1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
22 #include "ansidecl.h" /* For ATTRIBUTE_PACKED, must be bug in external.h. */
23 #include "elf/common.h"
24 #include "elf/external.h"
28 #include <sys/param.h>
29 #include <sys/ptrace.h>
31 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
44 #ifndef PTRACE_GETSIGINFO
45 # define PTRACE_GETSIGINFO 0x4202
46 # define PTRACE_SETSIGINFO 0x4203
53 /* If the system headers did not provide the constants, hard-code the normal
55 #ifndef PTRACE_EVENT_FORK
57 #define PTRACE_SETOPTIONS 0x4200
58 #define PTRACE_GETEVENTMSG 0x4201
60 /* options set using PTRACE_SETOPTIONS */
61 #define PTRACE_O_TRACESYSGOOD 0x00000001
62 #define PTRACE_O_TRACEFORK 0x00000002
63 #define PTRACE_O_TRACEVFORK 0x00000004
64 #define PTRACE_O_TRACECLONE 0x00000008
65 #define PTRACE_O_TRACEEXEC 0x00000010
66 #define PTRACE_O_TRACEVFORKDONE 0x00000020
67 #define PTRACE_O_TRACEEXIT 0x00000040
69 /* Wait extended result codes for the above trace options. */
70 #define PTRACE_EVENT_FORK 1
71 #define PTRACE_EVENT_VFORK 2
72 #define PTRACE_EVENT_CLONE 3
73 #define PTRACE_EVENT_EXEC 4
74 #define PTRACE_EVENT_VFORK_DONE 5
75 #define PTRACE_EVENT_EXIT 6
77 #endif /* PTRACE_EVENT_FORK */
79 /* We can't always assume that this flag is available, but all systems
80 with the ptrace event handlers also have __WALL, so it's safe to use
83 #define __WALL 0x40000000 /* Wait for any child. */
87 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
92 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
93 representation of the thread ID.
95 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
96 the same as the LWP ID.
98 ``all_processes'' is keyed by the "overall process ID", which
99 GNU/Linux calls tgid, "thread group ID". */
101 struct inferior_list all_lwps
;
103 /* A list of all unknown processes which receive stop signals. Some other
104 process will presumably claim each of these as forked children
107 struct inferior_list stopped_pids
;
109 /* FIXME this is a bit of a hack, and could be removed. */
110 int stopping_threads
;
112 /* FIXME make into a target method? */
113 int using_threads
= 1;
115 /* This flag is true iff we've just created or attached to our first
116 inferior but it has not stopped yet. As soon as it does, we need
117 to call the low target's arch_setup callback. Doing this only on
118 the first inferior avoids reinializing the architecture on every
119 inferior, and avoids messing with the register caches of the
120 already running inferiors. NOTE: this assumes all inferiors under
121 control of gdbserver have the same architecture. */
122 static int new_inferior
;
124 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
125 int step
, int signal
, siginfo_t
*info
);
126 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
127 static void stop_all_lwps (void);
128 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
129 static int check_removed_breakpoint (struct lwp_info
*event_child
);
130 static void *add_lwp (ptid_t ptid
);
131 static int my_waitpid (int pid
, int *status
, int flags
);
132 static int linux_stopped_by_watchpoint (void);
133 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
135 struct pending_signals
139 struct pending_signals
*prev
;
142 #define PTRACE_ARG3_TYPE long
143 #define PTRACE_XFER_TYPE long
145 #ifdef HAVE_LINUX_REGSETS
146 static char *disabled_regsets
;
147 static int num_regsets
;
150 /* The read/write ends of the pipe registered as waitable file in the
152 static int linux_event_pipe
[2] = { -1, -1 };
154 /* True if we're currently in async mode. */
155 #define target_is_async_p() (linux_event_pipe[0] != -1)
157 static void send_sigstop (struct inferior_list_entry
*entry
);
158 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
160 /* Accepts an integer PID; Returns a string representing a file that
161 can be opened to get info for the child process.
162 Space for the result is malloc'd, caller must free. */
165 linux_child_pid_to_exec_file (int pid
)
169 name1
= xmalloc (MAXPATHLEN
);
170 name2
= xmalloc (MAXPATHLEN
);
171 memset (name2
, 0, MAXPATHLEN
);
173 sprintf (name1
, "/proc/%d/exe", pid
);
174 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
186 /* Return non-zero if HEADER is a 64-bit ELF file. */
189 elf_64_header_p (const Elf64_External_Ehdr
*header
)
191 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
192 && header
->e_ident
[EI_MAG1
] == ELFMAG1
193 && header
->e_ident
[EI_MAG2
] == ELFMAG2
194 && header
->e_ident
[EI_MAG3
] == ELFMAG3
195 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
198 /* Return non-zero if FILE is a 64-bit ELF file,
199 zero if the file is not a 64-bit ELF file,
200 and -1 if the file is not accessible or doesn't exist. */
203 elf_64_file_p (const char *file
)
205 Elf64_External_Ehdr header
;
208 fd
= open (file
, O_RDONLY
);
212 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
219 return elf_64_header_p (&header
);
223 delete_lwp (struct lwp_info
*lwp
)
225 remove_thread (get_lwp_thread (lwp
));
226 remove_inferior (&all_lwps
, &lwp
->head
);
230 /* Add a process to the common process list, and set its private
233 static struct process_info
*
234 linux_add_process (int pid
, int attached
)
236 struct process_info
*proc
;
238 /* Is this the first process? If so, then set the arch. */
239 if (all_processes
.head
== NULL
)
242 proc
= add_process (pid
, attached
);
243 proc
->private = xcalloc (1, sizeof (*proc
->private));
248 /* Remove a process from the common process list,
249 also freeing all private data. */
252 linux_remove_process (struct process_info
*process
)
254 free (process
->private);
255 remove_process (process
);
258 /* Handle a GNU/Linux extended wait response. If we see a clone
259 event, we need to add the new LWP to our list (and not report the
260 trap to higher layers). */
263 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
265 int event
= wstat
>> 16;
266 struct lwp_info
*new_lwp
;
268 if (event
== PTRACE_EVENT_CLONE
)
271 unsigned long new_pid
;
272 int ret
, status
= W_STOPCODE (SIGSTOP
);
274 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
276 /* If we haven't already seen the new PID stop, wait for it now. */
277 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
279 /* The new child has a pending SIGSTOP. We can't affect it until it
280 hits the SIGSTOP, but we're already attached. */
282 ret
= my_waitpid (new_pid
, &status
, __WALL
);
285 perror_with_name ("waiting for new child");
286 else if (ret
!= new_pid
)
287 warning ("wait returned unexpected PID %d", ret
);
288 else if (!WIFSTOPPED (status
))
289 warning ("wait returned unexpected status 0x%x", status
);
292 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, PTRACE_O_TRACECLONE
);
294 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
295 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
296 add_thread (ptid
, new_lwp
);
298 /* Normally we will get the pending SIGSTOP. But in some cases
299 we might get another signal delivered to the group first.
300 If we do get another signal, be sure not to lose it. */
301 if (WSTOPSIG (status
) == SIGSTOP
)
303 if (stopping_threads
)
304 new_lwp
->stopped
= 1;
306 ptrace (PTRACE_CONT
, new_pid
, 0, 0);
310 new_lwp
->stop_expected
= 1;
311 if (stopping_threads
)
313 new_lwp
->stopped
= 1;
314 new_lwp
->status_pending_p
= 1;
315 new_lwp
->status_pending
= status
;
318 /* Pass the signal on. This is what GDB does - except
319 shouldn't we really report it instead? */
320 ptrace (PTRACE_CONT
, new_pid
, 0, WSTOPSIG (status
));
323 /* Always resume the current thread. If we are stopping
324 threads, it will have a pending SIGSTOP; we may as well
326 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
330 /* This function should only be called if the process got a SIGTRAP.
331 The SIGTRAP could mean several things.
333 On i386, where decr_pc_after_break is non-zero:
334 If we were single-stepping this process using PTRACE_SINGLESTEP,
335 we will get only the one SIGTRAP (even if the instruction we
336 stepped over was a breakpoint). The value of $eip will be the
338 If we continue the process using PTRACE_CONT, we will get a
339 SIGTRAP when we hit a breakpoint. The value of $eip will be
340 the instruction after the breakpoint (i.e. needs to be
341 decremented). If we report the SIGTRAP to GDB, we must also
342 report the undecremented PC. If we cancel the SIGTRAP, we
343 must resume at the decremented PC.
