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 lwp_info
*lwp
);
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 /* Wrapper function for waitpid which handles EINTR, and emulates
291 __WALL for systems where that is not available. */
294 my_waitpid (int pid
, int *status
, int flags
)
299 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
303 sigset_t block_mask
, org_mask
, wake_mask
;
306 wnohang
= (flags
& WNOHANG
) != 0;
307 flags
&= ~(__WALL
| __WCLONE
);
310 /* Block all signals while here. This avoids knowing about
311 LinuxThread's signals. */
312 sigfillset (&block_mask
);
313 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
315 /* ... except during the sigsuspend below. */
316 sigemptyset (&wake_mask
);
320 /* Since all signals are blocked, there's no need to check
322 ret
= waitpid (pid
, status
, flags
);
325 if (ret
== -1 && out_errno
!= ECHILD
)
330 if (flags
& __WCLONE
)
332 /* We've tried both flavors now. If WNOHANG is set,
333 there's nothing else to do, just bail out. */
338 fprintf (stderr
, "blocking\n");
340 /* Block waiting for signals. */
341 sigsuspend (&wake_mask
);
347 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
352 ret
= waitpid (pid
, status
, flags
);
353 while (ret
== -1 && errno
== EINTR
);
358 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
359 pid
, flags
, status
? *status
: -1, ret
);
365 /* Handle a GNU/Linux extended wait response. If we see a clone
366 event, we need to add the new LWP to our list (and not report the
367 trap to higher layers). */
370 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
372 int event
= wstat
>> 16;
373 struct lwp_info
*new_lwp
;
375 if (event
== PTRACE_EVENT_CLONE
)
378 unsigned long new_pid
;
379 int ret
, status
= W_STOPCODE (SIGSTOP
);
381 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
383 /* If we haven't already seen the new PID stop, wait for it now. */
384 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
386 /* The new child has a pending SIGSTOP. We can't affect it until it
387 hits the SIGSTOP, but we're already attached. */
389 ret
= my_waitpid (new_pid
, &status
, __WALL
);
392 perror_with_name ("waiting for new child");
393 else if (ret
!= new_pid
)
394 warning ("wait returned unexpected PID %d", ret
);
395 else if (!WIFSTOPPED (status
))
396 warning ("wait returned unexpected status 0x%x", status
);
399 ptrace (PTRACE_SETOPTIONS
, new_pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
401 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
402 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
403 add_thread (ptid
, new_lwp
);
405 /* Either we're going to immediately resume the new thread
406 or leave it stopped. linux_resume_one_lwp is a nop if it
407 thinks the thread is currently running, so set this first
408 before calling linux_resume_one_lwp. */
409 new_lwp
->stopped
= 1;
411 /* Normally we will get the pending SIGSTOP. But in some cases
412 we might get another signal delivered to the group first.
413 If we do get another signal, be sure not to lose it. */
414 if (WSTOPSIG (status
) == SIGSTOP
)
416 if (stopping_threads
)
417 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
419 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
423 new_lwp
->stop_expected
= 1;
425 if (stopping_threads
)
427 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
428 new_lwp
->status_pending_p
= 1;
429 new_lwp
->status_pending
= status
;
432 /* Pass the signal on. This is what GDB does - except
433 shouldn't we really report it instead? */
434 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
437 /* Always resume the current thread. If we are stopping
438 threads, it will have a pending SIGSTOP; we may as well
440 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
444 /* Return the PC as read from the regcache of LWP, without any
448 get_pc (struct lwp_info
*lwp
)
450 struct thread_info
*saved_inferior
;
451 struct regcache
*regcache
;
454 if (the_low_target
.get_pc
== NULL
)
457 saved_inferior
= current_inferior
;
458 current_inferior
= get_lwp_thread (lwp
);
460 regcache
= get_thread_regcache (current_inferior
, 1);
461 pc
= (*the_low_target
.get_pc
) (regcache
);
464 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
466 current_inferior
= saved_inferior
;
470 /* This function should only be called if LWP got a SIGTRAP.
471 The SIGTRAP could mean several things.
473 On i386, where decr_pc_after_break is non-zero:
474 If we were single-stepping this process using PTRACE_SINGLESTEP,
475 we will get only the one SIGTRAP (even if the instruction we
476 stepped over was a breakpoint). The value of $eip will be the
478 If we continue the process using PTRACE_CONT, we will get a
479 SIGTRAP when we hit a breakpoint. The value of $eip will be
480 the instruction after the breakpoint (i.e. needs to be
481 decremented). If we report the SIGTRAP to GDB, we must also
482 report the undecremented PC. If we cancel the SIGTRAP, we
483 must resume at the decremented PC.
485 (Presumably, not yet tested) On a non-decr_pc_after_break machine
486 with hardware or kernel single-step:
487 If we single-step over a breakpoint instruction, our PC will
488 point at the following instruction. If we continue and hit a
489 breakpoint instruction, our PC will point at the breakpoint
493 get_stop_pc (struct lwp_info
*lwp
)
497 if (the_low_target
.get_pc
== NULL
)
500 stop_pc
= get_pc (lwp
);
502 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
504 && !lwp
->stopped_by_watchpoint
505 && lwp
->last_status
>> 16 == 0)
506 stop_pc
-= the_low_target
.decr_pc_after_break
;
509 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
515 add_lwp (ptid_t ptid
)
517 struct lwp_info
*lwp
;
519 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
520 memset (lwp
, 0, sizeof (*lwp
));
524 if (the_low_target
.new_thread
!= NULL
)
525 lwp
->arch_private
= the_low_target
.new_thread ();
527 add_inferior_to_list (&all_lwps
, &lwp
->head
);
532 /* Start an inferior process and returns its pid.
533 ALLARGS is a vector of program-name and args. */
536 linux_create_inferior (char *program
, char **allargs
)
538 struct lwp_info
*new_lwp
;
542 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
548 perror_with_name ("fork");
552 ptrace (PTRACE_TRACEME
, 0, 0, 0);
554 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
555 signal (__SIGRTMIN
+ 1, SIG_DFL
);
560 execv (program
, allargs
);
562 execvp (program
, allargs
);
564 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
570 linux_add_process (pid
, 0);
572 ptid
= ptid_build (pid
, pid
, 0);
573 new_lwp
= add_lwp (ptid
);
574 add_thread (ptid
, new_lwp
);
575 new_lwp
->must_set_ptrace_flags
= 1;
580 /* Attach to an inferior process. */
583 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
586 struct lwp_info
*new_lwp
;
588 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
592 /* If we fail to attach to an LWP, just warn. */
593 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
594 strerror (errno
), errno
);
599 /* If we fail to attach to a process, report an error. */
600 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
601 strerror (errno
), errno
);
605 /* NOTE/FIXME: This lwp might have not been the tgid. */
606 ptid
= ptid_build (lwpid
, lwpid
, 0);
609 /* Note that extracting the pid from the current inferior is
610 safe, since we're always called in the context of the same
611 process as this new thread. */
612 int pid
= pid_of (get_thread_lwp (current_inferior
));
613 ptid
= ptid_build (pid
, lwpid
, 0);
616 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
617 add_thread (ptid
, new_lwp
);
619 /* We need to wait for SIGSTOP before being able to make the next
620 ptrace call on this LWP. */
621 new_lwp
->must_set_ptrace_flags
= 1;
623 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
626 There are several cases to consider here:
628 1) gdbserver has already attached to the process and is being notified
629 of a new thread that is being created.
630 In this case we should ignore that SIGSTOP and resume the
631 process. This is handled below by setting stop_expected = 1,
632 and the fact that add_thread sets last_resume_kind ==
635 2) This is the first thread (the process thread), and we're attaching
636 to it via attach_inferior.
637 In this case we want the process thread to stop.
638 This is handled by having linux_attach set last_resume_kind ==
639 resume_stop after we return.
640 ??? If the process already has several threads we leave the other
643 3) GDB is connecting to gdbserver and is requesting an enumeration of all
645 In this case we want the thread to stop.
646 FIXME: This case is currently not properly handled.
647 We should wait for the SIGSTOP but don't. Things work apparently
648 because enough time passes between when we ptrace (ATTACH) and when
649 gdb makes the next ptrace call on the thread.
