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
);
153 static void linux_enable_event_reporting (int pid
);
155 /* True if the low target can hardware single-step. Such targets
156 don't need a BREAKPOINT_REINSERT_ADDR callback. */
159 can_hardware_single_step (void)
161 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
164 /* True if the low target supports memory breakpoints. If so, we'll
165 have a GET_PC implementation. */
168 supports_breakpoints (void)
170 return (the_low_target
.get_pc
!= NULL
);
173 struct pending_signals
177 struct pending_signals
*prev
;
180 #define PTRACE_ARG3_TYPE void *
181 #define PTRACE_ARG4_TYPE void *
182 #define PTRACE_XFER_TYPE long
184 #ifdef HAVE_LINUX_REGSETS
185 static char *disabled_regsets
;
186 static int num_regsets
;
189 /* The read/write ends of the pipe registered as waitable file in the
191 static int linux_event_pipe
[2] = { -1, -1 };
193 /* True if we're currently in async mode. */
194 #define target_is_async_p() (linux_event_pipe[0] != -1)
196 static void send_sigstop (struct lwp_info
*lwp
);
197 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
199 /* Accepts an integer PID; Returns a string representing a file that
200 can be opened to get info for the child process.
201 Space for the result is malloc'd, caller must free. */
204 linux_child_pid_to_exec_file (int pid
)
208 name1
= xmalloc (MAXPATHLEN
);
209 name2
= xmalloc (MAXPATHLEN
);
210 memset (name2
, 0, MAXPATHLEN
);
212 sprintf (name1
, "/proc/%d/exe", pid
);
213 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
225 /* Return non-zero if HEADER is a 64-bit ELF file. */
228 elf_64_header_p (const Elf64_Ehdr
*header
)
230 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
231 && header
->e_ident
[EI_MAG1
] == ELFMAG1
232 && header
->e_ident
[EI_MAG2
] == ELFMAG2
233 && header
->e_ident
[EI_MAG3
] == ELFMAG3
234 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
237 /* Return non-zero if FILE is a 64-bit ELF file,
238 zero if the file is not a 64-bit ELF file,
239 and -1 if the file is not accessible or doesn't exist. */
242 elf_64_file_p (const char *file
)
247 fd
= open (file
, O_RDONLY
);
251 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
258 return elf_64_header_p (&header
);
262 delete_lwp (struct lwp_info
*lwp
)
264 remove_thread (get_lwp_thread (lwp
));
265 remove_inferior (&all_lwps
, &lwp
->head
);
266 free (lwp
->arch_private
);
270 /* Add a process to the common process list, and set its private
273 static struct process_info
*
274 linux_add_process (int pid
, int attached
)
276 struct process_info
*proc
;
278 /* Is this the first process? If so, then set the arch. */
279 if (all_processes
.head
== NULL
)
282 proc
= add_process (pid
, attached
);
283 proc
->private = xcalloc (1, sizeof (*proc
->private));
285 if (the_low_target
.new_process
!= NULL
)
286 proc
->private->arch_private
= the_low_target
.new_process ();
291 /* Wrapper function for waitpid which handles EINTR, and emulates
292 __WALL for systems where that is not available. */
295 my_waitpid (int pid
, int *status
, int flags
)
300 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
304 sigset_t block_mask
, org_mask
, wake_mask
;
307 wnohang
= (flags
& WNOHANG
) != 0;
308 flags
&= ~(__WALL
| __WCLONE
);
311 /* Block all signals while here. This avoids knowing about
312 LinuxThread's signals. */
313 sigfillset (&block_mask
);
314 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
316 /* ... except during the sigsuspend below. */
317 sigemptyset (&wake_mask
);
321 /* Since all signals are blocked, there's no need to check
323 ret
= waitpid (pid
, status
, flags
);
326 if (ret
== -1 && out_errno
!= ECHILD
)
331 if (flags
& __WCLONE
)
333 /* We've tried both flavors now. If WNOHANG is set,
334 there's nothing else to do, just bail out. */
339 fprintf (stderr
, "blocking\n");
341 /* Block waiting for signals. */
342 sigsuspend (&wake_mask
);
348 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
353 ret
= waitpid (pid
, status
, flags
);
354 while (ret
== -1 && errno
== EINTR
);
359 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
360 pid
, flags
, status
? *status
: -1, ret
);
366 /* Handle a GNU/Linux extended wait response. If we see a clone
367 event, we need to add the new LWP to our list (and not report the
368 trap to higher layers). */
371 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
373 int event
= wstat
>> 16;
374 struct lwp_info
*new_lwp
;
376 if (event
== PTRACE_EVENT_CLONE
)
379 unsigned long new_pid
;
380 int ret
, status
= W_STOPCODE (SIGSTOP
);
382 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
384 /* If we haven't already seen the new PID stop, wait for it now. */
385 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
387 /* The new child has a pending SIGSTOP. We can't affect it until it
388 hits the SIGSTOP, but we're already attached. */
390 ret
= my_waitpid (new_pid
, &status
, __WALL
);
393 perror_with_name ("waiting for new child");
394 else if (ret
!= new_pid
)
395 warning ("wait returned unexpected PID %d", ret
);
396 else if (!WIFSTOPPED (status
))
397 warning ("wait returned unexpected status 0x%x", status
);
400 linux_enable_event_reporting (new_pid
);
402 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
403 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
404 add_thread (ptid
, new_lwp
);
406 /* Either we're going to immediately resume the new thread
407 or leave it stopped. linux_resume_one_lwp is a nop if it
408 thinks the thread is currently running, so set this first
409 before calling linux_resume_one_lwp. */
410 new_lwp
->stopped
= 1;
412 /* Normally we will get the pending SIGSTOP. But in some cases
413 we might get another signal delivered to the group first.
414 If we do get another signal, be sure not to lose it. */
415 if (WSTOPSIG (status
) == SIGSTOP
)
417 if (stopping_threads
)
418 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
420 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
424 new_lwp
->stop_expected
= 1;
426 if (stopping_threads
)
428 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
429 new_lwp
->status_pending_p
= 1;
430 new_lwp
->status_pending
= status
;
433 /* Pass the signal on. This is what GDB does - except
434 shouldn't we really report it instead? */
435 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
438 /* Always resume the current thread. If we are stopping
439 threads, it will have a pending SIGSTOP; we may as well
441 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
445 /* Return the PC as read from the regcache of LWP, without any
449 get_pc (struct lwp_info
*lwp
)
451 struct thread_info
*saved_inferior
;
452 struct regcache
*regcache
;
455 if (the_low_target
.get_pc
== NULL
)
458 saved_inferior
= current_inferior
;
459 current_inferior
= get_lwp_thread (lwp
);
461 regcache
= get_thread_regcache (current_inferior
, 1);
462 pc
= (*the_low_target
.get_pc
) (regcache
);
465 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
467 current_inferior
= saved_inferior
;
471 /* This function should only be called if LWP got a SIGTRAP.
472 The SIGTRAP could mean several things.
474 On i386, where decr_pc_after_break is non-zero:
475 If we were single-stepping this process using PTRACE_SINGLESTEP,
476 we will get only the one SIGTRAP (even if the instruction we
477 stepped over was a breakpoint). The value of $eip will be the
479 If we continue the process using PTRACE_CONT, we will get a
480 SIGTRAP when we hit a breakpoint. The value of $eip will be
481 the instruction after the breakpoint (i.e. needs to be
482 decremented). If we report the SIGTRAP to GDB, we must also
483 report the undecremented PC. If we cancel the SIGTRAP, we
484 must resume at the decremented PC.
486 (Presumably, not yet tested) On a non-decr_pc_after_break machine
487 with hardware or kernel single-step:
488 If we single-step over a breakpoint instruction, our PC will
489 point at the following instruction. If we continue and hit a
490 breakpoint instruction, our PC will point at the breakpoint
494 get_stop_pc (struct lwp_info
*lwp
)
498 if (the_low_target
.get_pc
== NULL
)
501 stop_pc
= get_pc (lwp
);
503 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
505 && !lwp
->stopped_by_watchpoint
506 && lwp
->last_status
>> 16 == 0)
507 stop_pc
-= the_low_target
.decr_pc_after_break
;
510 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
516 add_lwp (ptid_t ptid
)
518 struct lwp_info
*lwp
;
520 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
521 memset (lwp
, 0, sizeof (*lwp
));
525 if (the_low_target
.new_thread
!= NULL
)
526 lwp
->arch_private
= the_low_target
.new_thread ();
528 add_inferior_to_list (&all_lwps
, &lwp
->head
);
533 /* Start an inferior process and returns its pid.
534 ALLARGS is a vector of program-name and args. */
537 linux_create_inferior (char *program
, char **allargs
)
539 struct lwp_info
*new_lwp
;
543 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
549 perror_with_name ("fork");
553 ptrace (PTRACE_TRACEME
, 0, 0, 0);
555 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
556 signal (__SIGRTMIN
+ 1, SIG_DFL
);
561 execv (program
, allargs
);
563 execvp (program
, allargs
);
565 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
571 linux_add_process (pid
, 0);
573 ptid
= ptid_build (pid
, pid
, 0);
574 new_lwp
= add_lwp (ptid
);
575 add_thread (ptid
, new_lwp
);
576 new_lwp
->must_set_ptrace_flags
= 1;
581 /* Attach to an inferior process. */
584 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
587 struct lwp_info
*new_lwp
;
589 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
593 /* If we fail to attach to an LWP, just warn. */
594 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
595 strerror (errno
), errno
);
600 /* If we fail to attach to a process, report an error. */
601 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
602 strerror (errno
), errno
);
606 /* NOTE/FIXME: This lwp might have not been the tgid. */
607 ptid
= ptid_build (lwpid
, lwpid
, 0);
610 /* Note that extracting the pid from the current inferior is
611 safe, since we're always called in the context of the same
612 process as this new thread. */
613 int pid
= pid_of (get_thread_lwp (current_inferior
));
614 ptid
= ptid_build (pid
, lwpid
, 0);
617 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
618 add_thread (ptid
, new_lwp
);
620 /* We need to wait for SIGSTOP before being able to make the next
621 ptrace call on this LWP. */
622 new_lwp
->must_set_ptrace_flags
= 1;
624 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
627 There are several cases to consider here:
629 1) gdbserver has already attached to the process and is being notified
630 of a new thread that is being created.
631 In this case we should ignore that SIGSTOP and resume the
632 process. This is handled below by setting stop_expected = 1,
633 and the fact that add_thread sets last_resume_kind ==
636 2) This is the first thread (the process thread), and we're attaching
637 to it via attach_inferior.
638 In this case we want the process thread to stop.
639 This is handled by having linux_attach set last_resume_kind ==
640 resume_stop after we return.
641 ??? If the process already has several threads we leave the other
644 3) GDB is connecting to gdbserver and is requesting an enumeration of all
646 In this case we want the thread to stop.
647 FIXME: This case is currently not properly handled.
648 We should wait for the SIGSTOP but don't. Things work apparently
649 because enough time passes between when we ptrace (ATTACH) and when
650 gdb makes the next ptrace call on the thread.
