1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
22 #include "ansidecl.h" /* For ATTRIBUTE_PACKED, must be bug in external.h. */
23 #include "elf/common.h"
24 #include "elf/external.h"
28 #include <sys/param.h>
29 #include <sys/ptrace.h>
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
44 #ifndef PTRACE_GETSIGINFO
45 # define PTRACE_GETSIGINFO 0x4202
46 # define PTRACE_SETSIGINFO 0x4203
53 /* If the system headers did not provide the constants, hard-code the normal
55 #ifndef PTRACE_EVENT_FORK
57 #define PTRACE_SETOPTIONS 0x4200
58 #define PTRACE_GETEVENTMSG 0x4201
60 /* options set using PTRACE_SETOPTIONS */
61 #define PTRACE_O_TRACESYSGOOD 0x00000001
62 #define PTRACE_O_TRACEFORK 0x00000002
63 #define PTRACE_O_TRACEVFORK 0x00000004
64 #define PTRACE_O_TRACECLONE 0x00000008
65 #define PTRACE_O_TRACEEXEC 0x00000010
66 #define PTRACE_O_TRACEVFORKDONE 0x00000020
67 #define PTRACE_O_TRACEEXIT 0x00000040
69 /* Wait extended result codes for the above trace options. */
70 #define PTRACE_EVENT_FORK 1
71 #define PTRACE_EVENT_VFORK 2
72 #define PTRACE_EVENT_CLONE 3
73 #define PTRACE_EVENT_EXEC 4
74 #define PTRACE_EVENT_VFORK_DONE 5
75 #define PTRACE_EVENT_EXIT 6
77 #endif /* PTRACE_EVENT_FORK */
79 /* We can't always assume that this flag is available, but all systems
80 with the ptrace event handlers also have __WALL, so it's safe to use
83 #define __WALL 0x40000000 /* Wait for any child. */
87 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
92 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
93 representation of the thread ID.
95 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
96 the same as the LWP ID.
98 ``all_processes'' is keyed by the "overall process ID", which
99 GNU/Linux calls tgid, "thread group ID". */
101 struct inferior_list all_lwps
;
103 /* A list of all unknown processes which receive stop signals. Some other
104 process will presumably claim each of these as forked children
107 struct inferior_list stopped_pids
;
109 /* FIXME this is a bit of a hack, and could be removed. */
110 int stopping_threads
;
112 /* FIXME make into a target method? */
113 int using_threads
= 1;
115 /* This flag is true iff we've just created or attached to our first
116 inferior but it has not stopped yet. As soon as it does, we need
117 to call the low target's arch_setup callback. Doing this only on
118 the first inferior avoids reinializing the architecture on every
119 inferior, and avoids messing with the register caches of the
120 already running inferiors. NOTE: this assumes all inferiors under
121 control of gdbserver have the same architecture. */
122 static int new_inferior
;
124 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
125 int step
, int signal
, siginfo_t
*info
);
126 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
127 static void stop_all_lwps (void);
128 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
129 static int check_removed_breakpoint (struct lwp_info
*event_child
);
130 static void *add_lwp (ptid_t ptid
);
131 static int my_waitpid (int pid
, int *status
, int flags
);
132 static int linux_stopped_by_watchpoint (void);
133 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
135 struct pending_signals
139 struct pending_signals
*prev
;
142 #define PTRACE_ARG3_TYPE long
143 #define PTRACE_XFER_TYPE long
145 #ifdef HAVE_LINUX_REGSETS
146 static char *disabled_regsets
;
147 static int num_regsets
;
150 /* The read/write ends of the pipe registered as waitable file in the
152 static int linux_event_pipe
[2] = { -1, -1 };
154 /* True if we're currently in async mode. */
155 #define target_is_async_p() (linux_event_pipe[0] != -1)
157 static void send_sigstop (struct inferior_list_entry
*entry
);
158 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
160 /* Accepts an integer PID; Returns a string representing a file that
161 can be opened to get info for the child process.
162 Space for the result is malloc'd, caller must free. */
165 linux_child_pid_to_exec_file (int pid
)
169 name1
= xmalloc (MAXPATHLEN
);
170 name2
= xmalloc (MAXPATHLEN
);
171 memset (name2
, 0, MAXPATHLEN
);
173 sprintf (name1
, "/proc/%d/exe", pid
);
174 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
186 /* Return non-zero if HEADER is a 64-bit ELF file. */
189 elf_64_header_p (const Elf64_External_Ehdr
*header
)
191 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
192 && header
->e_ident
[EI_MAG1
] == ELFMAG1
193 && header
->e_ident
[EI_MAG2
] == ELFMAG2
194 && header
->e_ident
[EI_MAG3
] == ELFMAG3
195 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
198 /* Return non-zero if FILE is a 64-bit ELF file,
199 zero if the file is not a 64-bit ELF file,
200 and -1 if the file is not accessible or doesn't exist. */
203 elf_64_file_p (const char *file
)
205 Elf64_External_Ehdr header
;
208 fd
= open (file
, O_RDONLY
);
212 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
219 return elf_64_header_p (&header
);
223 delete_lwp (struct lwp_info
*lwp
)
225 remove_thread (get_lwp_thread (lwp
));
226 remove_inferior (&all_lwps
, &lwp
->head
);
230 /* Add a process to the common process list, and set its private
233 static struct process_info
*
234 linux_add_process (int pid
, int attached
)
236 struct process_info
*proc
;
238 /* Is this the first process? If so, then set the arch. */
239 if (all_processes
.head
== NULL
)
242 proc
= add_process (pid
, attached
);
243 proc
->private = xcalloc (1, sizeof (*proc
->private));
248 /* Remove a process from the common process list,
249 also freeing all private data. */
252 linux_remove_process (struct process_info
*process
)
254 free (process
->private);
255 remove_process (process
);
258 /* Handle a GNU/Linux extended wait response. If we see a clone
259 event, we need to add the new LWP to our list (and not report the
260 trap to higher layers). */
263 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
265 int event
= wstat
>> 16;
266 struct lwp_info
*new_lwp
;
268 if (event
== PTRACE_EVENT_CLONE
)
271 unsigned long new_pid
;
272 int ret
, status
= W_STOPCODE (SIGSTOP
);
274 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
276 /* If we haven't already seen the new PID stop, wait for it now. */
277 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
279 /* The new child has a pending SIGSTOP. We can't affect it until it
280 hits the SIGSTOP, but we're already attached. */
282 ret
= my_waitpid (new_pid
, &status
, __WALL
);
285 perror_with_name ("waiting for new child");
286 else if (ret
!= new_pid
)
287 warning ("wait returned unexpected PID %d", ret
);
288 else if (!WIFSTOPPED (status
))
289 warning ("wait returned unexpected status 0x%x", status
);
292 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, PTRACE_O_TRACECLONE
);
294 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
295 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
296 add_thread (ptid
, new_lwp
);
298 /* Normally we will get the pending SIGSTOP. But in some cases
299 we might get another signal delivered to the group first.
300 If we do get another signal, be sure not to lose it. */
301 if (WSTOPSIG (status
) == SIGSTOP
)
303 if (stopping_threads
)
304 new_lwp
->stopped
= 1;
306 ptrace (PTRACE_CONT
, new_pid
, 0, 0);
310 new_lwp
->stop_expected
= 1;
311 if (stopping_threads
)
313 new_lwp
->stopped
= 1;
314 new_lwp
->status_pending_p
= 1;
315 new_lwp
->status_pending
= status
;
318 /* Pass the signal on. This is what GDB does - except
319 shouldn't we really report it instead? */
320 ptrace (PTRACE_CONT
, new_pid
, 0, WSTOPSIG (status
));
323 /* Always resume the current thread. If we are stopping
324 threads, it will have a pending SIGSTOP; we may as well
326 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
330 /* This function should only be called if the process got a SIGTRAP.
331 The SIGTRAP could mean several things.
333 On i386, where decr_pc_after_break is non-zero:
334 If we were single-stepping this process using PTRACE_SINGLESTEP,
335 we will get only the one SIGTRAP (even if the instruction we
336 stepped over was a breakpoint). The value of $eip will be the
338 If we continue the process using PTRACE_CONT, we will get a
339 SIGTRAP when we hit a breakpoint. The value of $eip will be
340 the instruction after the breakpoint (i.e. needs to be
341 decremented). If we report the SIGTRAP to GDB, we must also
342 report the undecremented PC. If we cancel the SIGTRAP, we
343 must resume at the decremented PC.
