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
);
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
*) malloc (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 current_inferior
= (struct thread_info
*)
646 find_inferior_id (&all_threads
, (*childp
)->lwpid
);
647 /* For testing only; i386_stop_pc prints out a diagnostic. */
648 if (the_low_target
.get_pc
!= NULL
)
654 linux_wait_for_event (struct thread_info
*child
)
657 struct process_info
*event_child
;
661 /* Check for a process with a pending status. */
662 /* It is possible that the user changed the pending task's registers since
663 it stopped. We correctly handle the change of PC if we hit a breakpoint
664 (in check_removed_breakpoint); signals should be reported anyway. */
667 event_child
= (struct process_info
*)
668 find_inferior (&all_processes
, status_pending_p
, NULL
);
669 if (debug_threads
&& event_child
)
670 fprintf (stderr
, "Got a pending child %ld\n", event_child
->lwpid
);
674 event_child
= get_thread_process (child
);
675 if (event_child
->status_pending_p
676 && check_removed_breakpoint (event_child
))
680 if (event_child
!= NULL
)
682 if (event_child
->status_pending_p
)
685 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
686 event_child
->lwpid
, event_child
->status_pending
);
687 wstat
= event_child
->status_pending
;
688 event_child
->status_pending_p
= 0;
689 event_child
->status_pending
= 0;
690 current_inferior
= get_process_thread (event_child
);
695 /* We only enter this loop if no process has a pending wait status. Thus
696 any action taken in response to a wait status inside this loop is
697 responding as soon as we detect the status, not after any pending
704 event_child
= get_thread_process (child
);
706 linux_wait_for_process (&event_child
, &wstat
);
708 if (event_child
== NULL
)
709 error ("event from unknown child");
711 current_inferior
= (struct thread_info
*)
712 find_inferior_id (&all_threads
, event_child
->lwpid
);
714 /* Check for thread exit. */
715 if (! WIFSTOPPED (wstat
))
718 fprintf (stderr
, "LWP %ld exiting\n", event_child
->head
.id
);
720 /* If the last thread is exiting, just return. */
721 if (all_threads
.head
== all_threads
.tail
)
724 dead_thread_notify (thread_id_to_gdb_id (event_child
->lwpid
));
726 remove_inferior (&all_processes
, &event_child
->head
);
728 remove_thread (current_inferior
);
729 current_inferior
= (struct thread_info
*) all_threads
.head
;
731 /* If we were waiting for this particular child to do something...
732 well, it did something. */
736 /* Wait for a more interesting event. */
740 if (WIFSTOPPED (wstat
)
741 && WSTOPSIG (wstat
) == SIGSTOP
742 && event_child
->stop_expected
)
745 fprintf (stderr
, "Expected stop.\n");
746 event_child
->stop_expected
= 0;
747 linux_resume_one_process (&event_child
->head
,
748 event_child
->stepping
, 0, NULL
);
752 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
755 handle_extended_wait (event_child
, wstat
);
759 /* If GDB is not interested in this signal, don't stop other
760 threads, and don't report it to GDB. Just resume the
761 inferior right away. We do this for threading-related
762 signals as well as any that GDB specifically requested we
763 ignore. But never ignore SIGSTOP if we sent it ourselves,
764 and do not ignore signals when stepping - they may require
765 special handling to skip the signal handler. */
766 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
768 if (WIFSTOPPED (wstat
)
769 && !event_child
->stepping
772 (thread_db_active
&& (WSTOPSIG (wstat
) == __SIGRTMIN
773 || WSTOPSIG (wstat
) == __SIGRTMIN
+ 1))
776 (pass_signals
[target_signal_from_host (WSTOPSIG (wstat
))]
777 && (WSTOPSIG (wstat
) != SIGSTOP
|| !stopping_threads
))))
779 siginfo_t info
, *info_p
;
782 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
783 WSTOPSIG (wstat
), event_child
->head
.id
);
785 if (ptrace (PTRACE_GETSIGINFO
, event_child
->lwpid
, 0, &info
) == 0)
789 linux_resume_one_process (&event_child
->head
,
790 event_child
->stepping
,
791 WSTOPSIG (wstat
), info_p
);
795 /* If this event was not handled above, and is not a SIGTRAP, report
797 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGTRAP
)
800 /* If this target does not support breakpoints, we simply report the
801 SIGTRAP; it's of no concern to us. */
802 if (the_low_target
.get_pc
== NULL
)
805 stop_pc
= get_stop_pc ();
807 /* bp_reinsert will only be set if we were single-stepping.