345 (Presumably, not yet tested) On a non-decr_pc_after_break machine
346 with hardware or kernel single-step:
347 If we single-step over a breakpoint instruction, our PC will
348 point at the following instruction. If we continue and hit a
349 breakpoint instruction, our PC will point at the breakpoint
355 CORE_ADDR stop_pc
= (*the_low_target
.get_pc
) ();
357 if (! get_thread_lwp (current_inferior
)->stepping
)
358 stop_pc
-= the_low_target
.decr_pc_after_break
;
361 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
367 add_lwp (ptid_t ptid
)
369 struct lwp_info
*lwp
;
371 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
372 memset (lwp
, 0, sizeof (*lwp
));
376 add_inferior_to_list (&all_lwps
, &lwp
->head
);
381 /* Start an inferior process and returns its pid.
382 ALLARGS is a vector of program-name and args. */
385 linux_create_inferior (char *program
, char **allargs
)
387 struct lwp_info
*new_lwp
;
391 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
397 perror_with_name ("fork");
401 ptrace (PTRACE_TRACEME
, 0, 0, 0);
403 signal (__SIGRTMIN
+ 1, SIG_DFL
);
407 execv (program
, allargs
);
409 execvp (program
, allargs
);
411 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
417 linux_add_process (pid
, 0);
419 ptid
= ptid_build (pid
, pid
, 0);
420 new_lwp
= add_lwp (ptid
);
421 add_thread (ptid
, new_lwp
);
422 new_lwp
->must_set_ptrace_flags
= 1;
427 /* Attach to an inferior process. */
430 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
433 struct lwp_info
*new_lwp
;
435 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
439 /* If we fail to attach to an LWP, just warn. */
440 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
441 strerror (errno
), errno
);
446 /* If we fail to attach to a process, report an error. */
447 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
448 strerror (errno
), errno
);
452 /* NOTE/FIXME: This lwp might have not been the tgid. */
453 ptid
= ptid_build (lwpid
, lwpid
, 0);
456 /* Note that extracting the pid from the current inferior is
457 safe, since we're always called in the context of the same
458 process as this new thread. */
459 int pid
= pid_of (get_thread_lwp (current_inferior
));
460 ptid
= ptid_build (pid
, lwpid
, 0);
463 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
464 add_thread (ptid
, new_lwp
);
467 /* We need to wait for SIGSTOP before being able to make the next
468 ptrace call on this LWP. */
469 new_lwp
->must_set_ptrace_flags
= 1;
471 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
474 There are several cases to consider here:
476 1) gdbserver has already attached to the process and is being notified
477 of a new thread that is being created.
478 In this case we should ignore that SIGSTOP and resume the process.
479 This is handled below by setting stop_expected = 1.
481 2) This is the first thread (the process thread), and we're attaching
482 to it via attach_inferior.
483 In this case we want the process thread to stop.
484 This is handled by having linux_attach clear stop_expected after
486 ??? If the process already has several threads we leave the other
489 3) GDB is connecting to gdbserver and is requesting an enumeration of all
491 In this case we want the thread to stop.
492 FIXME: This case is currently not properly handled.
493 We should wait for the SIGSTOP but don't. Things work apparently
494 because enough time passes between when we ptrace (ATTACH) and when
495 gdb makes the next ptrace call on the thread.
497 On the other hand, if we are currently trying to stop all threads, we
498 should treat the new thread as if we had sent it a SIGSTOP. This works
499 because we are guaranteed that the add_lwp call above added us to the
500 end of the list, and so the new thread has not yet reached
501 wait_for_sigstop (but will). */
502 if (! stopping_threads
)
503 new_lwp
->stop_expected
= 1;
507 linux_attach_lwp (unsigned long lwpid
)
509 linux_attach_lwp_1 (lwpid
, 0);
513 linux_attach (unsigned long pid
)
515 struct lwp_info
*lwp
;
517 linux_attach_lwp_1 (pid
, 1);
519 linux_add_process (pid
, 1);
523 /* Don't ignore the initial SIGSTOP if we just attached to this
524 process. It will be collected by wait shortly. */
525 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
526 ptid_build (pid
, pid
, 0));
527 lwp
->stop_expected
= 0;
540 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
542 struct counter
*counter
= args
;
544 if (ptid_get_pid (entry
->id
) == counter
->pid
)
546 if (++counter
->count
> 1)
554 last_thread_of_process_p (struct thread_info
*thread
)
556 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
557 int pid
= ptid_get_pid (ptid
);
558 struct counter counter
= { pid
, 0 };
560 return (find_inferior (&all_threads
,
561 second_thread_of_pid_p
, &counter
) == NULL
);
564 /* Kill the inferior lwp. */
567 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
569 struct thread_info
*thread
= (struct thread_info
*) entry
;
570 struct lwp_info
*lwp
= get_thread_lwp (thread
);
572 int pid
= * (int *) args
;
574 if (ptid_get_pid (entry
->id
) != pid
)
577 /* We avoid killing the first thread here, because of a Linux kernel (at
578 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
579 the children get a chance to be reaped, it will remain a zombie
582 if (last_thread_of_process_p (thread
))
585 fprintf (stderr
, "lkop: is last of process %s\n",
586 target_pid_to_str (entry
->id
));
590 /* If we're killing a running inferior, make sure it is stopped
591 first, as PTRACE_KILL will not work otherwise. */
593 send_sigstop (&lwp
->head
);
597 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
599 /* Make sure it died. The loop is most likely unnecessary. */
600 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
601 } while (pid
> 0 && WIFSTOPPED (wstat
));
609 struct process_info
*process
;
610 struct lwp_info
*lwp
;
611 struct thread_info
*thread
;
615 process
= find_process_pid (pid
);
619 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
621 /* See the comment in linux_kill_one_lwp. We did not kill the first
622 thread in the list, so do so now. */
623 lwp
= find_lwp_pid (pid_to_ptid (pid
));
624 thread
= get_lwp_thread (lwp
);
627 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
628 lwpid_of (lwp
), pid
);
630 /* If we're killing a running inferior, make sure it is stopped
631 first, as PTRACE_KILL will not work otherwise. */
633 send_sigstop (&lwp
->head
);
637 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
639 /* Make sure it died. The loop is most likely unnecessary. */
640 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
641 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
644 linux_remove_process (process
);
649 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
651 struct thread_info
*thread
= (struct thread_info
*) entry
;
652 struct lwp_info
*lwp
= get_thread_lwp (thread
);
653 int pid
= * (int *) args
;
655 if (ptid_get_pid (entry
->id
) != pid
)
658 /* If we're detaching from a running inferior, make sure it is
659 stopped first, as PTRACE_DETACH will not work otherwise. */
662 int lwpid
= lwpid_of (lwp
);
664 stopping_threads
= 1;
665 send_sigstop (&lwp
->head
);
667 /* If this detects a new thread through a clone event, the new
668 thread is appended to the end of the lwp list, so we'll
669 eventually detach from it. */
670 wait_for_sigstop (&lwp
->head
);
671 stopping_threads
= 0;
673 /* If LWP exits while we're trying to stop it, there's nothing
675 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
680 /* Make sure the process isn't stopped at a breakpoint that's
682 check_removed_breakpoint (lwp
);
684 /* If this process is stopped but is expecting a SIGSTOP, then make
685 sure we take care of that now. This isn't absolutely guaranteed
686 to collect the SIGSTOP, but is fairly likely to. */
687 if (lwp
->stop_expected
)
690 /* Clear stop_expected, so that the SIGSTOP will be reported. */
691 lwp
->stop_expected
= 0;
693 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
694 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
697 /* Flush any pending changes to the process's registers. */
698 regcache_invalidate_one ((struct inferior_list_entry
*)
699 get_lwp_thread (lwp
));
701 /* Finally, let it resume. */
702 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
709 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
713 if (ptid_get_pid (entry
->id
) == *pid_p
)
720 linux_detach (int pid
)
722 struct process_info
*process
;
724 process
= find_process_pid (pid
);
