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"
58 #ifdef HAVE_PERSONALITY
59 # include <sys/personality.h>
60 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
61 # define ADDR_NO_RANDOMIZE 0x0040000
63 #endif /* HAVE_PERSONALITY */
65 /* This comment documents high-level logic of this file.
67 Waiting for events in sync mode
68 ===============================
70 When waiting for an event in a specific thread, we just use waitpid, passing
71 the specific pid, and not passing WNOHANG.
73 When waiting for an event in all threads, waitpid is not quite good. Prior to
74 version 2.4, Linux can either wait for event in main thread, or in secondary
75 threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might
76 miss an event. The solution is to use non-blocking waitpid, together with
77 sigsuspend. First, we use non-blocking waitpid to get an event in the main
78 process, if any. Second, we use non-blocking waitpid with the __WCLONED
79 flag to check for events in cloned processes. If nothing is found, we use
80 sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something
81 happened to a child process -- and SIGCHLD will be delivered both for events
82 in main debugged process and in cloned processes. As soon as we know there's
83 an event, we get back to calling nonblocking waitpid with and without __WCLONED.
85 Note that SIGCHLD should be blocked between waitpid and sigsuspend calls,
86 so that we don't miss a signal. If SIGCHLD arrives in between, when it's
87 blocked, the signal becomes pending and sigsuspend immediately
88 notices it and returns.
90 Waiting for events in async mode
91 ================================
93 In async mode, GDB should always be ready to handle both user input
94 and target events, so neither blocking waitpid nor sigsuspend are
95 viable options. Instead, we should asynchronously notify the GDB main
96 event loop whenever there's an unprocessed event from the target. We
97 detect asynchronous target events by handling SIGCHLD signals. To
98 notify the event loop about target events, the self-pipe trick is used
99 --- a pipe is registered as waitable event source in the event loop,
100 the event loop select/poll's on the read end of this pipe (as well on
101 other event sources, e.g., stdin), and the SIGCHLD handler writes a
102 byte to this pipe. This is more portable than relying on
103 pselect/ppoll, since on kernels that lack those syscalls, libc
104 emulates them with select/poll+sigprocmask, and that is racy
105 (a.k.a. plain broken).
107 Obviously, if we fail to notify the event loop if there's a target
108 event, it's bad. OTOH, if we notify the event loop when there's no
109 event from the target, linux_nat_wait will detect that there's no real
110 event to report, and return event of type TARGET_WAITKIND_IGNORE.
111 This is mostly harmless, but it will waste time and is better avoided.
113 The main design point is that every time GDB is outside linux-nat.c,
114 we have a SIGCHLD handler installed that is called when something
115 happens to the target and notifies the GDB event loop. Whenever GDB
116 core decides to handle the event, and calls into linux-nat.c, we
117 process things as in sync mode, except that the we never block in
120 While processing an event, we may end up momentarily blocked in
121 waitpid calls. Those waitpid calls, while blocking, are guarantied to
122 return quickly. E.g., in all-stop mode, before reporting to the core
123 that an LWP hit a breakpoint, all LWPs are stopped by sending them
124 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
125 Note that this is different from blocking indefinitely waiting for the
126 next event --- here, we're already handling an event.
131 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
132 signal is not entirely significant; we just need for a signal to be delivered,
133 so that we can intercept it. SIGSTOP's advantage is that it can not be
134 blocked. A disadvantage is that it is not a real-time signal, so it can only
135 be queued once; we do not keep track of other sources of SIGSTOP.
137 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
138 use them, because they have special behavior when the signal is generated -
139 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
140 kills the entire thread group.
142 A delivered SIGSTOP would stop the entire thread group, not just the thread we
143 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
144 cancel it (by PTRACE_CONT without passing SIGSTOP).
146 We could use a real-time signal instead. This would solve those problems; we
147 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
148 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
149 generates it, and there are races with trying to find a signal that is not
153 #define O_LARGEFILE 0
156 /* If the system headers did not provide the constants, hard-code the normal
158 #ifndef PTRACE_EVENT_FORK
160 #define PTRACE_SETOPTIONS 0x4200
161 #define PTRACE_GETEVENTMSG 0x4201
163 /* options set using PTRACE_SETOPTIONS */
164 #define PTRACE_O_TRACESYSGOOD 0x00000001
165 #define PTRACE_O_TRACEFORK 0x00000002
166 #define PTRACE_O_TRACEVFORK 0x00000004
167 #define PTRACE_O_TRACECLONE 0x00000008
168 #define PTRACE_O_TRACEEXEC 0x00000010
169 #define PTRACE_O_TRACEVFORKDONE 0x00000020
170 #define PTRACE_O_TRACEEXIT 0x00000040
172 /* Wait extended result codes for the above trace options. */
173 #define PTRACE_EVENT_FORK 1
174 #define PTRACE_EVENT_VFORK 2
175 #define PTRACE_EVENT_CLONE 3
176 #define PTRACE_EVENT_EXEC 4
177 #define PTRACE_EVENT_VFORK_DONE 5
178 #define PTRACE_EVENT_EXIT 6
180 #endif /* PTRACE_EVENT_FORK */
182 /* We can't always assume that this flag is available, but all systems
183 with the ptrace event handlers also have __WALL, so it's safe to use
186 #define __WALL 0x40000000 /* Wait for any child. */
189 #ifndef PTRACE_GETSIGINFO
190 # define PTRACE_GETSIGINFO 0x4202
191 # define PTRACE_SETSIGINFO 0x4203
194 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
195 the use of the multi-threaded target. */
196 static struct target_ops *linux_ops;
197 static struct target_ops linux_ops_saved;
199 /* The method to call, if any, when a new thread is attached. */
200 static void (*linux_nat_new_thread) (ptid_t);
202 /* The method to call, if any, when the siginfo object needs to be
203 converted between the layout returned by ptrace, and the layout in
204 the architecture of the inferior. */
205 static int (*linux_nat_siginfo_fixup) (struct siginfo *,
209 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
210 Called by our to_xfer_partial. */
211 static LONGEST (*super_xfer_partial) (struct target_ops *,
213 const char *, gdb_byte *,
217 static int debug_linux_nat;
219 show_debug_linux_nat (struct ui_file *file, int from_tty,
220 struct cmd_list_element *c, const char *value)
222 fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"),
226 static int debug_linux_nat_async = 0;
228 show_debug_linux_nat_async (struct ui_file *file, int from_tty,
229 struct cmd_list_element *c, const char *value)
231 fprintf_filtered (file, _("Debugging of GNU/Linux async lwp module is %s.\n"),
235 static int disable_randomization = 1;
238 show_disable_randomization (struct ui_file *file, int from_tty,
239 struct cmd_list_element *c, const char *value)
241 #ifdef HAVE_PERSONALITY
242 fprintf_filtered (file, _("\
243 Disabling randomization of debuggee's virtual address space is %s.\n"),
245 #else /* !HAVE_PERSONALITY */
247 Disabling randomization of debuggee's virtual address space is unsupported on\n\
248 this platform.\n"), file);
249 #endif /* !HAVE_PERSONALITY */
253 set_disable_randomization (char *args, int from_tty, struct cmd_list_element *c)
255 #ifndef HAVE_PERSONALITY
257 Disabling randomization of debuggee's virtual address space is unsupported on\n\
259 #endif /* !HAVE_PERSONALITY */
262 static int linux_parent_pid;
264 struct simple_pid_list
268 struct simple_pid_list *next;
270 struct simple_pid_list *stopped_pids;
272 /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK
273 can not be used, 1 if it can. */
275 static int linux_supports_tracefork_flag = -1;
277 /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have
278 PTRACE_O_TRACEVFORKDONE. */
280 static int linux_supports_tracevforkdone_flag = -1;
282 /* Async mode support */
284 /* Zero if the async mode, although enabled, is masked, which means
285 linux_nat_wait should behave as if async mode was off. */
286 static int linux_nat_async_mask_value = 1;
288 /* The read/write ends of the pipe registered as waitable file in the
290 static int linux_nat_event_pipe[2] = { -1, -1 };
292 /* Flush the event pipe. */
295 async_file_flush (void)
302 ret = read (linux_nat_event_pipe[0], &buf, 1);
304 while (ret >= 0 || (ret == -1 && errno == EINTR));
307 /* Put something (anything, doesn't matter what, or how much) in event
308 pipe, so that the select/poll in the event-loop realizes we have
309 something to process. */
312 async_file_mark (void)
316 /* It doesn't really matter what the pipe contains, as long we end
317 up with something in it. Might as well flush the previous
323 ret = write (linux_nat_event_pipe[1], "+", 1);
325 while (ret == -1 && errno == EINTR);
327 /* Ignore EAGAIN. If the pipe is full, the event loop will already
328 be awakened anyway. */
331 static void linux_nat_async (void (*callback)
332 (enum inferior_event_type event_type, void *context),
334 static int linux_nat_async_mask (int mask);
335 static int kill_lwp (int lwpid, int signo);
337 static int stop_callback (struct lwp_info *lp, void *data);
339 static void block_child_signals (sigset_t *prev_mask);
340 static void restore_child_signals_mask (sigset_t *prev_mask);
342 /* Trivial list manipulation functions to keep track of a list of
343 new stopped processes. */
345 add_to_pid_list (struct simple_pid_list **listp, int pid, int status)
347 struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list));
349 new_pid->status = status;
350 new_pid->next = *listp;
355 pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status)
357 struct simple_pid_list **p;
359 for (p = listp; *p != NULL; p = &(*p)->next)
360 if ((*p)->pid == pid)
362 struct simple_pid_list *next = (*p)->next;
363 *status = (*p)->status;
372 linux_record_stopped_pid (int pid, int status)
374 add_to_pid_list (&stopped_pids, pid, status);
378 /* A helper function for linux_test_for_tracefork, called after fork (). */
381 linux_tracefork_child (void)
385 ptrace (PTRACE_TRACEME, 0, 0, 0);
386 kill (getpid (), SIGSTOP);
391 /* Wrapper function for waitpid which handles EINTR. */
394 my_waitpid (int pid, int *status, int flags)
400 ret = waitpid (pid, status, flags);
402 while (ret == -1 && errno == EINTR);
407 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events.
409 First, we try to enable fork tracing on ORIGINAL_PID. If this fails,
410 we know that the feature is not available. This may change the tracing
411 options for ORIGINAL_PID, but we'll be setting them shortly anyway.
413 However, if it succeeds, we don't know for sure that the feature is
414 available; old versions of PTRACE_SETOPTIONS ignored unknown options. We
415 create a child process, attach to it, use PTRACE_SETOPTIONS to enable
416 fork tracing, and let it fork. If the process exits, we assume that we
417 can't use TRACEFORK; if we get the fork notification, and we can extract
418 the new child's PID, then we assume that we can. */
421 linux_test_for_tracefork (int original_pid)
423 int child_pid, ret, status;
427 /* We don't want those ptrace calls to be interrupted. */
428 block_child_signals (&prev_mask);
430 linux_supports_tracefork_flag = 0;
431 linux_supports_tracevforkdone_flag = 0;
433 ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK);
436 restore_child_signals_mask (&prev_mask);
442 perror_with_name (("fork"));
445 linux_tracefork_child ();
447 ret = my_waitpid (child_pid, &status, 0);
449 perror_with_name (("waitpid"));
450 else if (ret != child_pid)
451 error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret);
452 if (! WIFSTOPPED (status))
453 error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status);
455 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
458 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
461 warning (_("linux_test_for_tracefork: failed to kill child"));
462 restore_child_signals_mask (&prev_mask);
466 ret = my_waitpid (child_pid, &status, 0);
467 if (ret != child_pid)
468 warning (_("linux_test_for_tracefork: failed to wait for killed child"));
469 else if (!WIFSIGNALED (status))
470 warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from "
471 "killed child"), status);
473 restore_child_signals_mask (&prev_mask);
477 /* Check whether PTRACE_O_TRACEVFORKDONE is available. */
478 ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
479 PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE);
480 linux_supports_tracevforkdone_flag = (ret == 0);
482 ret = ptrace (PTRACE_CONT, child_pid, 0, 0);
484 warning (_("linux_test_for_tracefork: failed to resume child"));
486 ret = my_waitpid (child_pid, &status, 0);
488 if (ret == child_pid && WIFSTOPPED (status)
489 && status >> 16 == PTRACE_EVENT_FORK)
492 ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid);
493 if (ret == 0 && second_pid != 0)
497 linux_supports_tracefork_flag = 1;
498 my_waitpid (second_pid, &second_status, 0);
499 ret = ptrace (PTRACE_KILL, second_pid, 0, 0);
501 warning (_("linux_test_for_tracefork: failed to kill second child"));
502 my_waitpid (second_pid, &status, 0);
506 warning (_("linux_test_for_tracefork: unexpected result from waitpid "
507 "(%d, status 0x%x)"), ret, status);
509 ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
511 warning (_("linux_test_for_tracefork: failed to kill child"));
512 my_waitpid (child_pid, &status, 0);
514 restore_child_signals_mask (&prev_mask);
517 /* Return non-zero iff we have tracefork functionality available.
518 This function also sets linux_supports_tracefork_flag. */
521 linux_supports_tracefork (int pid)
523 if (linux_supports_tracefork_flag == -1)
524 linux_test_for_tracefork (pid);
525 return linux_supports_tracefork_flag;
529 linux_supports_tracevforkdone (int pid)
531 if (linux_supports_tracefork_flag == -1)
532 linux_test_for_tracefork (pid);
533 return linux_supports_tracevforkdone_flag;
538 linux_enable_event_reporting (ptid_t ptid)
540 int pid = ptid_get_lwp (ptid);
544 pid = ptid_get_pid (ptid);
546 if (! linux_supports_tracefork (pid))
549 options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC
550 | PTRACE_O_TRACECLONE;
551 if (linux_supports_tracevforkdone (pid))
552 options |= PTRACE_O_TRACEVFORKDONE;
554 /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support
555 read-only process state. */
557 ptrace (PTRACE_SETOPTIONS, pid, 0, options);
561 linux_child_post_attach (int pid)
563 linux_enable_event_reporting (pid_to_ptid (pid));
564 check_for_thread_db ();
568 linux_child_post_startup_inferior (ptid_t ptid)
570 linux_enable_event_reporting (ptid);
571 check_for_thread_db ();
575 linux_child_follow_fork (struct target_ops *ops, int follow_child)
579 int parent_pid, child_pid;
581 block_child_signals (&prev_mask);
583 has_vforked = (inferior_thread ()->pending_follow.kind
584 == TARGET_WAITKIND_VFORKED);
585 parent_pid = ptid_get_lwp (inferior_ptid);
587 parent_pid = ptid_get_pid (inferior_ptid);
588 child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid);
592 /* We're already attached to the parent, by default. */
594 /* Before detaching from the child, remove all breakpoints from
595 it. If we forked, then this has already been taken care of
596 by infrun.c. If we vforked however, any breakpoint inserted
597 in the parent is visible in the child, even those added while
598 stopped in a vfork catchpoint. This won't actually modify
599 the breakpoint list, but will physically remove the
600 breakpoints from the child. This will remove the breakpoints
601 from the parent also, but they'll be reinserted below. */
603 detach_breakpoints (child_pid);
605 /* Detach new forked process? */
608 if (info_verbose || debug_linux_nat)
610 target_terminal_ours ();
611 fprintf_filtered (gdb_stdlog,
612 "Detaching after fork from child process %d.\n",
616 ptrace (PTRACE_DETACH, child_pid, 0, 0);
620 struct fork_info *fp;
621 struct inferior *parent_inf, *child_inf;
623 /* Add process to GDB's tables. */
624 child_inf = add_inferior (child_pid);
626 parent_inf = current_inferior ();
627 child_inf->attach_flag = parent_inf->attach_flag;
628 copy_terminal_info (child_inf, parent_inf);
630 /* Retain child fork in ptrace (stopped) state. */
631 fp = find_fork_pid (child_pid);
633 fp = add_fork (child_pid);
634 fork_save_infrun_state (fp, 0);
639 gdb_assert (linux_supports_tracefork_flag >= 0);
640 if (linux_supports_tracevforkdone (0))
644 ptrace (PTRACE_CONT, parent_pid, 0, 0);
645 my_waitpid (parent_pid, &status, __WALL);
646 if ((status >> 16) != PTRACE_EVENT_VFORK_DONE)
647 warning (_("Unexpected waitpid result %06x when waiting for "
648 "vfork-done"), status);
652 /* We can't insert breakpoints until the child has
653 finished with the shared memory region. We need to
654 wait until that happens. Ideal would be to just
656 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
657 - waitpid (parent_pid, &status, __WALL);
658 However, most architectures can't handle a syscall
659 being traced on the way out if it wasn't traced on
662 We might also think to loop, continuing the child
663 until it exits or gets a SIGTRAP. One problem is
664 that the child might call ptrace with PTRACE_TRACEME.