651 On the other hand, if we are currently trying to stop all threads, we
652 should treat the new thread as if we had sent it a SIGSTOP. This works
653 because we are guaranteed that the add_lwp call above added us to the
654 end of the list, and so the new thread has not yet reached
655 wait_for_sigstop (but will). */
656 new_lwp
->stop_expected
= 1;
660 linux_attach_lwp (unsigned long lwpid
)
662 linux_attach_lwp_1 (lwpid
, 0);
666 linux_attach (unsigned long pid
)
668 linux_attach_lwp_1 (pid
, 1);
669 linux_add_process (pid
, 1);
673 struct thread_info
*thread
;
675 /* Don't ignore the initial SIGSTOP if we just attached to this
676 process. It will be collected by wait shortly. */
677 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
678 thread
->last_resume_kind
= resume_stop
;
691 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
693 struct counter
*counter
= args
;
695 if (ptid_get_pid (entry
->id
) == counter
->pid
)
697 if (++counter
->count
> 1)
705 last_thread_of_process_p (struct thread_info
*thread
)
707 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
708 int pid
= ptid_get_pid (ptid
);
709 struct counter counter
= { pid
, 0 };
711 return (find_inferior (&all_threads
,
712 second_thread_of_pid_p
, &counter
) == NULL
);
715 /* Kill the inferior lwp. */
718 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
720 struct thread_info
*thread
= (struct thread_info
*) entry
;
721 struct lwp_info
*lwp
= get_thread_lwp (thread
);
723 int pid
= * (int *) args
;
725 if (ptid_get_pid (entry
->id
) != pid
)
728 /* We avoid killing the first thread here, because of a Linux kernel (at
729 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
730 the children get a chance to be reaped, it will remain a zombie
733 if (lwpid_of (lwp
) == pid
)
736 fprintf (stderr
, "lkop: is last of process %s\n",
737 target_pid_to_str (entry
->id
));
741 /* If we're killing a running inferior, make sure it is stopped
742 first, as PTRACE_KILL will not work otherwise. */
748 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
750 /* Make sure it died. The loop is most likely unnecessary. */
751 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
752 } while (pid
> 0 && WIFSTOPPED (wstat
));
760 struct process_info
*process
;
761 struct lwp_info
*lwp
;
762 struct thread_info
*thread
;
766 process
= find_process_pid (pid
);
770 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
772 /* See the comment in linux_kill_one_lwp. We did not kill the first
773 thread in the list, so do so now. */
774 lwp
= find_lwp_pid (pid_to_ptid (pid
));
775 thread
= get_lwp_thread (lwp
);
778 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
779 lwpid_of (lwp
), pid
);
781 /* If we're killing a running inferior, make sure it is stopped
782 first, as PTRACE_KILL will not work otherwise. */
788 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
790 /* Make sure it died. The loop is most likely unnecessary. */
791 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
792 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
796 the_target
->mourn (process
);
801 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
803 struct thread_info
*thread
= (struct thread_info
*) entry
;
804 struct lwp_info
*lwp
= get_thread_lwp (thread
);
805 int pid
= * (int *) args
;
807 if (ptid_get_pid (entry
->id
) != pid
)
810 /* If we're detaching from a running inferior, make sure it is
811 stopped first, as PTRACE_DETACH will not work otherwise. */
814 int lwpid
= lwpid_of (lwp
);
816 stopping_threads
= 1;
819 /* If this detects a new thread through a clone event, the new
820 thread is appended to the end of the lwp list, so we'll
821 eventually detach from it. */
822 wait_for_sigstop (&lwp
->head
);
823 stopping_threads
= 0;
825 /* If LWP exits while we're trying to stop it, there's nothing
827 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
832 /* If this process is stopped but is expecting a SIGSTOP, then make
833 sure we take care of that now. This isn't absolutely guaranteed
834 to collect the SIGSTOP, but is fairly likely to. */
835 if (lwp
->stop_expected
)
838 /* Clear stop_expected, so that the SIGSTOP will be reported. */
839 lwp
->stop_expected
= 0;
841 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
842 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
845 /* Flush any pending changes to the process's registers. */
846 regcache_invalidate_one ((struct inferior_list_entry
*)
847 get_lwp_thread (lwp
));
849 /* Finally, let it resume. */
850 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
857 any_thread_of (struct inferior_list_entry
*entry
, void *args
)
861 if (ptid_get_pid (entry
->id
) == *pid_p
)
868 linux_detach (int pid
)
870 struct process_info
*process
;
872 process
= find_process_pid (pid
);
877 thread_db_detach (process
);
881 (struct thread_info
*) find_inferior (&all_threads
, any_thread_of
, &pid
);
883 delete_all_breakpoints ();
884 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
886 the_target
->mourn (process
);
891 linux_mourn (struct process_info
*process
)
893 struct process_info_private
*priv
;
896 thread_db_mourn (process
);
899 /* Freeing all private data. */
900 priv
= process
->private;
901 free (priv
->arch_private
);
903 process
->private = NULL
;
905 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 (thread
->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
= (current_inferior
->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
;
1445 struct thread_info
*thread
= get_lwp_thread (lp
);
1448 gdb_assert (count
!= NULL
);
1450 /* Count only resumed LWPs that have a SIGTRAP event pending that
1451 should be reported to GDB. */
1452 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1453 && thread
->last_resume_kind
!= resume_stop
1454 && lp
->status_pending_p
1455 && WIFSTOPPED (lp
->status_pending
)
1456 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1457 && !breakpoint_inserted_here (lp
->stop_pc
))
1463 /* Select the LWP (if any) that is currently being single-stepped. */
1466 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1468 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1469 struct thread_info
*thread
= get_lwp_thread (lp
);
1471 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1472 && thread
->last_resume_kind
== resume_step
1473 && lp
->status_pending_p
)
1479 /* Select the Nth LWP that has had a SIGTRAP event that should be
1483 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1485 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1486 struct thread_info
*thread
= get_lwp_thread (lp
);
1487 int *selector
= data
;
1489 gdb_assert (selector
!= NULL
);
1491 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1492 if (thread
->last_resume_kind
!= resume_stop
1493 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1494 && lp
->status_pending_p
1495 && WIFSTOPPED (lp
->status_pending
)
1496 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1497 && !breakpoint_inserted_here (lp
->stop_pc
))
1498 if ((*selector
)-- == 0)
1505 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1507 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1508 struct thread_info
*thread
= get_lwp_thread (lp
);
1509 struct lwp_info
*event_lp
= data
;
1511 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1515 /* If a LWP other than the LWP that we're reporting an event for has
1516 hit a GDB breakpoint (as opposed to some random trap signal),
1517 then just arrange for it to hit it again later. We don't keep
1518 the SIGTRAP status and don't forward the SIGTRAP signal to the
1519 LWP. We will handle the current event, eventually we will resume
1520 all LWPs, and this one will get its breakpoint trap again.
1522 If we do not do this, then we run the risk that the user will
1523 delete or disable the breakpoint, but the LWP will have already
1526 if (thread
->last_resume_kind
!= resume_stop
1527 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1528 && lp
->status_pending_p
1529 && WIFSTOPPED (lp
->status_pending
)
1530 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1532 && !lp
->stopped_by_watchpoint
1533 && cancel_breakpoint (lp
))
1534 /* Throw away the SIGTRAP. */
1535 lp
->status_pending_p
= 0;
1540 /* Select one LWP out of those that have events pending. */
1543 select_event_lwp (struct lwp_info
**orig_lp
)
1546 int random_selector
;
1547 struct lwp_info
*event_lp
;
1549 /* Give preference to any LWP that is being single-stepped. */
1551 = (struct lwp_info
*) find_inferior (&all_lwps
,
1552 select_singlestep_lwp_callback
, NULL
);
1553 if (event_lp
!= NULL
)
1557 "SEL: Select single-step %s\n",
1558 target_pid_to_str (ptid_of (event_lp
)));
1562 /* No single-stepping LWP. Select one at random, out of those
1563 which have had SIGTRAP events. */
1565 /* First see how many SIGTRAP events we have. */
1566 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1568 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1569 random_selector
= (int)
1570 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1572 if (debug_threads
&& num_events
> 1)
1574 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1575 num_events
, random_selector
);
1577 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1578 select_event_lwp_callback
,
1582 if (event_lp
!= NULL
)
1584 /* Switch the event LWP. */
1585 *orig_lp
= event_lp
;
1589 /* Set this inferior LWP's state as "want-stopped". We won't resume
1590 this LWP until the client gives us another action for it. */
1593 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1595 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1596 struct thread_info
*thread
= get_lwp_thread (lwp
);
1598 /* Most threads are stopped implicitly (all-stop); tag that with
1599 signal 0. The thread being explicitly reported stopped to the
1600 client, gets it's status fixed up afterwards. */
1601 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1602 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1604 thread
->last_resume_kind
= resume_stop
;
1607 /* Set all LWP's states as "want-stopped". */
1610 gdb_wants_all_stopped (void)
1612 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1615 /* Wait for process, returns status. */
1618 linux_wait_1 (ptid_t ptid
,
1619 struct target_waitstatus
*ourstatus
, int target_options
)
1622 struct lwp_info
*event_child
;
1625 int step_over_finished
;
1626 int bp_explains_trap
;
1627 int maybe_internal_trap
;
1631 /* Translate generic target options into linux options. */
1633 if (target_options
& TARGET_WNOHANG
)
1637 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1639 /* If we were only supposed to resume one thread, only wait for
1640 that thread - if it's still alive. If it died, however - which
1641 can happen if we're coming from the thread death case below -
1642 then we need to make sure we restart the other threads. We could
1643 pick a thread at random or restart all; restarting all is less
1646 && !ptid_equal (cont_thread
, null_ptid
)
1647 && !ptid_equal (cont_thread
, minus_one_ptid
))
1649 struct thread_info
*thread
;
1651 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1654 /* No stepping, no signal - unless one is pending already, of course. */
1657 struct thread_resume resume_info
;
1658 resume_info
.thread
= minus_one_ptid
;
1659 resume_info
.kind
= resume_continue
;
1660 resume_info
.sig
= 0;
1661 linux_resume (&resume_info
, 1);
1667 if (ptid_equal (step_over_bkpt
, null_ptid
))
1668 pid
= linux_wait_for_event (ptid
, &w
, options
);
1672 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1673 target_pid_to_str (step_over_bkpt
));
1674 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1677 if (pid
== 0) /* only if TARGET_WNOHANG */
1680 event_child
= get_thread_lwp (current_inferior
);
1682 /* If we are waiting for a particular child, and it exited,
1683 linux_wait_for_event will return its exit status. Similarly if
1684 the last child exited. If this is not the last child, however,
1685 do not report it as exited until there is a 'thread exited' response
1686 available in the remote protocol. Instead, just wait for another event.