345 (Presumably, not yet tested) On a non-decr_pc_after_break machine
346 with hardware or kernel single-step:
347 If we single-step over a breakpoint instruction, our PC will
348 point at the following instruction. If we continue and hit a
349 breakpoint instruction, our PC will point at the breakpoint
355 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) ();
357 if (get_thread_lwp (current_inferior
)->stepping
)
360 return stop_pc
- the_low_target
.decr_pc_after_break
;
364 add_lwp (ptid_t ptid
)
366 struct lwp_info
*lwp
;
368 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
369 memset (lwp
, 0, sizeof (*lwp
));
373 add_inferior_to_list (&all_lwps
, &lwp
->head
);
378 /* Start an inferior process and returns its pid.
379 ALLARGS is a vector of program-name and args. */
382 linux_create_inferior (char *program
, char **allargs
)
384 struct lwp_info
*new_lwp
;
388 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
394 perror_with_name ("fork");
398 ptrace (PTRACE_TRACEME
, 0, 0, 0);
400 signal (__SIGRTMIN
+ 1, SIG_DFL
);
404 execv (program
, allargs
);
406 execvp (program
, allargs
);
408 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
414 linux_add_process (pid
, 0);
416 ptid
= ptid_build (pid
, pid
, 0);
417 new_lwp
= add_lwp (ptid
);
418 add_thread (ptid
, new_lwp
);
419 new_lwp
->must_set_ptrace_flags
= 1;
424 /* Attach to an inferior process. */
427 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
430 struct lwp_info
*new_lwp
;
432 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
436 /* If we fail to attach to an LWP, just warn. */
437 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
438 strerror (errno
), errno
);
443 /* If we fail to attach to a process, report an error. */
444 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
445 strerror (errno
), errno
);
449 /* NOTE/FIXME: This lwp might have not been the tgid. */
450 ptid
= ptid_build (lwpid
, lwpid
, 0);
453 /* Note that extracting the pid from the current inferior is
454 safe, since we're always called in the context of the same
455 process as this new thread. */
456 int pid
= pid_of (get_thread_lwp (current_inferior
));
457 ptid
= ptid_build (pid
, lwpid
, 0);
460 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
461 add_thread (ptid
, new_lwp
);
464 /* We need to wait for SIGSTOP before being able to make the next
465 ptrace call on this LWP. */
466 new_lwp
->must_set_ptrace_flags
= 1;
468 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
471 There are several cases to consider here:
473 1) gdbserver has already attached to the process and is being notified
474 of a new thread that is being created.
475 In this case we should ignore that SIGSTOP and resume the process.
476 This is handled below by setting stop_expected = 1.
478 2) This is the first thread (the process thread), and we're attaching
479 to it via attach_inferior.
480 In this case we want the process thread to stop.
481 This is handled by having linux_attach clear stop_expected after
483 ??? If the process already has several threads we leave the other
486 3) GDB is connecting to gdbserver and is requesting an enumeration of all
488 In this case we want the thread to stop.
489 FIXME: This case is currently not properly handled.
490 We should wait for the SIGSTOP but don't. Things work apparently
491 because enough time passes between when we ptrace (ATTACH) and when
492 gdb makes the next ptrace call on the thread.
494 On the other hand, if we are currently trying to stop all threads, we
495 should treat the new thread as if we had sent it a SIGSTOP. This works
496 because we are guaranteed that the add_lwp call above added us to the
497 end of the list, and so the new thread has not yet reached
498 wait_for_sigstop (but will). */
499 if (! stopping_threads
)
500 new_lwp
->stop_expected
= 1;
504 linux_attach_lwp (unsigned long lwpid
)
506 linux_attach_lwp_1 (lwpid
, 0);
510 linux_attach (unsigned long pid
)
512 struct lwp_info
*lwp
;
514 linux_attach_lwp_1 (pid
, 1);
516 linux_add_process (pid
, 1);
520 /* Don't ignore the initial SIGSTOP if we just attached to this
521 process. It will be collected by wait shortly. */
522 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
523 ptid_build (pid
, pid
, 0));
524 lwp
->stop_expected
= 0;
537 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
539 struct counter
*counter
= args
;
541 if (ptid_get_pid (entry
->id
) == counter
->pid
)
543 if (++counter
->count
> 1)
551 last_thread_of_process_p (struct thread_info
*thread
)
553 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
554 int pid
= ptid_get_pid (ptid
);
555 struct counter counter
= { pid
, 0 };
557 return (find_inferior (&all_threads
,
558 second_thread_of_pid_p
, &counter
) == NULL
);
561 /* Kill the inferior lwp. */
564 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
566 struct thread_info
*thread
= (struct thread_info
*) entry
;
567 struct lwp_info
*lwp
= get_thread_lwp (thread
);
569 int pid
= * (int *) args
;
571 if (ptid_get_pid (entry
->id
) != pid
)
574 /* We avoid killing the first thread here, because of a Linux kernel (at
575 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
576 the children get a chance to be reaped, it will remain a zombie
579 if (last_thread_of_process_p (thread
))
582 fprintf (stderr
, "lkop: is last of process %s\n",
583 target_pid_to_str (entry
->id
));
587 /* If we're killing a running inferior, make sure it is stopped
588 first, as PTRACE_KILL will not work otherwise. */
590 send_sigstop (&lwp
->head
);
594 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
596 /* Make sure it died. The loop is most likely unnecessary. */
597 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
598 } while (pid
> 0 && WIFSTOPPED (wstat
));
606 struct process_info
*process
;
607 struct lwp_info
*lwp
;
608 struct thread_info
*thread
;
612 process
= find_process_pid (pid
);
616 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
618 /* See the comment in linux_kill_one_lwp. We did not kill the first
619 thread in the list, so do so now. */
620 lwp
= find_lwp_pid (pid_to_ptid (pid
));
621 thread
= get_lwp_thread (lwp
);
624 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
625 lwpid_of (lwp
), pid
);
627 /* If we're killing a running inferior, make sure it is stopped
628 first, as PTRACE_KILL will not work otherwise. */
630 send_sigstop (&lwp
->head
);
634 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
636 /* Make sure it died. The loop is most likely unnecessary. */
637 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
638 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
641 linux_remove_process (process
);
646 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
648 struct thread_info
*thread
= (struct thread_info
*) entry
;
649 struct lwp_info
*lwp
= get_thread_lwp (thread
);
650 int pid
= * (int *) args
;
652 if (ptid_get_pid (entry
->id
) != pid
)
655 /* If we're detaching from a running inferior, make sure it is
656 stopped first, as PTRACE_DETACH will not work otherwise. */
659 int lwpid
= lwpid_of (lwp
);
661 stopping_threads
= 1;
662 send_sigstop (&lwp
->head
);
664 /* If this detects a new thread through a clone event, the new
665 thread is appended to the end of the lwp list, so we'll
666 eventually detach from it. */
667 wait_for_sigstop (&lwp
->head
);
668 stopping_threads
= 0;
670 /* If LWP exits while we're trying to stop it, there's nothing
672 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
677 /* Make sure the process isn't stopped at a breakpoint that's
679 check_removed_breakpoint (lwp
);
681 /* If this process is stopped but is expecting a SIGSTOP, then make
682 sure we take care of that now. This isn't absolutely guaranteed
683 to collect the SIGSTOP, but is fairly likely to. */
684 if (lwp
->stop_expected
)
687 /* Clear stop_expected, so that the SIGSTOP will be reported. */
688 lwp
->stop_expected
= 0;
690 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
691 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
694 /* Flush any pending changes to the process's registers. */
695 regcache_invalidate_one ((struct inferior_list_entry
*)
696 get_lwp_thread (lwp
));
698 /* Finally, let it resume. */
699 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
706 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
710 if (ptid_get_pid (entry
->id
) == *pid_p
)
717 linux_detach (int pid
)
719 struct process_info
*process
;
721 process
