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, 2011 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "linux-low.h"
22 #include "linux-osdata.h"
26 #include <sys/param.h>
27 #include <sys/ptrace.h>
28 #include "linux-ptrace.h"
30 #include <sys/ioctl.h>
36 #include <sys/syscall.h>
40 #include <sys/types.h>
46 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
47 then ELFMAG0 will have been defined. If it didn't get included by
48 gdb_proc_service.h then including it will likely introduce a duplicate
49 definition of elf_fpregset_t. */
54 #define SPUFS_MAGIC 0x23c9b64e
62 #define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
65 /* This is the kernel's hard limit. Not to be confused with
72 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
77 /* ``all_threads'' is keyed by the LWP ID, which we use as the GDB protocol
78 representation of the thread ID.
80 ``all_lwps'' is keyed by the process ID - which on Linux is (presently)
81 the same as the LWP ID.
83 ``all_processes'' is keyed by the "overall process ID", which
84 GNU/Linux calls tgid, "thread group ID". */
86 struct inferior_list all_lwps
;
88 /* A list of all unknown processes which receive stop signals. Some other
89 process will presumably claim each of these as forked children
92 struct inferior_list stopped_pids
;
94 /* FIXME this is a bit of a hack, and could be removed. */
97 /* FIXME make into a target method? */
98 int using_threads
= 1;
100 /* True if we're presently stabilizing threads (moving them out of
102 static int stabilizing_threads
;
104 /* This flag is true iff we've just created or attached to our first
105 inferior but it has not stopped yet. As soon as it does, we need
106 to call the low target's arch_setup callback. Doing this only on
107 the first inferior avoids reinializing the architecture on every
108 inferior, and avoids messing with the register caches of the
109 already running inferiors. NOTE: this assumes all inferiors under
110 control of gdbserver have the same architecture. */
111 static int new_inferior
;
113 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
114 int step
, int signal
, siginfo_t
*info
);
115 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
116 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
117 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
118 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
119 static void *add_lwp (ptid_t ptid
);
120 static int linux_stopped_by_watchpoint (void);
121 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
122 static void proceed_all_lwps (void);
123 static int finish_step_over (struct lwp_info
*lwp
);
124 static CORE_ADDR
get_stop_pc (struct lwp_info
*lwp
);
125 static int kill_lwp (unsigned long lwpid
, int signo
);
126 static void linux_enable_event_reporting (int pid
);
128 /* True if the low target can hardware single-step. Such targets
129 don't need a BREAKPOINT_REINSERT_ADDR callback. */
132 can_hardware_single_step (void)
134 return (the_low_target
.breakpoint_reinsert_addr
== NULL
);
137 /* True if the low target supports memory breakpoints. If so, we'll
138 have a GET_PC implementation. */
141 supports_breakpoints (void)
143 return (the_low_target
.get_pc
!= NULL
);
146 /* Returns true if this target can support fast tracepoints. This
147 does not mean that the in-process agent has been loaded in the
151 supports_fast_tracepoints (void)
153 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
156 struct pending_signals
160 struct pending_signals
*prev
;
163 #define PTRACE_ARG3_TYPE void *
164 #define PTRACE_ARG4_TYPE void *
165 #define PTRACE_XFER_TYPE long
167 #ifdef HAVE_LINUX_REGSETS
168 static char *disabled_regsets
;
169 static int num_regsets
;
172 /* The read/write ends of the pipe registered as waitable file in the
174 static int linux_event_pipe
[2] = { -1, -1 };
176 /* True if we're currently in async mode. */
177 #define target_is_async_p() (linux_event_pipe[0] != -1)
179 static void send_sigstop (struct lwp_info
*lwp
);
180 static void wait_for_sigstop (struct inferior_list_entry
*entry
);
182 /* Accepts an integer PID; Returns a string representing a file that
183 can be opened to get info for the child process.
184 Space for the result is malloc'd, caller must free. */
187 linux_child_pid_to_exec_file (int pid
)
191 name1
= xmalloc (MAXPATHLEN
);
192 name2
= xmalloc (MAXPATHLEN
);
193 memset (name2
, 0, MAXPATHLEN
);
195 sprintf (name1
, "/proc/%d/exe", pid
);
196 if (readlink (name1
, name2
, MAXPATHLEN
) > 0)
208 /* Return non-zero if HEADER is a 64-bit ELF file. */
211 elf_64_header_p (const Elf64_Ehdr
*header
)
213 return (header
->e_ident
[EI_MAG0
] == ELFMAG0
214 && header
->e_ident
[EI_MAG1
] == ELFMAG1
215 && header
->e_ident
[EI_MAG2
] == ELFMAG2
216 && header
->e_ident
[EI_MAG3
] == ELFMAG3
217 && header
->e_ident
[EI_CLASS
] == ELFCLASS64
);
220 /* Return non-zero if FILE is a 64-bit ELF file,
221 zero if the file is not a 64-bit ELF file,
222 and -1 if the file is not accessible or doesn't exist. */
225 elf_64_file_p (const char *file
)
230 fd
= open (file
, O_RDONLY
);
234 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
241 return elf_64_header_p (&header
);
245 delete_lwp (struct lwp_info
*lwp
)
247 remove_thread (get_lwp_thread (lwp
));
248 remove_inferior (&all_lwps
, &lwp
->head
);
249 free (lwp
->arch_private
);
253 /* Add a process to the common process list, and set its private
256 static struct process_info
*
257 linux_add_process (int pid
, int attached
)
259 struct process_info
*proc
;
261 /* Is this the first process? If so, then set the arch. */
262 if (all_processes
.head
== NULL
)
265 proc
= add_process (pid
, attached
);
266 proc
->private = xcalloc (1, sizeof (*proc
->private));
268 if (the_low_target
.new_process
!= NULL
)
269 proc
->private->arch_private
= the_low_target
.new_process ();
274 /* Wrapper function for waitpid which handles EINTR, and emulates
275 __WALL for systems where that is not available. */
278 my_waitpid (int pid
, int *status
, int flags
)
283 fprintf (stderr
, "my_waitpid (%d, 0x%x)\n", pid
, flags
);
287 sigset_t block_mask
, org_mask
, wake_mask
;
290 wnohang
= (flags
& WNOHANG
) != 0;
291 flags
&= ~(__WALL
| __WCLONE
);
294 /* Block all signals while here. This avoids knowing about
295 LinuxThread's signals. */
296 sigfillset (&block_mask
);
297 sigprocmask (SIG_BLOCK
, &block_mask
, &org_mask
);
299 /* ... except during the sigsuspend below. */
300 sigemptyset (&wake_mask
);
304 /* Since all signals are blocked, there's no need to check
306 ret
= waitpid (pid
, status
, flags
);
309 if (ret
== -1 && out_errno
!= ECHILD
)
314 if (flags
& __WCLONE
)
316 /* We've tried both flavors now. If WNOHANG is set,
317 there's nothing else to do, just bail out. */
322 fprintf (stderr
, "blocking\n");
324 /* Block waiting for signals. */
325 sigsuspend (&wake_mask
);
331 sigprocmask (SIG_SETMASK
, &org_mask
, NULL
);
336 ret
= waitpid (pid
, status
, flags
);
337 while (ret
== -1 && errno
== EINTR
);
342 fprintf (stderr
, "my_waitpid (%d, 0x%x): status(%x), %d\n",
343 pid
, flags
, status
? *status
: -1, ret
);
349 /* Handle a GNU/Linux extended wait response. If we see a clone
350 event, we need to add the new LWP to our list (and not report the
351 trap to higher layers). */
354 handle_extended_wait (struct lwp_info
*event_child
, int wstat
)
356 int event
= wstat
>> 16;
357 struct lwp_info
*new_lwp
;
359 if (event
== PTRACE_EVENT_CLONE
)
362 unsigned long new_pid
;
363 int ret
, status
= W_STOPCODE (SIGSTOP
);
365 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_child
), 0, &new_pid
);
367 /* If we haven't already seen the new PID stop, wait for it now. */
368 if (! pull_pid_from_list (&stopped_pids
, new_pid
))
370 /* The new child has a pending SIGSTOP. We can't affect it until it
371 hits the SIGSTOP, but we're already attached. */
373 ret
= my_waitpid (new_pid
, &status
, __WALL
);
376 perror_with_name ("waiting for new child");
377 else if (ret
!= new_pid
)
378 warning ("wait returned unexpected PID %d", ret
);
379 else if (!WIFSTOPPED (status
))
380 warning ("wait returned unexpected status 0x%x", status
);
383 linux_enable_event_reporting (new_pid
);
385 ptid
= ptid_build (pid_of (event_child
), new_pid
, 0);
386 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
387 add_thread (ptid
, new_lwp
);
389 /* Either we're going to immediately resume the new thread
390 or leave it stopped. linux_resume_one_lwp is a nop if it
391 thinks the thread is currently running, so set this first
392 before calling linux_resume_one_lwp. */
393 new_lwp
->stopped
= 1;
395 /* Normally we will get the pending SIGSTOP. But in some cases
396 we might get another signal delivered to the group first.
397 If we do get another signal, be sure not to lose it. */
398 if (WSTOPSIG (status
) == SIGSTOP
)
400 if (stopping_threads
)
401 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
403 linux_resume_one_lwp (new_lwp
, 0, 0, NULL
);
407 new_lwp
->stop_expected
= 1;
409 if (stopping_threads
)
411 new_lwp
->stop_pc
= get_stop_pc (new_lwp
);
412 new_lwp
->status_pending_p
= 1;
413 new_lwp
->status_pending
= status
;
416 /* Pass the signal on. This is what GDB does - except
417 shouldn't we really report it instead? */
418 linux_resume_one_lwp (new_lwp
, 0, WSTOPSIG (status
), NULL
);
421 /* Always resume the current thread. If we are stopping
422 threads, it will have a pending SIGSTOP; we may as well
424 linux_resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
428 /* Return the PC as read from the regcache of LWP, without any
432 get_pc (struct lwp_info
*lwp
)
434 struct thread_info
*saved_inferior
;
435 struct regcache
*regcache
;
438 if (the_low_target
.get_pc
== NULL
)
441 saved_inferior
= current_inferior
;
442 current_inferior
= get_lwp_thread (lwp
);
444 regcache
= get_thread_regcache (current_inferior
, 1);
445 pc
= (*the_low_target
.get_pc
) (regcache
);
448 fprintf (stderr
, "pc is 0x%lx\n", (long) pc
);
450 current_inferior
= saved_inferior
;
454 /* This function should only be called if LWP got a SIGTRAP.
455 The SIGTRAP could mean several things.
457 On i386, where decr_pc_after_break is non-zero:
458 If we were single-stepping this process using PTRACE_SINGLESTEP,
459 we will get only the one SIGTRAP (even if the instruction we
460 stepped over was a breakpoint). The value of $eip will be the
462 If we continue the process using PTRACE_CONT, we will get a
463 SIGTRAP when we hit a breakpoint. The value of $eip will be
464 the instruction after the breakpoint (i.e. needs to be
465 decremented). If we report the SIGTRAP to GDB, we must also
466 report the undecremented PC. If we cancel the SIGTRAP, we
467 must resume at the decremented PC.
469 (Presumably, not yet tested) On a non-decr_pc_after_break machine
470 with hardware or kernel single-step:
471 If we single-step over a breakpoint instruction, our PC will
472 point at the following instruction. If we continue and hit a
473 breakpoint instruction, our PC will point at the breakpoint
477 get_stop_pc (struct lwp_info
*lwp
)
481 if (the_low_target
.get_pc
== NULL
)
484 stop_pc
= get_pc (lwp
);
486 if (WSTOPSIG (lwp
->last_status
) == SIGTRAP
488 && !lwp
->stopped_by_watchpoint
489 && lwp
->last_status
>> 16 == 0)
490 stop_pc
-= the_low_target
.decr_pc_after_break
;
493 fprintf (stderr
, "stop pc is 0x%lx\n", (long) stop_pc
);
499 add_lwp (ptid_t ptid
)
501 struct lwp_info
*lwp
;
503 lwp
= (struct lwp_info
*) xmalloc (sizeof (*lwp
));
504 memset (lwp
, 0, sizeof (*lwp
));
508 if (the_low_target
.new_thread
!= NULL
)
509 lwp
->arch_private
= the_low_target
.new_thread ();
511 add_inferior_to_list (&all_lwps
, &lwp
->head
);
516 /* Start an inferior process and returns its pid.
517 ALLARGS is a vector of program-name and args. */
520 linux_create_inferior (char *program
, char **allargs
)
522 struct lwp_info
*new_lwp
;
526 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
532 perror_with_name ("fork");
536 ptrace (PTRACE_TRACEME
, 0, 0, 0);
538 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
539 signal (__SIGRTMIN
+ 1, SIG_DFL
);
544 execv (program
, allargs
);
546 execvp (program
, allargs
);
548 fprintf (stderr
, "Cannot exec %s: %s.\n", program
,
554 linux_add_process (pid
, 0);
556 ptid
= ptid_build (pid
, pid
, 0);
557 new_lwp
= add_lwp (ptid
);
558 add_thread (ptid
, new_lwp
);
559 new_lwp
->must_set_ptrace_flags
= 1;
564 /* Attach to an inferior process. */
567 linux_attach_lwp_1 (unsigned long lwpid
, int initial
)
570 struct lwp_info
*new_lwp
;
572 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) != 0)
576 /* If we fail to attach to an LWP, just warn. */
577 fprintf (stderr
, "Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
578 strerror (errno
), errno
);
583 /* If we fail to attach to a process, report an error. */
584 error ("Cannot attach to lwp %ld: %s (%d)\n", lwpid
,
585 strerror (errno
), errno
);
589 /* NOTE/FIXME: This lwp might have not been the tgid. */
590 ptid
= ptid_build (lwpid
, lwpid
, 0);
593 /* Note that extracting the pid from the current inferior is
594 safe, since we're always called in the context of the same
595 process as this new thread. */
596 int pid
= pid_of (get_thread_lwp (current_inferior
));
597 ptid
= ptid_build (pid
, lwpid
, 0);
600 new_lwp
= (struct lwp_info
*) add_lwp (ptid
);
601 add_thread (ptid
, new_lwp
);
603 /* We need to wait for SIGSTOP before being able to make the next
604 ptrace call on this LWP. */
605 new_lwp
->must_set_ptrace_flags
= 1;
607 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
610 There are several cases to consider here:
612 1) gdbserver has already attached to the process and is being notified
613 of a new thread that is being created.
614 In this case we should ignore that SIGSTOP and resume the
615 process. This is handled below by setting stop_expected = 1,
616 and the fact that add_thread sets last_resume_kind ==
619 2) This is the first thread (the process thread), and we're attaching
620 to it via attach_inferior.
621 In this case we want the process thread to stop.
622 This is handled by having linux_attach set last_resume_kind ==
623 resume_stop after we return.
624 ??? If the process already has several threads we leave the other
627 3) GDB is connecting to gdbserver and is requesting an enumeration of all
629 In this case we want the thread to stop.
630 FIXME: This case is currently not properly handled.
631 We should wait for the SIGSTOP but don't. Things work apparently
632 because enough time passes between when we ptrace (ATTACH) and when
633 gdb makes the next ptrace call on the thread.
