1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-2017 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "linux-low.h"
21 #include "nat/linux-osdata.h"
25 #include "signals-state-save-restore.h"
26 #include "nat/linux-nat.h"
27 #include "nat/linux-waitpid.h"
29 #include "nat/gdb_ptrace.h"
30 #include "nat/linux-ptrace.h"
31 #include "nat/linux-procfs.h"
32 #include "nat/linux-personality.h"
34 #include <sys/ioctl.h>
37 #include <sys/syscall.h>
41 #include <sys/types.h>
46 #include "filestuff.h"
47 #include "tracepoint.h"
50 #include "common-inferior.h"
51 #include "nat/fork-inferior.h"
54 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
55 then ELFMAG0 will have been defined. If it didn't get included by
56 gdb_proc_service.h then including it will likely introduce a duplicate
57 definition of elf_fpregset_t. */
60 #include "nat/linux-namespaces.h"
63 #define SPUFS_MAGIC 0x23c9b64e
66 #ifdef HAVE_PERSONALITY
67 # include <sys/personality.h>
68 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
69 # define ADDR_NO_RANDOMIZE 0x0040000
77 /* Some targets did not define these ptrace constants from the start,
78 so gdbserver defines them locally here. In the future, these may
79 be removed after they are added to asm/ptrace.h. */
80 #if !(defined(PT_TEXT_ADDR) \
81 || defined(PT_DATA_ADDR) \
82 || defined(PT_TEXT_END_ADDR))
83 #if defined(__mcoldfire__)
84 /* These are still undefined in 3.10 kernels. */
85 #define PT_TEXT_ADDR 49*4
86 #define PT_DATA_ADDR 50*4
87 #define PT_TEXT_END_ADDR 51*4
88 /* BFIN already defines these since at least 2.6.32 kernels. */
90 #define PT_TEXT_ADDR 220
91 #define PT_TEXT_END_ADDR 224
92 #define PT_DATA_ADDR 228
93 /* These are still undefined in 3.10 kernels. */
94 #elif defined(__TMS320C6X__)
95 #define PT_TEXT_ADDR (0x10000*4)
96 #define PT_DATA_ADDR (0x10004*4)
97 #define PT_TEXT_END_ADDR (0x10008*4)
101 #ifdef HAVE_LINUX_BTRACE
102 # include "nat/linux-btrace.h"
103 # include "btrace-common.h"
106 #ifndef HAVE_ELF32_AUXV_T
107 /* Copied from glibc's elf.h. */
110 uint32_t a_type
; /* Entry type */
113 uint32_t a_val
; /* Integer value */
114 /* We use to have pointer elements added here. We cannot do that,
115 though, since it does not work when using 32-bit definitions
116 on 64-bit platforms and vice versa. */
121 #ifndef HAVE_ELF64_AUXV_T
122 /* Copied from glibc's elf.h. */
125 uint64_t a_type
; /* Entry type */
128 uint64_t a_val
; /* Integer value */
129 /* We use to have pointer elements added here. We cannot do that,
130 though, since it does not work when using 32-bit definitions
131 on 64-bit platforms and vice versa. */
136 /* Does the current host support PTRACE_GETREGSET? */
137 int have_ptrace_getregset
= -1;
141 /* See nat/linux-nat.h. */
144 ptid_of_lwp (struct lwp_info
*lwp
)
146 return ptid_of (get_lwp_thread (lwp
));
149 /* See nat/linux-nat.h. */
152 lwp_set_arch_private_info (struct lwp_info
*lwp
,
153 struct arch_lwp_info
*info
)
155 lwp
->arch_private
= info
;
158 /* See nat/linux-nat.h. */
160 struct arch_lwp_info
*
161 lwp_arch_private_info (struct lwp_info
*lwp
)
163 return lwp
->arch_private
;
166 /* See nat/linux-nat.h. */
169 lwp_is_stopped (struct lwp_info
*lwp
)
174 /* See nat/linux-nat.h. */
176 enum target_stop_reason
177 lwp_stop_reason (struct lwp_info
*lwp
)
179 return lwp
->stop_reason
;
182 /* See nat/linux-nat.h. */
185 lwp_is_stepping (struct lwp_info
*lwp
)
187 return lwp
->stepping
;
190 /* A list of all unknown processes which receive stop signals. Some
191 other process will presumably claim each of these as forked
192 children momentarily. */
194 struct simple_pid_list
196 /* The process ID. */
199 /* The status as reported by waitpid. */
203 struct simple_pid_list
*next
;
205 struct simple_pid_list
*stopped_pids
;
207 /* Trivial list manipulation functions to keep track of a list of new
208 stopped processes. */
211 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
213 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
216 new_pid
->status
= status
;
217 new_pid
->next
= *listp
;
222 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
224 struct simple_pid_list
**p
;
226 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
227 if ((*p
)->pid
== pid
)
229 struct simple_pid_list
*next
= (*p
)->next
;
231 *statusp
= (*p
)->status
;
239 enum stopping_threads_kind
241 /* Not stopping threads presently. */
242 NOT_STOPPING_THREADS
,
244 /* Stopping threads. */
247 /* Stopping and suspending threads. */
248 STOPPING_AND_SUSPENDING_THREADS
251 /* This is set while stop_all_lwps is in effect. */
252 enum stopping_threads_kind stopping_threads
= NOT_STOPPING_THREADS
;
254 /* FIXME make into a target method? */
255 int using_threads
= 1;
257 /* True if we're presently stabilizing threads (moving them out of
259 static int stabilizing_threads
;
261 static void linux_resume_one_lwp (struct lwp_info
*lwp
,
262 int step
, int signal
, siginfo_t
*info
);
263 static void linux_resume (struct thread_resume
*resume_info
, size_t n
);
264 static void stop_all_lwps (int suspend
, struct lwp_info
*except
);
265 static void unstop_all_lwps (int unsuspend
, struct lwp_info
*except
);
266 static void unsuspend_all_lwps (struct lwp_info
*except
);
267 static int linux_wait_for_event_filtered (ptid_t wait_ptid
, ptid_t filter_ptid
,
268 int *wstat
, int options
);
269 static int linux_wait_for_event (ptid_t ptid
, int *wstat
, int options
);
270 static struct lwp_info
*add_lwp (ptid_t ptid
);
271 static void linux_mourn (struct process_info
*process
);
272 static int linux_stopped_by_watchpoint (void);
273 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
274 static int lwp_is_marked_dead (struct lwp_info
*lwp
);
275 static void proceed_all_lwps (void);
276 static int finish_step_over (struct lwp_info
*lwp
);
277 static int kill_lwp (unsigned long lwpid
, int signo
);
278 static void enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
);
279 static void complete_ongoing_step_over (void);
280 static int linux_low_ptrace_options (int attached
);
281 static int check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
);
282 static int proceed_one_lwp (thread_info
*thread
, void *except
);
284 /* When the event-loop is doing a step-over, this points at the thread
286 ptid_t step_over_bkpt
;
288 /* True if the low target can hardware single-step. */
291 can_hardware_single_step (void)
293 if (the_low_target
.supports_hardware_single_step
!= NULL
)
294 return the_low_target
.supports_hardware_single_step ();
299 /* True if the low target can software single-step. Such targets
300 implement the GET_NEXT_PCS callback. */
303 can_software_single_step (void)
305 return (the_low_target
.get_next_pcs
!= NULL
);
308 /* True if the low target supports memory breakpoints. If so, we'll
309 have a GET_PC implementation. */
312 supports_breakpoints (void)
314 return (the_low_target
.get_pc
!= NULL
);
317 /* Returns true if this target can support fast tracepoints. This
318 does not mean that the in-process agent has been loaded in the
322 supports_fast_tracepoints (void)
324 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
327 /* True if LWP is stopped in its stepping range. */
330 lwp_in_step_range (struct lwp_info
*lwp
)
332 CORE_ADDR pc
= lwp
->stop_pc
;
334 return (pc
>= lwp
->step_range_start
&& pc
< lwp
->step_range_end
);
337 struct pending_signals
341 struct pending_signals
*prev
;
344 /* The read/write ends of the pipe registered as waitable file in the
346 static int linux_event_pipe
[2] = { -1, -1 };
348 /* True if we're currently in async mode. */
349 #define target_is_async_p() (linux_event_pipe[0] != -1)
351 static void send_sigstop (struct lwp_info
*lwp
);
352 static void wait_for_sigstop (void);
354 /* Return non-zero if HEADER is a 64-bit ELF file. */
357 elf_64_header_p (const Elf64_Ehdr
*header
, unsigned int *machine
)
359 if (header
->e_ident
[EI_MAG0
] == ELFMAG0
360 && header
->e_ident
[EI_MAG1
] == ELFMAG1
361 && header
->e_ident
[EI_MAG2
] == ELFMAG2
362 && header
->e_ident
[EI_MAG3
] == ELFMAG3
)
364 *machine
= header
->e_machine
;
365 return header
->e_ident
[EI_CLASS
] == ELFCLASS64
;
372 /* Return non-zero if FILE is a 64-bit ELF file,
373 zero if the file is not a 64-bit ELF file,
374 and -1 if the file is not accessible or doesn't exist. */
377 elf_64_file_p (const char *file
, unsigned int *machine
)
382 fd
= open (file
, O_RDONLY
);
386 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
393 return elf_64_header_p (&header
, machine
);
396 /* Accepts an integer PID; Returns true if the executable PID is
397 running is a 64-bit ELF file.. */
400 linux_pid_exe_is_elf_64_file (int pid
, unsigned int *machine
)
404 sprintf (file
, "/proc/%d/exe", pid
);
405 return elf_64_file_p (file
, machine
);
409 delete_lwp (struct lwp_info
*lwp
)
411 struct thread_info
*thr
= get_lwp_thread (lwp
);
414 debug_printf ("deleting %ld\n", lwpid_of (thr
));
418 if (the_low_target
.delete_thread
!= NULL
)
419 the_low_target
.delete_thread (lwp
->arch_private
);
421 gdb_assert (lwp
->arch_private
== NULL
);
426 /* Add a process to the common process list, and set its private
429 static struct process_info
*
430 linux_add_process (int pid
, int attached
)
432 struct process_info
*proc
;
434 proc
= add_process (pid
, attached
);
435 proc
->priv
= XCNEW (struct process_info_private
);
437 if (the_low_target
.new_process
!= NULL
)
438 proc
->priv
->arch_private
= the_low_target
.new_process ();
443 static CORE_ADDR
get_pc (struct lwp_info
*lwp
);
445 /* Call the target arch_setup function on the current thread. */
448 linux_arch_setup (void)
450 the_low_target
.arch_setup ();
453 /* Call the target arch_setup function on THREAD. */
456 linux_arch_setup_thread (struct thread_info
*thread
)
458 struct thread_info
*saved_thread
;
460 saved_thread
= current_thread
;
461 current_thread
= thread
;
465 current_thread
= saved_thread
;
468 /* Handle a GNU/Linux extended wait response. If we see a clone,
469 fork, or vfork event, we need to add the new LWP to our list
470 (and return 0 so as not to report the trap to higher layers).
471 If we see an exec event, we will modify ORIG_EVENT_LWP to point
472 to a new LWP representing the new program. */
475 handle_extended_wait (struct lwp_info
**orig_event_lwp
, int wstat
)
477 struct lwp_info
*event_lwp
= *orig_event_lwp
;
478 int event
= linux_ptrace_get_extended_event (wstat
);
479 struct thread_info
*event_thr
= get_lwp_thread (event_lwp
);
480 struct lwp_info
*new_lwp
;
482 gdb_assert (event_lwp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
);
484 /* All extended events we currently use are mid-syscall. Only
485 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
486 you have to be using PTRACE_SEIZE to get that. */
487 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
489 if ((event
== PTRACE_EVENT_FORK
) || (event
== PTRACE_EVENT_VFORK
)
490 || (event
== PTRACE_EVENT_CLONE
))
493 unsigned long new_pid
;
496 /* Get the pid of the new lwp. */
497 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_thr
), (PTRACE_TYPE_ARG3
) 0,
500 /* If we haven't already seen the new PID stop, wait for it now. */
501 if (!pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
503 /* The new child has a pending SIGSTOP. We can't affect it until it
504 hits the SIGSTOP, but we're already attached. */
506 ret
= my_waitpid (new_pid
, &status
, __WALL
);
509 perror_with_name ("waiting for new child");
510 else if (ret
!= new_pid
)
511 warning ("wait returned unexpected PID %d", ret
);
512 else if (!WIFSTOPPED (status
))
513 warning ("wait returned unexpected status 0x%x", status
);
516 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
518 struct process_info
*parent_proc
;
519 struct process_info
*child_proc
;
520 struct lwp_info
*child_lwp
;
521 struct thread_info
*child_thr
;
522 struct target_desc
*tdesc
;
524 ptid
= ptid_build (new_pid
, new_pid
, 0);
528 debug_printf ("HEW: Got fork event from LWP %ld, "
530 ptid_get_lwp (ptid_of (event_thr
)),
531 ptid_get_pid (ptid
));
534 /* Add the new process to the tables and clone the breakpoint
535 lists of the parent. We need to do this even if the new process
536 will be detached, since we will need the process object and the
537 breakpoints to remove any breakpoints from memory when we
538 detach, and the client side will access registers. */
539 child_proc
= linux_add_process (new_pid
, 0);
540 gdb_assert (child_proc
!= NULL
);
541 child_lwp
= add_lwp (ptid
);
542 gdb_assert (child_lwp
!= NULL
);
543 child_lwp
->stopped
= 1;
544 child_lwp
->must_set_ptrace_flags
= 1;
545 child_lwp
->status_pending_p
= 0;
546 child_thr
= get_lwp_thread (child_lwp
);
547 child_thr
->last_resume_kind
= resume_stop
;
548 child_thr
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
550 /* If we're suspending all threads, leave this one suspended
551 too. If the fork/clone parent is stepping over a breakpoint,
552 all other threads have been suspended already. Leave the
553 child suspended too. */
554 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
555 || event_lwp
->bp_reinsert
!= 0)
558 debug_printf ("HEW: leaving child suspended\n");
559 child_lwp
->suspended
= 1;
562 parent_proc
= get_thread_process (event_thr
);
563 child_proc
->attached
= parent_proc
->attached
;
565 if (event_lwp
->bp_reinsert
!= 0
566 && can_software_single_step ()
567 && event
== PTRACE_EVENT_VFORK
)
569 /* If we leave single-step breakpoints there, child will
570 hit it, so uninsert single-step breakpoints from parent
571 (and child). Once vfork child is done, reinsert
572 them back to parent. */
573 uninsert_single_step_breakpoints (event_thr
);
576 clone_all_breakpoints (child_thr
, event_thr
);
578 tdesc
= allocate_target_description ();
579 copy_target_description (tdesc
, parent_proc
->tdesc
);
580 child_proc
->tdesc
= tdesc
;
582 /* Clone arch-specific process data. */
583 if (the_low_target
.new_fork
!= NULL
)
584 the_low_target
.new_fork (parent_proc
, child_proc
);
586 /* Save fork info in the parent thread. */
587 if (event
== PTRACE_EVENT_FORK
)
588 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_FORKED
;
589 else if (event
== PTRACE_EVENT_VFORK
)
590 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_VFORKED
;
592 event_lwp
->waitstatus
.value
.related_pid
= ptid
;
594 /* The status_pending field contains bits denoting the
595 extended event, so when the pending event is handled,
596 the handler will look at lwp->waitstatus. */
597 event_lwp
->status_pending_p
= 1;
598 event_lwp
->status_pending
= wstat
;
600 /* Link the threads until the parent event is passed on to
602 event_lwp
->fork_relative
= child_lwp
;
603 child_lwp
->fork_relative
= event_lwp
;
605 /* If the parent thread is doing step-over with single-step
606 breakpoints, the list of single-step breakpoints are cloned
607 from the parent's. Remove them from the child process.
608 In case of vfork, we'll reinsert them back once vforked
610 if (event_lwp
->bp_reinsert
!= 0
611 && can_software_single_step ())
613 /* The child process is forked and stopped, so it is safe
614 to access its memory without stopping all other threads
615 from other processes. */
616 delete_single_step_breakpoints (child_thr
);
618 gdb_assert (has_single_step_breakpoints (event_thr
));
619 gdb_assert (!has_single_step_breakpoints (child_thr
));
622 /* Report the event. */
627 debug_printf ("HEW: Got clone event "
628 "from LWP %ld, new child is LWP %ld\n",
629 lwpid_of (event_thr
), new_pid
);
631 ptid
= ptid_build (pid_of (event_thr
), new_pid
, 0);
632 new_lwp
= add_lwp (ptid
);
634 /* Either we're going to immediately resume the new thread
635 or leave it stopped. linux_resume_one_lwp is a nop if it
636 thinks the thread is currently running, so set this first
637 before calling linux_resume_one_lwp. */
638 new_lwp
->stopped
= 1;
640 /* If we're suspending all threads, leave this one suspended
641 too. If the fork/clone parent is stepping over a breakpoint,
642 all other threads have been suspended already. Leave the
643 child suspended too. */
644 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
645 || event_lwp
->bp_reinsert
!= 0)
646 new_lwp
->suspended
= 1;
648 /* Normally we will get the pending SIGSTOP. But in some cases
649 we might get another signal delivered to the group first.
650 If we do get another signal, be sure not to lose it. */
651 if (WSTOPSIG (status
) != SIGSTOP
)
653 new_lwp
->stop_expected
= 1;
654 new_lwp
->status_pending_p
= 1;
655 new_lwp
->status_pending
= status
;
657 else if (report_thread_events
)
659 new_lwp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
660 new_lwp
->status_pending_p
= 1;
661 new_lwp
->status_pending
= status
;
664 thread_db_notice_clone (event_thr
, ptid
);
666 /* Don't report the event. */
669 else if (event
== PTRACE_EVENT_VFORK_DONE
)
671 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
673 if (event_lwp
->bp_reinsert
!= 0 && can_software_single_step ())
675 reinsert_single_step_breakpoints (event_thr
);
677 gdb_assert (has_single_step_breakpoints (event_thr
));
680 /* Report the event. */
683 else if (event
== PTRACE_EVENT_EXEC
&& report_exec_events
)
685 struct process_info
*proc
;
686 std::vector
<int> syscalls_to_catch
;
692 debug_printf ("HEW: Got exec event from LWP %ld\n",
693 lwpid_of (event_thr
));
696 /* Get the event ptid. */
697 event_ptid
= ptid_of (event_thr
);
698 event_pid
= ptid_get_pid (event_ptid
);
700 /* Save the syscall list from the execing process. */
701 proc
= get_thread_process (event_thr
);
702 syscalls_to_catch
= std::move (proc
->syscalls_to_catch
);
704 /* Delete the execing process and all its threads. */
706 current_thread
= NULL
;
708 /* Create a new process/lwp/thread. */
709 proc
= linux_add_process (event_pid
, 0);
710 event_lwp
= add_lwp (event_ptid
);
711 event_thr
= get_lwp_thread (event_lwp
);
712 gdb_assert (current_thread
== event_thr
);
713 linux_arch_setup_thread (event_thr
);
715 /* Set the event status. */
716 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_EXECD
;
717 event_lwp
->waitstatus
.value
.execd_pathname
718 = xstrdup (linux_proc_pid_to_exec_file (lwpid_of (event_thr
)));
720 /* Mark the exec status as pending. */
721 event_lwp
->stopped
= 1;
722 event_lwp
->status_pending_p
= 1;
723 event_lwp
->status_pending
= wstat
;
724 event_thr
->last_resume_kind
= resume_continue
;
725 event_thr
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
727 /* Update syscall state in the new lwp, effectively mid-syscall too. */
728 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
730 /* Restore the list to catch. Don't rely on the client, which is free
731 to avoid sending a new list when the architecture doesn't change.
732 Also, for ANY_SYSCALL, the architecture doesn't really matter. */
733 proc
->syscalls_to_catch
= std::move (syscalls_to_catch
);
735 /* Report the event. */
736 *orig_event_lwp
= event_lwp
;
740 internal_error (__FILE__
, __LINE__
, _("unknown ptrace event %d"), event
);
743 /* Return the PC as read from the regcache of LWP, without any
747 get_pc (struct lwp_info
*lwp
)
749 struct thread_info
*saved_thread
;
750 struct regcache
*regcache
;
753 if (the_low_target
.get_pc
== NULL
)
756 saved_thread
= current_thread
;
757 current_thread
= get_lwp_thread (lwp
);
759 regcache
= get_thread_regcache (current_thread
, 1);
760 pc
= (*the_low_target
.get_pc
) (regcache
);
763 debug_printf ("pc is 0x%lx\n", (long) pc
);
765 current_thread
= saved_thread
;
769 /* This function should only be called if LWP got a SYSCALL_SIGTRAP.
770 Fill *SYSNO with the syscall nr trapped. */
773 get_syscall_trapinfo (struct lwp_info
*lwp
, int *sysno
)
775 struct thread_info
*saved_thread
;
776 struct regcache
*regcache
;
778 if (the_low_target
.get_syscall_trapinfo
== NULL
)
780 /* If we cannot get the syscall trapinfo, report an unknown
781 system call number. */
782 *sysno
= UNKNOWN_SYSCALL
;
786 saved_thread
= current_thread
;
787 current_thread
= get_lwp_thread (lwp
);
789 regcache
= get_thread_regcache (current_thread
, 1);
790 (*the_low_target
.get_syscall_trapinfo
) (regcache
, sysno
);
793 debug_printf ("get_syscall_trapinfo sysno %d\n", *sysno
);
795 current_thread
= saved_thread
;
798 static int check_stopped_by_watchpoint (struct lwp_info
*child
);
800 /* Called when the LWP stopped for a signal/trap. If it stopped for a
801 trap check what caused it (breakpoint, watchpoint, trace, etc.),
802 and save the result in the LWP's stop_reason field. If it stopped
803 for a breakpoint, decrement the PC if necessary on the lwp's
804 architecture. Returns true if we now have the LWP's stop PC. */
807 save_stop_reason (struct lwp_info
*lwp
)
810 CORE_ADDR sw_breakpoint_pc
;
811 struct thread_info
*saved_thread
;
812 #if USE_SIGTRAP_SIGINFO
816 if (the_low_target
.get_pc
== NULL
)
820 sw_breakpoint_pc
= pc
- the_low_target
.decr_pc_after_break
;
822 /* breakpoint_at reads from the current thread. */
823 saved_thread
= current_thread
;
824 current_thread
= get_lwp_thread (lwp
);
826 #if USE_SIGTRAP_SIGINFO
827 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
828 (PTRACE_TYPE_ARG3
) 0, &siginfo
) == 0)
830 if (siginfo
.si_signo
== SIGTRAP
)
832 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
833 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
835 /* The si_code is ambiguous on this arch -- check debug
837 if (!check_stopped_by_watchpoint (lwp
))
838 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
840 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
842 /* If we determine the LWP stopped for a SW breakpoint,
843 trust it. Particularly don't check watchpoint
844 registers, because at least on s390, we'd find
845 stopped-by-watchpoint as long as there's a watchpoint
847 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
849 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
851 /* This can indicate either a hardware breakpoint or
852 hardware watchpoint. Check debug registers. */
853 if (!check_stopped_by_watchpoint (lwp
))
854 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
856 else if (siginfo
.si_code
== TRAP_TRACE
)
858 /* We may have single stepped an instruction that
859 triggered a watchpoint. In that case, on some
860 architectures (such as x86), instead of TRAP_HWBKPT,
861 si_code indicates TRAP_TRACE, and we need to check
862 the debug registers separately. */
863 if (!check_stopped_by_watchpoint (lwp
))
864 lwp
->stop_reason
= TARGET_STOPPED_BY_SINGLE_STEP
;
869 /* We may have just stepped a breakpoint instruction. E.g., in
870 non-stop mode, GDB first tells the thread A to step a range, and
871 then the user inserts a breakpoint inside the range. In that
872 case we need to report the breakpoint PC. */
873 if ((!lwp
->stepping
|| lwp
->stop_pc
== sw_breakpoint_pc
)
874 && (*the_low_target
.breakpoint_at
) (sw_breakpoint_pc
))
875 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
877 if (hardware_breakpoint_inserted_here (pc
))
878 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
880 if (lwp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
881 check_stopped_by_watchpoint (lwp
);
884 if (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
888 struct thread_info
*thr
= get_lwp_thread (lwp
);
890 debug_printf ("CSBB: %s stopped by software breakpoint\n",
891 target_pid_to_str (ptid_of (thr
)));
894 /* Back up the PC if necessary. */
895 if (pc
!= sw_breakpoint_pc
)
897 struct regcache
*regcache
898 = get_thread_regcache (current_thread
, 1);
899 (*the_low_target
.set_pc
) (regcache
, sw_breakpoint_pc
);
902 /* Update this so we record the correct stop PC below. */
903 pc
= sw_breakpoint_pc
;
905 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
909 struct thread_info
*thr
= get_lwp_thread (lwp
);
911 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
912 target_pid_to_str (ptid_of (thr
)));
915 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
919 struct thread_info
*thr
= get_lwp_thread (lwp
);
921 debug_printf ("CSBB: %s stopped by hardware watchpoint\n",
922 target_pid_to_str (ptid_of (thr
)));
925 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
929 struct thread_info
*thr
= get_lwp_thread (lwp
);
931 debug_printf ("CSBB: %s stopped by trace\n",
932 target_pid_to_str (ptid_of (thr
)));
937 current_thread
= saved_thread
;
941 static struct lwp_info
*
942 add_lwp (ptid_t ptid
)
944 struct lwp_info
*lwp
;
946 lwp
= XCNEW (struct lwp_info
);
948 lwp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
950 if (the_low_target
.new_thread
!= NULL
)
951 the_low_target
.new_thread (lwp
);
953 lwp
->thread
= add_thread (ptid
, lwp
);
958 /* Callback to be used when calling fork_inferior, responsible for
959 actually initiating the tracing of the inferior. */
964 if (ptrace (PTRACE_TRACEME
, 0, (PTRACE_TYPE_ARG3
) 0,
965 (PTRACE_TYPE_ARG4
) 0) < 0)
966 trace_start_error_with_name ("ptrace");
968 if (setpgid (0, 0) < 0)
969 trace_start_error_with_name ("setpgid");
971 /* If GDBserver is connected to gdb via stdio, redirect the inferior's
972 stdout to stderr so that inferior i/o doesn't corrupt the connection.
