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"
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
);
124 static int my_waitpid (int pid
, int *status
, int flags
);
126 struct pending_signals
130 struct pending_signals
*prev
;
133 #define PTRACE_ARG3_TYPE long
134 #define PTRACE_XFER_TYPE long
136 #ifdef HAVE_LINUX_REGSETS
137 static char *disabled_regsets
;
138 static int num_regsets
;
141 #define pid_of(proc) ((proc)->head.id)
143 /* FIXME: Delete eventually. */
144 #define inferior_pid (pid_of (get_thread_process (current_inferior)))
147 handle_extended_wait (struct process_info
*event_child
, int wstat
)
149 int event
= wstat
>> 16;
150 struct process_info
*new_process
;
152 if (event
== PTRACE_EVENT_CLONE
)
154 unsigned long new_pid
;
155 int ret
, status
= W_STOPCODE (SIGSTOP
);
157 ptrace (PTRACE_GETEVENTMSG
, inferior_pid
, 0, &new_pid
);
159 /* If we haven't already seen the new PID stop, wait for it now. */
160 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
162 /* The new child has a pending SIGSTOP. We can't affect it until it
163 hits the SIGSTOP, but we're already attached. */
165 ret
= my_waitpid (new_pid
, &status
, __WALL
);
168 perror_with_name ("waiting for new child");
169 else if (ret
!= new_pid
)
170 warning ("wait returned unexpected PID %d", ret
);
171 else if (!WIFSTOPPED (status
))
172 warning ("wait returned unexpected status 0x%x", status
);
175 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, PTRACE_O_TRACECLONE
);
177 new_process
= (struct process_info
*) add_process (new_pid
);
178 add_thread (new_pid
, new_process
, new_pid
);
179 new_thread_notify (thread_id_to_gdb_id (new_process
->lwpid
));
181 /* Normally we will get the pending SIGSTOP. But in some cases
182 we might get another signal delivered to the group first.
183 If we do, be sure not to lose it. */
184 if (WSTOPSIG (status
) == SIGSTOP
)
186 if (stopping_threads
)
187 new_process
->stopped
= 1;
189 ptrace (PTRACE_CONT
, new_pid
, 0, 0);
193 new_process
->stop_expected
= 1;
194 if (stopping_threads
)
196 new_process
->stopped
= 1;
197 new_process
->status_pending_p
= 1;
198 new_process
->status_pending
= status
;
201 /* Pass the signal on. This is what GDB does - except
202 shouldn't we really report it instead? */
203 ptrace (PTRACE_CONT
, new_pid
, 0, WSTOPSIG (status
));
206 /* Always resume the current thread. If we are stopping
207 threads, it will have a pending SIGSTOP; we may as well
209 linux_resume_one_process (&event_child
->head
,
210 event_child
->stepping
, 0, NULL
);
214 /* This function should only be called if the process got a SIGTRAP.
215 The SIGTRAP could mean several things.
217 On i386, where decr_pc_after_break is non-zero:
218 If we were single-stepping this process using PTRACE_SINGLESTEP,
219 we will get only the one SIGTRAP (even if the instruction we
220 stepped over was a breakpoint). The value of $eip will be the
222 If we continue the process using PTRACE_CONT, we will get a
223 SIGTRAP when we hit a breakpoint. The value of $eip will be
224 the instruction after the breakpoint (i.e. needs to be
225 decremented). If we report the SIGTRAP to GDB, we must also
226 report the undecremented PC. If we cancel the SIGTRAP, we
227 must resume at the decremented PC.
229 (Presumably, not yet tested) On a non-decr_pc_after_break machine
230 with hardware or kernel single-step:
231 If we single-step over a breakpoint instruction, our PC will
232 point at the following instruction. If we continue and hit a
233 breakpoint instruction, our PC will point at the breakpoint
239 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) ();
241 if (get_thread_process (current_inferior
)->stepping
)
244 return stop_pc
- the_low_target
.decr_pc_after_break
;
248 add_process (unsigned long pid
)
250 struct process_info
*process
;
252 process
= (struct process_info
*) xmalloc (sizeof (*process
));
253 memset (process
, 0, sizeof (*process
));
255 process
->head
.id
= pid
;
256 process
->lwpid
= pid
;
258 add_inferior_to_list (&all_processes
, &process
->head
);
263 /* Start an inferior process and returns its pid.
264 ALLARGS is a vector of program-name and args. */
267 linux_create_inferior (char *program
, char **allargs
)
272 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
278 perror_with_name ("fork");
282 ptrace (PTRACE_TRACEME
, 0, 0, 0);
284 signal (__SIGRTMIN
+ 1, SIG_DFL
);
288 execv (program
, allargs
);
290 execvp (program
, allargs
);
292 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
298 new_process
= add_process (pid
);
299 add_thread (pid
, new_process
, pid
);
300 must_set_ptrace_flags
= 1;
306 /* Attach to an inferior process. */
309 linux_attach_lwp (unsigned long pid
)
311 struct process_info
*new_process
;
313 if (ptrace (PTRACE_ATTACH
, pid
, 0, 0) != 0)
315 if (all_threads
.head
!= NULL
)
317 /* If we fail to attach to an LWP, just warn. */
318 fprintf (stderr
, "Cannot attach to process %ld: %s (%d)\n", pid
,
319 strerror (errno
), errno
);
324 /* If we fail to attach to a process, report an error. */
325 error ("Cannot attach to process %ld: %s (%d)\n", pid
,
326 strerror (errno
), errno
);
329 ptrace (PTRACE_SETOPTIONS
, pid
, 0, PTRACE_O_TRACECLONE
);
331 new_process
= (struct process_info
*) add_process (pid
);
332 add_thread (pid
, new_process
, pid
);
333 new_thread_notify (thread_id_to_gdb_id (new_process
->lwpid
));
335 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
336 brings it to a halt. We should ignore that SIGSTOP and resume the process
337 (unless this is the first process, in which case the flag will be cleared
340 On the other hand, if we are currently trying to stop all threads, we
341 should treat the new thread as if we had sent it a SIGSTOP. This works
342 because we are guaranteed that add_process added us to the end of the
343 list, and so the new thread has not yet reached wait_for_sigstop (but
345 if (! stopping_threads
)
346 new_process
->stop_expected
= 1;
350 linux_attach (unsigned long pid
)
352 struct process_info
*process
;
354 linux_attach_lwp (pid
);
356 /* Don't ignore the initial SIGSTOP if we just attached to this process.