652 On the other hand, if we are currently trying to stop all threads, we
653 should treat the new thread as if we had sent it a SIGSTOP. This works
654 because we are guaranteed that the add_lwp call above added us to the
655 end of the list, and so the new thread has not yet reached
656 wait_for_sigstop (but will). */
657 new_lwp
->stop_expected
= 1;
661 linux_attach_lwp (unsigned long lwpid
)
663 linux_attach_lwp_1 (lwpid
, 0);
667 linux_attach (unsigned long pid
)
669 linux_attach_lwp_1 (pid
, 1);
670 linux_add_process (pid
, 1);
674 struct thread_info
*thread
;
676 /* Don't ignore the initial SIGSTOP if we just attached to this
677 process. It will be collected by wait shortly. */
678 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
679 thread
->last_resume_kind
= resume_stop
;
692 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
694 struct counter
*counter
= args
;
696 if (ptid_get_pid (entry
->id
) == counter
->pid
)
698 if (++counter
->count
> 1)
706 last_thread_of_process_p (struct thread_info
*thread
)
708 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
709 int pid
= ptid_get_pid (ptid
);
710 struct counter counter
= { pid
, 0 };
712 return (find_inferior (&all_threads
,
713 second_thread_of_pid_p
, &counter
) == NULL
);
716 /* Kill the inferior lwp. */
719 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
721 struct thread_info
*thread
= (struct thread_info
*) entry
;
722 struct lwp_info
*lwp
= get_thread_lwp (thread
);
724 int pid
= * (int *) args
;
726 if (ptid_get_pid (entry
->id
) != pid
)
729 /* We avoid killing the first thread here, because of a Linux kernel (at
730 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
731 the children get a chance to be reaped, it will remain a zombie
734 if (lwpid_of (lwp
) == pid
)
737 fprintf (stderr
, "lkop: is last of process %s\n",
738 target_pid_to_str (entry
->id
));
744 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
746 /* Make sure it died. The loop is most likely unnecessary. */
747 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
748 } while (pid
> 0 && WIFSTOPPED (wstat
));
756 struct process_info
*process
;
757 struct lwp_info
*lwp
;
758 struct thread_info
*thread
;
762 process
= find_process_pid (pid
);
766 /* If we're killing a running inferior, make sure it is stopped
767 first, as PTRACE_KILL will not work otherwise. */
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
);
783 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
785 /* Make sure it died. The loop is most likely unnecessary. */
786 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
787 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
789 the_target
->mourn (process
);
791 /* Since we presently can only stop all lwps of all processes, we
792 need to unstop lwps of other processes. */
793 unstop_all_lwps (NULL
);
798 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
800 struct thread_info
*thread
= (struct thread_info
*) entry
;
801 struct lwp_info
*lwp
= get_thread_lwp (thread
);
802 int pid
= * (int *) args
;
804 if (ptid_get_pid (entry
->id
) != pid
)
807 /* If this process is stopped but is expecting a SIGSTOP, then make
808 sure we take care of that now. This isn't absolutely guaranteed
809 to collect the SIGSTOP, but is fairly likely to. */
810 if (lwp
->stop_expected
)
813 /* Clear stop_expected, so that the SIGSTOP will be reported. */
814 lwp
->stop_expected
= 0;
815 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
816 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
819 /* Flush any pending changes to the process's registers. */
820 regcache_invalidate_one ((struct inferior_list_entry
*)
821 get_lwp_thread (lwp
));
823 /* Finally, let it resume. */
824 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
831 linux_detach (int pid
)
833 struct process_info
*process
;
835 process
= find_process_pid (pid
);
839 /* Stop all threads before detaching. First, ptrace requires that
840 the thread is stopped to sucessfully detach. Second, thread_db
841 may need to uninstall thread event breakpoints from memory, which
842 only works with a stopped process anyway. */
846 thread_db_detach (process
);
849 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
851 the_target
->mourn (process
);
853 /* Since we presently can only stop all lwps of all processes, we
854 need to unstop lwps of other processes. */
855 unstop_all_lwps (NULL
);
859 /* Remove all LWPs that belong to process PROC from the lwp list. */
862 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
864 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
865 struct process_info
*process
= proc
;
867 if (pid_of (lwp
) == pid_of (process
))
874 linux_mourn (struct process_info
*process
)
876 struct process_info_private
*priv
;
879 thread_db_mourn (process
);
882 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
884 /* Freeing all private data. */
885 priv
= process
->private;
886 free (priv
->arch_private
);
888 process
->private = NULL
;
890 remove_process (process
);
897 struct process_info
*process
;
899 process
= find_process_pid (pid
);
904 ret
= my_waitpid (pid
, &status
, 0);
905 if (WIFEXITED (status
) || WIFSIGNALED (status
))
907 } while (ret
!= -1 || errno
!= ECHILD
);
910 /* Return nonzero if the given thread is still alive. */
912 linux_thread_alive (ptid_t ptid
)
914 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
916 /* We assume we always know if a thread exits. If a whole process
917 exited but we still haven't been able to report it to GDB, we'll
918 hold on to the last lwp of the dead process. */
925 /* Return 1 if this lwp has an interesting status pending. */
927 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
929 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
930 ptid_t ptid
= * (ptid_t
*) arg
;
931 struct thread_info
*thread
= get_lwp_thread (lwp
);
933 /* Check if we're only interested in events from a specific process
935 if (!ptid_equal (minus_one_ptid
, ptid
)
936 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
939 thread
= get_lwp_thread (lwp
);
941 /* If we got a `vCont;t', but we haven't reported a stop yet, do
942 report any status pending the LWP may have. */
943 if (thread
->last_resume_kind
== resume_stop
944 && thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
)
947 return lwp
->status_pending_p
;
951 same_lwp (struct inferior_list_entry
*entry
, void *data
)
953 ptid_t ptid
= *(ptid_t
*) data
;
956 if (ptid_get_lwp (ptid
) != 0)
957 lwp
= ptid_get_lwp (ptid
);
959 lwp
= ptid_get_pid (ptid
);
961 if (ptid_get_lwp (entry
->id
) == lwp
)
968 find_lwp_pid (ptid_t ptid
)
970 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
973 static struct lwp_info
*
974 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
977 int to_wait_for
= -1;
978 struct lwp_info
*child
= NULL
;
981 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
983 if (ptid_equal (ptid
, minus_one_ptid
))
984 to_wait_for
= -1; /* any child */
986 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
992 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
993 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
996 perror_with_name ("waitpid");
999 && (!WIFSTOPPED (*wstatp
)
1000 || (WSTOPSIG (*wstatp
) != 32
1001 && WSTOPSIG (*wstatp
) != 33)))
1002 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
1004 child
= find_lwp_pid (pid_to_ptid (ret
));
1006 /* If we didn't find a process, one of two things presumably happened:
1007 - A process we started and then detached from has exited. Ignore it.
1008 - A process we are controlling has forked and the new child's stop
1009 was reported to us by the kernel. Save its PID. */
1010 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
1012 add_pid_to_list (&stopped_pids
, ret
);
1015 else if (child
== NULL
)
1020 child
->last_status
= *wstatp
;
1022 /* Architecture-specific setup after inferior is running.
1023 This needs to happen after we have attached to the inferior
1024 and it is stopped for the first time, but before we access
1025 any inferior registers. */
1028 the_low_target
.arch_setup ();
1029 #ifdef HAVE_LINUX_REGSETS
1030 memset (disabled_regsets
, 0, num_regsets
);
1035 /* Fetch the possibly triggered data watchpoint info and store it in
1038 On some archs, like x86, that use debug registers to set
1039 watchpoints, it's possible that the way to know which watched
1040 address trapped, is to check the register that is used to select
1041 which address to watch. Problem is, between setting the
1042 watchpoint and reading back which data address trapped, the user
1043 may change the set of watchpoints, and, as a consequence, GDB
1044 changes the debug registers in the inferior. To avoid reading
1045 back a stale stopped-data-address when that happens, we cache in
1046 LP the fact that a watchpoint trapped, and the corresponding data
1047 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1048 changes the debug registers meanwhile, we have the cached data we
1051 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1053 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1055 child
->stopped_by_watchpoint
= 0;
1059 struct thread_info
*saved_inferior
;
1061 saved_inferior
= current_inferior
;
1062 current_inferior
= get_lwp_thread (child
);
1064 child
->stopped_by_watchpoint
1065 = the_low_target
.stopped_by_watchpoint ();
1067 if (child
->stopped_by_watchpoint
)
1069 if (the_low_target
.stopped_data_address
!= NULL
)
1070 child
->stopped_data_address
1071 = the_low_target
.stopped_data_address ();
1073 child
->stopped_data_address
= 0;
1076 current_inferior
= saved_inferior
;
1080 /* Store the STOP_PC, with adjustment applied. This depends on the
1081 architecture being defined already (so that CHILD has a valid
1082 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1084 if (WIFSTOPPED (*wstatp
))
1085 child
->stop_pc
= get_stop_pc (child
);
1088 && WIFSTOPPED (*wstatp
)
1089 && the_low_target
.get_pc
!= NULL
)
1091 struct thread_info
*saved_inferior
= current_inferior
;
1092 struct regcache
*regcache
;
1095 current_inferior
= get_lwp_thread (child
);
1096 regcache
= get_thread_regcache (current_inferior
, 1);
1097 pc
= (*the_low_target
.get_pc
) (regcache
);
1098 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1099 current_inferior
= saved_inferior
;
1105 /* This function should only be called if the LWP got a SIGTRAP.
1107 Handle any tracepoint steps or hits. Return true if a tracepoint
1108 event was handled, 0 otherwise. */
1111 handle_tracepoints (struct lwp_info
*lwp
)
1113 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1114 int tpoint_related_event
= 0;
1116 /* And we need to be sure that any all-threads-stopping doesn't try
1117 to move threads out of the jump pads, as it could deadlock the
1118 inferior (LWP could be in the jump pad, maybe even holding the
1121 /* Do any necessary step collect actions. */
1122 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1124 /* See if we just hit a tracepoint and do its main collect
1126 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1128 if (tpoint_related_event
)
1131 fprintf (stderr
, "got a tracepoint event\n");
1138 /* Arrange for a breakpoint to be hit again later. We don't keep the
1139 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1140 will handle the current event, eventually we will resume this LWP,
1141 and this breakpoint will trap again. */
1144 cancel_breakpoint (struct lwp_info
*lwp
)
1146 struct thread_info
*saved_inferior
;
1148 /* There's nothing to do if we don't support breakpoints. */
1149 if (!supports_breakpoints ())
1152 /* breakpoint_at reads from current inferior. */
1153 saved_inferior
= current_inferior
;
1154 current_inferior
= get_lwp_thread (lwp
);
1156 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1160 "CB: Push back breakpoint for %s\n",
1161 target_pid_to_str (ptid_of (lwp
)));
1163 /* Back up the PC if necessary. */
1164 if (the_low_target
.decr_pc_after_break
)
1166 struct regcache
*regcache
1167 = get_thread_regcache (current_inferior
, 1);
1168 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1171 current_inferior
= saved_inferior
;
1178 "CB: No breakpoint found at %s for [%s]\n",
1179 paddress (lwp
->stop_pc
),
1180 target_pid_to_str (ptid_of (lwp
)));
1183 current_inferior
= saved_inferior
;
1187 /* When the event-loop is doing a step-over, this points at the thread
1189 ptid_t step_over_bkpt
;
1191 /* Wait for an event from child PID. If PID is -1, wait for any
1192 child. Store the stop status through the status pointer WSTAT.
