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, 2010 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>
44 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
45 then ELFMAG0 will have been defined. If it didn't get included by
46 gdb_proc_service.h then including it will likely introduce a duplicate
47 definition of elf_fpregset_t. */
52 #define SPUFS_MAGIC 0x23c9b64e
55 #ifndef PTRACE_GETSIGINFO
56 # define PTRACE_GETSIGINFO 0x4202
57 # define PTRACE_SETSIGINFO 0x4203
64 /* If the system headers did not provide the constants, hard-code the normal
66 #ifndef PTRACE_EVENT_FORK
68 #define PTRACE_SETOPTIONS 0x4200
69 #define PTRACE_GETEVENTMSG 0x4201
71 /* options set using PTRACE_SETOPTIONS */
72 #define PTRACE_O_TRACESYSGOOD 0x00000001
73 #define PTRACE_O_TRACEFORK 0x00000002
74 #define PTRACE_O_TRACEVFORK 0x00000004
75 #define PTRACE_O_TRACECLONE 0x00000008
76 #define PTRACE_O_TRACEEXEC 0x00000010
77 #define PTRACE_O_TRACEVFORKDONE 0x00000020
78 #define PTRACE_O_TRACEEXIT 0x00000040
80 /* Wait extended result codes for the above trace options. */
81 #define PTRACE_EVENT_FORK 1
82 #define PTRACE_EVENT_VFORK 2
83 #define PTRACE_EVENT_CLONE 3
84 #define PTRACE_EVENT_EXEC 4
85 #define PTRACE_EVENT_VFORK_DONE 5
86 #define PTRACE_EVENT_EXIT 6
88 #endif /* PTRACE_EVENT_FORK */
90 /* We can't always assume that this flag is available, but all systems
91 with the ptrace event handlers also have __WALL, so it's safe to use
94 #define __WALL 0x40000000 /* Wait for any child. */
98 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
102 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
107 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
108 representation of the thread ID.
110 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
111 the same as the LWP ID.
113 ``all_processes'' is keyed by the "overall process ID", which
114 GNU/Linux calls tgid, "thread group ID". */
116 struct inferior_list all_lwps
;
118 /* A list of all unknown processes which receive stop signals. Some other
119 process will presumably claim each of these as forked children
122 struct inferior_list stopped_pids
;
124 /* FIXME this is a bit of a hack, and could be removed. */
125 int stopping_threads
;
127 /* FIXME make into a target method? */
128 int using_threads
= 1;
130 /* This flag is true iff we've just created or attached to our first
131 inferior but it has not stopped yet. As soon as it does, we need
132 to call the low target's arch_setup callback. Doing this only on
133 the first inferior avoids reinializing the architecture on every
134 inferior, and avoids messing with the register caches of the
135 already running inferiors. NOTE: this assumes all inferiors under
136 control of gdbserver have the same architecture. */
137 static int new_inferior
;
139 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
140 int step
, int signal
, siginfo_t
*info
);
141 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
142 static void stop_all_lwps (void);
143 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
144 static void *add_lwp (ptid_t ptid
);
145 static int linux_stopped_by_watchpoint (void);
146 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
147 static int linux_core_of_thread (ptid_t ptid
);
148 static void proceed_all_lwps (void);
149 static void unstop_all_lwps (struct lwp_info
*except
);
150 static int finish_step_over (struct lwp_info
*lwp
);
151 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
152 static int kill_lwp (unsigned long lwpid
, int signo
);
154 /* True if the low target can hardware single-step. Such targets
155 don't need a BREAKPOINT_REINSERT_ADDR callback. */
158 can_hardware_single_step (void)
160 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
163 /* True if the low target supports memory breakpoints. If so, we'll
164 have a GET_PC implementation. */
167 supports_breakpoints (void)
169 return (the_low_target
.get_pc
!= NULL
);
172 struct pending_signals
176 struct pending_signals
*prev
;
179 #define PTRACE_ARG3_TYPE void *
180 #define PTRACE_ARG4_TYPE void *
181 #define PTRACE_XFER_TYPE long
183 #ifdef HAVE_LINUX_REGSETS
184 static char *disabled_regsets
;
185 static int num_regsets
;
188 /* The read/write ends of the pipe registered as waitable file in the
190 static int linux_event_pipe
[2] = { -1, -1 };
192 /* True if we're currently in async mode. */
193 #define target_is_async_p() (linux_event_pipe[0] != -1)
195 static void send_sigstop (struct inferior_list_entry
*entry
);
196 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
198 /* Accepts an integer PID; Returns a string representing a file that
199 can be opened to get info for the child process.
200 Space for the result is malloc'd, caller must free. */
203 linux_child_pid_to_exec_file (int pid
)
207 name1
= xmalloc (MAXPATHLEN
);
208 name2
= xmalloc (MAXPATHLEN
);
209 memset (name2
, 0, MAXPATHLEN
);
211 sprintf (name1
, "/proc/%d/exe", pid
);
212 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
224 /* Return non-zero if HEADER is a 64-bit ELF file. */
227 elf_64_header_p (const Elf64_Ehdr
*header
)
229 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
230 && header
->e_ident
[EI_MAG1
] == ELFMAG1
231 && header
->e_ident
[EI_MAG2
] == ELFMAG2
232 && header
->e_ident
[EI_MAG3
] == ELFMAG3
233 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
236 /* Return non-zero if FILE is a 64-bit ELF file,
237 zero if the file is not a 64-bit ELF file,
238 and -1 if the file is not accessible or doesn't exist. */
241 elf_64_file_p (const char *file
)
246 fd
= open (file
, O_RDONLY
);
250 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
257 return elf_64_header_p (&header
);
261 delete_lwp (struct lwp_info
*lwp
)
263 remove_thread (get_lwp_thread (lwp
));
264 remove_inferior (&all_lwps
, &lwp
->head
);
265 free (lwp
->arch_private
);
269 /* Add a process to the common process list, and set its private
272 static struct process_info
*
273 linux_add_process (int pid
, int attached
)
275 struct process_info
*proc
;
277 /* Is this the first process? If so, then set the arch. */
278 if (all_processes
.head
== NULL
)
281 proc
= add_process (pid
, attached
);
282 proc
->private = xcalloc (1, sizeof (*proc
->private));
284 if (the_low_target
.new_process
!= NULL
)
285 proc
->private->arch_private
= the_low_target
.new_process ();
290 /* Remove a process from the common process list,
291 also freeing all private data. */
294 linux_remove_process (struct process_info
*process
)
296 struct process_info_private
*priv
= process
->private;
298 free (priv
->arch_private
);
300 remove_process (process
);
303 /* Wrapper function for waitpid which handles EINTR, and emulates
304 __WALL for systems where that is not available. */
307 my_waitpid (int pid
, int *status
, int flags
)
312 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
316 sigset_t block_mask
, org_mask
, wake_mask
;
319 wnohang
= (flags
& WNOHANG
) != 0;
320 flags
&= ~(__WALL
| __WCLONE
);
323 /* Block all signals while here. This avoids knowing about
324 LinuxThread's signals. */
325 sigfillset (&block_mask
);
326 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
328 /* ... except during the sigsuspend below. */
329 sigemptyset (&wake_mask
);
333 /* Since all signals are blocked, there's no need to check
335 ret
= waitpid (pid
, status
, flags
);
338 if (ret
== -1 && out_errno
!= ECHILD
)
343 if (flags
& __WCLONE
)
345 /* We've tried both flavors now. If WNOHANG is set,
346 there's nothing else to do, just bail out. */
351 fprintf (stderr
, "blocking\n");
353 /* Block waiting for signals. */
354 sigsuspend (&wake_mask
);
360 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
365 ret
= waitpid (pid
, status
, flags
);
366 while (ret
== -1 && errno
== EINTR
);
371 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
372 pid
, flags
, status
? *status
: -1, ret
);
378 /* Handle a GNU/Linux extended wait response. If we see a clone
379 event, we need to add the new LWP to our list (and not report the
380 trap to higher layers). */
383 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
385 int event
= wstat
>> 16;
386 struct lwp_info
*new_lwp
;
388 if (event
== PTRACE_EVENT_CLONE
)
391 unsigned long new_pid
;
392 int ret
, status
= W_STOPCODE (SIGSTOP
);
394 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
396 /* If we haven't already seen the new PID stop, wait for it now. */
397 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
399 /* The new child has a pending SIGSTOP. We can't affect it until it
400 hits the SIGSTOP, but we're already attached. */
402 ret
= my_waitpid (new_pid
, &status
, __WALL
);
405 perror_with_name ("waiting for new child");
406 else if (ret
!= new_pid
)
407 warning ("wait returned unexpected PID %d", ret
);
408 else if (!WIFSTOPPED (status
))
409 warning ("wait returned unexpected status 0x%x", status
);
412 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
414 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
415 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
416 add_thread (ptid
, new_lwp
);
418 /* Either we're going to immediately resume the new thread
419 or leave it stopped. linux_resume_one_lwp is a nop if it
420 thinks the thread is currently running, so set this first
421 before calling linux_resume_one_lwp. */
422 new_lwp
->stopped
= 1;
424 /* Normally we will get the pending SIGSTOP. But in some cases
425 we might get another signal delivered to the group first.
426 If we do get another signal, be sure not to lose it. */
427 if (WSTOPSIG (status
) == SIGSTOP
)
429 if (stopping_threads
)
430 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
432 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
436 new_lwp
->stop_expected
= 1;
438 if (stopping_threads
)
440 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
441 new_lwp
->status_pending_p
= 1;
442 new_lwp
->status_pending
= status
;
445 /* Pass the signal on. This is what GDB does - except
446 shouldn't we really report it instead? */
447 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
450 /* Always resume the current thread. If we are stopping
451 threads, it will have a pending SIGSTOP; we may as well
453 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
457 /* Return the PC as read from the regcache of LWP, without any
461 get_pc (struct lwp_info
*lwp
)
463 struct thread_info
*saved_inferior
;
464 struct regcache
*regcache
;
467 if (the_low_target
.get_pc
== NULL
)
470 saved_inferior
= current_inferior
;
471 current_inferior
= get_lwp_thread (lwp
);
473 regcache
= get_thread_regcache (current_inferior
, 1);
474 pc
= (*the_low_target
.get_pc
) (regcache
);
477 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
479 current_inferior
= saved_inferior
;
483 /* This function should only be called if LWP got a SIGTRAP.
484 The SIGTRAP could mean several things.
486 On i386, where decr_pc_after_break is non-zero:
487 If we were single-stepping this process using PTRACE_SINGLESTEP,
488 we will get only the one SIGTRAP (even if the instruction we
489 stepped over was a breakpoint). The value of $eip will be the
491 If we continue the process using PTRACE_CONT, we will get a
492 SIGTRAP when we hit a breakpoint. The value of $eip will be
493 the instruction after the breakpoint (i.e. needs to be
494 decremented). If we report the SIGTRAP to GDB, we must also
495 report the undecremented PC. If we cancel the SIGTRAP, we
496 must resume at the decremented PC.