808 Notice that we will resume the process after hitting
809 a gdbserver breakpoint; single-stepping to/over one
810 is not supported (yet). */
811 if (event_child
->bp_reinsert
!= 0)
814 fprintf (stderr
, "Reinserted breakpoint.\n");
815 reinsert_breakpoint (event_child
->bp_reinsert
);
816 event_child
->bp_reinsert
= 0;
818 /* Clear the single-stepping flag and SIGTRAP as we resume. */
819 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
823 bp_status
= check_breakpoints (stop_pc
);
828 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
830 /* We hit one of our own breakpoints. We mark it as a pending
831 breakpoint, so that check_removed_breakpoint () will do the PC
832 adjustment for us at the appropriate time. */
833 event_child
->pending_is_breakpoint
= 1;
834 event_child
->pending_stop_pc
= stop_pc
;
836 /* We may need to put the breakpoint back. We continue in the event
837 loop instead of simply replacing the breakpoint right away,
838 in order to not lose signals sent to the thread that hit the
839 breakpoint. Unfortunately this increases the window where another
840 thread could sneak past the removed breakpoint. For the current
841 use of server-side breakpoints (thread creation) this is
842 acceptable; but it needs to be considered before this breakpoint
843 mechanism can be used in more general ways. For some breakpoints
844 it may be necessary to stop all other threads, but that should
845 be avoided where possible.
847 If breakpoint_reinsert_addr is NULL, that means that we can
848 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
849 mark it for reinsertion, and single-step.
851 Otherwise, call the target function to figure out where we need
852 our temporary breakpoint, create it, and continue executing this
855 /* No need to reinsert. */
856 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
857 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
859 event_child
->bp_reinsert
= stop_pc
;
860 uninsert_breakpoint (stop_pc
);
861 linux_resume_one_process (&event_child
->head
, 1, 0, NULL
);
865 reinsert_breakpoint_by_bp
866 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
867 linux_resume_one_process (&event_child
->head
, 0, 0, NULL
);
874 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
876 /* If we were single-stepping, we definitely want to report the
877 SIGTRAP. The single-step operation has completed, so also
878 clear the stepping flag; in general this does not matter,
879 because the SIGTRAP will be reported to the client, which
880 will give us a new action for this thread, but clear it for
881 consistency anyway. It's safe to clear the stepping flag
882 because the only consumer of get_stop_pc () after this point
883 is check_removed_breakpoint, and pending_is_breakpoint is not
884 set. It might be wiser to use a step_completed flag instead. */
885 if (event_child
->stepping
)
887 event_child
->stepping
= 0;
891 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
892 Check if it is a breakpoint, and if so mark the process information
893 accordingly. This will handle both the necessary fiddling with the
894 PC on decr_pc_after_break targets and suppressing extra threads
895 hitting a breakpoint if two hit it at once and then GDB removes it
896 after the first is reported. Arguably it would be better to report
897 multiple threads hitting breakpoints simultaneously, but the current
898 remote protocol does not allow this. */
899 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
901 event_child
->pending_is_breakpoint
= 1;
902 event_child
->pending_stop_pc
= stop_pc
;
912 /* Wait for process, returns status. */
915 linux_wait (char *status
)
918 struct thread_info
*child
= NULL
;
921 /* If we were only supposed to resume one thread, only wait for
922 that thread - if it's still alive. If it died, however - which
923 can happen if we're coming from the thread death case below -
924 then we need to make sure we restart the other threads. We could
925 pick a thread at random or restart all; restarting all is less
927 if (cont_thread
!= 0 && cont_thread
!= -1)
929 child
= (struct thread_info
*) find_inferior_id (&all_threads
,
932 /* No stepping, no signal - unless one is pending already, of course. */
935 struct thread_resume resume_info
;
936 resume_info
.thread
= -1;
937 resume_info
.step
= resume_info
.sig
= resume_info
.leave_stopped
= 0;
938 linux_resume (&resume_info
);
942 w
= linux_wait_for_event (child
);
943 stop_all_processes ();
945 if (must_set_ptrace_flags
)
947 ptrace (PTRACE_SETOPTIONS
, inferior_pid
, 0, PTRACE_O_TRACECLONE
);
948 must_set_ptrace_flags
= 0;
951 /* If we are waiting for a particular child, and it exited,
952 linux_wait_for_event will return its exit status. Similarly if
953 the last child exited. If this is not the last child, however,
954 do not report it as exited until there is a 'thread exited' response
955 available in the remote protocol. Instead, just wait for another event.
956 This should be safe, because if the thread crashed we will already
957 have reported the termination signal to GDB; that should stop any
958 in-progress stepping operations, etc.
