1 /* Low level interface to ptrace, for the remote server for GDB.
2 Copyright (C) 1995-2020 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"
22 #include "gdbsupport/agent.h"
24 #include "gdbsupport/rsp-low.h"
25 #include "gdbsupport/signals-state-save-restore.h"
26 #include "nat/linux-nat.h"
27 #include "nat/linux-waitpid.h"
28 #include "gdbsupport/gdb_wait.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 "gdbsupport/filestuff.h"
47 #include "tracepoint.h"
49 #include "gdbsupport/common-inferior.h"
50 #include "nat/fork-inferior.h"
51 #include "gdbsupport/environ.h"
52 #include "gdbsupport/gdb-sigmask.h"
53 #include "gdbsupport/scoped_restore.h"
55 /* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
56 then ELFMAG0 will have been defined. If it didn't get included by
57 gdb_proc_service.h then including it will likely introduce a duplicate
58 definition of elf_fpregset_t. */
61 #include "nat/linux-namespaces.h"
63 #ifdef HAVE_PERSONALITY
64 # include <sys/personality.h>
65 # if !HAVE_DECL_ADDR_NO_RANDOMIZE
66 # define ADDR_NO_RANDOMIZE 0x0040000
78 /* Some targets did not define these ptrace constants from the start,
79 so gdbserver defines them locally here. In the future, these may
80 be removed after they are added to asm/ptrace.h. */
81 #if !(defined(PT_TEXT_ADDR) \
82 || defined(PT_DATA_ADDR) \
83 || defined(PT_TEXT_END_ADDR))
84 #if defined(__mcoldfire__)
85 /* These are still undefined in 3.10 kernels. */
86 #define PT_TEXT_ADDR 49*4
87 #define PT_DATA_ADDR 50*4
88 #define PT_TEXT_END_ADDR 51*4
89 /* BFIN already defines these since at least 2.6.32 kernels. */
91 #define PT_TEXT_ADDR 220
92 #define PT_TEXT_END_ADDR 224
93 #define PT_DATA_ADDR 228
94 /* These are still undefined in 3.10 kernels. */
95 #elif defined(__TMS320C6X__)
96 #define PT_TEXT_ADDR (0x10000*4)
97 #define PT_DATA_ADDR (0x10004*4)
98 #define PT_TEXT_END_ADDR (0x10008*4)
102 #if (defined(__UCLIBC__) \
103 && defined(HAS_NOMMU) \
104 && defined(PT_TEXT_ADDR) \
105 && defined(PT_DATA_ADDR) \
106 && defined(PT_TEXT_END_ADDR))
107 #define SUPPORTS_READ_OFFSETS
110 #ifdef HAVE_LINUX_BTRACE
111 # include "nat/linux-btrace.h"
112 # include "gdbsupport/btrace-common.h"
115 #ifndef HAVE_ELF32_AUXV_T
116 /* Copied from glibc's elf.h. */
119 uint32_t a_type
; /* Entry type */
122 uint32_t a_val
; /* Integer value */
123 /* We use to have pointer elements added here. We cannot do that,
124 though, since it does not work when using 32-bit definitions
125 on 64-bit platforms and vice versa. */
130 #ifndef HAVE_ELF64_AUXV_T
131 /* Copied from glibc's elf.h. */
134 uint64_t a_type
; /* Entry type */
137 uint64_t a_val
; /* Integer value */
138 /* We use to have pointer elements added here. We cannot do that,
139 though, since it does not work when using 32-bit definitions
140 on 64-bit platforms and vice versa. */
145 /* Does the current host support PTRACE_GETREGSET? */
146 int have_ptrace_getregset
= -1;
150 /* See nat/linux-nat.h. */
153 ptid_of_lwp (struct lwp_info
*lwp
)
155 return ptid_of (get_lwp_thread (lwp
));
158 /* See nat/linux-nat.h. */
161 lwp_set_arch_private_info (struct lwp_info
*lwp
,
162 struct arch_lwp_info
*info
)
164 lwp
->arch_private
= info
;
167 /* See nat/linux-nat.h. */
169 struct arch_lwp_info
*
170 lwp_arch_private_info (struct lwp_info
*lwp
)
172 return lwp
->arch_private
;
175 /* See nat/linux-nat.h. */
178 lwp_is_stopped (struct lwp_info
*lwp
)
183 /* See nat/linux-nat.h. */
185 enum target_stop_reason
186 lwp_stop_reason (struct lwp_info
*lwp
)
188 return lwp
->stop_reason
;
191 /* See nat/linux-nat.h. */
194 lwp_is_stepping (struct lwp_info
*lwp
)
196 return lwp
->stepping
;
199 /* A list of all unknown processes which receive stop signals. Some
200 other process will presumably claim each of these as forked
201 children momentarily. */
203 struct simple_pid_list
205 /* The process ID. */
208 /* The status as reported by waitpid. */
212 struct simple_pid_list
*next
;
214 struct simple_pid_list
*stopped_pids
;
216 /* Trivial list manipulation functions to keep track of a list of new
217 stopped processes. */
220 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
222 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
225 new_pid
->status
= status
;
226 new_pid
->next
= *listp
;
231 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
233 struct simple_pid_list
**p
;
235 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
236 if ((*p
)->pid
== pid
)
238 struct simple_pid_list
*next
= (*p
)->next
;
240 *statusp
= (*p
)->status
;
248 enum stopping_threads_kind
250 /* Not stopping threads presently. */
251 NOT_STOPPING_THREADS
,
253 /* Stopping threads. */
256 /* Stopping and suspending threads. */
257 STOPPING_AND_SUSPENDING_THREADS
260 /* This is set while stop_all_lwps is in effect. */
261 enum stopping_threads_kind stopping_threads
= NOT_STOPPING_THREADS
;
263 /* FIXME make into a target method? */
264 int using_threads
= 1;
266 /* True if we're presently stabilizing threads (moving them out of
268 static int stabilizing_threads
;
270 static void unsuspend_all_lwps (struct lwp_info
*except
);
271 static struct lwp_info
*add_lwp (ptid_t ptid
);
272 static void mark_lwp_dead (struct lwp_info
*lwp
, int wstat
);
273 static int lwp_is_marked_dead (struct lwp_info
*lwp
);
274 static int finish_step_over (struct lwp_info
*lwp
);
275 static int kill_lwp (unsigned long lwpid
, int signo
);
276 static void enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
);
277 static int linux_low_ptrace_options (int attached
);
278 static int check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
);
280 /* When the event-loop is doing a step-over, this points at the thread
282 ptid_t step_over_bkpt
;
284 /* True if the low target can hardware single-step. */
287 can_hardware_single_step (void)
289 if (the_low_target
.supports_hardware_single_step
!= NULL
)
290 return the_low_target
.supports_hardware_single_step ();
296 linux_process_target::low_supports_breakpoints ()
302 linux_process_target::low_get_pc (regcache
*regcache
)
308 linux_process_target::low_set_pc (regcache
*regcache
, CORE_ADDR newpc
)
310 gdb_assert_not_reached ("linux target op low_set_pc is not implemented");
313 std::vector
<CORE_ADDR
>
314 linux_process_target::low_get_next_pcs (regcache
*regcache
)
316 gdb_assert_not_reached ("linux target op low_get_next_pcs is not "
321 linux_process_target::low_decr_pc_after_break ()
326 /* Returns true if this target can support fast tracepoints. This
327 does not mean that the in-process agent has been loaded in the
331 supports_fast_tracepoints (void)
333 return the_low_target
.install_fast_tracepoint_jump_pad
!= NULL
;
336 /* True if LWP is stopped in its stepping range. */
339 lwp_in_step_range (struct lwp_info
*lwp
)
341 CORE_ADDR pc
= lwp
->stop_pc
;
343 return (pc
>= lwp
->step_range_start
&& pc
< lwp
->step_range_end
);
346 struct pending_signals
350 struct pending_signals
*prev
;
353 /* The read/write ends of the pipe registered as waitable file in the
355 static int linux_event_pipe
[2] = { -1, -1 };
357 /* True if we're currently in async mode. */
358 #define target_is_async_p() (linux_event_pipe[0] != -1)
360 static void send_sigstop (struct lwp_info
*lwp
);
362 /* Return non-zero if HEADER is a 64-bit ELF file. */
365 elf_64_header_p (const Elf64_Ehdr
*header
, unsigned int *machine
)
367 if (header
->e_ident
[EI_MAG0
] == ELFMAG0
368 && header
->e_ident
[EI_MAG1
] == ELFMAG1
369 && header
->e_ident
[EI_MAG2
] == ELFMAG2
370 && header
->e_ident
[EI_MAG3
] == ELFMAG3
)
372 *machine
= header
->e_machine
;
373 return header
->e_ident
[EI_CLASS
] == ELFCLASS64
;
380 /* Return non-zero if FILE is a 64-bit ELF file,
381 zero if the file is not a 64-bit ELF file,
382 and -1 if the file is not accessible or doesn't exist. */
385 elf_64_file_p (const char *file
, unsigned int *machine
)
390 fd
= open (file
, O_RDONLY
);
394 if (read (fd
, &header
, sizeof (header
)) != sizeof (header
))
401 return elf_64_header_p (&header
, machine
);
404 /* Accepts an integer PID; Returns true if the executable PID is
405 running is a 64-bit ELF file.. */
408 linux_pid_exe_is_elf_64_file (int pid
, unsigned int *machine
)
412 sprintf (file
, "/proc/%d/exe", pid
);
413 return elf_64_file_p (file
, machine
);
417 delete_lwp (struct lwp_info
*lwp
)
419 struct thread_info
*thr
= get_lwp_thread (lwp
);
422 debug_printf ("deleting %ld\n", lwpid_of (thr
));
426 if (the_low_target
.delete_thread
!= NULL
)
427 the_low_target
.delete_thread (lwp
->arch_private
);
429 gdb_assert (lwp
->arch_private
== NULL
);
434 /* Add a process to the common process list, and set its private
437 static struct process_info
*
438 linux_add_process (int pid
, int attached
)
440 struct process_info
*proc
;
442 proc
= add_process (pid
, attached
);
443 proc
->priv
= XCNEW (struct process_info_private
);
445 if (the_low_target
.new_process
!= NULL
)
446 proc
->priv
->arch_private
= the_low_target
.new_process ();
452 linux_process_target::arch_setup_thread (thread_info
*thread
)
454 struct thread_info
*saved_thread
;
456 saved_thread
= current_thread
;
457 current_thread
= thread
;
461 current_thread
= saved_thread
;
465 linux_process_target::handle_extended_wait (lwp_info
**orig_event_lwp
,
468 client_state
&cs
= get_client_state ();
469 struct lwp_info
*event_lwp
= *orig_event_lwp
;
470 int event
= linux_ptrace_get_extended_event (wstat
);
471 struct thread_info
*event_thr
= get_lwp_thread (event_lwp
);
472 struct lwp_info
*new_lwp
;
474 gdb_assert (event_lwp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
);
476 /* All extended events we currently use are mid-syscall. Only
477 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
478 you have to be using PTRACE_SEIZE to get that. */
479 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
481 if ((event
== PTRACE_EVENT_FORK
) || (event
== PTRACE_EVENT_VFORK
)
482 || (event
== PTRACE_EVENT_CLONE
))
485 unsigned long new_pid
;
488 /* Get the pid of the new lwp. */
489 ptrace (PTRACE_GETEVENTMSG
, lwpid_of (event_thr
), (PTRACE_TYPE_ARG3
) 0,
492 /* If we haven't already seen the new PID stop, wait for it now. */
493 if (!pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
495 /* The new child has a pending SIGSTOP. We can't affect it until it
496 hits the SIGSTOP, but we're already attached. */
498 ret
= my_waitpid (new_pid
, &status
, __WALL
);
501 perror_with_name ("waiting for new child");
502 else if (ret
!= new_pid
)
503 warning ("wait returned unexpected PID %d", ret
);
504 else if (!WIFSTOPPED (status
))
505 warning ("wait returned unexpected status 0x%x", status
);
508 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
510 struct process_info
*parent_proc
;
511 struct process_info
*child_proc
;
512 struct lwp_info
*child_lwp
;
513 struct thread_info
*child_thr
;
514 struct target_desc
*tdesc
;
516 ptid
= ptid_t (new_pid
, new_pid
, 0);
520 debug_printf ("HEW: Got fork event from LWP %ld, "
522 ptid_of (event_thr
).lwp (),
526 /* Add the new process to the tables and clone the breakpoint
527 lists of the parent. We need to do this even if the new process
528 will be detached, since we will need the process object and the
529 breakpoints to remove any breakpoints from memory when we
530 detach, and the client side will access registers. */
531 child_proc
= linux_add_process (new_pid
, 0);
532 gdb_assert (child_proc
!= NULL
);
533 child_lwp
= add_lwp (ptid
);
534 gdb_assert (child_lwp
!= NULL
);
535 child_lwp
->stopped
= 1;
536 child_lwp
->must_set_ptrace_flags
= 1;
537 child_lwp
->status_pending_p
= 0;
538 child_thr
= get_lwp_thread (child_lwp
);
539 child_thr
->last_resume_kind
= resume_stop
;
540 child_thr
->last_status
.kind
= TARGET_WAITKIND_STOPPED
;
542 /* If we're suspending all threads, leave this one suspended
543 too. If the fork/clone parent is stepping over a breakpoint,
544 all other threads have been suspended already. Leave the
545 child suspended too. */
546 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
547 || event_lwp
->bp_reinsert
!= 0)
550 debug_printf ("HEW: leaving child suspended\n");
551 child_lwp
->suspended
= 1;
554 parent_proc
= get_thread_process (event_thr
);
555 child_proc
->attached
= parent_proc
->attached
;
557 if (event_lwp
->bp_reinsert
!= 0
558 && supports_software_single_step ()
559 && event
== PTRACE_EVENT_VFORK
)
561 /* If we leave single-step breakpoints there, child will
562 hit it, so uninsert single-step breakpoints from parent
563 (and child). Once vfork child is done, reinsert
564 them back to parent. */
565 uninsert_single_step_breakpoints (event_thr
);
568 clone_all_breakpoints (child_thr
, event_thr
);
570 tdesc
= allocate_target_description ();
571 copy_target_description (tdesc
, parent_proc
->tdesc
);
572 child_proc
->tdesc
= tdesc
;
574 /* Clone arch-specific process data. */
575 if (the_low_target
.new_fork
!= NULL
)
576 the_low_target
.new_fork (parent_proc
, child_proc
);
578 /* Save fork info in the parent thread. */
579 if (event
== PTRACE_EVENT_FORK
)
580 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_FORKED
;
581 else if (event
== PTRACE_EVENT_VFORK
)
582 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_VFORKED
;
584 event_lwp
->waitstatus
.value
.related_pid
= ptid
;
586 /* The status_pending field contains bits denoting the
587 extended event, so when the pending event is handled,
588 the handler will look at lwp->waitstatus. */
589 event_lwp
->status_pending_p
= 1;
590 event_lwp
->status_pending
= wstat
;
592 /* Link the threads until the parent event is passed on to
594 event_lwp
->fork_relative
= child_lwp
;
595 child_lwp
->fork_relative
= event_lwp
;
597 /* If the parent thread is doing step-over with single-step
598 breakpoints, the list of single-step breakpoints are cloned
599 from the parent's. Remove them from the child process.
600 In case of vfork, we'll reinsert them back once vforked
602 if (event_lwp
->bp_reinsert
!= 0
603 && supports_software_single_step ())
605 /* The child process is forked and stopped, so it is safe
606 to access its memory without stopping all other threads
607 from other processes. */
608 delete_single_step_breakpoints (child_thr
);
610 gdb_assert (has_single_step_breakpoints (event_thr
));
611 gdb_assert (!has_single_step_breakpoints (child_thr
));
614 /* Report the event. */
619 debug_printf ("HEW: Got clone event "
620 "from LWP %ld, new child is LWP %ld\n",
621 lwpid_of (event_thr
), new_pid
);
623 ptid
= ptid_t (pid_of (event_thr
), new_pid
, 0);
624 new_lwp
= add_lwp (ptid
);
626 /* Either we're going to immediately resume the new thread
627 or leave it stopped. resume_one_lwp is a nop if it
628 thinks the thread is currently running, so set this first
629 before calling resume_one_lwp. */
630 new_lwp
->stopped
= 1;
632 /* If we're suspending all threads, leave this one suspended
633 too. If the fork/clone parent is stepping over a breakpoint,
634 all other threads have been suspended already. Leave the
635 child suspended too. */
636 if (stopping_threads
== STOPPING_AND_SUSPENDING_THREADS
637 || event_lwp
->bp_reinsert
!= 0)
638 new_lwp
->suspended
= 1;
640 /* Normally we will get the pending SIGSTOP. But in some cases
641 we might get another signal delivered to the group first.
642 If we do get another signal, be sure not to lose it. */
643 if (WSTOPSIG (status
) != SIGSTOP
)
645 new_lwp
->stop_expected
= 1;
646 new_lwp
->status_pending_p
= 1;
647 new_lwp
->status_pending
= status
;
649 else if (cs
.report_thread_events
)
651 new_lwp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
652 new_lwp
->status_pending_p
= 1;
653 new_lwp
->status_pending
= status
;
657 thread_db_notice_clone (event_thr
, ptid
);
660 /* Don't report the event. */
663 else if (event
== PTRACE_EVENT_VFORK_DONE
)
665 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
667 if (event_lwp
->bp_reinsert
!= 0 && supports_software_single_step ())
669 reinsert_single_step_breakpoints (event_thr
);
671 gdb_assert (has_single_step_breakpoints (event_thr
));
674 /* Report the event. */
677 else if (event
== PTRACE_EVENT_EXEC
&& cs
.report_exec_events
)
679 struct process_info
*proc
;
680 std::vector
<int> syscalls_to_catch
;
686 debug_printf ("HEW: Got exec event from LWP %ld\n",
687 lwpid_of (event_thr
));
690 /* Get the event ptid. */
691 event_ptid
= ptid_of (event_thr
);
692 event_pid
= event_ptid
.pid ();
694 /* Save the syscall list from the execing process. */
695 proc
= get_thread_process (event_thr
);
696 syscalls_to_catch
= std::move (proc
->syscalls_to_catch
);
698 /* Delete the execing process and all its threads. */
700 current_thread
= NULL
;
702 /* Create a new process/lwp/thread. */
703 proc
= linux_add_process (event_pid
, 0);
704 event_lwp
= add_lwp (event_ptid
);
705 event_thr
= get_lwp_thread (event_lwp
);
706 gdb_assert (current_thread
== event_thr
);
707 arch_setup_thread (event_thr
);
709 /* Set the event status. */
710 event_lwp
->waitstatus
.kind
= TARGET_WAITKIND_EXECD
;
711 event_lwp
->waitstatus
.value
.execd_pathname
712 = xstrdup (linux_proc_pid_to_exec_file (lwpid_of (event_thr
)));
714 /* Mark the exec status as pending. */
715 event_lwp
->stopped
= 1;
716 event_lwp
->status_pending_p
= 1;
717 event_lwp
->status_pending
= wstat
;
718 event_thr
->last_resume_kind
= resume_continue
;
719 event_thr
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
721 /* Update syscall state in the new lwp, effectively mid-syscall too. */
722 event_lwp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
724 /* Restore the list to catch. Don't rely on the client, which is free
725 to avoid sending a new list when the architecture doesn't change.
726 Also, for ANY_SYSCALL, the architecture doesn't really matter. */
727 proc
->syscalls_to_catch
= std::move (syscalls_to_catch
);
729 /* Report the event. */
730 *orig_event_lwp
= event_lwp
;
734 internal_error (__FILE__
, __LINE__
, _("unknown ptrace event %d"), event
);
738 linux_process_target::get_pc (lwp_info
*lwp
)
740 struct thread_info
*saved_thread
;
741 struct regcache
*regcache
;
744 if (!low_supports_breakpoints ())
747 saved_thread
= current_thread
;
748 current_thread
= get_lwp_thread (lwp
);
750 regcache
= get_thread_regcache (current_thread
, 1);
751 pc
= low_get_pc (regcache
);
754 debug_printf ("pc is 0x%lx\n", (long) pc
);
756 current_thread
= saved_thread
;
760 /* This function should only be called if LWP got a SYSCALL_SIGTRAP.
761 Fill *SYSNO with the syscall nr trapped. */
764 get_syscall_trapinfo (struct lwp_info
*lwp
, int *sysno
)
766 struct thread_info
*saved_thread
;
767 struct regcache
*regcache
;
769 if (the_low_target
.get_syscall_trapinfo
== NULL
)
771 /* If we cannot get the syscall trapinfo, report an unknown
772 system call number. */
773 *sysno
= UNKNOWN_SYSCALL
;
777 saved_thread
= current_thread
;
778 current_thread
= get_lwp_thread (lwp
);
780 regcache
= get_thread_regcache (current_thread
, 1);
781 (*the_low_target
.get_syscall_trapinfo
) (regcache
, sysno
);
784 debug_printf ("get_syscall_trapinfo sysno %d\n", *sysno
);
786 current_thread
= saved_thread
;
789 static int check_stopped_by_watchpoint (struct lwp_info
*child
);
792 linux_process_target::save_stop_reason (lwp_info
*lwp
)
795 CORE_ADDR sw_breakpoint_pc
;
796 struct thread_info
*saved_thread
;
797 #if USE_SIGTRAP_SIGINFO
801 if (!low_supports_breakpoints ())
805 sw_breakpoint_pc
= pc
- low_decr_pc_after_break ();
807 /* breakpoint_at reads from the current thread. */
808 saved_thread
= current_thread
;
809 current_thread
= get_lwp_thread (lwp
);
811 #if USE_SIGTRAP_SIGINFO
812 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
813 (PTRACE_TYPE_ARG3
) 0, &siginfo
) == 0)
815 if (siginfo
.si_signo
== SIGTRAP
)
817 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
818 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
820 /* The si_code is ambiguous on this arch -- check debug
822 if (!check_stopped_by_watchpoint (lwp
))
823 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
825 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
827 /* If we determine the LWP stopped for a SW breakpoint,
828 trust it. Particularly don't check watchpoint
829 registers, because at least on s390, we'd find
830 stopped-by-watchpoint as long as there's a watchpoint
832 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
834 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
836 /* This can indicate either a hardware breakpoint or
837 hardware watchpoint. Check debug registers. */
838 if (!check_stopped_by_watchpoint (lwp
))
839 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
841 else if (siginfo
.si_code
== TRAP_TRACE
)
843 /* We may have single stepped an instruction that
844 triggered a watchpoint. In that case, on some
845 architectures (such as x86), instead of TRAP_HWBKPT,
846 si_code indicates TRAP_TRACE, and we need to check
847 the debug registers separately. */
848 if (!check_stopped_by_watchpoint (lwp
))
849 lwp
->stop_reason
= TARGET_STOPPED_BY_SINGLE_STEP
;
854 /* We may have just stepped a breakpoint instruction. E.g., in
855 non-stop mode, GDB first tells the thread A to step a range, and
856 then the user inserts a breakpoint inside the range. In that
857 case we need to report the breakpoint PC. */
858 if ((!lwp
->stepping
|| lwp
->stop_pc
== sw_breakpoint_pc
)
859 && (*the_low_target
.breakpoint_at
) (sw_breakpoint_pc
))
860 lwp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
862 if (hardware_breakpoint_inserted_here (pc
))
863 lwp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
865 if (lwp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
866 check_stopped_by_watchpoint (lwp
);
869 if (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
873 struct thread_info
*thr
= get_lwp_thread (lwp
);
875 debug_printf ("CSBB: %s stopped by software breakpoint\n",
876 target_pid_to_str (ptid_of (thr
)));
879 /* Back up the PC if necessary. */
880 if (pc
!= sw_breakpoint_pc
)
882 struct regcache
*regcache
883 = get_thread_regcache (current_thread
, 1);
884 low_set_pc (regcache
, sw_breakpoint_pc
);
887 /* Update this so we record the correct stop PC below. */
888 pc
= sw_breakpoint_pc
;
890 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
894 struct thread_info
*thr
= get_lwp_thread (lwp
);
896 debug_printf ("CSBB: %s stopped by hardware breakpoint\n",
897 target_pid_to_str (ptid_of (thr
)));
900 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
904 struct thread_info
*thr
= get_lwp_thread (lwp
);
906 debug_printf ("CSBB: %s stopped by hardware watchpoint\n",
907 target_pid_to_str (ptid_of (thr
)));
910 else if (lwp
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
914 struct thread_info
*thr
= get_lwp_thread (lwp
);
916 debug_printf ("CSBB: %s stopped by trace\n",
917 target_pid_to_str (ptid_of (thr
)));
922 current_thread
= saved_thread
;
926 static struct lwp_info
*
927 add_lwp (ptid_t ptid
)
929 struct lwp_info
*lwp
;
931 lwp
= XCNEW (struct lwp_info
);
933 lwp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
935 lwp
->thread
= add_thread (ptid
, lwp
);
937 if (the_low_target
.new_thread
!= NULL
)
938 the_low_target
.new_thread (lwp
);
943 /* Callback to be used when calling fork_inferior, responsible for
944 actually initiating the tracing of the inferior. */
949 if (ptrace (PTRACE_TRACEME
, 0, (PTRACE_TYPE_ARG3
) 0,
950 (PTRACE_TYPE_ARG4
) 0) < 0)
951 trace_start_error_with_name ("ptrace");
953 if (setpgid (0, 0) < 0)
954 trace_start_error_with_name ("setpgid");
956 /* If GDBserver is connected to gdb via stdio, redirect the inferior's
957 stdout to stderr so that inferior i/o doesn't corrupt the connection.