498 (Presumably, not yet tested) On a non-decr_pc_after_break machine
499 with hardware or kernel single-step:
500 If we single-step over a breakpoint instruction, our PC will
501 point at the following instruction. If we continue and hit a
502 breakpoint instruction, our PC will point at the breakpoint
506 get_stop_pc (struct lwp_info
*lwp
)
510 if (the_low_target
.get_pc
== NULL
)
513 stop_pc
= get_pc (lwp
);
515 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
517 && !lwp
->stopped_by_watchpoint
518 && lwp
->last_status
>> 16 == 0)
519 stop_pc
-= the_low_target
.decr_pc_after_break
;
522 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
528 add_lwp (ptid_t ptid
)
530 struct lwp_info
*lwp
;
532 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
533 memset (lwp
, 0, sizeof (*lwp
));
537 lwp
->last_resume_kind
= resume_continue
;
539 if (the_low_target
.new_thread
!= NULL
)
540 lwp
->arch_private
= the_low_target
.new_thread ();
542 add_inferior_to_list (&all_lwps
, &lwp
->head
);
547 /* Start an inferior process and returns its pid.
548 ALLARGS is a vector of program-name and args. */
551 linux_create_inferior (char *program
, char **allargs
)
553 struct lwp_info
*new_lwp
;
557 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
563 perror_with_name ("fork");
567 ptrace (PTRACE_TRACEME
, 0, 0, 0);
569 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
570 signal (__SIGRTMIN
+ 1, SIG_DFL
);
575 execv (program
, allargs
);
577 execvp (program
, allargs
);
579 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
585 linux_add_process (pid
, 0);
587 ptid
= ptid_build (pid
, pid
, 0);
588 new_lwp
= add_lwp (ptid
);
589 add_thread (ptid
, new_lwp
);
590 new_lwp
->must_set_ptrace_flags
= 1;
595 /* Attach to an inferior process. */
598 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
601 struct lwp_info
*new_lwp
;
603 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
607 /* If we fail to attach to an LWP, just warn. */
608 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
609 strerror (errno
), errno
);
614 /* If we fail to attach to a process, report an error. */
615 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
616 strerror (errno
), errno
);
620 /* NOTE/FIXME: This lwp might have not been the tgid. */
621 ptid
= ptid_build (lwpid
, lwpid
, 0);
624 /* Note that extracting the pid from the current inferior is
625 safe, since we're always called in the context of the same
626 process as this new thread. */
627 int pid
= pid_of (get_thread_lwp (current_inferior
));
628 ptid
= ptid_build (pid
, lwpid
, 0);
631 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
632 add_thread (ptid
, new_lwp
);
634 /* We need to wait for SIGSTOP before being able to make the next
635 ptrace call on this LWP. */
636 new_lwp
->must_set_ptrace_flags
= 1;
638 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
641 There are several cases to consider here:
643 1) gdbserver has already attached to the process and is being notified
644 of a new thread that is being created.
645 In this case we should ignore that SIGSTOP and resume the
646 process. This is handled below by setting stop_expected = 1,
647 and the fact that add_lwp sets last_resume_kind ==
650 2) This is the first thread (the process thread), and we're attaching
651 to it via attach_inferior.
652 In this case we want the process thread to stop.
653 This is handled by having linux_attach set last_resume_kind ==
654 resume_stop after we return.
655 ??? If the process already has several threads we leave the other
658 3) GDB is connecting to gdbserver and is requesting an enumeration of all
660 In this case we want the thread to stop.
661 FIXME: This case is currently not properly handled.
662 We should wait for the SIGSTOP but don't. Things work apparently
663 because enough time passes between when we ptrace (ATTACH) and when
664 gdb makes the next ptrace call on the thread.
666 On the other hand, if we are currently trying to stop all threads, we
667 should treat the new thread as if we had sent it a SIGSTOP. This works
668 because we are guaranteed that the add_lwp call above added us to the
669 end of the list, and so the new thread has not yet reached
670 wait_for_sigstop (but will). */
671 new_lwp
->stop_expected
= 1;
675 linux_attach_lwp (unsigned long lwpid
)
677 linux_attach_lwp_1 (lwpid
, 0);
681 linux_attach (unsigned long pid
)
683 struct lwp_info
*lwp
;
685 linux_attach_lwp_1 (pid
, 1);
687 linux_add_process (pid
, 1);
691 /* Don't ignore the initial SIGSTOP if we just attached to this
692 process. It will be collected by wait shortly. */
693 lwp
= (struct lwp_info
*) find_inferior_id (&all_lwps
,
694 ptid_build (pid
, pid
, 0));
695 lwp
->last_resume_kind
= resume_stop
;
708 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
710 struct counter
*counter
= args
;
712 if (ptid_get_pid (entry
->id
) == counter
->pid
)
714 if (++counter
->count
> 1)
722 last_thread_of_process_p (struct thread_info
*thread
)
724 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
725 int pid
= ptid_get_pid (ptid
);
726 struct counter counter
= { pid
, 0 };
728 return (find_inferior (&all_threads
,
729 second_thread_of_pid_p
, &counter
) == NULL
);
732 /* Kill the inferior lwp. */
735 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
737 struct thread_info
*thread
= (struct thread_info
*) entry
;
738 struct lwp_info
*lwp
= get_thread_lwp (thread
);
740 int pid
= * (int *) args
;
742 if (ptid_get_pid (entry
->id
) != pid
)
745 /* We avoid killing the first thread here, because of a Linux kernel (at
746 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
747 the children get a chance to be reaped, it will remain a zombie
750 if (lwpid_of (lwp
) == pid
)
753 fprintf (stderr
, "lkop: is last of process %s\n",
754 target_pid_to_str (entry
->id
));
758 /* If we're killing a running inferior, make sure it is stopped
759 first, as PTRACE_KILL will not work otherwise. */
761 send_sigstop (&lwp
->head
);
765 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
767 /* Make sure it died. The loop is most likely unnecessary. */
768 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
769 } while (pid
> 0 && WIFSTOPPED (wstat
));
777 struct process_info
*process
;
778 struct lwp_info
*lwp
;
779 struct thread_info
*thread
;
783 process
= find_process_pid (pid
);
787 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
789 /* See the comment in linux_kill_one_lwp. We did not kill the first
790 thread in the list, so do so now. */
791 lwp
= find_lwp_pid (pid_to_ptid (pid
));
792 thread
= get_lwp_thread (lwp
);
795 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
796 lwpid_of (lwp
), pid
);
798 /* If we're killing a running inferior, make sure it is stopped
799 first, as PTRACE_KILL will not work otherwise. */
801 send_sigstop (&lwp
->head
);
805 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
807 /* Make sure it died. The loop is most likely unnecessary. */
808 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
809 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
812 thread_db_free (process
, 0);
815 linux_remove_process (process
);
820 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
822 struct thread_info
*thread
= (struct thread_info
*) entry
;
823 struct lwp_info
*lwp
= get_thread_lwp (thread
);
824 int pid
= * (int *) args
;
826 if (ptid_get_pid (entry
->id
) != pid
)
829 /* If we're detaching from a running inferior, make sure it is
830 stopped first, as PTRACE_DETACH will not work otherwise. */
833 int lwpid
= lwpid_of (lwp
);
835 stopping_threads
= 1;
836 send_sigstop (&lwp
->head
);
838 /* If this detects a new thread through a clone event, the new
839 thread is appended to the end of the lwp list, so we'll
840 eventually detach from it. */
841 wait_for_sigstop (&lwp
->head
);
842 stopping_threads
= 0;
844 /* If LWP exits while we're trying to stop it, there's nothing
846 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
851 /* If this process is stopped but is expecting a SIGSTOP, then make
852 sure we take care of that now. This isn't absolutely guaranteed
853 to collect the SIGSTOP, but is fairly likely to. */
854 if (lwp
->stop_expected
)
857 /* Clear stop_expected, so that the SIGSTOP will be reported. */
858 lwp
->stop_expected
= 0;
860 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
861 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
864 /* Flush any pending changes to the process's registers. */
865 regcache_invalidate_one ((struct inferior_list_entry
*)
866 get_lwp_thread (lwp
));
868 /* Finally, let it resume. */
869 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
876 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
880 if (ptid_get_pid (entry
->id
) == *pid_p
)
887 linux_detach (int pid
)
889 struct process_info
*process
;
891 process
= find_process_pid (pid
);
896 thread_db_free (process
, 1);
900 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
902 delete_all_breakpoints ();
903 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
904 linux_remove_process (process
);
912 struct process_info
*process
;
914 process
= find_process_pid (pid
);
919 ret
= my_waitpid (pid
, &status
, 0);
920 if (WIFEXITED (status
) || WIFSIGNALED (status
))
922 } while (ret
!= -1 || errno
!= ECHILD
);
925 /* Return nonzero if the given thread is still alive. */
927 linux_thread_alive (ptid_t ptid
)
929 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
931 /* We assume we always know if a thread exits. If a whole process
932 exited but we still haven't been able to report it to GDB, we'll
933 hold on to the last lwp of the dead process. */
940 /* Return 1 if this lwp has an interesting status pending. */
942 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
944 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
945 ptid_t ptid
= * (ptid_t
*) arg
;
946 struct thread_info
*thread
= get_lwp_thread (lwp
);
948 /* Check if we're only interested in events from a specific process
950 if (!ptid_equal (minus_one_ptid
, ptid
)
951 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
954 thread
= get_lwp_thread (lwp
);
956 /* If we got a `vCont;t', but we haven't reported a stop yet, do
957 report any status pending the LWP may have. */
958 if (lwp
->last_resume_kind
== resume_stop
959 && thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
)
962 return lwp
->status_pending_p
;
966 same_lwp (struct inferior_list_entry
*entry
, void *data
)
968 ptid_t ptid
= *(ptid_t
*) data
;
971 if (ptid_get_lwp (ptid
) != 0)
972 lwp
= ptid_get_lwp (ptid
);
974 lwp
= ptid_get_pid (ptid
);
976 if (ptid_get_lwp (entry
->id
) == lwp
)
983 find_lwp_pid (ptid_t ptid
)
985 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
988 static struct lwp_info
*
989 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
992 int to_wait_for
= -1;
993 struct lwp_info
*child
= NULL
;
996 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
998 if (ptid_equal (ptid
, minus_one_ptid
))
999 to_wait_for
= -1; /* any child */
1001 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
1007 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
1008 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
1011 perror_with_name ("waitpid");
1014 && (!WIFSTOPPED (*wstatp
)
1015 || (WSTOPSIG (*wstatp
) != 32
1016 && WSTOPSIG (*wstatp
) != 33)))
1017 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1019 child
= find_lwp_pid (pid_to_ptid (ret
));
1021 /* If we didn't find a process, one of two things presumably happened:
1022 - A process we started and then detached from has exited. Ignore it.
1023 - A process we are controlling has forked and the new child's stop
1024 was reported to us by the kernel. Save its PID. */
1025 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1027 add_pid_to_list (&stopped_pids
, ret
);
1030 else if (child
== NULL
)
1035 child
->last_status
= *wstatp
;
1037 /* Architecture-specific setup after inferior is running.