960 Report the exit status of the last thread to exit. This matches
961 LinuxThreads' behavior. */
963 if (all_threads
.head
== all_threads
.tail
)
967 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
970 free (all_processes
.head
);
971 all_processes
.head
= all_processes
.tail
= NULL
;
972 return WEXITSTATUS (w
);
974 else if (!WIFSTOPPED (w
))
976 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
979 free (all_processes
.head
);
980 all_processes
.head
= all_processes
.tail
= NULL
;
981 return target_signal_from_host (WTERMSIG (w
));
991 return target_signal_from_host (WSTOPSIG (w
));
994 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
995 thread groups are in use, we need to use tkill. */
998 kill_lwp (unsigned long lwpid
, int signo
)
1000 static int tkill_failed
;
1007 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1008 if (errno
!= ENOSYS
)
1015 return kill (lwpid
, signo
);
1019 send_sigstop (struct inferior_list_entry
*entry
)
1021 struct process_info
*process
= (struct process_info
*) entry
;
1023 if (process
->stopped
)
1026 /* If we already have a pending stop signal for this process, don't
1028 if (process
->stop_expected
)
1031 fprintf (stderr
, "Have pending sigstop for process %ld\n",
1034 /* We clear the stop_expected flag so that wait_for_sigstop
1035 will receive the SIGSTOP event (instead of silently resuming and
1036 waiting again). It'll be reset below. */
1037 process
->stop_expected
= 0;
1042 fprintf (stderr
, "Sending sigstop to process %ld\n", process
->head
.id
);
1044 kill_lwp (process
->head
.id
, SIGSTOP
);
1048 wait_for_sigstop (struct inferior_list_entry
*entry
)
1050 struct process_info
*process
= (struct process_info
*) entry
;
1051 struct thread_info
*saved_inferior
, *thread
;
1053 unsigned long saved_tid
;
1055 if (process
->stopped
)
1058 saved_inferior
= current_inferior
;
1059 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1060 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1062 wstat
= linux_wait_for_event (thread
);
1064 /* If we stopped with a non-SIGSTOP signal, save it for later
1065 and record the pending SIGSTOP. If the process exited, just
1067 if (WIFSTOPPED (wstat
)
1068 && WSTOPSIG (wstat
) != SIGSTOP
)
1071 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1072 process
->lwpid
, wstat
);
1073 process
->status_pending_p
= 1;
1074 process
->status_pending
= wstat
;
1075 process
->stop_expected
= 1;
1078 if (linux_thread_alive (saved_tid
))
1079 current_inferior
= saved_inferior
;
1083 fprintf (stderr
, "Previously current thread died.\n");
1085 /* Set a valid thread as current. */
1086 set_desired_inferior (0);
1091 stop_all_processes (void)
1093 stopping_threads
= 1;
1094 for_each_inferior (&all_processes
, send_sigstop
);
1095 for_each_inferior (&all_processes
, wait_for_sigstop
);
1096 stopping_threads
= 0;
1099 /* Resume execution of the inferior process.
1100 If STEP is nonzero, single-step it.
1101 If SIGNAL is nonzero, give it that signal. */
1104 linux_resume_one_process (struct inferior_list_entry
*entry
,
1105 int step
, int signal
, siginfo_t
*info
)
1107 struct process_info
*process
= (struct process_info
*) entry
;
1108 struct thread_info
*saved_inferior
;
1110 if (process
->stopped
== 0)
1113 /* If we have pending signals or status, and a new signal, enqueue the
1114 signal. Also enqueue the signal if we are waiting to reinsert a
1115 breakpoint; it will be picked up again below. */
1117 && (process
->status_pending_p
|| process
->pending_signals
!= NULL
1118 || process
->bp_reinsert
!= 0))
1120 struct pending_signals
*p_sig
;
1121 p_sig
= malloc (sizeof (*p_sig
));
1122 p_sig
->prev
= process
->pending_signals
;
1123 p_sig
->signal
= signal
;
1125 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1127 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1128 process
->pending_signals
= p_sig
;
1131 if (process
->status_pending_p
&& !check_removed_breakpoint (process
))
1134 saved_inferior
= current_inferior
;
1135 current_inferior
= get_process_thread (process
);
1138 fprintf (stderr
, "Resuming process %ld (%s, signal %d, stop %s)\n", inferior_pid
,
1139 step
? "step" : "continue", signal
,
1140 process
->stop_expected
? "expected" : "not expected");
1142 /* This bit needs some thinking about. If we get a signal that
1143 we must report while a single-step reinsert is still pending,
1144 we often end up resuming the thread. It might be better to
1145 (ew) allow a stack of pending events; then we could be sure that
1146 the reinsert happened right away and not lose any signals.
