1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
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 static int linux_parent_pid;
275 struct simple_pid_list
279 struct simple_pid_list *next;
281 struct simple_pid_list *stopped_pids;
283 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
284 can not be used, 1 if it can. */
286 static int linux_supports_tracefork_flag = -1;
288 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACESYSGOOD
289 can not be used, 1 if it can. */
291 static int linux_supports_tracesysgood_flag = -1;
293 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
294 PTRACE_O_TRACEVFORKDONE. */
296 static int linux_supports_tracevforkdone_flag = -1;
298 /* Async mode support */
300 /* Zero if the async mode, although enabled, is masked, which means
301 linux_nat_wait should behave as if async mode was off. */
302 static int linux_nat_async_mask_value = 1;
304 /* Stores the current used ptrace() options. */
305 static int current_ptrace_options = 0;
307 /* The read/write ends of the pipe registered as waitable file in the
309 static int linux_nat_event_pipe[2] = { -1, -1 };
311 /* Flush the event pipe. */
314 async_file_flush (void)
321 ret = read (linux_nat_event_pipe[0], &buf, 1);
323 while (ret >= 0 || (ret == -1 && errno == EINTR));
326 /* Put something (anything, doesn't matter what, or how much) in event
327 pipe, so that the select/poll in the event-loop realizes we have
328 something to process. */
331 async_file_mark (void)
335 /* It doesn't really matter what the pipe contains, as long we end
336 up with something in it. Might as well flush the previous
342 ret = write (linux_nat_event_pipe[1], "+", 1);
344 while (ret == -1 && errno == EINTR);
346 /* Ignore EAGAIN. If the pipe is full, the event loop will already
347 be awakened anyway. */
350 static void linux_nat_async (void (*callback)
351 (enum inferior_event_type event_type, void *context),
353 static int linux_nat_async_mask (int mask);
354 static int kill_lwp (int lwpid, int signo);
356 static int stop_callback (struct lwp_info *lp, void *data);
358 static void block_child_signals (sigset_t *prev_mask);
359 static void restore_child_signals_mask (sigset_t *prev_mask);
362 static struct lwp_info *add_lwp (ptid_t ptid);
363 static void purge_lwp_list (int pid);
364 static struct lwp_info *find_lwp_pid (ptid_t ptid);
367 /* Trivial list manipulation functions to keep track of a list of
368 new stopped processes. */
370 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
372 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
374 new_pid->status = status;
375 new_pid->next = *listp;
380 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status)
382 struct simple_pid_list **p;
384 for (p = listp; *p != NULL; p = &(*p)->next)
385 if ((*p)->pid == pid)
387 struct simple_pid_list *next = (*p)->next;
388 *status = (*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)
410 ptrace (PTRACE_TRACEME, 0, 0, 0);
411 kill (getpid (), SIGSTOP);
416 /* Wrapper function for waitpid which handles EINTR. */
419 my_waitpid (int pid, int *status, int flags)
425 ret = waitpid (pid, status, flags);
427 while (ret == -1 && errno == EINTR);
432 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
434 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
435 we know that the feature is not available. This may change the tracing
436 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
438 However, if it succeeds, we don't know for sure that the feature is
439 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
440 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
441 fork tracing, and let it fork. If the process exits, we assume that we
442 can't use TRACEFORK; if we get the fork notification, and we can extract
443 the new child's PID, then we assume that we can. */
446 linux_test_for_tracefork (int original_pid)
448 int child_pid, ret, status;
452 /* We don't want those ptrace calls to be interrupted. */
453 block_child_signals (&prev_mask);
455 linux_supports_tracefork_flag = 0;
456 linux_supports_tracevforkdone_flag = 0;
458 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
461 restore_child_signals_mask (&prev_mask);
467 perror_with_name (("fork"));
470 linux_tracefork_child ();
472 ret = my_waitpid (child_pid, &status, 0);
474 perror_with_name (("waitpid"));
475 else if (ret != child_pid)
476 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
477 if (! WIFSTOPPED (status))
478 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status);
480 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
483 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
486 warning (_("linux_test_for_tracefork: failed to kill child"));
487 restore_child_signals_mask (&prev_mask);
491 ret = my_waitpid (child_pid, &status, 0);
492 if (ret != child_pid)
493 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
494 else if (!WIFSIGNALED (status))
495 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
496 "killed child"), status);
498 restore_child_signals_mask (&prev_mask);
502 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
503 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
504 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
505 linux_supports_tracevforkdone_flag = (ret == 0);
507 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
509 warning (_("linux_test_for_tracefork: failed to resume child"));
511 ret = my_waitpid (child_pid, &status, 0);
513 if (ret == child_pid && WIFSTOPPED (status)
514 && status >> 16 == PTRACE_EVENT_FORK)
517 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
518 if (ret == 0 && second_pid != 0)
522 linux_supports_tracefork_flag = 1;
523 my_waitpid (second_pid, &second_status, 0);
524 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
526 warning (_("linux_test_for_tracefork: failed to kill second child"));
527 my_waitpid (second_pid, &status, 0);
531 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
532 "(%d, status 0x%x)"), ret, status);
534 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
536 warning (_("linux_test_for_tracefork: failed to kill child"));
537 my_waitpid (child_pid, &status, 0);
539 restore_child_signals_mask (&prev_mask);
542 /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls.
544 We try to enable syscall tracing on ORIGINAL_PID. If this fails,
545 we know that the feature is not available. This may change the tracing
546 options for ORIGINAL_PID, but we'll be setting them shortly anyway. */
549 linux_test_for_tracesysgood (int original_pid)
554 /* We don't want those ptrace calls to be interrupted. */
555 block_child_signals (&prev_mask);
557 linux_supports_tracesysgood_flag = 0;
559 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD);
563 linux_supports_tracesysgood_flag = 1;
565 restore_child_signals_mask (&prev_mask);
568 /* Determine wether we support PTRACE_O_TRACESYSGOOD option available.
569 This function also sets linux_supports_tracesysgood_flag. */
572 linux_supports_tracesysgood (int pid)
574 if (linux_supports_tracesysgood_flag == -1)
575 linux_test_for_tracesysgood (pid);
576 return linux_supports_tracesysgood_flag;
579 /* Return non-zero iff we have tracefork functionality available.
580 This function also sets linux_supports_tracefork_flag. */
583 linux_supports_tracefork (int pid)
585 if (linux_supports_tracefork_flag == -1)
586 linux_test_for_tracefork (pid);
587 return linux_supports_tracefork_flag;
591 linux_supports_tracevforkdone (int pid)
593 if (linux_supports_tracefork_flag == -1)
594 linux_test_for_tracefork (pid);
595 return linux_supports_tracevforkdone_flag;
599 linux_enable_tracesysgood (ptid_t ptid)
601 int pid = ptid_get_lwp (ptid);
604 pid = ptid_get_pid (ptid);
606 if (linux_supports_tracesysgood (pid) == 0)
609 current_ptrace_options |= PTRACE_O_TRACESYSGOOD;
611 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
616 linux_enable_event_reporting (ptid_t ptid)
618 int pid = ptid_get_lwp (ptid);
621 pid = ptid_get_pid (ptid);
623 if (! linux_supports_tracefork (pid))
626 current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK
627 | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE;
629 if (linux_supports_tracevforkdone (pid))
630 current_ptrace_options |= PTRACE_O_TRACEVFORKDONE;
632 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
633 read-only process state. */
635 ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options);
639 linux_child_post_attach (int pid)
641 linux_enable_event_reporting (pid_to_ptid (pid));
642 check_for_thread_db ();
643 linux_enable_tracesysgood (pid_to_ptid (pid));
647 linux_child_post_startup_inferior (ptid_t ptid)
649 linux_enable_event_reporting (ptid);
650 check_for_thread_db ();
651 linux_enable_tracesysgood (ptid);
655 linux_child_follow_fork (struct target_ops *ops, int follow_child)
659 int parent_pid, child_pid;
661 block_child_signals (&prev_mask);
663 has_vforked = (inferior_thread ()->pending_follow.kind
664 == TARGET_WAITKIND_VFORKED);
665 parent_pid = ptid_get_lwp (inferior_ptid);
667 parent_pid = ptid_get_pid (inferior_ptid);
668 child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
671 linux_enable_event_reporting (pid_to_ptid (child_pid));
674 && !non_stop /* Non-stop always resumes both branches. */
675 && (!target_is_async_p () || sync_execution)
676 && !(follow_child || detach_fork || sched_multi))
678 /* The parent stays blocked inside the vfork syscall until the
679 child execs or exits. If we don't let the child run, then
680 the parent stays blocked. If we're telling the parent to run
681 in the foreground, the user will not be able to ctrl-c to get
682 back the terminal, effectively hanging the debug session. */
683 fprintf_filtered (gdb_stderr, _("\
684 Can not resume the parent process over vfork in the foreground while \n\
685 holding the child stopped. Try \"set detach-on-fork\" or \
686 \"set schedule-multiple\".\n"));
692 struct lwp_info *child_lp = NULL;
694 /* We're already attached to the parent, by default. */
696 /* Detach new forked process? */
699 /* Before detaching from the child, remove all breakpoints
700 from it. If we forked, then this has already been taken
701 care of by infrun.c. If we vforked however, any
702 breakpoint inserted in the parent is visible in the
703 child, even those added while stopped in a vfork
704 catchpoint. This will remove the breakpoints from the
705 parent also, but they'll be reinserted below. */
708 /* keep breakpoints list in sync. */
709 remove_breakpoints_pid (GET_PID (inferior_ptid));
712 if (info_verbose || debug_linux_nat)
714 target_terminal_ours ();
715 fprintf_filtered (gdb_stdlog,
716 "Detaching after fork from child process %d.\n",
720 ptrace (PTRACE_DETACH, child_pid, 0, 0);
724 struct inferior *parent_inf, *child_inf;
725 struct cleanup *old_chain;
727 /* Add process to GDB's tables. */
728 child_inf = add_inferior (child_pid);
730 parent_inf = current_inferior ();
731 child_inf->attach_flag = parent_inf->attach_flag;
732 copy_terminal_info (child_inf, parent_inf);
734 old_chain = save_inferior_ptid ();
735 save_current_program_space ();
737 inferior_ptid = ptid_build (child_pid, child_pid, 0);
738 add_thread (inferior_ptid);
739 child_lp = add_lwp (inferior_ptid);
740 child_lp->stopped = 1;
741 child_lp->resumed = 1;
743 /* If this is a vfork child, then the address-space is
744 shared with the parent. */
747 child_inf->pspace = parent_inf->pspace;
748 child_inf->aspace = parent_inf->aspace;
750 /* The parent will be frozen until the child is done
751 with the shared region. Keep track of the
753 child_inf->vfork_parent = parent_inf;
754 child_inf->pending_detach = 0;
755 parent_inf->vfork_child = child_inf;
756 parent_inf->pending_detach = 0;
760 child_inf->aspace = new_address_space ();
761 child_inf->pspace = add_program_space (child_inf->aspace);
762 child_inf->removable = 1;
763 set_current_program_space (child_inf->pspace);
764 clone_program_space (child_inf->pspace, parent_inf->pspace);
766 /* Let the shared library layer (solib-svr4) learn about
767 this new process, relocate the cloned exec, pull in
768 shared libraries, and install the solib event
769 breakpoint. If a "cloned-VM" event was propagated
770 better throughout the core, this wouldn't be
772 solib_create_inferior_hook ();
775 /* Let the thread_db layer learn about this new process. */
776 check_for_thread_db ();
778 do_cleanups (old_chain);
784 struct inferior *parent_inf;
786 parent_inf = current_inferior ();
788 /* If we detached from the child, then we have to be careful
789 to not insert breakpoints in the parent until the child
790 is done with the shared memory region. However, if we're
791 staying attached to the child, then we can and should
792 insert breakpoints, so that we can debug it. A
793 subsequent child exec or exit is enough to know when does
794 the child stops using the parent's address space. */
795 parent_inf->waiting_for_vfork_done = detach_fork;
797 lp = find_lwp_pid (pid_to_ptid (parent_pid));
798 gdb_assert (linux_supports_tracefork_flag >= 0);
799 if (linux_supports_tracevforkdone (0))
802 fprintf_unfiltered (gdb_stdlog,
803 "LCFF: waiting for VFORK_DONE on %d\n",
809 /* We'll handle the VFORK_DONE event like any other
810 event, in target_wait. */
814 /* We can't insert breakpoints until the child has
815 finished with the shared memory region. We need to
816 wait until that happens. Ideal would be to just
818 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
819 - waitpid (parent_pid, &status, __WALL);
820 However, most architectures can't handle a syscall
821 being traced on the way out if it wasn't traced on
824 We might also think to loop, continuing the child
825 until it exits or gets a SIGTRAP. One problem is
826 that the child might call ptrace with PTRACE_TRACEME.
828 There's no simple and reliable way to figure out when
829 the vforked child will be done with its copy of the
830 shared memory. We could step it out of the syscall,
831 two instructions, let it go, and then single-step the
832 parent once. When we have hardware single-step, this
833 would work; with software single-step it could still
834 be made to work but we'd have to be able to insert
835 single-step breakpoints in the child, and we'd have
836 to insert -just- the single-step breakpoint in the
837 parent. Very awkward.
839 In the end, the best we can do is to make sure it
840 runs for a little while. Hopefully it will be out of
841 range of any breakpoints we reinsert. Usually this
842 is only the single-step breakpoint at vfork's return
846 fprintf_unfiltered (gdb_stdlog,
847 "LCFF: no VFORK_DONE support, sleeping a bit\n");
851 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
852 and leave it pending. The next linux_nat_resume call
853 will notice a pending event, and bypasses actually
854 resuming the inferior. */
856 lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE;
860 /* If we're in async mode, need to tell the event loop
861 there's something here to process. */
862 if (target_can_async_p ())
869 struct thread_info *tp;
870 struct inferior *parent_inf, *child_inf;
872 struct program_space *parent_pspace;
874 if (info_verbose || debug_linux_nat)
876 target_terminal_ours ();
878 fprintf_filtered (gdb_stdlog, _("\
879 Attaching after process %d vfork to child process %d.\n"),
880 parent_pid, child_pid);
882 fprintf_filtered (gdb_stdlog, _("\
883 Attaching after process %d fork to child process %d.\n"),
884 parent_pid, child_pid);
887 /* Add the new inferior first, so that the target_detach below
888 doesn't unpush the target. */
890 child_inf = add_inferior (child_pid);
892 parent_inf = current_inferior ();
893 child_inf->attach_flag = parent_inf->attach_flag;
894 copy_terminal_info (child_inf, parent_inf);
896 parent_pspace = parent_inf->pspace;
898 /* If we're vforking, we want to hold on to the parent until the
899 child exits or execs. At child exec or exit time we can
900 remove the old breakpoints from the parent and detach or
901 resume debugging it. Otherwise, detach the parent now; we'll
902 want to reuse it's program/address spaces, but we can't set
903 them to the child before removing breakpoints from the
904 parent, otherwise, the breakpoints module could decide to
905 remove breakpoints from the wrong process (since they'd be
906 assigned to the same address space). */
910 gdb_assert (child_inf->vfork_parent == NULL);
911 gdb_assert (parent_inf->vfork_child == NULL);
912 child_inf->vfork_parent = parent_inf;
913 child_inf->pending_detach = 0;
914 parent_inf->vfork_child = child_inf;
915 parent_inf->pending_detach = detach_fork;
916 parent_inf->waiting_for_vfork_done = 0;
918 else if (detach_fork)
919 target_detach (NULL, 0);
921 /* Note that the detach above makes PARENT_INF dangling. */
923 /* Add the child thread to the appropriate lists, and switch to
924 this new thread, before cloning the program space, and
925 informing the solib layer about this new process. */
927 inferior_ptid = ptid_build (child_pid, child_pid, 0);
928 add_thread (inferior_ptid);
929 lp = add_lwp (inferior_ptid);
933 /* If this is a vfork child, then the address-space is shared
934 with the parent. If we detached from the parent, then we can
935 reuse the parent's program/address spaces. */
936 if (has_vforked || detach_fork)
938 child_inf->pspace = parent_pspace;
939 child_inf->aspace = child_inf->pspace->aspace;
943 child_inf->aspace = new_address_space ();
944 child_inf->pspace = add_program_space (child_inf->aspace);
945 child_inf->removable = 1;
946 set_current_program_space (child_inf->pspace);
947 clone_program_space (child_inf->pspace, parent_pspace);
949 /* Let the shared library layer (solib-svr4) learn about
950 this new process, relocate the cloned exec, pull in
951 shared libraries, and install the solib event breakpoint.