1038 This needs to happen after we have attached to the inferior
1039 and it is stopped for the first time, but before we access
1040 any inferior registers. */
1043 the_low_target
.arch_setup ();
1044 #ifdef HAVE_LINUX_REGSETS
1045 memset (disabled_regsets
, 0, num_regsets
);
1050 /* Fetch the possibly triggered data watchpoint info and store it in
1053 On some archs, like x86, that use debug registers to set
1054 watchpoints, it's possible that the way to know which watched
1055 address trapped, is to check the register that is used to select
1056 which address to watch. Problem is, between setting the
1057 watchpoint and reading back which data address trapped, the user
1058 may change the set of watchpoints, and, as a consequence, GDB
1059 changes the debug registers in the inferior. To avoid reading
1060 back a stale stopped-data-address when that happens, we cache in
1061 LP the fact that a watchpoint trapped, and the corresponding data
1062 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1063 changes the debug registers meanwhile, we have the cached data we
1066 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1068 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1070 child
->stopped_by_watchpoint
= 0;
1074 struct thread_info
*saved_inferior
;
1076 saved_inferior
= current_inferior
;
1077 current_inferior
= get_lwp_thread (child
);
1079 child
->stopped_by_watchpoint
1080 = the_low_target
.stopped_by_watchpoint ();
1082 if (child
->stopped_by_watchpoint
)
1084 if (the_low_target
.stopped_data_address
!= NULL
)
1085 child
->stopped_data_address
1086 = the_low_target
.stopped_data_address ();
1088 child
->stopped_data_address
= 0;
1091 current_inferior
= saved_inferior
;
1095 /* Store the STOP_PC, with adjustment applied. This depends on the
1096 architecture being defined already (so that CHILD has a valid
1097 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1099 if (WIFSTOPPED (*wstatp
))
1100 child
->stop_pc
= get_stop_pc (child
);
1103 && WIFSTOPPED (*wstatp
)
1104 && the_low_target
.get_pc
!= NULL
)
1106 struct thread_info
*saved_inferior
= current_inferior
;
1107 struct regcache
*regcache
;
1110 current_inferior
= get_lwp_thread (child
);
1111 regcache
= get_thread_regcache (current_inferior
, 1);
1112 pc
= (*the_low_target
.get_pc
) (regcache
);
1113 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1114 current_inferior
= saved_inferior
;
1120 /* This function should only be called if the LWP got a SIGTRAP.
1122 Handle any tracepoint steps or hits. Return true if a tracepoint
1123 event was handled, 0 otherwise. */
1126 handle_tracepoints (struct lwp_info
*lwp
)
1128 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1129 int tpoint_related_event
= 0;
1131 /* And we need to be sure that any all-threads-stopping doesn't try
1132 to move threads out of the jump pads, as it could deadlock the
1133 inferior (LWP could be in the jump pad, maybe even holding the
1136 /* Do any necessary step collect actions. */
1137 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1139 /* See if we just hit a tracepoint and do its main collect
1141 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1143 if (tpoint_related_event
)
1146 fprintf (stderr
, "got a tracepoint event\n");
1153 /* Arrange for a breakpoint to be hit again later. We don't keep the
1154 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1155 will handle the current event, eventually we will resume this LWP,
1156 and this breakpoint will trap again. */
1159 cancel_breakpoint (struct lwp_info
*lwp
)
1161 struct thread_info
*saved_inferior
;
1163 /* There's nothing to do if we don't support breakpoints. */
1164 if (!supports_breakpoints ())
1167 /* breakpoint_at reads from current inferior. */
1168 saved_inferior
= current_inferior
;
1169 current_inferior
= get_lwp_thread (lwp
);
1171 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1175 "CB: Push back breakpoint for %s\n",
1176 target_pid_to_str (ptid_of (lwp
)));
1178 /* Back up the PC if necessary. */
1179 if (the_low_target
.decr_pc_after_break
)
1181 struct regcache
*regcache
1182 = get_thread_regcache (current_inferior
, 1);
1183 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1186 current_inferior
= saved_inferior
;
1193 "CB: No breakpoint found at %s for [%s]\n",
1194 paddress (lwp
->stop_pc
),
1195 target_pid_to_str (ptid_of (lwp
)));
1198 current_inferior
= saved_inferior
;
1202 /* When the event-loop is doing a step-over, this points at the thread
1204 ptid_t step_over_bkpt
;
1206 /* Wait for an event from child PID. If PID is -1, wait for any
1207 child. Store the stop status through the status pointer WSTAT.
1208 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1209 event was found and OPTIONS contains WNOHANG. Return the PID of
1210 the stopped child otherwise. */
1213 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1215 struct lwp_info
*event_child
, *requested_child
;
1218 requested_child
= NULL
;
1220 /* Check for a lwp with a pending status. */
1222 if (ptid_equal (ptid
, minus_one_ptid
)
1223 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1225 event_child
= (struct lwp_info
*)
1226 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1227 if (debug_threads
&& event_child
)
1228 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1232 requested_child
= find_lwp_pid (ptid
);
1234 if (requested_child
->status_pending_p
)
1235 event_child
= requested_child
;
1238 if (event_child
!= NULL
)
1241 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1242 lwpid_of (event_child
), event_child
->status_pending
);
1243 *wstat
= event_child
->status_pending
;
1244 event_child
->status_pending_p
= 0;
1245 event_child
->status_pending
= 0;
1246 current_inferior
= get_lwp_thread (event_child
);
1247 return lwpid_of (event_child
);
1250 /* We only enter this loop if no process has a pending wait status. Thus
1251 any action taken in response to a wait status inside this loop is
1252 responding as soon as we detect the status, not after any pending
1256 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1258 if ((options
& WNOHANG
) && event_child
== NULL
)
1261 fprintf (stderr
, "WNOHANG set, no event found\n");
1265 if (event_child
== NULL
)
1266 error ("event from unknown child");
1268 current_inferior
= get_lwp_thread (event_child
);
1270 /* Check for thread exit. */
1271 if (! WIFSTOPPED (*wstat
))
1274 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1276 /* If the last thread is exiting, just return. */
1277 if (last_thread_of_process_p (current_inferior
))
1280 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1281 lwpid_of (event_child
));
1282 return lwpid_of (event_child
);
1287 current_inferior
= (struct thread_info
*) all_threads
.head
;
1289 fprintf (stderr
, "Current inferior is now %ld\n",
1290 lwpid_of (get_thread_lwp (current_inferior
)));
1294 current_inferior
= NULL
;
1296 fprintf (stderr
, "Current inferior is now <NULL>\n");
1299 /* If we were waiting for this particular child to do something...
1300 well, it did something. */
1301 if (requested_child
!= NULL
)
1303 int lwpid
= lwpid_of (event_child
);
1305 /* Cancel the step-over operation --- the thread that
1306 started it is gone. */
1307 if (finish_step_over (event_child
))
1308 unstop_all_lwps (event_child
);
1309 delete_lwp (event_child
);
1313 delete_lwp (event_child
);
1315 /* Wait for a more interesting event. */
1319 if (event_child
->must_set_ptrace_flags
)
1321 ptrace (PTRACE_SETOPTIONS
, lwpid_of (event_child
),
1322 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
1323 event_child
->must_set_ptrace_flags
= 0;
1326 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1327 && *wstat
>> 16 != 0)
1329 handle_extended_wait (event_child
, *wstat
);
1333 /* If GDB is not interested in this signal, don't stop other
1334 threads, and don't report it to GDB. Just resume the
1335 inferior right away. We do this for threading-related
1336 signals as well as any that GDB specifically requested we
1337 ignore. But never ignore SIGSTOP if we sent it ourselves,
1338 and do not ignore signals when stepping - they may require
1339 special handling to skip the signal handler. */
1340 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1342 if (WIFSTOPPED (*wstat
)
1343 && !event_child
->stepping
1345 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1346 (current_process ()->private->thread_db
!= NULL
1347 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1348 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1351 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1352 && !(WSTOPSIG (*wstat
) == SIGSTOP
1353 && event_child
->stop_expected
))))
1355 siginfo_t info
, *info_p
;
1358 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1359 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1361 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1365 linux_resume_one_lwp (event_child
, event_child
->stepping
,
1366 WSTOPSIG (*wstat
), info_p
);
1370 if (WIFSTOPPED (*wstat
)
1371 && WSTOPSIG (*wstat
) == SIGSTOP
1372 && event_child
->stop_expected
)
1377 fprintf (stderr
, "Expected stop.\n");
1378 event_child
->stop_expected
= 0;
1380 should_stop
= (event_child
->last_resume_kind
== resume_stop
1381 || stopping_threads
);
1385 linux_resume_one_lwp (event_child
,
1386 event_child
->stepping
, 0, NULL
);
1391 return lwpid_of (event_child
);
1399 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1403 if (ptid_is_pid (ptid
))
1405 /* A request to wait for a specific tgid. This is not possible
1406 with waitpid, so instead, we wait for any child, and leave
1407 children we're not interested in right now with a pending
1408 status to report later. */
1409 wait_ptid
= minus_one_ptid
;
1418 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1421 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1423 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1425 if (! WIFSTOPPED (*wstat
))
1426 mark_lwp_dead (event_child
, *wstat
);
1429 event_child
->status_pending_p
= 1;
1430 event_child
->status_pending
= *wstat
;
1439 /* Count the LWP's that have had events. */
1442 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1444 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1447 gdb_assert (count
!= NULL
);
1449 /* Count only resumed LWPs that have a SIGTRAP event pending that
1450 should be reported to GDB. */
1451 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1452 && lp
->last_resume_kind
!= resume_stop
1453 && lp
->status_pending_p
1454 && WIFSTOPPED (lp
->status_pending
)
1455 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1456 && !breakpoint_inserted_here (lp
->stop_pc
))
1462 /* Select the LWP (if any) that is currently being single-stepped. */
1465 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1467 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1469 if (get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1470 && lp
->last_resume_kind
== resume_step
1471 && lp
->status_pending_p
)
1477 /* Select the Nth LWP that has had a SIGTRAP event that should be
1481 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1483 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1484 int *selector
= data
;
1486 gdb_assert (selector
!= NULL
);
1488 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1489 if (lp
->last_resume_kind
!= resume_stop
1490 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1491 && lp
->status_pending_p
1492 && WIFSTOPPED (lp
->status_pending
)
1493 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1494 && !breakpoint_inserted_here (lp
->stop_pc
))
1495 if ((*selector
)-- == 0)
1502 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1504 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1505 struct lwp_info
*event_lp
= data
;
1507 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1511 /* If a LWP other than the LWP that we're reporting an event for has
1512 hit a GDB breakpoint (as opposed to some random trap signal),
1513 then just arrange for it to hit it again later. We don't keep
1514 the SIGTRAP status and don't forward the SIGTRAP signal to the
1515 LWP. We will handle the current event, eventually we will resume
1516 all LWPs, and this one will get its breakpoint trap again.