958 Also, redirect stdin to /dev/null. */
959 if (remote_connection_is_stdio ())
962 trace_start_error_with_name ("close");
963 if (open ("/dev/null", O_RDONLY
) < 0)
964 trace_start_error_with_name ("open");
966 trace_start_error_with_name ("dup2");
967 if (write (2, "stdin/stdout redirected\n",
968 sizeof ("stdin/stdout redirected\n") - 1) < 0)
970 /* Errors ignored. */;
975 /* Start an inferior process and returns its pid.
976 PROGRAM is the name of the program to be started, and PROGRAM_ARGS
977 are its arguments. */
980 linux_process_target::create_inferior (const char *program
,
981 const std::vector
<char *> &program_args
)
983 client_state
&cs
= get_client_state ();
984 struct lwp_info
*new_lwp
;
989 maybe_disable_address_space_randomization restore_personality
990 (cs
.disable_randomization
);
991 std::string str_program_args
= stringify_argv (program_args
);
993 pid
= fork_inferior (program
,
994 str_program_args
.c_str (),
995 get_environ ()->envp (), linux_ptrace_fun
,
996 NULL
, NULL
, NULL
, NULL
);
999 linux_add_process (pid
, 0);
1001 ptid
= ptid_t (pid
, pid
, 0);
1002 new_lwp
= add_lwp (ptid
);
1003 new_lwp
->must_set_ptrace_flags
= 1;
1005 post_fork_inferior (pid
, program
);
1010 /* Implement the post_create_inferior target_ops method. */
1013 linux_process_target::post_create_inferior ()
1015 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
1019 if (lwp
->must_set_ptrace_flags
)
1021 struct process_info
*proc
= current_process ();
1022 int options
= linux_low_ptrace_options (proc
->attached
);
1024 linux_enable_event_reporting (lwpid_of (current_thread
), options
);
1025 lwp
->must_set_ptrace_flags
= 0;
1029 /* Attach to an inferior process. Returns 0 on success, ERRNO on
1033 linux_attach_lwp (ptid_t ptid
)
1035 struct lwp_info
*new_lwp
;
1036 int lwpid
= ptid
.lwp ();
1038 if (ptrace (PTRACE_ATTACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0)
1042 new_lwp
= add_lwp (ptid
);
1044 /* We need to wait for SIGSTOP before being able to make the next
1045 ptrace call on this LWP. */
1046 new_lwp
->must_set_ptrace_flags
= 1;
1048 if (linux_proc_pid_is_stopped (lwpid
))
1051 debug_printf ("Attached to a stopped process\n");
1053 /* The process is definitely stopped. It is in a job control
1054 stop, unless the kernel predates the TASK_STOPPED /
1055 TASK_TRACED distinction, in which case it might be in a
1056 ptrace stop. Make sure it is in a ptrace stop; from there we
1057 can kill it, signal it, et cetera.
1059 First make sure there is a pending SIGSTOP. Since we are
1060 already attached, the process can not transition from stopped
1061 to running without a PTRACE_CONT; so we know this signal will
1062 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1063 probably already in the queue (unless this kernel is old
1064 enough to use TASK_STOPPED for ptrace stops); but since
1065 SIGSTOP is not an RT signal, it can only be queued once. */
1066 kill_lwp (lwpid
, SIGSTOP
);
1068 /* Finally, resume the stopped process. This will deliver the
1069 SIGSTOP (or a higher priority signal, just like normal
1070 PTRACE_ATTACH), which we'll catch later on. */
1071 ptrace (PTRACE_CONT
, lwpid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1074 /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH
1075 brings it to a halt.
1077 There are several cases to consider here:
1079 1) gdbserver has already attached to the process and is being notified
1080 of a new thread that is being created.
1081 In this case we should ignore that SIGSTOP and resume the
1082 process. This is handled below by setting stop_expected = 1,
1083 and the fact that add_thread sets last_resume_kind ==
1086 2) This is the first thread (the process thread), and we're attaching
1087 to it via attach_inferior.
1088 In this case we want the process thread to stop.
1089 This is handled by having linux_attach set last_resume_kind ==
1090 resume_stop after we return.
1092 If the pid we are attaching to is also the tgid, we attach to and
1093 stop all the existing threads. Otherwise, we attach to pid and
1094 ignore any other threads in the same group as this pid.
1096 3) GDB is connecting to gdbserver and is requesting an enumeration of all
1098 In this case we want the thread to stop.
1099 FIXME: This case is currently not properly handled.
1100 We should wait for the SIGSTOP but don't. Things work apparently
1101 because enough time passes between when we ptrace (ATTACH) and when
1102 gdb makes the next ptrace call on the thread.
1104 On the other hand, if we are currently trying to stop all threads, we
1105 should treat the new thread as if we had sent it a SIGSTOP. This works
1106 because we are guaranteed that the add_lwp call above added us to the
1107 end of the list, and so the new thread has not yet reached
1108 wait_for_sigstop (but will). */
1109 new_lwp
->stop_expected
= 1;
1114 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1115 already attached. Returns true if a new LWP is found, false
1119 attach_proc_task_lwp_callback (ptid_t ptid
)
1121 /* Is this a new thread? */
1122 if (find_thread_ptid (ptid
) == NULL
)
1124 int lwpid
= ptid
.lwp ();
1128 debug_printf ("Found new lwp %d\n", lwpid
);
1130 err
= linux_attach_lwp (ptid
);
1132 /* Be quiet if we simply raced with the thread exiting. EPERM
1133 is returned if the thread's task still exists, and is marked
1134 as exited or zombie, as well as other conditions, so in that
1135 case, confirm the status in /proc/PID/status. */
1137 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1141 debug_printf ("Cannot attach to lwp %d: "
1142 "thread is gone (%d: %s)\n",
1143 lwpid
, err
, safe_strerror (err
));
1149 = linux_ptrace_attach_fail_reason_string (ptid
, err
);
1151 warning (_("Cannot attach to lwp %d: %s"), lwpid
, reason
.c_str ());
1159 static void async_file_mark (void);
1161 /* Attach to PID. If PID is the tgid, attach to it and all
1165 linux_process_target::attach (unsigned long pid
)
1167 struct process_info
*proc
;
1168 struct thread_info
*initial_thread
;
1169 ptid_t ptid
= ptid_t (pid
, pid
, 0);
1172 proc
= linux_add_process (pid
, 1);
1174 /* Attach to PID. We will check for other threads
1176 err
= linux_attach_lwp (ptid
);
1179 remove_process (proc
);
1181 std::string reason
= linux_ptrace_attach_fail_reason_string (ptid
, err
);
1182 error ("Cannot attach to process %ld: %s", pid
, reason
.c_str ());
1185 /* Don't ignore the initial SIGSTOP if we just attached to this
1186 process. It will be collected by wait shortly. */
1187 initial_thread
= find_thread_ptid (ptid_t (pid
, pid
, 0));
1188 initial_thread
->last_resume_kind
= resume_stop
;
1190 /* We must attach to every LWP. If /proc is mounted, use that to
1191 find them now. On the one hand, the inferior may be using raw
1192 clone instead of using pthreads. On the other hand, even if it
1193 is using pthreads, GDB may not be connected yet (thread_db needs
1194 to do symbol lookups, through qSymbol). Also, thread_db walks
1195 structures in the inferior's address space to find the list of
1196 threads/LWPs, and those structures may well be corrupted. Note
1197 that once thread_db is loaded, we'll still use it to list threads
1198 and associate pthread info with each LWP. */
1199 linux_proc_attach_tgid_threads (pid
, attach_proc_task_lwp_callback
);
1201 /* GDB will shortly read the xml target description for this
1202 process, to figure out the process' architecture. But the target
1203 description is only filled in when the first process/thread in
1204 the thread group reports its initial PTRACE_ATTACH SIGSTOP. Do
1205 that now, otherwise, if GDB is fast enough, it could read the
1206 target description _before_ that initial stop. */
1209 struct lwp_info
*lwp
;
1211 ptid_t pid_ptid
= ptid_t (pid
);
1213 lwpid
= wait_for_event_filtered (pid_ptid
, pid_ptid
, &wstat
, __WALL
);
1214 gdb_assert (lwpid
> 0);
1216 lwp
= find_lwp_pid (ptid_t (lwpid
));
1218 if (!WIFSTOPPED (wstat
) || WSTOPSIG (wstat
) != SIGSTOP
)
1220 lwp
->status_pending_p
= 1;
1221 lwp
->status_pending
= wstat
;
1224 initial_thread
->last_resume_kind
= resume_continue
;
1228 gdb_assert (proc
->tdesc
!= NULL
);
1235 last_thread_of_process_p (int pid
)
1237 bool seen_one
= false;
1239 thread_info
*thread
= find_thread (pid
, [&] (thread_info
*thr_arg
)
1243 /* This is the first thread of this process we see. */
1249 /* This is the second thread of this process we see. */
1254 return thread
== NULL
;
1260 linux_kill_one_lwp (struct lwp_info
*lwp
)
1262 struct thread_info
*thr
= get_lwp_thread (lwp
);
1263 int pid
= lwpid_of (thr
);
1265 /* PTRACE_KILL is unreliable. After stepping into a signal handler,
1266 there is no signal context, and ptrace(PTRACE_KILL) (or
1267 ptrace(PTRACE_CONT, SIGKILL), pretty much the same) acts like
1268 ptrace(CONT, pid, 0,0) and just resumes the tracee. A better
1269 alternative is to kill with SIGKILL. We only need one SIGKILL
1270 per process, not one for each thread. But since we still support
1271 support debugging programs using raw clone without CLONE_THREAD,
1272 we send one for each thread. For years, we used PTRACE_KILL
1273 only, so we're being a bit paranoid about some old kernels where
1274 PTRACE_KILL might work better (dubious if there are any such, but
1275 that's why it's paranoia), so we try SIGKILL first, PTRACE_KILL
1276 second, and so we're fine everywhere. */
1279 kill_lwp (pid
, SIGKILL
);
1282 int save_errno
= errno
;
1284 debug_printf ("LKL: kill_lwp (SIGKILL) %s, 0, 0 (%s)\n",
1285 target_pid_to_str (ptid_of (thr
)),
1286 save_errno
? safe_strerror (save_errno
) : "OK");
1290 ptrace (PTRACE_KILL
, pid
, (PTRACE_TYPE_ARG3
) 0, (PTRACE_TYPE_ARG4
) 0);
1293 int save_errno
= errno
;
1295 debug_printf ("LKL: PTRACE_KILL %s, 0, 0 (%s)\n",
1296 target_pid_to_str (ptid_of (thr
)),
1297 save_errno
? safe_strerror (save_errno
) : "OK");
1301 /* Kill LWP and wait for it to die. */
1304 kill_wait_lwp (struct lwp_info
*lwp
)
1306 struct thread_info
*thr
= get_lwp_thread (lwp
);
1307 int pid
= ptid_of (thr
).pid ();
1308 int lwpid
= ptid_of (thr
).lwp ();
1313 debug_printf ("kwl: killing lwp %d, for pid: %d\n", lwpid
, pid
);
1317 linux_kill_one_lwp (lwp
);
1319 /* Make sure it died. Notes:
1321 - The loop is most likely unnecessary.
1323 - We don't use wait_for_event as that could delete lwps
1324 while we're iterating over them. We're not interested in
1325 any pending status at this point, only in making sure all
1326 wait status on the kernel side are collected until the
1329 - We don't use __WALL here as the __WALL emulation relies on
1330 SIGCHLD, and killing a stopped process doesn't generate
1331 one, nor an exit status.
1333 res
= my_waitpid (lwpid
, &wstat
, 0);
1334 if (res
== -1 && errno
== ECHILD
)
1335 res
= my_waitpid (lwpid
, &wstat
, __WCLONE
);
1336 } while (res
> 0 && WIFSTOPPED (wstat
));
1338 /* Even if it was stopped, the child may have already disappeared.
1339 E.g., if it was killed by SIGKILL. */
1340 if (res
< 0 && errno
!= ECHILD
)
1341 perror_with_name ("kill_wait_lwp");
1344 /* Callback for `for_each_thread'. Kills an lwp of a given process,
1345 except the leader. */
1348 kill_one_lwp_callback (thread_info
*thread
, int pid
)
1350 struct lwp_info
*lwp
= get_thread_lwp (thread
);
1352 /* We avoid killing the first thread here, because of a Linux kernel (at
1353 least 2.6.0-test7 through 2.6.8-rc4) bug; if we kill the parent before
1354 the children get a chance to be reaped, it will remain a zombie
1357 if (lwpid_of (thread
) == pid
)
1360 debug_printf ("lkop: is last of process %s\n",
1361 target_pid_to_str (thread
->id
));
1365 kill_wait_lwp (lwp
);
1369 linux_process_target::kill (process_info
*process
)
1371 int pid
= process
->pid
;
1373 /* If we're killing a running inferior, make sure it is stopped
1374 first, as PTRACE_KILL will not work otherwise. */
1375 stop_all_lwps (0, NULL
);
1377 for_each_thread (pid
, [&] (thread_info
*thread
)
1379 kill_one_lwp_callback (thread
, pid
);
1382 /* See the comment in linux_kill_one_lwp. We did not kill the first
1383 thread in the list, so do so now. */
1384 lwp_info
*lwp
= find_lwp_pid (ptid_t (pid
));
1389 debug_printf ("lk_1: cannot find lwp for pid: %d\n",
1393 kill_wait_lwp (lwp
);
1397 /* Since we presently can only stop all lwps of all processes, we
1398 need to unstop lwps of other processes. */
1399 unstop_all_lwps (0, NULL
);
1403 /* Get pending signal of THREAD, for detaching purposes. This is the
1404 signal the thread last stopped for, which we need to deliver to the
1405 thread when detaching, otherwise, it'd be suppressed/lost. */
1408 get_detach_signal (struct thread_info
*thread
)
1410 client_state
&cs
= get_client_state ();
1411 enum gdb_signal signo
= GDB_SIGNAL_0
;
1413 struct lwp_info
*lp
= get_thread_lwp (thread
);
1415 if (lp
->status_pending_p
)
1416 status
= lp
->status_pending
;
1419 /* If the thread had been suspended by gdbserver, and it stopped
1420 cleanly, then it'll have stopped with SIGSTOP. But we don't
1421 want to deliver that SIGSTOP. */
1422 if (thread
->last_status
.kind
!= TARGET_WAITKIND_STOPPED
1423 || thread
->last_status
.value
.sig
== GDB_SIGNAL_0
)
1426 /* Otherwise, we may need to deliver the signal we
1428 status
= lp
->last_status
;
1431 if (!WIFSTOPPED (status
))
1434 debug_printf ("GPS: lwp %s hasn't stopped: no pending signal\n",
1435 target_pid_to_str (ptid_of (thread
)));
1439 /* Extended wait statuses aren't real SIGTRAPs. */
1440 if (WSTOPSIG (status
) == SIGTRAP
&& linux_is_extended_waitstatus (status
))
1443 debug_printf ("GPS: lwp %s had stopped with extended "
1444 "status: no pending signal\n",
1445 target_pid_to_str (ptid_of (thread
)));
1449 signo
= gdb_signal_from_host (WSTOPSIG (status
));
1451 if (cs
.program_signals_p
&& !cs
.program_signals
[signo
])
1454 debug_printf ("GPS: lwp %s had signal %s, but it is in nopass state\n",
1455 target_pid_to_str (ptid_of (thread
)),
1456 gdb_signal_to_string (signo
));
1459 else if (!cs
.program_signals_p
1460 /* If we have no way to know which signals GDB does not
1461 want to have passed to the program, assume
1462 SIGTRAP/SIGINT, which is GDB's default. */
1463 && (signo
== GDB_SIGNAL_TRAP
|| signo
== GDB_SIGNAL_INT
))
1466 debug_printf ("GPS: lwp %s had signal %s, "
1467 "but we don't know if we should pass it. "
1468 "Default to not.\n",
1469 target_pid_to_str (ptid_of (thread
)),
1470 gdb_signal_to_string (signo
));
1476 debug_printf ("GPS: lwp %s has pending signal %s: delivering it.\n",
1477 target_pid_to_str (ptid_of (thread
)),
1478 gdb_signal_to_string (signo
));
1480 return WSTOPSIG (status
);
1484 /* Detach from LWP. */
1487 linux_detach_one_lwp (struct lwp_info
*lwp
)
1489 struct thread_info
*thread
= get_lwp_thread (lwp
);
1493 /* If there is a pending SIGSTOP, get rid of it. */
1494 if (lwp
->stop_expected
)
1497 debug_printf ("Sending SIGCONT to %s\n",
1498 target_pid_to_str (ptid_of (thread
)));
1500 kill_lwp (lwpid_of (thread
), SIGCONT
);
1501 lwp
->stop_expected
= 0;
1504 /* Pass on any pending signal for this thread. */
1505 sig
= get_detach_signal (thread
);
1507 /* Preparing to resume may try to write registers, and fail if the
1508 lwp is zombie. If that happens, ignore the error. We'll handle
1509 it below, when detach fails with ESRCH. */
1512 /* Flush any pending changes to the process's registers. */
1513 regcache_invalidate_thread (thread
);
1515 /* Finally, let it resume. */
1516 if (the_low_target
.prepare_to_resume
!= NULL
)
1517 the_low_target
.prepare_to_resume (lwp
);
1519 catch (const gdb_exception_error
&ex
)
1521 if (!check_ptrace_stopped_lwp_gone (lwp
))
1525 lwpid
= lwpid_of (thread
);
1526 if (ptrace (PTRACE_DETACH
, lwpid
, (PTRACE_TYPE_ARG3
) 0,
1527 (PTRACE_TYPE_ARG4
) (long) sig
) < 0)
1529 int save_errno
= errno
;
1531 /* We know the thread exists, so ESRCH must mean the lwp is
1532 zombie. This can happen if one of the already-detached
1533 threads exits the whole thread group. In that case we're
1534 still attached, and must reap the lwp. */
1535 if (save_errno
== ESRCH
)
1539 ret
= my_waitpid (lwpid
, &status
, __WALL
);
1542 warning (_("Couldn't reap LWP %d while detaching: %s"),
1543 lwpid
, safe_strerror (errno
));
1545 else if (!WIFEXITED (status
) && !WIFSIGNALED (status
))
1547 warning (_("Reaping LWP %d while detaching "
1548 "returned unexpected status 0x%x"),
1554 error (_("Can't detach %s: %s"),
1555 target_pid_to_str (ptid_of (thread
)),
1556 safe_strerror (save_errno
));
1559 else if (debug_threads
)
1561 debug_printf ("PTRACE_DETACH (%s, %s, 0) (OK)\n",
1562 target_pid_to_str (ptid_of (thread
)),
1569 /* Callback for for_each_thread. Detaches from non-leader threads of a
1573 linux_detach_lwp_callback (thread_info
*thread
)
1575 /* We don't actually detach from the thread group leader just yet.
1576 If the thread group exits, we must reap the zombie clone lwps
1577 before we're able to reap the leader. */
1578 if (thread
->id
.pid () == thread
->id
.lwp ())
1581 lwp_info
*lwp
= get_thread_lwp (thread
);
1582 linux_detach_one_lwp (lwp
);
1586 linux_process_target::detach (process_info
*process
)
1588 struct lwp_info
*main_lwp
;
1590 /* As there's a step over already in progress, let it finish first,
1591 otherwise nesting a stabilize_threads operation on top gets real
1593 complete_ongoing_step_over ();
1595 /* Stop all threads before detaching. First, ptrace requires that
1596 the thread is stopped to successfully detach. Second, thread_db
1597 may need to uninstall thread event breakpoints from memory, which
1598 only works with a stopped process anyway. */
1599 stop_all_lwps (0, NULL
);
1601 #ifdef USE_THREAD_DB
1602 thread_db_detach (process
);
1605 /* Stabilize threads (move out of jump pads). */
1606 target_stabilize_threads ();
1608 /* Detach from the clone lwps first. If the thread group exits just
1609 while we're detaching, we must reap the clone lwps before we're
1610 able to reap the leader. */
1611 for_each_thread (process
->pid
, linux_detach_lwp_callback
);
1613 main_lwp
= find_lwp_pid (ptid_t (process
->pid
));
1614 linux_detach_one_lwp (main_lwp
);
1618 /* Since we presently can only stop all lwps of all processes, we
1619 need to unstop lwps of other processes. */
1620 unstop_all_lwps (0, NULL
);
1624 /* Remove all LWPs that belong to process PROC from the lwp list. */
1627 linux_process_target::mourn (process_info
*process
)
1629 struct process_info_private
*priv
;
1631 #ifdef USE_THREAD_DB
1632 thread_db_mourn (process
);
1635 for_each_thread (process
->pid
, [] (thread_info
*thread
)
1637 delete_lwp (get_thread_lwp (thread
));
1640 /* Freeing all private data. */
1641 priv
= process
->priv
;
1642 if (the_low_target
.delete_process
!= NULL
)
1643 the_low_target
.delete_process (priv
->arch_private
);
1645 gdb_assert (priv
->arch_private
== NULL
);
1647 process
->priv
= NULL
;
1649 remove_process (process
);
1653 linux_process_target::join (int pid
)
1658 ret
= my_waitpid (pid
, &status
, 0);
1659 if (WIFEXITED (status
) || WIFSIGNALED (status
))
1661 } while (ret
!= -1 || errno
!= ECHILD
);
1664 /* Return true if the given thread is still alive. */
1667 linux_process_target::thread_alive (ptid_t ptid
)
1669 struct lwp_info
*lwp
= find_lwp_pid (ptid
);
1671 /* We assume we always know if a thread exits. If a whole process
1672 exited but we still haven't been able to report it to GDB, we'll
1673 hold on to the last lwp of the dead process. */
1675 return !lwp_is_marked_dead (lwp
);
1681 linux_process_target::thread_still_has_status_pending (thread_info
*thread
)
1683 struct lwp_info
*lp
= get_thread_lwp (thread
);
1685 if (!lp
->status_pending_p
)
1688 if (thread
->last_resume_kind
!= resume_stop
1689 && (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1690 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
1692 struct thread_info
*saved_thread
;
1696 gdb_assert (lp
->last_status
!= 0);
1700 saved_thread
= current_thread
;
1701 current_thread
= thread
;
1703 if (pc
!= lp
->stop_pc
)
1706 debug_printf ("PC of %ld changed\n",
1711 #if !USE_SIGTRAP_SIGINFO
1712 else if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
1713 && !(*the_low_target
.breakpoint_at
) (pc
))
1716 debug_printf ("previous SW breakpoint of %ld gone\n",
1720 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
1721 && !hardware_breakpoint_inserted_here (pc
))
1724 debug_printf ("previous HW breakpoint of %ld gone\n",
1730 current_thread
= saved_thread
;
1735 debug_printf ("discarding pending breakpoint status\n");
1736 lp
->status_pending_p
= 0;
1744 /* Returns true if LWP is resumed from the client's perspective. */
1747 lwp_resumed (struct lwp_info
*lwp
)
1749 struct thread_info
*thread
= get_lwp_thread (lwp
);
1751 if (thread
->last_resume_kind
!= resume_stop
)
1754 /* Did gdb send us a `vCont;t', but we haven't reported the
1755 corresponding stop to gdb yet? If so, the thread is still
1756 resumed/running from gdb's perspective. */
1757 if (thread
->last_resume_kind
== resume_stop
1758 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
1765 linux_process_target::status_pending_p_callback (thread_info
*thread
,
1768 struct lwp_info
*lp
= get_thread_lwp (thread
);
1770 /* Check if we're only interested in events from a specific process
1771 or a specific LWP. */
1772 if (!thread
->id
.matches (ptid
))
1775 if (!lwp_resumed (lp
))
1778 if (lp
->status_pending_p
1779 && !thread_still_has_status_pending (thread
))
1781 resume_one_lwp (lp
, lp
->stepping
, GDB_SIGNAL_0
, NULL
);
1785 return lp
->status_pending_p
;
1789 find_lwp_pid (ptid_t ptid
)
1791 thread_info
*thread
= find_thread ([&] (thread_info
*thr_arg
)
1793 int lwp
= ptid
.lwp () != 0 ? ptid
.lwp () : ptid
.pid ();
1794 return thr_arg
->id
.lwp () == lwp
;
1800 return get_thread_lwp (thread
);
1803 /* Return the number of known LWPs in the tgid given by PID. */
1810 for_each_thread (pid
, [&] (thread_info
*thread
)
1818 /* See nat/linux-nat.h. */
1821 iterate_over_lwps (ptid_t filter
,
1822 gdb::function_view
<iterate_over_lwps_ftype
> callback
)
1824 thread_info
*thread
= find_thread (filter
, [&] (thread_info
*thr_arg
)
1826 lwp_info
*lwp
= get_thread_lwp (thr_arg
);
1828 return callback (lwp
);
1834 return get_thread_lwp (thread
);
1837 /* Detect zombie thread group leaders, and "exit" them. We can't reap
1838 their exits until all other threads in the group have exited. */
1841 check_zombie_leaders (void)
1843 for_each_process ([] (process_info
*proc
) {
1844 pid_t leader_pid
= pid_of (proc
);
1845 struct lwp_info
*leader_lp
;
1847 leader_lp
= find_lwp_pid (ptid_t (leader_pid
));
1850 debug_printf ("leader_pid=%d, leader_lp!=NULL=%d, "
1851 "num_lwps=%d, zombie=%d\n",
1852 leader_pid
, leader_lp
!= NULL
, num_lwps (leader_pid
),
1853 linux_proc_pid_is_zombie (leader_pid
));
1855 if (leader_lp
!= NULL
&& !leader_lp
->stopped
1856 /* Check if there are other threads in the group, as we may
1857 have raced with the inferior simply exiting. */
1858 && !last_thread_of_process_p (leader_pid
)
1859 && linux_proc_pid_is_zombie (leader_pid
))
1861 /* A leader zombie can mean one of two things:
1863 - It exited, and there's an exit status pending
1864 available, or only the leader exited (not the whole
1865 program). In the latter case, we can't waitpid the
1866 leader's exit status until all other threads are gone.
