 sizeof (gregs))) != NULL
4245 && regset->collect_regset != NULL)
4246 regset->collect_regset (regset, regcache, -1,
4247 &gregs, sizeof (gregs));
4249 fill_gregset (regcache, &gregs, -1);
4251 note_data = (char *) elfcore_write_prstatus
4252 (obfd, note_data, note_size, lwp, target_signal_to_host (stop_signal),
4256 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
4257 sizeof (fpregs))) != NULL
4258 && regset->collect_regset != NULL)
4259 regset->collect_regset (regset, regcache, -1,
4260 &fpregs, sizeof (fpregs));
4262 fill_fpregset (regcache, &fpregs, -1);
4264 note_data = (char *) elfcore_write_prfpreg (obfd,
4267 &fpregs, sizeof (fpregs));
4273 struct linux_nat_corefile_thread_data
4279 enum target_signal stop_signal;
4282 /* Called by gdbthread.c once per thread. Records the thread's
4283 register state for the corefile note section. */
4286 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
4288 struct linux_nat_corefile_thread_data *args = data;
4290 args->note_data = linux_nat_do_thread_registers (args->obfd,
4300 /* Enumerate spufs IDs for process PID. */
4303 iterate_over_spus (int pid, void (*callback) (void *, int), void *data)
4307 struct dirent *entry;
4309 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4310 dir = opendir (path);
4315 while ((entry = readdir (dir)) != NULL)
4321 fd = atoi (entry->d_name);
4325 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4326 if (stat (path, &st) != 0)
4328 if (!S_ISDIR (st.st_mode))
4331 if (statfs (path, &stfs) != 0)
4333 if (stfs.f_type != SPUFS_MAGIC)
4336 callback (data, fd);
4342 /* Generate corefile notes for SPU contexts. */
4344 struct linux_spu_corefile_data
4352 linux_spu_corefile_callback (void *data, int fd)
4354 struct linux_spu_corefile_data *args = data;
4357 static const char *spu_files[] =
4379 for (i = 0; i < sizeof (spu_files) / sizeof (spu_files[0]); i++)
4381 char annex[32], note_name[32];
4385 xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[i]);
4386 spu_len = target_read_alloc (¤t_target, TARGET_OBJECT_SPU,
4390 xsnprintf (note_name, sizeof note_name, "SPU/%s", annex);
4391 args->note_data = elfcore_write_note (args->obfd, args->note_data,
4392 args->note_size, note_name,
4393 NT_SPU, spu_data, spu_len);
4400 linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size)
4402 struct linux_spu_corefile_data args;
4405 args.note_data = note_data;
4406 args.note_size = note_size;
4408 iterate_over_spus (PIDGET (inferior_ptid),
4409 linux_spu_corefile_callback, &args);
4411 return args.note_data;
4414 /* Fills the "to_make_corefile_note" target vector. Builds the note
4415 section for a corefile, and returns it in a malloc buffer. */
4418 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
4420 struct linux_nat_corefile_thread_data thread_args;
4421 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
4422 char fname[16] = { '\0' };
4423 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
4424 char psargs[80] = { '\0' };
4425 char *note_data = NULL;
4426 ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid));
4430 if (get_exec_file (0))
4432 strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
4433 strncpy (psargs, get_exec_file (0), sizeof (psargs));
4434 if (get_inferior_args ())
4437 char *psargs_end = psargs + sizeof (psargs);
4439 /* linux_elfcore_write_prpsinfo () handles zero unterminated
4441 string_end = memchr (psargs, 0, sizeof (psargs));
4442 if (string_end != NULL)
4444 *string_end++ = ' ';
4445 strncpy (string_end, get_inferior_args (),
4446 psargs_end - string_end);
4449 note_data = (char *) elfcore_write_prpsinfo (obfd,
4451 note_size, fname, psargs);
4454 /* Dump information for threads. */
4455 thread_args.obfd = obfd;
4456 thread_args.note_data = note_data;
4457 thread_args.note_size = note_size;
4458 thread_args.num_notes = 0;
4459 thread_args.stop_signal = find_stop_signal ();
4460 iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args);
4461 gdb_assert (thread_args.num_notes != 0);
4462 note_data = thread_args.note_data;
4464 auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
4468 note_data = elfcore_write_note (obfd, note_data, note_size,
4469 "CORE", NT_AUXV, auxv, auxv_len);
4473 note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size);
4475 make_cleanup (xfree, note_data);
4479 /* Implement the "info proc" command. */
4482 linux_nat_info_proc_cmd (char *args, int from_tty)