357 It will be collected by wait shortly. */
358 process
= (struct process_info
*) find_inferior_id (&all_processes
, pid
);
359 process
->stop_expected
= 0;
366 /* Kill the inferior process. Make us have no inferior. */
369 linux_kill_one_process (struct inferior_list_entry
*entry
)
371 struct thread_info
*thread
= (struct thread_info
*) entry
;
372 struct process_info
*process
= get_thread_process (thread
);
375 /* We avoid killing the first thread here, because of a Linux kernel (at
376 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
377 the children get a chance to be reaped, it will remain a zombie
379 if (entry
== all_threads
.head
)
384 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
386 /* Make sure it died. The loop is most likely unnecessary. */
387 wstat
= linux_wait_for_event (thread
);
388 } while (WIFSTOPPED (wstat
));
394 struct thread_info
*thread
= (struct thread_info
*) all_threads
.head
;
395 struct process_info
*process
;
401 for_each_inferior (&all_threads
, linux_kill_one_process
);
403 /* See the comment in linux_kill_one_process. We did not kill the first
404 thread in the list, so do so now. */
405 process
= get_thread_process (thread
);
408 ptrace (PTRACE_KILL
, pid_of (process
), 0, 0);
410 /* Make sure it died. The loop is most likely unnecessary. */
411 wstat
= linux_wait_for_event (thread
);
412 } while (WIFSTOPPED (wstat
));
415 free (all_processes
.head
);
416 all_processes
.head
= all_processes
.tail
= NULL
;
420 linux_detach_one_process (struct inferior_list_entry
*entry
)
422 struct thread_info
*thread
= (struct thread_info
*) entry
;
423 struct process_info
*process
= get_thread_process (thread
);
425 /* Make sure the process isn't stopped at a breakpoint that's
427 check_removed_breakpoint (process
);
429 /* If this process is stopped but is expecting a SIGSTOP, then make
430 sure we take care of that now. This isn't absolutely guaranteed
431 to collect the SIGSTOP, but is fairly likely to. */
432 if (process
->stop_expected
)
434 /* Clear stop_expected, so that the SIGSTOP will be reported. */
435 process
->stop_expected
= 0;
436 if (process
->stopped
)
437 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
438 linux_wait_for_event (thread
);
441 /* Flush any pending changes to the process's registers. */
442 regcache_invalidate_one ((struct inferior_list_entry
*)
443 get_process_thread (process
));
445 /* Finally, let it resume. */
446 ptrace (PTRACE_DETACH
, pid_of (process
), 0, 0);
452 delete_all_breakpoints ();
453 for_each_inferior (&all_threads
, linux_detach_one_process
);
455 free (all_processes
.head
);
456 all_processes
.head
= all_processes
.tail
= NULL
;
463 extern unsigned long signal_pid
;
467 ret
= waitpid (signal_pid
, &status
, 0);
468 if (WIFEXITED (status
) || WIFSIGNALED (status
))
470 } while (ret
!= -1 || errno
!= ECHILD
);
473 /* Return nonzero if the given thread is still alive. */
475 linux_thread_alive (unsigned long lwpid
)
477 if (find_inferior_id (&all_threads
, lwpid
) != NULL
)
483 /* Return nonzero if this process stopped at a breakpoint which
484 no longer appears to be inserted. Also adjust the PC
485 appropriately to resume where the breakpoint used to be. */
487 check_removed_breakpoint (struct process_info
*event_child
)
490 struct thread_info
*saved_inferior
;
492 if (event_child
->pending_is_breakpoint
== 0)
496 fprintf (stderr
, "Checking for breakpoint in process %ld.\n",
499 saved_inferior
= current_inferior
;
500 current_inferior
= get_process_thread (event_child
);
502 stop_pc
= get_stop_pc ();
504 /* If the PC has changed since we stopped, then we shouldn't do
505 anything. This happens if, for instance, GDB handled the
506 decr_pc_after_break subtraction itself. */
507 if (stop_pc
!= event_child
->pending_stop_pc
)
510 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
511 event_child
->pending_stop_pc
);
513 event_child
->pending_is_breakpoint
= 0;
514 current_inferior
= saved_inferior
;
518 /* If the breakpoint is still there, we will report hitting it. */
519 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
522 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
523 current_inferior
= saved_inferior
;
528 fprintf (stderr
, "Removed breakpoint.\n");
530 /* For decr_pc_after_break targets, here is where we perform the
531 decrement. We go immediately from this function to resuming,
532 and can not safely call get_stop_pc () again. */
533 if (the_low_target
.set_pc
!= NULL
)
534 (*the_low_target
.set_pc
) (stop_pc
);
536 /* We consumed the pending SIGTRAP. */
537 event_child
->pending_is_breakpoint
= 0;
538 event_child
->status_pending_p
= 0;
539 event_child
->status_pending
= 0;
541 current_inferior
= saved_inferior
;
545 /* Return 1 if this process has an interesting status pending. This function
546 may silently resume an inferior process. */
548 status_pending_p (struct inferior_list_entry
*entry
, void *dummy
)
550 struct process_info
*process
= (struct process_info
*) entry
;
552 if (process
->status_pending_p
)
553 if (check_removed_breakpoint (process
))
555 /* This thread was stopped at a breakpoint, and the breakpoint
556 is now gone. We were told to continue (or step...) all threads,
557 so GDB isn't trying to single-step past this breakpoint.
558 So instead of reporting the old SIGTRAP, pretend we got to
559 the breakpoint just after it was removed instead of just
560 before; resume the process. */
561 linux_resume_one_process (&process
->head
, 0, 0, NULL
);
565 return process
->status_pending_p
;
569 linux_wait_for_process (struct process_info
**childp
, int *wstatp
)
572 int to_wait_for
= -1;
575 to_wait_for
= (*childp
)->lwpid
;
580 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
);
585 perror_with_name ("waitpid");
590 ret
= waitpid (to_wait_for
, wstatp
, WNOHANG
| __WCLONE
);
595 perror_with_name ("waitpid (WCLONE)");
604 && (!WIFSTOPPED (*wstatp
)
605 || (WSTOPSIG (*wstatp
) != 32
606 && WSTOPSIG (*wstatp
) != 33)))
607 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
609 if (to_wait_for
== -1)
610 *childp
= (struct process_info
*) find_inferior_id (&all_processes
, ret
);
612 /* If we didn't find a process, one of two things presumably happened:
613 - A process we started and then detached from has exited. Ignore it.