= find_process_pid (pid
);
726 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
728 delete_all_breakpoints ();
729 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
730 linux_remove_process (process
);
738 struct process_info
*process
;
740 process
= find_process_pid (pid
);
745 ret
= my_waitpid (pid
, &status
, 0);
746 if (WIFEXITED (status
) || WIFSIGNALED (status
))
748 } while (ret
!= -1 || errno
!= ECHILD
);
751 /* Return nonzero if the given thread is still alive. */
753 linux_thread_alive (ptid_t ptid
)
755 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
757 /* We assume we always know if a thread exits. If a whole process
758 exited but we still haven't been able to report it to GDB, we'll
759 hold on to the last lwp of the dead process. */
766 /* Return nonzero if this process stopped at a breakpoint which
767 no longer appears to be inserted. Also adjust the PC
768 appropriately to resume where the breakpoint used to be. */
770 check_removed_breakpoint (struct lwp_info
*event_child
)
773 struct thread_info
*saved_inferior
;
775 if (event_child
->pending_is_breakpoint
== 0)
779 fprintf (stderr
, "Checking for breakpoint in lwp %ld.\n",
780 lwpid_of (event_child
));
782 saved_inferior
= current_inferior
;
783 current_inferior
= get_lwp_thread (event_child
);
785 stop_pc
= get_stop_pc ();
787 /* If the PC has changed since we stopped, then we shouldn't do
788 anything. This happens if, for instance, GDB handled the
789 decr_pc_after_break subtraction itself. */
790 if (stop_pc
!= event_child
->pending_stop_pc
)
793 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
794 event_child
->pending_stop_pc
);
796 event_child
->pending_is_breakpoint
= 0;
797 current_inferior
= saved_inferior
;
801 /* If the breakpoint is still there, we will report hitting it. */
802 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
805 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
806 current_inferior
= saved_inferior
;
811 fprintf (stderr
, "Removed breakpoint.\n");
813 /* For decr_pc_after_break targets, here is where we perform the
814 decrement. We go immediately from this function to resuming,
815 and can not safely call get_stop_pc () again. */
816 if (the_low_target
.set_pc
!= NULL
)
817 (*the_low_target
.set_pc
) (stop_pc
);
819 /* We consumed the pending SIGTRAP. */
820 event_child
->pending_is_breakpoint
= 0;
821 event_child
->status_pending_p
= 0;
822 event_child
->status_pending
= 0;
824 current_inferior
= saved_inferior
;
828 /* Return 1 if this lwp has an interesting status pending. This
829 function may silently resume an inferior lwp. */
831 status_pending_p (struct inferior_list_entry
*entry
, void *arg
)
833 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
834 ptid_t ptid
= * (ptid_t
*) arg
;
836 /* Check if we're only interested in events from a specific process
838 if (!ptid_equal (minus_one_ptid
, ptid
)
839 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
842 if (lwp
->status_pending_p
&& !lwp
->suspended
)
843 if (check_removed_breakpoint (lwp
))
845 /* This thread was stopped at a breakpoint, and the breakpoint
846 is now gone. We were told to continue (or step...) all threads,
847 so GDB isn't trying to single-step past this breakpoint.
848 So instead of reporting the old SIGTRAP, pretend we got to
849 the breakpoint just after it was removed instead of just
850 before; resume the process. */
851 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
855 return (lwp
->status_pending_p
&& !lwp
->suspended
);
859 same_lwp (struct inferior_list_entry
*entry
, void *data
)
861 ptid_t ptid
= *(ptid_t
*) data
;
864 if (ptid_get_lwp (ptid
) != 0)
865 lwp
= ptid_get_lwp (ptid
);
867 lwp
= ptid_get_pid (ptid
);
869 if (ptid_get_lwp (entry
->id
) == lwp
)
876 find_lwp_pid (ptid_t ptid
)
878 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
881 static struct lwp_info
*
882 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
885 int to_wait_for
= -1;
886 struct lwp_info
*child
= NULL
;
889 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
891 if (ptid_equal (ptid
, minus_one_ptid
))
892 to_wait_for
= -1; /* any child */
894 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
900 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
901 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
904 perror_with_name ("waitpid");
907 && (!WIFSTOPPED (*wstatp
)
908 || (WSTOPSIG (*wstatp
) != 32
909 && WSTOPSIG (*wstatp
) != 33)))
910 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
912 child
= find_lwp_pid (pid_to_ptid (ret
));
914 /* If we didn't find a process, one of two things presumably happened:
915 - A process we started and then detached from has exited. Ignore it.
916 - A process we are controlling has forked and the new child's stop
917 was reported to us by the kernel. Save its PID. */
918 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
920 add_pid_to_list (&stopped_pids
, ret
);
923 else if (child
== NULL
)
927 child
->pending_is_breakpoint
= 0;
929 child
->last_status
= *wstatp
;
931 /* Architecture-specific setup after inferior is running.
932 This needs to happen after we have attached to the inferior
933 and it is stopped for the first time, but before we access
934 any inferior registers. */
937 the_low_target
.arch_setup ();
938 #ifdef HAVE_LINUX_REGSETS
939 memset (disabled_regsets
, 0, num_regsets
);
945 && WIFSTOPPED (*wstatp
))
947 struct thread_info
*saved_inferior
= current_inferior
;
948 current_inferior
= (struct thread_info
*)
949 find_inferior_id (&all_threads
, child
->head
.id
);
950 /* For testing only; i386_stop_pc prints out a diagnostic. */
951 if (the_low_target
.get_pc
!= NULL
)
953 current_inferior
= saved_inferior
;
959 /* Wait for an event from child PID. If PID is -1, wait for any
960 child. Store the stop status through the status pointer WSTAT.
961 OPTIONS is passed to the waitpid call. Return 0 if no child stop
962 event was found and OPTIONS contains WNOHANG. Return the PID of
963 the stopped child otherwise. */
966 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
969 struct lwp_info
*event_child
= NULL
;
971 struct lwp_info
*requested_child
= NULL
;
973 /* Check for a lwp with a pending status. */
974 /* It is possible that the user changed the pending task's registers since
975 it stopped. We correctly handle the change of PC if we hit a breakpoint
976 (in check_removed_breakpoint); signals should be reported anyway. */
978 if (ptid_equal (ptid
, minus_one_ptid
)
979 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
981 event_child
= (struct lwp_info
*)
982 find_inferior (&all_lwps
, status_pending_p
, &ptid
);
983 if (debug_threads
&& event_child
)
984 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
988 requested_child
= find_lwp_pid (ptid
);
989 if (requested_child
->status_pending_p
990 && !check_removed_breakpoint (requested_child
))
991 event_child
= requested_child
;
994 if (event_child
!= NULL
)
997 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
998 lwpid_of (event_child
), event_child
->status_pending
);
999 *wstat
= event_child
->status_pending
;
1000 event_child
->status_pending_p
= 0;
1001 event_child
->status_pending
= 0;
1002 current_inferior
= get_lwp_thread (event_child
);
1003 return lwpid_of (event_child
);
1006 /* We only enter this loop if no process has a pending wait status. Thus
1007 any action taken in response to a wait status inside this loop is
1008 responding as soon as we detect the status, not after any pending
1012 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1014 if ((options
& WNOHANG
) && event_child
== NULL
)
1017 if (event_child
== NULL
)
1018 error ("event from unknown child");
1020 current_inferior
= get_lwp_thread (event_child
);
1022 /* Check for thread exit. */
1023 if (! WIFSTOPPED (*wstat
))
1026 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1028 /* If the last thread is exiting, just return. */
1029 if (last_thread_of_process_p (current_inferior
))
1032 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1033 lwpid_of (event_child
));
1034 return lwpid_of (event_child
);
1037 delete_lwp (event_child
);
1041 current_inferior
= (struct thread_info
*) all_threads
.head
;
1043 fprintf (stderr
, "Current inferior is now %ld\n",
1044 lwpid_of (get_thread_lwp (current_inferior
)));
1048 current_inferior
= NULL
;
1050 fprintf (stderr
, "Current inferior is now <NULL>\n");
1053 /* If we were waiting for this particular child to do something...