952 If a "cloned-VM" event was propagated better throughout
953 the core, this wouldn't be required. */
954 solib_create_inferior_hook ();
957 /* Let the thread_db layer learn about this new process. */
958 check_for_thread_db ();
961 restore_child_signals_mask (&prev_mask);
967 linux_child_insert_fork_catchpoint (int pid)
969 if (! linux_supports_tracefork (pid))
970 error (_("Your system does not support fork catchpoints."));
974 linux_child_insert_vfork_catchpoint (int pid)
976 if (!linux_supports_tracefork (pid))
977 error (_("Your system does not support vfork catchpoints."));
981 linux_child_insert_exec_catchpoint (int pid)
983 if (!linux_supports_tracefork (pid))
984 error (_("Your system does not support exec catchpoints."));
988 linux_child_set_syscall_catchpoint (int pid, int needed, int any_count,
989 int table_size, int *table)
991 if (! linux_supports_tracesysgood (pid))
992 error (_("Your system does not support syscall catchpoints."));
993 /* On GNU/Linux, we ignore the arguments. It means that we only
994 enable the syscall catchpoints, but do not disable them.
996 Also, we do not use the `table' information because we do not
997 filter system calls here. We let GDB do the logic for us. */
1001 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
1002 are processes sharing the same VM space. A multi-threaded process
1003 is basically a group of such processes. However, such a grouping
1004 is almost entirely a user-space issue; the kernel doesn't enforce
1005 such a grouping at all (this might change in the future). In
1006 general, we'll rely on the threads library (i.e. the GNU/Linux
1007 Threads library) to provide such a grouping.
1009 It is perfectly well possible to write a multi-threaded application
1010 without the assistance of a threads library, by using the clone
1011 system call directly. This module should be able to give some
1012 rudimentary support for debugging such applications if developers
1013 specify the CLONE_PTRACE flag in the clone system call, and are
1014 using the Linux kernel 2.4 or above.
1016 Note that there are some peculiarities in GNU/Linux that affect
1019 - In general one should specify the __WCLONE flag to waitpid in
1020 order to make it report events for any of the cloned processes
1021 (and leave it out for the initial process). However, if a cloned
1022 process has exited the exit status is only reported if the
1023 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
1024 we cannot use it since GDB must work on older systems too.
1026 - When a traced, cloned process exits and is waited for by the
1027 debugger, the kernel reassigns it to the original parent and
1028 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
1029 library doesn't notice this, which leads to the "zombie problem":
1030 When debugged a multi-threaded process that spawns a lot of
1031 threads will run out of processes, even if the threads exit,
1032 because the "zombies" stay around. */
1034 /* List of known LWPs. */
1035 struct lwp_info *lwp_list;
1038 /* Original signal mask. */
1039 static sigset_t normal_mask;
1041 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
1042 _initialize_linux_nat. */
1043 static sigset_t suspend_mask;
1045 /* Signals to block to make that sigsuspend work. */
1046 static sigset_t blocked_mask;
1048 /* SIGCHLD action. */
1049 struct sigaction sigchld_action;
1051 /* Block child signals (SIGCHLD and linux threads signals), and store
1052 the previous mask in PREV_MASK. */
1055 block_child_signals (sigset_t *prev_mask)
1057 /* Make sure SIGCHLD is blocked. */
1058 if (!sigismember (&blocked_mask, SIGCHLD))
1059 sigaddset (&blocked_mask, SIGCHLD);
1061 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
1064 /* Restore child signals mask, previously returned by
1065 block_child_signals. */
1068 restore_child_signals_mask (sigset_t *prev_mask)
1070 sigprocmask (SIG_SETMASK, prev_mask, NULL);
1074 /* Prototypes for local functions. */
1075 static int stop_wait_callback (struct lwp_info *lp, void *data);
1076 static int linux_thread_alive (ptid_t ptid);
1077 static char *linux_child_pid_to_exec_file (int pid);
1078 static int cancel_breakpoint (struct lwp_info *lp);
1081 /* Convert wait status STATUS to a string. Used for printing debug
1085 status_to_str (int status)
1087 static char buf[64];
1089 if (WIFSTOPPED (status))
1091 if (WSTOPSIG (status) == SYSCALL_SIGTRAP)
1092 snprintf (buf, sizeof (buf), "%s (stopped at syscall)",
1093 strsignal (SIGTRAP));
1095 snprintf (buf, sizeof (buf), "%s (stopped)",
1096 strsignal (WSTOPSIG (status)));
1098 else if (WIFSIGNALED (status))
1099 snprintf (buf, sizeof (buf), "%s (terminated)",
1100 strsignal (WSTOPSIG (status)));
1102 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
1107 /* Initialize the list of LWPs. Note that this module, contrary to
1108 what GDB's generic threads layer does for its thread list,
1109 re-initializes the LWP lists whenever we mourn or detach (which
1110 doesn't involve mourning) the inferior. */
1113 init_lwp_list (void)
1115 struct lwp_info *lp, *lpnext;
1117 for (lp = lwp_list; lp; lp = lpnext)
1126 /* Remove all LWPs belong to PID from the lwp list. */
1129 purge_lwp_list (int pid)
1131 struct lwp_info *lp, *lpprev, *lpnext;
1135 for (lp = lwp_list; lp; lp = lpnext)
1139 if (ptid_get_pid (lp->ptid) == pid)
1142 lwp_list = lp->next;
1144 lpprev->next = lp->next;
1153 /* Return the number of known LWPs in the tgid given by PID. */
1159 struct lwp_info *lp;
1161 for (lp = lwp_list; lp; lp = lp->next)
1162 if (ptid_get_pid (lp->ptid) == pid)
1168 /* Add the LWP specified by PID to the list. Return a pointer to the
1169 structure describing the new LWP. The LWP should already be stopped
1170 (with an exception for the very first LWP). */
1172 static struct lwp_info *
1173 add_lwp (ptid_t ptid)
1175 struct lwp_info *lp;
1177 gdb_assert (is_lwp (ptid));
1179 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
1181 memset (lp, 0, sizeof (struct lwp_info));
1183 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
1187 lp->next = lwp_list;
1190 if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
1191 linux_nat_new_thread (ptid);
1196 /* Remove the LWP specified by PID from the list. */
1199 delete_lwp (ptid_t ptid)
1201 struct lwp_info *lp, *lpprev;
1205 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
1206 if (ptid_equal (lp->ptid, ptid))
1213 lpprev->next = lp->next;
1215 lwp_list = lp->next;
1220 /* Return a pointer to the structure describing the LWP corresponding
1221 to PID. If no corresponding LWP could be found, return NULL. */
1223 static struct lwp_info *
1224 find_lwp_pid (ptid_t ptid)
1226 struct lwp_info *lp;
1230 lwp = GET_LWP (ptid);
1232 lwp = GET_PID (ptid);
1234 for (lp = lwp_list; lp; lp = lp->next)
1235 if (lwp == GET_LWP (lp->ptid))
1241 /* Returns true if PTID matches filter FILTER. FILTER can be the wild
1242 card MINUS_ONE_PTID (all ptid match it); can be a ptid representing
1243 a process (ptid_is_pid returns true), in which case, all lwps of
1244 that give process match, lwps of other process do not; or, it can
1245 represent a specific thread, in which case, only that thread will
1246 match true. PTID must represent an LWP, it can never be a wild
1250 ptid_match (ptid_t ptid, ptid_t filter)
1252 /* Since both parameters have the same type, prevent easy mistakes
1254 gdb_assert (!ptid_equal (ptid, minus_one_ptid)
1255 && !ptid_equal (ptid, null_ptid));
1257 if (ptid_equal (filter, minus_one_ptid))
1259 if (ptid_is_pid (filter)
1260 && ptid_get_pid (ptid) == ptid_get_pid (filter))
1262 else if (ptid_equal (ptid, filter))
1268 /* Call CALLBACK with its second argument set to DATA for every LWP in
1269 the list. If CALLBACK returns 1 for a particular LWP, return a
1270 pointer to the structure describing that LWP immediately.
1271 Otherwise return NULL. */
1274 iterate_over_lwps (ptid_t filter,
1275 int (*callback) (struct lwp_info *, void *),
1278 struct lwp_info *lp, *lpnext;
1280 for (lp = lwp_list; lp; lp = lpnext)
1284 if (ptid_match (lp->ptid, filter))
1286 if ((*callback) (lp, data))
1294 /* Update our internal state when changing from one checkpoint to
1295 another indicated by NEW_PTID. We can only switch single-threaded
1296 applications, so we only create one new LWP, and the previous list
1300 linux_nat_switch_fork (ptid_t new_ptid)
1302 struct lwp_info *lp;
1304 purge_lwp_list (GET_PID (inferior_ptid));
1306 lp = add_lwp (new_ptid);
1309 /* This changes the thread's ptid while preserving the gdb thread
1310 num. Also changes the inferior pid, while preserving the
1312 thread_change_ptid (inferior_ptid, new_ptid);
1314 /* We've just told GDB core that the thread changed target id, but,
1315 in fact, it really is a different thread, with different register
1317 registers_changed ();
1320 /* Handle the exit of a single thread LP. */
1323 exit_lwp (struct lwp_info *lp)
1325 struct thread_info *th = find_thread_ptid (lp->ptid);
1329 if (print_thread_events)
1330 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1332 delete_thread (lp->ptid);
1335 delete_lwp (lp->ptid);
1338 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1341 linux_proc_get_tgid (int lwpid)
1347 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
1348 status_file = fopen (buf, "r");
1349 if (status_file != NULL)
1351 while (fgets (buf, sizeof (buf), status_file))
1353 if (strncmp (buf, "Tgid:", 5) == 0)
1355 tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
1360 fclose (status_file);
1366 /* Detect `T (stopped)' in `/proc/PID/status'.
1367 Other states including `T (tracing stop)' are reported as false. */
1370 pid_is_stopped (pid_t pid)
1376 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1377 status_file = fopen (buf, "r");
1378 if (status_file != NULL)
1382 while (fgets (buf, sizeof (buf), status_file))
1384 if (strncmp (buf, "State:", 6) == 0)
1390 if (have_state && strstr (buf, "T (stopped)") != NULL)
1392 fclose (status_file);
1397 /* Wait for the LWP specified by LP, which we have just attached to.
1398 Returns a wait status for that LWP, to cache. */
1401 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1404 pid_t new_pid, pid = GET_LWP (ptid);
1407 if (pid_is_stopped (pid))
1409 if (debug_linux_nat)
1410 fprintf_unfiltered (gdb_stdlog,
1411 "LNPAW: Attaching to a stopped process\n");
1413 /* The process is definitely stopped. It is in a job control
1414 stop, unless the kernel predates the TASK_STOPPED /
1415 TASK_TRACED distinction, in which case it might be in a
1416 ptrace stop. Make sure it is in a ptrace stop; from there we
1417 can kill it, signal it, et cetera.
1419 First make sure there is a pending SIGSTOP. Since we are
1420 already attached, the process can not transition from stopped
1421 to running without a PTRACE_CONT; so we know this signal will
1422 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1423 probably already in the queue (unless this kernel is old
1424 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1425 is not an RT signal, it can only be queued once. */
1426 kill_lwp (pid, SIGSTOP);
1428 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1429 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1430 ptrace (PTRACE_CONT, pid, 0, 0);
1433 /* Make sure the initial process is stopped. The user-level threads
1434 layer might want to poke around in the inferior, and that won't
1435 work if things haven't stabilized yet. */
1436 new_pid = my_waitpid (pid, &status, 0);
1437 if (new_pid == -1 && errno == ECHILD)
1440 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1442 /* Try again with __WCLONE to check cloned processes. */
1443 new_pid = my_waitpid (pid, &status, __WCLONE);
1447 gdb_assert (pid == new_pid);
1449 if (!WIFSTOPPED (status))
1451 /* The pid we tried to attach has apparently just exited. */
1452 if (debug_linux_nat)
1453 fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s",
1454 pid, status_to_str (status));
1458 if (WSTOPSIG (status) != SIGSTOP)
1461 if (debug_linux_nat)
1462 fprintf_unfiltered (gdb_stdlog,
1463 "LNPAW: Received %s after attaching\n",
1464 status_to_str (status));
1470 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1471 if the new LWP could not be attached. */
1474 lin_lwp_attach_lwp (ptid_t ptid)
1476 struct lwp_info *lp;
1479 gdb_assert (is_lwp (ptid));
1481 block_child_signals (&prev_mask);
1483 lp = find_lwp_pid (ptid);
1485 /* We assume that we're already attached to any LWP that has an id
1486 equal to the overall process id, and to any LWP that is already
1487 in our list of LWPs. If we're not seeing exit events from threads
1488 and we've had PID wraparound since we last tried to stop all threads,
1489 this assumption might be wrong; fortunately, this is very unlikely
1491 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1493 int status, cloned = 0, signalled = 0;
1495 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1497 /* If we fail to attach to the thread, issue a warning,
1498 but continue. One way this can happen is if thread
1499 creation is interrupted; as of Linux kernel 2.6.19, a
1500 bug may place threads in the thread list and then fail
1502 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1503 safe_strerror (errno));
1504 restore_child_signals_mask (&prev_mask);
1508 if (debug_linux_nat)
1509 fprintf_unfiltered (gdb_stdlog,
1510 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1511 target_pid_to_str (ptid));
1513 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1514 if (!WIFSTOPPED (status))
1517 lp = add_lwp (ptid);
1519 lp->cloned = cloned;
1520 lp->signalled = signalled;
1521 if (WSTOPSIG (status) != SIGSTOP)
1524 lp->status = status;
1527 target_post_attach (GET_LWP (lp->ptid));
1529 if (debug_linux_nat)
1531 fprintf_unfiltered (gdb_stdlog,
1532 "LLAL: waitpid %s received %s\n",
1533 target_pid_to_str (ptid),
1534 status_to_str (status));
1539 /* We assume that the LWP representing the original process is
1540 already stopped. Mark it as stopped in the data structure
1541 that the GNU/linux ptrace layer uses to keep track of
1542 threads. Note that this won't have already been done since
1543 the main thread will have, we assume, been stopped by an
1544 attach from a different layer. */
1546 lp = add_lwp (ptid);
1550 restore_child_signals_mask (&prev_mask);
1555 linux_nat_create_inferior (struct target_ops *ops,
1556 char *exec_file, char *allargs, char **env,
1559 #ifdef HAVE_PERSONALITY
1560 int personality_orig = 0, personality_set = 0;
1561 #endif /* HAVE_PERSONALITY */
1563 /* The fork_child mechanism is synchronous and calls target_wait, so
1564 we have to mask the async mode. */
1566 #ifdef HAVE_PERSONALITY
1567 if (disable_randomization)
1570 personality_orig = personality (0xffffffff);
1571 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1573 personality_set = 1;
1574 personality (personality_orig | ADDR_NO_RANDOMIZE);
1576 if (errno != 0 || (personality_set
1577 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1578 warning (_("Error disabling address space randomization: %s"),
1579 safe_strerror (errno));
1581 #endif /* HAVE_PERSONALITY */
1583 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1585 #ifdef HAVE_PERSONALITY
1586 if (personality_set)
1589 personality (personality_orig);
1591 warning (_("Error restoring address space randomization: %s"),
1592 safe_strerror (errno));
1594 #endif /* HAVE_PERSONALITY */
1598 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1600 struct lwp_info *lp;
1604 linux_ops->to_attach (ops, args, from_tty);
1606 /* The ptrace base target adds the main thread with (pid,0,0)
1607 format. Decorate it with lwp info. */
1608 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1609 thread_change_ptid (inferior_ptid, ptid);
1611 /* Add the initial process as the first LWP to the list. */
1612 lp = add_lwp (ptid);
1614 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1616 if (!WIFSTOPPED (status))
1618 if (WIFEXITED (status))
1620 int exit_code = WEXITSTATUS (status);
1622 target_terminal_ours ();
1623 target_mourn_inferior ();
1625 error (_("Unable to attach: program exited normally."));
1627 error (_("Unable to attach: program exited with code %d."),
1630 else if (WIFSIGNALED (status))
1632 enum target_signal signo;
1634 target_terminal_ours ();
1635 target_mourn_inferior ();
1637 signo = target_signal_from_host (WTERMSIG (status));
1638 error (_("Unable to attach: program terminated with signal "
1640 target_signal_to_name (signo),
1641 target_signal_to_string (signo));
1644 internal_error (__FILE__, __LINE__,
1645 _("unexpected status %d for PID %ld"),
1646 status, (long) GET_LWP (ptid));
1651 /* Save the wait status to report later. */
1653 if (debug_linux_nat)
1654 fprintf_unfiltered (gdb_stdlog,
1655 "LNA: waitpid %ld, saving status %s\n",
1656 (long) GET_PID (lp->ptid), status_to_str (status));
1658 lp->status = status;
1660 if (target_can_async_p ())
1661 target_async (inferior_event_handler, 0);
1664 /* Get pending status of LP. */
1666 get_pending_status (struct lwp_info *lp, int *status)
1668 enum target_signal signo = TARGET_SIGNAL_0;
1670 /* If we paused threads momentarily, we may have stored pending
1671 events in lp->status or lp->waitstatus (see stop_wait_callback),
1672 and GDB core hasn't seen any signal for those threads.