614 - A process we are controlling has forked and the new child's stop
615 was reported to us by the kernel. Save its PID. */
616 if (*childp
== NULL
&& WIFSTOPPED (*wstatp
))
618 add_pid_to_list (&stopped_pids
, ret
);
621 else if (*childp
== NULL
)
624 (*childp
)->stopped
= 1;
625 (*childp
)->pending_is_breakpoint
= 0;
627 (*childp
)->last_status
= *wstatp
;
629 /* Architecture-specific setup after inferior is running.
630 This needs to happen after we have attached to the inferior
631 and it is stopped for the first time, but before we access
632 any inferior registers. */
635 the_low_target
.arch_setup ();
636 #ifdef HAVE_LINUX_REGSETS
637 memset (disabled_regsets
, 0, num_regsets
);
643 && WIFSTOPPED (*wstatp
))
645 struct thread_info
*saved_inferior
= current_inferior
;
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
)
651 current_inferior
= saved_inferior
;
656 linux_wait_for_event (struct thread_info
*child
)
659 struct process_info
*event_child
;
663 /* Check for a process with a pending status. */
664 /* It is possible that the user changed the pending task's registers since
665 it stopped. We correctly handle the change of PC if we hit a breakpoint
666 (in check_removed_breakpoint); signals should be reported anyway. */
669 event_child
= (struct process_info
*)
670 find_inferior (&all_processes
, status_pending_p
, NULL
);
671 if (debug_threads
&& event_child
)
672 fprintf (stderr
, "Got a pending child %ld\n", event_child
->lwpid
);
676 event_child
= get_thread_process (child
);
677 if (event_child
->status_pending_p
678 && check_removed_breakpoint (event_child
))
682 if (event_child
!= NULL
)
684 if (event_child
->status_pending_p
)
687 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
688 event_child
->lwpid
, event_child
->status_pending
);
689 wstat
= event_child
->status_pending
;
690 event_child
->status_pending_p
= 0;
691 event_child
->status_pending
= 0;
692 current_inferior
= get_process_thread (event_child
);
697 /* We only enter this loop if no process has a pending wait status. Thus
698 any action taken in response to a wait status inside this loop is
699 responding as soon as we detect the status, not after any pending
706 event_child
= get_thread_process (child
);
708 linux_wait_for_process (&event_child
, &wstat
);
710 if (event_child
== NULL
)
711 error ("event from unknown child");
713 current_inferior
= (struct thread_info
*)
714 find_inferior_id (&all_threads
, event_child
->lwpid
);
716 /* Check for thread exit. */
717 if (! WIFSTOPPED (wstat
))
720 fprintf (stderr
, "LWP %ld exiting\n", event_child
->head
.id
);
722 /* If the last thread is exiting, just return. */
723 if (all_threads
.head
== all_threads
.tail
)
726 dead_thread_notify (thread_id_to_gdb_id (event_child
->lwpid
));
728 remove_inferior (&all_processes
, &event_child
->head
);
730 remove_thread (current_inferior
);
731 current_inferior
= (struct thread_info
*) all_threads
.head
;
733 /* If we were waiting for this particular child to do something...
734 well, it did something. */
738 /* Wait for a more interesting event. */
742 if (WIFSTOPPED (wstat
)
743 && WSTOPSIG (wstat
) == SIGSTOP
744 && event_child
->stop_expected
)
747 fprintf (stderr
, "Expected stop.\n");
748 event_child
->stop_expected
= 0;
749 linux_resume_one_process (&event_child
->head
,
750 event_child
->stepping
, 0, NULL
);
754 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
757 handle_extended_wait (event_child
, wstat
);
761 /* If GDB is not interested in this signal, don't stop other
762 threads, and don't report it to GDB. Just resume the
763 inferior right away. We do this for threading-related
764 signals as well as any that GDB specifically requested we
765 ignore. But never ignore SIGSTOP if we sent it ourselves,
766 and do not ignore signals when stepping - they may require
767 special handling to skip the signal handler. */
768 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
770 if (WIFSTOPPED (wstat
)
771 && !event_child
->stepping
774 (thread_db_active
&& (WSTOPSIG (wstat
) == __SIGRTMIN
775 || WSTOPSIG (wstat
) == __SIGRTMIN
+ 1))
778 (pass_signals
[target_signal_from_host (WSTOPSIG (wstat
))]
779 && (WSTOPSIG (wstat
) != SIGSTOP
|| !stopping_threads
))))
781 siginfo_t info
, *info_p
;
784 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
785 WSTOPSIG (wstat
), event_child
->head
.id
);
787 if (ptrace (PTRACE_GETSIGINFO
, event_child
->lwpid
, 0, &info
) == 0)
791 linux_resume_one_process (&event_child
->head
,
792 event_child
->stepping
,
793 WSTOPSIG (wstat
), info_p
);
797 /* If this event was not handled above, and is not a SIGTRAP, report
799 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGTRAP
)
802 /* If this target does not support breakpoints, we simply report the
803 SIGTRAP; it's of no concern to us. */
804 if (the_low_target
.get_pc
== NULL
)
807 stop_pc
= get_stop_pc ();
809 /* bp_reinsert will only be set if we were single-stepping.