1518 If we do not do this, then we run the risk that the user will
1519 delete or disable the breakpoint, but the LWP will have already
1522 if (lp
->last_resume_kind
!= resume_stop
1523 && get_lwp_thread (lp
)->last_status
.kind
== TARGET_WAITKIND_IGNORE
1524 && lp
->status_pending_p
1525 && WIFSTOPPED (lp
->status_pending
)
1526 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1528 && !lp
->stopped_by_watchpoint
1529 && cancel_breakpoint (lp
))
1530 /* Throw away the SIGTRAP. */
1531 lp
->status_pending_p
= 0;
1536 /* Select one LWP out of those that have events pending. */
1539 select_event_lwp (struct lwp_info
**orig_lp
)
1542 int random_selector
;
1543 struct lwp_info
*event_lp
;
1545 /* Give preference to any LWP that is being single-stepped. */
1547 = (struct lwp_info
*) find_inferior (&all_lwps
,
1548 select_singlestep_lwp_callback
, NULL
);
1549 if (event_lp
!= NULL
)
1553 "SEL: Select single-step %s\n",
1554 target_pid_to_str (ptid_of (event_lp
)));
1558 /* No single-stepping LWP. Select one at random, out of those
1559 which have had SIGTRAP events. */
1561 /* First see how many SIGTRAP events we have. */
1562 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1564 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1565 random_selector
= (int)
1566 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1568 if (debug_threads
&& num_events
> 1)
1570 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1571 num_events
, random_selector
);
1573 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1574 select_event_lwp_callback
,
1578 if (event_lp
!= NULL
)
1580 /* Switch the event LWP. */
1581 *orig_lp
= event_lp
;
1585 /* Set this inferior LWP's state as "want-stopped". We won't resume
1586 this LWP until the client gives us another action for it. */
1589 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1591 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1592 struct thread_info
*thread
= get_lwp_thread (lwp
);
1594 /* Most threads are stopped implicitly (all-stop); tag that with
1595 signal 0. The thread being explicitly reported stopped to the
1596 client, gets it's status fixed up afterwards. */
1597 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1598 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1600 lwp
->last_resume_kind
= resume_stop
;
1603 /* Set all LWP's states as "want-stopped". */
1606 gdb_wants_all_stopped (void)
1608 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1611 /* Wait for process, returns status. */
1614 linux_wait_1 (ptid_t ptid
,
1615 struct target_waitstatus
*ourstatus
, int target_options
)
1618 struct lwp_info
*event_child
;
1621 int step_over_finished
;
1622 int bp_explains_trap
;
1623 int maybe_internal_trap
;
1627 /* Translate generic target options into linux options. */
1629 if (target_options
& TARGET_WNOHANG
)
1633 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1635 /* If we were only supposed to resume one thread, only wait for
1636 that thread - if it's still alive. If it died, however - which
1637 can happen if we're coming from the thread death case below -
1638 then we need to make sure we restart the other threads. We could
1639 pick a thread at random or restart all; restarting all is less
1642 && !ptid_equal (cont_thread
, null_ptid
)
1643 && !ptid_equal (cont_thread
, minus_one_ptid
))
1645 struct thread_info
*thread
;
1647 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1650 /* No stepping, no signal - unless one is pending already, of course. */
1653 struct thread_resume resume_info
;
1654 resume_info
.thread
= minus_one_ptid
;
1655 resume_info
.kind
= resume_continue
;
1656 resume_info
.sig
= 0;
1657 linux_resume (&resume_info
, 1);
1663 if (ptid_equal (step_over_bkpt
, null_ptid
))
1664 pid
= linux_wait_for_event (ptid
, &w
, options
);
1668 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1669 target_pid_to_str (step_over_bkpt
));
1670 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1673 if (pid
== 0) /* only if TARGET_WNOHANG */
1676 event_child
= get_thread_lwp (current_inferior
);
1678 /* If we are waiting for a particular child, and it exited,
1679 linux_wait_for_event will return its exit status. Similarly if
1680 the last child exited. If this is not the last child, however,
1681 do not report it as exited until there is a 'thread exited' response
1682 available in the remote protocol. Instead, just wait for another event.
1683 This should be safe, because if the thread crashed we will already
1684 have reported the termination signal to GDB; that should stop any
1685 in-progress stepping operations, etc.
1687 Report the exit status of the last thread to exit. This matches
1688 LinuxThreads' behavior. */
1690 if (last_thread_of_process_p (current_inferior
))
1692 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1694 int pid
= pid_of (event_child
);
1695 struct process_info
*process
= find_process_pid (pid
);
1697 #ifdef USE_THREAD_DB
1698 thread_db_free (process
, 0);
1700 delete_lwp (event_child
);
1701 linux_remove_process (process
);
1703 current_inferior
= NULL
;
1707 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1708 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1711 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1715 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1716 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1719 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1723 return pid_to_ptid (pid
);
1728 if (!WIFSTOPPED (w
))
1732 /* If this event was not handled before, and is not a SIGTRAP, we
1733 report it. SIGILL and SIGSEGV are also treated as traps in case
1734 a breakpoint is inserted at the current PC. If this target does
1735 not support internal breakpoints at all, we also report the
1736 SIGTRAP without further processing; it's of no concern to us. */
1738 = (supports_breakpoints ()
1739 && (WSTOPSIG (w
) == SIGTRAP
1740 || ((WSTOPSIG (w
) == SIGILL
1741 || WSTOPSIG (w
) == SIGSEGV
)
1742 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
1744 if (maybe_internal_trap
)
1746 /* Handle anything that requires bookkeeping before deciding to
1747 report the event or continue waiting. */
1749 /* First check if we can explain the SIGTRAP with an internal
1750 breakpoint, or if we should possibly report the event to GDB.
1751 Do this before anything that may remove or insert a
1753 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
1755 /* We have a SIGTRAP, possibly a step-over dance has just
1756 finished. If so, tweak the state machine accordingly,
1757 reinsert breakpoints and delete any reinsert (software
1758 single-step) breakpoints. */
1759 step_over_finished
= finish_step_over (event_child
);
1761 /* Now invoke the callbacks of any internal breakpoints there. */
1762 check_breakpoints (event_child
->stop_pc
);
1764 /* Handle tracepoint data collecting. This may overflow the
1765 trace buffer, and cause a tracing stop, removing
1767 trace_event
= handle_tracepoints (event_child
);
1769 if (bp_explains_trap
)
1771 /* If we stepped or ran into an internal breakpoint, we've
1772 already handled it. So next time we resume (from this
1773 PC), we should step over it. */
1775 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1777 if (breakpoint_here (event_child
->stop_pc
))
1778 event_child
->need_step_over
= 1;
1783 /* We have some other signal, possibly a step-over dance was in
1784 progress, and it should be cancelled too. */
1785 step_over_finished
= finish_step_over (event_child
);
1790 /* We have all the data we need. Either report the event to GDB, or
1791 resume threads and keep waiting for more. */
1793 /* Check If GDB would be interested in this event. If GDB wanted
1794 this thread to single step, we always want to report the SIGTRAP,
1795 and let GDB handle it. Watchpoints should always be reported.
1796 So should signals we can't explain. A SIGTRAP we can't explain
1797 could be a GDB breakpoint --- we may or not support Z0
1798 breakpoints. If we do, we're be able to handle GDB breakpoints
1799 on top of internal breakpoints, by handling the internal
1800 breakpoint and still reporting the event to GDB. If we don't,
1801 we're out of luck, GDB won't see the breakpoint hit. */
1802 report_to_gdb
= (!maybe_internal_trap
1803 || event_child
->last_resume_kind
== resume_step
1804 || event_child
->stopped_by_watchpoint
1805 || (!step_over_finished
&& !bp_explains_trap
&& !trace_event
)
1806 || gdb_breakpoint_here (event_child
->stop_pc
));
1808 /* We found no reason GDB would want us to stop. We either hit one
1809 of our own breakpoints, or finished an internal step GDB
1810 shouldn't know about. */
1815 if (bp_explains_trap
)
1816 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1817 if (step_over_finished
)
1818 fprintf (stderr
, "Step-over finished.\n");
1820 fprintf (stderr
, "Tracepoint event.\n");
1823 /* We're not reporting this breakpoint to GDB, so apply the
1824 decr_pc_after_break adjustment to the inferior's regcache
1827 if (the_low_target
.set_pc
!= NULL
)
1829 struct regcache
*regcache
1830 = get_thread_regcache (get_lwp_thread (event_child
), 1);
1831 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
1834 /* We've finished stepping over a breakpoint. We've stopped all
1835 LWPs momentarily except the stepping one. This is where we
1836 resume them all again. We're going to keep waiting, so use
1837 proceed, which handles stepping over the next breakpoint. */
1839 fprintf (stderr
, "proceeding all threads.\n");
1840 proceed_all_lwps ();
1846 if (event_child
->last_resume_kind
== resume_step
)
1847 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
1848 if (event_child
->stopped_by_watchpoint
)
1849 fprintf (stderr
, "Stopped by watchpoint.\n");
1850 if (gdb_breakpoint_here (event_child
->stop_pc
))
1851 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
1853 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
1856 /* Alright, we're going to report a stop. */
1860 /* In all-stop, stop all threads. */
1863 /* If we're not waiting for a specific LWP, choose an event LWP
1864 from among those that have had events. Giving equal priority
1865 to all LWPs that have had events helps prevent
1867 if (ptid_equal (ptid
, minus_one_ptid
))
1869 event_child
->status_pending_p
= 1;
1870 event_child
->status_pending
= w
;
1872 select_event_lwp (&event_child
);
1874 event_child
->status_pending_p
= 0;
1875 w
= event_child
->status_pending
;
1878 /* Now that we've selected our final event LWP, cancel any
1879 breakpoints in other LWPs that have hit a GDB breakpoint.