973 Also, redirect stdin to /dev/null. */
974 if (remote_connection_is_stdio ())
977 trace_start_error_with_name ("close");
978 if (open ("/dev/null", O_RDONLY
) < 0)
979 trace_start_error_with_name ("open");
981 trace_start_error_with_name ("dup2");
982 if (write (2, "stdin/stdout redirected\n",
983 sizeof ("stdin/stdout redirected\n") - 1) < 0)
985 /* Errors ignored. */;
990 /* Start an inferior process and returns its pid.
991 PROGRAM is the name of the program to be started, and PROGRAM_ARGS
992 are its arguments. */
995 linux_create_inferior (const char *program
,
996 const std::vector
<char *> &program_args
)
998 struct lwp_info
*new_lwp
;
1003 maybe_disable_address_space_randomization restore_personality
1004 (disable_randomization
);
1005 std::string str_program_args
= stringify_argv (program_args
);
1007 pid
= fork_inferior (program
,
1008 str_program_args
.c_str (),
1009 get_environ ()->envp (), linux_ptrace_fun
,
1010 NULL
, NULL
, NULL
, NULL
);
1013 linux_add_process (pid
, 0);
1015 ptid
= ptid_build (pid
, pid
, 0);
1016 new_lwp
= add_lwp (ptid
);
1017 new_lwp
->must_set_ptrace_flags
= 1;
1019 post_fork_inferior (pid
, program
);
1024 /* Implement the post_create_inferior target_ops method. */
1027 linux_post_create_inferior (void)
1029 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
1031 linux_arch_setup ();
1033 if (lwp
->must_set_ptrace_flags
)
1035 struct process_info
*proc
= current_process ();
1036 int options
= linux_low_ptrace_options (proc
->attached
);
1038 linux_enable_event_reporting (lwpid_of (current_thread
), options
);
1039 lwp
->must_set_ptrace_flags
= 0;
1043 /* Attach to an inferior process. Returns 0 on success, ERRNO on
1047 linux_attach_lwp (ptid_t ptid
)
1049 struct lwp_info
*new_lwp
;
1050 int lwpid
= ptid_get_lwp (ptid
);
1052 if (ptrace (PTRACE_ATTACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0)
1056 new_lwp
= add_lwp (ptid
);
1058 /* We need to wait for SIGSTOP before being able to make the next
1059 ptrace call on this LWP. */
1060 new_lwp
->must_set_ptrace_flags
= 1;
1062 if (linux_proc_pid_is_stopped (lwpid
))
1065 debug_printf ("Attached to a stopped process\n");
1067 /* The process is definitely stopped. It is in a job control
1068 stop, unless the kernel predates the TASK_STOPPED /
1069 TASK_TRACED distinction, in which case it might be in a
1070 ptrace stop. Make sure it is in a ptrace stop; from there we
1071 can kill it, signal it, et cetera.
1073 First make sure there is a pending SIGSTOP. Since we are
1074 already attached, the process can not transition from stopped
1075 to running without a PTRACE_CONT; so we know this signal will
1076 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1077 probably already in the queue (unless this kernel is old
1078 enough to use TASK_STOPPED for ptrace stops); but since
1079 SIGSTOP is not an RT signal, it can only be queued once. */
1080 kill_lwp (lwpid
, SIGSTOP
);
1082 /* Finally, resume the stopped process. This will deliver the
1083 SIGSTOP (or a higher priority signal, just like normal
1084 PTRACE_ATTACH), which we'll catch later on. */
1085 ptrace (PTRACE_CONT
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1088 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
1089 brings it to a halt.
1091 There are several cases to consider here:
1093 1) gdbserver has already attached to the process and is being notified
1094 of a new thread that is being created.
1095 In this case we should ignore that SIGSTOP and resume the
1096 process. This is handled below by setting stop_expected = 1,
1097 and the fact that add_thread sets last_resume_kind ==
1100 2) This is the first thread (the process thread), and we're attaching
1101 to it via attach_inferior.
1102 In this case we want the process thread to stop.
1103 This is handled by having linux_attach set last_resume_kind ==
1104 resume_stop after we return.
1106 If the pid we are attaching to is also the tgid, we attach to and
1107 stop all the existing threads. Otherwise, we attach to pid and
1108 ignore any other threads in the same group as this pid.
1110 3) GDB is connecting to gdbserver and is requesting an enumeration of all
1112 In this case we want the thread to stop.
1113 FIXME: This case is currently not properly handled.
1114 We should wait for the SIGSTOP but don't. Things work apparently
1115 because enough time passes between when we ptrace (ATTACH) and when
1116 gdb makes the next ptrace call on the thread.
1118 On the other hand, if we are currently trying to stop all threads, we
1119 should treat the new thread as if we had sent it a SIGSTOP. This works
1120 because we are guaranteed that the add_lwp call above added us to the
1121 end of the list, and so the new thread has not yet reached
1122 wait_for_sigstop (but will). */
1123 new_lwp
->stop_expected
= 1;
1128 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1129 already attached. Returns true if a new LWP is found, false
1133 attach_proc_task_lwp_callback (ptid_t ptid
)
1135 /* Is this a new thread? */
1136 if (find_thread_ptid (ptid
) == NULL
)
1138 int lwpid
= ptid_get_lwp (ptid
);
1142 debug_printf ("Found new lwp %d\n", lwpid
);
1144 err
= linux_attach_lwp (ptid
);
1146 /* Be quiet if we simply raced with the thread exiting. EPERM
1147 is returned if the thread's task still exists, and is marked
1148 as exited or zombie, as well as other conditions, so in that
1149 case, confirm the status in /proc/PID/status. */
1151 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1155 debug_printf ("Cannot attach to lwp %d: "
1156 "thread is gone (%d: %s)\n",
1157 lwpid
, err
, strerror (err
));
1162 warning (_("Cannot attach to lwp %d: %s"),
1164 linux_ptrace_attach_fail_reason_string (ptid
, err
));
1172 static void async_file_mark (void);
1174 /* Attach to PID. If PID is the tgid, attach to it and all
1178 linux_attach (unsigned long pid
)
1180 struct process_info
*proc
;
1181 struct thread_info
*initial_thread
;
1182 ptid_t ptid
= ptid_build (pid
, pid
, 0);
1185 /* Attach to PID. We will check for other threads
1187 err
= linux_attach_lwp (ptid
);
1189 error ("Cannot attach to process %ld: %s",
1190 pid
, linux_ptrace_attach_fail_reason_string (ptid
, err
));
1192 proc
= linux_add_process (pid
, 1);
1194 /* Don't ignore the initial SIGSTOP if we just attached to this
1195 process. It will be collected by wait shortly. */
1196 initial_thread
= find_thread_ptid (ptid_build (pid
, pid
, 0));
1197 initial_thread
->last_resume_kind
= resume_stop
;
1199 /* We must attach to every LWP. If /proc is mounted, use that to
1200 find them now. On the one hand, the inferior may be using raw
1201 clone instead of using pthreads. On the other hand, even if it
1202 is using pthreads, GDB may not be connected yet (thread_db needs
1203 to do symbol lookups, through qSymbol). Also, thread_db walks
1204 structures in the inferior's address space to find the list of
1205 threads/LWPs, and those structures may well be corrupted. Note
1206 that once thread_db is loaded, we'll still use it to list threads
1207 and associate pthread info with each LWP. */
1208 linux_proc_attach_tgid_threads (pid
, attach_proc_task_lwp_callback
);
1210 /* GDB will shortly read the xml target description for this
1211 process, to figure out the process' architecture. But the target
1212 description is only filled in when the first process/thread in
1213 the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do
1214 that now, otherwise, if GDB is fast enough, it could read the
1215 target description _before_ that initial stop. */
1218 struct lwp_info
*lwp
;
1220 ptid_t pid_ptid
= pid_to_ptid (pid
);
1222 lwpid
= linux_wait_for_event_filtered (pid_ptid
, pid_ptid
,
1224 gdb_assert (lwpid
> 0);
1226 lwp
= find_lwp_pid (pid_to_ptid (lwpid
));
1228 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGSTOP
)
1230 lwp
->status_pending_p
= 1;
1231 lwp
->status_pending
= wstat
;
1234 initial_thread
->last_resume_kind
= resume_continue
;
1238 gdb_assert (proc
->tdesc
!= NULL
);
1245 last_thread_of_process_p (int pid
)
1247 bool seen_one
= false;
1249 thread_info
*thread
= find_thread (pid
, [&] (thread_info
*thread
)
1253 /* This is the first thread of this process we see. */
1259 /* This is the second thread of this process we see. */
1264 return thread
== NULL
;
1270 linux_kill_one_lwp (struct lwp_info
*lwp
)
1272 struct thread_info
*thr
= get_lwp_thread (lwp
);
1273 int pid
= lwpid_of (thr
);
1275 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1276 there is no signal context, and ptrace(PTRACE_KILL) (or
1277 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1278 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1279 alternative is to kill with SIGKILL. We only need one SIGKILL
1280 per process, not one for each thread. But since we still support
1281 support debugging programs using raw clone without CLONE_THREAD,
1282 we send one for each thread. For years, we used PTRACE_KILL
1283 only, so we're being a bit paranoid about some old kernels where
1284 PTRACE_KILL might work better (dubious if there are any such, but
1285 that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL
1286 second, and so we're fine everywhere. */
1289 kill_lwp (pid
, SIGKILL
);
1292 int save_errno
= errno
;
1294 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1295 target_pid_to_str (ptid_of (thr
)),
1296 save_errno
? strerror (save_errno
) : "OK");
1300 ptrace (PTRACE_KILL
, pid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1303 int save_errno
= errno
;
1305 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1306 target_pid_to_str (ptid_of (thr
)),
1307 save_errno
? strerror (save_errno
) : "OK");
1311 /* Kill LWP and wait for it to die. */
1314 kill_wait_lwp (struct lwp_info
*lwp
)
1316 struct thread_info
*thr
= get_lwp_thread (lwp
);
1317 int pid
= ptid_get_pid (ptid_of (thr
));
1318 int lwpid
= ptid_get_lwp (ptid_of (thr
));
1323 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid
, pid
);
1327 linux_kill_one_lwp (lwp
);
1329 /* Make sure it died. Notes:
1331 - The loop is most likely unnecessary.
1333 - We don't use linux_wait_for_event as that could delete lwps
1334 while we're iterating over them. We're not interested in
1335 any pending status at this point, only in making sure all
1336 wait status on the kernel side are collected until the
1339 - We don't use __WALL here as the __WALL emulation relies on
1340 SIGCHLD, and killing a stopped process doesn't generate
1341 one, nor an exit status.
1343 res
= my_waitpid (lwpid
, &wstat
, 0);
1344 if (res
== -1 && errno
== ECHILD
)
1345 res
= my_waitpid (lwpid
, &wstat
, __WCLONE
);
1346 } while (res
> 0 && WIFSTOPPED (wstat
));
1348 /* Even if it was stopped, the child may have already disappeared.
1349 E.g., if it was killed by SIGKILL. */
1350 if (res
< 0 && errno
!= ECHILD
)
1351 perror_with_name ("kill_wait_lwp");
1354 /* Callback for `for_each_thread'. Kills an lwp of a given process,
1355 except the leader. */
1358 kill_one_lwp_callback (thread_info
*thread
, int pid
)
1360 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1362 /* We avoid killing the first thread here, because of a Linux kernel (at
1363 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1364 the children get a chance to be reaped, it will remain a zombie
1367 if (lwpid_of (thread
) == pid
)
1370 debug_printf ("lkop: is last of process %s\n",
1371 target_pid_to_str (thread
->id
));
1375 kill_wait_lwp (lwp
);
1379 linux_kill (int pid
)
1381 struct process_info
*process
;
1382 struct lwp_info
*lwp
;
1384 process
= find_process_pid (pid
);
1385 if (process
== NULL
)
1388 /* If we're killing a running inferior, make sure it is stopped
1389 first, as PTRACE_KILL will not work otherwise. */
1390 stop_all_lwps (0, NULL
);
1392 for_each_thread (pid
, [&] (thread_info
*thread
)
1394 kill_one_lwp_callback (thread
, pid
);
1397 /* See the comment in linux_kill_one_lwp. We did not kill the first
1398 thread in the list, so do so now. */
1399 lwp
= find_lwp_pid (pid_to_ptid (pid
));
1404 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1408 kill_wait_lwp (lwp
);
1410 the_target
->mourn (process
);
1412 /* Since we presently can only stop all lwps of all processes, we
1413 need to unstop lwps of other processes. */
1414 unstop_all_lwps (0, NULL
);
1418 /* Get pending signal of THREAD, for detaching purposes. This is the
1419 signal the thread last stopped for, which we need to deliver to the
1420 thread when detaching, otherwise, it'd be suppressed/lost. */
1423 get_detach_signal (struct thread_info
*thread
)
1425 enum gdb_signal signo
= GDB_SIGNAL_0
;
1427 struct lwp_info
*lp
= get_thread_lwp (thread
);
1429 if (lp
->status_pending_p
)
1430 status
= lp
->status_pending
;
1433 /* If the thread had been suspended by gdbserver, and it stopped
1434 cleanly, then it'll have stopped with SIGSTOP. But we don't
1435 want to deliver that SIGSTOP. */
1436 if (thread
->last_status
.kind
!= TARGET_WAITKIND_STOPPED
1437 || thread
->last_status
.value
.sig
== GDB_SIGNAL_0
)
1440 /* Otherwise, we may need to deliver the signal we
1442 status
= lp
->last_status
;
1445 if (!WIFSTOPPED (status
))
1448 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1449 target_pid_to_str (ptid_of (thread
)));
1453 /* Extended wait statuses aren't real SIGTRAPs. */
1454 if (WSTOPSIG (status
) == SIGTRAP
&& linux_is_extended_waitstatus (status
))
1457 debug_printf ("GPS: lwp %s had stopped with extended "
1458 "status: no pending signal\n",
1459 target_pid_to_str (ptid_of (thread
)));
1463 signo
= gdb_signal_from_host (WSTOPSIG (status
));
1465 if (program_signals_p
&& !program_signals
[signo
])
1468 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1469 target_pid_to_str (ptid_of (thread
)),
1470 gdb_signal_to_string (signo
));
1473 else if (!program_signals_p
1474 /* If we have no way to know which signals GDB does not
1475 want to have passed to the program, assume
1476 SIGTRAP/SIGINT, which is GDB's default. */
1477 && (signo
== GDB_SIGNAL_TRAP
|| signo
== GDB_SIGNAL_INT
))
1480 debug_printf ("GPS: lwp %s had signal %s, "
1481 "but we don't know if we should pass it. "
1482 "Default to not.\n",
1483 target_pid_to_str (ptid_of (thread
)),
1484 gdb_signal_to_string (signo
));
1490 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1491 target_pid_to_str (ptid_of (thread
)),
1492 gdb_signal_to_string (signo
));
1494 return WSTOPSIG (status
);
1498 /* Detach from LWP. */
1501 linux_detach_one_lwp (struct lwp_info
*lwp
)
1503 struct thread_info
*thread
= get_lwp_thread (lwp
);
1507 /* If there is a pending SIGSTOP, get rid of it. */
1508 if (lwp
->stop_expected
)
1511 debug_printf ("Sending SIGCONT to %s\n",
1512 target_pid_to_str (ptid_of (thread
)));
1514 kill_lwp (lwpid_of (thread
), SIGCONT
);
1515 lwp
->stop_expected
= 0;
1518 /* Pass on any pending signal for this thread. */
1519 sig
= get_detach_signal (thread
);
1521 /* Preparing to resume may try to write registers, and fail if the
1522 lwp is zombie. If that happens, ignore the error. We'll handle
1523 it below, when detach fails with ESRCH. */
1526 /* Flush any pending changes to the process's registers. */
1527 regcache_invalidate_thread (thread
);
1529 /* Finally, let it resume. */
1530 if (the_low_target
.prepare_to_resume
!= NULL
)
1531 the_low_target
.prepare_to_resume (lwp
);
1533 CATCH (ex
, RETURN_MASK_ERROR
)
1535 if (!check_ptrace_stopped_lwp_gone (lwp
))
1536 throw_exception (ex
);
1540 lwpid
= lwpid_of (thread
);
1541 if (ptrace (PTRACE_DETACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0,
1542 (PTRACE_TYPE_ARG4
) (long) sig
) < 0)
1544 int save_errno
= errno
;
1546 /* We know the thread exists, so ESRCH must mean the lwp is
1547 zombie. This can happen if one of the already-detached
1548 threads exits the whole thread group. In that case we're
1549 still attached, and must reap the lwp. */
1550 if (save_errno
== ESRCH
)
1554 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1557 warning (_("Couldn't reap LWP %d while detaching: %s"),
1558 lwpid
, strerror (errno
));
1560 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1562 warning (_("Reaping LWP %d while detaching "
1563 "returned unexpected status 0x%x"),
1569 error (_("Can't detach %s: %s"),
1570 target_pid_to_str (ptid_of (thread
)),
1571 strerror (save_errno
));
1574 else if (debug_threads
)
1576 debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)\n",
1577 target_pid_to_str (ptid_of (thread
)),
1584 /* Callback for for_each_thread. Detaches from non-leader threads of a
1588 linux_detach_lwp_callback (thread_info
*thread
)
1590 /* We don't actually detach from the thread group leader just yet.
1591 If the thread group exits, we must reap the zombie clone lwps
1592 before we're able to reap the leader. */
1593 if (thread
->id
.pid () == thread
->id
.lwp ())
1596 lwp_info
*lwp
= get_thread_lwp (thread
);
1597 linux_detach_one_lwp (lwp
);
1601 linux_detach (int pid
)
1603 struct process_info
*process
;
1604 struct lwp_info
*main_lwp
;
1606 process
= find_process_pid (pid
);
1607 if (process
== NULL
)
1610 /* As there's a step over already in progress, let it finish first,
1611 otherwise nesting a stabilize_threads operation on top gets real
1613 complete_ongoing_step_over ();
1615 /* Stop all threads before detaching. First, ptrace requires that
1616 the thread is stopped to sucessfully detach. Second, thread_db
1617 may need to uninstall thread event breakpoints from memory, which
1618 only works with a stopped process anyway. */
1619 stop_all_lwps (0, NULL
);
1621 #ifdef USE_THREAD_DB
1622 thread_db_detach (process
);
1625 /* Stabilize threads (move out of jump pads). */
1626 stabilize_threads ();
1628 /* Detach from the clone lwps first. If the thread group exits just
1629 while we're detaching, we must reap the clone lwps before we're
1630 able to reap the leader. */
1631 for_each_thread (pid
, linux_detach_lwp_callback
);
1633 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1634 linux_detach_one_lwp (main_lwp
);
1636 the_target
->mourn (process
);
1638 /* Since we presently can only stop all lwps of all processes, we
1639 need to unstop lwps of other processes. */
1640 unstop_all_lwps (0, NULL
);
1644 /* Remove all LWPs that belong to process PROC from the lwp list. */
1647 linux_mourn (struct process_info
*process
)
1649 struct process_info_private
*priv
;
1651 #ifdef USE_THREAD_DB
1652 thread_db_mourn (process
);
1655 for_each_thread (process
->pid
, [] (thread_info
*thread
)
1657 delete_lwp (get_thread_lwp (thread
));
1660 /* Freeing all private data. */
1661 priv
= process
->priv
;
1662 if (the_low_target
.delete_process
!= NULL
)
1663 the_low_target
.delete_process (priv
->arch_private
);
1665 gdb_assert (priv
->arch_private
== NULL
);
1667 process
->priv
= NULL
;
1669 remove_process (process
);
1673 linux_join (int pid
)
1678 ret
= my_waitpid (pid
, &status
, 0);
1679 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1681 } while (ret
!= -1 || errno
!= ECHILD
);
1684 /* Return nonzero if the given thread is still alive. */
1686 linux_thread_alive (ptid_t ptid
)
1688 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1690 /* We assume we always know if a thread exits. If a whole process
1691 exited but we still haven't been able to report it to GDB, we'll
1692 hold on to the last lwp of the dead process. */
1694 return !lwp_is_marked_dead (lwp
);
1699 /* Return 1 if this lwp still has an interesting status pending. If
1700 not (e.g., it had stopped for a breakpoint that is gone), return
1704 thread_still_has_status_pending_p (struct thread_info
*thread
)
1706 struct lwp_info
*lp
= get_thread_lwp (thread
);
1708 if (!lp
->status_pending_p
)
1711 if (thread
->last_resume_kind
!= resume_stop
1712 && (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1713 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
1715 struct thread_info
*saved_thread
;
1719 gdb_assert (lp
->last_status
!= 0);
1723 saved_thread
= current_thread
;
1724 current_thread
= thread
;
1726 if (pc
!= lp
->stop_pc
)
1729 debug_printf ("PC of %ld changed\n",
1734 #if !USE_SIGTRAP_SIGINFO
1735 else if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1736 && !(*the_low_target
.breakpoint_at
) (pc
))
1739 debug_printf ("previous SW breakpoint of %ld gone\n",
1743 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
1744 && !hardware_breakpoint_inserted_here (pc
))
1747 debug_printf ("previous HW breakpoint of %ld gone\n",
1753 current_thread
= saved_thread
;
1758 debug_printf ("discarding pending breakpoint status\n");
1759 lp
->status_pending_p
= 0;
1767 /* Returns true if LWP is resumed from the client's perspective. */
1770 lwp_resumed (struct lwp_info
*lwp
)
1772 struct thread_info
*thread
= get_lwp_thread (lwp
);
1774 if (thread
->last_resume_kind
!= resume_stop
)
1777 /* Did gdb send us a `vCont;t', but we haven't reported the
1778 corresponding stop to gdb yet? If so, the thread is still
1779 resumed/running from gdb's perspective. */
1780 if (thread
->last_resume_kind
== resume_stop
1781 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
1787 /* Return true if this lwp has an interesting status pending. */
1789 status_pending_p_callback (thread_info
*thread
, ptid_t ptid
)
1791 struct lwp_info
*lp
= get_thread_lwp (thread
);
1793 /* Check if we're only interested in events from a specific process
1794 or a specific LWP. */
1795 if (!thread
->id
.matches (ptid
))
1798 if (!lwp_resumed (lp
))
1801 if (lp
->status_pending_p
1802 && !thread_still_has_status_pending_p (thread
))
1804 linux_resume_one_lwp (lp
, lp
->stepping
, GDB_SIGNAL_0
, NULL
);
1808 return lp
->status_pending_p
;
1812 find_lwp_pid (ptid_t ptid
)
1814 thread_info
*thread
= find_thread ([&] (thread_info
*thread
)
1816 int lwp
= ptid
.lwp () != 0 ? ptid
.lwp () : ptid
.pid ();
1817 return thread
->id
.lwp () == lwp
;
1823 return get_thread_lwp (thread
);
1826 /* Return the number of known LWPs in the tgid given by PID. */
1833 for_each_thread (pid
, [&] (thread_info
*thread
)
1841 /* See nat/linux-nat.h. */
1844 iterate_over_lwps (ptid_t filter
,
1845 iterate_over_lwps_ftype callback
,
1848 thread_info
*thread
= find_thread (filter
, [&] (thread_info
*thread
)
1850 lwp_info
*lwp
= get_thread_lwp (thread
);
1852 return callback (lwp
, data
);
1858 return get_thread_lwp (thread
);
1861 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1862 their exits until all other threads in the group have exited. */
1865 check_zombie_leaders (void)
1867 for_each_process ([] (process_info
*proc
) {
1868 pid_t leader_pid
= pid_of (proc
);
1869 struct lwp_info
*leader_lp
;
1871 leader_lp
= find_lwp_pid (pid_to_ptid (leader_pid
));
1874 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1875 "num_lwps=%d, zombie=%d\n",
1876 leader_pid
, leader_lp
!= NULL
, num_lwps (leader_pid
),
1877 linux_proc_pid_is_zombie (leader_pid
));
1879 if (leader_lp
!= NULL
&& !leader_lp
->stopped
1880 /* Check if there are other threads in the group, as we may
1881 have raced with the inferior simply exiting. */
1882 && !last_thread_of_process_p (leader_pid
)
1883 && linux_proc_pid_is_zombie (leader_pid
))
1885 /* A leader zombie can mean one of two things:
1887 - It exited, and there's an exit status pending
1888 available, or only the leader exited (not the whole
1889 program). In the latter case, we can't waitpid the
1890 leader's exit status until all other threads are gone.