1687 This should be safe, because if the thread crashed we will already
1688 have reported the termination signal to GDB; that should stop any
1689 in-progress stepping operations, etc.
1691 Report the exit status of the last thread to exit. This matches
1692 LinuxThreads' behavior. */
1694 if (last_thread_of_process_p (current_inferior
))
1696 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1698 delete_lwp (event_child
);
1700 current_inferior
= NULL
;
1704 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1705 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1708 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1712 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1713 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1716 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1720 return pid_to_ptid (pid
);
1725 if (!WIFSTOPPED (w
))
1729 /* If this event was not handled before, and is not a SIGTRAP, we
1730 report it. SIGILL and SIGSEGV are also treated as traps in case
1731 a breakpoint is inserted at the current PC. If this target does
1732 not support internal breakpoints at all, we also report the
1733 SIGTRAP without further processing; it's of no concern to us. */
1735 = (supports_breakpoints ()
1736 && (WSTOPSIG (w
) == SIGTRAP
1737 || ((WSTOPSIG (w
) == SIGILL
1738 || WSTOPSIG (w
) == SIGSEGV
)
1739 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
1741 if (maybe_internal_trap
)
1743 /* Handle anything that requires bookkeeping before deciding to
1744 report the event or continue waiting. */
1746 /* First check if we can explain the SIGTRAP with an internal
1747 breakpoint, or if we should possibly report the event to GDB.
1748 Do this before anything that may remove or insert a
1750 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
1752 /* We have a SIGTRAP, possibly a step-over dance has just
1753 finished. If so, tweak the state machine accordingly,
1754 reinsert breakpoints and delete any reinsert (software
1755 single-step) breakpoints. */
1756 step_over_finished
= finish_step_over (event_child
);
1758 /* Now invoke the callbacks of any internal breakpoints there. */
1759 check_breakpoints (event_child
->stop_pc
);
1761 /* Handle tracepoint data collecting. This may overflow the
1762 trace buffer, and cause a tracing stop, removing
1764 trace_event
= handle_tracepoints (event_child
);
1766 if (bp_explains_trap
)
1768 /* If we stepped or ran into an internal breakpoint, we've
1769 already handled it. So next time we resume (from this
1770 PC), we should step over it. */
1772 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1774 if (breakpoint_here (event_child
->stop_pc
))
1775 event_child
->need_step_over
= 1;
1780 /* We have some other signal, possibly a step-over dance was in
1781 progress, and it should be cancelled too. */
1782 step_over_finished
= finish_step_over (event_child
);
1787 /* We have all the data we need. Either report the event to GDB, or
1788 resume threads and keep waiting for more. */
1790 /* Check If GDB would be interested in this event. If GDB wanted
1791 this thread to single step, we always want to report the SIGTRAP,
1792 and let GDB handle it. Watchpoints should always be reported.
1793 So should signals we can't explain. A SIGTRAP we can't explain
1794 could be a GDB breakpoint --- we may or not support Z0
1795 breakpoints. If we do, we're be able to handle GDB breakpoints
1796 on top of internal breakpoints, by handling the internal
1797 breakpoint and still reporting the event to GDB. If we don't,
1798 we're out of luck, GDB won't see the breakpoint hit. */
1799 report_to_gdb
= (!maybe_internal_trap
1800 || current_inferior
->last_resume_kind
== resume_step
1801 || event_child
->stopped_by_watchpoint
1802 || (!step_over_finished
&& !bp_explains_trap
&& !trace_event
)
1803 || gdb_breakpoint_here (event_child
->stop_pc
));
1805 /* We found no reason GDB would want us to stop. We either hit one
1806 of our own breakpoints, or finished an internal step GDB
1807 shouldn't know about. */
1812 if (bp_explains_trap
)
1813 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1814 if (step_over_finished
)
1815 fprintf (stderr
, "Step-over finished.\n");
1817 fprintf (stderr
, "Tracepoint event.\n");
1820 /* We're not reporting this breakpoint to GDB, so apply the
1821 decr_pc_after_break adjustment to the inferior's regcache
1824 if (the_low_target
.set_pc
!= NULL
)
1826 struct regcache
*regcache
1827 = get_thread_regcache (get_lwp_thread (event_child
), 1);
1828 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
1831 /* We've finished stepping over a breakpoint. We've stopped all
1832 LWPs momentarily except the stepping one. This is where we
1833 resume them all again. We're going to keep waiting, so use
1834 proceed, which handles stepping over the next breakpoint. */
1836 fprintf (stderr
, "proceeding all threads.\n");
1837 proceed_all_lwps ();
1843 if (current_inferior
->last_resume_kind
== resume_step
)
1844 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
1845 if (event_child
->stopped_by_watchpoint
)
1846 fprintf (stderr
, "Stopped by watchpoint.\n");
1847 if (gdb_breakpoint_here (event_child
->stop_pc
))
1848 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
1850 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
1853 /* Alright, we're going to report a stop. */
1857 /* In all-stop, stop all threads. */
1860 /* If we're not waiting for a specific LWP, choose an event LWP
1861 from among those that have had events. Giving equal priority
1862 to all LWPs that have had events helps prevent
1864 if (ptid_equal (ptid
, minus_one_ptid
))
1866 event_child
->status_pending_p
= 1;
1867 event_child
->status_pending
= w
;
1869 select_event_lwp (&event_child
);
1871 event_child
->status_pending_p
= 0;
1872 w
= event_child
->status_pending
;
1875 /* Now that we've selected our final event LWP, cancel any
1876 breakpoints in other LWPs that have hit a GDB breakpoint.
1877 See the comment in cancel_breakpoints_callback to find out
1879 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
1883 /* If we just finished a step-over, then all threads had been
1884 momentarily paused. In all-stop, that's fine, we want
1885 threads stopped by now anyway. In non-stop, we need to
1886 re-resume threads that GDB wanted to be running. */
1887 if (step_over_finished
)
1888 unstop_all_lwps (event_child
);
1891 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1893 /* Do this before the gdb_wants_all_stopped calls below, since they
1894 always set last_resume_kind to resume_stop. */
1895 if (current_inferior
->last_resume_kind
== resume_stop
1896 && WSTOPSIG (w
) == SIGSTOP
)
1898 /* A thread that has been requested to stop by GDB with vCont;t,
1899 and it stopped cleanly, so report as SIG0. The use of
1900 SIGSTOP is an implementation detail. */
1901 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1903 else if (current_inferior
->last_resume_kind
== resume_stop
1904 && WSTOPSIG (w
) != SIGSTOP
)
1906 /* A thread that has been requested to stop by GDB with vCont;t,
1907 but, it stopped for other reasons. */
1908 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1912 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1915 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
1919 /* From GDB's perspective, all-stop mode always stops all
1920 threads implicitly. Tag all threads as "want-stopped". */
1921 gdb_wants_all_stopped ();
1925 /* We're reporting this LWP as stopped. Update it's
1926 "want-stopped" state to what the client wants, until it gets
1927 a new resume action. */
1928 gdb_wants_lwp_stopped (&event_child
->head
);
1932 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1933 target_pid_to_str (ptid_of (event_child
)),
1935 ourstatus
->value
.sig
);
1937 get_lwp_thread (event_child
)->last_status
= *ourstatus
;
1938 return ptid_of (event_child
);
1941 /* Get rid of any pending event in the pipe. */
1943 async_file_flush (void)
1949 ret
= read (linux_event_pipe
[0], &buf
, 1);
1950 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1953 /* Put something in the pipe, so the event loop wakes up. */
1955 async_file_mark (void)
1959 async_file_flush ();
1962 ret
= write (linux_event_pipe
[1], "+", 1);
1963 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1965 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1966 be awakened anyway. */
1970 linux_wait (ptid_t ptid
,
1971 struct target_waitstatus
*ourstatus
, int target_options
)
1976 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1978 /* Flush the async file first. */
1979 if (target_is_async_p ())
1980 async_file_flush ();
1982 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1984 /* If at least one stop was reported, there may be more. A single
1985 SIGCHLD can signal more than one child stop. */
1986 if (target_is_async_p ()
1987 && (target_options
& TARGET_WNOHANG
) != 0
1988 && !ptid_equal (event_ptid
, null_ptid
))
1994 /* Send a signal to an LWP. */
1997 kill_lwp (unsigned long lwpid
, int signo
)
1999 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2000 fails, then we are not using nptl threads and we should be using kill. */
2004 static int tkill_failed
;
2011 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2012 if (errno
!= ENOSYS
)
2019 return kill (lwpid
, signo
);
2023 send_sigstop (struct lwp_info
*lwp
)
2027 pid
= lwpid_of (lwp
);
2029 /* If we already have a pending stop signal for this process, don't
2031 if (lwp
->stop_expected
)
2034 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2040 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2042 lwp
->stop_expected
= 1;
2043 kill_lwp (pid
, SIGSTOP
);
2047 send_sigstop_callback (struct inferior_list_entry
*entry
)
2049 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2058 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2060 /* It's dead, really. */
2063 /* Store the exit status for later. */
2064 lwp
->status_pending_p
= 1;
2065 lwp
->status_pending
= wstat
;
2067 /* Prevent trying to stop it. */
2070 /* No further stops are expected from a dead lwp. */
2071 lwp
->stop_expected
= 0;
2075 wait_for_sigstop (struct inferior_list_entry
*entry
)
2077 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2078 struct thread_info
*saved_inferior
;
2087 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2092 saved_inferior
= current_inferior
;
2093 if (saved_inferior
!= NULL
)
2094 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2096 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2098 ptid
= lwp
->head
.id
;
2101 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2103 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2105 /* If we stopped with a non-SIGSTOP signal, save it for later
2106 and record the pending SIGSTOP. If the process exited, just
2108 if (WIFSTOPPED (wstat
))
2111 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2112 lwpid_of (lwp
), WSTOPSIG (wstat
));
2114 if (WSTOPSIG (wstat
) != SIGSTOP
)
2117 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2118 lwpid_of (lwp
), wstat
);
2120 lwp
->status_pending_p
= 1;
2121 lwp
->status_pending
= wstat
;
2127 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2129 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2132 /* Leave this status pending for the next time we're able to
2133 report it. In the mean time, we'll report this lwp as
2134 dead to GDB, so GDB doesn't try to read registers and
2135 memory from it. This can only happen if this was the
2136 last thread of the process; otherwise, PID is removed
2137 from the thread tables before linux_wait_for_event
2139 mark_lwp_dead (lwp
, wstat
);
2143 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2144 current_inferior
= saved_inferior
;
2148 fprintf (stderr
, "Previously current thread died.\n");
2152 /* We can't change the current inferior behind GDB's back,
2153 otherwise, a subsequent command may apply to the wrong
2155 current_inferior
= NULL
;
2159 /* Set a valid thread as current. */
2160 set_desired_inferior (0);
2166 stop_all_lwps (void)
2168 stopping_threads
= 1;
2169 for_each_inferior (&all_lwps
, send_sigstop_callback
);
2170 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2171 stopping_threads
= 0;
2174 /* Resume execution of the inferior process.