1054 well, it did something. */
1055 if (requested_child
!= NULL
)
1056 return lwpid_of (event_child
);
1058 /* Wait for a more interesting event. */
1062 if (event_child
->must_set_ptrace_flags
)
1064 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1065 0, PTRACE_O_TRACECLONE
);
1066 event_child
->must_set_ptrace_flags
= 0;
1069 if (WIFSTOPPED (*wstat
)
1070 && WSTOPSIG (*wstat
) == SIGSTOP
1071 && event_child
->stop_expected
)
1074 fprintf (stderr
, "Expected stop.\n");
1075 event_child
->stop_expected
= 0;
1076 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
1080 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1081 && *wstat
>> 16 != 0)
1083 handle_extended_wait (event_child
, *wstat
);
1087 /* If GDB is not interested in this signal, don't stop other
1088 threads, and don't report it to GDB. Just resume the
1089 inferior right away. We do this for threading-related
1090 signals as well as any that GDB specifically requested we
1091 ignore. But never ignore SIGSTOP if we sent it ourselves,
1092 and do not ignore signals when stepping - they may require
1093 special handling to skip the signal handler. */
1094 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1096 if (WIFSTOPPED (*wstat
)
1097 && !event_child
->stepping
1099 #ifdef USE_THREAD_DB
1100 (current_process ()->private->thread_db_active
1101 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1102 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1105 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1106 && (WSTOPSIG (*wstat
) != SIGSTOP
|| !stopping_threads
))))
1108 siginfo_t info
, *info_p
;
1111 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1112 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1114 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1118 linux_resume_one_lwp (event_child
,
1119 event_child
->stepping
,
1120 WSTOPSIG (*wstat
), info_p
);
1124 /* If this event was not handled above, and is not a SIGTRAP, report
1126 if (!WIFSTOPPED (*wstat
) || WSTOPSIG (*wstat
) != SIGTRAP
)
1127 return lwpid_of (event_child
);
1129 /* If this target does not support breakpoints, we simply report the
1130 SIGTRAP; it's of no concern to us. */
1131 if (the_low_target
.get_pc
== NULL
)
1132 return lwpid_of (event_child
);
1134 stop_pc
= get_stop_pc ();
1136 /* bp_reinsert will only be set if we were single-stepping.
1137 Notice that we will resume the process after hitting
1138 a gdbserver breakpoint; single-stepping to/over one
1139 is not supported (yet). */
1140 if (event_child
->bp_reinsert
!= 0)
1143 fprintf (stderr
, "Reinserted breakpoint.\n");
1144 reinsert_breakpoint (event_child
->bp_reinsert
);
1145 event_child
->bp_reinsert
= 0;
1147 /* Clear the single-stepping flag and SIGTRAP as we resume. */
1148 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1152 bp_status
= check_breakpoints (stop_pc
);
1157 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1159 /* We hit one of our own breakpoints. We mark it as a pending
1160 breakpoint, so that check_removed_breakpoint () will do the PC
1161 adjustment for us at the appropriate time. */
1162 event_child
->pending_is_breakpoint
= 1;
1163 event_child
->pending_stop_pc
= stop_pc
;
1165 /* We may need to put the breakpoint back. We continue in the event
1166 loop instead of simply replacing the breakpoint right away,
1167 in order to not lose signals sent to the thread that hit the
1168 breakpoint. Unfortunately this increases the window where another
1169 thread could sneak past the removed breakpoint. For the current
1170 use of server-side breakpoints (thread creation) this is
1171 acceptable; but it needs to be considered before this breakpoint
1172 mechanism can be used in more general ways. For some breakpoints
1173 it may be necessary to stop all other threads, but that should
1174 be avoided where possible.
1176 If breakpoint_reinsert_addr is NULL, that means that we can
1177 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
1178 mark it for reinsertion, and single-step.
1180 Otherwise, call the target function to figure out where we need
1181 our temporary breakpoint, create it, and continue executing this
1184 /* NOTE: we're lifting breakpoints in non-stop mode. This
1185 is currently only used for thread event breakpoints, so
1186 it isn't that bad as long as we have PTRACE_EVENT_CLONE
1189 /* No need to reinsert. */
1190 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1191 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
1193 event_child
->bp_reinsert
= stop_pc
;
1194 uninsert_breakpoint (stop_pc
);
1195 linux_resume_one_lwp (event_child
, 1, 0, NULL
);
1199 reinsert_breakpoint_by_bp
1200 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
1201 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1208 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
1210 /* If we were single-stepping, we definitely want to report the
1211 SIGTRAP. Although the single-step operation has completed,
1212 do not clear clear the stepping flag yet; we need to check it
1213 in wait_for_sigstop. */
1214 if (event_child
->stepping
)
1215 return lwpid_of (event_child
);
1217 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
1218 Check if it is a breakpoint, and if so mark the process information
1219 accordingly. This will handle both the necessary fiddling with the
1220 PC on decr_pc_after_break targets and suppressing extra threads
1221 hitting a breakpoint if two hit it at once and then GDB removes it
1222 after the first is reported. Arguably it would be better to report
1223 multiple threads hitting breakpoints simultaneously, but the current
1224 remote protocol does not allow this. */
1225 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
1227 event_child
->pending_is_breakpoint
= 1;
1228 event_child
->pending_stop_pc
= stop_pc
;
1231 return lwpid_of (event_child
);
1239 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1243 if (ptid_is_pid (ptid
))
1245 /* A request to wait for a specific tgid. This is not possible
1246 with waitpid, so instead, we wait for any child, and leave
1247 children we're not interested in right now with a pending
1248 status to report later. */
1249 wait_ptid
= minus_one_ptid
;
1258 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1261 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1263 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1265 if (! WIFSTOPPED (*wstat
))
1266 mark_lwp_dead (event_child
, *wstat
);
1269 event_child
->status_pending_p
= 1;
1270 event_child
->status_pending
= *wstat
;
1278 /* Wait for process, returns status. */
1281 linux_wait_1 (ptid_t ptid
,
1282 struct target_waitstatus
*ourstatus
, int target_options
)
1285 struct thread_info
*thread
= NULL
;
1286 struct lwp_info
*lwp
= NULL
;
1290 /* Translate generic target options into linux options. */
1292 if (target_options
& TARGET_WNOHANG
)
1296 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1298 /* If we were only supposed to resume one thread, only wait for
1299 that thread - if it's still alive. If it died, however - which
1300 can happen if we're coming from the thread death case below -
1301 then we need to make sure we restart the other threads. We could
1302 pick a thread at random or restart all; restarting all is less
1305 && !ptid_equal (cont_thread
, null_ptid
)
1306 && !ptid_equal (cont_thread
, minus_one_ptid
))
1308 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1311 /* No stepping, no signal - unless one is pending already, of course. */
1314 struct thread_resume resume_info
;
1315 resume_info
.thread
= minus_one_ptid
;
1316 resume_info
.kind
= resume_continue
;
1317 resume_info
.sig
= 0;
1318 linux_resume (&resume_info
, 1);
1324 pid
= linux_wait_for_event (ptid
, &w
, options
);
1325 if (pid
== 0) /* only if TARGET_WNOHANG */
1328 lwp
= get_thread_lwp (current_inferior
);
1330 /* If we are waiting for a particular child, and it exited,
1331 linux_wait_for_event will return its exit status. Similarly if
1332 the last child exited. If this is not the last child, however,
1333 do not report it as exited until there is a 'thread exited' response
1334 available in the remote protocol. Instead, just wait for another event.
1335 This should be safe, because if the thread crashed we will already
1336 have reported the termination signal to GDB; that should stop any
1337 in-progress stepping operations, etc.