810 Notice that we will resume the process after hitting
811 a gdbserver breakpoint; single-stepping to/over one
812 is not supported (yet). */
813 if (event_child
->bp_reinsert
!= 0)
816 fprintf (stderr
, "Reinserted breakpoint.\n");
817 reinsert_breakpoint (event_child
->bp_reinsert
);
818 event_child
->bp_reinsert
= 0;
820 /* Clear the single-stepping flag and SIGTRAP as we resume. */
821 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
825 bp_status
= check_breakpoints (stop_pc
);
830 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
832 /* We hit one of our own breakpoints. We mark it as a pending
833 breakpoint, so that check_removed_breakpoint () will do the PC
834 adjustment for us at the appropriate time. */
835 event_child
->pending_is_breakpoint
= 1;
836 event_child
->pending_stop_pc
= stop_pc
;
838 /* We may need to put the breakpoint back. We continue in the event
839 loop instead of simply replacing the breakpoint right away,
840 in order to not lose signals sent to the thread that hit the
841 breakpoint. Unfortunately this increases the window where another
842 thread could sneak past the removed breakpoint. For the current
843 use of server-side breakpoints (thread creation) this is
844 acceptable; but it needs to be considered before this breakpoint
845 mechanism can be used in more general ways. For some breakpoints
846 it may be necessary to stop all other threads, but that should
847 be avoided where possible.
849 If breakpoint_reinsert_addr is NULL, that means that we can
850 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
851 mark it for reinsertion, and single-step.
853 Otherwise, call the target function to figure out where we need
854 our temporary breakpoint, create it, and continue executing this
857 /* No need to reinsert. */
858 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
859 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
861 event_child
->bp_reinsert
= stop_pc
;
862 uninsert_breakpoint (stop_pc
);
863 linux_resume_one_process (&event_child
->head
, 1, 0, NULL
);
867 reinsert_breakpoint_by_bp
868 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
869 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
876 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
878 /* If we were single-stepping, we definitely want to report the
879 SIGTRAP. The single-step operation has completed, so also
880 clear the stepping flag; in general this does not matter,
881 because the SIGTRAP will be reported to the client, which
882 will give us a new action for this thread, but clear it for
883 consistency anyway. It's safe to clear the stepping flag
884 because the only consumer of get_stop_pc () after this point
885 is check_removed_breakpoint, and pending_is_breakpoint is not
886 set. It might be wiser to use a step_completed flag instead. */
887 if (event_child
->stepping
)
889 event_child
->stepping
= 0;
893 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
894 Check if it is a breakpoint, and if so mark the process information
895 accordingly. This will handle both the necessary fiddling with the
896 PC on decr_pc_after_break targets and suppressing extra threads
897 hitting a breakpoint if two hit it at once and then GDB removes it
898 after the first is reported. Arguably it would be better to report
899 multiple threads hitting breakpoints simultaneously, but the current
900 remote protocol does not allow this. */
901 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
903 event_child
->pending_is_breakpoint
= 1;
904 event_child
->pending_stop_pc
= stop_pc
;
914 /* Wait for process, returns status. */
917 linux_wait (char *status
)
920 struct thread_info
*child
= NULL
;
923 /* If we were only supposed to resume one thread, only wait for
924 that thread - if it's still alive. If it died, however - which
925 can happen if we're coming from the thread death case below -
926 then we need to make sure we restart the other threads. We could
927 pick a thread at random or restart all; restarting all is less
929 if (cont_thread
!= 0 && cont_thread
!= -1)
931 child
= (struct thread_info
*) find_inferior_id (&all_threads
,
934 /* No stepping, no signal - unless one is pending already, of course. */
937 struct thread_resume resume_info
;
938 resume_info
.thread
= -1;
939 resume_info
.step
= resume_info
.sig
= resume_info
.leave_stopped
= 0;
940 linux_resume (&resume_info
);
944 w
= linux_wait_for_event (child
);
945 stop_all_processes ();
947 if (must_set_ptrace_flags
)
949 ptrace (PTRACE_SETOPTIONS
, inferior_pid
, 0, PTRACE_O_TRACECLONE
);
950 must_set_ptrace_flags
= 0;
953 /* If we are waiting for a particular child, and it exited,
954 linux_wait_for_event will return its exit status. Similarly if
955 the last child exited. If this is not the last child, however,
956 do not report it as exited until there is a 'thread exited' response
957 available in the remote protocol. Instead, just wait for another event.
958 This should be safe, because if the thread crashed we will already
959 have reported the termination signal to GDB; that should stop any
960 in-progress stepping operations, etc.
962 Report the exit status of the last thread to exit. This matches
963 LinuxThreads' behavior. */
965 if (all_threads
.head
== all_threads
.tail
)
969 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
972 free (all_processes
.head
);
973 all_processes
.head
= all_processes
.tail
= NULL
;
974 return WEXITSTATUS (w
);
976 else if (!WIFSTOPPED (w
))
978 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
981 free (all_processes
.head
);
982 all_processes
.head
= all_processes
.tail
= NULL
;
983 return target_signal_from_host (WTERMSIG (w
));
993 return target_signal_from_host (WSTOPSIG (w
));
996 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
997 thread groups are in use, we need to use tkill. */
1000 kill_lwp (unsigned long lwpid
, int signo
)
1002 static int tkill_failed
;
1009 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1010 if (errno
!= ENOSYS
)
1017 return kill (lwpid
, signo
);
1021 send_sigstop (struct inferior_list_entry
*entry
)
1023 struct process_info
*process
= (struct process_info
*) entry
;
1025 if (process
->stopped
)
1028 /* If we already have a pending stop signal for this process, don't
1030 if (process
->stop_expected
)
1033 fprintf (stderr
, "Have pending sigstop for process %ld\n",
1036 /* We clear the stop_expected flag so that wait_for_sigstop
1037 will receive the SIGSTOP event (instead of silently resuming and
1038 waiting again). It'll be reset below. */
1039 process
->stop_expected
= 0;
1044 fprintf (stderr
, "Sending sigstop to process %ld\n", process
->head
.id
);
1046 kill_lwp (process
->head
.id
, SIGSTOP
);
1050 wait_for_sigstop (struct inferior_list_entry
*entry
)
1052 struct process_info
*process
= (struct process_info
*) entry
;
1053 struct thread_info
*saved_inferior
, *thread
;
1055 unsigned long saved_tid
;
1057 if (process
->stopped
)
1060 saved_inferior
= current_inferior
;
1061 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1062 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1064 wstat
= linux_wait_for_event (thread
);
1066 /* If we stopped with a non-SIGSTOP signal, save it for later
1067 and record the pending SIGSTOP. If the process exited, just
1069 if (WIFSTOPPED (wstat
)
1070 && WSTOPSIG (wstat
) != SIGSTOP
)
1073 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1074 process
->lwpid
, wstat
);
1075 process
->status_pending_p
= 1;
1076 process
->status_pending
= wstat
;
1077 process
->stop_expected
= 1;
1080 if (linux_thread_alive (saved_tid
))
1081 current_inferior
= saved_inferior
;
1085 fprintf (stderr
, "Previously current thread died.\n");
1087 /* Set a valid thread as current. */
1088 set_desired_inferior (0);
1093 stop_all_processes (void)
1095 stopping_threads
= 1;
1096 for_each_inferior (&all_processes
, send_sigstop
);
1097 for_each_inferior (&all_processes
, wait_for_sigstop
);
1098 stopping_threads
= 0;
1101 /* Resume execution of the inferior process.