4484 /* A long is used for pid instead of an int to avoid a loss of precision
4485 compiler warning from the output of strtoul. */
4486 long pid = PIDGET (inferior_ptid);
4489 char buffer[MAXPATHLEN];
4490 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
4502 /* Break up 'args' into an argv array. */
4503 argv = gdb_buildargv (args);
4504 make_cleanup_freeargv (argv);
4506 while (argv != NULL && *argv != NULL)
4508 if (isdigit (argv[0][0]))
4510 pid = strtoul (argv[0], NULL, 10);
4512 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
4516 else if (strcmp (argv[0], "status") == 0)
4520 else if (strcmp (argv[0], "stat") == 0)
4524 else if (strcmp (argv[0], "cmd") == 0)
4528 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
4532 else if (strcmp (argv[0], "cwd") == 0)
4536 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
4542 /* [...] (future options here) */
4547 error (_("No current process: you must name one."));
4549 sprintf (fname1, "/proc/%ld", pid);
4550 if (stat (fname1, &dummy) != 0)
4551 error (_("No /proc directory: '%s'"), fname1);
4553 printf_filtered (_("process %ld\n"), pid);
4554 if (cmdline_f || all)
4556 sprintf (fname1, "/proc/%ld/cmdline", pid);
4557 if ((procfile = fopen (fname1, "r")) != NULL)
4559 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4561 if (fgets (buffer, sizeof (buffer), procfile))
4562 printf_filtered ("cmdline = '%s'\n", buffer);
4564 warning (_("unable to read '%s'"), fname1);
4565 do_cleanups (cleanup);
4568 warning (_("unable to open /proc file '%s'"), fname1);
4572 sprintf (fname1, "/proc/%ld/cwd", pid);
4573 memset (fname2, 0, sizeof (fname2));
4574 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4575 printf_filtered ("cwd = '%s'\n", fname2);
4577 warning (_("unable to read link '%s'"), fname1);
4581 sprintf (fname1, "/proc/%ld/exe", pid);
4582 memset (fname2, 0, sizeof (fname2));
4583 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4584 printf_filtered ("exe = '%s'\n", fname2);
4586 warning (_("unable to read link '%s'"), fname1);
4588 if (mappings_f || all)
4590 sprintf (fname1, "/proc/%ld/maps", pid);
4591 if ((procfile = fopen (fname1, "r")) != NULL)
4593 long long addr, endaddr, size, offset, inode;
4594 char permissions[8], device[8], filename[MAXPATHLEN];
4595 struct cleanup *cleanup;
4597 cleanup = make_cleanup_fclose (procfile);
4598 printf_filtered (_("Mapped address spaces:\n\n"));
4599 if (gdbarch_addr_bit (target_gdbarch) == 32)
4601 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
4604 " Size", " Offset", "objfile");
4608 printf_filtered (" %18s %18s %10s %10s %7s\n",
4611 " Size", " Offset", "objfile");
4614 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
4615 &offset, &device[0], &inode, &filename[0]))
4617 size = endaddr - addr;
4619 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
4620 calls here (and possibly above) should be abstracted
4621 out into their own functions? Andrew suggests using
4622 a generic local_address_string instead to print out
4623 the addresses; that makes sense to me, too. */
4625 if (gdbarch_addr_bit (target_gdbarch) == 32)
4627 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
4628 (unsigned long) addr, /* FIXME: pr_addr */
4629 (unsigned long) endaddr,
4631 (unsigned int) offset,
4632 filename[0] ? filename : "");
4636 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
4637 (unsigned long) addr, /* FIXME: pr_addr */
4638 (unsigned long) endaddr,
4640 (unsigned int) offset,
4641 filename[0] ? filename : "");
4645 do_cleanups (cleanup);
4648 warning (_("unable to open /proc file '%s'"), fname1);
4650 if (status_f || all)
4652 sprintf (fname1, "/proc/%ld/status", pid);
4653 if ((procfile = fopen (fname1, "r")) != NULL)
4655 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4657 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
4658 puts_filtered (buffer);
4659 do_cleanups (cleanup);
4662 warning (_("unable to open /proc file '%s'"), fname1);
4666 sprintf (fname1, "/proc/%ld/stat", pid);
4667 if ((procfile = fopen (fname1, "r")) != NULL)
4672 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4674 if (fscanf (procfile, "%d ", &itmp) > 0)
4675 printf_filtered (_("Process: %d\n"), itmp);
4676 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
4677 printf_filtered (_("Exec file: %s\n"), buffer);
4678 if (fscanf (procfile, "%c ", &ctmp) > 0)
4679 printf_filtered (_("State: %c\n"), ctmp);