729 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
731 delete_all_breakpoints ();
732 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
733 linux_remove_process (process
);
741 struct process_info
*process
;
743 process
= find_process_pid (pid
);
748 ret
= my_waitpid (pid
, &status
, 0);
749 if (WIFEXITED (status
) || WIFSIGNALED (status
))
751 } while (ret
!= -1 || errno
!= ECHILD
);
754 /* Return nonzero if the given thread is still alive. */
756 linux_thread_alive (ptid_t ptid
)
758 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
760 /* We assume we always know if a thread exits. If a whole process
761 exited but we still haven't been able to report it to GDB, we'll
762 hold on to the last lwp of the dead process. */
769 /* Return nonzero if this process stopped at a breakpoint which
770 no longer appears to be inserted. Also adjust the PC
771 appropriately to resume where the breakpoint used to be. */
773 check_removed_breakpoint (struct lwp_info
*event_child
)
776 struct thread_info
*saved_inferior
;
778 if (event_child
->pending_is_breakpoint
== 0)
782 fprintf (stderr
, "Checking for breakpoint in lwp %ld.\n",
783 lwpid_of (event_child
));
785 saved_inferior
= current_inferior
;
786 current_inferior
= get_lwp_thread (event_child
);
788 stop_pc
= get_stop_pc ();
790 /* If the PC has changed since we stopped, then we shouldn't do
791 anything. This happens if, for instance, GDB handled the
792 decr_pc_after_break subtraction itself. */
793 if (stop_pc
!= event_child
->pending_stop_pc
)
796 fprintf (stderr
, "Ignoring, PC was changed. Old PC was 0x%08llx\n",
797 event_child
->pending_stop_pc
);
799 event_child
->pending_is_breakpoint
= 0;
800 current_inferior
= saved_inferior
;
804 /* If the breakpoint is still there, we will report hitting it. */
805 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
808 fprintf (stderr
, "Ignoring, breakpoint is still present.\n");
809 current_inferior
= saved_inferior
;
814 fprintf (stderr
, "Removed breakpoint.\n");
816 /* For decr_pc_after_break targets, here is where we perform the
817 decrement. We go immediately from this function to resuming,
818 and can not safely call get_stop_pc () again. */
819 if (the_low_target
.set_pc
!= NULL
)
822 fprintf (stderr
, "Set pc to 0x%lx\n", (long) stop_pc
);
823 (*the_low_target
.set_pc
) (stop_pc
);
826 /* We consumed the pending SIGTRAP. */
827 event_child
->pending_is_breakpoint
= 0;
828 event_child
->status_pending_p
= 0;
829 event_child
->status_pending
= 0;
831 current_inferior
= saved_inferior
;
835 /* Return 1 if this lwp has an interesting status pending. This
836 function may silently resume an inferior lwp. */
838 status_pending_p (struct inferior_list_entry
*entry
, void *arg
)
840 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
841 ptid_t ptid
= * (ptid_t
*) arg
;
843 /* Check if we're only interested in events from a specific process
845 if (!ptid_equal (minus_one_ptid
, ptid
)
846 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
849 if (lwp
->status_pending_p
&& !lwp
->suspended
)
850 if (check_removed_breakpoint (lwp
))
852 /* This thread was stopped at a breakpoint, and the breakpoint
853 is now gone. We were told to continue (or step...) all threads,
854 so GDB isn't trying to single-step past this breakpoint.
855 So instead of reporting the old SIGTRAP, pretend we got to
856 the breakpoint just after it was removed instead of just
857 before; resume the process. */
858 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
862 return (lwp
->status_pending_p
&& !lwp
->suspended
);
866 same_lwp (struct inferior_list_entry
*entry
, void *data
)
868 ptid_t ptid
= *(ptid_t
*) data
;
871 if (ptid_get_lwp (ptid
) != 0)
872 lwp
= ptid_get_lwp (ptid
);
874 lwp
= ptid_get_pid (ptid
);
876 if (ptid_get_lwp (entry
->id
) == lwp
)
883 find_lwp_pid (ptid_t ptid
)
885 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
888 static struct lwp_info
*
889 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
892 int to_wait_for
= -1;
893 struct lwp_info
*child
= NULL
;
896 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
898 if (ptid_equal (ptid
, minus_one_ptid
))
899 to_wait_for
= -1; /* any child */
901 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
907 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
908 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
911 perror_with_name ("waitpid");
914 && (!WIFSTOPPED (*wstatp
)
915 || (WSTOPSIG (*wstatp
) != 32
916 && WSTOPSIG (*wstatp
) != 33)))
917 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
919 child
= find_lwp_pid (pid_to_ptid (ret
));
921 /* If we didn't find a process, one of two things presumably happened:
922 - A process we started and then detached from has exited. Ignore it.
923 - A process we are controlling has forked and the new child's stop
924 was reported to us by the kernel. Save its PID. */
925 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
927 add_pid_to_list (&stopped_pids
, ret
);
930 else if (child
== NULL
)
934 child
->pending_is_breakpoint
= 0;
936 child
->last_status
= *wstatp
;
938 /* Architecture-specific setup after inferior is running.
939 This needs to happen after we have attached to the inferior
940 and it is stopped for the first time, but before we access
941 any inferior registers. */
944 the_low_target
.arch_setup ();
945 #ifdef HAVE_LINUX_REGSETS
946 memset (disabled_regsets
, 0, num_regsets
);
952 && WIFSTOPPED (*wstatp
)
953 && the_low_target
.get_pc
!= NULL
)
955 struct thread_info
*saved_inferior
= current_inferior
;
958 current_inferior
= (struct thread_info
*)
959 find_inferior_id (&all_threads
, child
->head
.id
);
960 pc
= (*the_low_target
.get_pc
) ();
961 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
962 current_inferior
= saved_inferior
;
968 /* Wait for an event from child PID. If PID is -1, wait for any
969 child. Store the stop status through the status pointer WSTAT.
970 OPTIONS is passed to the waitpid call. Return 0 if no child stop
971 event was found and OPTIONS contains WNOHANG. Return the PID of
972 the stopped child otherwise. */
975 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
978 struct lwp_info
*event_child
= NULL
;
980 struct lwp_info
*requested_child
= NULL
;
982 /* Check for a lwp with a pending status. */
983 /* It is possible that the user changed the pending task's registers since
984 it stopped. We correctly handle the change of PC if we hit a breakpoint
985 (in check_removed_breakpoint); signals should be reported anyway. */
987 if (ptid_equal (ptid
, minus_one_ptid
)
988 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
990 event_child
= (struct lwp_info
*)
991 find_inferior (&all_lwps
, status_pending_p
, &ptid
);
992 if (debug_threads
&& event_child
)
993 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
997 requested_child
= find_lwp_pid (ptid
);
998 if (requested_child
->status_pending_p
999 && !check_removed_breakpoint (requested_child
))
1000 event_child
= requested_child
;
1003 if (event_child
!= NULL
)
1006 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1007 lwpid_of (event_child
), event_child
->status_pending
);
1008 *wstat
= event_child
->status_pending
;
1009 event_child
->status_pending_p
= 0;
1010 event_child
->status_pending
= 0;
1011 current_inferior
= get_lwp_thread (event_child
);
1012 return lwpid_of (event_child
);
1015 /* We only enter this loop if no process has a pending wait status. Thus
1016 any action taken in response to a wait status inside this loop is
1017 responding as soon as we detect the status, not after any pending
1021 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1023 if ((options
& WNOHANG
) && event_child
== NULL
)
1026 if (event_child
== NULL
)
1027 error ("event from unknown child");
1029 current_inferior
= get_lwp_thread (event_child
);
1031 /* Check for thread exit. */
1032 if (! WIFSTOPPED (*wstat
))
1035 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1037 /* If the last thread is exiting, just return. */
1038 if (last_thread_of_process_p (current_inferior
))
1041 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1042 lwpid_of (event_child
));
1043 return lwpid_of (event_child
);
1046 delete_lwp (event_child
);
1050 current_inferior
= (struct thread_info
*) all_threads
.head
;
1052 fprintf (stderr
, "Current inferior is now %ld\n",
1053 lwpid_of (get_thread_lwp (current_inferior
)));
1057 current_inferior
= NULL
;
1059 fprintf (stderr
, "Current inferior is now <NULL>\n");
1062 /* If we were waiting for this particular child to do something...