1102 If STEP is nonzero, single-step it.
1103 If SIGNAL is nonzero, give it that signal. */
1106 linux_resume_one_process (struct inferior_list_entry
*entry
,
1107 int step
, int signal
, siginfo_t
*info
)
1109 struct process_info
*process
= (struct process_info
*) entry
;
1110 struct thread_info
*saved_inferior
;
1112 if (process
->stopped
== 0)
1115 /* If we have pending signals or status, and a new signal, enqueue the
1116 signal. Also enqueue the signal if we are waiting to reinsert a
1117 breakpoint; it will be picked up again below. */
1119 && (process
->status_pending_p
|| process
->pending_signals
!= NULL
1120 || process
->bp_reinsert
!= 0))
1122 struct pending_signals
*p_sig
;
1123 p_sig
= xmalloc (sizeof (*p_sig
));
1124 p_sig
->prev
= process
->pending_signals
;
1125 p_sig
->signal
= signal
;
1127 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1129 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1130 process
->pending_signals
= p_sig
;
1133 if (process
->status_pending_p
&& !check_removed_breakpoint (process
))
1136 saved_inferior
= current_inferior
;
1137 current_inferior
= get_process_thread (process
);
1140 fprintf (stderr
, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid
,
1141 step
? "step" : "continue", signal
,
1142 process
->stop_expected
? "expected" : "not expected");
1144 /* This bit needs some thinking about. If we get a signal that
1145 we must report while a single-step reinsert is still pending,
1146 we often end up resuming the thread. It might be better to
1147 (ew) allow a stack of pending events; then we could be sure that
1148 the reinsert happened right away and not lose any signals.
1150 Making this stack would also shrink the window in which breakpoints are
1151 uninserted (see comment in linux_wait_for_process) but not enough for
1152 complete correctness, so it won't solve that problem. It may be
1153 worthwhile just to solve this one, however. */
1154 if (process
->bp_reinsert
!= 0)
1157 fprintf (stderr
, " pending reinsert at %08lx", (long)process
->bp_reinsert
);
1159 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1162 /* Postpone any pending signal. It was enqueued above. */
1166 check_removed_breakpoint (process
);
1168 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1170 fprintf (stderr
, " ");
1171 (*the_low_target
.get_pc
) ();
1174 /* If we have pending signals, consume one unless we are trying to reinsert
1176 if (process
->pending_signals
!= NULL
&& process
->bp_reinsert
== 0)
1178 struct pending_signals
**p_sig
;
1180 p_sig
= &process
->pending_signals
;
1181 while ((*p_sig
)->prev
!= NULL
)
1182 p_sig
= &(*p_sig
)->prev
;
1184 signal
= (*p_sig
)->signal
;
1185 if ((*p_sig
)->info
.si_signo
!= 0)
1186 ptrace (PTRACE_SETSIGINFO
, process
->lwpid
, 0, &(*p_sig
)->info
);
1192 regcache_invalidate_one ((struct inferior_list_entry
*)
1193 get_process_thread (process
));
1195 process
->stopped
= 0;
1196 process
->stepping
= step
;
1197 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, process
->lwpid
, 0, signal
);
1199 current_inferior
= saved_inferior
;
1202 /* ESRCH from ptrace either means that the thread was already
1203 running (an error) or that it is gone (a race condition). If
1204 it's gone, we will get a notification the next time we wait,
1205 so we can ignore the error. We could differentiate these
1206 two, but it's tricky without waiting; the thread still exists
1207 as a zombie, so sending it signal 0 would succeed. So just
1212 perror_with_name ("ptrace");
1216 static struct thread_resume
*resume_ptr
;
1218 /* This function is called once per thread. We look up the thread
1219 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1222 This algorithm is O(threads * resume elements), but resume elements
1223 is small (and will remain small at least until GDB supports thread
1226 linux_set_resume_request (struct inferior_list_entry
*entry
)
1228 struct process_info
*process
;
1229 struct thread_info
*thread
;
1232 thread
= (struct thread_info
*) entry
;
1233 process
= get_thread_process (thread
);
1236 while (resume_ptr
[ndx
].thread
!= -1 && resume_ptr
[ndx
].thread
!= entry
->id
)
1239 process
->resume
= &resume_ptr
[ndx
];
1242 /* This function is called once per thread. We check the thread's resume
1243 request, which will tell us whether to resume, step, or leave the thread
1244 stopped; and what signal, if any, it should be sent. For threads which
1245 we aren't explicitly told otherwise, we preserve the stepping flag; this
1246 is used for stepping over gdbserver-placed breakpoints. */
1249 linux_continue_one_thread (struct inferior_list_entry
*entry
)
1251 struct process_info
*process
;
1252 struct thread_info
*thread
;
1255 thread
= (struct thread_info
*) entry
;
1256 process
= get_thread_process (thread
);
1258 if (process
->resume
->leave_stopped
)
1261 if (process
->resume
->thread
== -1)
1262 step
= process
->stepping
|| process
->resume
->step
;
1264 step
= process
->resume
->step
;
1266 linux_resume_one_process (&process
->head
, step
, process
->resume
->sig
, NULL
);
1268 process
->resume
= NULL
;
1271 /* This function is called once per thread. We check the thread's resume
1272 request, which will tell us whether to resume, step, or leave the thread
1273 stopped; and what signal, if any, it should be sent. We queue any needed
1274 signals, since we won't actually resume. We already have a pending event