1673 Otherwise, the last signal reported to the core is found in the
1674 thread object's stop_signal.
1676 There's a corner case that isn't handled here at present. Only
1677 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1678 stop_signal make sense as a real signal to pass to the inferior.
1679 Some catchpoint related events, like
1680 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1681 to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1682 those traps are debug API (ptrace in our case) related and
1683 induced; the inferior wouldn't see them if it wasn't being
1684 traced. Hence, we should never pass them to the inferior, even
1685 when set to pass state. Since this corner case isn't handled by
1686 infrun.c when proceeding with a signal, for consistency, neither
1687 do we handle it here (or elsewhere in the file we check for
1688 signal pass state). Normally SIGTRAP isn't set to pass state, so
1689 this is really a corner case. */
1691 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1692 signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */
1693 else if (lp->status)
1694 signo = target_signal_from_host (WSTOPSIG (lp->status));
1695 else if (non_stop && !is_executing (lp->ptid))
1697 struct thread_info *tp = find_thread_ptid (lp->ptid);
1698 signo = tp->stop_signal;
1702 struct target_waitstatus last;
1705 get_last_target_status (&last_ptid, &last);
1707 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1709 struct thread_info *tp = find_thread_ptid (lp->ptid);
1710 signo = tp->stop_signal;
1716 if (signo == TARGET_SIGNAL_0)
1718 if (debug_linux_nat)
1719 fprintf_unfiltered (gdb_stdlog,
1720 "GPT: lwp %s has no pending signal\n",
1721 target_pid_to_str (lp->ptid));
1723 else if (!signal_pass_state (signo))
1725 if (debug_linux_nat)
1726 fprintf_unfiltered (gdb_stdlog, "\
1727 GPT: lwp %s had signal %s, but it is in no pass state\n",
1728 target_pid_to_str (lp->ptid),
1729 target_signal_to_string (signo));
1733 *status = W_STOPCODE (target_signal_to_host (signo));
1735 if (debug_linux_nat)
1736 fprintf_unfiltered (gdb_stdlog,
1737 "GPT: lwp %s has pending signal %s\n",
1738 target_pid_to_str (lp->ptid),
1739 target_signal_to_string (signo));
1746 detach_callback (struct lwp_info *lp, void *data)
1748 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1750 if (debug_linux_nat && lp->status)
1751 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1752 strsignal (WSTOPSIG (lp->status)),
1753 target_pid_to_str (lp->ptid));
1755 /* If there is a pending SIGSTOP, get rid of it. */
1758 if (debug_linux_nat)
1759 fprintf_unfiltered (gdb_stdlog,
1760 "DC: Sending SIGCONT to %s\n",
1761 target_pid_to_str (lp->ptid));
1763 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1767 /* We don't actually detach from the LWP that has an id equal to the
1768 overall process id just yet. */
1769 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1773 /* Pass on any pending signal for this LWP. */
1774 get_pending_status (lp, &status);
1777 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1778 WSTOPSIG (status)) < 0)
1779 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1780 safe_strerror (errno));
1782 if (debug_linux_nat)
1783 fprintf_unfiltered (gdb_stdlog,
1784 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1785 target_pid_to_str (lp->ptid),
1786 strsignal (WSTOPSIG (status)));
1788 delete_lwp (lp->ptid);
1795 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1799 enum target_signal sig;
1800 struct lwp_info *main_lwp;
1802 pid = GET_PID (inferior_ptid);
1804 if (target_can_async_p ())
1805 linux_nat_async (NULL, 0);
1807 /* Stop all threads before detaching. ptrace requires that the
1808 thread is stopped to sucessfully detach. */
1809 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1810 /* ... and wait until all of them have reported back that
1811 they're no longer running. */
1812 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1814 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1816 /* Only the initial process should be left right now. */
1817 gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1);
1819 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1821 /* Pass on any pending signal for the last LWP. */
1822 if ((args == NULL || *args == '\0')
1823 && get_pending_status (main_lwp, &status) != -1
1824 && WIFSTOPPED (status))
1826 /* Put the signal number in ARGS so that inf_ptrace_detach will
1827 pass it along with PTRACE_DETACH. */
1829 sprintf (args, "%d", (int) WSTOPSIG (status));
1830 fprintf_unfiltered (gdb_stdlog,
1831 "LND: Sending signal %s to %s\n",
1833 target_pid_to_str (main_lwp->ptid));
1836 delete_lwp (main_lwp->ptid);
1838 if (forks_exist_p ())
1840 /* Multi-fork case. The current inferior_ptid is being detached
1841 from, but there are other viable forks to debug. Detach from
1842 the current fork, and context-switch to the first
1844 linux_fork_detach (args, from_tty);
1846 if (non_stop && target_can_async_p ())
1847 target_async (inferior_event_handler, 0);
1850 linux_ops->to_detach (ops, args, from_tty);
1856 resume_callback (struct lwp_info *lp, void *data)
1858 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
1860 if (lp->stopped && inf->vfork_child != NULL)
1862 if (debug_linux_nat)
1863 fprintf_unfiltered (gdb_stdlog,
1864 "RC: Not resuming %s (vfork parent)\n",
1865 target_pid_to_str (lp->ptid));
1867 else if (lp->stopped && lp->status == 0)
1869 if (debug_linux_nat)
1870 fprintf_unfiltered (gdb_stdlog,
1871 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1872 target_pid_to_str (lp->ptid));
1874 linux_ops->to_resume (linux_ops,
1875 pid_to_ptid (GET_LWP (lp->ptid)),
1876 0, TARGET_SIGNAL_0);
1877 if (debug_linux_nat)
1878 fprintf_unfiltered (gdb_stdlog,
1879 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1880 target_pid_to_str (lp->ptid));
1883 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1885 else if (lp->stopped && debug_linux_nat)
1886 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
1887 target_pid_to_str (lp->ptid));
1888 else if (debug_linux_nat)
1889 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
1890 target_pid_to_str (lp->ptid));
1896 resume_clear_callback (struct lwp_info *lp, void *data)
1903 resume_set_callback (struct lwp_info *lp, void *data)
1910 linux_nat_resume (struct target_ops *ops,
1911 ptid_t ptid, int step, enum target_signal signo)
1914 struct lwp_info *lp;
1917 if (debug_linux_nat)
1918 fprintf_unfiltered (gdb_stdlog,
1919 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1920 step ? "step" : "resume",
1921 target_pid_to_str (ptid),
1922 signo ? strsignal (signo) : "0",
1923 target_pid_to_str (inferior_ptid));
1925 block_child_signals (&prev_mask);
1927 /* A specific PTID means `step only this process id'. */
1928 resume_many = (ptid_equal (minus_one_ptid, ptid)
1929 || ptid_is_pid (ptid));
1933 /* Mark the lwps we're resuming as resumed. */
1934 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
1935 iterate_over_lwps (ptid, resume_set_callback, NULL);
1938 iterate_over_lwps (minus_one_ptid, resume_set_callback, NULL);
1940 /* See if it's the current inferior that should be handled
1943 lp = find_lwp_pid (inferior_ptid);
1945 lp = find_lwp_pid (ptid);
1946 gdb_assert (lp != NULL);
1948 /* Remember if we're stepping. */
1951 /* If we have a pending wait status for this thread, there is no
1952 point in resuming the process. But first make sure that
1953 linux_nat_wait won't preemptively handle the event - we
1954 should never take this short-circuit if we are going to
1955 leave LP running, since we have skipped resuming all the
1956 other threads. This bit of code needs to be synchronized
1957 with linux_nat_wait. */
1959 if (lp->status && WIFSTOPPED (lp->status))
1962 struct inferior *inf;
1964 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
1966 saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
1968 /* Defer to common code if we're gaining control of the
1970 if (inf->stop_soon == NO_STOP_QUIETLY
1971 && signal_stop_state (saved_signo) == 0
1972 && signal_print_state (saved_signo) == 0
1973 && signal_pass_state (saved_signo) == 1)
1975 if (debug_linux_nat)
1976 fprintf_unfiltered (gdb_stdlog,
1977 "LLR: Not short circuiting for ignored "
1978 "status 0x%x\n", lp->status);
1980 /* FIXME: What should we do if we are supposed to continue
1981 this thread with a signal? */
1982 gdb_assert (signo == TARGET_SIGNAL_0);
1983 signo = saved_signo;
1988 if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
1990 /* FIXME: What should we do if we are supposed to continue
1991 this thread with a signal? */
1992 gdb_assert (signo == TARGET_SIGNAL_0);
1994 if (debug_linux_nat)
1995 fprintf_unfiltered (gdb_stdlog,
1996 "LLR: Short circuiting for status 0x%x\n",
1999 restore_child_signals_mask (&prev_mask);
2000 if (target_can_async_p ())
2002 target_async (inferior_event_handler, 0);
2003 /* Tell the event loop we have something to process. */
2009 /* Mark LWP as not stopped to prevent it from being continued by
2014 iterate_over_lwps (ptid, resume_callback, NULL);
2016 /* Convert to something the lower layer understands. */
2017 ptid = pid_to_ptid (GET_LWP (lp->ptid));
2019 linux_ops->to_resume (linux_ops, ptid, step, signo);
2020 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2022 if (debug_linux_nat)
2023 fprintf_unfiltered (gdb_stdlog,
2024 "LLR: %s %s, %s (resume event thread)\n",
2025 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2026 target_pid_to_str (ptid),
2027 signo ? strsignal (signo) : "0");
2029 restore_child_signals_mask (&prev_mask);
2030 if (target_can_async_p ())
2031 target_async (inferior_event_handler, 0);
2034 /* Issue kill to specified lwp. */
2036 static int tkill_failed;
2039 kill_lwp (int lwpid, int signo)
2043 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2044 fails, then we are not using nptl threads and we should be using kill. */
2046 #ifdef HAVE_TKILL_SYSCALL
2049 int ret = syscall (__NR_tkill, lwpid, signo);
2050 if (errno != ENOSYS)
2057 return kill (lwpid, signo);
2060 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
2061 event, check if the core is interested in it: if not, ignore the
2062 event, and keep waiting; otherwise, we need to toggle the LWP's
2063 syscall entry/exit status, since the ptrace event itself doesn't
2064 indicate it, and report the trap to higher layers. */
2067 linux_handle_syscall_trap (struct lwp_info *lp, int stopping)
2069 struct target_waitstatus *ourstatus = &lp->waitstatus;
2070 struct gdbarch *gdbarch = target_thread_architecture (lp->ptid);
2071 int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid);
2075 /* If we're stopping threads, there's a SIGSTOP pending, which
2076 makes it so that the LWP reports an immediate syscall return,
2077 followed by the SIGSTOP. Skip seeing that "return" using
2078 PTRACE_CONT directly, and let stop_wait_callback collect the
2079 SIGSTOP. Later when the thread is resumed, a new syscall
2080 entry event. If we didn't do this (and returned 0), we'd
2081 leave a syscall entry pending, and our caller, by using
2082 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
2083 itself. Later, when the user re-resumes this LWP, we'd see
2084 another syscall entry event and we'd mistake it for a return.
2086 If stop_wait_callback didn't force the SIGSTOP out of the LWP
2087 (leaving immediately with LWP->signalled set, without issuing
2088 a PTRACE_CONT), it would still be problematic to leave this
2089 syscall enter pending, as later when the thread is resumed,
2090 it would then see the same syscall exit mentioned above,
2091 followed by the delayed SIGSTOP, while the syscall didn't
2092 actually get to execute. It seems it would be even more
2093 confusing to the user. */
2095 if (debug_linux_nat)
2096 fprintf_unfiltered (gdb_stdlog,
2097 "LHST: ignoring syscall %d "
2098 "for LWP %ld (stopping threads), "
2099 "resuming with PTRACE_CONT for SIGSTOP\n",
2101 GET_LWP (lp->ptid));
2103 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2104 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2108 if (catch_syscall_enabled ())
2110 /* Always update the entry/return state, even if this particular
2111 syscall isn't interesting to the core now. In async mode,
2112 the user could install a new catchpoint for this syscall
2113 between syscall enter/return, and we'll need to know to
2114 report a syscall return if that happens. */
2115 lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2116 ? TARGET_WAITKIND_SYSCALL_RETURN
2117 : TARGET_WAITKIND_SYSCALL_ENTRY);
2119 if (catching_syscall_number (syscall_number))
2121 /* Alright, an event to report. */
2122 ourstatus->kind = lp->syscall_state;
2123 ourstatus->value.syscall_number = syscall_number;
2125 if (debug_linux_nat)
2126 fprintf_unfiltered (gdb_stdlog,
2127 "LHST: stopping for %s of syscall %d"
2129 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2130 ? "entry" : "return",
2132 GET_LWP (lp->ptid));
2136 if (debug_linux_nat)
2137 fprintf_unfiltered (gdb_stdlog,
2138 "LHST: ignoring %s of syscall %d "
2140 lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY
2141 ? "entry" : "return",
2143 GET_LWP (lp->ptid));
2147 /* If we had been syscall tracing, and hence used PT_SYSCALL
2148 before on this LWP, it could happen that the user removes all
2149 syscall catchpoints before we get to process this event.
2150 There are two noteworthy issues here:
2152 - When stopped at a syscall entry event, resuming with
2153 PT_STEP still resumes executing the syscall and reports a
2156 - Only PT_SYSCALL catches syscall enters. If we last
2157 single-stepped this thread, then this event can't be a
2158 syscall enter. If we last single-stepped this thread, this
2159 has to be a syscall exit.
2161 The points above mean that the next resume, be it PT_STEP or
2162 PT_CONTINUE, can not trigger a syscall trace event. */
2163 if (debug_linux_nat)
2164 fprintf_unfiltered (gdb_stdlog,
2165 "LHST: caught syscall event with no syscall catchpoints."
2166 " %d for LWP %ld, ignoring\n",
2168 GET_LWP (lp->ptid));
2169 lp->syscall_state = TARGET_WAITKIND_IGNORE;
2172 /* The core isn't interested in this event. For efficiency, avoid
2173 stopping all threads only to have the core resume them all again.
