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 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"
25 #include <sys/param.h>
26 #include <sys/ptrace.h>
28 #include <sys/ioctl.h>
34 #include <sys/syscall.h>
38 #include <sys/types.h>
41 #ifndef PTRACE_GETSIGINFO
42 # define PTRACE_GETSIGINFO 0x4202
43 # define PTRACE_SETSIGINFO 0x4203
50 /* If the system headers did not provide the constants, hard-code the normal
52 #ifndef PTRACE_EVENT_FORK
54 #define PTRACE_SETOPTIONS 0x4200
55 #define PTRACE_GETEVENTMSG 0x4201
57 /* options set using PTRACE_SETOPTIONS */
58 #define PTRACE_O_TRACESYSGOOD 0x00000001
59 #define PTRACE_O_TRACEFORK 0x00000002
60 #define PTRACE_O_TRACEVFORK 0x00000004
61 #define PTRACE_O_TRACECLONE 0x00000008
62 #define PTRACE_O_TRACEEXEC 0x00000010
63 #define PTRACE_O_TRACEVFORKDONE 0x00000020
64 #define PTRACE_O_TRACEEXIT 0x00000040
66 /* Wait extended result codes for the above trace options. */
67 #define PTRACE_EVENT_FORK 1
68 #define PTRACE_EVENT_VFORK 2
69 #define PTRACE_EVENT_CLONE 3
70 #define PTRACE_EVENT_EXEC 4
71 #define PTRACE_EVENT_VFORK_DONE 5
72 #define PTRACE_EVENT_EXIT 6
74 #endif /* PTRACE_EVENT_FORK */
76 /* We can't always assume that this flag is available, but all systems
77 with the ptrace event handlers also have __WALL, so it's safe to use
80 #define __WALL 0x40000000 /* Wait for any child. */
84 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
89 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
90 representation of the thread ID.
92 ``all_processes'' is keyed by the process ID - which on Linux is (presently)
93 the same as the LWP ID. */
95 struct inferior_list all_processes
;
97 /* A list of all unknown processes which receive stop signals. Some other
98 process will presumably claim each of these as forked children
101 struct inferior_list stopped_pids
;
103 /* FIXME this is a bit of a hack, and could be removed. */
104 int stopping_threads
;
106 /* FIXME make into a target method? */
107 int using_threads
= 1;
108 static int thread_db_active
;
110 static int must_set_ptrace_flags
;
112 /* This flag is true iff we've just created or attached to a new inferior
113 but it has not stopped yet. As soon as it does, we need to call the
114 low target's arch_setup callback. */
115 static int new_inferior
;
117 static void linux_resume_one_process (struct inferior_list_entry
*entry
,
118 int step
, int signal
, siginfo_t
*info
);
119 static void linux_resume (struct thread_resume
*resume_info
);
120 static void stop_all_processes (void);
121 static int linux_wait_for_event (struct thread_info
*child
);
122 static int check_removed_breakpoint (struct process_info
*event_child
);
123 static void *add_process (unsigned long pid
);
125 struct pending_signals
129 struct pending_signals
*prev
;
132 #define PTRACE_ARG3_TYPE long
133 #define PTRACE_XFER_TYPE long
135 #ifdef HAVE_LINUX_REGSETS
136 static char *disabled_regsets
;
137 static int num_regsets
;
140 #define pid_of(proc) ((proc)->head.id)
142 /* FIXME: Delete eventually. */
143 #define inferior_pid (pid_of (get_thread_process (current_inferior)))
146 handle_extended_wait (struct process_info
*event_child
, int wstat
)
148 int event
= wstat
>> 16;
149 struct process_info
*new_process
;
151 if (event
== PTRACE_EVENT_CLONE
)
153 unsigned long new_pid
;
154 int ret
, status
= W_STOPCODE (SIGSTOP
);
156 ptrace (PTRACE_GETEVENTMSG
, inferior_pid
, 0, &new_pid
);
158 /* If we haven't already seen the new PID stop, wait for it now. */
159 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
161 /* The new child has a pending SIGSTOP. We can't affect it until it
162 hits the SIGSTOP, but we're already attached. */
165 ret
= waitpid (new_pid
, &status
, __WALL
);
166 } while (ret
== -1 && errno
== EINTR
);
169 perror_with_name ("waiting for new child");
170 else if (ret
!= new_pid
)
171 warning ("wait returned unexpected PID %d", ret
);
172 else if (!WIFSTOPPED (status
))
173 warning ("wait returned unexpected status 0x%x", status
);
176 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, PTRACE_O_TRACECLONE
);
178 new_process
= (struct process_info
*) add_process (new_pid
);
179 add_thread (new_pid
, new_process
, new_pid
);
180 new_thread_notify (thread_id_to_gdb_id (new_process
->lwpid
));
182 /* Normally we will get the pending SIGSTOP. But in some cases
183 we might get another signal delivered to the group first.
184 If we do, be sure not to lose it. */
185 if (WSTOPSIG (status
) == SIGSTOP
)
187 if (stopping_threads
)
188 new_process
->stopped
= 1;
190 ptrace (PTRACE_CONT
, new_pid
, 0, 0);
194 new_process
->stop_expected
= 1;
195 if (stopping_threads
)
197 new_process
->stopped
= 1;
198 new_process
->status_pending_p
= 1;
199 new_process
->status_pending
= status
;
202 /* Pass the signal on. This is what GDB does - except
203 shouldn't we really report it instead? */
204 ptrace (PTRACE_CONT
, new_pid
, 0, WSTOPSIG (status
));
207 /* Always resume the current thread. If we are stopping
208 threads, it will have a pending SIGSTOP; we may as well
210 linux_resume_one_process (&event_child
->head
,
211 event_child
->stepping
, 0, NULL
);
215 /* This function should only be called if the process got a SIGTRAP.
216 The SIGTRAP could mean several things.
218 On i386, where decr_pc_after_break is non-zero:
219 If we were single-stepping this process using PTRACE_SINGLESTEP,
220 we will get only the one SIGTRAP (even if the instruction we
221 stepped over was a breakpoint). The value of $eip will be the
223 If we continue the process using PTRACE_CONT, we will get a
224 SIGTRAP when we hit a breakpoint. The value of $eip will be
225 the instruction after the breakpoint (i.e. needs to be
226 decremented). If we report the SIGTRAP to GDB, we must also
227 report the undecremented PC. If we cancel the SIGTRAP, we
228 must resume at the decremented PC.