2175 If STEP is nonzero, single-step it.
2176 If SIGNAL is nonzero, give it that signal. */
2179 linux_resume_one_lwp (struct lwp_info
*lwp
,
2180 int step
, int signal
, siginfo_t
*info
)
2182 struct thread_info
*saved_inferior
;
2184 if (lwp
->stopped
== 0)
2187 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2188 user used the "jump" command, or "set $pc = foo"). */
2189 if (lwp
->stop_pc
!= get_pc (lwp
))
2191 /* Collecting 'while-stepping' actions doesn't make sense
2193 release_while_stepping_state_list (get_lwp_thread (lwp
));
2196 /* If we have pending signals or status, and a new signal, enqueue the
2197 signal. Also enqueue the signal if we are waiting to reinsert a
2198 breakpoint; it will be picked up again below. */
2200 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
2201 || lwp
->bp_reinsert
!= 0))
2203 struct pending_signals
*p_sig
;
2204 p_sig
= xmalloc (sizeof (*p_sig
));
2205 p_sig
->prev
= lwp
->pending_signals
;
2206 p_sig
->signal
= signal
;
2208 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2210 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2211 lwp
->pending_signals
= p_sig
;
2214 if (lwp
->status_pending_p
)
2217 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2218 " has pending status\n",
2219 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2220 lwp
->stop_expected
? "expected" : "not expected");
2224 saved_inferior
= current_inferior
;
2225 current_inferior
= get_lwp_thread (lwp
);
2228 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2229 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2230 lwp
->stop_expected
? "expected" : "not expected");
2232 /* This bit needs some thinking about. If we get a signal that
2233 we must report while a single-step reinsert is still pending,
2234 we often end up resuming the thread. It might be better to
2235 (ew) allow a stack of pending events; then we could be sure that
2236 the reinsert happened right away and not lose any signals.
2238 Making this stack would also shrink the window in which breakpoints are
2239 uninserted (see comment in linux_wait_for_lwp) but not enough for
2240 complete correctness, so it won't solve that problem. It may be
2241 worthwhile just to solve this one, however. */
2242 if (lwp
->bp_reinsert
!= 0)
2245 fprintf (stderr
, " pending reinsert at 0x%s\n",
2246 paddress (lwp
->bp_reinsert
));
2248 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2251 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2256 /* Postpone any pending signal. It was enqueued above. */
2260 /* If we have while-stepping actions in this thread set it stepping.
2261 If we have a signal to deliver, it may or may not be set to
2262 SIG_IGN, we don't know. Assume so, and allow collecting
2263 while-stepping into a signal handler. A possible smart thing to
2264 do would be to set an internal breakpoint at the signal return
2265 address, continue, and carry on catching this while-stepping
2266 action only when that breakpoint is hit. A future
2268 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2269 && can_hardware_single_step ())
2273 "lwp %ld has a while-stepping action -> forcing step.\n",
2278 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2280 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2281 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2282 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2285 /* If we have pending signals, consume one unless we are trying to reinsert
2287 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
2289 struct pending_signals
**p_sig
;
2291 p_sig
= &lwp
->pending_signals
;
2292 while ((*p_sig
)->prev
!= NULL
)
2293 p_sig
= &(*p_sig
)->prev
;
2295 signal
= (*p_sig
)->signal
;
2296 if ((*p_sig
)->info
.si_signo
!= 0)
2297 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2303 if (the_low_target
.prepare_to_resume
!= NULL
)
2304 the_low_target
.prepare_to_resume (lwp
);
2306 regcache_invalidate_one ((struct inferior_list_entry
*)
2307 get_lwp_thread (lwp
));
2310 lwp
->stopped_by_watchpoint
= 0;
2311 lwp
->stepping
= step
;
2312 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2313 /* Coerce to a uintptr_t first to avoid potential gcc warning
2314 of coercing an 8 byte integer to a 4 byte pointer. */
2315 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2317 current_inferior
= saved_inferior
;
2320 /* ESRCH from ptrace either means that the thread was already
2321 running (an error) or that it is gone (a race condition). If
2322 it's gone, we will get a notification the next time we wait,
2323 so we can ignore the error. We could differentiate these
2324 two, but it's tricky without waiting; the thread still exists
2325 as a zombie, so sending it signal 0 would succeed. So just
2330 perror_with_name ("ptrace");
2334 struct thread_resume_array
2336 struct thread_resume
*resume
;
2340 /* This function is called once per thread. We look up the thread
2341 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2344 This algorithm is O(threads * resume elements), but resume elements
2345 is small (and will remain small at least until GDB supports thread
2348 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2350 struct lwp_info
*lwp
;
2351 struct thread_info
*thread
;
2353 struct thread_resume_array
*r
;
2355 thread
= (struct thread_info
*) entry
;
2356 lwp
= get_thread_lwp (thread
);
2359 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2361 ptid_t ptid
= r
->resume
[ndx
].thread
;
2362 if (ptid_equal (ptid
, minus_one_ptid
)
2363 || ptid_equal (ptid
, entry
->id
)
2364 || (ptid_is_pid (ptid
)
2365 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2366 || (ptid_get_lwp (ptid
) == -1
2367 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2369 if (r
->resume
[ndx
].kind
== resume_stop
2370 && thread
->last_resume_kind
== resume_stop
)
2373 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2374 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2382 lwp
->resume
= &r
->resume
[ndx
];
2383 thread
->last_resume_kind
= lwp
->resume
->kind
;
2388 /* No resume action for this thread. */
2395 /* Set *FLAG_P if this lwp has an interesting status pending. */
2397 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
2399 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2401 /* LWPs which will not be resumed are not interesting, because
2402 we might not wait for them next time through linux_wait. */
2403 if (lwp
->resume
== NULL
)
2406 if (lwp
->status_pending_p
)
2407 * (int *) flag_p
= 1;
2412 /* Return 1 if this lwp that GDB wants running is stopped at an
2413 internal breakpoint that we need to step over. It assumes that any
2414 required STOP_PC adjustment has already been propagated to the
2415 inferior's regcache. */
2418 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
2420 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2421 struct thread_info
*thread
;
2422 struct thread_info
*saved_inferior
;
2425 /* LWPs which will not be resumed are not interesting, because we
2426 might not wait for them next time through linux_wait. */
2432 "Need step over [LWP %ld]? Ignoring, not stopped\n",
2437 thread
= get_lwp_thread (lwp
);
2439 if (thread
->last_resume_kind
== resume_stop
)
2443 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
2448 if (!lwp
->need_step_over
)
2452 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
2455 if (lwp
->status_pending_p
)
2459 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
2464 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
2468 /* If the PC has changed since we stopped, then don't do anything,
2469 and let the breakpoint/tracepoint be hit. This happens if, for
2470 instance, GDB handled the decr_pc_after_break subtraction itself,
2471 GDB is OOL stepping this thread, or the user has issued a "jump"
2472 command, or poked thread's registers herself. */
2473 if (pc
!= lwp
->stop_pc
)
2477 "Need step over [LWP %ld]? Cancelling, PC was changed. "
2478 "Old stop_pc was 0x%s, PC is now 0x%s\n",
2479 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
2481 lwp
->need_step_over
= 0;
2485 saved_inferior
= current_inferior
;
2486 current_inferior
= thread
;
2488 /* We can only step over breakpoints we know about. */
2489 if (breakpoint_here (pc
))
2491 /* Don't step over a breakpoint that GDB expects to hit
2493 if (gdb_breakpoint_here (pc
))
2497 "Need step over [LWP %ld]? yes, but found"
2498 " GDB breakpoint at 0x%s; skipping step over\n",
2499 lwpid_of (lwp
), paddress (pc
));
2501 current_inferior
= saved_inferior
;
2508 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
2509 lwpid_of (lwp
), paddress (pc
));