1892 - There are 3 or more threads in the group, and a thread
1893 other than the leader exec'd. On an exec, the Linux
1894 kernel destroys all other threads (except the execing
1895 one) in the thread group, and resets the execing thread's
1896 tid to the tgid. No exit notification is sent for the
1897 execing thread -- from the ptracer's perspective, it
1898 appears as though the execing thread just vanishes.
1899 Until we reap all other threads except the leader and the
1900 execing thread, the leader will be zombie, and the
1901 execing thread will be in `D (disc sleep)'. As soon as
1902 all other threads are reaped, the execing thread changes
1903 it's tid to the tgid, and the previous (zombie) leader
1904 vanishes, giving place to the "new" leader. We could try
1905 distinguishing the exit and exec cases, by waiting once
1906 more, and seeing if something comes out, but it doesn't
1907 sound useful. The previous leader _does_ go away, and
1908 we'll re-add the new one once we see the exec event
1909 (which is just the same as what would happen if the
1910 previous leader did exit voluntarily before some other
1914 debug_printf ("CZL: Thread group leader %d zombie "
1915 "(it exited, or another thread execd).\n",
1918 delete_lwp (leader_lp
);
1923 /* Callback for `find_thread'. Returns the first LWP that is not
1927 not_stopped_callback (thread_info
*thread
, ptid_t filter
)
1929 if (!thread
->id
.matches (filter
))
1932 lwp_info
*lwp
= get_thread_lwp (thread
);
1934 return !lwp
->stopped
;
1937 /* Increment LWP's suspend count. */
1940 lwp_suspended_inc (struct lwp_info
*lwp
)
1944 if (debug_threads
&& lwp
->suspended
> 4)
1946 struct thread_info
*thread
= get_lwp_thread (lwp
);
1948 debug_printf ("LWP %ld has a suspiciously high suspend count,"
1949 " suspended=%d\n", lwpid_of (thread
), lwp
->suspended
);
1953 /* Decrement LWP's suspend count. */
1956 lwp_suspended_decr (struct lwp_info
*lwp
)
1960 if (lwp
->suspended
< 0)
1962 struct thread_info
*thread
= get_lwp_thread (lwp
);
1964 internal_error (__FILE__
, __LINE__
,
1965 "unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread
),
1970 /* This function should only be called if the LWP got a SIGTRAP.
1972 Handle any tracepoint steps or hits. Return true if a tracepoint
1973 event was handled, 0 otherwise. */
1976 handle_tracepoints (struct lwp_info
*lwp
)
1978 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1979 int tpoint_related_event
= 0;
1981 gdb_assert (lwp
->suspended
== 0);
1983 /* If this tracepoint hit causes a tracing stop, we'll immediately
1984 uninsert tracepoints. To do this, we temporarily pause all
1985 threads, unpatch away, and then unpause threads. We need to make
1986 sure the unpausing doesn't resume LWP too. */
1987 lwp_suspended_inc (lwp
);
1989 /* And we need to be sure that any all-threads-stopping doesn't try
1990 to move threads out of the jump pads, as it could deadlock the
1991 inferior (LWP could be in the jump pad, maybe even holding the
1994 /* Do any necessary step collect actions. */
1995 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1997 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1999 /* See if we just hit a tracepoint and do its main collect
2001 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
2003 lwp_suspended_decr (lwp
);
2005 gdb_assert (lwp
->suspended
== 0);
2006 gdb_assert (!stabilizing_threads
2007 || (lwp
->collecting_fast_tracepoint
2008 != fast_tpoint_collect_result::not_collecting
));
2010 if (tpoint_related_event
)
2013 debug_printf ("got a tracepoint event\n");
2020 /* Convenience wrapper. Returns information about LWP's fast tracepoint
2021 collection status. */
2023 static fast_tpoint_collect_result
2024 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
2025 struct fast_tpoint_collect_status
*status
)
2027 CORE_ADDR thread_area
;
2028 struct thread_info
*thread
= get_lwp_thread (lwp
);
2030 if (the_low_target
.get_thread_area
== NULL
)
2031 return fast_tpoint_collect_result::not_collecting
;
2033 /* Get the thread area address. This is used to recognize which
2034 thread is which when tracing with the in-process agent library.
2035 We don't read anything from the address, and treat it as opaque;
2036 it's the address itself that we assume is unique per-thread. */
2037 if ((*the_low_target
.get_thread_area
) (lwpid_of (thread
), &thread_area
) == -1)
2038 return fast_tpoint_collect_result::not_collecting
;
2040 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
2043 /* The reason we resume in the caller, is because we want to be able
2044 to pass lwp->status_pending as WSTAT, and we need to clear
2045 status_pending_p before resuming, otherwise, linux_resume_one_lwp
2046 refuses to resume. */
2049 maybe_move_out_of_jump_pad (struct lwp_info
*lwp
, int *wstat
)
2051 struct thread_info
*saved_thread
;
2053 saved_thread
= current_thread
;
2054 current_thread
= get_lwp_thread (lwp
);
2057 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
2058 && supports_fast_tracepoints ()
2059 && agent_loaded_p ())
2061 struct fast_tpoint_collect_status status
;
2064 debug_printf ("Checking whether LWP %ld needs to move out of the "
2066 lwpid_of (current_thread
));
2068 fast_tpoint_collect_result r
2069 = linux_fast_tracepoint_collecting (lwp
, &status
);
2072 || (WSTOPSIG (*wstat
) != SIGILL
2073 && WSTOPSIG (*wstat
) != SIGFPE
2074 && WSTOPSIG (*wstat
) != SIGSEGV
2075 && WSTOPSIG (*wstat
) != SIGBUS
))
2077 lwp
->collecting_fast_tracepoint
= r
;
2079 if (r
!= fast_tpoint_collect_result::not_collecting
)
2081 if (r
== fast_tpoint_collect_result::before_insn
2082 && lwp
->exit_jump_pad_bkpt
== NULL
)
2084 /* Haven't executed the original instruction yet.
2085 Set breakpoint there, and wait till it's hit,
2086 then single-step until exiting the jump pad. */
2087 lwp
->exit_jump_pad_bkpt
2088 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
2092 debug_printf ("Checking whether LWP %ld needs to move out of "
2093 "the jump pad...it does\n",
2094 lwpid_of (current_thread
));
2095 current_thread
= saved_thread
;
2102 /* If we get a synchronous signal while collecting, *and*
2103 while executing the (relocated) original instruction,
2104 reset the PC to point at the tpoint address, before
2105 reporting to GDB. Otherwise, it's an IPA lib bug: just
2106 report the signal to GDB, and pray for the best. */
2108 lwp
->collecting_fast_tracepoint
2109 = fast_tpoint_collect_result::not_collecting
;
2111 if (r
!= fast_tpoint_collect_result::not_collecting
2112 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
2113 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
2116 struct regcache
*regcache
;
2118 /* The si_addr on a few signals references the address
2119 of the faulting instruction. Adjust that as
2121 if ((WSTOPSIG (*wstat
) == SIGILL
2122 || WSTOPSIG (*wstat
) == SIGFPE
2123 || WSTOPSIG (*wstat
) == SIGBUS
2124 || WSTOPSIG (*wstat
) == SIGSEGV
)
2125 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
2126 (PTRACE_TYPE_ARG3
) 0, &info
) == 0
2127 /* Final check just to make sure we don't clobber
2128 the siginfo of non-kernel-sent signals. */
2129 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
2131 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
2132 ptrace (PTRACE_SETSIGINFO
, lwpid_of (current_thread
),
2133 (PTRACE_TYPE_ARG3
) 0, &info
);
2136 regcache
= get_thread_regcache (current_thread
, 1);
2137 (*the_low_target
.set_pc
) (regcache
, status
.tpoint_addr
);
2138 lwp
->stop_pc
= status
.tpoint_addr
;
2140 /* Cancel any fast tracepoint lock this thread was
2142 force_unlock_trace_buffer ();
2145 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
2148 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
2149 "stopping all threads momentarily.\n");
2151 stop_all_lwps (1, lwp
);
2153 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
2154 lwp
->exit_jump_pad_bkpt
= NULL
;
2156 unstop_all_lwps (1, lwp
);
2158 gdb_assert (lwp
->suspended
>= 0);
2164 debug_printf ("Checking whether LWP %ld needs to move out of the "
2166 lwpid_of (current_thread
));
2168 current_thread
= saved_thread
;
2172 /* Enqueue one signal in the "signals to report later when out of the
2176 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2178 struct pending_signals
*p_sig
;
2179 struct thread_info
*thread
= get_lwp_thread (lwp
);
2182 debug_printf ("Deferring signal %d for LWP %ld.\n",
2183 WSTOPSIG (*wstat
), lwpid_of (thread
));
2187 struct pending_signals
*sig
;
2189 for (sig
= lwp
->pending_signals_to_report
;
2192 debug_printf (" Already queued %d\n",
2195 debug_printf (" (no more currently queued signals)\n");
2198 /* Don't enqueue non-RT signals if they are already in the deferred
2199 queue. (SIGSTOP being the easiest signal to see ending up here
2201 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
2203 struct pending_signals
*sig
;
2205 for (sig
= lwp
->pending_signals_to_report
;
2209 if (sig
->signal
== WSTOPSIG (*wstat
))
2212 debug_printf ("Not requeuing already queued non-RT signal %d"
2221 p_sig
= XCNEW (struct pending_signals
);
2222 p_sig
->prev
= lwp
->pending_signals_to_report
;
2223 p_sig
->signal
= WSTOPSIG (*wstat
);
2225 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2228 lwp
->pending_signals_to_report
= p_sig
;
2231 /* Dequeue one signal from the "signals to report later when out of
2232 the jump pad" list. */
2235 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2237 struct thread_info
*thread
= get_lwp_thread (lwp
);
2239 if (lwp
->pending_signals_to_report
!= NULL
)
2241 struct pending_signals
**p_sig
;
2243 p_sig
= &lwp
->pending_signals_to_report
;
2244 while ((*p_sig
)->prev
!= NULL
)
2245 p_sig
= &(*p_sig
)->prev
;
2247 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
2248 if ((*p_sig
)->info
.si_signo
!= 0)
2249 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2255 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
2256 WSTOPSIG (*wstat
), lwpid_of (thread
));
2260 struct pending_signals
*sig
;
2262 for (sig
= lwp
->pending_signals_to_report
;
2265 debug_printf (" Still queued %d\n",
2268 debug_printf (" (no more queued signals)\n");
2277 /* Fetch the possibly triggered data watchpoint info and store it in
2280 On some archs, like x86, that use debug registers to set
2281 watchpoints, it's possible that the way to know which watched
2282 address trapped, is to check the register that is used to select
2283 which address to watch. Problem is, between setting the watchpoint
2284 and reading back which data address trapped, the user may change
2285 the set of watchpoints, and, as a consequence, GDB changes the
2286 debug registers in the inferior. To avoid reading back a stale
2287 stopped-data-address when that happens, we cache in LP the fact
2288 that a watchpoint trapped, and the corresponding data address, as
2289 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
2290 registers meanwhile, we have the cached data we can rely on. */
2293 check_stopped_by_watchpoint (struct lwp_info
*child
)
2295 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2297 struct thread_info
*saved_thread
;
2299 saved_thread
= current_thread
;
2300 current_thread
= get_lwp_thread (child
);
2302 if (the_low_target
.stopped_by_watchpoint ())
2304 child
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2306 if (the_low_target
.stopped_data_address
!= NULL
)
2307 child
->stopped_data_address
2308 = the_low_target
.stopped_data_address ();
2310 child
->stopped_data_address
= 0;
2313 current_thread
= saved_thread
;
2316 return child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2319 /* Return the ptrace options that we want to try to enable. */
2322 linux_low_ptrace_options (int attached
)
2327 options
|= PTRACE_O_EXITKILL
;
2329 if (report_fork_events
)
2330 options
|= PTRACE_O_TRACEFORK
;
2332 if (report_vfork_events
)
2333 options
|= (PTRACE_O_TRACEVFORK
| PTRACE_O_TRACEVFORKDONE
);
2335 if (report_exec_events
)
2336 options
|= PTRACE_O_TRACEEXEC
;
2338 options
|= PTRACE_O_TRACESYSGOOD
;
2343 /* Do low-level handling of the event, and check if we should go on
2344 and pass it to caller code. Return the affected lwp if we are, or
2347 static struct lwp_info
*
2348 linux_low_filter_event (int lwpid
, int wstat
)
2350 struct lwp_info
*child
;
2351 struct thread_info
*thread
;
2352 int have_stop_pc
= 0;
2354 child
= find_lwp_pid (pid_to_ptid (lwpid
));
2356 /* Check for stop events reported by a process we didn't already
2357 know about - anything not already in our LWP list.
2359 If we're expecting to receive stopped processes after
2360 fork, vfork, and clone events, then we'll just add the
2361 new one to our list and go back to waiting for the event
2362 to be reported - the stopped process might be returned
2363 from waitpid before or after the event is.
2365 But note the case of a non-leader thread exec'ing after the
2366 leader having exited, and gone from our lists (because
2367 check_zombie_leaders deleted it). The non-leader thread
2368 changes its tid to the tgid. */
2370 if (WIFSTOPPED (wstat
) && child
== NULL
&& WSTOPSIG (wstat
) == SIGTRAP
2371 && linux_ptrace_get_extended_event (wstat
) == PTRACE_EVENT_EXEC
)
2375 /* A multi-thread exec after we had seen the leader exiting. */
2378 debug_printf ("LLW: Re-adding thread group leader LWP %d"
2379 "after exec.\n", lwpid
);
2382 child_ptid
= ptid_build (lwpid
, lwpid
, 0);
2383 child
= add_lwp (child_ptid
);
2385 current_thread
= child
->thread
;
2388 /* If we didn't find a process, one of two things presumably happened:
2389 - A process we started and then detached from has exited. Ignore it.
2390 - A process we are controlling has forked and the new child's stop
2391 was reported to us by the kernel. Save its PID. */
2392 if (child
== NULL
&& WIFSTOPPED (wstat
))
2394 add_to_pid_list (&stopped_pids
, lwpid
, wstat
);
2397 else if (child
== NULL
)
2400 thread
= get_lwp_thread (child
);
2404 child
->last_status
= wstat
;
2406 /* Check if the thread has exited. */
2407 if ((WIFEXITED (wstat
) || WIFSIGNALED (wstat
)))
2410 debug_printf ("LLFE: %d exited.\n", lwpid
);
2412 if (finish_step_over (child
))
2414 /* Unsuspend all other LWPs, and set them back running again. */
2415 unsuspend_all_lwps (child
);
2418 /* If there is at least one more LWP, then the exit signal was
2419 not the end of the debugged application and should be
2420 ignored, unless GDB wants to hear about thread exits. */
2421 if (report_thread_events
2422 || last_thread_of_process_p (pid_of (thread
)))
2424 /* Since events are serialized to GDB core, and we can't
2425 report this one right now. Leave the status pending for
2426 the next time we're able to report it. */
2427 mark_lwp_dead (child
, wstat
);
2437 gdb_assert (WIFSTOPPED (wstat
));
2439 if (WIFSTOPPED (wstat
))
2441 struct process_info
*proc
;
2443 /* Architecture-specific setup after inferior is running. */
2444 proc
= find_process_pid (pid_of (thread
));
2445 if (proc
->tdesc
== NULL
)
2449 /* This needs to happen after we have attached to the
2450 inferior and it is stopped for the first time, but
2451 before we access any inferior registers. */
2452 linux_arch_setup_thread (thread
);
2456 /* The process is started, but GDBserver will do
2457 architecture-specific setup after the program stops at
2458 the first instruction. */
2459 child
->status_pending_p
= 1;
2460 child
->status_pending
= wstat
;
2466 if (WIFSTOPPED (wstat
) && child
->must_set_ptrace_flags
)
2468 struct process_info
*proc
= find_process_pid (pid_of (thread
));
2469 int options
= linux_low_ptrace_options (proc
->attached
);
2471 linux_enable_event_reporting (lwpid
, options
);
2472 child
->must_set_ptrace_flags
= 0;
2475 /* Always update syscall_state, even if it will be filtered later. */
2476 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SYSCALL_SIGTRAP
)
2478 child
->syscall_state
2479 = (child
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2480 ? TARGET_WAITKIND_SYSCALL_RETURN
2481 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2485 /* Almost all other ptrace-stops are known to be outside of system
2486 calls, with further exceptions in handle_extended_wait. */
2487 child
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2490 /* Be careful to not overwrite stop_pc until save_stop_reason is
2492 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2493 && linux_is_extended_waitstatus (wstat
))
2495 child
->stop_pc
= get_pc (child
);
2496 if (handle_extended_wait (&child
, wstat
))
2498 /* The event has been handled, so just return without
2504 if (linux_wstatus_maybe_breakpoint (wstat
))
2506 if (save_stop_reason (child
))
2511 child
->stop_pc
= get_pc (child
);
2513 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGSTOP
2514 && child
->stop_expected
)
2517 debug_printf ("Expected stop.\n");
2518 child
->stop_expected
= 0;
2520 if (thread
->last_resume_kind
== resume_stop
)
2522 /* We want to report the stop to the core. Treat the
2523 SIGSTOP as a normal event. */
2525 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2526 target_pid_to_str (ptid_of (thread
)));
2528 else if (stopping_threads
!= NOT_STOPPING_THREADS
)
2530 /* Stopping threads. We don't want this SIGSTOP to end up
2533 debug_printf ("LLW: SIGSTOP caught for %s "
2534 "while stopping threads.\n",
2535 target_pid_to_str (ptid_of (thread
)));
2540 /* This is a delayed SIGSTOP. Filter out the event. */
2542 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2543 child
->stepping
? "step" : "continue",
2544 target_pid_to_str (ptid_of (thread
)));
2546 linux_resume_one_lwp (child
, child
->stepping
, 0, NULL
);
2551 child
->status_pending_p
= 1;
2552 child
->status_pending
= wstat
;
2556 /* Return true if THREAD is doing hardware single step. */
2559 maybe_hw_step (struct thread_info
*thread
)
2561 if (can_hardware_single_step ())
2565 /* GDBserver must insert single-step breakpoint for software
2567 gdb_assert (has_single_step_breakpoints (thread
));
2572 /* Resume LWPs that are currently stopped without any pending status
2573 to report, but are resumed from the core's perspective. */
2576 resume_stopped_resumed_lwps (thread_info
*thread
)
2578 struct lwp_info
*lp
= get_thread_lwp (thread
);
2582 && !lp
->status_pending_p
2583 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
2587 if (thread
->last_resume_kind
== resume_step
)
2588 step
= maybe_hw_step (thread
);
2591 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2592 target_pid_to_str (ptid_of (thread
)),
2593 paddress (lp
->stop_pc
),
2596 linux_resume_one_lwp (lp
, step
, GDB_SIGNAL_0
, NULL
);
2600 /* Wait for an event from child(ren) WAIT_PTID, and return any that
2601 match FILTER_PTID (leaving others pending). The PTIDs can be:
2602 minus_one_ptid, to specify any child; a pid PTID, specifying all
2603 lwps of a thread group; or a PTID representing a single lwp. Store
2604 the stop status through the status pointer WSTAT. OPTIONS is
2605 passed to the waitpid call. Return 0 if no event was found and
2606 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2607 was found. Return the PID of the stopped child otherwise. */
2610 linux_wait_for_event_filtered (ptid_t wait_ptid
, ptid_t filter_ptid
,
2611 int *wstatp
, int options
)
2613 struct thread_info
*event_thread
;
2614 struct lwp_info
*event_child
, *requested_child
;
2615 sigset_t block_mask
, prev_mask
;
2618 /* N.B. event_thread points to the thread_info struct that contains
2619 event_child. Keep them in sync. */
2620 event_thread
= NULL
;
2622 requested_child
= NULL
;
2624 /* Check for a lwp with a pending status. */
2626 if (ptid_equal (filter_ptid
, minus_one_ptid
) || ptid_is_pid (filter_ptid
))
2628 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2630 return status_pending_p_callback (thread
, filter_ptid
);
2633 if (event_thread
!= NULL
)
2634 event_child
= get_thread_lwp (event_thread
);
2635 if (debug_threads
&& event_thread
)
2636 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread
));
2638 else if (!ptid_equal (filter_ptid
, null_ptid
))
2640 requested_child
= find_lwp_pid (filter_ptid
);
2642 if (stopping_threads
== NOT_STOPPING_THREADS
2643 && requested_child
->status_pending_p
2644 && (requested_child
->collecting_fast_tracepoint
2645 != fast_tpoint_collect_result::not_collecting
))
2647 enqueue_one_deferred_signal (requested_child
,
2648 &requested_child
->status_pending
);
2649 requested_child
->status_pending_p
= 0;
2650 requested_child
->status_pending
= 0;
2651 linux_resume_one_lwp (requested_child
, 0, 0, NULL
);
2654 if (requested_child
->suspended
2655 && requested_child
->status_pending_p
)
2657 internal_error (__FILE__
, __LINE__
,
2658 "requesting an event out of a"
2659 " suspended child?");
2662 if (requested_child
->status_pending_p
)
2664 event_child
= requested_child
;
2665 event_thread
= get_lwp_thread (event_child
);
2669 if (event_child
!= NULL
)
2672 debug_printf ("Got an event from pending child %ld (%04x)\n",
2673 lwpid_of (event_thread
), event_child
->status_pending
);
2674 *wstatp
= event_child
->status_pending
;
2675 event_child
->status_pending_p
= 0;
2676 event_child
->status_pending
= 0;
2677 current_thread
= event_thread
;
2678 return lwpid_of (event_thread
);
2681 /* But if we don't find a pending event, we'll have to wait.