635 On the other hand, if we are currently trying to stop all threads, we
636 should treat the new thread as if we had sent it a SIGSTOP. This works
637 because we are guaranteed that the add_lwp call above added us to the
638 end of the list, and so the new thread has not yet reached
639 wait_for_sigstop (but will). */
640 new_lwp
->stop_expected
= 1;
644 linux_attach_lwp (unsigned long lwpid
)
646 linux_attach_lwp_1 (lwpid
, 0);
650 linux_attach (unsigned long pid
)
652 linux_attach_lwp_1 (pid
, 1);
653 linux_add_process (pid
, 1);
657 struct thread_info
*thread
;
659 /* Don't ignore the initial SIGSTOP if we just attached to this
660 process. It will be collected by wait shortly. */
661 thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
662 thread
->last_resume_kind
= resume_stop
;
675 second_thread_of_pid_p (struct inferior_list_entry
*entry
, void *args
)
677 struct counter
*counter
= args
;
679 if (ptid_get_pid (entry
->id
) == counter
->pid
)
681 if (++counter
->count
> 1)
689 last_thread_of_process_p (struct thread_info
*thread
)
691 ptid_t ptid
= ((struct inferior_list_entry
*)thread
)->id
;
692 int pid
= ptid_get_pid (ptid
);
693 struct counter counter
= { pid
, 0 };
695 return (find_inferior (&all_threads
,
696 second_thread_of_pid_p
, &counter
) == NULL
);
699 /* Kill the inferior lwp. */
702 linux_kill_one_lwp (struct inferior_list_entry
*entry
, void *args
)
704 struct thread_info
*thread
= (struct thread_info
*) entry
;
705 struct lwp_info
*lwp
= get_thread_lwp (thread
);
707 int pid
= * (int *) args
;
709 if (ptid_get_pid (entry
->id
) != pid
)
712 /* We avoid killing the first thread here, because of a Linux kernel (at
713 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
714 the children get a chance to be reaped, it will remain a zombie
717 if (lwpid_of (lwp
) == pid
)
720 fprintf (stderr
, "lkop: is last of process %s\n",
721 target_pid_to_str (entry
->id
));
727 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
729 /* Make sure it died. The loop is most likely unnecessary. */
730 pid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
731 } while (pid
> 0 && WIFSTOPPED (wstat
));
739 struct process_info
*process
;
740 struct lwp_info
*lwp
;
744 process
= find_process_pid (pid
);
748 /* If we're killing a running inferior, make sure it is stopped
749 first, as PTRACE_KILL will not work otherwise. */
750 stop_all_lwps (0, NULL
);
752 find_inferior (&all_threads
, linux_kill_one_lwp
, &pid
);
754 /* See the comment in linux_kill_one_lwp. We did not kill the first
755 thread in the list, so do so now. */
756 lwp
= find_lwp_pid (pid_to_ptid (pid
));
759 fprintf (stderr
, "lk_1: killing lwp %ld, for pid: %d\n",
760 lwpid_of (lwp
), pid
);
764 ptrace (PTRACE_KILL
, lwpid_of (lwp
), 0, 0);
766 /* Make sure it died. The loop is most likely unnecessary. */
767 lwpid
= linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
768 } while (lwpid
> 0 && WIFSTOPPED (wstat
));
770 the_target
->mourn (process
);
772 /* Since we presently can only stop all lwps of all processes, we
773 need to unstop lwps of other processes. */
774 unstop_all_lwps (0, NULL
);
779 linux_detach_one_lwp (struct inferior_list_entry
*entry
, void *args
)
781 struct thread_info
*thread
= (struct thread_info
*) entry
;
782 struct lwp_info
*lwp
= get_thread_lwp (thread
);
783 int pid
= * (int *) args
;
785 if (ptid_get_pid (entry
->id
) != pid
)
788 /* If this process is stopped but is expecting a SIGSTOP, then make
789 sure we take care of that now. This isn't absolutely guaranteed
790 to collect the SIGSTOP, but is fairly likely to. */
791 if (lwp
->stop_expected
)
794 /* Clear stop_expected, so that the SIGSTOP will be reported. */
795 lwp
->stop_expected
= 0;
796 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
797 linux_wait_for_event (lwp
->head
.id
, &wstat
, __WALL
);
800 /* Flush any pending changes to the process's registers. */
801 regcache_invalidate_one ((struct inferior_list_entry
*)
802 get_lwp_thread (lwp
));
804 /* Finally, let it resume. */
805 ptrace (PTRACE_DETACH
, lwpid_of (lwp
), 0, 0);
812 linux_detach (int pid
)
814 struct process_info
*process
;
816 process
= find_process_pid (pid
);
820 /* Stop all threads before detaching. First, ptrace requires that
821 the thread is stopped to sucessfully detach. Second, thread_db
822 may need to uninstall thread event breakpoints from memory, which
823 only works with a stopped process anyway. */
824 stop_all_lwps (0, NULL
);
827 thread_db_detach (process
);
830 /* Stabilize threads (move out of jump pads). */
831 stabilize_threads ();
833 find_inferior (&all_threads
, linux_detach_one_lwp
, &pid
);
835 the_target
->mourn (process
);
837 /* Since we presently can only stop all lwps of all processes, we
838 need to unstop lwps of other processes. */
839 unstop_all_lwps (0, NULL
);
843 /* Remove all LWPs that belong to process PROC from the lwp list. */
846 delete_lwp_callback (struct inferior_list_entry
*entry
, void *proc
)
848 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
849 struct process_info
*process
= proc
;
851 if (pid_of (lwp
) == pid_of (process
))
858 linux_mourn (struct process_info
*process
)
860 struct process_info_private
*priv
;
863 thread_db_mourn (process
);
866 find_inferior (&all_lwps
, delete_lwp_callback
, process
);
868 /* Freeing all private data. */
869 priv
= process
->private;
870 free (priv
->arch_private
);
872 process
->private = NULL
;
874 remove_process (process
);
883 ret
= my_waitpid (pid
, &status
, 0);
884 if (WIFEXITED (status
) || WIFSIGNALED (status
))
886 } while (ret
!= -1 || errno
!= ECHILD
);
889 /* Return nonzero if the given thread is still alive. */
891 linux_thread_alive (ptid_t ptid
)
893 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
895 /* We assume we always know if a thread exits. If a whole process
896 exited but we still haven't been able to report it to GDB, we'll
897 hold on to the last lwp of the dead process. */
904 /* Return 1 if this lwp has an interesting status pending. */
906 status_pending_p_callback (struct inferior_list_entry
*entry
, void *arg
)
908 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
909 ptid_t ptid
= * (ptid_t
*) arg
;
910 struct thread_info
*thread
;
912 /* Check if we're only interested in events from a specific process
914 if (!ptid_equal (minus_one_ptid
, ptid
)
915 && ptid_get_pid (ptid
) != ptid_get_pid (lwp
->head
.id
))
918 thread
= get_lwp_thread (lwp
);
920 /* If we got a `vCont;t', but we haven't reported a stop yet, do
921 report any status pending the LWP may have. */
922 if (thread
->last_resume_kind
== resume_stop
923 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
926 return lwp
->status_pending_p
;
930 same_lwp (struct inferior_list_entry
*entry
, void *data
)
932 ptid_t ptid
= *(ptid_t
*) data
;
935 if (ptid_get_lwp (ptid
) != 0)
936 lwp
= ptid_get_lwp (ptid
);
938 lwp
= ptid_get_pid (ptid
);
940 if (ptid_get_lwp (entry
->id
) == lwp
)
947 find_lwp_pid (ptid_t ptid
)
949 return (struct lwp_info
*) find_inferior (&all_lwps
, same_lwp
, &ptid
);
952 static struct lwp_info
*
953 linux_wait_for_lwp (ptid_t ptid
, int *wstatp
, int options
)
956 int to_wait_for
= -1;
957 struct lwp_info
*child
= NULL
;
960 fprintf (stderr
, "linux_wait_for_lwp: %s\n", target_pid_to_str (ptid
));
962 if (ptid_equal (ptid
, minus_one_ptid
))
963 to_wait_for
= -1; /* any child */
965 to_wait_for
= ptid_get_lwp (ptid
); /* this lwp only */
971 ret
= my_waitpid (to_wait_for
, wstatp
, options
);
972 if (ret
== 0 || (ret
== -1 && errno
== ECHILD
&& (options
& WNOHANG
)))
975 perror_with_name ("waitpid");
978 && (!WIFSTOPPED (*wstatp
)
979 || (WSTOPSIG (*wstatp
) != 32
980 && WSTOPSIG (*wstatp
) != 33)))
981 fprintf (stderr
, "Got an event from %d (%x)\n", ret
, *wstatp
);
983 child
= find_lwp_pid (pid_to_ptid (ret
));
985 /* If we didn't find a process, one of two things presumably happened:
986 - A process we started and then detached from has exited. Ignore it.
987 - A process we are controlling has forked and the new child's stop
988 was reported to us by the kernel. Save its PID. */
989 if (child
== NULL
&& WIFSTOPPED (*wstatp
))
991 add_pid_to_list (&stopped_pids
, ret
);
994 else if (child
== NULL
)
999 child
->last_status
= *wstatp
;
1001 /* Architecture-specific setup after inferior is running.
1002 This needs to happen after we have attached to the inferior
1003 and it is stopped for the first time, but before we access
1004 any inferior registers. */
1007 the_low_target
.arch_setup ();
1008 #ifdef HAVE_LINUX_REGSETS
1009 memset (disabled_regsets
, 0, num_regsets
);
1014 /* Fetch the possibly triggered data watchpoint info and store it in
1017 On some archs, like x86, that use debug registers to set
1018 watchpoints, it's possible that the way to know which watched
1019 address trapped, is to check the register that is used to select
1020 which address to watch. Problem is, between setting the
1021 watchpoint and reading back which data address trapped, the user
1022 may change the set of watchpoints, and, as a consequence, GDB
1023 changes the debug registers in the inferior. To avoid reading
1024 back a stale stopped-data-address when that happens, we cache in
1025 LP the fact that a watchpoint trapped, and the corresponding data
1026 address, as soon as we see CHILD stop with a SIGTRAP. If GDB
1027 changes the debug registers meanwhile, we have the cached data we
1030 if (WIFSTOPPED (*wstatp
) && WSTOPSIG (*wstatp
) == SIGTRAP
)
1032 if (the_low_target
.stopped_by_watchpoint
== NULL
)
1034 child
->stopped_by_watchpoint
= 0;
1038 struct thread_info
*saved_inferior
;
1040 saved_inferior
= current_inferior
;
1041 current_inferior
= get_lwp_thread (child
);
1043 child
->stopped_by_watchpoint
1044 = the_low_target
.stopped_by_watchpoint ();
1046 if (child
->stopped_by_watchpoint
)
1048 if (the_low_target
.stopped_data_address
!= NULL
)
1049 child
->stopped_data_address
1050 = the_low_target
.stopped_data_address ();
1052 child
->stopped_data_address
= 0;
1055 current_inferior
= saved_inferior
;
1059 /* Store the STOP_PC, with adjustment applied. This depends on the
1060 architecture being defined already (so that CHILD has a valid
1061 regcache), and on LAST_STATUS being set (to check for SIGTRAP or
1063 if (WIFSTOPPED (*wstatp
))
1064 child
->stop_pc
= get_stop_pc (child
);
1067 && WIFSTOPPED (*wstatp
)
1068 && the_low_target
.get_pc
!= NULL
)
1070 struct thread_info
*saved_inferior
= current_inferior
;
1071 struct regcache
*regcache
;
1074 current_inferior
= get_lwp_thread (child
);
1075 regcache
= get_thread_regcache (current_inferior
, 1);
1076 pc
= (*the_low_target
.get_pc
) (regcache
);
1077 fprintf (stderr
, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc
);
1078 current_inferior
= saved_inferior
;
1084 /* This function should only be called if the LWP got a SIGTRAP.
1086 Handle any tracepoint steps or hits. Return true if a tracepoint
1087 event was handled, 0 otherwise. */
1090 handle_tracepoints (struct lwp_info
*lwp
)
1092 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1093 int tpoint_related_event
= 0;
1095 /* If this tracepoint hit causes a tracing stop, we'll immediately
1096 uninsert tracepoints. To do this, we temporarily pause all
1097 threads, unpatch away, and then unpause threads. We need to make
1098 sure the unpausing doesn't resume LWP too. */
1101 /* And we need to be sure that any all-threads-stopping doesn't try
1102 to move threads out of the jump pads, as it could deadlock the
1103 inferior (LWP could be in the jump pad, maybe even holding the
1106 /* Do any necessary step collect actions. */
1107 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1109 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1111 /* See if we just hit a tracepoint and do its main collect
1113 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1117 gdb_assert (lwp
->suspended
== 0);
1118 gdb_assert (!stabilizing_threads
|| lwp
->collecting_fast_tracepoint
);
1120 if (tpoint_related_event
)
1123 fprintf (stderr
, "got a tracepoint event\n");
1130 /* Convenience wrapper. Returns true if LWP is presently collecting a
1134 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
1135 struct fast_tpoint_collect_status
*status
)
1137 CORE_ADDR thread_area
;
1139 if (the_low_target
.get_thread_area
== NULL
)
1142 /* Get the thread area address. This is used to recognize which
1143 thread is which when tracing with the in-process agent library.
1144 We don't read anything from the address, and treat it as opaque;
1145 it's the address itself that we assume is unique per-thread. */
1146 if ((*the_low_target
.get_thread_area
) (lwpid_of (lwp
), &thread_area
) == -1)
1149 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
1152 /* The reason we resume in the caller, is because we want to be able
1153 to pass lwp->status_pending as WSTAT, and we need to clear
1154 status_pending_p before resuming, otherwise, linux_resume_one_lwp
1155 refuses to resume. */
1158 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
1160 struct thread_info
*saved_inferior
;
1162 saved_inferior
= current_inferior
;
1163 current_inferior
= get_lwp_thread (lwp
);
1166 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
1167 && supports_fast_tracepoints ()
1168 && in_process_agent_loaded ())
1170 struct fast_tpoint_collect_status status
;
1175 Checking whether LWP %ld needs to move out of the jump pad.\n",
1178 r
= linux_fast_tracepoint_collecting (lwp
, &status
);
1181 || (WSTOPSIG (*wstat
) != SIGILL
1182 && WSTOPSIG (*wstat
) != SIGFPE
1183 && WSTOPSIG (*wstat
) != SIGSEGV
1184 && WSTOPSIG (*wstat
) != SIGBUS
))
1186 lwp
->collecting_fast_tracepoint
= r
;
1190 if (r
== 1 && lwp
->exit_jump_pad_bkpt
== NULL
)
1192 /* Haven't executed the original instruction yet.