666 There's no simple and reliable way to figure out when
667 the vforked child will be done with its copy of the
668 shared memory. We could step it out of the syscall,
669 two instructions, let it go, and then single-step the
670 parent once. When we have hardware single-step, this
671 would work; with software single-step it could still
672 be made to work but we'd have to be able to insert
673 single-step breakpoints in the child, and we'd have
674 to insert -just- the single-step breakpoint in the
675 parent. Very awkward.
677 In the end, the best we can do is to make sure it
678 runs for a little while. Hopefully it will be out of
679 range of any breakpoints we reinsert. Usually this
680 is only the single-step breakpoint at vfork's return
686 /* Since we vforked, breakpoints were removed in the parent
687 too. Put them back. */
688 reattach_breakpoints (parent_pid);
693 struct thread_info *tp;
694 struct inferior *parent_inf, *child_inf;
696 /* Before detaching from the parent, remove all breakpoints from it. */
697 remove_breakpoints ();
699 if (info_verbose || debug_linux_nat)
701 target_terminal_ours ();
702 fprintf_filtered (gdb_stdlog,
703 "Attaching after fork to child process %d.\n",
707 /* Add the new inferior first, so that the target_detach below
708 doesn't unpush the target. */
710 child_inf = add_inferior (child_pid);
712 parent_inf = current_inferior ();
713 child_inf->attach_flag = parent_inf->attach_flag;
714 copy_terminal_info (child_inf, parent_inf);
716 /* If we're vforking, we may want to hold on to the parent until
717 the child exits or execs. At exec time we can remove the old
718 breakpoints from the parent and detach it; at exit time we
719 could do the same (or even, sneakily, resume debugging it - the
720 child's exec has failed, or something similar).
722 This doesn't clean up "properly", because we can't call
723 target_detach, but that's OK; if the current target is "child",
724 then it doesn't need any further cleanups, and lin_lwp will
725 generally not encounter vfork (vfork is defined to fork
728 The holding part is very easy if we have VFORKDONE events;
729 but keeping track of both processes is beyond GDB at the
730 moment. So we don't expose the parent to the rest of GDB.
731 Instead we quietly hold onto it until such time as we can
736 linux_parent_pid = parent_pid;
737 detach_inferior (parent_pid);
739 else if (!detach_fork)
741 struct fork_info *fp;
742 /* Retain parent fork in ptrace (stopped) state. */
743 fp = find_fork_pid (parent_pid);
745 fp = add_fork (parent_pid);
746 fork_save_infrun_state (fp, 0);
748 /* Also add an entry for the child fork. */
749 fp = find_fork_pid (child_pid);
751 fp = add_fork (child_pid);
752 fork_save_infrun_state (fp, 0);
755 target_detach (NULL, 0);
757 inferior_ptid = ptid_build (child_pid, child_pid, 0);
759 linux_nat_switch_fork (inferior_ptid);
760 check_for_thread_db ();
763 restore_child_signals_mask (&prev_mask);
769 linux_child_insert_fork_catchpoint (int pid)
771 if (! linux_supports_tracefork (pid))
772 error (_("Your system does not support fork catchpoints."));
776 linux_child_insert_vfork_catchpoint (int pid)
778 if (!linux_supports_tracefork (pid))
779 error (_("Your system does not support vfork catchpoints."));
783 linux_child_insert_exec_catchpoint (int pid)
785 if (!linux_supports_tracefork (pid))
786 error (_("Your system does not support exec catchpoints."));
789 /* On GNU/Linux there are no real LWP's. The closest thing to LWP's
790 are processes sharing the same VM space. A multi-threaded process
791 is basically a group of such processes. However, such a grouping
792 is almost entirely a user-space issue; the kernel doesn't enforce
793 such a grouping at all (this might change in the future). In
794 general, we'll rely on the threads library (i.e. the GNU/Linux
795 Threads library) to provide such a grouping.
797 It is perfectly well possible to write a multi-threaded application
798 without the assistance of a threads library, by using the clone
799 system call directly. This module should be able to give some
800 rudimentary support for debugging such applications if developers
801 specify the CLONE_PTRACE flag in the clone system call, and are
802 using the Linux kernel 2.4 or above.
804 Note that there are some peculiarities in GNU/Linux that affect
807 - In general one should specify the __WCLONE flag to waitpid in
808 order to make it report events for any of the cloned processes
809 (and leave it out for the initial process). However, if a cloned
810 process has exited the exit status is only reported if the
811 __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but
812 we cannot use it since GDB must work on older systems too.
814 - When a traced, cloned process exits and is waited for by the
815 debugger, the kernel reassigns it to the original parent and
816 keeps it around as a "zombie". Somehow, the GNU/Linux Threads
817 library doesn't notice this, which leads to the "zombie problem":
818 When debugged a multi-threaded process that spawns a lot of
819 threads will run out of processes, even if the threads exit,
820 because the "zombies" stay around. */
822 /* List of known LWPs. */
823 struct lwp_info *lwp_list;
826 /* Original signal mask. */
827 static sigset_t normal_mask;
829 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
830 _initialize_linux_nat. */
831 static sigset_t suspend_mask;
833 /* Signals to block to make that sigsuspend work. */
834 static sigset_t blocked_mask;
836 /* SIGCHLD action. */
837 struct sigaction sigchld_action;
839 /* Block child signals (SIGCHLD and linux threads signals), and store
840 the previous mask in PREV_MASK. */
843 block_child_signals (sigset_t *prev_mask)
845 /* Make sure SIGCHLD is blocked. */
846 if (!sigismember (&blocked_mask, SIGCHLD))
847 sigaddset (&blocked_mask, SIGCHLD);
849 sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask);
852 /* Restore child signals mask, previously returned by
853 block_child_signals. */
856 restore_child_signals_mask (sigset_t *prev_mask)
858 sigprocmask (SIG_SETMASK, prev_mask, NULL);
862 /* Prototypes for local functions. */
863 static int stop_wait_callback (struct lwp_info *lp, void *data);
864 static int linux_thread_alive (ptid_t ptid);
865 static char *linux_child_pid_to_exec_file (int pid);
866 static int cancel_breakpoint (struct lwp_info *lp);
869 /* Convert wait status STATUS to a string. Used for printing debug
873 status_to_str (int status)
877 if (WIFSTOPPED (status))
878 snprintf (buf, sizeof (buf), "%s (stopped)",
879 strsignal (WSTOPSIG (status)));
880 else if (WIFSIGNALED (status))
881 snprintf (buf, sizeof (buf), "%s (terminated)",
882 strsignal (WSTOPSIG (status)));
884 snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status));
889 /* Initialize the list of LWPs. Note that this module, contrary to
890 what GDB's generic threads layer does for its thread list,
891 re-initializes the LWP lists whenever we mourn or detach (which
892 doesn't involve mourning) the inferior. */
897 struct lwp_info *lp, *lpnext;
899 for (lp = lwp_list; lp; lp = lpnext)
908 /* Remove all LWPs belong to PID from the lwp list. */
911 purge_lwp_list (int pid)
913 struct lwp_info *lp, *lpprev, *lpnext;
917 for (lp = lwp_list; lp; lp = lpnext)
921 if (ptid_get_pid (lp->ptid) == pid)
926 lpprev->next = lp->next;
935 /* Return the number of known LWPs in the tgid given by PID. */
943 for (lp = lwp_list; lp; lp = lp->next)
944 if (ptid_get_pid (lp->ptid) == pid)
950 /* Add the LWP specified by PID to the list. Return a pointer to the
951 structure describing the new LWP. The LWP should already be stopped
952 (with an exception for the very first LWP). */
954 static struct lwp_info *
955 add_lwp (ptid_t ptid)
959 gdb_assert (is_lwp (ptid));
961 lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info));
963 memset (lp, 0, sizeof (struct lwp_info));
965 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
972 if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL)
973 linux_nat_new_thread (ptid);
978 /* Remove the LWP specified by PID from the list. */
981 delete_lwp (ptid_t ptid)
983 struct lwp_info *lp, *lpprev;
987 for (lp = lwp_list; lp; lpprev = lp, lp = lp->next)
988 if (ptid_equal (lp->ptid, ptid))
995 lpprev->next = lp->next;
1002 /* Return a pointer to the structure describing the LWP corresponding
1003 to PID. If no corresponding LWP could be found, return NULL. */
1005 static struct lwp_info *
1006 find_lwp_pid (ptid_t ptid)
1008 struct lwp_info *lp;
1012 lwp = GET_LWP (ptid);
1014 lwp = GET_PID (ptid);
1016 for (lp = lwp_list; lp; lp = lp->next)
1017 if (lwp == GET_LWP (lp->ptid))
1023 /* Returns true if PTID matches filter FILTER. FILTER can be the wild
1024 card MINUS_ONE_PTID (all ptid match it); can be a ptid representing
1025 a process (ptid_is_pid returns true), in which case, all lwps of
1026 that give process match, lwps of other process do not; or, it can
1027 represent a specific thread, in which case, only that thread will
1028 match true. PTID must represent an LWP, it can never be a wild
1032 ptid_match (ptid_t ptid, ptid_t filter)
1034 /* Since both parameters have the same type, prevent easy mistakes
1036 gdb_assert (!ptid_equal (ptid, minus_one_ptid)
1037 && !ptid_equal (ptid, null_ptid));
1039 if (ptid_equal (filter, minus_one_ptid))
1041 if (ptid_is_pid (filter)
1042 && ptid_get_pid (ptid) == ptid_get_pid (filter))
1044 else if (ptid_equal (ptid, filter))
1050 /* Call CALLBACK with its second argument set to DATA for every LWP in
1051 the list. If CALLBACK returns 1 for a particular LWP, return a
1052 pointer to the structure describing that LWP immediately.
1053 Otherwise return NULL. */
1056 iterate_over_lwps (ptid_t filter,
1057 int (*callback) (struct lwp_info *, void *),
1060 struct lwp_info *lp, *lpnext;
1062 for (lp = lwp_list; lp; lp = lpnext)
1066 if (ptid_match (lp->ptid, filter))
1068 if ((*callback) (lp, data))
1076 /* Update our internal state when changing from one fork (checkpoint,
1077 et cetera) to another indicated by NEW_PTID. We can only switch
1078 single-threaded applications, so we only create one new LWP, and
1079 the previous list is discarded. */
1082 linux_nat_switch_fork (ptid_t new_ptid)
1084 struct lwp_info *lp;
1087 lp = add_lwp (new_ptid);
1090 init_thread_list ();
1091 add_thread_silent (new_ptid);
1094 /* Handle the exit of a single thread LP. */
1097 exit_lwp (struct lwp_info *lp)
1099 struct thread_info *th = find_thread_pid (lp->ptid);
1103 if (print_thread_events)
1104 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid));
1106 delete_thread (lp->ptid);
1109 delete_lwp (lp->ptid);
1112 /* Return an lwp's tgid, found in `/proc/PID/status'. */
1115 linux_proc_get_tgid (int lwpid)
1121 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
1122 status_file = fopen (buf, "r");
1123 if (status_file != NULL)
1125 while (fgets (buf, sizeof (buf), status_file))
1127 if (strncmp (buf, "Tgid:", 5) == 0)
1129 tgid = strtoul (buf + strlen ("Tgid:"), NULL, 10);
1134 fclose (status_file);
1140 /* Detect `T (stopped)' in `/proc/PID/status'.
1141 Other states including `T (tracing stop)' are reported as false. */
1144 pid_is_stopped (pid_t pid)
1150 snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid);
1151 status_file = fopen (buf, "r");
1152 if (status_file != NULL)
1156 while (fgets (buf, sizeof (buf), status_file))
1158 if (strncmp (buf, "State:", 6) == 0)
1164 if (have_state && strstr (buf, "T (stopped)") != NULL)
1166 fclose (status_file);
1171 /* Wait for the LWP specified by LP, which we have just attached to.
1172 Returns a wait status for that LWP, to cache. */
1175 linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned,
1178 pid_t new_pid, pid = GET_LWP (ptid);
1181 if (pid_is_stopped (pid))
1183 if (debug_linux_nat)
1184 fprintf_unfiltered (gdb_stdlog,
1185 "LNPAW: Attaching to a stopped process\n");
1187 /* The process is definitely stopped. It is in a job control
1188 stop, unless the kernel predates the TASK_STOPPED /
1189 TASK_TRACED distinction, in which case it might be in a
1190 ptrace stop. Make sure it is in a ptrace stop; from there we
1191 can kill it, signal it, et cetera.