230 (Presumably, not yet tested) On a non-decr_pc_after_break machine
231 with hardware or kernel single-step:
232 If we single-step over a breakpoint instruction, our PC will
233 point at the following instruction. If we continue and hit a
234 breakpoint instruction, our PC will point at the breakpoint
240 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) ();
242 if (get_thread_process (current_inferior
)->stepping
)
245 return stop_pc
- the_low_target
.decr_pc_after_break
;
249 add_process (unsigned long pid
)
251 struct process_info
*process
;
253 process
= (struct process_info
*) malloc (sizeof (*process
));
254 memset (process
, 0, sizeof (*process
));
256 process
->head
.id
= pid
;
257 process
->lwpid
= pid
;
259 add_inferior_to_list (&all_processes
, &process
->head
);
264 /* Start an inferior process and returns its pid.
265 ALLARGS is a vector of program-name and args. */
268 linux_create_inferior (char *program
, char **allargs
)
273 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
279 perror_with_name ("fork");
283 ptrace (PTRACE_TRACEME
, 0, 0, 0);
285 signal (__SIGRTMIN
+ 1, SIG_DFL
);
289 execv (program
, allargs
);
291 execvp (program
, allargs
);
293 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
299 new_process
= add_process (pid
);
300 add_thread (pid
, new_process
, pid
);
301 must_set_ptrace_flags
= 1;
307 /* Attach to an inferior process. */
310 linux_attach_lwp (unsigned long pid
)
312 struct process_info
*new_process
;
314 if (ptrace (PTRACE_ATTACH
, pid
, 0, 0) != 0)
316 if (all_threads
.head
!= NULL
)
318 /* If we fail to attach to an LWP, just warn. */
319 fprintf (stderr
, "Cannot attach to process %ld: %s (%d)\n", pid
,
320 strerror (errno
), errno
);
325 /* If we fail to attach to a process, report an error. */
326 error ("Cannot attach to process %ld: %s (%d)\n", pid
,
327 strerror (errno
), errno
);
330 ptrace (PTRACE_SETOPTIONS
, pid
, 0, PTRACE_O_TRACECLONE
);
332 new_process
= (struct process_info
*) add_process (pid
);
333 add_thread (pid
, new_process
, pid
);
334 new_thread_notify (thread_id_to_gdb_id (new_process
->lwpid
));
336 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
337 brings it to a halt. We should ignore that SIGSTOP and resume the process
338 (unless this is the first process, in which case the flag will be cleared
341 On the other hand, if we are currently trying to stop all threads, we
342 should treat the new thread as if we had sent it a SIGSTOP. This works
343 because we are guaranteed that add_process added us to the end of the
344 list, and so the new thread has not yet reached wait_for_sigstop (but
346 if (! stopping_threads
)
347 new_process
->stop_expected
= 1;
351 linux_attach (unsigned long pid
)
353 struct process_info
*process
;
355 linux_attach_lwp (pid
);
357 /* Don't ignore the initial SIGSTOP if we just attached to this process.
358 It will be collected by wait shortly. */
359 process
= (struct process_info
*) find_inferior_id (&all_processes
, pid
);
360 process
->stop_expected
= 0;
367 /* Kill the inferior process. Make us have no inferior. */
370 linux_kill_one_process (struct inferior_list_entry
*entry
)
372 struct thread_info
*thread
= (struct thread_info
*) entry
;
373 struct process_info
*process
= get_thread_process (thread
);
376 /* We avoid killing the first thread here, because of a Linux kernel (at
377 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
378 the children get a chance to be reaped, it will remain a zombie
380 if (entry
== all_threads
.head
)
385 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
387 /* Make sure it died. The loop is most likely unnecessary. */
388 wstat
= linux_wait_for_event (thread
);
389 } while (WIFSTOPPED (wstat
));
395 struct thread_info
*thread
= (struct thread_info
*) all_threads
.head
;
396 struct process_info
*process
;
402 for_each_inferior (&all_threads
, linux_kill_one_process
);
404 /* See the comment in linux_kill_one_process. We did not kill the first
405 thread in the list, so do so now. */
406 process
= get_thread_process (thread
);
409 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
411 /* Make sure it died. The loop is most likely unnecessary. */
412 wstat
= linux_wait_for_event (thread
);
413 } while (WIFSTOPPED (wstat
));
416 free (all_processes
.head
);
417 all_processes
.head
= all_processes
.tail
= NULL
;
421 linux_detach_one_process (struct inferior_list_entry
*entry
)
423 struct thread_info
*thread
= (struct thread_info
*) entry
;
424 struct process_info
*process
= get_thread_process (thread
);
426 /* Make sure the process isn't stopped at a breakpoint that's
428 check_removed_breakpoint (process
);
430 /* If this process is stopped but is expecting a SIGSTOP, then make
431 sure we take care of that now. This isn't absolutely guaranteed
432 to collect the SIGSTOP, but is fairly likely to. */
433 if (process
->stop_expected
)
435 /* Clear stop_expected, so that the SIGSTOP will be reported. */
436 process
->stop_expected
= 0;
437 if (process
->stopped
)
438 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
439 linux_wait_for_event (thread
);
442 /* Flush any pending changes to the process's registers. */
443 regcache_invalidate_one ((struct inferior_list_entry
*)
444 get_process_thread (process
));
446 /* Finally, let it resume. */
447 ptrace (PTRACE_DETACH
, pid_of (process
), 0, 0);
453 delete_all_breakpoints ();
454 for_each_inferior (&all_threads
, linux_detach_one_process
);
456 free (all_processes
.head
);
457 all_processes
.head
= all_processes
.tail
= NULL
;
464 extern unsigned long signal_pid
;
468 ret
= waitpid (signal_pid
, &status
, 0);
469 if (WIFEXITED (status
) || WIFSIGNALED (status
))
471 } while (ret
!= -1 || errno
!= ECHILD
);
474 /* Return nonzero if the given thread is still alive. */
476 linux_thread_alive (unsigned long lwpid
)
478 if (find_inferior_id (&all_threads
, lwpid
) != NULL
)
484 /* Return nonzero if this process stopped at a breakpoint which
485 no longer appears to be inserted. Also adjust the PC
486 appropriately to resume where the breakpoint used to be. */
488 check_removed_breakpoint (struct process_info
*event_child
)
491 struct thread_info
*saved_inferior
;
493 if (event_child
->pending_is_breakpoint
== 0)
497 fprintf (stderr
, "Checking for breakpoint in process %ld.\n",
500 saved_inferior
= current_inferior
;
501 current_inferior
= get_process_thread (event_child
);
503 stop_pc
= get_stop_pc ();
505 /* If the PC has changed since we stopped, then we shouldn't do
506 anything. This happens if, for instance, GDB handled the
507 decr_pc_after_break subtraction itself. */
508 if (stop_pc
!= event_child
->pending_stop_pc
)
511 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
512 event_child
->pending_stop_pc
);
514 event_child
->pending_is_breakpoint
= 0;
515 current_inferior
= saved_inferior
;
519 /* If the breakpoint is still there, we will report hitting it. */
520 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
523 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
524 current_inferior
= saved_inferior
;
529 fprintf (stderr
, "Removed breakpoint.\n");
531 /* For decr_pc_after_break targets, here is where we perform the
532 decrement. We go immediately from this function to resuming,
533 and can not safely call get_stop_pc () again. */
534 if (the_low_target
.set_pc
!= NULL
)
535 (*the_low_target
.set_pc
) (stop_pc
);
537 /* We consumed the pending SIGTRAP. */
538 event_child
->pending_is_breakpoint
= 0;
539 event_child
->status_pending_p
= 0;
540 event_child
->status_pending
= 0;
542 current_inferior
= saved_inferior
;
546 /* Return 1 if this process has an interesting status pending. This function
547 may silently resume an inferior process. */
549 status_pending_p (struct inferior_list_entry
*entry
, void *dummy
)
551 struct process_info
*process
= (struct process_info
*) entry
;
553 if (process
->status_pending_p
)
554 if (check_removed_breakpoint (process
))
556 /* This thread was stopped at a breakpoint, and the breakpoint
557 is now gone. We were told to continue (or step...) all threads,
558 so GDB isn't trying to single-step past this breakpoint.