4680 if (fscanf (procfile, "%d ", &itmp) > 0)
4681 printf_filtered (_("Parent process: %d\n"), itmp);
4682 if (fscanf (procfile, "%d ", &itmp) > 0)
4683 printf_filtered (_("Process group: %d\n"), itmp);
4684 if (fscanf (procfile, "%d ", &itmp) > 0)
4685 printf_filtered (_("Session id: %d\n"), itmp);
4686 if (fscanf (procfile, "%d ", &itmp) > 0)
4687 printf_filtered (_("TTY: %d\n"), itmp);
4688 if (fscanf (procfile, "%d ", &itmp) > 0)
4689 printf_filtered (_("TTY owner process group: %d\n"), itmp);
4690 if (fscanf (procfile, "%lu ", <mp) > 0)
4691 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
4692 if (fscanf (procfile, "%lu ", <mp) > 0)
4693 printf_filtered (_("Minor faults (no memory page): %lu\n"),
4694 (unsigned long) ltmp);
4695 if (fscanf (procfile, "%lu ", <mp) > 0)
4696 printf_filtered (_("Minor faults, children: %lu\n"),
4697 (unsigned long) ltmp);
4698 if (fscanf (procfile, "%lu ", <mp) > 0)
4699 printf_filtered (_("Major faults (memory page faults): %lu\n"),
4700 (unsigned long) ltmp);
4701 if (fscanf (procfile, "%lu ", <mp) > 0)
4702 printf_filtered (_("Major faults, children: %lu\n"),
4703 (unsigned long) ltmp);
4704 if (fscanf (procfile, "%ld ", <mp) > 0)
4705 printf_filtered (_("utime: %ld\n"), ltmp);
4706 if (fscanf (procfile, "%ld ", <mp) > 0)
4707 printf_filtered (_("stime: %ld\n"), ltmp);
4708 if (fscanf (procfile, "%ld ", <mp) > 0)
4709 printf_filtered (_("utime, children: %ld\n"), ltmp);
4710 if (fscanf (procfile, "%ld ", <mp) > 0)
4711 printf_filtered (_("stime, children: %ld\n"), ltmp);
4712 if (fscanf (procfile, "%ld ", <mp) > 0)
4713 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
4715 if (fscanf (procfile, "%ld ", <mp) > 0)
4716 printf_filtered (_("'nice' value: %ld\n"), ltmp);
4717 if (fscanf (procfile, "%lu ", <mp) > 0)
4718 printf_filtered (_("jiffies until next timeout: %lu\n"),
4719 (unsigned long) ltmp);
4720 if (fscanf (procfile, "%lu ", <mp) > 0)
4721 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
4722 (unsigned long) ltmp);
4723 if (fscanf (procfile, "%ld ", <mp) > 0)
4724 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
4726 if (fscanf (procfile, "%lu ", <mp) > 0)
4727 printf_filtered (_("Virtual memory size: %lu\n"),
4728 (unsigned long) ltmp);
4729 if (fscanf (procfile, "%lu ", <mp) > 0)
4730 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp);
4731 if (fscanf (procfile, "%lu ", <mp) > 0)
4732 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
4733 if (fscanf (procfile, "%lu ", <mp) > 0)
4734 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
4735 if (fscanf (procfile, "%lu ", <mp) > 0)
4736 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
4737 if (fscanf (procfile, "%lu ", <mp) > 0)
4738 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
4739 #if 0 /* Don't know how architecture-dependent the rest is...
4740 Anyway the signal bitmap info is available from "status". */
4741 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4742 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
4743 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4744 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
4745 if (fscanf (procfile, "%ld ", <mp) > 0)
4746 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
4747 if (fscanf (procfile, "%ld ", <mp) > 0)
4748 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
4749 if (fscanf (procfile, "%ld ", <mp) > 0)
4750 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
4751 if (fscanf (procfile, "%ld ", <mp) > 0)
4752 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
4753 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4754 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
4756 do_cleanups (cleanup);
4759 warning (_("unable to open /proc file '%s'"), fname1);
4763 /* Implement the to_xfer_partial interface for memory reads using the /proc
4764 filesystem. Because we can use a single read() call for /proc, this
4765 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4766 but it doesn't support writes. */
4769 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4770 const char *annex, gdb_byte *readbuf,
4771 const gdb_byte *writebuf,
4772 ULONGEST offset, LONGEST len)
4778 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4781 /* Don't bother for one word. */
4782 if (len < 3 * sizeof (long))
4785 /* We could keep this file open and cache it - possibly one per
4786 thread. That requires some juggling, but is even faster. */