1193 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1194 event was found and OPTIONS contains WNOHANG. Return the PID of
1195 the stopped child otherwise. */
1198 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1200 struct lwp_info
*event_child
, *requested_child
;
1203 requested_child
= NULL
;
1205 /* Check for a lwp with a pending status. */
1207 if (ptid_equal (ptid
, minus_one_ptid
)
1208 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1210 event_child
= (struct lwp_info
*)
1211 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1212 if (debug_threads
&& event_child
)
1213 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1217 requested_child
= find_lwp_pid (ptid
);
1219 if (requested_child
->status_pending_p
)
1220 event_child
= requested_child
;
1223 if (event_child
!= NULL
)
1226 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1227 lwpid_of (event_child
), event_child
->status_pending
);
1228 *wstat
= event_child
->status_pending
;
1229 event_child
->status_pending_p
= 0;
1230 event_child
->status_pending
= 0;
1231 current_inferior
= get_lwp_thread (event_child
);
1232 return lwpid_of (event_child
);
1235 /* We only enter this loop if no process has a pending wait status. Thus
1236 any action taken in response to a wait status inside this loop is
1237 responding as soon as we detect the status, not after any pending
1241 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1243 if ((options
& WNOHANG
) && event_child
== NULL
)
1246 fprintf (stderr
, "WNOHANG set, no event found\n");
1250 if (event_child
== NULL
)
1251 error ("event from unknown child");
1253 current_inferior
= get_lwp_thread (event_child
);
1255 /* Check for thread exit. */
1256 if (! WIFSTOPPED (*wstat
))
1259 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1261 /* If the last thread is exiting, just return. */
1262 if (last_thread_of_process_p (current_inferior
))
1265 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1266 lwpid_of (event_child
));
1267 return lwpid_of (event_child
);
1272 current_inferior
= (struct thread_info
*) all_threads
.head
;
1274 fprintf (stderr
, "Current inferior is now %ld\n",
1275 lwpid_of (get_thread_lwp (current_inferior
)));
1279 current_inferior
= NULL
;
1281 fprintf (stderr
, "Current inferior is now <NULL>\n");
1284 /* If we were waiting for this particular child to do something...
1285 well, it did something. */
1286 if (requested_child
!= NULL
)
1288 int lwpid
= lwpid_of (event_child
);
1290 /* Cancel the step-over operation --- the thread that
1291 started it is gone. */
1292 if (finish_step_over (event_child
))
1293 unstop_all_lwps (event_child
);
1294 delete_lwp (event_child
);
1298 delete_lwp (event_child
);
1300 /* Wait for a more interesting event. */
1304 if (event_child
->must_set_ptrace_flags
)
1306 linux_enable_event_reporting (lwpid_of (event_child
));
1307 event_child
->must_set_ptrace_flags
= 0;
1310 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1311 && *wstat
>> 16 != 0)
1313 handle_extended_wait (event_child
, *wstat
);
1317 /* If GDB is not interested in this signal, don't stop other
1318 threads, and don't report it to GDB. Just resume the
1319 inferior right away. We do this for threading-related
1320 signals as well as any that GDB specifically requested we
1321 ignore. But never ignore SIGSTOP if we sent it ourselves,
1322 and do not ignore signals when stepping - they may require
1323 special handling to skip the signal handler. */
1324 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
1326 if (WIFSTOPPED (*wstat
)
1327 && !event_child
->stepping
1329 #if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
1330 (current_process ()->private->thread_db
!= NULL
1331 && (WSTOPSIG (*wstat
) == __SIGRTMIN
1332 || WSTOPSIG (*wstat
) == __SIGRTMIN
+ 1))
1335 (pass_signals
[target_signal_from_host (WSTOPSIG (*wstat
))]
1336 && !(WSTOPSIG (*wstat
) == SIGSTOP
1337 && event_child
->stop_expected
))))
1339 siginfo_t info
, *info_p
;
1342 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
1343 WSTOPSIG (*wstat
), lwpid_of (event_child
));
1345 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
1349 linux_resume_one_lwp (event_child
, event_child
->stepping
,
1350 WSTOPSIG (*wstat
), info_p
);
1354 if (WIFSTOPPED (*wstat
)
1355 && WSTOPSIG (*wstat
) == SIGSTOP
1356 && event_child
->stop_expected
)
1361 fprintf (stderr
, "Expected stop.\n");
1362 event_child
->stop_expected
= 0;
1364 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1365 || stopping_threads
);
1369 linux_resume_one_lwp (event_child
,
1370 event_child
->stepping
, 0, NULL
);
1375 return lwpid_of (event_child
);
1383 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1387 if (ptid_is_pid (ptid
))
1389 /* A request to wait for a specific tgid. This is not possible
1390 with waitpid, so instead, we wait for any child, and leave
1391 children we're not interested in right now with a pending
1392 status to report later. */
1393 wait_ptid
= minus_one_ptid
;
1402 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1405 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1407 struct lwp_info
*event_child
= find_lwp_pid (pid_to_ptid (event_pid
));
1409 if (! WIFSTOPPED (*wstat
))
1410 mark_lwp_dead (event_child
, *wstat
);
1413 event_child
->status_pending_p
= 1;
1414 event_child
->status_pending
= *wstat
;
1423 /* Count the LWP's that have had events. */
1426 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1428 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1429 struct thread_info
*thread
= get_lwp_thread (lp
);
1432 gdb_assert (count
!= NULL
);
1434 /* Count only resumed LWPs that have a SIGTRAP event pending that
1435 should be reported to GDB. */
1436 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1437 && thread
->last_resume_kind
!= resume_stop
1438 && lp
->status_pending_p
1439 && WIFSTOPPED (lp
->status_pending
)
1440 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1441 && !breakpoint_inserted_here (lp
->stop_pc
))
1447 /* Select the LWP (if any) that is currently being single-stepped. */
1450 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1452 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1453 struct thread_info
*thread
= get_lwp_thread (lp
);
1455 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1456 && thread
->last_resume_kind
== resume_step
1457 && lp
->status_pending_p
)
1463 /* Select the Nth LWP that has had a SIGTRAP event that should be
1467 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1469 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1470 struct thread_info
*thread
= get_lwp_thread (lp
);
1471 int *selector
= data
;
1473 gdb_assert (selector
!= NULL
);
1475 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1476 if (thread
->last_resume_kind
!= resume_stop
1477 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1478 && lp
->status_pending_p
1479 && WIFSTOPPED (lp
->status_pending
)
1480 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1481 && !breakpoint_inserted_here (lp
->stop_pc
))
1482 if ((*selector
)-- == 0)
1489 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1491 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1492 struct thread_info
*thread
= get_lwp_thread (lp
);
1493 struct lwp_info
*event_lp
= data
;
1495 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1499 /* If a LWP other than the LWP that we're reporting an event for has
1500 hit a GDB breakpoint (as opposed to some random trap signal),
1501 then just arrange for it to hit it again later. We don't keep
1502 the SIGTRAP status and don't forward the SIGTRAP signal to the
1503 LWP. We will handle the current event, eventually we will resume
1504 all LWPs, and this one will get its breakpoint trap again.
1506 If we do not do this, then we run the risk that the user will
1507 delete or disable the breakpoint, but the LWP will have already
1510 if (thread
->last_resume_kind
!= resume_stop
1511 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1512 && lp
->status_pending_p
1513 && WIFSTOPPED (lp
->status_pending
)
1514 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1516 && !lp
->stopped_by_watchpoint
1517 && cancel_breakpoint (lp
))
1518 /* Throw away the SIGTRAP. */
1519 lp
->status_pending_p
= 0;
1524 /* Select one LWP out of those that have events pending. */
1527 select_event_lwp (struct lwp_info
**orig_lp
)
1530 int random_selector
;
1531 struct lwp_info
*event_lp
;
1533 /* Give preference to any LWP that is being single-stepped. */
1535 = (struct lwp_info
*) find_inferior (&all_lwps
,
1536 select_singlestep_lwp_callback
, NULL
);
1537 if (event_lp
!= NULL
)
1541 "SEL: Select single-step %s\n",
1542 target_pid_to_str (ptid_of (event_lp
)));
1546 /* No single-stepping LWP. Select one at random, out of those
1547 which have had SIGTRAP events. */
1549 /* First see how many SIGTRAP events we have. */
1550 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1552 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1553 random_selector
= (int)
1554 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1556 if (debug_threads
&& num_events
> 1)
1558 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1559 num_events
, random_selector
);
1561 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1562 select_event_lwp_callback
,
1566 if (event_lp
!= NULL
)
1568 /* Switch the event LWP. */
1569 *orig_lp
= event_lp
;
1573 /* Set this inferior LWP's state as "want-stopped". We won't resume
1574 this LWP until the client gives us another action for it. */
1577 gdb_wants_lwp_stopped (struct inferior_list_entry
*entry
)
1579 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1580 struct thread_info
*thread
= get_lwp_thread (lwp
);
1582 /* Most threads are stopped implicitly (all-stop); tag that with
1583 signal 0. The thread being explicitly reported stopped to the
1584 client, gets it's status fixed up afterwards. */
1585 thread
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
1586 thread
->last_status
.value
.sig
= TARGET_SIGNAL_0
;
1588 thread
->last_resume_kind
= resume_stop
;
1591 /* Set all LWP's states as "want-stopped". */
1594 gdb_wants_all_stopped (void)
1596 for_each_inferior (&all_lwps
, gdb_wants_lwp_stopped
);
1599 /* Wait for process, returns status. */
1602 linux_wait_1 (ptid_t ptid
,
1603 struct target_waitstatus
*ourstatus
, int target_options
)
1606 struct lwp_info
*event_child
;
1609 int step_over_finished
;
1610 int bp_explains_trap
;
1611 int maybe_internal_trap
;
1615 /* Translate generic target options into linux options. */
1617 if (target_options
& TARGET_WNOHANG
)
1621 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1623 /* If we were only supposed to resume one thread, only wait for
1624 that thread - if it's still alive. If it died, however - which
1625 can happen if we're coming from the thread death case below -
1626 then we need to make sure we restart the other threads. We could
1627 pick a thread at random or restart all; restarting all is less
1630 && !ptid_equal (cont_thread
, null_ptid
)
1631 && !ptid_equal (cont_thread
, minus_one_ptid
))
1633 struct thread_info
*thread
;
1635 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1638 /* No stepping, no signal - unless one is pending already, of course. */
1641 struct thread_resume resume_info
;
1642 resume_info
.thread
= minus_one_ptid
;
1643 resume_info
.kind
= resume_continue
;
1644 resume_info
.sig
= 0;
1645 linux_resume (&resume_info
, 1);
1651 if (ptid_equal (step_over_bkpt
, null_ptid
))
1652 pid
= linux_wait_for_event (ptid
, &w
, options
);
1656 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1657 target_pid_to_str (step_over_bkpt
));
1658 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1661 if (pid
== 0) /* only if TARGET_WNOHANG */
1664 event_child
= get_thread_lwp (current_inferior
);
1666 /* If we are waiting for a particular child, and it exited,
1667 linux_wait_for_event will return its exit status. Similarly if
1668 the last child exited. If this is not the last child, however,
1669 do not report it as exited until there is a 'thread exited' response
1670 available in the remote protocol. Instead, just wait for another event.
1671 This should be safe, because if the thread crashed we will already
1672 have reported the termination signal to GDB; that should stop any
1673 in-progress stepping operations, etc.