559 So instead of reporting the old SIGTRAP, pretend we got to
560 the breakpoint just after it was removed instead of just
561 before; resume the process. */
562 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
566 return process
->status_pending_p
;
570 linux_wait_for_process (struct process_info
**childp
, int *wstatp
)
573 int to_wait_for
= -1;
576 to_wait_for
= (*childp
)->lwpid
;
581 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
);
586 perror_with_name ("waitpid");
591 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
| __WCLONE
);
596 perror_with_name ("waitpid (WCLONE)");
605 && (!WIFSTOPPED (*wstatp
)
606 || (WSTOPSIG (*wstatp
) != 32
607 && WSTOPSIG (*wstatp
) != 33)))
608 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
610 if (to_wait_for
== -1)
611 *childp
= (struct process_info
*) find_inferior_id (&all_processes
, ret
);
613 /* If we didn't find a process, one of two things presumably happened:
614 - A process we started and then detached from has exited. Ignore it.
615 - A process we are controlling has forked and the new child's stop
616 was reported to us by the kernel. Save its PID. */
617 if (*childp
== NULL
&& WIFSTOPPED (*wstatp
))
619 add_pid_to_list (&stopped_pids
, ret
);
622 else if (*childp
== NULL
)
625 (*childp
)->stopped
= 1;
626 (*childp
)->pending_is_breakpoint
= 0;
628 (*childp
)->last_status
= *wstatp
;
630 /* Architecture-specific setup after inferior is running.
631 This needs to happen after we have attached to the inferior
632 and it is stopped for the first time, but before we access
633 any inferior registers. */
636 the_low_target
.arch_setup ();
637 #ifdef HAVE_LINUX_REGSETS
638 memset (disabled_regsets
, 0, num_regsets
);
644 && WIFSTOPPED (*wstatp
))
646 current_inferior
= (struct thread_info
*)
647 find_inferior_id (&all_threads
, (*childp
)->lwpid
);
648 /* For testing only; i386_stop_pc prints out a diagnostic. */
649 if (the_low_target
.get_pc
!= NULL
)
655 linux_wait_for_event (struct thread_info
*child
)
658 struct process_info
*event_child
;
662 /* Check for a process with a pending status. */
663 /* It is possible that the user changed the pending task's registers since
664 it stopped. We correctly handle the change of PC if we hit a breakpoint
665 (in check_removed_breakpoint); signals should be reported anyway. */
668 event_child
= (struct process_info
*)
669 find_inferior (&all_processes
, status_pending_p
, NULL
);
670 if (debug_threads
&& event_child
)
671 fprintf (stderr
, "Got a pending child %ld\n", event_child
->lwpid
);
675 event_child
= get_thread_process (child
);
676 if (event_child
->status_pending_p
677 && check_removed_breakpoint (event_child
))
681 if (event_child
!= NULL
)
683 if (event_child
->status_pending_p
)
686 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
687 event_child
->lwpid
, event_child
->status_pending
);
688 wstat
= event_child
->status_pending
;
689 event_child
->status_pending_p
= 0;
690 event_child
->status_pending
= 0;
691 current_inferior
= get_process_thread (event_child
);
696 /* We only enter this loop if no process has a pending wait status. Thus
697 any action taken in response to a wait status inside this loop is
698 responding as soon as we detect the status, not after any pending
705 event_child
= get_thread_process (child
);
707 linux_wait_for_process (&event_child
, &wstat
);
709 if (event_child
== NULL
)
710 error ("event from unknown child");
712 current_inferior
= (struct thread_info
*)
713 find_inferior_id (&all_threads
, event_child
->lwpid
);
715 /* Check for thread exit. */
716 if (! WIFSTOPPED (wstat
))
719 fprintf (stderr
, "LWP %ld exiting\n", event_child
->head
.id
);
721 /* If the last thread is exiting, just return. */
722 if (all_threads
.head
== all_threads
.tail
)
725 dead_thread_notify (thread_id_to_gdb_id (event_child
->lwpid
));
727 remove_inferior (&all_processes
, &event_child
->head
);
729 remove_thread (current_inferior
);
730 current_inferior
= (struct thread_info
*) all_threads
.head
;
732 /* If we were waiting for this particular child to do something...