1063 well, it did something. */
1064 if (requested_child
!= NULL
)
1065 return lwpid_of (event_child
);
1067 /* Wait for a more interesting event. */
1071 if (event_child
->must_set_ptrace_flags
)
1073 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1074 0, PTRACE_O_TRACECLONE
);
1075 event_child
->must_set_ptrace_flags
= 0;
1078 if (WIFSTOPPED (*wstat
)
1079 && WSTOPSIG (*wstat
) == SIGSTOP
1080 && event_child
->stop_expected
)
1083 fprintf (stderr
, "Expected stop.\n");
1084 event_child
->stop_expected
= 0;
1085 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
1089 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1090 && *wstat
>> 16 != 0)
1092 handle_extended_wait (event_child
, *wstat
);
1096 /* If GDB is not interested in this signal, don't stop other
1097 threads, and don't report it to GDB. Just resume the
1098 inferior right away. We do this for threading-related
1099 signals as well as any that GDB specifically requested we
1100 ignore. But never ignore SIGSTOP if we sent it ourselves,
1101 and do not ignore signals when stepping - they may require
1102 special handling to skip the signal handler. */
1103 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1105 if (WIFSTOPPED (*wstat
)
1106 && !event_child
->stepping
1108 #ifdef USE_THREAD_DB
1109 (current_process ()->private->thread_db_active
1110 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1111 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1114 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1115 && (WSTOPSIG (*wstat
) != SIGSTOP
|| !stopping_threads
))))
1117 siginfo_t info
, *info_p
;
1120 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1121 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1123 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1127 linux_resume_one_lwp (event_child
,
1128 event_child
->stepping
,
1129 WSTOPSIG (*wstat
), info_p
);
1133 /* If this event was not handled above, and is not a SIGTRAP, report
1135 if (!WIFSTOPPED (*wstat
) || WSTOPSIG (*wstat
) != SIGTRAP
)
1136 return lwpid_of (event_child
);
1138 /* If this target does not support breakpoints, we simply report the
1139 SIGTRAP; it's of no concern to us. */
1140 if (the_low_target
.get_pc
== NULL
)
1141 return lwpid_of (event_child
);
1143 stop_pc
= get_stop_pc ();
1145 /* bp_reinsert will only be set if we were single-stepping.
1146 Notice that we will resume the process after hitting
1147 a gdbserver breakpoint; single-stepping to/over one
1148 is not supported (yet). */
1149 if (event_child
->bp_reinsert
!= 0)
1152 fprintf (stderr
, "Reinserted breakpoint.\n");
1153 reinsert_breakpoint (event_child
->bp_reinsert
);
1154 event_child
->bp_reinsert
= 0;
1156 /* Clear the single-stepping flag and SIGTRAP as we resume. */
1157 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1161 bp_status
= check_breakpoints (stop_pc
);
1166 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1168 /* We hit one of our own breakpoints. We mark it as a pending
1169 breakpoint, so that check_removed_breakpoint () will do the PC
1170 adjustment for us at the appropriate time. */
1171 event_child
->pending_is_breakpoint
= 1;
1172 event_child
->pending_stop_pc
= stop_pc
;
1174 /* We may need to put the breakpoint back. We continue in the event
1175 loop instead of simply replacing the breakpoint right away,
1176 in order to not lose signals sent to the thread that hit the
1177 breakpoint. Unfortunately this increases the window where another
1178 thread could sneak past the removed breakpoint. For the current
1179 use of server-side breakpoints (thread creation) this is
1180 acceptable; but it needs to be considered before this breakpoint
1181 mechanism can be used in more general ways. For some breakpoints
1182 it may be necessary to stop all other threads, but that should
1183 be avoided where possible.
1185 If breakpoint_reinsert_addr is NULL, that means that we can
1186 use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint,
1187 mark it for reinsertion, and single-step.
1189 Otherwise, call the target function to figure out where we need
1190 our temporary breakpoint, create it, and continue executing this
1193 /* NOTE: we're lifting breakpoints in non-stop mode. This
1194 is currently only used for thread event breakpoints, so
1195 it isn't that bad as long as we have PTRACE_EVENT_CLONE
1198 /* No need to reinsert. */
1199 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1200 else if (the_low_target
.breakpoint_reinsert_addr
== NULL
)
1202 event_child
->bp_reinsert
= stop_pc
;
1203 uninsert_breakpoint (stop_pc
);
1204 linux_resume_one_lwp (event_child
, 1, 0, NULL
);
1208 reinsert_breakpoint_by_bp
1209 (stop_pc
, (*the_low_target
.breakpoint_reinsert_addr
) ());
1210 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
1217 fprintf (stderr
, "Hit a non-gdbserver breakpoint.\n");
1219 /* If we were single-stepping, we definitely want to report the
1220 SIGTRAP. Although the single-step operation has completed,
1221 do not clear clear the stepping flag yet; we need to check it
1222 in wait_for_sigstop. */
1223 if (event_child
->stepping
)
1224 return lwpid_of (event_child
);
1226 /* A SIGTRAP that we can't explain. It may have been a breakpoint.
1227 Check if it is a breakpoint, and if so mark the process information
1228 accordingly. This will handle both the necessary fiddling with the
1229 PC on decr_pc_after_break targets and suppressing extra threads
1230 hitting a breakpoint if two hit it at once and then GDB removes it
1231 after the first is reported. Arguably it would be better to report
1232 multiple threads hitting breakpoints simultaneously, but the current
1233 remote protocol does not allow this. */
1234 if ((*the_low_target
.breakpoint_at
) (stop_pc
))
1236 event_child
->pending_is_breakpoint
= 1;
1237 event_child
->pending_stop_pc
= stop_pc
;
1240 return lwpid_of (event_child
);
1248 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1252 if (ptid_is_pid (ptid
))
1254 /* A request to wait for a specific tgid. This is not possible
1255 with waitpid, so instead, we wait for any child, and leave
1256 children we're not interested in right now with a pending
1257 status to report later. */
1258 wait_ptid
= minus_one_ptid
;
1267 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1270 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1272 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1274 if (! WIFSTOPPED (*wstat
))
1275 mark_lwp_dead (event_child
, *wstat
);
1278 event_child
->status_pending_p
= 1;
1279 event_child
->status_pending
= *wstat
;
1287 /* Wait for process, returns status. */
1290 linux_wait_1 (ptid_t ptid
,
1291 struct target_waitstatus
*ourstatus
, int target_options
)
1294 struct thread_info
*thread
= NULL
;
1295 struct lwp_info
*lwp
= NULL
;
1299 /* Translate generic target options into linux options. */
1301 if (target_options
& TARGET_WNOHANG
)
1305 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1307 /* If we were only supposed to resume one thread, only wait for
1308 that thread - if it's still alive. If it died, however - which
1309 can happen if we're coming from the thread death case below -
1310 then we need to make sure we restart the other threads. We could
1311 pick a thread at random or restart all; restarting all is less
1314 && !ptid_equal (cont_thread
, null_ptid
)
1315 && !ptid_equal (cont_thread
, minus_one_ptid
))
1317 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1320 /* No stepping, no signal - unless one is pending already, of course. */
1323 struct thread_resume resume_info
;
1324 resume_info
.thread
= minus_one_ptid
;
1325 resume_info
.kind
= resume_continue
;
1326 resume_info
.sig
= 0;
1327 linux_resume (&resume_info
, 1);
1333 pid
= linux_wait_for_event (ptid
, &w
, options
);
1334 if (pid
== 0) /* only if TARGET_WNOHANG */
1337 lwp
= get_thread_lwp (current_inferior
);
1339 /* If we are waiting for a particular child, and it exited,
1340 linux_wait_for_event will return its exit status. Similarly if
1341 the last child exited. If this is not the last child, however,
1342 do not report it as exited until there is a 'thread exited' response
1343 available in the remote protocol. Instead, just wait for another event.
1344 This should be safe, because if the thread crashed we will already
1345 have reported the termination signal to GDB; that should stop any
1346 in-progress stepping operations, etc.