1339 Report the exit status of the last thread to exit. This matches
1340 LinuxThreads' behavior. */
1342 if (last_thread_of_process_p (current_inferior
))
1344 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1346 int pid
= pid_of (lwp
);
1347 struct process_info
*process
= find_process_pid (pid
);
1350 linux_remove_process (process
);
1352 current_inferior
= NULL
;
1356 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1357 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1360 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1364 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1365 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1368 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1372 return pid_to_ptid (pid
);
1377 if (!WIFSTOPPED (w
))
1381 /* In all-stop, stop all threads. Be careful to only do this if
1382 we're about to report an event to GDB. */
1386 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1388 if (lwp
->suspended
&& WSTOPSIG (w
) == SIGSTOP
)
1390 /* A thread that has been requested to stop by GDB with vCont;t,
1391 and it stopped cleanly, so report as SIG0. The use of
1392 SIGSTOP is an implementation detail. */
1393 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1395 else if (lwp
->suspended
&& WSTOPSIG (w
) != SIGSTOP
)
1397 /* A thread that has been requested to stop by GDB with vCont;t,
1398 but, it stopped for other reasons. Set stop_expected so the
1399 pending SIGSTOP is ignored and the LWP is resumed. */
1400 lwp
->stop_expected
= 1;
1401 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1405 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1409 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1410 target_pid_to_str (lwp
->head
.id
),
1412 ourstatus
->value
.sig
);
1414 return lwp
->head
.id
;
1417 /* Get rid of any pending event in the pipe. */
1419 async_file_flush (void)
1425 ret
= read (linux_event_pipe
[0], &buf
, 1);
1426 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1429 /* Put something in the pipe, so the event loop wakes up. */
1431 async_file_mark (void)
1435 async_file_flush ();
1438 ret
= write (linux_event_pipe
[1], "+", 1);
1439 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1441 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1442 be awakened anyway. */
1446 linux_wait (ptid_t ptid
,
1447 struct target_waitstatus
*ourstatus
, int target_options
)
1452 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1454 /* Flush the async file first. */
1455 if (target_is_async_p ())
1456 async_file_flush ();
1458 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1460 /* If at least one stop was reported, there may be more. A single
1461 SIGCHLD can signal more than one child stop. */
1462 if (target_is_async_p ()
1463 && (target_options
& TARGET_WNOHANG
) != 0
1464 && !ptid_equal (event_ptid
, null_ptid
))
1470 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1471 thread groups are in use, we need to use tkill. */
1474 kill_lwp (unsigned long lwpid
, int signo
)
1476 static int tkill_failed
;
1483 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1484 if (errno
!= ENOSYS
)
1491 return kill (lwpid
, signo
);
1495 send_sigstop (struct inferior_list_entry
*entry
)
1497 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1503 pid
= lwpid_of (lwp
);
1505 /* If we already have a pending stop signal for this process, don't
1507 if (lwp
->stop_expected
)
1510 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
1512 /* We clear the stop_expected flag so that wait_for_sigstop
1513 will receive the SIGSTOP event (instead of silently resuming and
1514 waiting again). It'll be reset below. */
1515 lwp
->stop_expected
= 0;
1520 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
1522 kill_lwp (pid
, SIGSTOP
);
1526 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
1528 /* It's dead, really. */
1531 /* Store the exit status for later. */
1532 lwp
->status_pending_p
= 1;
1533 lwp
->status_pending
= wstat
;
1535 /* So that check_removed_breakpoint doesn't try to figure out if
1536 this is stopped at a breakpoint. */
1537 lwp
->pending_is_breakpoint
= 0;
1539 /* Prevent trying to stop it. */
1542 /* No further stops are expected from a dead lwp. */
1543 lwp
->stop_expected
= 0;
1547 wait_for_sigstop (struct inferior_list_entry
*entry
)
1549 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1550 struct thread_info
*saved_inferior
;
1558 saved_inferior
= current_inferior
;
1559 if (saved_inferior
!= NULL
)
1560 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1562 saved_tid
= null_ptid
; /* avoid bogus unused warning */
1564 ptid
= lwp
->head
.id
;
1566 linux_wait_for_event (ptid
, &wstat
, __WALL
);
1568 /* If we stopped with a non-SIGSTOP signal, save it for later
1569 and record the pending SIGSTOP. If the process exited, just
1571 if (WIFSTOPPED (wstat
)
1572 && WSTOPSIG (wstat
) != SIGSTOP
)
1575 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1576 lwpid_of (lwp
), wstat
);
1578 /* Do not leave a pending single-step finish to be reported to
1579 the client. The client will give us a new action for this
1580 thread, possibly a continue request --- otherwise, the client
1581 would consider this pending SIGTRAP reported later a spurious
1583 if (WSTOPSIG (wstat
) == SIGTRAP
1585 && !linux_stopped_by_watchpoint ())
1588 fprintf (stderr
, " single-step SIGTRAP ignored\n");
1592 lwp
->status_pending_p
= 1;
1593 lwp
->status_pending
= wstat
;
1595 lwp
->stop_expected
= 1;
1597 else if (!WIFSTOPPED (wstat
))
1600 fprintf (stderr
, "Process %ld exited while stopping LWPs\n",
1603 /* Leave this status pending for the next time we're able to
1604 report it. In the mean time, we'll report this lwp as dead
1605 to GDB, so GDB doesn't try to read registers and memory from
1607 mark_lwp_dead (lwp
, wstat
);
1610 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
1611 current_inferior
= saved_inferior
;
1615 fprintf (stderr
, "Previously current thread died.\n");
1619 /* We can't change the current inferior behind GDB's back,
1620 otherwise, a subsequent command may apply to the wrong
1622 current_inferior
= NULL
;
1626 /* Set a valid thread as current. */
1627 set_desired_inferior (0);
1633 stop_all_lwps (void)
1635 stopping_threads
= 1;
1636 for_each_inferior (&all_lwps
, send_sigstop
);
1637 for_each_inferior (&all_lwps
, wait_for_sigstop
);
1638 stopping_threads
= 0;
1641 /* Resume execution of the inferior process.
1642 If STEP is nonzero, single-step it.
1643 If SIGNAL is nonzero, give it that signal. */
1646 linux_resume_one_lwp (struct lwp_info
*lwp
,
1647 int step
, int signal
, siginfo_t
*info
)
1649 struct thread_info
*saved_inferior
;
1651 if (lwp
->stopped
== 0)
1654 /* If we have pending signals or status, and a new signal, enqueue the
1655 signal. Also enqueue the signal if we are waiting to reinsert a
1656 breakpoint; it will be picked up again below. */
1658 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
1659 || lwp
->bp_reinsert
!= 0))
1661 struct pending_signals
*p_sig
;
1662 p_sig
= xmalloc (sizeof (*p_sig
));
1663 p_sig
->prev
= lwp
->pending_signals
;
1664 p_sig
->signal
= signal
;
1666 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1668 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1669 lwp
->pending_signals
= p_sig
;
1672 if (lwp
->status_pending_p
&& !check_removed_breakpoint (lwp
))
1675 saved_inferior
= current_inferior
;
1676 current_inferior
= get_lwp_thread (lwp
);
1679 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1680 lwpid_of (lwp
), step
? "step" : "continue", signal
,
1681 lwp
->stop_expected
? "expected" : "not expected");
1683 /* This bit needs some thinking about. If we get a signal that
1684 we must report while a single-step reinsert is still pending,
1685 we often end up resuming the thread. It might be better to
1686 (ew) allow a stack of pending events; then we could be sure that
1687 the reinsert happened right away and not lose any signals.
1689 Making this stack would also shrink the window in which breakpoints are
1690 uninserted (see comment in linux_wait_for_lwp) but not enough for
1691 complete correctness, so it won't solve that problem. It may be
1692 worthwhile just to solve this one, however. */
1693 if (lwp
->bp_reinsert
!= 0)
1696 fprintf (stderr
, " pending reinsert at %08lx", (long)lwp
->bp_reinsert
);
1698 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1701 /* Postpone any pending signal. It was enqueued above. */
1705 check_removed_breakpoint (lwp
);
1707 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1709 fprintf (stderr
, " ");
1710 (*the_low_target
.get_pc
) ();
1713 /* If we have pending signals, consume one unless we are trying to reinsert
1715 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
1717 struct pending_signals
**p_sig
;
1719 p_sig
= &lwp
->pending_signals
;
1720 while ((*p_sig
)->prev
!= NULL
)
1721 p_sig
= &(*p_sig
)->prev
;
1723 signal
= (*p_sig
)->signal
;
1724 if ((*p_sig
)->info
.si_signo
!= 0)
1725 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1731 regcache_invalidate_one ((struct inferior_list_entry
*)
1732 get_lwp_thread (lwp
));
1735 lwp
->stepping
= step
;
1736 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0, signal
);
1738 current_inferior
= saved_inferior
;
1741 /* ESRCH from ptrace either means that the thread was already
1742 running (an error) or that it is gone (a race condition). If
1743 it's gone, we will get a notification the next time we wait,
1744 so we can ignore the error. We could differentiate these
1745 two, but it's tricky without waiting; the thread still exists
1746 as a zombie, so sending it signal 0 would succeed. So just
1751 perror_with_name ("ptrace");
1755 struct thread_resume_array
1757 struct thread_resume
*resume
;
1761 /* This function is called once per thread. We look up the thread
1762 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1765 This algorithm is O(threads * resume elements), but resume elements
1766 is small (and will remain small at least until GDB supports thread
1769 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
1771 struct lwp_info
*lwp
;
1772 struct thread_info
*thread
;
1774 struct thread_resume_array
*r
;
1776 thread
= (struct thread_info
*) entry
;
1777 lwp
= get_thread_lwp (thread
);
1780 for (ndx
= 0; ndx
< r
->n
; ndx
++)
1782 ptid_t ptid
= r
->resume
[ndx
].thread
;
1783 if (ptid_equal (ptid
, minus_one_ptid
)
1784 || ptid_equal (ptid
, entry
->id
)
1785 || (ptid_is_pid (ptid
)
1786 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
1787 || (ptid_get_lwp (ptid
) == -1
1788 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
1790 lwp
->resume
= &r
->resume
[ndx
];
1795 /* No resume action for this thread. */
1802 /* Set *FLAG_P if this lwp has an interesting status pending. */
1804 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1806 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1808 /* LWPs which will not be resumed are not interesting, because
1809 we might not wait for them next time through linux_wait. */
1810 if (lwp
->resume
== NULL
)
1813 /* If this thread has a removed breakpoint, we won't have any
1814 events to report later, so check now. check_removed_breakpoint
1815 may clear status_pending_p. We avoid calling check_removed_breakpoint
1816 for any thread that we are not otherwise going to resume - this
1817 lets us preserve stopped status when two threads hit a breakpoint.