1868 - There are 3 or more threads in the group, and a thread
1869 other than the leader exec'd. On an exec, the Linux
1870 kernel destroys all other threads (except the execing
1871 one) in the thread group, and resets the execing thread's
1872 tid to the tgid. No exit notification is sent for the
1873 execing thread -- from the ptracer's perspective, it
1874 appears as though the execing thread just vanishes.
1875 Until we reap all other threads except the leader and the
1876 execing thread, the leader will be zombie, and the
1877 execing thread will be in `D (disc sleep)'. As soon as
1878 all other threads are reaped, the execing thread changes
1879 it's tid to the tgid, and the previous (zombie) leader
1880 vanishes, giving place to the "new" leader. We could try
1881 distinguishing the exit and exec cases, by waiting once
1882 more, and seeing if something comes out, but it doesn't
1883 sound useful. The previous leader _does_ go away, and
1884 we'll re-add the new one once we see the exec event
1885 (which is just the same as what would happen if the
1886 previous leader did exit voluntarily before some other
1890 debug_printf ("CZL: Thread group leader %d zombie "
1891 "(it exited, or another thread execd).\n",
1894 delete_lwp (leader_lp
);
1899 /* Callback for `find_thread'. Returns the first LWP that is not
1903 not_stopped_callback (thread_info
*thread
, ptid_t filter
)
1905 if (!thread
->id
.matches (filter
))
1908 lwp_info
*lwp
= get_thread_lwp (thread
);
1910 return !lwp
->stopped
;
1913 /* Increment LWP's suspend count. */
1916 lwp_suspended_inc (struct lwp_info
*lwp
)
1920 if (debug_threads
&& lwp
->suspended
> 4)
1922 struct thread_info
*thread
= get_lwp_thread (lwp
);
1924 debug_printf ("LWP %ld has a suspiciously high suspend count,"
1925 " suspended=%d\n", lwpid_of (thread
), lwp
->suspended
);
1929 /* Decrement LWP's suspend count. */
1932 lwp_suspended_decr (struct lwp_info
*lwp
)
1936 if (lwp
->suspended
< 0)
1938 struct thread_info
*thread
= get_lwp_thread (lwp
);
1940 internal_error (__FILE__
, __LINE__
,
1941 "unsuspend LWP %ld, suspended=%d\n", lwpid_of (thread
),
1946 /* This function should only be called if the LWP got a SIGTRAP.
1948 Handle any tracepoint steps or hits. Return true if a tracepoint
1949 event was handled, 0 otherwise. */
1952 handle_tracepoints (struct lwp_info
*lwp
)
1954 struct thread_info
*tinfo
= get_lwp_thread (lwp
);
1955 int tpoint_related_event
= 0;
1957 gdb_assert (lwp
->suspended
== 0);
1959 /* If this tracepoint hit causes a tracing stop, we'll immediately
1960 uninsert tracepoints. To do this, we temporarily pause all
1961 threads, unpatch away, and then unpause threads. We need to make
1962 sure the unpausing doesn't resume LWP too. */
1963 lwp_suspended_inc (lwp
);
1965 /* And we need to be sure that any all-threads-stopping doesn't try
1966 to move threads out of the jump pads, as it could deadlock the
1967 inferior (LWP could be in the jump pad, maybe even holding the
1970 /* Do any necessary step collect actions. */
1971 tpoint_related_event
|= tracepoint_finished_step (tinfo
, lwp
->stop_pc
);
1973 tpoint_related_event
|= handle_tracepoint_bkpts (tinfo
, lwp
->stop_pc
);
1975 /* See if we just hit a tracepoint and do its main collect
1977 tpoint_related_event
|= tracepoint_was_hit (tinfo
, lwp
->stop_pc
);
1979 lwp_suspended_decr (lwp
);
1981 gdb_assert (lwp
->suspended
== 0);
1982 gdb_assert (!stabilizing_threads
1983 || (lwp
->collecting_fast_tracepoint
1984 != fast_tpoint_collect_result::not_collecting
));
1986 if (tpoint_related_event
)
1989 debug_printf ("got a tracepoint event\n");
1996 /* Convenience wrapper. Returns information about LWP's fast tracepoint
1997 collection status. */
1999 static fast_tpoint_collect_result
2000 linux_fast_tracepoint_collecting (struct lwp_info
*lwp
,
2001 struct fast_tpoint_collect_status
*status
)
2003 CORE_ADDR thread_area
;
2004 struct thread_info
*thread
= get_lwp_thread (lwp
);
2006 if (the_low_target
.get_thread_area
== NULL
)
2007 return fast_tpoint_collect_result::not_collecting
;
2009 /* Get the thread area address. This is used to recognize which
2010 thread is which when tracing with the in-process agent library.
2011 We don't read anything from the address, and treat it as opaque;
2012 it's the address itself that we assume is unique per-thread. */
2013 if ((*the_low_target
.get_thread_area
) (lwpid_of (thread
), &thread_area
) == -1)
2014 return fast_tpoint_collect_result::not_collecting
;
2016 return fast_tracepoint_collecting (thread_area
, lwp
->stop_pc
, status
);
2020 linux_process_target::maybe_move_out_of_jump_pad (lwp_info
*lwp
, int *wstat
)
2022 struct thread_info
*saved_thread
;
2024 saved_thread
= current_thread
;
2025 current_thread
= get_lwp_thread (lwp
);
2028 || (WIFSTOPPED (*wstat
) && WSTOPSIG (*wstat
) != SIGTRAP
))
2029 && supports_fast_tracepoints ()
2030 && agent_loaded_p ())
2032 struct fast_tpoint_collect_status status
;
2035 debug_printf ("Checking whether LWP %ld needs to move out of the "
2037 lwpid_of (current_thread
));
2039 fast_tpoint_collect_result r
2040 = linux_fast_tracepoint_collecting (lwp
, &status
);
2043 || (WSTOPSIG (*wstat
) != SIGILL
2044 && WSTOPSIG (*wstat
) != SIGFPE
2045 && WSTOPSIG (*wstat
) != SIGSEGV
2046 && WSTOPSIG (*wstat
) != SIGBUS
))
2048 lwp
->collecting_fast_tracepoint
= r
;
2050 if (r
!= fast_tpoint_collect_result::not_collecting
)
2052 if (r
== fast_tpoint_collect_result::before_insn
2053 && lwp
->exit_jump_pad_bkpt
== NULL
)
2055 /* Haven't executed the original instruction yet.
2056 Set breakpoint there, and wait till it's hit,
2057 then single-step until exiting the jump pad. */
2058 lwp
->exit_jump_pad_bkpt
2059 = set_breakpoint_at (status
.adjusted_insn_addr
, NULL
);
2063 debug_printf ("Checking whether LWP %ld needs to move out of "
2064 "the jump pad...it does\n",
2065 lwpid_of (current_thread
));
2066 current_thread
= saved_thread
;
2073 /* If we get a synchronous signal while collecting, *and*
2074 while executing the (relocated) original instruction,
2075 reset the PC to point at the tpoint address, before
2076 reporting to GDB. Otherwise, it's an IPA lib bug: just
2077 report the signal to GDB, and pray for the best. */
2079 lwp
->collecting_fast_tracepoint
2080 = fast_tpoint_collect_result::not_collecting
;
2082 if (r
!= fast_tpoint_collect_result::not_collecting
2083 && (status
.adjusted_insn_addr
<= lwp
->stop_pc
2084 && lwp
->stop_pc
< status
.adjusted_insn_addr_end
))
2087 struct regcache
*regcache
;
2089 /* The si_addr on a few signals references the address
2090 of the faulting instruction. Adjust that as
2092 if ((WSTOPSIG (*wstat
) == SIGILL
2093 || WSTOPSIG (*wstat
) == SIGFPE
2094 || WSTOPSIG (*wstat
) == SIGBUS
2095 || WSTOPSIG (*wstat
) == SIGSEGV
)
2096 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
2097 (PTRACE_TYPE_ARG3
) 0, &info
) == 0
2098 /* Final check just to make sure we don't clobber
2099 the siginfo of non-kernel-sent signals. */
2100 && (uintptr_t) info
.si_addr
== lwp
->stop_pc
)
2102 info
.si_addr
= (void *) (uintptr_t) status
.tpoint_addr
;
2103 ptrace (PTRACE_SETSIGINFO
, lwpid_of (current_thread
),
2104 (PTRACE_TYPE_ARG3
) 0, &info
);
2107 regcache
= get_thread_regcache (current_thread
, 1);
2108 low_set_pc (regcache
, status
.tpoint_addr
);
2109 lwp
->stop_pc
= status
.tpoint_addr
;
2111 /* Cancel any fast tracepoint lock this thread was
2113 force_unlock_trace_buffer ();
2116 if (lwp
->exit_jump_pad_bkpt
!= NULL
)
2119 debug_printf ("Cancelling fast exit-jump-pad: removing bkpt. "
2120 "stopping all threads momentarily.\n");
2122 stop_all_lwps (1, lwp
);
2124 delete_breakpoint (lwp
->exit_jump_pad_bkpt
);
2125 lwp
->exit_jump_pad_bkpt
= NULL
;
2127 unstop_all_lwps (1, lwp
);
2129 gdb_assert (lwp
->suspended
>= 0);
2135 debug_printf ("Checking whether LWP %ld needs to move out of the "
2137 lwpid_of (current_thread
));
2139 current_thread
= saved_thread
;
2143 /* Enqueue one signal in the "signals to report later when out of the
2147 enqueue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2149 struct pending_signals
*p_sig
;
2150 struct thread_info
*thread
= get_lwp_thread (lwp
);
2153 debug_printf ("Deferring signal %d for LWP %ld.\n",
2154 WSTOPSIG (*wstat
), lwpid_of (thread
));
2158 struct pending_signals
*sig
;
2160 for (sig
= lwp
->pending_signals_to_report
;
2163 debug_printf (" Already queued %d\n",
2166 debug_printf (" (no more currently queued signals)\n");
2169 /* Don't enqueue non-RT signals if they are already in the deferred
2170 queue. (SIGSTOP being the easiest signal to see ending up here
2172 if (WSTOPSIG (*wstat
) < __SIGRTMIN
)
2174 struct pending_signals
*sig
;
2176 for (sig
= lwp
->pending_signals_to_report
;
2180 if (sig
->signal
== WSTOPSIG (*wstat
))
2183 debug_printf ("Not requeuing already queued non-RT signal %d"
2192 p_sig
= XCNEW (struct pending_signals
);
2193 p_sig
->prev
= lwp
->pending_signals_to_report
;
2194 p_sig
->signal
= WSTOPSIG (*wstat
);
2196 ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2199 lwp
->pending_signals_to_report
= p_sig
;
2202 /* Dequeue one signal from the "signals to report later when out of
2203 the jump pad" list. */
2206 dequeue_one_deferred_signal (struct lwp_info
*lwp
, int *wstat
)
2208 struct thread_info
*thread
= get_lwp_thread (lwp
);
2210 if (lwp
->pending_signals_to_report
!= NULL
)
2212 struct pending_signals
**p_sig
;
2214 p_sig
= &lwp
->pending_signals_to_report
;
2215 while ((*p_sig
)->prev
!= NULL
)
2216 p_sig
= &(*p_sig
)->prev
;
2218 *wstat
= W_STOPCODE ((*p_sig
)->signal
);
2219 if ((*p_sig
)->info
.si_signo
!= 0)
2220 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
2226 debug_printf ("Reporting deferred signal %d for LWP %ld.\n",
2227 WSTOPSIG (*wstat
), lwpid_of (thread
));
2231 struct pending_signals
*sig
;
2233 for (sig
= lwp
->pending_signals_to_report
;
2236 debug_printf (" Still queued %d\n",
2239 debug_printf (" (no more queued signals)\n");
2248 /* Fetch the possibly triggered data watchpoint info and store it in
2251 On some archs, like x86, that use debug registers to set
2252 watchpoints, it's possible that the way to know which watched
2253 address trapped, is to check the register that is used to select
2254 which address to watch. Problem is, between setting the watchpoint
2255 and reading back which data address trapped, the user may change
2256 the set of watchpoints, and, as a consequence, GDB changes the
2257 debug registers in the inferior. To avoid reading back a stale
2258 stopped-data-address when that happens, we cache in LP the fact
2259 that a watchpoint trapped, and the corresponding data address, as
2260 soon as we see CHILD stop with a SIGTRAP. If GDB changes the debug
2261 registers meanwhile, we have the cached data we can rely on. */
2264 check_stopped_by_watchpoint (struct lwp_info
*child
)
2266 if (the_low_target
.stopped_by_watchpoint
!= NULL
)
2268 struct thread_info
*saved_thread
;
2270 saved_thread
= current_thread
;
2271 current_thread
= get_lwp_thread (child
);
2273 if (the_low_target
.stopped_by_watchpoint ())
2275 child
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2277 if (the_low_target
.stopped_data_address
!= NULL
)
2278 child
->stopped_data_address
2279 = the_low_target
.stopped_data_address ();
2281 child
->stopped_data_address
= 0;
2284 current_thread
= saved_thread
;
2287 return child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2290 /* Return the ptrace options that we want to try to enable. */
2293 linux_low_ptrace_options (int attached
)
2295 client_state
&cs
= get_client_state ();
2299 options
|= PTRACE_O_EXITKILL
;
2301 if (cs
.report_fork_events
)
2302 options
|= PTRACE_O_TRACEFORK
;
2304 if (cs
.report_vfork_events
)
2305 options
|= (PTRACE_O_TRACEVFORK
| PTRACE_O_TRACEVFORKDONE
);
2307 if (cs
.report_exec_events
)
2308 options
|= PTRACE_O_TRACEEXEC
;
2310 options
|= PTRACE_O_TRACESYSGOOD
;
2316 linux_process_target::filter_event (int lwpid
, int wstat
)
2318 client_state
&cs
= get_client_state ();
2319 struct lwp_info
*child
;
2320 struct thread_info
*thread
;
2321 int have_stop_pc
= 0;
2323 child
= find_lwp_pid (ptid_t (lwpid
));
2325 /* Check for stop events reported by a process we didn't already
2326 know about - anything not already in our LWP list.
2328 If we're expecting to receive stopped processes after
2329 fork, vfork, and clone events, then we'll just add the
2330 new one to our list and go back to waiting for the event
2331 to be reported - the stopped process might be returned
2332 from waitpid before or after the event is.
2334 But note the case of a non-leader thread exec'ing after the
2335 leader having exited, and gone from our lists (because
2336 check_zombie_leaders deleted it). The non-leader thread
2337 changes its tid to the tgid. */
2339 if (WIFSTOPPED (wstat
) && child
== NULL
&& WSTOPSIG (wstat
) == SIGTRAP
2340 && linux_ptrace_get_extended_event (wstat
) == PTRACE_EVENT_EXEC
)
2344 /* A multi-thread exec after we had seen the leader exiting. */
2347 debug_printf ("LLW: Re-adding thread group leader LWP %d"
2348 "after exec.\n", lwpid
);
2351 child_ptid
= ptid_t (lwpid
, lwpid
, 0);
2352 child
= add_lwp (child_ptid
);
2354 current_thread
= child
->thread
;
2357 /* If we didn't find a process, one of two things presumably happened:
2358 - A process we started and then detached from has exited. Ignore it.
2359 - A process we are controlling has forked and the new child's stop
2360 was reported to us by the kernel. Save its PID. */
2361 if (child
== NULL
&& WIFSTOPPED (wstat
))
2363 add_to_pid_list (&stopped_pids
, lwpid
, wstat
);
2366 else if (child
== NULL
)
2369 thread
= get_lwp_thread (child
);
2373 child
->last_status
= wstat
;
2375 /* Check if the thread has exited. */
2376 if ((WIFEXITED (wstat
) || WIFSIGNALED (wstat
)))
2379 debug_printf ("LLFE: %d exited.\n", lwpid
);
2381 if (finish_step_over (child
))
2383 /* Unsuspend all other LWPs, and set them back running again. */
2384 unsuspend_all_lwps (child
);
2387 /* If there is at least one more LWP, then the exit signal was
2388 not the end of the debugged application and should be
2389 ignored, unless GDB wants to hear about thread exits. */
2390 if (cs
.report_thread_events
2391 || last_thread_of_process_p (pid_of (thread
)))
2393 /* Since events are serialized to GDB core, and we can't
2394 report this one right now. Leave the status pending for
2395 the next time we're able to report it. */
2396 mark_lwp_dead (child
, wstat
);
2406 gdb_assert (WIFSTOPPED (wstat
));
2408 if (WIFSTOPPED (wstat
))
2410 struct process_info
*proc
;
2412 /* Architecture-specific setup after inferior is running. */
2413 proc
= find_process_pid (pid_of (thread
));
2414 if (proc
->tdesc
== NULL
)
2418 /* This needs to happen after we have attached to the
2419 inferior and it is stopped for the first time, but
2420 before we access any inferior registers. */
2421 arch_setup_thread (thread
);
2425 /* The process is started, but GDBserver will do
2426 architecture-specific setup after the program stops at
2427 the first instruction. */
2428 child
->status_pending_p
= 1;
2429 child
->status_pending
= wstat
;
2435 if (WIFSTOPPED (wstat
) && child
->must_set_ptrace_flags
)
2437 struct process_info
*proc
= find_process_pid (pid_of (thread
));
2438 int options
= linux_low_ptrace_options (proc
->attached
);
2440 linux_enable_event_reporting (lwpid
, options
);
2441 child
->must_set_ptrace_flags
= 0;
2444 /* Always update syscall_state, even if it will be filtered later. */
2445 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SYSCALL_SIGTRAP
)
2447 child
->syscall_state
2448 = (child
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
2449 ? TARGET_WAITKIND_SYSCALL_RETURN
2450 : TARGET_WAITKIND_SYSCALL_ENTRY
);
2454 /* Almost all other ptrace-stops are known to be outside of system
2455 calls, with further exceptions in handle_extended_wait. */
2456 child
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2459 /* Be careful to not overwrite stop_pc until save_stop_reason is
2461 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGTRAP
2462 && linux_is_extended_waitstatus (wstat
))
2464 child
->stop_pc
= get_pc (child
);
2465 if (handle_extended_wait (&child
, wstat
))
2467 /* The event has been handled, so just return without
2473 if (linux_wstatus_maybe_breakpoint (wstat
))
2475 if (save_stop_reason (child
))
2480 child
->stop_pc
= get_pc (child
);
2482 if (WIFSTOPPED (wstat
) && WSTOPSIG (wstat
) == SIGSTOP
2483 && child
->stop_expected
)
2486 debug_printf ("Expected stop.\n");
2487 child
->stop_expected
= 0;
2489 if (thread
->last_resume_kind
== resume_stop
)
2491 /* We want to report the stop to the core. Treat the
2492 SIGSTOP as a normal event. */
2494 debug_printf ("LLW: resume_stop SIGSTOP caught for %s.\n",
2495 target_pid_to_str (ptid_of (thread
)));
2497 else if (stopping_threads
!= NOT_STOPPING_THREADS
)
2499 /* Stopping threads. We don't want this SIGSTOP to end up
2502 debug_printf ("LLW: SIGSTOP caught for %s "
2503 "while stopping threads.\n",
2504 target_pid_to_str (ptid_of (thread
)));
2509 /* This is a delayed SIGSTOP. Filter out the event. */
2511 debug_printf ("LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
2512 child
->stepping
? "step" : "continue",
2513 target_pid_to_str (ptid_of (thread
)));
2515 resume_one_lwp (child
, child
->stepping
, 0, NULL
);
2520 child
->status_pending_p
= 1;
2521 child
->status_pending
= wstat
;
2525 /* Return true if THREAD is doing hardware single step. */
2528 maybe_hw_step (struct thread_info
*thread
)
2530 if (can_hardware_single_step ())
2534 /* GDBserver must insert single-step breakpoint for software
2536 gdb_assert (has_single_step_breakpoints (thread
));
2542 linux_process_target::resume_stopped_resumed_lwps (thread_info
*thread
)
2544 struct lwp_info
*lp
= get_thread_lwp (thread
);
2548 && !lp
->status_pending_p
2549 && thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
)
2553 if (thread
->last_resume_kind
== resume_step
)
2554 step
= maybe_hw_step (thread
);
2557 debug_printf ("RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n",
2558 target_pid_to_str (ptid_of (thread
)),
2559 paddress (lp
->stop_pc
),
2562 resume_one_lwp (lp
, step
, GDB_SIGNAL_0
, NULL
);
2567 linux_process_target::wait_for_event_filtered (ptid_t wait_ptid
,
2569 int *wstatp
, int options
)
2571 struct thread_info
*event_thread
;
2572 struct lwp_info
*event_child
, *requested_child
;
2573 sigset_t block_mask
, prev_mask
;
2576 /* N.B. event_thread points to the thread_info struct that contains
2577 event_child. Keep them in sync. */
2578 event_thread
= NULL
;
2580 requested_child
= NULL
;
2582 /* Check for a lwp with a pending status. */
2584 if (filter_ptid
== minus_one_ptid
|| filter_ptid
.is_pid ())
2586 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2588 return status_pending_p_callback (thread
, filter_ptid
);
2591 if (event_thread
!= NULL
)
2592 event_child
= get_thread_lwp (event_thread
);
2593 if (debug_threads
&& event_thread
)
2594 debug_printf ("Got a pending child %ld\n", lwpid_of (event_thread
));
2596 else if (filter_ptid
!= null_ptid
)
2598 requested_child
= find_lwp_pid (filter_ptid
);
2600 if (stopping_threads
== NOT_STOPPING_THREADS
2601 && requested_child
->status_pending_p
2602 && (requested_child
->collecting_fast_tracepoint
2603 != fast_tpoint_collect_result::not_collecting
))
2605 enqueue_one_deferred_signal (requested_child
,
2606 &requested_child
->status_pending
);
2607 requested_child
->status_pending_p
= 0;
2608 requested_child
->status_pending
= 0;
2609 resume_one_lwp (requested_child
, 0, 0, NULL
);
2612 if (requested_child
->suspended
2613 && requested_child
->status_pending_p
)
2615 internal_error (__FILE__
, __LINE__
,
2616 "requesting an event out of a"
2617 " suspended child?");
2620 if (requested_child
->status_pending_p
)
2622 event_child
= requested_child
;
2623 event_thread
= get_lwp_thread (event_child
);
2627 if (event_child
!= NULL
)
2630 debug_printf ("Got an event from pending child %ld (%04x)\n",
2631 lwpid_of (event_thread
), event_child
->status_pending
);
2632 *wstatp
= event_child
->status_pending
;
2633 event_child
->status_pending_p
= 0;
2634 event_child
->status_pending
= 0;
2635 current_thread
= event_thread
;
2636 return lwpid_of (event_thread
);
2639 /* But if we don't find a pending event, we'll have to wait.
2641 We only enter this loop if no process has a pending wait status.
2642 Thus any action taken in response to a wait status inside this
2643 loop is responding as soon as we detect the status, not after any
2646 /* Make sure SIGCHLD is blocked until the sigsuspend below. Block
2647 all signals while here. */
2648 sigfillset (&block_mask
);
2649 gdb_sigmask (SIG_BLOCK
, &block_mask
, &prev_mask
);
2651 /* Always pull all events out of the kernel. We'll randomly select
2652 an event LWP out of all that have events, to prevent
2654 while (event_child
== NULL
)
2658 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
2661 - If the thread group leader exits while other threads in the
2662 thread group still exist, waitpid(TGID, ...) hangs. That
2663 waitpid won't return an exit status until the other threads
2664 in the group are reaped.