2511 /* We've found an lwp that needs stepping over --- return 1 so
2512 that find_inferior stops looking. */
2513 current_inferior
= saved_inferior
;
2515 /* If the step over is cancelled, this is set again. */
2516 lwp
->need_step_over
= 0;
2521 current_inferior
= saved_inferior
;
2525 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
2526 lwpid_of (lwp
), paddress (pc
));
2531 /* Start a step-over operation on LWP. When LWP stopped at a
2532 breakpoint, to make progress, we need to remove the breakpoint out
2533 of the way. If we let other threads run while we do that, they may
2534 pass by the breakpoint location and miss hitting it. To avoid
2535 that, a step-over momentarily stops all threads while LWP is
2536 single-stepped while the breakpoint is temporarily uninserted from
2537 the inferior. When the single-step finishes, we reinsert the
2538 breakpoint, and let all threads that are supposed to be running,
2541 On targets that don't support hardware single-step, we don't
2542 currently support full software single-stepping. Instead, we only
2543 support stepping over the thread event breakpoint, by asking the
2544 low target where to place a reinsert breakpoint. Since this
2545 routine assumes the breakpoint being stepped over is a thread event
2546 breakpoint, it usually assumes the return address of the current
2547 function is a good enough place to set the reinsert breakpoint. */
2550 start_step_over (struct lwp_info
*lwp
)
2552 struct thread_info
*saved_inferior
;
2558 "Starting step-over on LWP %ld. Stopping all threads\n",
2564 fprintf (stderr
, "Done stopping all threads for step-over.\n");
2566 /* Note, we should always reach here with an already adjusted PC,
2567 either by GDB (if we're resuming due to GDB's request), or by our
2568 caller, if we just finished handling an internal breakpoint GDB
2569 shouldn't care about. */
2572 saved_inferior
= current_inferior
;
2573 current_inferior
= get_lwp_thread (lwp
);
2575 lwp
->bp_reinsert
= pc
;
2576 uninsert_breakpoints_at (pc
);
2578 if (can_hardware_single_step ())
2584 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
2585 set_reinsert_breakpoint (raddr
);
2589 current_inferior
= saved_inferior
;
2591 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2593 /* Require next event from this LWP. */
2594 step_over_bkpt
= lwp
->head
.id
;
2598 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
2599 start_step_over, if still there, and delete any reinsert
2600 breakpoints we've set, on non hardware single-step targets. */
2603 finish_step_over (struct lwp_info
*lwp
)
2605 if (lwp
->bp_reinsert
!= 0)
2608 fprintf (stderr
, "Finished step over.\n");
2610 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
2611 may be no breakpoint to reinsert there by now. */
2612 reinsert_breakpoints_at (lwp
->bp_reinsert
);
2614 lwp
->bp_reinsert
= 0;
2616 /* Delete any software-single-step reinsert breakpoints. No
2617 longer needed. We don't have to worry about other threads
2618 hitting this trap, and later not being able to explain it,
2619 because we were stepping over a breakpoint, and we hold all
2620 threads but LWP stopped while doing that. */
2621 if (!can_hardware_single_step ())
2622 delete_reinsert_breakpoints ();
2624 step_over_bkpt
= null_ptid
;
2631 /* This function is called once per thread. We check the thread's resume
2632 request, which will tell us whether to resume, step, or leave the thread
2633 stopped; and what signal, if any, it should be sent.
2635 For threads which we aren't explicitly told otherwise, we preserve
2636 the stepping flag; this is used for stepping over gdbserver-placed
2639 If pending_flags was set in any thread, we queue any needed
2640 signals, since we won't actually resume. We already have a pending
2641 event to report, so we don't need to preserve any step requests;
2642 they should be re-issued if necessary. */
2645 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
2647 struct lwp_info
*lwp
;
2648 struct thread_info
*thread
;
2650 int leave_all_stopped
= * (int *) arg
;
2653 thread
= (struct thread_info
*) entry
;
2654 lwp
= get_thread_lwp (thread
);
2656 if (lwp
->resume
== NULL
)
2659 if (lwp
->resume
->kind
== resume_stop
)
2662 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
2667 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
2669 /* Stop the thread, and wait for the event asynchronously,
2670 through the event loop. */
2676 fprintf (stderr
, "already stopped LWP %ld\n",
2679 /* The LWP may have been stopped in an internal event that
2680 was not meant to be notified back to GDB (e.g., gdbserver
2681 breakpoint), so we should be reporting a stop event in
2684 /* If the thread already has a pending SIGSTOP, this is a
2685 no-op. Otherwise, something later will presumably resume
2686 the thread and this will cause it to cancel any pending
2687 operation, due to last_resume_kind == resume_stop. If
2688 the thread already has a pending status to report, we
2689 will still report it the next time we wait - see
2690 status_pending_p_callback. */
2694 /* For stop requests, we're done. */
2696 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2700 /* If this thread which is about to be resumed has a pending status,
2701 then don't resume any threads - we can just report the pending
2702 status. Make sure to queue any signals that would otherwise be
2703 sent. In all-stop mode, we do this decision based on if *any*
2704 thread has a pending status. If there's a thread that needs the
2705 step-over-breakpoint dance, then don't resume any other thread
2706 but that particular one. */
2707 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
2712 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2714 step
= (lwp
->resume
->kind
== resume_step
);
2715 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2720 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2722 /* If we have a new signal, enqueue the signal. */
2723 if (lwp
->resume
->sig
!= 0)
2725 struct pending_signals
*p_sig
;
2726 p_sig
= xmalloc (sizeof (*p_sig
));
2727 p_sig
->prev
= lwp
->pending_signals
;
2728 p_sig
->signal
= lwp
->resume
->sig
;
2729 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2731 /* If this is the same signal we were previously stopped by,
2732 make sure to queue its siginfo. We can ignore the return
2733 value of ptrace; if it fails, we'll skip
2734 PTRACE_SETSIGINFO. */
2735 if (WIFSTOPPED (lwp
->last_status
)
2736 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2737 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2739 lwp
->pending_signals
= p_sig
;
2743 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2749 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2751 struct thread_resume_array array
= { resume_info
, n
};
2752 struct lwp_info
*need_step_over
= NULL
;
2754 int leave_all_stopped
;
2756 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2758 /* If there is a thread which would otherwise be resumed, which has
2759 a pending status, then don't resume any threads - we can just
2760 report the pending status. Make sure to queue any signals that
2761 would otherwise be sent. In non-stop mode, we'll apply this
2762 logic to each thread individually. We consume all pending events
2763 before considering to start a step-over (in all-stop). */
2766 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
2768 /* If there is a thread which would otherwise be resumed, which is
2769 stopped at a breakpoint that needs stepping over, then don't
2770 resume any threads - have it step over the breakpoint with all
2771 other threads stopped, then resume all threads again. Make sure
2772 to queue any signals that would otherwise be delivered or
2774 if (!any_pending
&& supports_breakpoints ())
2776 = (struct lwp_info
*) find_inferior (&all_lwps
,
2777 need_step_over_p
, NULL
);
2779 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
2783 if (need_step_over
!= NULL
)
2784 fprintf (stderr
, "Not resuming all, need step over\n");
2785 else if (any_pending
)
2787 "Not resuming, all-stop and found "
2788 "an LWP with pending status\n");
2790 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
2793 /* Even if we're leaving threads stopped, queue all signals we'd
2794 otherwise deliver. */
2795 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
2798 start_step_over (need_step_over
);
2801 /* This function is called once per thread. We check the thread's
2802 last resume request, which will tell us whether to resume, step, or
2803 leave the thread stopped. Any signal the client requested to be
2804 delivered has already been enqueued at this point.