1880 See the comment in cancel_breakpoints_callback to find out
1882 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
1886 /* If we just finished a step-over, then all threads had been
1887 momentarily paused. In all-stop, that's fine, we want
1888 threads stopped by now anyway. In non-stop, we need to
1889 re-resume threads that GDB wanted to be running. */
1890 if (step_over_finished
)
1891 unstop_all_lwps (event_child
);
1894 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1896 /* Do this before the gdb_wants_all_stopped calls below, since they
1897 always set last_resume_kind to resume_stop. */
1898 if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) == SIGSTOP
)
1900 /* A thread that has been requested to stop by GDB with vCont;t,
1901 and it stopped cleanly, so report as SIG0. The use of
1902 SIGSTOP is an implementation detail. */
1903 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1905 else if (event_child
->last_resume_kind
== resume_stop
&& WSTOPSIG (w
) != SIGSTOP
)
1907 /* A thread that has been requested to stop by GDB with vCont;t,
1908 but, it stopped for other reasons. */
1909 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1913 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1916 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
1920 /* From GDB's perspective, all-stop mode always stops all
1921 threads implicitly. Tag all threads as "want-stopped". */
1922 gdb_wants_all_stopped ();
1926 /* We're reporting this LWP as stopped. Update it's
1927 "want-stopped" state to what the client wants, until it gets
1928 a new resume action. */
1929 gdb_wants_lwp_stopped (&event_child
->head
);
1933 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1934 target_pid_to_str (ptid_of (event_child
)),
1936 ourstatus
->value
.sig
);
1938 get_lwp_thread (event_child
)->last_status
= *ourstatus
;
1939 return ptid_of (event_child
);
1942 /* Get rid of any pending event in the pipe. */
1944 async_file_flush (void)
1950 ret
= read (linux_event_pipe
[0], &buf
, 1);
1951 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1954 /* Put something in the pipe, so the event loop wakes up. */
1956 async_file_mark (void)
1960 async_file_flush ();
1963 ret
= write (linux_event_pipe
[1], "+", 1);
1964 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1966 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1967 be awakened anyway. */
1971 linux_wait (ptid_t ptid
,
1972 struct target_waitstatus
*ourstatus
, int target_options
)
1977 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1979 /* Flush the async file first. */
1980 if (target_is_async_p ())
1981 async_file_flush ();
1983 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1985 /* If at least one stop was reported, there may be more. A single
1986 SIGCHLD can signal more than one child stop. */
1987 if (target_is_async_p ()
1988 && (target_options
& TARGET_WNOHANG
) != 0
1989 && !ptid_equal (event_ptid
, null_ptid
))
1995 /* Send a signal to an LWP. */
1998 kill_lwp (unsigned long lwpid
, int signo
)
2000 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2001 fails, then we are not using nptl threads and we should be using kill. */
2005 static int tkill_failed
;
2012 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2013 if (errno
!= ENOSYS
)
2020 return kill (lwpid
, signo
);
2024 send_sigstop (struct inferior_list_entry
*entry
)
2026 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2032 pid
= lwpid_of (lwp
);
2034 /* If we already have a pending stop signal for this process, don't
2036 if (lwp
->stop_expected
)
2039 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2045 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2047 lwp
->stop_expected
= 1;
2048 kill_lwp (pid
, SIGSTOP
);
2052 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2054 /* It's dead, really. */
2057 /* Store the exit status for later. */
2058 lwp
->status_pending_p
= 1;
2059 lwp
->status_pending
= wstat
;
2061 /* Prevent trying to stop it. */
2064 /* No further stops are expected from a dead lwp. */
2065 lwp
->stop_expected
= 0;
2069 wait_for_sigstop (struct inferior_list_entry
*entry
)
2071 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2072 struct thread_info
*saved_inferior
;
2081 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2086 saved_inferior
= current_inferior
;
2087 if (saved_inferior
!= NULL
)
2088 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2090 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2092 ptid
= lwp
->head
.id
;
2095 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2097 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2099 /* If we stopped with a non-SIGSTOP signal, save it for later
2100 and record the pending SIGSTOP. If the process exited, just
2102 if (WIFSTOPPED (wstat
))
2105 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2106 lwpid_of (lwp
), WSTOPSIG (wstat
));
2108 if (WSTOPSIG (wstat
) != SIGSTOP
)
2111 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2112 lwpid_of (lwp
), wstat
);
2114 lwp
->status_pending_p
= 1;
2115 lwp
->status_pending
= wstat
;
2121 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2123 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2126 /* Leave this status pending for the next time we're able to
2127 report it. In the mean time, we'll report this lwp as
2128 dead to GDB, so GDB doesn't try to read registers and
2129 memory from it. This can only happen if this was the
2130 last thread of the process; otherwise, PID is removed
2131 from the thread tables before linux_wait_for_event
2133 mark_lwp_dead (lwp
, wstat
);
2137 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2138 current_inferior
= saved_inferior
;
2142 fprintf (stderr
, "Previously current thread died.\n");
2146 /* We can't change the current inferior behind GDB's back,
2147 otherwise, a subsequent command may apply to the wrong
2149 current_inferior
= NULL
;
2153 /* Set a valid thread as current. */
2154 set_desired_inferior (0);
2160 stop_all_lwps (void)
2162 stopping_threads
= 1;
2163 for_each_inferior (&all_lwps
, send_sigstop
);
2164 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2165 stopping_threads
= 0;
2168 /* Resume execution of the inferior process.
2169 If STEP is nonzero, single-step it.
2170 If SIGNAL is nonzero, give it that signal. */
2173 linux_resume_one_lwp (struct lwp_info
*lwp
,
2174 int step
, int signal
, siginfo_t
*info
)
2176 struct thread_info
*saved_inferior
;
2178 if (lwp
->stopped
== 0)
2181 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2182 user used the "jump" command, or "set $pc = foo"). */
2183 if (lwp
->stop_pc
!= get_pc (lwp
))
2185 /* Collecting 'while-stepping' actions doesn't make sense
2187 release_while_stepping_state_list (get_lwp_thread (lwp
));
2190 /* If we have pending signals or status, and a new signal, enqueue the
2191 signal. Also enqueue the signal if we are waiting to reinsert a
2192 breakpoint; it will be picked up again below. */
2194 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
2195 || lwp
->bp_reinsert
!= 0))
2197 struct pending_signals
*p_sig
;
2198 p_sig
= xmalloc (sizeof (*p_sig
));
2199 p_sig
->prev
= lwp
->pending_signals
;
2200 p_sig
->signal
= signal
;
2202 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2204 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2205 lwp
->pending_signals
= p_sig
;
2208 if (lwp
->status_pending_p
)
2211 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2212 " has pending status\n",
2213 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2214 lwp
->stop_expected
? "expected" : "not expected");
2218 saved_inferior
= current_inferior
;
2219 current_inferior
= get_lwp_thread (lwp
);
2222 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2223 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2224 lwp
->stop_expected
? "expected" : "not expected");
2226 /* This bit needs some thinking about. If we get a signal that
2227 we must report while a single-step reinsert is still pending,
2228 we often end up resuming the thread. It might be better to
2229 (ew) allow a stack of pending events; then we could be sure that
2230 the reinsert happened right away and not lose any signals.
2232 Making this stack would also shrink the window in which breakpoints are
2233 uninserted (see comment in linux_wait_for_lwp) but not enough for
2234 complete correctness, so it won't solve that problem. It may be
2235 worthwhile just to solve this one, however. */
2236 if (lwp
->bp_reinsert
!= 0)
2239 fprintf (stderr
, " pending reinsert at 0x%s\n",
2240 paddress (lwp
->bp_reinsert
));
2242 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2245 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2250 /* Postpone any pending signal. It was enqueued above. */
2254 /* If we have while-stepping actions in this thread set it stepping.
2255 If we have a signal to deliver, it may or may not be set to
2256 SIG_IGN, we don't know. Assume so, and allow collecting
2257 while-stepping into a signal handler. A possible smart thing to
2258 do would be to set an internal breakpoint at the signal return
2259 address, continue, and carry on catching this while-stepping
2260 action only when that breakpoint is hit. A future
2262 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2263 && can_hardware_single_step ())
2267 "lwp %ld has a while-stepping action -> forcing step.\n",
2272 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2274 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2275 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2276 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2279 /* If we have pending signals, consume one unless we are trying to reinsert
2281 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
2283 struct pending_signals
**p_sig
;
2285 p_sig
= &lwp
->pending_signals
;
2286 while ((*p_sig
)->prev
!= NULL
)
2287 p_sig
= &(*p_sig
)->prev
;
2289 signal
= (*p_sig
)->signal
;
2290 if ((*p_sig
)->info
.si_signo
!= 0)
2291 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2297 if (the_low_target
.prepare_to_resume
!= NULL
)
2298 the_low_target
.prepare_to_resume (lwp
);
2300 regcache_invalidate_one ((struct inferior_list_entry
*)
2301 get_lwp_thread (lwp
));
2304 lwp
->stopped_by_watchpoint
= 0;
2305 lwp
->stepping
= step
;
2306 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2307 /* Coerce to a uintptr_t first to avoid potential gcc warning
2308 of coercing an 8 byte integer to a 4 byte pointer. */
2309 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2311 current_inferior
= saved_inferior
;
2314 /* ESRCH from ptrace either means that the thread was already
2315 running (an error) or that it is gone (a race condition). If
2316 it's gone, we will get a notification the next time we wait,
2317 so we can ignore the error. We could differentiate these
2318 two, but it's tricky without waiting; the thread still exists
2319 as a zombie, so sending it signal 0 would succeed. So just
2324 perror_with_name ("ptrace");
2328 struct thread_resume_array
2330 struct thread_resume
*resume
;
2334 /* This function is called once per thread. We look up the thread
2335 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2338 This algorithm is O(threads * resume elements), but resume elements
2339 is small (and will remain small at least until GDB supports thread
2342 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2344 struct lwp_info
*lwp
;
2345 struct thread_info
*thread
;
2347 struct thread_resume_array
*r
;
2349 thread
= (struct thread_info
*) entry
;
2350 lwp
= get_thread_lwp (thread
);
2353 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2355 ptid_t ptid
= r
->resume
[ndx
].thread
;
2356 if (ptid_equal (ptid
, minus_one_ptid
)
2357 || ptid_equal (ptid
, entry
->id
)
2358 || (ptid_is_pid (ptid
)
2359 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2360 || (ptid_get_lwp (ptid
) == -1
2361 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2363 if (r
->resume
[ndx
].kind
== resume_stop
2364 && lwp
->last_resume_kind
== resume_stop
)
2367 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2368 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2376 lwp
->resume
= &r
->resume
[ndx
];
2377 lwp
->last_resume_kind
= lwp
->resume
->kind
;
2382 /* No resume action for this thread. */
2389 /* Set *FLAG_P if this lwp has an interesting status pending. */
2391 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
2393 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2395 /* LWPs which will not be resumed are not interesting, because
2396 we might not wait for them next time through linux_wait. */
2397 if (lwp
->resume
== NULL
)
2400 if (lwp
->status_pending_p
)
2401 * (int *) flag_p
= 1;
2406 /* Return 1 if this lwp that GDB wants running is stopped at an
2407 internal breakpoint that we need to step over. It assumes that any
2408 required STOP_PC adjustment has already been propagated to the
2409 inferior's regcache. */
2412 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
2414 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2415 struct thread_info
*saved_inferior
;
2418 /* LWPs which will not be resumed are not interesting, because we
2419 might not wait for them next time through linux_wait. */
2425 "Need step over [LWP %ld]? Ignoring, not stopped\n",
2430 if (lwp
->last_resume_kind
== resume_stop
)
2434 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
2439 if (!lwp
->need_step_over
)
2443 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
2446 if (lwp
->status_pending_p
)
2450 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
2455 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
2459 /* If the PC has changed since we stopped, then don't do anything,
2460 and let the breakpoint/tracepoint be hit. This happens if, for
2461 instance, GDB handled the decr_pc_after_break subtraction itself,
2462 GDB is OOL stepping this thread, or the user has issued a "jump"
2463 command, or poked thread's registers herself. */
2464 if (pc
!= lwp
->stop_pc
)
2468 "Need step over [LWP %ld]? Cancelling, PC was changed. "
2469 "Old stop_pc was 0x%s, PC is now 0x%s\n",
2470 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
2472 lwp
->need_step_over
= 0;
2476 saved_inferior
= current_inferior
;
2477 current_inferior
= get_lwp_thread (lwp
);
2479 /* We can only step over breakpoints we know about. */
2480 if (breakpoint_here (pc
))
2482 /* Don't step over a breakpoint that GDB expects to hit
2484 if (gdb_breakpoint_here (pc
))
2488 "Need step over [LWP %ld]? yes, but found"
2489 " GDB breakpoint at 0x%s; skipping step over\n",
2490 lwpid_of (lwp
), paddress (pc
));
2492 current_inferior
= saved_inferior
;
2499 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
2500 lwpid_of (lwp
), paddress (pc
));
2502 /* We've found an lwp that needs stepping over --- return 1 so
2503 that find_inferior stops looking. */
2504 current_inferior
= saved_inferior
;
2506 /* If the step over is cancelled, this is set again. */
2507 lwp
->need_step_over
= 0;
2512 current_inferior
= saved_inferior
;
2516 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
2517 lwpid_of (lwp
), paddress (pc
));
2522 /* Start a step-over operation on LWP. When LWP stopped at a
2523 breakpoint, to make progress, we need to remove the breakpoint out
2524 of the way. If we let other threads run while we do that, they may
2525 pass by the breakpoint location and miss hitting it. To avoid
2526 that, a step-over momentarily stops all threads while LWP is
2527 single-stepped while the breakpoint is temporarily uninserted from
2528 the inferior. When the single-step finishes, we reinsert the
2529 breakpoint, and let all threads that are supposed to be running,
2532 On targets that don't support hardware single-step, we don't
2533 currently support full software single-stepping. Instead, we only
2534 support stepping over the thread event breakpoint, by asking the
2535 low target where to place a reinsert breakpoint. Since this
2536 routine assumes the breakpoint being stepped over is a thread event
2537 breakpoint, it usually assumes the return address of the current
2538 function is a good enough place to set the reinsert breakpoint. */
2541 start_step_over (struct lwp_info
*lwp
)
2543 struct thread_info
*saved_inferior
;
2549 "Starting step-over on LWP %ld. Stopping all threads\n",
2555 fprintf (stderr
, "Done stopping all threads for step-over.\n");
2557 /* Note, we should always reach here with an already adjusted PC,
2558 either by GDB (if we're resuming due to GDB's request), or by our
2559 caller, if we just finished handling an internal breakpoint GDB
2560 shouldn't care about. */
2563 saved_inferior
= current_inferior
;
2564 current_inferior
= get_lwp_thread (lwp
);
2566 lwp
->bp_reinsert
= pc
;
2567 uninsert_breakpoints_at (pc
);
2569 if (can_hardware_single_step ())
2575 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
2576 set_reinsert_breakpoint (raddr
);
2580 current_inferior
= saved_inferior
;
2582 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2584 /* Require next event from this LWP. */
2585 step_over_bkpt
= lwp
->head
.id
;
2589 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
2590 start_step_over, if still there, and delete any reinsert
2591 breakpoints we've set, on non hardware single-step targets. */
2594 finish_step_over (struct lwp_info
*lwp
)
2596 if (lwp
->bp_reinsert
!= 0)
2599 fprintf (stderr
, "Finished step over.\n");
2601 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
2602 may be no breakpoint to reinsert there by now. */
2603 reinsert_breakpoints_at (lwp
->bp_reinsert
);
2605 lwp
->bp_reinsert
= 0;
2607 /* Delete any software-single-step reinsert breakpoints. No
2608 longer needed. We don't have to worry about other threads
2609 hitting this trap, and later not being able to explain it,
2610 because we were stepping over a breakpoint, and we hold all
2611 threads but LWP stopped while doing that. */
2612 if (!can_hardware_single_step ())
2613 delete_reinsert_breakpoints ();
2615 step_over_bkpt
= null_ptid
;
2622 /* This function is called once per thread. We check the thread's resume
2623 request, which will tell us whether to resume, step, or leave the thread
2624 stopped; and what signal, if any, it should be sent.