1675 Report the exit status of the last thread to exit. This matches
1676 LinuxThreads' behavior. */
1678 if (last_thread_of_process_p (current_inferior
))
1680 if (WIFEXITED (w
) || WIFSIGNALED (w
))
1684 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
1685 ourstatus
->value
.integer
= WEXITSTATUS (w
);
1688 fprintf (stderr
, "\nChild exited with retcode = %x \n", WEXITSTATUS (w
));
1692 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
1693 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
1696 fprintf (stderr
, "\nChild terminated with signal = %x \n", WTERMSIG (w
));
1700 return pid_to_ptid (pid
);
1705 if (!WIFSTOPPED (w
))
1709 /* If this event was not handled before, and is not a SIGTRAP, we
1710 report it. SIGILL and SIGSEGV are also treated as traps in case
1711 a breakpoint is inserted at the current PC. If this target does
1712 not support internal breakpoints at all, we also report the
1713 SIGTRAP without further processing; it's of no concern to us. */
1715 = (supports_breakpoints ()
1716 && (WSTOPSIG (w
) == SIGTRAP
1717 || ((WSTOPSIG (w
) == SIGILL
1718 || WSTOPSIG (w
) == SIGSEGV
)
1719 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
1721 if (maybe_internal_trap
)
1723 /* Handle anything that requires bookkeeping before deciding to
1724 report the event or continue waiting. */
1726 /* First check if we can explain the SIGTRAP with an internal
1727 breakpoint, or if we should possibly report the event to GDB.
1728 Do this before anything that may remove or insert a
1730 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
1732 /* We have a SIGTRAP, possibly a step-over dance has just
1733 finished. If so, tweak the state machine accordingly,
1734 reinsert breakpoints and delete any reinsert (software
1735 single-step) breakpoints. */
1736 step_over_finished
= finish_step_over (event_child
);
1738 /* Now invoke the callbacks of any internal breakpoints there. */
1739 check_breakpoints (event_child
->stop_pc
);
1741 /* Handle tracepoint data collecting. This may overflow the
1742 trace buffer, and cause a tracing stop, removing
1744 trace_event
= handle_tracepoints (event_child
);
1746 if (bp_explains_trap
)
1748 /* If we stepped or ran into an internal breakpoint, we've
1749 already handled it. So next time we resume (from this
1750 PC), we should step over it. */
1752 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1754 if (breakpoint_here (event_child
->stop_pc
))
1755 event_child
->need_step_over
= 1;
1760 /* We have some other signal, possibly a step-over dance was in
1761 progress, and it should be cancelled too. */
1762 step_over_finished
= finish_step_over (event_child
);
1767 /* We have all the data we need. Either report the event to GDB, or
1768 resume threads and keep waiting for more. */
1770 /* Check If GDB would be interested in this event. If GDB wanted
1771 this thread to single step, we always want to report the SIGTRAP,
1772 and let GDB handle it. Watchpoints should always be reported.
1773 So should signals we can't explain. A SIGTRAP we can't explain
1774 could be a GDB breakpoint --- we may or not support Z0
1775 breakpoints. If we do, we're be able to handle GDB breakpoints
1776 on top of internal breakpoints, by handling the internal
1777 breakpoint and still reporting the event to GDB. If we don't,
1778 we're out of luck, GDB won't see the breakpoint hit. */
1779 report_to_gdb
= (!maybe_internal_trap
1780 || current_inferior
->last_resume_kind
== resume_step
1781 || event_child
->stopped_by_watchpoint
1782 || (!step_over_finished
&& !bp_explains_trap
&& !trace_event
)
1783 || gdb_breakpoint_here (event_child
->stop_pc
));
1785 /* We found no reason GDB would want us to stop. We either hit one
1786 of our own breakpoints, or finished an internal step GDB
1787 shouldn't know about. */
1792 if (bp_explains_trap
)
1793 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
1794 if (step_over_finished
)
1795 fprintf (stderr
, "Step-over finished.\n");
1797 fprintf (stderr
, "Tracepoint event.\n");
1800 /* We're not reporting this breakpoint to GDB, so apply the
1801 decr_pc_after_break adjustment to the inferior's regcache
1804 if (the_low_target
.set_pc
!= NULL
)
1806 struct regcache
*regcache
1807 = get_thread_regcache (get_lwp_thread (event_child
), 1);
1808 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
1811 /* We've finished stepping over a breakpoint. We've stopped all
1812 LWPs momentarily except the stepping one. This is where we
1813 resume them all again. We're going to keep waiting, so use
1814 proceed, which handles stepping over the next breakpoint. */
1816 fprintf (stderr
, "proceeding all threads.\n");
1817 proceed_all_lwps ();
1823 if (current_inferior
->last_resume_kind
== resume_step
)
1824 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
1825 if (event_child
->stopped_by_watchpoint
)
1826 fprintf (stderr
, "Stopped by watchpoint.\n");
1827 if (gdb_breakpoint_here (event_child
->stop_pc
))
1828 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
1830 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
1833 /* Alright, we're going to report a stop. */
1837 /* In all-stop, stop all threads. */
1840 /* If we're not waiting for a specific LWP, choose an event LWP
1841 from among those that have had events. Giving equal priority
1842 to all LWPs that have had events helps prevent
1844 if (ptid_equal (ptid
, minus_one_ptid
))
1846 event_child
->status_pending_p
= 1;
1847 event_child
->status_pending
= w
;
1849 select_event_lwp (&event_child
);
1851 event_child
->status_pending_p
= 0;
1852 w
= event_child
->status_pending
;
1855 /* Now that we've selected our final event LWP, cancel any
1856 breakpoints in other LWPs that have hit a GDB breakpoint.
1857 See the comment in cancel_breakpoints_callback to find out
1859 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
1863 /* If we just finished a step-over, then all threads had been
1864 momentarily paused. In all-stop, that's fine, we want
1865 threads stopped by now anyway. In non-stop, we need to
1866 re-resume threads that GDB wanted to be running. */
1867 if (step_over_finished
)
1868 unstop_all_lwps (event_child
);
1871 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
1873 /* Do this before the gdb_wants_all_stopped calls below, since they
1874 always set last_resume_kind to resume_stop. */
1875 if (current_inferior
->last_resume_kind
== resume_stop
1876 && WSTOPSIG (w
) == SIGSTOP
)
1878 /* A thread that has been requested to stop by GDB with vCont;t,
1879 and it stopped cleanly, so report as SIG0. The use of
1880 SIGSTOP is an implementation detail. */
1881 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
1883 else if (current_inferior
->last_resume_kind
== resume_stop
1884 && WSTOPSIG (w
) != SIGSTOP
)
1886 /* A thread that has been requested to stop by GDB with vCont;t,
1887 but, it stopped for other reasons. */
1888 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1892 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
1895 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
1899 /* From GDB's perspective, all-stop mode always stops all
1900 threads implicitly. Tag all threads as "want-stopped". */
1901 gdb_wants_all_stopped ();
1905 /* We're reporting this LWP as stopped. Update it's
1906 "want-stopped" state to what the client wants, until it gets
1907 a new resume action. */
1908 gdb_wants_lwp_stopped (&event_child
->head
);
1912 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
1913 target_pid_to_str (ptid_of (event_child
)),
1915 ourstatus
->value
.sig
);
1917 get_lwp_thread (event_child
)->last_status
= *ourstatus
;
1918 return ptid_of (event_child
);
1921 /* Get rid of any pending event in the pipe. */
1923 async_file_flush (void)
1929 ret
= read (linux_event_pipe
[0], &buf
, 1);
1930 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
1933 /* Put something in the pipe, so the event loop wakes up. */
1935 async_file_mark (void)
1939 async_file_flush ();
1942 ret
= write (linux_event_pipe
[1], "+", 1);
1943 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
1945 /* Ignore EAGAIN. If the pipe is full, the event loop will already
1946 be awakened anyway. */
1950 linux_wait (ptid_t ptid
,
1951 struct target_waitstatus
*ourstatus
, int target_options
)
1956 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
1958 /* Flush the async file first. */
1959 if (target_is_async_p ())
1960 async_file_flush ();
1962 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
1964 /* If at least one stop was reported, there may be more. A single
1965 SIGCHLD can signal more than one child stop. */
1966 if (target_is_async_p ()
1967 && (target_options
& TARGET_WNOHANG
) != 0
1968 && !ptid_equal (event_ptid
, null_ptid
))
1974 /* Send a signal to an LWP. */
1977 kill_lwp (unsigned long lwpid
, int signo
)
1979 /* Use tkill, if possible, in case we are using nptl threads. If tkill
1980 fails, then we are not using nptl threads and we should be using kill. */
1984 static int tkill_failed
;
1991 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1992 if (errno
!= ENOSYS
)
1999 return kill (lwpid
, signo
);
2003 send_sigstop (struct lwp_info
*lwp
)
2007 pid
= lwpid_of (lwp
);
2009 /* If we already have a pending stop signal for this process, don't
2011 if (lwp
->stop_expected
)
2014 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2020 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2022 lwp
->stop_expected
= 1;
2023 kill_lwp (pid
, SIGSTOP
);
2027 send_sigstop_callback (struct inferior_list_entry
*entry
)
2029 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2038 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2040 /* It's dead, really. */
2043 /* Store the exit status for later. */
2044 lwp
->status_pending_p
= 1;
2045 lwp
->status_pending
= wstat
;
2047 /* Prevent trying to stop it. */
2050 /* No further stops are expected from a dead lwp. */
2051 lwp
->stop_expected
= 0;
2055 wait_for_sigstop (struct inferior_list_entry
*entry
)
2057 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2058 struct thread_info
*saved_inferior
;
2067 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2072 saved_inferior
= current_inferior
;
2073 if (saved_inferior
!= NULL
)
2074 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2076 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2078 ptid
= lwp
->head
.id
;
2081 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2083 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2085 /* If we stopped with a non-SIGSTOP signal, save it for later
2086 and record the pending SIGSTOP. If the process exited, just
2088 if (WIFSTOPPED (wstat
))
2091 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2092 lwpid_of (lwp
), WSTOPSIG (wstat
));
2094 if (WSTOPSIG (wstat
) != SIGSTOP
)
2097 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2098 lwpid_of (lwp
), wstat
);
2100 lwp
->status_pending_p
= 1;
2101 lwp
->status_pending
= wstat
;
2107 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2109 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2112 /* Leave this status pending for the next time we're able to
2113 report it. In the mean time, we'll report this lwp as
2114 dead to GDB, so GDB doesn't try to read registers and
2115 memory from it. This can only happen if this was the
2116 last thread of the process; otherwise, PID is removed
2117 from the thread tables before linux_wait_for_event
2119 mark_lwp_dead (lwp
, wstat
);
2123 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2124 current_inferior
= saved_inferior
;
2128 fprintf (stderr
, "Previously current thread died.\n");
2132 /* We can't change the current inferior behind GDB's back,
2133 otherwise, a subsequent command may apply to the wrong
2135 current_inferior
= NULL
;
2139 /* Set a valid thread as current. */
2140 set_desired_inferior (0);
2146 stop_all_lwps (void)
2148 stopping_threads
= 1;
2149 for_each_inferior (&all_lwps
, send_sigstop_callback
);
2150 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2151 stopping_threads
= 0;
2154 /* Resume execution of the inferior process.