1193 First make sure there is a pending SIGSTOP. Since we are
1194 already attached, the process can not transition from stopped
1195 to running without a PTRACE_CONT; so we know this signal will
1196 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1197 probably already in the queue (unless this kernel is old
1198 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1199 is not an RT signal, it can only be queued once. */
1200 kill_lwp (pid, SIGSTOP);
1202 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1203 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1204 ptrace (PTRACE_CONT, pid, 0, 0);
1207 /* Make sure the initial process is stopped. The user-level threads
1208 layer might want to poke around in the inferior, and that won't
1209 work if things haven't stabilized yet. */
1210 new_pid = my_waitpid (pid, &status, 0);
1211 if (new_pid == -1 && errno == ECHILD)
1214 warning (_("%s is a cloned process"), target_pid_to_str (ptid));
1216 /* Try again with __WCLONE to check cloned processes. */
1217 new_pid = my_waitpid (pid, &status, __WCLONE);
1221 gdb_assert (pid == new_pid && WIFSTOPPED (status));
1223 if (WSTOPSIG (status) != SIGSTOP)
1226 if (debug_linux_nat)
1227 fprintf_unfiltered (gdb_stdlog,
1228 "LNPAW: Received %s after attaching\n",
1229 status_to_str (status));
1235 /* Attach to the LWP specified by PID. Return 0 if successful or -1
1236 if the new LWP could not be attached. */
1239 lin_lwp_attach_lwp (ptid_t ptid)
1241 struct lwp_info *lp;
1244 gdb_assert (is_lwp (ptid));
1246 block_child_signals (&prev_mask);
1248 lp = find_lwp_pid (ptid);
1250 /* We assume that we're already attached to any LWP that has an id
1251 equal to the overall process id, and to any LWP that is already
1252 in our list of LWPs. If we're not seeing exit events from threads
1253 and we've had PID wraparound since we last tried to stop all threads,
1254 this assumption might be wrong; fortunately, this is very unlikely
1256 if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL)
1258 int status, cloned = 0, signalled = 0;
1260 if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0)
1262 /* If we fail to attach to the thread, issue a warning,
1263 but continue. One way this can happen is if thread
1264 creation is interrupted; as of Linux kernel 2.6.19, a
1265 bug may place threads in the thread list and then fail
1267 warning (_("Can't attach %s: %s"), target_pid_to_str (ptid),
1268 safe_strerror (errno));
1269 restore_child_signals_mask (&prev_mask);
1273 if (debug_linux_nat)
1274 fprintf_unfiltered (gdb_stdlog,
1275 "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n",
1276 target_pid_to_str (ptid));
1278 status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled);
1279 lp = add_lwp (ptid);
1281 lp->cloned = cloned;
1282 lp->signalled = signalled;
1283 if (WSTOPSIG (status) != SIGSTOP)
1286 lp->status = status;
1289 target_post_attach (GET_LWP (lp->ptid));
1291 if (debug_linux_nat)
1293 fprintf_unfiltered (gdb_stdlog,
1294 "LLAL: waitpid %s received %s\n",
1295 target_pid_to_str (ptid),
1296 status_to_str (status));
1301 /* We assume that the LWP representing the original process is
1302 already stopped. Mark it as stopped in the data structure
1303 that the GNU/linux ptrace layer uses to keep track of
1304 threads. Note that this won't have already been done since
1305 the main thread will have, we assume, been stopped by an
1306 attach from a different layer. */
1308 lp = add_lwp (ptid);
1312 restore_child_signals_mask (&prev_mask);
1317 linux_nat_create_inferior (struct target_ops *ops,
1318 char *exec_file, char *allargs, char **env,
1321 #ifdef HAVE_PERSONALITY
1322 int personality_orig = 0, personality_set = 0;
1323 #endif /* HAVE_PERSONALITY */
1325 /* The fork_child mechanism is synchronous and calls target_wait, so
1326 we have to mask the async mode. */
1328 #ifdef HAVE_PERSONALITY
1329 if (disable_randomization)
1332 personality_orig = personality (0xffffffff);
1333 if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE))
1335 personality_set = 1;
1336 personality (personality_orig | ADDR_NO_RANDOMIZE);
1338 if (errno != 0 || (personality_set
1339 && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE)))
1340 warning (_("Error disabling address space randomization: %s"),
1341 safe_strerror (errno));
1343 #endif /* HAVE_PERSONALITY */
1345 linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty);
1347 #ifdef HAVE_PERSONALITY
1348 if (personality_set)
1351 personality (personality_orig);
1353 warning (_("Error restoring address space randomization: %s"),
1354 safe_strerror (errno));
1356 #endif /* HAVE_PERSONALITY */
1360 linux_nat_attach (struct target_ops *ops, char *args, int from_tty)
1362 struct lwp_info *lp;
1366 linux_ops->to_attach (ops, args, from_tty);
1368 /* The ptrace base target adds the main thread with (pid,0,0)
1369 format. Decorate it with lwp info. */
1370 ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid));
1371 thread_change_ptid (inferior_ptid, ptid);
1373 /* Add the initial process as the first LWP to the list. */
1374 lp = add_lwp (ptid);
1376 status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned,
1380 /* Save the wait status to report later. */
1382 if (debug_linux_nat)
1383 fprintf_unfiltered (gdb_stdlog,
1384 "LNA: waitpid %ld, saving status %s\n",
1385 (long) GET_PID (lp->ptid), status_to_str (status));
1387 lp->status = status;
1389 if (target_can_async_p ())
1390 target_async (inferior_event_handler, 0);
1393 /* Get pending status of LP. */
1395 get_pending_status (struct lwp_info *lp, int *status)
1397 struct target_waitstatus last;
1400 get_last_target_status (&last_ptid, &last);
1402 /* If this lwp is the ptid that GDB is processing an event from, the
1403 signal will be in stop_signal. Otherwise, we may cache pending
1404 events in lp->status while trying to stop all threads (see
1405 stop_wait_callback). */
1411 enum target_signal signo = TARGET_SIGNAL_0;
1413 if (is_executing (lp->ptid))
1415 /* If the core thought this lwp was executing --- e.g., the
1416 executing property hasn't been updated yet, but the
1417 thread has been stopped with a stop_callback /
1418 stop_wait_callback sequence (see linux_nat_detach for
1419 example) --- we can only have pending events in the local
1421 signo = target_signal_from_host (WSTOPSIG (lp->status));
1425 /* If the core knows the thread is not executing, then we
1426 have the last signal recorded in
1427 thread_info->stop_signal. */
1429 struct thread_info *tp = find_thread_pid (lp->ptid);
1430 signo = tp->stop_signal;
1433 if (signo != TARGET_SIGNAL_0
1434 && !signal_pass_state (signo))
1436 if (debug_linux_nat)
1437 fprintf_unfiltered (gdb_stdlog, "\
1438 GPT: lwp %s had signal %s, but it is in no pass state\n",
1439 target_pid_to_str (lp->ptid),
1440 target_signal_to_string (signo));
1444 if (signo != TARGET_SIGNAL_0)
1445 *status = W_STOPCODE (target_signal_to_host (signo));
1447 if (debug_linux_nat)
1448 fprintf_unfiltered (gdb_stdlog,
1449 "GPT: lwp %s as pending signal %s\n",
1450 target_pid_to_str (lp->ptid),
1451 target_signal_to_string (signo));
1456 if (GET_LWP (lp->ptid) == GET_LWP (last_ptid))
1458 struct thread_info *tp = find_thread_pid (lp->ptid);
1459 if (tp->stop_signal != TARGET_SIGNAL_0
1460 && signal_pass_state (tp->stop_signal))
1461 *status = W_STOPCODE (target_signal_to_host (tp->stop_signal));
1464 *status = lp->status;
1471 detach_callback (struct lwp_info *lp, void *data)
1473 gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status));
1475 if (debug_linux_nat && lp->status)
1476 fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n",
1477 strsignal (WSTOPSIG (lp->status)),
1478 target_pid_to_str (lp->ptid));
1480 /* If there is a pending SIGSTOP, get rid of it. */
1483 if (debug_linux_nat)
1484 fprintf_unfiltered (gdb_stdlog,
1485 "DC: Sending SIGCONT to %s\n",
1486 target_pid_to_str (lp->ptid));
1488 kill_lwp (GET_LWP (lp->ptid), SIGCONT);
1492 /* We don't actually detach from the LWP that has an id equal to the
1493 overall process id just yet. */
1494 if (GET_LWP (lp->ptid) != GET_PID (lp->ptid))
1498 /* Pass on any pending signal for this LWP. */
1499 get_pending_status (lp, &status);
1502 if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0,
1503 WSTOPSIG (status)) < 0)
1504 error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid),
1505 safe_strerror (errno));
1507 if (debug_linux_nat)
1508 fprintf_unfiltered (gdb_stdlog,
1509 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1510 target_pid_to_str (lp->ptid),
1511 strsignal (WSTOPSIG (status)));
1513 delete_lwp (lp->ptid);
1520 linux_nat_detach (struct target_ops *ops, char *args, int from_tty)
1524 enum target_signal sig;
1525 struct lwp_info *main_lwp;
1527 pid = GET_PID (inferior_ptid);
1529 if (target_can_async_p ())
1530 linux_nat_async (NULL, 0);
1532 /* Stop all threads before detaching. ptrace requires that the
1533 thread is stopped to sucessfully detach. */
1534 iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL);
1535 /* ... and wait until all of them have reported back that
1536 they're no longer running. */
1537 iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL);
1539 iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL);
1541 /* Only the initial process should be left right now. */
1542 gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1);
1544 main_lwp = find_lwp_pid (pid_to_ptid (pid));
1546 /* Pass on any pending signal for the last LWP. */
1547 if ((args == NULL || *args == '\0')
1548 && get_pending_status (main_lwp, &status) != -1
1549 && WIFSTOPPED (status))
1551 /* Put the signal number in ARGS so that inf_ptrace_detach will
1552 pass it along with PTRACE_DETACH. */
1554 sprintf (args, "%d", (int) WSTOPSIG (status));
1555 fprintf_unfiltered (gdb_stdlog,
1556 "LND: Sending signal %s to %s\n",
1558 target_pid_to_str (main_lwp->ptid));
1561 delete_lwp (main_lwp->ptid);
1563 if (forks_exist_p ())
1565 /* Multi-fork case. The current inferior_ptid is being detached
1566 from, but there are other viable forks to debug. Detach from
1567 the current fork, and context-switch to the first
1569 linux_fork_detach (args, from_tty);
1571 if (non_stop && target_can_async_p ())
1572 target_async (inferior_event_handler, 0);
1575 linux_ops->to_detach (ops, args, from_tty);
1581 resume_callback (struct lwp_info *lp, void *data)
1583 if (lp->stopped && lp->status == 0)
1585 if (debug_linux_nat)
1586 fprintf_unfiltered (gdb_stdlog,
1587 "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n",
1588 target_pid_to_str (lp->ptid));
1590 linux_ops->to_resume (linux_ops,
1591 pid_to_ptid (GET_LWP (lp->ptid)),
1592 0, TARGET_SIGNAL_0);
1593 if (debug_linux_nat)
1594 fprintf_unfiltered (gdb_stdlog,
1595 "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n",
1596 target_pid_to_str (lp->ptid));
1599 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1601 else if (lp->stopped && debug_linux_nat)
1602 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (has pending)\n",
1603 target_pid_to_str (lp->ptid));
1604 else if (debug_linux_nat)
1605 fprintf_unfiltered (gdb_stdlog, "RC: Not resuming sibling %s (not stopped)\n",
1606 target_pid_to_str (lp->ptid));
1612 resume_clear_callback (struct lwp_info *lp, void *data)
1619 resume_set_callback (struct lwp_info *lp, void *data)
1626 linux_nat_resume (struct target_ops *ops,
1627 ptid_t ptid, int step, enum target_signal signo)
1630 struct lwp_info *lp;
1633 if (debug_linux_nat)
1634 fprintf_unfiltered (gdb_stdlog,
1635 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1636 step ? "step" : "resume",
1637 target_pid_to_str (ptid),
1638 signo ? strsignal (signo) : "0",
1639 target_pid_to_str (inferior_ptid));
1641 block_child_signals (&prev_mask);
1643 /* A specific PTID means `step only this process id'. */
1644 resume_many = (ptid_equal (minus_one_ptid, ptid)
1645 || ptid_is_pid (ptid));
1649 /* Mark the lwps we're resuming as resumed. */
1650 iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL);
1651 iterate_over_lwps (ptid, resume_set_callback, NULL);
1654 iterate_over_lwps (minus_one_ptid, resume_set_callback, NULL);
1656 /* See if it's the current inferior that should be handled
1659 lp = find_lwp_pid (inferior_ptid);
1661 lp = find_lwp_pid (ptid);
1662 gdb_assert (lp != NULL);
1664 /* Remember if we're stepping. */
1667 /* If we have a pending wait status for this thread, there is no
1668 point in resuming the process. But first make sure that
1669 linux_nat_wait won't preemptively handle the event - we
1670 should never take this short-circuit if we are going to
1671 leave LP running, since we have skipped resuming all the
1672 other threads. This bit of code needs to be synchronized
1673 with linux_nat_wait. */
1675 if (lp->status && WIFSTOPPED (lp->status))
1678 struct inferior *inf;
1680 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
1682 saved_signo = target_signal_from_host (WSTOPSIG (lp->status));
1684 /* Defer to common code if we're gaining control of the
1686 if (inf->stop_soon == NO_STOP_QUIETLY
1687 && signal_stop_state (saved_signo) == 0
1688 && signal_print_state (saved_signo) == 0
1689 && signal_pass_state (saved_signo) == 1)
1691 if (debug_linux_nat)
1692 fprintf_unfiltered (gdb_stdlog,
1693 "LLR: Not short circuiting for ignored "
1694 "status 0x%x\n", lp->status);
1696 /* FIXME: What should we do if we are supposed to continue
1697 this thread with a signal? */
1698 gdb_assert (signo == TARGET_SIGNAL_0);
1699 signo = saved_signo;
1706 /* FIXME: What should we do if we are supposed to continue
1707 this thread with a signal? */
1708 gdb_assert (signo == TARGET_SIGNAL_0);
1710 if (debug_linux_nat)
1711 fprintf_unfiltered (gdb_stdlog,
1712 "LLR: Short circuiting for status 0x%x\n",
1715 restore_child_signals_mask (&prev_mask);
1716 if (target_can_async_p ())
1718 target_async (inferior_event_handler, 0);
1719 /* Tell the event loop we have something to process. */
1725 /* Mark LWP as not stopped to prevent it from being continued by
1730 iterate_over_lwps (ptid, resume_callback, NULL);
1732 /* Convert to something the lower layer understands. */
1733 ptid = pid_to_ptid (GET_LWP (lp->ptid));
1735 linux_ops->to_resume (linux_ops, ptid, step, signo);
1736 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
1738 if (debug_linux_nat)
1739 fprintf_unfiltered (gdb_stdlog,
1740 "LLR: %s %s, %s (resume event thread)\n",
1741 step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1742 target_pid_to_str (ptid),
1743 signo ? strsignal (signo) : "0");
1745 restore_child_signals_mask (&prev_mask);
1746 if (target_can_async_p ())
1747 target_async (inferior_event_handler, 0);
1750 /* Issue kill to specified lwp. */
1752 static int tkill_failed;
1755 kill_lwp (int lwpid, int signo)
1759 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1760 fails, then we are not using nptl threads and we should be using kill. */
1762 #ifdef HAVE_TKILL_SYSCALL
1765 int ret = syscall (__NR_tkill, lwpid, signo);
1766 if (errno != ENOSYS)
1773 return kill (lwpid, signo);
1776 /* Handle a GNU/Linux extended wait response. If we see a clone
1777 event, we need to add the new LWP to our list (and not report the
1778 trap to higher layers). This function returns non-zero if the
1779 event should be ignored and we should wait again. If STOPPING is
1780 true, the new LWP remains stopped, otherwise it is continued. */
1783 linux_handle_extended_wait (struct lwp_info *lp, int status,
1786 int pid = GET_LWP (lp->ptid);
1787 struct target_waitstatus *ourstatus = &lp->waitstatus;
1788 struct lwp_info *new_lp = NULL;
1789 int event = status >> 16;
1791 if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK
1792 || event == PTRACE_EVENT_CLONE)
1794 unsigned long new_pid;
1797 ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
1799 /* If we haven't already seen the new PID stop, wait for it now. */
1800 if (! pull_pid_from_list (&stopped_pids, new_pid, &status))
1802 /* The new child has a pending SIGSTOP. We can't affect it until it
1803 hits the SIGSTOP, but we're already attached. */
1804 ret = my_waitpid (new_pid, &status,
1805 (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0);
1807 perror_with_name (_("waiting for new child"));
1808 else if (ret != new_pid)
1809 internal_error (__FILE__, __LINE__,
1810 _("wait returned unexpected PID %d"), ret);
1811 else if (!WIFSTOPPED (status))
1812 internal_error (__FILE__, __LINE__,
1813 _("wait returned unexpected status 0x%x"), status);
1816 ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0);
1818 if (event == PTRACE_EVENT_FORK)
1819 ourstatus->kind = TARGET_WAITKIND_FORKED;
1820 else if (event == PTRACE_EVENT_VFORK)
1821 ourstatus->kind = TARGET_WAITKIND_VFORKED;
1824 struct cleanup *old_chain;
1826 ourstatus->kind = TARGET_WAITKIND_IGNORE;
1827 new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid)));
1829 new_lp->stopped = 1;
1831 if (WSTOPSIG (status) != SIGSTOP)
1833 /* This can happen if someone starts sending signals to
1834 the new thread before it gets a chance to run, which
1835 have a lower number than SIGSTOP (e.g. SIGUSR1).