4787 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
4788 fd = open (filename, O_RDONLY | O_LARGEFILE);
4792 /* If pread64 is available, use it. It's faster if the kernel
4793 supports it (only one syscall), and it's 64-bit safe even on
4794 32-bit platforms (for instance, SPARC debugging a SPARC64
4797 if (pread64 (fd, readbuf, len, offset) != len)
4799 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4810 /* Enumerate spufs IDs for process PID. */
4812 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len)
4814 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
4816 LONGEST written = 0;
4819 struct dirent *entry;
4821 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4822 dir = opendir (path);
4827 while ((entry = readdir (dir)) != NULL)
4833 fd = atoi (entry->d_name);
4837 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4838 if (stat (path, &st) != 0)
4840 if (!S_ISDIR (st.st_mode))
4843 if (statfs (path, &stfs) != 0)
4845 if (stfs.f_type != SPUFS_MAGIC)
4848 if (pos >= offset && pos + 4 <= offset + len)
4850 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4860 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4861 object type, using the /proc file system. */
4863 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4864 const char *annex, gdb_byte *readbuf,
4865 const gdb_byte *writebuf,
4866 ULONGEST offset, LONGEST len)
4871 int pid = PIDGET (inferior_ptid);
4878 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4881 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4882 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4887 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4894 ret = write (fd, writebuf, (size_t) len);
4896 ret = read (fd, readbuf, (size_t) len);
4903 /* Parse LINE as a signal set and add its set bits to SIGS. */
4906 add_line_to_sigset (const char *line, sigset_t *sigs)
4908 int len = strlen (line) - 1;
4912 if (line[len] != '\n')
4913 error (_("Could not parse signal set: %s"), line);
4921 if (*p >= '0' && *p <= '9')
4923 else if (*p >= 'a' && *p <= 'f')
4924 digit = *p - 'a' + 10;
4926 error (_("Could not parse signal set: %s"), line);
4931 sigaddset (sigs, signum + 1);
4933 sigaddset (sigs, signum + 2);
4935 sigaddset (sigs, signum + 3);
4937 sigaddset (sigs, signum + 4);
4943 /* Find process PID's pending signals from /proc/pid/status and set
4947 linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
4950 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
4951 struct cleanup *cleanup;
4953 sigemptyset (pending);
4954 sigemptyset (blocked);
4955 sigemptyset (ignored);
4956 sprintf (fname, "/proc/%d/status", pid);
4957 procfile = fopen (fname, "r");
4958 if (procfile == NULL)
4959 error (_("Could not open %s"), fname);
4960 cleanup = make_cleanup_fclose (procfile);
4962 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
4964 /* Normal queued signals are on the SigPnd line in the status
4965 file. However, 2.6 kernels also have a "shared" pending
4966 queue for delivering signals to a thread group, so check for
4969 Unfortunately some Red Hat kernels include the shared pending
4970 queue but not the ShdPnd status field. */
4972 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
4973 add_line_to_sigset (buffer + 8, pending);
4974 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
4975 add_line_to_sigset (buffer + 8, pending);
4976 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
4977 add_line_to_sigset (buffer + 8, blocked);
4978 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
4979 add_line_to_sigset (buffer + 8, ignored);
4982 do_cleanups (cleanup);
4986 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4987 const char *annex, gdb_byte *readbuf,
4988 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4990 /* We make the process list snapshot when the object starts to be
4992 static const char *buf;
4993 static LONGEST len_avail = -1;
4994 static struct obstack obstack;
4998 gdb_assert (object == TARGET_OBJECT_OSDATA);
5004 if (len_avail != -1 && len_avail != 0)
5005 obstack_free (&obstack, NULL);
5008 obstack_init (&obstack);
5009 obstack_grow_str (&obstack, "<osdata type=\"types\">\n");
5011 obstack_xml_printf (
5014 "<column name=\"Type\">processes</column>"
5015 "<column name=\"Description\">Listing of all processes</column>"
5018 obstack_grow_str0 (&obstack, "</osdata>\n");
5019 buf = obstack_finish (&obstack);
5020 len_avail = strlen (buf);