2155 If STEP is nonzero, single-step it.
2156 If SIGNAL is nonzero, give it that signal. */
2159 linux_resume_one_lwp (struct lwp_info
*lwp
,
2160 int step
, int signal
, siginfo_t
*info
)
2162 struct thread_info
*saved_inferior
;
2164 if (lwp
->stopped
== 0)
2167 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2168 user used the "jump" command, or "set $pc = foo"). */
2169 if (lwp
->stop_pc
!= get_pc (lwp
))
2171 /* Collecting 'while-stepping' actions doesn't make sense
2173 release_while_stepping_state_list (get_lwp_thread (lwp
));
2176 /* If we have pending signals or status, and a new signal, enqueue the
2177 signal. Also enqueue the signal if we are waiting to reinsert a
2178 breakpoint; it will be picked up again below. */
2180 && (lwp
->status_pending_p
|| lwp
->pending_signals
!= NULL
2181 || lwp
->bp_reinsert
!= 0))
2183 struct pending_signals
*p_sig
;
2184 p_sig
= xmalloc (sizeof (*p_sig
));
2185 p_sig
->prev
= lwp
->pending_signals
;
2186 p_sig
->signal
= signal
;
2188 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2190 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2191 lwp
->pending_signals
= p_sig
;
2194 if (lwp
->status_pending_p
)
2197 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2198 " has pending status\n",
2199 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2200 lwp
->stop_expected
? "expected" : "not expected");
2204 saved_inferior
= current_inferior
;
2205 current_inferior
= get_lwp_thread (lwp
);
2208 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2209 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2210 lwp
->stop_expected
? "expected" : "not expected");
2212 /* This bit needs some thinking about. If we get a signal that
2213 we must report while a single-step reinsert is still pending,
2214 we often end up resuming the thread. It might be better to
2215 (ew) allow a stack of pending events; then we could be sure that
2216 the reinsert happened right away and not lose any signals.
2218 Making this stack would also shrink the window in which breakpoints are
2219 uninserted (see comment in linux_wait_for_lwp) but not enough for
2220 complete correctness, so it won't solve that problem. It may be
2221 worthwhile just to solve this one, however. */
2222 if (lwp
->bp_reinsert
!= 0)
2225 fprintf (stderr
, " pending reinsert at 0x%s\n",
2226 paddress (lwp
->bp_reinsert
));
2228 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2231 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2236 /* Postpone any pending signal. It was enqueued above. */
2240 /* If we have while-stepping actions in this thread set it stepping.
2241 If we have a signal to deliver, it may or may not be set to
2242 SIG_IGN, we don't know. Assume so, and allow collecting
2243 while-stepping into a signal handler. A possible smart thing to
2244 do would be to set an internal breakpoint at the signal return
2245 address, continue, and carry on catching this while-stepping
2246 action only when that breakpoint is hit. A future
2248 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2249 && can_hardware_single_step ())
2253 "lwp %ld has a while-stepping action -> forcing step.\n",
2258 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2260 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2261 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2262 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2265 /* If we have pending signals, consume one unless we are trying to reinsert
2267 if (lwp
->pending_signals
!= NULL
&& lwp
->bp_reinsert
== 0)
2269 struct pending_signals
**p_sig
;
2271 p_sig
= &lwp
->pending_signals
;
2272 while ((*p_sig
)->prev
!= NULL
)
2273 p_sig
= &(*p_sig
)->prev
;
2275 signal
= (*p_sig
)->signal
;
2276 if ((*p_sig
)->info
.si_signo
!= 0)
2277 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2283 if (the_low_target
.prepare_to_resume
!= NULL
)
2284 the_low_target
.prepare_to_resume (lwp
);
2286 regcache_invalidate_one ((struct inferior_list_entry
*)
2287 get_lwp_thread (lwp
));
2290 lwp
->stopped_by_watchpoint
= 0;
2291 lwp
->stepping
= step
;
2292 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2293 /* Coerce to a uintptr_t first to avoid potential gcc warning
2294 of coercing an 8 byte integer to a 4 byte pointer. */
2295 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2297 current_inferior
= saved_inferior
;
2300 /* ESRCH from ptrace either means that the thread was already
2301 running (an error) or that it is gone (a race condition). If
2302 it's gone, we will get a notification the next time we wait,
2303 so we can ignore the error. We could differentiate these
2304 two, but it's tricky without waiting; the thread still exists
2305 as a zombie, so sending it signal 0 would succeed. So just
2310 perror_with_name ("ptrace");
2314 struct thread_resume_array
2316 struct thread_resume
*resume
;
2320 /* This function is called once per thread. We look up the thread
2321 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2324 This algorithm is O(threads * resume elements), but resume elements
2325 is small (and will remain small at least until GDB supports thread
2328 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2330 struct lwp_info
*lwp
;
2331 struct thread_info
*thread
;
2333 struct thread_resume_array
*r
;
2335 thread
= (struct thread_info
*) entry
;
2336 lwp
= get_thread_lwp (thread
);
2339 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2341 ptid_t ptid
= r
->resume
[ndx
].thread
;
2342 if (ptid_equal (ptid
, minus_one_ptid
)
2343 || ptid_equal (ptid
, entry
->id
)
2344 || (ptid_is_pid (ptid
)
2345 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2346 || (ptid_get_lwp (ptid
) == -1
2347 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2349 if (r
->resume
[ndx
].kind
== resume_stop
2350 && thread
->last_resume_kind
== resume_stop
)
2353 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2354 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2362 lwp
->resume
= &r
->resume
[ndx
];
2363 thread
->last_resume_kind
= lwp
->resume
->kind
;
2368 /* No resume action for this thread. */
2375 /* Set *FLAG_P if this lwp has an interesting status pending. */
2377 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
2379 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2381 /* LWPs which will not be resumed are not interesting, because
2382 we might not wait for them next time through linux_wait. */
2383 if (lwp
->resume
== NULL
)
2386 if (lwp
->status_pending_p
)
2387 * (int *) flag_p
= 1;
2392 /* Return 1 if this lwp that GDB wants running is stopped at an
2393 internal breakpoint that we need to step over. It assumes that any
2394 required STOP_PC adjustment has already been propagated to the
2395 inferior's regcache. */
2398 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
2400 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2401 struct thread_info
*thread
;
2402 struct thread_info
*saved_inferior
;
2405 /* LWPs which will not be resumed are not interesting, because we
2406 might not wait for them next time through linux_wait. */
2412 "Need step over [LWP %ld]? Ignoring, not stopped\n",
2417 thread
= get_lwp_thread (lwp
);
2419 if (thread
->last_resume_kind
== resume_stop
)
2423 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
2428 if (!lwp
->need_step_over
)
2432 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
2435 if (lwp
->status_pending_p
)
2439 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
2444 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
2448 /* If the PC has changed since we stopped, then don't do anything,
2449 and let the breakpoint/tracepoint be hit. This happens if, for
2450 instance, GDB handled the decr_pc_after_break subtraction itself,
2451 GDB is OOL stepping this thread, or the user has issued a "jump"
2452 command, or poked thread's registers herself. */
2453 if (pc
!= lwp
->stop_pc
)
2457 "Need step over [LWP %ld]? Cancelling, PC was changed. "
2458 "Old stop_pc was 0x%s, PC is now 0x%s\n",
2459 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
2461 lwp
->need_step_over
= 0;
2465 saved_inferior
= current_inferior
;
2466 current_inferior
= thread
;
2468 /* We can only step over breakpoints we know about. */
2469 if (breakpoint_here (pc
))
2471 /* Don't step over a breakpoint that GDB expects to hit
2473 if (gdb_breakpoint_here (pc
))
2477 "Need step over [LWP %ld]? yes, but found"
2478 " GDB breakpoint at 0x%s; skipping step over\n",
2479 lwpid_of (lwp
), paddress (pc
));
2481 current_inferior
= saved_inferior
;
2488 "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
2489 lwpid_of (lwp
), paddress (pc
));
2491 /* We've found an lwp that needs stepping over --- return 1 so
2492 that find_inferior stops looking. */
2493 current_inferior
= saved_inferior
;
2495 /* If the step over is cancelled, this is set again. */
2496 lwp
->need_step_over
= 0;
2501 current_inferior
= saved_inferior
;
2505 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
2506 lwpid_of (lwp
), paddress (pc
));
2511 /* Start a step-over operation on LWP. When LWP stopped at a
2512 breakpoint, to make progress, we need to remove the breakpoint out
2513 of the way. If we let other threads run while we do that, they may
2514 pass by the breakpoint location and miss hitting it. To avoid
2515 that, a step-over momentarily stops all threads while LWP is
2516 single-stepped while the breakpoint is temporarily uninserted from
2517 the inferior. When the single-step finishes, we reinsert the
2518 breakpoint, and let all threads that are supposed to be running,
2521 On targets that don't support hardware single-step, we don't
2522 currently support full software single-stepping. Instead, we only
2523 support stepping over the thread event breakpoint, by asking the
2524 low target where to place a reinsert breakpoint. Since this
2525 routine assumes the breakpoint being stepped over is a thread event
2526 breakpoint, it usually assumes the return address of the current
2527 function is a good enough place to set the reinsert breakpoint. */
2530 start_step_over (struct lwp_info
*lwp
)
2532 struct thread_info
*saved_inferior
;
2538 "Starting step-over on LWP %ld. Stopping all threads\n",
2544 fprintf (stderr
, "Done stopping all threads for step-over.\n");
2546 /* Note, we should always reach here with an already adjusted PC,
2547 either by GDB (if we're resuming due to GDB's request), or by our
2548 caller, if we just finished handling an internal breakpoint GDB
2549 shouldn't care about. */
2552 saved_inferior
= current_inferior
;
2553 current_inferior
= get_lwp_thread (lwp
);
2555 lwp
->bp_reinsert
= pc
;
2556 uninsert_breakpoints_at (pc
);
2558 if (can_hardware_single_step ())
2564 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
2565 set_reinsert_breakpoint (raddr
);
2569 current_inferior
= saved_inferior
;
2571 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2573 /* Require next event from this LWP. */
2574 step_over_bkpt
= lwp
->head
.id
;
2578 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
2579 start_step_over, if still there, and delete any reinsert
2580 breakpoints we've set, on non hardware single-step targets. */
2583 finish_step_over (struct lwp_info
*lwp
)
2585 if (lwp
->bp_reinsert
!= 0)
2588 fprintf (stderr
, "Finished step over.\n");
2590 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
2591 may be no breakpoint to reinsert there by now. */
2592 reinsert_breakpoints_at (lwp
->bp_reinsert
);
2594 lwp
->bp_reinsert
= 0;
2596 /* Delete any software-single-step reinsert breakpoints. No
2597 longer needed. We don't have to worry about other threads
2598 hitting this trap, and later not being able to explain it,
2599 because we were stepping over a breakpoint, and we hold all
2600 threads but LWP stopped while doing that. */
2601 if (!can_hardware_single_step ())
2602 delete_reinsert_breakpoints ();
2604 step_over_bkpt
= null_ptid
;
2611 /* This function is called once per thread. We check the thread's resume
2612 request, which will tell us whether to resume, step, or leave the thread
2613 stopped; and what signal, if any, it should be sent.