2174 Since we're not stopping threads, if we're still syscall tracing
2175 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
2176 subsequent syscall. Simply resume using the inf-ptrace layer,
2177 which knows when to use PT_SYSCALL or PT_CONTINUE. */
2179 /* Note that gdbarch_get_syscall_number may access registers, hence
2181 registers_changed ();
2182 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2183 lp->step, TARGET_SIGNAL_0);
2187 /* Handle a GNU/Linux extended wait response. If we see a clone
2188 event, we need to add the new LWP to our list (and not report the
2189 trap to higher layers). This function returns non-zero if the
2190 event should be ignored and we should wait again. If STOPPING is
2191 true, the new LWP remains stopped, otherwise it is continued. */
2194 linux_handle_extended_wait (struct lwp_info *lp, int status,
2197 int pid = GET_LWP (lp->ptid);
2198 struct target_waitstatus *ourstatus = &lp->waitstatus;
2199 struct lwp_info *new_lp = NULL;
2200 int event = status >> 16;
2202 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
2203 || event == PTRACE_EVENT_CLONE)
2205 unsigned long new_pid;
2208 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
2210 /* If we haven't already seen the new PID stop, wait for it now. */
2211 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
2213 /* The new child has a pending SIGSTOP. We can't affect it until it
2214 hits the SIGSTOP, but we're already attached. */
2215 ret = my_waitpid (new_pid, &status,
2216 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
2218 perror_with_name (_("waiting for new child"));
2219 else if (ret != new_pid)
2220 internal_error (__FILE__, __LINE__,
2221 _("wait returned unexpected PID %d"), ret);
2222 else if (!WIFSTOPPED (status))
2223 internal_error (__FILE__, __LINE__,
2224 _("wait returned unexpected status 0x%x"), status);
2227 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
2229 if (event == PTRACE_EVENT_FORK
2230 && linux_fork_checkpointing_p (GET_PID (lp->ptid)))
2232 struct fork_info *fp;
2234 /* Handle checkpointing by linux-fork.c here as a special
2235 case. We don't want the follow-fork-mode or 'catch fork'
2236 to interfere with this. */
2238 /* This won't actually modify the breakpoint list, but will
2239 physically remove the breakpoints from the child. */
2240 detach_breakpoints (new_pid);
2242 /* Retain child fork in ptrace (stopped) state. */
2243 fp = find_fork_pid (new_pid);
2245 fp = add_fork (new_pid);
2247 /* Report as spurious, so that infrun doesn't want to follow
2248 this fork. We're actually doing an infcall in
2250 ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
2251 linux_enable_event_reporting (pid_to_ptid (new_pid));
2253 /* Report the stop to the core. */
2257 if (event == PTRACE_EVENT_FORK)
2258 ourstatus->kind = TARGET_WAITKIND_FORKED;
2259 else if (event == PTRACE_EVENT_VFORK)
2260 ourstatus->kind = TARGET_WAITKIND_VFORKED;
2263 struct cleanup *old_chain;
2265 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2266 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
2268 new_lp->stopped = 1;
2270 if (WSTOPSIG (status) != SIGSTOP)
2272 /* This can happen if someone starts sending signals to
2273 the new thread before it gets a chance to run, which
2274 have a lower number than SIGSTOP (e.g. SIGUSR1).
2275 This is an unlikely case, and harder to handle for
2276 fork / vfork than for clone, so we do not try - but
2277 we handle it for clone events here. We'll send
2278 the other signal on to the thread below. */
2280 new_lp->signalled = 1;
2287 /* Add the new thread to GDB's lists as soon as possible
2290 1) the frontend doesn't have to wait for a stop to
2293 2) we tag it with the correct running state. */
2295 /* If the thread_db layer is active, let it know about
2296 this new thread, and add it to GDB's list. */
2297 if (!thread_db_attach_lwp (new_lp->ptid))
2299 /* We're not using thread_db. Add it to GDB's
2301 target_post_attach (GET_LWP (new_lp->ptid));
2302 add_thread (new_lp->ptid);
2307 set_running (new_lp->ptid, 1);
2308 set_executing (new_lp->ptid, 1);
2312 /* Note the need to use the low target ops to resume, to
2313 handle resuming with PT_SYSCALL if we have syscall
2319 new_lp->stopped = 0;
2320 new_lp->resumed = 1;
2323 ? target_signal_from_host (WSTOPSIG (status))
2326 linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
2330 if (debug_linux_nat)
2331 fprintf_unfiltered (gdb_stdlog,
2332 "LHEW: Got clone event from LWP %ld, resuming\n",
2333 GET_LWP (lp->ptid));
2334 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2335 0, TARGET_SIGNAL_0);
2343 if (event == PTRACE_EVENT_EXEC)
2345 if (debug_linux_nat)
2346 fprintf_unfiltered (gdb_stdlog,
2347 "LHEW: Got exec event from LWP %ld\n",
2348 GET_LWP (lp->ptid));
2350 ourstatus->kind = TARGET_WAITKIND_EXECD;
2351 ourstatus->value.execd_pathname
2352 = xstrdup (linux_child_pid_to_exec_file (pid));
2357 if (event == PTRACE_EVENT_VFORK_DONE)
2359 if (current_inferior ()->waiting_for_vfork_done)
2361 if (debug_linux_nat)
2362 fprintf_unfiltered (gdb_stdlog, "\
2363 LHEW: Got expected PTRACE_EVENT_VFORK_DONE from LWP %ld: stopping\n",
2364 GET_LWP (lp->ptid));
2366 ourstatus->kind = TARGET_WAITKIND_VFORK_DONE;
2370 if (debug_linux_nat)
2371 fprintf_unfiltered (gdb_stdlog, "\
2372 LHEW: Got PTRACE_EVENT_VFORK_DONE from LWP %ld: resuming\n",
2373 GET_LWP (lp->ptid));
2374 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2378 internal_error (__FILE__, __LINE__,
2379 _("unknown ptrace event %d"), event);
2382 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2386 wait_lwp (struct lwp_info *lp)
2390 int thread_dead = 0;
2392 gdb_assert (!lp->stopped);
2393 gdb_assert (lp->status == 0);
2395 pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
2396 if (pid == -1 && errno == ECHILD)
2398 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
2399 if (pid == -1 && errno == ECHILD)
2401 /* The thread has previously exited. We need to delete it
2402 now because, for some vendor 2.4 kernels with NPTL
2403 support backported, there won't be an exit event unless
2404 it is the main thread. 2.6 kernels will report an exit
2405 event for each thread that exits, as expected. */
2407 if (debug_linux_nat)
2408 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
2409 target_pid_to_str (lp->ptid));
2415 gdb_assert (pid == GET_LWP (lp->ptid));
2417 if (debug_linux_nat)
2419 fprintf_unfiltered (gdb_stdlog,
2420 "WL: waitpid %s received %s\n",
2421 target_pid_to_str (lp->ptid),
2422 status_to_str (status));
2426 /* Check if the thread has exited. */
2427 if (WIFEXITED (status) || WIFSIGNALED (status))
2430 if (debug_linux_nat)
2431 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
2432 target_pid_to_str (lp->ptid));
2441 gdb_assert (WIFSTOPPED (status));
2443 /* Handle GNU/Linux's syscall SIGTRAPs. */
2444 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
2446 /* No longer need the sysgood bit. The ptrace event ends up
2447 recorded in lp->waitstatus if we care for it. We can carry
2448 on handling the event like a regular SIGTRAP from here
2450 status = W_STOPCODE (SIGTRAP);
2451 if (linux_handle_syscall_trap (lp, 1))
2452 return wait_lwp (lp);
2455 /* Handle GNU/Linux's extended waitstatus for trace events. */
2456 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2458 if (debug_linux_nat)
2459 fprintf_unfiltered (gdb_stdlog,
2460 "WL: Handling extended status 0x%06x\n",
2462 if (linux_handle_extended_wait (lp, status, 1))
2463 return wait_lwp (lp);
2469 /* Save the most recent siginfo for LP. This is currently only called
2470 for SIGTRAP; some ports use the si_addr field for
2471 target_stopped_data_address. In the future, it may also be used to
2472 restore the siginfo of requeued signals. */
2475 save_siginfo (struct lwp_info *lp)
2478 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2479 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2482 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2485 /* Send a SIGSTOP to LP. */
2488 stop_callback (struct lwp_info *lp, void *data)
2490 if (!lp->stopped && !lp->signalled)
2494 if (debug_linux_nat)
2496 fprintf_unfiltered (gdb_stdlog,
2497 "SC: kill %s **<SIGSTOP>**\n",
2498 target_pid_to_str (lp->ptid));
2501 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2502 if (debug_linux_nat)
2504 fprintf_unfiltered (gdb_stdlog,
2505 "SC: lwp kill %d %s\n",
2507 errno ? safe_strerror (errno) : "ERRNO-OK");
2511 gdb_assert (lp->status == 0);
2517 /* Return non-zero if LWP PID has a pending SIGINT. */
2520 linux_nat_has_pending_sigint (int pid)
2522 sigset_t pending, blocked, ignored;
2525 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2527 if (sigismember (&pending, SIGINT)
2528 && !sigismember (&ignored, SIGINT))
2534 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2537 set_ignore_sigint (struct lwp_info *lp, void *data)
2539 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2540 flag to consume the next one. */
2541 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2542 && WSTOPSIG (lp->status) == SIGINT)
2545 lp->ignore_sigint = 1;
2550 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2551 This function is called after we know the LWP has stopped; if the LWP
2552 stopped before the expected SIGINT was delivered, then it will never have
2553 arrived. Also, if the signal was delivered to a shared queue and consumed
2554 by a different thread, it will never be delivered to this LWP. */
2557 maybe_clear_ignore_sigint (struct lwp_info *lp)
2559 if (!lp->ignore_sigint)
2562 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2564 if (debug_linux_nat)
2565 fprintf_unfiltered (gdb_stdlog,
2566 "MCIS: Clearing bogus flag for %s\n",
2567 target_pid_to_str (lp->ptid));
2568 lp->ignore_sigint = 0;
2572 /* Wait until LP is stopped. */
2575 stop_wait_callback (struct lwp_info *lp, void *data)
2577 struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid));
2579 /* If this is a vfork parent, bail out, it is not going to report
2580 any SIGSTOP until the vfork is done with. */
2581 if (inf->vfork_child != NULL)
2588 status = wait_lwp (lp);
2592 if (lp->ignore_sigint && WIFSTOPPED (status)
2593 && WSTOPSIG (status) == SIGINT)
2595 lp->ignore_sigint = 0;
2598 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2599 if (debug_linux_nat)
2600 fprintf_unfiltered (gdb_stdlog,
2601 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2602 target_pid_to_str (lp->ptid),
2603 errno ? safe_strerror (errno) : "OK");
2605 return stop_wait_callback (lp, NULL);
2608 maybe_clear_ignore_sigint (lp);
2610 if (WSTOPSIG (status) != SIGSTOP)
2612 if (WSTOPSIG (status) == SIGTRAP)
2614 /* If a LWP other than the LWP that we're reporting an
2615 event for has hit a GDB breakpoint (as opposed to
2616 some random trap signal), then just arrange for it to
2617 hit it again later. We don't keep the SIGTRAP status
2618 and don't forward the SIGTRAP signal to the LWP. We
2619 will handle the current event, eventually we will
2620 resume all LWPs, and this one will get its breakpoint
2623 If we do not do this, then we run the risk that the
2624 user will delete or disable the breakpoint, but the
2625 thread will have already tripped on it. */
2627 /* Save the trap's siginfo in case we need it later. */
2630 /* Now resume this LWP and get the SIGSTOP event. */
2632 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2633 if (debug_linux_nat)
2635 fprintf_unfiltered (gdb_stdlog,
2636 "PTRACE_CONT %s, 0, 0 (%s)\n",
2637 target_pid_to_str (lp->ptid),
2638 errno ? safe_strerror (errno) : "OK");
2640 fprintf_unfiltered (gdb_stdlog,
2641 "SWC: Candidate SIGTRAP event in %s\n",
2642 target_pid_to_str (lp->ptid));
2644 /* Hold this event/waitstatus while we check to see if
2645 there are any more (we still want to get that SIGSTOP). */
2646 stop_wait_callback (lp, NULL);
2648 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2649 there's another event, throw it back into the
2653 if (debug_linux_nat)
2654 fprintf_unfiltered (gdb_stdlog,
2655 "SWC: kill %s, %s\n",
2656 target_pid_to_str (lp->ptid),
2657 status_to_str ((int) status));
2658 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2661 /* Save the sigtrap event. */
2662 lp->status = status;
2667 /* The thread was stopped with a signal other than
2668 SIGSTOP, and didn't accidentally trip a breakpoint. */
2670 if (debug_linux_nat)
2672 fprintf_unfiltered (gdb_stdlog,
2673 "SWC: Pending event %s in %s\n",
2674 status_to_str ((int) status),
2675 target_pid_to_str (lp->ptid));
2677 /* Now resume this LWP and get the SIGSTOP event. */
2679 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2680 if (debug_linux_nat)
2681 fprintf_unfiltered (gdb_stdlog,
2682 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2683 target_pid_to_str (lp->ptid),
2684 errno ? safe_strerror (errno) : "OK");
2686 /* Hold this event/waitstatus while we check to see if
2687 there are any more (we still want to get that SIGSTOP). */
2688 stop_wait_callback (lp, NULL);
2690 /* If the lp->status field is still empty, use it to
2691 hold this event. If not, then this event must be
2692 returned to the event queue of the LWP. */
2695 if (debug_linux_nat)
2697 fprintf_unfiltered (gdb_stdlog,
2698 "SWC: kill %s, %s\n",
2699 target_pid_to_str (lp->ptid),
2700 status_to_str ((int) status));
2702 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2705 lp->status = status;
2711 /* We caught the SIGSTOP that we intended to catch, so
2712 there's no SIGSTOP pending. */
2721 /* Return non-zero if LP has a wait status pending. */
2724 status_callback (struct lwp_info *lp, void *data)
2726 /* Only report a pending wait status if we pretend that this has
2727 indeed been resumed. */
2731 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2733 /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event,
2734 or a a pending process exit. Note that `W_EXITCODE(0,0) ==
2735 0', so a clean process exit can not be stored pending in
2736 lp->status, it is indistinguishable from
2737 no-pending-status. */
2741 if (lp->status != 0)
2747 /* Return non-zero if LP isn't stopped. */
2750 running_callback (struct lwp_info *lp, void *data)
2752 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2755 /* Count the LWP's that have had events. */
2758 count_events_callback (struct lwp_info *lp, void *data)
2762 gdb_assert (count != NULL);
2764 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2765 if (lp->status != 0 && lp->resumed
2766 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2772 /* Select the LWP (if any) that is currently being single-stepped. */
2775 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2777 if (lp->step && lp->status != 0)
2783 /* Select the Nth LWP that has had a SIGTRAP event. */
2786 select_event_lwp_callback (struct lwp_info *lp, void *data)
2788 int *selector = data;
2790 gdb_assert (selector != NULL);
2792 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2793 if (lp->status != 0 && lp->resumed
2794 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2795 if ((*selector)-- == 0)
2802 cancel_breakpoint (struct lwp_info *lp)
2804 /* Arrange for a breakpoint to be hit again later. We don't keep
2805 the SIGTRAP status and don't forward the SIGTRAP signal to the
2806 LWP. We will handle the current event, eventually we will resume
2807 this LWP, and this breakpoint will trap again.
2809 If we do not do this, then we run the risk that the user will
2810 delete or disable the breakpoint, but the LWP will have already
2813 struct regcache *regcache = get_thread_regcache (lp->ptid);
2814 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2817 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2818 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
2820 if (debug_linux_nat)
2821 fprintf_unfiltered (gdb_stdlog,
2822 "CB: Push back breakpoint for %s\n",
2823 target_pid_to_str (lp->ptid));
2825 /* Back up the PC if necessary. */
2826 if (gdbarch_decr_pc_after_break (gdbarch))
2827 regcache_write_pc (regcache, pc);
2835 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2837 struct lwp_info *event_lp = data;
2839 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2843 /* If a LWP other than the LWP that we're reporting an event for has
2844 hit a GDB breakpoint (as opposed to some random trap signal),
2845 then just arrange for it to hit it again later. We don't keep
2846 the SIGTRAP status and don't forward the SIGTRAP signal to the
2847 LWP. We will handle the current event, eventually we will resume
2848 all LWPs, and this one will get its breakpoint trap again.