733 well, it did something. */
737 /* Wait for a more interesting event. */
741 if (WIFSTOPPED (wstat
)
742 && WSTOPSIG (wstat
) == SIGSTOP
743 && event_child
->stop_expected
)
746 fprintf (stderr
, "Expected stop.\n");
747 event_child
->stop_expected
= 0;
748 linux_resume_one_process (&event_child
->head
,
749 event_child
->stepping
, 0, NULL
);
753 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
756 handle_extended_wait (event_child
, wstat
);
760 /* If GDB is not interested in this signal, don't stop other
761 threads, and don't report it to GDB. Just resume the
762 inferior right away. We do this for threading-related
763 signals as well as any that GDB specifically requested we
764 ignore. But never ignore SIGSTOP if we sent it ourselves,
765 and do not ignore signals when stepping - they may require
766 special handling to skip the signal handler. */
767 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
769 if (WIFSTOPPED (wstat
)
770 && !event_child
->stepping
773 (thread_db_active
&& (WSTOPSIG (wstat
) == __SIGRTMIN
774 || WSTOPSIG (wstat
) == __SIGRTMIN
+ 1))
777 (pass_signals
[target_signal_from_host (WSTOPSIG (wstat
))]
778 && (WSTOPSIG (wstat
) != SIGSTOP
|| !stopping_threads
))))
780 siginfo_t info
, *info_p
;
783 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
784 WSTOPSIG (wstat
), event_child
->head
.id
);
786 if (ptrace (PTRACE_GETSIGINFO
, event_child
->lwpid
, 0, &info
) == 0)
790 linux_resume_one_process (&event_child
->head
,
791 event_child
->stepping
,
792 WSTOPSIG (wstat
), info_p
);
796 /* If this event was not handled above, and is not a SIGTRAP, report
798 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGTRAP
)
801 /* If this target does not support breakpoints, we simply report the
802 SIGTRAP; it's of no concern to us. */
803 if (the_low_target
.get_pc
== NULL
)
806 stop_pc
= get_stop_pc ();
808 /* bp_reinsert will only be set if we were single-stepping.
809 Notice that we will resume the process after hitting
810 a gdbserver breakpoint; single-stepping to/over one
811 is not supported (yet). */
812 if (event_child
->bp_reinsert
!= 0)
815 fprintf (stderr
, "Reinserted breakpoint.\n");
816 reinsert_breakpoint (event_child
->bp_reinsert
);
817 event_child
->bp_reinsert
= 0;
819 /* Clear the single-stepping flag and SIGTRAP as we resume. */
820 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
824 bp_status
= check_breakpoints (stop_pc
);
829 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
831 /* We hit one of our own breakpoints. We mark it as a pending
832 breakpoint, so that check_removed_breakpoint () will do the PC
833 adjustment for us at the appropriate time. */
834 event_child
->pending_is_breakpoint
= 1;
835 event_child
->pending_stop_pc
= stop_pc
;
837 /* We may need to put the breakpoint back. We continue in the event
838 loop instead of simply replacing the breakpoint right away,
839 in order to not lose signals sent to the thread that hit the
840 breakpoint. Unfortunately this increases the window where another
841 thread could sneak past the removed breakpoint. For the current
842 use of server-side breakpoints (thread creation) this is
843 acceptable; but it needs to be considered before this breakpoint
844 mechanism can be used in more general ways. For some breakpoints
845 it may be necessary to stop all other threads, but that should
846 be avoided where possible.
848 If breakpoint_reinsert_addr is NULL, that means that we can
849 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
850 mark it for reinsertion, and single-step.
852 Otherwise, call the target function to figure out where we need
853 our temporary breakpoint, create it, and continue executing this
856 /* No need to reinsert. */
857 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
858 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
860 event_child
->bp_reinsert
= stop_pc
;
861 uninsert_breakpoint (stop_pc
);
862 linux_resume_one_process (&event_child
->head
, 1, 0, NULL
);
866 reinsert_breakpoint_by_bp
867 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
868 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
875 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
877 /* If we were single-stepping, we definitely want to report the
878 SIGTRAP. The single-step operation has completed, so also
879 clear the stepping flag; in general this does not matter,
880 because the SIGTRAP will be reported to the client, which
881 will give us a new action for this thread, but clear it for
882 consistency anyway. It's safe to clear the stepping flag
883 because the only consumer of get_stop_pc () after this point
884 is check_removed_breakpoint, and pending_is_breakpoint is not
885 set. It might be wiser to use a step_completed flag instead. */
886 if (event_child
->stepping
)
888 event_child
->stepping
= 0;
892 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
893 Check if it is a breakpoint, and if so mark the process information
894 accordingly. This will handle both the necessary fiddling with the
895 PC on decr_pc_after_break targets and suppressing extra threads
896 hitting a breakpoint if two hit it at once and then GDB removes it
897 after the first is reported. Arguably it would be better to report
898 multiple threads hitting breakpoints simultaneously, but the current
899 remote protocol does not allow this. */
900 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
902 event_child
->pending_is_breakpoint
= 1;
903 event_child
->pending_stop_pc
= stop_pc
;
913 /* Wait for process, returns status. */
916 linux_wait (char *status
)
919 struct thread_info
*child
= NULL
;
922 /* If we were only supposed to resume one thread, only wait for
923 that thread - if it's still alive. If it died, however - which
924 can happen if we're coming from the thread death case below -
925 then we need to make sure we restart the other threads. We could
926 pick a thread at random or restart all; restarting all is less
928 if (cont_thread
!= 0 && cont_thread
!= -1)
930 child
= (struct thread_info
*) find_inferior_id (&all_threads
,
933 /* No stepping, no signal - unless one is pending already, of course. */
936 struct thread_resume resume_info
;
937 resume_info
.thread
= -1;
938 resume_info
.step
= resume_info
.sig
= resume_info
.leave_stopped
= 0;
939 linux_resume (&resume_info
);
943 w
= linux_wait_for_event (child
);
944 stop_all_processes ();
946 if (must_set_ptrace_flags
)
948 ptrace (PTRACE_SETOPTIONS
, inferior_pid
, 0, PTRACE_O_TRACECLONE
);
949 must_set_ptrace_flags
= 0;
952 /* If we are waiting for a particular child, and it exited,
953 linux_wait_for_event will return its exit status. Similarly if
954 the last child exited. If this is not the last child, however,
955 do not report it as exited until there is a 'thread exited' response
956 available in the remote protocol. Instead, just wait for another event.
957 This should be safe, because if the thread crashed we will already
958 have reported the termination signal to GDB; that should stop any
959 in-progress stepping operations, etc.