2626 For threads which we aren't explicitly told otherwise, we preserve
2627 the stepping flag; this is used for stepping over gdbserver-placed
2630 If pending_flags was set in any thread, we queue any needed
2631 signals, since we won't actually resume. We already have a pending
2632 event to report, so we don't need to preserve any step requests;
2633 they should be re-issued if necessary. */
2636 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
2638 struct lwp_info
*lwp
;
2639 struct thread_info
*thread
;
2641 int leave_all_stopped
= * (int *) arg
;
2644 thread
= (struct thread_info
*) entry
;
2645 lwp
= get_thread_lwp (thread
);
2647 if (lwp
->resume
== NULL
)
2650 if (lwp
->resume
->kind
== resume_stop
)
2653 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
2658 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
2660 /* Stop the thread, and wait for the event asynchronously,
2661 through the event loop. */
2662 send_sigstop (&lwp
->head
);
2667 fprintf (stderr
, "already stopped LWP %ld\n",
2670 /* The LWP may have been stopped in an internal event that
2671 was not meant to be notified back to GDB (e.g., gdbserver
2672 breakpoint), so we should be reporting a stop event in
2675 /* If the thread already has a pending SIGSTOP, this is a
2676 no-op. Otherwise, something later will presumably resume
2677 the thread and this will cause it to cancel any pending
2678 operation, due to last_resume_kind == resume_stop. If
2679 the thread already has a pending status to report, we
2680 will still report it the next time we wait - see
2681 status_pending_p_callback. */
2682 send_sigstop (&lwp
->head
);
2685 /* For stop requests, we're done. */
2687 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2691 /* If this thread which is about to be resumed has a pending status,
2692 then don't resume any threads - we can just report the pending
2693 status. Make sure to queue any signals that would otherwise be
2694 sent. In all-stop mode, we do this decision based on if *any*
2695 thread has a pending status. If there's a thread that needs the
2696 step-over-breakpoint dance, then don't resume any other thread
2697 but that particular one. */
2698 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
2703 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2705 step
= (lwp
->resume
->kind
== resume_step
);
2706 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2711 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2713 /* If we have a new signal, enqueue the signal. */
2714 if (lwp
->resume
->sig
!= 0)
2716 struct pending_signals
*p_sig
;
2717 p_sig
= xmalloc (sizeof (*p_sig
));
2718 p_sig
->prev
= lwp
->pending_signals
;
2719 p_sig
->signal
= lwp
->resume
->sig
;
2720 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2722 /* If this is the same signal we were previously stopped by,
2723 make sure to queue its siginfo. We can ignore the return
2724 value of ptrace; if it fails, we'll skip
2725 PTRACE_SETSIGINFO. */
2726 if (WIFSTOPPED (lwp
->last_status
)
2727 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2728 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2730 lwp
->pending_signals
= p_sig
;
2734 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2740 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2742 struct thread_resume_array array
= { resume_info
, n
};
2743 struct lwp_info
*need_step_over
= NULL
;
2745 int leave_all_stopped
;
2747 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2749 /* If there is a thread which would otherwise be resumed, which has
2750 a pending status, then don't resume any threads - we can just
2751 report the pending status. Make sure to queue any signals that
2752 would otherwise be sent. In non-stop mode, we'll apply this
2753 logic to each thread individually. We consume all pending events
2754 before considering to start a step-over (in all-stop). */
2757 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
2759 /* If there is a thread which would otherwise be resumed, which is
2760 stopped at a breakpoint that needs stepping over, then don't
2761 resume any threads - have it step over the breakpoint with all
2762 other threads stopped, then resume all threads again. Make sure
2763 to queue any signals that would otherwise be delivered or
2765 if (!any_pending
&& supports_breakpoints ())
2767 = (struct lwp_info
*) find_inferior (&all_lwps
,
2768 need_step_over_p
, NULL
);
2770 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
2774 if (need_step_over
!= NULL
)
2775 fprintf (stderr
, "Not resuming all, need step over\n");
2776 else if (any_pending
)
2778 "Not resuming, all-stop and found "
2779 "an LWP with pending status\n");
2781 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
2784 /* Even if we're leaving threads stopped, queue all signals we'd
2785 otherwise deliver. */
2786 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
2789 start_step_over (need_step_over
);
2792 /* This function is called once per thread. We check the thread's
2793 last resume request, which will tell us whether to resume, step, or
2794 leave the thread stopped. Any signal the client requested to be
2795 delivered has already been enqueued at this point.
2797 If any thread that GDB wants running is stopped at an internal
2798 breakpoint that needs stepping over, we start a step-over operation
2799 on that particular thread, and leave all others stopped. */
2802 proceed_one_lwp (struct inferior_list_entry
*entry
)
2804 struct lwp_info
*lwp
;
2807 lwp
= (struct lwp_info
*) entry
;
2811 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
2816 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
2820 if (lwp
->last_resume_kind
== resume_stop
)
2823 fprintf (stderr
, " client wants LWP %ld stopped\n", lwpid_of (lwp
));
2827 if (lwp
->status_pending_p
)
2830 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
2838 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
2842 step
= lwp
->last_resume_kind
== resume_step
;
2843 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2846 /* When we finish a step-over, set threads running again. If there's
2847 another thread that may need a step-over, now's the time to start
2848 it. Eventually, we'll move all threads past their breakpoints. */
2851 proceed_all_lwps (void)
2853 struct lwp_info
*need_step_over
;
2855 /* If there is a thread which would otherwise be resumed, which is
2856 stopped at a breakpoint that needs stepping over, then don't
2857 resume any threads - have it step over the breakpoint with all
2858 other threads stopped, then resume all threads again. */
2860 if (supports_breakpoints ())
2863 = (struct lwp_info
*) find_inferior (&all_lwps
,
2864 need_step_over_p
, NULL
);
2866 if (need_step_over
!= NULL
)
2869 fprintf (stderr
, "proceed_all_lwps: found "
2870 "thread %ld needing a step-over\n",
2871 lwpid_of (need_step_over
));
2873 start_step_over (need_step_over
);
2879 fprintf (stderr
, "Proceeding, no step-over needed\n");
2881 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2884 /* Stopped LWPs that the client wanted to be running, that don't have
2885 pending statuses, are set to run again, except for EXCEPT, if not
2886 NULL. This undoes a stop_all_lwps call. */
2889 unstop_all_lwps (struct lwp_info
*except
)
2895 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
2898 "unstopping all lwps\n");
2901 /* Make sure proceed_one_lwp doesn't try to resume this thread. */
2903 ++except
->suspended
;
2905 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2908 --except
->suspended
;
2911 #ifdef HAVE_LINUX_USRREGS
2914 register_addr (int regnum
)
2918 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2919 error ("Invalid register number %d.", regnum
);
2921 addr
= the_low_target
.regmap
[regnum
];
2926 /* Fetch one register. */
2928 fetch_register (struct regcache
*regcache
, int regno
)
2935 if (regno
>= the_low_target
.num_regs
)
2937 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2940 regaddr
= register_addr (regno
);
2944 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2945 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2946 & - sizeof (PTRACE_XFER_TYPE
));
2947 buf
= alloca (size
);
2948 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2951 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2952 ptrace (PTRACE_PEEKUSER
, pid
,
2953 /* Coerce to a uintptr_t first to avoid potential gcc warning
2954 of coercing an 8 byte integer to a 4 byte pointer. */
2955 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2956 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2958 error ("reading register %d: %s", regno
, strerror (errno
));
2961 if (the_low_target
.supply_ptrace_register
)
2962 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2964 supply_register (regcache
, regno
, buf
);
2967 /* Fetch all registers, or just one, from the child process. */
2969 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
2972 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2973 fetch_register (regcache
, regno
);
2975 fetch_register (regcache
, regno
);
2978 /* Store our register values back into the inferior.