2683 We only enter this loop if no process has a pending wait status.
2684 Thus any action taken in response to a wait status inside this
2685 loop is responding as soon as we detect the status, not after any
2688 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2689 all signals while here. */
2690 sigfillset (&block_mask
);
2691 sigprocmask (SIG_BLOCK
, &block_mask
, &prev_mask
);
2693 /* Always pull all events out of the kernel. We'll randomly select
2694 an event LWP out of all that have events, to prevent
2696 while (event_child
== NULL
)
2700 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2703 - If the thread group leader exits while other threads in the
2704 thread group still exist, waitpid(TGID, ...) hangs. That
2705 waitpid won't return an exit status until the other threads
2706 in the group are reaped.
2708 - When a non-leader thread execs, that thread just vanishes
2709 without reporting an exit (so we'd hang if we waited for it
2710 explicitly in that case). The exec event is reported to
2713 ret
= my_waitpid (-1, wstatp
, options
| WNOHANG
);
2716 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2717 ret
, errno
? strerror (errno
) : "ERRNO-OK");
2723 debug_printf ("LLW: waitpid %ld received %s\n",
2724 (long) ret
, status_to_str (*wstatp
));
2727 /* Filter all events. IOW, leave all events pending. We'll
2728 randomly select an event LWP out of all that have events
2730 linux_low_filter_event (ret
, *wstatp
);
2731 /* Retry until nothing comes out of waitpid. A single
2732 SIGCHLD can indicate more than one child stopped. */
2736 /* Now that we've pulled all events out of the kernel, resume
2737 LWPs that don't have an interesting event to report. */
2738 if (stopping_threads
== NOT_STOPPING_THREADS
)
2739 for_each_inferior (&all_threads
, resume_stopped_resumed_lwps
);
2741 /* ... and find an LWP with a status to report to the core, if
2743 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2745 return status_pending_p_callback (thread
, filter_ptid
);
2748 if (event_thread
!= NULL
)
2750 event_child
= get_thread_lwp (event_thread
);
2751 *wstatp
= event_child
->status_pending
;
2752 event_child
->status_pending_p
= 0;
2753 event_child
->status_pending
= 0;
2757 /* Check for zombie thread group leaders. Those can't be reaped
2758 until all other threads in the thread group are. */
2759 check_zombie_leaders ();
2761 auto not_stopped
= [&] (thread_info
*thread
)
2763 return not_stopped_callback (thread
, wait_ptid
);
2766 /* If there are no resumed children left in the set of LWPs we
2767 want to wait for, bail. We can't just block in
2768 waitpid/sigsuspend, because lwps might have been left stopped
2769 in trace-stop state, and we'd be stuck forever waiting for
2770 their status to change (which would only happen if we resumed
2771 them). Even if WNOHANG is set, this return code is preferred
2772 over 0 (below), as it is more detailed. */
2773 if (find_thread (not_stopped
) == NULL
)
2776 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2777 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2781 /* No interesting event to report to the caller. */
2782 if ((options
& WNOHANG
))
2785 debug_printf ("WNOHANG set, no event found\n");
2787 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2791 /* Block until we get an event reported with SIGCHLD. */
2793 debug_printf ("sigsuspend'ing\n");
2795 sigsuspend (&prev_mask
);
2796 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2800 sigprocmask (SIG_SETMASK
, &prev_mask
, NULL
);
2802 current_thread
= event_thread
;
2804 return lwpid_of (event_thread
);
2807 /* Wait for an event from child(ren) PTID. PTIDs can be:
2808 minus_one_ptid, to specify any child; a pid PTID, specifying all
2809 lwps of a thread group; or a PTID representing a single lwp. Store
2810 the stop status through the status pointer WSTAT. OPTIONS is
2811 passed to the waitpid call. Return 0 if no event was found and
2812 OPTIONS contains WNOHANG. Return -1 if no unwaited-for children
2813 was found. Return the PID of the stopped child otherwise. */
2816 linux_wait_for_event (ptid_t ptid
, int *wstatp
, int options
)
2818 return linux_wait_for_event_filtered (ptid
, ptid
, wstatp
, options
);
2821 /* Select one LWP out of those that have events pending. */
2824 select_event_lwp (struct lwp_info
**orig_lp
)
2826 int random_selector
;
2827 struct thread_info
*event_thread
= NULL
;
2829 /* In all-stop, give preference to the LWP that is being
2830 single-stepped. There will be at most one, and it's the LWP that
2831 the core is most interested in. If we didn't do this, then we'd
2832 have to handle pending step SIGTRAPs somehow in case the core
2833 later continues the previously-stepped thread, otherwise we'd
2834 report the pending SIGTRAP, and the core, not having stepped the
2835 thread, wouldn't understand what the trap was for, and therefore
2836 would report it to the user as a random signal. */
2839 event_thread
= find_thread ([] (thread_info
*thread
)
2841 lwp_info
*lp
= get_thread_lwp (thread
);
2843 return (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2844 && thread
->last_resume_kind
== resume_step
2845 && lp
->status_pending_p
);
2848 if (event_thread
!= NULL
)
2851 debug_printf ("SEL: Select single-step %s\n",
2852 target_pid_to_str (ptid_of (event_thread
)));
2855 if (event_thread
== NULL
)
2857 /* No single-stepping LWP. Select one at random, out of those
2858 which have had events. */
2860 /* First see how many events we have. */
2862 for_each_thread ([&] (thread_info
*thread
)
2864 lwp_info
*lp
= get_thread_lwp (thread
);
2866 /* Count only resumed LWPs that have an event pending. */
2867 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2868 && lp
->status_pending_p
)
2871 gdb_assert (num_events
> 0);
2873 /* Now randomly pick a LWP out of those that have had
2875 random_selector
= (int)
2876 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2878 if (debug_threads
&& num_events
> 1)
2879 debug_printf ("SEL: Found %d SIGTRAP events, selecting #%d\n",
2880 num_events
, random_selector
);
2882 event_thread
= find_thread ([&] (thread_info
*thread
)
2884 lwp_info
*lp
= get_thread_lwp (thread
);
2886 /* Select only resumed LWPs that have an event pending. */
2887 if (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2888 && lp
->status_pending_p
)
2889 if (random_selector
-- == 0)
2896 if (event_thread
!= NULL
)
2898 struct lwp_info
*event_lp
= get_thread_lwp (event_thread
);
2900 /* Switch the event LWP. */
2901 *orig_lp
= event_lp
;
2905 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2909 unsuspend_all_lwps (struct lwp_info
*except
)
2911 for_each_thread ([&] (thread_info
*thread
)
2913 lwp_info
*lwp
= get_thread_lwp (thread
);
2916 lwp_suspended_decr (lwp
);
2920 static void move_out_of_jump_pad_callback (thread_info
*thread
);
2921 static bool stuck_in_jump_pad_callback (thread_info
*thread
);
2922 static bool lwp_running (thread_info
*thread
);
2923 static ptid_t
linux_wait_1 (ptid_t ptid
,
2924 struct target_waitstatus
*ourstatus
,
2925 int target_options
);
2927 /* Stabilize threads (move out of jump pads).
2929 If a thread is midway collecting a fast tracepoint, we need to
2930 finish the collection and move it out of the jump pad before
2931 reporting the signal.
2933 This avoids recursion while collecting (when a signal arrives
2934 midway, and the signal handler itself collects), which would trash
2935 the trace buffer. In case the user set a breakpoint in a signal
2936 handler, this avoids the backtrace showing the jump pad, etc..
2937 Most importantly, there are certain things we can't do safely if
2938 threads are stopped in a jump pad (or in its callee's). For
2941 - starting a new trace run. A thread still collecting the
2942 previous run, could trash the trace buffer when resumed. The trace
2943 buffer control structures would have been reset but the thread had
2944 no way to tell. The thread could even midway memcpy'ing to the
2945 buffer, which would mean that when resumed, it would clobber the
2946 trace buffer that had been set for a new run.
2948 - we can't rewrite/reuse the jump pads for new tracepoints
2949 safely. Say you do tstart while a thread is stopped midway while
2950 collecting. When the thread is later resumed, it finishes the
2951 collection, and returns to the jump pad, to execute the original
2952 instruction that was under the tracepoint jump at the time the
2953 older run had been started. If the jump pad had been rewritten
2954 since for something else in the new run, the thread would now
2955 execute the wrong / random instructions. */
2958 linux_stabilize_threads (void)
2960 thread_info
*thread_stuck
= find_thread (stuck_in_jump_pad_callback
);
2962 if (thread_stuck
!= NULL
)
2965 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2966 lwpid_of (thread_stuck
));
2970 thread_info
*saved_thread
= current_thread
;
2972 stabilizing_threads
= 1;
2975 for_each_inferior (&all_threads
, move_out_of_jump_pad_callback
);
2977 /* Loop until all are stopped out of the jump pads. */
2978 while (find_thread (lwp_running
) != NULL
)
2980 struct target_waitstatus ourstatus
;
2981 struct lwp_info
*lwp
;
2984 /* Note that we go through the full wait even loop. While
2985 moving threads out of jump pad, we need to be able to step
2986 over internal breakpoints and such. */
2987 linux_wait_1 (minus_one_ptid
, &ourstatus
, 0);
2989 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
2991 lwp
= get_thread_lwp (current_thread
);
2994 lwp_suspended_inc (lwp
);
2996 if (ourstatus
.value
.sig
!= GDB_SIGNAL_0
2997 || current_thread
->last_resume_kind
== resume_stop
)
2999 wstat
= W_STOPCODE (gdb_signal_to_host (ourstatus
.value
.sig
));
3000 enqueue_one_deferred_signal (lwp
, &wstat
);
3005 unsuspend_all_lwps (NULL
);
3007 stabilizing_threads
= 0;
3009 current_thread
= saved_thread
;
3013 thread_stuck
= find_thread (stuck_in_jump_pad_callback
);
3015 if (thread_stuck
!= NULL
)
3016 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
3017 lwpid_of (thread_stuck
));
3021 /* Convenience function that is called when the kernel reports an
3022 event that is not passed out to GDB. */
3025 ignore_event (struct target_waitstatus
*ourstatus
)
3027 /* If we got an event, there may still be others, as a single
3028 SIGCHLD can indicate more than one child stopped. This forces
3029 another target_wait call. */
3032 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3036 /* Convenience function that is called when the kernel reports an exit
3037 event. This decides whether to report the event to GDB as a
3038 process exit event, a thread exit event, or to suppress the
3042 filter_exit_event (struct lwp_info
*event_child
,
3043 struct target_waitstatus
*ourstatus
)
3045 struct thread_info
*thread
= get_lwp_thread (event_child
);
3046 ptid_t ptid
= ptid_of (thread
);
3048 if (!last_thread_of_process_p (pid_of (thread
)))
3050 if (report_thread_events
)
3051 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3053 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3055 delete_lwp (event_child
);
3060 /* Returns 1 if GDB is interested in any event_child syscalls. */
3063 gdb_catching_syscalls_p (struct lwp_info
*event_child
)
3065 struct thread_info
*thread
= get_lwp_thread (event_child
);
3066 struct process_info
*proc
= get_thread_process (thread
);
3068 return !proc
->syscalls_to_catch
.empty ();
3071 /* Returns 1 if GDB is interested in the event_child syscall.
3072 Only to be called when stopped reason is SYSCALL_SIGTRAP. */
3075 gdb_catch_this_syscall_p (struct lwp_info
*event_child
)
3078 struct thread_info
*thread
= get_lwp_thread (event_child
);
3079 struct process_info
*proc
= get_thread_process (thread
);
3081 if (proc
->syscalls_to_catch
.empty ())
3084 if (proc
->syscalls_to_catch
[0] == ANY_SYSCALL
)
3087 get_syscall_trapinfo (event_child
, &sysno
);
3089 for (int iter
: proc
->syscalls_to_catch
)
3096 /* Wait for process, returns status. */
3099 linux_wait_1 (ptid_t ptid
,
3100 struct target_waitstatus
*ourstatus
, int target_options
)
3103 struct lwp_info
*event_child
;
3106 int step_over_finished
;
3107 int bp_explains_trap
;
3108 int maybe_internal_trap
;
3117 debug_printf ("linux_wait_1: [%s]\n", target_pid_to_str (ptid
));
3120 /* Translate generic target options into linux options. */
3122 if (target_options
& TARGET_WNOHANG
)
3125 bp_explains_trap
= 0;
3128 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3130 auto status_pending_p_any
= [&] (thread_info
*thread
)
3132 return status_pending_p_callback (thread
, minus_one_ptid
);
3135 auto not_stopped
= [&] (thread_info
*thread
)
3137 return not_stopped_callback (thread
, minus_one_ptid
);
3140 /* Find a resumed LWP, if any. */
3141 if (find_thread (status_pending_p_any
) != NULL
)
3143 else if (find_thread (not_stopped
) != NULL
)
3148 if (ptid_equal (step_over_bkpt
, null_ptid
))
3149 pid
= linux_wait_for_event (ptid
, &w
, options
);
3153 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
3154 target_pid_to_str (step_over_bkpt
));
3155 pid
= linux_wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
3158 if (pid
== 0 || (pid
== -1 && !any_resumed
))
3160 gdb_assert (target_options
& TARGET_WNOHANG
);
3164 debug_printf ("linux_wait_1 ret = null_ptid, "
3165 "TARGET_WAITKIND_IGNORE\n");
3169 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3176 debug_printf ("linux_wait_1 ret = null_ptid, "
3177 "TARGET_WAITKIND_NO_RESUMED\n");
3181 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3185 event_child
= get_thread_lwp (current_thread
);
3187 /* linux_wait_for_event only returns an exit status for the last
3188 child of a process. Report it. */
3189 if (WIFEXITED (w
) || WIFSIGNALED (w
))
3193 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
3194 ourstatus
->value
.integer
= WEXITSTATUS (w
);
3198 debug_printf ("linux_wait_1 ret = %s, exited with "
3200 target_pid_to_str (ptid_of (current_thread
)),
3207 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
3208 ourstatus
->value
.sig
= gdb_signal_from_host (WTERMSIG (w
));
3212 debug_printf ("linux_wait_1 ret = %s, terminated with "
3214 target_pid_to_str (ptid_of (current_thread
)),
3220 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3221 return filter_exit_event (event_child
, ourstatus
);
3223 return ptid_of (current_thread
);
3226 /* If step-over executes a breakpoint instruction, in the case of a
3227 hardware single step it means a gdb/gdbserver breakpoint had been
3228 planted on top of a permanent breakpoint, in the case of a software
3229 single step it may just mean that gdbserver hit the reinsert breakpoint.
3230 The PC has been adjusted by save_stop_reason to point at
3231 the breakpoint address.
3232 So in the case of the hardware single step advance the PC manually
3233 past the breakpoint and in the case of software single step advance only
3234 if it's not the single_step_breakpoint we are hitting.
3235 This avoids that a program would keep trapping a permanent breakpoint
3237 if (!ptid_equal (step_over_bkpt
, null_ptid
)
3238 && event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3239 && (event_child
->stepping
3240 || !single_step_breakpoint_inserted_here (event_child
->stop_pc
)))
3242 int increment_pc
= 0;
3243 int breakpoint_kind
= 0;
3244 CORE_ADDR stop_pc
= event_child
->stop_pc
;
3247 the_target
->breakpoint_kind_from_current_state (&stop_pc
);
3248 the_target
->sw_breakpoint_from_kind (breakpoint_kind
, &increment_pc
);
3252 debug_printf ("step-over for %s executed software breakpoint\n",
3253 target_pid_to_str (ptid_of (current_thread
)));
3256 if (increment_pc
!= 0)
3258 struct regcache
*regcache
3259 = get_thread_regcache (current_thread
, 1);
3261 event_child
->stop_pc
+= increment_pc
;
3262 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
3264 if (!(*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))
3265 event_child
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3269 /* If this event was not handled before, and is not a SIGTRAP, we
3270 report it. SIGILL and SIGSEGV are also treated as traps in case
3271 a breakpoint is inserted at the current PC. If this target does
3272 not support internal breakpoints at all, we also report the
3273 SIGTRAP without further processing; it's of no concern to us. */
3275 = (supports_breakpoints ()
3276 && (WSTOPSIG (w
) == SIGTRAP
3277 || ((WSTOPSIG (w
) == SIGILL
3278 || WSTOPSIG (w
) == SIGSEGV
)
3279 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
3281 if (maybe_internal_trap
)
3283 /* Handle anything that requires bookkeeping before deciding to
3284 report the event or continue waiting. */
3286 /* First check if we can explain the SIGTRAP with an internal
3287 breakpoint, or if we should possibly report the event to GDB.
3288 Do this before anything that may remove or insert a
3290 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
3292 /* We have a SIGTRAP, possibly a step-over dance has just
3293 finished. If so, tweak the state machine accordingly,
3294 reinsert breakpoints and delete any single-step
3296 step_over_finished
= finish_step_over (event_child
);
3298 /* Now invoke the callbacks of any internal breakpoints there. */
3299 check_breakpoints (event_child
->stop_pc
);
3301 /* Handle tracepoint data collecting. This may overflow the
3302 trace buffer, and cause a tracing stop, removing
3304 trace_event
= handle_tracepoints (event_child
);
3306 if (bp_explains_trap
)
3309 debug_printf ("Hit a gdbserver breakpoint.\n");
3314 /* We have some other signal, possibly a step-over dance was in
3315 progress, and it should be cancelled too. */
3316 step_over_finished
= finish_step_over (event_child
);
3319 /* We have all the data we need. Either report the event to GDB, or
3320 resume threads and keep waiting for more. */
3322 /* If we're collecting a fast tracepoint, finish the collection and
3323 move out of the jump pad before delivering a signal. See
3324 linux_stabilize_threads. */
3327 && WSTOPSIG (w
) != SIGTRAP
3328 && supports_fast_tracepoints ()
3329 && agent_loaded_p ())
3332 debug_printf ("Got signal %d for LWP %ld. Check if we need "
3333 "to defer or adjust it.\n",
3334 WSTOPSIG (w
), lwpid_of (current_thread
));
3336 /* Allow debugging the jump pad itself. */
3337 if (current_thread
->last_resume_kind
!= resume_step
3338 && maybe_move_out_of_jump_pad (event_child
, &w
))
3340 enqueue_one_deferred_signal (event_child
, &w
);
3343 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
3344 WSTOPSIG (w
), lwpid_of (current_thread
));
3346 linux_resume_one_lwp (event_child
, 0, 0, NULL
);
3350 return ignore_event (ourstatus
);
3354 if (event_child
->collecting_fast_tracepoint
3355 != fast_tpoint_collect_result::not_collecting
)
3358 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
3359 "Check if we're already there.\n",
3360 lwpid_of (current_thread
),
3361 (int) event_child
->collecting_fast_tracepoint
);
3365 event_child
->collecting_fast_tracepoint
3366 = linux_fast_tracepoint_collecting (event_child
, NULL
);
3368 if (event_child
->collecting_fast_tracepoint
3369 != fast_tpoint_collect_result::before_insn
)
3371 /* No longer need this breakpoint. */
3372 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
3375 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
3376 "stopping all threads momentarily.\n");
3378 /* Other running threads could hit this breakpoint.
3379 We don't handle moribund locations like GDB does,
3380 instead we always pause all threads when removing
3381 breakpoints, so that any step-over or
3382 decr_pc_after_break adjustment is always taken
3383 care of while the breakpoint is still
3385 stop_all_lwps (1, event_child
);
3387 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
3388 event_child
->exit_jump_pad_bkpt
= NULL
;
3390 unstop_all_lwps (1, event_child
);
3392 gdb_assert (event_child
->suspended
>= 0);
3396 if (event_child
->collecting_fast_tracepoint
3397 == fast_tpoint_collect_result::not_collecting
)
3400 debug_printf ("fast tracepoint finished "
3401 "collecting successfully.\n");
3403 /* We may have a deferred signal to report. */
3404 if (dequeue_one_deferred_signal (event_child
, &w
))
3407 debug_printf ("dequeued one signal.\n");
3412 debug_printf ("no deferred signals.\n");
3414 if (stabilizing_threads
)
3416 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3417 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3421 debug_printf ("linux_wait_1 ret = %s, stopped "
3422 "while stabilizing threads\n",
3423 target_pid_to_str (ptid_of (current_thread
)));
3427 return ptid_of (current_thread
);
3433 /* Check whether GDB would be interested in this event. */
3435 /* Check if GDB is interested in this syscall. */
3437 && WSTOPSIG (w
) == SYSCALL_SIGTRAP
3438 && !gdb_catch_this_syscall_p (event_child
))
3442 debug_printf ("Ignored syscall for LWP %ld.\n",
3443 lwpid_of (current_thread
));
3446 linux_resume_one_lwp (event_child
, event_child
->stepping
,
3451 return ignore_event (ourstatus
);
3454 /* If GDB is not interested in this signal, don't stop other
3455 threads, and don't report it to GDB. Just resume the inferior
3456 right away. We do this for threading-related signals as well as
3457 any that GDB specifically requested we ignore. But never ignore
3458 SIGSTOP if we sent it ourselves, and do not ignore signals when
3459 stepping - they may require special handling to skip the signal
3460 handler. Also never ignore signals that could be caused by a
3463 && current_thread
->last_resume_kind
!= resume_step
3465 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3466 (current_process ()->priv
->thread_db
!= NULL
3467 && (WSTOPSIG (w
) == __SIGRTMIN
3468 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
3471 (pass_signals
[gdb_signal_from_host (WSTOPSIG (w
))]
3472 && !(WSTOPSIG (w
) == SIGSTOP
3473 && current_thread
->last_resume_kind
== resume_stop
)
3474 && !linux_wstatus_maybe_breakpoint (w
))))
3476 siginfo_t info
, *info_p
;
3479 debug_printf ("Ignored signal %d for LWP %ld.\n",
3480 WSTOPSIG (w
), lwpid_of (current_thread
));
3482 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
3483 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
3488 if (step_over_finished
)
3490 /* We cancelled this thread's step-over above. We still
3491 need to unsuspend all other LWPs, and set them back
3492 running again while the signal handler runs. */
3493 unsuspend_all_lwps (event_child
);
3495 /* Enqueue the pending signal info so that proceed_all_lwps
3497 enqueue_pending_signal (event_child
, WSTOPSIG (w
), info_p
);
3499 proceed_all_lwps ();
3503 linux_resume_one_lwp (event_child
, event_child
->stepping
,
3504 WSTOPSIG (w
), info_p
);
3510 return ignore_event (ourstatus
);
3513 /* Note that all addresses are always "out of the step range" when
3514 there's no range to begin with. */
3515 in_step_range
= lwp_in_step_range (event_child
);
3517 /* If GDB wanted this thread to single step, and the thread is out
3518 of the step range, we always want to report the SIGTRAP, and let
3519 GDB handle it. Watchpoints should always be reported. So should
3520 signals we can't explain. A SIGTRAP we can't explain could be a
3521 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3522 do, we're be able to handle GDB breakpoints on top of internal
3523 breakpoints, by handling the internal breakpoint and still
3524 reporting the event to GDB. If we don't, we're out of luck, GDB
3525 won't see the breakpoint hit. If we see a single-step event but
3526 the thread should be continuing, don't pass the trap to gdb.