1193 Set breakpoint there, and wait till it's hit,
1194 then single-step until exiting the jump pad. */
1195 lwp
->exit_jump_pad_bkpt
1196 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
1201 Checking whether LWP %ld needs to move out of the jump pad...it does\n",
1203 current_inferior
= saved_inferior
;
1210 /* If we get a synchronous signal while collecting, *and*
1211 while executing the (relocated) original instruction,
1212 reset the PC to point at the tpoint address, before
1213 reporting to GDB. Otherwise, it's an IPA lib bug: just
1214 report the signal to GDB, and pray for the best. */
1216 lwp
->collecting_fast_tracepoint
= 0;
1219 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
1220 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
1223 struct regcache
*regcache
;
1225 /* The si_addr on a few signals references the address
1226 of the faulting instruction. Adjust that as
1228 if ((WSTOPSIG (*wstat
) == SIGILL
1229 || WSTOPSIG (*wstat
) == SIGFPE
1230 || WSTOPSIG (*wstat
) == SIGBUS
1231 || WSTOPSIG (*wstat
) == SIGSEGV
)
1232 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &info
) == 0
1233 /* Final check just to make sure we don't clobber
1234 the siginfo of non-kernel-sent signals. */
1235 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
1237 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
1238 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &info
);
1241 regcache
= get_thread_regcache (get_lwp_thread (lwp
), 1);
1242 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
1243 lwp
->stop_pc
= status
.tpoint_addr
;
1245 /* Cancel any fast tracepoint lock this thread was
1247 force_unlock_trace_buffer ();
1250 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
1254 "Cancelling fast exit-jump-pad: removing bkpt. "
1255 "stopping all threads momentarily.\n");
1257 stop_all_lwps (1, lwp
);
1258 cancel_breakpoints ();
1260 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
1261 lwp
->exit_jump_pad_bkpt
= NULL
;
1263 unstop_all_lwps (1, lwp
);
1265 gdb_assert (lwp
->suspended
>= 0);
1272 Checking whether LWP %ld needs to move out of the jump pad...no\n",
1275 current_inferior
= saved_inferior
;
1279 /* Enqueue one signal in the "signals to report later when out of the
1283 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1285 struct pending_signals
*p_sig
;
1289 Deferring signal %d for LWP %ld.\n", WSTOPSIG (*wstat
), lwpid_of (lwp
));
1293 struct pending_signals
*sig
;
1295 for (sig
= lwp
->pending_signals_to_report
;
1299 " Already queued %d\n",
1302 fprintf (stderr
, " (no more currently queued signals)\n");
1305 /* Don't enqueue non-RT signals if they are already in the deferred
1306 queue. (SIGSTOP being the easiest signal to see ending up here
1308 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
1310 struct pending_signals
*sig
;
1312 for (sig
= lwp
->pending_signals_to_report
;
1316 if (sig
->signal
== WSTOPSIG (*wstat
))
1320 "Not requeuing already queued non-RT signal %d"
1329 p_sig
= xmalloc (sizeof (*p_sig
));
1330 p_sig
->prev
= lwp
->pending_signals_to_report
;
1331 p_sig
->signal
= WSTOPSIG (*wstat
);
1332 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
1333 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
1335 lwp
->pending_signals_to_report
= p_sig
;
1338 /* Dequeue one signal from the "signals to report later when out of
1339 the jump pad" list. */
1342 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
1344 if (lwp
->pending_signals_to_report
!= NULL
)
1346 struct pending_signals
**p_sig
;
1348 p_sig
= &lwp
->pending_signals_to_report
;
1349 while ((*p_sig
)->prev
!= NULL
)
1350 p_sig
= &(*p_sig
)->prev
;
1352 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
1353 if ((*p_sig
)->info
.si_signo
!= 0)
1354 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
1359 fprintf (stderr
, "Reporting deferred signal %d for LWP %ld.\n",
1360 WSTOPSIG (*wstat
), lwpid_of (lwp
));
1364 struct pending_signals
*sig
;
1366 for (sig
= lwp
->pending_signals_to_report
;
1370 " Still queued %d\n",
1373 fprintf (stderr
, " (no more queued signals)\n");
1382 /* Arrange for a breakpoint to be hit again later. We don't keep the
1383 SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
1384 will handle the current event, eventually we will resume this LWP,
1385 and this breakpoint will trap again. */
1388 cancel_breakpoint (struct lwp_info
*lwp
)
1390 struct thread_info
*saved_inferior
;
1392 /* There's nothing to do if we don't support breakpoints. */
1393 if (!supports_breakpoints ())
1396 /* breakpoint_at reads from current inferior. */
1397 saved_inferior
= current_inferior
;
1398 current_inferior
= get_lwp_thread (lwp
);
1400 if ((*the_low_target
.breakpoint_at
) (lwp
->stop_pc
))
1404 "CB: Push back breakpoint for %s\n",
1405 target_pid_to_str (ptid_of (lwp
)));
1407 /* Back up the PC if necessary. */
1408 if (the_low_target
.decr_pc_after_break
)
1410 struct regcache
*regcache
1411 = get_thread_regcache (current_inferior
, 1);
1412 (*the_low_target
.set_pc
) (regcache
, lwp
->stop_pc
);
1415 current_inferior
= saved_inferior
;
1422 "CB: No breakpoint found at %s for [%s]\n",
1423 paddress (lwp
->stop_pc
),
1424 target_pid_to_str (ptid_of (lwp
)));
1427 current_inferior
= saved_inferior
;
1431 /* When the event-loop is doing a step-over, this points at the thread
1433 ptid_t step_over_bkpt
;
1435 /* Wait for an event from child PID. If PID is -1, wait for any
1436 child. Store the stop status through the status pointer WSTAT.
1437 OPTIONS is passed to the waitpid call. Return 0 if no child stop
1438 event was found and OPTIONS contains WNOHANG. Return the PID of
1439 the stopped child otherwise. */
1442 linux_wait_for_event_1 (ptid_t ptid
, int *wstat
, int options
)
1444 struct lwp_info
*event_child
, *requested_child
;
1447 requested_child
= NULL
;
1449 /* Check for a lwp with a pending status. */
1451 if (ptid_equal (ptid
, minus_one_ptid
)
1452 || ptid_equal (pid_to_ptid (ptid_get_pid (ptid
)), ptid
))
1454 event_child
= (struct lwp_info
*)
1455 find_inferior (&all_lwps
, status_pending_p_callback
, &ptid
);
1456 if (debug_threads
&& event_child
)
1457 fprintf (stderr
, "Got a pending child %ld\n", lwpid_of (event_child
));
1461 requested_child
= find_lwp_pid (ptid
);
1463 if (!stopping_threads
1464 && requested_child
->status_pending_p
1465 && requested_child
->collecting_fast_tracepoint
)
1467 enqueue_one_deferred_signal (requested_child
,
1468 &requested_child
->status_pending
);
1469 requested_child
->status_pending_p
= 0;
1470 requested_child
->status_pending
= 0;
1471 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
1474 if (requested_child
->suspended
1475 && requested_child
->status_pending_p
)
1476 fatal ("requesting an event out of a suspended child?");
1478 if (requested_child
->status_pending_p
)
1479 event_child
= requested_child
;
1482 if (event_child
!= NULL
)
1485 fprintf (stderr
, "Got an event from pending child %ld (%04x)\n",
1486 lwpid_of (event_child
), event_child
->status_pending
);
1487 *wstat
= event_child
->status_pending
;
1488 event_child
->status_pending_p
= 0;
1489 event_child
->status_pending
= 0;
1490 current_inferior
= get_lwp_thread (event_child
);
1491 return lwpid_of (event_child
);
1494 /* We only enter this loop if no process has a pending wait status. Thus
1495 any action taken in response to a wait status inside this loop is
1496 responding as soon as we detect the status, not after any pending
1500 event_child
= linux_wait_for_lwp (ptid
, wstat
, options
);
1502 if ((options
& WNOHANG
) && event_child
== NULL
)
1505 fprintf (stderr
, "WNOHANG set, no event found\n");
1509 if (event_child
== NULL
)
1510 error ("event from unknown child");
1512 current_inferior
= get_lwp_thread (event_child
);
1514 /* Check for thread exit. */
1515 if (! WIFSTOPPED (*wstat
))
1518 fprintf (stderr
, "LWP %ld exiting\n", lwpid_of (event_child
));
1520 /* If the last thread is exiting, just return. */
1521 if (last_thread_of_process_p (current_inferior
))
1524 fprintf (stderr
, "LWP %ld is last lwp of process\n",
1525 lwpid_of (event_child
));
1526 return lwpid_of (event_child
);
1531 current_inferior
= (struct thread_info
*) all_threads
.head
;
1533 fprintf (stderr
, "Current inferior is now %ld\n",
1534 lwpid_of (get_thread_lwp (current_inferior
)));
1538 current_inferior
= NULL
;
1540 fprintf (stderr
, "Current inferior is now <NULL>\n");
1543 /* If we were waiting for this particular child to do something...
1544 well, it did something. */
1545 if (requested_child
!= NULL
)
1547 int lwpid
= lwpid_of (event_child
);
1549 /* Cancel the step-over operation --- the thread that
1550 started it is gone. */
1551 if (finish_step_over (event_child
))
1552 unstop_all_lwps (1, event_child
);
1553 delete_lwp (event_child
);
1557 delete_lwp (event_child
);
1559 /* Wait for a more interesting event. */
1563 if (event_child
->must_set_ptrace_flags
)
1565 linux_enable_event_reporting (lwpid_of (event_child
));
1566 event_child
->must_set_ptrace_flags
= 0;
1569 if (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) == SIGTRAP
1570 && *wstat
>> 16 != 0)
1572 handle_extended_wait (event_child
, *wstat
);
1576 if (WIFSTOPPED (*wstat
)
1577 && WSTOPSIG (*wstat
) == SIGSTOP
1578 && event_child
->stop_expected
)
1583 fprintf (stderr
, "Expected stop.\n");
1584 event_child
->stop_expected
= 0;
1586 should_stop
= (current_inferior
->last_resume_kind
== resume_stop
1587 || stopping_threads
);
1591 linux_resume_one_lwp (event_child
,
1592 event_child
->stepping
, 0, NULL
);
1597 return lwpid_of (event_child
);
1605 linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
)
1609 if (ptid_is_pid (ptid
))
1611 /* A request to wait for a specific tgid. This is not possible
1612 with waitpid, so instead, we wait for any child, and leave
1613 children we're not interested in right now with a pending
1614 status to report later. */
1615 wait_ptid
= minus_one_ptid
;
1624 event_pid
= linux_wait_for_event_1 (wait_ptid
, wstat
, options
);
1627 && ptid_is_pid (ptid
) && ptid_get_pid (ptid
) != event_pid
)
1629 struct lwp_info
*event_child
1630 = find_lwp_pid (pid_to_ptid (event_pid
));
1632 if (! WIFSTOPPED (*wstat
))
1633 mark_lwp_dead (event_child
, *wstat
);
1636 event_child
->status_pending_p
= 1;
1637 event_child
->status_pending
= *wstat
;
1646 /* Count the LWP's that have had events. */
1649 count_events_callback (struct inferior_list_entry
*entry
, void *data
)
1651 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1652 struct thread_info
*thread
= get_lwp_thread (lp
);
1655 gdb_assert (count
!= NULL
);
1657 /* Count only resumed LWPs that have a SIGTRAP event pending that
1658 should be reported to GDB. */
1659 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1660 && thread
->last_resume_kind
!= resume_stop
1661 && lp
->status_pending_p
1662 && WIFSTOPPED (lp
->status_pending
)
1663 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1664 && !breakpoint_inserted_here (lp
->stop_pc
))
1670 /* Select the LWP (if any) that is currently being single-stepped. */
1673 select_singlestep_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1675 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1676 struct thread_info
*thread
= get_lwp_thread (lp
);
1678 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1679 && thread
->last_resume_kind
== resume_step
1680 && lp
->status_pending_p
)
1686 /* Select the Nth LWP that has had a SIGTRAP event that should be
1690 select_event_lwp_callback (struct inferior_list_entry
*entry
, void *data
)
1692 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1693 struct thread_info
*thread
= get_lwp_thread (lp
);
1694 int *selector
= data
;
1696 gdb_assert (selector
!= NULL
);
1698 /* Select only resumed LWPs that have a SIGTRAP event pending. */
1699 if (thread
->last_resume_kind
!= resume_stop
1700 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1701 && lp
->status_pending_p
1702 && WIFSTOPPED (lp
->status_pending
)
1703 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1704 && !breakpoint_inserted_here (lp
->stop_pc
))
1705 if ((*selector
)-- == 0)
1712 cancel_breakpoints_callback (struct inferior_list_entry
*entry
, void *data
)
1714 struct lwp_info
*lp
= (struct lwp_info
*) entry
;
1715 struct thread_info
*thread
= get_lwp_thread (lp
);
1716 struct lwp_info
*event_lp
= data
;
1718 /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
1722 /* If a LWP other than the LWP that we're reporting an event for has
1723 hit a GDB breakpoint (as opposed to some random trap signal),
1724 then just arrange for it to hit it again later. We don't keep
1725 the SIGTRAP status and don't forward the SIGTRAP signal to the
1726 LWP. We will handle the current event, eventually we will resume
1727 all LWPs, and this one will get its breakpoint trap again.
1729 If we do not do this, then we run the risk that the user will
1730 delete or disable the breakpoint, but the LWP will have already
1733 if (thread
->last_resume_kind
!= resume_stop
1734 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
1735 && lp
->status_pending_p
1736 && WIFSTOPPED (lp
->status_pending
)
1737 && WSTOPSIG (lp
->status_pending
) == SIGTRAP
1739 && !lp
->stopped_by_watchpoint
1740 && cancel_breakpoint (lp
))
1741 /* Throw away the SIGTRAP. */
1742 lp
->status_pending_p
= 0;
1748 linux_cancel_breakpoints (void)
1750 find_inferior (&all_lwps
, cancel_breakpoints_callback
, NULL
);
1753 /* Select one LWP out of those that have events pending. */
1756 select_event_lwp (struct lwp_info
**orig_lp
)
1759 int random_selector
;
1760 struct lwp_info
*event_lp
;
1762 /* Give preference to any LWP that is being single-stepped. */
1764 = (struct lwp_info
*) find_inferior (&all_lwps
,
1765 select_singlestep_lwp_callback
, NULL
);
1766 if (event_lp
!= NULL
)
1770 "SEL: Select single-step %s\n",
1771 target_pid_to_str (ptid_of (event_lp
)));
1775 /* No single-stepping LWP. Select one at random, out of those
1776 which have had SIGTRAP events. */
1778 /* First see how many SIGTRAP events we have. */
1779 find_inferior (&all_lwps
, count_events_callback
, &num_events
);
1781 /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
1782 random_selector
= (int)
1783 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
1785 if (debug_threads
&& num_events
> 1)
1787 "SEL: Found %d SIGTRAP events, selecting #%d\n",
1788 num_events
, random_selector
);
1790 event_lp
= (struct lwp_info
*) find_inferior (&all_lwps
,
1791 select_event_lwp_callback
,
1795 if (event_lp
!= NULL
)
1797 /* Switch the event LWP. */
1798 *orig_lp
= event_lp
;
1802 /* Decrement the suspend count of an LWP. */
1805 unsuspend_one_lwp (struct inferior_list_entry
*entry
, void *except
)
1807 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
1809 /* Ignore EXCEPT. */
1815 gdb_assert (lwp
->suspended
>= 0);
1819 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
1823 unsuspend_all_lwps (struct lwp_info
*except
)
1825 find_inferior (&all_lwps
, unsuspend_one_lwp
, except
);
1828 static void move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
);
1829 static int stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
,
1831 static int lwp_running (struct inferior_list_entry
*entry
, void *data
);
1832 static ptid_t
linux_wait_1 (ptid_t ptid
,
1833 struct target_waitstatus
*ourstatus
,
1834 int target_options
);
1836 /* Stabilize threads (move out of jump pads).