2850 If we do not do this, then we run the risk that the user will
2851 delete or disable the breakpoint, but the LWP will have already
2854 if (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE
2856 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
2857 && cancel_breakpoint (lp))
2858 /* Throw away the SIGTRAP. */
2864 /* Select one LWP out of those that have events pending. */
2867 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2870 int random_selector;
2871 struct lwp_info *event_lp;
2873 /* Record the wait status for the original LWP. */
2874 (*orig_lp)->status = *status;
2876 /* Give preference to any LWP that is being single-stepped. */
2877 event_lp = iterate_over_lwps (filter,
2878 select_singlestep_lwp_callback, NULL);
2879 if (event_lp != NULL)
2881 if (debug_linux_nat)
2882 fprintf_unfiltered (gdb_stdlog,
2883 "SEL: Select single-step %s\n",
2884 target_pid_to_str (event_lp->ptid));
2888 /* No single-stepping LWP. Select one at random, out of those
2889 which have had SIGTRAP events. */
2891 /* First see how many SIGTRAP events we have. */
2892 iterate_over_lwps (filter, count_events_callback, &num_events);
2894 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2895 random_selector = (int)
2896 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2898 if (debug_linux_nat && num_events > 1)
2899 fprintf_unfiltered (gdb_stdlog,
2900 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2901 num_events, random_selector);
2903 event_lp = iterate_over_lwps (filter,
2904 select_event_lwp_callback,
2908 if (event_lp != NULL)
2910 /* Switch the event LWP. */
2911 *orig_lp = event_lp;
2912 *status = event_lp->status;
2915 /* Flush the wait status for the event LWP. */
2916 (*orig_lp)->status = 0;
2919 /* Return non-zero if LP has been resumed. */
2922 resumed_callback (struct lwp_info *lp, void *data)
2927 /* Stop an active thread, verify it still exists, then resume it. */
2930 stop_and_resume_callback (struct lwp_info *lp, void *data)
2932 struct lwp_info *ptr;
2934 if (!lp->stopped && !lp->signalled)
2936 stop_callback (lp, NULL);
2937 stop_wait_callback (lp, NULL);
2938 /* Resume if the lwp still exists. */
2939 for (ptr = lwp_list; ptr; ptr = ptr->next)
2942 resume_callback (lp, NULL);
2943 resume_set_callback (lp, NULL);
2949 /* Check if we should go on and pass this event to common code.
2950 Return the affected lwp if we are, or NULL otherwise. */
2951 static struct lwp_info *
2952 linux_nat_filter_event (int lwpid, int status, int options)
2954 struct lwp_info *lp;
2956 lp = find_lwp_pid (pid_to_ptid (lwpid));
2958 /* Check for stop events reported by a process we didn't already
2959 know about - anything not already in our LWP list.
2961 If we're expecting to receive stopped processes after
2962 fork, vfork, and clone events, then we'll just add the
2963 new one to our list and go back to waiting for the event
2964 to be reported - the stopped process might be returned
2965 from waitpid before or after the event is. */
2966 if (WIFSTOPPED (status) && !lp)
2968 linux_record_stopped_pid (lwpid, status);
2972 /* Make sure we don't report an event for the exit of an LWP not in
2973 our list, i.e. not part of the current process. This can happen
2974 if we detach from a program we original forked and then it
2976 if (!WIFSTOPPED (status) && !lp)
2979 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
2980 CLONE_PTRACE processes which do not use the thread library -
2981 otherwise we wouldn't find the new LWP this way. That doesn't
2982 currently work, and the following code is currently unreachable
2983 due to the two blocks above. If it's fixed some day, this code
2984 should be broken out into a function so that we can also pick up
2985 LWPs from the new interface. */
2988 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
2989 if (options & __WCLONE)
2992 gdb_assert (WIFSTOPPED (status)
2993 && WSTOPSIG (status) == SIGSTOP);
2996 if (!in_thread_list (inferior_ptid))
2998 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
2999 GET_PID (inferior_ptid));
3000 add_thread (inferior_ptid);
3003 add_thread (lp->ptid);
3006 /* Handle GNU/Linux's syscall SIGTRAPs. */
3007 if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP)
3009 /* No longer need the sysgood bit. The ptrace event ends up
3010 recorded in lp->waitstatus if we care for it. We can carry
3011 on handling the event like a regular SIGTRAP from here
3013 status = W_STOPCODE (SIGTRAP);
3014 if (linux_handle_syscall_trap (lp, 0))
3018 /* Handle GNU/Linux's extended waitstatus for trace events. */
3019 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
3021 if (debug_linux_nat)
3022 fprintf_unfiltered (gdb_stdlog,
3023 "LLW: Handling extended status 0x%06x\n",
3025 if (linux_handle_extended_wait (lp, status, 0))
3029 /* Save the trap's siginfo in case we need it later. */
3030 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
3033 /* Check if the thread has exited. */
3034 if ((WIFEXITED (status) || WIFSIGNALED (status))
3035 && num_lwps (GET_PID (lp->ptid)) > 1)
3037 /* If this is the main thread, we must stop all threads and verify
3038 if they are still alive. This is because in the nptl thread model
3039 on Linux 2.4, there is no signal issued for exiting LWPs
3040 other than the main thread. We only get the main thread exit
3041 signal once all child threads have already exited. If we
3042 stop all the threads and use the stop_wait_callback to check
3043 if they have exited we can determine whether this signal
3044 should be ignored or whether it means the end of the debugged
3045 application, regardless of which threading model is being
3047 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
3050 iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
3051 stop_and_resume_callback, NULL);
3054 if (debug_linux_nat)
3055 fprintf_unfiltered (gdb_stdlog,
3056 "LLW: %s exited.\n",
3057 target_pid_to_str (lp->ptid));
3059 if (num_lwps (GET_PID (lp->ptid)) > 1)
3061 /* If there is at least one more LWP, then the exit signal
3062 was not the end of the debugged application and should be
3069 /* Check if the current LWP has previously exited. In the nptl
3070 thread model, LWPs other than the main thread do not issue
3071 signals when they exit so we must check whenever the thread has
3072 stopped. A similar check is made in stop_wait_callback(). */
3073 if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
3075 ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid));
3077 if (debug_linux_nat)
3078 fprintf_unfiltered (gdb_stdlog,
3079 "LLW: %s exited.\n",
3080 target_pid_to_str (lp->ptid));
3084 /* Make sure there is at least one thread running. */
3085 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
3087 /* Discard the event. */
3091 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3092 an attempt to stop an LWP. */
3094 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
3096 if (debug_linux_nat)
3097 fprintf_unfiltered (gdb_stdlog,
3098 "LLW: Delayed SIGSTOP caught for %s.\n",
3099 target_pid_to_str (lp->ptid));
3101 /* This is a delayed SIGSTOP. */
3104 registers_changed ();
3106 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3107 lp->step, TARGET_SIGNAL_0);
3108 if (debug_linux_nat)
3109 fprintf_unfiltered (gdb_stdlog,
3110 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
3112 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3113 target_pid_to_str (lp->ptid));
3116 gdb_assert (lp->resumed);
3118 /* Discard the event. */
3122 /* Make sure we don't report a SIGINT that we have already displayed
3123 for another thread. */
3124 if (lp->ignore_sigint
3125 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
3127 if (debug_linux_nat)
3128 fprintf_unfiltered (gdb_stdlog,
3129 "LLW: Delayed SIGINT caught for %s.\n",
3130 target_pid_to_str (lp->ptid));
3132 /* This is a delayed SIGINT. */
3133 lp->ignore_sigint = 0;
3135 registers_changed ();
3136 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3137 lp->step, TARGET_SIGNAL_0);
3138 if (debug_linux_nat)
3139 fprintf_unfiltered (gdb_stdlog,
3140 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3142 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3143 target_pid_to_str (lp->ptid));
3146 gdb_assert (lp->resumed);
3148 /* Discard the event. */
3152 /* An interesting event. */
3154 lp->status = status;
3159 linux_nat_wait_1 (struct target_ops *ops,
3160 ptid_t ptid, struct target_waitstatus *ourstatus,
3163 static sigset_t prev_mask;
3164 struct lwp_info *lp = NULL;
3169 if (debug_linux_nat_async)
3170 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
3172 /* The first time we get here after starting a new inferior, we may
3173 not have added it to the LWP list yet - this is the earliest
3174 moment at which we know its PID. */
3175 if (ptid_is_pid (inferior_ptid))
3177 /* Upgrade the main thread's ptid. */
3178 thread_change_ptid (inferior_ptid,
3179 BUILD_LWP (GET_PID (inferior_ptid),
3180 GET_PID (inferior_ptid)));
3182 lp = add_lwp (inferior_ptid);
3186 /* Make sure SIGCHLD is blocked. */
3187 block_child_signals (&prev_mask);
3189 if (ptid_equal (ptid, minus_one_ptid))
3191 else if (ptid_is_pid (ptid))
3192 /* A request to wait for a specific tgid. This is not possible
3193 with waitpid, so instead, we wait for any child, and leave
3194 children we're not interested in right now with a pending
3195 status to report later. */
3198 pid = GET_LWP (ptid);
3204 /* Make sure there is at least one LWP that has been resumed. */
3205 gdb_assert (iterate_over_lwps (ptid, resumed_callback, NULL));
3207 /* First check if there is a LWP with a wait status pending. */
3210 /* Any LWP that's been resumed will do. */
3211 lp = iterate_over_lwps (ptid, status_callback, NULL);
3214 if (debug_linux_nat && lp->status)
3215 fprintf_unfiltered (gdb_stdlog,
3216 "LLW: Using pending wait status %s for %s.\n",
3217 status_to_str (lp->status),
3218 target_pid_to_str (lp->ptid));
3221 /* But if we don't find one, we'll have to wait, and check both
3222 cloned and uncloned processes. We start with the cloned
3224 options = __WCLONE | WNOHANG;
3226 else if (is_lwp (ptid))
3228 if (debug_linux_nat)
3229 fprintf_unfiltered (gdb_stdlog,
3230 "LLW: Waiting for specific LWP %s.\n",
3231 target_pid_to_str (ptid));
3233 /* We have a specific LWP to check. */
3234 lp = find_lwp_pid (ptid);
3237 if (debug_linux_nat && lp->status)
3238 fprintf_unfiltered (gdb_stdlog,
3239 "LLW: Using pending wait status %s for %s.\n",
3240 status_to_str (lp->status),
3241 target_pid_to_str (lp->ptid));
3243 /* If we have to wait, take into account whether PID is a cloned
3244 process or not. And we have to convert it to something that
3245 the layer beneath us can understand. */
3246 options = lp->cloned ? __WCLONE : 0;
3247 pid = GET_LWP (ptid);
3249 /* We check for lp->waitstatus in addition to lp->status,
3250 because we can have pending process exits recorded in
3251 lp->status and W_EXITCODE(0,0) == 0. We should probably have
3252 an additional lp->status_p flag. */
3253 if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
3257 if (lp && lp->signalled)
3259 /* A pending SIGSTOP may interfere with the normal stream of
3260 events. In a typical case where interference is a problem,
3261 we have a SIGSTOP signal pending for LWP A while
3262 single-stepping it, encounter an event in LWP B, and take the
3263 pending SIGSTOP while trying to stop LWP A. After processing
3264 the event in LWP B, LWP A is continued, and we'll never see
3265 the SIGTRAP associated with the last time we were
3266 single-stepping LWP A. */
3268 /* Resume the thread. It should halt immediately returning the
3270 registers_changed ();
3271 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3272 lp->step, TARGET_SIGNAL_0);
3273 if (debug_linux_nat)
3274 fprintf_unfiltered (gdb_stdlog,
3275 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
3276 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3277 target_pid_to_str (lp->ptid));
3279 gdb_assert (lp->resumed);
3281 /* Catch the pending SIGSTOP. */
3282 status = lp->status;
3285 stop_wait_callback (lp, NULL);
3287 /* If the lp->status field isn't empty, we caught another signal
3288 while flushing the SIGSTOP. Return it back to the event
3289 queue of the LWP, as we already have an event to handle. */
3292 if (debug_linux_nat)
3293 fprintf_unfiltered (gdb_stdlog,
3294 "LLW: kill %s, %s\n",
3295 target_pid_to_str (lp->ptid),
3296 status_to_str (lp->status));
3297 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
3300 lp->status = status;
3303 if (!target_can_async_p ())
3305 /* Causes SIGINT to be passed on to the attached process. */
3309 /* Translate generic target_wait options into waitpid options. */
3310 if (target_options & TARGET_WNOHANG)
3317 lwpid = my_waitpid (pid, &status, options);
3321 gdb_assert (pid == -1 || lwpid == pid);
3323 if (debug_linux_nat)
3325 fprintf_unfiltered (gdb_stdlog,
3326 "LLW: waitpid %ld received %s\n",
3327 (long) lwpid, status_to_str (status));
3330 lp = linux_nat_filter_event (lwpid, status, options);
3333 && ptid_is_pid (ptid)
3334 && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
3336 if (debug_linux_nat)
3337 fprintf (stderr, "LWP %ld got an event %06x, leaving pending.\n",
3338 ptid_get_lwp (lp->ptid), status);
3340 if (WIFSTOPPED (lp->status))
3342 if (WSTOPSIG (lp->status) != SIGSTOP)
3344 stop_callback (lp, NULL);
3346 /* Resume in order to collect the sigstop. */
3347 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
3349 stop_wait_callback (lp, NULL);
3357 else if (WIFEXITED (status) || WIFSIGNALED (status))
3359 if (debug_linux_nat)
3360 fprintf (stderr, "Process %ld exited while stopping LWPs\n",
3361 ptid_get_lwp (lp->ptid));
3363 /* This was the last lwp in the process. Since
3364 events are serialized to GDB core, and we can't
3365 report this one right now, but GDB core and the
3366 other target layers will want to be notified
3367 about the exit code/signal, leave the status
3368 pending for the next time we're able to report
3371 /* Prevent trying to stop this thread again. We'll
3372 never try to resume it because it has a pending
3376 /* Dead LWP's aren't expected to reported a pending
3380 /* Store the pending event in the waitstatus as
3381 well, because W_EXITCODE(0,0) == 0. */
3382 store_waitstatus (&lp->waitstatus, lp->status);
3396 /* waitpid did return something. Restart over. */
3397 options |= __WCLONE;
3405 /* Alternate between checking cloned and uncloned processes. */
3406 options ^= __WCLONE;
3408 /* And every time we have checked both:
3409 In async mode, return to event loop;
3410 In sync mode, suspend waiting for a SIGCHLD signal. */
3411 if (options & __WCLONE)
3413 if (target_options & TARGET_WNOHANG)
3415 /* No interesting event. */
3416 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3418 if (debug_linux_nat_async)
3419 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3421 restore_child_signals_mask (&prev_mask);
3422 return minus_one_ptid;
3425 sigsuspend (&suspend_mask);
3428 else if (target_options & TARGET_WNOHANG)
3430 /* No interesting event for PID yet. */
3431 ourstatus->kind = TARGET_WAITKIND_IGNORE;
3433 if (debug_linux_nat_async)
3434 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
3436 restore_child_signals_mask (&prev_mask);
3437 return minus_one_ptid;
3440 /* We shouldn't end up here unless we want to try again. */
3441 gdb_assert (lp == NULL);
3444 if (!target_can_async_p ())
3445 clear_sigint_trap ();
3449 status = lp->status;
3452 /* Don't report signals that GDB isn't interested in, such as
3453 signals that are neither printed nor stopped upon. Stopping all
3454 threads can be a bit time-consuming so if we want decent
3455 performance with heavily multi-threaded programs, especially when
3456 they're using a high frequency timer, we'd better avoid it if we
3459 if (WIFSTOPPED (status))
3461 int signo = target_signal_from_host (WSTOPSIG (status));
3462 struct inferior *inf;
3464 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
3467 /* Defer to common code if we get a signal while
3468 single-stepping, since that may need special care, e.g. to
3469 skip the signal handler, or, if we're gaining control of the
3472 && inf->stop_soon == NO_STOP_QUIETLY
3473 && signal_stop_state (signo) == 0
3474 && signal_print_state (signo) == 0
3475 && signal_pass_state (signo) == 1)
3477 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
3478 here? It is not clear we should. GDB may not expect
3479 other threads to run. On the other hand, not resuming
3480 newly attached threads may cause an unwanted delay in
3481 getting them running. */
3482 registers_changed ();
3483 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
3485 if (debug_linux_nat)
3486 fprintf_unfiltered (gdb_stdlog,
3487 "LLW: %s %s, %s (preempt 'handle')\n",
3489 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3490 target_pid_to_str (lp->ptid),