2666 - When a non-leader thread execs, that thread just vanishes
2667 without reporting an exit (so we'd hang if we waited for it
2668 explicitly in that case). The exec event is reported to
2671 ret
= my_waitpid (-1, wstatp
, options
| WNOHANG
);
2674 debug_printf ("LWFE: waitpid(-1, ...) returned %d, %s\n",
2675 ret
, errno
? safe_strerror (errno
) : "ERRNO-OK");
2681 debug_printf ("LLW: waitpid %ld received %s\n",
2682 (long) ret
, status_to_str (*wstatp
));
2685 /* Filter all events. IOW, leave all events pending. We'll
2686 randomly select an event LWP out of all that have events
2688 filter_event (ret
, *wstatp
);
2689 /* Retry until nothing comes out of waitpid. A single
2690 SIGCHLD can indicate more than one child stopped. */
2694 /* Now that we've pulled all events out of the kernel, resume
2695 LWPs that don't have an interesting event to report. */
2696 if (stopping_threads
== NOT_STOPPING_THREADS
)
2697 for_each_thread ([this] (thread_info
*thread
)
2699 resume_stopped_resumed_lwps (thread
);
2702 /* ... and find an LWP with a status to report to the core, if
2704 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2706 return status_pending_p_callback (thread
, filter_ptid
);
2709 if (event_thread
!= NULL
)
2711 event_child
= get_thread_lwp (event_thread
);
2712 *wstatp
= event_child
->status_pending
;
2713 event_child
->status_pending_p
= 0;
2714 event_child
->status_pending
= 0;
2718 /* Check for zombie thread group leaders. Those can't be reaped
2719 until all other threads in the thread group are. */
2720 check_zombie_leaders ();
2722 auto not_stopped
= [&] (thread_info
*thread
)
2724 return not_stopped_callback (thread
, wait_ptid
);
2727 /* If there are no resumed children left in the set of LWPs we
2728 want to wait for, bail. We can't just block in
2729 waitpid/sigsuspend, because lwps might have been left stopped
2730 in trace-stop state, and we'd be stuck forever waiting for
2731 their status to change (which would only happen if we resumed
2732 them). Even if WNOHANG is set, this return code is preferred
2733 over 0 (below), as it is more detailed. */
2734 if (find_thread (not_stopped
) == NULL
)
2737 debug_printf ("LLW: exit (no unwaited-for LWP)\n");
2738 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2742 /* No interesting event to report to the caller. */
2743 if ((options
& WNOHANG
))
2746 debug_printf ("WNOHANG set, no event found\n");
2748 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2752 /* Block until we get an event reported with SIGCHLD. */
2754 debug_printf ("sigsuspend'ing\n");
2756 sigsuspend (&prev_mask
);
2757 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2761 gdb_sigmask (SIG_SETMASK
, &prev_mask
, NULL
);
2763 current_thread
= event_thread
;
2765 return lwpid_of (event_thread
);
2769 linux_process_target::wait_for_event (ptid_t ptid
, int *wstatp
, int options
)
2771 return wait_for_event_filtered (ptid
, ptid
, wstatp
, options
);
2774 /* Select one LWP out of those that have events pending. */
2777 select_event_lwp (struct lwp_info
**orig_lp
)
2779 struct thread_info
*event_thread
= NULL
;
2781 /* In all-stop, give preference to the LWP that is being
2782 single-stepped. There will be at most one, and it's the LWP that
2783 the core is most interested in. If we didn't do this, then we'd
2784 have to handle pending step SIGTRAPs somehow in case the core
2785 later continues the previously-stepped thread, otherwise we'd
2786 report the pending SIGTRAP, and the core, not having stepped the
2787 thread, wouldn't understand what the trap was for, and therefore
2788 would report it to the user as a random signal. */
2791 event_thread
= find_thread ([] (thread_info
*thread
)
2793 lwp_info
*lp
= get_thread_lwp (thread
);
2795 return (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2796 && thread
->last_resume_kind
== resume_step
2797 && lp
->status_pending_p
);
2800 if (event_thread
!= NULL
)
2803 debug_printf ("SEL: Select single-step %s\n",
2804 target_pid_to_str (ptid_of (event_thread
)));
2807 if (event_thread
== NULL
)
2809 /* No single-stepping LWP. Select one at random, out of those
2810 which have had events. */
2812 event_thread
= find_thread_in_random ([&] (thread_info
*thread
)
2814 lwp_info
*lp
= get_thread_lwp (thread
);
2816 /* Only resumed LWPs that have an event pending. */
2817 return (thread
->last_status
.kind
== TARGET_WAITKIND_IGNORE
2818 && lp
->status_pending_p
);
2822 if (event_thread
!= NULL
)
2824 struct lwp_info
*event_lp
= get_thread_lwp (event_thread
);
2826 /* Switch the event LWP. */
2827 *orig_lp
= event_lp
;
2831 /* Decrement the suspend count of all LWPs, except EXCEPT, if non
2835 unsuspend_all_lwps (struct lwp_info
*except
)
2837 for_each_thread ([&] (thread_info
*thread
)
2839 lwp_info
*lwp
= get_thread_lwp (thread
);
2842 lwp_suspended_decr (lwp
);
2846 static bool stuck_in_jump_pad_callback (thread_info
*thread
);
2847 static bool lwp_running (thread_info
*thread
);
2849 /* Stabilize threads (move out of jump pads).
2851 If a thread is midway collecting a fast tracepoint, we need to
2852 finish the collection and move it out of the jump pad before
2853 reporting the signal.
2855 This avoids recursion while collecting (when a signal arrives
2856 midway, and the signal handler itself collects), which would trash
2857 the trace buffer. In case the user set a breakpoint in a signal
2858 handler, this avoids the backtrace showing the jump pad, etc..
2859 Most importantly, there are certain things we can't do safely if
2860 threads are stopped in a jump pad (or in its callee's). For
2863 - starting a new trace run. A thread still collecting the
2864 previous run, could trash the trace buffer when resumed. The trace
2865 buffer control structures would have been reset but the thread had
2866 no way to tell. The thread could even midway memcpy'ing to the
2867 buffer, which would mean that when resumed, it would clobber the
2868 trace buffer that had been set for a new run.
2870 - we can't rewrite/reuse the jump pads for new tracepoints
2871 safely. Say you do tstart while a thread is stopped midway while
2872 collecting. When the thread is later resumed, it finishes the
2873 collection, and returns to the jump pad, to execute the original
2874 instruction that was under the tracepoint jump at the time the
2875 older run had been started. If the jump pad had been rewritten
2876 since for something else in the new run, the thread would now
2877 execute the wrong / random instructions. */
2880 linux_process_target::stabilize_threads ()
2882 thread_info
*thread_stuck
= find_thread (stuck_in_jump_pad_callback
);
2884 if (thread_stuck
!= NULL
)
2887 debug_printf ("can't stabilize, LWP %ld is stuck in jump pad\n",
2888 lwpid_of (thread_stuck
));
2892 thread_info
*saved_thread
= current_thread
;
2894 stabilizing_threads
= 1;
2897 for_each_thread ([this] (thread_info
*thread
)
2899 move_out_of_jump_pad (thread
);
2902 /* Loop until all are stopped out of the jump pads. */
2903 while (find_thread (lwp_running
) != NULL
)
2905 struct target_waitstatus ourstatus
;
2906 struct lwp_info
*lwp
;
2909 /* Note that we go through the full wait even loop. While
2910 moving threads out of jump pad, we need to be able to step
2911 over internal breakpoints and such. */
2912 wait_1 (minus_one_ptid
, &ourstatus
, 0);
2914 if (ourstatus
.kind
== TARGET_WAITKIND_STOPPED
)
2916 lwp
= get_thread_lwp (current_thread
);
2919 lwp_suspended_inc (lwp
);
2921 if (ourstatus
.value
.sig
!= GDB_SIGNAL_0
2922 || current_thread
->last_resume_kind
== resume_stop
)
2924 wstat
= W_STOPCODE (gdb_signal_to_host (ourstatus
.value
.sig
));
2925 enqueue_one_deferred_signal (lwp
, &wstat
);
2930 unsuspend_all_lwps (NULL
);
2932 stabilizing_threads
= 0;
2934 current_thread
= saved_thread
;
2938 thread_stuck
= find_thread (stuck_in_jump_pad_callback
);
2940 if (thread_stuck
!= NULL
)
2941 debug_printf ("couldn't stabilize, LWP %ld got stuck in jump pad\n",
2942 lwpid_of (thread_stuck
));
2946 /* Convenience function that is called when the kernel reports an
2947 event that is not passed out to GDB. */
2950 ignore_event (struct target_waitstatus
*ourstatus
)
2952 /* If we got an event, there may still be others, as a single
2953 SIGCHLD can indicate more than one child stopped. This forces
2954 another target_wait call. */
2957 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2961 /* Convenience function that is called when the kernel reports an exit
2962 event. This decides whether to report the event to GDB as a
2963 process exit event, a thread exit event, or to suppress the
2967 filter_exit_event (struct lwp_info
*event_child
,
2968 struct target_waitstatus
*ourstatus
)
2970 client_state
&cs
= get_client_state ();
2971 struct thread_info
*thread
= get_lwp_thread (event_child
);
2972 ptid_t ptid
= ptid_of (thread
);
2974 if (!last_thread_of_process_p (pid_of (thread
)))
2976 if (cs
.report_thread_events
)
2977 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
2979 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
2981 delete_lwp (event_child
);
2986 /* Returns 1 if GDB is interested in any event_child syscalls. */
2989 gdb_catching_syscalls_p (struct lwp_info
*event_child
)
2991 struct thread_info
*thread
= get_lwp_thread (event_child
);
2992 struct process_info
*proc
= get_thread_process (thread
);
2994 return !proc
->syscalls_to_catch
.empty ();
2997 /* Returns 1 if GDB is interested in the event_child syscall.
2998 Only to be called when stopped reason is SYSCALL_SIGTRAP. */
3001 gdb_catch_this_syscall_p (struct lwp_info
*event_child
)
3004 struct thread_info
*thread
= get_lwp_thread (event_child
);
3005 struct process_info
*proc
= get_thread_process (thread
);
3007 if (proc
->syscalls_to_catch
.empty ())
3010 if (proc
->syscalls_to_catch
[0] == ANY_SYSCALL
)
3013 get_syscall_trapinfo (event_child
, &sysno
);
3015 for (int iter
: proc
->syscalls_to_catch
)
3023 linux_process_target::wait_1 (ptid_t ptid
, target_waitstatus
*ourstatus
,
3026 client_state
&cs
= get_client_state ();
3028 struct lwp_info
*event_child
;
3031 int step_over_finished
;
3032 int bp_explains_trap
;
3033 int maybe_internal_trap
;
3042 debug_printf ("wait_1: [%s]\n", target_pid_to_str (ptid
));
3045 /* Translate generic target options into linux options. */
3047 if (target_options
& TARGET_WNOHANG
)
3050 bp_explains_trap
= 0;
3053 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3055 auto status_pending_p_any
= [&] (thread_info
*thread
)
3057 return status_pending_p_callback (thread
, minus_one_ptid
);
3060 auto not_stopped
= [&] (thread_info
*thread
)
3062 return not_stopped_callback (thread
, minus_one_ptid
);
3065 /* Find a resumed LWP, if any. */
3066 if (find_thread (status_pending_p_any
) != NULL
)
3068 else if (find_thread (not_stopped
) != NULL
)
3073 if (step_over_bkpt
== null_ptid
)
3074 pid
= wait_for_event (ptid
, &w
, options
);
3078 debug_printf ("step_over_bkpt set [%s], doing a blocking wait\n",
3079 target_pid_to_str (step_over_bkpt
));
3080 pid
= wait_for_event (step_over_bkpt
, &w
, options
& ~WNOHANG
);
3083 if (pid
== 0 || (pid
== -1 && !any_resumed
))
3085 gdb_assert (target_options
& TARGET_WNOHANG
);
3089 debug_printf ("wait_1 ret = null_ptid, "
3090 "TARGET_WAITKIND_IGNORE\n");
3094 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3101 debug_printf ("wait_1 ret = null_ptid, "
3102 "TARGET_WAITKIND_NO_RESUMED\n");
3106 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3110 event_child
= get_thread_lwp (current_thread
);
3112 /* wait_for_event only returns an exit status for the last
3113 child of a process. Report it. */
3114 if (WIFEXITED (w
) || WIFSIGNALED (w
))
3118 ourstatus
->kind
= TARGET_WAITKIND_EXITED
;
3119 ourstatus
->value
.integer
= WEXITSTATUS (w
);
3123 debug_printf ("wait_1 ret = %s, exited with "
3125 target_pid_to_str (ptid_of (current_thread
)),
3132 ourstatus
->kind
= TARGET_WAITKIND_SIGNALLED
;
3133 ourstatus
->value
.sig
= gdb_signal_from_host (WTERMSIG (w
));
3137 debug_printf ("wait_1 ret = %s, terminated with "
3139 target_pid_to_str (ptid_of (current_thread
)),
3145 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3146 return filter_exit_event (event_child
, ourstatus
);
3148 return ptid_of (current_thread
);
3151 /* If step-over executes a breakpoint instruction, in the case of a
3152 hardware single step it means a gdb/gdbserver breakpoint had been
3153 planted on top of a permanent breakpoint, in the case of a software
3154 single step it may just mean that gdbserver hit the reinsert breakpoint.
3155 The PC has been adjusted by save_stop_reason to point at
3156 the breakpoint address.
3157 So in the case of the hardware single step advance the PC manually
3158 past the breakpoint and in the case of software single step advance only
3159 if it's not the single_step_breakpoint we are hitting.
3160 This avoids that a program would keep trapping a permanent breakpoint
3162 if (step_over_bkpt
!= null_ptid
3163 && event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3164 && (event_child
->stepping
3165 || !single_step_breakpoint_inserted_here (event_child
->stop_pc
)))
3167 int increment_pc
= 0;
3168 int breakpoint_kind
= 0;
3169 CORE_ADDR stop_pc
= event_child
->stop_pc
;
3171 breakpoint_kind
= breakpoint_kind_from_current_state (&stop_pc
);
3172 sw_breakpoint_from_kind (breakpoint_kind
, &increment_pc
);
3176 debug_printf ("step-over for %s executed software breakpoint\n",
3177 target_pid_to_str (ptid_of (current_thread
)));
3180 if (increment_pc
!= 0)
3182 struct regcache
*regcache
3183 = get_thread_regcache (current_thread
, 1);
3185 event_child
->stop_pc
+= increment_pc
;
3186 low_set_pc (regcache
, event_child
->stop_pc
);
3188 if (!(*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))
3189 event_child
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3193 /* If this event was not handled before, and is not a SIGTRAP, we
3194 report it. SIGILL and SIGSEGV are also treated as traps in case
3195 a breakpoint is inserted at the current PC. If this target does
3196 not support internal breakpoints at all, we also report the
3197 SIGTRAP without further processing; it's of no concern to us. */
3199 = (low_supports_breakpoints ()
3200 && (WSTOPSIG (w
) == SIGTRAP
3201 || ((WSTOPSIG (w
) == SIGILL
3202 || WSTOPSIG (w
) == SIGSEGV
)
3203 && (*the_low_target
.breakpoint_at
) (event_child
->stop_pc
))));
3205 if (maybe_internal_trap
)
3207 /* Handle anything that requires bookkeeping before deciding to
3208 report the event or continue waiting. */
3210 /* First check if we can explain the SIGTRAP with an internal
3211 breakpoint, or if we should possibly report the event to GDB.
3212 Do this before anything that may remove or insert a
3214 bp_explains_trap
= breakpoint_inserted_here (event_child
->stop_pc
);
3216 /* We have a SIGTRAP, possibly a step-over dance has just
3217 finished. If so, tweak the state machine accordingly,
3218 reinsert breakpoints and delete any single-step
3220 step_over_finished
= finish_step_over (event_child
);
3222 /* Now invoke the callbacks of any internal breakpoints there. */
3223 check_breakpoints (event_child
->stop_pc
);
3225 /* Handle tracepoint data collecting. This may overflow the
3226 trace buffer, and cause a tracing stop, removing
3228 trace_event
= handle_tracepoints (event_child
);
3230 if (bp_explains_trap
)
3233 debug_printf ("Hit a gdbserver breakpoint.\n");
3238 /* We have some other signal, possibly a step-over dance was in
3239 progress, and it should be cancelled too. */
3240 step_over_finished
= finish_step_over (event_child
);
3243 /* We have all the data we need. Either report the event to GDB, or
3244 resume threads and keep waiting for more. */
3246 /* If we're collecting a fast tracepoint, finish the collection and
3247 move out of the jump pad before delivering a signal. See
3248 linux_stabilize_threads. */
3251 && WSTOPSIG (w
) != SIGTRAP
3252 && supports_fast_tracepoints ()
3253 && agent_loaded_p ())
3256 debug_printf ("Got signal %d for LWP %ld. Check if we need "
3257 "to defer or adjust it.\n",
3258 WSTOPSIG (w
), lwpid_of (current_thread
));
3260 /* Allow debugging the jump pad itself. */
3261 if (current_thread
->last_resume_kind
!= resume_step
3262 && maybe_move_out_of_jump_pad (event_child
, &w
))
3264 enqueue_one_deferred_signal (event_child
, &w
);
3267 debug_printf ("Signal %d for LWP %ld deferred (in jump pad)\n",
3268 WSTOPSIG (w
), lwpid_of (current_thread
));
3270 resume_one_lwp (event_child
, 0, 0, NULL
);
3274 return ignore_event (ourstatus
);
3278 if (event_child
->collecting_fast_tracepoint
3279 != fast_tpoint_collect_result::not_collecting
)
3282 debug_printf ("LWP %ld was trying to move out of the jump pad (%d). "
3283 "Check if we're already there.\n",
3284 lwpid_of (current_thread
),
3285 (int) event_child
->collecting_fast_tracepoint
);
3289 event_child
->collecting_fast_tracepoint
3290 = linux_fast_tracepoint_collecting (event_child
, NULL
);
3292 if (event_child
->collecting_fast_tracepoint
3293 != fast_tpoint_collect_result::before_insn
)
3295 /* No longer need this breakpoint. */
3296 if (event_child
->exit_jump_pad_bkpt
!= NULL
)
3299 debug_printf ("No longer need exit-jump-pad bkpt; removing it."
3300 "stopping all threads momentarily.\n");
3302 /* Other running threads could hit this breakpoint.
3303 We don't handle moribund locations like GDB does,
3304 instead we always pause all threads when removing
3305 breakpoints, so that any step-over or
3306 decr_pc_after_break adjustment is always taken
3307 care of while the breakpoint is still
3309 stop_all_lwps (1, event_child
);
3311 delete_breakpoint (event_child
->exit_jump_pad_bkpt
);
3312 event_child
->exit_jump_pad_bkpt
= NULL
;
3314 unstop_all_lwps (1, event_child
);
3316 gdb_assert (event_child
->suspended
>= 0);
3320 if (event_child
->collecting_fast_tracepoint
3321 == fast_tpoint_collect_result::not_collecting
)
3324 debug_printf ("fast tracepoint finished "
3325 "collecting successfully.\n");
3327 /* We may have a deferred signal to report. */
3328 if (dequeue_one_deferred_signal (event_child
, &w
))
3331 debug_printf ("dequeued one signal.\n");
3336 debug_printf ("no deferred signals.\n");
3338 if (stabilizing_threads
)
3340 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3341 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3345 debug_printf ("wait_1 ret = %s, stopped "
3346 "while stabilizing threads\n",
3347 target_pid_to_str (ptid_of (current_thread
)));
3351 return ptid_of (current_thread
);
3357 /* Check whether GDB would be interested in this event. */
3359 /* Check if GDB is interested in this syscall. */
3361 && WSTOPSIG (w
) == SYSCALL_SIGTRAP
3362 && !gdb_catch_this_syscall_p (event_child
))
3366 debug_printf ("Ignored syscall for LWP %ld.\n",
3367 lwpid_of (current_thread
));
3370 resume_one_lwp (event_child
, event_child
->stepping
, 0, NULL
);
3374 return ignore_event (ourstatus
);
3377 /* If GDB is not interested in this signal, don't stop other
3378 threads, and don't report it to GDB. Just resume the inferior
3379 right away. We do this for threading-related signals as well as
3380 any that GDB specifically requested we ignore. But never ignore
3381 SIGSTOP if we sent it ourselves, and do not ignore signals when
3382 stepping - they may require special handling to skip the signal
3383 handler. Also never ignore signals that could be caused by a
3386 && current_thread
->last_resume_kind
!= resume_step
3388 #if defined (USE_THREAD_DB) && !defined (__ANDROID__)
3389 (current_process ()->priv
->thread_db
!= NULL
3390 && (WSTOPSIG (w
) == __SIGRTMIN
3391 || WSTOPSIG (w
) == __SIGRTMIN
+ 1))
3394 (cs
.pass_signals
[gdb_signal_from_host (WSTOPSIG (w
))]
3395 && !(WSTOPSIG (w
) == SIGSTOP
3396 && current_thread
->last_resume_kind
== resume_stop
)
3397 && !linux_wstatus_maybe_breakpoint (w
))))
3399 siginfo_t info
, *info_p
;
3402 debug_printf ("Ignored signal %d for LWP %ld.\n",
3403 WSTOPSIG (w
), lwpid_of (current_thread
));
3405 if (ptrace (PTRACE_GETSIGINFO
, lwpid_of (current_thread
),
3406 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
3411 if (step_over_finished
)
3413 /* We cancelled this thread's step-over above. We still
3414 need to unsuspend all other LWPs, and set them back
3415 running again while the signal handler runs. */
3416 unsuspend_all_lwps (event_child
);
3418 /* Enqueue the pending signal info so that proceed_all_lwps
3420 enqueue_pending_signal (event_child
, WSTOPSIG (w
), info_p
);
3422 proceed_all_lwps ();
3426 resume_one_lwp (event_child
, event_child
->stepping
,
3427 WSTOPSIG (w
), info_p
);
3433 return ignore_event (ourstatus
);
3436 /* Note that all addresses are always "out of the step range" when
3437 there's no range to begin with. */
3438 in_step_range
= lwp_in_step_range (event_child
);
3440 /* If GDB wanted this thread to single step, and the thread is out
3441 of the step range, we always want to report the SIGTRAP, and let
3442 GDB handle it. Watchpoints should always be reported. So should
3443 signals we can't explain. A SIGTRAP we can't explain could be a
3444 GDB breakpoint --- we may or not support Z0 breakpoints. If we
3445 do, we're be able to handle GDB breakpoints on top of internal
3446 breakpoints, by handling the internal breakpoint and still
3447 reporting the event to GDB. If we don't, we're out of luck, GDB
3448 won't see the breakpoint hit. If we see a single-step event but
3449 the thread should be continuing, don't pass the trap to gdb.
3450 That indicates that we had previously finished a single-step but
3451 left the single-step pending -- see
3452 complete_ongoing_step_over. */
3453 report_to_gdb
= (!maybe_internal_trap
3454 || (current_thread
->last_resume_kind
== resume_step
3456 || event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3458 && !bp_explains_trap
3460 && !step_over_finished
3461 && !(current_thread
->last_resume_kind
== resume_continue
3462 && event_child
->stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
))
3463 || (gdb_breakpoint_here (event_child
->stop_pc
)
3464 && gdb_condition_true_at_breakpoint (event_child
->stop_pc
)
3465 && gdb_no_commands_at_breakpoint (event_child
->stop_pc
))
3466 || event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
);
3468 run_breakpoint_commands (event_child
->stop_pc
);
3470 /* We found no reason GDB would want us to stop. We either hit one
3471 of our own breakpoints, or finished an internal step GDB
3472 shouldn't know about. */
3477 if (bp_explains_trap
)
3478 debug_printf ("Hit a gdbserver breakpoint.\n");
3479 if (step_over_finished
)
3480 debug_printf ("Step-over finished.\n");
3482 debug_printf ("Tracepoint event.\n");
3483 if (lwp_in_step_range (event_child
))
3484 debug_printf ("Range stepping pc 0x%s [0x%s, 0x%s).\n",
3485 paddress (event_child
->stop_pc
),
3486 paddress (event_child
->step_range_start
),
3487 paddress (event_child
->step_range_end
));
3490 /* We're not reporting this breakpoint to GDB, so apply the
3491 decr_pc_after_break adjustment to the inferior's regcache
3494 if (low_supports_breakpoints ())
3496 struct regcache
*regcache
3497 = get_thread_regcache (current_thread
, 1);
3498 low_set_pc (regcache
, event_child
->stop_pc
);
3501 if (step_over_finished
)
3503 /* If we have finished stepping over a breakpoint, we've
3504 stopped and suspended all LWPs momentarily except the
3505 stepping one. This is where we resume them all again.