2615 For threads which we aren't explicitly told otherwise, we preserve
2616 the stepping flag; this is used for stepping over gdbserver-placed
2619 If pending_flags was set in any thread, we queue any needed
2620 signals, since we won't actually resume. We already have a pending
2621 event to report, so we don't need to preserve any step requests;
2622 they should be re-issued if necessary. */
2625 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
2627 struct lwp_info
*lwp
;
2628 struct thread_info
*thread
;
2630 int leave_all_stopped
= * (int *) arg
;
2633 thread
= (struct thread_info
*) entry
;
2634 lwp
= get_thread_lwp (thread
);
2636 if (lwp
->resume
== NULL
)
2639 if (lwp
->resume
->kind
== resume_stop
)
2642 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
2647 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
2649 /* Stop the thread, and wait for the event asynchronously,
2650 through the event loop. */
2656 fprintf (stderr
, "already stopped LWP %ld\n",
2659 /* The LWP may have been stopped in an internal event that
2660 was not meant to be notified back to GDB (e.g., gdbserver
2661 breakpoint), so we should be reporting a stop event in
2664 /* If the thread already has a pending SIGSTOP, this is a
2665 no-op. Otherwise, something later will presumably resume
2666 the thread and this will cause it to cancel any pending
2667 operation, due to last_resume_kind == resume_stop. If
2668 the thread already has a pending status to report, we
2669 will still report it the next time we wait - see
2670 status_pending_p_callback. */
2674 /* For stop requests, we're done. */
2676 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2680 /* If this thread which is about to be resumed has a pending status,
2681 then don't resume any threads - we can just report the pending
2682 status. Make sure to queue any signals that would otherwise be
2683 sent. In all-stop mode, we do this decision based on if *any*
2684 thread has a pending status. If there's a thread that needs the
2685 step-over-breakpoint dance, then don't resume any other thread
2686 but that particular one. */
2687 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
2692 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
2694 step
= (lwp
->resume
->kind
== resume_step
);
2695 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
2700 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
2702 /* If we have a new signal, enqueue the signal. */
2703 if (lwp
->resume
->sig
!= 0)
2705 struct pending_signals
*p_sig
;
2706 p_sig
= xmalloc (sizeof (*p_sig
));
2707 p_sig
->prev
= lwp
->pending_signals
;
2708 p_sig
->signal
= lwp
->resume
->sig
;
2709 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2711 /* If this is the same signal we were previously stopped by,
2712 make sure to queue its siginfo. We can ignore the return
2713 value of ptrace; if it fails, we'll skip
2714 PTRACE_SETSIGINFO. */
2715 if (WIFSTOPPED (lwp
->last_status
)
2716 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
2717 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
2719 lwp
->pending_signals
= p_sig
;
2723 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
2729 linux_resume (struct thread_resume
*resume_info
, size_t n
)
2731 struct thread_resume_array array
= { resume_info
, n
};
2732 struct lwp_info
*need_step_over
= NULL
;
2734 int leave_all_stopped
;
2736 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
2738 /* If there is a thread which would otherwise be resumed, which has
2739 a pending status, then don't resume any threads - we can just
2740 report the pending status. Make sure to queue any signals that
2741 would otherwise be sent. In non-stop mode, we'll apply this
2742 logic to each thread individually. We consume all pending events
2743 before considering to start a step-over (in all-stop). */
2746 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
2748 /* If there is a thread which would otherwise be resumed, which is
2749 stopped at a breakpoint that needs stepping over, then don't
2750 resume any threads - have it step over the breakpoint with all
2751 other threads stopped, then resume all threads again. Make sure
2752 to queue any signals that would otherwise be delivered or
2754 if (!any_pending
&& supports_breakpoints ())
2756 = (struct lwp_info
*) find_inferior (&all_lwps
,
2757 need_step_over_p
, NULL
);
2759 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
2763 if (need_step_over
!= NULL
)
2764 fprintf (stderr
, "Not resuming all, need step over\n");
2765 else if (any_pending
)
2767 "Not resuming, all-stop and found "
2768 "an LWP with pending status\n");
2770 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
2773 /* Even if we're leaving threads stopped, queue all signals we'd
2774 otherwise deliver. */
2775 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
2778 start_step_over (need_step_over
);
2781 /* This function is called once per thread. We check the thread's
2782 last resume request, which will tell us whether to resume, step, or
2783 leave the thread stopped. Any signal the client requested to be
2784 delivered has already been enqueued at this point.
2786 If any thread that GDB wants running is stopped at an internal
2787 breakpoint that needs stepping over, we start a step-over operation
2788 on that particular thread, and leave all others stopped. */
2791 proceed_one_lwp (struct inferior_list_entry
*entry
)
2793 struct lwp_info
*lwp
;
2794 struct thread_info
*thread
;
2797 lwp
= (struct lwp_info
*) entry
;
2801 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
2806 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
2810 thread
= get_lwp_thread (lwp
);
2812 if (thread
->last_resume_kind
== resume_stop
2813 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
2816 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
2821 if (lwp
->status_pending_p
)
2824 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
2832 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
2836 if (thread
->last_resume_kind
== resume_stop
)
2838 /* We haven't reported this LWP as stopped yet (otherwise, the
2839 last_status.kind check above would catch it, and we wouldn't
2840 reach here. This LWP may have been momentarily paused by a
2841 stop_all_lwps call while handling for example, another LWP's
2842 step-over. In that case, the pending expected SIGSTOP signal
2843 that was queued at vCont;t handling time will have already
2844 been consumed by wait_for_sigstop, and so we need to requeue
2845 another one here. Note that if the LWP already has a SIGSTOP
2846 pending, this is a no-op. */
2850 "Client wants LWP %ld to stop. "
2851 "Making sure it has a SIGSTOP pending\n",
2857 step
= thread
->last_resume_kind
== resume_step
;
2858 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
2861 /* When we finish a step-over, set threads running again. If there's
2862 another thread that may need a step-over, now's the time to start
2863 it. Eventually, we'll move all threads past their breakpoints. */
2866 proceed_all_lwps (void)
2868 struct lwp_info
*need_step_over
;
2870 /* If there is a thread which would otherwise be resumed, which is
2871 stopped at a breakpoint that needs stepping over, then don't
2872 resume any threads - have it step over the breakpoint with all
2873 other threads stopped, then resume all threads again. */
2875 if (supports_breakpoints ())
2878 = (struct lwp_info
*) find_inferior (&all_lwps
,
2879 need_step_over_p
, NULL
);
2881 if (need_step_over
!= NULL
)
2884 fprintf (stderr
, "proceed_all_lwps: found "
2885 "thread %ld needing a step-over\n",
2886 lwpid_of (need_step_over
));
2888 start_step_over (need_step_over
);
2894 fprintf (stderr
, "Proceeding, no step-over needed\n");
2896 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2899 /* Stopped LWPs that the client wanted to be running, that don't have
2900 pending statuses, are set to run again, except for EXCEPT, if not
2901 NULL. This undoes a stop_all_lwps call. */
2904 unstop_all_lwps (struct lwp_info
*except
)
2910 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
2913 "unstopping all lwps\n");
2916 /* Make sure proceed_one_lwp doesn't try to resume this thread. */
2918 ++except
->suspended
;
2920 for_each_inferior (&all_lwps
, proceed_one_lwp
);
2923 --except
->suspended
;
2926 #ifdef HAVE_LINUX_USRREGS
2929 register_addr (int regnum
)
2933 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
2934 error ("Invalid register number %d.", regnum
);
2936 addr
= the_low_target
.regmap
[regnum
];
2941 /* Fetch one register. */
2943 fetch_register (struct regcache
*regcache
, int regno
)
2950 if (regno
>= the_low_target
.num_regs
)
2952 if ((*the_low_target
.cannot_fetch_register
) (regno
))
2955 regaddr
= register_addr (regno
);
2959 pid
= lwpid_of (get_thread_lwp (current_inferior
));
2960 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
2961 & - sizeof (PTRACE_XFER_TYPE
));
2962 buf
= alloca (size
);
2963 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
2966 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
2967 ptrace (PTRACE_PEEKUSER
, pid
,
2968 /* Coerce to a uintptr_t first to avoid potential gcc warning
2969 of coercing an 8 byte integer to a 4 byte pointer. */
2970 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
2971 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
2973 error ("reading register %d: %s", regno
, strerror (errno
));
2976 if (the_low_target
.supply_ptrace_register
)
2977 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
2979 supply_register (regcache
, regno
, buf
);
2982 /* Fetch all registers, or just one, from the child process. */
2984 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
2987 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
2988 fetch_register (regcache
, regno
);
2990 fetch_register (regcache
, regno
);
2993 /* Store our register values back into the inferior.