3491 signo ? strsignal (signo) : "0");
3498 /* Only do the below in all-stop, as we currently use SIGINT
3499 to implement target_stop (see linux_nat_stop) in
3501 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
3503 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3504 forwarded to the entire process group, that is, all LWPs
3505 will receive it - unless they're using CLONE_THREAD to
3506 share signals. Since we only want to report it once, we
3507 mark it as ignored for all LWPs except this one. */
3508 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
3509 set_ignore_sigint, NULL);
3510 lp->ignore_sigint = 0;
3513 maybe_clear_ignore_sigint (lp);
3517 /* This LWP is stopped now. */
3520 if (debug_linux_nat)
3521 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
3522 status_to_str (status), target_pid_to_str (lp->ptid));
3526 /* Now stop all other LWP's ... */
3527 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3529 /* ... and wait until all of them have reported back that
3530 they're no longer running. */
3531 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3533 /* If we're not waiting for a specific LWP, choose an event LWP
3534 from among those that have had events. Giving equal priority
3535 to all LWPs that have had events helps prevent
3538 select_event_lwp (ptid, &lp, &status);
3541 /* Now that we've selected our final event LWP, cancel any
3542 breakpoints in other LWPs that have hit a GDB breakpoint. See
3543 the comment in cancel_breakpoints_callback to find out why. */
3544 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3546 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
3548 if (debug_linux_nat)
3549 fprintf_unfiltered (gdb_stdlog,
3550 "LLW: trap ptid is %s.\n",
3551 target_pid_to_str (lp->ptid));
3554 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3556 *ourstatus = lp->waitstatus;
3557 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3560 store_waitstatus (ourstatus, status);
3562 if (debug_linux_nat_async)
3563 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3565 restore_child_signals_mask (&prev_mask);
3570 linux_nat_wait (struct target_ops *ops,
3571 ptid_t ptid, struct target_waitstatus *ourstatus,
3576 if (debug_linux_nat)
3577 fprintf_unfiltered (gdb_stdlog, "linux_nat_wait: [%s]\n", target_pid_to_str (ptid));
3579 /* Flush the async file first. */
3580 if (target_can_async_p ())
3581 async_file_flush ();
3583 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3585 /* If we requested any event, and something came out, assume there
3586 may be more. If we requested a specific lwp or process, also
3587 assume there may be more. */
3588 if (target_can_async_p ()
3589 && (ourstatus->kind != TARGET_WAITKIND_IGNORE
3590 || !ptid_equal (ptid, minus_one_ptid)))
3593 /* Get ready for the next event. */
3594 if (target_can_async_p ())
3595 target_async (inferior_event_handler, 0);
3601 kill_callback (struct lwp_info *lp, void *data)
3604 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3605 if (debug_linux_nat)
3606 fprintf_unfiltered (gdb_stdlog,
3607 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3608 target_pid_to_str (lp->ptid),
3609 errno ? safe_strerror (errno) : "OK");
3615 kill_wait_callback (struct lwp_info *lp, void *data)
3619 /* We must make sure that there are no pending events (delayed
3620 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3621 program doesn't interfere with any following debugging session. */
3623 /* For cloned processes we must check both with __WCLONE and
3624 without, since the exit status of a cloned process isn't reported
3630 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3631 if (pid != (pid_t) -1)
3633 if (debug_linux_nat)
3634 fprintf_unfiltered (gdb_stdlog,
3635 "KWC: wait %s received unknown.\n",
3636 target_pid_to_str (lp->ptid));
3637 /* The Linux kernel sometimes fails to kill a thread
3638 completely after PTRACE_KILL; that goes from the stop
3639 point in do_fork out to the one in
3640 get_signal_to_deliever and waits again. So kill it
3642 kill_callback (lp, NULL);
3645 while (pid == GET_LWP (lp->ptid));
3647 gdb_assert (pid == -1 && errno == ECHILD);
3652 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3653 if (pid != (pid_t) -1)
3655 if (debug_linux_nat)
3656 fprintf_unfiltered (gdb_stdlog,
3657 "KWC: wait %s received unk.\n",
3658 target_pid_to_str (lp->ptid));
3659 /* See the call to kill_callback above. */
3660 kill_callback (lp, NULL);
3663 while (pid == GET_LWP (lp->ptid));
3665 gdb_assert (pid == -1 && errno == ECHILD);
3670 linux_nat_kill (struct target_ops *ops)
3672 struct target_waitstatus last;
3676 /* If we're stopped while forking and we haven't followed yet,
3677 kill the other task. We need to do this first because the
3678 parent will be sleeping if this is a vfork. */
3680 get_last_target_status (&last_ptid, &last);
3682 if (last.kind == TARGET_WAITKIND_FORKED
3683 || last.kind == TARGET_WAITKIND_VFORKED)
3685 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3689 if (forks_exist_p ())
3690 linux_fork_killall ();
3693 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3694 /* Stop all threads before killing them, since ptrace requires
3695 that the thread is stopped to sucessfully PTRACE_KILL. */
3696 iterate_over_lwps (ptid, stop_callback, NULL);
3697 /* ... and wait until all of them have reported back that
3698 they're no longer running. */
3699 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3701 /* Kill all LWP's ... */
3702 iterate_over_lwps (ptid, kill_callback, NULL);
3704 /* ... and wait until we've flushed all events. */
3705 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3708 target_mourn_inferior ();
3712 linux_nat_mourn_inferior (struct target_ops *ops)
3714 purge_lwp_list (ptid_get_pid (inferior_ptid));
3716 if (! forks_exist_p ())
3717 /* Normal case, no other forks available. */
3718 linux_ops->to_mourn_inferior (ops);
3720 /* Multi-fork case. The current inferior_ptid has exited, but
3721 there are other viable forks to debug. Delete the exiting
3722 one and context-switch to the first available. */
3723 linux_fork_mourn_inferior ();
3726 /* Convert a native/host siginfo object, into/from the siginfo in the
3727 layout of the inferiors' architecture. */
3730 siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction)
3734 if (linux_nat_siginfo_fixup != NULL)
3735 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3737 /* If there was no callback, or the callback didn't do anything,
3738 then just do a straight memcpy. */
3742 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
3744 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
3749 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3750 const char *annex, gdb_byte *readbuf,
3751 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
3754 struct siginfo siginfo;
3755 gdb_byte inf_siginfo[sizeof (struct siginfo)];
3757 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3758 gdb_assert (readbuf || writebuf);
3760 pid = GET_LWP (inferior_ptid);
3762 pid = GET_PID (inferior_ptid);
3764 if (offset > sizeof (siginfo))
3768 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3772 /* When GDB is built as a 64-bit application, ptrace writes into
3773 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3774 inferior with a 64-bit GDB should look the same as debugging it
3775 with a 32-bit GDB, we need to convert it. GDB core always sees
3776 the converted layout, so any read/write will have to be done
3778 siginfo_fixup (&siginfo, inf_siginfo, 0);
3780 if (offset + len > sizeof (siginfo))
3781 len = sizeof (siginfo) - offset;
3783 if (readbuf != NULL)
3784 memcpy (readbuf, inf_siginfo + offset, len);
3787 memcpy (inf_siginfo + offset, writebuf, len);
3789 /* Convert back to ptrace layout before flushing it out. */
3790 siginfo_fixup (&siginfo, inf_siginfo, 1);
3793 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3802 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3803 const char *annex, gdb_byte *readbuf,
3804 const gdb_byte *writebuf,
3805 ULONGEST offset, LONGEST len)
3807 struct cleanup *old_chain;
3810 if (object == TARGET_OBJECT_SIGNAL_INFO)
3811 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3814 /* The target is connected but no live inferior is selected. Pass
3815 this request down to a lower stratum (e.g., the executable
3817 if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid))
3820 old_chain = save_inferior_ptid ();
3822 if (is_lwp (inferior_ptid))
3823 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
3825 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3828 do_cleanups (old_chain);
3833 linux_thread_alive (ptid_t ptid)
3837 gdb_assert (is_lwp (ptid));
3839 /* Send signal 0 instead of anything ptrace, because ptracing a
3840 running thread errors out claiming that the thread doesn't
3842 err = kill_lwp (GET_LWP (ptid), 0);
3844 if (debug_linux_nat)
3845 fprintf_unfiltered (gdb_stdlog,
3846 "LLTA: KILL(SIG0) %s (%s)\n",
3847 target_pid_to_str (ptid),
3848 err ? safe_strerror (err) : "OK");
3857 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3859 return linux_thread_alive (ptid);
3863 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3865 static char buf[64];
3868 && (GET_PID (ptid) != GET_LWP (ptid)
3869 || num_lwps (GET_PID (ptid)) > 1))
3871 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
3875 return normal_pid_to_str (ptid);
3878 /* Accepts an integer PID; Returns a string representing a file that
3879 can be opened to get the symbols for the child process. */
3882 linux_child_pid_to_exec_file (int pid)
3884 char *name1, *name2;
3886 name1 = xmalloc (MAXPATHLEN);
3887 name2 = xmalloc (MAXPATHLEN);
3888 make_cleanup (xfree, name1);
3889 make_cleanup (xfree, name2);
3890 memset (name2, 0, MAXPATHLEN);
3892 sprintf (name1, "/proc/%d/exe", pid);
3893 if (readlink (name1, name2, MAXPATHLEN) > 0)
3899 /* Service function for corefiles and info proc. */
3902 read_mapping (FILE *mapfile,
3907 char *device, long long *inode, char *filename)
3909 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
3910 addr, endaddr, permissions, offset, device, inode);
3913 if (ret > 0 && ret != EOF)
3915 /* Eat everything up to EOL for the filename. This will prevent
3916 weird filenames (such as one with embedded whitespace) from
3917 confusing this code. It also makes this code more robust in
3918 respect to annotations the kernel may add after the filename.
3920 Note the filename is used for informational purposes
3922 ret += fscanf (mapfile, "%[^\n]\n", filename);
3925 return (ret != 0 && ret != EOF);
3928 /* Fills the "to_find_memory_regions" target vector. Lists the memory
3929 regions in the inferior for a corefile. */
3932 linux_nat_find_memory_regions (int (*func) (CORE_ADDR,
3934 int, int, int, void *), void *obfd)
3936 int pid = PIDGET (inferior_ptid);
3937 char mapsfilename[MAXPATHLEN];
3939 long long addr, endaddr, size, offset, inode;
3940 char permissions[8], device[8], filename[MAXPATHLEN];
3941 int read, write, exec;
3943 struct cleanup *cleanup;
3945 /* Compose the filename for the /proc memory map, and open it. */
3946 sprintf (mapsfilename, "/proc/%d/maps", pid);
3947 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
3948 error (_("Could not open %s."), mapsfilename);
3949 cleanup = make_cleanup_fclose (mapsfile);
3952 fprintf_filtered (gdb_stdout,
3953 "Reading memory regions from %s\n", mapsfilename);
3955 /* Now iterate until end-of-file. */
3956 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
3957 &offset, &device[0], &inode, &filename[0]))
3959 size = endaddr - addr;
3961 /* Get the segment's permissions. */
3962 read = (strchr (permissions, 'r') != 0);
3963 write = (strchr (permissions, 'w') != 0);
3964 exec = (strchr (permissions, 'x') != 0);
3968 fprintf_filtered (gdb_stdout,
3969 "Save segment, %lld bytes at %s (%c%c%c)",
3970 size, paddress (target_gdbarch, addr),
3972 write ? 'w' : ' ', exec ? 'x' : ' ');
3974 fprintf_filtered (gdb_stdout, " for %s", filename);
3975 fprintf_filtered (gdb_stdout, "\n");
3978 /* Invoke the callback function to create the corefile
3980 func (addr, size, read, write, exec, obfd);
3982 do_cleanups (cleanup);
3987 find_signalled_thread (struct thread_info *info, void *data)
3989 if (info->stop_signal != TARGET_SIGNAL_0
3990 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
3996 static enum target_signal
3997 find_stop_signal (void)
3999 struct thread_info *info =
4000 iterate_over_threads (find_signalled_thread, NULL);
4003 return info->stop_signal;
4005 return TARGET_SIGNAL_0;
4008 /* Records the thread's register state for the corefile note
4012 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
4013 char *note_data, int *note_size,
4014 enum target_signal stop_signal)
4016 gdb_gregset_t gregs;
4017 gdb_fpregset_t fpregs;
4018 unsigned long lwp = ptid_get_lwp (ptid);
4019 struct gdbarch *gdbarch = target_gdbarch;
4020 struct regcache *regcache = get_thread_arch_regcache (ptid, gdbarch);
4021 const struct regset *regset;
4023 struct cleanup *old_chain;
4024 struct core_regset_section *sect_list;
4027 old_chain = save_inferior_ptid ();
4028 inferior_ptid = ptid;
4029 target_fetch_registers (regcache, -1);
4030 do_cleanups (old_chain);
4032 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
4033 sect_list = gdbarch_core_regset_sections (gdbarch);
4036 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
4037 sizeof (gregs))) != NULL
4038 && regset->collect_regset != NULL)
4039 regset->collect_regset (regset, regcache, -1,
4040 &gregs, sizeof (gregs));
4042 fill_gregset (regcache, &gregs, -1);
4044 note_data = (char *) elfcore_write_prstatus (obfd,
4048 stop_signal, &gregs);
4050 /* The loop below uses the new struct core_regset_section, which stores
4051 the supported section names and sizes for the core file. Note that
4052 note PRSTATUS needs to be treated specially. But the other notes are
4053 structurally the same, so they can benefit from the new struct. */
4054 if (core_regset_p && sect_list != NULL)
4055 while (sect_list->sect_name != NULL)
4057 /* .reg was already handled above. */
4058 if (strcmp (sect_list->sect_name, ".reg") == 0)
4063 regset = gdbarch_regset_from_core_section (gdbarch,
4064 sect_list->sect_name,
4066 gdb_assert (regset && regset->collect_regset);
4067 gdb_regset = xmalloc (sect_list->size);
4068 regset->collect_regset (regset, regcache, -1,
4069 gdb_regset, sect_list->size);
4070 note_data = (char *) elfcore_write_register_note (obfd,
4073 sect_list->sect_name,
4080 /* For architectures that does not have the struct core_regset_section
4081 implemented, we use the old method. When all the architectures have
4082 the new support, the code below should be deleted. */
4086 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
4087 sizeof (fpregs))) != NULL
4088 && regset->collect_regset != NULL)
4089 regset->collect_regset (regset, regcache, -1,
4090 &fpregs, sizeof (fpregs));
4092 fill_fpregset (regcache, &fpregs, -1);
4094 note_data = (char *) elfcore_write_prfpreg (obfd,
4097 &fpregs, sizeof (fpregs));
4103 struct linux_nat_corefile_thread_data
4109 enum target_signal stop_signal;
4112 /* Called by gdbthread.c once per thread. Records the thread's
4113 register state for the corefile note section. */
4116 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
4118 struct linux_nat_corefile_thread_data *args = data;
4120 args->note_data = linux_nat_do_thread_registers (args->obfd,
4130 /* Enumerate spufs IDs for process PID. */
4133 iterate_over_spus (int pid, void (*callback) (void *, int), void *data)
4137 struct dirent *entry;
4139 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4140 dir = opendir (path);
4145 while ((entry = readdir (dir)) != NULL)
4151 fd = atoi (entry->d_name);
4155 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4156 if (stat (path, &st) != 0)
4158 if (!S_ISDIR (st.st_mode))
4161 if (statfs (path, &stfs) != 0)
4163 if (stfs.f_type != SPUFS_MAGIC)
4166 callback (data, fd);
4172 /* Generate corefile notes for SPU contexts. */
4174 struct linux_spu_corefile_data
4182 linux_spu_corefile_callback (void *data, int fd)
4184 struct linux_spu_corefile_data *args = data;
4187 static const char *spu_files[] =
4209 for (i = 0; i < sizeof (spu_files) / sizeof (spu_files[0]); i++)
4211 char annex[32], note_name[32];
4215 xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[i]);
4216 spu_len = target_read_alloc (¤t_target, TARGET_OBJECT_SPU,
4220 xsnprintf (note_name, sizeof note_name, "SPU/%s", annex);
4221 args->note_data = elfcore_write_note (args->obfd, args->note_data,
4222 args->note_size, note_name,
4223 NT_SPU, spu_data, spu_len);
4230 linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size)
4232 struct linux_spu_corefile_data args;
4234 args.note_data = note_data;
4235 args.note_size = note_size;
4237 iterate_over_spus (PIDGET (inferior_ptid),