1838 If a thread is midway collecting a fast tracepoint, we need to
1839 finish the collection and move it out of the jump pad before
1840 reporting the signal.
1842 This avoids recursion while collecting (when a signal arrives
1843 midway, and the signal handler itself collects), which would trash
1844 the trace buffer. In case the user set a breakpoint in a signal
1845 handler, this avoids the backtrace showing the jump pad, etc..
1846 Most importantly, there are certain things we can't do safely if
1847 threads are stopped in a jump pad (or in its callee's). For
1850 - starting a new trace run. A thread still collecting the
1851 previous run, could trash the trace buffer when resumed. The trace
1852 buffer control structures would have been reset but the thread had
1853 no way to tell. The thread could even midway memcpy'ing to the
1854 buffer, which would mean that when resumed, it would clobber the
1855 trace buffer that had been set for a new run.
1857 - we can't rewrite/reuse the jump pads for new tracepoints
1858 safely. Say you do tstart while a thread is stopped midway while
1859 collecting. When the thread is later resumed, it finishes the
1860 collection, and returns to the jump pad, to execute the original
1861 instruction that was under the tracepoint jump at the time the
1862 older run had been started. If the jump pad had been rewritten
1863 since for something else in the new run, the thread would now
1864 execute the wrong / random instructions. */
1867 linux_stabilize_threads (void)
1869 struct thread_info
*save_inferior
;
1870 struct lwp_info
*lwp_stuck
;
1873 = (struct lwp_info
*) find_inferior (&all_lwps
,
1874 stuck_in_jump_pad_callback
, NULL
);
1875 if (lwp_stuck
!= NULL
)
1878 fprintf (stderr
, "can't stabilize, LWP %ld is stuck in jump pad\n",
1879 lwpid_of (lwp_stuck
));
1883 save_inferior
= current_inferior
;
1885 stabilizing_threads
= 1;
1888 for_each_inferior (&all_lwps
, move_out_of_jump_pad_callback
);
1890 /* Loop until all are stopped out of the jump pads. */
1891 while (find_inferior (&all_lwps
, lwp_running
, NULL
) != NULL
)
1893 struct target_waitstatus ourstatus
;
1894 struct lwp_info
*lwp
;
1897 /* Note that we go through the full wait even loop. While
1898 moving threads out of jump pad, we need to be able to step
1899 over internal breakpoints and such. */
1900 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
1902 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
1904 lwp
= get_thread_lwp (current_inferior
);
1909 if (ourstatus
.value
.sig
!= TARGET_SIGNAL_0
1910 || current_inferior
->last_resume_kind
== resume_stop
)
1912 wstat
= W_STOPCODE (target_signal_to_host (ourstatus
.value
.sig
));
1913 enqueue_one_deferred_signal (lwp
, &wstat
);
1918 find_inferior (&all_lwps
, unsuspend_one_lwp
, NULL
);
1920 stabilizing_threads
= 0;
1922 current_inferior
= save_inferior
;
1927 = (struct lwp_info
*) find_inferior (&all_lwps
,
1928 stuck_in_jump_pad_callback
, NULL
);
1929 if (lwp_stuck
!= NULL
)
1930 fprintf (stderr
, "couldn't stabilize, LWP %ld got stuck in jump pad\n",
1931 lwpid_of (lwp_stuck
));
1935 /* Wait for process, returns status. */
1938 linux_wait_1 (ptid_t ptid
,
1939 struct target_waitstatus
*ourstatus
, int target_options
)
1942 struct lwp_info
*event_child
;
1945 int step_over_finished
;
1946 int bp_explains_trap
;
1947 int maybe_internal_trap
;
1951 /* Translate generic target options into linux options. */
1953 if (target_options
& TARGET_WNOHANG
)
1957 bp_explains_trap
= 0;
1959 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1961 /* If we were only supposed to resume one thread, only wait for
1962 that thread - if it's still alive. If it died, however - which
1963 can happen if we're coming from the thread death case below -
1964 then we need to make sure we restart the other threads. We could
1965 pick a thread at random or restart all; restarting all is less
1968 && !ptid_equal (cont_thread
, null_ptid
)
1969 && !ptid_equal (cont_thread
, minus_one_ptid
))
1971 struct thread_info
*thread
;
1973 thread
= (struct thread_info
*) find_inferior_id (&all_threads
,
1976 /* No stepping, no signal - unless one is pending already, of course. */
1979 struct thread_resume resume_info
;
1980 resume_info
.thread
= minus_one_ptid
;
1981 resume_info
.kind
= resume_continue
;
1982 resume_info
.sig
= 0;
1983 linux_resume (&resume_info
, 1);
1989 if (ptid_equal (step_over_bkpt
, null_ptid
))
1990 pid
= linux_wait_for_event (ptid
, &w
, options
);
1994 fprintf (stderr
, "step_over_bkpt set [%s], doing a blocking wait\n",
1995 target_pid_to_str (step_over_bkpt
));
1996 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
1999 if (pid
== 0) /* only if TARGET_WNOHANG */
2002 event_child
= get_thread_lwp (current_inferior
);
2004 /* If we are waiting for a particular child, and it exited,
2005 linux_wait_for_event will return its exit status. Similarly if
2006 the last child exited. If this is not the last child, however,
2007 do not report it as exited until there is a 'thread exited' response
2008 available in the remote protocol. Instead, just wait for another event.
2009 This should be safe, because if the thread crashed we will already
2010 have reported the termination signal to GDB; that should stop any
2011 in-progress stepping operations, etc.
2013 Report the exit status of the last thread to exit. This matches
2014 LinuxThreads' behavior. */
2016 if (last_thread_of_process_p (current_inferior
))
2018 if (WIFEXITED (w
) || WIFSIGNALED (w
))
2022 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
2023 ourstatus
->value
.integer
= WEXITSTATUS (w
);
2027 "\nChild exited with retcode = %x \n",
2032 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
2033 ourstatus
->value
.sig
= target_signal_from_host (WTERMSIG (w
));
2037 "\nChild terminated with signal = %x \n",
2042 return ptid_of (event_child
);
2047 if (!WIFSTOPPED (w
))
2051 /* If this event was not handled before, and is not a SIGTRAP, we
2052 report it. SIGILL and SIGSEGV are also treated as traps in case
2053 a breakpoint is inserted at the current PC. If this target does
2054 not support internal breakpoints at all, we also report the
2055 SIGTRAP without further processing; it's of no concern to us. */
2057 = (supports_breakpoints ()
2058 && (WSTOPSIG (w
) == SIGTRAP
2059 || ((WSTOPSIG (w
) == SIGILL
2060 || WSTOPSIG (w
) == SIGSEGV
)
2061 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
2063 if (maybe_internal_trap
)
2065 /* Handle anything that requires bookkeeping before deciding to
2066 report the event or continue waiting. */
2068 /* First check if we can explain the SIGTRAP with an internal
2069 breakpoint, or if we should possibly report the event to GDB.
2070 Do this before anything that may remove or insert a
2072 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
2074 /* We have a SIGTRAP, possibly a step-over dance has just
2075 finished. If so, tweak the state machine accordingly,
2076 reinsert breakpoints and delete any reinsert (software
2077 single-step) breakpoints. */
2078 step_over_finished
= finish_step_over (event_child
);
2080 /* Now invoke the callbacks of any internal breakpoints there. */
2081 check_breakpoints (event_child
->stop_pc
);
2083 /* Handle tracepoint data collecting. This may overflow the
2084 trace buffer, and cause a tracing stop, removing
2086 trace_event
= handle_tracepoints (event_child
);
2088 if (bp_explains_trap
)
2090 /* If we stepped or ran into an internal breakpoint, we've
2091 already handled it. So next time we resume (from this
2092 PC), we should step over it. */
2094 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2096 if (breakpoint_here (event_child
->stop_pc
))
2097 event_child
->need_step_over
= 1;
2102 /* We have some other signal, possibly a step-over dance was in
2103 progress, and it should be cancelled too. */
2104 step_over_finished
= finish_step_over (event_child
);
2107 /* We have all the data we need. Either report the event to GDB, or
2108 resume threads and keep waiting for more. */
2110 /* If we're collecting a fast tracepoint, finish the collection and
2111 move out of the jump pad before delivering a signal. See
2112 linux_stabilize_threads. */
2115 && WSTOPSIG (w
) != SIGTRAP
2116 && supports_fast_tracepoints ()
2117 && in_process_agent_loaded ())
2121 "Got signal %d for LWP %ld. Check if we need "
2122 "to defer or adjust it.\n",
2123 WSTOPSIG (w
), lwpid_of (event_child
));
2125 /* Allow debugging the jump pad itself. */
2126 if (current_inferior
->last_resume_kind
!= resume_step
2127 && maybe_move_out_of_jump_pad (event_child
, &w
))
2129 enqueue_one_deferred_signal (event_child
, &w
);
2133 "Signal %d for LWP %ld deferred (in jump pad)\n",
2134 WSTOPSIG (w
), lwpid_of (event_child
));
2136 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
2141 if (event_child
->collecting_fast_tracepoint
)
2145 LWP %ld was trying to move out of the jump pad (%d). \
2146 Check if we're already there.\n",
2147 lwpid_of (event_child
),
2148 event_child
->collecting_fast_tracepoint
);
2152 event_child
->collecting_fast_tracepoint
2153 = linux_fast_tracepoint_collecting (event_child
, NULL
);
2155 if (event_child
->collecting_fast_tracepoint
!= 1)
2157 /* No longer need this breakpoint. */
2158 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
2162 "No longer need exit-jump-pad bkpt; removing it."
2163 "stopping all threads momentarily.\n");
2165 /* Other running threads could hit this breakpoint.
2166 We don't handle moribund locations like GDB does,
2167 instead we always pause all threads when removing
2168 breakpoints, so that any step-over or
2169 decr_pc_after_break adjustment is always taken
2170 care of while the breakpoint is still
2172 stop_all_lwps (1, event_child
);
2173 cancel_breakpoints ();
2175 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
2176 event_child
->exit_jump_pad_bkpt
= NULL
;
2178 unstop_all_lwps (1, event_child
);
2180 gdb_assert (event_child
->suspended
>= 0);
2184 if (event_child
->collecting_fast_tracepoint
== 0)
2188 "fast tracepoint finished "
2189 "collecting successfully.\n");
2191 /* We may have a deferred signal to report. */
2192 if (dequeue_one_deferred_signal (event_child
, &w
))
2195 fprintf (stderr
, "dequeued one signal.\n");
2200 fprintf (stderr
, "no deferred signals.\n");
2202 if (stabilizing_threads
)
2204 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2205 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2206 return ptid_of (event_child
);
2212 /* Check whether GDB would be interested in this event. */
2214 /* If GDB is not interested in this signal, don't stop other
2215 threads, and don't report it to GDB. Just resume the inferior
2216 right away. We do this for threading-related signals as well as
2217 any that GDB specifically requested we ignore. But never ignore
2218 SIGSTOP if we sent it ourselves, and do not ignore signals when
2219 stepping - they may require special handling to skip the signal
2221 /* FIXME drow/2002-06-09: Get signal numbers from the inferior's
2224 && current_inferior
->last_resume_kind
!= resume_step
2226 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
2227 (current_process ()->private->thread_db
!= NULL
2228 && (WSTOPSIG (w
) == __SIGRTMIN
2229 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
2232 (pass_signals
[target_signal_from_host (WSTOPSIG (w
))]
2233 && !(WSTOPSIG (w
) == SIGSTOP
2234 && current_inferior
->last_resume_kind
== resume_stop
))))
2236 siginfo_t info
, *info_p
;
2239 fprintf (stderr
, "Ignored signal %d for LWP %ld.\n",
2240 WSTOPSIG (w
), lwpid_of (event_child
));
2242 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (event_child
), 0, &info
) == 0)
2246 linux_resume_one_lwp (event_child
, event_child
->stepping
,
2247 WSTOPSIG (w
), info_p
);
2251 /* If GDB wanted this thread to single step, we always want to
2252 report the SIGTRAP, and let GDB handle it. Watchpoints should
2253 always be reported. So should signals we can't explain. A
2254 SIGTRAP we can't explain could be a GDB breakpoint --- we may or
2255 not support Z0 breakpoints. If we do, we're be able to handle
2256 GDB breakpoints on top of internal breakpoints, by handling the
2257 internal breakpoint and still reporting the event to GDB. If we
2258 don't, we're out of luck, GDB won't see the breakpoint hit. */
2259 report_to_gdb
= (!maybe_internal_trap
2260 || current_inferior
->last_resume_kind
== resume_step
2261 || event_child
->stopped_by_watchpoint
2262 || (!step_over_finished
2263 && !bp_explains_trap
&& !trace_event
)
2264 || gdb_breakpoint_here (event_child
->stop_pc
));
2266 /* We found no reason GDB would want us to stop. We either hit one
2267 of our own breakpoints, or finished an internal step GDB
2268 shouldn't know about. */
2273 if (bp_explains_trap
)
2274 fprintf (stderr
, "Hit a gdbserver breakpoint.\n");
2275 if (step_over_finished
)
2276 fprintf (stderr
, "Step-over finished.\n");
2278 fprintf (stderr
, "Tracepoint event.\n");
2281 /* We're not reporting this breakpoint to GDB, so apply the
2282 decr_pc_after_break adjustment to the inferior's regcache
2285 if (the_low_target
.set_pc
!= NULL
)
2287 struct regcache
*regcache
2288 = get_thread_regcache (get_lwp_thread (event_child
), 1);
2289 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
2292 /* We may have finished stepping over a breakpoint. If so,
2293 we've stopped and suspended all LWPs momentarily except the
2294 stepping one. This is where we resume them all again. We're
2295 going to keep waiting, so use proceed, which handles stepping
2296 over the next breakpoint. */
2298 fprintf (stderr
, "proceeding all threads.\n");
2300 if (step_over_finished
)
2301 unsuspend_all_lwps (event_child
);
2303 proceed_all_lwps ();
2309 if (current_inferior
->last_resume_kind
== resume_step
)
2310 fprintf (stderr
, "GDB wanted to single-step, reporting event.\n");
2311 if (event_child
->stopped_by_watchpoint
)
2312 fprintf (stderr
, "Stopped by watchpoint.\n");
2313 if (gdb_breakpoint_here (event_child
->stop_pc
))
2314 fprintf (stderr
, "Stopped by GDB breakpoint.\n");
2316 fprintf (stderr
, "Hit a non-gdbserver trap event.\n");
2319 /* Alright, we're going to report a stop. */
2321 if (!non_stop
&& !stabilizing_threads
)
2323 /* In all-stop, stop all threads. */
2324 stop_all_lwps (0, NULL
);
2326 /* If we're not waiting for a specific LWP, choose an event LWP
2327 from among those that have had events. Giving equal priority
2328 to all LWPs that have had events helps prevent
2330 if (ptid_equal (ptid
, minus_one_ptid
))
2332 event_child
->status_pending_p
= 1;
2333 event_child
->status_pending
= w
;
2335 select_event_lwp (&event_child
);
2337 event_child
->status_pending_p
= 0;
2338 w
= event_child
->status_pending
;
2341 /* Now that we've selected our final event LWP, cancel any
2342 breakpoints in other LWPs that have hit a GDB breakpoint.