1348 Report the exit status of the last thread to exit. This matches
1349 LinuxThreads' behavior. */
1351 if (last_thread_of_process_p (current_inferior
))
1353 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1355 int pid
= pid_of (lwp
);
1356 struct process_info
*process
= find_process_pid (pid
);
1359 linux_remove_process (process
);
1361 current_inferior
= NULL
;
1365 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1366 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1369 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1373 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1374 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1377 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1381 return pid_to_ptid (pid
);
1386 if (!WIFSTOPPED (w
))
1390 /* In all-stop, stop all threads. Be careful to only do this if
1391 we're about to report an event to GDB. */
1395 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1397 if (lwp
->suspended
&& WSTOPSIG (w
) == SIGSTOP
)
1399 /* A thread that has been requested to stop by GDB with vCont;t,
1400 and it stopped cleanly, so report as SIG0. The use of
1401 SIGSTOP is an implementation detail. */
1402 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1404 else if (lwp
->suspended
&& WSTOPSIG (w
) != SIGSTOP
)
1406 /* A thread that has been requested to stop by GDB with vCont;t,
1407 but, it stopped for other reasons. Set stop_expected so the
1408 pending SIGSTOP is ignored and the LWP is resumed. */
1409 lwp
->stop_expected
= 1;
1410 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1414 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1418 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1419 target_pid_to_str (lwp
->head
.id
),
1421 ourstatus
->value
.sig
);
1423 return lwp
->head
.id
;
1426 /* Get rid of any pending event in the pipe. */
1428 async_file_flush (void)
1434 ret
= read (linux_event_pipe
[0], &buf
, 1);
1435 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1438 /* Put something in the pipe, so the event loop wakes up. */
1440 async_file_mark (void)
1444 async_file_flush ();
1447 ret
= write (linux_event_pipe
[1], "+", 1);
1448 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1450 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1451 be awakened anyway. */
1455 linux_wait (ptid_t ptid
,
1456 struct target_waitstatus
*ourstatus
, int target_options
)
1461 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1463 /* Flush the async file first. */
1464 if (target_is_async_p ())
1465 async_file_flush ();
1467 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1469 /* If at least one stop was reported, there may be more. A single
1470 SIGCHLD can signal more than one child stop. */
1471 if (target_is_async_p ()
1472 && (target_options
& TARGET_WNOHANG
) != 0
1473 && !ptid_equal (event_ptid
, null_ptid
))
1479 /* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
1480 thread groups are in use, we need to use tkill. */
1483 kill_lwp (unsigned long lwpid
, int signo
)
1485 static int tkill_failed
;
1492 int ret
= syscall (SYS_tkill
, lwpid
, signo
);
1493 if (errno
!= ENOSYS
)
1500 return kill (lwpid
, signo
);
1504 send_sigstop (struct inferior_list_entry
*entry
)
1506 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1512 pid
= lwpid_of (lwp
);
1514 /* If we already have a pending stop signal for this process, don't
1516 if (lwp
->stop_expected
)
1519 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
1521 /* We clear the stop_expected flag so that wait_for_sigstop
1522 will receive the SIGSTOP event (instead of silently resuming and
1523 waiting again). It'll be reset below. */
1524 lwp
->stop_expected
= 0;
1529 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
1531 kill_lwp (pid
, SIGSTOP
);
1535 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
1537 /* It's dead, really. */
1540 /* Store the exit status for later. */
1541 lwp
->status_pending_p
= 1;
1542 lwp
->status_pending
= wstat
;
1544 /* So that check_removed_breakpoint doesn't try to figure out if
1545 this is stopped at a breakpoint. */
1546 lwp
->pending_is_breakpoint
= 0;
1548 /* Prevent trying to stop it. */
1551 /* No further stops are expected from a dead lwp. */
1552 lwp
->stop_expected
= 0;
1556 wait_for_sigstop (struct inferior_list_entry
*entry
)
1558 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1559 struct thread_info
*saved_inferior
;
1567 saved_inferior
= current_inferior
;
1568 if (saved_inferior
!= NULL
)
1569 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
1571 saved_tid
= null_ptid
; /* avoid bogus unused warning */
1573 ptid
= lwp
->head
.id
;
1575 linux_wait_for_event (ptid
, &wstat
, __WALL
);
1577 /* If we stopped with a non-SIGSTOP signal, save it for later
1578 and record the pending SIGSTOP. If the process exited, just
1580 if (WIFSTOPPED (wstat
)
1581 && WSTOPSIG (wstat
) != SIGSTOP
)
1584 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
1585 lwpid_of (lwp
), wstat
);
1587 /* Do not leave a pending single-step finish to be reported to
1588 the client. The client will give us a new action for this
1589 thread, possibly a continue request --- otherwise, the client
1590 would consider this pending SIGTRAP reported later a spurious
1592 if (WSTOPSIG (wstat
) == SIGTRAP
1594 && !linux_stopped_by_watchpoint ())
1597 fprintf (stderr
, " single-step SIGTRAP ignored\n");
1601 lwp
->status_pending_p
= 1;
1602 lwp
->status_pending
= wstat
;
1604 lwp
->stop_expected
= 1;
1606 else if (!WIFSTOPPED (wstat
))
1609 fprintf (stderr
, "Process %ld exited while stopping LWPs\n",
1612 /* Leave this status pending for the next time we're able to
1613 report it. In the mean time, we'll report this lwp as dead
1614 to GDB, so GDB doesn't try to read registers and memory from
1616 mark_lwp_dead (lwp
, wstat
);
1619 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
1620 current_inferior
= saved_inferior
;
1624 fprintf (stderr
, "Previously current thread died.\n");
1628 /* We can't change the current inferior behind GDB's back,
1629 otherwise, a subsequent command may apply to the wrong
1631 current_inferior
= NULL
;
1635 /* Set a valid thread as current. */
1636 set_desired_inferior (0);
1642 stop_all_lwps (void)
1644 stopping_threads
= 1;
1645 for_each_inferior (&all_lwps
, send_sigstop
);
1646 for_each_inferior (&all_lwps
, wait_for_sigstop
);
1647 stopping_threads
= 0;
1650 /* Resume execution of the inferior process.
1651 If STEP is nonzero, single-step it.
1652 If SIGNAL is nonzero, give it that signal. */
1655 linux_resume_one_lwp (struct lwp_info
*lwp
,
1656 int step
, int signal
, siginfo_t
*info
)
1658 struct thread_info
*saved_inferior
;
1660 if (lwp
->stopped
== 0)
1663 /* If we have pending signals or status, and a new signal, enqueue the
1664 signal. Also enqueue the signal if we are waiting to reinsert a
1665 breakpoint; it will be picked up again below. */
1667 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
1668 || lwp
->bp_reinsert
!= 0))
1670 struct pending_signals
*p_sig
;
1671 p_sig
= xmalloc (sizeof (*p_sig
));
1672 p_sig
->prev
= lwp
->pending_signals
;
1673 p_sig
->signal
= signal
;
1675 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1677 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
1678 lwp
->pending_signals
= p_sig
;
1681 if (lwp
->status_pending_p
&& !check_removed_breakpoint (lwp
))
1684 saved_inferior
= current_inferior
;
1685 current_inferior
= get_lwp_thread (lwp
);
1688 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
1689 lwpid_of (lwp
), step
? "step" : "continue", signal
,
1690 lwp
->stop_expected
? "expected" : "not expected");
1692 /* This bit needs some thinking about. If we get a signal that
1693 we must report while a single-step reinsert is still pending,
1694 we often end up resuming the thread. It might be better to
1695 (ew) allow a stack of pending events; then we could be sure that
1696 the reinsert happened right away and not lose any signals.
1698 Making this stack would also shrink the window in which breakpoints are
1699 uninserted (see comment in linux_wait_for_lwp) but not enough for
1700 complete correctness, so it won't solve that problem. It may be
1701 worthwhile just to solve this one, however. */
1702 if (lwp
->bp_reinsert
!= 0)
1705 fprintf (stderr
, " pending reinsert at %08lx", (long)lwp
->bp_reinsert
);
1707 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
1710 /* Postpone any pending signal. It was enqueued above. */
1714 check_removed_breakpoint (lwp
);
1716 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
1718 CORE_ADDR pc
= (*the_low_target
.get_pc
) ();
1719 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
1722 /* If we have pending signals, consume one unless we are trying to reinsert
1724 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
1726 struct pending_signals
**p_sig
;
1728 p_sig
= &lwp
->pending_signals
;
1729 while ((*p_sig
)->prev
!= NULL
)
1730 p_sig
= &(*p_sig
)->prev
;
1732 signal
= (*p_sig
)->signal
;
1733 if ((*p_sig
)->info
.si_signo
!= 0)
1734 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1740 regcache_invalidate_one ((struct inferior_list_entry
*)
1741 get_lwp_thread (lwp
));
1744 lwp
->stepping
= step
;
1745 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0, signal
);
1747 current_inferior
= saved_inferior
;
1750 /* ESRCH from ptrace either means that the thread was already
1751 running (an error) or that it is gone (a race condition). If
1752 it's gone, we will get a notification the next time we wait,
1753 so we can ignore the error. We could differentiate these
1754 two, but it's tricky without waiting; the thread still exists
1755 as a zombie, so sending it signal 0 would succeed. So just
1760 perror_with_name ("ptrace");
1764 struct thread_resume_array
1766 struct thread_resume
*resume
;
1770 /* This function is called once per thread. We look up the thread
1771 in RESUME_PTR, and mark the thread with a pointer to the appropriate
1774 This algorithm is O(threads * resume elements), but resume elements
1775 is small (and will remain small at least until GDB supports thread
1778 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
1780 struct lwp_info
*lwp
;
1781 struct thread_info
*thread
;
1783 struct thread_resume_array
*r
;
1785 thread
= (struct thread_info
*) entry
;
1786 lwp
= get_thread_lwp (thread
);
1789 for (ndx
= 0; ndx
< r
->n
; ndx
++)
1791 ptid_t ptid
= r
->resume
[ndx
].thread
;
1792 if (ptid_equal (ptid
, minus_one_ptid
)
1793 || ptid_equal (ptid
, entry
->id
)
1794 || (ptid_is_pid (ptid
)
1795 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
1796 || (ptid_get_lwp (ptid
) == -1
1797 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
1799 lwp
->resume
= &r
->resume
[ndx
];
1804 /* No resume action for this thread. */
1811 /* Set *FLAG_P if this lwp has an interesting status pending. */
1813 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
1815 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1817 /* LWPs which will not be resumed are not interesting, because
1818 we might not wait for them next time through linux_wait. */
1819 if (lwp
->resume
== NULL
)
1822 /* If this thread has a removed breakpoint, we won't have any
1823 events to report later, so check now. check_removed_breakpoint
1824 may clear status_pending_p. We avoid calling check_removed_breakpoint
1825 for any thread that we are not otherwise going to resume - this
1826 lets us preserve stopped status when two threads hit a breakpoint.