4238 linux_spu_corefile_callback, &args);
4240 return args.note_data;
4243 /* Fills the "to_make_corefile_note" target vector. Builds the note
4244 section for a corefile, and returns it in a malloc buffer. */
4247 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
4249 struct linux_nat_corefile_thread_data thread_args;
4250 struct cleanup *old_chain;
4251 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
4252 char fname[16] = { '\0' };
4253 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
4254 char psargs[80] = { '\0' };
4255 char *note_data = NULL;
4256 ptid_t current_ptid = inferior_ptid;
4257 ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid));
4261 if (get_exec_file (0))
4263 strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
4264 strncpy (psargs, get_exec_file (0), sizeof (psargs));
4265 if (get_inferior_args ())
4268 char *psargs_end = psargs + sizeof (psargs);
4270 /* linux_elfcore_write_prpsinfo () handles zero unterminated
4272 string_end = memchr (psargs, 0, sizeof (psargs));
4273 if (string_end != NULL)
4275 *string_end++ = ' ';
4276 strncpy (string_end, get_inferior_args (),
4277 psargs_end - string_end);
4280 note_data = (char *) elfcore_write_prpsinfo (obfd,
4282 note_size, fname, psargs);
4285 /* Dump information for threads. */
4286 thread_args.obfd = obfd;
4287 thread_args.note_data = note_data;
4288 thread_args.note_size = note_size;
4289 thread_args.num_notes = 0;
4290 thread_args.stop_signal = find_stop_signal ();
4291 iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args);
4292 gdb_assert (thread_args.num_notes != 0);
4293 note_data = thread_args.note_data;
4295 auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
4299 note_data = elfcore_write_note (obfd, note_data, note_size,
4300 "CORE", NT_AUXV, auxv, auxv_len);
4304 note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size);
4306 make_cleanup (xfree, note_data);
4310 /* Implement the "info proc" command. */
4313 linux_nat_info_proc_cmd (char *args, int from_tty)
4315 /* A long is used for pid instead of an int to avoid a loss of precision
4316 compiler warning from the output of strtoul. */
4317 long pid = PIDGET (inferior_ptid);
4320 char buffer[MAXPATHLEN];
4321 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
4334 /* Break up 'args' into an argv array. */
4335 argv = gdb_buildargv (args);
4336 make_cleanup_freeargv (argv);
4338 while (argv != NULL && *argv != NULL)
4340 if (isdigit (argv[0][0]))
4342 pid = strtoul (argv[0], NULL, 10);
4344 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
4348 else if (strcmp (argv[0], "status") == 0)
4352 else if (strcmp (argv[0], "stat") == 0)
4356 else if (strcmp (argv[0], "cmd") == 0)
4360 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
4364 else if (strcmp (argv[0], "cwd") == 0)
4368 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
4374 /* [...] (future options here) */
4379 error (_("No current process: you must name one."));
4381 sprintf (fname1, "/proc/%ld", pid);
4382 if (stat (fname1, &dummy) != 0)
4383 error (_("No /proc directory: '%s'"), fname1);
4385 printf_filtered (_("process %ld\n"), pid);
4386 if (cmdline_f || all)
4388 sprintf (fname1, "/proc/%ld/cmdline", pid);
4389 if ((procfile = fopen (fname1, "r")) != NULL)
4391 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4392 if (fgets (buffer, sizeof (buffer), procfile))
4393 printf_filtered ("cmdline = '%s'\n", buffer);
4395 warning (_("unable to read '%s'"), fname1);
4396 do_cleanups (cleanup);
4399 warning (_("unable to open /proc file '%s'"), fname1);
4403 sprintf (fname1, "/proc/%ld/cwd", pid);
4404 memset (fname2, 0, sizeof (fname2));
4405 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4406 printf_filtered ("cwd = '%s'\n", fname2);
4408 warning (_("unable to read link '%s'"), fname1);
4412 sprintf (fname1, "/proc/%ld/exe", pid);
4413 memset (fname2, 0, sizeof (fname2));
4414 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
4415 printf_filtered ("exe = '%s'\n", fname2);
4417 warning (_("unable to read link '%s'"), fname1);
4419 if (mappings_f || all)
4421 sprintf (fname1, "/proc/%ld/maps", pid);
4422 if ((procfile = fopen (fname1, "r")) != NULL)
4424 long long addr, endaddr, size, offset, inode;
4425 char permissions[8], device[8], filename[MAXPATHLEN];
4426 struct cleanup *cleanup;
4428 cleanup = make_cleanup_fclose (procfile);
4429 printf_filtered (_("Mapped address spaces:\n\n"));
4430 if (gdbarch_addr_bit (target_gdbarch) == 32)
4432 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
4435 " Size", " Offset", "objfile");
4439 printf_filtered (" %18s %18s %10s %10s %7s\n",
4442 " Size", " Offset", "objfile");
4445 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
4446 &offset, &device[0], &inode, &filename[0]))
4448 size = endaddr - addr;
4450 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
4451 calls here (and possibly above) should be abstracted
4452 out into their own functions? Andrew suggests using
4453 a generic local_address_string instead to print out
4454 the addresses; that makes sense to me, too. */
4456 if (gdbarch_addr_bit (target_gdbarch) == 32)
4458 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
4459 (unsigned long) addr, /* FIXME: pr_addr */
4460 (unsigned long) endaddr,
4462 (unsigned int) offset,
4463 filename[0] ? filename : "");
4467 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
4468 (unsigned long) addr, /* FIXME: pr_addr */
4469 (unsigned long) endaddr,
4471 (unsigned int) offset,
4472 filename[0] ? filename : "");
4476 do_cleanups (cleanup);
4479 warning (_("unable to open /proc file '%s'"), fname1);
4481 if (status_f || all)
4483 sprintf (fname1, "/proc/%ld/status", pid);
4484 if ((procfile = fopen (fname1, "r")) != NULL)
4486 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4487 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
4488 puts_filtered (buffer);
4489 do_cleanups (cleanup);
4492 warning (_("unable to open /proc file '%s'"), fname1);
4496 sprintf (fname1, "/proc/%ld/stat", pid);
4497 if ((procfile = fopen (fname1, "r")) != NULL)
4502 struct cleanup *cleanup = make_cleanup_fclose (procfile);
4504 if (fscanf (procfile, "%d ", &itmp) > 0)
4505 printf_filtered (_("Process: %d\n"), itmp);
4506 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
4507 printf_filtered (_("Exec file: %s\n"), buffer);
4508 if (fscanf (procfile, "%c ", &ctmp) > 0)
4509 printf_filtered (_("State: %c\n"), ctmp);
4510 if (fscanf (procfile, "%d ", &itmp) > 0)
4511 printf_filtered (_("Parent process: %d\n"), itmp);
4512 if (fscanf (procfile, "%d ", &itmp) > 0)
4513 printf_filtered (_("Process group: %d\n"), itmp);
4514 if (fscanf (procfile, "%d ", &itmp) > 0)
4515 printf_filtered (_("Session id: %d\n"), itmp);
4516 if (fscanf (procfile, "%d ", &itmp) > 0)
4517 printf_filtered (_("TTY: %d\n"), itmp);
4518 if (fscanf (procfile, "%d ", &itmp) > 0)
4519 printf_filtered (_("TTY owner process group: %d\n"), itmp);
4520 if (fscanf (procfile, "%lu ", <mp) > 0)
4521 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
4522 if (fscanf (procfile, "%lu ", <mp) > 0)
4523 printf_filtered (_("Minor faults (no memory page): %lu\n"),
4524 (unsigned long) ltmp);
4525 if (fscanf (procfile, "%lu ", <mp) > 0)
4526 printf_filtered (_("Minor faults, children: %lu\n"),
4527 (unsigned long) ltmp);
4528 if (fscanf (procfile, "%lu ", <mp) > 0)
4529 printf_filtered (_("Major faults (memory page faults): %lu\n"),
4530 (unsigned long) ltmp);
4531 if (fscanf (procfile, "%lu ", <mp) > 0)
4532 printf_filtered (_("Major faults, children: %lu\n"),
4533 (unsigned long) ltmp);
4534 if (fscanf (procfile, "%ld ", <mp) > 0)
4535 printf_filtered (_("utime: %ld\n"), ltmp);
4536 if (fscanf (procfile, "%ld ", <mp) > 0)
4537 printf_filtered (_("stime: %ld\n"), ltmp);
4538 if (fscanf (procfile, "%ld ", <mp) > 0)
4539 printf_filtered (_("utime, children: %ld\n"), ltmp);
4540 if (fscanf (procfile, "%ld ", <mp) > 0)
4541 printf_filtered (_("stime, children: %ld\n"), ltmp);
4542 if (fscanf (procfile, "%ld ", <mp) > 0)
4543 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
4545 if (fscanf (procfile, "%ld ", <mp) > 0)
4546 printf_filtered (_("'nice' value: %ld\n"), ltmp);
4547 if (fscanf (procfile, "%lu ", <mp) > 0)
4548 printf_filtered (_("jiffies until next timeout: %lu\n"),
4549 (unsigned long) ltmp);
4550 if (fscanf (procfile, "%lu ", <mp) > 0)
4551 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
4552 (unsigned long) ltmp);
4553 if (fscanf (procfile, "%ld ", <mp) > 0)
4554 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
4556 if (fscanf (procfile, "%lu ", <mp) > 0)
4557 printf_filtered (_("Virtual memory size: %lu\n"),
4558 (unsigned long) ltmp);
4559 if (fscanf (procfile, "%lu ", <mp) > 0)
4560 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp);
4561 if (fscanf (procfile, "%lu ", <mp) > 0)
4562 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
4563 if (fscanf (procfile, "%lu ", <mp) > 0)
4564 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
4565 if (fscanf (procfile, "%lu ", <mp) > 0)
4566 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
4567 if (fscanf (procfile, "%lu ", <mp) > 0)
4568 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
4569 #if 0 /* Don't know how architecture-dependent the rest is...
4570 Anyway the signal bitmap info is available from "status". */
4571 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4572 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
4573 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4574 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
4575 if (fscanf (procfile, "%ld ", <mp) > 0)
4576 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
4577 if (fscanf (procfile, "%ld ", <mp) > 0)
4578 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
4579 if (fscanf (procfile, "%ld ", <mp) > 0)
4580 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
4581 if (fscanf (procfile, "%ld ", <mp) > 0)
4582 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
4583 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
4584 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
4586 do_cleanups (cleanup);
4589 warning (_("unable to open /proc file '%s'"), fname1);
4593 /* Implement the to_xfer_partial interface for memory reads using the /proc
4594 filesystem. Because we can use a single read() call for /proc, this
4595 can be much more efficient than banging away at PTRACE_PEEKTEXT,
4596 but it doesn't support writes. */
4599 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
4600 const char *annex, gdb_byte *readbuf,
4601 const gdb_byte *writebuf,
4602 ULONGEST offset, LONGEST len)
4608 if (object != TARGET_OBJECT_MEMORY || !readbuf)
4611 /* Don't bother for one word. */
4612 if (len < 3 * sizeof (long))
4615 /* We could keep this file open and cache it - possibly one per
4616 thread. That requires some juggling, but is even faster. */
4617 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
4618 fd = open (filename, O_RDONLY | O_LARGEFILE);
4622 /* If pread64 is available, use it. It's faster if the kernel
4623 supports it (only one syscall), and it's 64-bit safe even on
4624 32-bit platforms (for instance, SPARC debugging a SPARC64
4627 if (pread64 (fd, readbuf, len, offset) != len)
4629 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
4640 /* Enumerate spufs IDs for process PID. */
4642 spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len)
4644 enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
4646 LONGEST written = 0;
4649 struct dirent *entry;
4651 xsnprintf (path, sizeof path, "/proc/%d/fd", pid);
4652 dir = opendir (path);
4657 while ((entry = readdir (dir)) != NULL)
4663 fd = atoi (entry->d_name);
4667 xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd);
4668 if (stat (path, &st) != 0)
4670 if (!S_ISDIR (st.st_mode))
4673 if (statfs (path, &stfs) != 0)
4675 if (stfs.f_type != SPUFS_MAGIC)
4678 if (pos >= offset && pos + 4 <= offset + len)
4680 store_unsigned_integer (buf + pos - offset, 4, byte_order, fd);
4690 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4691 object type, using the /proc file system. */
4693 linux_proc_xfer_spu (struct target_ops *ops, enum target_object object,
4694 const char *annex, gdb_byte *readbuf,
4695 const gdb_byte *writebuf,
4696 ULONGEST offset, LONGEST len)
4701 int pid = PIDGET (inferior_ptid);
4708 return spu_enumerate_spu_ids (pid, readbuf, offset, len);
4711 xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex);
4712 fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
4717 && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
4724 ret = write (fd, writebuf, (size_t) len);
4726 ret = read (fd, readbuf, (size_t) len);
4733 /* Parse LINE as a signal set and add its set bits to SIGS. */
4736 add_line_to_sigset (const char *line, sigset_t *sigs)
4738 int len = strlen (line) - 1;
4742 if (line[len] != '\n')
4743 error (_("Could not parse signal set: %s"), line);
4751 if (*p >= '0' && *p <= '9')
4753 else if (*p >= 'a' && *p <= 'f')
4754 digit = *p - 'a' + 10;
4756 error (_("Could not parse signal set: %s"), line);
4761 sigaddset (sigs, signum + 1);
4763 sigaddset (sigs, signum + 2);
4765 sigaddset (sigs, signum + 3);
4767 sigaddset (sigs, signum + 4);
4773 /* Find process PID's pending signals from /proc/pid/status and set
4777 linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
4780 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
4782 struct cleanup *cleanup;
4784 sigemptyset (pending);
4785 sigemptyset (blocked);
4786 sigemptyset (ignored);
4787 sprintf (fname, "/proc/%d/status", pid);
4788 procfile = fopen (fname, "r");
4789 if (procfile == NULL)
4790 error (_("Could not open %s"), fname);
4791 cleanup = make_cleanup_fclose (procfile);
4793 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
4795 /* Normal queued signals are on the SigPnd line in the status
4796 file. However, 2.6 kernels also have a "shared" pending
4797 queue for delivering signals to a thread group, so check for
4800 Unfortunately some Red Hat kernels include the shared pending
4801 queue but not the ShdPnd status field. */
4803 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
4804 add_line_to_sigset (buffer + 8, pending);
4805 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
4806 add_line_to_sigset (buffer + 8, pending);
4807 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
4808 add_line_to_sigset (buffer + 8, blocked);
4809 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
4810 add_line_to_sigset (buffer + 8, ignored);
4813 do_cleanups (cleanup);
4817 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4818 const char *annex, gdb_byte *readbuf,
4819 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4821 /* We make the process list snapshot when the object starts to be
4823 static const char *buf;
4824 static LONGEST len_avail = -1;
4825 static struct obstack obstack;
4829 gdb_assert (object == TARGET_OBJECT_OSDATA);
4831 if (strcmp (annex, "processes") != 0)
4834 gdb_assert (readbuf && !writebuf);
4838 if (len_avail != -1 && len_avail != 0)
4839 obstack_free (&obstack, NULL);
4842 obstack_init (&obstack);
4843 obstack_grow_str (&obstack, "<osdata type=\"processes\">\n");
4845 dirp = opendir ("/proc");
4849 while ((dp = readdir (dirp)) != NULL)
4851 struct stat statbuf;
4852 char procentry[sizeof ("/proc/4294967295")];
4854 if (!isdigit (dp->d_name[0])
4855 || NAMELEN (dp) > sizeof ("4294967295") - 1)
4858 sprintf (procentry, "/proc/%s", dp->d_name);
4859 if (stat (procentry, &statbuf) == 0
4860 && S_ISDIR (statbuf.st_mode))
4864 char cmd[MAXPATHLEN + 1];
4865 struct passwd *entry;
4867 pathname = xstrprintf ("/proc/%s/cmdline", dp->d_name);
4868 entry = getpwuid (statbuf.st_uid);
4870 if ((f = fopen (pathname, "r")) != NULL)
4872 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
4876 for (i = 0; i < len; i++)
4881 obstack_xml_printf (
4884 "<column name=\"pid\">%s</column>"
4885 "<column name=\"user\">%s</column>"
4886 "<column name=\"command\">%s</column>"
4889 entry ? entry->pw_name : "?",
4902 obstack_grow_str0 (&obstack, "</osdata>\n");
4903 buf = obstack_finish (&obstack);
4904 len_avail = strlen (buf);
4907 if (offset >= len_avail)
4909 /* Done. Get rid of the obstack. */
4910 obstack_free (&obstack, NULL);
4916 if (len > len_avail - offset)
4917 len = len_avail - offset;
4918 memcpy (readbuf, buf + offset, len);
4924 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4925 const char *annex, gdb_byte *readbuf,
4926 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4930 if (object == TARGET_OBJECT_AUXV)
4931 return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
4934 if (object == TARGET_OBJECT_OSDATA)
4935 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4938 if (object == TARGET_OBJECT_SPU)
4939 return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf,
4942 /* GDB calculates all the addresses in possibly larget width of the address.