1818 GDB removes the breakpoint to single-step a particular thread
1819 past it, then re-inserts it and resumes all threads. We want
1820 to report the second thread without resuming it in the interim. */
1821 if (lwp
->status_pending_p
)
1822 check_removed_breakpoint (lwp
);
1824 if (lwp
->status_pending_p
)
1825 * (int *) flag_p
= 1;
1830 /* This function is called once per thread. We check the thread's resume
1831 request, which will tell us whether to resume, step, or leave the thread
1832 stopped; and what signal, if any, it should be sent.
1834 For threads which we aren't explicitly told otherwise, we preserve
1835 the stepping flag; this is used for stepping over gdbserver-placed
1838 If pending_flags was set in any thread, we queue any needed
1839 signals, since we won't actually resume. We already have a pending
1840 event to report, so we don't need to preserve any step requests;
1841 they should be re-issued if necessary. */
1844 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
1846 struct lwp_info
*lwp
;
1847 struct thread_info
*thread
;
1849 int pending_flag
= * (int *) arg
;
1851 thread
= (struct thread_info
*) entry
;
1852 lwp
= get_thread_lwp (thread
);
1854 if (lwp
->resume
== NULL
)
1857 if (lwp
->resume
->kind
== resume_stop
)
1860 fprintf (stderr
, "suspending LWP %ld\n", lwpid_of (lwp
));
1865 fprintf (stderr
, "running -> suspending LWP %ld\n", lwpid_of (lwp
));
1868 send_sigstop (&lwp
->head
);
1875 fprintf (stderr
, "already stopped/suspended LWP %ld\n",
1878 fprintf (stderr
, "already stopped/not suspended LWP %ld\n",
1882 /* Make sure we leave the LWP suspended, so we don't try to
1883 resume it without GDB telling us to. FIXME: The LWP may
1884 have been stopped in an internal event that was not meant
1885 to be notified back to GDB (e.g., gdbserver breakpoint),
1886 so we should be reporting a stop event in that case
1891 /* For stop requests, we're done. */
1898 /* If this thread which is about to be resumed has a pending status,
1899 then don't resume any threads - we can just report the pending
1900 status. Make sure to queue any signals that would otherwise be
1901 sent. In all-stop mode, we do this decision based on if *any*
1902 thread has a pending status. */
1904 resume_status_pending_p (&lwp
->head
, &pending_flag
);
1909 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
1911 if (ptid_equal (lwp
->resume
->thread
, minus_one_ptid
)
1913 && lwp
->pending_is_breakpoint
)
1916 step
= (lwp
->resume
->kind
== resume_step
);
1918 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
1923 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
1925 /* If we have a new signal, enqueue the signal. */
1926 if (lwp
->resume
->sig
!= 0)
1928 struct pending_signals
*p_sig
;
1929 p_sig
= xmalloc (sizeof (*p_sig
));
1930 p_sig
->prev
= lwp
->pending_signals
;
1931 p_sig
->signal
= lwp
->resume
->sig
;
1932 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1934 /* If this is the same signal we were previously stopped by,
1935 make sure to queue its siginfo. We can ignore the return
1936 value of ptrace; if it fails, we'll skip
1937 PTRACE_SETSIGINFO. */
1938 if (WIFSTOPPED (lwp
->last_status
)
1939 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
1940 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1942 lwp
->pending_signals
= p_sig
;
1951 linux_resume (struct thread_resume
*resume_info
, size_t n
)
1954 struct thread_resume_array array
= { resume_info
, n
};
1956 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
1958 /* If there is a thread which would otherwise be resumed, which
1959 has a pending status, then don't resume any threads - we can just
1960 report the pending status. Make sure to queue any signals
1961 that would otherwise be sent. In non-stop mode, we'll apply this
1962 logic to each thread individually. */
1965 find_inferior (&all_lwps
, resume_status_pending_p
, &pending_flag
);
1970 fprintf (stderr
, "Not resuming, pending status\n");
1972 fprintf (stderr
, "Resuming, no pending status\n");
1975 find_inferior (&all_threads
, linux_resume_one_thread
, &pending_flag
);
1978 #ifdef HAVE_LINUX_USRREGS
1981 register_addr (int regnum
)
1985 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1986 error ("Invalid register number %d.", regnum
);
1988 addr
= the_low_target
.regmap
[regnum
];
1993 /* Fetch one register. */
1995 fetch_register (int regno
)
2002 if (regno
>= the_low_target
.num_regs
)
2004 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2007 regaddr
= register_addr (regno
);
2011 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2012 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2013 & - sizeof (PTRACE_XFER_TYPE
));
2014 buf
= alloca (size
);
2015 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2018 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2019 ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
2020 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2023 /* Warning, not error, in case we are attached; sometimes the
2024 kernel doesn't let us at the registers. */
2025 char *err
= strerror (errno
);
2026 char *msg
= alloca (strlen (err
) + 128);
2027 sprintf (msg
, "reading register %d: %s", regno
, err
);
2033 if (the_low_target
.supply_ptrace_register
)
2034 the_low_target
.supply_ptrace_register (regno
, buf
);
2036 supply_register (regno
, buf
);
2041 /* Fetch all registers, or just one, from the child process. */
2043 usr_fetch_inferior_registers (int regno
)
2045 if (regno
== -1 || regno
== 0)
2046 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2047 fetch_register (regno
);
2049 fetch_register (regno
);
2052 /* Store our register values back into the inferior.