961 Report the exit status of the last thread to exit. This matches
962 LinuxThreads' behavior. */
964 if (all_threads
.head
== all_threads
.tail
)
968 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
971 free (all_processes
.head
);
972 all_processes
.head
= all_processes
.tail
= NULL
;
973 return WEXITSTATUS (w
);
975 else if (!WIFSTOPPED (w
))
977 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
980 free (all_processes
.head
);
981 all_processes
.head
= all_processes
.tail
= NULL
;
982 return target_signal_from_host (WTERMSIG (w
));
992 return target_signal_from_host (WSTOPSIG (w
));
995 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
996 thread groups are in use, we need to use tkill. */
999 kill_lwp (unsigned long lwpid
, int signo
)
1001 static int tkill_failed
;
1008 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1009 if (errno
!= ENOSYS
)
1016 return kill (lwpid
, signo
);
1020 send_sigstop (struct inferior_list_entry
*entry
)
1022 struct process_info
*process
= (struct process_info
*) entry
;
1024 if (process
->stopped
)
1027 /* If we already have a pending stop signal for this process, don't
1029 if (process
->stop_expected
)
1032 fprintf (stderr
, "Have pending sigstop for process %ld\n",
1035 /* We clear the stop_expected flag so that wait_for_sigstop
1036 will receive the SIGSTOP event (instead of silently resuming and
1037 waiting again). It'll be reset below. */
1038 process
->stop_expected
= 0;
1043 fprintf (stderr
, "Sending sigstop to process %ld\n", process
->head
.id
);
1045 kill_lwp (process
->head
.id
, SIGSTOP
);
1049 wait_for_sigstop (struct inferior_list_entry
*entry
)
1051 struct process_info
*process
= (struct process_info
*) entry
;
1052 struct thread_info
*saved_inferior
, *thread
;
1054 unsigned long saved_tid
;
1056 if (process
->stopped
)
1059 saved_inferior
= current_inferior
;
1060 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1061 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1063 wstat
= linux_wait_for_event (thread
);
1065 /* If we stopped with a non-SIGSTOP signal, save it for later
1066 and record the pending SIGSTOP. If the process exited, just
1068 if (WIFSTOPPED (wstat
)
1069 && WSTOPSIG (wstat
) != SIGSTOP
)
1072 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1073 process
->lwpid
, wstat
);
1074 process
->status_pending_p
= 1;
1075 process
->status_pending
= wstat
;
1076 process
->stop_expected
= 1;
1079 if (linux_thread_alive (saved_tid
))
1080 current_inferior
= saved_inferior
;
1084 fprintf (stderr
, "Previously current thread died.\n");
1086 /* Set a valid thread as current. */
1087 set_desired_inferior (0);
1092 stop_all_processes (void)
1094 stopping_threads
= 1;
1095 for_each_inferior (&all_processes
, send_sigstop
);
1096 for_each_inferior (&all_processes
, wait_for_sigstop
);
1097 stopping_threads
= 0;
1100 /* Resume execution of the inferior process.
1101 If STEP is nonzero, single-step it.
1102 If SIGNAL is nonzero, give it that signal. */
1105 linux_resume_one_process (struct inferior_list_entry
*entry
,
1106 int step
, int signal
, siginfo_t
*info
)
1108 struct process_info
*process
= (struct process_info
*) entry
;
1109 struct thread_info
*saved_inferior
;
1111 if (process
->stopped
== 0)
1114 /* If we have pending signals or status, and a new signal, enqueue the
1115 signal. Also enqueue the signal if we are waiting to reinsert a
1116 breakpoint; it will be picked up again below. */
1118 && (process
->status_pending_p
|| process
->pending_signals
!= NULL
1119 || process
->bp_reinsert
!= 0))
1121 struct pending_signals
*p_sig
;
1122 p_sig
= malloc (sizeof (*p_sig
));
1123 p_sig
->prev
= process
->pending_signals
;
1124 p_sig
->signal
= signal
;
1126 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1128 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1129 process
->pending_signals
= p_sig
;
1132 if (process
->status_pending_p
&& !check_removed_breakpoint (process
))
1135 saved_inferior
= current_inferior
;
1136 current_inferior
= get_process_thread (process
);
1139 fprintf (stderr
, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid
,
1140 step
? "step" : "continue", signal
,
1141 process
->stop_expected
? "expected" : "not expected");
1143 /* This bit needs some thinking about. If we get a signal that
1144 we must report while a single-step reinsert is still pending,
1145 we often end up resuming the thread. It might be better to
1146 (ew) allow a stack of pending events; then we could be sure that
1147 the reinsert happened right away and not lose any signals.
1149 Making this stack would also shrink the window in which breakpoints are
1150 uninserted (see comment in linux_wait_for_process) but not enough for
1151 complete correctness, so it won't solve that problem. It may be
1152 worthwhile just to solve this one, however. */
1153 if (process
->bp_reinsert
!= 0)
1156 fprintf (stderr
, " pending reinsert at %08lx", (long)process
->bp_reinsert
);
1158 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1161 /* Postpone any pending signal. It was enqueued above. */
1165 check_removed_breakpoint (process
);
1167 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1169 fprintf (stderr
, " ");
1170 (*the_low_target
.get_pc
) ();
1173 /* If we have pending signals, consume one unless we are trying to reinsert
1175 if (process
->pending_signals
!= NULL
&& process
->bp_reinsert
== 0)
1177 struct pending_signals
**p_sig
;
1179 p_sig
= &process
->pending_signals
;
1180 while ((*p_sig
)->prev
!= NULL
)
1181 p_sig
= &(*p_sig
)->prev
;
1183 signal
= (*p_sig
)->signal
;
1184 if ((*p_sig
)->info
.si_signo
!= 0)
1185 ptrace (PTRACE_SETSIGINFO
, process
->lwpid
, 0, &(*p_sig
)->info
);
1191 regcache_invalidate_one ((struct inferior_list_entry
*)
1192 get_process_thread (process
));
1194 process
->stopped
= 0;
1195 process
->stepping
= step
;
1196 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, process
->lwpid
, 0, signal
);
1198 current_inferior
= saved_inferior
;
1201 /* ESRCH from ptrace either means that the thread was already
1202 running (an error) or that it is gone (a race condition). If
1203 it's gone, we will get a notification the next time we wait,
1204 so we can ignore the error. We could differentiate these
1205 two, but it's tricky without waiting; the thread still exists
1206 as a zombie, so sending it signal 0 would succeed. So just
1211 perror_with_name ("ptrace");
1215 static struct thread_resume
*resume_ptr
;
1217 /* This function is called once per thread. We look up the thread
1218 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1221 This algorithm is O(threads * resume elements), but resume elements
1222 is small (and will remain small at least until GDB supports thread
1225 linux_set_resume_request (struct inferior_list_entry
*entry
)
1227 struct process_info
*process
;
1228 struct thread_info
*thread
;
1231 thread
= (struct thread_info