2979 If REGNO is -1, do this for all registers.
2980 Otherwise, REGNO specifies which register (so we can save time). */
2982 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
2991 if (regno
>= the_low_target
.num_regs
)
2994 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
2997 regaddr
= register_addr (regno
);
3001 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3002 & - sizeof (PTRACE_XFER_TYPE
);
3003 buf
= alloca (size
);
3004 memset (buf
, 0, size
);
3006 if (the_low_target
.collect_ptrace_register
)
3007 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3009 collect_register (regcache
, regno
, buf
);
3011 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3012 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3015 ptrace (PTRACE_POKEUSER
, pid
,
3016 /* Coerce to a uintptr_t first to avoid potential gcc warning
3017 about coercing an 8 byte integer to a 4 byte pointer. */
3018 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3019 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3022 /* At this point, ESRCH should mean the process is
3023 already gone, in which case we simply ignore attempts
3024 to change its registers. See also the related
3025 comment in linux_resume_one_lwp. */
3029 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3030 error ("writing register %d: %s", regno
, strerror (errno
));
3032 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3036 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3037 usr_store_inferior_registers (regcache
, regno
);
3039 #endif /* HAVE_LINUX_USRREGS */
3043 #ifdef HAVE_LINUX_REGSETS
3046 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3048 struct regset_info
*regset
;
3049 int saw_general_regs
= 0;
3053 regset
= target_regsets
;
3055 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3056 while (regset
->size
>= 0)
3061 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3067 buf
= xmalloc (regset
->size
);
3069 nt_type
= regset
->nt_type
;
3073 iov
.iov_len
= regset
->size
;
3074 data
= (void *) &iov
;
3080 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3082 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3088 /* If we get EIO on a regset, do not try it again for
3090 disabled_regsets
[regset
- target_regsets
] = 1;
3097 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3102 else if (regset
->type
== GENERAL_REGS
)
3103 saw_general_regs
= 1;
3104 regset
->store_function (regcache
, buf
);
3108 if (saw_general_regs
)
3115 regsets_store_inferior_registers (struct regcache
*regcache
)
3117 struct regset_info
*regset
;
3118 int saw_general_regs
= 0;
3122 regset
= target_regsets
;
3124 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3125 while (regset
->size
>= 0)
3130 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3136 buf
= xmalloc (regset
->size
);
3138 /* First fill the buffer with the current register set contents,
3139 in case there are any items in the kernel's regset that are
3140 not in gdbserver's regcache. */
3142 nt_type
= regset
->nt_type
;
3146 iov
.iov_len
= regset
->size
;
3147 data
= (void *) &iov
;
3153 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3155 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3160 /* Then overlay our cached registers on that. */
3161 regset
->fill_function (regcache
, buf
);
3163 /* Only now do we write the register set. */
3165 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3167 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3175 /* If we get EIO on a regset, do not try it again for
3177 disabled_regsets
[regset
- target_regsets
] = 1;
3181 else if (errno
== ESRCH
)
3183 /* At this point, ESRCH should mean the process is
3184 already gone, in which case we simply ignore attempts
3185 to change its registers. See also the related
3186 comment in linux_resume_one_lwp. */
3192 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3195 else if (regset
->type
== GENERAL_REGS
)
3196 saw_general_regs
= 1;
3200 if (saw_general_regs
)
3207 #endif /* HAVE_LINUX_REGSETS */
3211 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3213 #ifdef HAVE_LINUX_REGSETS
3214 if (regsets_fetch_inferior_registers (regcache
) == 0)
3217 #ifdef HAVE_LINUX_USRREGS
3218 usr_fetch_inferior_registers (regcache
, regno
);
3223 linux_store_registers (struct regcache
*regcache
, int regno
)
3225 #ifdef HAVE_LINUX_REGSETS
3226 if (regsets_store_inferior_registers (regcache
) == 0)
3229 #ifdef HAVE_LINUX_USRREGS
3230 usr_store_inferior_registers (regcache
, regno
);
3235 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3236 to debugger memory starting at MYADDR. */
3239 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3242 /* Round starting address down to longword boundary. */
3243 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3244 /* Round ending address up; get number of longwords that makes. */
3246 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3247 / sizeof (PTRACE_XFER_TYPE
);
3248 /* Allocate buffer of that many longwords. */
3249 register PTRACE_XFER_TYPE
*buffer
3250 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3253 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3255 /* Try using /proc. Don't bother for one word. */
3256 if (len
>= 3 * sizeof (long))
3258 /* We could keep this file open and cache it - possibly one per
3259 thread. That requires some juggling, but is even faster. */
3260 sprintf (filename
, "/proc/%d/mem", pid
);
3261 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3265 /* If pread64 is available, use it. It's faster if the kernel
3266 supports it (only one syscall), and it's 64-bit safe even on
3267 32-bit platforms (for instance, SPARC debugging a SPARC64
3270 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3272 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3284 /* Read all the longwords */
3285 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3288 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3289 about coercing an 8 byte integer to a 4 byte pointer. */
3290 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3291 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3296 /* Copy appropriate bytes out of the buffer. */
3298 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
3304 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3305 memory at MEMADDR. On failure (cannot write to the inferior)
3306 returns the value of errno. */
3309 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
3312 /* Round starting address down to longword boundary. */
3313 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3314 /* Round ending address up; get number of longwords that makes. */
3316 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
3317 /* Allocate buffer of that many longwords. */
3318 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3319 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3323 /* Dump up to four bytes. */
3324 unsigned int val
= * (unsigned int *) myaddr
;
3330 val
= val
& 0xffffff;
3331 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
3332 val
, (long)memaddr
);
3335 /* Fill start and end extra bytes of buffer with existing memory data. */
3338 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3339 about coercing an 8 byte integer to a 4 byte pointer. */
3340 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
3341 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3349 = ptrace (PTRACE_PEEKTEXT
, pid
,
3350 /* Coerce to a uintptr_t first to avoid potential gcc warning
3351 about coercing an 8 byte integer to a 4 byte pointer. */
3352 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
3353 * sizeof (PTRACE_XFER_TYPE
)),
3359 /* Copy data to be written over corresponding part of buffer. */
3361 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
3363 /* Write the entire buffer. */
3365 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3368 ptrace (PTRACE_POKETEXT
, pid
,
3369 /* Coerce to a uintptr_t first to avoid potential gcc warning
3370 about coercing an 8 byte integer to a 4 byte pointer. */
3371 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
3372 (PTRACE_ARG4_TYPE
) buffer
[i
]);
3380 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
3381 static int linux_supports_tracefork_flag
;
3383 /* Helper functions for linux_test_for_tracefork, called via clone (). */
3386 linux_tracefork_grandchild (void *arg
)
3391 #define STACK_SIZE 4096
3394 linux_tracefork_child (void *arg
)
3396 ptrace (PTRACE_TRACEME
, 0, 0, 0);
3397 kill (getpid (), SIGSTOP
);
3399 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3402 linux_tracefork_grandchild (NULL
);
3404 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3407 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
3408 CLONE_VM
| SIGCHLD
, NULL
);
3410 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
3411 CLONE_VM
| SIGCHLD
, NULL
);
3414 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3419 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
3420 sure that we can enable the option, and that it had the desired
3424 linux_test_for_tracefork (void)
3426 int child_pid
, ret
, status
;
3428 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3429 char *stack
= xmalloc (STACK_SIZE
* 4);
3430 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3432 linux_supports_tracefork_flag
= 0;
3434 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3436 child_pid
= fork ();
3438 linux_tracefork_child (NULL
);
3440 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3442 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
3444 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
3445 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3446 #else /* !__ia64__ */
3447 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
3448 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3449 #endif /* !__ia64__ */
3451 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3453 if (child_pid
== -1)
3454 perror_with_name ("clone");
3456 ret
= my_waitpid (child_pid
, &status
, 0);
3458 perror_with_name ("waitpid");
3459 else if (ret
!= child_pid
)
3460 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
3461 if (! WIFSTOPPED (status
))
3462 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
3464 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
3465 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
3468 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3471 warning ("linux_test_for_tracefork: failed to kill child");
3475 ret
= my_waitpid (child_pid
, &status
, 0);
3476 if (ret
!= child_pid
)
3477 warning ("linux_test_for_tracefork: failed to wait for killed child");
3478 else if (!WIFSIGNALED (status
))
3479 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
3480 "killed child", status
);
3485 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
3487 warning ("linux_test_for_tracefork: failed to resume child");
3489 ret
= my_waitpid (child_pid
, &status
, 0);
3491 if (ret
== child_pid
&& WIFSTOPPED (status
)
3492 && status
>> 16 == PTRACE_EVENT_FORK
)
3495 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
3496 if (ret
== 0 && second_pid
!= 0)
3500 linux_supports_tracefork_flag
= 1;
3501 my_waitpid (second_pid
, &second_status
, 0);
3502 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
3504 warning ("linux_test_for_tracefork: failed to kill second child");
3505 my_waitpid (second_pid
, &status
, 0);
3509 warning ("linux_test_for_tracefork: unexpected result from waitpid "
3510 "(%d, status 0x%x)", ret
, status
);
3514 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3516 warning ("linux_test_for_tracefork: failed to kill child");
3517 my_waitpid (child_pid
, &status
, 0);
3519 while (WIFSTOPPED (status
));
3521 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3523 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3528 linux_look_up_symbols (void)
3530 #ifdef USE_THREAD_DB
3531 struct process_info
*proc
= current_process ();
3533 if (proc
->private->thread_db
!= NULL
)
3536 /* If the kernel supports tracing forks then it also supports tracing
3537 clones, and then we don't need to use the magic thread event breakpoint
3538 to learn about threads. */
3539 thread_db_init (!linux_supports_tracefork_flag
);
3544 linux_request_interrupt (void)
3546 extern unsigned long signal_pid
;
3548 if (!ptid_equal (cont_thread
, null_ptid
)
3549 && !ptid_equal (cont_thread
, minus_one_ptid
))
3551 struct lwp_info
*lwp
;
3554 lwp
= get_thread_lwp (current_inferior
);
3555 lwpid
= lwpid_of (lwp
);
3556 kill_lwp (lwpid
, SIGINT
);
3559 kill_lwp (signal_pid
, SIGINT
);
3562 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
3563 to debugger memory starting at MYADDR. */
3566 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
3568 char filename
[PATH_MAX
];
3570 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3572 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
3574 fd
= open (filename
, O_RDONLY
);
3578 if (offset
!= (CORE_ADDR
) 0
3579 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3582 n
= read (fd
, myaddr
, len
);
3589 /* These breakpoint and watchpoint related wrapper functions simply
3590 pass on the function call if the target has registered a
3591 corresponding function. */
3594 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
3596 if (the_low_target
.insert_point
!= NULL
)
3597 return the_low_target
.insert_point (type
, addr
, len
);
3599 /* Unsupported (see target.h). */
3604 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
3606 if (the_low_target
.remove_point
!= NULL
)
3607 return the_low_target
.remove_point (type
, addr
, len
);
3609 /* Unsupported (see target.h). */
3614 linux_stopped_by_watchpoint (void)
3616 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3618 return lwp
->stopped_by_watchpoint
;
3622 linux_stopped_data_address (void)
3624 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3626 return lwp
->stopped_data_address
;
3629 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3630 #if defined(__mcoldfire__)
3631 /* These should really be defined in the kernel's ptrace.h header. */
3632 #define PT_TEXT_ADDR 49*4
3633 #define PT_DATA_ADDR 50*4
3634 #define PT_TEXT_END_ADDR 51*4
3637 /* Under uClinux, programs are loaded at non-zero offsets, which we need
3638 to tell gdb about. */
3641 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
3643 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
3644 unsigned long text
, text_end
, data
;
3645 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3649 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
3650 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
3651 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
3655 /* Both text and data offsets produced at compile-time (and so
3656 used by gdb) are relative to the beginning of the program,
3657 with the data segment immediately following the text segment.