1275 to report, so we don't need to preserve any step requests; they should
1276 be re-issued if necessary. */
1279 linux_queue_one_thread (struct inferior_list_entry
*entry
)
1281 struct process_info
*process
;
1282 struct thread_info
*thread
;
1284 thread
= (struct thread_info
*) entry
;
1285 process
= get_thread_process (thread
);
1287 if (process
->resume
->leave_stopped
)
1290 /* If we have a new signal, enqueue the signal. */
1291 if (process
->resume
->sig
!= 0)
1293 struct pending_signals
*p_sig
;
1294 p_sig
= xmalloc (sizeof (*p_sig
));
1295 p_sig
->prev
= process
->pending_signals
;
1296 p_sig
->signal
= process
->resume
->sig
;
1297 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1299 /* If this is the same signal we were previously stopped by,
1300 make sure to queue its siginfo. We can ignore the return
1301 value of ptrace; if it fails, we'll skip
1302 PTRACE_SETSIGINFO. */
1303 if (WIFSTOPPED (process
->last_status
)
1304 && WSTOPSIG (process
->last_status
) == process
->resume
->sig
)
1305 ptrace (PTRACE_GETSIGINFO
, process
->lwpid
, 0, &p_sig
->info
);
1307 process
->pending_signals
= p_sig
;
1310 process
->resume
= NULL
;
1313 /* Set DUMMY if this process has an interesting status pending. */
1315 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1317 struct process_info
*process
= (struct process_info
*) entry
;
1319 /* Processes which will not be resumed are not interesting, because
1320 we might not wait for them next time through linux_wait. */
1321 if (process
->resume
->leave_stopped
)
1324 /* If this thread has a removed breakpoint, we won't have any
1325 events to report later, so check now. check_removed_breakpoint
1326 may clear status_pending_p. We avoid calling check_removed_breakpoint
1327 for any thread that we are not otherwise going to resume - this
1328 lets us preserve stopped status when two threads hit a breakpoint.
1329 GDB removes the breakpoint to single-step a particular thread
1330 past it, then re-inserts it and resumes all threads. We want
1331 to report the second thread without resuming it in the interim. */
1332 if (process
->status_pending_p
)
1333 check_removed_breakpoint (process
);
1335 if (process
->status_pending_p
)
1336 * (int *) flag_p
= 1;
1342 linux_resume (struct thread_resume
*resume_info
)
1346 /* Yes, the use of a global here is rather ugly. */
1347 resume_ptr
= resume_info
;
1349 for_each_inferior (&all_threads
, linux_set_resume_request
);
1351 /* If there is a thread which would otherwise be resumed, which
1352 has a pending status, then don't resume any threads - we can just
1353 report the pending status. Make sure to queue any signals
1354 that would otherwise be sent. */
1356 find_inferior (&all_processes
, resume_status_pending_p
, &pending_flag
);
1361 fprintf (stderr
, "Not resuming, pending status\n");
1363 fprintf (stderr
, "Resuming, no pending status\n");
1367 for_each_inferior (&all_threads
, linux_queue_one_thread
);
1369 for_each_inferior (&all_threads
, linux_continue_one_thread
);
1372 #ifdef HAVE_LINUX_USRREGS
1375 register_addr (int regnum
)
1379 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1380 error ("Invalid register number %d.", regnum
);
1382 addr
= the_low_target
.regmap
[regnum
];
1387 /* Fetch one register. */
1389 fetch_register (int regno
)
1395 if (regno
>= the_low_target
.num_regs
)
1397 if ((*the_low_target
.cannot_fetch_register
) (regno
))
1400 regaddr
= register_addr (regno
);
1403 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1404 & - sizeof (PTRACE_XFER_TYPE
);
1405 buf
= alloca (size
);
1406 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1409 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
1410 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
1411 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1414 /* Warning, not error, in case we are attached; sometimes the
1415 kernel doesn't let us at the registers. */
1416 char *err
= strerror (errno
);
1417 char *msg
= alloca (strlen (err
) + 128);
1418 sprintf (msg
, "reading register %d: %s", regno
, err
);
1424 if (the_low_target
.supply_ptrace_register
)
1425 the_low_target
.supply_ptrace_register (regno
, buf
);
1427 supply_register (regno
, buf
);
1432 /* Fetch all registers, or just one, from the child process. */
1434 usr_fetch_inferior_registers (int regno
)
1436 if (regno
== -1 || regno
== 0)
1437 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1438 fetch_register (regno
);
1440 fetch_register (regno
);
1443 /* Store our register values back into the inferior.
1444 If REGNO is -1, do this for all registers.
1445 Otherwise, REGNO specifies which register (so we can save time). */
1447 usr_store_inferior_registers (int regno
)
1455 if (regno
>= the_low_target
.num_regs
)
1458 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
1461 regaddr
= register_addr (regno
);
1465 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1466 & - sizeof (PTRACE_XFER_TYPE
);
1467 buf
= alloca (size
);
1468 memset (buf
, 0, size
);
1470 if (the_low_target
.collect_ptrace_register
)
1471 the_low_target
.collect_ptrace_register (regno
, buf
);
1473 collect_register (regno
, buf
);
1475 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1478 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
1479 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
1482 /* At this point, ESRCH should mean the process is already gone,
1483 in which case we simply ignore attempts to change its registers.