1148 Making this stack would also shrink the window in which breakpoints are
1149 uninserted (see comment in linux_wait_for_process) but not enough for
1150 complete correctness, so it won't solve that problem. It may be
1151 worthwhile just to solve this one, however. */
1152 if (process
->bp_reinsert
!= 0)
1155 fprintf (stderr
, " pending reinsert at %08lx", (long)process
->bp_reinsert
);
1157 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1160 /* Postpone any pending signal. It was enqueued above. */
1164 check_removed_breakpoint (process
);
1166 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1168 fprintf (stderr
, " ");
1169 (*the_low_target
.get_pc
) ();
1172 /* If we have pending signals, consume one unless we are trying to reinsert
1174 if (process
->pending_signals
!= NULL
&& process
->bp_reinsert
== 0)
1176 struct pending_signals
**p_sig
;
1178 p_sig
= &process
->pending_signals
;
1179 while ((*p_sig
)->prev
!= NULL
)
1180 p_sig
= &(*p_sig
)->prev
;
1182 signal
= (*p_sig
)->signal
;
1183 if ((*p_sig
)->info
.si_signo
!= 0)
1184 ptrace (PTRACE_SETSIGINFO
, process
->lwpid
, 0, &(*p_sig
)->info
);
1190 regcache_invalidate_one ((struct inferior_list_entry
*)
1191 get_process_thread (process
));
1193 process
->stopped
= 0;
1194 process
->stepping
= step
;
1195 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, process
->lwpid
, 0, signal
);
1197 current_inferior
= saved_inferior
;
1200 /* ESRCH from ptrace either means that the thread was already
1201 running (an error) or that it is gone (a race condition). If
1202 it's gone, we will get a notification the next time we wait,
1203 so we can ignore the error. We could differentiate these
1204 two, but it's tricky without waiting; the thread still exists
1205 as a zombie, so sending it signal 0 would succeed. So just
1210 perror_with_name ("ptrace");
1214 static struct thread_resume
*resume_ptr
;
1216 /* This function is called once per thread. We look up the thread
1217 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1220 This algorithm is O(threads * resume elements), but resume elements
1221 is small (and will remain small at least until GDB supports thread
1224 linux_set_resume_request (struct inferior_list_entry
*entry
)
1226 struct process_info
*process
;
1227 struct thread_info
*thread
;
1230 thread
= (struct thread_info
*) entry
;
1231 process
= get_thread_process (thread
);
1234 while (resume_ptr
[ndx
].thread
!= -1 && resume_ptr
[ndx
].thread
!= entry
->id
)
1237 process
->resume
= &resume_ptr
[ndx
];
1240 /* This function is called once per thread. We check the thread's resume
1241 request, which will tell us whether to resume, step, or leave the thread
1242 stopped; and what signal, if any, it should be sent. For threads which
1243 we aren't explicitly told otherwise, we preserve the stepping flag; this
1244 is used for stepping over gdbserver-placed breakpoints. */
1247 linux_continue_one_thread (struct inferior_list_entry
*entry
)
1249 struct process_info
*process
;
1250 struct thread_info
*thread
;
1253 thread
= (struct thread_info
*) entry
;
1254 process
= get_thread_process (thread
);
1256 if (process
->resume
->leave_stopped
)
1259 if (process
->resume
->thread
== -1)
1260 step
= process
->stepping
|| process
->resume
->step
;
1262 step
= process
->resume
->step
;
1264 linux_resume_one_process (&process
->head
, step
, process
->resume
->sig
, NULL
);
1266 process
->resume
= NULL
;
1269 /* This function is called once per thread. We check the thread's resume
1270 request, which will tell us whether to resume, step, or leave the thread
1271 stopped; and what signal, if any, it should be sent. We queue any needed
1272 signals, since we won't actually resume. We already have a pending event
1273 to report, so we don't need to preserve any step requests; they should
1274 be re-issued if necessary. */
1277 linux_queue_one_thread (struct inferior_list_entry
*entry
)
1279 struct process_info
*process
;
1280 struct thread_info
*thread
;
1282 thread
= (struct thread_info
*) entry
;
1283 process
= get_thread_process (thread
);
1285 if (process
->resume
->leave_stopped
)
1288 /* If we have a new signal, enqueue the signal. */
1289 if (process
->resume
->sig
!= 0)
1291 struct pending_signals
*p_sig
;
1292 p_sig
= malloc (sizeof (*p_sig
));
1293 p_sig
->prev
= process
->pending_signals
;
1294 p_sig
->signal
= process
->resume
->sig
;
1295 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1297 /* If this is the same signal we were previously stopped by,
1298 make sure to queue its siginfo. We can ignore the return
1299 value of ptrace; if it fails, we'll skip
1300 PTRACE_SETSIGINFO. */
1301 if (WIFSTOPPED (process
->last_status
)
1302 && WSTOPSIG (process
->last_status
) == process
->resume
->sig
)
1303 ptrace (PTRACE_GETSIGINFO
, process
->lwpid
, 0, &p_sig
->info
);
1305 process
->pending_signals
= p_sig
;
1308 process
->resume
= NULL
;
1311 /* Set DUMMY if this process has an interesting status pending. */
1313 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1315 struct process_info
*process
= (struct process_info
*) entry
;
1317 /* Processes which will not be resumed are not interesting, because
1318 we might not wait for them next time through linux_wait. */
1319 if (process
->resume
->leave_stopped
)
1322 /* If this thread has a removed breakpoint, we won't have any
1323 events to report later, so check now. check_removed_breakpoint
1324 may clear status_pending_p. We avoid calling check_removed_breakpoint
1325 for any thread that we are not otherwise going to resume - this
1326 lets us preserve stopped status when two threads hit a breakpoint.