2343 See the comment in cancel_breakpoints_callback to find out
2345 find_inferior (&all_lwps
, cancel_breakpoints_callback
, event_child
);
2347 /* Stabilize threads (move out of jump pads). */
2348 stabilize_threads ();
2352 /* If we just finished a step-over, then all threads had been
2353 momentarily paused. In all-stop, that's fine, we want
2354 threads stopped by now anyway. In non-stop, we need to
2355 re-resume threads that GDB wanted to be running. */
2356 if (step_over_finished
)
2357 unstop_all_lwps (1, event_child
);
2360 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
2362 if (current_inferior
->last_resume_kind
== resume_stop
2363 && WSTOPSIG (w
) == SIGSTOP
)
2365 /* A thread that has been requested to stop by GDB with vCont;t,
2366 and it stopped cleanly, so report as SIG0. The use of
2367 SIGSTOP is an implementation detail. */
2368 ourstatus
->value
.sig
= TARGET_SIGNAL_0
;
2370 else if (current_inferior
->last_resume_kind
== resume_stop
2371 && WSTOPSIG (w
) != SIGSTOP
)
2373 /* A thread that has been requested to stop by GDB with vCont;t,
2374 but, it stopped for other reasons. */
2375 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2379 ourstatus
->value
.sig
= target_signal_from_host (WSTOPSIG (w
));
2382 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
2385 fprintf (stderr
, "linux_wait ret = %s, %d, %d\n",
2386 target_pid_to_str (ptid_of (event_child
)),
2388 ourstatus
->value
.sig
);
2390 return ptid_of (event_child
);
2393 /* Get rid of any pending event in the pipe. */
2395 async_file_flush (void)
2401 ret
= read (linux_event_pipe
[0], &buf
, 1);
2402 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
2405 /* Put something in the pipe, so the event loop wakes up. */
2407 async_file_mark (void)
2411 async_file_flush ();
2414 ret
= write (linux_event_pipe
[1], "+", 1);
2415 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
2417 /* Ignore EAGAIN. If the pipe is full, the event loop will already
2418 be awakened anyway. */
2422 linux_wait (ptid_t ptid
,
2423 struct target_waitstatus
*ourstatus
, int target_options
)
2428 fprintf (stderr
, "linux_wait: [%s]\n", target_pid_to_str (ptid
));
2430 /* Flush the async file first. */
2431 if (target_is_async_p ())
2432 async_file_flush ();
2434 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
2436 /* If at least one stop was reported, there may be more. A single
2437 SIGCHLD can signal more than one child stop. */
2438 if (target_is_async_p ()
2439 && (target_options
& TARGET_WNOHANG
) != 0
2440 && !ptid_equal (event_ptid
, null_ptid
))
2446 /* Send a signal to an LWP. */
2449 kill_lwp (unsigned long lwpid
, int signo
)
2451 /* Use tkill, if possible, in case we are using nptl threads. If tkill
2452 fails, then we are not using nptl threads and we should be using kill. */
2456 static int tkill_failed
;
2463 ret
= syscall (__NR_tkill
, lwpid
, signo
);
2464 if (errno
!= ENOSYS
)
2471 return kill (lwpid
, signo
);
2475 linux_stop_lwp (struct lwp_info
*lwp
)
2481 send_sigstop (struct lwp_info
*lwp
)
2485 pid
= lwpid_of (lwp
);
2487 /* If we already have a pending stop signal for this process, don't
2489 if (lwp
->stop_expected
)
2492 fprintf (stderr
, "Have pending sigstop for lwp %d\n", pid
);
2498 fprintf (stderr
, "Sending sigstop to lwp %d\n", pid
);
2500 lwp
->stop_expected
= 1;
2501 kill_lwp (pid
, SIGSTOP
);
2505 send_sigstop_callback (struct inferior_list_entry
*entry
, void *except
)
2507 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2509 /* Ignore EXCEPT. */
2520 /* Increment the suspend count of an LWP, and stop it, if not stopped
2523 suspend_and_send_sigstop_callback (struct inferior_list_entry
*entry
,
2526 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2528 /* Ignore EXCEPT. */
2534 return send_sigstop_callback (entry
, except
);
2538 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
2540 /* It's dead, really. */
2543 /* Store the exit status for later. */
2544 lwp
->status_pending_p
= 1;
2545 lwp
->status_pending
= wstat
;
2547 /* Prevent trying to stop it. */
2550 /* No further stops are expected from a dead lwp. */
2551 lwp
->stop_expected
= 0;
2555 wait_for_sigstop (struct inferior_list_entry
*entry
)
2557 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2558 struct thread_info
*saved_inferior
;
2567 fprintf (stderr
, "wait_for_sigstop: LWP %ld already stopped\n",
2572 saved_inferior
= current_inferior
;
2573 if (saved_inferior
!= NULL
)
2574 saved_tid
= ((struct inferior_list_entry
*) saved_inferior
)->id
;
2576 saved_tid
= null_ptid
; /* avoid bogus unused warning */
2578 ptid
= lwp
->head
.id
;
2581 fprintf (stderr
, "wait_for_sigstop: pulling one event\n");
2583 pid
= linux_wait_for_event (ptid
, &wstat
, __WALL
);
2585 /* If we stopped with a non-SIGSTOP signal, save it for later
2586 and record the pending SIGSTOP. If the process exited, just
2588 if (WIFSTOPPED (wstat
))
2591 fprintf (stderr
, "LWP %ld stopped with signal %d\n",
2592 lwpid_of (lwp
), WSTOPSIG (wstat
));
2594 if (WSTOPSIG (wstat
) != SIGSTOP
)
2597 fprintf (stderr
, "LWP %ld stopped with non-sigstop status %06x\n",
2598 lwpid_of (lwp
), wstat
);
2600 lwp
->status_pending_p
= 1;
2601 lwp
->status_pending
= wstat
;
2607 fprintf (stderr
, "Process %d exited while stopping LWPs\n", pid
);
2609 lwp
= find_lwp_pid (pid_to_ptid (pid
));
2612 /* Leave this status pending for the next time we're able to
2613 report it. In the mean time, we'll report this lwp as
2614 dead to GDB, so GDB doesn't try to read registers and
2615 memory from it. This can only happen if this was the
2616 last thread of the process; otherwise, PID is removed
2617 from the thread tables before linux_wait_for_event
2619 mark_lwp_dead (lwp
, wstat
);
2623 if (saved_inferior
== NULL
|| linux_thread_alive (saved_tid
))
2624 current_inferior
= saved_inferior
;
2628 fprintf (stderr
, "Previously current thread died.\n");
2632 /* We can't change the current inferior behind GDB's back,
2633 otherwise, a subsequent command may apply to the wrong
2635 current_inferior
= NULL
;
2639 /* Set a valid thread as current. */
2640 set_desired_inferior (0);
2645 /* Returns true if LWP ENTRY is stopped in a jump pad, and we can't
2646 move it out, because we need to report the stop event to GDB. For
2647 example, if the user puts a breakpoint in the jump pad, it's
2648 because she wants to debug it. */
2651 stuck_in_jump_pad_callback (struct inferior_list_entry
*entry
, void *data
)
2653 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2654 struct thread_info
*thread
= get_lwp_thread (lwp
);
2656 gdb_assert (lwp
->suspended
== 0);
2657 gdb_assert (lwp
->stopped
);
2659 /* Allow debugging the jump pad, gdb_collect, etc.. */
2660 return (supports_fast_tracepoints ()
2661 && in_process_agent_loaded ()
2662 && (gdb_breakpoint_here (lwp
->stop_pc
)
2663 || lwp
->stopped_by_watchpoint
2664 || thread
->last_resume_kind
== resume_step
)
2665 && linux_fast_tracepoint_collecting (lwp
, NULL
));
2669 move_out_of_jump_pad_callback (struct inferior_list_entry
*entry
)
2671 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2672 struct thread_info
*thread
= get_lwp_thread (lwp
);
2675 gdb_assert (lwp
->suspended
== 0);
2676 gdb_assert (lwp
->stopped
);
2678 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
2680 /* Allow debugging the jump pad, gdb_collect, etc. */
2681 if (!gdb_breakpoint_here (lwp
->stop_pc
)
2682 && !lwp
->stopped_by_watchpoint
2683 && thread
->last_resume_kind
!= resume_step
2684 && maybe_move_out_of_jump_pad (lwp
, wstat
))
2688 "LWP %ld needs stabilizing (in jump pad)\n",
2693 lwp
->status_pending_p
= 0;
2694 enqueue_one_deferred_signal (lwp
, wstat
);
2698 "Signal %d for LWP %ld deferred "
2700 WSTOPSIG (*wstat
), lwpid_of (lwp
));
2703 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
2710 lwp_running (struct inferior_list_entry
*entry
, void *data
)
2712 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
2721 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
2722 If SUSPEND, then also increase the suspend count of every LWP,
2726 stop_all_lwps (int suspend
, struct lwp_info
*except
)
2728 stopping_threads
= 1;
2731 find_inferior (&all_lwps
, suspend_and_send_sigstop_callback
, except
);
2733 find_inferior (&all_lwps
, send_sigstop_callback
, except
);
2734 for_each_inferior (&all_lwps
, wait_for_sigstop
);
2735 stopping_threads
= 0;
2738 /* Resume execution of the inferior process.
2739 If STEP is nonzero, single-step it.
2740 If SIGNAL is nonzero, give it that signal. */
2743 linux_resume_one_lwp (struct lwp_info
*lwp
,
2744 int step
, int signal
, siginfo_t
*info
)
2746 struct thread_info
*saved_inferior
;
2747 int fast_tp_collecting
;
2749 if (lwp
->stopped
== 0)
2752 fast_tp_collecting
= lwp
->collecting_fast_tracepoint
;
2754 gdb_assert (!stabilizing_threads
|| fast_tp_collecting
);
2756 /* Cancel actions that rely on GDB not changing the PC (e.g., the
2757 user used the "jump" command, or "set $pc = foo"). */
2758 if (lwp
->stop_pc
!= get_pc (lwp
))
2760 /* Collecting 'while-stepping' actions doesn't make sense
2762 release_while_stepping_state_list (get_lwp_thread (lwp
));
2765 /* If we have pending signals or status, and a new signal, enqueue the
2766 signal. Also enqueue the signal if we are waiting to reinsert a
2767 breakpoint; it will be picked up again below. */
2769 && (lwp
->status_pending_p
2770 || lwp
->pending_signals
!= NULL
2771 || lwp
->bp_reinsert
!= 0
2772 || fast_tp_collecting
))
2774 struct pending_signals
*p_sig
;
2775 p_sig
= xmalloc (sizeof (*p_sig
));
2776 p_sig
->prev
= lwp
->pending_signals
;
2777 p_sig
->signal
= signal
;
2779 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
2781 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
2782 lwp
->pending_signals
= p_sig
;
2785 if (lwp
->status_pending_p
)
2788 fprintf (stderr
, "Not resuming lwp %ld (%s, signal %d, stop %s);"
2789 " has pending status\n",
2790 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2791 lwp
->stop_expected
? "expected" : "not expected");
2795 saved_inferior
= current_inferior
;
2796 current_inferior
= get_lwp_thread (lwp
);
2799 fprintf (stderr
, "Resuming lwp %ld (%s, signal %d, stop %s)\n",
2800 lwpid_of (lwp
), step
? "step" : "continue", signal
,
2801 lwp
->stop_expected
? "expected" : "not expected");
2803 /* This bit needs some thinking about. If we get a signal that
2804 we must report while a single-step reinsert is still pending,
2805 we often end up resuming the thread. It might be better to
2806 (ew) allow a stack of pending events; then we could be sure that
2807 the reinsert happened right away and not lose any signals.
2809 Making this stack would also shrink the window in which breakpoints are
2810 uninserted (see comment in linux_wait_for_lwp) but not enough for
2811 complete correctness, so it won't solve that problem. It may be
2812 worthwhile just to solve this one, however. */
2813 if (lwp
->bp_reinsert
!= 0)
2816 fprintf (stderr
, " pending reinsert at 0x%s\n",
2817 paddress (lwp
->bp_reinsert
));
2819 if (lwp
->bp_reinsert
!= 0 && can_hardware_single_step ())
2821 if (fast_tp_collecting
== 0)
2824 fprintf (stderr
, "BAD - reinserting but not stepping.\n");
2826 fprintf (stderr
, "BAD - reinserting and suspended(%d).\n",
2833 /* Postpone any pending signal. It was enqueued above. */
2837 if (fast_tp_collecting
== 1)
2841 lwp %ld wants to get out of fast tracepoint jump pad (exit-jump-pad-bkpt)\n",
2844 /* Postpone any pending signal. It was enqueued above. */
2847 else if (fast_tp_collecting
== 2)
2851 lwp %ld wants to get out of fast tracepoint jump pad single-stepping\n",
2854 if (can_hardware_single_step ())
2857 fatal ("moving out of jump pad single-stepping"
2858 " not implemented on this target");
2860 /* Postpone any pending signal. It was enqueued above. */
2864 /* If we have while-stepping actions in this thread set it stepping.
2865 If we have a signal to deliver, it may or may not be set to
2866 SIG_IGN, we don't know. Assume so, and allow collecting
2867 while-stepping into a signal handler. A possible smart thing to
2868 do would be to set an internal breakpoint at the signal return
2869 address, continue, and carry on catching this while-stepping
2870 action only when that breakpoint is hit. A future
2872 if (get_lwp_thread (lwp
)->while_stepping
!= NULL
2873 && can_hardware_single_step ())
2877 "lwp %ld has a while-stepping action -> forcing step.\n",
2882 if (debug_threads
&& the_low_target
.get_pc
!= NULL
)
2884 struct regcache
*regcache
= get_thread_regcache (current_inferior
, 1);
2885 CORE_ADDR pc
= (*the_low_target
.get_pc
) (regcache
);
2886 fprintf (stderr
, " resuming from pc 0x%lx\n", (long) pc
);
2889 /* If we have pending signals, consume one unless we are trying to
2890 reinsert a breakpoint or we're trying to finish a fast tracepoint
2892 if (lwp
->pending_signals
!= NULL
2893 && lwp
->bp_reinsert
== 0
2894 && fast_tp_collecting
== 0)
2896 struct pending_signals
**p_sig
;
2898 p_sig
= &lwp
->pending_signals
;
2899 while ((*p_sig
)->prev
!= NULL
)
2900 p_sig
= &(*p_sig
)->prev
;
2902 signal
= (*p_sig
)->signal
;
2903 if ((*p_sig
)->info
.si_signo
!= 0)
2904 ptrace (PTRACE_SETSIGINFO
, lwpid_of (lwp
), 0, &(*p_sig
)->info
);
2910 if (the_low_target
.prepare_to_resume
!= NULL
)
2911 the_low_target
.prepare_to_resume (lwp
);
2913 regcache_invalidate_one ((struct inferior_list_entry
*)
2914 get_lwp_thread (lwp
));
2917 lwp
->stopped_by_watchpoint
= 0;
2918 lwp
->stepping
= step
;
2919 ptrace (step
? PTRACE_SINGLESTEP
: PTRACE_CONT
, lwpid_of (lwp
), 0,
2920 /* Coerce to a uintptr_t first to avoid potential gcc warning
2921 of coercing an 8 byte integer to a 4 byte pointer. */
2922 (PTRACE_ARG4_TYPE
) (uintptr_t) signal
);
2924 current_inferior
= saved_inferior
;
2927 /* ESRCH from ptrace either means that the thread was already
2928 running (an error) or that it is gone (a race condition). If
2929 it's gone, we will get a notification the next time we wait,
2930 so we can ignore the error. We could differentiate these
2931 two, but it's tricky without waiting; the thread still exists
2932 as a zombie, so sending it signal 0 would succeed. So just
2937 perror_with_name ("ptrace");
2941 struct thread_resume_array
2943 struct thread_resume
*resume
;
2947 /* This function is called once per thread. We look up the thread
2948 in RESUME_PTR, and mark the thread with a pointer to the appropriate
2951 This algorithm is O(threads * resume elements), but resume elements
2952 is small (and will remain small at least until GDB supports thread
2955 linux_set_resume_request (struct inferior_list_entry
*entry
, void *arg
)
2957 struct lwp_info
*lwp
;
2958 struct thread_info
*thread
;
2960 struct thread_resume_array
*r
;
2962 thread
= (struct thread_info
*) entry
;
2963 lwp
= get_thread_lwp (thread
);
2966 for (ndx
= 0; ndx
< r
->n
; ndx
++)
2968 ptid_t ptid
= r
->resume
[ndx
].thread
;
2969 if (ptid_equal (ptid
, minus_one_ptid
)
2970 || ptid_equal (ptid
, entry
->id
)
2971 || (ptid_is_pid (ptid
)
2972 && (ptid_get_pid (ptid
) == pid_of (lwp
)))
2973 || (ptid_get_lwp (ptid
) == -1
2974 && (ptid_get_pid (ptid
) == pid_of (lwp
))))
2976 if (r
->resume
[ndx
].kind
== resume_stop
2977 && thread
->last_resume_kind
== resume_stop
)
2980 fprintf (stderr
, "already %s LWP %ld at GDB's request\n",
2981 thread
->last_status
.kind
== TARGET_WAITKIND_STOPPED
2989 lwp
->resume
= &r
->resume
[ndx
];
2990 thread
->last_resume_kind
= lwp
->resume
->kind
;
2992 /* If we had a deferred signal to report, dequeue one now.