3506 We're going to keep waiting, so use proceed, which
3507 handles stepping over the next breakpoint. */
3508 unsuspend_all_lwps (event_child
);
3512 /* Remove the single-step breakpoints if any. Note that
3513 there isn't single-step breakpoint if we finished stepping
3515 if (supports_software_single_step ()
3516 && has_single_step_breakpoints (current_thread
))
3518 stop_all_lwps (0, event_child
);
3519 delete_single_step_breakpoints (current_thread
);
3520 unstop_all_lwps (0, event_child
);
3525 debug_printf ("proceeding all threads.\n");
3526 proceed_all_lwps ();
3531 return ignore_event (ourstatus
);
3536 if (event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3539 = target_waitstatus_to_string (&event_child
->waitstatus
);
3541 debug_printf ("LWP %ld: extended event with waitstatus %s\n",
3542 lwpid_of (get_lwp_thread (event_child
)), str
.c_str ());
3544 if (current_thread
->last_resume_kind
== resume_step
)
3546 if (event_child
->step_range_start
== event_child
->step_range_end
)
3547 debug_printf ("GDB wanted to single-step, reporting event.\n");
3548 else if (!lwp_in_step_range (event_child
))
3549 debug_printf ("Out of step range, reporting event.\n");
3551 if (event_child
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
3552 debug_printf ("Stopped by watchpoint.\n");
3553 else if (gdb_breakpoint_here (event_child
->stop_pc
))
3554 debug_printf ("Stopped by GDB breakpoint.\n");
3556 debug_printf ("Hit a non-gdbserver trap event.\n");
3559 /* Alright, we're going to report a stop. */
3561 /* Remove single-step breakpoints. */
3562 if (supports_software_single_step ())
3564 /* Remove single-step breakpoints or not. It it is true, stop all
3565 lwps, so that other threads won't hit the breakpoint in the
3567 int remove_single_step_breakpoints_p
= 0;
3571 remove_single_step_breakpoints_p
3572 = has_single_step_breakpoints (current_thread
);
3576 /* In all-stop, a stop reply cancels all previous resume
3577 requests. Delete all single-step breakpoints. */
3579 find_thread ([&] (thread_info
*thread
) {
3580 if (has_single_step_breakpoints (thread
))
3582 remove_single_step_breakpoints_p
= 1;
3590 if (remove_single_step_breakpoints_p
)
3592 /* If we remove single-step breakpoints from memory, stop all lwps,
3593 so that other threads won't hit the breakpoint in the staled
3595 stop_all_lwps (0, event_child
);
3599 gdb_assert (has_single_step_breakpoints (current_thread
));
3600 delete_single_step_breakpoints (current_thread
);
3604 for_each_thread ([] (thread_info
*thread
){
3605 if (has_single_step_breakpoints (thread
))
3606 delete_single_step_breakpoints (thread
);
3610 unstop_all_lwps (0, event_child
);
3614 if (!stabilizing_threads
)
3616 /* In all-stop, stop all threads. */
3618 stop_all_lwps (0, NULL
);
3620 if (step_over_finished
)
3624 /* If we were doing a step-over, all other threads but
3625 the stepping one had been paused in start_step_over,
3626 with their suspend counts incremented. We don't want
3627 to do a full unstop/unpause, because we're in
3628 all-stop mode (so we want threads stopped), but we
3629 still need to unsuspend the other threads, to
3630 decrement their `suspended' count back. */
3631 unsuspend_all_lwps (event_child
);
3635 /* If we just finished a step-over, then all threads had
3636 been momentarily paused. In all-stop, that's fine,
3637 we want threads stopped by now anyway. In non-stop,
3638 we need to re-resume threads that GDB wanted to be
3640 unstop_all_lwps (1, event_child
);
3644 /* If we're not waiting for a specific LWP, choose an event LWP
3645 from among those that have had events. Giving equal priority
3646 to all LWPs that have had events helps prevent
3648 if (ptid
== minus_one_ptid
)
3650 event_child
->status_pending_p
= 1;
3651 event_child
->status_pending
= w
;
3653 select_event_lwp (&event_child
);
3655 /* current_thread and event_child must stay in sync. */
3656 current_thread
= get_lwp_thread (event_child
);
3658 event_child
->status_pending_p
= 0;
3659 w
= event_child
->status_pending
;
3663 /* Stabilize threads (move out of jump pads). */
3665 target_stabilize_threads ();
3669 /* If we just finished a step-over, then all threads had been
3670 momentarily paused. In all-stop, that's fine, we want
3671 threads stopped by now anyway. In non-stop, we need to
3672 re-resume threads that GDB wanted to be running. */
3673 if (step_over_finished
)
3674 unstop_all_lwps (1, event_child
);
3677 if (event_child
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3679 /* If the reported event is an exit, fork, vfork or exec, let
3682 /* Break the unreported fork relationship chain. */
3683 if (event_child
->waitstatus
.kind
== TARGET_WAITKIND_FORKED
3684 || event_child
->waitstatus
.kind
== TARGET_WAITKIND_VFORKED
)
3686 event_child
->fork_relative
->fork_relative
= NULL
;
3687 event_child
->fork_relative
= NULL
;
3690 *ourstatus
= event_child
->waitstatus
;
3691 /* Clear the event lwp's waitstatus since we handled it already. */
3692 event_child
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3695 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
3697 /* Now that we've selected our final event LWP, un-adjust its PC if
3698 it was a software breakpoint, and the client doesn't know we can
3699 adjust the breakpoint ourselves. */
3700 if (event_child
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3701 && !cs
.swbreak_feature
)
3703 int decr_pc
= low_decr_pc_after_break ();
3707 struct regcache
*regcache
3708 = get_thread_regcache (current_thread
, 1);
3709 low_set_pc (regcache
, event_child
->stop_pc
+ decr_pc
);
3713 if (WSTOPSIG (w
) == SYSCALL_SIGTRAP
)
3715 get_syscall_trapinfo (event_child
,
3716 &ourstatus
->value
.syscall_number
);
3717 ourstatus
->kind
= event_child
->syscall_state
;
3719 else if (current_thread
->last_resume_kind
== resume_stop
3720 && WSTOPSIG (w
) == SIGSTOP
)
3722 /* A thread that has been requested to stop by GDB with vCont;t,
3723 and it stopped cleanly, so report as SIG0. The use of
3724 SIGSTOP is an implementation detail. */
3725 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3727 else if (current_thread
->last_resume_kind
== resume_stop
3728 && WSTOPSIG (w
) != SIGSTOP
)
3730 /* A thread that has been requested to stop by GDB with vCont;t,
3731 but, it stopped for other reasons. */
3732 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3734 else if (ourstatus
->kind
== TARGET_WAITKIND_STOPPED
)
3736 ourstatus
->value
.sig
= gdb_signal_from_host (WSTOPSIG (w
));
3739 gdb_assert (step_over_bkpt
== null_ptid
);
3743 debug_printf ("wait_1 ret = %s, %d, %d\n",
3744 target_pid_to_str (ptid_of (current_thread
)),
3745 ourstatus
->kind
, ourstatus
->value
.sig
);
3749 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3750 return filter_exit_event (event_child
, ourstatus
);
3752 return ptid_of (current_thread
);
3755 /* Get rid of any pending event in the pipe. */
3757 async_file_flush (void)
3763 ret
= read (linux_event_pipe
[0], &buf
, 1);
3764 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
3767 /* Put something in the pipe, so the event loop wakes up. */
3769 async_file_mark (void)
3773 async_file_flush ();
3776 ret
= write (linux_event_pipe
[1], "+", 1);
3777 while (ret
== 0 || (ret
== -1 && errno
== EINTR
));
3779 /* Ignore EAGAIN. If the pipe is full, the event loop will already
3780 be awakened anyway. */
3784 linux_process_target::wait (ptid_t ptid
,
3785 target_waitstatus
*ourstatus
,
3790 /* Flush the async file first. */
3791 if (target_is_async_p ())
3792 async_file_flush ();
3796 event_ptid
= wait_1 (ptid
, ourstatus
, target_options
);
3798 while ((target_options
& TARGET_WNOHANG
) == 0
3799 && event_ptid
== null_ptid
3800 && ourstatus
->kind
== TARGET_WAITKIND_IGNORE
);
3802 /* If at least one stop was reported, there may be more. A single
3803 SIGCHLD can signal more than one child stop. */
3804 if (target_is_async_p ()
3805 && (target_options
& TARGET_WNOHANG
) != 0
3806 && event_ptid
!= null_ptid
)
3812 /* Send a signal to an LWP. */
3815 kill_lwp (unsigned long lwpid
, int signo
)
3820 ret
= syscall (__NR_tkill
, lwpid
, signo
);
3821 if (errno
== ENOSYS
)
3823 /* If tkill fails, then we are not using nptl threads, a
3824 configuration we no longer support. */
3825 perror_with_name (("tkill"));
3831 linux_stop_lwp (struct lwp_info
*lwp
)
3837 send_sigstop (struct lwp_info
*lwp
)
3841 pid
= lwpid_of (get_lwp_thread (lwp
));
3843 /* If we already have a pending stop signal for this process, don't
3845 if (lwp
->stop_expected
)
3848 debug_printf ("Have pending sigstop for lwp %d\n", pid
);
3854 debug_printf ("Sending sigstop to lwp %d\n", pid
);
3856 lwp
->stop_expected
= 1;
3857 kill_lwp (pid
, SIGSTOP
);
3861 send_sigstop (thread_info
*thread
, lwp_info
*except
)
3863 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3865 /* Ignore EXCEPT. */
3875 /* Increment the suspend count of an LWP, and stop it, if not stopped
3878 suspend_and_send_sigstop (thread_info
*thread
, lwp_info
*except
)
3880 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3882 /* Ignore EXCEPT. */
3886 lwp_suspended_inc (lwp
);
3888 send_sigstop (thread
, except
);
3892 mark_lwp_dead (struct lwp_info
*lwp
, int wstat
)
3894 /* Store the exit status for later. */
3895 lwp
->status_pending_p
= 1;
3896 lwp
->status_pending
= wstat
;
3898 /* Store in waitstatus as well, as there's nothing else to process
3900 if (WIFEXITED (wstat
))
3902 lwp
->waitstatus
.kind
= TARGET_WAITKIND_EXITED
;
3903 lwp
->waitstatus
.value
.integer
= WEXITSTATUS (wstat
);
3905 else if (WIFSIGNALED (wstat
))
3907 lwp
->waitstatus
.kind
= TARGET_WAITKIND_SIGNALLED
;
3908 lwp
->waitstatus
.value
.sig
= gdb_signal_from_host (WTERMSIG (wstat
));
3911 /* Prevent trying to stop it. */
3914 /* No further stops are expected from a dead lwp. */
3915 lwp
->stop_expected
= 0;
3918 /* Return true if LWP has exited already, and has a pending exit event
3919 to report to GDB. */
3922 lwp_is_marked_dead (struct lwp_info
*lwp
)
3924 return (lwp
->status_pending_p
3925 && (WIFEXITED (lwp
->status_pending
)
3926 || WIFSIGNALED (lwp
->status_pending
)));
3930 linux_process_target::wait_for_sigstop ()
3932 struct thread_info
*saved_thread
;
3937 saved_thread
= current_thread
;
3938 if (saved_thread
!= NULL
)
3939 saved_tid
= saved_thread
->id
;
3941 saved_tid
= null_ptid
; /* avoid bogus unused warning */
3944 debug_printf ("wait_for_sigstop: pulling events\n");
3946 /* Passing NULL_PTID as filter indicates we want all events to be
3947 left pending. Eventually this returns when there are no
3948 unwaited-for children left. */
3949 ret
= wait_for_event_filtered (minus_one_ptid
, null_ptid
, &wstat
, __WALL
);
3950 gdb_assert (ret
== -1);
3952 if (saved_thread
== NULL
|| mythread_alive (saved_tid
))
3953 current_thread
= saved_thread
;
3957 debug_printf ("Previously current thread died.\n");
3959 /* We can't change the current inferior behind GDB's back,
3960 otherwise, a subsequent command may apply to the wrong
3962 current_thread
= NULL
;
3966 /* Returns true if THREAD is stopped in a jump pad, and we can't
3967 move it out, because we need to report the stop event to GDB. For
3968 example, if the user puts a breakpoint in the jump pad, it's
3969 because she wants to debug it. */
3972 stuck_in_jump_pad_callback (thread_info
*thread
)
3974 struct lwp_info
*lwp
= get_thread_lwp (thread
);
3976 if (lwp
->suspended
!= 0)
3978 internal_error (__FILE__
, __LINE__
,
3979 "LWP %ld is suspended, suspended=%d\n",
3980 lwpid_of (thread
), lwp
->suspended
);
3982 gdb_assert (lwp
->stopped
);
3984 /* Allow debugging the jump pad, gdb_collect, etc.. */
3985 return (supports_fast_tracepoints ()
3986 && agent_loaded_p ()
3987 && (gdb_breakpoint_here (lwp
->stop_pc
)
3988 || lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
3989 || thread
->last_resume_kind
== resume_step
)
3990 && (linux_fast_tracepoint_collecting (lwp
, NULL
)
3991 != fast_tpoint_collect_result::not_collecting
));
3995 linux_process_target::move_out_of_jump_pad (thread_info
*thread
)
3997 struct thread_info
*saved_thread
;
3998 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4001 if (lwp
->suspended
!= 0)
4003 internal_error (__FILE__
, __LINE__
,
4004 "LWP %ld is suspended, suspended=%d\n",
4005 lwpid_of (thread
), lwp
->suspended
);
4007 gdb_assert (lwp
->stopped
);
4009 /* For gdb_breakpoint_here. */
4010 saved_thread
= current_thread
;
4011 current_thread
= thread
;
4013 wstat
= lwp
->status_pending_p
? &lwp
->status_pending
: NULL
;
4015 /* Allow debugging the jump pad, gdb_collect, etc. */
4016 if (!gdb_breakpoint_here (lwp
->stop_pc
)
4017 && lwp
->stop_reason
!= TARGET_STOPPED_BY_WATCHPOINT
4018 && thread
->last_resume_kind
!= resume_step
4019 && maybe_move_out_of_jump_pad (lwp
, wstat
))
4022 debug_printf ("LWP %ld needs stabilizing (in jump pad)\n",
4027 lwp
->status_pending_p
= 0;
4028 enqueue_one_deferred_signal (lwp
, wstat
);
4031 debug_printf ("Signal %d for LWP %ld deferred "
4033 WSTOPSIG (*wstat
), lwpid_of (thread
));
4036 resume_one_lwp (lwp
, 0, 0, NULL
);
4039 lwp_suspended_inc (lwp
);
4041 current_thread
= saved_thread
;
4045 lwp_running (thread_info
*thread
)
4047 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4049 if (lwp_is_marked_dead (lwp
))
4052 return !lwp
->stopped
;
4056 linux_process_target::stop_all_lwps (int suspend
, lwp_info
*except
)
4058 /* Should not be called recursively. */
4059 gdb_assert (stopping_threads
== NOT_STOPPING_THREADS
);
4064 debug_printf ("stop_all_lwps (%s, except=%s)\n",
4065 suspend
? "stop-and-suspend" : "stop",
4067 ? target_pid_to_str (ptid_of (get_lwp_thread (except
)))
4071 stopping_threads
= (suspend
4072 ? STOPPING_AND_SUSPENDING_THREADS
4073 : STOPPING_THREADS
);
4076 for_each_thread ([&] (thread_info
*thread
)
4078 suspend_and_send_sigstop (thread
, except
);
4081 for_each_thread ([&] (thread_info
*thread
)
4083 send_sigstop (thread
, except
);
4086 wait_for_sigstop ();
4087 stopping_threads
= NOT_STOPPING_THREADS
;
4091 debug_printf ("stop_all_lwps done, setting stopping_threads "
4092 "back to !stopping\n");
4097 /* Enqueue one signal in the chain of signals which need to be
4098 delivered to this process on next resume. */
4101 enqueue_pending_signal (struct lwp_info
*lwp
, int signal
, siginfo_t
*info
)
4103 struct pending_signals
*p_sig
= XNEW (struct pending_signals
);
4105 p_sig
->prev
= lwp
->pending_signals
;
4106 p_sig
->signal
= signal
;
4108 memset (&p_sig
->info
, 0, sizeof (siginfo_t
));
4110 memcpy (&p_sig
->info
, info
, sizeof (siginfo_t
));
4111 lwp
->pending_signals
= p_sig
;
4115 linux_process_target::install_software_single_step_breakpoints (lwp_info
*lwp
)
4117 struct thread_info
*thread
= get_lwp_thread (lwp
);
4118 struct regcache
*regcache
= get_thread_regcache (thread
, 1);
4120 scoped_restore save_current_thread
= make_scoped_restore (¤t_thread
);
4122 current_thread
= thread
;
4123 std::vector
<CORE_ADDR
> next_pcs
= low_get_next_pcs (regcache
);
4125 for (CORE_ADDR pc
: next_pcs
)
4126 set_single_step_breakpoint (pc
, current_ptid
);
4130 linux_process_target::single_step (lwp_info
* lwp
)
4134 if (can_hardware_single_step ())
4138 else if (supports_software_single_step ())
4140 install_software_single_step_breakpoints (lwp
);
4146 debug_printf ("stepping is not implemented on this target");
4152 /* The signal can be delivered to the inferior if we are not trying to
4153 finish a fast tracepoint collect. Since signal can be delivered in
4154 the step-over, the program may go to signal handler and trap again
4155 after return from the signal handler. We can live with the spurious
4159 lwp_signal_can_be_delivered (struct lwp_info
*lwp
)
4161 return (lwp
->collecting_fast_tracepoint
4162 == fast_tpoint_collect_result::not_collecting
);
4166 linux_process_target::resume_one_lwp_throw (lwp_info
*lwp
, int step
,
4167 int signal
, siginfo_t
*info
)
4169 struct thread_info
*thread
= get_lwp_thread (lwp
);
4170 struct thread_info
*saved_thread
;
4172 struct process_info
*proc
= get_thread_process (thread
);
4174 /* Note that target description may not be initialised
4175 (proc->tdesc == NULL) at this point because the program hasn't
4176 stopped at the first instruction yet. It means GDBserver skips
4177 the extra traps from the wrapper program (see option --wrapper).
4178 Code in this function that requires register access should be
4179 guarded by proc->tdesc == NULL or something else. */
4181 if (lwp
->stopped
== 0)
4184 gdb_assert (lwp
->waitstatus
.kind
== TARGET_WAITKIND_IGNORE
);
4186 fast_tpoint_collect_result fast_tp_collecting
4187 = lwp
->collecting_fast_tracepoint
;
4189 gdb_assert (!stabilizing_threads
4190 || (fast_tp_collecting
4191 != fast_tpoint_collect_result::not_collecting
));
4193 /* Cancel actions that rely on GDB not changing the PC (e.g., the
4194 user used the "jump" command, or "set $pc = foo"). */
4195 if (thread
->while_stepping
!= NULL
&& lwp
->stop_pc
!= get_pc (lwp
))
4197 /* Collecting 'while-stepping' actions doesn't make sense
4199 release_while_stepping_state_list (thread
);
4202 /* If we have pending signals or status, and a new signal, enqueue the
4203 signal. Also enqueue the signal if it can't be delivered to the
4204 inferior right now. */
4206 && (lwp
->status_pending_p
4207 || lwp
->pending_signals
!= NULL
4208 || !lwp_signal_can_be_delivered (lwp
)))
4210 enqueue_pending_signal (lwp
, signal
, info
);
4212 /* Postpone any pending signal. It was enqueued above. */
4216 if (lwp
->status_pending_p
)
4219 debug_printf ("Not resuming lwp %ld (%s, stop %s);"
4220 " has pending status\n",
4221 lwpid_of (thread
), step
? "step" : "continue",
4222 lwp
->stop_expected
? "expected" : "not expected");
4226 saved_thread
= current_thread
;
4227 current_thread
= thread
;
4229 /* This bit needs some thinking about. If we get a signal that
4230 we must report while a single-step reinsert is still pending,
4231 we often end up resuming the thread. It might be better to
4232 (ew) allow a stack of pending events; then we could be sure that
4233 the reinsert happened right away and not lose any signals.
4235 Making this stack would also shrink the window in which breakpoints are
4236 uninserted (see comment in linux_wait_for_lwp) but not enough for
4237 complete correctness, so it won't solve that problem. It may be
4238 worthwhile just to solve this one, however. */
4239 if (lwp
->bp_reinsert
!= 0)
4242 debug_printf (" pending reinsert at 0x%s\n",
4243 paddress (lwp
->bp_reinsert
));
4245 if (can_hardware_single_step ())
4247 if (fast_tp_collecting
== fast_tpoint_collect_result::not_collecting
)
4250 warning ("BAD - reinserting but not stepping.");
4252 warning ("BAD - reinserting and suspended(%d).",
4257 step
= maybe_hw_step (thread
);
4260 if (fast_tp_collecting
== fast_tpoint_collect_result::before_insn
)
4263 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
4264 " (exit-jump-pad-bkpt)\n",
4267 else if (fast_tp_collecting
== fast_tpoint_collect_result::at_insn
)
4270 debug_printf ("lwp %ld wants to get out of fast tracepoint jump pad"
4271 " single-stepping\n",
4274 if (can_hardware_single_step ())
4278 internal_error (__FILE__
, __LINE__
,
4279 "moving out of jump pad single-stepping"
4280 " not implemented on this target");
4284 /* If we have while-stepping actions in this thread set it stepping.
4285 If we have a signal to deliver, it may or may not be set to
4286 SIG_IGN, we don't know. Assume so, and allow collecting
4287 while-stepping into a signal handler. A possible smart thing to
4288 do would be to set an internal breakpoint at the signal return
4289 address, continue, and carry on catching this while-stepping
4290 action only when that breakpoint is hit. A future
4292 if (thread
->while_stepping
!= NULL
)
4295 debug_printf ("lwp %ld has a while-stepping action -> forcing step.\n",
4298 step
= single_step (lwp
);
4301 if (proc
->tdesc
!= NULL
&& low_supports_breakpoints ())
4303 struct regcache
*regcache
= get_thread_regcache (current_thread
, 1);
4305 lwp
->stop_pc
= low_get_pc (regcache
);
4309 debug_printf (" %s from pc 0x%lx\n", step
? "step" : "continue",
4310 (long) lwp
->stop_pc
);
4314 /* If we have pending signals, consume one if it can be delivered to
4316 if (lwp
->pending_signals
!= NULL
&& lwp_signal_can_be_delivered (lwp
))
4318 struct pending_signals
**p_sig
;
4320 p_sig
= &lwp
->pending_signals
;
4321 while ((*p_sig
)->prev
!= NULL
)
4322 p_sig
= &(*p_sig
)->prev
;
4324 signal
= (*p_sig
)->signal
;
4325 if ((*p_sig
)->info
.si_signo
!= 0)
4326 ptrace (PTRACE_SETSIGINFO
, lwpid_of (thread
), (PTRACE_TYPE_ARG3
) 0,
4334 debug_printf ("Resuming lwp %ld (%s, signal %d, stop %s)\n",
4335 lwpid_of (thread
), step
? "step" : "continue", signal
,
4336 lwp
->stop_expected
? "expected" : "not expected");
4338 if (the_low_target
.prepare_to_resume
!= NULL
)
4339 the_low_target
.prepare_to_resume (lwp
);
4341 regcache_invalidate_thread (thread
);
4343 lwp
->stepping
= step
;
4345 ptrace_request
= PTRACE_SINGLESTEP
;
4346 else if (gdb_catching_syscalls_p (lwp
))
4347 ptrace_request
= PTRACE_SYSCALL
;
4349 ptrace_request
= PTRACE_CONT
;
4350 ptrace (ptrace_request
,
4352 (PTRACE_TYPE_ARG3
) 0,
4353 /* Coerce to a uintptr_t first to avoid potential gcc warning
4354 of coercing an 8 byte integer to a 4 byte pointer. */
4355 (PTRACE_TYPE_ARG4
) (uintptr_t) signal
);
4357 current_thread
= saved_thread
;
4359 perror_with_name ("resuming thread");
4361 /* Successfully resumed. Clear state that no longer makes sense,
4362 and mark the LWP as running. Must not do this before resuming
4363 otherwise if that fails other code will be confused. E.g., we'd
4364 later try to stop the LWP and hang forever waiting for a stop
4365 status. Note that we must not throw after this is cleared,
4366 otherwise handle_zombie_lwp_error would get confused. */
4368 lwp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4371 /* Called when we try to resume a stopped LWP and that errors out. If
4372 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
4373 or about to become), discard the error, clear any pending status
4374 the LWP may have, and return true (we'll collect the exit status
4375 soon enough). Otherwise, return false. */
4378 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
4380 struct thread_info
*thread
= get_lwp_thread (lp
);
4382 /* If we get an error after resuming the LWP successfully, we'd
4383 confuse !T state for the LWP being gone. */
4384 gdb_assert (lp
->stopped
);
4386 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
4387 because even if ptrace failed with ESRCH, the tracee may be "not
4388 yet fully dead", but already refusing ptrace requests. In that
4389 case the tracee has 'R (Running)' state for a little bit
4390 (observed in Linux 3.18). See also the note on ESRCH in the
4391 ptrace(2) man page. Instead, check whether the LWP has any state
4392 other than ptrace-stopped. */
4394 /* Don't assume anything if /proc/PID/status can't be read. */
4395 if (linux_proc_pid_is_trace_stopped_nowarn (lwpid_of (thread
)) == 0)
4397 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
4398 lp
->status_pending_p
= 0;
4405 linux_process_target::resume_one_lwp (lwp_info
*lwp
, int step
, int signal
,
4410 resume_one_lwp_throw (lwp
, step
, signal
, info
);
4412 catch (const gdb_exception_error
&ex
)
4414 if (!check_ptrace_stopped_lwp_gone (lwp
))
4419 /* This function is called once per thread via for_each_thread.