3527 That indicates that we had previously finished a single-step but
3528 left the single-step pending -- see
3529 complete_ongoing_step_over. */
3530 report_to_gdb
= (!maybe_internal_trap
3531 || (current_thread
->last_resume_kind
== resume_step
3533 || event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3535 && !bp_explains_trap
3537 && !step_over_finished
3538 && !(current_thread
->last_resume_kind
== resume_continue
3539 && event_child
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
))
3540 || (gdb_breakpoint_here (event_child
->stop_pc
)
3541 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)
3542 && gdb_no_commands_at_breakpoint (event_child
->stop_pc
))
3543 || event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
);
3545 run_breakpoint_commands (event_child
->stop_pc
);
3547 /* We found no reason GDB would want us to stop. We either hit one
3548 of our own breakpoints, or finished an internal step GDB
3549 shouldn't know about. */
3554 if (bp_explains_trap
)
3555 debug_printf ("Hit a gdbserver breakpoint.\n");
3556 if (step_over_finished
)
3557 debug_printf ("Step-over finished.\n");
3559 debug_printf ("Tracepoint event.\n");
3560 if (lwp_in_step_range (event_child
))
3561 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3562 paddress (event_child
->stop_pc
),
3563 paddress (event_child
->step_range_start
),
3564 paddress (event_child
->step_range_end
));
3567 /* We're not reporting this breakpoint to GDB, so apply the
3568 decr_pc_after_break adjustment to the inferior's regcache
3571 if (the_low_target
.set_pc
!= NULL
)
3573 struct regcache
*regcache
3574 = get_thread_regcache (current_thread
, 1);
3575 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
);
3578 if (step_over_finished
)
3580 /* If we have finished stepping over a breakpoint, we've
3581 stopped and suspended all LWPs momentarily except the
3582 stepping one. This is where we resume them all again.
3583 We're going to keep waiting, so use proceed, which
3584 handles stepping over the next breakpoint. */
3585 unsuspend_all_lwps (event_child
);
3589 /* Remove the single-step breakpoints if any. Note that
3590 there isn't single-step breakpoint if we finished stepping
3592 if (can_software_single_step ()
3593 && has_single_step_breakpoints (current_thread
))
3595 stop_all_lwps (0, event_child
);
3596 delete_single_step_breakpoints (current_thread
);
3597 unstop_all_lwps (0, event_child
);
3602 debug_printf ("proceeding all threads.\n");
3603 proceed_all_lwps ();
3608 return ignore_event (ourstatus
);
3613 if (event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3616 = target_waitstatus_to_string (&event_child
->waitstatus
);
3618 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3619 lwpid_of (get_lwp_thread (event_child
)), str
.c_str ());
3621 if (current_thread
->last_resume_kind
== resume_step
)
3623 if (event_child
->step_range_start
== event_child
->step_range_end
)
3624 debug_printf ("GDB wanted to single-step, reporting event.\n");
3625 else if (!lwp_in_step_range (event_child
))
3626 debug_printf ("Out of step range, reporting event.\n");
3628 if (event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
3629 debug_printf ("Stopped by watchpoint.\n");
3630 else if (gdb_breakpoint_here (event_child
->stop_pc
))
3631 debug_printf ("Stopped by GDB breakpoint.\n");
3633 debug_printf ("Hit a non-gdbserver trap event.\n");
3636 /* Alright, we're going to report a stop. */
3638 /* Remove single-step breakpoints. */
3639 if (can_software_single_step ())
3641 /* Remove single-step breakpoints or not. It it is true, stop all
3642 lwps, so that other threads won't hit the breakpoint in the
3644 int remove_single_step_breakpoints_p
= 0;
3648 remove_single_step_breakpoints_p
3649 = has_single_step_breakpoints (current_thread
);
3653 /* In all-stop, a stop reply cancels all previous resume
3654 requests. Delete all single-step breakpoints. */
3656 find_thread ([&] (thread_info
*thread
) {
3657 if (has_single_step_breakpoints (thread
))
3659 remove_single_step_breakpoints_p
= 1;
3667 if (remove_single_step_breakpoints_p
)
3669 /* If we remove single-step breakpoints from memory, stop all lwps,
3670 so that other threads won't hit the breakpoint in the staled
3672 stop_all_lwps (0, event_child
);
3676 gdb_assert (has_single_step_breakpoints (current_thread
));
3677 delete_single_step_breakpoints (current_thread
);
3681 for_each_thread ([] (thread_info
*thread
){
3682 if (has_single_step_breakpoints (thread
))
3683 delete_single_step_breakpoints (thread
);
3687 unstop_all_lwps (0, event_child
);
3691 if (!stabilizing_threads
)
3693 /* In all-stop, stop all threads. */
3695 stop_all_lwps (0, NULL
);
3697 if (step_over_finished
)
3701 /* If we were doing a step-over, all other threads but
3702 the stepping one had been paused in start_step_over,
3703 with their suspend counts incremented. We don't want
3704 to do a full unstop/unpause, because we're in
3705 all-stop mode (so we want threads stopped), but we
3706 still need to unsuspend the other threads, to
3707 decrement their `suspended' count back. */
3708 unsuspend_all_lwps (event_child
);
3712 /* If we just finished a step-over, then all threads had
3713 been momentarily paused. In all-stop, that's fine,
3714 we want threads stopped by now anyway. In non-stop,
3715 we need to re-resume threads that GDB wanted to be
3717 unstop_all_lwps (1, event_child
);
3721 /* If we're not waiting for a specific LWP, choose an event LWP
3722 from among those that have had events. Giving equal priority
3723 to all LWPs that have had events helps prevent
3725 if (ptid_equal (ptid
, minus_one_ptid
))
3727 event_child
->status_pending_p
= 1;
3728 event_child
->status_pending
= w
;
3730 select_event_lwp (&event_child
);
3732 /* current_thread and event_child must stay in sync. */
3733 current_thread
= get_lwp_thread (event_child
);
3735 event_child
->status_pending_p
= 0;
3736 w
= event_child
->status_pending
;
3740 /* Stabilize threads (move out of jump pads). */
3742 stabilize_threads ();
3746 /* If we just finished a step-over, then all threads had been
3747 momentarily paused. In all-stop, that's fine, we want
3748 threads stopped by now anyway. In non-stop, we need to
3749 re-resume threads that GDB wanted to be running. */
3750 if (step_over_finished
)
3751 unstop_all_lwps (1, event_child
);
3754 if (event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3756 /* If the reported event is an exit, fork, vfork or exec, let
3759 /* Break the unreported fork relationship chain. */
3760 if (event_child
->waitstatus
.kind
== TARGET_WAITKIND_FORKED
3761 || event_child
->waitstatus
.kind
== TARGET_WAITKIND_VFORKED
)
3763 event_child
->fork_relative
->fork_relative
= NULL
;
3764 event_child
->fork_relative
= NULL
;
3767 *ourstatus
= event_child
->waitstatus
;
3768 /* Clear the event lwp's waitstatus since we handled it already. */
3769 event_child
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3772 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3774 /* Now that we've selected our final event LWP, un-adjust its PC if
3775 it was a software breakpoint, and the client doesn't know we can
3776 adjust the breakpoint ourselves. */
3777 if (event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3778 && !swbreak_feature
)
3780 int decr_pc
= the_low_target
.decr_pc_after_break
;
3784 struct regcache
*regcache
3785 = get_thread_regcache (current_thread
, 1);
3786 (*the_low_target
.set_pc
) (regcache
, event_child
->stop_pc
+ decr_pc
);
3790 if (WSTOPSIG (w
) == SYSCALL_SIGTRAP
)
3792 get_syscall_trapinfo (event_child
,
3793 &ourstatus
->value
.syscall_number
);
3794 ourstatus
->kind
= event_child
->syscall_state
;
3796 else if (current_thread
->last_resume_kind
== resume_stop
3797 && WSTOPSIG (w
) == SIGSTOP
)
3799 /* A thread that has been requested to stop by GDB with vCont;t,
3800 and it stopped cleanly, so report as SIG0. The use of
3801 SIGSTOP is an implementation detail. */
3802 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3804 else if (current_thread
->last_resume_kind
== resume_stop
3805 && WSTOPSIG (w
) != SIGSTOP
)
3807 /* A thread that has been requested to stop by GDB with vCont;t,
3808 but, it stopped for other reasons. */
3809 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3811 else if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
)
3813 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3816 gdb_assert (ptid_equal (step_over_bkpt
, null_ptid
));
3820 debug_printf ("linux_wait_1 ret = %s, %d, %d\n",
3821 target_pid_to_str (ptid_of (current_thread
)),
3822 ourstatus
->kind
, ourstatus
->value
.sig
);
3826 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3827 return filter_exit_event (event_child
, ourstatus
);
3829 return ptid_of (current_thread
);
3832 /* Get rid of any pending event in the pipe. */
3834 async_file_flush (void)
3840 ret
= read (linux_event_pipe
[0], &buf
, 1);
3841 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
3844 /* Put something in the pipe, so the event loop wakes up. */
3846 async_file_mark (void)
3850 async_file_flush ();
3853 ret
= write (linux_event_pipe
[1], "+", 1);
3854 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
3856 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3857 be awakened anyway. */
3861 linux_wait (ptid_t ptid
,
3862 struct target_waitstatus
*ourstatus
, int target_options
)
3866 /* Flush the async file first. */
3867 if (target_is_async_p ())
3868 async_file_flush ();
3872 event_ptid
= linux_wait_1 (ptid
, ourstatus
, target_options
);
3874 while ((target_options
& TARGET_WNOHANG
) == 0
3875 && ptid_equal (event_ptid
, null_ptid
)
3876 && ourstatus
->kind
== TARGET_WAITKIND_IGNORE
);
3878 /* If at least one stop was reported, there may be more. A single
3879 SIGCHLD can signal more than one child stop. */
3880 if (target_is_async_p ()
3881 && (target_options
& TARGET_WNOHANG
) != 0
3882 && !ptid_equal (event_ptid
, null_ptid
))
3888 /* Send a signal to an LWP. */
3891 kill_lwp (unsigned long lwpid
, int signo
)
3896 ret
= syscall (__NR_tkill
, lwpid
, signo
);
3897 if (errno
== ENOSYS
)
3899 /* If tkill fails, then we are not using nptl threads, a
3900 configuration we no longer support. */
3901 perror_with_name (("tkill"));
3907 linux_stop_lwp (struct lwp_info
*lwp
)
3913 send_sigstop (struct lwp_info
*lwp
)
3917 pid
= lwpid_of (get_lwp_thread (lwp
));
3919 /* If we already have a pending stop signal for this process, don't
3921 if (lwp
->stop_expected
)
3924 debug_printf ("Have pending sigstop for lwp %d\n", pid
);
3930 debug_printf ("Sending sigstop to lwp %d\n", pid
);
3932 lwp
->stop_expected
= 1;
3933 kill_lwp (pid
, SIGSTOP
);
3937 send_sigstop_callback (thread_info
*thread
, void *except
)
3939 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3941 /* Ignore EXCEPT. */
3952 /* Increment the suspend count of an LWP, and stop it, if not stopped
3955 suspend_and_send_sigstop_callback (thread_info
*thread
, void *except
)
3957 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3959 /* Ignore EXCEPT. */
3963 lwp_suspended_inc (lwp
);
3965 return send_sigstop_callback (thread
, except
);
3969 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
3971 /* Store the exit status for later. */
3972 lwp
->status_pending_p
= 1;
3973 lwp
->status_pending
= wstat
;
3975 /* Store in waitstatus as well, as there's nothing else to process
3977 if (WIFEXITED (wstat
))
3979 lwp
->waitstatus
.kind
= TARGET_WAITKIND_EXITED
;
3980 lwp
->waitstatus
.value
.integer
= WEXITSTATUS (wstat
);
3982 else if (WIFSIGNALED (wstat
))
3984 lwp
->waitstatus
.kind
= TARGET_WAITKIND_SIGNALLED
;
3985 lwp
->waitstatus
.value
.sig
= gdb_signal_from_host (WTERMSIG (wstat
));
3988 /* Prevent trying to stop it. */
3991 /* No further stops are expected from a dead lwp. */
3992 lwp
->stop_expected
= 0;
3995 /* Return true if LWP has exited already, and has a pending exit event
3996 to report to GDB. */
3999 lwp_is_marked_dead (struct lwp_info
*lwp
)
4001 return (lwp
->status_pending_p
4002 && (WIFEXITED (lwp
->status_pending
)
4003 || WIFSIGNALED (lwp
->status_pending
)));
4006 /* Wait for all children to stop for the SIGSTOPs we just queued. */
4009 wait_for_sigstop (void)
4011 struct thread_info
*saved_thread
;
4016 saved_thread
= current_thread
;
4017 if (saved_thread
!= NULL
)
4018 saved_tid
= saved_thread
->id
;
4020 saved_tid
= null_ptid
; /* avoid bogus unused warning */
4023 debug_printf ("wait_for_sigstop: pulling events\n");
4025 /* Passing NULL_PTID as filter indicates we want all events to be
4026 left pending. Eventually this returns when there are no
4027 unwaited-for children left. */
4028 ret
= linux_wait_for_event_filtered (minus_one_ptid
, null_ptid
,
4030 gdb_assert (ret
== -1);
4032 if (saved_thread
== NULL
|| linux_thread_alive (saved_tid
))
4033 current_thread
= saved_thread
;
4037 debug_printf ("Previously current thread died.\n");
4039 /* We can't change the current inferior behind GDB's back,
4040 otherwise, a subsequent command may apply to the wrong
4042 current_thread
= NULL
;
4046 /* Returns true if THREAD is stopped in a jump pad, and we can't
4047 move it out, because we need to report the stop event to GDB. For
4048 example, if the user puts a breakpoint in the jump pad, it's
4049 because she wants to debug it. */
4052 stuck_in_jump_pad_callback (thread_info
*thread
)
4054 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4056 if (lwp
->suspended
!= 0)
4058 internal_error (__FILE__
, __LINE__
,
4059 "LWP %ld is suspended, suspended=%d\n",
4060 lwpid_of (thread
), lwp
->suspended
);
4062 gdb_assert (lwp
->stopped
);
4064 /* Allow debugging the jump pad, gdb_collect, etc.. */
4065 return (supports_fast_tracepoints ()
4066 && agent_loaded_p ()
4067 && (gdb_breakpoint_here (lwp
->stop_pc
)
4068 || lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
4069 || thread
->last_resume_kind
== resume_step
)
4070 && (linux_fast_tracepoint_collecting (lwp
, NULL
)
4071 != fast_tpoint_collect_result::not_collecting
));
4075 move_out_of_jump_pad_callback (thread_info
*thread
)
4077 struct thread_info
*saved_thread
;
4078 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4081 if (lwp
->suspended
!= 0)
4083 internal_error (__FILE__
, __LINE__
,
4084 "LWP %ld is suspended, suspended=%d\n",
4085 lwpid_of (thread
), lwp
->suspended
);
4087 gdb_assert (lwp
->stopped
);
4089 /* For gdb_breakpoint_here. */
4090 saved_thread
= current_thread
;
4091 current_thread
= thread
;
4093 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
4095 /* Allow debugging the jump pad, gdb_collect, etc. */
4096 if (!gdb_breakpoint_here (lwp
->stop_pc
)
4097 && lwp
->stop_reason
!= TARGET_STOPPED_BY_WATCHPOINT
4098 && thread
->last_resume_kind
!= resume_step
4099 && maybe_move_out_of_jump_pad (lwp
, wstat
))
4102 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
4107 lwp
->status_pending_p
= 0;
4108 enqueue_one_deferred_signal (lwp
, wstat
);
4111 debug_printf ("Signal %d for LWP %ld deferred "
4113 WSTOPSIG (*wstat
), lwpid_of (thread
));
4116 linux_resume_one_lwp (lwp
, 0, 0, NULL
);
4119 lwp_suspended_inc (lwp
);
4121 current_thread
= saved_thread
;
4125 lwp_running (thread_info
*thread
)
4127 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4129 if (lwp_is_marked_dead (lwp
))
4132 return !lwp
->stopped
;
4135 /* Stop all lwps that aren't stopped yet, except EXCEPT, if not NULL.
4136 If SUSPEND, then also increase the suspend count of every LWP,
4140 stop_all_lwps (int suspend
, struct lwp_info
*except
)
4142 /* Should not be called recursively. */
4143 gdb_assert (stopping_threads
== NOT_STOPPING_THREADS
);
4148 debug_printf ("stop_all_lwps (%s, except=%s)\n",
4149 suspend
? "stop-and-suspend" : "stop",
4151 ? target_pid_to_str (ptid_of (get_lwp_thread (except
)))
4155 stopping_threads
= (suspend
4156 ? STOPPING_AND_SUSPENDING_THREADS
4157 : STOPPING_THREADS
);
4160 find_inferior (&all_threads
, suspend_and_send_sigstop_callback
, except
);
4162 find_inferior (&all_threads
, send_sigstop_callback
, except
);
4163 wait_for_sigstop ();
4164 stopping_threads
= NOT_STOPPING_THREADS
;
4168 debug_printf ("stop_all_lwps done, setting stopping_threads "
4169 "back to !stopping\n");
4174 /* Enqueue one signal in the chain of signals which need to be
4175 delivered to this process on next resume. */
4178 enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
)
4180 struct pending_signals
*p_sig
= XNEW (struct pending_signals
);
4182 p_sig
->prev
= lwp
->pending_signals
;
4183 p_sig
->signal
= signal
;
4185 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
4187 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
4188 lwp
->pending_signals
= p_sig
;
4191 /* Install breakpoints for software single stepping. */
4194 install_software_single_step_breakpoints (struct lwp_info
*lwp
)
4196 struct thread_info
*thread
= get_lwp_thread (lwp
);
4197 struct regcache
*regcache
= get_thread_regcache (thread
, 1);
4198 struct cleanup
*old_chain
= make_cleanup_restore_current_thread ();
4200 current_thread
= thread
;
4201 std::vector
<CORE_ADDR
> next_pcs
= the_low_target
.get_next_pcs (regcache
);
4203 for (CORE_ADDR pc
: next_pcs
)
4204 set_single_step_breakpoint (pc
, current_ptid
);
4206 do_cleanups (old_chain
);
4209 /* Single step via hardware or software single step.
4210 Return 1 if hardware single stepping, 0 if software single stepping
4211 or can't single step. */
4214 single_step (struct lwp_info
* lwp
)
4218 if (can_hardware_single_step ())
4222 else if (can_software_single_step ())
4224 install_software_single_step_breakpoints (lwp
);
4230 debug_printf ("stepping is not implemented on this target");
4236 /* The signal can be delivered to the inferior if we are not trying to
4237 finish a fast tracepoint collect. Since signal can be delivered in
4238 the step-over, the program may go to signal handler and trap again
4239 after return from the signal handler. We can live with the spurious
4243 lwp_signal_can_be_delivered (struct lwp_info
*lwp
)
4245 return (lwp
->collecting_fast_tracepoint
4246 == fast_tpoint_collect_result::not_collecting
);
4249 /* Resume execution of LWP. If STEP is nonzero, single-step it. If
4250 SIGNAL is nonzero, give it that signal. */
4253 linux_resume_one_lwp_throw (struct lwp_info
*lwp
,
4254 int step
, int signal
, siginfo_t
*info
)
4256 struct thread_info
*thread
= get_lwp_thread (lwp
);
4257 struct thread_info
*saved_thread
;
4259 struct process_info
*proc
= get_thread_process (thread
);
4261 /* Note that target description may not be initialised
4262 (proc->tdesc == NULL) at this point because the program hasn't
4263 stopped at the first instruction yet. It means GDBserver skips
4264 the extra traps from the wrapper program (see option --wrapper).
4265 Code in this function that requires register access should be
4266 guarded by proc->tdesc == NULL or something else. */
4268 if (lwp
->stopped
== 0)
4271 gdb_assert (lwp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
);
4273 fast_tpoint_collect_result fast_tp_collecting
4274 = lwp
->collecting_fast_tracepoint
;
4276 gdb_assert (!stabilizing_threads
4277 || (fast_tp_collecting
4278 != fast_tpoint_collect_result::not_collecting
));
4280 /* Cancel actions that rely on GDB not changing the PC (e.g., the
4281 user used the "jump" command, or "set $pc = foo"). */
4282 if (thread
->while_stepping
!= NULL
&& lwp
->stop_pc
!= get_pc (lwp
))
4284 /* Collecting 'while-stepping' actions doesn't make sense
4286 release_while_stepping_state_list (thread
);
4289 /* If we have pending signals or status, and a new signal, enqueue the
4290 signal. Also enqueue the signal if it can't be delivered to the
4291 inferior right now. */
4293 && (lwp
->status_pending_p
4294 || lwp
->pending_signals
!= NULL
4295 || !lwp_signal_can_be_delivered (lwp
)))
4297 enqueue_pending_signal (lwp
, signal
, info
);
4299 /* Postpone any pending signal. It was enqueued above. */
4303 if (lwp
->status_pending_p
)
4306 debug_printf ("Not resuming lwp %ld (%s, stop %s);"
4307 " has pending status\n",
4308 lwpid_of (thread
), step
? "step" : "continue",
4309 lwp
->stop_expected
? "expected" : "not expected");
4313 saved_thread
= current_thread
;
4314 current_thread
= thread
;
4316 /* This bit needs some thinking about. If we get a signal that
4317 we must report while a single-step reinsert is still pending,
4318 we often end up resuming the thread. It might be better to
4319 (ew) allow a stack of pending events; then we could be sure that
4320 the reinsert happened right away and not lose any signals.
4322 Making this stack would also shrink the window in which breakpoints are
4323 uninserted (see comment in linux_wait_for_lwp) but not enough for
4324 complete correctness, so it won't solve that problem. It may be
4325 worthwhile just to solve this one, however. */
4326 if (lwp
->bp_reinsert
!= 0)
4329 debug_printf (" pending reinsert at 0x%s\n",
4330 paddress (lwp
->bp_reinsert
));
4332 if (can_hardware_single_step ())
4334 if (fast_tp_collecting
== fast_tpoint_collect_result::not_collecting
)
4337 warning ("BAD - reinserting but not stepping.");
4339 warning ("BAD - reinserting and suspended(%d).",
4344 step
= maybe_hw_step (thread
);
4347 if (fast_tp_collecting
== fast_tpoint_collect_result::before_insn
)
4350 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
4351 " (exit-jump-pad-bkpt)\n",
4354 else if (fast_tp_collecting
== fast_tpoint_collect_result::at_insn
)
4357 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
4358 " single-stepping\n",
4361 if (can_hardware_single_step ())
4365 internal_error (__FILE__
, __LINE__
,
4366 "moving out of jump pad single-stepping"
4367 " not implemented on this target");
4371 /* If we have while-stepping actions in this thread set it stepping.