4943 Address width needs to be masked before its final use - either by
4944 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4946 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4948 if (object == TARGET_OBJECT_MEMORY)
4950 int addr_bit = gdbarch_addr_bit (target_gdbarch);
4952 if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT))
4953 offset &= ((ULONGEST) 1 << addr_bit) - 1;
4956 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4961 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4965 /* Create a prototype generic GNU/Linux target. The client can override
4966 it with local methods. */
4969 linux_target_install_ops (struct target_ops *t)
4971 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4972 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4973 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4974 t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint;
4975 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4976 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4977 t->to_post_attach = linux_child_post_attach;
4978 t->to_follow_fork = linux_child_follow_fork;
4979 t->to_find_memory_regions = linux_nat_find_memory_regions;
4980 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
4982 super_xfer_partial = t->to_xfer_partial;
4983 t->to_xfer_partial = linux_xfer_partial;
4989 struct target_ops *t;
4991 t = inf_ptrace_target ();
4992 linux_target_install_ops (t);
4998 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
5000 struct target_ops *t;
5002 t = inf_ptrace_trad_target (register_u_offset);
5003 linux_target_install_ops (t);
5008 /* target_is_async_p implementation. */
5011 linux_nat_is_async_p (void)
5013 /* NOTE: palves 2008-03-21: We're only async when the user requests
5014 it explicitly with the "set target-async" command.
5015 Someday, linux will always be async. */
5016 if (!target_async_permitted)
5019 /* See target.h/target_async_mask. */
5020 return linux_nat_async_mask_value;
5023 /* target_can_async_p implementation. */
5026 linux_nat_can_async_p (void)
5028 /* NOTE: palves 2008-03-21: We're only async when the user requests
5029 it explicitly with the "set target-async" command.
5030 Someday, linux will always be async. */
5031 if (!target_async_permitted)
5034 /* See target.h/target_async_mask. */
5035 return linux_nat_async_mask_value;
5039 linux_nat_supports_non_stop (void)
5044 /* True if we want to support multi-process. To be removed when GDB
5045 supports multi-exec. */
5047 int linux_multi_process = 1;
5050 linux_nat_supports_multi_process (void)
5052 return linux_multi_process;
5055 /* target_async_mask implementation. */
5058 linux_nat_async_mask (int new_mask)
5060 int curr_mask = linux_nat_async_mask_value;
5062 if (curr_mask != new_mask)
5066 linux_nat_async (NULL, 0);
5067 linux_nat_async_mask_value = new_mask;
5071 linux_nat_async_mask_value = new_mask;
5073 /* If we're going out of async-mask in all-stop, then the
5074 inferior is stopped. The next resume will call
5075 target_async. In non-stop, the target event source
5076 should be always registered in the event loop. Do so
5079 linux_nat_async (inferior_event_handler, 0);
5086 static int async_terminal_is_ours = 1;
5088 /* target_terminal_inferior implementation. */
5091 linux_nat_terminal_inferior (void)
5093 if (!target_is_async_p ())
5095 /* Async mode is disabled. */
5096 terminal_inferior ();
5100 terminal_inferior ();
5102 /* Calls to target_terminal_*() are meant to be idempotent. */
5103 if (!async_terminal_is_ours)
5106 delete_file_handler (input_fd);
5107 async_terminal_is_ours = 0;
5111 /* target_terminal_ours implementation. */
5114 linux_nat_terminal_ours (void)
5116 if (!target_is_async_p ())
5118 /* Async mode is disabled. */
5123 /* GDB should never give the terminal to the inferior if the
5124 inferior is running in the background (run&, continue&, etc.),
5125 but claiming it sure should. */
5128 if (async_terminal_is_ours)
5131 clear_sigint_trap ();
5132 add_file_handler (input_fd, stdin_event_handler, 0);
5133 async_terminal_is_ours = 1;
5136 static void (*async_client_callback) (enum inferior_event_type event_type,
5138 static void *async_client_context;
5140 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
5141 so we notice when any child changes state, and notify the
5142 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
5143 above to wait for the arrival of a SIGCHLD. */
5146 sigchld_handler (int signo)
5148 int old_errno = errno;
5150 if (debug_linux_nat_async)
5151 fprintf_unfiltered (gdb_stdlog, "sigchld\n");
5153 if (signo == SIGCHLD
5154 && linux_nat_event_pipe[0] != -1)
5155 async_file_mark (); /* Let the event loop know that there are
5156 events to handle. */
5161 /* Callback registered with the target events file descriptor. */
5164 handle_target_event (int error, gdb_client_data client_data)
5166 (*async_client_callback) (INF_REG_EVENT, async_client_context);
5169 /* Create/destroy the target events pipe. Returns previous state. */
5172 linux_async_pipe (int enable)
5174 int previous = (linux_nat_event_pipe[0] != -1);
5176 if (previous != enable)
5180 block_child_signals (&prev_mask);
5184 if (pipe (linux_nat_event_pipe) == -1)
5185 internal_error (__FILE__, __LINE__,
5186 "creating event pipe failed.");
5188 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
5189 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
5193 close (linux_nat_event_pipe[0]);
5194 close (linux_nat_event_pipe[1]);
5195 linux_nat_event_pipe[0] = -1;
5196 linux_nat_event_pipe[1] = -1;
5199 restore_child_signals_mask (&prev_mask);
5205 /* target_async implementation. */
5208 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
5209 void *context), void *context)
5211 if (linux_nat_async_mask_value == 0 || !target_async_permitted)
5212 internal_error (__FILE__, __LINE__,
5213 "Calling target_async when async is masked");
5215 if (callback != NULL)
5217 async_client_callback = callback;
5218 async_client_context = context;
5219 if (!linux_async_pipe (1))
5221 add_file_handler (linux_nat_event_pipe[0],
5222 handle_target_event, NULL);
5223 /* There may be pending events to handle. Tell the event loop
5230 async_client_callback = callback;
5231 async_client_context = context;
5232 delete_file_handler (linux_nat_event_pipe[0]);
5233 linux_async_pipe (0);
5238 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
5242 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
5247 ptid_t ptid = lwp->ptid;
5249 if (debug_linux_nat)
5250 fprintf_unfiltered (gdb_stdlog,
5251 "LNSL: running -> suspending %s\n",
5252 target_pid_to_str (lwp->ptid));
5255 stop_callback (lwp, NULL);
5256 stop_wait_callback (lwp, NULL);
5258 /* If the lwp exits while we try to stop it, there's nothing
5260 lwp = find_lwp_pid (ptid);
5264 /* If we didn't collect any signal other than SIGSTOP while
5265 stopping the LWP, push a SIGNAL_0 event. In either case, the
5266 event-loop will end up calling target_wait which will collect
5268 if (lwp->status == 0)
5269 lwp->status = W_STOPCODE (0);
5274 /* Already known to be stopped; do nothing. */
5276 if (debug_linux_nat)
5278 if (find_thread_ptid (lwp->ptid)->stop_requested)
5279 fprintf_unfiltered (gdb_stdlog, "\
5280 LNSL: already stopped/stop_requested %s\n",
5281 target_pid_to_str (lwp->ptid));
5283 fprintf_unfiltered (gdb_stdlog, "\
5284 LNSL: already stopped/no stop_requested yet %s\n",
5285 target_pid_to_str (lwp->ptid));
5292 linux_nat_stop (ptid_t ptid)
5295 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
5297 linux_ops->to_stop (ptid);
5301 linux_nat_close (int quitting)
5303 /* Unregister from the event loop. */
5304 if (target_is_async_p ())
5305 target_async (NULL, 0);
5307 /* Reset the async_masking. */
5308 linux_nat_async_mask_value = 1;
5310 if (linux_ops->to_close)
5311 linux_ops->to_close (quitting);
5314 /* When requests are passed down from the linux-nat layer to the
5315 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
5316 used. The address space pointer is stored in the inferior object,
5317 but the common code that is passed such ptid can't tell whether
5318 lwpid is a "main" process id or not (it assumes so). We reverse
5319 look up the "main" process id from the lwp here. */
5321 struct address_space *
5322 linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid)
5324 struct lwp_info *lwp;
5325 struct inferior *inf;
5328 pid = GET_LWP (ptid);
5329 if (GET_LWP (ptid) == 0)
5331 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
5333 lwp = find_lwp_pid (ptid);
5334 pid = GET_PID (lwp->ptid);
5338 /* A (pid,lwpid,0) ptid. */
5339 pid = GET_PID (ptid);
5342 inf = find_inferior_pid (pid);
5343 gdb_assert (inf != NULL);
5348 linux_nat_add_target (struct target_ops *t)
5350 /* Save the provided single-threaded target. We save this in a separate
5351 variable because another target we've inherited from (e.g. inf-ptrace)
5352 may have saved a pointer to T; we want to use it for the final
5353 process stratum target. */
5354 linux_ops_saved = *t;
5355 linux_ops = &linux_ops_saved;
5357 /* Override some methods for multithreading. */
5358 t->to_create_inferior = linux_nat_create_inferior;
5359 t->to_attach = linux_nat_attach;
5360 t->to_detach = linux_nat_detach;
5361 t->to_resume = linux_nat_resume;
5362 t->to_wait = linux_nat_wait;
5363 t->to_xfer_partial = linux_nat_xfer_partial;
5364 t->to_kill = linux_nat_kill;
5365 t->to_mourn_inferior = linux_nat_mourn_inferior;
5366 t->to_thread_alive = linux_nat_thread_alive;
5367 t->to_pid_to_str = linux_nat_pid_to_str;
5368 t->to_has_thread_control = tc_schedlock;
5369 t->to_thread_address_space = linux_nat_thread_address_space;
5371 t->to_can_async_p = linux_nat_can_async_p;
5372 t->to_is_async_p = linux_nat_is_async_p;
5373 t->to_supports_non_stop = linux_nat_supports_non_stop;
5374 t->to_async = linux_nat_async;
5375 t->to_async_mask = linux_nat_async_mask;
5376 t->to_terminal_inferior = linux_nat_terminal_inferior;
5377 t->to_terminal_ours = linux_nat_terminal_ours;
5378 t->to_close = linux_nat_close;
5380 /* Methods for non-stop support. */
5381 t->to_stop = linux_nat_stop;
5383 t->to_supports_multi_process = linux_nat_supports_multi_process;
5385 /* We don't change the stratum; this target will sit at
5386 process_stratum and thread_db will set at thread_stratum. This
5387 is a little strange, since this is a multi-threaded-capable
5388 target, but we want to be on the stack below thread_db, and we
5389 also want to be used for single-threaded processes. */
5394 /* Register a method to call whenever a new thread is attached. */
5396 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
5398 /* Save the pointer. We only support a single registered instance
5399 of the GNU/Linux native target, so we do not need to map this to
5401 linux_nat_new_thread = new_thread;
5404 /* Register a method that converts a siginfo object between the layout
5405 that ptrace returns, and the layout in the architecture of the
5408 linux_nat_set_siginfo_fixup (struct target_ops *t,
5409 int (*siginfo_fixup) (struct siginfo *,
5413 /* Save the pointer. */
5414 linux_nat_siginfo_fixup = siginfo_fixup;
5417 /* Return the saved siginfo associated with PTID. */
5419 linux_nat_get_siginfo (ptid_t ptid)
5421 struct lwp_info *lp = find_lwp_pid (ptid);
5423 gdb_assert (lp != NULL);
5425 return &lp->siginfo;
5428 /* Provide a prototype to silence -Wmissing-prototypes. */
5429 extern initialize_file_ftype _initialize_linux_nat;
5432 _initialize_linux_nat (void)
5436 add_info ("proc", linux_nat_info_proc_cmd, _("\
5437 Show /proc process information about any running process.\n\
5438 Specify any process id, or use the program being debugged by default.\n\
5439 Specify any of the following keywords for detailed info:\n\
5440 mappings -- list of mapped memory regions.\n\
5441 stat -- list a bunch of random process info.\n\
5442 status -- list a different bunch of random process info.\n\
5443 all -- list all available /proc info."));
5445 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
5446 &debug_linux_nat, _("\
5447 Set debugging of GNU/Linux lwp module."), _("\
5448 Show debugging of GNU/Linux lwp module."), _("\
5449 Enables printf debugging output."),
5451 show_debug_linux_nat,
5452 &setdebuglist, &showdebuglist);
5454 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
5455 &debug_linux_nat_async, _("\
5456 Set debugging of GNU/Linux async lwp module."), _("\
5457 Show debugging of GNU/Linux async lwp module."), _("\
5458 Enables printf debugging output."),
5460 show_debug_linux_nat_async,
5461 &setdebuglist, &showdebuglist);
5463 /* Save this mask as the default. */
5464 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
5466 /* Install a SIGCHLD handler. */
5467 sigchld_action.sa_handler = sigchld_handler;
5468 sigemptyset (&sigchld_action.sa_mask);
5469 sigchld_action.sa_flags = SA_RESTART;
5471 /* Make it the default. */
5472 sigaction (SIGCHLD, &sigchld_action, NULL);
5474 /* Make sure we don't block SIGCHLD during a sigsuspend. */
5475 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
5476 sigdelset (&suspend_mask, SIGCHLD);
5478 sigemptyset (&blocked_mask);
5480 add_setshow_boolean_cmd ("disable-randomization", class_support,
5481 &disable_randomization, _("\
5482 Set disabling of debuggee's virtual address space randomization."), _("\
5483 Show disabling of debuggee's virtual address space randomization."), _("\
5484 When this mode is on (which is the default), randomization of the virtual\n\
5485 address space is disabled. Standalone programs run with the randomization\n\
5486 enabled by default on some platforms."),
5487 &set_disable_randomization,
5488 &show_disable_randomization,
5489 &setlist, &showlist);
5493 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
5494 the GNU/Linux Threads library and therefore doesn't really belong
5497 /* Read variable NAME in the target and return its value if found.
5498 Otherwise return zero. It is assumed that the type of the variable
5502 get_signo (const char *name)
5504 struct minimal_symbol *ms;
5507 ms = lookup_minimal_symbol (name, NULL, NULL);
5511 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
5512 sizeof (signo)) != 0)
5518 /* Return the set of signals used by the threads library in *SET. */
5521 lin_thread_get_thread_signals (sigset_t *set)
5523 struct sigaction action;
5524 int restart, cancel;
5526 sigemptyset (&blocked_mask);
5529 restart = get_signo ("__pthread_sig_restart");
5530 cancel = get_signo ("__pthread_sig_cancel");
5532 /* LinuxThreads normally uses the first two RT signals, but in some legacy
5533 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
5534 not provide any way for the debugger to query the signal numbers -
5535 fortunately they don't change! */
5538 restart = __SIGRTMIN;
5541 cancel = __SIGRTMIN + 1;
5543 sigaddset (set, restart);
5544 sigaddset (set, cancel);
5546 /* The GNU/Linux Threads library makes terminating threads send a
5547 special "cancel" signal instead of SIGCHLD. Make sure we catch
5548 those (to prevent them from terminating GDB itself, which is
5549 likely to be their default action) and treat them the same way as
5552 action.sa_handler = sigchld_handler;
5553 sigemptyset (&action.sa_mask);
5554 action.sa_flags = SA_RESTART;
5555 sigaction (cancel, &action, NULL);
5557 /* We block the "cancel" signal throughout this code ... */
5558 sigaddset (&blocked_mask, cancel);
5559 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
5561 /* ... except during a sigsuspend. */
5562 sigdelset (&suspend_mask, cancel);