4420 We look up which resume request applies to THREAD and mark it with a
4421 pointer to the appropriate resume request.
4423 This algorithm is O(threads * resume elements), but resume elements
4424 is small (and will remain small at least until GDB supports thread
4428 linux_set_resume_request (thread_info
*thread
, thread_resume
*resume
, size_t n
)
4430 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4432 for (int ndx
= 0; ndx
< n
; ndx
++)
4434 ptid_t ptid
= resume
[ndx
].thread
;
4435 if (ptid
== minus_one_ptid
4436 || ptid
== thread
->id
4437 /* Handle both 'pPID' and 'pPID.-1' as meaning 'all threads
4439 || (ptid
.pid () == pid_of (thread
)
4441 || ptid
.lwp () == -1)))
4443 if (resume
[ndx
].kind
== resume_stop
4444 && thread
->last_resume_kind
== resume_stop
)
4447 debug_printf ("already %s LWP %ld at GDB's request\n",
4448 (thread
->last_status
.kind
4449 == TARGET_WAITKIND_STOPPED
)
4457 /* Ignore (wildcard) resume requests for already-resumed
4459 if (resume
[ndx
].kind
!= resume_stop
4460 && thread
->last_resume_kind
!= resume_stop
)
4463 debug_printf ("already %s LWP %ld at GDB's request\n",
4464 (thread
->last_resume_kind
4472 /* Don't let wildcard resumes resume fork children that GDB
4473 does not yet know are new fork children. */
4474 if (lwp
->fork_relative
!= NULL
)
4476 struct lwp_info
*rel
= lwp
->fork_relative
;
4478 if (rel
->status_pending_p
4479 && (rel
->waitstatus
.kind
== TARGET_WAITKIND_FORKED
4480 || rel
->waitstatus
.kind
== TARGET_WAITKIND_VFORKED
))
4483 debug_printf ("not resuming LWP %ld: has queued stop reply\n",
4489 /* If the thread has a pending event that has already been
4490 reported to GDBserver core, but GDB has not pulled the
4491 event out of the vStopped queue yet, likewise, ignore the
4492 (wildcard) resume request. */
4493 if (in_queued_stop_replies (thread
->id
))
4496 debug_printf ("not resuming LWP %ld: has queued stop reply\n",
4501 lwp
->resume
= &resume
[ndx
];
4502 thread
->last_resume_kind
= lwp
->resume
->kind
;
4504 lwp
->step_range_start
= lwp
->resume
->step_range_start
;
4505 lwp
->step_range_end
= lwp
->resume
->step_range_end
;
4507 /* If we had a deferred signal to report, dequeue one now.
4508 This can happen if LWP gets more than one signal while
4509 trying to get out of a jump pad. */
4511 && !lwp
->status_pending_p
4512 && dequeue_one_deferred_signal (lwp
, &lwp
->status_pending
))
4514 lwp
->status_pending_p
= 1;
4517 debug_printf ("Dequeueing deferred signal %d for LWP %ld, "
4518 "leaving status pending.\n",
4519 WSTOPSIG (lwp
->status_pending
),
4527 /* No resume action for this thread. */
4532 linux_process_target::resume_status_pending (thread_info
*thread
)
4534 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4536 /* LWPs which will not be resumed are not interesting, because
4537 we might not wait for them next time through linux_wait. */
4538 if (lwp
->resume
== NULL
)
4541 return thread_still_has_status_pending (thread
);
4545 linux_process_target::thread_needs_step_over (thread_info
*thread
)
4547 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4548 struct thread_info
*saved_thread
;
4550 struct process_info
*proc
= get_thread_process (thread
);
4552 /* GDBserver is skipping the extra traps from the wrapper program,
4553 don't have to do step over. */
4554 if (proc
->tdesc
== NULL
)
4557 /* LWPs which will not be resumed are not interesting, because we
4558 might not wait for them next time through linux_wait. */
4563 debug_printf ("Need step over [LWP %ld]? Ignoring, not stopped\n",
4568 if (thread
->last_resume_kind
== resume_stop
)
4571 debug_printf ("Need step over [LWP %ld]? Ignoring, should remain"
4577 gdb_assert (lwp
->suspended
>= 0);
4582 debug_printf ("Need step over [LWP %ld]? Ignoring, suspended\n",
4587 if (lwp
->status_pending_p
)
4590 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4596 /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
4600 /* If the PC has changed since we stopped, then don't do anything,
4601 and let the breakpoint/tracepoint be hit. This happens if, for
4602 instance, GDB handled the decr_pc_after_break subtraction itself,
4603 GDB is OOL stepping this thread, or the user has issued a "jump"
4604 command, or poked thread's registers herself. */
4605 if (pc
!= lwp
->stop_pc
)
4608 debug_printf ("Need step over [LWP %ld]? Cancelling, PC was changed. "
4609 "Old stop_pc was 0x%s, PC is now 0x%s\n",
4611 paddress (lwp
->stop_pc
), paddress (pc
));
4615 /* On software single step target, resume the inferior with signal
4616 rather than stepping over. */
4617 if (supports_software_single_step ()
4618 && lwp
->pending_signals
!= NULL
4619 && lwp_signal_can_be_delivered (lwp
))
4622 debug_printf ("Need step over [LWP %ld]? Ignoring, has pending"
4629 saved_thread
= current_thread
;
4630 current_thread
= thread
;
4632 /* We can only step over breakpoints we know about. */
4633 if (breakpoint_here (pc
) || fast_tracepoint_jump_here (pc
))
4635 /* Don't step over a breakpoint that GDB expects to hit
4636 though. If the condition is being evaluated on the target's side
4637 and it evaluate to false, step over this breakpoint as well. */
4638 if (gdb_breakpoint_here (pc
)
4639 && gdb_condition_true_at_breakpoint (pc
)
4640 && gdb_no_commands_at_breakpoint (pc
))
4643 debug_printf ("Need step over [LWP %ld]? yes, but found"
4644 " GDB breakpoint at 0x%s; skipping step over\n",
4645 lwpid_of (thread
), paddress (pc
));
4647 current_thread
= saved_thread
;
4653 debug_printf ("Need step over [LWP %ld]? yes, "
4654 "found breakpoint at 0x%s\n",
4655 lwpid_of (thread
), paddress (pc
));
4657 /* We've found an lwp that needs stepping over --- return 1 so
4658 that find_thread stops looking. */
4659 current_thread
= saved_thread
;
4665 current_thread
= saved_thread
;
4668 debug_printf ("Need step over [LWP %ld]? No, no breakpoint found"
4670 lwpid_of (thread
), paddress (pc
));
4676 linux_process_target::start_step_over (lwp_info
*lwp
)
4678 struct thread_info
*thread
= get_lwp_thread (lwp
);
4679 struct thread_info
*saved_thread
;
4684 debug_printf ("Starting step-over on LWP %ld. Stopping all threads\n",
4687 stop_all_lwps (1, lwp
);
4689 if (lwp
->suspended
!= 0)
4691 internal_error (__FILE__
, __LINE__
,
4692 "LWP %ld suspended=%d\n", lwpid_of (thread
),
4697 debug_printf ("Done stopping all threads for step-over.\n");
4699 /* Note, we should always reach here with an already adjusted PC,
4700 either by GDB (if we're resuming due to GDB's request), or by our
4701 caller, if we just finished handling an internal breakpoint GDB
4702 shouldn't care about. */
4705 saved_thread
= current_thread
;
4706 current_thread
= thread
;
4708 lwp
->bp_reinsert
= pc
;
4709 uninsert_breakpoints_at (pc
);
4710 uninsert_fast_tracepoint_jumps_at (pc
);
4712 step
= single_step (lwp
);
4714 current_thread
= saved_thread
;
4716 resume_one_lwp (lwp
, step
, 0, NULL
);
4718 /* Require next event from this LWP. */
4719 step_over_bkpt
= thread
->id
;
4722 /* Finish a step-over. Reinsert the breakpoint we had uninserted in
4723 start_step_over, if still there, and delete any single-step
4724 breakpoints we've set, on non hardware single-step targets. */
4727 finish_step_over (struct lwp_info
*lwp
)
4729 if (lwp
->bp_reinsert
!= 0)
4731 struct thread_info
*saved_thread
= current_thread
;
4734 debug_printf ("Finished step over.\n");
4736 current_thread
= get_lwp_thread (lwp
);
4738 /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
4739 may be no breakpoint to reinsert there by now. */
4740 reinsert_breakpoints_at (lwp
->bp_reinsert
);
4741 reinsert_fast_tracepoint_jumps_at (lwp
->bp_reinsert
);
4743 lwp
->bp_reinsert
= 0;
4745 /* Delete any single-step breakpoints. No longer needed. We
4746 don't have to worry about other threads hitting this trap,
4747 and later not being able to explain it, because we were
4748 stepping over a breakpoint, and we hold all threads but
4749 LWP stopped while doing that. */
4750 if (!can_hardware_single_step ())
4752 gdb_assert (has_single_step_breakpoints (current_thread
));
4753 delete_single_step_breakpoints (current_thread
);
4756 step_over_bkpt
= null_ptid
;
4757 current_thread
= saved_thread
;
4765 linux_process_target::complete_ongoing_step_over ()
4767 if (step_over_bkpt
!= null_ptid
)
4769 struct lwp_info
*lwp
;
4774 debug_printf ("detach: step over in progress, finish it first\n");
4776 /* Passing NULL_PTID as filter indicates we want all events to
4777 be left pending. Eventually this returns when there are no
4778 unwaited-for children left. */
4779 ret
= wait_for_event_filtered (minus_one_ptid
, null_ptid
, &wstat
,
4781 gdb_assert (ret
== -1);
4783 lwp
= find_lwp_pid (step_over_bkpt
);
4785 finish_step_over (lwp
);
4786 step_over_bkpt
= null_ptid
;
4787 unsuspend_all_lwps (lwp
);
4792 linux_process_target::resume_one_thread (thread_info
*thread
,
4793 bool leave_all_stopped
)
4795 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4798 if (lwp
->resume
== NULL
)
4801 if (lwp
->resume
->kind
== resume_stop
)
4804 debug_printf ("resume_stop request for LWP %ld\n", lwpid_of (thread
));
4809 debug_printf ("stopping LWP %ld\n", lwpid_of (thread
));
4811 /* Stop the thread, and wait for the event asynchronously,
4812 through the event loop. */
4818 debug_printf ("already stopped LWP %ld\n",
4821 /* The LWP may have been stopped in an internal event that
4822 was not meant to be notified back to GDB (e.g., gdbserver
4823 breakpoint), so we should be reporting a stop event in
4826 /* If the thread already has a pending SIGSTOP, this is a
4827 no-op. Otherwise, something later will presumably resume
4828 the thread and this will cause it to cancel any pending
4829 operation, due to last_resume_kind == resume_stop. If
4830 the thread already has a pending status to report, we
4831 will still report it the next time we wait - see
4832 status_pending_p_callback. */
4834 /* If we already have a pending signal to report, then
4835 there's no need to queue a SIGSTOP, as this means we're
4836 midway through moving the LWP out of the jumppad, and we
4837 will report the pending signal as soon as that is
4839 if (lwp
->pending_signals_to_report
== NULL
)
4843 /* For stop requests, we're done. */
4845 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4849 /* If this thread which is about to be resumed has a pending status,
4850 then don't resume it - we can just report the pending status.
4851 Likewise if it is suspended, because e.g., another thread is
4852 stepping past a breakpoint. Make sure to queue any signals that
4853 would otherwise be sent. In all-stop mode, we do this decision
4854 based on if *any* thread has a pending status. If there's a
4855 thread that needs the step-over-breakpoint dance, then don't
4856 resume any other thread but that particular one. */
4857 leave_pending
= (lwp
->suspended
4858 || lwp
->status_pending_p
4859 || leave_all_stopped
);
4861 /* If we have a new signal, enqueue the signal. */
4862 if (lwp
->resume
->sig
!= 0)
4864 siginfo_t info
, *info_p
;
4866 /* If this is the same signal we were previously stopped by,
4867 make sure to queue its siginfo. */
4868 if (WIFSTOPPED (lwp
->last_status
)
4869 && WSTOPSIG (lwp
->last_status
) == lwp
->resume
->sig
4870 && ptrace (PTRACE_GETSIGINFO
, lwpid_of (thread
),
4871 (PTRACE_TYPE_ARG3
) 0, &info
) == 0)
4876 enqueue_pending_signal (lwp
, lwp
->resume
->sig
, info_p
);
4882 debug_printf ("resuming LWP %ld\n", lwpid_of (thread
));
4884 proceed_one_lwp (thread
, NULL
);
4889 debug_printf ("leaving LWP %ld stopped\n", lwpid_of (thread
));
4892 thread
->last_status
.kind
= TARGET_WAITKIND_IGNORE
;
4897 linux_process_target::resume (thread_resume
*resume_info
, size_t n
)
4899 struct thread_info
*need_step_over
= NULL
;
4904 debug_printf ("linux_resume:\n");
4907 for_each_thread ([&] (thread_info
*thread
)
4909 linux_set_resume_request (thread
, resume_info
, n
);
4912 /* If there is a thread which would otherwise be resumed, which has
4913 a pending status, then don't resume any threads - we can just
4914 report the pending status. Make sure to queue any signals that
4915 would otherwise be sent. In non-stop mode, we'll apply this
4916 logic to each thread individually. We consume all pending events
4917 before considering to start a step-over (in all-stop). */
4918 bool any_pending
= false;
4920 any_pending
= find_thread ([this] (thread_info
*thread
)
4922 return resume_status_pending (thread
);
4925 /* If there is a thread which would otherwise be resumed, which is
4926 stopped at a breakpoint that needs stepping over, then don't
4927 resume any threads - have it step over the breakpoint with all
4928 other threads stopped, then resume all threads again. Make sure
4929 to queue any signals that would otherwise be delivered or
4931 if (!any_pending
&& low_supports_breakpoints ())
4932 need_step_over
= find_thread ([this] (thread_info
*thread
)
4934 return thread_needs_step_over (thread
);
4937 bool leave_all_stopped
= (need_step_over
!= NULL
|| any_pending
);
4941 if (need_step_over
!= NULL
)
4942 debug_printf ("Not resuming all, need step over\n");
4943 else if (any_pending
)
4944 debug_printf ("Not resuming, all-stop and found "
4945 "an LWP with pending status\n");
4947 debug_printf ("Resuming, no pending status or step over needed\n");
4950 /* Even if we're leaving threads stopped, queue all signals we'd
4951 otherwise deliver. */
4952 for_each_thread ([&] (thread_info
*thread
)
4954 resume_one_thread (thread
, leave_all_stopped
);
4958 start_step_over (get_thread_lwp (need_step_over
));
4962 debug_printf ("linux_resume done\n");
4966 /* We may have events that were pending that can/should be sent to
4967 the client now. Trigger a linux_wait call. */
4968 if (target_is_async_p ())
4973 linux_process_target::proceed_one_lwp (thread_info
*thread
, lwp_info
*except
)
4975 struct lwp_info
*lwp
= get_thread_lwp (thread
);
4982 debug_printf ("proceed_one_lwp: lwp %ld\n", lwpid_of (thread
));
4987 debug_printf (" LWP %ld already running\n", lwpid_of (thread
));
4991 if (thread
->last_resume_kind
== resume_stop
4992 && thread
->last_status
.kind
!= TARGET_WAITKIND_IGNORE
)
4995 debug_printf (" client wants LWP to remain %ld stopped\n",
5000 if (lwp
->status_pending_p
)
5003 debug_printf (" LWP %ld has pending status, leaving stopped\n",
5008 gdb_assert (lwp
->suspended
>= 0);
5013 debug_printf (" LWP %ld is suspended\n", lwpid_of (thread
));
5017 if (thread
->last_resume_kind
== resume_stop
5018 && lwp
->pending_signals_to_report
== NULL
5019 && (lwp
->collecting_fast_tracepoint
5020 == fast_tpoint_collect_result::not_collecting
))
5022 /* We haven't reported this LWP as stopped yet (otherwise, the
5023 last_status.kind check above would catch it, and we wouldn't
5024 reach here. This LWP may have been momentarily paused by a
5025 stop_all_lwps call while handling for example, another LWP's
5026 step-over. In that case, the pending expected SIGSTOP signal
5027 that was queued at vCont;t handling time will have already
5028 been consumed by wait_for_sigstop, and so we need to requeue
5029 another one here. Note that if the LWP already has a SIGSTOP
5030 pending, this is a no-op. */
5033 debug_printf ("Client wants LWP %ld to stop. "
5034 "Making sure it has a SIGSTOP pending\n",
5040 if (thread
->last_resume_kind
== resume_step
)
5043 debug_printf (" stepping LWP %ld, client wants it stepping\n",
5046 /* If resume_step is requested by GDB, install single-step
5047 breakpoints when the thread is about to be actually resumed if
5048 the single-step breakpoints weren't removed. */
5049 if (supports_software_single_step ()
5050 && !has_single_step_breakpoints (thread
))
5051 install_software_single_step_breakpoints (lwp
);
5053 step
= maybe_hw_step (thread
);
5055 else if (lwp
->bp_reinsert
!= 0)
5058 debug_printf (" stepping LWP %ld, reinsert set\n",
5061 step
= maybe_hw_step (thread
);
5066 resume_one_lwp (lwp
, step
, 0, NULL
);
5070 linux_process_target::unsuspend_and_proceed_one_lwp (thread_info
*thread
,
5073 struct lwp_info
*lwp
= get_thread_lwp (thread
);
5078 lwp_suspended_decr (lwp
);
5080 proceed_one_lwp (thread
, except
);
5084 linux_process_target::proceed_all_lwps ()
5086 struct thread_info
*need_step_over
;
5088 /* If there is a thread which would otherwise be resumed, which is
5089 stopped at a breakpoint that needs stepping over, then don't
5090 resume any threads - have it step over the breakpoint with all
5091 other threads stopped, then resume all threads again. */
5093 if (low_supports_breakpoints ())
5095 need_step_over
= find_thread ([this] (thread_info
*thread
)
5097 return thread_needs_step_over (thread
);
5100 if (need_step_over
!= NULL
)
5103 debug_printf ("proceed_all_lwps: found "
5104 "thread %ld needing a step-over\n",
5105 lwpid_of (need_step_over
));
5107 start_step_over (get_thread_lwp (need_step_over
));
5113 debug_printf ("Proceeding, no step-over needed\n");
5115 for_each_thread ([this] (thread_info
*thread
)
5117 proceed_one_lwp (thread
, NULL
);
5122 linux_process_target::unstop_all_lwps (int unsuspend
, lwp_info
*except
)
5128 debug_printf ("unstopping all lwps, except=(LWP %ld)\n",
5129 lwpid_of (get_lwp_thread (except
)));
5131 debug_printf ("unstopping all lwps\n");
5135 for_each_thread ([&] (thread_info
*thread
)
5137 unsuspend_and_proceed_one_lwp (thread
, except
);
5140 for_each_thread ([&] (thread_info
*thread
)
5142 proceed_one_lwp (thread
, except
);
5147 debug_printf ("unstop_all_lwps done\n");
5153 #ifdef HAVE_LINUX_REGSETS
5155 #define use_linux_regsets 1
5157 /* Returns true if REGSET has been disabled. */
5160 regset_disabled (struct regsets_info
*info
, struct regset_info
*regset
)
5162 return (info
->disabled_regsets
!= NULL
5163 && info
->disabled_regsets
[regset
- info
->regsets
]);
5166 /* Disable REGSET. */
5169 disable_regset (struct regsets_info
*info
, struct regset_info
*regset
)
5173 dr_offset
= regset
- info
->regsets
;
5174 if (info
->disabled_regsets
== NULL
)
5175 info
->disabled_regsets
= (char *) xcalloc (1, info
->num_regsets
);
5176 info
->disabled_regsets
[dr_offset
] = 1;
5180 regsets_fetch_inferior_registers (struct regsets_info
*regsets_info
,
5181 struct regcache
*regcache
)
5183 struct regset_info
*regset
;
5184 int saw_general_regs
= 0;
5188 pid
= lwpid_of (current_thread
);
5189 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
5194 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
))
5197 buf
= xmalloc (regset
->size
);
5199 nt_type
= regset
->nt_type
;
5203 iov
.iov_len
= regset
->size
;
5204 data
= (void *) &iov
;
5210 res
= ptrace (regset
->get_request
, pid
,
5211 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5213 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
5218 || (errno
== EINVAL
&& regset
->type
== OPTIONAL_REGS
))
5220 /* If we get EIO on a regset, or an EINVAL and the regset is
5221 optional, do not try it again for this process mode. */
5222 disable_regset (regsets_info
, regset
);
5224 else if (errno
== ENODATA
)
5226 /* ENODATA may be returned if the regset is currently
5227 not "active". This can happen in normal operation,
5228 so suppress the warning in this case. */
5230 else if (errno
== ESRCH
)
5232 /* At this point, ESRCH should mean the process is
5233 already gone, in which case we simply ignore attempts
5234 to read its registers. */
5239 sprintf (s
, "ptrace(regsets_fetch_inferior_registers) PID=%d",
5246 if (regset
->type
== GENERAL_REGS
)
5247 saw_general_regs
= 1;
5248 regset
->store_function (regcache
, buf
);
5252 if (saw_general_regs
)
5259 regsets_store_inferior_registers (struct regsets_info
*regsets_info
,
5260 struct regcache
*regcache
)
5262 struct regset_info
*regset
;
5263 int saw_general_regs
= 0;
5267 pid
= lwpid_of (current_thread
);
5268 for (regset
= regsets_info
->regsets
; regset
->size
>= 0; regset
++)
5273 if (regset
->size
== 0 || regset_disabled (regsets_info
, regset
)
5274 || regset
->fill_function
== NULL
)
5277 buf
= xmalloc (regset
->size
);
5279 /* First fill the buffer with the current register set contents,
5280 in case there are any items in the kernel's regset that are
5281 not in gdbserver's regcache. */
5283 nt_type
= regset
->nt_type
;
5287 iov
.iov_len
= regset
->size
;
5288 data
= (void *) &iov
;
5294 res
= ptrace (regset
->get_request
, pid
,
5295 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5297 res
= ptrace (regset
->get_request
, pid
, data
, nt_type
);
5302 /* Then overlay our cached registers on that. */
5303 regset
->fill_function (regcache
, buf
);
5305 /* Only now do we write the register set. */
5307 res
= ptrace (regset
->set_request
, pid
,
5308 (PTRACE_TYPE_ARG3
) (long) nt_type
, data
);
5310 res
= ptrace (regset
->set_request
, pid
, data
, nt_type
);
5317 || (errno
== EINVAL
&& regset
->type
== OPTIONAL_REGS
))
5319 /* If we get EIO on a regset, or an EINVAL and the regset is
5320 optional, do not try it again for this process mode. */
5321 disable_regset (regsets_info
, regset
);
5323 else if (errno
== ESRCH
)
5325 /* At this point, ESRCH should mean the process is
5326 already gone, in which case we simply ignore attempts
5327 to change its registers. See also the related
5328 comment in resume_one_lwp. */
5334 perror ("Warning: ptrace(regsets_store_inferior_registers)");
5337 else if (regset
->type
== GENERAL_REGS
)
5338 saw_general_regs
= 1;
5341 if (saw_general_regs
)
5347 #else /* !HAVE_LINUX_REGSETS */
5349 #define use_linux_regsets 0
5350 #define regsets_fetch_inferior_registers(regsets_info, regcache) 1
5351 #define regsets_store_inferior_registers(regsets_info, regcache) 1
5355 /* Return 1 if register REGNO is supported by one of the regset ptrace
5356 calls or 0 if it has to be transferred individually. */
5359 linux_register_in_regsets (const struct regs_info
*regs_info
, int regno
)
5361 unsigned char mask
= 1 << (regno
% 8);
5362 size_t index
= regno
/ 8;
5364 return (use_linux_regsets
5365 && (regs_info
->regset_bitmap
== NULL
5366 || (regs_info
->regset_bitmap
[index
] & mask
) != 0));
5369 #ifdef HAVE_LINUX_USRREGS
5372 register_addr (const struct usrregs_info
*usrregs
, int regnum
)
5376 if (regnum
< 0 || regnum
>= usrregs
->num_regs
)
5377 error ("Invalid register number %d.", regnum
);
5379 addr
= usrregs
->regmap
[regnum
];
5386 linux_process_target::fetch_register (const usrregs_info
*usrregs
,
5387 regcache
*regcache
, int regno
)
5394 if (regno
>= usrregs
->num_regs
)
5396 if (low_cannot_fetch_register (regno
))
5399 regaddr
= register_addr (usrregs
, regno
);
5403 size
= ((register_size (regcache
->tdesc
, regno
)
5404 + sizeof (PTRACE_XFER_TYPE
) - 1)
5405 & -sizeof (PTRACE_XFER_TYPE
));
5406 buf
= (char *) alloca (size
);
5408 pid
= lwpid_of (current_thread
);
5409 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5412 *(PTRACE_XFER_TYPE
*) (buf
+ i
) =
5413 ptrace (PTRACE_PEEKUSER
, pid
,
5414 /* Coerce to a uintptr_t first to avoid potential gcc warning
5415 of coercing an 8 byte integer to a 4 byte pointer. */
5416 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
, (PTRACE_TYPE_ARG4
) 0);
5417 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5420 /* Mark register REGNO unavailable. */
5421 supply_register (regcache
, regno
, NULL
);
5426 if (the_low_target
.supply_ptrace_register
)
5427 the_low_target
.supply_ptrace_register (regcache
, regno
, buf
);
5429 supply_register (regcache
, regno
, buf
);
5433 linux_process_target::store_register (const usrregs_info
*usrregs
,
5434 regcache
*regcache
, int regno
)
5441 if (regno
>= usrregs
->num_regs
)
5443 if (low_cannot_store_register (regno
))
5446 regaddr
= register_addr (usrregs
, regno
);
5450 size
= ((register_size (regcache
->tdesc
, regno
)
5451 + sizeof (PTRACE_XFER_TYPE
) - 1)
5452 & -sizeof (PTRACE_XFER_TYPE
));
5453 buf
= (char *) alloca (size
);
5454 memset (buf
, 0, size
);
5456 if (the_low_target
.collect_ptrace_register
)
5457 the_low_target
.collect_ptrace_register (regcache
, regno
, buf
);
5459 collect_register (regcache
, regno
, buf
);
5461 pid
= lwpid_of (current_thread
);
5462 for (i
= 0; i
< size
; i
+= sizeof (PTRACE_XFER_TYPE
))
5465 ptrace (PTRACE_POKEUSER
, pid
,
5466 /* Coerce to a uintptr_t first to avoid potential gcc warning
5467 about coercing an 8 byte integer to a 4 byte pointer. */
5468 (PTRACE_TYPE_ARG3
) (uintptr_t) regaddr
,
5469 (PTRACE_TYPE_ARG4
) *(PTRACE_XFER_TYPE
*) (buf
+ i
));
5472 /* At this point, ESRCH should mean the process is
5473 already gone, in which case we simply ignore attempts
5474 to change its registers. See also the related
5475 comment in resume_one_lwp. */
5480 if (!low_cannot_store_register (regno
))
5481 error ("writing register %d: %s", regno
, safe_strerror (errno
));
5483 regaddr
+= sizeof (PTRACE_XFER_TYPE
);
5486 #endif /* HAVE_LINUX_USRREGS */
5489 linux_process_target::usr_fetch_inferior_registers (const regs_info
*regs_info
,
5493 #ifdef HAVE_LINUX_USRREGS
5494 struct usrregs_info
*usr
= regs_info
->usrregs
;
5498 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5499 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5500 fetch_register (usr
, regcache
, regno
);
5503 fetch_register (usr
, regcache
, regno
);