*) entry
;
1232 process
= get_thread_process (thread
);
1235 while (resume_ptr
[ndx
].thread
!= -1 && resume_ptr
[ndx
].thread
!= entry
->id
)
1238 process
->resume
= &resume_ptr
[ndx
];
1241 /* This function is called once per thread. We check the thread's resume
1242 request, which will tell us whether to resume, step, or leave the thread
1243 stopped; and what signal, if any, it should be sent. For threads which
1244 we aren't explicitly told otherwise, we preserve the stepping flag; this
1245 is used for stepping over gdbserver-placed breakpoints. */
1248 linux_continue_one_thread (struct inferior_list_entry
*entry
)
1250 struct process_info
*process
;
1251 struct thread_info
*thread
;
1254 thread
= (struct thread_info
*) entry
;
1255 process
= get_thread_process (thread
);
1257 if (process
->resume
->leave_stopped
)
1260 if (process
->resume
->thread
== -1)
1261 step
= process
->stepping
|| process
->resume
->step
;
1263 step
= process
->resume
->step
;
1265 linux_resume_one_process (&process
->head
, step
, process
->resume
->sig
, NULL
);
1267 process
->resume
= NULL
;
1270 /* This function is called once per thread. We check the thread's resume
1271 request, which will tell us whether to resume, step, or leave the thread
1272 stopped; and what signal, if any, it should be sent. We queue any needed
1273 signals, since we won't actually resume. We already have a pending event
1274 to report, so we don't need to preserve any step requests; they should
1275 be re-issued if necessary. */
1278 linux_queue_one_thread (struct inferior_list_entry
*entry
)
1280 struct process_info
*process
;
1281 struct thread_info
*thread
;
1283 thread
= (struct thread_info
*) entry
;
1284 process
= get_thread_process (thread
);
1286 if (process
->resume
->leave_stopped
)
1289 /* If we have a new signal, enqueue the signal. */
1290 if (process
->resume
->sig
!= 0)
1292 struct pending_signals
*p_sig
;
1293 p_sig
= malloc (sizeof (*p_sig
));
1294 p_sig
->prev
= process
->pending_signals
;
1295 p_sig
->signal
= process
->resume
->sig
;
1296 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1298 /* If this is the same signal we were previously stopped by,
1299 make sure to queue its siginfo. We can ignore the return
1300 value of ptrace; if it fails, we'll skip
1301 PTRACE_SETSIGINFO. */
1302 if (WIFSTOPPED (process
->last_status
)
1303 && WSTOPSIG (process
->last_status
) == process
->resume
->sig
)
1304 ptrace (PTRACE_GETSIGINFO
, process
->lwpid
, 0, &p_sig
->info
);
1306 process
->pending_signals
= p_sig
;
1309 process
->resume
= NULL
;
1312 /* Set DUMMY if this process has an interesting status pending. */
1314 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1316 struct process_info
*process
= (struct process_info
*) entry
;
1318 /* Processes which will not be resumed are not interesting, because
1319 we might not wait for them next time through linux_wait. */
1320 if (process
->resume
->leave_stopped
)
1323 /* If this thread has a removed breakpoint, we won't have any
1324 events to report later, so check now. check_removed_breakpoint
1325 may clear status_pending_p. We avoid calling check_removed_breakpoint
1326 for any thread that we are not otherwise going to resume - this
1327 lets us preserve stopped status when two threads hit a breakpoint.
1328 GDB removes the breakpoint to single-step a particular thread
1329 past it, then re-inserts it and resumes all threads. We want
1330 to report the second thread without resuming it in the interim. */
1331 if (process
->status_pending_p
)
1332 check_removed_breakpoint (process
);
1334 if (process
->status_pending_p
)
1335 * (int *) flag_p
= 1;
1341 linux_resume (struct thread_resume
*resume_info
)
1345 /* Yes, the use of a global here is rather ugly. */
1346 resume_ptr
= resume_info
;
1348 for_each_inferior (&all_threads
, linux_set_resume_request
);
1350 /* If there is a thread which would otherwise be resumed, which
1351 has a pending status, then don't resume any threads - we can just
1352 report the pending status. Make sure to queue any signals
1353 that would otherwise be sent. */
1355 find_inferior (&all_processes
, resume_status_pending_p
, &pending_flag
);
1360 fprintf (stderr
, "Not resuming, pending status\n");
1362 fprintf (stderr
, "Resuming, no pending status\n");
1366 for_each_inferior (&all_threads
, linux_queue_one_thread
);
1368 for_each_inferior (&all_threads
, linux_continue_one_thread
);
1371 #ifdef HAVE_LINUX_USRREGS
1374 register_addr (int regnum
)
1378 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1379 error ("Invalid register number %d.", regnum
);
1381 addr
= the_low_target
.regmap
[regnum
];
1386 /* Fetch one register. */
1388 fetch_register (int regno
)
1394 if (regno
>= the_low_target
.num_regs
)
1396 if ((*the_low_target
.cannot_fetch_register
) (regno
))
1399 regaddr
= register_addr (regno
);
1402 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1403 & - sizeof (PTRACE_XFER_TYPE
);
1404 buf
= alloca (size
);
1405 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1408 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
1409 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
1410 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1413 /* Warning, not error, in case we are attached; sometimes the
1414 kernel doesn't let us at the registers. */
1415 char *err
= strerror (errno
);
1416 char *msg
= alloca (strlen (err
) + 128);
1417 sprintf (msg
, "reading register %d: %s", regno
, err
);
1423 if (the_low_target
.supply_ptrace_register
)
1424 the_low_target
.supply_ptrace_register (regno
, buf
);
1426 supply_register (regno
, buf
);
1431 /* Fetch all registers, or just one, from the child process. */
1433 usr_fetch_inferior_registers (int regno
)
1435 if (regno
== -1 || regno
== 0)
1436 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1437 fetch_register (regno
);
1439 fetch_register (regno
);
1442 /* Store our register values back into the inferior.
1443 If REGNO is -1, do this for all registers.
1444 Otherwise, REGNO specifies which register (so we can save time). */
1446 usr_store_inferior_registers (int regno
)
1454 if (regno
>= the_low_target
.num_regs
)
1457 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
1460 regaddr
= register_addr (regno
);
1464 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1465 & - sizeof (PTRACE_XFER_TYPE
);
1466 buf
= alloca (size
);
1467 memset (buf
, 0, size
);
1469 if (the_low_target
.collect_ptrace_register
)
1470 the_low_target
.collect_ptrace_register (regno
, buf
);
1472 collect_register (regno
, buf
);
1474 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1477 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
1478 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
1481 /* At this point, ESRCH should mean the process is already gone,
1482 in which case we simply ignore attempts to change its registers.