2806 If any thread that GDB wants running is stopped at an internal
2807 breakpoint that needs stepping over, we start a step-over operation
2808 on that particular thread, and leave all others stopped. */
2811 proceed_one_lwp (struct inferior_list_entry
*entry
)
2813 struct lwp_info
*lwp
;
2814 struct thread_info
*thread
;
2817 lwp
= (struct lwp_info
*) entry
;
2821 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
2826 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
2830 thread
= get_lwp_thread (lwp
);
2832 if (thread
->last_resume_kind
== resume_stop
2833 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
2836 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
2841 if (lwp
->status_pending_p
)
2844 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
2852 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
2856 if (thread
->last_resume_kind
== resume_stop
)
2858 /* We haven't reported this LWP as stopped yet (otherwise, the
2859 last_status.kind check above would catch it, and we wouldn't
2860 reach here. This LWP may have been momentarily paused by a
2861 stop_all_lwps call while handling for example, another LWP's
2862 step-over. In that case, the pending expected SIGSTOP signal
2863 that was queued at vCont;t handling time will have already
2864 been consumed by wait_for_sigstop, and so we need to requeue
2865 another one here. Note that if the LWP already has a SIGSTOP
2866 pending, this is a no-op. */
2870 "Client wants LWP %ld to stop. "
2871 "Making sure it has a SIGSTOP pending\n",
2877 step
= thread
->last_resume_kind
== resume_step
;
2878 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2881 /* When we finish a step-over, set threads running again. If there's
2882 another thread that may need a step-over, now's the time to start
2883 it. Eventually, we'll move all threads past their breakpoints. */
2886 proceed_all_lwps (void)
2888 struct lwp_info
*need_step_over
;
2890 /* If there is a thread which would otherwise be resumed, which is
2891 stopped at a breakpoint that needs stepping over, then don't
2892 resume any threads - have it step over the breakpoint with all
2893 other threads stopped, then resume all threads again. */
2895 if (supports_breakpoints ())
2898 = (struct lwp_info
*) find_inferior (&all_lwps
,
2899 need_step_over_p
, NULL
);
2901 if (need_step_over
!= NULL
)
2904 fprintf (stderr
, "proceed_all_lwps: found "
2905 "thread %ld needing a step-over\n",
2906 lwpid_of (need_step_over
));
2908 start_step_over (need_step_over
);
2914 fprintf (stderr
, "Proceeding, no step-over needed\n");
2916 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2919 /* Stopped LWPs that the client wanted to be running, that don't have
2920 pending statuses, are set to run again, except for EXCEPT, if not
2921 NULL. This undoes a stop_all_lwps call. */
2924 unstop_all_lwps (struct lwp_info
*except
)
2930 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
2933 "unstopping all lwps\n");
2936 /* Make sure proceed_one_lwp doesn't try to resume this thread. */
2938 ++except
->suspended
;
2940 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2943 --except
->suspended
;
2946 #ifdef HAVE_LINUX_USRREGS
2949 register_addr (int regnum
)
2953 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2954 error ("Invalid register number %d.", regnum
);
2956 addr
= the_low_target
.regmap
[regnum
];
2961 /* Fetch one register. */
2963 fetch_register (struct regcache
*regcache
, int regno
)
2970 if (regno
>= the_low_target
.num_regs
)
2972 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2975 regaddr
= register_addr (regno
);
2979 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2980 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2981 & - sizeof (PTRACE_XFER_TYPE
));
2982 buf
= alloca (size
);
2983 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2986 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2987 ptrace (PTRACE_PEEKUSER
, pid
,
2988 /* Coerce to a uintptr_t first to avoid potential gcc warning
2989 of coercing an 8 byte integer to a 4 byte pointer. */
2990 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2991 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2993 error ("reading register %d: %s", regno
, strerror (errno
));
2996 if (the_low_target
.supply_ptrace_register
)
2997 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2999 supply_register (regcache
, regno
, buf
);
3002 /* Fetch all registers, or just one, from the child process. */
3004 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
3007 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3008 fetch_register (regcache
, regno
);
3010 fetch_register (regcache
, regno
);
3013 /* Store our register values back into the inferior.
3014 If REGNO is -1, do this for all registers.
3015 Otherwise, REGNO specifies which register (so we can save time). */
3017 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3026 if (regno
>= the_low_target
.num_regs
)
3029 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3032 regaddr
= register_addr (regno
);
3036 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3037 & - sizeof (PTRACE_XFER_TYPE
);
3038 buf
= alloca (size
);
3039 memset (buf
, 0, size
);
3041 if (the_low_target
.collect_ptrace_register
)
3042 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3044 collect_register (regcache
, regno
, buf
);
3046 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3047 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3050 ptrace (PTRACE_POKEUSER
, pid
,
3051 /* Coerce to a uintptr_t first to avoid potential gcc warning
3052 about coercing an 8 byte integer to a 4 byte pointer. */
3053 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3054 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3057 /* At this point, ESRCH should mean the process is
3058 already gone, in which case we simply ignore attempts
3059 to change its registers. See also the related
3060 comment in linux_resume_one_lwp. */
3064 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3065 error ("writing register %d: %s", regno
, strerror (errno
));
3067 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3071 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3072 usr_store_inferior_registers (regcache
, regno
);
3074 #endif /* HAVE_LINUX_USRREGS */
3078 #ifdef HAVE_LINUX_REGSETS
3081 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3083 struct regset_info
*regset
;
3084 int saw_general_regs
= 0;
3088 regset
= target_regsets
;
3090 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3091 while (regset
->size
>= 0)
3096 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3102 buf
= xmalloc (regset
->size
);
3104 nt_type
= regset
->nt_type
;
3108 iov
.iov_len
= regset
->size
;
3109 data
= (void *) &iov
;
3115 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3117 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3123 /* If we get EIO on a regset, do not try it again for
3125 disabled_regsets
[regset
- target_regsets
] = 1;
3132 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3137 else if (regset
->type
== GENERAL_REGS
)
3138 saw_general_regs
= 1;
3139 regset
->store_function (regcache
, buf
);
3143 if (saw_general_regs
)
3150 regsets_store_inferior_registers (struct regcache
*regcache
)
3152 struct regset_info
*regset
;
3153 int saw_general_regs
= 0;
3157 regset
= target_regsets
;
3159 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3160 while (regset
->size
>= 0)
3165 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3171 buf
= xmalloc (regset
->size
);
3173 /* First fill the buffer with the current register set contents,
3174 in case there are any items in the kernel's regset that are
3175 not in gdbserver's regcache. */
3177 nt_type
= regset
->nt_type
;
3181 iov
.iov_len
= regset
->size
;
3182 data
= (void *) &iov
;
3188 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3190 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3195 /* Then overlay our cached registers on that. */
3196 regset
->fill_function (regcache
, buf
);
3198 /* Only now do we write the register set. */
3200 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3202 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3210 /* If we get EIO on a regset, do not try it again for
3212 disabled_regsets
[regset
- target_regsets
] = 1;
3216 else if (errno
== ESRCH
)
3218 /* At this point, ESRCH should mean the process is
3219 already gone, in which case we simply ignore attempts
3220 to change its registers. See also the related
3221 comment in linux_resume_one_lwp. */
3227 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3230 else if (regset
->type
== GENERAL_REGS
)
3231 saw_general_regs
= 1;
3235 if (saw_general_regs
)
3242 #endif /* HAVE_LINUX_REGSETS */
3246 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3248 #ifdef HAVE_LINUX_REGSETS
3249 if (regsets_fetch_inferior_registers (regcache
) == 0)
3252 #ifdef HAVE_LINUX_USRREGS
3253 usr_fetch_inferior_registers (regcache
, regno
);
3258 linux_store_registers (struct regcache
*regcache
, int regno
)
3260 #ifdef HAVE_LINUX_REGSETS
3261 if (regsets_store_inferior_registers (regcache
) == 0)
3264 #ifdef HAVE_LINUX_USRREGS
3265 usr_store_inferior_registers (regcache
, regno
);
3270 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3271 to debugger memory starting at MYADDR. */
3274 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3277 /* Round starting address down to longword boundary. */
3278 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3279 /* Round ending address up; get number of longwords that makes. */
3281 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3282 / sizeof (PTRACE_XFER_TYPE
);
3283 /* Allocate buffer of that many longwords. */
3284 register PTRACE_XFER_TYPE
*buffer
3285 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3288 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3290 /* Try using /proc. Don't bother for one word. */
3291 if (len
>= 3 * sizeof (long))
3293 /* We could keep this file open and cache it - possibly one per
3294 thread. That requires some juggling, but is even faster. */