1836 This is an unlikely case, and harder to handle for
1837 fork / vfork than for clone, so we do not try - but
1838 we handle it for clone events here. We'll send
1839 the other signal on to the thread below. */
1841 new_lp->signalled = 1;
1848 /* Add the new thread to GDB's lists as soon as possible
1851 1) the frontend doesn't have to wait for a stop to
1854 2) we tag it with the correct running state. */
1856 /* If the thread_db layer is active, let it know about
1857 this new thread, and add it to GDB's list. */
1858 if (!thread_db_attach_lwp (new_lp->ptid))
1860 /* We're not using thread_db. Add it to GDB's
1862 target_post_attach (GET_LWP (new_lp->ptid));
1863 add_thread (new_lp->ptid);
1868 set_running (new_lp->ptid, 1);
1869 set_executing (new_lp->ptid, 1);
1875 new_lp->stopped = 0;
1876 new_lp->resumed = 1;
1877 ptrace (PTRACE_CONT, new_pid, 0,
1878 status ? WSTOPSIG (status) : 0);
1881 if (debug_linux_nat)
1882 fprintf_unfiltered (gdb_stdlog,
1883 "LHEW: Got clone event from LWP %ld, resuming\n",
1884 GET_LWP (lp->ptid));
1885 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
1893 if (event == PTRACE_EVENT_EXEC)
1895 ourstatus->kind = TARGET_WAITKIND_EXECD;
1896 ourstatus->value.execd_pathname
1897 = xstrdup (linux_child_pid_to_exec_file (pid));
1899 if (linux_parent_pid)
1901 detach_breakpoints (linux_parent_pid);
1902 ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0);
1904 linux_parent_pid = 0;
1907 /* At this point, all inserted breakpoints are gone. Doing this
1908 as soon as we detect an exec prevents the badness of deleting
1909 a breakpoint writing the current "shadow contents" to lift
1910 the bp. That shadow is NOT valid after an exec.
1912 Note that we have to do this after the detach_breakpoints
1913 call above, otherwise breakpoints wouldn't be lifted from the
1914 parent on a vfork, because detach_breakpoints would think
1915 that breakpoints are not inserted. */
1916 mark_breakpoints_out ();
1920 internal_error (__FILE__, __LINE__,
1921 _("unknown ptrace event %d"), event);
1924 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
1928 wait_lwp (struct lwp_info *lp)
1932 int thread_dead = 0;
1934 gdb_assert (!lp->stopped);
1935 gdb_assert (lp->status == 0);
1937 pid = my_waitpid (GET_LWP (lp->ptid), &status, 0);
1938 if (pid == -1 && errno == ECHILD)
1940 pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE);
1941 if (pid == -1 && errno == ECHILD)
1943 /* The thread has previously exited. We need to delete it
1944 now because, for some vendor 2.4 kernels with NPTL
1945 support backported, there won't be an exit event unless
1946 it is the main thread. 2.6 kernels will report an exit
1947 event for each thread that exits, as expected. */
1949 if (debug_linux_nat)
1950 fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n",
1951 target_pid_to_str (lp->ptid));
1957 gdb_assert (pid == GET_LWP (lp->ptid));
1959 if (debug_linux_nat)
1961 fprintf_unfiltered (gdb_stdlog,
1962 "WL: waitpid %s received %s\n",
1963 target_pid_to_str (lp->ptid),
1964 status_to_str (status));
1968 /* Check if the thread has exited. */
1969 if (WIFEXITED (status) || WIFSIGNALED (status))
1972 if (debug_linux_nat)
1973 fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n",
1974 target_pid_to_str (lp->ptid));
1983 gdb_assert (WIFSTOPPED (status));
1985 /* Handle GNU/Linux's extended waitstatus for trace events. */
1986 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
1988 if (debug_linux_nat)
1989 fprintf_unfiltered (gdb_stdlog,
1990 "WL: Handling extended status 0x%06x\n",
1992 if (linux_handle_extended_wait (lp, status, 1))
1993 return wait_lwp (lp);
1999 /* Save the most recent siginfo for LP. This is currently only called
2000 for SIGTRAP; some ports use the si_addr field for
2001 target_stopped_data_address. In the future, it may also be used to
2002 restore the siginfo of requeued signals. */
2005 save_siginfo (struct lwp_info *lp)
2008 ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid),
2009 (PTRACE_TYPE_ARG3) 0, &lp->siginfo);
2012 memset (&lp->siginfo, 0, sizeof (lp->siginfo));
2015 /* Send a SIGSTOP to LP. */
2018 stop_callback (struct lwp_info *lp, void *data)
2020 if (!lp->stopped && !lp->signalled)
2024 if (debug_linux_nat)
2026 fprintf_unfiltered (gdb_stdlog,
2027 "SC: kill %s **<SIGSTOP>**\n",
2028 target_pid_to_str (lp->ptid));
2031 ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);
2032 if (debug_linux_nat)
2034 fprintf_unfiltered (gdb_stdlog,
2035 "SC: lwp kill %d %s\n",
2037 errno ? safe_strerror (errno) : "ERRNO-OK");
2041 gdb_assert (lp->status == 0);
2047 /* Return non-zero if LWP PID has a pending SIGINT. */
2050 linux_nat_has_pending_sigint (int pid)
2052 sigset_t pending, blocked, ignored;
2055 linux_proc_pending_signals (pid, &pending, &blocked, &ignored);
2057 if (sigismember (&pending, SIGINT)
2058 && !sigismember (&ignored, SIGINT))
2064 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2067 set_ignore_sigint (struct lwp_info *lp, void *data)
2069 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2070 flag to consume the next one. */
2071 if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status)
2072 && WSTOPSIG (lp->status) == SIGINT)
2075 lp->ignore_sigint = 1;
2080 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2081 This function is called after we know the LWP has stopped; if the LWP
2082 stopped before the expected SIGINT was delivered, then it will never have
2083 arrived. Also, if the signal was delivered to a shared queue and consumed
2084 by a different thread, it will never be delivered to this LWP. */
2087 maybe_clear_ignore_sigint (struct lwp_info *lp)
2089 if (!lp->ignore_sigint)
2092 if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid)))
2094 if (debug_linux_nat)
2095 fprintf_unfiltered (gdb_stdlog,
2096 "MCIS: Clearing bogus flag for %s\n",
2097 target_pid_to_str (lp->ptid));
2098 lp->ignore_sigint = 0;
2102 /* Wait until LP is stopped. */
2105 stop_wait_callback (struct lwp_info *lp, void *data)
2111 status = wait_lwp (lp);
2115 if (lp->ignore_sigint && WIFSTOPPED (status)
2116 && WSTOPSIG (status) == SIGINT)
2118 lp->ignore_sigint = 0;
2121 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2122 if (debug_linux_nat)
2123 fprintf_unfiltered (gdb_stdlog,
2124 "PTRACE_CONT %s, 0, 0 (%s) (discarding SIGINT)\n",
2125 target_pid_to_str (lp->ptid),
2126 errno ? safe_strerror (errno) : "OK");
2128 return stop_wait_callback (lp, NULL);
2131 maybe_clear_ignore_sigint (lp);
2133 if (WSTOPSIG (status) != SIGSTOP)
2135 if (WSTOPSIG (status) == SIGTRAP)
2137 /* If a LWP other than the LWP that we're reporting an
2138 event for has hit a GDB breakpoint (as opposed to
2139 some random trap signal), then just arrange for it to
2140 hit it again later. We don't keep the SIGTRAP status
2141 and don't forward the SIGTRAP signal to the LWP. We
2142 will handle the current event, eventually we will
2143 resume all LWPs, and this one will get its breakpoint
2146 If we do not do this, then we run the risk that the
2147 user will delete or disable the breakpoint, but the
2148 thread will have already tripped on it. */
2150 /* Save the trap's siginfo in case we need it later. */
2153 /* Now resume this LWP and get the SIGSTOP event. */
2155 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2156 if (debug_linux_nat)
2158 fprintf_unfiltered (gdb_stdlog,
2159 "PTRACE_CONT %s, 0, 0 (%s)\n",
2160 target_pid_to_str (lp->ptid),
2161 errno ? safe_strerror (errno) : "OK");
2163 fprintf_unfiltered (gdb_stdlog,
2164 "SWC: Candidate SIGTRAP event in %s\n",
2165 target_pid_to_str (lp->ptid));
2167 /* Hold this event/waitstatus while we check to see if
2168 there are any more (we still want to get that SIGSTOP). */
2169 stop_wait_callback (lp, NULL);
2171 /* Hold the SIGTRAP for handling by linux_nat_wait. If
2172 there's another event, throw it back into the
2176 if (debug_linux_nat)
2177 fprintf_unfiltered (gdb_stdlog,
2178 "SWC: kill %s, %s\n",
2179 target_pid_to_str (lp->ptid),
2180 status_to_str ((int) status));
2181 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status));
2184 /* Save the sigtrap event. */
2185 lp->status = status;
2190 /* The thread was stopped with a signal other than
2191 SIGSTOP, and didn't accidentally trip a breakpoint. */
2193 if (debug_linux_nat)
2195 fprintf_unfiltered (gdb_stdlog,
2196 "SWC: Pending event %s in %s\n",
2197 status_to_str ((int) status),
2198 target_pid_to_str (lp->ptid));
2200 /* Now resume this LWP and get the SIGSTOP event. */
2202 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2203 if (debug_linux_nat)
2204 fprintf_unfiltered (gdb_stdlog,
2205 "SWC: PTRACE_CONT %s, 0, 0 (%s)\n",
2206 target_pid_to_str (lp->ptid),
2207 errno ? safe_strerror (errno) : "OK");
2209 /* Hold this event/waitstatus while we check to see if
2210 there are any more (we still want to get that SIGSTOP). */
2211 stop_wait_callback (lp, NULL);
2213 /* If the lp->status field is still empty, use it to
2214 hold this event. If not, then this event must be
2215 returned to the event queue of the LWP. */
2218 if (debug_linux_nat)
2220 fprintf_unfiltered (gdb_stdlog,
2221 "SWC: kill %s, %s\n",
2222 target_pid_to_str (lp->ptid),
2223 status_to_str ((int) status));
2225 kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status));
2228 lp->status = status;
2234 /* We caught the SIGSTOP that we intended to catch, so
2235 there's no SIGSTOP pending. */
2244 /* Return non-zero if LP has a wait status pending. */
2247 status_callback (struct lwp_info *lp, void *data)
2249 /* Only report a pending wait status if we pretend that this has
2250 indeed been resumed. */
2251 /* We check for lp->waitstatus in addition to lp->status, because we
2252 can have pending process exits recorded in lp->waitstatus, and
2253 W_EXITCODE(0,0) == 0. */
2254 return ((lp->status != 0
2255 || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
2259 /* Return non-zero if LP isn't stopped. */
2262 running_callback (struct lwp_info *lp, void *data)
2264 return (lp->stopped == 0 || (lp->status != 0 && lp->resumed));
2267 /* Count the LWP's that have had events. */
2270 count_events_callback (struct lwp_info *lp, void *data)
2274 gdb_assert (count != NULL);
2276 /* Count only resumed LWPs that have a SIGTRAP event pending. */
2277 if (lp->status != 0 && lp->resumed
2278 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2284 /* Select the LWP (if any) that is currently being single-stepped. */
2287 select_singlestep_lwp_callback (struct lwp_info *lp, void *data)
2289 if (lp->step && lp->status != 0)
2295 /* Select the Nth LWP that has had a SIGTRAP event. */
2298 select_event_lwp_callback (struct lwp_info *lp, void *data)
2300 int *selector = data;
2302 gdb_assert (selector != NULL);
2304 /* Select only resumed LWPs that have a SIGTRAP event pending. */
2305 if (lp->status != 0 && lp->resumed
2306 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP)
2307 if ((*selector)-- == 0)
2314 cancel_breakpoint (struct lwp_info *lp)
2316 /* Arrange for a breakpoint to be hit again later. We don't keep
2317 the SIGTRAP status and don't forward the SIGTRAP signal to the
2318 LWP. We will handle the current event, eventually we will resume
2319 this LWP, and this breakpoint will trap again.
2321 If we do not do this, then we run the risk that the user will
2322 delete or disable the breakpoint, but the LWP will have already
2325 struct regcache *regcache = get_thread_regcache (lp->ptid);
2326 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2329 pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch);
2330 if (breakpoint_inserted_here_p (pc))
2332 if (debug_linux_nat)
2333 fprintf_unfiltered (gdb_stdlog,
2334 "CB: Push back breakpoint for %s\n",
2335 target_pid_to_str (lp->ptid));
2337 /* Back up the PC if necessary. */
2338 if (gdbarch_decr_pc_after_break (gdbarch))
2339 regcache_write_pc (regcache, pc);
2347 cancel_breakpoints_callback (struct lwp_info *lp, void *data)
2349 struct lwp_info *event_lp = data;
2351 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
2355 /* If a LWP other than the LWP that we're reporting an event for has
2356 hit a GDB breakpoint (as opposed to some random trap signal),
2357 then just arrange for it to hit it again later. We don't keep
2358 the SIGTRAP status and don't forward the SIGTRAP signal to the
2359 LWP. We will handle the current event, eventually we will resume
2360 all LWPs, and this one will get its breakpoint trap again.
2362 If we do not do this, then we run the risk that the user will
2363 delete or disable the breakpoint, but the LWP will have already
2367 && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP
2368 && cancel_breakpoint (lp))
2369 /* Throw away the SIGTRAP. */
2375 /* Select one LWP out of those that have events pending. */
2378 select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status)
2381 int random_selector;
2382 struct lwp_info *event_lp;
2384 /* Record the wait status for the original LWP. */
2385 (*orig_lp)->status = *status;
2387 /* Give preference to any LWP that is being single-stepped. */
2388 event_lp = iterate_over_lwps (filter,
2389 select_singlestep_lwp_callback, NULL);
2390 if (event_lp != NULL)
2392 if (debug_linux_nat)
2393 fprintf_unfiltered (gdb_stdlog,
2394 "SEL: Select single-step %s\n",
2395 target_pid_to_str (event_lp->ptid));
2399 /* No single-stepping LWP. Select one at random, out of those
2400 which have had SIGTRAP events. */
2402 /* First see how many SIGTRAP events we have. */
2403 iterate_over_lwps (filter, count_events_callback, &num_events);
2405 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
2406 random_selector = (int)
2407 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
2409 if (debug_linux_nat && num_events > 1)
2410 fprintf_unfiltered (gdb_stdlog,
2411 "SEL: Found %d SIGTRAP events, selecting #%d\n",
2412 num_events, random_selector);
2414 event_lp = iterate_over_lwps (filter,
2415 select_event_lwp_callback,
2419 if (event_lp != NULL)
2421 /* Switch the event LWP. */
2422 *orig_lp = event_lp;
2423 *status = event_lp->status;
2426 /* Flush the wait status for the event LWP. */
2427 (*orig_lp)->status = 0;
2430 /* Return non-zero if LP has been resumed. */
2433 resumed_callback (struct lwp_info *lp, void *data)
2438 /* Stop an active thread, verify it still exists, then resume it. */
2441 stop_and_resume_callback (struct lwp_info *lp, void *data)
2443 struct lwp_info *ptr;
2445 if (!lp->stopped && !lp->signalled)
2447 stop_callback (lp, NULL);
2448 stop_wait_callback (lp, NULL);
2449 /* Resume if the lwp still exists. */
2450 for (ptr = lwp_list; ptr; ptr = ptr->next)
2453 resume_callback (lp, NULL);
2454 resume_set_callback (lp, NULL);
2460 /* Check if we should go on and pass this event to common code.