4372 If we have a signal to deliver, it may or may not be set to
4373 SIG_IGN, we don't know. Assume so, and allow collecting
4374 while-stepping into a signal handler. A possible smart thing to
4375 do would be to set an internal breakpoint at the signal return
4376 address, continue, and carry on catching this while-stepping
4377 action only when that breakpoint is hit. A future
4379 if (thread
->while_stepping
!= NULL
)
4382 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
4385 step
= single_step (lwp
);
4388 if (proc
->tdesc
!= NULL
&& the_low_target
.get_pc
!= NULL
)
4390 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
4392 lwp
->stop_pc
= (*the_low_target
.get_pc
) (regcache
);
4396 debug_printf (" %s from pc 0x%lx\n", step
? "step" : "continue",
4397 (long) lwp
->stop_pc
);
4401 /* If we have pending signals, consume one if it can be delivered to
4403 if (lwp
->pending_signals
!= NULL
&& lwp_signal_can_be_delivered (lwp
))
4405 struct pending_signals
**p_sig
;
4407 p_sig
= &lwp
->pending_signals
;
4408 while ((*p_sig
)->prev
!= NULL
)
4409 p_sig
= &(*p_sig
)->prev
;
4411 signal
= (*p_sig
)->signal
;
4412 if ((*p_sig
)->info
.si_signo
!= 0)
4413 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
4421 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
4422 lwpid_of (thread
), step
? "step" : "continue", signal
,
4423 lwp
->stop_expected
? "expected" : "not expected");
4425 if (the_low_target
.prepare_to_resume
!= NULL
)
4426 the_low_target
.prepare_to_resume (lwp
);
4428 regcache_invalidate_thread (thread
);
4430 lwp
->stepping
= step
;
4432 ptrace_request
= PTRACE_SINGLESTEP
;
4433 else if (gdb_catching_syscalls_p (lwp
))
4434 ptrace_request
= PTRACE_SYSCALL
;
4436 ptrace_request
= PTRACE_CONT
;
4437 ptrace (ptrace_request
,
4439 (PTRACE_TYPE_ARG3
) 0,
4440 /* Coerce to a uintptr_t first to avoid potential gcc warning
4441 of coercing an 8 byte integer to a 4 byte pointer. */
4442 (PTRACE_TYPE_ARG4
) (uintptr_t) signal
);
4444 current_thread
= saved_thread
;
4446 perror_with_name ("resuming thread");
4448 /* Successfully resumed. Clear state that no longer makes sense,
4449 and mark the LWP as running. Must not do this before resuming
4450 otherwise if that fails other code will be confused. E.g., we'd
4451 later try to stop the LWP and hang forever waiting for a stop
4452 status. Note that we must not throw after this is cleared,
4453 otherwise handle_zombie_lwp_error would get confused. */
4455 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4458 /* Called when we try to resume a stopped LWP and that errors out. If
4459 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
4460 or about to become), discard the error, clear any pending status
4461 the LWP may have, and return true (we'll collect the exit status
4462 soon enough). Otherwise, return false. */
4465 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
4467 struct thread_info
*thread
= get_lwp_thread (lp
);
4469 /* If we get an error after resuming the LWP successfully, we'd
4470 confuse !T state for the LWP being gone. */
4471 gdb_assert (lp
->stopped
);
4473 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
4474 because even if ptrace failed with ESRCH, the tracee may be "not
4475 yet fully dead", but already refusing ptrace requests. In that
4476 case the tracee has 'R (Running)' state for a little bit
4477 (observed in Linux 3.18). See also the note on ESRCH in the
4478 ptrace(2) man page. Instead, check whether the LWP has any state
4479 other than ptrace-stopped. */
4481 /* Don't assume anything if /proc/PID/status can't be read. */
4482 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread
)) == 0)
4484 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4485 lp
->status_pending_p
= 0;
4491 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
4492 disappears while we try to resume it. */
4495 linux_resume_one_lwp (struct lwp_info
*lwp
,
4496 int step
, int signal
, siginfo_t
*info
)
4500 linux_resume_one_lwp_throw (lwp
, step
, signal
, info
);
4502 CATCH (ex
, RETURN_MASK_ERROR
)
4504 if (!check_ptrace_stopped_lwp_gone (lwp
))
4505 throw_exception (ex
);
4510 /* This function is called once per thread via for_each_thread.
4511 We look up which resume request applies to THREAD and mark it with a
4512 pointer to the appropriate resume request.
4514 This algorithm is O(threads * resume elements), but resume elements
4515 is small (and will remain small at least until GDB supports thread
4519 linux_set_resume_request (thread_info
*thread
, thread_resume
*resume
, size_t n
)
4521 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4523 for (int ndx
= 0; ndx
< n
; ndx
++)
4525 ptid_t ptid
= resume
[ndx
].thread
;
4526 if (ptid_equal (ptid
, minus_one_ptid
)
4527 || ptid
== thread
->id
4528 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
4530 || (ptid_get_pid (ptid
) == pid_of (thread
)
4531 && (ptid_is_pid (ptid
)
4532 || ptid_get_lwp (ptid
) == -1)))
4534 if (resume
[ndx
].kind
== resume_stop
4535 && thread
->last_resume_kind
== resume_stop
)
4538 debug_printf ("already %s LWP %ld at GDB's request\n",
4539 (thread
->last_status
.kind
4540 == TARGET_WAITKIND_STOPPED
)
4548 /* Ignore (wildcard) resume requests for already-resumed
4550 if (resume
[ndx
].kind
!= resume_stop
4551 && thread
->last_resume_kind
!= resume_stop
)
4554 debug_printf ("already %s LWP %ld at GDB's request\n",
4555 (thread
->last_resume_kind
4563 /* Don't let wildcard resumes resume fork children that GDB
4564 does not yet know are new fork children. */
4565 if (lwp
->fork_relative
!= NULL
)
4567 struct lwp_info
*rel
= lwp
->fork_relative
;
4569 if (rel
->status_pending_p
4570 && (rel
->waitstatus
.kind
== TARGET_WAITKIND_FORKED
4571 || rel
->waitstatus
.kind
== TARGET_WAITKIND_VFORKED
))
4574 debug_printf ("not resuming LWP %ld: has queued stop reply\n",
4580 /* If the thread has a pending event that has already been
4581 reported to GDBserver core, but GDB has not pulled the
4582 event out of the vStopped queue yet, likewise, ignore the
4583 (wildcard) resume request. */
4584 if (in_queued_stop_replies (thread
->id
))
4587 debug_printf ("not resuming LWP %ld: has queued stop reply\n",
4592 lwp
->resume
= &resume
[ndx
];
4593 thread
->last_resume_kind
= lwp
->resume
->kind
;
4595 lwp
->step_range_start
= lwp
->resume
->step_range_start
;
4596 lwp
->step_range_end
= lwp
->resume
->step_range_end
;
4598 /* If we had a deferred signal to report, dequeue one now.
4599 This can happen if LWP gets more than one signal while
4600 trying to get out of a jump pad. */
4602 && !lwp
->status_pending_p
4603 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
4605 lwp
->status_pending_p
= 1;
4608 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
4609 "leaving status pending.\n",
4610 WSTOPSIG (lwp
->status_pending
),
4618 /* No resume action for this thread. */
4622 /* find_inferior callback for linux_resume.
4623 Set *FLAG_P if this lwp has an interesting status pending. */
4626 resume_status_pending_p (thread_info
*thread
)
4628 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4630 /* LWPs which will not be resumed are not interesting, because
4631 we might not wait for them next time through linux_wait. */
4632 if (lwp
->resume
== NULL
)
4635 return thread_still_has_status_pending_p (thread
);
4638 /* Return 1 if this lwp that GDB wants running is stopped at an
4639 internal breakpoint that we need to step over. It assumes that any
4640 required STOP_PC adjustment has already been propagated to the
4641 inferior's regcache. */
4644 need_step_over_p (thread_info
*thread
)
4646 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4647 struct thread_info
*saved_thread
;
4649 struct process_info
*proc
= get_thread_process (thread
);
4651 /* GDBserver is skipping the extra traps from the wrapper program,
4652 don't have to do step over. */
4653 if (proc
->tdesc
== NULL
)
4656 /* LWPs which will not be resumed are not interesting, because we
4657 might not wait for them next time through linux_wait. */
4662 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
4667 if (thread
->last_resume_kind
== resume_stop
)
4670 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4676 gdb_assert (lwp
->suspended
>= 0);
4681 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4686 if (lwp
->status_pending_p
)
4689 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4695 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4699 /* If the PC has changed since we stopped, then don't do anything,
4700 and let the breakpoint/tracepoint be hit. This happens if, for
4701 instance, GDB handled the decr_pc_after_break subtraction itself,
4702 GDB is OOL stepping this thread, or the user has issued a "jump"
4703 command, or poked thread's registers herself. */
4704 if (pc
!= lwp
->stop_pc
)
4707 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4708 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4710 paddress (lwp
->stop_pc
), paddress (pc
));
4714 /* On software single step target, resume the inferior with signal
4715 rather than stepping over. */
4716 if (can_software_single_step ()
4717 && lwp
->pending_signals
!= NULL
4718 && lwp_signal_can_be_delivered (lwp
))
4721 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4728 saved_thread
= current_thread
;
4729 current_thread
= thread
;
4731 /* We can only step over breakpoints we know about. */
4732 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
4734 /* Don't step over a breakpoint that GDB expects to hit
4735 though. If the condition is being evaluated on the target's side
4736 and it evaluate to false, step over this breakpoint as well. */
4737 if (gdb_breakpoint_here (pc
)
4738 && gdb_condition_true_at_breakpoint (pc
)
4739 && gdb_no_commands_at_breakpoint (pc
))
4742 debug_printf ("Need step over [LWP %ld]? yes, but found"
4743 " GDB breakpoint at 0x%s; skipping step over\n",
4744 lwpid_of (thread
), paddress (pc
));
4746 current_thread
= saved_thread
;
4752 debug_printf ("Need step over [LWP %ld]? yes, "
4753 "found breakpoint at 0x%s\n",
4754 lwpid_of (thread
), paddress (pc
));
4756 /* We've found an lwp that needs stepping over --- return 1 so
4757 that find_inferior stops looking. */
4758 current_thread
= saved_thread
;
4764 current_thread
= saved_thread
;
4767 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4769 lwpid_of (thread
), paddress (pc
));
4774 /* Start a step-over operation on LWP. When LWP stopped at a
4775 breakpoint, to make progress, we need to remove the breakpoint out
4776 of the way. If we let other threads run while we do that, they may
4777 pass by the breakpoint location and miss hitting it. To avoid
4778 that, a step-over momentarily stops all threads while LWP is
4779 single-stepped by either hardware or software while the breakpoint
4780 is temporarily uninserted from the inferior. When the single-step
4781 finishes, we reinsert the breakpoint, and let all threads that are
4782 supposed to be running, run again. */
4785 start_step_over (struct lwp_info
*lwp
)
4787 struct thread_info
*thread
= get_lwp_thread (lwp
);
4788 struct thread_info
*saved_thread
;
4793 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4796 stop_all_lwps (1, lwp
);
4798 if (lwp
->suspended
!= 0)
4800 internal_error (__FILE__
, __LINE__
,
4801 "LWP %ld suspended=%d\n", lwpid_of (thread
),
4806 debug_printf ("Done stopping all threads for step-over.\n");
4808 /* Note, we should always reach here with an already adjusted PC,
4809 either by GDB (if we're resuming due to GDB's request), or by our
4810 caller, if we just finished handling an internal breakpoint GDB
4811 shouldn't care about. */
4814 saved_thread
= current_thread
;
4815 current_thread
= thread
;
4817 lwp
->bp_reinsert
= pc
;
4818 uninsert_breakpoints_at (pc
);
4819 uninsert_fast_tracepoint_jumps_at (pc
);
4821 step
= single_step (lwp
);
4823 current_thread
= saved_thread
;
4825 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
4827 /* Require next event from this LWP. */
4828 step_over_bkpt
= thread
->id
;
4832 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4833 start_step_over, if still there, and delete any single-step
4834 breakpoints we've set, on non hardware single-step targets. */
4837 finish_step_over (struct lwp_info
*lwp
)
4839 if (lwp
->bp_reinsert
!= 0)
4841 struct thread_info
*saved_thread
= current_thread
;
4844 debug_printf ("Finished step over.\n");
4846 current_thread
= get_lwp_thread (lwp
);
4848 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4849 may be no breakpoint to reinsert there by now. */
4850 reinsert_breakpoints_at (lwp
->bp_reinsert
);
4851 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
4853 lwp
->bp_reinsert
= 0;
4855 /* Delete any single-step breakpoints. No longer needed. We
4856 don't have to worry about other threads hitting this trap,
4857 and later not being able to explain it, because we were
4858 stepping over a breakpoint, and we hold all threads but
4859 LWP stopped while doing that. */
4860 if (!can_hardware_single_step ())
4862 gdb_assert (has_single_step_breakpoints (current_thread
));
4863 delete_single_step_breakpoints (current_thread
);
4866 step_over_bkpt
= null_ptid
;
4867 current_thread
= saved_thread
;
4874 /* If there's a step over in progress, wait until all threads stop
4875 (that is, until the stepping thread finishes its step), and
4876 unsuspend all lwps. The stepping thread ends with its status
4877 pending, which is processed later when we get back to processing
4881 complete_ongoing_step_over (void)
4883 if (!ptid_equal (step_over_bkpt
, null_ptid
))
4885 struct lwp_info
*lwp
;
4890 debug_printf ("detach: step over in progress, finish it first\n");
4892 /* Passing NULL_PTID as filter indicates we want all events to
4893 be left pending. Eventually this returns when there are no
4894 unwaited-for children left. */
4895 ret
= linux_wait_for_event_filtered (minus_one_ptid
, null_ptid
,
4897 gdb_assert (ret
== -1);
4899 lwp
= find_lwp_pid (step_over_bkpt
);
4901 finish_step_over (lwp
);
4902 step_over_bkpt
= null_ptid
;
4903 unsuspend_all_lwps (lwp
);
4907 /* This function is called once per thread. We check the thread's resume
4908 request, which will tell us whether to resume, step, or leave the thread
4909 stopped; and what signal, if any, it should be sent.
4911 For threads which we aren't explicitly told otherwise, we preserve
4912 the stepping flag; this is used for stepping over gdbserver-placed
4915 If pending_flags was set in any thread, we queue any needed
4916 signals, since we won't actually resume. We already have a pending
4917 event to report, so we don't need to preserve any step requests;
4918 they should be re-issued if necessary. */
4921 linux_resume_one_thread (thread_info
*thread
, void *arg
)
4923 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4924 int leave_all_stopped
= * (int *) arg
;
4927 if (lwp
->resume
== NULL
)
4930 if (lwp
->resume
->kind
== resume_stop
)
4933 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread
));
4938 debug_printf ("stopping LWP %ld\n", lwpid_of (thread
));
4940 /* Stop the thread, and wait for the event asynchronously,
4941 through the event loop. */
4947 debug_printf ("already stopped LWP %ld\n",
4950 /* The LWP may have been stopped in an internal event that
4951 was not meant to be notified back to GDB (e.g., gdbserver
4952 breakpoint), so we should be reporting a stop event in
4955 /* If the thread already has a pending SIGSTOP, this is a
4956 no-op. Otherwise, something later will presumably resume
4957 the thread and this will cause it to cancel any pending
4958 operation, due to last_resume_kind == resume_stop. If
4959 the thread already has a pending status to report, we
4960 will still report it the next time we wait - see
4961 status_pending_p_callback. */
4963 /* If we already have a pending signal to report, then
4964 there's no need to queue a SIGSTOP, as this means we're
4965 midway through moving the LWP out of the jumppad, and we
4966 will report the pending signal as soon as that is
4968 if (lwp
->pending_signals_to_report
== NULL
)
4972 /* For stop requests, we're done. */
4974 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4978 /* If this thread which is about to be resumed has a pending status,
4979 then don't resume it - we can just report the pending status.
4980 Likewise if it is suspended, because e.g., another thread is
4981 stepping past a breakpoint. Make sure to queue any signals that
4982 would otherwise be sent. In all-stop mode, we do this decision
4983 based on if *any* thread has a pending status. If there's a
4984 thread that needs the step-over-breakpoint dance, then don't
4985 resume any other thread but that particular one. */
4986 leave_pending
= (lwp
->suspended
4987 || lwp
->status_pending_p
4988 || leave_all_stopped
);
4990 /* If we have a new signal, enqueue the signal. */
4991 if (lwp
->resume
->sig
!= 0)
4993 siginfo_t info
, *info_p
;
4995 /* If this is the same signal we were previously stopped by,
4996 make sure to queue its siginfo. */
4997 if (WIFSTOPPED (lwp
->last_status
)
4998 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
4999 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
),
5000 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
5005 enqueue_pending_signal (lwp
, lwp
->resume
->sig
, info_p
);
5011 debug_printf ("resuming LWP %ld\n", lwpid_of (thread
));
5013 proceed_one_lwp (thread
, NULL
);
5018 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread
));
5021 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
5027 linux_resume (struct thread_resume
*resume_info
, size_t n
)
5029 struct thread_info
*need_step_over
= NULL
;
5030 int leave_all_stopped
;
5035 debug_printf ("linux_resume:\n");
5038 for_each_thread ([&] (thread_info
*thread
)
5040 linux_set_resume_request (thread
, resume_info
, n
);
5043 /* If there is a thread which would otherwise be resumed, which has
5044 a pending status, then don't resume any threads - we can just
5045 report the pending status. Make sure to queue any signals that
5046 would otherwise be sent. In non-stop mode, we'll apply this
5047 logic to each thread individually. We consume all pending events
5048 before considering to start a step-over (in all-stop). */
5049 bool any_pending
= false;
5051 any_pending
= find_thread (resume_status_pending_p
) != NULL
;
5053 /* If there is a thread which would otherwise be resumed, which is
5054 stopped at a breakpoint that needs stepping over, then don't
5055 resume any threads - have it step over the breakpoint with all
5056 other threads stopped, then resume all threads again. Make sure
5057 to queue any signals that would otherwise be delivered or
5059 if (!any_pending
&& supports_breakpoints ())
5060 need_step_over
= find_thread (need_step_over_p
);
5062 leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
5066 if (need_step_over
!= NULL
)
5067 debug_printf ("Not resuming all, need step over\n");
5068 else if (any_pending
)
5069 debug_printf ("Not resuming, all-stop and found "
5070 "an LWP with pending status\n");
5072 debug_printf ("Resuming, no pending status or step over needed\n");
5075 /* Even if we're leaving threads stopped, queue all signals we'd
5076 otherwise deliver. */
5077 find_inferior (&all_threads
, linux_resume_one_thread
, &leave_all_stopped
);
5080 start_step_over (get_thread_lwp (need_step_over
));
5084 debug_printf ("linux_resume done\n");
5088 /* We may have events that were pending that can/should be sent to
5089 the client now. Trigger a linux_wait call. */
5090 if (target_is_async_p ())
5094 /* This function is called once per thread. We check the thread's
5095 last resume request, which will tell us whether to resume, step, or
5096 leave the thread stopped. Any signal the client requested to be
5097 delivered has already been enqueued at this point.
5099 If any thread that GDB wants running is stopped at an internal
5100 breakpoint that needs stepping over, we start a step-over operation
5101 on that particular thread, and leave all others stopped. */
5104 proceed_one_lwp (thread_info
*thread
, void *except
)
5106 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5113 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread
));
5118 debug_printf (" LWP %ld already running\n", lwpid_of (thread
));
5122 if (thread
->last_resume_kind
== resume_stop
5123 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
5126 debug_printf (" client wants LWP to remain %ld stopped\n",
5131 if (lwp
->status_pending_p
)
5134 debug_printf (" LWP %ld has pending status, leaving stopped\n",
5139 gdb_assert (lwp
->suspended
>= 0);
5144 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread
));
5148 if (thread
->last_resume_kind
== resume_stop
5149 && lwp
->pending_signals_to_report
== NULL
5150 && (lwp
->collecting_fast_tracepoint
5151 == fast_tpoint_collect_result::not_collecting
))
5153 /* We haven't reported this LWP as stopped yet (otherwise, the
5154 last_status.kind check above would catch it, and we wouldn't
5155 reach here. This LWP may have been momentarily paused by a
5156 stop_all_lwps call while handling for example, another LWP's
5157 step-over. In that case, the pending expected SIGSTOP signal
5158 that was queued at vCont;t handling time will have already
5159 been consumed by wait_for_sigstop, and so we need to requeue
5160 another one here. Note that if the LWP already has a SIGSTOP
5161 pending, this is a no-op. */
5164 debug_printf ("Client wants LWP %ld to stop. "
5165 "Making sure it has a SIGSTOP pending\n",
5171 if (thread
->last_resume_kind
== resume_step
)
5174 debug_printf (" stepping LWP %ld, client wants it stepping\n",
5177 /* If resume_step is requested by GDB, install single-step
5178 breakpoints when the thread is about to be actually resumed if
5179 the single-step breakpoints weren't removed. */
5180 if (can_software_single_step ()
5181 && !has_single_step_breakpoints (thread
))
5182 install_software_single_step_breakpoints (lwp
);
5184 step
= maybe_hw_step (thread
);
5186 else if (lwp
->bp_reinsert
!= 0)
5189 debug_printf (" stepping LWP %ld, reinsert set\n",
5192 step
= maybe_hw_step (thread
);
5197 linux_resume_one_lwp (lwp
, step
, 0, NULL
);
5202 unsuspend_and_proceed_one_lwp (thread_info
*thread
, void *except
)
5204 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5209 lwp_suspended_decr (lwp
);
5211 return proceed_one_lwp (thread
, except
);
5214 /* When we finish a step-over, set threads running again. If there's
5215 another thread that may need a step-over, now's the time to start
5216 it. Eventually, we'll move all threads past their breakpoints. */
5219 proceed_all_lwps (void)
5221 struct thread_info
*need_step_over
;
5223 /* If there is a thread which would otherwise be resumed, which is
5224 stopped at a breakpoint that needs stepping over, then don't
5225 resume any threads - have it step over the breakpoint with all
5226 other threads stopped, then resume all threads again. */
5228 if (supports_breakpoints ())
5230 need_step_over
= find_thread (need_step_over_p
);
5232 if (need_step_over
!= NULL
)
5235 debug_printf ("proceed_all_lwps: found "
5236 "thread %ld needing a step-over\n",
5237 lwpid_of (need_step_over
));
5239 start_step_over (get_thread_lwp (need_step_over
));
5245 debug_printf ("Proceeding, no step-over needed\n");
5247 find_inferior (&all_threads
, proceed_one_lwp
, NULL
);
5250 /* Stopped LWPs that the client wanted to be running, that don't have
5251 pending statuses, are set to run again, except for EXCEPT, if not
5252 NULL. This undoes a stop_all_lwps call. */
5255 unstop_all_lwps (int unsuspend
, struct lwp_info
*except
)
5261 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
5262 lwpid_of (get_lwp_thread (except
)));
5264 debug_printf ("unstopping all lwps\n");
5268 find_inferior (&all_threads
, unsuspend_and_proceed_one_lwp
, except
);
5270 find_inferior (&all_threads
, proceed_one_lwp
, except
);
5274 debug_printf ("unstop_all_lwps done\n");
5280 #ifdef HAVE_LINUX_REGSETS
5282 #define use_linux_regsets 1
5284 /* Returns true if REGSET has been disabled. */
5287 regset_disabled (struct regsets_info
*info
, struct regset_info
*regset
)
5289 return (info
->disabled_regsets
!= NULL
5290 && info
->disabled_regsets
[regset
- info
->regsets
]);
5293 /* Disable REGSET. */
5296 disable_regset (struct regsets_info
*info
, struct regset_info
*regset
)
5300 dr_offset
= regset
- info
->regsets
;
5301 if (info
->disabled_regsets
== NULL
)
5302 info
->disabled_regsets
= (char *) xcalloc (1, info
->num_regsets
);
5303 info
->disabled_regsets
[dr_offset
] = 1;
5307 regsets_fetch_inferior_registers (struct regsets_info
*regsets_info
,
5308 struct regcache
*regcache
)
5310 struct regset_info
*regset
;
5311 int saw_general_regs
= 0;
5315 pid
= lwpid_of (current_thread
);
5316 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
5321 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
))
5324 buf
= xmalloc (regset
->size
);
5326 nt_type
= regset
->nt_type
;
5330 iov
.iov_len
= regset
->size
;
5331 data
= (void *) &iov
;
5337 res
= ptrace (regset
->get_request
, pid
,
5338 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5340 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
5346 /* If we get EIO on a regset, do not try it again for
5347 this process mode. */
5348 disable_regset (regsets_info
, regset
);
5350 else if (errno
== ENODATA
)
5352 /* ENODATA may be returned if the regset is currently
5353 not "active". This can happen in normal operation,
5354 so suppress the warning in this case. */
5356 else if (errno
== ESRCH
)
5358 /* At this point, ESRCH should mean the process is
5359 already gone, in which case we simply ignore attempts
5360 to read its registers. */
5365 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
5372 if (regset
->type
== GENERAL_REGS
)
5373 saw_general_regs
= 1;
5374 regset
->store_function (regcache
, buf
);
5378 if (saw_general_regs
)
5385 regsets_store_inferior_registers (struct regsets_info
*regsets_info
,
5386 struct regcache
*regcache
)
5388 struct regset_info
*regset
;
5389 int saw_general_regs
= 0;
5393 pid
= lwpid_of (current_thread
);
5394 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
5399 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
)
5400 || regset
->fill_function
== NULL
)
5403 buf
= xmalloc (regset
->size
);
5405 /* First fill the buffer with the current register set contents,
5406 in case there are any items in the kernel's regset that are
5407 not in gdbserver's regcache. */
5409 nt_type
= regset
->nt_type
;
5413 iov
.iov_len
= regset
->size
;
5414 data
= (void *) &iov
;
5420 res
= ptrace (regset
->get_request
, pid
,
5421 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5423 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
5428 /* Then overlay our cached registers on that. */
5429 regset
->fill_function (regcache
, buf
);
5431 /* Only now do we write the register set. */
5433 res
= ptrace (regset
->set_request
, pid
,
5434 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5436 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
5444 /* If we get EIO on a regset, do not try it again for
5445 this process mode. */
5446 disable_regset (regsets_info
, regset
);
5448 else if (errno
== ESRCH
)
5450 /* At this point, ESRCH should mean the process is
5451 already gone, in which case we simply ignore attempts
5452 to change its registers. See also the related
5453 comment in linux_resume_one_lwp. */
5459 perror ("Warning: ptrace(regsets_store_inferior_registers)");
5462 else if (regset
->type
== GENERAL_REGS
)
5463 saw_general_regs
= 1;
5466 if (saw_general_regs
)
5472 #else /* !HAVE_LINUX_REGSETS */
5474 #define use_linux_regsets 0
5475 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
5476 #define regsets_store_inferior_registers(regsets_info, regcache) 1
5480 /* Return 1 if register REGNO is supported by one of the regset ptrace
5481 calls or 0 if it has to be transferred individually. */
5484 linux_register_in_regsets (const struct regs_info
*regs_info
, int regno
)
5486 unsigned char mask
= 1 << (regno
% 8);
5487 size_t index
= regno
/ 8;
5489 return (use_linux_regsets
5490 && (regs_info
->regset_bitmap
== NULL
5491 || (regs_info
->regset_bitmap
[index
] & mask
) != 0));
5494 #ifdef HAVE_LINUX_USRREGS
5497 register_addr (const struct usrregs_info
*usrregs
, int regnum
)
5501 if (regnum
< 0 || regnum
>= usrregs
->num_regs
)
5502 error ("Invalid register number %d.", regnum
);
5504 addr
= usrregs
->regmap
[regnum
];
5509 /* Fetch one register. */
5511 fetch_register (const struct usrregs_info
*usrregs
,
5512 struct regcache
*regcache
, int regno
)
5519 if (regno
>= usrregs
->num_regs
)
5521 if ((*the_low_target
.cannot_fetch_register
) (regno
))
5524 regaddr
= register_addr (usrregs
, regno
);
5528 size
= ((register_size (regcache
->tdesc
, regno
)
5529 + sizeof (PTRACE_XFER_TYPE
) - 1)
5530 & -sizeof (PTRACE_XFER_TYPE
));
5531 buf
= (char *) alloca (size
);
5533 pid
= lwpid_of (current_thread
);
5534 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5537 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
5538 ptrace (PTRACE_PEEKUSER
, pid
,
5539 /* Coerce to a uintptr_t first to avoid potential gcc warning
5540 of coercing an 8 byte integer to a 4 byte pointer. */
5541 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
, (PTRACE_TYPE_ARG4
) 0);
5542 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5544 error ("reading register %d: %s", regno
, strerror (errno
));
5547 if (the_low_target
.supply_ptrace_register
)
5548 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
5550 supply_register (regcache
, regno
, buf
);
5553 /* Store one register. */
5555 store_register (const struct usrregs_info
*usrregs
,
5556 struct regcache
*regcache
, int regno
)
5563 if (regno
>= usrregs
->num_regs
)
5565 if ((*the_low_target
.cannot_store_register
) (regno
))
5568 regaddr
= register_addr (usrregs
, regno
);
5572 size
= ((register_size (regcache
->tdesc
, regno
)
5573 + sizeof (PTRACE_XFER_TYPE
) - 1)
5574 & -sizeof (PTRACE_XFER_TYPE
));
5575 buf
= (char *) alloca (size
);
5576 memset (buf
, 0, size
);
5578 if (the_low_target
.collect_ptrace_register
)
5579 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
5581 collect_register (regcache
, regno
, buf
);
5583 pid
= lwpid_of (current_thread
);
5584 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5587 ptrace (PTRACE_POKEUSER
, pid
,
5588 /* Coerce to a uintptr_t first to avoid potential gcc warning
5589 about coercing an 8 byte integer to a 4 byte pointer. */
5590 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
,
5591 (PTRACE_TYPE_ARG4
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
5594 /* At this point, ESRCH should mean the process is
5595 already gone, in which case we simply ignore attempts
5596 to change its registers. See also the related
5597 comment in linux_resume_one_lwp. */
5601 if ((*the_low_target
.cannot_store_register
) (regno
) == 0)
5602 error ("writing register %d: %s", regno
, strerror (errno
));
5604 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5608 /* Fetch all registers, or just one, from the child process.