5023 if (offset >= len_avail)
5025 /* Done. Get rid of the obstack. */
5026 obstack_free (&obstack, NULL);
5032 if (len > len_avail - offset)
5033 len = len_avail - offset;
5034 memcpy (readbuf, buf + offset, len);
5039 if (strcmp (annex, "processes") != 0)
5042 gdb_assert (readbuf && !writebuf);
5046 if (len_avail != -1 && len_avail != 0)
5047 obstack_free (&obstack, NULL);
5050 obstack_init (&obstack);
5051 obstack_grow_str (&obstack, "<osdata type=\"processes\">\n");
5053 dirp = opendir ("/proc");
5058 while ((dp = readdir (dirp)) != NULL)
5060 struct stat statbuf;
5061 char procentry[sizeof ("/proc/4294967295")];
5063 if (!isdigit (dp->d_name[0])
5064 || NAMELEN (dp) > sizeof ("4294967295") - 1)
5067 sprintf (procentry, "/proc/%s", dp->d_name);
5068 if (stat (procentry, &statbuf) == 0
5069 && S_ISDIR (statbuf.st_mode))
5073 char cmd[MAXPATHLEN + 1];
5074 struct passwd *entry;
5076 pathname = xstrprintf ("/proc/%s/cmdline", dp->d_name);
5077 entry = getpwuid (statbuf.st_uid);
5079 if ((f = fopen (pathname, "r")) != NULL)
5081 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
5087 for (i = 0; i < len; i++)
5092 obstack_xml_printf (
5095 "<column name=\"pid\">%s</column>"
5096 "<column name=\"user\">%s</column>"
5097 "<column name=\"command\">%s</column>"
5100 entry ? entry->pw_name : "?",
5113 obstack_grow_str0 (&obstack, "</osdata>\n");
5114 buf = obstack_finish (&obstack);
5115 len_avail = strlen (buf);
5118 if (offset >= len_avail)
5120 /* Done. Get rid of the obstack. */
5121 obstack_free (&obstack, NULL);
5127 if (len > len_avail - offset)
5128 len = len_avail - offset;
5129 memcpy (readbuf, buf + offset, len);
5135 linux_xfer_partial (struct target_ops *ops, enum target_object object,
5136 const char *annex, gdb_byte *readbuf,
5137 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
5141 if (object == TARGET_OBJECT_AUXV)
5142 return memory_xfer_auxv (ops, object, annex, readbuf, writebuf,
5145 if (object == TARGET_OBJECT_OSDATA)
5146 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
5149 if (object == TARGET_OBJECT_SPU)
5150 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
5153 /* GDB calculates all the addresses in possibly larget width of the address.
5154 Address width needs to be masked before its final use - either by
5155 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
5157 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
5159 if (object == TARGET_OBJECT_MEMORY)
5161 int addr_bit = gdbarch_addr_bit (target_gdbarch);
5163 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
5164 offset &= ((ULONGEST) 1 << addr_bit) - 1;
5167 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
5172 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
5176 /* Create a prototype generic GNU/Linux target. The client can override
5177 it with local methods. */
5180 linux_target_install_ops (struct target_ops *t)
5182 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
5183 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
5184 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
5185 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
5186 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
5187 t->to_post_startup_inferior = linux_child_post_startup_inferior;
5188 t->to_post_attach = linux_child_post_attach;
5189 t->to_follow_fork = linux_child_follow_fork;
5190 t->to_find_memory_regions = linux_nat_find_memory_regions;
5191 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
5193 super_xfer_partial = t->to_xfer_partial;
5194 t->to_xfer_partial = linux_xfer_partial;
5200 struct target_ops *t;
5202 t = inf_ptrace_target ();
5203 linux_target_install_ops (t);
5209 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
5211 struct target_ops *t;
5213 t = inf_ptrace_trad_target (register_u_offset);
5214 linux_target_install_ops (t);
5219 /* target_is_async_p implementation. */
5222 linux_nat_is_async_p (void)
5224 /* NOTE: palves 2008-03-21: We're only async when the user requests
5225 it explicitly with the "set target-async" command.
5226 Someday, linux will always be async. */
5227 if (!target_async_permitted)
5230 /* See target.h/target_async_mask. */
5231 return linux_nat_async_mask_value;
5234 /* target_can_async_p implementation. */
5237 linux_nat_can_async_p (void)
5239 /* NOTE: palves 2008-03-21: We're only async when the user requests
5240 it explicitly with the "set target-async" command.