3658 However, the actual runtime layout in memory may put the data
3659 somewhere else, so when we send gdb a data base-address, we
3660 use the real data base address and subtract the compile-time
3661 data base-address from it (which is just the length of the
3662 text segment). BSS immediately follows data in both
3665 *data_p
= data
- (text_end
- text
);
3675 compare_ints (const void *xa
, const void *xb
)
3677 int a
= *(const int *)xa
;
3678 int b
= *(const int *)xb
;
3684 unique (int *b
, int *e
)
3693 /* Given PID, iterates over all threads in that process.
3695 Information about each thread, in a format suitable for qXfer:osdata:thread
3696 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
3697 initialized, and the caller is responsible for finishing and appending '\0'
3700 The list of cores that threads are running on is assigned to *CORES, if it
3701 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
3702 should free *CORES. */
3705 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
3709 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
3713 struct stat statbuf
;
3715 sprintf (pathname
, "/proc/%d/task", pid
);
3716 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
3718 dir
= opendir (pathname
);
3721 free (core_numbers
);
3725 while ((dp
= readdir (dir
)) != NULL
)
3727 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
3731 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
3735 char s
[sizeof ("4294967295")];
3736 sprintf (s
, "%u", core
);
3738 if (count
== allocated
)
3741 core_numbers
= realloc (core_numbers
,
3742 sizeof (int) * allocated
);
3744 core_numbers
[count
++] = core
;
3746 buffer_xml_printf (buffer
,
3748 "<column name=\"pid\">%d</column>"
3749 "<column name=\"tid\">%s</column>"
3750 "<column name=\"core\">%s</column>"
3751 "</item>", pid
, dp
->d_name
, s
);
3756 buffer_xml_printf (buffer
,
3758 "<column name=\"pid\">%d</column>"
3759 "<column name=\"tid\">%s</column>"
3760 "</item>", pid
, dp
->d_name
);
3771 struct buffer buffer2
;
3774 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
3776 /* Remove duplicates. */
3778 e
= unique (b
, core_numbers
+ count
);
3780 buffer_init (&buffer2
);
3782 for (b
= core_numbers
; b
!= e
; ++b
)
3784 char number
[sizeof ("4294967295")];
3785 sprintf (number
, "%u", *b
);
3786 buffer_xml_printf (&buffer2
, "%s%s",
3787 (b
== core_numbers
) ? "" : ",", number
);
3789 buffer_grow_str0 (&buffer2
, "");
3791 *cores
= buffer_finish (&buffer2
);
3794 free (core_numbers
);
3798 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3802 char cmd
[MAXPATHLEN
+ 1];
3804 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3806 if ((f
= fopen (pathname
, "r")) != NULL
)
3808 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3813 for (i
= 0; i
< len
; i
++)
3818 buffer_xml_printf (buffer
,
3820 "<column name=\"pid\">%d</column>"
3821 "<column name=\"user\">%s</column>"
3822 "<column name=\"command\">%s</column>",
3827 /* This only collects core numbers, and does not print threads. */
3828 list_threads (pid
, NULL
, &cores
);
3832 buffer_xml_printf (buffer
,
3833 "<column name=\"cores\">%s</column>", cores
);
3837 buffer_xml_printf (buffer
, "</item>");
3844 linux_qxfer_osdata (const char *annex
,
3845 unsigned char *readbuf
, unsigned const char *writebuf
,
3846 CORE_ADDR offset
, int len
)
3848 /* We make the process list snapshot when the object starts to be
3850 static const char *buf
;
3851 static long len_avail
= -1;
3852 static struct buffer buffer
;
3858 if (strcmp (annex
, "processes") == 0)
3860 else if (strcmp (annex
, "threads") == 0)
3865 if (!readbuf
|| writebuf
)
3870 if (len_avail
!= -1 && len_avail
!= 0)
3871 buffer_free (&buffer
);
3874 buffer_init (&buffer
);
3876 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3878 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3880 dirp
= opendir ("/proc");
3884 while ((dp
= readdir (dirp
)) != NULL
)
3886 struct stat statbuf
;
3887 char procentry
[sizeof ("/proc/4294967295")];
3889 if (!isdigit (dp
->d_name
[0])
3890 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3893 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3894 if (stat (procentry
, &statbuf
) == 0
3895 && S_ISDIR (statbuf
.st_mode
))
3897 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3901 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3902 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3906 list_threads (pid
, &buffer
, NULL
);
3913 buffer_grow_str0 (&buffer
, "</osdata>\n");
3914 buf
= buffer_finish (&buffer
);
3915 len_avail
= strlen (buf
);
3918 if (offset
>= len_avail
)
3920 /* Done. Get rid of the data. */
3921 buffer_free (&buffer
);
3927 if (len
> len_avail
- offset
)
3928 len
= len_avail
- offset
;
3929 memcpy (readbuf
, buf
+ offset
, len
);
3934 /* Convert a native/host siginfo object, into/from the siginfo in the
3935 layout of the inferiors' architecture. */
3938 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3942 if (the_low_target
.siginfo_fixup
!= NULL
)
3943 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3945 /* If there was no callback, or the callback didn't do anything,
3946 then just do a straight memcpy. */
3950 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3952 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3957 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3958 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3961 struct siginfo siginfo
;
3962 char inf_siginfo
[sizeof (struct siginfo
)];
3964 if (current_inferior
== NULL
)
3967 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3970 fprintf (stderr
, "%s siginfo for lwp %d.\n",
3971 readbuf
!= NULL
? "Reading" : "Writing",
3974 if (offset
> sizeof (siginfo
))
3977 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
3980 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
3981 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3982 inferior with a 64-bit GDBSERVER should look the same as debugging it
3983 with a 32-bit GDBSERVER, we need to convert it. */
3984 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3986 if (offset
+ len
> sizeof (siginfo
))
3987 len
= sizeof (siginfo
) - offset
;
3989 if (readbuf
!= NULL
)
3990 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3993 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3995 /* Convert back to ptrace layout before flushing it out. */
3996 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3998 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4005 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4006 so we notice when children change state; as the handler for the
4007 sigsuspend in my_waitpid. */
4010 sigchld_handler (int signo
)
4012 int old_errno
= errno
;
4015 /* fprintf is not async-signal-safe, so call write directly. */
4016 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
4018 if (target_is_async_p ())
4019 async_file_mark (); /* trigger a linux_wait */
4025 linux_supports_non_stop (void)
4031 linux_async (int enable
)
4033 int previous
= (linux_event_pipe
[0] != -1);
4035 if (previous
!= enable
)
4038 sigemptyset (&mask
);
4039 sigaddset (&mask
, SIGCHLD
);
4041 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4045 if (pipe (linux_event_pipe
) == -1)
4046 fatal ("creating event pipe failed.");
4048 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4049 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4051 /* Register the event loop handler. */
4052 add_file_handler (linux_event_pipe
[0],
4053 handle_target_event
, NULL
);
4055 /* Always trigger a linux_wait. */
4060 delete_file_handler (linux_event_pipe
[0]);
4062 close (linux_event_pipe
[0]);
4063 close (linux_event_pipe
[1]);
4064 linux_event_pipe
[0] = -1;
4065 linux_event_pipe
[1] = -1;
4068 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4075 linux_start_non_stop (int nonstop
)
4077 /* Register or unregister from event-loop accordingly. */
4078 linux_async (nonstop
);
4083 linux_supports_multi_process (void)
4089 /* Enumerate spufs IDs for process PID. */
4091 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4097 struct dirent
*entry
;
4099 sprintf (path
, "/proc/%ld/fd", pid
);
4100 dir
= opendir (path
);
4105 while ((entry
= readdir (dir
)) != NULL
)
4111 fd
= atoi (entry
->d_name
);
4115 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4116 if (stat (path
, &st
) != 0)
4118 if (!S_ISDIR (st
.st_mode
))
4121 if (statfs (path
, &stfs
) != 0)
4123 if (stfs
.f_type
!= SPUFS_MAGIC
)
4126 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4128 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4138 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4139 object type, using the /proc file system. */
4141 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4142 unsigned const char *writebuf
,
4143 CORE_ADDR offset
, int len
)
4145 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4150 if (!writebuf
&& !readbuf
)
4158 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4161 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4162 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4167 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4174 ret
= write (fd
, writebuf
, (size_t) len
);
4176 ret
= read (fd
, readbuf
, (size_t) len
);
4183 linux_core_of_thread (ptid_t ptid
)
4185 char filename
[sizeof ("/proc//task//stat")
4186 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4189 char *content
= NULL
;
4192 int content_read
= 0;
4196 sprintf (filename
, "/proc/%d/task/%ld/stat",
4197 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4198 f
= fopen (filename
, "r");
4205 content
= realloc (content
, content_read
+ 1024);
4206 n
= fread (content
+ content_read
, 1, 1024, f
);
4210 content
[content_read
] = '\0';
4215 p
= strchr (content
, '(');
4216 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
4218 p
= strtok_r (p
, " ", &ts
);
4219 for (i
= 0; i
!= 36; ++i
)
4220 p
= strtok_r (NULL
, " ", &ts
);
4222 if (sscanf (p
, "%d", &core
) == 0)
4232 linux_process_qsupported (const char *query
)
4234 if (the_low_target
.process_qsupported
!= NULL
)
4235 the_low_target
.process_qsupported (query
);
4239 linux_supports_tracepoints (void)
4241 if (*the_low_target
.supports_tracepoints
== NULL
)
4244 return (*the_low_target
.supports_tracepoints
) ();
4248 linux_read_pc (struct regcache
*regcache
)
4250 if (the_low_target
.get_pc
== NULL
)
4253 return (*the_low_target
.get_pc
) (regcache
);
4257 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
4259 gdb_assert (the_low_target
.set_pc
!= NULL
);
4261 (*the_low_target
.set_pc
) (regcache
, pc
);
4264 static struct target_ops linux_target_ops
= {
4265 linux_create_inferior
,
4273 linux_fetch_registers
,
4274 linux_store_registers
,
4277 linux_look_up_symbols
,
4278 linux_request_interrupt
,
4282 linux_stopped_by_watchpoint
,
4283 linux_stopped_data_address
,
4284 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4289 #ifdef USE_THREAD_DB
4290 thread_db_get_tls_address
,
4295 hostio_last_error_from_errno
,
4298 linux_supports_non_stop
,
4300 linux_start_non_stop
,
4301 linux_supports_multi_process
,
4302 #ifdef USE_THREAD_DB
4303 thread_db_handle_monitor_command
,
4307 linux_core_of_thread
,
4308 linux_process_qsupported
,
4309 linux_supports_tracepoints
,
4315 linux_init_signals ()
4317 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4318 to find what the cancel signal actually is. */
4319 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
4320 signal (__SIGRTMIN
+1, SIG_IGN
);
4325 initialize_low (void)
4327 struct sigaction sigchld_action
;
4328 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4329 set_target_ops (&linux_target_ops
);
4330 set_breakpoint_data (the_low_target
.breakpoint
,
4331 the_low_target
.breakpoint_len
);
4332 linux_init_signals ();
4333 linux_test_for_tracefork ();
4334 #ifdef HAVE_LINUX_REGSETS
4335 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4337 disabled_regsets
= xmalloc (num_regsets
);
4340 sigchld_action
.sa_handler
= sigchld_handler
;
4341 sigemptyset (&sigchld_action
.sa_mask
);
4342 sigchld_action
.sa_flags
= SA_RESTART
;
4343 sigaction (SIGCHLD
, &sigchld_action
, NULL
);