5508 linux_process_target::usr_store_inferior_registers (const regs_info
*regs_info
,
5512 #ifdef HAVE_LINUX_USRREGS
5513 struct usrregs_info
*usr
= regs_info
->usrregs
;
5517 for (regno
= 0; regno
< usr
->num_regs
; regno
++)
5518 if (all
|| !linux_register_in_regsets (regs_info
, regno
))
5519 store_register (usr
, regcache
, regno
);
5522 store_register (usr
, regcache
, regno
);
5527 linux_process_target::fetch_registers (regcache
*regcache
, int regno
)
5531 const regs_info
*regs_info
= get_regs_info ();
5535 if (regs_info
->usrregs
!= NULL
)
5536 for (regno
= 0; regno
< regs_info
->usrregs
->num_regs
; regno
++)
5537 low_fetch_register (regcache
, regno
);
5539 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
, regcache
);
5540 if (regs_info
->usrregs
!= NULL
)
5541 usr_fetch_inferior_registers (regs_info
, regcache
, -1, all
);
5545 if (low_fetch_register (regcache
, regno
))
5548 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5550 all
= regsets_fetch_inferior_registers (regs_info
->regsets_info
,
5552 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5553 usr_fetch_inferior_registers (regs_info
, regcache
, regno
, 1);
5558 linux_process_target::store_registers (regcache
*regcache
, int regno
)
5562 const regs_info
*regs_info
= get_regs_info ();
5566 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5568 if (regs_info
->usrregs
!= NULL
)
5569 usr_store_inferior_registers (regs_info
, regcache
, regno
, all
);
5573 use_regsets
= linux_register_in_regsets (regs_info
, regno
);
5575 all
= regsets_store_inferior_registers (regs_info
->regsets_info
,
5577 if ((!use_regsets
|| all
) && regs_info
->usrregs
!= NULL
)
5578 usr_store_inferior_registers (regs_info
, regcache
, regno
, 1);
5583 linux_process_target::low_fetch_register (regcache
*regcache
, int regno
)
5588 /* A wrapper for the read_memory target op. */
5591 linux_read_memory (CORE_ADDR memaddr
, unsigned char *myaddr
, int len
)
5593 return the_target
->read_memory (memaddr
, myaddr
, len
);
5596 /* Copy LEN bytes from inferior's memory starting at MEMADDR
5597 to debugger memory starting at MYADDR. */
5600 linux_process_target::read_memory (CORE_ADDR memaddr
,
5601 unsigned char *myaddr
, int len
)
5603 int pid
= lwpid_of (current_thread
);
5604 PTRACE_XFER_TYPE
*buffer
;
5612 /* Try using /proc. Don't bother for one word. */
5613 if (len
>= 3 * sizeof (long))
5617 /* We could keep this file open and cache it - possibly one per
5618 thread. That requires some juggling, but is even faster. */
5619 sprintf (filename
, "/proc/%d/mem", pid
);
5620 fd
= open (filename
, O_RDONLY
| O_LARGEFILE
);
5624 /* If pread64 is available, use it. It's faster if the kernel
5625 supports it (only one syscall), and it's 64-bit safe even on
5626 32-bit platforms (for instance, SPARC debugging a SPARC64
5629 bytes
= pread64 (fd
, myaddr
, len
, memaddr
);
5632 if (lseek (fd
, memaddr
, SEEK_SET
) != -1)
5633 bytes
= read (fd
, myaddr
, len
);
5640 /* Some data was read, we'll try to get the rest with ptrace. */
5650 /* Round starting address down to longword boundary. */
5651 addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5652 /* Round ending address up; get number of longwords that makes. */
5653 count
= ((((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5654 / sizeof (PTRACE_XFER_TYPE
));
5655 /* Allocate buffer of that many longwords. */
5656 buffer
= XALLOCAVEC (PTRACE_XFER_TYPE
, count
);
5658 /* Read all the longwords */
5660 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5662 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5663 about coercing an 8 byte integer to a 4 byte pointer. */
5664 buffer
[i
] = ptrace (PTRACE_PEEKTEXT
, pid
,
5665 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5666 (PTRACE_TYPE_ARG4
) 0);
5672 /* Copy appropriate bytes out of the buffer. */
5675 i
*= sizeof (PTRACE_XFER_TYPE
);
5676 i
-= memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1);
5678 (char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5685 /* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
5686 memory at MEMADDR. On failure (cannot write to the inferior)
5687 returns the value of errno. Always succeeds if LEN is zero. */
5690 linux_process_target::write_memory (CORE_ADDR memaddr
,
5691 const unsigned char *myaddr
, int len
)
5694 /* Round starting address down to longword boundary. */
5695 CORE_ADDR addr
= memaddr
& -(CORE_ADDR
) sizeof (PTRACE_XFER_TYPE
);
5696 /* Round ending address up; get number of longwords that makes. */
5698 = (((memaddr
+ len
) - addr
) + sizeof (PTRACE_XFER_TYPE
) - 1)
5699 / sizeof (PTRACE_XFER_TYPE
);
5701 /* Allocate buffer of that many longwords. */
5702 PTRACE_XFER_TYPE
*buffer
= XALLOCAVEC (PTRACE_XFER_TYPE
, count
);
5704 int pid
= lwpid_of (current_thread
);
5708 /* Zero length write always succeeds. */
5714 /* Dump up to four bytes. */
5715 char str
[4 * 2 + 1];
5717 int dump
= len
< 4 ? len
: 4;
5719 for (i
= 0; i
< dump
; i
++)
5721 sprintf (p
, "%02x", myaddr
[i
]);
5726 debug_printf ("Writing %s to 0x%08lx in process %d\n",
5727 str
, (long) memaddr
, pid
);
5730 /* Fill start and end extra bytes of buffer with existing memory data. */
5733 /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
5734 about coercing an 8 byte integer to a 4 byte pointer. */
5735 buffer
[0] = ptrace (PTRACE_PEEKTEXT
, pid
,
5736 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5737 (PTRACE_TYPE_ARG4
) 0);
5745 = ptrace (PTRACE_PEEKTEXT
, pid
,
5746 /* Coerce to a uintptr_t first to avoid potential gcc warning
5747 about coercing an 8 byte integer to a 4 byte pointer. */
5748 (PTRACE_TYPE_ARG3
) (uintptr_t) (addr
+ (count
- 1)
5749 * sizeof (PTRACE_XFER_TYPE
)),
5750 (PTRACE_TYPE_ARG4
) 0);
5755 /* Copy data to be written over corresponding part of buffer. */
5757 memcpy ((char *) buffer
+ (memaddr
& (sizeof (PTRACE_XFER_TYPE
) - 1)),
5760 /* Write the entire buffer. */
5762 for (i
= 0; i
< count
; i
++, addr
+= sizeof (PTRACE_XFER_TYPE
))
5765 ptrace (PTRACE_POKETEXT
, pid
,
5766 /* Coerce to a uintptr_t first to avoid potential gcc warning
5767 about coercing an 8 byte integer to a 4 byte pointer. */
5768 (PTRACE_TYPE_ARG3
) (uintptr_t) addr
,
5769 (PTRACE_TYPE_ARG4
) buffer
[i
]);
5778 linux_process_target::look_up_symbols ()
5780 #ifdef USE_THREAD_DB
5781 struct process_info
*proc
= current_process ();
5783 if (proc
->priv
->thread_db
!= NULL
)
5791 linux_process_target::request_interrupt ()
5793 /* Send a SIGINT to the process group. This acts just like the user
5794 typed a ^C on the controlling terminal. */
5795 ::kill (-signal_pid
, SIGINT
);
5799 linux_process_target::supports_read_auxv ()
5804 /* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
5805 to debugger memory starting at MYADDR. */
5808 linux_process_target::read_auxv (CORE_ADDR offset
, unsigned char *myaddr
,
5811 char filename
[PATH_MAX
];
5813 int pid
= lwpid_of (current_thread
);
5815 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
5817 fd
= open (filename
, O_RDONLY
);
5821 if (offset
!= (CORE_ADDR
) 0
5822 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
5825 n
= read (fd
, myaddr
, len
);
5832 /* These breakpoint and watchpoint related wrapper functions simply
5833 pass on the function call if the target has registered a
5834 corresponding function. */
5837 linux_process_target::supports_z_point_type (char z_type
)
5839 return (the_low_target
.supports_z_point_type
!= NULL
5840 && the_low_target
.supports_z_point_type (z_type
));
5844 linux_process_target::insert_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5845 int size
, raw_breakpoint
*bp
)
5847 if (type
== raw_bkpt_type_sw
)
5848 return insert_memory_breakpoint (bp
);
5849 else if (the_low_target
.insert_point
!= NULL
)
5850 return the_low_target
.insert_point (type
, addr
, size
, bp
);
5852 /* Unsupported (see target.h). */
5857 linux_process_target::remove_point (enum raw_bkpt_type type
, CORE_ADDR addr
,
5858 int size
, raw_breakpoint
*bp
)
5860 if (type
== raw_bkpt_type_sw
)
5861 return remove_memory_breakpoint (bp
);
5862 else if (the_low_target
.remove_point
!= NULL
)
5863 return the_low_target
.remove_point (type
, addr
, size
, bp
);
5865 /* Unsupported (see target.h). */
5869 /* Implement the stopped_by_sw_breakpoint target_ops
5873 linux_process_target::stopped_by_sw_breakpoint ()
5875 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5877 return (lwp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
);
5880 /* Implement the supports_stopped_by_sw_breakpoint target_ops
5884 linux_process_target::supports_stopped_by_sw_breakpoint ()
5886 return USE_SIGTRAP_SIGINFO
;
5889 /* Implement the stopped_by_hw_breakpoint target_ops
5893 linux_process_target::stopped_by_hw_breakpoint ()
5895 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5897 return (lwp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
);
5900 /* Implement the supports_stopped_by_hw_breakpoint target_ops
5904 linux_process_target::supports_stopped_by_hw_breakpoint ()
5906 return USE_SIGTRAP_SIGINFO
;
5909 /* Implement the supports_hardware_single_step target_ops method. */
5912 linux_process_target::supports_hardware_single_step ()
5914 return can_hardware_single_step ();
5918 linux_process_target::stopped_by_watchpoint ()
5920 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5922 return lwp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
5926 linux_process_target::stopped_data_address ()
5928 struct lwp_info
*lwp
= get_thread_lwp (current_thread
);
5930 return lwp
->stopped_data_address
;
5933 /* This is only used for targets that define PT_TEXT_ADDR,
5934 PT_DATA_ADDR and PT_TEXT_END_ADDR. If those are not defined, supposedly
5935 the target has different ways of acquiring this information, like
5939 linux_process_target::supports_read_offsets ()
5941 #ifdef SUPPORTS_READ_OFFSETS
5948 /* Under uClinux, programs are loaded at non-zero offsets, which we need
5949 to tell gdb about. */
5952 linux_process_target::read_offsets (CORE_ADDR
*text_p
, CORE_ADDR
*data_p
)
5954 #ifdef SUPPORTS_READ_OFFSETS
5955 unsigned long text
, text_end
, data
;
5956 int pid
= lwpid_of (current_thread
);
5960 text
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_ADDR
,
5961 (PTRACE_TYPE_ARG4
) 0);
5962 text_end
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_TEXT_END_ADDR
,
5963 (PTRACE_TYPE_ARG4
) 0);
5964 data
= ptrace (PTRACE_PEEKUSER
, pid
, (PTRACE_TYPE_ARG3
) PT_DATA_ADDR
,
5965 (PTRACE_TYPE_ARG4
) 0);
5969 /* Both text and data offsets produced at compile-time (and so
5970 used by gdb) are relative to the beginning of the program,
5971 with the data segment immediately following the text segment.
5972 However, the actual runtime layout in memory may put the data
5973 somewhere else, so when we send gdb a data base-address, we
5974 use the real data base address and subtract the compile-time
5975 data base-address from it (which is just the length of the
5976 text segment). BSS immediately follows data in both
5979 *data_p
= data
- (text_end
- text
);
5985 gdb_assert_not_reached ("target op read_offsets not supported");
5990 linux_process_target::supports_get_tls_address ()
5992 #ifdef USE_THREAD_DB
6000 linux_process_target::get_tls_address (thread_info
*thread
,
6002 CORE_ADDR load_module
,
6005 #ifdef USE_THREAD_DB
6006 return thread_db_get_tls_address (thread
, offset
, load_module
, address
);
6013 linux_process_target::supports_qxfer_osdata ()
6019 linux_process_target::qxfer_osdata (const char *annex
,
6020 unsigned char *readbuf
,
6021 unsigned const char *writebuf
,
6022 CORE_ADDR offset
, int len
)
6024 return linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
6027 /* Convert a native/host siginfo object, into/from the siginfo in the
6028 layout of the inferiors' architecture. */
6031 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
6035 if (the_low_target
.siginfo_fixup
!= NULL
)
6036 done
= the_low_target
.siginfo_fixup (siginfo
, inf_siginfo
, direction
);
6038 /* If there was no callback, or the callback didn't do anything,
6039 then just do a straight memcpy. */
6043 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
6045 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
6050 linux_process_target::supports_qxfer_siginfo ()
6056 linux_process_target::qxfer_siginfo (const char *annex
,
6057 unsigned char *readbuf
,
6058 unsigned const char *writebuf
,
6059 CORE_ADDR offset
, int len
)
6063 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
6065 if (current_thread
== NULL
)
6068 pid
= lwpid_of (current_thread
);
6071 debug_printf ("%s siginfo for lwp %d.\n",
6072 readbuf
!= NULL
? "Reading" : "Writing",
6075 if (offset
>= sizeof (siginfo
))
6078 if (ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
6081 /* When GDBSERVER is built as a 64-bit application, ptrace writes into
6082 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
6083 inferior with a 64-bit GDBSERVER should look the same as debugging it
6084 with a 32-bit GDBSERVER, we need to convert it. */
6085 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
6087 if (offset
+ len
> sizeof (siginfo
))
6088 len
= sizeof (siginfo
) - offset
;
6090 if (readbuf
!= NULL
)
6091 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
6094 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
6096 /* Convert back to ptrace layout before flushing it out. */
6097 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
6099 if (ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
) != 0)
6106 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
6107 so we notice when children change state; as the handler for the
6108 sigsuspend in my_waitpid. */
6111 sigchld_handler (int signo
)
6113 int old_errno
= errno
;
6119 /* Use the async signal safe debug function. */
6120 if (debug_write ("sigchld_handler\n",
6121 sizeof ("sigchld_handler\n") - 1) < 0)
6122 break; /* just ignore */
6126 if (target_is_async_p ())
6127 async_file_mark (); /* trigger a linux_wait */
6133 linux_process_target::supports_non_stop ()
6139 linux_process_target::async (bool enable
)
6141 bool previous
= target_is_async_p ();
6144 debug_printf ("linux_async (%d), previous=%d\n",
6147 if (previous
!= enable
)
6150 sigemptyset (&mask
);
6151 sigaddset (&mask
, SIGCHLD
);
6153 gdb_sigmask (SIG_BLOCK
, &mask
, NULL
);
6157 if (pipe (linux_event_pipe
) == -1)
6159 linux_event_pipe
[0] = -1;
6160 linux_event_pipe
[1] = -1;
6161 gdb_sigmask (SIG_UNBLOCK
, &mask
, NULL
);
6163 warning ("creating event pipe failed.");
6167 fcntl (linux_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
6168 fcntl (linux_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
6170 /* Register the event loop handler. */
6171 add_file_handler (linux_event_pipe
[0],
6172 handle_target_event
, NULL
);
6174 /* Always trigger a linux_wait. */
6179 delete_file_handler (linux_event_pipe
[0]);
6181 close (linux_event_pipe
[0]);
6182 close (linux_event_pipe
[1]);
6183 linux_event_pipe
[0] = -1;
6184 linux_event_pipe
[1] = -1;
6187 gdb_sigmask (SIG_UNBLOCK
, &mask
, NULL
);
6194 linux_process_target::start_non_stop (bool nonstop
)
6196 /* Register or unregister from event-loop accordingly. */
6197 target_async (nonstop
);
6199 if (target_is_async_p () != (nonstop
!= false))
6206 linux_process_target::supports_multi_process ()
6211 /* Check if fork events are supported. */
6214 linux_process_target::supports_fork_events ()
6216 return linux_supports_tracefork ();
6219 /* Check if vfork events are supported. */
6222 linux_process_target::supports_vfork_events ()
6224 return linux_supports_tracefork ();
6227 /* Check if exec events are supported. */
6230 linux_process_target::supports_exec_events ()
6232 return linux_supports_traceexec ();
6235 /* Target hook for 'handle_new_gdb_connection'. Causes a reset of the
6236 ptrace flags for all inferiors. This is in case the new GDB connection
6237 doesn't support the same set of events that the previous one did. */
6240 linux_process_target::handle_new_gdb_connection ()
6242 /* Request that all the lwps reset their ptrace options. */
6243 for_each_thread ([] (thread_info
*thread
)
6245 struct lwp_info
*lwp
= get_thread_lwp (thread
);
6249 /* Stop the lwp so we can modify its ptrace options. */
6250 lwp
->must_set_ptrace_flags
= 1;
6251 linux_stop_lwp (lwp
);
6255 /* Already stopped; go ahead and set the ptrace options. */
6256 struct process_info
*proc
= find_process_pid (pid_of (thread
));
6257 int options
= linux_low_ptrace_options (proc
->attached
);
6259 linux_enable_event_reporting (lwpid_of (thread
), options
);
6260 lwp
->must_set_ptrace_flags
= 0;
6266 linux_process_target::handle_monitor_command (char *mon
)
6268 #ifdef USE_THREAD_DB
6269 return thread_db_handle_monitor_command (mon
);
6276 linux_process_target::core_of_thread (ptid_t ptid
)
6278 return linux_common_core_of_thread (ptid
);
6282 linux_process_target::supports_disable_randomization ()
6284 #ifdef HAVE_PERSONALITY
6292 linux_process_target::supports_agent ()
6298 linux_process_target::supports_range_stepping ()
6300 if (supports_software_single_step ())
6302 if (*the_low_target
.supports_range_stepping
== NULL
)
6305 return (*the_low_target
.supports_range_stepping
) ();
6309 linux_process_target::supports_pid_to_exec_file ()
6315 linux_process_target::pid_to_exec_file (int pid
)
6317 return linux_proc_pid_to_exec_file (pid
);
6321 linux_process_target::supports_multifs ()
6327 linux_process_target::multifs_open (int pid
, const char *filename
,
6328 int flags
, mode_t mode
)
6330 return linux_mntns_open_cloexec (pid
, filename
, flags
, mode
);
6334 linux_process_target::multifs_unlink (int pid
, const char *filename
)
6336 return linux_mntns_unlink (pid
, filename
);
6340 linux_process_target::multifs_readlink (int pid
, const char *filename
,
6341 char *buf
, size_t bufsiz
)
6343 return linux_mntns_readlink (pid
, filename
, buf
, bufsiz
);
6346 #if defined PT_GETDSBT || defined PTRACE_GETFDPIC
6347 struct target_loadseg
6349 /* Core address to which the segment is mapped. */
6351 /* VMA recorded in the program header. */
6353 /* Size of this segment in memory. */
6357 # if defined PT_GETDSBT
6358 struct target_loadmap
6360 /* Protocol version number, must be zero. */
6362 /* Pointer to the DSBT table, its size, and the DSBT index. */
6363 unsigned *dsbt_table
;
6364 unsigned dsbt_size
, dsbt_index
;
6365 /* Number of segments in this map. */
6367 /* The actual memory map. */
6368 struct target_loadseg segs
[/*nsegs*/];
6370 # define LINUX_LOADMAP PT_GETDSBT
6371 # define LINUX_LOADMAP_EXEC PTRACE_GETDSBT_EXEC
6372 # define LINUX_LOADMAP_INTERP PTRACE_GETDSBT_INTERP
6374 struct target_loadmap
6376 /* Protocol version number, must be zero. */
6378 /* Number of segments in this map. */
6380 /* The actual memory map. */
6381 struct target_loadseg segs
[/*nsegs*/];
6383 # define LINUX_LOADMAP PTRACE_GETFDPIC
6384 # define LINUX_LOADMAP_EXEC PTRACE_GETFDPIC_EXEC
6385 # define LINUX_LOADMAP_INTERP PTRACE_GETFDPIC_INTERP
6389 linux_process_target::supports_read_loadmap ()
6395 linux_process_target::read_loadmap (const char *annex
, CORE_ADDR offset
,
6396 unsigned char *myaddr
, unsigned int len
)
6398 int pid
= lwpid_of (current_thread
);
6400 struct target_loadmap
*data
= NULL
;
6401 unsigned int actual_length
, copy_length
;
6403 if (strcmp (annex
, "exec") == 0)
6404 addr
= (int) LINUX_LOADMAP_EXEC
;
6405 else if (strcmp (annex
, "interp") == 0)
6406 addr
= (int) LINUX_LOADMAP_INTERP
;
6410 if (ptrace (LINUX_LOADMAP
, pid
, addr
, &data
) != 0)
6416 actual_length
= sizeof (struct target_loadmap
)
6417 + sizeof (struct target_loadseg
) * data
->nsegs
;
6419 if (offset
< 0 || offset
> actual_length
)
6422 copy_length
= actual_length
- offset
< len
? actual_length
- offset
: len
;
6423 memcpy (myaddr
, (char *) data
+ offset
, copy_length
);
6426 #endif /* defined PT_GETDSBT || defined PTRACE_GETFDPIC */
6429 linux_process_target::process_qsupported (char **features
, int count
)
6431 if (the_low_target
.process_qsupported
!= NULL
)
6432 the_low_target
.process_qsupported (features
, count
);
6436 linux_process_target::supports_catch_syscall ()
6438 return (the_low_target
.get_syscall_trapinfo
!= NULL
6439 && linux_supports_tracesysgood ());
6443 linux_process_target::get_ipa_tdesc_idx ()
6445 if (the_low_target
.get_ipa_tdesc_idx
== NULL
)
6448 return (*the_low_target
.get_ipa_tdesc_idx
) ();
6452 linux_process_target::supports_tracepoints ()
6454 if (*the_low_target
.supports_tracepoints
== NULL
)
6457 return (*the_low_target
.supports_tracepoints
) ();
6461 linux_process_target::read_pc (regcache
*regcache
)
6463 if (!low_supports_breakpoints ())
6466 return low_get_pc (regcache
);
6470 linux_process_target::write_pc (regcache
*regcache
, CORE_ADDR pc
)
6472 gdb_assert (low_supports_breakpoints ());
6474 low_set_pc (regcache
, pc
);
6478 linux_process_target::supports_thread_stopped ()
6484 linux_process_target::thread_stopped (thread_info
*thread
)
6486 return get_thread_lwp (thread
)->stopped
;
6489 /* This exposes stop-all-threads functionality to other modules. */
6492 linux_process_target::pause_all (bool freeze
)
6494 stop_all_lwps (freeze
, NULL
);
6497 /* This exposes unstop-all-threads functionality to other gdbserver
6501 linux_process_target::unpause_all (bool unfreeze
)
6503 unstop_all_lwps (unfreeze
, NULL
);
6507 linux_process_target::prepare_to_access_memory ()
6509 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
6512 target_pause_all (true);
6517 linux_process_target::done_accessing_memory ()
6519 /* Neither ptrace nor /proc/PID/mem allow accessing memory through a
6522 target_unpause_all (true);
6526 linux_process_target::supports_fast_tracepoints ()
6528 return the_low_target
.install_fast_tracepoint_jump_pad
!= nullptr;
6532 linux_process_target::install_fast_tracepoint_jump_pad
6533 (CORE_ADDR tpoint
, CORE_ADDR tpaddr
, CORE_ADDR collector
,
6534 CORE_ADDR lockaddr
, ULONGEST orig_size
, CORE_ADDR
*jump_entry
,
6535 CORE_ADDR
*trampoline
, ULONGEST
*trampoline_size
,
6536 unsigned char *jjump_pad_insn
, ULONGEST
*jjump_pad_insn_size
,
6537 CORE_ADDR
*adjusted_insn_addr
, CORE_ADDR
*adjusted_insn_addr_end
,
6540 return (*the_low_target
.install_fast_tracepoint_jump_pad
)
6541 (tpoint
, tpaddr
, collector
, lockaddr
, orig_size
,
6542 jump_entry
, trampoline
, trampoline_size
,
6543 jjump_pad_insn
, jjump_pad_insn_size
,
6544 adjusted_insn_addr
, adjusted_insn_addr_end
,
6549 linux_process_target::emit_ops ()
6551 if (the_low_target
.emit_ops
!= NULL
)
6552 return (*the_low_target
.emit_ops
) ();
6558 linux_process_target::get_min_fast_tracepoint_insn_len ()
6560 return (*the_low_target
.get_min_fast_tracepoint_insn_len
) ();
6563 /* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
6566 get_phdr_phnum_from_proc_auxv (const int pid
, const int is_elf64
,
6567 CORE_ADDR
*phdr_memaddr
, int *num_phdr
)
6569 char filename
[PATH_MAX
];
6571 const int auxv_size
= is_elf64
6572 ? sizeof (Elf64_auxv_t
) : sizeof (Elf32_auxv_t
);
6573 char buf
[sizeof (Elf64_auxv_t
)]; /* The larger of the two. */
6575 xsnprintf (filename
, sizeof filename
, "/proc/%d/auxv", pid
);
6577 fd
= open (filename
, O_RDONLY
);
6583 while (read (fd
, buf
, auxv_size
) == auxv_size
6584 && (*phdr_memaddr
== 0 || *num_phdr
== 0))
6588 Elf64_auxv_t
*const aux
= (Elf64_auxv_t
*) buf
;
6590 switch (aux
->a_type
)
6593 *phdr_memaddr
= aux
->a_un
.a_val
;
6596 *num_phdr
= aux
->a_un
.a_val
;
6602 Elf32_auxv_t
*const aux
= (Elf32_auxv_t
*) buf
;
6604 switch (aux
->a_type
)
6607 *phdr_memaddr
= aux
->a_un
.a_val
;
6610 *num_phdr
= aux
->a_un
.a_val
;
6618 if (*phdr_memaddr
== 0 || *num_phdr
== 0)
6620 warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
6621 "phdr_memaddr = %ld, phdr_num = %d",
6622 (long) *phdr_memaddr
, *num_phdr
);
6629 /* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
6632 get_dynamic (const int pid
, const int is_elf64
)
6634 CORE_ADDR phdr_memaddr
, relocation
;
6636 unsigned char *phdr_buf
;
6637 const int phdr_size
= is_elf64
? sizeof (Elf64_Phdr
) : sizeof (Elf32_Phdr
);
6639 if (get_phdr_phnum_from_proc_auxv (pid
, is_elf64
, &phdr_memaddr
, &num_phdr
))
6642 gdb_assert (num_phdr
< 100); /* Basic sanity check. */
6643 phdr_buf
= (unsigned char *) alloca (num_phdr
* phdr_size
);
6645 if (linux_read_memory (phdr_memaddr
, phdr_buf
, num_phdr
* phdr_size
))
6648 /* Compute relocation: it is expected to be 0 for "regular" executables,
6649 non-zero for PIE ones. */
6651 for (i
= 0; relocation
== -1 && i
< num_phdr
; i
++)
6654 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6656 if (p
->p_type
== PT_PHDR
)
6657 relocation
= phdr_memaddr
- p
->p_vaddr
;
6661 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6663 if (p
->p_type
== PT_PHDR
)
6664 relocation
= phdr_memaddr
- p
->p_vaddr
;
6667 if (relocation
== -1)
6669 /* PT_PHDR is optional, but necessary for PIE in general. Fortunately
6670 any real world executables, including PIE executables, have always
6671 PT_PHDR present. PT_PHDR is not present in some shared libraries or
6672 in fpc (Free Pascal 2.4) binaries but neither of those have a need for
6673 or present DT_DEBUG anyway (fpc binaries are statically linked).