5241 Someday, linux will always be async. */
5242 if (!target_async_permitted)
5245 /* See target.h/target_async_mask. */
5246 return linux_nat_async_mask_value;
5250 linux_nat_supports_non_stop (void)
5255 /* True if we want to support multi-process. To be removed when GDB
5256 supports multi-exec. */
5258 int linux_multi_process = 1;
5261 linux_nat_supports_multi_process (void)
5263 return linux_multi_process;
5266 /* target_async_mask implementation. */
5269 linux_nat_async_mask (int new_mask)
5271 int curr_mask = linux_nat_async_mask_value;
5273 if (curr_mask != new_mask)
5277 linux_nat_async (NULL, 0);
5278 linux_nat_async_mask_value = new_mask;
5282 linux_nat_async_mask_value = new_mask;
5284 /* If we're going out of async-mask in all-stop, then the
5285 inferior is stopped. The next resume will call
5286 target_async. In non-stop, the target event source
5287 should be always registered in the event loop. Do so
5290 linux_nat_async (inferior_event_handler, 0);
5297 static int async_terminal_is_ours = 1;
5299 /* target_terminal_inferior implementation. */
5302 linux_nat_terminal_inferior (void)
5304 if (!target_is_async_p ())
5306 /* Async mode is disabled. */
5307 terminal_inferior ();
5311 terminal_inferior ();
5313 /* Calls to target_terminal_*() are meant to be idempotent. */
5314 if (!async_terminal_is_ours)
5317 delete_file_handler (input_fd);
5318 async_terminal_is_ours = 0;
5322 /* target_terminal_ours implementation. */
5325 linux_nat_terminal_ours (void)
5327 if (!target_is_async_p ())
5329 /* Async mode is disabled. */
5334 /* GDB should never give the terminal to the inferior if the
5335 inferior is running in the background (run&, continue&, etc.),
5336 but claiming it sure should. */
5339 if (async_terminal_is_ours)
5342 clear_sigint_trap ();
5343 add_file_handler (input_fd, stdin_event_handler, 0);
5344 async_terminal_is_ours = 1;
5347 static void (*async_client_callback) (enum inferior_event_type event_type,
5349 static void *async_client_context;
5351 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5352 so we notice when any child changes state, and notify the
5353 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
5354 above to wait for the arrival of a SIGCHLD. */
5357 sigchld_handler (int signo)
5359 int old_errno = errno;
5361 if (debug_linux_nat_async)
5362 fprintf_unfiltered (gdb_stdlog, "sigchld\n");
5364 if (signo == SIGCHLD
5365 && linux_nat_event_pipe[0] != -1)
5366 async_file_mark (); /* Let the event loop know that there are
5367 events to handle. */
5372 /* Callback registered with the target events file descriptor. */
5375 handle_target_event (int error, gdb_client_data client_data)
5377 (*async_client_callback) (INF_REG_EVENT, async_client_context);
5380 /* Create/destroy the target events pipe. Returns previous state. */
5383 linux_async_pipe (int enable)
5385 int previous = (linux_nat_event_pipe[0] != -1);
5387 if (previous != enable)
5391 block_child_signals (&prev_mask);
5395 if (pipe (linux_nat_event_pipe) == -1)
5396 internal_error (__FILE__, __LINE__,
5397 "creating event pipe failed.");
5399 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
5400 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
5404 close (linux_nat_event_pipe[0]);
5405 close (linux_nat_event_pipe[1]);
5406 linux_nat_event_pipe[0] = -1;
5407 linux_nat_event_pipe[1] = -1;
5410 restore_child_signals_mask (&prev_mask);
5416 /* target_async implementation. */
5419 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
5420 void *context), void *context)
5422 if (linux_nat_async_mask_value == 0 || !target_async_permitted)
5423 internal_error (__FILE__, __LINE__,
5424 "Calling target_async when async is masked");
5426 if (callback != NULL)
5428 async_client_callback = callback;
5429 async_client_context = context;
5430 if (!linux_async_pipe (1))
5432 add_file_handler (linux_nat_event_pipe[0],
5433 handle_target_event, NULL);
5434 /* There may be pending events to handle. Tell the event loop
5441 async_client_callback = callback;
5442 async_client_context = context;
5443 delete_file_handler (linux_nat_event_pipe[0]);
5444 linux_async_pipe (0);
5449 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5453 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
5457 ptid_t ptid = lwp->ptid;
5459 if (debug_linux_nat)
5460 fprintf_unfiltered (gdb_stdlog,
5461 "LNSL: running -> suspending %s\n",
5462 target_pid_to_str (lwp->ptid));
5465 stop_callback (lwp, NULL);
5466 stop_wait_callback (lwp, NULL);
5468 /* If the lwp exits while we try to stop it, there's nothing
5470 lwp = find_lwp_pid (ptid);
5474 /* If we didn't collect any signal other than SIGSTOP while
5475 stopping the LWP, push a SIGNAL_0 event. In either case, the
5476 event-loop will end up calling target_wait which will collect
5478 if (lwp->status == 0)
5479 lwp->status = W_STOPCODE (0);