2994 If REGNO is -1, do this for all registers.
2995 Otherwise, REGNO specifies which register (so we can save time). */
2997 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3006 if (regno
>= the_low_target
.num_regs
)
3009 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3012 regaddr
= register_addr (regno
);
3016 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3017 & - sizeof (PTRACE_XFER_TYPE
);
3018 buf
= alloca (size
);
3019 memset (buf
, 0, size
);
3021 if (the_low_target
.collect_ptrace_register
)
3022 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3024 collect_register (regcache
, regno
, buf
);
3026 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3027 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3030 ptrace (PTRACE_POKEUSER
, pid
,
3031 /* Coerce to a uintptr_t first to avoid potential gcc warning
3032 about coercing an 8 byte integer to a 4 byte pointer. */
3033 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3034 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3037 /* At this point, ESRCH should mean the process is
3038 already gone, in which case we simply ignore attempts
3039 to change its registers. See also the related
3040 comment in linux_resume_one_lwp. */
3044 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3045 error ("writing register %d: %s", regno
, strerror (errno
));
3047 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3051 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3052 usr_store_inferior_registers (regcache
, regno
);
3054 #endif /* HAVE_LINUX_USRREGS */
3058 #ifdef HAVE_LINUX_REGSETS
3061 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3063 struct regset_info
*regset
;
3064 int saw_general_regs
= 0;
3068 regset
= target_regsets
;
3070 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3071 while (regset
->size
>= 0)
3076 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3082 buf
= xmalloc (regset
->size
);
3084 nt_type
= regset
->nt_type
;
3088 iov
.iov_len
= regset
->size
;
3089 data
= (void *) &iov
;
3095 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3097 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3103 /* If we get EIO on a regset, do not try it again for
3105 disabled_regsets
[regset
- target_regsets
] = 1;
3112 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3117 else if (regset
->type
== GENERAL_REGS
)
3118 saw_general_regs
= 1;
3119 regset
->store_function (regcache
, buf
);
3123 if (saw_general_regs
)
3130 regsets_store_inferior_registers (struct regcache
*regcache
)
3132 struct regset_info
*regset
;
3133 int saw_general_regs
= 0;
3137 regset
= target_regsets
;
3139 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3140 while (regset
->size
>= 0)
3145 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3151 buf
= xmalloc (regset
->size
);
3153 /* First fill the buffer with the current register set contents,
3154 in case there are any items in the kernel's regset that are
3155 not in gdbserver's regcache. */
3157 nt_type
= regset
->nt_type
;
3161 iov
.iov_len
= regset
->size
;
3162 data
= (void *) &iov
;
3168 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3170 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3175 /* Then overlay our cached registers on that. */
3176 regset
->fill_function (regcache
, buf
);
3178 /* Only now do we write the register set. */
3180 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3182 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3190 /* If we get EIO on a regset, do not try it again for
3192 disabled_regsets
[regset
- target_regsets
] = 1;
3196 else if (errno
== ESRCH
)
3198 /* At this point, ESRCH should mean the process is
3199 already gone, in which case we simply ignore attempts
3200 to change its registers. See also the related
3201 comment in linux_resume_one_lwp. */
3207 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3210 else if (regset
->type
== GENERAL_REGS
)
3211 saw_general_regs
= 1;
3215 if (saw_general_regs
)
3222 #endif /* HAVE_LINUX_REGSETS */
3226 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3228 #ifdef HAVE_LINUX_REGSETS
3229 if (regsets_fetch_inferior_registers (regcache
) == 0)
3232 #ifdef HAVE_LINUX_USRREGS
3233 usr_fetch_inferior_registers (regcache
, regno
);
3238 linux_store_registers (struct regcache
*regcache
, int regno
)
3240 #ifdef HAVE_LINUX_REGSETS
3241 if (regsets_store_inferior_registers (regcache
) == 0)
3244 #ifdef HAVE_LINUX_USRREGS
3245 usr_store_inferior_registers (regcache
, regno
);
3250 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3251 to debugger memory starting at MYADDR. */
3254 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3257 /* Round starting address down to longword boundary. */
3258 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3259 /* Round ending address up; get number of longwords that makes. */
3261 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3262 / sizeof (PTRACE_XFER_TYPE
);
3263 /* Allocate buffer of that many longwords. */
3264 register PTRACE_XFER_TYPE
*buffer
3265 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3268 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3270 /* Try using /proc. Don't bother for one word. */
3271 if (len
>= 3 * sizeof (long))
3273 /* We could keep this file open and cache it - possibly one per
3274 thread. That requires some juggling, but is even faster. */
3275 sprintf (filename
, "/proc/%d/mem", pid
);
3276 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3280 /* If pread64 is available, use it. It's faster if the kernel
3281 supports it (only one syscall), and it's 64-bit safe even on
3282 32-bit platforms (for instance, SPARC debugging a SPARC64
3285 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3287 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3299 /* Read all the longwords */
3300 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3303 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3304 about coercing an 8 byte integer to a 4 byte pointer. */
3305 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3306 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3311 /* Copy appropriate bytes out of the buffer. */
3313 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
3319 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
3320 memory at MEMADDR. On failure (cannot write to the inferior)
3321 returns the value of errno. */
3324 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
3327 /* Round starting address down to longword boundary. */
3328 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3329 /* Round ending address up; get number of longwords that makes. */
3331 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1) / sizeof (PTRACE_XFER_TYPE
);
3332 /* Allocate buffer of that many longwords. */
3333 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3334 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3338 /* Dump up to four bytes. */
3339 unsigned int val
= * (unsigned int *) myaddr
;
3345 val
= val
& 0xffffff;
3346 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
3347 val
, (long)memaddr
);
3350 /* Fill start and end extra bytes of buffer with existing memory data. */
3353 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3354 about coercing an 8 byte integer to a 4 byte pointer. */
3355 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
3356 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3364 = ptrace (PTRACE_PEEKTEXT
, pid
,
3365 /* Coerce to a uintptr_t first to avoid potential gcc warning
3366 about coercing an 8 byte integer to a 4 byte pointer. */
3367 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
3368 * sizeof (PTRACE_XFER_TYPE
)),
3374 /* Copy data to be written over corresponding part of buffer. */
3376 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)), myaddr
, len
);
3378 /* Write the entire buffer. */
3380 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3383 ptrace (PTRACE_POKETEXT
, pid
,
3384 /* Coerce to a uintptr_t first to avoid potential gcc warning
3385 about coercing an 8 byte integer to a 4 byte pointer. */
3386 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
3387 (PTRACE_ARG4_TYPE
) buffer
[i
]);
3395 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
3396 static int linux_supports_tracefork_flag
;
3399 linux_enable_event_reporting (int pid
)
3401 if (!linux_supports_tracefork_flag
)
3404 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
3407 /* Helper functions for linux_test_for_tracefork, called via clone (). */
3410 linux_tracefork_grandchild (void *arg
)
3415 #define STACK_SIZE 4096
3418 linux_tracefork_child (void *arg
)
3420 ptrace (PTRACE_TRACEME
, 0, 0, 0);
3421 kill (getpid (), SIGSTOP
);
3423 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3426 linux_tracefork_grandchild (NULL
);
3428 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3431 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
3432 CLONE_VM
| SIGCHLD
, NULL
);
3434 clone (linux_tracefork_grandchild
, arg
+ STACK_SIZE
,
3435 CLONE_VM
| SIGCHLD
, NULL
);
3438 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3443 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
3444 sure that we can enable the option, and that it had the desired
3448 linux_test_for_tracefork (void)
3450 int child_pid
, ret
, status
;
3452 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3453 char *stack
= xmalloc (STACK_SIZE
* 4);
3454 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3456 linux_supports_tracefork_flag
= 0;
3458 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
3460 child_pid
= fork ();
3462 linux_tracefork_child (NULL
);
3464 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3466 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
3468 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
3469 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3470 #else /* !__ia64__ */
3471 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
3472 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
3473 #endif /* !__ia64__ */
3475 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3477 if (child_pid
== -1)
3478 perror_with_name ("clone");
3480 ret
= my_waitpid (child_pid
, &status
, 0);
3482 perror_with_name ("waitpid");
3483 else if (ret
!= child_pid
)
3484 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
3485 if (! WIFSTOPPED (status
))
3486 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
3488 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
3489 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
3492 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3495 warning ("linux_test_for_tracefork: failed to kill child");
3499 ret
= my_waitpid (child_pid
, &status
, 0);
3500 if (ret
!= child_pid
)
3501 warning ("linux_test_for_tracefork: failed to wait for killed child");
3502 else if (!WIFSIGNALED (status
))
3503 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
3504 "killed child", status
);
3509 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
3511 warning ("linux_test_for_tracefork: failed to resume child");
3513 ret
= my_waitpid (child_pid
, &status
, 0);
3515 if (ret
== child_pid
&& WIFSTOPPED (status
)
3516 && status
>> 16 == PTRACE_EVENT_FORK
)
3519 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
3520 if (ret
== 0 && second_pid
!= 0)
3524 linux_supports_tracefork_flag
= 1;
3525 my_waitpid (second_pid
, &second_status
, 0);
3526 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
3528 warning ("linux_test_for_tracefork: failed to kill second child");
3529 my_waitpid (second_pid
, &status
, 0);
3533 warning ("linux_test_for_tracefork: unexpected result from waitpid "
3534 "(%d, status 0x%x)", ret
, status
);
3538 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
3540 warning ("linux_test_for_tracefork: failed to kill child");
3541 my_waitpid (child_pid
, &status
, 0);
3543 while (WIFSTOPPED (status
));
3545 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3547 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
3552 linux_look_up_symbols (void)
3554 #ifdef USE_THREAD_DB
3555 struct process_info
*proc
= current_process ();
3557 if (proc
->private->thread_db
!= NULL
)
3560 /* If the kernel supports tracing forks then it also supports tracing
3561 clones, and then we don't need to use the magic thread event breakpoint
3562 to learn about threads. */
3563 thread_db_init (!linux_supports_tracefork_flag
);
3568 linux_request_interrupt (void)
3570 extern unsigned long signal_pid
;
3572 if (!ptid_equal (cont_thread
, null_ptid
)
3573 && !ptid_equal (cont_thread
, minus_one_ptid
))
3575 struct lwp_info
*lwp
;
3578 lwp
= get_thread_lwp (current_inferior
);
3579 lwpid
= lwpid_of (lwp
);
3580 kill_lwp (lwpid
, SIGINT
);
3583 kill_lwp (signal_pid
, SIGINT
);
3586 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
3587 to debugger memory starting at MYADDR. */
3590 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
3592 char filename
[PATH_MAX
];
3594 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3596 snprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
3598 fd
= open (filename
, O_RDONLY
);
3602 if (offset
!= (CORE_ADDR
) 0
3603 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
3606 n
= read (fd
, myaddr
, len
);
3613 /* These breakpoint and watchpoint related wrapper functions simply
3614 pass on the function call if the target has registered a
3615 corresponding function. */
3618 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
3620 if (the_low_target
.insert_point
!= NULL
)
3621 return the_low_target
.insert_point (type
, addr
, len
);
3623 /* Unsupported (see target.h). */
3628 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
3630 if (the_low_target
.remove_point
!= NULL
)
3631 return the_low_target
.remove_point (type
, addr
, len
);
3633 /* Unsupported (see target.h). */
3638 linux_stopped_by_watchpoint (void)
3640 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3642 return lwp
->stopped_by_watchpoint
;
3646 linux_stopped_data_address (void)
3648 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
3650 return lwp
->stopped_data_address
;
3653 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
3654 #if defined(__mcoldfire__)
3655 /* These should really be defined in the kernel's ptrace.h header. */
3656 #define PT_TEXT_ADDR 49*4
3657 #define PT_DATA_ADDR 50*4
3658 #define PT_TEXT_END_ADDR 51*4
3661 /* Under uClinux, programs are loaded at non-zero offsets, which we need
3662 to tell gdb about. */
3665 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
3667 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
3668 unsigned long text
, text_end
, data
;
3669 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3673 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
3674 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
3675 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
3679 /* Both text and data offsets produced at compile-time (and so
3680 used by gdb) are relative to the beginning of the program,
3681 with the data segment immediately following the text segment.
3682 However, the actual runtime layout in memory may put the data
3683 somewhere else, so when we send gdb a data base-address, we
3684 use the real data base address and subtract the compile-time
3685 data base-address from it (which is just the length of the
3686 text segment). BSS immediately follows data in both
3689 *data_p
= data
- (text_end
- text
);
3699 compare_ints (const void *xa
, const void *xb
)
3701 int a
= *(const int *)xa
;
3702 int b
= *(const int *)xb
;
3708 unique (int *b
, int *e
)
3717 /* Given PID, iterates over all threads in that process.