2461 Return the affected lwp if we are, or NULL otherwise. */
2462 static struct lwp_info *
2463 linux_nat_filter_event (int lwpid, int status, int options)
2465 struct lwp_info *lp;
2467 lp = find_lwp_pid (pid_to_ptid (lwpid));
2469 /* Check for stop events reported by a process we didn't already
2470 know about - anything not already in our LWP list.
2472 If we're expecting to receive stopped processes after
2473 fork, vfork, and clone events, then we'll just add the
2474 new one to our list and go back to waiting for the event
2475 to be reported - the stopped process might be returned
2476 from waitpid before or after the event is. */
2477 if (WIFSTOPPED (status) && !lp)
2479 linux_record_stopped_pid (lwpid, status);
2483 /* Make sure we don't report an event for the exit of an LWP not in
2484 our list, i.e. not part of the current process. This can happen
2485 if we detach from a program we original forked and then it
2487 if (!WIFSTOPPED (status) && !lp)
2490 /* NOTE drow/2003-06-17: This code seems to be meant for debugging
2491 CLONE_PTRACE processes which do not use the thread library -
2492 otherwise we wouldn't find the new LWP this way. That doesn't
2493 currently work, and the following code is currently unreachable
2494 due to the two blocks above. If it's fixed some day, this code
2495 should be broken out into a function so that we can also pick up
2496 LWPs from the new interface. */
2499 lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid)));
2500 if (options & __WCLONE)
2503 gdb_assert (WIFSTOPPED (status)
2504 && WSTOPSIG (status) == SIGSTOP);
2507 if (!in_thread_list (inferior_ptid))
2509 inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid),
2510 GET_PID (inferior_ptid));
2511 add_thread (inferior_ptid);
2514 add_thread (lp->ptid);
2517 /* Save the trap's siginfo in case we need it later. */
2518 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
2521 /* Handle GNU/Linux's extended waitstatus for trace events. */
2522 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0)
2524 if (debug_linux_nat)
2525 fprintf_unfiltered (gdb_stdlog,
2526 "LLW: Handling extended status 0x%06x\n",
2528 if (linux_handle_extended_wait (lp, status, 0))
2532 /* Check if the thread has exited. */
2533 if ((WIFEXITED (status) || WIFSIGNALED (status))
2534 && num_lwps (GET_PID (lp->ptid)) > 1)
2536 /* If this is the main thread, we must stop all threads and verify
2537 if they are still alive. This is because in the nptl thread model
2538 on Linux 2.4, there is no signal issued for exiting LWPs
2539 other than the main thread. We only get the main thread exit
2540 signal once all child threads have already exited. If we
2541 stop all the threads and use the stop_wait_callback to check
2542 if they have exited we can determine whether this signal
2543 should be ignored or whether it means the end of the debugged
2544 application, regardless of which threading model is being
2546 if (GET_PID (lp->ptid) == GET_LWP (lp->ptid))
2549 iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)),
2550 stop_and_resume_callback, NULL);
2553 if (debug_linux_nat)
2554 fprintf_unfiltered (gdb_stdlog,
2555 "LLW: %s exited.\n",
2556 target_pid_to_str (lp->ptid));
2558 if (num_lwps (GET_PID (lp->ptid)) > 1)
2560 /* If there is at least one more LWP, then the exit signal
2561 was not the end of the debugged application and should be
2568 /* Check if the current LWP has previously exited. In the nptl
2569 thread model, LWPs other than the main thread do not issue
2570 signals when they exit so we must check whenever the thread has
2571 stopped. A similar check is made in stop_wait_callback(). */
2572 if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid))
2574 ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid));
2576 if (debug_linux_nat)
2577 fprintf_unfiltered (gdb_stdlog,
2578 "LLW: %s exited.\n",
2579 target_pid_to_str (lp->ptid));
2583 /* Make sure there is at least one thread running. */
2584 gdb_assert (iterate_over_lwps (ptid, running_callback, NULL));
2586 /* Discard the event. */
2590 /* Make sure we don't report a SIGSTOP that we sent ourselves in
2591 an attempt to stop an LWP. */
2593 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
2595 if (debug_linux_nat)
2596 fprintf_unfiltered (gdb_stdlog,
2597 "LLW: Delayed SIGSTOP caught for %s.\n",
2598 target_pid_to_str (lp->ptid));
2600 /* This is a delayed SIGSTOP. */
2603 registers_changed ();
2605 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2606 lp->step, TARGET_SIGNAL_0);
2607 if (debug_linux_nat)
2608 fprintf_unfiltered (gdb_stdlog,
2609 "LLW: %s %s, 0, 0 (discard SIGSTOP)\n",
2611 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2612 target_pid_to_str (lp->ptid));
2615 gdb_assert (lp->resumed);
2617 /* Discard the event. */
2621 /* Make sure we don't report a SIGINT that we have already displayed
2622 for another thread. */
2623 if (lp->ignore_sigint
2624 && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT)
2626 if (debug_linux_nat)
2627 fprintf_unfiltered (gdb_stdlog,
2628 "LLW: Delayed SIGINT caught for %s.\n",
2629 target_pid_to_str (lp->ptid));
2631 /* This is a delayed SIGINT. */
2632 lp->ignore_sigint = 0;
2634 registers_changed ();
2635 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2636 lp->step, TARGET_SIGNAL_0);
2637 if (debug_linux_nat)
2638 fprintf_unfiltered (gdb_stdlog,
2639 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
2641 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2642 target_pid_to_str (lp->ptid));
2645 gdb_assert (lp->resumed);
2647 /* Discard the event. */
2651 /* An interesting event. */
2657 linux_nat_wait_1 (struct target_ops *ops,
2658 ptid_t ptid, struct target_waitstatus *ourstatus,
2661 static sigset_t prev_mask;
2662 struct lwp_info *lp = NULL;
2667 if (debug_linux_nat_async)
2668 fprintf_unfiltered (gdb_stdlog, "LLW: enter\n");
2670 /* The first time we get here after starting a new inferior, we may
2671 not have added it to the LWP list yet - this is the earliest
2672 moment at which we know its PID. */
2673 if (ptid_is_pid (inferior_ptid))
2675 /* Upgrade the main thread's ptid. */
2676 thread_change_ptid (inferior_ptid,
2677 BUILD_LWP (GET_PID (inferior_ptid),
2678 GET_PID (inferior_ptid)));
2680 lp = add_lwp (inferior_ptid);
2684 /* Make sure SIGCHLD is blocked. */
2685 block_child_signals (&prev_mask);
2687 if (ptid_equal (ptid, minus_one_ptid))
2689 else if (ptid_is_pid (ptid))
2690 /* A request to wait for a specific tgid. This is not possible
2691 with waitpid, so instead, we wait for any child, and leave
2692 children we're not interested in right now with a pending
2693 status to report later. */
2696 pid = GET_LWP (ptid);
2702 /* Make sure there is at least one LWP that has been resumed. */
2703 gdb_assert (iterate_over_lwps (ptid, resumed_callback, NULL));
2705 /* First check if there is a LWP with a wait status pending. */
2708 /* Any LWP that's been resumed will do. */
2709 lp = iterate_over_lwps (ptid, status_callback, NULL);
2712 status = lp->status;
2715 if (debug_linux_nat && status)
2716 fprintf_unfiltered (gdb_stdlog,
2717 "LLW: Using pending wait status %s for %s.\n",
2718 status_to_str (status),
2719 target_pid_to_str (lp->ptid));
2722 /* But if we don't find one, we'll have to wait, and check both
2723 cloned and uncloned processes. We start with the cloned
2725 options = __WCLONE | WNOHANG;
2727 else if (is_lwp (ptid))
2729 if (debug_linux_nat)
2730 fprintf_unfiltered (gdb_stdlog,
2731 "LLW: Waiting for specific LWP %s.\n",
2732 target_pid_to_str (ptid));
2734 /* We have a specific LWP to check. */
2735 lp = find_lwp_pid (ptid);
2737 status = lp->status;
2740 if (debug_linux_nat && status)
2741 fprintf_unfiltered (gdb_stdlog,
2742 "LLW: Using pending wait status %s for %s.\n",
2743 status_to_str (status),
2744 target_pid_to_str (lp->ptid));
2746 /* If we have to wait, take into account whether PID is a cloned
2747 process or not. And we have to convert it to something that
2748 the layer beneath us can understand. */
2749 options = lp->cloned ? __WCLONE : 0;
2750 pid = GET_LWP (ptid);
2752 /* We check for lp->waitstatus in addition to lp->status,
2753 because we can have pending process exits recorded in
2754 lp->status and W_EXITCODE(0,0) == 0. We should probably have
2755 an additional lp->status_p flag. */
2756 if (status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE)
2760 if (lp && lp->signalled)
2762 /* A pending SIGSTOP may interfere with the normal stream of
2763 events. In a typical case where interference is a problem,
2764 we have a SIGSTOP signal pending for LWP A while
2765 single-stepping it, encounter an event in LWP B, and take the
2766 pending SIGSTOP while trying to stop LWP A. After processing
2767 the event in LWP B, LWP A is continued, and we'll never see
2768 the SIGTRAP associated with the last time we were
2769 single-stepping LWP A. */
2771 /* Resume the thread. It should halt immediately returning the
2773 registers_changed ();
2774 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2775 lp->step, TARGET_SIGNAL_0);
2776 if (debug_linux_nat)
2777 fprintf_unfiltered (gdb_stdlog,
2778 "LLW: %s %s, 0, 0 (expect SIGSTOP)\n",
2779 lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2780 target_pid_to_str (lp->ptid));
2782 gdb_assert (lp->resumed);
2784 /* This should catch the pending SIGSTOP. */
2785 stop_wait_callback (lp, NULL);
2788 if (!target_can_async_p ())
2790 /* Causes SIGINT to be passed on to the attached process. */
2794 /* Translate generic target_wait options into waitpid options. */
2795 if (target_options & TARGET_WNOHANG)
2802 lwpid = my_waitpid (pid, &status, options);
2806 gdb_assert (pid == -1 || lwpid == pid);
2808 if (debug_linux_nat)
2810 fprintf_unfiltered (gdb_stdlog,
2811 "LLW: waitpid %ld received %s\n",
2812 (long) lwpid, status_to_str (status));
2815 lp = linux_nat_filter_event (lwpid, status, options);
2818 && ptid_is_pid (ptid)
2819 && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid))
2821 if (debug_linux_nat)
2822 fprintf (stderr, "LWP %ld got an event %06x, leaving pending.\n",
2823 ptid_get_lwp (lp->ptid), status);
2825 if (WIFSTOPPED (status))
2827 if (WSTOPSIG (status) != SIGSTOP)
2829 lp->status = status;
2831 stop_callback (lp, NULL);
2833 /* Resume in order to collect the sigstop. */
2834 ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0);
2836 stop_wait_callback (lp, NULL);
2844 else if (WIFEXITED (status) || WIFSIGNALED (status))
2846 if (debug_linux_nat)
2847 fprintf (stderr, "Process %ld exited while stopping LWPs\n",
2848 ptid_get_lwp (lp->ptid));
2850 /* This was the last lwp in the process. Since
2851 events are serialized to GDB core, and we can't
2852 report this one right now, but GDB core and the
2853 other target layers will want to be notified
2854 about the exit code/signal, leave the status
2855 pending for the next time we're able to report
2857 lp->status = status;
2859 /* Prevent trying to stop this thread again. We'll
2860 never try to resume it because it has a pending
2864 /* Dead LWP's aren't expected to reported a pending
2868 /* Store the pending event in the waitstatus as
2869 well, because W_EXITCODE(0,0) == 0. */
2870 store_waitstatus (&lp->waitstatus, status);
2884 /* waitpid did return something. Restart over. */
2885 options |= __WCLONE;
2893 /* Alternate between checking cloned and uncloned processes. */
2894 options ^= __WCLONE;
2896 /* And every time we have checked both:
2897 In async mode, return to event loop;
2898 In sync mode, suspend waiting for a SIGCHLD signal. */
2899 if (options & __WCLONE)
2901 if (target_options & TARGET_WNOHANG)
2903 /* No interesting event. */
2904 ourstatus->kind = TARGET_WAITKIND_IGNORE;
2906 if (debug_linux_nat_async)
2907 fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n");
2909 restore_child_signals_mask (&prev_mask);
2910 return minus_one_ptid;
2913 sigsuspend (&suspend_mask);
2917 /* We shouldn't end up here unless we want to try again. */
2918 gdb_assert (lp == NULL);
2921 if (!target_can_async_p ())
2922 clear_sigint_trap ();
2926 /* Don't report signals that GDB isn't interested in, such as
2927 signals that are neither printed nor stopped upon. Stopping all
2928 threads can be a bit time-consuming so if we want decent
2929 performance with heavily multi-threaded programs, especially when
2930 they're using a high frequency timer, we'd better avoid it if we
2933 if (WIFSTOPPED (status))
2935 int signo = target_signal_from_host (WSTOPSIG (status));
2936 struct inferior *inf;
2938 inf = find_inferior_pid (ptid_get_pid (lp->ptid));
2941 /* Defer to common code if we get a signal while
2942 single-stepping, since that may need special care, e.g. to
2943 skip the signal handler, or, if we're gaining control of the
2946 && inf->stop_soon == NO_STOP_QUIETLY
2947 && signal_stop_state (signo) == 0
2948 && signal_print_state (signo) == 0
2949 && signal_pass_state (signo) == 1)
2951 /* FIMXE: kettenis/2001-06-06: Should we resume all threads
2952 here? It is not clear we should. GDB may not expect
2953 other threads to run. On the other hand, not resuming
2954 newly attached threads may cause an unwanted delay in
2955 getting them running. */
2956 registers_changed ();
2957 linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)),
2959 if (debug_linux_nat)
2960 fprintf_unfiltered (gdb_stdlog,
2961 "LLW: %s %s, %s (preempt 'handle')\n",
2963 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
2964 target_pid_to_str (lp->ptid),
2965 signo ? strsignal (signo) : "0");
2972 /* Only do the below in all-stop, as we currently use SIGINT
2973 to implement target_stop (see linux_nat_stop) in
2975 if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0)
2977 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
2978 forwarded to the entire process group, that is, all LWPs
2979 will receive it - unless they're using CLONE_THREAD to
2980 share signals. Since we only want to report it once, we
2981 mark it as ignored for all LWPs except this one. */
2982 iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)),
2983 set_ignore_sigint, NULL);
2984 lp->ignore_sigint = 0;
2987 maybe_clear_ignore_sigint (lp);
2991 /* This LWP is stopped now. */
2994 if (debug_linux_nat)
2995 fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n",
2996 status_to_str (status), target_pid_to_str (lp->ptid));
3000 /* Now stop all other LWP's ... */
3001 iterate_over_lwps (minus_one_ptid, stop_callback, NULL);
3003 /* ... and wait until all of them have reported back that
3004 they're no longer running. */
3005 iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL);
3007 /* If we're not waiting for a specific LWP, choose an event LWP
3008 from among those that have had events. Giving equal priority
3009 to all LWPs that have had events helps prevent
3012 select_event_lwp (ptid, &lp, &status);
3015 /* Now that we've selected our final event LWP, cancel any
3016 breakpoints in other LWPs that have hit a GDB breakpoint. See
3017 the comment in cancel_breakpoints_callback to find out why. */
3018 iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp);
3020 if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP)
3022 if (debug_linux_nat)
3023 fprintf_unfiltered (gdb_stdlog,