1827 GDB removes the breakpoint to single-step a particular thread
1828 past it, then re-inserts it and resumes all threads. We want
1829 to report the second thread without resuming it in the interim. */
1830 if (lwp
->status_pending_p
)
1831 check_removed_breakpoint (lwp
);
1833 if (lwp
->status_pending_p
)
1834 * (int *) flag_p
= 1;
1839 /* This function is called once per thread. We check the thread's resume
1840 request, which will tell us whether to resume, step, or leave the thread
1841 stopped; and what signal, if any, it should be sent.
1843 For threads which we aren't explicitly told otherwise, we preserve
1844 the stepping flag; this is used for stepping over gdbserver-placed
1847 If pending_flags was set in any thread, we queue any needed
1848 signals, since we won't actually resume. We already have a pending
1849 event to report, so we don't need to preserve any step requests;
1850 they should be re-issued if necessary. */
1853 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
1855 struct lwp_info
*lwp
;
1856 struct thread_info
*thread
;
1858 int pending_flag
= * (int *) arg
;
1860 thread
= (struct thread_info
*) entry
;
1861 lwp
= get_thread_lwp (thread
);
1863 if (lwp
->resume
== NULL
)
1866 if (lwp
->resume
->kind
== resume_stop
)
1869 fprintf (stderr
, "suspending LWP %ld\n", lwpid_of (lwp
));
1874 fprintf (stderr
, "running -> suspending LWP %ld\n", lwpid_of (lwp
));
1877 send_sigstop (&lwp
->head
);
1884 fprintf (stderr
, "already stopped/suspended LWP %ld\n",
1887 fprintf (stderr
, "already stopped/not suspended LWP %ld\n",
1891 /* Make sure we leave the LWP suspended, so we don't try to
1892 resume it without GDB telling us to. FIXME: The LWP may
1893 have been stopped in an internal event that was not meant
1894 to be notified back to GDB (e.g., gdbserver breakpoint),
1895 so we should be reporting a stop event in that case
1900 /* For stop requests, we're done. */
1907 /* If this thread which is about to be resumed has a pending status,
1908 then don't resume any threads - we can just report the pending
1909 status. Make sure to queue any signals that would otherwise be
1910 sent. In all-stop mode, we do this decision based on if *any*
1911 thread has a pending status. */
1913 resume_status_pending_p (&lwp
->head
, &pending_flag
);
1918 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
1920 if (ptid_equal (lwp
->resume
->thread
, minus_one_ptid
)
1922 && lwp
->pending_is_breakpoint
)
1925 step
= (lwp
->resume
->kind
== resume_step
);
1927 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
1932 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
1934 /* If we have a new signal, enqueue the signal. */
1935 if (lwp
->resume
->sig
!= 0)
1937 struct pending_signals
*p_sig
;
1938 p_sig
= xmalloc (sizeof (*p_sig
));
1939 p_sig
->prev
= lwp
->pending_signals
;
1940 p_sig
->signal
= lwp
->resume
->sig
;
1941 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1943 /* If this is the same signal we were previously stopped by,
1944 make sure to queue its siginfo. We can ignore the return
1945 value of ptrace; if it fails, we'll skip
1946 PTRACE_SETSIGINFO. */
1947 if (WIFSTOPPED (lwp
->last_status
)
1948 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
1949 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1951 lwp
->pending_signals
= p_sig
;
1960 linux_resume (struct thread_resume
*resume_info
, size_t n
)
1963 struct thread_resume_array array
= { resume_info
, n
};
1965 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
1967 /* If there is a thread which would otherwise be resumed, which
1968 has a pending status, then don't resume any threads - we can just
1969 report the pending status. Make sure to queue any signals
1970 that would otherwise be sent. In non-stop mode, we'll apply this
1971 logic to each thread individually. */
1974 find_inferior (&all_lwps
, resume_status_pending_p
, &pending_flag
);
1979 fprintf (stderr
, "Not resuming, pending status\n");
1981 fprintf (stderr
, "Resuming, no pending status\n");
1984 find_inferior (&all_threads
, linux_resume_one_thread
, &pending_flag
);
1987 #ifdef HAVE_LINUX_USRREGS
1990 register_addr (int regnum
)
1994 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
1995 error ("Invalid register number %d.", regnum
);
1997 addr
= the_low_target
.regmap
[regnum
];
2002 /* Fetch one register. */
2004 fetch_register (int regno
)
2011 if (regno
>= the_low_target
.num_regs
)
2013 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2016 regaddr
= register_addr (regno
);
2020 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2021 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2022 & - sizeof (PTRACE_XFER_TYPE
));
2023 buf
= alloca (size
);
2024 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2027 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2028 ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_ARG3_TYPE
) regaddr
, 0);
2029 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2032 /* Warning, not error, in case we are attached; sometimes the
2033 kernel doesn't let us at the registers. */
2034 char *err
= strerror (errno
);
2035 char *msg
= alloca (strlen (err
) + 128);
2036 sprintf (msg
, "reading register %d: %s", regno
, err
);
2042 if (the_low_target
.supply_ptrace_register
)
2043 the_low_target
.supply_ptrace_register (regno
, buf
);
2045 supply_register (regno
, buf
);
2050 /* Fetch all registers, or just one, from the child process. */
2052 usr_fetch_inferior_registers (int regno
)
2054 if (regno
== -1 || regno
== 0)
2055 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2056 fetch_register (regno
);
2058 fetch_register (regno
);
2061 /* Store our register values back into the inferior.