3295 sprintf (filename
, "/proc/%d/mem", pid
);
3296 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3300 /* If pread64 is available, use it. It's faster if the kernel
3301 supports it (only one syscall), and it's 64-bit safe even on
3302 32-bit platforms (for instance, SPARC debugging a SPARC64
3305 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3307 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3319 /* Read all the longwords */
3320 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3323 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3324 about coercing an 8 byte integer to a 4 byte pointer. */
3325 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3326 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3331 /* Copy appropriate bytes out of the buffer. */
3333 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
3339 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3340 memory at MEMADDR. On failure (cannot write to the inferior)
3341 returns the value of errno. */
3344 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
3347 /* Round starting address down to longword boundary. */
3348 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3349 /* Round ending address up; get number of longwords that makes. */
3351 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
3352 /* Allocate buffer of that many longwords. */
3353 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3354 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3358 /* Dump up to four bytes. */
3359 unsigned int val
= * (unsigned int *) myaddr
;
3365 val
= val
& 0xffffff;
3366 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
3367 val
, (long)memaddr
);
3370 /* Fill start and end extra bytes of buffer with existing memory data. */
3373 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3374 about coercing an 8 byte integer to a 4 byte pointer. */
3375 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
3376 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3384 = ptrace (PTRACE_PEEKTEXT
, pid
,
3385 /* Coerce to a uintptr_t first to avoid potential gcc warning
3386 about coercing an 8 byte integer to a 4 byte pointer. */
3387 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
3388 * sizeof (PTRACE_XFER_TYPE
)),
3394 /* Copy data to be written over corresponding part of buffer. */
3396 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
3398 /* Write the entire buffer. */
3400 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3403 ptrace (PTRACE_POKETEXT
, pid
,
3404 /* Coerce to a uintptr_t first to avoid potential gcc warning
3405 about coercing an 8 byte integer to a 4 byte pointer. */
3406 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
3407 (PTRACE_ARG4_TYPE
) buffer
[i
]);
3415 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
3416 static int linux_supports_tracefork_flag
;
3418 /* Helper functions for linux_test_for_tracefork, called via clone (). */
3421 linux_tracefork_grandchild (void *arg
)
3426 #define STACK_SIZE 4096
3429 linux_tracefork_child (void *arg
)
3431 ptrace (PTRACE_TRACEME
, 0, 0, 0);
3432 kill (getpid (), SIGSTOP
);
3434 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3437 linux_tracefork_grandchild (NULL
);
3439 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3442 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
3443 CLONE_VM
| SIGCHLD
, NULL
);
3445 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
3446 CLONE_VM
| SIGCHLD
, NULL
);
3449 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3454 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
3455 sure that we can enable the option, and that it had the desired
3459 linux_test_for_tracefork (void)
3461 int child_pid
, ret
, status
;
3463 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3464 char *stack
= xmalloc (STACK_SIZE
* 4);
3465 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3467 linux_supports_tracefork_flag
= 0;
3469 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3471 child_pid
= fork ();
3473 linux_tracefork_child (NULL
);
3475 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3477 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
3479 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
3480 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3481 #else /* !__ia64__ */
3482 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
3483 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3484 #endif /* !__ia64__ */
3486 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3488 if (child_pid
== -1)
3489 perror_with_name ("clone");
3491 ret
= my_waitpid (child_pid
, &status
, 0);
3493 perror_with_name ("waitpid");
3494 else if (ret
!= child_pid
)
3495 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
3496 if (! WIFSTOPPED (status
))
3497 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
3499 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
3500 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
3503 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3506 warning ("linux_test_for_tracefork: failed to kill child");
3510 ret
= my_waitpid (child_pid
, &status
, 0);
3511 if (ret
!= child_pid
)
3512 warning ("linux_test_for_tracefork: failed to wait for killed child");
3513 else if (!WIFSIGNALED (status
))
3514 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
3515 "killed child", status
);
3520 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
3522 warning ("linux_test_for_tracefork: failed to resume child");
3524 ret
= my_waitpid (child_pid
, &status
, 0);
3526 if (ret
== child_pid
&& WIFSTOPPED (status
)
3527 && status
>> 16 == PTRACE_EVENT_FORK
)
3530 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
3531 if (ret
== 0 && second_pid
!= 0)
3535 linux_supports_tracefork_flag
= 1;
3536 my_waitpid (second_pid
, &second_status
, 0);
3537 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
3539 warning ("linux_test_for_tracefork: failed to kill second child");
3540 my_waitpid (second_pid
, &status
, 0);
3544 warning ("linux_test_for_tracefork: unexpected result from waitpid "
3545 "(%d, status 0x%x)", ret
, status
);
3549 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3551 warning ("linux_test_for_tracefork: failed to kill child");
3552 my_waitpid (child_pid
, &status
, 0);
3554 while (WIFSTOPPED (status
));
3556 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3558 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3563 linux_look_up_symbols (void)
3565 #ifdef USE_THREAD_DB
3566 struct process_info
*proc
= current_process ();
3568 if (proc
->private->thread_db
!= NULL
)
3571 /* If the kernel supports tracing forks then it also supports tracing
3572 clones, and then we don't need to use the magic thread event breakpoint
3573 to learn about threads. */
3574 thread_db_init (!linux_supports_tracefork_flag
);
3579 linux_request_interrupt (void)
3581 extern unsigned long signal_pid
;
3583 if (!ptid_equal (cont_thread
, null_ptid
)
3584 && !ptid_equal (cont_thread
, minus_one_ptid
))
3586 struct lwp_info
*lwp
;
3589 lwp
= get_thread_lwp (current_inferior
);
3590 lwpid
= lwpid_of (lwp
);
3591 kill_lwp (lwpid
, SIGINT
);
3594 kill_lwp (signal_pid
, SIGINT
);
3597 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
3598 to debugger memory starting at MYADDR. */
3601 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
3603 char filename
[PATH_MAX
];
3605 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3607 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
3609 fd
= open (filename
, O_RDONLY
);
3613 if (offset
!= (CORE_ADDR
) 0
3614 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3617 n
= read (fd
, myaddr
, len
);
3624 /* These breakpoint and watchpoint related wrapper functions simply
3625 pass on the function call if the target has registered a
3626 corresponding function. */
3629 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
3631 if (the_low_target
.insert_point
!= NULL
)
3632 return the_low_target
.insert_point (type
, addr
, len
);
3634 /* Unsupported (see target.h). */
3639 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
3641 if (the_low_target
.remove_point
!= NULL
)
3642 return the_low_target
.remove_point (type
, addr
, len
);
3644 /* Unsupported (see target.h). */
3649 linux_stopped_by_watchpoint (void)
3651 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3653 return lwp
->stopped_by_watchpoint
;
3657 linux_stopped_data_address (void)
3659 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3661 return lwp
->stopped_data_address
;
3664 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3665 #if defined(__mcoldfire__)
3666 /* These should really be defined in the kernel's ptrace.h header. */
3667 #define PT_TEXT_ADDR 49*4
3668 #define PT_DATA_ADDR 50*4
3669 #define PT_TEXT_END_ADDR 51*4
3672 /* Under uClinux, programs are loaded at non-zero offsets, which we need
3673 to tell gdb about. */
3676 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
3678 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
3679 unsigned long text
, text_end
, data
;
3680 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3684 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
3685 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
3686 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
3690 /* Both text and data offsets produced at compile-time (and so
3691 used by gdb) are relative to the beginning of the program,
3692 with the data segment immediately following the text segment.
3693 However, the actual runtime layout in memory may put the data
3694 somewhere else, so when we send gdb a data base-address, we
3695 use the real data base address and subtract the compile-time
3696 data base-address from it (which is just the length of the
3697 text segment). BSS immediately follows data in both
3700 *data_p
= data
- (text_end
- text
);
3710 compare_ints (const void *xa
, const void *xb
)
3712 int a
= *(const int *)xa
;
3713 int b
= *(const int *)xb
;
3719 unique (int *b
, int *e
)
3728 /* Given PID, iterates over all threads in that process.