3024 "LLW: trap ptid is %s.\n",
3025 target_pid_to_str (lp->ptid));
3028 if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE)
3030 *ourstatus = lp->waitstatus;
3031 lp->waitstatus.kind = TARGET_WAITKIND_IGNORE;
3034 store_waitstatus (ourstatus, status);
3036 if (debug_linux_nat_async)
3037 fprintf_unfiltered (gdb_stdlog, "LLW: exit\n");
3039 restore_child_signals_mask (&prev_mask);
3044 linux_nat_wait (struct target_ops *ops,
3045 ptid_t ptid, struct target_waitstatus *ourstatus,
3050 if (debug_linux_nat)
3051 fprintf_unfiltered (gdb_stdlog, "linux_nat_wait: [%s]\n", target_pid_to_str (ptid));
3053 /* Flush the async file first. */
3054 if (target_can_async_p ())
3055 async_file_flush ();
3057 event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options);
3059 /* If we requested any event, and something came out, assume there
3060 may be more. If we requested a specific lwp or process, also
3061 assume there may be more. */
3062 if (target_can_async_p ()
3063 && (ourstatus->kind != TARGET_WAITKIND_IGNORE
3064 || !ptid_equal (ptid, minus_one_ptid)))
3067 /* Get ready for the next event. */
3068 if (target_can_async_p ())
3069 target_async (inferior_event_handler, 0);
3075 kill_callback (struct lwp_info *lp, void *data)
3078 ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0);
3079 if (debug_linux_nat)
3080 fprintf_unfiltered (gdb_stdlog,
3081 "KC: PTRACE_KILL %s, 0, 0 (%s)\n",
3082 target_pid_to_str (lp->ptid),
3083 errno ? safe_strerror (errno) : "OK");
3089 kill_wait_callback (struct lwp_info *lp, void *data)
3093 /* We must make sure that there are no pending events (delayed
3094 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3095 program doesn't interfere with any following debugging session. */
3097 /* For cloned processes we must check both with __WCLONE and
3098 without, since the exit status of a cloned process isn't reported
3104 pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE);
3105 if (pid != (pid_t) -1)
3107 if (debug_linux_nat)
3108 fprintf_unfiltered (gdb_stdlog,
3109 "KWC: wait %s received unknown.\n",
3110 target_pid_to_str (lp->ptid));
3111 /* The Linux kernel sometimes fails to kill a thread
3112 completely after PTRACE_KILL; that goes from the stop
3113 point in do_fork out to the one in
3114 get_signal_to_deliever and waits again. So kill it
3116 kill_callback (lp, NULL);
3119 while (pid == GET_LWP (lp->ptid));
3121 gdb_assert (pid == -1 && errno == ECHILD);
3126 pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0);
3127 if (pid != (pid_t) -1)
3129 if (debug_linux_nat)
3130 fprintf_unfiltered (gdb_stdlog,
3131 "KWC: wait %s received unk.\n",
3132 target_pid_to_str (lp->ptid));
3133 /* See the call to kill_callback above. */
3134 kill_callback (lp, NULL);
3137 while (pid == GET_LWP (lp->ptid));
3139 gdb_assert (pid == -1 && errno == ECHILD);
3144 linux_nat_kill (struct target_ops *ops)
3146 struct target_waitstatus last;
3150 /* If we're stopped while forking and we haven't followed yet,
3151 kill the other task. We need to do this first because the
3152 parent will be sleeping if this is a vfork. */
3154 get_last_target_status (&last_ptid, &last);
3156 if (last.kind == TARGET_WAITKIND_FORKED
3157 || last.kind == TARGET_WAITKIND_VFORKED)
3159 ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0);
3163 if (forks_exist_p ())
3164 linux_fork_killall ();
3167 ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
3168 /* Stop all threads before killing them, since ptrace requires
3169 that the thread is stopped to sucessfully PTRACE_KILL. */
3170 iterate_over_lwps (ptid, stop_callback, NULL);
3171 /* ... and wait until all of them have reported back that
3172 they're no longer running. */
3173 iterate_over_lwps (ptid, stop_wait_callback, NULL);
3175 /* Kill all LWP's ... */
3176 iterate_over_lwps (ptid, kill_callback, NULL);
3178 /* ... and wait until we've flushed all events. */
3179 iterate_over_lwps (ptid, kill_wait_callback, NULL);
3182 target_mourn_inferior ();
3186 linux_nat_mourn_inferior (struct target_ops *ops)
3188 purge_lwp_list (ptid_get_pid (inferior_ptid));
3190 if (! forks_exist_p ())
3191 /* Normal case, no other forks available. */
3192 linux_ops->to_mourn_inferior (ops);
3194 /* Multi-fork case. The current inferior_ptid has exited, but
3195 there are other viable forks to debug. Delete the exiting
3196 one and context-switch to the first available. */
3197 linux_fork_mourn_inferior ();
3200 /* Convert a native/host siginfo object, into/from the siginfo in the
3201 layout of the inferiors' architecture. */
3204 siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction)
3208 if (linux_nat_siginfo_fixup != NULL)
3209 done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction);
3211 /* If there was no callback, or the callback didn't do anything,
3212 then just do a straight memcpy. */
3216 memcpy (siginfo, inf_siginfo, sizeof (struct siginfo));
3218 memcpy (inf_siginfo, siginfo, sizeof (struct siginfo));
3223 linux_xfer_siginfo (struct target_ops *ops, enum target_object object,
3224 const char *annex, gdb_byte *readbuf,
3225 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
3228 struct siginfo siginfo;
3229 gdb_byte inf_siginfo[sizeof (struct siginfo)];
3231 gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO);
3232 gdb_assert (readbuf || writebuf);
3234 pid = GET_LWP (inferior_ptid);
3236 pid = GET_PID (inferior_ptid);
3238 if (offset > sizeof (siginfo))
3242 ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3246 /* When GDB is built as a 64-bit application, ptrace writes into
3247 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3248 inferior with a 64-bit GDB should look the same as debugging it
3249 with a 32-bit GDB, we need to convert it. GDB core always sees
3250 the converted layout, so any read/write will have to be done
3252 siginfo_fixup (&siginfo, inf_siginfo, 0);
3254 if (offset + len > sizeof (siginfo))
3255 len = sizeof (siginfo) - offset;
3257 if (readbuf != NULL)
3258 memcpy (readbuf, inf_siginfo + offset, len);
3261 memcpy (inf_siginfo + offset, writebuf, len);
3263 /* Convert back to ptrace layout before flushing it out. */
3264 siginfo_fixup (&siginfo, inf_siginfo, 1);
3267 ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo);
3276 linux_nat_xfer_partial (struct target_ops *ops, enum target_object object,
3277 const char *annex, gdb_byte *readbuf,
3278 const gdb_byte *writebuf,
3279 ULONGEST offset, LONGEST len)
3281 struct cleanup *old_chain;
3284 if (object == TARGET_OBJECT_SIGNAL_INFO)
3285 return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf,
3288 old_chain = save_inferior_ptid ();
3290 if (is_lwp (inferior_ptid))
3291 inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid));
3293 xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf,
3296 do_cleanups (old_chain);
3301 linux_thread_alive (ptid_t ptid)
3305 gdb_assert (is_lwp (ptid));
3307 /* Send signal 0 instead of anything ptrace, because ptracing a
3308 running thread errors out claiming that the thread doesn't
3310 err = kill_lwp (GET_LWP (ptid), 0);
3312 if (debug_linux_nat)
3313 fprintf_unfiltered (gdb_stdlog,
3314 "LLTA: KILL(SIG0) %s (%s)\n",
3315 target_pid_to_str (ptid),
3316 err ? safe_strerror (err) : "OK");
3325 linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid)
3327 return linux_thread_alive (ptid);
3331 linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid)
3333 static char buf[64];
3336 && (GET_PID (ptid) != GET_LWP (ptid)
3337 || num_lwps (GET_PID (ptid)) > 1))
3339 snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid));
3343 return normal_pid_to_str (ptid);
3346 /* Accepts an integer PID; Returns a string representing a file that
3347 can be opened to get the symbols for the child process. */
3350 linux_child_pid_to_exec_file (int pid)
3352 char *name1, *name2;
3354 name1 = xmalloc (MAXPATHLEN);
3355 name2 = xmalloc (MAXPATHLEN);
3356 make_cleanup (xfree, name1);
3357 make_cleanup (xfree, name2);
3358 memset (name2, 0, MAXPATHLEN);
3360 sprintf (name1, "/proc/%d/exe", pid);
3361 if (readlink (name1, name2, MAXPATHLEN) > 0)
3367 /* Service function for corefiles and info proc. */
3370 read_mapping (FILE *mapfile,
3375 char *device, long long *inode, char *filename)
3377 int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
3378 addr, endaddr, permissions, offset, device, inode);
3381 if (ret > 0 && ret != EOF)
3383 /* Eat everything up to EOL for the filename. This will prevent
3384 weird filenames (such as one with embedded whitespace) from
3385 confusing this code. It also makes this code more robust in
3386 respect to annotations the kernel may add after the filename.
3388 Note the filename is used for informational purposes
3390 ret += fscanf (mapfile, "%[^\n]\n", filename);
3393 return (ret != 0 && ret != EOF);
3396 /* Fills the "to_find_memory_regions" target vector. Lists the memory
3397 regions in the inferior for a corefile. */
3400 linux_nat_find_memory_regions (int (*func) (CORE_ADDR,
3402 int, int, int, void *), void *obfd)
3404 int pid = PIDGET (inferior_ptid);
3405 char mapsfilename[MAXPATHLEN];
3407 long long addr, endaddr, size, offset, inode;
3408 char permissions[8], device[8], filename[MAXPATHLEN];
3409 int read, write, exec;
3411 struct cleanup *cleanup;
3413 /* Compose the filename for the /proc memory map, and open it. */
3414 sprintf (mapsfilename, "/proc/%d/maps", pid);
3415 if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
3416 error (_("Could not open %s."), mapsfilename);
3417 cleanup = make_cleanup_fclose (mapsfile);
3420 fprintf_filtered (gdb_stdout,
3421 "Reading memory regions from %s\n", mapsfilename);
3423 /* Now iterate until end-of-file. */
3424 while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
3425 &offset, &device[0], &inode, &filename[0]))
3427 size = endaddr - addr;
3429 /* Get the segment's permissions. */
3430 read = (strchr (permissions, 'r') != 0);
3431 write = (strchr (permissions, 'w') != 0);
3432 exec = (strchr (permissions, 'x') != 0);
3436 fprintf_filtered (gdb_stdout,
3437 "Save segment, %lld bytes at 0x%s (%c%c%c)",
3438 size, paddr_nz (addr),
3440 write ? 'w' : ' ', exec ? 'x' : ' ');
3442 fprintf_filtered (gdb_stdout, " for %s", filename);
3443 fprintf_filtered (gdb_stdout, "\n");
3446 /* Invoke the callback function to create the corefile
3448 func (addr, size, read, write, exec, obfd);
3450 do_cleanups (cleanup);
3455 find_signalled_thread (struct thread_info *info, void *data)
3457 if (info->stop_signal != TARGET_SIGNAL_0
3458 && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid))
3464 static enum target_signal
3465 find_stop_signal (void)
3467 struct thread_info *info =
3468 iterate_over_threads (find_signalled_thread, NULL);
3471 return info->stop_signal;
3473 return TARGET_SIGNAL_0;
3476 /* Records the thread's register state for the corefile note
3480 linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid,
3481 char *note_data, int *note_size,
3482 enum target_signal stop_signal)
3484 gdb_gregset_t gregs;
3485 gdb_fpregset_t fpregs;
3486 unsigned long lwp = ptid_get_lwp (ptid);
3487 struct regcache *regcache = get_thread_regcache (ptid);
3488 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3489 const struct regset *regset;
3491 struct cleanup *old_chain;
3492 struct core_regset_section *sect_list;
3495 old_chain = save_inferior_ptid ();
3496 inferior_ptid = ptid;
3497 target_fetch_registers (regcache, -1);
3498 do_cleanups (old_chain);
3500 core_regset_p = gdbarch_regset_from_core_section_p (gdbarch);
3501 sect_list = gdbarch_core_regset_sections (gdbarch);
3504 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg",
3505 sizeof (gregs))) != NULL
3506 && regset->collect_regset != NULL)
3507 regset->collect_regset (regset, regcache, -1,
3508 &gregs, sizeof (gregs));
3510 fill_gregset (regcache, &gregs, -1);
3512 note_data = (char *) elfcore_write_prstatus (obfd,
3516 stop_signal, &gregs);
3518 /* The loop below uses the new struct core_regset_section, which stores
3519 the supported section names and sizes for the core file. Note that
3520 note PRSTATUS needs to be treated specially. But the other notes are
3521 structurally the same, so they can benefit from the new struct. */
3522 if (core_regset_p && sect_list != NULL)
3523 while (sect_list->sect_name != NULL)
3525 /* .reg was already handled above. */
3526 if (strcmp (sect_list->sect_name, ".reg") == 0)
3531 regset = gdbarch_regset_from_core_section (gdbarch,
3532 sect_list->sect_name,
3534 gdb_assert (regset && regset->collect_regset);
3535 gdb_regset = xmalloc (sect_list->size);
3536 regset->collect_regset (regset, regcache, -1,
3537 gdb_regset, sect_list->size);
3538 note_data = (char *) elfcore_write_register_note (obfd,
3541 sect_list->sect_name,
3548 /* For architectures that does not have the struct core_regset_section
3549 implemented, we use the old method. When all the architectures have
3550 the new support, the code below should be deleted. */
3554 && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2",
3555 sizeof (fpregs))) != NULL
3556 && regset->collect_regset != NULL)
3557 regset->collect_regset (regset, regcache, -1,
3558 &fpregs, sizeof (fpregs));
3560 fill_fpregset (regcache, &fpregs, -1);
3562 note_data = (char *) elfcore_write_prfpreg (obfd,
3565 &fpregs, sizeof (fpregs));
3571 struct linux_nat_corefile_thread_data
3577 enum target_signal stop_signal;
3580 /* Called by gdbthread.c once per thread. Records the thread's
3581 register state for the corefile note section. */
3584 linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data)
3586 struct linux_nat_corefile_thread_data *args = data;
3588 args->note_data = linux_nat_do_thread_registers (args->obfd,
3598 /* Fills the "to_make_corefile_note" target vector. Builds the note
3599 section for a corefile, and returns it in a malloc buffer. */
3602 linux_nat_make_corefile_notes (bfd *obfd, int *note_size)
3604 struct linux_nat_corefile_thread_data thread_args;
3605 struct cleanup *old_chain;
3606 /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */
3607 char fname[16] = { '\0' };
3608 /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */
3609 char psargs[80] = { '\0' };
3610 char *note_data = NULL;
3611 ptid_t current_ptid = inferior_ptid;
3612 ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid));
3616 if (get_exec_file (0))
3618 strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname));
3619 strncpy (psargs, get_exec_file (0), sizeof (psargs));
3620 if (get_inferior_args ())
3623 char *psargs_end = psargs + sizeof (psargs);
3625 /* linux_elfcore_write_prpsinfo () handles zero unterminated
3627 string_end = memchr (psargs, 0, sizeof (psargs));
3628 if (string_end != NULL)
3630 *string_end++ = ' ';
3631 strncpy (string_end, get_inferior_args (),
3632 psargs_end - string_end);
3635 note_data = (char *) elfcore_write_prpsinfo (obfd,
3637 note_size, fname, psargs);
3640 /* Dump information for threads. */
3641 thread_args.obfd = obfd;
3642 thread_args.note_data = note_data;
3643 thread_args.note_size = note_size;
3644 thread_args.num_notes = 0;
3645 thread_args.stop_signal = find_stop_signal ();
3646 iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args);
3647 gdb_assert (thread_args.num_notes != 0);