2053 If REGNO is -1, do this for all registers.
2054 Otherwise, REGNO specifies which register (so we can save time). */
2056 usr_store_inferior_registers (int regno
)
2065 if (regno
>= the_low_target
.num_regs
)
2068 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2071 regaddr
= register_addr (regno
);
2075 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2076 & - sizeof (PTRACE_XFER_TYPE
);
2077 buf
= alloca (size
);
2078 memset (buf
, 0, size
);
2080 if (the_low_target
.collect_ptrace_register
)
2081 the_low_target
.collect_ptrace_register (regno
, buf
);
2083 collect_register (regno
, buf
);
2085 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2086 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2089 ptrace (PTRACE_POKEUSER
, pid
, (PTRACE_ARG3_TYPE
) regaddr
,
2090 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
2093 /* At this point, ESRCH should mean the process is
2094 already gone, in which case we simply ignore attempts
2095 to change its registers. See also the related
2096 comment in linux_resume_one_lwp. */
2100 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
2102 char *err
= strerror (errno
);
2103 char *msg
= alloca (strlen (err
) + 128);
2104 sprintf (msg
, "writing register %d: %s",
2110 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2114 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2115 usr_store_inferior_registers (regno
);
2117 #endif /* HAVE_LINUX_USRREGS */
2121 #ifdef HAVE_LINUX_REGSETS
2124 regsets_fetch_inferior_registers ()
2126 struct regset_info
*regset
;
2127 int saw_general_regs
= 0;
2130 regset
= target_regsets
;
2132 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2133 while (regset
->size
>= 0)
2138 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2144 buf
= xmalloc (regset
->size
);
2146 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2148 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2154 /* If we get EIO on a regset, do not try it again for
2156 disabled_regsets
[regset
- target_regsets
] = 1;
2163 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
2168 else if (regset
->type
== GENERAL_REGS
)
2169 saw_general_regs
= 1;
2170 regset
->store_function (buf
);
2174 if (saw_general_regs
)
2181 regsets_store_inferior_registers ()
2183 struct regset_info
*regset
;
2184 int saw_general_regs
= 0;
2187 regset
= target_regsets
;
2189 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2190 while (regset
->size
>= 0)
2195 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2201 buf
= xmalloc (regset
->size
);
2203 /* First fill the buffer with the current register set contents,
2204 in case there are any items in the kernel's regset that are
2205 not in gdbserver's regcache. */
2207 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2209 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2214 /* Then overlay our cached registers on that. */
2215 regset
->fill_function (buf
);
2217 /* Only now do we write the register set. */
2219 res
= ptrace (regset
->set_request
, pid
, 0, buf
);
2221 res
= ptrace (regset
->set_request
, pid
, buf
, 0);
2229 /* If we get EIO on a regset, do not try it again for
2231 disabled_regsets
[regset
- target_regsets
] = 1;
2235 else if (errno
== ESRCH
)
2237 /* At this point, ESRCH should mean the process is
2238 already gone, in which case we simply ignore attempts
2239 to change its registers. See also the related
2240 comment in linux_resume_one_lwp. */
2246 perror ("Warning: ptrace(regsets_store_inferior_registers)");
2249 else if (regset
->type
== GENERAL_REGS
)
2250 saw_general_regs
= 1;
2254 if (saw_general_regs
)
2261 #endif /* HAVE_LINUX_REGSETS */
2265 linux_fetch_registers (int regno
)
2267 #ifdef HAVE_LINUX_REGSETS
2268 if (regsets_fetch_inferior_registers () == 0)
2271 #ifdef HAVE_LINUX_USRREGS
2272 usr_fetch_inferior_registers (regno
);
2277 linux_store_registers (int regno
)
2279 #ifdef HAVE_LINUX_REGSETS
2280 if (regsets_store_inferior_registers () == 0)
2283 #ifdef HAVE_LINUX_USRREGS
2284 usr_store_inferior_registers (regno
);
2289 /* Copy LEN bytes from inferior's memory starting at MEMADDR
2290 to debugger memory starting at MYADDR. */
2293 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
2296 /* Round starting address down to longword boundary. */
2297 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2298 /* Round ending address up; get number of longwords that makes. */
2300 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2301 / sizeof (PTRACE_XFER_TYPE
);
2302 /* Allocate buffer of that many longwords. */
2303 register PTRACE_XFER_TYPE
*buffer
2304 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2307 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2309 /* Try using /proc. Don't bother for one word. */
2310 if (len
>= 3 * sizeof (long))
2312 /* We could keep this file open and cache it - possibly one per
2313 thread. That requires some juggling, but is even faster. */
2314 sprintf (filename
, "/proc/%d/mem", pid
);
2315 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
2319 /* If pread64 is available, use it. It's faster if the kernel
2320 supports it (only one syscall), and it's 64-bit safe even on
2321 32-bit platforms (for instance, SPARC debugging a SPARC64
2324 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
2326 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
2338 /* Read all the longwords */
2339 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2342 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
2347 /* Copy appropriate bytes out of the buffer. */
2349 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
2355 /* Copy LEN bytes of data from debugger memory at MYADDR
2356 to inferior's memory at MEMADDR.
2357 On failure (cannot write the inferior)
2358 returns the value of errno. */
2361 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
2364 /* Round starting address down to longword boundary. */
2365 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2366 /* Round ending address up; get number of longwords that makes. */
2368 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
2369 /* Allocate buffer of that many longwords. */
2370 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2371 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2375 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
2378 /* Fill start and end extra bytes of buffer with existing memory data. */
2380 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
2385 = ptrace (PTRACE_PEEKTEXT
, pid
,
2386 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
2387 * sizeof (PTRACE_XFER_TYPE
)),
2391 /* Copy data to be written over corresponding part of buffer */
2393 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
2395 /* Write the entire buffer. */
2397 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2400 ptrace (PTRACE_POKETEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
2408 static int linux_supports_tracefork_flag
;
2410 /* Helper functions for linux_test_for_tracefork, called via clone (). */
2413 linux_tracefork_grandchild (void *arg
)
2418 #define STACK_SIZE 4096
2421 linux_tracefork_child (void *arg
)
2423 ptrace (PTRACE_TRACEME
, 0, 0, 0);
2424 kill (getpid (), SIGSTOP
);
2426 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
2427 CLONE_VM
| SIGCHLD
, NULL
);
2429 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
2430 CLONE_VM
| SIGCHLD
, NULL
);
2435 /* Wrapper function for waitpid which handles EINTR, and emulates
2436 __WALL for systems where that is not available. */
2439 my_waitpid (int pid
, int *status
, int flags
)
2444 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
2448 sigset_t block_mask
, org_mask
, wake_mask
;
2451 wnohang
= (flags
& WNOHANG
) != 0;
2452 flags
&= ~(__WALL
| __WCLONE
);
2455 /* Block all signals while here. This avoids knowing about
2456 LinuxThread's signals. */
2457 sigfillset (&block_mask
);
2458 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
2460 /* ... except during the sigsuspend below. */
2461 sigemptyset (&wake_mask
);
2465 /* Since all signals are blocked, there's no need to check
2467 ret
= waitpid (pid
, status
, flags
);
2470 if (ret
== -1 && out_errno
!= ECHILD
)
2475 if (flags
& __WCLONE
)
2477 /* We've tried both flavors now. If WNOHANG is set,
2478 there's nothing else to do, just bail out. */
2483 fprintf (stderr
, "blocking\n");
2485 /* Block waiting for signals. */
2486 sigsuspend (&wake_mask
);
2492 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
2497 ret
= waitpid (pid
, status
, flags
);
2498 while (ret
== -1 && errno
== EINTR
);
2503 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
2504 pid
, flags
, status
? *status
: -1, ret
);
2510 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
2511 sure that we can enable the option, and that it had the desired
2515 linux_test_for_tracefork (void)
2517 int child_pid
, ret
, status
;
2519 char *stack
= xmalloc (STACK_SIZE
* 4);
2521 linux_supports_tracefork_flag
= 0;
2523 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
2525 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
2526 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2528 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
2529 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2531 if (child_pid
== -1)
2532 perror_with_name ("clone");
2534 ret
= my_waitpid (child_pid
, &status
, 0);
2536 perror_with_name ("waitpid");
2537 else if (ret
!= child_pid
)
2538 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
2539 if (! WIFSTOPPED (status
))
2540 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
2542 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
2545 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2548 warning ("linux_test_for_tracefork: failed to kill child");
2552 ret
= my_waitpid (child_pid
, &status
, 0);
2553 if (ret
!= child_pid
)
2554 warning ("linux_test_for_tracefork: failed to wait for killed child");
2555 else if (!WIFSIGNALED (status
))
2556 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
2557 "killed child", status
);
2562 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
2564 warning ("linux_test_for_tracefork: failed to resume child");
2566 ret
= my_waitpid (child_pid
, &status
, 0);
2568 if (ret
== child_pid
&& WIFSTOPPED (status
)
2569 && status
>> 16 == PTRACE_EVENT_FORK
)
2572 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
2573 if (ret
== 0 && second_pid
!= 0)
2577 linux_supports_tracefork_flag
= 1;
2578 my_waitpid (second_pid
, &second_status
, 0);
2579 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
2581 warning ("linux_test_for_tracefork: failed to kill second child");
2582 my_waitpid (second_pid
, &status
, 0);
2586 warning ("linux_test_for_tracefork: unexpected result from waitpid "
2587 "(%d, status 0x%x)", ret
, status
);
2591 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2593 warning ("linux_test_for_tracefork: failed to kill child");
2594 my_waitpid (child_pid
, &status
, 0);
2596 while (WIFSTOPPED (status
));
2603 linux_look_up_symbols (void)
2605 #ifdef USE_THREAD_DB
2606 struct process_info
*proc
= current_process ();
2608 if (proc
->private->thread_db_active
)
2611 proc
->private->thread_db_active
2612 = thread_db_init (!linux_supports_tracefork_flag
);
2617 linux_request_interrupt (void)
2619 extern unsigned long signal_pid
;
2621 if (!ptid_equal (cont_thread
, null_ptid
)
2622 && !ptid_equal (cont_thread
, minus_one_ptid
))
2624 struct lwp_info
*lwp
;
2627 lwp
= get_thread_lwp (current_inferior
);
2628 lwpid
= lwpid_of (lwp
);
2629 kill_lwp (lwpid
, SIGINT
);
2632 kill_lwp (signal_pid
, SIGINT
);
2635 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2636 to debugger memory starting at MYADDR. */
2639 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
2641 char filename
[PATH_MAX
];
2643 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2645 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
2647 fd
= open (filename
, O_RDONLY
);
2651 if (offset
!= (CORE_ADDR
) 0
2652 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
2655 n
= read (fd
, myaddr
, len
);
2662 /* These watchpoint related wrapper functions simply pass on the function call
2663 if the target has registered a corresponding function. */
2666 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
2668 if (the_low_target
.insert_watchpoint
!= NULL
)
2669 return the_low_target
.insert_watchpoint (type
, addr
, len
);
2671 /* Unsupported (see target.h). */
2676 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
2678 if (the_low_target
.remove_watchpoint
!= NULL
)
2679 return the_low_target
.remove_watchpoint (type
, addr
, len
);
2681 /* Unsupported (see target.h). */
2686 linux_stopped_by_watchpoint (void)
2688 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2689 return the_low_target
.stopped_by_watchpoint ();
2695 linux_stopped_data_address (void)
2697 if (the_low_target
.stopped_data_address
!= NULL
)
2698 return the_low_target
.stopped_data_address ();
2703 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2704 #if defined(__mcoldfire__)
2705 /* These should really be defined in the kernel's ptrace.h header. */
2706 #define PT_TEXT_ADDR 49*4
2707 #define PT_DATA_ADDR 50*4
2708 #define PT_TEXT_END_ADDR 51*4
2711 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2712 to tell gdb about. */
2715 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2717 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2718 unsigned long text
, text_end
, data
;
2719 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2723 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2724 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2725 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2729 /* Both text and data offsets produced at compile-time (and so
2730 used by gdb) are relative to the beginning of the program,
2731 with the data segment immediately following the text segment.