1484 See also the related comment in linux_resume_one_process. */
1488 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
1490 char *err
= strerror (errno
);
1491 char *msg
= alloca (strlen (err
) + 128);
1492 sprintf (msg
, "writing register %d: %s",
1498 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1502 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1503 usr_store_inferior_registers (regno
);
1505 #endif /* HAVE_LINUX_USRREGS */
1509 #ifdef HAVE_LINUX_REGSETS
1512 regsets_fetch_inferior_registers ()
1514 struct regset_info
*regset
;
1515 int saw_general_regs
= 0;
1517 regset
= target_regsets
;
1519 while (regset
->size
>= 0)
1524 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1530 buf
= xmalloc (regset
->size
);
1532 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1534 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1540 /* If we get EIO on a regset, do not try it again for
1542 disabled_regsets
[regset
- target_regsets
] = 1;
1548 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1553 else if (regset
->type
== GENERAL_REGS
)
1554 saw_general_regs
= 1;
1555 regset
->store_function (buf
);
1558 if (saw_general_regs
)
1565 regsets_store_inferior_registers ()
1567 struct regset_info
*regset
;
1568 int saw_general_regs
= 0;
1570 regset
= target_regsets
;
1572 while (regset
->size
>= 0)
1577 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1583 buf
= xmalloc (regset
->size
);
1585 /* First fill the buffer with the current register set contents,
1586 in case there are any items in the kernel's regset that are
1587 not in gdbserver's regcache. */
1589 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1591 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1596 /* Then overlay our cached registers on that. */
1597 regset
->fill_function (buf
);
1599 /* Only now do we write the register set. */
1601 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
1603 res
= ptrace (regset
->set_request
, inferior_pid
, buf
, 0);
1611 /* If we get EIO on a regset, do not try it again for
1613 disabled_regsets
[regset
- target_regsets
] = 1;
1616 else if (errno
== ESRCH
)
1618 /* At this point, ESRCH should mean the process is already gone,
1619 in which case we simply ignore attempts to change its registers.
1620 See also the related comment in linux_resume_one_process. */
1625 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1628 else if (regset
->type
== GENERAL_REGS
)
1629 saw_general_regs
= 1;
1633 if (saw_general_regs
)
1640 #endif /* HAVE_LINUX_REGSETS */
1644 linux_fetch_registers (int regno
)
1646 #ifdef HAVE_LINUX_REGSETS
1647 if (regsets_fetch_inferior_registers () == 0)
1650 #ifdef HAVE_LINUX_USRREGS
1651 usr_fetch_inferior_registers (regno
);
1656 linux_store_registers (int regno
)
1658 #ifdef HAVE_LINUX_REGSETS
1659 if (regsets_store_inferior_registers () == 0)
1662 #ifdef HAVE_LINUX_USRREGS
1663 usr_store_inferior_registers (regno
);
1668 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1669 to debugger memory starting at MYADDR. */
1672 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
1675 /* Round starting address down to longword boundary. */
1676 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1677 /* Round ending address up; get number of longwords that makes. */
1679 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1680 / sizeof (PTRACE_XFER_TYPE
);
1681 /* Allocate buffer of that many longwords. */
1682 register PTRACE_XFER_TYPE
*buffer
1683 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1687 /* Try using /proc. Don't bother for one word. */
1688 if (len
>= 3 * sizeof (long))
1690 /* We could keep this file open and cache it - possibly one per
1691 thread. That requires some juggling, but is even faster. */
1692 sprintf (filename
, "/proc/%ld/mem", inferior_pid
);
1693 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
1697 /* If pread64 is available, use it. It's faster if the kernel
1698 supports it (only one syscall), and it's 64-bit safe even on
1699 32-bit platforms (for instance, SPARC debugging a SPARC64
1702 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
1704 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
1716 /* Read all the longwords */
1717 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1720 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
1725 /* Copy appropriate bytes out of the buffer. */
1726 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), len
);
1731 /* Copy LEN bytes of data from debugger memory at MYADDR
1732 to inferior's memory at MEMADDR.
1733 On failure (cannot write the inferior)
1734 returns the value of errno. */
1737 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
1740 /* Round starting address down to longword boundary. */
1741 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1742 /* Round ending address up; get number of longwords that makes. */
1744 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
1745 /* Allocate buffer of that many longwords. */
1746 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1750 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
1753 /* Fill start and end extra bytes of buffer with existing memory data. */
1755 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1756 (PTRACE_ARG3_TYPE
) addr
, 0);
1761 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1762 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
1763 * sizeof (PTRACE_XFER_TYPE
)),
1767 /* Copy data to be written over corresponding part of buffer */
1769 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
1771 /* Write the entire buffer. */
1773 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1776 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
1784 static int linux_supports_tracefork_flag
;
1786 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1789 linux_tracefork_grandchild (void *arg
)
1794 #define STACK_SIZE 4096
1797 linux_tracefork_child (void *arg
)
1799 ptrace (PTRACE_TRACEME
, 0, 0, 0);
1800 kill (getpid (), SIGSTOP
);
1802 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
1803 CLONE_VM
| SIGCHLD
, NULL
);
1805 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
1806 CLONE_VM
| SIGCHLD
, NULL
);
1811 /* Wrapper function for waitpid which handles EINTR. */
1814 my_waitpid (int pid
, int *status
, int flags
)
1819 ret
= waitpid (pid
, status
, flags
);
1821 while (ret
== -1 && errno
== EINTR
);
1826 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1827 sure that we can enable the option, and that it had the desired
1831 linux_test_for_tracefork (void)
1833 int child_pid
, ret
, status
;
1835 char *stack
= xmalloc (STACK_SIZE
* 4);
1837 linux_supports_tracefork_flag
= 0;
1839 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1841 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
1842 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1844 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
1845 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1847 if (child_pid
== -1)
1848 perror_with_name ("clone");
1850 ret
= my_waitpid (child_pid
, &status
, 0);
1852 perror_with_name ("waitpid");
1853 else if (ret
!= child_pid
)
1854 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
1855 if (! WIFSTOPPED (status
))
1856 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