3648 note_data = thread_args.note_data;
3650 auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV,
3654 note_data = elfcore_write_note (obfd, note_data, note_size,
3655 "CORE", NT_AUXV, auxv, auxv_len);
3659 make_cleanup (xfree, note_data);
3663 /* Implement the "info proc" command. */
3666 linux_nat_info_proc_cmd (char *args, int from_tty)
3668 /* A long is used for pid instead of an int to avoid a loss of precision
3669 compiler warning from the output of strtoul. */
3670 long pid = PIDGET (inferior_ptid);
3673 char buffer[MAXPATHLEN];
3674 char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
3687 /* Break up 'args' into an argv array. */
3688 argv = gdb_buildargv (args);
3689 make_cleanup_freeargv (argv);
3691 while (argv != NULL && *argv != NULL)
3693 if (isdigit (argv[0][0]))
3695 pid = strtoul (argv[0], NULL, 10);
3697 else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
3701 else if (strcmp (argv[0], "status") == 0)
3705 else if (strcmp (argv[0], "stat") == 0)
3709 else if (strcmp (argv[0], "cmd") == 0)
3713 else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
3717 else if (strcmp (argv[0], "cwd") == 0)
3721 else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
3727 /* [...] (future options here) */
3732 error (_("No current process: you must name one."));
3734 sprintf (fname1, "/proc/%ld", pid);
3735 if (stat (fname1, &dummy) != 0)
3736 error (_("No /proc directory: '%s'"), fname1);
3738 printf_filtered (_("process %ld\n"), pid);
3739 if (cmdline_f || all)
3741 sprintf (fname1, "/proc/%ld/cmdline", pid);
3742 if ((procfile = fopen (fname1, "r")) != NULL)
3744 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3745 if (fgets (buffer, sizeof (buffer), procfile))
3746 printf_filtered ("cmdline = '%s'\n", buffer);
3748 warning (_("unable to read '%s'"), fname1);
3749 do_cleanups (cleanup);
3752 warning (_("unable to open /proc file '%s'"), fname1);
3756 sprintf (fname1, "/proc/%ld/cwd", pid);
3757 memset (fname2, 0, sizeof (fname2));
3758 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
3759 printf_filtered ("cwd = '%s'\n", fname2);
3761 warning (_("unable to read link '%s'"), fname1);
3765 sprintf (fname1, "/proc/%ld/exe", pid);
3766 memset (fname2, 0, sizeof (fname2));
3767 if (readlink (fname1, fname2, sizeof (fname2)) > 0)
3768 printf_filtered ("exe = '%s'\n", fname2);
3770 warning (_("unable to read link '%s'"), fname1);
3772 if (mappings_f || all)
3774 sprintf (fname1, "/proc/%ld/maps", pid);
3775 if ((procfile = fopen (fname1, "r")) != NULL)
3777 long long addr, endaddr, size, offset, inode;
3778 char permissions[8], device[8], filename[MAXPATHLEN];
3779 struct cleanup *cleanup;
3781 cleanup = make_cleanup_fclose (procfile);
3782 printf_filtered (_("Mapped address spaces:\n\n"));
3783 if (gdbarch_addr_bit (current_gdbarch) == 32)
3785 printf_filtered ("\t%10s %10s %10s %10s %7s\n",
3788 " Size", " Offset", "objfile");
3792 printf_filtered (" %18s %18s %10s %10s %7s\n",
3795 " Size", " Offset", "objfile");
3798 while (read_mapping (procfile, &addr, &endaddr, &permissions[0],
3799 &offset, &device[0], &inode, &filename[0]))
3801 size = endaddr - addr;
3803 /* FIXME: carlton/2003-08-27: Maybe the printf_filtered
3804 calls here (and possibly above) should be abstracted
3805 out into their own functions? Andrew suggests using
3806 a generic local_address_string instead to print out
3807 the addresses; that makes sense to me, too. */
3809 if (gdbarch_addr_bit (current_gdbarch) == 32)
3811 printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n",
3812 (unsigned long) addr, /* FIXME: pr_addr */
3813 (unsigned long) endaddr,
3815 (unsigned int) offset,
3816 filename[0] ? filename : "");
3820 printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n",
3821 (unsigned long) addr, /* FIXME: pr_addr */
3822 (unsigned long) endaddr,
3824 (unsigned int) offset,
3825 filename[0] ? filename : "");
3829 do_cleanups (cleanup);
3832 warning (_("unable to open /proc file '%s'"), fname1);
3834 if (status_f || all)
3836 sprintf (fname1, "/proc/%ld/status", pid);
3837 if ((procfile = fopen (fname1, "r")) != NULL)
3839 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3840 while (fgets (buffer, sizeof (buffer), procfile) != NULL)
3841 puts_filtered (buffer);
3842 do_cleanups (cleanup);
3845 warning (_("unable to open /proc file '%s'"), fname1);
3849 sprintf (fname1, "/proc/%ld/stat", pid);
3850 if ((procfile = fopen (fname1, "r")) != NULL)
3855 struct cleanup *cleanup = make_cleanup_fclose (procfile);
3857 if (fscanf (procfile, "%d ", &itmp) > 0)
3858 printf_filtered (_("Process: %d\n"), itmp);
3859 if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0)
3860 printf_filtered (_("Exec file: %s\n"), buffer);
3861 if (fscanf (procfile, "%c ", &ctmp) > 0)
3862 printf_filtered (_("State: %c\n"), ctmp);
3863 if (fscanf (procfile, "%d ", &itmp) > 0)
3864 printf_filtered (_("Parent process: %d\n"), itmp);
3865 if (fscanf (procfile, "%d ", &itmp) > 0)
3866 printf_filtered (_("Process group: %d\n"), itmp);
3867 if (fscanf (procfile, "%d ", &itmp) > 0)
3868 printf_filtered (_("Session id: %d\n"), itmp);
3869 if (fscanf (procfile, "%d ", &itmp) > 0)
3870 printf_filtered (_("TTY: %d\n"), itmp);
3871 if (fscanf (procfile, "%d ", &itmp) > 0)
3872 printf_filtered (_("TTY owner process group: %d\n"), itmp);
3873 if (fscanf (procfile, "%lu ", <mp) > 0)
3874 printf_filtered (_("Flags: 0x%lx\n"), ltmp);
3875 if (fscanf (procfile, "%lu ", <mp) > 0)
3876 printf_filtered (_("Minor faults (no memory page): %lu\n"),
3877 (unsigned long) ltmp);
3878 if (fscanf (procfile, "%lu ", <mp) > 0)
3879 printf_filtered (_("Minor faults, children: %lu\n"),
3880 (unsigned long) ltmp);
3881 if (fscanf (procfile, "%lu ", <mp) > 0)
3882 printf_filtered (_("Major faults (memory page faults): %lu\n"),
3883 (unsigned long) ltmp);
3884 if (fscanf (procfile, "%lu ", <mp) > 0)
3885 printf_filtered (_("Major faults, children: %lu\n"),
3886 (unsigned long) ltmp);
3887 if (fscanf (procfile, "%ld ", <mp) > 0)
3888 printf_filtered (_("utime: %ld\n"), ltmp);
3889 if (fscanf (procfile, "%ld ", <mp) > 0)
3890 printf_filtered (_("stime: %ld\n"), ltmp);
3891 if (fscanf (procfile, "%ld ", <mp) > 0)
3892 printf_filtered (_("utime, children: %ld\n"), ltmp);
3893 if (fscanf (procfile, "%ld ", <mp) > 0)
3894 printf_filtered (_("stime, children: %ld\n"), ltmp);
3895 if (fscanf (procfile, "%ld ", <mp) > 0)
3896 printf_filtered (_("jiffies remaining in current time slice: %ld\n"),
3898 if (fscanf (procfile, "%ld ", <mp) > 0)
3899 printf_filtered (_("'nice' value: %ld\n"), ltmp);
3900 if (fscanf (procfile, "%lu ", <mp) > 0)
3901 printf_filtered (_("jiffies until next timeout: %lu\n"),
3902 (unsigned long) ltmp);
3903 if (fscanf (procfile, "%lu ", <mp) > 0)
3904 printf_filtered (_("jiffies until next SIGALRM: %lu\n"),
3905 (unsigned long) ltmp);
3906 if (fscanf (procfile, "%ld ", <mp) > 0)
3907 printf_filtered (_("start time (jiffies since system boot): %ld\n"),
3909 if (fscanf (procfile, "%lu ", <mp) > 0)
3910 printf_filtered (_("Virtual memory size: %lu\n"),
3911 (unsigned long) ltmp);
3912 if (fscanf (procfile, "%lu ", <mp) > 0)
3913 printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp);
3914 if (fscanf (procfile, "%lu ", <mp) > 0)
3915 printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp);
3916 if (fscanf (procfile, "%lu ", <mp) > 0)
3917 printf_filtered (_("Start of text: 0x%lx\n"), ltmp);
3918 if (fscanf (procfile, "%lu ", <mp) > 0)
3919 printf_filtered (_("End of text: 0x%lx\n"), ltmp);
3920 if (fscanf (procfile, "%lu ", <mp) > 0)
3921 printf_filtered (_("Start of stack: 0x%lx\n"), ltmp);
3922 #if 0 /* Don't know how architecture-dependent the rest is...
3923 Anyway the signal bitmap info is available from "status". */
3924 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3925 printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp);
3926 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3927 printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp);
3928 if (fscanf (procfile, "%ld ", <mp) > 0)
3929 printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp);
3930 if (fscanf (procfile, "%ld ", <mp) > 0)
3931 printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp);
3932 if (fscanf (procfile, "%ld ", <mp) > 0)
3933 printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp);
3934 if (fscanf (procfile, "%ld ", <mp) > 0)
3935 printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp);
3936 if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */
3937 printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp);
3939 do_cleanups (cleanup);
3942 warning (_("unable to open /proc file '%s'"), fname1);
3946 /* Implement the to_xfer_partial interface for memory reads using the /proc
3947 filesystem. Because we can use a single read() call for /proc, this
3948 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3949 but it doesn't support writes. */
3952 linux_proc_xfer_partial (struct target_ops *ops, enum target_object object,
3953 const char *annex, gdb_byte *readbuf,
3954 const gdb_byte *writebuf,
3955 ULONGEST offset, LONGEST len)
3961 if (object != TARGET_OBJECT_MEMORY || !readbuf)
3964 /* Don't bother for one word. */
3965 if (len < 3 * sizeof (long))
3968 /* We could keep this file open and cache it - possibly one per
3969 thread. That requires some juggling, but is even faster. */
3970 sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid));
3971 fd = open (filename, O_RDONLY | O_LARGEFILE);
3975 /* If pread64 is available, use it. It's faster if the kernel
3976 supports it (only one syscall), and it's 64-bit safe even on
3977 32-bit platforms (for instance, SPARC debugging a SPARC64
3980 if (pread64 (fd, readbuf, len, offset) != len)
3982 if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len)
3992 /* Parse LINE as a signal set and add its set bits to SIGS. */
3995 add_line_to_sigset (const char *line, sigset_t *sigs)
3997 int len = strlen (line) - 1;
4001 if (line[len] != '\n')
4002 error (_("Could not parse signal set: %s"), line);
4010 if (*p >= '0' && *p <= '9')
4012 else if (*p >= 'a' && *p <= 'f')
4013 digit = *p - 'a' + 10;
4015 error (_("Could not parse signal set: %s"), line);
4020 sigaddset (sigs, signum + 1);
4022 sigaddset (sigs, signum + 2);
4024 sigaddset (sigs, signum + 3);
4026 sigaddset (sigs, signum + 4);
4032 /* Find process PID's pending signals from /proc/pid/status and set
4036 linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored)
4039 char buffer[MAXPATHLEN], fname[MAXPATHLEN];
4041 struct cleanup *cleanup;
4043 sigemptyset (pending);
4044 sigemptyset (blocked);
4045 sigemptyset (ignored);
4046 sprintf (fname, "/proc/%d/status", pid);
4047 procfile = fopen (fname, "r");
4048 if (procfile == NULL)
4049 error (_("Could not open %s"), fname);
4050 cleanup = make_cleanup_fclose (procfile);
4052 while (fgets (buffer, MAXPATHLEN, procfile) != NULL)
4054 /* Normal queued signals are on the SigPnd line in the status
4055 file. However, 2.6 kernels also have a "shared" pending
4056 queue for delivering signals to a thread group, so check for
4059 Unfortunately some Red Hat kernels include the shared pending
4060 queue but not the ShdPnd status field. */
4062 if (strncmp (buffer, "SigPnd:\t", 8) == 0)
4063 add_line_to_sigset (buffer + 8, pending);
4064 else if (strncmp (buffer, "ShdPnd:\t", 8) == 0)
4065 add_line_to_sigset (buffer + 8, pending);
4066 else if (strncmp (buffer, "SigBlk:\t", 8) == 0)
4067 add_line_to_sigset (buffer + 8, blocked);
4068 else if (strncmp (buffer, "SigIgn:\t", 8) == 0)
4069 add_line_to_sigset (buffer + 8, ignored);
4072 do_cleanups (cleanup);
4076 linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object,
4077 const char *annex, gdb_byte *readbuf,
4078 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4080 /* We make the process list snapshot when the object starts to be
4082 static const char *buf;
4083 static LONGEST len_avail = -1;
4084 static struct obstack obstack;
4088 gdb_assert (object == TARGET_OBJECT_OSDATA);
4090 if (strcmp (annex, "processes") != 0)
4093 gdb_assert (readbuf && !writebuf);
4097 if (len_avail != -1 && len_avail != 0)
4098 obstack_free (&obstack, NULL);
4101 obstack_init (&obstack);
4102 obstack_grow_str (&obstack, "<osdata type=\"processes\">\n");
4104 dirp = opendir ("/proc");
4108 while ((dp = readdir (dirp)) != NULL)
4110 struct stat statbuf;
4111 char procentry[sizeof ("/proc/4294967295")];
4113 if (!isdigit (dp->d_name[0])
4114 || NAMELEN (dp) > sizeof ("4294967295") - 1)
4117 sprintf (procentry, "/proc/%s", dp->d_name);
4118 if (stat (procentry, &statbuf) == 0
4119 && S_ISDIR (statbuf.st_mode))
4123 char cmd[MAXPATHLEN + 1];
4124 struct passwd *entry;
4126 pathname = xstrprintf ("/proc/%s/cmdline", dp->d_name);
4127 entry = getpwuid (statbuf.st_uid);
4129 if ((f = fopen (pathname, "r")) != NULL)
4131 size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
4135 for (i = 0; i < len; i++)
4140 obstack_xml_printf (
4143 "<column name=\"pid\">%s</column>"
4144 "<column name=\"user\">%s</column>"
4145 "<column name=\"command\">%s</column>"
4148 entry ? entry->pw_name : "?",
4161 obstack_grow_str0 (&obstack, "</osdata>\n");
4162 buf = obstack_finish (&obstack);
4163 len_avail = strlen (buf);
4166 if (offset >= len_avail)
4168 /* Done. Get rid of the obstack. */
4169 obstack_free (&obstack, NULL);
4175 if (len > len_avail - offset)
4176 len = len_avail - offset;
4177 memcpy (readbuf, buf + offset, len);
4183 linux_xfer_partial (struct target_ops *ops, enum target_object object,
4184 const char *annex, gdb_byte *readbuf,
4185 const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
4189 if (object == TARGET_OBJECT_AUXV)
4190 return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf,
4193 if (object == TARGET_OBJECT_OSDATA)
4194 return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf,
4197 xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf,
4202 return super_xfer_partial (ops, object, annex, readbuf, writebuf,
4206 /* Create a prototype generic GNU/Linux target. The client can override
4207 it with local methods. */
4210 linux_target_install_ops (struct target_ops *t)
4212 t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint;
4213 t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint;
4214 t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint;
4215 t->to_pid_to_exec_file = linux_child_pid_to_exec_file;
4216 t->to_post_startup_inferior = linux_child_post_startup_inferior;
4217 t->to_post_attach = linux_child_post_attach;
4218 t->to_follow_fork = linux_child_follow_fork;
4219 t->to_find_memory_regions = linux_nat_find_memory_regions;
4220 t->to_make_corefile_notes = linux_nat_make_corefile_notes;
4222 super_xfer_partial = t->to_xfer_partial;
4223 t->to_xfer_partial = linux_xfer_partial;
4229 struct target_ops *t;
4231 t = inf_ptrace_target ();
4232 linux_target_install_ops (t);
4238 linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int))
4240 struct target_ops *t;
4242 t = inf_ptrace_trad_target (register_u_offset);
4243 linux_target_install_ops (t);
4248 /* target_is_async_p implementation. */
4251 linux_nat_is_async_p (void)
4253 /* NOTE: palves 2008-03-21: We're only async when the user requests
4254 it explicitly with the "set target-async" command.