6675 Therefore if there exists DT_DEBUG there is always also PT_PHDR.
6677 GDB could find RELOCATION also from AT_ENTRY - e_entry. */
6682 for (i
= 0; i
< num_phdr
; i
++)
6686 Elf64_Phdr
*const p
= (Elf64_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6688 if (p
->p_type
== PT_DYNAMIC
)
6689 return p
->p_vaddr
+ relocation
;
6693 Elf32_Phdr
*const p
= (Elf32_Phdr
*) (phdr_buf
+ i
* phdr_size
);
6695 if (p
->p_type
== PT_DYNAMIC
)
6696 return p
->p_vaddr
+ relocation
;
6703 /* Return &_r_debug in the inferior, or -1 if not present. Return value
6704 can be 0 if the inferior does not yet have the library list initialized.
6705 We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
6706 DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
6709 get_r_debug (const int pid
, const int is_elf64
)
6711 CORE_ADDR dynamic_memaddr
;
6712 const int dyn_size
= is_elf64
? sizeof (Elf64_Dyn
) : sizeof (Elf32_Dyn
);
6713 unsigned char buf
[sizeof (Elf64_Dyn
)]; /* The larger of the two. */
6716 dynamic_memaddr
= get_dynamic (pid
, is_elf64
);
6717 if (dynamic_memaddr
== 0)
6720 while (linux_read_memory (dynamic_memaddr
, buf
, dyn_size
) == 0)
6724 Elf64_Dyn
*const dyn
= (Elf64_Dyn
*) buf
;
6725 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6729 unsigned char buf
[sizeof (Elf64_Xword
)];
6733 #ifdef DT_MIPS_RLD_MAP
6734 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6736 if (linux_read_memory (dyn
->d_un
.d_val
,
6737 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6742 #endif /* DT_MIPS_RLD_MAP */
6743 #ifdef DT_MIPS_RLD_MAP_REL
6744 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6746 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6747 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6752 #endif /* DT_MIPS_RLD_MAP_REL */
6754 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6755 map
= dyn
->d_un
.d_val
;
6757 if (dyn
->d_tag
== DT_NULL
)
6762 Elf32_Dyn
*const dyn
= (Elf32_Dyn
*) buf
;
6763 #if defined DT_MIPS_RLD_MAP || defined DT_MIPS_RLD_MAP_REL
6767 unsigned char buf
[sizeof (Elf32_Word
)];
6771 #ifdef DT_MIPS_RLD_MAP
6772 if (dyn
->d_tag
== DT_MIPS_RLD_MAP
)
6774 if (linux_read_memory (dyn
->d_un
.d_val
,
6775 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6780 #endif /* DT_MIPS_RLD_MAP */
6781 #ifdef DT_MIPS_RLD_MAP_REL
6782 if (dyn
->d_tag
== DT_MIPS_RLD_MAP_REL
)
6784 if (linux_read_memory (dyn
->d_un
.d_val
+ dynamic_memaddr
,
6785 rld_map
.buf
, sizeof (rld_map
.buf
)) == 0)
6790 #endif /* DT_MIPS_RLD_MAP_REL */
6792 if (dyn
->d_tag
== DT_DEBUG
&& map
== -1)
6793 map
= dyn
->d_un
.d_val
;
6795 if (dyn
->d_tag
== DT_NULL
)
6799 dynamic_memaddr
+= dyn_size
;
6805 /* Read one pointer from MEMADDR in the inferior. */
6808 read_one_ptr (CORE_ADDR memaddr
, CORE_ADDR
*ptr
, int ptr_size
)
6812 /* Go through a union so this works on either big or little endian
6813 hosts, when the inferior's pointer size is smaller than the size
6814 of CORE_ADDR. It is assumed the inferior's endianness is the
6815 same of the superior's. */
6818 CORE_ADDR core_addr
;
6823 ret
= linux_read_memory (memaddr
, &addr
.uc
, ptr_size
);
6826 if (ptr_size
== sizeof (CORE_ADDR
))
6827 *ptr
= addr
.core_addr
;
6828 else if (ptr_size
== sizeof (unsigned int))
6831 gdb_assert_not_reached ("unhandled pointer size");
6837 linux_process_target::supports_qxfer_libraries_svr4 ()
6842 struct link_map_offsets
6844 /* Offset and size of r_debug.r_version. */
6845 int r_version_offset
;
6847 /* Offset and size of r_debug.r_map. */
6850 /* Offset to l_addr field in struct link_map. */
6853 /* Offset to l_name field in struct link_map. */
6856 /* Offset to l_ld field in struct link_map. */
6859 /* Offset to l_next field in struct link_map. */
6862 /* Offset to l_prev field in struct link_map. */
6866 /* Construct qXfer:libraries-svr4:read reply. */
6869 linux_process_target::qxfer_libraries_svr4 (const char *annex
,
6870 unsigned char *readbuf
,
6871 unsigned const char *writebuf
,
6872 CORE_ADDR offset
, int len
)
6874 struct process_info_private
*const priv
= current_process ()->priv
;
6875 char filename
[PATH_MAX
];
6878 static const struct link_map_offsets lmo_32bit_offsets
=
6880 0, /* r_version offset. */
6881 4, /* r_debug.r_map offset. */
6882 0, /* l_addr offset in link_map. */
6883 4, /* l_name offset in link_map. */
6884 8, /* l_ld offset in link_map. */
6885 12, /* l_next offset in link_map. */
6886 16 /* l_prev offset in link_map. */
6889 static const struct link_map_offsets lmo_64bit_offsets
=
6891 0, /* r_version offset. */
6892 8, /* r_debug.r_map offset. */
6893 0, /* l_addr offset in link_map. */
6894 8, /* l_name offset in link_map. */
6895 16, /* l_ld offset in link_map. */
6896 24, /* l_next offset in link_map. */
6897 32 /* l_prev offset in link_map. */
6899 const struct link_map_offsets
*lmo
;
6900 unsigned int machine
;
6902 CORE_ADDR lm_addr
= 0, lm_prev
= 0;
6903 CORE_ADDR l_name
, l_addr
, l_ld
, l_next
, l_prev
;
6904 int header_done
= 0;
6906 if (writebuf
!= NULL
)
6908 if (readbuf
== NULL
)
6911 pid
= lwpid_of (current_thread
);
6912 xsnprintf (filename
, sizeof filename
, "/proc/%d/exe", pid
);
6913 is_elf64
= elf_64_file_p (filename
, &machine
);
6914 lmo
= is_elf64
? &lmo_64bit_offsets
: &lmo_32bit_offsets
;
6915 ptr_size
= is_elf64
? 8 : 4;
6917 while (annex
[0] != '\0')
6923 sep
= strchr (annex
, '=');
6927 name_len
= sep
- annex
;
6928 if (name_len
== 5 && startswith (annex
, "start"))
6930 else if (name_len
== 4 && startswith (annex
, "prev"))
6934 annex
= strchr (sep
, ';');
6941 annex
= decode_address_to_semicolon (addrp
, sep
+ 1);
6948 if (priv
->r_debug
== 0)
6949 priv
->r_debug
= get_r_debug (pid
, is_elf64
);
6951 /* We failed to find DT_DEBUG. Such situation will not change
6952 for this inferior - do not retry it. Report it to GDB as
6953 E01, see for the reasons at the GDB solib-svr4.c side. */
6954 if (priv
->r_debug
== (CORE_ADDR
) -1)
6957 if (priv
->r_debug
!= 0)
6959 if (linux_read_memory (priv
->r_debug
+ lmo
->r_version_offset
,
6960 (unsigned char *) &r_version
,
6961 sizeof (r_version
)) != 0
6964 warning ("unexpected r_debug version %d", r_version
);
6966 else if (read_one_ptr (priv
->r_debug
+ lmo
->r_map_offset
,
6967 &lm_addr
, ptr_size
) != 0)
6969 warning ("unable to read r_map from 0x%lx",
6970 (long) priv
->r_debug
+ lmo
->r_map_offset
);
6975 std::string document
= "<library-list-svr4 version=\"1.0\"";
6978 && read_one_ptr (lm_addr
+ lmo
->l_name_offset
,
6979 &l_name
, ptr_size
) == 0
6980 && read_one_ptr (lm_addr
+ lmo
->l_addr_offset
,
6981 &l_addr
, ptr_size
) == 0
6982 && read_one_ptr (lm_addr
+ lmo
->l_ld_offset
,
6983 &l_ld
, ptr_size
) == 0
6984 && read_one_ptr (lm_addr
+ lmo
->l_prev_offset
,
6985 &l_prev
, ptr_size
) == 0
6986 && read_one_ptr (lm_addr
+ lmo
->l_next_offset
,
6987 &l_next
, ptr_size
) == 0)
6989 unsigned char libname
[PATH_MAX
];
6991 if (lm_prev
!= l_prev
)
6993 warning ("Corrupted shared library list: 0x%lx != 0x%lx",
6994 (long) lm_prev
, (long) l_prev
);
6998 /* Ignore the first entry even if it has valid name as the first entry
6999 corresponds to the main executable. The first entry should not be
7000 skipped if the dynamic loader was loaded late by a static executable
7001 (see solib-svr4.c parameter ignore_first). But in such case the main
7002 executable does not have PT_DYNAMIC present and this function already
7003 exited above due to failed get_r_debug. */
7005 string_appendf (document
, " main-lm=\"0x%lx\"", (unsigned long) lm_addr
);
7008 /* Not checking for error because reading may stop before
7009 we've got PATH_MAX worth of characters. */
7011 linux_read_memory (l_name
, libname
, sizeof (libname
) - 1);
7012 libname
[sizeof (libname
) - 1] = '\0';
7013 if (libname
[0] != '\0')
7017 /* Terminate `<library-list-svr4'. */
7022 string_appendf (document
, "<library name=\"");
7023 xml_escape_text_append (&document
, (char *) libname
);
7024 string_appendf (document
, "\" lm=\"0x%lx\" "
7025 "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
7026 (unsigned long) lm_addr
, (unsigned long) l_addr
,
7027 (unsigned long) l_ld
);
7037 /* Empty list; terminate `<library-list-svr4'. */
7041 document
+= "</library-list-svr4>";
7043 int document_len
= document
.length ();
7044 if (offset
< document_len
)
7045 document_len
-= offset
;
7048 if (len
> document_len
)
7051 memcpy (readbuf
, document
.data () + offset
, len
);
7056 #ifdef HAVE_LINUX_BTRACE
7058 btrace_target_info
*
7059 linux_process_target::enable_btrace (ptid_t ptid
,
7060 const btrace_config
*conf
)
7062 return linux_enable_btrace (ptid
, conf
);
7065 /* See to_disable_btrace target method. */
7068 linux_process_target::disable_btrace (btrace_target_info
*tinfo
)
7070 enum btrace_error err
;
7072 err
= linux_disable_btrace (tinfo
);
7073 return (err
== BTRACE_ERR_NONE
? 0 : -1);
7076 /* Encode an Intel Processor Trace configuration. */
7079 linux_low_encode_pt_config (struct buffer
*buffer
,
7080 const struct btrace_data_pt_config
*config
)
7082 buffer_grow_str (buffer
, "<pt-config>\n");
7084 switch (config
->cpu
.vendor
)
7087 buffer_xml_printf (buffer
, "<cpu vendor=\"GenuineIntel\" family=\"%u\" "
7088 "model=\"%u\" stepping=\"%u\"/>\n",
7089 config
->cpu
.family
, config
->cpu
.model
,
7090 config
->cpu
.stepping
);
7097 buffer_grow_str (buffer
, "</pt-config>\n");
7100 /* Encode a raw buffer. */
7103 linux_low_encode_raw (struct buffer
*buffer
, const gdb_byte
*data
,
7109 /* We use hex encoding - see gdbsupport/rsp-low.h. */
7110 buffer_grow_str (buffer
, "<raw>\n");
7116 elem
[0] = tohex ((*data
>> 4) & 0xf);
7117 elem
[1] = tohex (*data
++ & 0xf);
7119 buffer_grow (buffer
, elem
, 2);
7122 buffer_grow_str (buffer
, "</raw>\n");
7125 /* See to_read_btrace target method. */
7128 linux_process_target::read_btrace (btrace_target_info
*tinfo
,
7130 enum btrace_read_type type
)
7132 struct btrace_data btrace
;
7133 enum btrace_error err
;
7135 err
= linux_read_btrace (&btrace
, tinfo
, type
);
7136 if (err
!= BTRACE_ERR_NONE
)
7138 if (err
== BTRACE_ERR_OVERFLOW
)
7139 buffer_grow_str0 (buffer
, "E.Overflow.");
7141 buffer_grow_str0 (buffer
, "E.Generic Error.");
7146 switch (btrace
.format
)
7148 case BTRACE_FORMAT_NONE
:
7149 buffer_grow_str0 (buffer
, "E.No Trace.");
7152 case BTRACE_FORMAT_BTS
:
7153 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
7154 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
7156 for (const btrace_block
&block
: *btrace
.variant
.bts
.blocks
)
7157 buffer_xml_printf (buffer
, "<block begin=\"0x%s\" end=\"0x%s\"/>\n",
7158 paddress (block
.begin
), paddress (block
.end
));
7160 buffer_grow_str0 (buffer
, "</btrace>\n");
7163 case BTRACE_FORMAT_PT
:
7164 buffer_grow_str (buffer
, "<!DOCTYPE btrace SYSTEM \"btrace.dtd\">\n");
7165 buffer_grow_str (buffer
, "<btrace version=\"1.0\">\n");
7166 buffer_grow_str (buffer
, "<pt>\n");
7168 linux_low_encode_pt_config (buffer
, &btrace
.variant
.pt
.config
);
7170 linux_low_encode_raw (buffer
, btrace
.variant
.pt
.data
,
7171 btrace
.variant
.pt
.size
);
7173 buffer_grow_str (buffer
, "</pt>\n");
7174 buffer_grow_str0 (buffer
, "</btrace>\n");
7178 buffer_grow_str0 (buffer
, "E.Unsupported Trace Format.");
7185 /* See to_btrace_conf target method. */
7188 linux_process_target::read_btrace_conf (const btrace_target_info
*tinfo
,
7191 const struct btrace_config
*conf
;
7193 buffer_grow_str (buffer
, "<!DOCTYPE btrace-conf SYSTEM \"btrace-conf.dtd\">\n");
7194 buffer_grow_str (buffer
, "<btrace-conf version=\"1.0\">\n");
7196 conf
= linux_btrace_conf (tinfo
);
7199 switch (conf
->format
)
7201 case BTRACE_FORMAT_NONE
:
7204 case BTRACE_FORMAT_BTS
:
7205 buffer_xml_printf (buffer
, "<bts");
7206 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->bts
.size
);
7207 buffer_xml_printf (buffer
, " />\n");
7210 case BTRACE_FORMAT_PT
:
7211 buffer_xml_printf (buffer
, "<pt");
7212 buffer_xml_printf (buffer
, " size=\"0x%x\"", conf
->pt
.size
);
7213 buffer_xml_printf (buffer
, "/>\n");
7218 buffer_grow_str0 (buffer
, "</btrace-conf>\n");
7221 #endif /* HAVE_LINUX_BTRACE */
7223 /* See nat/linux-nat.h. */
7226 current_lwp_ptid (void)
7228 return ptid_of (current_thread
);
7232 linux_process_target::thread_name (ptid_t thread
)
7234 return linux_proc_tid_get_name (thread
);
7239 linux_process_target::thread_handle (ptid_t ptid
, gdb_byte
**handle
,
7242 return thread_db_thread_handle (ptid
, handle
, handle_len
);
7246 /* Default implementation of linux_target_ops method "set_pc" for
7247 32-bit pc register which is literally named "pc". */
7250 linux_set_pc_32bit (struct regcache
*regcache
, CORE_ADDR pc
)
7252 uint32_t newpc
= pc
;
7254 supply_register_by_name (regcache
, "pc", &newpc
);
7257 /* Default implementation of linux_target_ops method "get_pc" for
7258 32-bit pc register which is literally named "pc". */
7261 linux_get_pc_32bit (struct regcache
*regcache
)
7265 collect_register_by_name (regcache
, "pc", &pc
);
7267 debug_printf ("stop pc is 0x%" PRIx32
"\n", pc
);
7271 /* Default implementation of linux_target_ops method "set_pc" for
7272 64-bit pc register which is literally named "pc". */
7275 linux_set_pc_64bit (struct regcache
*regcache
, CORE_ADDR pc
)
7277 uint64_t newpc
= pc
;
7279 supply_register_by_name (regcache
, "pc", &newpc
);
7282 /* Default implementation of linux_target_ops method "get_pc" for
7283 64-bit pc register which is literally named "pc". */
7286 linux_get_pc_64bit (struct regcache
*regcache
)
7290 collect_register_by_name (regcache
, "pc", &pc
);
7292 debug_printf ("stop pc is 0x%" PRIx64
"\n", pc
);
7296 /* See linux-low.h. */
7299 linux_get_auxv (int wordsize
, CORE_ADDR match
, CORE_ADDR
*valp
)
7301 gdb_byte
*data
= (gdb_byte
*) alloca (2 * wordsize
);
7304 gdb_assert (wordsize
== 4 || wordsize
== 8);
7306 while (the_target
->read_auxv (offset
, data
, 2 * wordsize
) == 2 * wordsize
)
7310 uint32_t *data_p
= (uint32_t *) data
;
7311 if (data_p
[0] == match
)
7319 uint64_t *data_p
= (uint64_t *) data
;
7320 if (data_p
[0] == match
)
7327 offset
+= 2 * wordsize
;
7333 /* See linux-low.h. */
7336 linux_get_hwcap (int wordsize
)
7338 CORE_ADDR hwcap
= 0;
7339 linux_get_auxv (wordsize
, AT_HWCAP
, &hwcap
);
7343 /* See linux-low.h. */
7346 linux_get_hwcap2 (int wordsize
)
7348 CORE_ADDR hwcap2
= 0;
7349 linux_get_auxv (wordsize
, AT_HWCAP2
, &hwcap2
);
7353 #ifdef HAVE_LINUX_REGSETS
7355 initialize_regsets_info (struct regsets_info
*info
)
7357 for (info
->num_regsets
= 0;
7358 info
->regsets
[info
->num_regsets
].size
>= 0;
7359 info
->num_regsets
++)
7365 initialize_low (void)
7367 struct sigaction sigchld_action
;
7369 memset (&sigchld_action
, 0, sizeof (sigchld_action
));
7370 set_target_ops (the_linux_target
);
7372 linux_ptrace_init_warnings ();
7373 linux_proc_init_warnings ();
7375 sigchld_action
.sa_handler
= sigchld_handler
;
7376 sigemptyset (&sigchld_action
.sa_mask
);
7377 sigchld_action
.sa_flags
= SA_RESTART
;
7378 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
7380 initialize_low_arch ();
7382 linux_check_ptrace_features ();