1483 See also the related comment in linux_resume_one_process. */
1487 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
1489 char *err
= strerror (errno
);
1490 char *msg
= alloca (strlen (err
) + 128);
1491 sprintf (msg
, "writing register %d: %s",
1497 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1501 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1502 usr_store_inferior_registers (regno
);
1504 #endif /* HAVE_LINUX_USRREGS */
1508 #ifdef HAVE_LINUX_REGSETS
1511 regsets_fetch_inferior_registers ()
1513 struct regset_info
*regset
;
1514 int saw_general_regs
= 0;
1516 regset
= target_regsets
;
1518 while (regset
->size
>= 0)
1523 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1529 buf
= malloc (regset
->size
);
1531 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1533 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1539 /* If we get EIO on a regset, do not try it again for
1541 disabled_regsets
[regset
- target_regsets
] = 1;
1547 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1552 else if (regset
->type
== GENERAL_REGS
)
1553 saw_general_regs
= 1;
1554 regset
->store_function (buf
);
1557 if (saw_general_regs
)
1564 regsets_store_inferior_registers ()
1566 struct regset_info
*regset
;
1567 int saw_general_regs
= 0;
1569 regset
= target_regsets
;
1571 while (regset
->size
>= 0)
1576 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1582 buf
= malloc (regset
->size
);
1584 /* First fill the buffer with the current register set contents,
1585 in case there are any items in the kernel's regset that are
1586 not in gdbserver's regcache. */
1588 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1590 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1595 /* Then overlay our cached registers on that. */
1596 regset
->fill_function (buf
);
1598 /* Only now do we write the register set. */
1600 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
1602 res
= ptrace (regset
->set_request
, inferior_pid
, buf
, 0);
1610 /* If we get EIO on a regset, do not try it again for
1612 disabled_regsets
[regset
- target_regsets
] = 1;
1615 else if (errno
== ESRCH
)
1617 /* At this point, ESRCH should mean the process is already gone,
1618 in which case we simply ignore attempts to change its registers.
1619 See also the related comment in linux_resume_one_process. */
1624 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1627 else if (regset
->type
== GENERAL_REGS
)
1628 saw_general_regs
= 1;
1632 if (saw_general_regs
)
1639 #endif /* HAVE_LINUX_REGSETS */
1643 linux_fetch_registers (int regno
)
1645 #ifdef HAVE_LINUX_REGSETS
1646 if (regsets_fetch_inferior_registers () == 0)
1649 #ifdef HAVE_LINUX_USRREGS
1650 usr_fetch_inferior_registers (regno
);
1655 linux_store_registers (int regno
)
1657 #ifdef HAVE_LINUX_REGSETS
1658 if (regsets_store_inferior_registers () == 0)
1661 #ifdef HAVE_LINUX_USRREGS
1662 usr_store_inferior_registers (regno
);
1667 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1668 to debugger memory starting at MYADDR. */
1671 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
1674 /* Round starting address down to longword boundary. */
1675 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1676 /* Round ending address up; get number of longwords that makes. */
1678 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1679 / sizeof (PTRACE_XFER_TYPE
);
1680 /* Allocate buffer of that many longwords. */
1681 register PTRACE_XFER_TYPE
*buffer
1682 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1686 /* Try using /proc. Don't bother for one word. */
1687 if (len
>= 3 * sizeof (long))
1689 /* We could keep this file open and cache it - possibly one per
1690 thread. That requires some juggling, but is even faster. */
1691 sprintf (filename
, "/proc/%ld/mem", inferior_pid
);
1692 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
1696 /* If pread64 is available, use it. It's faster if the kernel
1697 supports it (only one syscall), and it's 64-bit safe even on
1698 32-bit platforms (for instance, SPARC debugging a SPARC64
1701 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
1703 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
1715 /* Read all the longwords */
1716 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1719 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
1724 /* Copy appropriate bytes out of the buffer. */
1725 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), len
);
1730 /* Copy LEN bytes of data from debugger memory at MYADDR
1731 to inferior's memory at MEMADDR.
1732 On failure (cannot write the inferior)
1733 returns the value of errno. */
1736 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
1739 /* Round starting address down to longword boundary. */
1740 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1741 /* Round ending address up; get number of longwords that makes. */
1743 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
1744 /* Allocate buffer of that many longwords. */
1745 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1749 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
1752 /* Fill start and end extra bytes of buffer with existing memory data. */
1754 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1755 (PTRACE_ARG3_TYPE
) addr
, 0);
1760 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1761 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
1762 * sizeof (PTRACE_XFER_TYPE
)),
1766 /* Copy data to be written over corresponding part of buffer */
1768 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
1770 /* Write the entire buffer. */
1772 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1775 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
1783 static int linux_supports_tracefork_flag
;
1785 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1788 linux_tracefork_grandchild (void *arg
)
1793 #define STACK_SIZE 4096
1796 linux_tracefork_child (void *arg
)
1798 ptrace (PTRACE_TRACEME
, 0, 0, 0);
1799 kill (getpid (), SIGSTOP
);
1801 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
1802 CLONE_VM
| SIGCHLD
, NULL
);
1804 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
1805 CLONE_VM
| SIGCHLD
, NULL
);
1810 /* Wrapper function for waitpid which handles EINTR. */
1813 my_waitpid (int pid
, int *status
, int flags
)
1818 ret
= waitpid (pid
, status
, flags
);
1820 while (ret
== -1 && errno
== EINTR
);
1825 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1826 sure that we can enable the option, and that it had the desired
1830 linux_test_for_tracefork (void)
1832 int child_pid
, ret
, status
;
1834 char *stack
= malloc (STACK_SIZE
* 4);
1836 linux_supports_tracefork_flag
= 0;
1838 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1840 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
1841 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1843 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
1844 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1846 if (child_pid
== -1)
1847 perror_with_name ("clone");
1849 ret
= my_waitpid (child_pid
, &status
, 0);
1851 perror_with_name ("waitpid");
1852 else if (ret
!= child_pid
)
1853 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
1854 if (! WIFSTOPPED (status
))
1855 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