2993 This can happen if LWP gets more than one signal while
2994 trying to get out of a jump pad. */
2996 && !lwp
->status_pending_p
2997 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
2999 lwp
->status_pending_p
= 1;
3003 "Dequeueing deferred signal %d for LWP %ld, "
3004 "leaving status pending.\n",
3005 WSTOPSIG (lwp
->status_pending
), lwpid_of (lwp
));
3012 /* No resume action for this thread. */
3019 /* Set *FLAG_P if this lwp has an interesting status pending. */
3021 resume_status_pending_p (struct inferior_list_entry
*entry
, void *flag_p
)
3023 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3025 /* LWPs which will not be resumed are not interesting, because
3026 we might not wait for them next time through linux_wait. */
3027 if (lwp
->resume
== NULL
)
3030 if (lwp
->status_pending_p
)
3031 * (int *) flag_p
= 1;
3036 /* Return 1 if this lwp that GDB wants running is stopped at an
3037 internal breakpoint that we need to step over. It assumes that any
3038 required STOP_PC adjustment has already been propagated to the
3039 inferior's regcache. */
3042 need_step_over_p (struct inferior_list_entry
*entry
, void *dummy
)
3044 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3045 struct thread_info
*thread
;
3046 struct thread_info
*saved_inferior
;
3049 /* LWPs which will not be resumed are not interesting, because we
3050 might not wait for them next time through linux_wait. */
3056 "Need step over [LWP %ld]? Ignoring, not stopped\n",
3061 thread
= get_lwp_thread (lwp
);
3063 if (thread
->last_resume_kind
== resume_stop
)
3067 "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
3072 gdb_assert (lwp
->suspended
>= 0);
3078 "Need step over [LWP %ld]? Ignoring, suspended\n",
3083 if (!lwp
->need_step_over
)
3087 "Need step over [LWP %ld]? No\n", lwpid_of (lwp
));
3090 if (lwp
->status_pending_p
)
3094 "Need step over [LWP %ld]? Ignoring, has pending status.\n",
3099 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
3103 /* If the PC has changed since we stopped, then don't do anything,
3104 and let the breakpoint/tracepoint be hit. This happens if, for
3105 instance, GDB handled the decr_pc_after_break subtraction itself,
3106 GDB is OOL stepping this thread, or the user has issued a "jump"
3107 command, or poked thread's registers herself. */
3108 if (pc
!= lwp
->stop_pc
)
3112 "Need step over [LWP %ld]? Cancelling, PC was changed. "
3113 "Old stop_pc was 0x%s, PC is now 0x%s\n",
3114 lwpid_of (lwp
), paddress (lwp
->stop_pc
), paddress (pc
));
3116 lwp
->need_step_over
= 0;
3120 saved_inferior
= current_inferior
;
3121 current_inferior
= thread
;
3123 /* We can only step over breakpoints we know about. */
3124 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
3126 /* Don't step over a breakpoint that GDB expects to hit
3128 if (gdb_breakpoint_here (pc
))
3132 "Need step over [LWP %ld]? yes, but found"
3133 " GDB breakpoint at 0x%s; skipping step over\n",
3134 lwpid_of (lwp
), paddress (pc
));
3136 current_inferior
= saved_inferior
;
3143 "Need step over [LWP %ld]? yes, "
3144 "found breakpoint at 0x%s\n",
3145 lwpid_of (lwp
), paddress (pc
));
3147 /* We've found an lwp that needs stepping over --- return 1 so
3148 that find_inferior stops looking. */
3149 current_inferior
= saved_inferior
;
3151 /* If the step over is cancelled, this is set again. */
3152 lwp
->need_step_over
= 0;
3157 current_inferior
= saved_inferior
;
3161 "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
3162 lwpid_of (lwp
), paddress (pc
));
3167 /* Start a step-over operation on LWP. When LWP stopped at a
3168 breakpoint, to make progress, we need to remove the breakpoint out
3169 of the way. If we let other threads run while we do that, they may
3170 pass by the breakpoint location and miss hitting it. To avoid
3171 that, a step-over momentarily stops all threads while LWP is
3172 single-stepped while the breakpoint is temporarily uninserted from
3173 the inferior. When the single-step finishes, we reinsert the
3174 breakpoint, and let all threads that are supposed to be running,
3177 On targets that don't support hardware single-step, we don't
3178 currently support full software single-stepping. Instead, we only
3179 support stepping over the thread event breakpoint, by asking the
3180 low target where to place a reinsert breakpoint. Since this
3181 routine assumes the breakpoint being stepped over is a thread event
3182 breakpoint, it usually assumes the return address of the current
3183 function is a good enough place to set the reinsert breakpoint. */
3186 start_step_over (struct lwp_info
*lwp
)
3188 struct thread_info
*saved_inferior
;
3194 "Starting step-over on LWP %ld. Stopping all threads\n",
3197 stop_all_lwps (1, lwp
);
3198 gdb_assert (lwp
->suspended
== 0);
3201 fprintf (stderr
, "Done stopping all threads for step-over.\n");
3203 /* Note, we should always reach here with an already adjusted PC,
3204 either by GDB (if we're resuming due to GDB's request), or by our
3205 caller, if we just finished handling an internal breakpoint GDB
3206 shouldn't care about. */
3209 saved_inferior
= current_inferior
;
3210 current_inferior
= get_lwp_thread (lwp
);
3212 lwp
->bp_reinsert
= pc
;
3213 uninsert_breakpoints_at (pc
);
3214 uninsert_fast_tracepoint_jumps_at (pc
);
3216 if (can_hardware_single_step ())
3222 CORE_ADDR raddr
= (*the_low_target
.breakpoint_reinsert_addr
) ();
3223 set_reinsert_breakpoint (raddr
);
3227 current_inferior
= saved_inferior
;
3229 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3231 /* Require next event from this LWP. */
3232 step_over_bkpt
= lwp
->head
.id
;
3236 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
3237 start_step_over, if still there, and delete any reinsert
3238 breakpoints we've set, on non hardware single-step targets. */
3241 finish_step_over (struct lwp_info
*lwp
)
3243 if (lwp
->bp_reinsert
!= 0)
3246 fprintf (stderr
, "Finished step over.\n");
3248 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
3249 may be no breakpoint to reinsert there by now. */
3250 reinsert_breakpoints_at (lwp
->bp_reinsert
);
3251 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
3253 lwp
->bp_reinsert
= 0;
3255 /* Delete any software-single-step reinsert breakpoints. No
3256 longer needed. We don't have to worry about other threads
3257 hitting this trap, and later not being able to explain it,
3258 because we were stepping over a breakpoint, and we hold all
3259 threads but LWP stopped while doing that. */
3260 if (!can_hardware_single_step ())
3261 delete_reinsert_breakpoints ();
3263 step_over_bkpt
= null_ptid
;
3270 /* This function is called once per thread. We check the thread's resume
3271 request, which will tell us whether to resume, step, or leave the thread
3272 stopped; and what signal, if any, it should be sent.
3274 For threads which we aren't explicitly told otherwise, we preserve
3275 the stepping flag; this is used for stepping over gdbserver-placed
3278 If pending_flags was set in any thread, we queue any needed
3279 signals, since we won't actually resume. We already have a pending
3280 event to report, so we don't need to preserve any step requests;
3281 they should be re-issued if necessary. */
3284 linux_resume_one_thread (struct inferior_list_entry
*entry
, void *arg
)
3286 struct lwp_info
*lwp
;
3287 struct thread_info
*thread
;
3289 int leave_all_stopped
= * (int *) arg
;
3292 thread
= (struct thread_info
*) entry
;
3293 lwp
= get_thread_lwp (thread
);
3295 if (lwp
->resume
== NULL
)
3298 if (lwp
->resume
->kind
== resume_stop
)
3301 fprintf (stderr
, "resume_stop request for LWP %ld\n", lwpid_of (lwp
));
3306 fprintf (stderr
, "stopping LWP %ld\n", lwpid_of (lwp
));
3308 /* Stop the thread, and wait for the event asynchronously,
3309 through the event loop. */
3315 fprintf (stderr
, "already stopped LWP %ld\n",
3318 /* The LWP may have been stopped in an internal event that
3319 was not meant to be notified back to GDB (e.g., gdbserver
3320 breakpoint), so we should be reporting a stop event in
3323 /* If the thread already has a pending SIGSTOP, this is a
3324 no-op. Otherwise, something later will presumably resume
3325 the thread and this will cause it to cancel any pending
3326 operation, due to last_resume_kind == resume_stop. If
3327 the thread already has a pending status to report, we
3328 will still report it the next time we wait - see
3329 status_pending_p_callback. */
3331 /* If we already have a pending signal to report, then
3332 there's no need to queue a SIGSTOP, as this means we're
3333 midway through moving the LWP out of the jumppad, and we
3334 will report the pending signal as soon as that is
3336 if (lwp
->pending_signals_to_report
== NULL
)
3340 /* For stop requests, we're done. */
3342 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3346 /* If this thread which is about to be resumed has a pending status,
3347 then don't resume any threads - we can just report the pending
3348 status. Make sure to queue any signals that would otherwise be
3349 sent. In all-stop mode, we do this decision based on if *any*
3350 thread has a pending status. If there's a thread that needs the
3351 step-over-breakpoint dance, then don't resume any other thread
3352 but that particular one. */
3353 leave_pending
= (lwp
->status_pending_p
|| leave_all_stopped
);
3358 fprintf (stderr
, "resuming LWP %ld\n", lwpid_of (lwp
));
3360 step
= (lwp
->resume
->kind
== resume_step
);
3361 linux_resume_one_lwp (lwp
, step
, lwp
->resume
->sig
, NULL
);
3366 fprintf (stderr
, "leaving LWP %ld stopped\n", lwpid_of (lwp
));
3368 /* If we have a new signal, enqueue the signal. */
3369 if (lwp
->resume
->sig
!= 0)
3371 struct pending_signals
*p_sig
;
3372 p_sig
= xmalloc (sizeof (*p_sig
));
3373 p_sig
->prev
= lwp
->pending_signals
;
3374 p_sig
->signal
= lwp
->resume
->sig
;
3375 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
3377 /* If this is the same signal we were previously stopped by,
3378 make sure to queue its siginfo. We can ignore the return
3379 value of ptrace; if it fails, we'll skip
3380 PTRACE_SETSIGINFO. */
3381 if (WIFSTOPPED (lwp
->last_status
)
3382 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
)
3383 ptrace (PTRACE_GETSIGINFO
, lwpid_of (lwp
), 0, &p_sig
->info
);
3385 lwp
->pending_signals
= p_sig
;
3389 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
3395 linux_resume (struct thread_resume
*resume_info
, size_t n
)
3397 struct thread_resume_array array
= { resume_info
, n
};
3398 struct lwp_info
*need_step_over
= NULL
;
3400 int leave_all_stopped
;
3402 find_inferior (&all_threads
, linux_set_resume_request
, &array
);
3404 /* If there is a thread which would otherwise be resumed, which has
3405 a pending status, then don't resume any threads - we can just
3406 report the pending status. Make sure to queue any signals that
3407 would otherwise be sent. In non-stop mode, we'll apply this
3408 logic to each thread individually. We consume all pending events
3409 before considering to start a step-over (in all-stop). */
3412 find_inferior (&all_lwps
, resume_status_pending_p
, &any_pending
);
3414 /* If there is a thread which would otherwise be resumed, which is
3415 stopped at a breakpoint that needs stepping over, then don't
3416 resume any threads - have it step over the breakpoint with all
3417 other threads stopped, then resume all threads again. Make sure
3418 to queue any signals that would otherwise be delivered or
3420 if (!any_pending
&& supports_breakpoints ())
3422 = (struct lwp_info
*) find_inferior (&all_lwps
,
3423 need_step_over_p
, NULL
);
3425 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
3429 if (need_step_over
!= NULL
)
3430 fprintf (stderr
, "Not resuming all, need step over\n");
3431 else if (any_pending
)
3433 "Not resuming, all-stop and found "
3434 "an LWP with pending status\n");
3436 fprintf (stderr
, "Resuming, no pending status or step over needed\n");
3439 /* Even if we're leaving threads stopped, queue all signals we'd
3440 otherwise deliver. */
3441 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
3444 start_step_over (need_step_over
);
3447 /* This function is called once per thread. We check the thread's
3448 last resume request, which will tell us whether to resume, step, or
3449 leave the thread stopped. Any signal the client requested to be
3450 delivered has already been enqueued at this point.