2732 However, the actual runtime layout in memory may put the data
2733 somewhere else, so when we send gdb a data base-address, we
2734 use the real data base address and subtract the compile-time
2735 data base-address from it (which is just the length of the
2736 text segment). BSS immediately follows data in both
2739 *data_p
= data
- (text_end
- text
);
2749 linux_qxfer_osdata (const char *annex
,
2750 unsigned char *readbuf
, unsigned const char *writebuf
,
2751 CORE_ADDR offset
, int len
)
2753 /* We make the process list snapshot when the object starts to be
2755 static const char *buf
;
2756 static long len_avail
= -1;
2757 static struct buffer buffer
;
2761 if (strcmp (annex
, "processes") != 0)
2764 if (!readbuf
|| writebuf
)
2769 if (len_avail
!= -1 && len_avail
!= 0)
2770 buffer_free (&buffer
);
2773 buffer_init (&buffer
);
2774 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2776 dirp
= opendir ("/proc");
2780 while ((dp
= readdir (dirp
)) != NULL
)
2782 struct stat statbuf
;
2783 char procentry
[sizeof ("/proc/4294967295")];
2785 if (!isdigit (dp
->d_name
[0])
2786 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2789 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2790 if (stat (procentry
, &statbuf
) == 0
2791 && S_ISDIR (statbuf
.st_mode
))
2795 char cmd
[MAXPATHLEN
+ 1];
2796 struct passwd
*entry
;
2798 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2799 entry
= getpwuid (statbuf
.st_uid
);
2801 if ((f
= fopen (pathname
, "r")) != NULL
)
2803 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2807 for (i
= 0; i
< len
; i
++)
2815 "<column name=\"pid\">%s</column>"
2816 "<column name=\"user\">%s</column>"
2817 "<column name=\"command\">%s</column>"
2820 entry
? entry
->pw_name
: "?",
2830 buffer_grow_str0 (&buffer
, "</osdata>\n");
2831 buf
= buffer_finish (&buffer
);
2832 len_avail
= strlen (buf
);
2835 if (offset
>= len_avail
)
2837 /* Done. Get rid of the data. */
2838 buffer_free (&buffer
);
2844 if (len
> len_avail
- offset
)
2845 len
= len_avail
- offset
;
2846 memcpy (readbuf
, buf
+ offset
, len
);
2851 /* Convert a native/host siginfo object, into/from the siginfo in the
2852 layout of the inferiors' architecture. */
2855 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
2859 if (the_low_target
.siginfo_fixup
!= NULL
)
2860 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
2862 /* If there was no callback, or the callback didn't do anything,
2863 then just do a straight memcpy. */
2867 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
2869 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
2874 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
2875 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
2878 struct siginfo siginfo
;
2879 char inf_siginfo
[sizeof (struct siginfo
)];
2881 if (current_inferior
== NULL
)
2884 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2887 fprintf (stderr
, "%s siginfo for lwp %d.\n",
2888 readbuf
!= NULL
? "Reading" : "Writing",
2891 if (offset
> sizeof (siginfo
))
2894 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
2897 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
2898 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
2899 inferior with a 64-bit GDBSERVER should look the same as debugging it
2900 with a 32-bit GDBSERVER, we need to convert it. */
2901 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
2903 if (offset
+ len
> sizeof (siginfo
))
2904 len
= sizeof (siginfo
) - offset
;
2906 if (readbuf
!= NULL
)
2907 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
2910 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
2912 /* Convert back to ptrace layout before flushing it out. */
2913 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
2915 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
2922 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
2923 so we notice when children change state; as the handler for the
2924 sigsuspend in my_waitpid. */
2927 sigchld_handler (int signo
)
2929 int old_errno
= errno
;
2932 /* fprintf is not async-signal-safe, so call write directly. */
2933 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
2935 if (target_is_async_p ())
2936 async_file_mark (); /* trigger a linux_wait */
2942 linux_supports_non_stop (void)
2948 linux_async (int enable
)
2950 int previous
= (linux_event_pipe
[0] != -1);
2952 if (previous
!= enable
)
2955 sigemptyset (&mask
);
2956 sigaddset (&mask
, SIGCHLD
);
2958 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
2962 if (pipe (linux_event_pipe
) == -1)
2963 fatal ("creating event pipe failed.");
2965 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
2966 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
2968 /* Register the event loop handler. */
2969 add_file_handler (linux_event_pipe
[0],
2970 handle_target_event
, NULL
);
2972 /* Always trigger a linux_wait. */
2977 delete_file_handler (linux_event_pipe
[0]);
2979 close (linux_event_pipe
[0]);
2980 close (linux_event_pipe
[1]);
2981 linux_event_pipe
[0] = -1;
2982 linux_event_pipe
[1] = -1;
2985 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
2992 linux_start_non_stop (int nonstop
)
2994 /* Register or unregister from event-loop accordingly. */
2995 linux_async (nonstop
);
2999 static struct target_ops linux_target_ops
= {
3000 linux_create_inferior
,
3008 linux_fetch_registers
,
3009 linux_store_registers
,
3012 linux_look_up_symbols
,
3013 linux_request_interrupt
,
3015 linux_insert_watchpoint
,
3016 linux_remove_watchpoint
,
3017 linux_stopped_by_watchpoint
,
3018 linux_stopped_data_address
,
3019 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3024 #ifdef USE_THREAD_DB
3025 thread_db_get_tls_address
,
3030 hostio_last_error_from_errno
,
3033 linux_supports_non_stop
,
3035 linux_start_non_stop
,
3039 linux_init_signals ()
3041 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
3042 to find what the cancel signal actually is. */
3043 signal (__SIGRTMIN
+1, SIG_IGN
);
3047 initialize_low (void)
3049 struct sigaction sigchld_action
;
3050 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
3051 set_target_ops (&linux_target_ops
);
3052 set_breakpoint_data (the_low_target
.breakpoint
,
3053 the_low_target
.breakpoint_len
);
3054 linux_init_signals ();
3055 linux_test_for_tracefork ();
3056 #ifdef HAVE_LINUX_REGSETS
3057 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
3059 disabled_regsets
= xmalloc (num_regsets
);
3062 sigchld_action
.sa_handler
= sigchld_handler
;
3063 sigemptyset (&sigchld_action
.sa_mask
);
3064 sigchld_action
.sa_flags
= SA_RESTART
;
3065 sigaction (SIGCHLD
, &sigchld_action
, NULL
);