4255 Someday, linux will always be async. */
4256 if (!target_async_permitted)
4259 /* See target.h/target_async_mask. */
4260 return linux_nat_async_mask_value;
4263 /* target_can_async_p implementation. */
4266 linux_nat_can_async_p (void)
4268 /* NOTE: palves 2008-03-21: We're only async when the user requests
4269 it explicitly with the "set target-async" command.
4270 Someday, linux will always be async. */
4271 if (!target_async_permitted)
4274 /* See target.h/target_async_mask. */
4275 return linux_nat_async_mask_value;
4279 linux_nat_supports_non_stop (void)
4284 /* True if we want to support multi-process. To be removed when GDB
4285 supports multi-exec. */
4287 int linux_multi_process = 0;
4290 linux_nat_supports_multi_process (void)
4292 return linux_multi_process;
4295 /* target_async_mask implementation. */
4298 linux_nat_async_mask (int new_mask)
4300 int curr_mask = linux_nat_async_mask_value;
4302 if (curr_mask != new_mask)
4306 linux_nat_async (NULL, 0);
4307 linux_nat_async_mask_value = new_mask;
4311 linux_nat_async_mask_value = new_mask;
4313 /* If we're going out of async-mask in all-stop, then the
4314 inferior is stopped. The next resume will call
4315 target_async. In non-stop, the target event source
4316 should be always registered in the event loop. Do so
4319 linux_nat_async (inferior_event_handler, 0);
4326 static int async_terminal_is_ours = 1;
4328 /* target_terminal_inferior implementation. */
4331 linux_nat_terminal_inferior (void)
4333 if (!target_is_async_p ())
4335 /* Async mode is disabled. */
4336 terminal_inferior ();
4340 terminal_inferior ();
4342 /* Calls to target_terminal_*() are meant to be idempotent. */
4343 if (!async_terminal_is_ours)
4346 delete_file_handler (input_fd);
4347 async_terminal_is_ours = 0;
4351 /* target_terminal_ours implementation. */
4354 linux_nat_terminal_ours (void)
4356 if (!target_is_async_p ())
4358 /* Async mode is disabled. */
4363 /* GDB should never give the terminal to the inferior if the
4364 inferior is running in the background (run&, continue&, etc.),
4365 but claiming it sure should. */
4368 if (async_terminal_is_ours)
4371 clear_sigint_trap ();
4372 add_file_handler (input_fd, stdin_event_handler, 0);
4373 async_terminal_is_ours = 1;
4376 static void (*async_client_callback) (enum inferior_event_type event_type,
4378 static void *async_client_context;
4380 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4381 so we notice when any child changes state, and notify the
4382 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4383 above to wait for the arrival of a SIGCHLD. */
4386 sigchld_handler (int signo)
4388 int old_errno = errno;
4390 if (debug_linux_nat_async)
4391 fprintf_unfiltered (gdb_stdlog, "sigchld\n");
4393 if (signo == SIGCHLD
4394 && linux_nat_event_pipe[0] != -1)
4395 async_file_mark (); /* Let the event loop know that there are
4396 events to handle. */
4401 /* Callback registered with the target events file descriptor. */
4404 handle_target_event (int error, gdb_client_data client_data)
4406 (*async_client_callback) (INF_REG_EVENT, async_client_context);
4409 /* Create/destroy the target events pipe. Returns previous state. */
4412 linux_async_pipe (int enable)
4414 int previous = (linux_nat_event_pipe[0] != -1);
4416 if (previous != enable)
4420 block_child_signals (&prev_mask);
4424 if (pipe (linux_nat_event_pipe) == -1)
4425 internal_error (__FILE__, __LINE__,
4426 "creating event pipe failed.");
4428 fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK);
4429 fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK);
4433 close (linux_nat_event_pipe[0]);
4434 close (linux_nat_event_pipe[1]);
4435 linux_nat_event_pipe[0] = -1;
4436 linux_nat_event_pipe[1] = -1;
4439 restore_child_signals_mask (&prev_mask);
4445 /* target_async implementation. */
4448 linux_nat_async (void (*callback) (enum inferior_event_type event_type,
4449 void *context), void *context)
4451 if (linux_nat_async_mask_value == 0 || !target_async_permitted)
4452 internal_error (__FILE__, __LINE__,
4453 "Calling target_async when async is masked");
4455 if (callback != NULL)
4457 async_client_callback = callback;
4458 async_client_context = context;
4459 if (!linux_async_pipe (1))
4461 add_file_handler (linux_nat_event_pipe[0],
4462 handle_target_event, NULL);
4463 /* There may be pending events to handle. Tell the event loop
4470 async_client_callback = callback;
4471 async_client_context = context;
4472 delete_file_handler (linux_nat_event_pipe[0]);
4473 linux_async_pipe (0);
4478 /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other
4482 linux_nat_stop_lwp (struct lwp_info *lwp, void *data)
4487 ptid_t ptid = lwp->ptid;
4489 if (debug_linux_nat)
4490 fprintf_unfiltered (gdb_stdlog,
4491 "LNSL: running -> suspending %s\n",
4492 target_pid_to_str (lwp->ptid));
4495 stop_callback (lwp, NULL);
4496 stop_wait_callback (lwp, NULL);
4498 /* If the lwp exits while we try to stop it, there's nothing
4500 lwp = find_lwp_pid (ptid);
4504 /* If we didn't collect any signal other than SIGSTOP while
4505 stopping the LWP, push a SIGNAL_0 event. In either case, the
4506 event-loop will end up calling target_wait which will collect
4508 if (lwp->status == 0)
4509 lwp->status = W_STOPCODE (0);
4514 /* Already known to be stopped; do nothing. */
4516 if (debug_linux_nat)
4518 if (find_thread_pid (lwp->ptid)->stop_requested)
4519 fprintf_unfiltered (gdb_stdlog, "\
4520 LNSL: already stopped/stop_requested %s\n",
4521 target_pid_to_str (lwp->ptid));
4523 fprintf_unfiltered (gdb_stdlog, "\
4524 LNSL: already stopped/no stop_requested yet %s\n",
4525 target_pid_to_str (lwp->ptid));
4532 linux_nat_stop (ptid_t ptid)
4535 iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL);
4537 linux_ops->to_stop (ptid);
4541 linux_nat_close (int quitting)
4543 /* Unregister from the event loop. */
4544 if (target_is_async_p ())
4545 target_async (NULL, 0);
4547 /* Reset the async_masking. */
4548 linux_nat_async_mask_value = 1;
4550 if (linux_ops->to_close)
4551 linux_ops->to_close (quitting);
4555 linux_nat_add_target (struct target_ops *t)
4557 /* Save the provided single-threaded target. We save this in a separate
4558 variable because another target we've inherited from (e.g. inf-ptrace)
4559 may have saved a pointer to T; we want to use it for the final
4560 process stratum target. */
4561 linux_ops_saved = *t;
4562 linux_ops = &linux_ops_saved;
4564 /* Override some methods for multithreading. */
4565 t->to_create_inferior = linux_nat_create_inferior;
4566 t->to_attach = linux_nat_attach;
4567 t->to_detach = linux_nat_detach;
4568 t->to_resume = linux_nat_resume;
4569 t->to_wait = linux_nat_wait;
4570 t->to_xfer_partial = linux_nat_xfer_partial;
4571 t->to_kill = linux_nat_kill;
4572 t->to_mourn_inferior = linux_nat_mourn_inferior;
4573 t->to_thread_alive = linux_nat_thread_alive;
4574 t->to_pid_to_str = linux_nat_pid_to_str;
4575 t->to_has_thread_control = tc_schedlock;
4577 t->to_can_async_p = linux_nat_can_async_p;
4578 t->to_is_async_p = linux_nat_is_async_p;
4579 t->to_supports_non_stop = linux_nat_supports_non_stop;
4580 t->to_async = linux_nat_async;
4581 t->to_async_mask = linux_nat_async_mask;
4582 t->to_terminal_inferior = linux_nat_terminal_inferior;
4583 t->to_terminal_ours = linux_nat_terminal_ours;
4584 t->to_close = linux_nat_close;
4586 /* Methods for non-stop support. */
4587 t->to_stop = linux_nat_stop;
4589 t->to_supports_multi_process = linux_nat_supports_multi_process;
4591 /* We don't change the stratum; this target will sit at
4592 process_stratum and thread_db will set at thread_stratum. This
4593 is a little strange, since this is a multi-threaded-capable
4594 target, but we want to be on the stack below thread_db, and we
4595 also want to be used for single-threaded processes. */
4600 /* Register a method to call whenever a new thread is attached. */
4602 linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t))
4604 /* Save the pointer. We only support a single registered instance
4605 of the GNU/Linux native target, so we do not need to map this to
4607 linux_nat_new_thread = new_thread;
4610 /* Register a method that converts a siginfo object between the layout
4611 that ptrace returns, and the layout in the architecture of the
4614 linux_nat_set_siginfo_fixup (struct target_ops *t,
4615 int (*siginfo_fixup) (struct siginfo *,
4619 /* Save the pointer. */
4620 linux_nat_siginfo_fixup = siginfo_fixup;
4623 /* Return the saved siginfo associated with PTID. */
4625 linux_nat_get_siginfo (ptid_t ptid)
4627 struct lwp_info *lp = find_lwp_pid (ptid);
4629 gdb_assert (lp != NULL);
4631 return &lp->siginfo;
4634 /* Provide a prototype to silence -Wmissing-prototypes. */
4635 extern initialize_file_ftype _initialize_linux_nat;
4638 _initialize_linux_nat (void)
4642 add_info ("proc", linux_nat_info_proc_cmd, _("\
4643 Show /proc process information about any running process.\n\
4644 Specify any process id, or use the program being debugged by default.\n\
4645 Specify any of the following keywords for detailed info:\n\
4646 mappings -- list of mapped memory regions.\n\
4647 stat -- list a bunch of random process info.\n\
4648 status -- list a different bunch of random process info.\n\
4649 all -- list all available /proc info."));
4651 add_setshow_zinteger_cmd ("lin-lwp", class_maintenance,
4652 &debug_linux_nat, _("\
4653 Set debugging of GNU/Linux lwp module."), _("\
4654 Show debugging of GNU/Linux lwp module."), _("\
4655 Enables printf debugging output."),
4657 show_debug_linux_nat,
4658 &setdebuglist, &showdebuglist);
4660 add_setshow_zinteger_cmd ("lin-lwp-async", class_maintenance,
4661 &debug_linux_nat_async, _("\
4662 Set debugging of GNU/Linux async lwp module."), _("\
4663 Show debugging of GNU/Linux async lwp module."), _("\
4664 Enables printf debugging output."),
4666 show_debug_linux_nat_async,
4667 &setdebuglist, &showdebuglist);
4669 /* Save this mask as the default. */
4670 sigprocmask (SIG_SETMASK, NULL, &normal_mask);
4672 /* Install a SIGCHLD handler. */
4673 sigchld_action.sa_handler = sigchld_handler;
4674 sigemptyset (&sigchld_action.sa_mask);
4675 sigchld_action.sa_flags = SA_RESTART;
4677 /* Make it the default. */
4678 sigaction (SIGCHLD, &sigchld_action, NULL);
4680 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4681 sigprocmask (SIG_SETMASK, NULL, &suspend_mask);
4682 sigdelset (&suspend_mask, SIGCHLD);
4684 sigemptyset (&blocked_mask);
4686 add_setshow_boolean_cmd ("disable-randomization", class_support,
4687 &disable_randomization, _("\
4688 Set disabling of debuggee's virtual address space randomization."), _("\
4689 Show disabling of debuggee's virtual address space randomization."), _("\
4690 When this mode is on (which is the default), randomization of the virtual\n\
4691 address space is disabled. Standalone programs run with the randomization\n\
4692 enabled by default on some platforms."),
4693 &set_disable_randomization,
4694 &show_disable_randomization,
4695 &setlist, &showlist);
4699 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4700 the GNU/Linux Threads library and therefore doesn't really belong
4703 /* Read variable NAME in the target and return its value if found.
4704 Otherwise return zero. It is assumed that the type of the variable
4708 get_signo (const char *name)
4710 struct minimal_symbol *ms;
4713 ms = lookup_minimal_symbol (name, NULL, NULL);
4717 if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo,
4718 sizeof (signo)) != 0)
4724 /* Return the set of signals used by the threads library in *SET. */
4727 lin_thread_get_thread_signals (sigset_t *set)
4729 struct sigaction action;
4730 int restart, cancel;
4732 sigemptyset (&blocked_mask);
4735 restart = get_signo ("__pthread_sig_restart");
4736 cancel = get_signo ("__pthread_sig_cancel");
4738 /* LinuxThreads normally uses the first two RT signals, but in some legacy
4739 cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does
4740 not provide any way for the debugger to query the signal numbers -
4741 fortunately they don't change! */
4744 restart = __SIGRTMIN;
4747 cancel = __SIGRTMIN + 1;
4749 sigaddset (set, restart);
4750 sigaddset (set, cancel);
4752 /* The GNU/Linux Threads library makes terminating threads send a
4753 special "cancel" signal instead of SIGCHLD. Make sure we catch
4754 those (to prevent them from terminating GDB itself, which is
4755 likely to be their default action) and treat them the same way as
4758 action.sa_handler = sigchld_handler;
4759 sigemptyset (&action.sa_mask);
4760 action.sa_flags = SA_RESTART;
4761 sigaction (cancel, &action, NULL);
4763 /* We block the "cancel" signal throughout this code ... */
4764 sigaddset (&blocked_mask, cancel);
4765 sigprocmask (SIG_BLOCK, &blocked_mask, NULL);
4767 /* ... except during a sigsuspend. */
4768 sigdelset (&suspend_mask, cancel);