3452 If any thread that GDB wants running is stopped at an internal
3453 breakpoint that needs stepping over, we start a step-over operation
3454 on that particular thread, and leave all others stopped. */
3457 proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3459 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3460 struct thread_info
*thread
;
3468 "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp
));
3473 fprintf (stderr
, " LWP %ld already running\n", lwpid_of (lwp
));
3477 thread
= get_lwp_thread (lwp
);
3479 if (thread
->last_resume_kind
== resume_stop
3480 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
3483 fprintf (stderr
, " client wants LWP to remain %ld stopped\n",
3488 if (lwp
->status_pending_p
)
3491 fprintf (stderr
, " LWP %ld has pending status, leaving stopped\n",
3496 gdb_assert (lwp
->suspended
>= 0);
3501 fprintf (stderr
, " LWP %ld is suspended\n", lwpid_of (lwp
));
3505 if (thread
->last_resume_kind
== resume_stop
3506 && lwp
->pending_signals_to_report
== NULL
3507 && lwp
->collecting_fast_tracepoint
== 0)
3509 /* We haven't reported this LWP as stopped yet (otherwise, the
3510 last_status.kind check above would catch it, and we wouldn't
3511 reach here. This LWP may have been momentarily paused by a
3512 stop_all_lwps call while handling for example, another LWP's
3513 step-over. In that case, the pending expected SIGSTOP signal
3514 that was queued at vCont;t handling time will have already
3515 been consumed by wait_for_sigstop, and so we need to requeue
3516 another one here. Note that if the LWP already has a SIGSTOP
3517 pending, this is a no-op. */
3521 "Client wants LWP %ld to stop. "
3522 "Making sure it has a SIGSTOP pending\n",
3528 step
= thread
->last_resume_kind
== resume_step
;
3529 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
3534 unsuspend_and_proceed_one_lwp (struct inferior_list_entry
*entry
, void *except
)
3536 struct lwp_info
*lwp
= (struct lwp_info
*) entry
;
3542 gdb_assert (lwp
->suspended
>= 0);
3544 return proceed_one_lwp (entry
, except
);
3547 /* When we finish a step-over, set threads running again. If there's
3548 another thread that may need a step-over, now's the time to start
3549 it. Eventually, we'll move all threads past their breakpoints. */
3552 proceed_all_lwps (void)
3554 struct lwp_info
*need_step_over
;
3556 /* If there is a thread which would otherwise be resumed, which is
3557 stopped at a breakpoint that needs stepping over, then don't
3558 resume any threads - have it step over the breakpoint with all
3559 other threads stopped, then resume all threads again. */
3561 if (supports_breakpoints ())
3564 = (struct lwp_info
*) find_inferior (&all_lwps
,
3565 need_step_over_p
, NULL
);
3567 if (need_step_over
!= NULL
)
3570 fprintf (stderr
, "proceed_all_lwps: found "
3571 "thread %ld needing a step-over\n",
3572 lwpid_of (need_step_over
));
3574 start_step_over (need_step_over
);
3580 fprintf (stderr
, "Proceeding, no step-over needed\n");
3582 find_inferior (&all_lwps
, proceed_one_lwp
, NULL
);
3585 /* Stopped LWPs that the client wanted to be running, that don't have
3586 pending statuses, are set to run again, except for EXCEPT, if not
3587 NULL. This undoes a stop_all_lwps call. */
3590 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
3596 "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except
));
3599 "unstopping all lwps\n");
3603 find_inferior (&all_lwps
, unsuspend_and_proceed_one_lwp
, except
);
3605 find_inferior (&all_lwps
, proceed_one_lwp
, except
);
3608 #ifdef HAVE_LINUX_USRREGS
3611 register_addr (int regnum
)
3615 if (regnum
< 0 || regnum
>= the_low_target
.num_regs
)
3616 error ("Invalid register number %d.", regnum
);
3618 addr
= the_low_target
.regmap
[regnum
];
3623 /* Fetch one register. */
3625 fetch_register (struct regcache
*regcache
, int regno
)
3632 if (regno
>= the_low_target
.num_regs
)
3634 if ((*the_low_target
.cannot_fetch_register
) (regno
))
3637 regaddr
= register_addr (regno
);
3641 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3642 size
= ((register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3643 & - sizeof (PTRACE_XFER_TYPE
));
3644 buf
= alloca (size
);
3645 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3648 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
3649 ptrace (PTRACE_PEEKUSER
, pid
,
3650 /* Coerce to a uintptr_t first to avoid potential gcc warning
3651 of coercing an 8 byte integer to a 4 byte pointer. */
3652 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
, 0);
3653 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3655 error ("reading register %d: %s", regno
, strerror (errno
));
3658 if (the_low_target
.supply_ptrace_register
)
3659 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
3661 supply_register (regcache
, regno
, buf
);
3664 /* Fetch all registers, or just one, from the child process. */
3666 usr_fetch_inferior_registers (struct regcache
*regcache
, int regno
)
3669 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3670 fetch_register (regcache
, regno
);
3672 fetch_register (regcache
, regno
);
3675 /* Store our register values back into the inferior.
3676 If REGNO is -1, do this for all registers.
3677 Otherwise, REGNO specifies which register (so we can save time). */
3679 usr_store_inferior_registers (struct regcache
*regcache
, int regno
)
3688 if (regno
>= the_low_target
.num_regs
)
3691 if ((*the_low_target
.cannot_store_register
) (regno
) == 1)
3694 regaddr
= register_addr (regno
);
3698 size
= (register_size (regno
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3699 & - sizeof (PTRACE_XFER_TYPE
);
3700 buf
= alloca (size
);
3701 memset (buf
, 0, size
);
3703 if (the_low_target
.collect_ptrace_register
)
3704 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
3706 collect_register (regcache
, regno
, buf
);
3708 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3709 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
3712 ptrace (PTRACE_POKEUSER
, pid
,
3713 /* Coerce to a uintptr_t first to avoid potential gcc warning
3714 about coercing an 8 byte integer to a 4 byte pointer. */
3715 (PTRACE_ARG3_TYPE
) (uintptr_t) regaddr
,
3716 (PTRACE_ARG4_TYPE
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
3719 /* At this point, ESRCH should mean the process is
3720 already gone, in which case we simply ignore attempts
3721 to change its registers. See also the related
3722 comment in linux_resume_one_lwp. */
3726 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
3727 error ("writing register %d: %s", regno
, strerror (errno
));
3729 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
3733 for (regno
= 0; regno
< the_low_target
.num_regs
; regno
++)
3734 usr_store_inferior_registers (regcache
, regno
);
3736 #endif /* HAVE_LINUX_USRREGS */
3740 #ifdef HAVE_LINUX_REGSETS
3743 regsets_fetch_inferior_registers (struct regcache
*regcache
)
3745 struct regset_info
*regset
;
3746 int saw_general_regs
= 0;
3750 regset
= target_regsets
;
3752 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3753 while (regset
->size
>= 0)
3758 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3764 buf
= xmalloc (regset
->size
);
3766 nt_type
= regset
->nt_type
;
3770 iov
.iov_len
= regset
->size
;
3771 data
= (void *) &iov
;
3777 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3779 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
3785 /* If we get EIO on a regset, do not try it again for
3787 disabled_regsets
[regset
- target_regsets
] = 1;
3794 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
3799 else if (regset
->type
== GENERAL_REGS
)
3800 saw_general_regs
= 1;
3801 regset
->store_function (regcache
, buf
);
3805 if (saw_general_regs
)
3812 regsets_store_inferior_registers (struct regcache
*regcache
)
3814 struct regset_info
*regset
;
3815 int saw_general_regs
= 0;
3819 regset
= target_regsets
;
3821 pid
= lwpid_of (get_thread_lwp (current_inferior
));
3822 while (regset
->size
>= 0)
3827 if (regset
->size
== 0 || disabled_regsets
[regset
- target_regsets
])
3833 buf
= xmalloc (regset
->size
);
3835 /* First fill the buffer with the current register set contents,
3836 in case there are any items in the kernel's regset that are
3837 not in gdbserver's regcache. */
3839 nt_type
= regset
->nt_type
;
3843 iov
.iov_len
= regset
->size
;
3844 data
= (void *) &iov
;
3850 res
= ptrace (regset
->get_request
, pid
, nt_type
, data
);
3852 res
= ptrace (regset
->get_request
, pid
, &iov
, data
);
3857 /* Then overlay our cached registers on that. */
3858 regset
->fill_function (regcache
, buf
);
3860 /* Only now do we write the register set. */
3862 res
= ptrace (regset
->set_request
, pid
, nt_type
, data
);
3864 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
3872 /* If we get EIO on a regset, do not try it again for
3874 disabled_regsets
[regset
- target_regsets
] = 1;
3878 else if (errno
== ESRCH
)
3880 /* At this point, ESRCH should mean the process is
3881 already gone, in which case we simply ignore attempts
3882 to change its registers. See also the related
3883 comment in linux_resume_one_lwp. */
3889 perror ("Warning: ptrace(regsets_store_inferior_registers)");
3892 else if (regset
->type
== GENERAL_REGS
)
3893 saw_general_regs
= 1;
3897 if (saw_general_regs
)
3904 #endif /* HAVE_LINUX_REGSETS */
3908 linux_fetch_registers (struct regcache
*regcache
, int regno
)
3910 #ifdef HAVE_LINUX_REGSETS
3911 if (regsets_fetch_inferior_registers (regcache
) == 0)
3914 #ifdef HAVE_LINUX_USRREGS
3915 usr_fetch_inferior_registers (regcache
, regno
);
3920 linux_store_registers (struct regcache
*regcache
, int regno
)
3922 #ifdef HAVE_LINUX_REGSETS
3923 if (regsets_store_inferior_registers (regcache
) == 0)
3926 #ifdef HAVE_LINUX_USRREGS
3927 usr_store_inferior_registers (regcache
, regno
);
3932 /* Copy LEN bytes from inferior's memory starting at MEMADDR
3933 to debugger memory starting at MYADDR. */
3936 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
3939 /* Round starting address down to longword boundary. */
3940 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
3941 /* Round ending address up; get number of longwords that makes. */
3943 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
3944 / sizeof (PTRACE_XFER_TYPE
);
3945 /* Allocate buffer of that many longwords. */
3946 register PTRACE_XFER_TYPE
*buffer
3947 = (PTRACE_XFER_TYPE
*) alloca (count
* sizeof (PTRACE_XFER_TYPE
));
3950 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
3952 /* Try using /proc. Don't bother for one word. */
3953 if (len
>= 3 * sizeof (long))
3955 /* We could keep this file open and cache it - possibly one per
3956 thread. That requires some juggling, but is even faster. */
3957 sprintf (filename
, "/proc/%d/mem", pid
);
3958 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
3962 /* If pread64 is available, use it. It's faster if the kernel
3963 supports it (only one syscall), and it's 64-bit safe even on
3964 32-bit platforms (for instance, SPARC debugging a SPARC64
3967 if (pread64 (fd
, myaddr
, len
, memaddr
) != len
)
3969 if (lseek (fd
, memaddr
, SEEK_SET
) == -1 || read (fd
, myaddr
, len
) != len
)
3981 /* Read all the longwords */
3982 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
3985 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
3986 about coercing an 8 byte integer to a 4 byte pointer. */
3987 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
3988 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
3993 /* Copy appropriate bytes out of the buffer. */
3995 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4001 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
4002 memory at MEMADDR. On failure (cannot write to the inferior)
4003 returns the value of errno. */
4006 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
4009 /* Round starting address down to longword boundary. */
4010 register CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
4011 /* Round ending address up; get number of longwords that makes. */
4013 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
4014 / sizeof (PTRACE_XFER_TYPE
);
4016 /* Allocate buffer of that many longwords. */
4017 register PTRACE_XFER_TYPE
*buffer
= (PTRACE_XFER_TYPE
*)
4018 alloca (count
* sizeof (PTRACE_XFER_TYPE
));
4020 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4024 /* Dump up to four bytes. */
4025 unsigned int val
= * (unsigned int *) myaddr
;
4031 val
= val
& 0xffffff;
4032 fprintf (stderr
, "Writing %0*x to 0x%08lx\n", 2 * ((len
< 4) ? len
: 4),
4033 val
, (long)memaddr
);
4036 /* Fill start and end extra bytes of buffer with existing memory data. */
4039 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
4040 about coercing an 8 byte integer to a 4 byte pointer. */
4041 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
4042 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
, 0);
4050 = ptrace (PTRACE_PEEKTEXT
, pid
,
4051 /* Coerce to a uintptr_t first to avoid potential gcc warning
4052 about coercing an 8 byte integer to a 4 byte pointer. */
4053 (PTRACE_ARG3_TYPE
) (uintptr_t) (addr
+ (count
- 1)
4054 * sizeof (PTRACE_XFER_TYPE
)),
4060 /* Copy data to be written over corresponding part of buffer. */
4062 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
4065 /* Write the entire buffer. */
4067 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
4070 ptrace (PTRACE_POKETEXT
, pid
,
4071 /* Coerce to a uintptr_t first to avoid potential gcc warning
4072 about coercing an 8 byte integer to a 4 byte pointer. */
4073 (PTRACE_ARG3_TYPE
) (uintptr_t) addr
,
4074 (PTRACE_ARG4_TYPE
) buffer
[i
]);
4082 /* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
4083 static int linux_supports_tracefork_flag
;
4086 linux_enable_event_reporting (int pid
)
4088 if (!linux_supports_tracefork_flag
)
4091 ptrace (PTRACE_SETOPTIONS
, pid
, 0, (PTRACE_ARG4_TYPE
) PTRACE_O_TRACECLONE
);
4094 /* Helper functions for linux_test_for_tracefork, called via clone (). */
4097 linux_tracefork_grandchild (void *arg
)
4102 #define STACK_SIZE 4096
4105 linux_tracefork_child (void *arg
)
4107 ptrace (PTRACE_TRACEME
, 0, 0, 0);
4108 kill (getpid (), SIGSTOP
);
4110 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4113 linux_tracefork_grandchild (NULL
);
4115 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4118 __clone2 (linux_tracefork_grandchild
, arg
, STACK_SIZE
,
4119 CLONE_VM
| SIGCHLD
, NULL
);
4121 clone (linux_tracefork_grandchild
, (char *) arg
+ STACK_SIZE
,
4122 CLONE_VM
| SIGCHLD
, NULL
);
4125 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4130 /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. Make
4131 sure that we can enable the option, and that it had the desired
4135 linux_test_for_tracefork (void)
4137 int child_pid
, ret
, status
;
4139 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4140 char *stack
= xmalloc (STACK_SIZE
* 4);
4141 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4143 linux_supports_tracefork_flag
= 0;
4145 #if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
4147 child_pid
= fork ();
4149 linux_tracefork_child (NULL
);
4151 #else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4153 /* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
4155 child_pid
= __clone2 (linux_tracefork_child
, stack
, STACK_SIZE
,
4156 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4157 #else /* !__ia64__ */
4158 child_pid
= clone (linux_tracefork_child
, stack
+ STACK_SIZE
,
4159 CLONE_VM
| SIGCHLD
, stack
+ STACK_SIZE
* 2);
4160 #endif /* !__ia64__ */