5609 If REGNO is -1, do this for all registers, skipping any that are
5610 assumed to have been retrieved by regsets_fetch_inferior_registers,
5611 unless ALL is non-zero.
5612 Otherwise, REGNO specifies which register (so we can save time). */
5614 usr_fetch_inferior_registers (const struct regs_info
*regs_info
,
5615 struct regcache
*regcache
, int regno
, int all
)
5617 struct usrregs_info
*usr
= regs_info
->usrregs
;
5621 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5622 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5623 fetch_register (usr
, regcache
, regno
);
5626 fetch_register (usr
, regcache
, regno
);
5629 /* Store our register values back into the inferior.
5630 If REGNO is -1, do this for all registers, skipping any that are
5631 assumed to have been saved by regsets_store_inferior_registers,
5632 unless ALL is non-zero.
5633 Otherwise, REGNO specifies which register (so we can save time). */
5635 usr_store_inferior_registers (const struct regs_info
*regs_info
,
5636 struct regcache
*regcache
, int regno
, int all
)
5638 struct usrregs_info
*usr
= regs_info
->usrregs
;
5642 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5643 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5644 store_register (usr
, regcache
, regno
);
5647 store_register (usr
, regcache
, regno
);
5650 #else /* !HAVE_LINUX_USRREGS */
5652 #define usr_fetch_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
5653 #define usr_store_inferior_registers(regs_info, regcache, regno, all) do {} while (0)
5659 linux_fetch_registers (struct regcache
*regcache
, int regno
)
5663 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
5667 if (the_low_target
.fetch_register
!= NULL
5668 && regs_info
->usrregs
!= NULL
)
5669 for (regno
= 0; regno
< regs_info
->usrregs
->num_regs
; regno
++)
5670 (*the_low_target
.fetch_register
) (regcache
, regno
);
5672 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
, regcache
);
5673 if (regs_info
->usrregs
!= NULL
)
5674 usr_fetch_inferior_registers (regs_info
, regcache
, -1, all
);
5678 if (the_low_target
.fetch_register
!= NULL
5679 && (*the_low_target
.fetch_register
) (regcache
, regno
))
5682 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5684 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
,
5686 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5687 usr_fetch_inferior_registers (regs_info
, regcache
, regno
, 1);
5692 linux_store_registers (struct regcache
*regcache
, int regno
)
5696 const struct regs_info
*regs_info
= (*the_low_target
.regs_info
) ();
5700 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5702 if (regs_info
->usrregs
!= NULL
)
5703 usr_store_inferior_registers (regs_info
, regcache
, regno
, all
);
5707 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5709 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5711 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5712 usr_store_inferior_registers (regs_info
, regcache
, regno
, 1);
5717 /* Copy LEN bytes from inferior's memory starting at MEMADDR
5718 to debugger memory starting at MYADDR. */
5721 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
5723 int pid
= lwpid_of (current_thread
);
5724 PTRACE_XFER_TYPE
*buffer
;
5732 /* Try using /proc. Don't bother for one word. */
5733 if (len
>= 3 * sizeof (long))
5737 /* We could keep this file open and cache it - possibly one per
5738 thread. That requires some juggling, but is even faster. */
5739 sprintf (filename
, "/proc/%d/mem", pid
);
5740 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
5744 /* If pread64 is available, use it. It's faster if the kernel
5745 supports it (only one syscall), and it's 64-bit safe even on
5746 32-bit platforms (for instance, SPARC debugging a SPARC64
5749 bytes
= pread64 (fd
, myaddr
, len
, memaddr
);
5752 if (lseek (fd
, memaddr
, SEEK_SET
) != -1)
5753 bytes
= read (fd
, myaddr
, len
);
5760 /* Some data was read, we'll try to get the rest with ptrace. */
5770 /* Round starting address down to longword boundary. */
5771 addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5772 /* Round ending address up; get number of longwords that makes. */
5773 count
= ((((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5774 / sizeof (PTRACE_XFER_TYPE
));
5775 /* Allocate buffer of that many longwords. */
5776 buffer
= XALLOCAVEC (PTRACE_XFER_TYPE
, count
);
5778 /* Read all the longwords */
5780 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5782 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5783 about coercing an 8 byte integer to a 4 byte pointer. */
5784 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
5785 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5786 (PTRACE_TYPE_ARG4
) 0);
5792 /* Copy appropriate bytes out of the buffer. */
5795 i
*= sizeof (PTRACE_XFER_TYPE
);
5796 i
-= memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1);
5798 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5805 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5806 memory at MEMADDR. On failure (cannot write to the inferior)
5807 returns the value of errno. Always succeeds if LEN is zero. */
5810 linux_write_memory (CORE_ADDR memaddr
, const unsigned char *myaddr
, int len
)
5813 /* Round starting address down to longword boundary. */
5814 CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5815 /* Round ending address up; get number of longwords that makes. */
5817 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5818 / sizeof (PTRACE_XFER_TYPE
);
5820 /* Allocate buffer of that many longwords. */
5821 PTRACE_XFER_TYPE
*buffer
= XALLOCAVEC (PTRACE_XFER_TYPE
, count
);
5823 int pid
= lwpid_of (current_thread
);
5827 /* Zero length write always succeeds. */
5833 /* Dump up to four bytes. */
5834 char str
[4 * 2 + 1];
5836 int dump
= len
< 4 ? len
: 4;
5838 for (i
= 0; i
< dump
; i
++)
5840 sprintf (p
, "%02x", myaddr
[i
]);
5845 debug_printf ("Writing %s to 0x%08lx in process %d\n",
5846 str
, (long) memaddr
, pid
);
5849 /* Fill start and end extra bytes of buffer with existing memory data. */
5852 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5853 about coercing an 8 byte integer to a 4 byte pointer. */
5854 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
5855 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5856 (PTRACE_TYPE_ARG4
) 0);
5864 = ptrace (PTRACE_PEEKTEXT
, pid
,
5865 /* Coerce to a uintptr_t first to avoid potential gcc warning
5866 about coercing an 8 byte integer to a 4 byte pointer. */
5867 (PTRACE_TYPE_ARG3
) (uintptr_t) (addr
+ (count
- 1)
5868 * sizeof (PTRACE_XFER_TYPE
)),
5869 (PTRACE_TYPE_ARG4
) 0);
5874 /* Copy data to be written over corresponding part of buffer. */
5876 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5879 /* Write the entire buffer. */
5881 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5884 ptrace (PTRACE_POKETEXT
, pid
,
5885 /* Coerce to a uintptr_t first to avoid potential gcc warning
5886 about coercing an 8 byte integer to a 4 byte pointer. */
5887 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5888 (PTRACE_TYPE_ARG4
) buffer
[i
]);
5897 linux_look_up_symbols (void)
5899 #ifdef USE_THREAD_DB
5900 struct process_info
*proc
= current_process ();
5902 if (proc
->priv
->thread_db
!= NULL
)
5910 linux_request_interrupt (void)
5912 /* Send a SIGINT to the process group. This acts just like the user
5913 typed a ^C on the controlling terminal. */
5914 kill (-signal_pid
, SIGINT
);
5917 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5918 to debugger memory starting at MYADDR. */
5921 linux_read_auxv (CORE_ADDR offset
, unsigned char *myaddr
, unsigned int len
)
5923 char filename
[PATH_MAX
];
5925 int pid
= lwpid_of (current_thread
);
5927 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5929 fd
= open (filename
, O_RDONLY
);
5933 if (offset
!= (CORE_ADDR
) 0
5934 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5937 n
= read (fd
, myaddr
, len
);
5944 /* These breakpoint and watchpoint related wrapper functions simply
5945 pass on the function call if the target has registered a
5946 corresponding function. */
5949 linux_supports_z_point_type (char z_type
)
5951 return (the_low_target
.supports_z_point_type
!= NULL
5952 && the_low_target
.supports_z_point_type (z_type
));
5956 linux_insert_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5957 int size
, struct raw_breakpoint
*bp
)
5959 if (type
== raw_bkpt_type_sw
)
5960 return insert_memory_breakpoint (bp
);
5961 else if (the_low_target
.insert_point
!= NULL
)
5962 return the_low_target
.insert_point (type
, addr
, size
, bp
);
5964 /* Unsupported (see target.h). */
5969 linux_remove_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5970 int size
, struct raw_breakpoint
*bp
)
5972 if (type
== raw_bkpt_type_sw
)
5973 return remove_memory_breakpoint (bp
);
5974 else if (the_low_target
.remove_point
!= NULL
)
5975 return the_low_target
.remove_point (type
, addr
, size
, bp
);
5977 /* Unsupported (see target.h). */
5981 /* Implement the to_stopped_by_sw_breakpoint target_ops
5985 linux_stopped_by_sw_breakpoint (void)
5987 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5989 return (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
);
5992 /* Implement the to_supports_stopped_by_sw_breakpoint target_ops
5996 linux_supports_stopped_by_sw_breakpoint (void)
5998 return USE_SIGTRAP_SIGINFO
;
6001 /* Implement the to_stopped_by_hw_breakpoint target_ops
6005 linux_stopped_by_hw_breakpoint (void)
6007 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
6009 return (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
);
6012 /* Implement the to_supports_stopped_by_hw_breakpoint target_ops
6016 linux_supports_stopped_by_hw_breakpoint (void)
6018 return USE_SIGTRAP_SIGINFO
;
6021 /* Implement the supports_hardware_single_step target_ops method. */
6024 linux_supports_hardware_single_step (void)
6026 return can_hardware_single_step ();
6030 linux_supports_software_single_step (void)
6032 return can_software_single_step ();
6036 linux_stopped_by_watchpoint (void)
6038 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
6040 return lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
6044 linux_stopped_data_address (void)
6046 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
6048 return lwp
->stopped_data_address
;
6051 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
6052 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
6053 && defined(PT_TEXT_END_ADDR)
6055 /* This is only used for targets that define PT_TEXT_ADDR,
6056 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
6057 the target has different ways of acquiring this information, like
6060 /* Under uClinux, programs are loaded at non-zero offsets, which we need
6061 to tell gdb about. */
6064 linux_read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
6066 unsigned long text
, text_end
, data
;
6067 int pid
= lwpid_of (current_thread
);
6071 text
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_ADDR
,
6072 (PTRACE_TYPE_ARG4
) 0);
6073 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_END_ADDR
,
6074 (PTRACE_TYPE_ARG4
) 0);
6075 data
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_DATA_ADDR
,
6076 (PTRACE_TYPE_ARG4
) 0);
6080 /* Both text and data offsets produced at compile-time (and so
6081 used by gdb) are relative to the beginning of the program,
6082 with the data segment immediately following the text segment.
6083 However, the actual runtime layout in memory may put the data
6084 somewhere else, so when we send gdb a data base-address, we
6085 use the real data base address and subtract the compile-time
6086 data base-address from it (which is just the length of the
6087 text segment). BSS immediately follows data in both
6090 *data_p
= data
- (text_end
- text
);
6099 linux_qxfer_osdata (const char *annex
,
6100 unsigned char *readbuf
, unsigned const char *writebuf
,
6101 CORE_ADDR offset
, int len
)
6103 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
6106 /* Convert a native/host siginfo object, into/from the siginfo in the
6107 layout of the inferiors' architecture. */
6110 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
6114 if (the_low_target
.siginfo_fixup
!= NULL
)
6115 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
6117 /* If there was no callback, or the callback didn't do anything,
6118 then just do a straight memcpy. */
6122 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
6124 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
6129 linux_xfer_siginfo (const char *annex
, unsigned char *readbuf
,
6130 unsigned const char *writebuf
, CORE_ADDR offset
, int len
)
6134 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
6136 if (current_thread
== NULL
)
6139 pid
= lwpid_of (current_thread
);
6142 debug_printf ("%s siginfo for lwp %d.\n",
6143 readbuf
!= NULL
? "Reading" : "Writing",
6146 if (offset
>= sizeof (siginfo
))
6149 if (ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
6152 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
6153 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
6154 inferior with a 64-bit GDBSERVER should look the same as debugging it
6155 with a 32-bit GDBSERVER, we need to convert it. */
6156 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
6158 if (offset
+ len
> sizeof (siginfo
))
6159 len
= sizeof (siginfo
) - offset
;
6161 if (readbuf
!= NULL
)
6162 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
6165 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
6167 /* Convert back to ptrace layout before flushing it out. */
6168 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
6170 if (ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
6177 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
6178 so we notice when children change state; as the handler for the
6179 sigsuspend in my_waitpid. */
6182 sigchld_handler (int signo
)
6184 int old_errno
= errno
;
6190 /* fprintf is not async-signal-safe, so call write
6192 if (write (2, "sigchld_handler\n",
6193 sizeof ("sigchld_handler\n") - 1) < 0)
6194 break; /* just ignore */
6198 if (target_is_async_p ())
6199 async_file_mark (); /* trigger a linux_wait */
6205 linux_supports_non_stop (void)
6211 linux_async (int enable
)
6213 int previous
= target_is_async_p ();
6216 debug_printf ("linux_async (%d), previous=%d\n",
6219 if (previous
!= enable
)
6222 sigemptyset (&mask
);
6223 sigaddset (&mask
, SIGCHLD
);
6225 sigprocmask (SIG_BLOCK
, &mask
, NULL
);
6229 if (pipe (linux_event_pipe
) == -1)
6231 linux_event_pipe
[0] = -1;
6232 linux_event_pipe
[1] = -1;
6233 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
6235 warning ("creating event pipe failed.");
6239 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
6240 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
6242 /* Register the event loop handler. */
6243 add_file_handler (linux_event_pipe
[0],
6244 handle_target_event
, NULL
);
6246 /* Always trigger a linux_wait. */
6251 delete_file_handler (linux_event_pipe
[0]);
6253 close (linux_event_pipe
[0]);
6254 close (linux_event_pipe
[1]);
6255 linux_event_pipe
[0] = -1;
6256 linux_event_pipe
[1] = -1;
6259 sigprocmask (SIG_UNBLOCK
, &mask
, NULL
);
6266 linux_start_non_stop (int nonstop
)
6268 /* Register or unregister from event-loop accordingly. */
6269 linux_async (nonstop
);
6271 if (target_is_async_p () != (nonstop
!= 0))
6278 linux_supports_multi_process (void)
6283 /* Check if fork events are supported. */
6286 linux_supports_fork_events (void)
6288 return linux_supports_tracefork ();
6291 /* Check if vfork events are supported. */
6294 linux_supports_vfork_events (void)
6296 return linux_supports_tracefork ();
6299 /* Check if exec events are supported. */
6302 linux_supports_exec_events (void)
6304 return linux_supports_traceexec ();
6307 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
6308 ptrace flags for all inferiors. This is in case the new GDB connection
6309 doesn't support the same set of events that the previous one did. */
6312 linux_handle_new_gdb_connection (void)
6314 /* Request that all the lwps reset their ptrace options. */
6315 for_each_thread ([] (thread_info
*thread
)
6317 struct lwp_info
*lwp
= get_thread_lwp (thread
);
6321 /* Stop the lwp so we can modify its ptrace options. */
6322 lwp
->must_set_ptrace_flags
= 1;
6323 linux_stop_lwp (lwp
);
6327 /* Already stopped; go ahead and set the ptrace options. */
6328 struct process_info
*proc
= find_process_pid (pid_of (thread
));
6329 int options
= linux_low_ptrace_options (proc
->attached
);
6331 linux_enable_event_reporting (lwpid_of (thread
), options
);
6332 lwp
->must_set_ptrace_flags
= 0;
6338 linux_supports_disable_randomization (void)
6340 #ifdef HAVE_PERSONALITY
6348 linux_supports_agent (void)
6354 linux_supports_range_stepping (void)
6356 if (can_software_single_step ())
6358 if (*the_low_target
.supports_range_stepping
== NULL
)
6361 return (*the_low_target
.supports_range_stepping
) ();
6364 /* Enumerate spufs IDs for process PID. */
6366 spu_enumerate_spu_ids (long pid
, unsigned char *buf
, CORE_ADDR offset
, int len
)
6372 struct dirent
*entry
;
6374 sprintf (path
, "/proc/%ld/fd", pid
);
6375 dir
= opendir (path
);
6380 while ((entry
= readdir (dir
)) != NULL
)
6386 fd
= atoi (entry
->d_name
);
6390 sprintf (path
, "/proc/%ld/fd/%d", pid
, fd
);
6391 if (stat (path
, &st
) != 0)
6393 if (!S_ISDIR (st
.st_mode
))
6396 if (statfs (path
, &stfs
) != 0)
6398 if (stfs
.f_type
!= SPUFS_MAGIC
)
6401 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
6403 *(unsigned int *)(buf
+ pos
- offset
) = fd
;
6413 /* Implements the to_xfer_partial interface for the TARGET_OBJECT_SPU
6414 object type, using the /proc file system. */
6416 linux_qxfer_spu (const char *annex
, unsigned char *readbuf
,
6417 unsigned const char *writebuf
,
6418 CORE_ADDR offset
, int len
)
6420 long pid
= lwpid_of (current_thread
);
6425 if (!writebuf
&& !readbuf
)
6433 return spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
6436 sprintf (buf
, "/proc/%ld/fd/%s", pid
, annex
);
6437 fd
= open (buf
, writebuf
? O_WRONLY
: O_RDONLY
);
6442 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
6449 ret
= write (fd
, writebuf
, (size_t) len
);
6451 ret
= read (fd
, readbuf
, (size_t) len
);
6457 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
6458 struct target_loadseg
6460 /* Core address to which the segment is mapped. */
6462 /* VMA recorded in the program header. */
6464 /* Size of this segment in memory. */
6468 # if defined PT_GETDSBT
6469 struct target_loadmap
6471 /* Protocol version number, must be zero. */
6473 /* Pointer to the DSBT table, its size, and the DSBT index. */
6474 unsigned *dsbt_table
;
6475 unsigned dsbt_size
, dsbt_index
;
6476 /* Number of segments in this map. */
6478 /* The actual memory map. */
6479 struct target_loadseg segs
[/*nsegs*/];
6481 # define LINUX_LOADMAP PT_GETDSBT
6482 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
6483 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
6485 struct target_loadmap
6487 /* Protocol version number, must be zero. */
6489 /* Number of segments in this map. */
6491 /* The actual memory map. */
6492 struct target_loadseg segs
[/*nsegs*/];
6494 # define LINUX_LOADMAP PTRACE_GETFDPIC
6495 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
6496 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
6500 linux_read_loadmap (const char *annex
, CORE_ADDR offset
,
6501 unsigned char *myaddr
, unsigned int len
)
6503 int pid
= lwpid_of (current_thread
);
6505 struct target_loadmap
*data
= NULL
;
6506 unsigned int actual_length
, copy_length
;
6508 if (strcmp (annex
, "exec") == 0)
6509 addr
= (int) LINUX_LOADMAP_EXEC
;
6510 else if (strcmp (annex
, "interp") == 0)
6511 addr
= (int) LINUX_LOADMAP_INTERP
;
6515 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
6521 actual_length
= sizeof (struct target_loadmap
)
6522 + sizeof (struct target_loadseg
) * data
->nsegs
;
6524 if (offset
< 0 || offset
> actual_length
)
6527 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
6528 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
6532 # define linux_read_loadmap NULL
6533 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
6536 linux_process_qsupported (char **features
, int count
)
6538 if (the_low_target
.process_qsupported
!= NULL
)
6539 the_low_target
.process_qsupported (features
, count
);
6543 linux_supports_catch_syscall (void)
6545 return (the_low_target
.get_syscall_trapinfo
!= NULL
6546 && linux_supports_tracesysgood ());
6550 linux_get_ipa_tdesc_idx (void)
6552 if (the_low_target
.get_ipa_tdesc_idx
== NULL
)
6555 return (*the_low_target
.get_ipa_tdesc_idx
) ();
6559 linux_supports_tracepoints (void)
6561 if (*the_low_target
.supports_tracepoints
== NULL
)
6564 return (*the_low_target
.supports_tracepoints
) ();
6568 linux_read_pc (struct regcache
*regcache
)
6570 if (the_low_target
.get_pc
== NULL
)
6573 return (*the_low_target
.get_pc
) (regcache
);
6577 linux_write_pc (struct regcache
*regcache
, CORE_ADDR pc
)
6579 gdb_assert (the_low_target
.set_pc
!= NULL
);
6581 (*the_low_target
.set_pc
) (regcache
, pc
);
6585 linux_thread_stopped (struct thread_info
*thread
)
6587 return get_thread_lwp (thread
)->stopped
;
6590 /* This exposes stop-all-threads functionality to other modules. */
6593 linux_pause_all (int freeze
)
6595 stop_all_lwps (freeze
, NULL
);
6598 /* This exposes unstop-all-threads functionality to other gdbserver
6602 linux_unpause_all (int unfreeze
)
6604 unstop_all_lwps (unfreeze
, NULL
);
6608 linux_prepare_to_access_memory (void)
6610 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
6613 linux_pause_all (1);
6618 linux_done_accessing_memory (void)
6620 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
6623 linux_unpause_all (1);
6627 linux_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint
, CORE_ADDR tpaddr
,
6628 CORE_ADDR collector
,
6631 CORE_ADDR
*jump_entry
,
6632 CORE_ADDR
*trampoline
,
6633 ULONGEST
*trampoline_size
,
6634 unsigned char *jjump_pad_insn
,
6635 ULONGEST
*jjump_pad_insn_size
,
6636 CORE_ADDR
*adjusted_insn_addr
,
6637 CORE_ADDR
*adjusted_insn_addr_end
,
6640 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
6641 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
6642 jump_entry
, trampoline
, trampoline_size
,
6643 jjump_pad_insn
, jjump_pad_insn_size
,
6644 adjusted_insn_addr
, adjusted_insn_addr_end
,
6648 static struct emit_ops
*
6649 linux_emit_ops (void)
6651 if (the_low_target
.emit_ops
!= NULL
)
6652 return (*the_low_target
.emit_ops
) ();
6658 linux_get_min_fast_tracepoint_insn_len (void)
6660 return (*the_low_target
.get_min_fast_tracepoint_insn_len
) ();
6663 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
6666 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
6667 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
6669 char filename
[PATH_MAX
];
6671 const int auxv_size
= is_elf64
6672 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
6673 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
6675 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
6677 fd
= open (filename
, O_RDONLY
);
6683 while (read (fd
, buf
, auxv_size
) == auxv_size
6684 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
6688 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
6690 switch (aux
->a_type
)
6693 *phdr_memaddr
= aux
->a_un
.a_val
;
6696 *num_phdr
= aux
->a_un
.a_val
;
6702 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
6704 switch (aux
->a_type
)
6707 *phdr_memaddr
= aux
->a_un
.a_val
;
6710 *num_phdr
= aux
->a_un
.a_val
;
6718 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
6720 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
6721 "phdr_memaddr = %ld, phdr_num = %d",
6722 (long) *phdr_memaddr
, *num_phdr
);
6729 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
6732 get_dynamic (const int pid
, const int is_elf64
)
6734 CORE_ADDR phdr_memaddr
, relocation
;
6736 unsigned char *phdr_buf
;
6737 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
6739 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
6742 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
6743 phdr_buf
= (unsigned char *) alloca (num_phdr
* phdr_size
);
6745 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
6748 /* Compute relocation: it is expected to be 0 for "regular" executables,
6749 non-zero for PIE ones. */
6751 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
6754 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6756 if (p
->p_type
== PT_PHDR
)
6757 relocation
= phdr_memaddr
- p
->p_vaddr
;
6761 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6763 if (p
->p_type
== PT_PHDR
)
6764 relocation
= phdr_memaddr
- p
->p_vaddr
;
6767 if (relocation
== -1)
6769 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6770 any real world executables, including PIE executables, have always
6771 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6772 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6773 or present DT_DEBUG anyway (fpc binaries are statically linked).