5484 /* Already known to be stopped; do nothing. */
5486 if (debug_linux_nat)
5488 if (find_thread_ptid (lwp->ptid)->stop_requested)
5489 fprintf_unfiltered (gdb_stdlog, "\
5490 LNSL: already stopped/stop_requested %s\n",
5491 target_pid_to_str (lwp->ptid));
5493 fprintf_unfiltered (gdb_stdlog, "\
5494 LNSL: already stopped/no stop_requested yet %s\n",
5495 target_pid_to_str (lwp->ptid));
5502 linux_nat_stop (ptid_t ptid)
5505 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
5507 linux_ops->to_stop (ptid);
5511 linux_nat_close (int quitting)
5513 /* Unregister from the event loop. */
5514 if (target_is_async_p ())
5515 target_async (NULL, 0);
5517 /* Reset the async_masking. */
5518 linux_nat_async_mask_value = 1;
5520 if (linux_ops->to_close)
5521 linux_ops->to_close (quitting);
5524 /* When requests are passed down from the linux-nat layer to the
5525 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5526 used. The address space pointer is stored in the inferior object,
5527 but the common code that is passed such ptid can't tell whether
5528 lwpid is a "main" process id or not (it assumes so). We reverse
5529 look up the "main" process id from the lwp here. */
5531 struct address_space *
5532 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
5534 struct lwp_info *lwp;
5535 struct inferior *inf;
5538 pid = GET_LWP (ptid);
5539 if (GET_LWP (ptid) == 0)
5541 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5543 lwp = find_lwp_pid (ptid);
5544 pid = GET_PID (lwp->ptid);
5548 /* A (pid,lwpid,0) ptid. */
5549 pid = GET_PID (ptid);
5552 inf = find_inferior_pid (pid);
5553 gdb_assert (inf != NULL);
5558 linux_nat_core_of_thread_1 (ptid_t ptid)
5560 struct cleanup *back_to;
5563 char *content = NULL;
5566 int content_read = 0;
5570 filename = xstrprintf ("/proc/%d/task/%ld/stat",
5571 GET_PID (ptid), GET_LWP (ptid));
5572 back_to = make_cleanup (xfree, filename);
5574 f = fopen (filename, "r");
5577 do_cleanups (back_to);
5581 make_cleanup_fclose (f);
5587 content = xrealloc (content, content_read + 1024);
5588 n = fread (content + content_read, 1, 1024, f);
5592 content[content_read] = '\0';
5597 make_cleanup (xfree, content);
5599 p = strchr (content, '(');
5603 p = strchr (p, ')');
5607 /* If the first field after program name has index 0, then core number is
5608 the field with index 36. There's no constant for that anywhere. */
5610 p = strtok_r (p, " ", &ts);
5611 for (i = 0; p != NULL && i != 36; ++i)
5612 p = strtok_r (NULL, " ", &ts);
5614 if (p == NULL || sscanf (p, "%d", &core) == 0)
5617 do_cleanups (back_to);
5622 /* Return the cached value of the processor core for thread PTID. */
5625 linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid)
5627 struct lwp_info *info = find_lwp_pid (ptid);
5635 linux_nat_add_target (struct target_ops *t)
5637 /* Save the provided single-threaded target. We save this in a separate
5638 variable because another target we've inherited from (e.g. inf-ptrace)
5639 may have saved a pointer to T; we want to use it for the final
5640 process stratum target. */
5641 linux_ops_saved = *t;
5642 linux_ops = &linux_ops_saved;
5644 /* Override some methods for multithreading. */
5645 t->to_create_inferior = linux_nat_create_inferior;
5646 t->to_attach = linux_nat_attach;
5647 t->to_detach = linux_nat_detach;
5648 t->to_resume = linux_nat_resume;
5649 t->to_wait = linux_nat_wait;
5650 t->to_xfer_partial = linux_nat_xfer_partial;
5651 t->to_kill = linux_nat_kill;
5652 t->to_mourn_inferior = linux_nat_mourn_inferior;
5653 t->to_thread_alive = linux_nat_thread_alive;
5654 t->to_pid_to_str = linux_nat_pid_to_str;
5655 t->to_has_thread_control = tc_schedlock;
5656 t->to_thread_address_space = linux_nat_thread_address_space;
5657 t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint;
5658 t->to_stopped_data_address = linux_nat_stopped_data_address;
5660 t->to_can_async_p = linux_nat_can_async_p;
5661 t->to_is_async_p = linux_nat_is_async_p;
5662 t->to_supports_non_stop = linux_nat_supports_non_stop;
5663 t->to_async = linux_nat_async;
5664 t->to_async_mask = linux_nat_async_mask;
5665 t->to_terminal_inferior = linux_nat_terminal_inferior;
5666 t->to_terminal_ours = linux_nat_terminal_ours;
5667 t->to_close = linux_nat_close;
5669 /* Methods for non-stop support. */
5670 t->to_stop = linux_nat_stop;
5672 t->to_supports_multi_process = linux_nat_supports_multi_process;
5674 t->to_core_of_thread = linux_nat_core_of_thread;
5676 /* We don't change the stratum; this target will sit at
5677 process_stratum and thread_db will set at thread_stratum. This
5678 is a little strange, since this is a multi-threaded-capable
5679 target, but we want to be on the stack below thread_db, and we
5680 also want to be used for single-threaded processes. */
5685 /* Register a method to call whenever a new thread is attached. */
5687 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