3730 Information about each thread, in a format suitable for qXfer:osdata:thread
3731 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
3732 initialized, and the caller is responsible for finishing and appending '\0'
3735 The list of cores that threads are running on is assigned to *CORES, if it
3736 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
3737 should free *CORES. */
3740 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
3744 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
3748 struct stat statbuf
;
3750 sprintf (pathname
, "/proc/%d/task", pid
);
3751 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
3753 dir
= opendir (pathname
);
3756 free (core_numbers
);
3760 while ((dp
= readdir (dir
)) != NULL
)
3762 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
3766 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
3770 char s
[sizeof ("4294967295")];
3771 sprintf (s
, "%u", core
);
3773 if (count
== allocated
)
3776 core_numbers
= realloc (core_numbers
,
3777 sizeof (int) * allocated
);
3779 core_numbers
[count
++] = core
;
3781 buffer_xml_printf (buffer
,
3783 "<column name=\"pid\">%d</column>"
3784 "<column name=\"tid\">%s</column>"
3785 "<column name=\"core\">%s</column>"
3786 "</item>", pid
, dp
->d_name
, s
);
3791 buffer_xml_printf (buffer
,
3793 "<column name=\"pid\">%d</column>"
3794 "<column name=\"tid\">%s</column>"
3795 "</item>", pid
, dp
->d_name
);
3806 struct buffer buffer2
;
3809 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
3811 /* Remove duplicates. */
3813 e
= unique (b
, core_numbers
+ count
);
3815 buffer_init (&buffer2
);
3817 for (b
= core_numbers
; b
!= e
; ++b
)
3819 char number
[sizeof ("4294967295")];
3820 sprintf (number
, "%u", *b
);
3821 buffer_xml_printf (&buffer2
, "%s%s",
3822 (b
== core_numbers
) ? "" : ",", number
);
3824 buffer_grow_str0 (&buffer2
, "");
3826 *cores
= buffer_finish (&buffer2
);
3829 free (core_numbers
);
3833 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3837 char cmd
[MAXPATHLEN
+ 1];
3839 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3841 if ((f
= fopen (pathname
, "r")) != NULL
)
3843 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3848 for (i
= 0; i
< len
; i
++)
3853 buffer_xml_printf (buffer
,
3855 "<column name=\"pid\">%d</column>"
3856 "<column name=\"user\">%s</column>"
3857 "<column name=\"command\">%s</column>",
3862 /* This only collects core numbers, and does not print threads. */
3863 list_threads (pid
, NULL
, &cores
);
3867 buffer_xml_printf (buffer
,
3868 "<column name=\"cores\">%s</column>", cores
);
3872 buffer_xml_printf (buffer
, "</item>");
3879 linux_qxfer_osdata (const char *annex
,
3880 unsigned char *readbuf
, unsigned const char *writebuf
,
3881 CORE_ADDR offset
, int len
)
3883 /* We make the process list snapshot when the object starts to be
3885 static const char *buf
;
3886 static long len_avail
= -1;
3887 static struct buffer buffer
;
3893 if (strcmp (annex
, "processes") == 0)
3895 else if (strcmp (annex
, "threads") == 0)
3900 if (!readbuf
|| writebuf
)
3905 if (len_avail
!= -1 && len_avail
!= 0)
3906 buffer_free (&buffer
);
3909 buffer_init (&buffer
);
3911 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3913 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3915 dirp
= opendir ("/proc");
3919 while ((dp
= readdir (dirp
)) != NULL
)
3921 struct stat statbuf
;
3922 char procentry
[sizeof ("/proc/4294967295")];
3924 if (!isdigit (dp
->d_name
[0])
3925 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3928 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3929 if (stat (procentry
, &statbuf
) == 0
3930 && S_ISDIR (statbuf
.st_mode
))
3932 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3936 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3937 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3941 list_threads (pid
, &buffer
, NULL
);
3948 buffer_grow_str0 (&buffer
, "</osdata>\n");
3949 buf
= buffer_finish (&buffer
);
3950 len_avail
= strlen (buf
);
3953 if (offset
>= len_avail
)
3955 /* Done. Get rid of the data. */
3956 buffer_free (&buffer
);
3962 if (len
> len_avail
- offset
)
3963 len
= len_avail
- offset
;
3964 memcpy (readbuf
, buf
+ offset
, len
);
3969 /* Convert a native/host siginfo object, into/from the siginfo in the
3970 layout of the inferiors' architecture. */
3973 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3977 if (the_low_target
.siginfo_fixup
!= NULL
)
3978 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3980 /* If there was no callback, or the callback didn't do anything,
3981 then just do a straight memcpy. */
3985 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3987 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3992 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3993 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3996 struct siginfo siginfo
;
3997 char inf_siginfo
[sizeof (struct siginfo
)];
3999 if (current_inferior
== NULL
)
4002 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4005 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4006 readbuf
!= NULL
? "Reading" : "Writing",
4009 if (offset
> sizeof (siginfo
))
4012 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4015 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4016 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4017 inferior with a 64-bit GDBSERVER should look the same as debugging it
4018 with a 32-bit GDBSERVER, we need to convert it. */
4019 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4021 if (offset
+ len
> sizeof (siginfo
))
4022 len
= sizeof (siginfo
) - offset
;
4024 if (readbuf
!= NULL
)
4025 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4028 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4030 /* Convert back to ptrace layout before flushing it out. */
4031 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4033 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4040 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4041 so we notice when children change state; as the handler for the
4042 sigsuspend in my_waitpid. */
4045 sigchld_handler (int signo
)
4047 int old_errno
= errno
;
4050 /* fprintf is not async-signal-safe, so call write directly. */
4051 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
4053 if (target_is_async_p ())
4054 async_file_mark (); /* trigger a linux_wait */
4060 linux_supports_non_stop (void)
4066 linux_async (int enable
)
4068 int previous
= (linux_event_pipe
[0] != -1);
4071 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4074 if (previous
!= enable
)
4077 sigemptyset (&mask
);
4078 sigaddset (&mask
, SIGCHLD
);
4080 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4084 if (pipe (linux_event_pipe
) == -1)
4085 fatal ("creating event pipe failed.");
4087 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4088 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4090 /* Register the event loop handler. */
4091 add_file_handler (linux_event_pipe
[0],
4092 handle_target_event
, NULL
);
4094 /* Always trigger a linux_wait. */
4099 delete_file_handler (linux_event_pipe
[0]);
4101 close (linux_event_pipe
[0]);
4102 close (linux_event_pipe
[1]);
4103 linux_event_pipe
[0] = -1;
4104 linux_event_pipe
[1] = -1;
4107 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4114 linux_start_non_stop (int nonstop
)
4116 /* Register or unregister from event-loop accordingly. */
4117 linux_async (nonstop
);
4122 linux_supports_multi_process (void)
4128 /* Enumerate spufs IDs for process PID. */
4130 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4136 struct dirent
*entry
;
4138 sprintf (path
, "/proc/%ld/fd", pid
);
4139 dir
= opendir (path
);
4144 while ((entry
= readdir (dir
)) != NULL
)
4150 fd
= atoi (entry
->d_name
);
4154 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4155 if (stat (path
, &st
) != 0)
4157 if (!S_ISDIR (st
.st_mode
))
4160 if (statfs (path
, &stfs
) != 0)
4162 if (stfs
.f_type
!= SPUFS_MAGIC
)
4165 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4167 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4177 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4178 object type, using the /proc file system. */
4180 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4181 unsigned const char *writebuf
,
4182 CORE_ADDR offset
, int len
)
4184 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4189 if (!writebuf
&& !readbuf
)
4197 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4200 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4201 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4206 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4213 ret
= write (fd
, writebuf
, (size_t) len
);
4215 ret
= read (fd
, readbuf
, (size_t) len
);
4222 linux_core_of_thread (ptid_t ptid
)
4224 char filename
[sizeof ("/proc//task//stat")
4225 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4228 char *content
= NULL
;
4231 int content_read
= 0;
4235 sprintf (filename
, "/proc/%d/task/%ld/stat",
4236 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4237 f
= fopen (filename
, "r");
4244 content
= realloc (content
, content_read
+ 1024);
4245 n
= fread (content
+ content_read
, 1, 1024, f
);
4249 content
[content_read
] = '\0';
4254 p
= strchr (content
, '(');
4255 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
4257 p
= strtok_r (p
, " ", &ts
);
4258 for (i
= 0; i
!= 36; ++i
)
4259 p
= strtok_r (NULL
, " ", &ts
);
4261 if (sscanf (p
, "%d", &core
) == 0)
4271 linux_process_qsupported (const char *query
)
4273 if (the_low_target
.process_qsupported
!= NULL
)
4274 the_low_target
.process_qsupported (query
);
4278 linux_supports_tracepoints (void)
4280 if (*the_low_target
.supports_tracepoints
== NULL
)
4283 return (*the_low_target
.supports_tracepoints
) ();
4287 linux_read_pc (struct regcache
*regcache
)
4289 if (the_low_target
.get_pc
== NULL
)
4292 return (*the_low_target
.get_pc
) (regcache
);
4296 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
4298 gdb_assert (the_low_target
.set_pc
!= NULL
);
4300 (*the_low_target
.set_pc
) (regcache
, pc
);
4304 linux_thread_stopped (struct thread_info
*thread
)
4306 return get_thread_lwp (thread
)->stopped
;
4309 /* This exposes stop-all-threads functionality to other modules. */
4312 linux_pause_all (void)
4317 static struct target_ops linux_target_ops
= {
4318 linux_create_inferior
,
4327 linux_fetch_registers
,
4328 linux_store_registers
,
4331 linux_look_up_symbols
,
4332 linux_request_interrupt
,
4336 linux_stopped_by_watchpoint
,
4337 linux_stopped_data_address
,
4338 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4343 #ifdef USE_THREAD_DB
4344 thread_db_get_tls_address
,
4349 hostio_last_error_from_errno
,
4352 linux_supports_non_stop
,
4354 linux_start_non_stop
,
4355 linux_supports_multi_process
,
4356 #ifdef USE_THREAD_DB
4357 thread_db_handle_monitor_command
,
4361 linux_core_of_thread
,
4362 linux_process_qsupported
,
4363 linux_supports_tracepoints
,
4366 linux_thread_stopped
,
4368 NULL
, /* get_tib_address (Windows OS specific). */
4372 linux_init_signals ()
4374 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4375 to find what the cancel signal actually is. */
4376 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
4377 signal (__SIGRTMIN
+1, SIG_IGN
);
4382 initialize_low (void)
4384 struct sigaction sigchld_action
;
4385 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4386 set_target_ops (&linux_target_ops
);
4387 set_breakpoint_data (the_low_target
.breakpoint
,
4388 the_low_target
.breakpoint_len
);
4389 linux_init_signals ();
4390 linux_test_for_tracefork ();
4391 #ifdef HAVE_LINUX_REGSETS
4392 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4394 disabled_regsets
= xmalloc (num_regsets
);
4397 sigchld_action
.sa_handler
= sigchld_handler
;
4398 sigemptyset (&sigchld_action
.sa_mask
);
4399 sigchld_action
.sa_flags
= SA_RESTART
;
4400 sigaction (SIGCHLD
, &sigchld_action
, NULL
);