3719 Information about each thread, in a format suitable for qXfer:osdata:thread
3720 is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
3721 initialized, and the caller is responsible for finishing and appending '\0'
3724 The list of cores that threads are running on is assigned to *CORES, if it
3725 is not NULL. If no cores are found, *CORES will be set to NULL. Caller
3726 should free *CORES. */
3729 list_threads (int pid
, struct buffer
*buffer
, char **cores
)
3733 int *core_numbers
= xmalloc (sizeof (int) * allocated
);
3737 struct stat statbuf
;
3739 sprintf (pathname
, "/proc/%d/task", pid
);
3740 if (stat (pathname
, &statbuf
) == 0 && S_ISDIR (statbuf
.st_mode
))
3742 dir
= opendir (pathname
);
3745 free (core_numbers
);
3749 while ((dp
= readdir (dir
)) != NULL
)
3751 unsigned long lwp
= strtoul (dp
->d_name
, NULL
, 10);
3755 unsigned core
= linux_core_of_thread (ptid_build (pid
, lwp
, 0));
3759 char s
[sizeof ("4294967295")];
3760 sprintf (s
, "%u", core
);
3762 if (count
== allocated
)
3765 core_numbers
= realloc (core_numbers
,
3766 sizeof (int) * allocated
);
3768 core_numbers
[count
++] = core
;
3770 buffer_xml_printf (buffer
,
3772 "<column name=\"pid\">%d</column>"
3773 "<column name=\"tid\">%s</column>"
3774 "<column name=\"core\">%s</column>"
3775 "</item>", pid
, dp
->d_name
, s
);
3780 buffer_xml_printf (buffer
,
3782 "<column name=\"pid\">%d</column>"
3783 "<column name=\"tid\">%s</column>"
3784 "</item>", pid
, dp
->d_name
);
3795 struct buffer buffer2
;
3798 qsort (core_numbers
, count
, sizeof (int), compare_ints
);
3800 /* Remove duplicates. */
3802 e
= unique (b
, core_numbers
+ count
);
3804 buffer_init (&buffer2
);
3806 for (b
= core_numbers
; b
!= e
; ++b
)
3808 char number
[sizeof ("4294967295")];
3809 sprintf (number
, "%u", *b
);
3810 buffer_xml_printf (&buffer2
, "%s%s",
3811 (b
== core_numbers
) ? "" : ",", number
);
3813 buffer_grow_str0 (&buffer2
, "");
3815 *cores
= buffer_finish (&buffer2
);
3818 free (core_numbers
);
3822 show_process (int pid
, const char *username
, struct buffer
*buffer
)
3826 char cmd
[MAXPATHLEN
+ 1];
3828 sprintf (pathname
, "/proc/%d/cmdline", pid
);
3830 if ((f
= fopen (pathname
, "r")) != NULL
)
3832 size_t len
= fread (cmd
, 1, sizeof (cmd
) - 1, f
);
3837 for (i
= 0; i
< len
; i
++)
3842 buffer_xml_printf (buffer
,
3844 "<column name=\"pid\">%d</column>"
3845 "<column name=\"user\">%s</column>"
3846 "<column name=\"command\">%s</column>",
3851 /* This only collects core numbers, and does not print threads. */
3852 list_threads (pid
, NULL
, &cores
);
3856 buffer_xml_printf (buffer
,
3857 "<column name=\"cores\">%s</column>", cores
);
3861 buffer_xml_printf (buffer
, "</item>");
3868 linux_qxfer_osdata (const char *annex
,
3869 unsigned char *readbuf
, unsigned const char *writebuf
,
3870 CORE_ADDR offset
, int len
)
3872 /* We make the process list snapshot when the object starts to be
3874 static const char *buf
;
3875 static long len_avail
= -1;
3876 static struct buffer buffer
;
3882 if (strcmp (annex
, "processes") == 0)
3884 else if (strcmp (annex
, "threads") == 0)
3889 if (!readbuf
|| writebuf
)
3894 if (len_avail
!= -1 && len_avail
!= 0)
3895 buffer_free (&buffer
);
3898 buffer_init (&buffer
);
3900 buffer_grow_str (&buffer
, "<osdata type=\"processes\">");
3902 buffer_grow_str (&buffer
, "<osdata type=\"threads\">");
3904 dirp
= opendir ("/proc");
3908 while ((dp
= readdir (dirp
)) != NULL
)
3910 struct stat statbuf
;
3911 char procentry
[sizeof ("/proc/4294967295")];
3913 if (!isdigit (dp
->d_name
[0])
3914 || strlen (dp
->d_name
) > sizeof ("4294967295") - 1)
3917 sprintf (procentry
, "/proc/%s", dp
->d_name
);
3918 if (stat (procentry
, &statbuf
) == 0
3919 && S_ISDIR (statbuf
.st_mode
))
3921 int pid
= (int) strtoul (dp
->d_name
, NULL
, 10);
3925 struct passwd
*entry
= getpwuid (statbuf
.st_uid
);
3926 show_process (pid
, entry
? entry
->pw_name
: "?", &buffer
);
3930 list_threads (pid
, &buffer
, NULL
);
3937 buffer_grow_str0 (&buffer
, "</osdata>\n");
3938 buf
= buffer_finish (&buffer
);
3939 len_avail
= strlen (buf
);
3942 if (offset
>= len_avail
)
3944 /* Done. Get rid of the data. */
3945 buffer_free (&buffer
);
3951 if (len
> len_avail
- offset
)
3952 len
= len_avail
- offset
;
3953 memcpy (readbuf
, buf
+ offset
, len
);
3958 /* Convert a native/host siginfo object, into/from the siginfo in the
3959 layout of the inferiors' architecture. */
3962 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
3966 if (the_low_target
.siginfo_fixup
!= NULL
)
3967 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3969 /* If there was no callback, or the callback didn't do anything,
3970 then just do a straight memcpy. */
3974 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
3976 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
3981 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
3982 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
3985 struct siginfo siginfo
;
3986 char inf_siginfo
[sizeof (struct siginfo
)];
3988 if (current_inferior
== NULL
)
3991 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3994 fprintf (stderr
, "%s siginfo for lwp %d.\n",
3995 readbuf
!= NULL
? "Reading" : "Writing",
3998 if (offset
> sizeof (siginfo
))
4001 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4004 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4005 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4006 inferior with a 64-bit GDBSERVER should look the same as debugging it
4007 with a 32-bit GDBSERVER, we need to convert it. */
4008 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4010 if (offset
+ len
> sizeof (siginfo
))
4011 len
= sizeof (siginfo
) - offset
;
4013 if (readbuf
!= NULL
)
4014 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4017 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4019 /* Convert back to ptrace layout before flushing it out. */
4020 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4022 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4029 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4030 so we notice when children change state; as the handler for the
4031 sigsuspend in my_waitpid. */
4034 sigchld_handler (int signo
)
4036 int old_errno
= errno
;
4039 /* fprintf is not async-signal-safe, so call write directly. */
4040 write (2, "sigchld_handler\n", sizeof ("sigchld_handler\n") - 1);
4042 if (target_is_async_p ())
4043 async_file_mark (); /* trigger a linux_wait */
4049 linux_supports_non_stop (void)
4055 linux_async (int enable
)
4057 int previous
= (linux_event_pipe
[0] != -1);
4060 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4063 if (previous
!= enable
)
4066 sigemptyset (&mask
);
4067 sigaddset (&mask
, SIGCHLD
);
4069 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4073 if (pipe (linux_event_pipe
) == -1)
4074 fatal ("creating event pipe failed.");
4076 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4077 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4079 /* Register the event loop handler. */
4080 add_file_handler (linux_event_pipe
[0],
4081 handle_target_event
, NULL
);
4083 /* Always trigger a linux_wait. */
4088 delete_file_handler (linux_event_pipe
[0]);
4090 close (linux_event_pipe
[0]);
4091 close (linux_event_pipe
[1]);
4092 linux_event_pipe
[0] = -1;
4093 linux_event_pipe
[1] = -1;
4096 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4103 linux_start_non_stop (int nonstop
)
4105 /* Register or unregister from event-loop accordingly. */
4106 linux_async (nonstop
);
4111 linux_supports_multi_process (void)
4117 /* Enumerate spufs IDs for process PID. */
4119 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4125 struct dirent
*entry
;
4127 sprintf (path
, "/proc/%ld/fd", pid
);
4128 dir
= opendir (path
);
4133 while ((entry
= readdir (dir
)) != NULL
)
4139 fd
= atoi (entry
->d_name
);
4143 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4144 if (stat (path
, &st
) != 0)
4146 if (!S_ISDIR (st
.st_mode
))
4149 if (statfs (path
, &stfs
) != 0)
4151 if (stfs
.f_type
!= SPUFS_MAGIC
)
4154 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4156 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4166 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4167 object type, using the /proc file system. */
4169 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4170 unsigned const char *writebuf
,
4171 CORE_ADDR offset
, int len
)
4173 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4178 if (!writebuf
&& !readbuf
)
4186 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4189 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4190 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4195 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4202 ret
= write (fd
, writebuf
, (size_t) len
);
4204 ret
= read (fd
, readbuf
, (size_t) len
);
4211 linux_core_of_thread (ptid_t ptid
)
4213 char filename
[sizeof ("/proc//task//stat")
4214 + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
4217 char *content
= NULL
;
4220 int content_read
= 0;
4224 sprintf (filename
, "/proc/%d/task/%ld/stat",
4225 ptid_get_pid (ptid
), ptid_get_lwp (ptid
));
4226 f
= fopen (filename
, "r");
4233 content
= realloc (content
, content_read
+ 1024);
4234 n
= fread (content
+ content_read
, 1, 1024, f
);
4238 content
[content_read
] = '\0';
4243 p
= strchr (content
, '(');
4244 p
= strchr (p
, ')') + 2; /* skip ")" and a whitespace. */
4246 p
= strtok_r (p
, " ", &ts
);
4247 for (i
= 0; i
!= 36; ++i
)
4248 p
= strtok_r (NULL
, " ", &ts
);
4250 if (sscanf (p
, "%d", &core
) == 0)
4260 linux_process_qsupported (const char *query
)
4262 if (the_low_target
.process_qsupported
!= NULL
)
4263 the_low_target
.process_qsupported (query
);
4267 linux_supports_tracepoints (void)
4269 if (*the_low_target
.supports_tracepoints
== NULL
)
4272 return (*the_low_target
.supports_tracepoints
) ();
4276 linux_read_pc (struct regcache
*regcache
)
4278 if (the_low_target
.get_pc
== NULL
)
4281 return (*the_low_target
.get_pc
) (regcache
);
4285 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
4287 gdb_assert (the_low_target
.set_pc
!= NULL
);
4289 (*the_low_target
.set_pc
) (regcache
, pc
);
4293 linux_thread_stopped (struct thread_info
*thread
)
4295 return get_thread_lwp (thread
)->stopped
;
4298 /* This exposes stop-all-threads functionality to other modules. */
4301 linux_pause_all (void)
4306 static struct target_ops linux_target_ops
= {
4307 linux_create_inferior
,
4316 linux_fetch_registers
,
4317 linux_store_registers
,
4320 linux_look_up_symbols
,
4321 linux_request_interrupt
,
4325 linux_stopped_by_watchpoint
,
4326 linux_stopped_data_address
,
4327 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4332 #ifdef USE_THREAD_DB
4333 thread_db_get_tls_address
,
4338 hostio_last_error_from_errno
,
4341 linux_supports_non_stop
,
4343 linux_start_non_stop
,
4344 linux_supports_multi_process
,
4345 #ifdef USE_THREAD_DB
4346 thread_db_handle_monitor_command
,
4350 linux_core_of_thread
,
4351 linux_process_qsupported
,
4352 linux_supports_tracepoints
,
4355 linux_thread_stopped
,
4357 NULL
, /* get_tib_address (Windows OS specific). */
4361 linux_init_signals ()
4363 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4364 to find what the cancel signal actually is. */
4365 #ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
4366 signal (__SIGRTMIN
+1, SIG_IGN
);
4371 initialize_low (void)
4373 struct sigaction sigchld_action
;
4374 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4375 set_target_ops (&linux_target_ops
);
4376 set_breakpoint_data (the_low_target
.breakpoint
,
4377 the_low_target
.breakpoint_len
);
4378 linux_init_signals ();
4379 linux_test_for_tracefork ();
4380 #ifdef HAVE_LINUX_REGSETS
4381 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4383 disabled_regsets
= xmalloc (num_regsets
);
4386 sigchld_action
.sa_handler
= sigchld_handler
;
4387 sigemptyset (&sigchld_action
.sa_mask
);
4388 sigchld_action
.sa_flags
= SA_RESTART
;
4389 sigaction (SIGCHLD
, &sigchld_action
, NULL
);