1857 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
1860 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1863 warning ("linux_test_for_tracefork: failed to kill child");
1867 ret
= my_waitpid (child_pid
, &status
, 0);
1868 if (ret
!= child_pid
)
1869 warning ("linux_test_for_tracefork: failed to wait for killed child");
1870 else if (!WIFSIGNALED (status
))
1871 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1872 "killed child", status
);
1877 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
1879 warning ("linux_test_for_tracefork: failed to resume child");
1881 ret
= my_waitpid (child_pid
, &status
, 0);
1883 if (ret
== child_pid
&& WIFSTOPPED (status
)
1884 && status
>> 16 == PTRACE_EVENT_FORK
)
1887 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
1888 if (ret
== 0 && second_pid
!= 0)
1892 linux_supports_tracefork_flag
= 1;
1893 my_waitpid (second_pid
, &second_status
, 0);
1894 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
1896 warning ("linux_test_for_tracefork: failed to kill second child");
1897 my_waitpid (second_pid
, &status
, 0);
1901 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1902 "(%d, status 0x%x)", ret
, status
);
1906 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1908 warning ("linux_test_for_tracefork: failed to kill child");
1909 my_waitpid (child_pid
, &status
, 0);
1911 while (WIFSTOPPED (status
));
1918 linux_look_up_symbols (void)
1920 #ifdef USE_THREAD_DB
1921 if (thread_db_active
)
1924 thread_db_active
= thread_db_init (!linux_supports_tracefork_flag
);
1929 linux_request_interrupt (void)
1931 extern unsigned long signal_pid
;
1933 if (cont_thread
!= 0 && cont_thread
!= -1)
1935 struct process_info
*process
;
1937 process
= get_thread_process (current_inferior
);
1938 kill_lwp (process
->lwpid
, SIGINT
);
1941 kill_lwp (signal_pid
, SIGINT
);
1944 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1945 to debugger memory starting at MYADDR. */
1948 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
1950 char filename
[PATH_MAX
];
1953 snprintf (filename
, sizeof filename
, "/proc/%ld/auxv", inferior_pid
);
1955 fd
= open (filename
, O_RDONLY
);
1959 if (offset
!= (CORE_ADDR
) 0
1960 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
1963 n
= read (fd
, myaddr
, len
);
1970 /* These watchpoint related wrapper functions simply pass on the function call
1971 if the target has registered a corresponding function. */
1974 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
1976 if (the_low_target
.insert_watchpoint
!= NULL
)
1977 return the_low_target
.insert_watchpoint (type
, addr
, len
);
1979 /* Unsupported (see target.h). */
1984 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
1986 if (the_low_target
.remove_watchpoint
!= NULL
)
1987 return the_low_target
.remove_watchpoint (type
, addr
, len
);
1989 /* Unsupported (see target.h). */
1994 linux_stopped_by_watchpoint (void)
1996 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1997 return the_low_target
.stopped_by_watchpoint ();
2003 linux_stopped_data_address (void)
2005 if (the_low_target
.stopped_data_address
!= NULL
)
2006 return the_low_target
.stopped_data_address ();
2011 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2012 #if defined(__mcoldfire__)
2013 /* These should really be defined in the kernel's ptrace.h header. */
2014 #define PT_TEXT_ADDR 49*4
2015 #define PT_DATA_ADDR 50*4
2016 #define PT_TEXT_END_ADDR 51*4
2019 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2020 to tell gdb about. */
2023 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2025 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2026 unsigned long text
, text_end
, data
;
2027 int pid
= get_thread_process (current_inferior
)->head
.id
;
2031 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2032 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2033 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2037 /* Both text and data offsets produced at compile-time (and so
2038 used by gdb) are relative to the beginning of the program,
2039 with the data segment immediately following the text segment.
2040 However, the actual runtime layout in memory may put the data
2041 somewhere else, so when we send gdb a data base-address, we
2042 use the real data base address and subtract the compile-time
2043 data base-address from it (which is just the length of the
2044 text segment). BSS immediately follows data in both
2047 *data_p
= data
- (text_end
- text
);
2057 linux_qxfer_osdata (const char *annex
,
2058 unsigned char *readbuf
, unsigned const char *writebuf
,
2059 CORE_ADDR offset
, int len
)
2061 /* We make the process list snapshot when the object starts to be
2063 static const char *buf
;
2064 static long len_avail
= -1;
2065 static struct buffer buffer
;
2069 if (strcmp (annex
, "processes") != 0)
2072 if (!readbuf
|| writebuf
)
2077 if (len_avail
!= -1 && len_avail
!= 0)
2078 buffer_free (&buffer
);
2081 buffer_init (&buffer
);
2082 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2084 dirp
= opendir ("/proc");
2088 while ((dp
= readdir (dirp
)) != NULL
)
2090 struct stat statbuf
;
2091 char procentry
[sizeof ("/proc/4294967295")];
2093 if (!isdigit (dp
->d_name
[0])
2094 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2097 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2098 if (stat (procentry
, &statbuf
) == 0
2099 && S_ISDIR (statbuf
.st_mode
))
2103 char cmd
[MAXPATHLEN
+ 1];
2104 struct passwd
*entry
;
2106 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2107 entry
= getpwuid (statbuf
.st_uid
);
2109 if ((f
= fopen (pathname
, "r")) != NULL
)
2111 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2115 for (i
= 0; i
< len
; i
++)
2123 "<column name=\"pid\">%s</column>"
2124 "<column name=\"user\">%s</column>"
2125 "<column name=\"command\">%s</column>"
2128 entry
? entry
->pw_name
: "?",
2138 buffer_grow_str0 (&buffer
, "</osdata>\n");
2139 buf
= buffer_finish (&buffer
);
2140 len_avail
= strlen (buf
);
2143 if (offset
>= len_avail
)
2145 /* Done. Get rid of the data. */
2146 buffer_free (&buffer
);
2152 if (len
> len_avail
- offset
)
2153 len
= len_avail
- offset
;
2154 memcpy (readbuf
, buf
+ offset
, len
);
2159 static struct target_ops linux_target_ops
= {
2160 linux_create_inferior
,
2168 linux_fetch_registers
,
2169 linux_store_registers
,
2172 linux_look_up_symbols
,
2173 linux_request_interrupt
,
2175 linux_insert_watchpoint
,
2176 linux_remove_watchpoint
,
2177 linux_stopped_by_watchpoint
,
2178 linux_stopped_data_address
,
2179 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2184 #ifdef USE_THREAD_DB
2185 thread_db_get_tls_address
,
2190 hostio_last_error_from_errno
,
2195 linux_init_signals ()
2197 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2198 to find what the cancel signal actually is. */
2199 signal (__SIGRTMIN
+1, SIG_IGN
);
2203 initialize_low (void)
2205 thread_db_active
= 0;
2206 set_target_ops (&linux_target_ops
);
2207 set_breakpoint_data (the_low_target
.breakpoint
,
2208 the_low_target
.breakpoint_len
);
2209 linux_init_signals ();
2210 linux_test_for_tracefork ();
2211 #ifdef HAVE_LINUX_REGSETS
2212 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
2214 disabled_regsets
= malloc (num_regsets
);