2062 If REGNO is -1, do this for all registers.
2063 Otherwise, REGNO specifies which register (so we can save time). */
2065 usr_store_inferior_registers (int regno
)
2074 if (regno
>= the_low_target
.num_regs
)
2077 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2080 regaddr
= register_addr (regno
);
2084 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2085 & - sizeof (PTRACE_XFER_TYPE
);
2086 buf
= alloca (size
);
2087 memset (buf
, 0, size
);
2089 if (the_low_target
.collect_ptrace_register
)
2090 the_low_target
.collect_ptrace_register (regno
, buf
);
2092 collect_register (regno
, buf
);
2094 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2095 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2098 ptrace (PTRACE_POKEUSER
, pid
, (PTRACE_ARG3_TYPE
) regaddr
,
2099 *(PTRACE_XFER_TYPE
*) (buf
+ i
));
2102 /* At this point, ESRCH should mean the process is
2103 already gone, in which case we simply ignore attempts
2104 to change its registers. See also the related
2105 comment in linux_resume_one_lwp. */
2109 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
2111 char *err
= strerror (errno
);
2112 char *msg
= alloca (strlen (err
) + 128);
2113 sprintf (msg
, "writing register %d: %s",
2119 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2123 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2124 usr_store_inferior_registers (regno
);
2126 #endif /* HAVE_LINUX_USRREGS */
2130 #ifdef HAVE_LINUX_REGSETS
2133 regsets_fetch_inferior_registers ()
2135 struct regset_info
*regset
;
2136 int saw_general_regs
= 0;
2139 regset
= target_regsets
;
2141 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2142 while (regset
->size
>= 0)
2147 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2153 buf
= xmalloc (regset
->size
);
2155 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2157 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2163 /* If we get EIO on a regset, do not try it again for
2165 disabled_regsets
[regset
- target_regsets
] = 1;
2172 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
2177 else if (regset
->type
== GENERAL_REGS
)
2178 saw_general_regs
= 1;
2179 regset
->store_function (buf
);
2183 if (saw_general_regs
)
2190 regsets_store_inferior_registers ()
2192 struct regset_info
*regset
;
2193 int saw_general_regs
= 0;
2196 regset
= target_regsets
;
2198 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2199 while (regset
->size
>= 0)
2204 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
2210 buf
= xmalloc (regset
->size
);
2212 /* First fill the buffer with the current register set contents,
2213 in case there are any items in the kernel's regset that are
2214 not in gdbserver's regcache. */
2216 res
= ptrace (regset
->get_request
, pid
, 0, buf
);
2218 res
= ptrace (regset
->get_request
, pid
, buf
, 0);
2223 /* Then overlay our cached registers on that. */
2224 regset
->fill_function (buf
);
2226 /* Only now do we write the register set. */
2228 res
= ptrace (regset
->set_request
, pid
, 0, buf
);
2230 res
= ptrace (regset
->set_request
, pid
, buf
, 0);
2238 /* If we get EIO on a regset, do not try it again for
2240 disabled_regsets
[regset
- target_regsets
] = 1;
2244 else if (errno
== ESRCH
)
2246 /* At this point, ESRCH should mean the process is
2247 already gone, in which case we simply ignore attempts
2248 to change its registers. See also the related
2249 comment in linux_resume_one_lwp. */
2255 perror ("Warning: ptrace(regsets_store_inferior_registers)");
2258 else if (regset
->type
== GENERAL_REGS
)
2259 saw_general_regs
= 1;
2263 if (saw_general_regs
)
2270 #endif /* HAVE_LINUX_REGSETS */
2274 linux_fetch_registers (int regno
)
2276 #ifdef HAVE_LINUX_REGSETS
2277 if (regsets_fetch_inferior_registers () == 0)
2280 #ifdef HAVE_LINUX_USRREGS
2281 usr_fetch_inferior_registers (regno
);
2286 linux_store_registers (int regno
)
2288 #ifdef HAVE_LINUX_REGSETS
2289 if (regsets_store_inferior_registers () == 0)
2292 #ifdef HAVE_LINUX_USRREGS
2293 usr_store_inferior_registers (regno
);
2298 /* Copy LEN bytes from inferior's memory starting at MEMADDR
2299 to debugger memory starting at MYADDR. */
2302 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
2305 /* Round starting address down to longword boundary. */
2306 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2307 /* Round ending address up; get number of longwords that makes. */
2309 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2310 / sizeof (PTRACE_XFER_TYPE
);
2311 /* Allocate buffer of that many longwords. */
2312 register PTRACE_XFER_TYPE
*buffer
2313 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2316 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2318 /* Try using /proc. Don't bother for one word. */
2319 if (len
>= 3 * sizeof (long))
2321 /* We could keep this file open and cache it - possibly one per
2322 thread. That requires some juggling, but is even faster. */
2323 sprintf (filename
, "/proc/%d/mem", pid
);
2324 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
2328 /* If pread64 is available, use it. It's faster if the kernel
2329 supports it (only one syscall), and it's 64-bit safe even on
2330 32-bit platforms (for instance, SPARC debugging a SPARC64
2333 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
2335 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, memaddr
, len
) != len
)
2347 /* Read all the longwords */
2348 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2351 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
2356 /* Copy appropriate bytes out of the buffer. */
2358 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
2364 /* Copy LEN bytes of data from debugger memory at MYADDR
2365 to inferior's memory at MEMADDR.
2366 On failure (cannot write the inferior)
2367 returns the value of errno. */
2370 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
2373 /* Round starting address down to longword boundary. */
2374 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
2375 /* Round ending address up; get number of longwords that makes. */
2377 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
2378 /* Allocate buffer of that many longwords. */
2379 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
2380 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2384 fprintf (stderr
, "Writing %02x to %08lx\n", (unsigned)myaddr
[0], (long)memaddr
);
2387 /* Fill start and end extra bytes of buffer with existing memory data. */
2389 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, 0);
2394 = ptrace (PTRACE_PEEKTEXT
, pid
,
2395 (PTRACE_ARG3_TYPE
) (addr
+ (count
- 1)
2396 * sizeof (PTRACE_XFER_TYPE
)),
2400 /* Copy data to be written over corresponding part of buffer */
2402 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
2404 /* Write the entire buffer. */
2406 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
2409 ptrace (PTRACE_POKETEXT
, pid
, (PTRACE_ARG3_TYPE
) addr
, buffer
[i
]);
2417 static int linux_supports_tracefork_flag
;
2419 /* Helper functions for linux_test_for_tracefork, called via clone (). */
2422 linux_tracefork_grandchild (void *arg
)
2427 #define STACK_SIZE 4096
2430 linux_tracefork_child (void *arg
)
2432 ptrace (PTRACE_TRACEME
, 0, 0, 0);
2433 kill (getpid (), SIGSTOP
);
2435 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
2436 CLONE_VM
| SIGCHLD
, NULL
);
2438 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
2439 CLONE_VM
| SIGCHLD
, NULL
);
2444 /* Wrapper function for waitpid which handles EINTR, and emulates
2445 __WALL for systems where that is not available. */
2448 my_waitpid (int pid
, int *status
, int flags
)
2453 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
2457 sigset_t block_mask
, org_mask
, wake_mask
;
2460 wnohang
= (flags
& WNOHANG
) != 0;
2461 flags
&= ~(__WALL
| __WCLONE
);
2464 /* Block all signals while here. This avoids knowing about
2465 LinuxThread's signals. */
2466 sigfillset (&block_mask
);
2467 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
2469 /* ... except during the sigsuspend below. */
2470 sigemptyset (&wake_mask
);
2474 /* Since all signals are blocked, there's no need to check
2476 ret
= waitpid (pid
, status
, flags
);
2479 if (ret
== -1 && out_errno
!= ECHILD
)
2484 if (flags
& __WCLONE
)
2486 /* We've tried both flavors now. If WNOHANG is set,
2487 there's nothing else to do, just bail out. */
2492 fprintf (stderr
, "blocking\n");
2494 /* Block waiting for signals. */
2495 sigsuspend (&wake_mask
);
2501 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
2506 ret
= waitpid (pid
, status
, flags
);
2507 while (ret
== -1 && errno
== EINTR
);
2512 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
2513 pid
, flags
, status
? *status
: -1, ret
);
2519 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
2520 sure that we can enable the option, and that it had the desired
2524 linux_test_for_tracefork (void)
2526 int child_pid
, ret
, status
;
2528 char *stack
= xmalloc (STACK_SIZE
* 4);
2530 linux_supports_tracefork_flag
= 0;
2532 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
2534 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
2535 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2537 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
2538 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
2540 if (child_pid
== -1)
2541 perror_with_name ("clone");
2543 ret
= my_waitpid (child_pid
, &status
, 0);
2545 perror_with_name ("waitpid");
2546 else if (ret
!= child_pid
)
2547 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
2548 if (! WIFSTOPPED (status
))
2549 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
2551 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0, PTRACE_O_TRACEFORK
);
2554 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2557 warning ("linux_test_for_tracefork: failed to kill child");
2561 ret
= my_waitpid (child_pid
, &status
, 0);
2562 if (ret
!= child_pid
)
2563 warning ("linux_test_for_tracefork: failed to wait for killed child");
2564 else if (!WIFSIGNALED (status
))
2565 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
2566 "killed child", status
);
2571 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
2573 warning ("linux_test_for_tracefork: failed to resume child");
2575 ret
= my_waitpid (child_pid
, &status
, 0);
2577 if (ret
== child_pid
&& WIFSTOPPED (status
)
2578 && status
>> 16 == PTRACE_EVENT_FORK
)
2581 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
2582 if (ret
== 0 && second_pid
!= 0)
2586 linux_supports_tracefork_flag
= 1;
2587 my_waitpid (second_pid
, &second_status
, 0);
2588 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
2590 warning ("linux_test_for_tracefork: failed to kill second child");
2591 my_waitpid (second_pid
, &status
, 0);
2595 warning ("linux_test_for_tracefork: unexpected result from waitpid "
2596 "(%d, status 0x%x)", ret
, status
);
2600 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
2602 warning ("linux_test_for_tracefork: failed to kill child");
2603 my_waitpid (child_pid
, &status
, 0);
2605 while (WIFSTOPPED (status
));
2612 linux_look_up_symbols (void)
2614 #ifdef USE_THREAD_DB
2615 struct process_info
*proc
= current_process ();
2617 if (proc
->private->thread_db_active
)
2620 proc
->private->thread_db_active
2621 = thread_db_init (!linux_supports_tracefork_flag
);
2626 linux_request_interrupt (void)
2628 extern unsigned long signal_pid
;
2630 if (!ptid_equal (cont_thread
, null_ptid
)
2631 && !ptid_equal (cont_thread
, minus_one_ptid
))
2633 struct lwp_info
*lwp
;
2636 lwp
= get_thread_lwp (current_inferior
);
2637 lwpid
= lwpid_of (lwp
);
2638 kill_lwp (lwpid
, SIGINT
);
2641 kill_lwp (signal_pid
, SIGINT
);
2644 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
2645 to debugger memory starting at MYADDR. */
2648 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
2650 char filename
[PATH_MAX
];
2652 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2654 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
2656 fd
= open (filename
, O_RDONLY
);
2660 if (offset
!= (CORE_ADDR
) 0
2661 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
2664 n
= read (fd
, myaddr
, len
);
2671 /* These watchpoint related wrapper functions simply pass on the function call
2672 if the target has registered a corresponding function. */
2675 linux_insert_watchpoint (char type
, CORE_ADDR addr
, int len
)
2677 if (the_low_target
.insert_watchpoint
!= NULL
)
2678 return the_low_target
.insert_watchpoint (type
, addr
, len
);
2680 /* Unsupported (see target.h). */
2685 linux_remove_watchpoint (char type
, CORE_ADDR addr
, int len
)
2687 if (the_low_target
.remove_watchpoint
!= NULL
)
2688 return the_low_target
.remove_watchpoint (type
, addr
, len
);
2690 /* Unsupported (see target.h). */
2695 linux_stopped_by_watchpoint (void)
2697 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2698 return the_low_target
.stopped_by_watchpoint ();
2704 linux_stopped_data_address (void)
2706 if (the_low_target
.stopped_data_address
!= NULL
)
2707 return the_low_target
.stopped_data_address ();
2712 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
2713 #if defined(__mcoldfire__)
2714 /* These should really be defined in the kernel's ptrace.h header. */
2715 #define PT_TEXT_ADDR 49*4
2716 #define PT_DATA_ADDR 50*4
2717 #define PT_TEXT_END_ADDR 51*4
2720 /* Under uClinux, programs are loaded at non-zero offsets, which we need
2721 to tell gdb about. */
2724 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
2726 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
2727 unsigned long text
, text_end
, data
;
2728 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
2732 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
2733 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
2734 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
2738 /* Both text and data offsets produced at compile-time (and so
2739 used by gdb) are relative to the beginning of the program,
2740 with the data segment immediately following the text segment.