6775 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6777 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6782 for (i
= 0; i
< num_phdr
; i
++)
6786 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6788 if (p
->p_type
== PT_DYNAMIC
)
6789 return p
->p_vaddr
+ relocation
;
6793 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6795 if (p
->p_type
== PT_DYNAMIC
)
6796 return p
->p_vaddr
+ relocation
;
6803 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6804 can be 0 if the inferior does not yet have the library list initialized.
6805 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6806 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6809 get_r_debug (const int pid
, const int is_elf64
)
6811 CORE_ADDR dynamic_memaddr
;
6812 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
6813 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
6816 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
6817 if (dynamic_memaddr
== 0)
6820 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
6824 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
6825 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6829 unsigned char buf
[sizeof (Elf64_Xword
)];
6833 #ifdef DT_MIPS_RLD_MAP
6834 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6836 if (linux_read_memory (dyn
->d_un
.d_val
,
6837 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6842 #endif /* DT_MIPS_RLD_MAP */
6843 #ifdef DT_MIPS_RLD_MAP_REL
6844 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6846 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6847 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6852 #endif /* DT_MIPS_RLD_MAP_REL */
6854 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6855 map
= dyn
->d_un
.d_val
;
6857 if (dyn
->d_tag
== DT_NULL
)
6862 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
6863 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6867 unsigned char buf
[sizeof (Elf32_Word
)];
6871 #ifdef DT_MIPS_RLD_MAP
6872 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6874 if (linux_read_memory (dyn
->d_un
.d_val
,
6875 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6880 #endif /* DT_MIPS_RLD_MAP */
6881 #ifdef DT_MIPS_RLD_MAP_REL
6882 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6884 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6885 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6890 #endif /* DT_MIPS_RLD_MAP_REL */
6892 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6893 map
= dyn
->d_un
.d_val
;
6895 if (dyn
->d_tag
== DT_NULL
)
6899 dynamic_memaddr
+= dyn_size
;
6905 /* Read one pointer from MEMADDR in the inferior. */
6908 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
6912 /* Go through a union so this works on either big or little endian
6913 hosts, when the inferior's pointer size is smaller than the size
6914 of CORE_ADDR. It is assumed the inferior's endianness is the
6915 same of the superior's. */
6918 CORE_ADDR core_addr
;
6923 ret
= linux_read_memory (memaddr
, &addr
.uc
, ptr_size
);
6926 if (ptr_size
== sizeof (CORE_ADDR
))
6927 *ptr
= addr
.core_addr
;
6928 else if (ptr_size
== sizeof (unsigned int))
6931 gdb_assert_not_reached ("unhandled pointer size");
6936 struct link_map_offsets
6938 /* Offset and size of r_debug.r_version. */
6939 int r_version_offset
;
6941 /* Offset and size of r_debug.r_map. */
6944 /* Offset to l_addr field in struct link_map. */
6947 /* Offset to l_name field in struct link_map. */
6950 /* Offset to l_ld field in struct link_map. */
6953 /* Offset to l_next field in struct link_map. */
6956 /* Offset to l_prev field in struct link_map. */
6960 /* Construct qXfer:libraries-svr4:read reply. */
6963 linux_qxfer_libraries_svr4 (const char *annex
, unsigned char *readbuf
,
6964 unsigned const char *writebuf
,
6965 CORE_ADDR offset
, int len
)
6968 unsigned document_len
;
6969 struct process_info_private
*const priv
= current_process ()->priv
;
6970 char filename
[PATH_MAX
];
6973 static const struct link_map_offsets lmo_32bit_offsets
=
6975 0, /* r_version offset. */
6976 4, /* r_debug.r_map offset. */
6977 0, /* l_addr offset in link_map. */
6978 4, /* l_name offset in link_map. */
6979 8, /* l_ld offset in link_map. */
6980 12, /* l_next offset in link_map. */
6981 16 /* l_prev offset in link_map. */
6984 static const struct link_map_offsets lmo_64bit_offsets
=
6986 0, /* r_version offset. */
6987 8, /* r_debug.r_map offset. */
6988 0, /* l_addr offset in link_map. */
6989 8, /* l_name offset in link_map. */
6990 16, /* l_ld offset in link_map. */
6991 24, /* l_next offset in link_map. */
6992 32 /* l_prev offset in link_map. */
6994 const struct link_map_offsets
*lmo
;
6995 unsigned int machine
;
6997 CORE_ADDR lm_addr
= 0, lm_prev
= 0;
6998 int allocated
= 1024;
7000 CORE_ADDR l_name
, l_addr
, l_ld
, l_next
, l_prev
;
7001 int header_done
= 0;
7003 if (writebuf
!= NULL
)
7005 if (readbuf
== NULL
)
7008 pid
= lwpid_of (current_thread
);
7009 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
7010 is_elf64
= elf_64_file_p (filename
, &machine
);
7011 lmo
= is_elf64
? &lmo_64bit_offsets
: &lmo_32bit_offsets
;
7012 ptr_size
= is_elf64
? 8 : 4;
7014 while (annex
[0] != '\0')
7020 sep
= strchr (annex
, '=');
7025 if (len
== 5 && startswith (annex
, "start"))
7027 else if (len
== 4 && startswith (annex
, "prev"))
7031 annex
= strchr (sep
, ';');
7038 annex
= decode_address_to_semicolon (addrp
, sep
+ 1);
7045 if (priv
->r_debug
== 0)
7046 priv
->r_debug
= get_r_debug (pid
, is_elf64
);
7048 /* We failed to find DT_DEBUG. Such situation will not change
7049 for this inferior - do not retry it. Report it to GDB as
7050 E01, see for the reasons at the GDB solib-svr4.c side. */
7051 if (priv
->r_debug
== (CORE_ADDR
) -1)
7054 if (priv
->r_debug
!= 0)
7056 if (linux_read_memory (priv
->r_debug
+ lmo
->r_version_offset
,
7057 (unsigned char *) &r_version
,
7058 sizeof (r_version
)) != 0
7061 warning ("unexpected r_debug version %d", r_version
);
7063 else if (read_one_ptr (priv
->r_debug
+ lmo
->r_map_offset
,
7064 &lm_addr
, ptr_size
) != 0)
7066 warning ("unable to read r_map from 0x%lx",
7067 (long) priv
->r_debug
+ lmo
->r_map_offset
);
7072 document
= (char *) xmalloc (allocated
);
7073 strcpy (document
, "<library-list-svr4 version=\"1.0\"");
7074 p
= document
+ strlen (document
);
7077 && read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
7078 &l_name
, ptr_size
) == 0
7079 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
7080 &l_addr
, ptr_size
) == 0
7081 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
7082 &l_ld
, ptr_size
) == 0
7083 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
7084 &l_prev
, ptr_size
) == 0
7085 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
7086 &l_next
, ptr_size
) == 0)
7088 unsigned char libname
[PATH_MAX
];
7090 if (lm_prev
!= l_prev
)
7092 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
7093 (long) lm_prev
, (long) l_prev
);
7097 /* Ignore the first entry even if it has valid name as the first entry
7098 corresponds to the main executable. The first entry should not be
7099 skipped if the dynamic loader was loaded late by a static executable
7100 (see solib-svr4.c parameter ignore_first). But in such case the main
7101 executable does not have PT_DYNAMIC present and this function already
7102 exited above due to failed get_r_debug. */
7105 sprintf (p
, " main-lm=\"0x%lx\"", (unsigned long) lm_addr
);
7110 /* Not checking for error because reading may stop before
7111 we've got PATH_MAX worth of characters. */
7113 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
7114 libname
[sizeof (libname
) - 1] = '\0';
7115 if (libname
[0] != '\0')
7117 /* 6x the size for xml_escape_text below. */
7118 size_t len
= 6 * strlen ((char *) libname
);
7122 /* Terminate `<library-list-svr4'. */
7127 while (allocated
< p
- document
+ len
+ 200)
7129 /* Expand to guarantee sufficient storage. */
7130 uintptr_t document_len
= p
- document
;
7132 document
= (char *) xrealloc (document
, 2 * allocated
);
7134 p
= document
+ document_len
;
7137 std::string name
= xml_escape_text ((char *) libname
);
7138 p
+= sprintf (p
, "<library name=\"%s\" lm=\"0x%lx\" "
7139 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
7140 name
.c_str (), (unsigned long) lm_addr
,
7141 (unsigned long) l_addr
, (unsigned long) l_ld
);
7151 /* Empty list; terminate `<library-list-svr4'. */
7155 strcpy (p
, "</library-list-svr4>");
7157 document_len
= strlen (document
);
7158 if (offset
< document_len
)
7159 document_len
-= offset
;
7162 if (len
> document_len
)
7165 memcpy (readbuf
, document
+ offset
, len
);
7171 #ifdef HAVE_LINUX_BTRACE
7173 /* See to_disable_btrace target method. */
7176 linux_low_disable_btrace (struct btrace_target_info
*tinfo
)
7178 enum btrace_error err
;
7180 err
= linux_disable_btrace (tinfo
);
7181 return (err
== BTRACE_ERR_NONE
? 0 : -1);
7184 /* Encode an Intel Processor Trace configuration. */
7187 linux_low_encode_pt_config (struct buffer
*buffer
,
7188 const struct btrace_data_pt_config
*config
)
7190 buffer_grow_str (buffer
, "<pt-config>\n");
7192 switch (config
->cpu
.vendor
)
7195 buffer_xml_printf (buffer
, "<cpu vendor=\"GenuineIntel\" family=\"%u\" "
7196 "model=\"%u\" stepping=\"%u\"/>\n",
7197 config
->cpu
.family
, config
->cpu
.model
,
7198 config
->cpu
.stepping
);
7205 buffer_grow_str (buffer
, "</pt-config>\n");
7208 /* Encode a raw buffer. */
7211 linux_low_encode_raw (struct buffer
*buffer
, const gdb_byte
*data
,
7217 /* We use hex encoding - see common/rsp-low.h. */
7218 buffer_grow_str (buffer
, "<raw>\n");
7224 elem
[0] = tohex ((*data
>> 4) & 0xf);
7225 elem
[1] = tohex (*data
++ & 0xf);
7227 buffer_grow (buffer
, elem
, 2);
7230 buffer_grow_str (buffer
, "</raw>\n");
7233 /* See to_read_btrace target method. */
7236 linux_low_read_btrace (struct btrace_target_info
*tinfo
, struct buffer
*buffer
,
7237 enum btrace_read_type type
)
7239 struct btrace_data btrace
;
7240 struct btrace_block
*block
;
7241 enum btrace_error err
;
7244 btrace_data_init (&btrace
);
7246 err
= linux_read_btrace (&btrace
, tinfo
, type
);
7247 if (err
!= BTRACE_ERR_NONE
)
7249 if (err
== BTRACE_ERR_OVERFLOW
)
7250 buffer_grow_str0 (buffer
, "E.Overflow.");
7252 buffer_grow_str0 (buffer
, "E.Generic Error.");
7257 switch (btrace
.format
)
7259 case BTRACE_FORMAT_NONE
:
7260 buffer_grow_str0 (buffer
, "E.No Trace.");
7263 case BTRACE_FORMAT_BTS
:
7264 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
7265 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
7268 VEC_iterate (btrace_block_s
, btrace
.variant
.bts
.blocks
, i
, block
);
7270 buffer_xml_printf (buffer
, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
7271 paddress (block
->begin
), paddress (block
->end
));
7273 buffer_grow_str0 (buffer
, "</btrace>\n");
7276 case BTRACE_FORMAT_PT
:
7277 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
7278 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
7279 buffer_grow_str (buffer
, "<pt>\n");
7281 linux_low_encode_pt_config (buffer
, &btrace
.variant
.pt
.config
);
7283 linux_low_encode_raw (buffer
, btrace
.variant
.pt
.data
,
7284 btrace
.variant
.pt
.size
);
7286 buffer_grow_str (buffer
, "</pt>\n");
7287 buffer_grow_str0 (buffer
, "</btrace>\n");
7291 buffer_grow_str0 (buffer
, "E.Unsupported Trace Format.");
7295 btrace_data_fini (&btrace
);
7299 btrace_data_fini (&btrace
);
7303 /* See to_btrace_conf target method. */
7306 linux_low_btrace_conf (const struct btrace_target_info
*tinfo
,
7307 struct buffer
*buffer
)
7309 const struct btrace_config
*conf
;
7311 buffer_grow_str (buffer
, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
7312 buffer_grow_str (buffer
, "<btrace-conf version=\"1.0\">\n");
7314 conf
= linux_btrace_conf (tinfo
);
7317 switch (conf
->format
)
7319 case BTRACE_FORMAT_NONE
:
7322 case BTRACE_FORMAT_BTS
:
7323 buffer_xml_printf (buffer
, "<bts");
7324 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->bts
.size
);
7325 buffer_xml_printf (buffer
, " />\n");
7328 case BTRACE_FORMAT_PT
:
7329 buffer_xml_printf (buffer
, "<pt");
7330 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->pt
.size
);
7331 buffer_xml_printf (buffer
, "/>\n");
7336 buffer_grow_str0 (buffer
, "</btrace-conf>\n");
7339 #endif /* HAVE_LINUX_BTRACE */
7341 /* See nat/linux-nat.h. */
7344 current_lwp_ptid (void)
7346 return ptid_of (current_thread
);
7349 /* Implementation of the target_ops method "breakpoint_kind_from_pc". */
7352 linux_breakpoint_kind_from_pc (CORE_ADDR
*pcptr
)
7354 if (the_low_target
.breakpoint_kind_from_pc
!= NULL
)
7355 return (*the_low_target
.breakpoint_kind_from_pc
) (pcptr
);
7357 return default_breakpoint_kind_from_pc (pcptr
);
7360 /* Implementation of the target_ops method "sw_breakpoint_from_kind". */
7362 static const gdb_byte
*
7363 linux_sw_breakpoint_from_kind (int kind
, int *size
)
7365 gdb_assert (the_low_target
.sw_breakpoint_from_kind
!= NULL
);
7367 return (*the_low_target
.sw_breakpoint_from_kind
) (kind
, size
);
7370 /* Implementation of the target_ops method
7371 "breakpoint_kind_from_current_state". */
7374 linux_breakpoint_kind_from_current_state (CORE_ADDR
*pcptr
)
7376 if (the_low_target
.breakpoint_kind_from_current_state
!= NULL
)
7377 return (*the_low_target
.breakpoint_kind_from_current_state
) (pcptr
);
7379 return linux_breakpoint_kind_from_pc (pcptr
);
7382 /* Default implementation of linux_target_ops method "set_pc" for
7383 32-bit pc register which is literally named "pc". */
7386 linux_set_pc_32bit (struct regcache
*regcache
, CORE_ADDR pc
)
7388 uint32_t newpc
= pc
;
7390 supply_register_by_name (regcache
, "pc", &newpc
);
7393 /* Default implementation of linux_target_ops method "get_pc" for
7394 32-bit pc register which is literally named "pc". */
7397 linux_get_pc_32bit (struct regcache
*regcache
)
7401 collect_register_by_name (regcache
, "pc", &pc
);
7403 debug_printf ("stop pc is 0x%" PRIx32
"\n", pc
);
7407 /* Default implementation of linux_target_ops method "set_pc" for
7408 64-bit pc register which is literally named "pc". */
7411 linux_set_pc_64bit (struct regcache
*regcache
, CORE_ADDR pc
)
7413 uint64_t newpc
= pc
;
7415 supply_register_by_name (regcache
, "pc", &newpc
);
7418 /* Default implementation of linux_target_ops method "get_pc" for
7419 64-bit pc register which is literally named "pc". */
7422 linux_get_pc_64bit (struct regcache
*regcache
)
7426 collect_register_by_name (regcache
, "pc", &pc
);
7428 debug_printf ("stop pc is 0x%" PRIx64
"\n", pc
);
7433 static struct target_ops linux_target_ops
= {
7434 linux_create_inferior
,
7435 linux_post_create_inferior
,
7444 linux_fetch_registers
,
7445 linux_store_registers
,
7446 linux_prepare_to_access_memory
,
7447 linux_done_accessing_memory
,
7450 linux_look_up_symbols
,
7451 linux_request_interrupt
,
7453 linux_supports_z_point_type
,
7456 linux_stopped_by_sw_breakpoint
,
7457 linux_supports_stopped_by_sw_breakpoint
,
7458 linux_stopped_by_hw_breakpoint
,
7459 linux_supports_stopped_by_hw_breakpoint
,
7460 linux_supports_hardware_single_step
,
7461 linux_stopped_by_watchpoint
,
7462 linux_stopped_data_address
,
7463 #if defined(__UCLIBC__) && defined(HAS_NOMMU) \
7464 && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
7465 && defined(PT_TEXT_END_ADDR)
7470 #ifdef USE_THREAD_DB
7471 thread_db_get_tls_address
,
7476 hostio_last_error_from_errno
,
7479 linux_supports_non_stop
,
7481 linux_start_non_stop
,
7482 linux_supports_multi_process
,
7483 linux_supports_fork_events
,
7484 linux_supports_vfork_events
,
7485 linux_supports_exec_events
,
7486 linux_handle_new_gdb_connection
,
7487 #ifdef USE_THREAD_DB
7488 thread_db_handle_monitor_command
,
7492 linux_common_core_of_thread
,
7494 linux_process_qsupported
,
7495 linux_supports_tracepoints
,
7498 linux_thread_stopped
,
7502 linux_stabilize_threads
,
7503 linux_install_fast_tracepoint_jump_pad
,
7505 linux_supports_disable_randomization
,
7506 linux_get_min_fast_tracepoint_insn_len
,
7507 linux_qxfer_libraries_svr4
,
7508 linux_supports_agent
,
7509 #ifdef HAVE_LINUX_BTRACE
7510 linux_supports_btrace
,
7511 linux_enable_btrace
,
7512 linux_low_disable_btrace
,
7513 linux_low_read_btrace
,
7514 linux_low_btrace_conf
,
7522 linux_supports_range_stepping
,
7523 linux_proc_pid_to_exec_file
,
7524 linux_mntns_open_cloexec
,
7526 linux_mntns_readlink
,
7527 linux_breakpoint_kind_from_pc
,
7528 linux_sw_breakpoint_from_kind
,
7529 linux_proc_tid_get_name
,
7530 linux_breakpoint_kind_from_current_state
,
7531 linux_supports_software_single_step
,
7532 linux_supports_catch_syscall
,
7533 linux_get_ipa_tdesc_idx
,
7535 thread_db_thread_handle
,
7541 #ifdef HAVE_LINUX_REGSETS
7543 initialize_regsets_info (struct regsets_info
*info
)
7545 for (info
->num_regsets
= 0;
7546 info
->regsets
[info
->num_regsets
].size
>= 0;
7547 info
->num_regsets
++)
7553 initialize_low (void)
7555 struct sigaction sigchld_action
;
7557 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
7558 set_target_ops (&linux_target_ops
);
7560 linux_ptrace_init_warnings ();
7562 sigchld_action
.sa_handler
= sigchld_handler
;
7563 sigemptyset (&sigchld_action
.sa_mask
);
7564 sigchld_action
.sa_flags
= SA_RESTART
;
7565 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
7567 initialize_low_arch ();
7569 linux_check_ptrace_features ();