1327 GDB removes the breakpoint to single-step a particular thread
1328 past it, then re-inserts it and resumes all threads. We want
1329 to report the second thread without resuming it in the interim. */
1330 if (process
->status_pending_p
)
1331 check_removed_breakpoint (process
);
1333 if (process
->status_pending_p
)
1334 * (int *) flag_p
= 1;
1340 linux_resume (struct thread_resume
*resume_info
)
1344 /* Yes, the use of a global here is rather ugly. */
1345 resume_ptr
= resume_info
;
1347 for_each_inferior (&all_threads
, linux_set_resume_request
);
1349 /* If there is a thread which would otherwise be resumed, which
1350 has a pending status, then don't resume any threads - we can just
1351 report the pending status. Make sure to queue any signals
1352 that would otherwise be sent. */
1354 find_inferior (&all_processes
, resume_status_pending_p
, &pending_flag
);
1359 fprintf (stderr
, "Not resuming, pending status\n");
1361 fprintf (stderr
, "Resuming, no pending status\n");
1365 for_each_inferior (&all_threads
, linux_queue_one_thread
);
1367 for_each_inferior (&all_threads
, linux_continue_one_thread
);
1370 #ifdef HAVE_LINUX_USRREGS
1373 register_addr (int regnum
)
1377 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1378 error ("Invalid register number %d.", regnum
);
1380 addr
= the_low_target
.regmap
[regnum
];
1385 /* Fetch one register. */
1387 fetch_register (int regno
)
1393 if (regno
>= the_low_target
.num_regs
)
1395 if ((*the_low_target
.cannot_fetch_register
) (regno
))
1398 regaddr
= register_addr (regno
);
1401 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1402 & - sizeof (PTRACE_XFER_TYPE
);
1403 buf
= alloca (size
);
1404 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1407 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
1408 ptrace (PTRACE_PEEKUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
1409 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1412 /* Warning, not error, in case we are attached; sometimes the
1413 kernel doesn't let us at the registers. */
1414 char *err
= strerror (errno
);
1415 char *msg
= alloca (strlen (err
) + 128);
1416 sprintf (msg
, "reading register %d: %s", regno
, err
);
1422 if (the_low_target
.supply_ptrace_register
)
1423 the_low_target
.supply_ptrace_register (regno
, buf
);
1425 supply_register (regno
, buf
);
1430 /* Fetch all registers, or just one, from the child process. */
1432 usr_fetch_inferior_registers (int regno
)
1434 if (regno
== -1 || regno
== 0)
1435 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1436 fetch_register (regno
);
1438 fetch_register (regno
);
1441 /* Store our register values back into the inferior.
1442 If REGNO is -1, do this for all registers.
1443 Otherwise, REGNO specifies which register (so we can save time). */
1445 usr_store_inferior_registers (int regno
)
1453 if (regno
>= the_low_target
.num_regs
)
1456 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
1459 regaddr
= register_addr (regno
);
1463 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1464 & - sizeof (PTRACE_XFER_TYPE
);
1465 buf
= alloca (size
);
1466 memset (buf
, 0, size
);
1468 if (the_low_target
.collect_ptrace_register
)
1469 the_low_target
.collect_ptrace_register (regno
, buf
);
1471 collect_register (regno
, buf
);
1473 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
1476 ptrace (PTRACE_POKEUSER
, inferior_pid
, (PTRACE_ARG3_TYPE
) regaddr
,
1477 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
1480 /* At this point, ESRCH should mean the process is already gone,
1481 in which case we simply ignore attempts to change its registers.