5689 /* Save the pointer. We only support a single registered instance
5690 of the GNU/Linux native target, so we do not need to map this to
5692 linux_nat_new_thread = new_thread;
5695 /* Register a method that converts a siginfo object between the layout
5696 that ptrace returns, and the layout in the architecture of the
5699 linux_nat_set_siginfo_fixup (struct target_ops *t,
5700 int (*siginfo_fixup) (struct siginfo *,
5704 /* Save the pointer. */
5705 linux_nat_siginfo_fixup = siginfo_fixup;
5708 /* Return the saved siginfo associated with PTID. */
5710 linux_nat_get_siginfo (ptid_t ptid)
5712 struct lwp_info *lp = find_lwp_pid (ptid);
5714 gdb_assert (lp != NULL);
5716 return &lp->siginfo;
5719 /* Provide a prototype to silence -Wmissing-prototypes. */
5720 extern initialize_file_ftype _initialize_linux_nat;
5723 _initialize_linux_nat (void)
5725 add_info ("proc", linux_nat_info_proc_cmd, _("\
5726 Show /proc process information about any running process.\n\
5727 Specify any process id, or use the program being debugged by default.\n\
5728 Specify any of the following keywords for detailed info:\n\
5729 mappings -- list of mapped memory regions.\n\
5730 stat -- list a bunch of random process info.\n\
5731 status -- list a different bunch of random process info.\n\
5732 all -- list all available /proc info."));
5734 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
5735 &debug_linux_nat, _("\
5736 Set debugging of GNU/Linux lwp module."), _("\
5737 Show debugging of GNU/Linux lwp module."), _("\
5738 Enables printf debugging output."),
5740 show_debug_linux_nat,
5741 &setdebuglist, &showdebuglist);
5743 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
5744 &debug_linux_nat_async, _("\
5745 Set debugging of GNU/Linux async lwp module."), _("\
5746 Show debugging of GNU/Linux async lwp module."), _("\
5747 Enables printf debugging output."),
5749 show_debug_linux_nat_async,
5750 &setdebuglist, &showdebuglist);
5752 /* Save this mask as the default. */
5753 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
5755 /* Install a SIGCHLD handler. */
5756 sigchld_action.sa_handler = sigchld_handler;
5757 sigemptyset (&sigchld_action.sa_mask);
5758 sigchld_action.sa_flags = SA_RESTART;
5760 /* Make it the default. */
5761 sigaction (SIGCHLD, &sigchld_action, NULL);
5763 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5764 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5765 sigdelset (&suspend_mask, SIGCHLD);
5767 sigemptyset (&blocked_mask);
5769 add_setshow_boolean_cmd ("disable-randomization", class_support,
5770 &disable_randomization, _("\
5771 Set disabling of debuggee's virtual address space randomization."), _("\
5772 Show disabling of debuggee's virtual address space randomization."), _("\
5773 When this mode is on (which is the default), randomization of the virtual\n\
5774 address space is disabled. Standalone programs run with the randomization\n\
5775 enabled by default on some platforms."),
5776 &set_disable_randomization,
5777 &show_disable_randomization,
5778 &setlist, &showlist);
5782 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5783 the GNU/Linux Threads library and therefore doesn't really belong
5786 /* Read variable NAME in the target and return its value if found.
5787 Otherwise return zero. It is assumed that the type of the variable
5791 get_signo (const char *name)
5793 struct minimal_symbol *ms;
5796 ms = lookup_minimal_symbol (name, NULL, NULL);
5800 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5801 sizeof (signo)) != 0)
5807 /* Return the set of signals used by the threads library in *SET. */
5810 lin_thread_get_thread_signals (sigset_t *set)
5812 struct sigaction action;
5813 int restart, cancel;
5815 sigemptyset (&blocked_mask);
5818 restart = get_signo ("__pthread_sig_restart");
5819 cancel = get_signo ("__pthread_sig_cancel");
5821 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5822 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5823 not provide any way for the debugger to query the signal numbers -
5824 fortunately they don't change! */
5827 restart = __SIGRTMIN;
5830 cancel = __SIGRTMIN + 1;
5832 sigaddset (set, restart);
5833 sigaddset (set, cancel);
5835 /* The GNU/Linux Threads library makes terminating threads send a
5836 special "cancel" signal instead of SIGCHLD. Make sure we catch
5837 those (to prevent them from terminating GDB itself, which is
5838 likely to be their default action) and treat them the same way as
5841 action.sa_handler = sigchld_handler;
5842 sigemptyset (&action.sa_mask);
5843 action.sa_flags = SA_RESTART;
5844 sigaction (cancel, &action, NULL);
5846 /* We block the "cancel" signal throughout this code ... */
5847 sigaddset (&blocked_mask, cancel);
5848 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5850 /* ... except during a sigsuspend. */
5851 sigdelset (&suspend_mask, cancel);