1858 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
1861 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1864 warning ("linux_test_for_tracefork: failed to kill child");
1868 ret
= my_waitpid (child_pid
, &status
, 0);
1869 if (ret
!= child_pid
)
1870 warning ("linux_test_for_tracefork: failed to wait for killed child");
1871 else if (!WIFSIGNALED (status
))
1872 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1873 "killed child", status
);
1878 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
1880 warning ("linux_test_for_tracefork: failed to resume child");
1882 ret
= my_waitpid (child_pid
, &status
, 0);
1884 if (ret
== child_pid
&& WIFSTOPPED (status
)
1885 && status
>> 16 == PTRACE_EVENT_FORK
)
1888 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
1889 if (ret
== 0 && second_pid
!= 0)
1893 linux_supports_tracefork_flag
= 1;
1894 my_waitpid (second_pid
, &second_status
, 0);
1895 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
1897 warning ("linux_test_for_tracefork: failed to kill second child");
1898 my_waitpid (second_pid
, &status
, 0);
1902 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1903 "(%d, status 0x%x)", ret
, status
);
1907 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1909 warning ("linux_test_for_tracefork: failed to kill child");
1910 my_waitpid (child_pid
, &status
, 0);
1912 while (WIFSTOPPED (status
));
1919 linux_look_up_symbols (void)
1921 #ifdef USE_THREAD_DB
1922 if (thread_db_active
)
1925 thread_db_active
= thread_db_init (!linux_supports_tracefork_flag
);
1930 linux_request_interrupt (void)
1932 extern unsigned long signal_pid
;
1934 if (cont_thread
!= 0 && cont_thread
!= -1)
1936 struct process_info
*process
;
1938 process
= get_thread_process (current_inferior
);
1939 kill_lwp (process
->lwpid
, SIGINT
);
1942 kill_lwp (signal_pid
, SIGINT
);
1945 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1946 to debugger memory starting at MYADDR. */
1949 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
1951 char filename
[PATH_MAX
];
1954 snprintf (filename
, sizeof filename
, "/proc/%ld/auxv", inferior_pid
);
1956 fd
= open (filename
, O_RDONLY
);
1960 if (offset
!= (CORE_ADDR
) 0
1961 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
1964 n
= read (fd
, myaddr
, len
);
1971 /* These watchpoint related wrapper functions simply pass on the function call
1972 if the target has registered a corresponding function. */
1975 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
1977 if (the_low_target
.insert_watchpoint
!= NULL
)
1978 return the_low_target
.insert_watchpoint (type
, addr
, len
);
1980 /* Unsupported (see target.h). */
1985 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
1987 if (the_low_target
.remove_watchpoint
!= NULL
)
1988 return the_low_target
.remove_watchpoint (type
, addr
, len
);
1990 /* Unsupported (see target.h). */
1995 linux_stopped_by_watchpoint (void)
1997 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1998 return the_low_target
.stopped_by_watchpoint ();
2004 linux_stopped_data_address (void)
2006 if (the_low_target
.stopped_data_address
!= NULL
)
2007 return the_low_target
.stopped_data_address ();
2012 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2013 #if defined(__mcoldfire__)
2014 /* These should really be defined in the kernel's ptrace.h header. */
2015 #define PT_TEXT_ADDR 49*4
2016 #define PT_DATA_ADDR 50*4
2017 #define PT_TEXT_END_ADDR 51*4
2020 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2021 to tell gdb about. */
2024 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2026 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2027 unsigned long text
, text_end
, data
;
2028 int pid
= get_thread_process (current_inferior
)->head
.id
;
2032 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2033 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2034 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2038 /* Both text and data offsets produced at compile-time (and so
2039 used by gdb) are relative to the beginning of the program,
2040 with the data segment immediately following the text segment.
2041 However, the actual runtime layout in memory may put the data
2042 somewhere else, so when we send gdb a data base-address, we
2043 use the real data base address and subtract the compile-time
2044 data base-address from it (which is just the length of the
2045 text segment). BSS immediately follows data in both
2048 *data_p
= data
- (text_end
- text
);
2058 linux_qxfer_osdata (const char *annex
,
2059 unsigned char *readbuf
, unsigned const char *writebuf
,
2060 CORE_ADDR offset
, int len
)
2062 /* We make the process list snapshot when the object starts to be
2064 static const char *buf
;
2065 static long len_avail
= -1;
2066 static struct buffer buffer
;
2070 if (strcmp (annex
, "processes") != 0)
2073 if (!readbuf
|| writebuf
)
2078 if (len_avail
!= -1 && len_avail
!= 0)
2079 buffer_free (&buffer
);
2082 buffer_init (&buffer
);
2083 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2085 dirp
= opendir ("/proc");
2089 while ((dp
= readdir (dirp
)) != NULL
)
2091 struct stat statbuf
;
2092 char procentry
[sizeof ("/proc/4294967295")];
2094 if (!isdigit (dp
->d_name
[0])
2095 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2098 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2099 if (stat (procentry
, &statbuf
) == 0
2100 && S_ISDIR (statbuf
.st_mode
))
2104 char cmd
[MAXPATHLEN
+ 1];
2105 struct passwd
*entry
;
2107 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2108 entry
= getpwuid (statbuf
.st_uid
);
2110 if ((f
= fopen (pathname
, "r")) != NULL
)
2112 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2116 for (i
= 0; i
< len
; i
++)
2124 "<column name=\"pid\">%s</column>"
2125 "<column name=\"user\">%s</column>"
2126 "<column name=\"command\">%s</column>"
2129 entry
? entry
->pw_name
: "?",
2139 buffer_grow_str0 (&buffer
, "</osdata>\n");
2140 buf
= buffer_finish (&buffer
);
2141 len_avail
= strlen (buf
);
2144 if (offset
>= len_avail
)
2146 /* Done. Get rid of the data. */
2147 buffer_free (&buffer
);
2153 if (len
> len_avail
- offset
)
2154 len
= len_avail
- offset
;
2155 memcpy (readbuf
, buf
+ offset
, len
);
2160 static struct target_ops linux_target_ops
= {
2161 linux_create_inferior
,
2169 linux_fetch_registers
,
2170 linux_store_registers
,
2173 linux_look_up_symbols
,
2174 linux_request_interrupt
,
2176 linux_insert_watchpoint
,
2177 linux_remove_watchpoint
,
2178 linux_stopped_by_watchpoint
,
2179 linux_stopped_data_address
,
2180 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2185 #ifdef USE_THREAD_DB
2186 thread_db_get_tls_address
,
2191 hostio_last_error_from_errno
,
2196 linux_init_signals ()
2198 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2199 to find what the cancel signal actually is. */
2200 signal (__SIGRTMIN
+1, SIG_IGN
);
2204 initialize_low (void)
2206 thread_db_active
= 0;
2207 set_target_ops (&linux_target_ops
);
2208 set_breakpoint_data (the_low_target
.breakpoint
,
2209 the_low_target
.breakpoint_len
);
2210 linux_init_signals ();
2211 linux_test_for_tracefork ();
2212 #ifdef HAVE_LINUX_REGSETS
2213 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
2215 disabled_regsets
= xmalloc (num_regsets
);