1482 See also the related comment in linux_resume_one_process. */
1486 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
1488 char *err
= strerror (errno
);
1489 char *msg
= alloca (strlen (err
) + 128);
1490 sprintf (msg
, "writing register %d: %s",
1496 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
1500 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
1501 usr_store_inferior_registers (regno
);
1503 #endif /* HAVE_LINUX_USRREGS */
1507 #ifdef HAVE_LINUX_REGSETS
1510 regsets_fetch_inferior_registers ()
1512 struct regset_info
*regset
;
1513 int saw_general_regs
= 0;
1515 regset
= target_regsets
;
1517 while (regset
->size
>= 0)
1522 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1528 buf
= malloc (regset
->size
);
1530 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1532 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1538 /* If we get EIO on a regset, do not try it again for
1540 disabled_regsets
[regset
- target_regsets
] = 1;
1546 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%ld",
1551 else if (regset
->type
== GENERAL_REGS
)
1552 saw_general_regs
= 1;
1553 regset
->store_function (buf
);
1556 if (saw_general_regs
)
1563 regsets_store_inferior_registers ()
1565 struct regset_info
*regset
;
1566 int saw_general_regs
= 0;
1568 regset
= target_regsets
;
1570 while (regset
->size
>= 0)
1575 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
1581 buf
= malloc (regset
->size
);
1583 /* First fill the buffer with the current register set contents,
1584 in case there are any items in the kernel's regset that are
1585 not in gdbserver's regcache. */
1587 res
= ptrace (regset
->get_request
, inferior_pid
, 0, buf
);
1589 res
= ptrace (regset
->get_request
, inferior_pid
, buf
, 0);
1594 /* Then overlay our cached registers on that. */
1595 regset
->fill_function (buf
);
1597 /* Only now do we write the register set. */
1599 res
= ptrace (regset
->set_request
, inferior_pid
, 0, buf
);
1601 res
= ptrace (regset
->set_request
, inferior_pid
, buf
, 0);
1609 /* If we get EIO on a regset, do not try it again for
1611 disabled_regsets
[regset
- target_regsets
] = 1;
1614 else if (errno
== ESRCH
)
1616 /* At this point, ESRCH should mean the process is already gone,
1617 in which case we simply ignore attempts to change its registers.
1618 See also the related comment in linux_resume_one_process. */
1623 perror ("Warning: ptrace(regsets_store_inferior_registers)");
1626 else if (regset
->type
== GENERAL_REGS
)
1627 saw_general_regs
= 1;
1631 if (saw_general_regs
)
1638 #endif /* HAVE_LINUX_REGSETS */
1642 linux_fetch_registers (int regno
)
1644 #ifdef HAVE_LINUX_REGSETS
1645 if (regsets_fetch_inferior_registers () == 0)
1648 #ifdef HAVE_LINUX_USRREGS
1649 usr_fetch_inferior_registers (regno
);
1654 linux_store_registers (int regno
)
1656 #ifdef HAVE_LINUX_REGSETS
1657 if (regsets_store_inferior_registers () == 0)
1660 #ifdef HAVE_LINUX_USRREGS
1661 usr_store_inferior_registers (regno
);
1666 /* Copy LEN bytes from inferior's memory starting at MEMADDR
1667 to debugger memory starting at MYADDR. */
1670 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
1673 /* Round starting address down to longword boundary. */
1674 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1675 /* Round ending address up; get number of longwords that makes. */
1677 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
1678 / sizeof (PTRACE_XFER_TYPE
);
1679 /* Allocate buffer of that many longwords. */
1680 register PTRACE_XFER_TYPE
*buffer
1681 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1685 /* Try using /proc. Don't bother for one word. */
1686 if (len
>= 3 * sizeof (long))
1688 /* We could keep this file open and cache it - possibly one per
1689 thread. That requires some juggling, but is even faster. */
1690 sprintf (filename
, "/proc/%ld/mem", inferior_pid
);
1691 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
1695 /* If pread64 is available, use it. It's faster if the kernel
1696 supports it (only one syscall), and it's 64-bit safe even on
1697 32-bit platforms (for instance, SPARC debugging a SPARC64
1700 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
1702 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
1714 /* Read all the longwords */
1715 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1718 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
1723 /* Copy appropriate bytes out of the buffer. */
1724 memcpy (myaddr
, (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), len
);
1729 /* Copy LEN bytes of data from debugger memory at MYADDR
1730 to inferior's memory at MEMADDR.