2741 However, the actual runtime layout in memory may put the data
2742 somewhere else, so when we send gdb a data base-address, we
2743 use the real data base address and subtract the compile-time
2744 data base-address from it (which is just the length of the
2745 text segment). BSS immediately follows data in both
2748 *data_p
= data
- (text_end
- text
);
2758 linux_qxfer_osdata (const char *annex
,
2759 unsigned char *readbuf
, unsigned const char *writebuf
,
2760 CORE_ADDR offset
, int len
)
2762 /* We make the process list snapshot when the object starts to be
2764 static const char *buf
;
2765 static long len_avail
= -1;
2766 static struct buffer buffer
;
2770 if (strcmp (annex
, "processes") != 0)
2773 if (!readbuf
|| writebuf
)
2778 if (len_avail
!= -1 && len_avail
!= 0)
2779 buffer_free (&buffer
);
2782 buffer_init (&buffer
);
2783 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
2785 dirp
= opendir ("/proc");
2789 while ((dp
= readdir (dirp
)) != NULL
)
2791 struct stat statbuf
;
2792 char procentry
[sizeof ("/proc/4294967295")];
2794 if (!isdigit (dp
->d_name
[0])
2795 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
2798 sprintf (procentry
, "/proc/%s", dp
->d_name
);
2799 if (stat (procentry
, &statbuf
) == 0
2800 && S_ISDIR (statbuf
.st_mode
))
2804 char cmd
[MAXPATHLEN
+ 1];
2805 struct passwd
*entry
;
2807 sprintf (pathname
, "/proc/%s/cmdline", dp
->d_name
);
2808 entry
= getpwuid (statbuf
.st_uid
);
2810 if ((f
= fopen (pathname
, "r")) != NULL
)
2812 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
2816 for (i
= 0; i
< len
; i
++)
2824 "<column name=\"pid\">%s</column>"
2825 "<column name=\"user\">%s</column>"
2826 "<column name=\"command\">%s</column>"
2829 entry
? entry
->pw_name
: "?",
2839 buffer_grow_str0 (&buffer
, "</osdata>\n");
2840 buf
= buffer_finish (&buffer
);
2841 len_avail
= strlen (buf
);
2844 if (offset
>= len_avail
)
2846 /* Done. Get rid of the data. */
2847 buffer_free (&buffer
);
2853 if (len
> len_avail
- offset
)
2854 len
= len_avail
- offset
;
2855 memcpy (readbuf
, buf
+ offset
, len
);
2860 /* Convert a native/host siginfo object, into/from the siginfo in the
2861 layout of the inferiors' architecture. */
2864 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
2868 if (the_low_target
.siginfo_fixup
!= NULL
)
2869 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
2871 /* If there was no callback, or the callback didn't do anything,
2872 then just do a straight memcpy. */
2876 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
2878 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
2883 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
2884 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
2887 struct siginfo siginfo
;
2888 char inf_siginfo
[sizeof (struct siginfo
)];
2890 if (current_inferior
== NULL
)
2893 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2896 fprintf (stderr
, "%s siginfo for lwp %d.\n",
2897 readbuf
!= NULL
? "Reading" : "Writing",
2900 if (offset
> sizeof (siginfo
))
2903 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
2906 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
2907 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
2908 inferior with a 64-bit GDBSERVER should look the same as debugging it
2909 with a 32-bit GDBSERVER, we need to convert it. */
2910 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
2912 if (offset
+ len
> sizeof (siginfo
))
2913 len
= sizeof (siginfo
) - offset
;
2915 if (readbuf
!= NULL
)
2916 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
2919 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
2921 /* Convert back to ptrace layout before flushing it out. */
2922 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
2924 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
2931 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
2932 so we notice when children change state; as the handler for the
2933 sigsuspend in my_waitpid. */
2936 sigchld_handler (int signo
)
2938 int old_errno
= errno
;
2941 /* fprintf is not async-signal-safe, so call write directly. */
2942 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
2944 if (target_is_async_p ())
2945 async_file_mark (); /* trigger a linux_wait */
2951 linux_supports_non_stop (void)
2957 linux_async (int enable
)
2959 int previous
= (linux_event_pipe
[0] != -1);
2961 if (previous
!= enable
)
2964 sigemptyset (&mask
);
2965 sigaddset (&mask
, SIGCHLD
);
2967 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
2971 if (pipe (linux_event_pipe
) == -1)
2972 fatal ("creating event pipe failed.");
2974 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
2975 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
2977 /* Register the event loop handler. */
2978 add_file_handler (linux_event_pipe
[0],
2979 handle_target_event
, NULL
);
2981 /* Always trigger a linux_wait. */
2986 delete_file_handler (linux_event_pipe
[0]);
2988 close (linux_event_pipe
[0]);
2989 close (linux_event_pipe
[1]);
2990 linux_event_pipe
[0] = -1;
2991 linux_event_pipe
[1] = -1;
2994 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
3001 linux_start_non_stop (int nonstop
)
3003 /* Register or unregister from event-loop accordingly. */
3004 linux_async (nonstop
);
3008 static struct target_ops linux_target_ops
= {
3009 linux_create_inferior
,
3017 linux_fetch_registers
,
3018 linux_store_registers
,
3021 linux_look_up_symbols
,
3022 linux_request_interrupt
,
3024 linux_insert_watchpoint
,
3025 linux_remove_watchpoint
,
3026 linux_stopped_by_watchpoint
,
3027 linux_stopped_data_address
,
3028 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3033 #ifdef USE_THREAD_DB
3034 thread_db_get_tls_address
,
3039 hostio_last_error_from_errno
,
3042 linux_supports_non_stop
,
3044 linux_start_non_stop
,
3048 linux_init_signals ()
3050 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
3051 to find what the cancel signal actually is. */
3052 signal (__SIGRTMIN
+1, SIG_IGN
);
3056 initialize_low (void)
3058 struct sigaction sigchld_action
;
3059 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
3060 set_target_ops (&linux_target_ops
);
3061 set_breakpoint_data (the_low_target
.breakpoint
,
3062 the_low_target
.breakpoint_len
);
3063 linux_init_signals ();
3064 linux_test_for_tracefork ();
3065 #ifdef HAVE_LINUX_REGSETS
3066 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
3068 disabled_regsets
= xmalloc (num_regsets
);
3071 sigchld_action
.sa_handler
= sigchld_handler
;
3072 sigemptyset (&sigchld_action
.sa_mask
);
3073 sigchld_action
.sa_flags
= SA_RESTART
;
3074 sigaction (SIGCHLD
, &sigchld_action
, NULL
);