4162 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4164 if (child_pid
== -1)
4165 perror_with_name ("clone");
4167 ret
= my_waitpid (child_pid
, &status
, 0);
4169 perror_with_name ("waitpid");
4170 else if (ret
!= child_pid
)
4171 error ("linux_test_for_tracefork: waitpid: unexpected result %d.", ret
);
4172 if (! WIFSTOPPED (status
))
4173 error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status
);
4175 ret
= ptrace (PTRACE_SETOPTIONS
, child_pid
, 0,
4176 (PTRACE_ARG4_TYPE
) PTRACE_O_TRACEFORK
);
4179 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4182 warning ("linux_test_for_tracefork: failed to kill child");
4186 ret
= my_waitpid (child_pid
, &status
, 0);
4187 if (ret
!= child_pid
)
4188 warning ("linux_test_for_tracefork: failed to wait for killed child");
4189 else if (!WIFSIGNALED (status
))
4190 warning ("linux_test_for_tracefork: unexpected wait status 0x%x from "
4191 "killed child", status
);
4196 ret
= ptrace (PTRACE_CONT
, child_pid
, 0, 0);
4198 warning ("linux_test_for_tracefork: failed to resume child");
4200 ret
= my_waitpid (child_pid
, &status
, 0);
4202 if (ret
== child_pid
&& WIFSTOPPED (status
)
4203 && status
>> 16 == PTRACE_EVENT_FORK
)
4206 ret
= ptrace (PTRACE_GETEVENTMSG
, child_pid
, 0, &second_pid
);
4207 if (ret
== 0 && second_pid
!= 0)
4211 linux_supports_tracefork_flag
= 1;
4212 my_waitpid (second_pid
, &second_status
, 0);
4213 ret
= ptrace (PTRACE_KILL
, second_pid
, 0, 0);
4215 warning ("linux_test_for_tracefork: failed to kill second child");
4216 my_waitpid (second_pid
, &status
, 0);
4220 warning ("linux_test_for_tracefork: unexpected result from waitpid "
4221 "(%d, status 0x%x)", ret
, status
);
4225 ret
= ptrace (PTRACE_KILL
, child_pid
, 0, 0);
4227 warning ("linux_test_for_tracefork: failed to kill child");
4228 my_waitpid (child_pid
, &status
, 0);
4230 while (WIFSTOPPED (status
));
4232 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4234 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
4239 linux_look_up_symbols (void)
4241 #ifdef USE_THREAD_DB
4242 struct process_info
*proc
= current_process ();
4244 if (proc
->private->thread_db
!= NULL
)
4247 /* If the kernel supports tracing forks then it also supports tracing
4248 clones, and then we don't need to use the magic thread event breakpoint
4249 to learn about threads. */
4250 thread_db_init (!linux_supports_tracefork_flag
);
4255 linux_request_interrupt (void)
4257 extern unsigned long signal_pid
;
4259 if (!ptid_equal (cont_thread
, null_ptid
)
4260 && !ptid_equal (cont_thread
, minus_one_ptid
))
4262 struct lwp_info
*lwp
;
4265 lwp
= get_thread_lwp (current_inferior
);
4266 lwpid
= lwpid_of (lwp
);
4267 kill_lwp (lwpid
, SIGINT
);
4270 kill_lwp (signal_pid
, SIGINT
);
4273 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
4274 to debugger memory starting at MYADDR. */
4277 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
4279 char filename
[PATH_MAX
];
4281 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4283 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
4285 fd
= open (filename
, O_RDONLY
);
4289 if (offset
!= (CORE_ADDR
) 0
4290 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4293 n
= read (fd
, myaddr
, len
);
4300 /* These breakpoint and watchpoint related wrapper functions simply
4301 pass on the function call if the target has registered a
4302 corresponding function. */
4305 linux_insert_point (char type
, CORE_ADDR addr
, int len
)
4307 if (the_low_target
.insert_point
!= NULL
)
4308 return the_low_target
.insert_point (type
, addr
, len
);
4310 /* Unsupported (see target.h). */
4315 linux_remove_point (char type
, CORE_ADDR addr
, int len
)
4317 if (the_low_target
.remove_point
!= NULL
)
4318 return the_low_target
.remove_point (type
, addr
, len
);
4320 /* Unsupported (see target.h). */
4325 linux_stopped_by_watchpoint (void)
4327 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4329 return lwp
->stopped_by_watchpoint
;
4333 linux_stopped_data_address (void)
4335 struct lwp_info
*lwp
= get_thread_lwp (current_inferior
);
4337 return lwp
->stopped_data_address
;
4340 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4341 #if defined(__mcoldfire__)
4342 /* These should really be defined in the kernel's ptrace.h header. */
4343 #define PT_TEXT_ADDR 49*4
4344 #define PT_DATA_ADDR 50*4
4345 #define PT_TEXT_END_ADDR 51*4
4347 #define PT_TEXT_ADDR 220
4348 #define PT_TEXT_END_ADDR 224
4349 #define PT_DATA_ADDR 228
4352 /* Under uClinux, programs are loaded at non-zero offsets, which we need
4353 to tell gdb about. */
4356 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
4358 #if defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) && defined(PT_TEXT_END_ADDR)
4359 unsigned long text
, text_end
, data
;
4360 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4364 text
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_ADDR
, 0);
4365 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_TEXT_END_ADDR
, 0);
4366 data
= ptrace (PTRACE_PEEKUSER
, pid
, (long)PT_DATA_ADDR
, 0);
4370 /* Both text and data offsets produced at compile-time (and so
4371 used by gdb) are relative to the beginning of the program,
4372 with the data segment immediately following the text segment.
4373 However, the actual runtime layout in memory may put the data
4374 somewhere else, so when we send gdb a data base-address, we
4375 use the real data base address and subtract the compile-time
4376 data base-address from it (which is just the length of the
4377 text segment). BSS immediately follows data in both
4380 *data_p
= data
- (text_end
- text
);
4390 linux_qxfer_osdata (const char *annex
,
4391 unsigned char *readbuf
, unsigned const char *writebuf
,
4392 CORE_ADDR offset
, int len
)
4394 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4397 /* Convert a native/host siginfo object, into/from the siginfo in the
4398 layout of the inferiors' architecture. */
4401 siginfo_fixup (struct siginfo
*siginfo
, void *inf_siginfo
, int direction
)
4405 if (the_low_target
.siginfo_fixup
!= NULL
)
4406 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
4408 /* If there was no callback, or the callback didn't do anything,
4409 then just do a straight memcpy. */
4413 memcpy (siginfo
, inf_siginfo
, sizeof (struct siginfo
));
4415 memcpy (inf_siginfo
, siginfo
, sizeof (struct siginfo
));
4420 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
4421 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
4424 struct siginfo siginfo
;
4425 char inf_siginfo
[sizeof (struct siginfo
)];
4427 if (current_inferior
== NULL
)
4430 pid
= lwpid_of (get_thread_lwp (current_inferior
));
4433 fprintf (stderr
, "%s siginfo for lwp %d.\n",
4434 readbuf
!= NULL
? "Reading" : "Writing",
4437 if (offset
>= sizeof (siginfo
))
4440 if (ptrace (PTRACE_GETSIGINFO
, pid
, 0, &siginfo
) != 0)
4443 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
4444 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
4445 inferior with a 64-bit GDBSERVER should look the same as debugging it
4446 with a 32-bit GDBSERVER, we need to convert it. */
4447 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
4449 if (offset
+ len
> sizeof (siginfo
))
4450 len
= sizeof (siginfo
) - offset
;
4452 if (readbuf
!= NULL
)
4453 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
4456 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
4458 /* Convert back to ptrace layout before flushing it out. */
4459 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
4461 if (ptrace (PTRACE_SETSIGINFO
, pid
, 0, &siginfo
) != 0)
4468 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4469 so we notice when children change state; as the handler for the
4470 sigsuspend in my_waitpid. */
4473 sigchld_handler (int signo
)
4475 int old_errno
= errno
;
4481 /* fprintf is not async-signal-safe, so call write
4483 if (write (2, "sigchld_handler\n",
4484 sizeof ("sigchld_handler\n") - 1) < 0)
4485 break; /* just ignore */
4489 if (target_is_async_p ())
4490 async_file_mark (); /* trigger a linux_wait */
4496 linux_supports_non_stop (void)
4502 linux_async (int enable
)
4504 int previous
= (linux_event_pipe
[0] != -1);
4507 fprintf (stderr
, "linux_async (%d), previous=%d\n",
4510 if (previous
!= enable
)
4513 sigemptyset (&mask
);
4514 sigaddset (&mask
, SIGCHLD
);
4516 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
4520 if (pipe (linux_event_pipe
) == -1)
4521 fatal ("creating event pipe failed.");
4523 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4524 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4526 /* Register the event loop handler. */
4527 add_file_handler (linux_event_pipe
[0],
4528 handle_target_event
, NULL
);
4530 /* Always trigger a linux_wait. */
4535 delete_file_handler (linux_event_pipe
[0]);
4537 close (linux_event_pipe
[0]);
4538 close (linux_event_pipe
[1]);
4539 linux_event_pipe
[0] = -1;
4540 linux_event_pipe
[1] = -1;
4543 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
4550 linux_start_non_stop (int nonstop
)
4552 /* Register or unregister from event-loop accordingly. */
4553 linux_async (nonstop
);
4558 linux_supports_multi_process (void)
4564 /* Enumerate spufs IDs for process PID. */
4566 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
4572 struct dirent
*entry
;
4574 sprintf (path
, "/proc/%ld/fd", pid
);
4575 dir
= opendir (path
);
4580 while ((entry
= readdir (dir
)) != NULL
)
4586 fd
= atoi (entry
->d_name
);
4590 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
4591 if (stat (path
, &st
) != 0)
4593 if (!S_ISDIR (st
.st_mode
))
4596 if (statfs (path
, &stfs
) != 0)
4598 if (stfs
.f_type
!= SPUFS_MAGIC
)
4601 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4603 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
4613 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
4614 object type, using the /proc file system. */
4616 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
4617 unsigned const char *writebuf
,
4618 CORE_ADDR offset
, int len
)
4620 long pid
= lwpid_of (get_thread_lwp (current_inferior
));
4625 if (!writebuf
&& !readbuf
)
4633 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4636 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
4637 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
4642 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4649 ret
= write (fd
, writebuf
, (size_t) len
);
4651 ret
= read (fd
, readbuf
, (size_t) len
);
4657 #if defined PT_GETDSBT
4658 struct target_loadseg
4660 /* Core address to which the segment is mapped. */
4662 /* VMA recorded in the program header. */
4664 /* Size of this segment in memory. */
4668 struct target_loadmap
4670 /* Protocol version number, must be zero. */
4672 /* Pointer to the DSBT table, its size, and the DSBT index. */
4673 unsigned *dsbt_table
;
4674 unsigned dsbt_size
, dsbt_index
;
4675 /* Number of segments in this map. */
4677 /* The actual memory map. */
4678 struct target_loadseg segs
[/*nsegs*/];
4682 #if defined PT_GETDSBT
4684 linux_read_loadmap (const char *annex
, CORE_ADDR offset
,
4685 unsigned char *myaddr
, unsigned int len
)
4687 int pid
= lwpid_of (get_thread_lwp (current_inferior
));
4689 struct target_loadmap
*data
= NULL
;
4690 unsigned int actual_length
, copy_length
;
4692 if (strcmp (annex
, "exec") == 0)
4693 addr
= (int) PTRACE_GETDSBT_EXEC
;
4694 else if (strcmp (annex
, "interp") == 0)
4695 addr
= (int) PTRACE_GETDSBT_INTERP
;
4699 if (ptrace (PT_GETDSBT
, pid
, addr
, &data
) != 0)
4705 actual_length
= sizeof (struct target_loadmap
)
4706 + sizeof (struct target_loadseg
) * data
->nsegs
;
4708 if (offset
< 0 || offset
> actual_length
)
4711 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
4712 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
4715 #endif /* defined PT_GETDSBT */
4718 linux_process_qsupported (const char *query
)
4720 if (the_low_target
.process_qsupported
!= NULL
)
4721 the_low_target
.process_qsupported (query
);
4725 linux_supports_tracepoints (void)
4727 if (*the_low_target
.supports_tracepoints
== NULL
)
4730 return (*the_low_target
.supports_tracepoints
) ();
4734 linux_read_pc (struct regcache
*regcache
)
4736 if (the_low_target
.get_pc
== NULL
)
4739 return (*the_low_target
.get_pc
) (regcache
);
4743 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
4745 gdb_assert (the_low_target
.set_pc
!= NULL
);
4747 (*the_low_target
.set_pc
) (regcache
, pc
);
4751 linux_thread_stopped (struct thread_info
*thread
)
4753 return get_thread_lwp (thread
)->stopped
;
4756 /* This exposes stop-all-threads functionality to other modules. */
4759 linux_pause_all (int freeze
)
4761 stop_all_lwps (freeze
, NULL
);
4764 /* This exposes unstop-all-threads functionality to other gdbserver
4768 linux_unpause_all (int unfreeze
)
4770 unstop_all_lwps (unfreeze
, NULL
);
4774 linux_prepare_to_access_memory (void)
4776 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4779 linux_pause_all (1);
4784 linux_done_accessing_memory (void)
4786 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
4789 linux_unpause_all (1);
4793 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
4794 CORE_ADDR collector
,
4797 CORE_ADDR
*jump_entry
,
4798 unsigned char *jjump_pad_insn
,
4799 ULONGEST
*jjump_pad_insn_size
,
4800 CORE_ADDR
*adjusted_insn_addr
,
4801 CORE_ADDR
*adjusted_insn_addr_end
)
4803 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
4804 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
4805 jump_entry
, jjump_pad_insn
, jjump_pad_insn_size
,
4806 adjusted_insn_addr
, adjusted_insn_addr_end
);
4809 static struct emit_ops
*
4810 linux_emit_ops (void)
4812 if (the_low_target
.emit_ops
!= NULL
)
4813 return (*the_low_target
.emit_ops
) ();
4818 static struct target_ops linux_target_ops
= {
4819 linux_create_inferior
,
4828 linux_fetch_registers
,
4829 linux_store_registers
,
4830 linux_prepare_to_access_memory
,
4831 linux_done_accessing_memory
,
4834 linux_look_up_symbols
,
4835 linux_request_interrupt
,
4839 linux_stopped_by_watchpoint
,
4840 linux_stopped_data_address
,
4841 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
4846 #ifdef USE_THREAD_DB
4847 thread_db_get_tls_address
,
4852 hostio_last_error_from_errno
,
4855 linux_supports_non_stop
,
4857 linux_start_non_stop
,
4858 linux_supports_multi_process
,
4859 #ifdef USE_THREAD_DB
4860 thread_db_handle_monitor_command
,
4864 linux_common_core_of_thread
,
4865 #if defined PT_GETDSBT
4870 linux_process_qsupported
,
4871 linux_supports_tracepoints
,
4874 linux_thread_stopped
,
4878 linux_cancel_breakpoints
,
4879 linux_stabilize_threads
,
4880 linux_install_fast_tracepoint_jump_pad
,
4885 linux_init_signals ()
4887 /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
4888 to find what the cancel signal actually is. */
4889 #ifndef __ANDROID__ /* Bionic doesn't use SIGRTMIN the way glibc does. */
4890 signal (__SIGRTMIN
+1, SIG_IGN
);
4895 initialize_low (void)
4897 struct sigaction sigchld_action
;
4898 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
4899 set_target_ops (&linux_target_ops
);
4900 set_breakpoint_data (the_low_target
.breakpoint
,
4901 the_low_target
.breakpoint_len
);
4902 linux_init_signals ();
4903 linux_test_for_tracefork ();
4904 #ifdef HAVE_LINUX_REGSETS
4905 for (num_regsets
= 0; target_regsets
[num_regsets
].size
>= 0; num_regsets
++)
4907 disabled_regsets
= xmalloc (num_regsets
);
4910 sigchld_action
.sa_handler
= sigchld_handler
;
4911 sigemptyset (&sigchld_action
.sa_mask
);
4912 sigchld_action
.sa_flags
= SA_RESTART
;
4913 sigaction (SIGCHLD
, &sigchld_action
, NULL
);