1731 On failure (cannot write the inferior)
1732 returns the value of errno. */
1735 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
1738 /* Round starting address down to longword boundary. */
1739 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
1740 /* Round ending address up; get number of longwords that makes. */
1742 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
1743 /* Allocate buffer of that many longwords. */
1744 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
1748 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
1751 /* Fill start and end extra bytes of buffer with existing memory data. */
1753 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1754 (PTRACE_ARG3_TYPE
) addr
, 0);
1759 = ptrace (PTRACE_PEEKTEXT
, inferior_pid
,
1760 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
1761 * sizeof (PTRACE_XFER_TYPE
)),
1765 /* Copy data to be written over corresponding part of buffer */
1767 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
1769 /* Write the entire buffer. */
1771 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
1774 ptrace (PTRACE_POKETEXT
, inferior_pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
1782 static int linux_supports_tracefork_flag
;
1784 /* Helper functions for linux_test_for_tracefork, called via clone (). */
1787 linux_tracefork_grandchild (void *arg
)
1792 #define STACK_SIZE 4096
1795 linux_tracefork_child (void *arg
)
1797 ptrace (PTRACE_TRACEME
, 0, 0, 0);
1798 kill (getpid (), SIGSTOP
);
1800 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
1801 CLONE_VM
| SIGCHLD
, NULL
);
1803 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
1804 CLONE_VM
| SIGCHLD
, NULL
);
1809 /* Wrapper function for waitpid which handles EINTR. */
1812 my_waitpid (int pid
, int *status
, int flags
)
1817 ret
= waitpid (pid
, status
, flags
);
1819 while (ret
== -1 && errno
== EINTR
);
1824 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
1825 sure that we can enable the option, and that it had the desired
1829 linux_test_for_tracefork (void)
1831 int child_pid
, ret
, status
;
1833 char *stack
= malloc (STACK_SIZE
* 4);
1835 linux_supports_tracefork_flag
= 0;
1837 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
1839 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
1840 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1842 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
1843 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
1845 if (child_pid
== -1)
1846 perror_with_name ("clone");
1848 ret
= my_waitpid (child_pid
, &status
, 0);
1850 perror_with_name ("waitpid");
1851 else if (ret
!= child_pid
)
1852 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
1853 if (! WIFSTOPPED (status
))
1854 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
1856 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
1859 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1862 warning ("linux_test_for_tracefork: failed to kill child");
1866 ret
= my_waitpid (child_pid
, &status
, 0);
1867 if (ret
!= child_pid
)
1868 warning ("linux_test_for_tracefork: failed to wait for killed child");
1869 else if (!WIFSIGNALED (status
))
1870 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
1871 "killed child", status
);
1876 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
1878 warning ("linux_test_for_tracefork: failed to resume child");
1880 ret
= my_waitpid (child_pid
, &status
, 0);
1882 if (ret
== child_pid
&& WIFSTOPPED (status
)
1883 && status
>> 16 == PTRACE_EVENT_FORK
)
1886 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
1887 if (ret
== 0 && second_pid
!= 0)
1891 linux_supports_tracefork_flag
= 1;
1892 my_waitpid (second_pid
, &second_status
, 0);
1893 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
1895 warning ("linux_test_for_tracefork: failed to kill second child");
1896 my_waitpid (second_pid
, &status
, 0);
1900 warning ("linux_test_for_tracefork: unexpected result from waitpid "
1901 "(%d, status 0x%x)", ret
, status
);
1905 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
1907 warning ("linux_test_for_tracefork: failed to kill child");
1908 my_waitpid (child_pid
, &status
, 0);
1910 while (WIFSTOPPED (status
));
1917 linux_look_up_symbols (void)
1919 #ifdef USE_THREAD_DB
1920 if (thread_db_active
)
1923 thread_db_active
= thread_db_init (!linux_supports_tracefork_flag
);
1928 linux_request_interrupt (void)
1930 extern unsigned long signal_pid
;
1932 if (cont_thread
!= 0 && cont_thread
!= -1)
1934 struct process_info
*process
;
1936 process
= get_thread_process (current_inferior
);
1937 kill_lwp (process
->lwpid
, SIGINT
);
1940 kill_lwp (signal_pid
, SIGINT
);
1943 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
1944 to debugger memory starting at MYADDR. */
1947 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
1949 char filename
[PATH_MAX
];
1952 snprintf (filename
, sizeof filename
, "/proc/%ld/auxv", inferior_pid
);
1954 fd
= open (filename
, O_RDONLY
);
1958 if (offset
!= (CORE_ADDR
) 0
1959 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
1962 n
= read (fd
, myaddr
, len
);
1969 /* These watchpoint related wrapper functions simply pass on the function call
1970 if the target has registered a corresponding function. */
1973 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
1975 if (the_low_target
.insert_watchpoint
!= NULL
)
1976 return the_low_target
.insert_watchpoint (type
, addr
, len
);
1978 /* Unsupported (see target.h). */
1983 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
1985 if (the_low_target
.remove_watchpoint
!= NULL
)
1986 return the_low_target
.remove_watchpoint (type
, addr
, len
);
1988 /* Unsupported (see target.h). */
1993 linux_stopped_by_watchpoint (void)
1995 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
1996 return the_low_target
.stopped_by_watchpoint ();
2002 linux_stopped_data_address (void)
2004 if (the_low_target
.stopped_data_address
!= NULL
)
2005 return the_low_target
.stopped_data_address ();
2010 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2011 #if defined(__mcoldfire__)
2012 /* These should really be defined in the kernel's ptrace.h header. */
2013 #define PT_TEXT_ADDR 49*4
2014 #define PT_DATA_ADDR 50*4
2015 #define PT_TEXT_END_ADDR 51*4
2018 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2019 to tell gdb about. */
2022 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2024 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2025 unsigned long text
, text_end
, data
;
2026 int pid
= get_thread_process (current_inferior
)->head
.id
;
2030 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2031 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2032 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2036 /* Both text and data offsets produced at compile-time (and so
2037 used by gdb) are relative to the beginning of the program,
2038 with the data segment immediately following the text segment.
2039 However, the actual runtime layout in memory may put the data
2040 somewhere else, so when we send gdb a data base-address, we
2041 use the real data base address and subtract the compile-time
2042 data base-address from it (which is just the length of the
2043 text segment). BSS immediately follows data in both
2046 *data_p
= data
- (text_end
- text
);
2056 linux_qxfer_osdata (const char *annex
,
2057 unsigned char *readbuf
, unsigned const char *writebuf
,
2058 CORE_ADDR offset
, int len
)
2060 /* We make the process list snapshot when the object starts to be
2062 static const char *buf
;
2063 static long len_avail
= -1;
2064 static struct buffer buffer
;
2068 if (strcmp (annex
, "processes") != 0)
2071 if (!readbuf
|| writebuf
)
2076 if (len_avail
!= -1 && len_avail
!= 0)
2077 buffer_free (&buffer
);
2080 buffer_init (&buffer
);
2081 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2083 dirp
= opendir ("/proc");
2087 while ((dp
= readdir (dirp
)) != NULL
)
2089 struct stat statbuf
;
2090 char procentry
[sizeof ("/proc/4294967295")];
2092 if (!isdigit (dp
->d_name
[0])
2093 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2096 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2097 if (stat (procentry
, &statbuf
) == 0
2098 && S_ISDIR (statbuf
.st_mode
))
2102 char cmd
[MAXPATHLEN
+ 1];
2103 struct passwd
*entry
;
2105 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2106 entry
= getpwuid (statbuf
.st_uid
);
2108 if ((f
= fopen (pathname
, "r")) != NULL
)
2110 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2114 for (i
= 0; i
< len
; i
++)
2122 "<column name=\"pid\">%s</column>"
2123 "<column name=\"user\">%s</column>"
2124 "<column name=\"command\">%s</column>"
2127 entry
? entry
->pw_name
: "?",
2137 buffer_grow_str0 (&buffer
, "</osdata>\n");
2138 buf
= buffer_finish (&buffer
);
2139 len_avail
= strlen (buf
);
2142 if (offset
>= len_avail
)
2144 /* Done. Get rid of the data. */
2145 buffer_free (&buffer
);
2151 if (len
> len_avail
- offset
)
2152 len
= len_avail
- offset
;
2153 memcpy (readbuf
, buf
+ offset
, len
);
2158 static struct target_ops linux_target_ops
= {
2159 linux_create_inferior
,
2167 linux_fetch_registers
,
2168 linux_store_registers
,
2171 linux_look_up_symbols
,
2172 linux_request_interrupt
,
2174 linux_insert_watchpoint
,
2175 linux_remove_watchpoint
,
2176 linux_stopped_by_watchpoint
,
2177 linux_stopped_data_address
,
2178 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2183 #ifdef USE_THREAD_DB
2184 thread_db_get_tls_address
,
2189 hostio_last_error_from_errno
,
2194 linux_init_signals ()
2196 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
2197 to find what the cancel signal actually is. */
2198 signal (__SIGRTMIN
+1, SIG_IGN
);
2202 initialize_low (void)
2204 thread_db_active
= 0;
2205 set_target_ops (&linux_target_ops
);
2206 set_breakpoint_data (the_low_target
.breakpoint
,
2207 the_low_target
.breakpoint_len
);
2208 linux_init_signals ();
2209 linux_test_for_tracefork ();
2210 #ifdef HAVE_LINUX_REGSETS
2211 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
2213 disabled_regsets
= malloc (num_regsets
);